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1

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

2

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

3

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

4

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

5

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

6

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

7

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

Sparrow, Christopher R.

8

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

9

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

10

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

Domínguez de María, Pablo; Maugeri, Zaira

2010-11-26

11

Recent progress in G-quadruplex DNA in deep eutectic solvent.  

PubMed

Guanine-rich nucleic acids are known to form four-stranded G-quadruplex structures which are attracting increasing attention in diverse areas such as biology, medicinal chemistry, supramolecular chemistry and nanotechnology. To date, the handling media for DNA has largely been limited to an aqueous phase. Since many chemical reactions and devices are required to be performed under strictly anhydrous conditions, even at high temperature, it is meaningful but challenging to conduct G-quadruplex DNA in water-free medium. Recently, deep eutectic solvent (DES), a related material to ionic liquilds (ILs) was considered as a new class of anhydrous media for DNA. This review highlights the stability, structure, folding dynamics and thermodynamics of G-quadruplex in DES. Spectroscopic methodologies, like circular dichroism, UV and fluorescence, are mainly employed in these studies. PMID:23628945

Zhao, Chuanqi; Qu, Xiaogang

2013-04-27

12

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

PubMed

A special group of ionic liquids, deep eutectic solvents (DESs) have been tested as cosolvents in enzyme-catalyzed hydrolysis of a chiral (1,2)-trans-2-methylstyrene oxide. The choline chloride:ethane diol (ET), choline chloride:glycerol (GLY) and choline:chloride:urea (REL) DESs were included in the reaction mixtures with epoxide and the potato epoxide hydrolase StEH1. The effect of the DESs on enzyme function was primarily elevations of K(M) (up to 20-fold) and with lesser effects on turnover numbers (twofold variation). The regioselectivity in hydrolysis of the (1R,2R)-2-trans-methylstyrene oxide was altered in the presence of GLY or ET to favor epoxide ring opening at the benzylic carbon (R=2.33), enhancing the regioselectivity observed in buffer-only systems (R=1.35). The DES solutions dissolved 1.5-fold higher epoxide concentrations as compared to phosphate buffer. The total conversion of high concentration (40 g/l) of (1S,2S)-MeSO was not negatively affected by addition of 40% GLY. PMID:20438773

Lindberg, Diana; de la Fuente Revenga, Mario; Widersten, Mikael

2010-05-07

13

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

PubMed

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

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

2013-06-25

14

G-quadruplexes form ultrastable parallel structures in deep eutectic solvent.  

PubMed

G-quadruplex DNA is highly polymorphic. Its conformation transition is involved in a series of important life events. These controllable diverse structures also make G-quadruplex DNA a promising candidate as catalyst, biosensor, and DNA-based architecture. So far, G-quadruplex DNA-based applications are restricted done in aqueous media. Since many chemical reactions and devices are required to be performed under strictly anhydrous conditions, even at high temperature, it is challenging and meaningful to conduct G-quadruplex DNA in water-free medium. In this report, we systemically studied 10 representative G-quadruplexes in anhydrous room-temperature deep eutectic solvents (DESs). The results indicate that intramolecular, intermolecular, and even higher-order G-quadruplex structures can be formed in DES. Intriguingly, in DES, parallel structure becomes the G-quadruplex DNA preferred conformation. More importantly, compared to aqueous media, G-quadruplex has ultrastability in DES and, surprisingly, some G-quadruplex DNA can survive even beyond 110 °C. Our work would shed light on the applications of G-quadruplex DNA to chemical reactions and DNA-based devices performed in an anhydrous environment, even at high temperature. PMID:23282194

Zhao, Chuanqi; Ren, Jinsong; Qu, Xiaogang

2013-01-11

15

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

16

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

PubMed

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

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

2013-09-24

17

Use of dilute hydrofluoric acid and deep eutectic solvent systems for back end of line cleaning in integrated circuit fabrication  

NASA Astrophysics Data System (ADS)

Fabrication of current generation integrated circuits involves the creation of multilevel copper/low-k dielectric structures during the back end of line processing. This is done by plasma etching of low-k dielectric layers to form vias and trenches, and this process typically leaves behind polymer-like post etch residues (PER) containing copper oxides, copper fluorides and fluoro carbons, on underlying copper and sidewalls of low-k dielectrics. Effective removal of PER is crucial for achieving good adhesion and low contact resistance in the interconnect structure, and this is accomplished using wet cleaning and rinsing steps. Currently, the removal of PER is carried out using semi-aqueous fluoride based formulations. To reduce the environmental burden and meet the semiconductor industry's environmental health and safety requirements, there is a desire to completely eliminate solvents in the cleaning formulations and explore the use of organic solvent-free formulations. The main objective of this work is to investigate the selective removal of PER over copper and low-k (Coral and Black DiamondRTM) dielectrics using all-aqueous dilute HF (DHF) solutions and choline chloride (CC) -- urea (U) based deep eutectic solvent (DES) system. Initial investigations were performed on plasma oxidized copper films. Copper oxide and copper fluoride based PER films representative of etch products were prepared by ashing g-line and deep UV photoresist films coated on copper in CF4/O2 plasma. PER removal process was characterized using scanning electron microscopy and X-ray photoelectron spectroscopy and verified using electrochemical impedance spectroscopy measurements. A PER removal rate of ~60 A/min was obtained using a 0.2 vol% HF (pH 2.8). Deaeration of DHF solutions improved the selectivity of PER over Cu mainly due to reduced Cu removal rate. A PER/Cu selectivity of ~20:1 was observed in a 0.05 vol% deaerated HF (pH 3). DES systems containing 2:1 U/CC removed PER at a rate of ~10 and ~20 A/min at 40 and 70°C respectively. A mixture of 10-90 vol% de-ionized water (W) with 2:1 U/CC in the temperature range of 20 to 40°C also effectively removed PER. Importantly, etch rate of copper and low-k dielectric in DES formulations were lower than that in conventional DHF cleaning solutions.

Padmanabhan Ramalekshmi Thanu, Dinesh

18

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

PubMed

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

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

2013-08-01

19

Synthesis of monoclinic structured BiVO4 spindly microtubes in deep eutectic solvent and their application for dye degradation.  

PubMed

Monoclinic structured spindly bismuth vanadate microtubes were fabricated on a large scale by a simple ionothermal treatment in the environment-friendly green solvent of urea/choline chloride. The as-prepared samples were characterized by XRD, SEM, TEM, IR and their photocatalytic activity was evaluated by photocatalytic decolorization of rhodamine B aqueous solution under visible-light irradiation. As-obtained BiVO(4) microtubes exhibit the spindly shape with a side length of ca. 800 nm and a wall thickness of ca. 100 nm. The opening of these microtubes presents a saw-toothed structure, which is seldom in other tube-shaped materials. The formation mechanism of the spindly microtubes is ascribed to the complex cooperation of the reaction-crystallization process controlled by BiOCl and the nucleation-growth process of nanosheets induced by solvent molecules attached on the surface of microtubes. Such spindly microtubes exhibit much higher visible-light photocatalytic activity than that of bulk BiVO(4) prepared by solid-state reaction, possibly resulting from their large surface area and improved crystallinity. PMID:20576353

Liu, Wei; Yu, Yaqin; Cao, Lixin; Su, Ge; Liu, Xiaoyun; Zhang, Lan; Wang, Yonggang

2010-06-04

20

Frontal polymerizations carried out in Deep-Eutectic mixtures providing both the monomers and the polymerization medium.  

PubMed

Deep Eutectic Solvents (DESs) based upon mixtures of Acrylic Acid (AA) or Methacrylic Acid (MAA) and Choline Chloride (CCl) demonstrated superior performance than regular organic solvents and even ionic liquids for frontal polymerizations (FPs). Full recovering of CCl after FP provided an interesting green character to the process. PMID:21455538

Mota-Morales, Josué D; Gutiérrez, María C; Sanchez, Isaac C; Luna-Bárcenas, Gabriel; del Monte, Francisco

2011-04-01

21

Nanogravimetric observation of unexpected ion exchange characteristics for polypyrrole film p-doping in a deep eutectic ionic liquid.  

PubMed

The electrochemical quartz crystal microbalance was used to determine redox-driven ion transfers accompanying p-doping of polypyrrole (PPy) films in the choline chloride-based deep eutectic ionic liquid ethaline; electroneutrality maintenance is gravimetrically dominated by choline cation transfer and this requires the presence within the undoped film of ionic liquid, when this finite reservoir of choline is exhausted there is a shift to chloride transfer. PMID:19214321

Skopek, Magdalena A; Mohamoud, Mohamoud A; Ryder, Karl S; Hillman, A Robert

2009-01-15

22

High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts.  

PubMed

Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability. However, the cells with the best performance use volatile solvents in their electrolytes, which may be prohibitive for outdoor solar panels in view of the need for robust encapsulation. Solvent-free room-temperature ionic liquids have been pursued as an attractive solution to this dilemma, and device efficiencies of over 7% were achieved by using some low-viscosity formulations containing 1-ethyl-3-methylimidazolium thiocyanate, selenocyanate, tricyanomethide or tetracyanoborate. Unfortunately, apart from tetracyanoborate, all of these low-viscosity melts proved to be unstable under prolonged thermal stress and light soaking. Here, we introduce the concept of using eutectic melts to produce solvent-free liquid redox electrolytes. Using a ternary melt in conjunction with a nanocrystalline titania film and the amphiphilic heteroleptic ruthenium complex Z907Na (ref. 10) as a sensitizer, we reach excellent stability and an unprecedented efficiency of 8.2% under air-mass 1.5 global illumination. Our results are of importance to realize large-scale outdoor applications of mesoscopic DSCs. PMID:18587401

Bai, Yu; Cao, Yiming; Zhang, Jing; Wang, Mingkui; Li, Renzhi; Wang, Peng; Zakeeruddin, Shaik M; Grätzel, Michael

2008-06-29

23

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

24

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

25

Ionic liquids and eutectic mixtures as solvent and template in synthesis of zeolite analogues  

Microsoft Academic Search

The challenges associated with synthesizing porous materials mean that new classes of zeolites (zeotypes)-such as aluminosilicate zeolites and zeolite analogues-together with new methods of preparing known zeotypes, continue to be of great importance. Normally these materials are prepared hydrothermally with water as the solvent in a sealed autoclave under autogenous pressure. The reaction mixture usually includes an organic template or

Emily R. Cooper; Christopher D. Andrews; Paul S. Wheatley; Paul B. Webb; Philip Wormald; Russell E. Morris

2004-01-01

26

One-step fabrication of nanostructured Ni film with lotus effect from deep eutectic solvent.  

PubMed

We report a procedure to fabricate nanostructured Ni films via programmed electrochemical deposition from a choline-chloride-based ionic liquid at a high temperature of 90 °C. Three electrodeposition modes using constant voltage, pulse voltage, and reverse pulse voltage produce a variety of nanostructured Ni films with micro/nanobinary surface architectures, such as nanosheets, aligned nanostrips, and hierarchical flowers. The nanostructured Ni films possess face-centered cubic crystal structure. Amazingly, it is found that the electrodeposited Ni films deliver the superhydrophobic surfaces without any further modifications by low surface-energy materials, which might be attributed to the vigorous micro/nanobinary architectures and the surface chemical composition. The electrochemical measurements reveal that the superhydrophobic Ni film exhibit an obvious passivation phenomenon, which could provide enhanced corrosion resistance for the substrate in the aqueous solutions. PMID:21739965

Gu, Changdong; Tu, Jiangping

2011-07-19

27

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

28

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

29

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

30

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

31

Ultra-deep x-ray lithography of densely packed SU-8 features: I. An SU-8 casting procedure to obtain uniform solvent content with accompanying experimental results  

NASA Astrophysics Data System (ADS)

Although the benefits of SU-8 as a thick photoresist material for MEMS applications have been shown by various researchers, its use for ultra-thick applications (>1 mm) has been hampered by the difficulties associated with the high solvent gradient of the resultant layers. In this paper, the lithographic performance of the traditional methods of thick resist formation based on the casting of high solvent content SU-8 is presented. As an extension of the work, a new photoresist preparation method called 'dry chip casting' was developed. The new method involves the reduction of the solvent content of a given photoresist until the desired content is reached, the collection of the 'dry' chips and re-constitution on a substrate with the aid of heat and vacuum. The dry chip casting method yielded average solvent contents of about 7% (±0.5%) throughout the thickness of the SU-8 layers, with excellent x-ray lithographic characteristics. Results of ultra-deep x-ray lithography experiments in SU-8 layers as thick as 3 mm are presented in this paper.

Becnel, Charles; Desta, Yohannes; Kelly, Kevin

2005-06-01

32

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

33

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

34

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

35

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

36

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

37

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

38

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

39

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

40

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

41

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 1170°C, 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

42

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; Lü, Y J; Wei, B

2002-12-10

43

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

44

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

45

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

46

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 7.02×1013 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

47

Ultra-deep x-ray lithography of densely packed SU8 features: I. An SU8 casting procedure to obtain uniform solvent content with accompanying experimental results  

Microsoft Academic Search

Although the benefits of SU-8 as a thick photoresist material for MEMS applications have been shown by various researchers, its use for ultra-thick applications (>1 mm) has been hampered by the difficulties associated with the high solvent gradient of the resultant layers. In this paper, the lithographic performance of the traditional methods of thick resist formation based on the casting

Charles Becnel; Yohannes Desta; Kevin Kelly

2005-01-01

48

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

49

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

50

Enzymatic hybridization of ?-lipoic acid with bioactive compounds in ionic solvents.  

PubMed

The lipase-catalyzed molecular hybridization of ?-lipoic acid (LA) with bioactive compounds pyridoxine, tyrosol and tyramine was performed in ionic solvents and deep eutectic solvents. The biocatalytic reactions were catalyzed by Candida antarctica lipase B immobilized onto various functionalized multi-walled carbon nanotubes (f-CNTs-CaLB), as well as by commercial Novozym 435. The use of f-CNTs-CaLB leads, in most cases, to higher conversion yields as compared to Novozym 435. The nature and ion composition of ionic solvents affect the performance of the biocatalytic process. The highest conversion yield was observed in (mtoa)NTf2. The high enzyme stability and the relatively low solubility of substrates in specific media account for the improved biocatalytic synthesis of molecular hybrids of LA. Principal component analysis was used to screen for potential lipoxygenase inhibitors. In vitro studies showed that the synthesized compounds exhibit up to 10-fold increased inhibitory activity on lipoxygenase mediated lipid peroxidation as compared to parent molecules. PMID:23567667

Papadopoulou, Athena A; Katsoura, Maria H; Chatzikonstantinou, Alexandra; Kyriakou, Eleni; Polydera, Angeliki C; Tzakos, Andreas G; Stamatis, Haralambos

2013-02-27

51

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

52

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

53

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

54

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 7.02×1013

Y. C. Chuang; C. Y. Liu

2006-01-01

55

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

56

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

57

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% Na2CO3–71% K2CO3 and ternary 43.5% Li2CO3–31.5% Na2CO3–25% K2CO3 eutectic catalyst systems. A

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

2003-01-01

58

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

59

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

60

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

61

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

62

Solvent substitution  

SciTech Connect

The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

Not Available

1990-01-01

63

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

64

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

65

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

66

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

67

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

68

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

69

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

70

Corrosion of ODS steels in lead–bismuth 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 lead–bismuth eutectic cooled reactors and spallation sources. Corrosion tests on five different ODS alloys were performed in flowing liquid lead–bismuth eutectic

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

2008-01-01

71

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 Al2O3–36.8at.% ZrO2 and metallic Ni–18.7at.% 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

72

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

73

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

74

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 eutectic—mixture of anomalous and regular structures—regular eutectic” along the sample axis due to the inhomogeneity of sound field distribution. In the top zone with the highest sound intensity, the cavitation effect promotes the three eutectic phases to nucleate independently, while the acoustic streaming efficiently suppresses the coupled growth of eutectic phases. In the meantime, the ultrasonic field accelerates the solute transportation at the solid-liquid interface, which reduces the solute solubility of eutectic phases.

Zhai, Wei; Hong, Zhenyu; Wei, Bingbo

2007-08-01

75

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

76

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

77

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

78

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

79

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

80

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

81

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

82

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

83

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

84

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

85

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

86

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

87

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

88

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

89

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

90

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; Rodríguez, M A; Turrillas, X; De Aza, S; De Aza, A H

2009-05-04

91

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

92

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

93

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

94

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

95

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

96

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

97

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

98

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

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

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

101

Lead–lithium 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 Pb–Li 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

102

Dry sliding wear of eutectic Al–Si  

Microsoft Academic Search

The wear of as-cast eutectic Al–Si 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 Al–Si 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

103

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

104

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 7×10-6\\/ s and in specimens fatigued at 0.1% to 0.2% strain range

Seong-Min Lee

1995-01-01

105

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

106

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 190°C. The evolution of microstructure during aging was examined.

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

1994-01-01

107

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

108

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

109

Solvent wash solution  

DOEpatents

A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

Neace, J.C.

1984-03-13

110

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

111

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

112

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 390°C 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

113

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

114

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

115

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

116

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

117

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

118

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

119

Solvent recovery targeting  

SciTech Connect

One of the environmental challenges faced by the pharmaceutical and specialty chemical industries is the widespread use of organic solvents. With a solvent-based chemistry, the solvent necessarily has to be separated from the product. Chemical species in waste-solvent streams typically form multicomponent azeotropic mixtures, and this often complicates separation and, hence, recovery of solvents. A design approach is presented whereby process modifications proposed by the engineer to reduce the formation of waste-solvent streams can be evaluated systematically. This approach, called solvent recovery targeting, exploits a recently developed algorithm for elucidating the separation alternatives achievable when applying batch distillation to homogeneous multicomponent mixtures. The approach places the composition of the waste-solvent mixture correctly in the relevant residue curve map and computes the maximum amount of pure material that can be recovered via batch distillation. Solvent recovery targeting is applied to two case studies derived from real industrial processes.

Ahmad, B.S.; Barton, P.I. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1999-02-01

120

Working with Industrial Solvents.  

National Technical Information Service (NTIS)

A pamphlet provides information on the occupational safety aspects of work with solvents. Topics include uses of solvents, definition, health problems associated with use, exposure control, management responsibilities, and workers' responsibilities. All o...

1972-01-01

121

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

122

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

123

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

124

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 7×10-6/ s and in specimens fatigued at 0.1% to 0.2% strain range and a frequency of 1.67×10-2/ 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

125

Solvent dehydration system  

SciTech Connect

Improvements are described in processes for stripping solvent from dewaxed oils and deoiled waxes; such as the use of an inert gas (such as nitrogen) as a stripping agent for removing solvent from dewaxed oils, deoiled waxes and slack waxes resultant from solvent dewaxing processes.

Button, H.O.; McCall, T.F.; Meyer, D.W.

1980-04-22

126

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

127

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

128

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

129

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

130

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

131

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

132

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

133

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

134

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

135

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

136

Halogenated solvent remediation  

Microsoft Academic Search

Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C.sub.2-C.sub.4 carboxylic acids

Kent S

2008-01-01

137

Organic solvent topical report  

Microsoft Academic Search

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will

1999-01-01

138

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

139

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

140

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; Górny, Marcin; Lopez, Hugo F.; Kawalec, Magdalena

2013-06-01

141

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

142

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

143

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

144

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 190°C. 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

145

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

146

Deep earthquakes  

SciTech Connect

Earthquakes are often recorded at depths as great as 650 kilometers or more. These deep events mark regions where plates of the earth's surface are consumed in the mantle. But the earthquakes themselves present a conundrum: the high pressures and temperatures at such depths should keep rock from fracturing suddenly and generating a tremor. This paper reviews the research on this problem. Almost all deep earthquakes conform to the pattern described by Wadati, namely, they generally occur at the edge of a deep ocean and define an inclined zone extending from near the surface to a depth of 600 kilometers of more, known as the Wadati-Benioff zone. Several scenarios are described that were proposed to explain the fracturing and slipping of rocks at this depth.

Frohlich, C.

1989-01-01

147

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

148

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

149

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

150

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

151

ONSITE SOLVENT RECOVERY  

EPA Science Inventory

This study evaluated the product quality, waste reduction/pollution prevention, and economic aspects of three technologies for onsite solvent recovery: atmospheric batch distillation, vacuum heat-pump distillation, and a low-emission vapor degreaser with closed solvent, liquid an...

152

Deep Time  

NSDL National Science Digital Library

In this video a Penn State professor refers to National Park canyons carved out by water and wind as he explains “deep time” - the notion that the earth is billions of years old; another professor states how the theory of evolution is supported by evidence of an ancient Earth recorded in rocks.

Wpsu

2010-05-04

153

Deep Trouble.  

ERIC Educational Resources Information Center

|Discusses how the safety-related ruling by the National Federation of State High School Associations to eliminate the option of using 18-inch starting platforms in pools less than 4 feet deep may affect operators of swimming pools and the swim teams who use them. (EV)|

Popke, Michael

2002-01-01

154

Deep-Sky Companions: The Secret Deep  

NASA Astrophysics Data System (ADS)

Preface; Acknowledgments; 1. About this book; 2. The secret deep; Appendix A. The secret deep: basic data; Appendix B. Twenty additional secret deep objects; Appendix C. Deep-sky lists: comparison table; Appendix D. Photo credits; Index; The Secret Deep checklist.

O'Meara, Stephen James; Motta, Photographs by Mario

2011-06-01

155

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

156

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

157

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

158

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

159

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

160

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

161

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,705°C, 1,880°C, and 1,870°C, respectively.

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

1992-06-01

162

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 2×103 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

163

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 2×103 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

164

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

165

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

166

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

167

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

168

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

169

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 Poâ 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

170

Solid–liquid 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 Gibbs–Thomson coefficient and solid–liquid interfacial energy for solid SCN in equilibrium with the SCN DCB eutectic liquid have been determined to be (5.43±0.27)×10?8Km and (7.95±0.80)×10?3Jm?2 with present numerical method

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

2006-01-01

171

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

Microsoft Academic Search

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

Y Sakamura; O Shirai; T Iwai; Y Suzuki

2001-01-01

172

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

173

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

174

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

175

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

176

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

177

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

178

SOLVENT EXTRACTION PROCESS  

DOEpatents

In improved solvent extraction process is described for the extraction of metal values from highly dilute aqueous solutions. The process comprises contacting an aqueous solution with an organic substantially water-immiscible solvent, whereby metal values are taken up by a solvent extract phase; scrubbing the solvent extract phase with an aqueous scrubbing solution; separating an aqueous solution from the scrubbed solvent extract phase; and contacting the scrubbed solvent phase with an aqueous medium whereby the extracted metal values are removed from the solvent phase and taken up by said medium to form a strip solution containing said metal values, the aqueous scrubbing solution being a mixture of strip solution and an aqueous solution which contains mineral acids anions and is free of the metal values. The process is particularly effective for purifying uranium, where one starts with impure aqueous uranyl nitrate, extracts with tributyl phosphate dissolved in carbon tetrachloride, scrubs with aqueous nitric acid and employs water to strip the uranium from the scrubbed organic phase.

Jonke, A.A.

1957-10-01

179

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

180

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

181

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 200°C, 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

182

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

183

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

184

Onsite Solvent Recovery.  

National Technical Information Service (NTIS)

This study evaluated the product quality, waste reduction/pollution prevention, and economic aspects of three technologies for onsite solvent recovery. The technologies were (1) atmospheric batch distillation, (2) vacuum heat-pump distillation, and (3) lo...

A. R. Gavaskar R. F. Olfenbuttel L. A. Hernon-Kenny J. A. Jones M. A. Salem J. R. Becker J. E. Tabor

1993-01-01

185

Managing solvent wastes  

SciTech Connect

There are economic and regulatory incentives for considering alternatives to the direct land disposal of solvent-bearing hazardous waste streams (EPA Hazardous Waste Codes: F001, F002, F003, F004, and F005). These alternatives include recycle/reuse (including use as a fuel substitute), destruction of a stream's solvent component, and treatment prior to land disposal. This paper reviews these three waste management alternatives and discusses their applicability to solvent waste streams having various physical characteristics. Seven waste treatment techniques which may be used to handle solvent wastes are described: incineration, agitated thin-film evaporation, fractional distillation, steam stripping, wet oxidation, carbon adsorption, and activated sludge biological treatment.3 tables.

Blaney, B.L.

1986-03-01

186

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

187

Cleaning without chlorinated solvents  

SciTech Connect

Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92%. The program has been a twofold effort. Vapor degreasers used in batch cleaning-operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting and bonding. Cleaning ability was determined using techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes and swelling of epoxies.

Thompson, L.M.; Simandl, R.F.

1994-12-31

188

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

189

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

190

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

191

Deep smarts.  

PubMed

When a person sizes up a complex situation and rapidly comes to a decision that proves to be not just good but brilliant, you think, "That was smart." After you watch him do this a few times, you realize you're in the presence of something special. It's not raw brainpower, though that helps. It's not emotional intelligence, either, though that, too, is often involved. It's deep smarts. Deep smarts are not philosophical--they're not"wisdom" in that sense, but they're as close to wisdom as business gets. You see them in the manager who understands when and how to move into a new international market, in the executive who knows just what kind of talk to give when her organization is in crisis, in the technician who can track a product failure back to an interaction between independently produced elements. These are people whose knowledge would be hard to purchase on the open market. Their insight is based on know-how more than on know-what; it comprises a system view as well as expertise in individual areas. Because deep smarts are experienced based and often context specific, they can't be produced overnight or readily imported into an organization. It takes years for an individual to develop them--and no time at all for an organization to lose them when a valued veteran walks out the door. They can be taught, however, with the right techniques. Drawing on their forthcoming book Deep Smarts, Dorothy Leonard and Walter Swap say the best way to transfer such expertise to novices--and, on a larger scale, to make individual knowledge institutional--isn't through PowerPoint slides, a Web site of best practices, online training, project reports, or lectures. Rather, the sage needs to teach the neophyte individually how to draw wisdom from experience. Companies have to be willing to dedicate time and effort to such extensive training, but the investment more than pays for itself. PMID:15449858

Leonard, Dorothy; Swap, Walter

2004-09-01

192

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

193

Leakage of a trapped fluorescent marker from liposomes: effects of eutectic crystallization of NaCl and internal freezing.  

PubMed

Leakage of trapped carboxyfluorescein from DL-alpha-dipalmitoylphosphatidylcholine multilamellar liposomes (diameter 1-2 microns) in NaCl solutions was measured after rapid freezing to temperatures between -15 and -55 degrees C. Leakage was low after freezing between -15 and -35 degrees C, but increased steeply between -35 and -45 degrees C. From DSC measurements it was found that the increase in leakage was associated with two crystallization processes: Eutectic crystallization of NaCl and freezing of undercooled solvent trapped in the interior of the liposomes ("internal freezing"). Damage caused by the former process could effectively be prevented by small amounts of trehalose (1% less than or equal to w less than or equal to 1.5%). Trehalose in these concentration also decreased damage due to internal freezing, but to a minor degree. In addition to these damaging transitions, a time-dependent process was found to cause leakage from the liposomes at -25 degrees C. The association between leakage and thermal activity suggests that DSC supplements cryomicroscopy and leakage measurements in the characterization of cryostability of liposomes. PMID:1424714

Kristiansen, J

1992-10-01

194

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

195

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

196

Halogenated solvent remediation  

DOEpatents

Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof, of which lactic acid, salts of lactic acid--such as sodium lactate, lactate esters, and mixtures thereof are particularly illustrative. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the electron donor.

Sorenson, Jr., Kent S. (Windsor, CO)

2008-11-11

197

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

198

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

199

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

200

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

201

Solvent Evaporation Rates  

Microsoft Academic Search

A system of equations for predicting the evaporation rates of solvents is presented. These equations may be used by the industrial hygienist, in conjunction with the diffusion equations developed elsewhere, to predict the atmospheric concentrations of vapors from spilled toxic liquids. The equations are derived from wind tunnel tests and applied to predictions for spills both indoors and outdoors.

DOUGLAS C. GRAY

1974-01-01

202

Organic solvent topical report  

SciTech Connect

This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel.

Cowley, W.L.

1998-04-30

203

Organic solvent topical report  

SciTech Connect

This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

COWLEY, W.L.

1999-05-13

204

Hazardous solvent source reduction  

Microsoft Academic Search

This book is written for the managers, production leaders, and operations staff tasked with the job of eliminating hazardous cleaning solvents from their workplace. Information regarding the location, evaluation, and implementation of environmentally preferred cleaning technologies is offered for a broad range of applications. These include: removal of grease and grime from a piece of equipment during maintenance, cleaning small

M. S. Callahan; B. Green

1995-01-01

205

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

206

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.; Serrière, M.

2013-02-01

207

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 1200–1520°C. 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

208

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

209

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

210

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

211

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

212

The effect of solvent on solvent refined coal (SRC) denitrification  

Microsoft Academic Search

Wyodak coal containing 0.93Vertical Bar3< by wt nitrogen was hydrogenated in a batch autoclave by heating 2:1 by wt coal\\/solvent mixtures to 715°K at 2000 psi hydrogen. The solvents used were a Wyodak coal recycle solvent (RS), RS mildly or severely hydrogenated over a Co-Mo\\/AlâOâ catalyst, light and heavy fractions distilled from the above solvents, and two coal tars from

David W. Staubs; Ronald L. Miller; Howard F. Silver; Robert J. Hurtubise

1979-01-01

213

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

214

Deep breathing after surgery  

MedlinePLUS

... take an active role is by doing deep breathing exercises. Deep breathing keeps your lungs healthy while you ... or as your doctor prescribes. Do these deep-breathing exercises as directed by your doctor or nurse.

215

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

216

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

217

Solvent substitution for electronic products  

SciTech Connect

Allied-Signal Inc., Kansas City Division (KCD), manufactures the electrical, electrochemical, mechanical, and plastic components for nuclear weapons. The KCD has made a commitment to eliminate the use of chlorohydrocarbon (CHC) and chlorofluorocarbon (CFC) solvents to the greatest technical extent possible consistent with nuclear safety and stockpile reliability requirements. Current cleaning processes in the production departments use trichloroethylene, 1,1,1-trichloroethane, and various CFC-113 based solvents. Several non-halogenated solvents (Solvent A - an aqueous solvent based on N,N-dimethylacetamide, Solvent B - an aqueous mixture of ethanol amines, Solvent C - a hydrocarbon solvent based on octadecyl acetate, Solvent D - a terpene (d-limonene) hydrocarbon solvent combined with emulsifiers, Solvent E - a terpene (d-limonene) hydrocarbon solvent combined with a separation agent, d-limonene, and isopropyl alcohol) were evaluated to determine the most effective, non-chlorinated, non-fluorinated, alternate solvent cleaning system. All of these solvents were evaluated using current manual spray cleaning processes. The solvents were evaluated for their effectiveness in removing a rosin based RMA solder flux, a particular silicone mold release, and oils, greases, mold releases, resins, etc. The Meseran Surface Analyzer was used to measure organic contamination on the samples before and after cleaning. An Omega Meter Model 600 was also used to detect solder flux residues. Solvents C, D, E and d-limonene the best alternatives to trichloroethylene for removing all of the contaminants tested. For this particular electronic assembly, d-limonene was chosen as the alternate because of material compatibility and long-term reliability concerns.

Benkovich, M.K.

1992-01-01

218

Production of low-density poly (4-methyl-1-pentene) foam via phase inversion from binary solvent/nonsovent systems  

SciTech Connect

Phase inversion from durene/naphthalene, durene/tmpdo, and durene/hexadecanol binary solvent/nonsolvent systems produced well interconnected, radiographically homogeneous, open-celled poly (4- methyl-1-pentene) or pmp foams. These foams ranged in density from 5 to 50 mg/cm{sup 2}. Foam homogeneity and casting efficiency were dependent on casting scheme, durene quality, solvent-to-nonsolvent ratio, and quench temperature. Foam density tracked linearly with dissolved-polymer content. Homogeneous, ultralow-density (5 to 6 mg/cm{sup 3}) foams were produced by using a 49/51 durene/naphthalene solvent eutectic. Foam hardness or firmness tracked somewhat linearly with foam density. Foams with densities above 20 mg/cm{sup 3} were too fragile to handle without damage.

Simandl, R.F.; Robinson, D.N.; Bolinger, W.L.; Davis, W.E.

1991-11-01

219

PARIS II: DESIGNING GREENER SOLVENTS  

EPA Science Inventory

PARIS II (the program for assisting the replacement of industrial solvents, version II), developed at the USEPA, is a unique software tool that can be used for customizing the design of replacement solvents and for the formulation of new solvents. This program helps users avoid ...

220

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.-Å. Schweitz; L. Smith; S. Johansson

1994-01-01

221

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

222

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

223

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

224

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

225

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

226

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

227

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

228

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

229

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

230

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

231

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

232

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. Solid–liquid 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

233

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

234

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

235

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

236

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

237

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

238

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

239

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

240

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

241

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

242

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

243

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

244

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

245

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

246

Twin Astir: An irradiation experiment in liquid Pb–Bi 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. Aït Abderrahim

2008-01-01

247

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

248

SOLVENT FIRE BY-PRODUCTS  

SciTech Connect

Southwest Research Institute (SwRI) conducted a burn test of the Caustic-Side Solvent Extraction (CSSX) solvent to determine the combustion products. The testing showed hydrogen fluoride gas is not a combustion product from a solvent fire when up to 70% of the solvent is consumed. The absence of HF in the combustion gases may reflect concentration of the modifier containing the fluoride groups in the unburned portion. SwRI reported results for other gases (CO, HCN, NOx, formaldehyde, and hydrocarbons). The results, with other supporting information, can be used for evaluating the consequences of a facility fire involving the CSSX solvent inventory.

Walker, D; Samuel Fink, S

2006-05-22

249

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

250

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

251

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 300°C. Eutectic solder alloys are generally favored due to their excellent fatigue resistance. Performance of Au-Ge and Au-Si eutectic solder alloys at 300°C 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 300°C, 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 300°C 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 300°C 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

252

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

253

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

254

Stability and optical limiting properties of a single wall carbon nanotubes dispersion in a binary water-glycerol solvent  

NASA Astrophysics Data System (ADS)

We report the temporal stability of the dispersion of single-wall carbon nanotubes in a binary solvent ``water + glycerol'' having eutectic composition (ca. 67% wt.) with sodium dodecylbenzene sulfonate as a dispersant. The system procures good temporal and thermal stability: its absorption spectra demonstrate no changes during one-year storage with temperature spanning -40 to +40 °C. The system provides non-linear optical power limiting of the incident laser radiation (532 nm) in a one-shot and pulse-periodic regimes of its applying.

Venediktova, Anastasiya V.; Vlasov, Andrey Yu.; Obraztsova, Elena D.; Videnichev, Dmitry A.; Kislyakov, Ivan M.; Sokolova, Ekaterina P.

2012-06-01

255

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

256

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

257

Hazardous solvent source reduction  

SciTech Connect

This book is written for the managers, production leaders, and operations staff tasked with the job of eliminating hazardous cleaning solvents from their workplace. Information regarding the location, evaluation, and implementation of environmentally preferred cleaning technologies is offered for a broad range of applications. These include: removal of grease and grime from a piece of equipment during maintenance, cleaning small parts before assembly, defluxing printed circuit boards and assemblies, and stripping paint from field vehicles and aircraft. Moving beyond the limits of source reduction alone, this book provides complete information on the planning, staffing, and execution of a pollution prevention program, alternative and in-use cleaner testing, waste recycling and treatment, air emission control, replacement system design, and system economics. For the environmental specialist, this book helps to bridge the gap between regulatory requirements and shop-floor constraints.

Callahan, M.S.; Green, B.

1995-09-01

258

Compatibility of surface-coated steels, refractory metals and ceramics to high temperature lead–bismuth eutectic  

Microsoft Academic Search

Compatibility of cladding material with lead–bismuth eutectic at temperature higher than 650°C is one of the most crucial issues for feasibility of lead–bismuth-cooled fast reactors with cycle efficiency as high as 40%. In order to search for corrosion-resistant materials with lead–bismuth eutectic at temperature higher than 650°C, surface-coated steels, some refractory metals and various ceramics were tested by means of

Abu Khalid Rivai; Minoru Takahashi

2008-01-01

259

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

260

Crystallographic texture in Al 2O 3–ZrO 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 Al2O3–ZrO2 (12mol% Y2O3) eutectic rods by means of X-ray and electron backscattering diffraction. The

J. Ramírez-Rico; A. R. de Arellano-López; J. Martínez-Fernández; J. I. Peña; A. Larrea

2008-01-01

261

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

262

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

263

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

264

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

265

Solvent-Solvent Energy Migration in Liquid Scintillation. Part Ii.  

National Technical Information Service (NTIS)

The quenching of benzene monomer fluorescence by biacetyl at 28C is studied as a function of dilution with hexane and cyclohexane. The component of the overall transfer rate constant, attributable to solvent-solvent energy migration is shown to vary linea...

J. W. van Loben Sels J. T. Dubois

1966-01-01

266

Correlation of surface tension of mixed solvents with solvent composition.  

PubMed

A simple computational method for calculating surface tension of solvent mixtures based on the Redlich-Kister extension was proposed. The model was applied to the experimental surface tension of binary solvent mixtures and showed accurate results. Overall average percentage deviation (APD) between calculated and experimental surface tensions was calculated as an accuracy criterion. The overall APD for correlating surface tensions in binary solvents was 4.30%. The accuracy of the proposed model has also been compared with those of previously published models and the results showed that the proposed model was superior and capable of providing more accurate results. An extension of the model was also proposed to correlate surface tension of ternary solvents and the overall APD for ternary solvent data was 2.06%. PMID:15638082

Jouyban, A; Azarbayjani, A Fathi; Barzegar-Jalali, M; Acree, W E

2004-12-01

267

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

268

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

269

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

270

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=5.660-15,352T±0.093 lga=6.074-15,839T±0.093 Activity coefficients of ?-La and super cooled liquid lanthanum in this system at 617-1073 K are described by the following equations:lg?=3.786-12,216T±0.171 lg?=4.199-12,703T±0.171 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

271

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

272

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

273

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

274

Nucleation Effect of Ti6Al4V Powder on Al–Si Eutectic Alloy  

Microsoft Academic Search

In this research nucleation effect of Ti-6Al-4 V powder on grain size and tensile strength of Al-12.1% Si eutectic alloy was studied. Metal powder produced from Ti-6Al-4 V 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 0.15 wt% consists of grain with average size of 6 µm,

Zohair Sarajan

2009-01-01

275

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 2200°F. 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

276

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. Peña; V. M. Orera

2008-01-01

277

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. Peña; R. I. Merino; V. M. Orera

2005-01-01

278

Investigation of TiC C Eutectic and WC C Peritectic High-Temperature Fixed Points  

NASA Astrophysics Data System (ADS)

TiC C eutectic (2,761°C) and WC C peritectic (2,749°C) 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

279

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

280

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

281

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 500°C. 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

282

Electrode reaction of the Np3+\\/Np couple in LiCl–KCl eutectic melts  

Microsoft Academic Search

The electrochemical behaviour of the Np3+\\/Np couple in the LiCl–KCl 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

283

Electrochemical behavior of actinide ions in LiCl–KCl eutectic melts  

Microsoft Academic Search

The electrodeposition and dissolution of uranium and plutonium in LiCl–KCl 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

284

Study on the distillation rates of LiCl–KCl eutectic salt under different vacuum conditions  

Microsoft Academic Search

A study on the distillation rate of LiCl–KCl 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?4–10?5molcm?2s?1 was obtainable at temperatures of 1200–1300K and vacuums of 5–50Torr. 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

285

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

286

Electrolysis of plutonium nitride in LiCl–KCl eutectic melts  

Microsoft Academic Search

The electrolysis of plutonium nitride, PuN, was investigated in the LiCl–KCl 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

287

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

288

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 530°C. The bonding process took place through a sequential occurrence of solid-state\\u000a diffusion

Waled M. Elthalabawy; Tahir I. Khan

2011-01-01

289

Enhancement of oxygen transfer in liquid lead and lead–bismuth 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 lead–bismuth 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

290

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

291

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. González-Rivera; M. H. Cruz; H. A. García; J. A. Juarez-Islas

1999-01-01

292

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

293

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. Baré; C. Michaux

1993-01-01

294

Electrochemical studies on the redox mechanism of uranium chloride in molten LiCl–KCl eutectic  

Microsoft Academic Search

The reduction and oxidation processes on platinum and glassy carbon electrodes in molten LiCl–KCl eutectic containing UCl3 were investigated by cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS) in the temperature range 660–780K. 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

295

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

296

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

297

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

298

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; Gonçalo Lopes; Ana C. Ferreira

2011-01-01

299

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

300

Lauric and palmitic acids eutectic mixture as latent heat storage material for low temperature heating applications  

Microsoft Academic Search

Palmitic acid (PA, 59.8°C) and lauric acid (LA, 42.6°C) 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 Tunçbilek; Ahmet Sari; Sefa Tarhan; Gazanfer Ergüne?; Kamil Kaygusuz

2005-01-01

301

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 150°C. 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

302

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

303

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

304

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 140°C. The measured drift velocity was found to be 0.3 Å\\/sec\\u000a when the solder stripe was stressed under 4.9×104 A\\/cm2 at 80°C, and it increased as the current density or the

C. K. Chou; Y. C. Hsu; Chih Chen

2006-01-01

305

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 140°C. The measured drift velocity was found to be 0.3 Å\\/sec when the solder stripe was stressed under 4.9×104 A\\/cm2 at 80°C, and it increased as the current density or the

C. K. Chou; Y. C. Hsu; Chih Chen

2006-01-01

306

Strain-rate effects on low cycle fatigue mechanism of eutectic Sn–Pb solder  

Microsoft Academic Search

Low cycle fatigue tests of as-casted Sn–Pb eutectic solder (63Sn\\/37Pb) were carried out using the non-contact strain-controlled system at 20°C 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

307

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

308

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

309

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

310

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

311

Phase Diagram of EC–DMC 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

312

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

313

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

314

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+6.210×10-4TV (vs. Cl2|Cl-).

Uehara, Akihiro; Nagai, Takayuki; Fujii, Toshiyuki; Shirai, Osamu; Yamana, Hajimu

2013-06-01

315

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 38±1 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

316

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 65°C, 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

317

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

318

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

319

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

320

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

321

Solvent Retention and Fibre Chemistry.  

National Technical Information Service (NTIS)

The aim of this study was to understand in which way different chemical and physical treatments affect the solvent retention properties of pulps used in the middle layer of folding boxboard. The solvent retention properties of the treated pulps were exami...

M. Rantanen

2003-01-01

322

SOLV-DB: Solvents Database  

NSDL National Science Digital Library

The purpose of SOLV-DB is to help you find a wide variety of data on solvents quickly and easily, including health and safety data, chemical and physical data, regulatory responsibilities, and environmental fate information. SOLV-DB is maintained by the National Center for Manufacturing Sciences and is considered a "one-stop source for solvents data."

2008-08-27

323

Desorption of chlorine organic solvents  

Microsoft Academic Search

Adsorption methods are being used more and more widely to treat gaseous discharges containing chlorohydrocarbons. However, recovery of the chlorohydrocarbons has not been studied sufficiently, and the desorption of the solvents with steam is particularly understudied. We investigated desorption of a number of solvents from industrial active carbon AR-3. Desorption was done with live steam in the 105 to 150°C.

N. I. Petrova; K. M. Nikolaev

1982-01-01

324

Laboratory solvent reuse -- Liquid chromatography  

SciTech Connect

The objective of this work was to develop a method for reduction of waste solvent in the Process Engineering Chemistry Laboratory. The liquid chromatographs are the largest generators of explosive-contaminated waste in the laboratory. We developed a successful process for the reuse of solvents from the liquid chromatographs and demonstrated the utility of the process in the assay of hexanitrostilbene.

Quinlin, W.T.; Schaffer, C.L.

1992-11-01

325

Exxon donor solvent liquefaction process  

Microsoft Academic Search

The Exxon donor solvent (EDS) coal liquefaction system is a direct liquefaction procedure. Coal is chemically reacted and dissolved in a recycle solvent that is hydrogenated between passes to the liquefaction reactor. More than 2.6 barrels of a synthetic crude boiling below 1000 F are produced per ton of dry, high volatile coal feed. Other ranks of coal can be

R. C. Neavel

1981-01-01

326

Solvent influence on base stacking.  

PubMed Central

In this paper we present a detailed analysis of the base-stacking phenomenon in different solvents, using nanosecond molecular dynamics simulations. The investigation focuses on deoxyribo- and ribodinucleoside monophosphates in aqueous and organic solutions. Organic solvents with a low dielectric constant, such as chloroform, and solvents with intermediate dielectric constants, such as dimethyl sulfoxide and methanol, were analyzed. This was also done for water, which is highly polar and has a high dielectric constant. Structural parameters such as the sugar puckering and the base-versus-base orientations, as well as the energetics of the solute-solvent interactions, were examined in the different solvents. The obtained data demonstrate that base stacking is favored in the high dielectric aqueous solution, followed by methanol and dimethyl sulfoxide with intermediate dielectric constants, and chloroform, with a low dielectric constant.

Norberg, J; Nilsson, L

1998-01-01

327

Solvent degradation products in nuclear fuel processing solvents  

SciTech Connect

The Savannah River Plant uses a modified Purex process to recover enriched uranium and separate fission products. This process uses 7.5% tri-n-butyl phosphate (TBP) dissolved in normal paraffin hydrocarbons for the solvent extraction of a nitric acid solution containing the materials to be separated. Periodic problems in product decontamination result from solvent degradation. A study to improve process efficiency has identified certain solvent degradation products and suggested mitigation measures. Undecanoic acid, lauric acid, and tridecanoic acid were tentatively identified as diluent degradation products in recycle solvent. These long-chain organic acids affect phase separation and lead to low decontamination factors. Solid phase extraction (SPE) was used to concentrate the organic acids in solvent prior to analysis by high performance liquid chromatography (HPLC). SPE and HPLC methods were optimized in this work for analysis of decanoic acid, undecanoic acid, and lauric acid in solvent. Accelerated solvent degradation studies with 7.5% TBP in normal paraffin hydrocarbons showed that long-chain organic acids and long-chain alkyl butyl phosphoric acids are formed by reactions with nitric acid. Degradation of both tributyl phosphate and hydrocarbon can be minimized with purified normal paraffin replacing the standard grade presently used. 12 refs., 1 fig., 3 tabs.

Shook, H.E. Jr.

1988-06-01

328

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

329

Solvent Selection for Extraction from Dilute Solution  

Microsoft Academic Search

An improved strategy for the selection of solvents for recovery of chemicals from dilute solution is presented. Low solvent losses and a high solute distribution coefficient are primary goals for solvent selection. High relative volatility of the solvent also is an important property if the solute is to be recovered from the extract by distillation. Low solvent losses will ensure

M. C. M. Cockrem; J. H. Flatt; E. N. Lightfoot

1989-01-01

330

WASH SOLVENT REUSE IN PAINT PRODUCTION  

EPA Science Inventory

This project evaluated solvent used to clean paint manufacture equipment for its utility in production of subsequent batches of solvent-borne paint. eusing wash solvent would reduce the amount of solvent disposed of as waste. he evaluation of this wash-solvent recovery technology...

331

Helpful hints for physical solvent absorption  

Microsoft Academic Search

Review of experience with natural gas treatment using physical solvents points to design and operating suggestions. Experiences with three plants using either Selexol or Sepasolv MPE solvent shows that both solvents perform well. The solvents offer economical and problem-free purification of natural gas. The Sepasolv MPE and Selexol solvents are very similar in chemical structure and physical properties. Thus, their

Wolfer

1982-01-01

332

Comparison of Fluor Solvent and Selexol processes  

Microsoft Academic Search

Physical solvent processes can be useful for acid gas removal applications. The necessity for screening physical solvent characteristics to eliminate those solvents that are unsuitable or noncompetitive for a particular application is discussed. The Fluor Solvent and Selexol processes are compared. Selexol has an advantage over other solvents in oil applications involving HâS and COâ removal in hydrocarbon systems. Fluor

R. W. Bucklin; R. L. Schendel

1984-01-01

333

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

334

Fabrication of transparent ceramics through melt solidification of near eutectic compositions in HfO 2–Al 2O 3–GdAlO 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 HfO2–Al2O3–GdAlO3 for the first time. It has the near eutectic composition of HfO2 (14mol%), Al2O3 (63mol%) and

Shunji Araki; Masahiro Yoshimura

2005-01-01

335

Fabrication of transparent ceramics through melt solidification of near eutectic compositions in HfO 2–Al 2O 3–GdAlO 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 HfO2–Al2O3–GdAlO3 for the first time. It has the near eutectic composition of HfO2 (14mol%), Al2O3 (63mol%) and

Shunji Araki; Masahiro Yoshimura

2006-01-01

336

Pyrochemical extraction of transition metals from Pacific Ocean deep sea nodules  

SciTech Connect

Considerable success has been achieved in lixiviation transition metals from Pacific Ocean deep sea nodules. These nodules typically contain approx.30 wt% Mn, approx.7 wt% Fe, approx.1 wt% Ni, approx.1 wt% Cu, and approx.0.3 wt% Co. Samples of the nodules have been subjected to extraction tests at 450C using LiCl-KCl eutectic and MgCl2-NaCl-KCl eutectic. The most impressive results came from studies using the Mg, Na, K/Cl eutectic. With this salt, nearly 100% of the Co, Cu, Fe, Mn, and Ni are brought into solution. The dissolution reaction is quite vigorous, with nearly complete extraction occurring in a very short time (minutes) following melting of the eutectic. Quantitative recovery of cobalt is achieved with nodule-to-salt weight ratios as high as 1:3. Electronic absorption spectroscopy (carried out on the molten extract solution at the test temperature) showed that the oxidation state of the dissolved transition metals are CoS , CuS , FeT , MnS , and NiS . At temperatures greater than or equal to450C, the FeT and CuS distill out of the extract solution at a rapid rate and condense as binary halides or halide complexes. Using a combination of distillation followed by electrochemical reduction of the CoS and NiS in the extract salt, it appears possible to recover a fairly high grade of cobalt metal and nickel metal as well as high grade CuS , FeT , and MnS in the form of a halide salt (CuCl2, FeCl3) or an oxide precipitate (Mn2O3).

von Winbush, S.; Maroni, V.A.

1987-01-01

337

Swelling of lignites in organic solvents  

SciTech Connect

Data on the swelling of Turkish lignites can be summarized using linear multiparameter equations that take into account various properties of solvents. Factors responsible for the amounts of absorbed solvents are the basicity and cohesion energy density of the solvents.

R.G. Makitra; D.V. Bryk [Institute of the Geology and Geochemistry of Fossil Fuels, Lviv (Ukraine)

2008-10-15

338

Improved Purex Solvent Scrubbing Methods.  

National Technical Information Service (NTIS)

Studies of hydrazine and hydroxylamine salts as solvent scrubbing agents that can be decomposed into gases are summarized. Results from testing of countercurrent scrubbers and solid sorber columns that produce lesser amounts of permanent salts are reporte...

J. C. Mailen O. K. Tallent

1984-01-01

339

SAGE--SOLVENT ALTERNATIVES GUIDE  

EPA Science Inventory

SAGE is a comprehensive guide designed to provide pollution prevention information on solvent and process alternatives for parts cleaning and degreasing. SAGE does not recommend any ozone depleting chemicals. SAGE was developed by the Surface Cleaning Program at Research Triang...

340

Exxon Donor Solvent Liquefaction Process  

Microsoft Academic Search

The Exxon Donor Solvent (EDS) coal liquefaction system is a direct liquefaction procedure being developed by the Exxon Corporation. Coal is chemically reacted and dissolved in a recycle solvent that is hydrogenated between passes to the liquefaction reactor. More than 2.6 barrels (0.41 m3) of a synthetic crude boiling below 1000 degrees F (538 degrees C) are produced per ton

R. C. Neavel

1981-01-01

341

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

342

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

343

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 eutectic solders, and solid solution strengthened eutectic solders. Mechanical properties of the solder alloys and the life times under creep-fatigue conditions were evaluated. Damage produced in the course of creep or fatigue deformation was studied by metallography, scanning electron microscopy, precision density measurement, and the observation of grain boundary sliding. Based on the damage characteristics, the dominant failure mechanism was proved to be cavity growth. Three cavity growth models were applied to four types of solder alloys to predict creep-fatigue life by taking into account the tensile loading component as well as the compressive loading component when reversed process can occur. An algorithm to calculate cavity growth in each fatigue cycle is used to predict the number of fatigue cycles to failure, where failure is defined as a critical cavity size. Calculated lives are compared to experimental data under six types of creep-fatigue loading histories. The method predicts the creep-fatigue lives within a factor of two with the incorporation of appropriate compressive healing factor. Discrepancy between calculated lives and experimental results is discussed.

Kuo, C.W.

1994-01-01

344

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

SciTech Connect

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 microstructure of the joint, the metallurgical mechanisms of failure are surprisingly constant. When the cyclic load is in shear at temperatures above room temperature the shear strain is inhomogeneous, and induces a rapid coarsening of the eutectic microstructure that concentrates the deformation in well-defined bands parallel to the joint interface. Fatigue cracks propagate along the Sn--Sn grain boundaries and join across the Pb-rich regions to cause ultimate failure. The failure occurs through the bulk solder unless the joint is so thin that the intermetallic layer at the interface is a significant fraction of the joint thickness, in which case failure may be accelerated by cracking through the intermetallic layer. The coarsening and subsequent failure is influenced more strongly by the number of thermal cycles than by the time of exposure to high temperature, at least for hold times up to one hour. Thermal fatigue in tension does not cause well-defined coarsened bands, but often leads to rapid failure through cracking of the brittle intermetallic layer. Implications are drawn for the design of accelerated fatigue tests and the development of new solders with exceptional fatigue resistance. 28 refs., 21 figs.

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

1989-01-01

345

Internal zone growth method for producing metal oxide metal eutectic composites  

DOEpatents

An improved method for preparing a cermet comprises preparing a compact having about 85 to 95 percent theoretical density from a mixture of metal and metal oxide powders from a system containing a eutectic composition, and inductively heating the compact in a radiofrequency field to cause the formation of an internal molten zone. The metal oxide particles in the powder mixture are effectively sized relative to the metal particles to permit direct inductive heating of the compact by radiofrequency from room temperature. Surface melting is prevented by external cooling or by effectively sizing the particles in the powder mixture.

Clark, Grady W. (Oak Ridge, TN); Holder, John D. (Knoxville, TN); Pasto, Arvid E. (Oak Ridge, TN)

1980-01-01

346

Microstructure and physical properties of some oxide eutectic composites processed by directional solidification  

Microsoft Academic Search

Eutectic composites of lamellar ZrO2–CaO and ZrO2–NiO and fibrous Al2O3–ZrO2, Al2O3–ZrO2(Y2O3), ZrO2–MgO and CaF2–MgO wide gap materials have been grown from the melt by unidirectional solidification using laser floating zone and Bridgman techniques. The unique microstructure and interface morphology of these composites led to some remarkable mechanical (strength and toughness), optical (light guiding) and transport (ionic conduction) properties. The underlying

V. M Orera; R. I Merino; J. A Pardo; A Larrea; J. I Peña; C González; P Poza; J. Y Pastor; J LLorca

2000-01-01

347

Structural Characterization of Lead-Bismuth Eutectic Corrosion of Stainless Steel by Ultrasonic and Metallographic Analysis  

SciTech Connect

Metallic test coupons subjected to corrosion in a lead–bismuth eutectic (LBE) were analyzed by both ultrasound and scanning electron microscope (SEM). The advantages and disadvantages of each method are given, and the possibility of using ultrasound as a screening process for SEM is presented. Visual data from each method are given, and the data derived from each method are compared and contrasted. Use of both ultrasound and SEM is recommended for future analysis of corrosion coupons, and development of a better methodology will increase the portion of the analysis workload obtainable by ultrasound.

Loewen, Eric Paul; Bisanz, George

2002-12-01

348

Thermal stability of Cr-Cr3Si eutectic microstructures  

SciTech Connect

The thermal stability of Cr-Cr{sub 3}Si lamellar eutectic composites was investigated at temperatures up to 1400 C. In drop-cast Cr-Cr{sub 3}Si, coarsening was found to be interface controlled. The coarsening rate could be reduced by microalloying with Ce and Re, two elements which were chosen because they were expected to segregate to the Cr-Cr{sub 3}Si interfaces. Similarly, directional solidification, which is also expected to lower the Cr-Cr{sub 3}Si interfacial energy, was found to dramatically decrease the coarsening rate.

Gali, Aravind [ORNL; Bei, Hongbin [ORNL; George, Easo P [ORNL

2009-01-01

349

Long-time dynamics of the directional solidification of rodlike eutectics.  

PubMed

We report long-duration real-time observations of the dynamics of hexagonal (rodlike) directional-solidification patterns in bulk samples of a transparent eutectic alloy. A slight forward curvature of the isotherms induces a slow dilatation of the growth pattern at constant solidification rate and triggers the rod-splitting instability. At long times, the rod-splitting frequency exactly balances the dilatation driven by the curved isotherms. The growth pattern is then disordered and nonstationary but has a sharply selected mean spacing. Well-ordered growth patterns can be grown using time-dependent solidification rates. PMID:19391999

Perrut, Mikaël; Akamatsu, Silvère; Bottin-Rousseau, Sabine; Faivre, Gabriel

2009-03-17

350

Eu-doped 6LiF-SrF2 eutectic scintillators for neutron detection  

NASA Astrophysics Data System (ADS)

Eu2+ 0.05%, 0.1%, and 0.2% activated LiF-SrF2 eutectic scintillators were prepared by the Bridgman method using 6Li enriched (95%) raw material. The ?-ray-induced radio luminescence spectra showed intense emission peak at 430 nm due to an emission from Eu2+ 5d-4f transition in the Eu:SrF2 layers. When excited by 252Cf neutrons, all the samples exhibited almost the same light yields of 5000-7000 ph/n with a typical decay times of several hundreds ns.

Yanagida, Takayuki; Fukuda, Kentaro; Fujimoto, Yutaka; Kawaguchi, Noriaki; Kurosawa, Shunsuke; Yamazaki, Atsushi; Watanabe, Kenichi; Futami, Yoshisuke; Yokota, Yuui; Pejchal, Jan; Yoshikawa, Akira; Uritani, Akira; Iguchi, Tetsuo

2012-03-01

351

Microstructural changes in eutectic tin-lead alloy due to severe bending  

SciTech Connect

Severe plastic deformation in an eutectic tin-lead alloy is studied by imposing fast bending at room temperature, in an attempt to examine the microstructural response in the absence of thermally activated diffusion processes. A change in microstructure due to this purely mechanically imposed load is observed: the tin-rich matrix phase appears to be extruded out of the narrow region between neighboring layers of the lead-rich phase and alterations in the colony structure occur. A micromechanism is proposed to rationalize the experimental observations.

SHEN,Y.-L.; ABEYTA,M.C.; FANG,HUEI ELIOT

2000-02-29

352

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

353

The microstructure of eutectic Au-Sn solder bumps on Cu\\/electroless Ni\\/Au  

Microsoft Academic Search

In this work we studied the initial microstructure and microstructural evolution of eutectic Au-Sn solder bumps on Cu\\/electroless\\u000a Ni\\/Au. The solder bumps were 150–160 m in diameter and 45–50 m tall, reflowed on Cu\\/electroless Ni\\/Au, and then aged at 200°C\\u000a for up to 365 days. In addition, Au-Ni-Sn-alloys were made and analyzed to help identify the phases that appear at

H. G. Song; J. P. Ahn

2001-01-01

354

Real-time study of thin and bulk eutectic growth in succinonitrile–( d)camphor alloys  

Microsoft Academic Search

We study the directional-growth patterns of the transparent nonfaceted alloy succinonitrile–(d)camphor (SCN–DC) at eutectic concentration in thin and bulk samples using real-time observation methods. We measure in situ the minimum-undercooling spacing ?m and the small-spacing stability limit ?c of the thin, quasi-lamellar patterns. We find ?m2V?10.2?m3s-1 and ?c?0.65?m. This last result is contrary to the common conjecture that ?c=?m in

S. Akamatsu; S. Bottin-Rousseau; M. Perrut; G. Faivre; V. T. Witusiewicz; L. Sturz

2007-01-01

355

Solid–liquid interface energies in the succinonitrile and succinonitrile–carbon tetrabromide eutectic system  

Microsoft Academic Search

The equilibrated grain boundary groove shapes for the commercial purity succinonitrile (SCN) and succinonitrile–carbon tetrabromide (CTB) eutectic system were directly observed. From the observed grain boundary groove shapes, the Gibbs–Thomson coefficients for the solid SCN–liquid SCN and solid SCN–liquid SCN CTB have been determined to be (5.43±0.27)×10?8Km and (5.56±0.28)×10?8Km, respectively, with numerical method. The solid–liquid interface energies for the solid

N. Marasli; K. Ke?l?o?lu; B. Arslan

2003-01-01

356

Embedded binary eutectic alloy nanostructures: a new class of phase change materials.  

PubMed

Phase change materials are essential to a number of technologies ranging from optical data storage to energy storage and transport applications. This widespread interest has given rise to a substantial effort to develop bulk phase change materials well suited for desired applications. Here, we suggest a novel and complementary approach, the use of binary eutectic alloy nanoparticles embedded within a matrix. Using GeSn nanoparticles embedded in silica as an example, we establish that the presence of a nanoparticle/matrix interface enables one to stabilize both nanobicrystal and homogeneous alloy morphologies. Further, the kinetics of switching between the two morphologies can be tuned simply by altering the composition. PMID:20698591

Shin, S J; Guzman, J; Yuan, C-W; Liao, Christopher Y; Boswell-Koller, Cosima N; Stone, P R; Dubon, O D; Minor, A M; Watanabe, Masashi; Beeman, Jeffrey W; Yu, K M; Ager, J W; Chrzan, D C; Haller, E E

2010-08-11

357

Determination of the elastic moduli of a directionally solidified nickel-based TaC eutectic  

NASA Astrophysics Data System (ADS)

Measurements of ultrasonic wave velocities in a polycrystalline directionally solidified nickel based eutectic alloy are used to evaluate the three independent single crystal elastic moduli at temperatures between 298 to 925 K. The Cu and C44 moduli are obtained directly from high frequency wave propagation along the D.S. axis, corresponding to <100>. Evaluation of C12 requires measurements at lower frequencies to obtain (C11 - E <100>). The elastic anisotropy and temperature dependence of the elastic moduli are almost identical to those reported for pure Ni, indicating that neither TaC fiber reinforcement nor ?' precipitate have strong effects on elastic properties of Ni based turbine blade alloys.

Fisher, E. S.

1980-12-01

358

The peculiarities of crystallization of low-temperature eutectic in magnesium-lead system  

NASA Astrophysics Data System (ADS)

Density of low-temperature eutectic in magnesium-lead system (83.06 at. % Pb) has been measured by gamma-raying of the samples with narrow beam from cesium-137 isotope over the temperature range 293-1000 K of solid and liquid states. Approximation density dependences have been obtained and data of this work and other authors have been compared. Reference tables of temperature dependences of the alloy thermal properties have been compiled for the entire range of measurements and their errors estimated. It is shown that differences in the values of volumetric changes obtained during melting and crystallization are bound with the metastable ?'-phase formation.

Stankus, S. V.; Khairulin, R. A.

2010-06-01

359

The effect of low Au concentrations on the properties of eutectic Sn/Pb  

SciTech Connect

This study was of the effects moderately low Au concentrations ({le} 10 wt%) have on the mechanical properties and microstructure of an eutectic Sn/Pb alloy. Vibration (60--90 Hz swept sine wave for 30 hours) and thermal cycling (0--110C for 1450 cycles) reliability tests were performed on fine pitch leaded chip carriers using eutectic Sn/Pb solder on PCBs (printed circuit boards) with 0, 5, 10, 20, and 50{mu}in nominal Au thicknesses. Testing was also performed on double shear creep specimens consisting of arrays of regular pitch joints. There was a dramatic increase in the number of joints containing voids with increasing Au concentration, an effect more pronounced in the creep joints than in the reliability joints. These voids tended to coalesce and grow during rework simulation of the reliability joints. AuSn{sub 4} intermetallics present in toe of 4.8 wt% (50 {mu}in) Au vibration joints rotated from initial vertical perpendicular to surface of PCB metallization, solidification positions to roughly horizontal (parallel to plating surface) orientations during rework simulation and during aging of the parts. The AuSn{sub 4} intermetallics in the toe of the 4.8 wt% (50{mu}in) Au reflowed joints also rotated after vibration testing. No joint failures were observed in either vibration tested or thermally cycled specimens. Cracks formed in some of the vibration tested specimen joints under the heel of the gull-wing lead at Pb-rich phases. Thermally cycled specimens showed eutectic microstructure and intermetallic coarsening without crack formation. Creep tests showed loss of the superplasticity in eutectic Sn/Pb alloys with even the lowest Au concentration tested of 0.2 wt% Au. Intermetallic rotation was not a factor in crack propagation, but void presence was. Cracks tended to form in joints containing voids before forming in void-free joints. Crack propagation followed Sn/Sn grain boundaries and Sn/Pb phase boundaries from Pb-rich phase to Pb-rich phase.

Kramer, P.A.

1992-05-01

360

Fractographic analysis of vitreous calcia-alumina eutectic fibres produced by inviscid melt spinning (IMS)  

Microsoft Academic Search

The mechanical properties of inviscid melt spun (IMS) CaO-Al2O3 (46.5 wt % CaO-53.5 wt % Al2O3) eutectic fibres were examined by fractographic analysis as well as four-point bending and micro-indentation. The averaged fracture strength and elastic modulus values of the IMS Calcia-Alumina (CA) fibre were determined to be 460 MPa and 99.8 GPa, respectively by using four-point bending tests. The

Yun-Mo Sung; Il-Mo Sung

1996-01-01

361

Loss of anatomical landmarks with eutectic mixture of local anesthetic cream for neonatal male circumcision.  

PubMed

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

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

2012-10-24

362

Thermodynamics of binary solutions of the eutectic type with several intermediate phases of constant composition  

NASA Astrophysics Data System (ADS)

An universal method is proposed for calculating the phase diagrams of binary solutions with several intermediate phases of constant composition. The proposed method is based on the nonlinear transformations of the concentration axes and makes it possible to correctly reduce the calculation of the phase diagrams with several intermediate phases to a sequence of phase diagrams of individual subsystems. The thermodynamics of binary solutions of the eutectic type with several intermediate phases of constant composition is described using the proposed method within the framework of the generalized lattice model. The results of the calculations performed are compared with phase diagrams of real binary solutions.

Panov, G. A.; Zakharov, M. A.

2013-08-01

363

Direct Observations of Silver Nanoink Sintering and Eutectic Remelt Reaction with Copper  

SciTech Connect

Ag nanoink sintering kinetics and subsequent melting is studied using in-situ synchrotron based x-ray diffraction. Direct observations of Ag nanoink sintering on Cu demonstrate its potential for materials joining since the Ag nanoink sinters at low temperatures but melts at high temperatures. Results show low expansion coefficient of sintered Ag, non-linear expansion as Ag densifies and interdiffuses with Cu above 500 C, remelting consistent with bulk Ag, and eutectic reaction with Cu demonstrating its usefulness as a high temperature bonding medium

Elmer, J. W. [Lawrence Livermore National Laboratory (LLNL); Specht, Eliot D [ORNL

2010-01-01

364

Study of Heterogeneous Nucleation of Eutectic Si in High-Purity Al-Si Alloys with Sr Addition  

NASA Astrophysics Data System (ADS)

Al-5 wt pct Si master-alloys with controlled Sr and/or P addition/s were produced using super purity Al 99.99 wt pct and Si 99.999 wt pct materials in an arc melter. The master-alloy was melt-spun resulting in the production of thin ribbons. The Al matrix of the ribbons contained entrained Al-Si eutectic droplets that were subsequently investigated. Differential scanning calorimetry, thermodynamic calculations, and transmission electron microscopy techniques were employed to examine the effect of the Sr and P additions on eutectic undercoolings and nucleation phenomenon. Results indicate that, unlike P, Sr does not promote nucleation. Increasing Sr additions depressed the eutectic nucleation temperature. This may be a result of the formation of a Sr phase that could consume or detrimentally affect potent AlP nucleation sites.

Zarif, Muhammad; McKay, Brian; Schumacher, Peter

2011-06-01

365

REVIEW ARTICLE: Metal (carbide) carbon eutectics for thermometry and radiometry: a review of the first seven years  

NASA Astrophysics Data System (ADS)

Since 1999, when the first high temperature fixed-points based on the metal-carbon eutectic phase transitions were realized, more than 60 papers have been published on this topic. Eutectic based fixed-points are already being considered as secondary reference points for the International Temperature Scale and have been introduced into industrial laboratories. This rapid progress has been possible through the combined effort of scientists around the world, from national metrology institutes, universities and industry. It has been proposed that these fixed-points should be officially adopted as a way to improve the realization and dissemination of temperature scales above the silver point. In radiometry, the availability of stable high temperature fixed-points will give greater flexibility and at some wavelengths the potential for greater accuracy for spectral radiance and irradiance scale realization. This paper summarizes the major progress in eutectic research so far.

Woolliams, Emma R.; Machin, Graham; Lowe, David H.; Winkler, Rainer

2006-12-01

366

Dissolution of coal in solvents  

SciTech Connect

Experimental studies were effected in a 1-liter batch reactor to determine the role of the solvent and temperature on the dissolution of a Kentucky No. 9 coal. The goal was to increase the dissolution yield, defined as conversion of coal to pyridine-soluble material, while decreasing the hydrogen demand. The experiments were carried out in the absence of hydrogen gas. The solvent and coal were heated at a constant rate of temperature rise to 300 to 400/sup 0/C and held at a constant temperature for periods of 0 to 50 minutes before rapidly quenching the reaction mixture. 2-Methylnaphalene, 1,2,3,4-tetrahydronaphthalene (tetralin), p-cresol or ..beta..-naphthol, and ..gamma..-picoline were used in different ratios as the solvent. These compounds represented, respectively, the polycondensed aromatics, hydroaromatics (hydrogen donor), monophenols, and basic nitrogen compounds found in coal liquefaction recycle solvents. Dissolution yield of the coal reached a maximum in a solvent containing equal parts of 2-methylnaphthalene and tetralin. The H/C ratio of the preasphaltenes remained virtually constant when the tetralin content ranged from 20 to 65 wt % in mixtures with 2-methylnaphthalene. A slight increase was noted when pure tetralin was the solvent. Addition of small amounts of ..beta..-naphthol and ..gamma..-picoline to a 1:4 weight ratio of tetralin and 2-methylnaphthalene improved the dissolution yield. Coal was dissolved with no or minor chemical reactions up to the temperature of approx. 340/sup 0/C in a solvent containing 46.1 wt % tetralin, 46.1 wt % 2-methylnaphthalene, 4.9 wt % ..beta..-naphthol, and 2.9 wt % ..gamma..-picoline. Beyond this temperature dissolution yield increased exponentially typical of thermal cracking reactions.

Ebnesajjad, S.

1982-01-01

367

NCMS solvent substitution and material compatibility databases  

Microsoft Academic Search

The NCMS Solvent Database collects information on alternatives to ODC-based solvents used in electronics manufacturing. The database contains over 320 pure solvents and trade name mixtures. Each record includes 15 fields of environmental fate, 31 fields of health and safety, 21 fields of regulatory status, 36 fields of chemical\\/physical properties, and 19 fields of descriptive and supplier data. The Solvent

M. R. Wixom

1994-01-01

368

Coal liquefaction process with enhanced process solvent  

DOEpatents

In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

Givens, Edwin N. (Bethlehem, PA); Kang, Dohee (Macungie, PA)

1984-01-01

369

Coal liquefaction process with enhanced process solvent  

SciTech Connect

In an improved coal liquefaction process, including a critical solvent deashing stage, high value product recovery is improved and enhanced process-derived solvent is provided by recycling second separator underflow in the critical solvent deashing stage to the coal slurry mix, for inclusion in the process solvent pool.

Givens, E.N.; Kang, D.

1984-07-24

370

Reading Knee-Deep  

Microsoft Academic Search

Freire told his audience at a seminar at the University of Massachusetts, “You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it” (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading knee-deep

Pamela Jewett

2007-01-01

371

Thermal performance of a eutectic mixture of lauric and stearic acids as PCM encapsulated in the annulus of two concentric pipes  

Microsoft Academic Search

Thermal performance characteristics of a eutectic mixture of lauric and stearic acids as phase change material (PCM) during the melting and solidification processes were determined experimentally in a vertical two concentric pipe-energy storage system. This study deals with three important subjects: The first one is to determine the eutectic composition ratio of the lauric acid (LA) and stearic acid (SA)

Ahmet Sari; Kamil Kaygusuz

2002-01-01

372

Phase change and heat transfer characteristics of a eutectic mixture of palmitic and stearic acids as PCM in a latent heat storage system  

Microsoft Academic Search

The phase change and heat transfer characteristics of a eutectic mixture of palmitic and stearic acids as phase change material (PCM) during the melting and solidification processes were determined experimentally in a vertical two concentric pipes energy storage system. This study deals with three important subjects. First is determination of the eutectic composition ratio of the palmitic acid (PA) and

Gülseren Baran; Ahmet Sari

2003-01-01

373

[Deep neck infections].  

PubMed

Deep neck infection is relatively rare but potentially life threatening complication of common oropharyngeal infections. This retrospective study was aimed at analyzing the occurrence of complications, diagnostic methods and proper management of deep neck infection. A review was conducted in 32 cases who were diagnosed as having deep neck infection from 1995 to 2005. The causes of deep neck infections were tonsillitis (16 cases), tooth diseases (6 cases), paratonsillar abscess (4 cases), parotitis (1 case), pussy lymphonodes after tonsillectomy (2 cases), pussy congenital neck cyst (1 case), chronic otitis media (1 case), parotitis (1 case), foreign body of the esophagus (1 case). All the puss bacterial cultivation were positive. All the patients were treated by different ways of chirurgical drainage and use of large dosage of antibiotics. Deep neck infection should be suspected in patients with long lasting fever and painful swelling of the neck and treatment should begin quick as possible. PMID:17152800

Nowak, Katarzyna; Szyfter, Witold

2006-01-01

374

DOE solvent handbook information sheet  

SciTech Connect

Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

Chavez, A.A.

1992-05-01

375

Investigation of interfacial reaction between SnAg eutectic solder and Au\\/Ni\\/Cu\\/Ti thin film metallization  

Microsoft Academic Search

This paper reports the formation of intermetallic compounds in Au\\/Ni\\/Cu\\/Ti under-bump-metallization (UBM) structure reacted\\u000a with Ag-Sn eutectic solder. In this study, UBM is prepared by evaporating Au(500 ?)\\/Ni(1000 ?)\\/Cu(7500 ?) \\/Ti (700 ?) thin\\u000a films on top of Si substrates. It is then reacted with Ag-Sn eutectic solder at 260 C for various times to induce different\\u000a stages of the

J. Y. Park; C. W. Yang; J. S. Ha; C.-U. Kim; E. J. Kwon; S. B. Jung; C. S. Kang

2001-01-01

376

Phase-Field Modeling of Eutectic Growth in a Ti-Fe System with Multiple Nuclei and Misorientations  

NASA Astrophysics Data System (ADS)

In this article a phase-field model to investigate the formation of eutectic structures in a Ti-Fe alloy with high elastic misfit is introduced. Based on linear microelasticity theory, an elastic model is designed to incorporate the elastic energy into the phase-field formalism and later on adopted to growth of multiple nuclei with arbitrary orientations by including the orientation energy in phase-field ansatz. By using this model, we investigate the free growth of a limited number of eutectic nuclei and examine the influence of orientation free energies on elastic fields and the resulting microstructure.

Ebrahimi, Zohreh; Rezende, Joao Luiz Lopez; Emmerich, H.

2013-04-01

377

Composition and temperature of eutectics in the system A/sup III/B/sup V/-Ge(Si)  

SciTech Connect

The authors present correlations which make it possible to evaluate the composition and temperature of not-yet-studied eutectics of the InP-Ge (30/1100), InAs-Si (82/1190), GaN-Si (32/1550), GaP-Si (29/1580), and AlAs-Si (1/1770) systems. Their correlations also indicate the presence of degenerate eutectics in the A/sup III/B/sup V/-Si and A/sup III/B/sup V/-Ge systems if the respective melting points are above 2050 and 1670 K or below 1030 and 570 K.

Leonov, V.V.

1987-02-01

378

Ag3Sn plate formation in the solidification of near-ternary eutectic Sn-Ag-Cu  

NASA Astrophysics Data System (ADS)

Near-ternary eutectic Sn-Ag-Cu alloys are leading lead-free candidate solders for various applications. These alloys yield three phases upon solidification: ?-Sn,Ag3Sn, and Cu6Sn5. Large, plate-like, pro-eutectic Ag3Sn structures can grow rapidly within the liquid phase, potentially adversely affecting the mechanical behavior and reducing the fatigue life of solder joints. This article reports on the formation of such plates in Sn-Ag-Cu solder balls and joints and demonstrates how large Ag3Sn plate formation can be minimized.

Kang, Sung K.; Shih, Da-Yuan; Donald, Ny.; Henderson, W.; Gosselin, Timothy; Sarkhel, Amit; Charles Goldsmith, Ny.; Puttlitz, Karl J.; Choi, Won Kyoung

2003-06-01

379

Ag 3 Sn plate formation in the solidification of near-ternary eutectic Sn-Ag-Cu  

Microsoft Academic Search

Near-ternary eutectic Sn-Ag-Cu alloys are leading lead-free candidate solders for various applications. These alloys yield\\u000a three phases upon solidification: ?-Sn,Ag3Sn, and Cu6Sn5. Large, plate-like, pro-eutectic Ag3Sn structures can grow rapidly within the liquid phase, potentially adversely affecting the mechanical behavior and reducing\\u000a the fatigue life of solder joints. This article reports on the formation of such plates in Sn-Ag-Cu solder

Sung K. Kang; Da-Yuan Shih; Ny. Donald; W. Henderson; Timothy Gosselin; Amit Sarkhel; N. Y. Charles Goldsmith; Karl J. Puttlitz; Won Kyoung Choi

2003-01-01

380

Helpful hints for physical solvent absorption  

SciTech Connect

Review of experience with natural gas treatment using physical solvents points to design and operating suggestions. Experiences with three plants using either Selexol or Sepasolv MPE solvent shows that both solvents perform well. The solvents offer economical and problem-free purification of natural gas. The Sepasolv MPE and Selexol solvents are very similar in chemical structure and physical properties. Thus, their application range is almost similar. An exchange is possible in most plants without equipment modification and/or process data.

Wolfer, W.

1982-11-01

381

Structure of molten Al and eutectic Al-Si alloy studied by neutron diffraction  

SciTech Connect

The structure of molten eutectic Al87.8Si12.2 alloy has been studied by neutron diffraction during a temperature cycle. For comparison measurements were performed on pure molten Al. The measurements show that the alloy after heating above the liquidus contains particles of two kinds, aluminum-rich and silicon-rich. The silicon-rich particles are partly dissolved after a further heating. Earlier published data obtained by the ?-ray absorption technique of the density of the molten eutectic Al–Si alloy had demonstrated the existence of two temperatures above the liquidus temperature: A dissolution temperature Td, at which the microstructure of the melt inherited from the ingot starts to dissolve and a branching temperature, Tb, at which the melt reaches a fully mixed state. The highest temperature that was possible to reach during the neutron experiments lies between Td and Tb. The obtained results support these conclusions that molten alloys after melting are inhomogeneous up to a temperature well above the liquidus. Moreover, the difference in shape between the static structure factors measured by neutron and X-ray diffraction on molten aluminum is observed and is found to be more accentuated and to extend to larger wavevectors than in earlier works.

Dahlborg, U. [University of Rouen; Kramer, Matthew J. [Ames Laboratory; Besser, M. [Ames Laboratory; Morris, J. R. [Oak Ridge National Laboratory; Calvo-Dahlborg, M. [University of Rouen

2012-11-24

382

Thermodynamics of reaction of praseodymium with gallium-indium eutectic alloy  

NASA Astrophysics Data System (ADS)

Thermodynamic properties of Ga-In eutectic alloys saturated with praseodymium were determined for the first time employing the electromotive force method. The equilibrium potentials of the Pr-In alloys saturated with praseodymium (8.7-12.1 mol.% Pr) and Pr-Ga-In alloys (containing 0.0012-6.71 mol.% Pr) were measured between 573-1073 K. Pr-In alloy containing solid PrIn3 with known thermodynamic properties was used as the reference electrode when measuring the potentials of ternary Pr-In-Ga alloys. Activity, partial and excessive thermodynamic functions of praseodymium in alloys with indium and Ga-In eutectic were calculated. Activity (a), activity coefficients (?) and solubility (X) of praseodymium in the studied temperature range can be expressed by the following equations:lga?-Pr(In) = 4.425 - 11965/T ± 0.026.lg?-Pr(Ga-In) = 5.866 - 14766/T ± 0.190.lg??-Pr(Ga-In) = 2.351 - 9996/T ± 0.39.lg&\\HcyPr(Ga-In) = 3.515 - 4770/T ± 0.20.

Melchakov, S. Yu.; Ivanov, V. A.; Yamshchikov, L. F.; Volkovich, V. A.; Osipenko, A. G.; Kormilitsyn, M. V.

2013-06-01

383

Evaluation of the Pd-C eutectic fixed point and the Pt/Pd thermocouple  

NASA Astrophysics Data System (ADS)

A Pd-C eutectic fixed point cell (1492 °C) was constructed to investigate its utility for thermocouple calibration. The primary aim of the study was to evaluate the long-term stability, immersion characteristics (influence of heat conduction along the thermocouple stem) and robustness of a Pd-C fixed point using a Pt/Pd thermocouple, especially constructed for this purpose. The performance of both devices at this relatively high temperature could therefore be tested. The melting and freezing plateaux at the Pd-C eutectic point were measured using the Pt/Pd thermocouple. The total exposure to the Pd-C melting temperature was about 850 h for the fixed point cell and 550 h for the thermocouple. The standard deviations of the melting and freezing points were 1.03 µV (0.041 °C) and 0.77 µV (0.031 °C) respectively. The emfs of the thermocouple at the melting point were observed to drift by about 0.1 °C. The immersion measurements show that for the current cell design, the measuring junction should be at most 30 mm from the bottom of the thermowell to be properly immersed. The long-term performance and robustness of the fixed point indicate a promising future for its use as a fixed point for calibration of noble metal thermocouples.

Pearce, J. V.; Ogura, H.; Izuchi, M.; Machin, G.

2009-10-01

384

Thermal Effects in the HTBB-3200pg Furnace on Metal-Carbon Eutectic Point Implementation  

NASA Astrophysics Data System (ADS)

The general statement that a temperature fixed-point cell will show better melting and freezing plateaux with better temperature uniformity along the dimensions of the fixed point is understood to be valid for metal-carbon (M-C) eutectics as well as for pure metal fixed points. In this article, it is shown that improved temperature uniformity in the central part of the high-temperature blackbody BB3200pg (HTBB), where the M-C fixed point is implemented, results in flatter and longer plateaux. Pyrolitic graphite rings, clamped together by a spring, form the heated cavity of the HTBB. As a first step, the relative electrical resistivity of each pyrolitic graphite ring was measured using a method advised by the furnace manufacturer. Next, the ring positions were optimized, taking into account their relative resistivities, in order to obtain a more homogeneous temperature distribution. Subsequent measurement of the temperature uniformity at the furnace walls confirmed the improvement. Measuring the melting plateaux of the Pt-C eutectic with different arrangements of the rings, and thereby operating the fixed-point cell in different temperature distributions, confirmed the influence of the temperature distribution on the plateau shape, with the best plateau shape corresponding to the most homogeneous temperature distribution.

Sadli, M.; Anhalt, K.; Bourson, F.; Schiller, S.; Hartmann, J.

2009-02-01

385

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

386

Research into the microstructure and mechanical behavior of eutectic Bi-Sn and In-Sn  

SciTech Connect

This manuscript reports on research into two low-melting, lead-free solder alloys, eutectic Bi-Sn and eutectic In-Sn. The microstructures were found to depend on both cooling rate and substrate, with the greatest variability in the In-Sn alloy. The nature of the intermetallic layer formed at the solder-substrate interface depends on both the solder and the substrate (Cu versus Ni). Also, the microstructure of the Bi-Sn can recrystallize during deformation, which is not the case with In-Sn. Data from creep and constant strain rate tests are given for slowly cooled samples. The creep behavior of In-Sn is constant with temperature, but the creep seems to be controlled by the In-rich phase in In-Sn on Cu and by the Sn-rich phase in In-Sn on Ni. Bi-Sn exhibits different creep behavior at temperatures above 40 {degrees}C than at 20 {degrees}C or lower. Stress-strain curves of Bi-Sn on Cu and In-Sn on Cu are similar, while In-Sn on Ni behaves differently. This is explained in terms of the deformation patterns in the alloys.

Goldstein, J.L.F.; Mei, Z.; Morris, J.W. Jr. [Lawrence Berkeley Lab., CA (United States)]|[California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

1993-08-01

387

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

PubMed Central

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

Handa, T; Saito, H; Miyajima, K

1993-01-01

388

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.

389

THE THERMAL EXPANSION OF THE DIRECTIONALLY SOLIDIFIED Al-CuAl{sub 2} EUTECTIC  

SciTech Connect

Alloys of Al- CuAl{sub 2} eutectic composition were prepared from 99.999% pure materials and directionally solidified in a temperature gradient of about 45°C/cm at different growth rates R. The {lambda}{sup 2}R = constant relation was verified and lamellar spacings of 7.5, 3.5, 2.6, 1.8 and 1.4 ~m were obtained. Dilatometer specimens were machined with axes aligned in the principal lamellae coordinate directions. Thermal expansion was measured by standard dilatometry (Cu standard) using a set point program cycling between room temperature and 500°C . Thermal expansion of the directionally solidified Al-CuAl{sub 2} eutectic is greatest in the growth direction (in the plane of the lamellae), least in the transverse direction (orthogonal to the growth direction in the plane of the lamellae) and intermediate in the vertical direction (normal to the lamellae) . The most significant finding of the study is that the thermal expansion increases with decreasing lamellar spacing between limits defined approximately by the thermal expansion of the CuAl{sub 2} phase alone and the predicted thermal expansion of an isotropic elastic model of the composite.

Baker, Dennis F.; Bragg, Robert H.

1980-03-01

390

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

391

Phase Structure and Cyclic Deformation in Eutectic Tin-Lead Alloy: A Numerical Analysis  

SciTech Connect

This study is devoted to providing a mechanistic rationale of coarsening induced failure in solder alloys during thermomechanical fatigue. Micromechanical modeling of cyclic deformation of eutectic tin-lead alloy was undertaken using the finite element method. The models consist of regularly arranged tin-rich and lead-rich phases, simulating the lamellar array and colony structure in a typical eutectic system. A fine structure and a coarse structure, bearing the same phase fraction but different in the aspect ratio of each lead-rich layer and in the number of lead-rich layers in each colony, are utilized for representing the microstructure before and after coarsening, respectively. Both phases are treated as elastic-plastic solids with their respective properties. For simplicity the creep effect is ignored without compromising the main objective of this study. Cyclic loading under pure shear and uniaxial conditions is modeled. It is found that both the fine and coarse structures exhibit essentially the same macroscopic stress-strain response. The coarse structure, however, shows a greater maximum effective plastic strain on a local scale throughout the deformation. The numerical result implies that, in a solder joint, a locally coarsened region may not be mechanically weaker than its surrounding, but it is subject to early damage initiation due to accumulated plasticity. Other implications regarding solder alloy failure and micromechanical modeling of two-phase materials are discussed.

FANG,HUEI ELIOT; Li,W; SHEN,Y.-L

1999-09-09

392

Solvent-regenerated activated carbon  

SciTech Connect

This report summarizes the results of a University/Industry research project, sponsored by the New York State Energy Research and Development Authority and Fluids Design Corporation. The research project studied the solvent regeneration of activated carbon. Activate carbon was used to remove trace organics from aqueous streams, then regenerated by desorbing the adsorbates with organic solvents. The project included a survey of the potential applications in New York State industries, fundamental research on the adsorption/desorption phenomena, and design of a full-scale process. The economics of the full-scale process were evaluated and compared to alternate available technologies. The result of this work is a versatile process with attractive economics. A wide range of adsorbates and solvents were found to be acceptable for this process. The design methodologies are developed and the techniques for evaluating a new application are delineated. 13 refs., 12 figs., 4 tabs.

McLaughlin, H. (Fluids Design Corp., Troy, NY (USA))

1988-07-01

393

Combined thermal and solvent stimulation  

SciTech Connect

This invention provides a method for recovering heavy crude oil from an underground reservoir penetrated by a well, which comprises (a) heating the reservoir surrounding the wellbore with steam at a temperature below coking temperature but sufficient to increase the temperature 40/sup 0/-200/sup 0/ F. above the reservoir temperature; (b) producing the formation until most of the injected water is produced; (c) injecting a liquid solvent having a ratio of crude viscosity to solvent viscosity of at least about 10 and in an amount ranging from about 5 to about 25 barrels per foot of oil-bearing formation; (d) producing a solvent-crude mixture; and (e) repeating steps (c) and (d).

McMillen, J. M.

1985-05-28

394

Deep gas. Technology status report.  

National Technical Information Service (NTIS)

Deep gas research emphasizes studies of natural gas in subduction emplaced sediments and in deep sedimentary basins. Deep gas research in subduction-emplaced sediments is based on the hypothesis that natural gas is generated in sediments carried to great ...

W. J. Gwilliam

1990-01-01

395

Solvent-induced symmetry breaking: Varying solvent strength  

NASA Astrophysics Data System (ADS)

The triiodide ion is an example of a system where symmetry breaking may be induced by a solvent. The Landau free energy is expected to have a similar form to that for the mean field Ising model, but with solvent strength rather than temperature as the control parameter determining whether there is symmetry breaking. In order to examine the extent of anomalous behavior near the critical point we have studied the properties of the ion in a solvent based on a model for water with charges scaled by a factor ? . As ? is increased from zero the solvent strength increases and the system changes from one with no symmetry breaking to one with strong symmetry breaking. The Shannon entropy as a function of ? shows only a weak maximum near the critical value of ?=?c , while the susceptibility has no anomalous behavior. We examine a simple model and show that anomalies near the critical point would increase as the temperature decreases, but divergences associated with a second order phase transition would only be seen in the limit of zero temperature.

Zhang, F. S.; Lynden-Bell, R. M.

2005-02-01

396

Solvent-induced symmetry breaking: varying solvent strength.  

PubMed

The triiodide ion is an example of a system where symmetry breaking may be induced by a solvent. The Landau free energy is expected to have a similar form to that for the mean field Ising model, but with solvent strength rather than temperature as the control parameter determining whether there is symmetry breaking. In order to examine the extent of anomalous behavior near the critical point we have studied the properties of the ion in a solvent based on a model for water with charges scaled by a factor lambda . As lambda is increased from zero the solvent strength increases and the system changes from one with no symmetry breaking to one with strong symmetry breaking. The Shannon entropy as a function of lambda shows only a weak maximum near the critical value of lambda= lambda(c) , while the susceptibility has no anomalous behavior. We examine a simple model and show that anomalies near the critical point would increase as the temperature decreases, but divergences associated with a second order phase transition would only be seen in the limit of zero temperature. PMID:15783328

Zhang, F S; Lynden-Bell, R M

2005-02-23

397

Deep subsurface microbial processes  

NASA Astrophysics Data System (ADS)

Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of other habitats, the study of deep subsurface microbiology is still in its infancy.

Lovley, Derek R.; Chapelle, Francis H.

1995-01-01

398

Thermodynamics of polymer-supercritical solvent mixtures  

NASA Astrophysics Data System (ADS)

The objectives of this research are to experimentally investigate the high pressure fluid phase behavior of polymer solutions and to characterize the resultant phase behavior using contemporary polymer solution theories. The polymer solutions of interest are of three types: (1) a binary mixture of polymer and organic solvent; (2) a binary mixture of polymer and supercritical fluid (SCF) solvent; and (3) a ternary mixture of polymer, organic solvent, and SCF solvent. There are three goals of the experimental phase of this project. The first goal is to determine the effect of high pressure on the lower critical solution temperature (LCST) of the polymer-organic solvent mixture at conditions close to the critical point of the organic solvent. The second goal is to study the phase behavior of polymer - SCF solvent mixtures. The final experimental goal is to study the high pressure phase behavior of tenary mixtures consisting of a polymer, an organic solvent, and an SCF solvent.

McHugh, M. A.

1985-07-01

399

Why is the Challenger Deep so deep?  

NASA Astrophysics Data System (ADS)

Recent sidescan surveys of the deepest segment of the southern Mariana Trench in the western Pacific Ocean provide the first detailed images of this plate boundary, which includes the world's greatest ocean depth, the Challenger Deep. The surveys reveal details of the southern Mariana plate margin, identify another deep rivaling the Challenger, and document widespread deformation of the overriding plate. Our data show a subduction-generated deep ocean trench, not the transform fault boundary suggested by other work [D.E. Karig, Geol. Soc. Am. Bull. 82 (1971) 323-344 D.E. Karig et al., J. Geophys. Res. 83 (1978) 1213-1226 D.E. Karig, B. Ranken, in: The Tectonic and Geologic Evolution of Southeast Asian Seas and Islands, Part 2, American Geophysical Union, Washington, DC, 1983, pp. 266-280 K. Fujioka et al., Geophys. Res. Lett. 19 (2002) 1-4]. We present the geological characteristics of the region, including seismic evidence for a tear in the subducting plate that has influenced the deformation of the overriding plate. The rollback caused by this tear creates greater depths along the southern part of the trench than elsewhere along its length.

Fryer, Patricia; Becker, Nathan; Appelgate, Bruce; Martinez, Fernando; Edwards, Margo; Fryer, Gerard

2003-06-01

400

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1970-01-01

401

Physical solvent for gas sweetening  

SciTech Connect

This invention relates to a novel solvent, N-2-methoxyethyl-2-pyrrolidone, that can be used in two ways. First, in the pure or undiluted form, it absorbs hydrogen sulfide and other sulfurous gases selectively and simultaneously dries the gas. Second, when mixed with an alkanolamine and water, it is a superior absorbent of mercaptans, sulfides, and disulfides, and removes acid gases.

Ferrin, C. R.; Manning, W. P.

1984-11-27

402

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1971-01-01

403

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1972-01-01

404

Solvent Refined Coal (SRC) Process.  

National Technical Information Service (NTIS)

These monthly reports trace the progress of the Solvent Refined Coal (SRC) process developed by The Pittsburg and Midway Coal Mining Co. under contract to the Office of Coal Research since 1966. The process will undergo testing in a pilot plant recently c...

1973-01-01

405

Improved Purex solvent scrubbing methods  

SciTech Connect

Studies of hydrazine and hydroxylamine salts as solvent scrubbing agents that can be decomposed into gases are summarized. Results from testing of countercurrent scrubbers and solid sorber columns that produce lesser amounts of permanent salts are reported. The status of studies of the acid-degradation of paraffin diluent and the options for removal of long-chain organic acids is given.

Mailen, J.C.; Tallent, O.K.

1984-01-01

406

Project DEEP STEAM.  

National Technical Information Service (NTIS)

Development of technology for thermally efficient downhole delivery of surface-generated steam and for downhole steam generators are the major elements of Project DEEP STEAM. Specific activities include development of advanced concept thermal packers, eva...

B. W. Marshall

1982-01-01

407

Extraction of 3D Transition Metals from Molten Cesium-Sodium-Potassium/Acetate Eutectic into Dodecane Using Organophosphorous Ligands.  

National Technical Information Service (NTIS)

Measurements have been made of the transfer of the transition metal cations Cr exp 3+ , Fe exp 2+ , Co exp 2+ , Ni exp 2+ from molten cesium acetate-sodium acetate-potassium acetate eutectic (50-25-25 mol%, mp approx. 90 exp 0 C) into dodecane solutions c...

V. A. Maroni C. E. Philbin R. M. Yonco

1983-01-01

408

Thermal residual stresses in directionally-solidified alumina-YAG and alumina-zirconia eutectic composites: Measurement and modeling  

Microsoft Academic Search

Single crystal ceramic oxides have excellent oxidation resistance and creep properties, vital to aerospace and high temperature applications. Directionally-solidified eutectic ceramic fibers have high strength and improved flaw tolerance over single crystal fibers but often have lower toughness due to the high degree of interfacial bonding between the phases which prevents crack deflection. The toughness is affected by the residual

Colleen Shea Frazer

2004-01-01

409

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

410

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

411

Adjoint Variable Method for the Thermal Design of Eutectic Directional Solidification Processes in AN Open-Boat Configuration  

Microsoft Academic Search

A computational method for the inverse design of a directional solidiécation process of a near-eutectic binary alloy driven by the coupled action of buoyancy, thermocapillary, and electromagnetic convection is presented. The objective is to calculate the mold cooling\\/heating conditions suchthat a stable desired interface growthwith growthvelocity vf and thermal gradient G is achieved. The interface velocity vf and thermal gradient

Rajiv Sampath; Nicholas Zabaras

2001-01-01

412

Cavitation and cracking in as-cast and superplastic Pb-Sn eutectic during high-temperature fatigue  

Microsoft Academic Search

A variety of solder joints, particular in the computer\\/ electronics industry are subject to mechanical and thermal fatigue. Although extensive data have been published on solder joint lifetimes under various fatigue loading conditions, very limited information is available on the microstructural features that contribute to failure. We have examined the behaviour of Pb-Sn eutectic solder under fatigue deformation, with particular

V. Raman; T. C. Reiley

1987-01-01

413

Ce-doped LiF-SrF2 eutectic scintillators for thermal neutron detection produced at different solidification rates  

NASA Astrophysics Data System (ADS)

Ce-doped LiF-SrF2 eutectic scintillators are reported for the first time.The optimum layer thickness was determined experimentally.The brightest sample exhibited the light yield of 5500 ph/n.In scintillation decay times, both Ce3+ 5d-4f and STE emissions were observed.

Yanagida, Takayuki; Fujimoto, Yutaka; Fukuda, Kentaro; Kawaguchi, Noriaki; Watanabe, Kenichi; Yamazaki, Atsushi; Uritani, Akira; Chani, Valery

2013-05-01

414

Electrochemical Reduction of Chromate in the Presence of Nickel Chloride in Molten Lithium Chloride-Potassium Chloride Eutectic.  

National Technical Information Service (NTIS)

Chronopotentiometry of chromate in the presence of NiCl2 in molten LiCl-KCl eutectic reveals a diffusion controlled, three electron reduction step. In the presence of excess NiCl2, chromate is reduced at -0.35V vs. Pt(II)/Pt reference electrode and the el...

B. Popov H. A. Laitinen

1969-01-01

415

Microstructural Evolution of Hypoeutectic, Near-Eutectic, and Hypereutectic High-Carbon Cr-Based Hard-Facing Alloys  

NASA Astrophysics Data System (ADS)

A series of high-carbon Cr-based hard-facing alloys were successfully fabricated on a substrate of 0.45 pct C carbon steel by gas tungsten arc welding (GTAW) process using various alloy fillers with chromium and chromium carbide, CrC (Cr:C = 4:1) powders. These claddings were designed to observe hypoeutectic, near-eutectic, and hypereutectic structures with various (Cr,Fe)23C6 and (Cr,Fe)7C3 carbides at room temperature. According to X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and optical microscopy (OM), in 3.8 pct C cladding, the microstructure consisted of the primary carbides with outer shells (Cr,Fe)23C6 surrounding (Cr,Fe)7C3 cores and [ ? + (Cr,Fe)23C6] eutectic structures. In 5.9 pct C cladding, the composite comprised primary (Cr,Fe)7C3 as the reinforcing phase and [? + (Cr,Fe)7C3] eutectic structures as matrix. Various morphologies of carbides were found in primary and eutectic (Cr,Fe)7C3 carbides, which included bladelike and rodlike (with a hexagonal cross section). The 5.9C cladding with great amounts of primary (Cr,Fe)7C3 carbides had the highest hardness (approximately HRC 63.9) of the all conditions.

Lin, Chi-Ming; Chang, Chia-Ming; Chen, Jie-Hao; Hsieh, Chih-Chun; Wu, Weite

2009-05-01

416

Influence of additives on the microstructure and tensile properties of near-eutectic Al–10.8%Si cast alloy  

Microsoft Academic Search

The continuing quest for aluminum castings with enhanced mechanical properties for applications in the automotive industries has intensified the interest in aluminum–silicon alloys. In Al–Si alloys, the properties are influenced by the shape and distribution of the eutectic silicon particles in the matrix, as also by the iron intermetallics and copper phases that occur upon solidification. The detailed microstructure and

A. M. A. Mohamed; A. M. Samuel; F. H. Samuel; H. W. Doty

2009-01-01

417

Interactions between carbamazepine and polyethylene glycol (PEG) 6000: characterisations of the physical, solid dispersed and eutectic mixtures  

Microsoft Academic Search

The influence of a hydrophilic carrier (PEG 6000) on the polymorphism of carbamazepine, an antiepileptic drug, was investigated in binary physical mixtures and solid dispersions by means of differential scanning calorimetry (DSC), thermal gravimetry, hot-stage microscopy (HSM), and X-ray diffractometry, respectively. This study provides also an attempt to develop a method to calculate more precisely the eutectic composition. In rather

Zerrouk Naima; Toscani Siro; Gines-Dorado Juan-Manuel; Chemtob Chantal; Ceólin René; Dugué Jerome

2001-01-01

418

Direct measurement of the magnetocaloric effect of microstructured Gd eutectic compounds using a new fast automatic device  

Microsoft Academic Search

A newly designed experimental device for direct measurement of the magnetocaloric effect has been assembled and tested. Details about calibration and preliminary measurements performed on Gd as a standard reference material are reported together with results concerning the magnetocaloric effect of three different Gd eutectic compositions (Gd–Gd7Pd3, Gd–GdZn, Gd–GdCd).

Fabio Canepa; Salvino Cirafici; Myrta Napoletano; Carlo Ciccarelli; Claudio Belfortini

2005-01-01

419

Fabrication and Characterization of RF MEMS Package Based on LTCC Lid Substrate and Gold-Tin Eutectic Bonding  

Microsoft Academic Search

This paper reports on an RF MEMS package based on LTCC technology and gold-tin eutectic bonding, and also evaluates physical and RF characteristics of the proposed structure. The package consists of an LTCC lid substrate and a bottom substrate, and assembled by gold-tin layer (80 wt. % gold 20 wt. % tin) for hermetic sealing and low temperature bonding. The

Yong-Seung Bang; Jong-Man Kim; Yongsung Kim; Jung-Mu Kim; Yong-Kweon Kim

2007-01-01

420

Characterizing the Icy H2O-MgSO4 Eutectic System: Preliminary Results on Microstructure and Mechanical Properties  

NASA Astrophysics Data System (ADS)

A columnar multiphase ice-rich system, with column diameter of 1-2 mm, has been produced through unidirectional solidification of the H2O-MgSO4 eutectic solution and was characterized using thin sections and scanning electron microscopy (SEM). Phases have been identified using electron dispersion spectroscopy (EDS). Elastic properties were determined using acoustic emission and the ductile-brittle transition was determined from uniaxial compression. Measurements of fracture toughness, by three point bending at -10 oC, indicate the columnar eutectic material is ~1.3 times tougher than freshwater columnar ice, while cantilever bending tests at -10 oC indicate the eutectic system is ~1.6 times stronger. Measurements of the kinetic coefficient of friction, by double shear sliding at temperatures of -10 oC and -175 oC, indicate that friction for the eutectic system is ~1.6 times larger compared to freshwater columnar ice. These initial results are of importance in modeling the behavior of extraterrestrial icy material, with particular attention to Europa and the possibility of a subsurface ocean.

Burks, C. E.; Lucas, K. N.; Golding, N.; Schulson, E. M.

2011-12-01

421

Investigation of Phase Equilibria of TAC-Fibre Reinforced Cobalt Alloys Having Directionally Solidified Eutectic Structure Aimed at Matrix Hardening.  

National Technical Information Service (NTIS)

The possiblity of improving the 900 C creep strength of directionally solidified two phase eutectic alloys by precipitation of a third phase which is stable at high temperatures was investigated. It was found that: (1) the aluminum content necessary for t...

A. Donner

1978-01-01

422

A Finite-Element-Based Methodology for Evaluating Solder Electromigration Current Limits of Sn\\/Pb Eutectic Solder Bumps  

Microsoft Academic Search

This paper investigates the effect of current distribution to the bump and current crowding on the electromigration (EM) of Sn\\/Pb eutectic solder bumps. The peak current density in the bump is found to have a significant effect on the EM lifetime of the tested structures and, thus, impacts the maximum allowable bump current. A finite-element model is developed which accurately

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

2008-01-01

423

Solid–liquid interfacial energy of solid succinonitrile solution in equilibrium with succinonitrile–neopentylglycol eutectic liquid  

NASA Astrophysics Data System (ADS)

The grain boundary groove shapes for solid succinonitrile solution (SCN–5 mole% NPG) in equilibrium with the succinonitrile (SCN)–neopentylglycol (NPG) eutectic liquid (SCN–9.55 mole% NPG) have been directly observed by using a horizontal linear temperature gradient apparatus at 317.1 K equilibrium temperature. From the observed grain boundary groove shapes, the Gibbs–Thomson coefficient (?) and solid-liquid interfacial energy (?SL) of solid SCN solution have been determined to be (5.43±0.50)×10?8 K m and (8.09±1.21)×10?3 J m?2, respectively. The grain boundary energy of solid SCN solution has been determined to be (14.22±2.28)×10?3 J m?2 from the observed grain boundary groove shapes. The thermal conductivity for SCN–9.55 mole% NPG eutectic solid phase and the thermal conductivity ratio of eutectic liquid phase to eutectic solid phase at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus, respectively.

Karada?, Saadet B.; Alt?ntas, Yemliha; Öztürk, Esra; Aksöz, Sezen; Ke?lio?lu, Kâz?m; Mara?l?, Necmettin

2013-10-01

424

Reading Knee-Deep  

ERIC Educational Resources Information Center

Freire told his audience at a seminar at the University of Massachusetts, "You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it" (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading knee-deep as we…

Jewett, Pamela

2007-01-01

425

Exploration for deep coal  

SciTech Connect

The most important factor in safe mining is the quality of the roof. The article explains how the Rosebud Mining Co. conducts drilling and exploration in 11 deep coal mine throughout Pennsylvania and Ohio. Rosebud uses two Atlas Copco CS10 core drilling rigs mounted on 4-wheel drive trucks. The article first appeared in Atlas Copco's in-house magazine, Deep Hole Driller. 3 photos.

NONE

2008-12-15

426

Investigation on the effect of metallic impurity Zn in solvent during photolithography process  

NASA Astrophysics Data System (ADS)

The trend toward narrower line widths in the manufacture of integrated circuits has put an increasing burden on contamination control in every aspect of semiconductor fabrication. For a deep sub micrometer device, metal contamination appearing on the device can cause fatal problems including increasing the leakage current at the p-n junction, decreasing the breakdown voltage of oxide. Many lithographic defects have been known and evaluated, however, the effects of metallic impurity (Zn) in solvent are seldom reported during lithography process. Solvents are component material for Photoresist and have been used for prewet, strippers, EBR, rinse and so on during photolithography process. Lithography plays a very important role because it is applied repeatedly onto the wafer surface during device manufacturing. Unfortunately, pattern lifting happened to well formation layer wafers that were reworked on a normal iline litho process after stripping the Photoresist with solvent (PGMEA). We also detected blocked pattern defect at 0.18 CMOS gate pattern coated with DUV resist applied solvent prewet step after BARC coating. From various investigations, we could know that pattern lifting and blocked defect were derived from solvent (PGMEA). In this paper, we show mechanism of adhesion fails and blocked defect happened by metallic impurity Zn in solvent during solvent rework and prewet on organic BARC film. It shows that proper control of metallic impurities in thinner is an important item in FAB.

Jeon, Byoung-Tak; Kim, Ook-Hyun; Baik, Jeong-Heon; Ha, Jeong-Hyuk; Lee, Il-Ho; Yang, Weon-Sik

2005-05-01

427

Mechanism for the Role of Silicon on the Transition from Graphite to Cementite Eutectic in Cast Iron  

NASA Astrophysics Data System (ADS)

In this work, an analytical solution is proposed to explain the influence of silicon on the transition from graphite to cementite eutectic in cast iron. It is found that this transition can be related to (1) the graphite nucleation potential (directly characterized by the cell count N and indirectly by the nucleation coefficients N s and b), (2) the growth rate coefficient of graphite eutectic cells ?, (3) the temperature range ? T sc = T s - T c (where T s and T c are the equilibrium temperature for graphite eutectic and the formation temperature for cementite eutectic, respectively), and (4) the liquid volume fraction f l after preeutectic austenite solidification. Analytical equations were derived that describe the absolute and the relative chilling tendencies (CT and CTr, respectively) as well as the critical cooling rate Q cr and, hence, the chill w of the cast iron. Theoretical arguments are experimentally verified for castings with various silicon contents. This work also describes the methods used in the determination of N s, b, and ? values. It is found that the main role of silicon on the transition from graphite to cementite eutectic is to raise the density of the graphite nuclei N and temperature range ? T sc. In addition, it is shown that increasing the silicon content of cast iron leads to an increasing value of Q cr and decreasing values of CT and CTr, and of the chill width w. In particular, this work shows that the chilling tendency indexes and, hence, the chill all can be estimated from a simple thermal analysis using reference castings.

Fra?, Edward; Górny, Marcin; Lopez, Hugo F.

2012-11-01

428

Slow strain rate tensile tests on T91 in static lead bismuth eutectic  

NASA Astrophysics Data System (ADS)

The embrittlement effect of liquid lead bismuth eutectic (LBE) on martensitic steel T91 has been studied by performing slow-strain-rate tensile (SSRT) tests in static LBE with about 1 wppm oxygen at temperatures ranging from 250 °C to 425 °C. Two groups of samples were used. Group-I samples with microcracks on the lateral surfaces indicated clearly LBE embrittlement effect at temperatures ?300 °C, while Group-II samples without microcracks did not show the effect. The LBE embrittlement effect occurred after the necking of specimens started. The yield and ultimate tensile strengths and uniform elongation were not affected. SEM observations showed the specimens ruptured in a brittle fracture mode when the embrittlement occurred. It is concluded that the requirements for the susceptibility of LBE embrittlement effect on the T91 steel are: surface cracks or flaws, wetting and a certain level of stress concentration at crack tips.

Dai, Y.; Long, B.; Groeschel, F.

2006-09-01

429

Wetting and Soldering Behavior of Eutectic Au-Ge Alloy on Cu and Ni Substrates  

NASA Astrophysics Data System (ADS)

Au-Ge-based alloys are interesting as novel high-temperature lead-free solders because of their low melting point, good thermal and electrical conductivity, and high corrosion resistance. In the present work, the wetting and soldering behavior of the eutectic Au-28Ge (at.%) alloy on Cu and Ni substrates have been investigated. Good wetting on both substrates with final contact angles of 13° to 14° was observed. In addition, solder joints with bond shear strength of 30 MPa to 35 MPa could be produced under controlled conditions. Cu substrates exhibit pronounced dissolution into the Au-Ge filler metal. On Ni substrates, the NiGe intermetallic compound was formed at the filler/substrate interface, which prevents dissolution of Ni into the solder. Using thin filler metal foils (25 ?m), complete consumption of Ge in the reaction at the Ni interface was observed, leading to the formation of an almost pure Au layer in the soldering zone.

Leinenbach, C.; Valenza, F.; Giuranno, D.; Elsener, H. R.; Jin, S.; Novakovic, R.

2011-07-01

430

Phase-field investigation of rod eutectic morphologies under geometrical confinement  

NASA Astrophysics Data System (ADS)

Three-dimensional phase-field simulations are employed to investigate rod-type eutectic growth morphologies in confined geometry. Distinct steady-state solutions are found to depend on this confinement effect with the rod array basis vectors and their included angle (?) changing to accommodate the geometrical constraint. Specific morphologies are observed, including rods of circular cross sections, rods of distorted (elliptical) cross sections, rods of peanut-shaped cross-sections, and lamellar structures. The results show that, for a fixed value of ?>10?, the usual (triangular) arrays of circular rods are stable in a broad range of spacings, with a transition to the peanut-shaped cross sectioned rods occurring at large spacings (above 1.5 times the minimum undercooling spacing ?m), and the advent of rod eliminations at low spacings. Furthermore, a transition from rod to lamellar structures is observed for ?<10? for the phase fraction of 10.5% used in the present paper.

?erefo?lu, Melis; Napolitano, R. E.; Plapp, Mathis

2011-07-01

431

Some aspects of superplastic flow of eutectic alloys connected with metastability  

NASA Astrophysics Data System (ADS)

Some features of the manifestation of superplastic properties in the Pb-62% Sn alloy have been investigated depending on the duration of aging after preliminary reduction. Mechanical tests have been conducted under creep conditions at a constant applied stress. Metallographic studies of the structure transformation in the process of superplastic flow have been performed at mesoscopic and macroscopic levels. X-ray diffraction investigations have been carried out. The experimental results have been analyzed in combination with the earlier data on the internal friction and changes in Young’s modulus depending on the regimes of aging. Based on the results of the analysis, a conclusion has been made which confirms the previously suggested assumptions that the superplasticity effect in the eutectic Pb-62% Sn alloy is determined by the interaction between the processes of plastic deformation and phase transformations under the action of an external tensile load.

Korshak, V. F.; Shapovalov, Yu. A.

2009-04-01

432

Miniature Co-C eutectic fixed-point cells for self-validating thermocouples  

NASA Astrophysics Data System (ADS)

Miniature fixed-point cells have been constructed using ingots of Co-C eutectic alloy, with the aim of constructing self-validating thermocouples for in situ calibration. The design consists of a cylindrical graphite crucible, diameter 6 mm, containing the ingot, integrated into the measuring junction of a type R thermocouple. Two sizes of cell were studied, with internal volumes 124 and 64 mm3 respectively. A detailed study of the characteristics of the two designs shows a correlation between the emf at the melting temperature, and the furnace temperature. This correlation is dramatically reduced for the smaller cell. The correlation is characterized extensively. The smaller cell provides the best overall performance. The repeatability of both cells is of the order of 0.1 °C.

Ongrai, O.; Pearce, J. V.; Machin, G.; Sweeney, S. J.

2011-01-01

433

Fe-C eutectic fixed-point cells for contact thermometry: an investigation and comparison  

NASA Astrophysics Data System (ADS)

Five iron-carbon (Fe-C) eutectic fixed-point cells have been constructed between NPL and LNE-Cnam to investigate the robustness and to measure the agreement of their melting temperatures. Each cell was constructed with a different selection of materials sourced by NPL and LNE-Cnam. The measured emfs at the Fe-C fixed-point temperature (~1153 °C), compared between cells, agree within around 1.98 µV (~90 mK), where the most important contribution to the uncertainty of each measurement is the inhomogeneity associated with the measuring Pt/Pd thermocouple. This demonstrates that these cells are suitable for use as secondary fixed-point cells in contact thermometry but the robustness of the presented cells is not found to be sufficient for maintaining their integrity during repeated cycling procedures.

Elliott, C. J.; Pearce, J. V.; Failleau, G.; Deuzé, T.; Briaudeau, S.; Sadli, M.; Machin, G.

2012-02-01

434

Tailoring nickel coatings via electrodeposition from a eutectic-based ionic liquid doped with nicotinic acid  

NASA Astrophysics Data System (ADS)

Pure nickel (Ni) was electrodeposited onto a copper (Cu) substrate from choline chloride-urea (1:2 molar ratio) eutectic-based ionic liquid (1:2 ChCl-urea IL) with 0-1200 mg/L additions of nicotinic acid (NA). The effect of NA on the voltammetric behavior of Ni (II) was investigated by cyclic voltammetry, whilst the nucleation/growth of Ni deposits was studied by chronoamperometry. The resultant surface morphologies and microstructures of the Ni coatings were revealed by SEM/EDXS, XRD and TEM, demonstrating that NA can inhibit, hence tailor, the Ni deposition and serve as a very effective brightener producing highly uniform and smooth Ni deposits. The nucleation/growth process of Ni was not affected by the presence of NA, proceeding via three-dimensional instantaneous nucleation. NA has a profound grain refining effect with a grain size of ˜4.2 nm achievable.

Yang, Haiyan; Guo, Xingwu; Birbilis, Nick; Wu, Guohua; Ding, Wenjiang

2011-08-01

435

Crystalline Surface Phases of the Liquid Au-Si Eutectic Alloy  

SciTech Connect

A two-dimensional crystalline layer is found at the surface of the liquid eutectic Au82Si18 alloy above its melting point TM=359 C. Underlying this crystalline layer, we find a layered structure, 6-7 atomic layers thick. This surface layer undergoes a first-order solid-solid phase transition occurring at 371 C. The crystalline phase observed for T>371 C is stable up to at least 430 C. Grazing-incidence x-ray diffraction data at T>371 C imply lateral order comprising two coexisting phases of different oblique unit cells, in stark contrast with the single phase with a rectangular unit cell found for low-temperature crystalline phase, 359 C

Shpyrko,O.; Streitel, R.; Balagurusamy, V.; Grigoriev, A.; Deutsch, M.; Ocko, B.; Meron, M.; Lin, B.; Pershan, P.

2007-01-01

436

3D CAFE modeling of grain structures: application to primary dendritic and secondary eutectic solidification  

NASA Astrophysics Data System (ADS)

A three-dimensional model is presented for the prediction of grain structures formed in casting. It is based on direct tracking of grain boundaries using a cellular automaton (CA) method. The model is fully coupled with a solution of the heat flow computed with a finite element (FE) method. Several unique capabilities are implemented including (i) the possibility to track the development of several types of grain structures, e.g. dendritic and eutectic grains, (ii) a coupling scheme that permits iterations between the FE method and the CA method, and (iii) tabulated enthalpy curves for the solid and liquid phases that offer the possibility to work with multicomponent alloys. The present CAFE model is also fully parallelized and runs on a cluster of computers. Demonstration is provided by direct comparison between simulated and recorded cooling curves for a directionally solidified aluminum-7 wt% silicon alloy.

Carozzani, T.; Digonnet, H.; Gandin, Ch-A.

2012-01-01

437

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

438

Comparison of Co-C eutectic fixed-point cells between VNIIM and VNIIOFI  

NASA Astrophysics Data System (ADS)

Two national metrological institutes of the Russian Federation, VNIIM and VNIIOFI, take part in the international research plan of CCT WG5 for investigation of high-temperature fixed points (HTFP). In the framework of this CCT-WG5 HTFP Research Plan the both institutes have designed and built independently cobalt-carbon (Co-C) eutectic radiation cells. The comparison of the Co-C cells developed by the institutes was carried out with the aim of determination of a difference in the melting temperature due to difference in the constructional characteristics of the cells. The radiance-mode radiation thermometers with central wavelength nearby 650 nm were used for the fixed-point melting temperature measurements. The article presents preliminary results of the comparison, which shows agreement between melting temperature of the compared cells within 20 mK. The details of the comparison are reported.

Sild, Y.; Khlevnoy, B.; Matveyev, M.; Grigorieva, I. A.; Fuksov, V. M.

2013-09-01

439

Competitive growth of stable and metastable Fe- C- X eutectics: Part I. experiments  

NASA Astrophysics Data System (ADS)

The effect of small additions of Si, P, Cr, Mn, Ti, Al, and S to pure Fe-C eutectic, upon the transi-tion velocities from grey to white and white to grey cast iron, has been measured by varying the growth rate during directional solidification. As a result, it is found that alloying elements can be classified into three types: graphitizing (Si, Al, P, and S), carburizing (Cr), and “hysteretic effect” (Mn, Ti). The well-known influence of a thermal gradient (or the superheat) has been shown to af-fect only the grey-to-white transition. Growth undercoolings were measured as a function of growth rate, while the average lamellar spacings were determined from transverse sections of directionally solidified samples. A small addition of the element studied can have a marked effect upon these parameters.

Magnin, P.; Kurz, W.

1988-08-01

440

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, NaCl·2H(2)O, and surface-adsorbed water. PMID:20954232

K?epelová, Adéla; Huthwelker, Thomas; Bluhm, Hendrik; Ammann, Markus

2010-12-17

441

Spatial Development of Superconductivity in the Sr2RuO4-Ru Eutectic System  

NASA Astrophysics Data System (ADS)

We have clarified how the enhanced superconductivity, often referred to as the 3-K phase superconductivity, develops in the Sr2RuO4-Ru eutectic system. From the detailed ac and dc susceptibility measurements on well-characterized crystals, we revealed strongly anisotropic shielding, governed by the direction of the screening current dominated within the RuO2 plane rather than by the orientation of the Ru lamellae. The onset temperature of the 3-K phase superconductivity probed by diamagnetic screening is as high as 3.5 K. The temperature dependence of the diamagnetic shielding above around 2 K is well ascribed by the interfacial screening around each Ru lamella. Below around 2 K, the rapid development of the shielding fraction as well as its peculiar response to ac and dc magnetic fields are explained by the formation of the Josephson network consisting of inter-lamellar supercurrents.

Kittaka, Shunichiro; Nakamura, Taketomo; Yaguchi, Hiroshi; Yonezawa, Shingo; Maeno, Yoshiteru

2009-06-01

442

Lead-Bismuth Eutectic Compatibility with Materials in the Concept of Spallation Target for ADS  

NASA Astrophysics Data System (ADS)

Lead bismuth eutectic (LBE) is favored by spallation neutron sources and coolant in the sub-critical reactor at the accelerator driven nuclear transmutation system (ADS). Technical issues of ADS are material technology of how to compromise with flowing lead bismuth, high-energy proton accelerator technology and a sub-critical reactor system technology. This paper describes LBE technology developed at JAERI. First a scenario in order to realize the ADS is shown. The concept of spallation target test facility is introduced with a target design of thermo-fluid dynamics. Base data of flow rate and temperature of Pb-Bi during LBE circulation are described. The results of LBE loop operation under the flowing conditions of target design concept are reported. The stagnant corrosion tests were done to know the controlling parameters among the various steels. The tube-type oxygen sensor with having the solid electrolyte was studied. Cleaning techniques were developed to remove LBE from materials.

Kikuchi, Kenji; Saito, Shigeru; Kurata, Yuji; Futakawa, Masatoshi; Sasa, Toshinobu; Oigawa, Hiroyuki; Wakai, Eiichi; Umeno, Makoto; Mizubayashi, Hiroshi; Miura, Kuniaki

443

Numerical Modeling of Lead Oxidation in Controlled Lead Bismuth Eutectic Systems: Chemical Kinetics and Hydrodynamic Effects  

SciTech Connect

Using liquid Lead-Bismuth Eutectic (LBE) as coolant in nuclear systems has been studied for more than 50 years. And LBE has many unique nuclear, thermo physical and chemical attributes which are attractive for practical application. But, corrosion is one of the greatest concerns in using liquid Lead-Bismuth Eutectic (LBE) as spallation target in the Accelerator-driven Transmutation of Waste (ATW) program. Los Alamos National Laboratory has designed and built the Liquid Lead-Bismuth Materials Test Loop (MTL) to study the materials behavior in a flow of molten LBE. A difference of 100 deg. C was designed between the coldest and the hottest parts at a nominal flow rate of 8.84 GPM. Liquid LBE flow was activated by a mechanical sump pump or by natural convection. In order to maintain a self-healing protective film on the surface of the stainless steel pipe, a certain concentration of oxygen has to be maintained in the liquid metal. Therefore, it is of importance to understand what the oxygen concentrations are in the LBE loop related to the corrosion effects on the metal surface, the temperature profiles, the flow rates, and diffusion rates through the metal surface. The chemical kinetics also needs to be fully understood in the corrosion processes coupled with the hydrodynamics. The numerical simulation will be developed and used to analyze the system corrosion effects with different kind of oxygen concentrations, flow rates, chemical kinetics, and geometries. The hydrodynamics modeling of using computational fluid dynamics will provide the necessary the levels of oxygen and corrosion products close to the boundary or surface. This paper presents an approach towards the above explained tasks by analyzing the reactions between the Lead and oxygen at a couple of sections in the MTL. Attempt is also made to understand the surface chemistry by choosing an example model and estimating the near wall surface concentration values for propane and oxygen. (authors)

Wu, Chao; Kanthi Kiran Dasika; Chen, Yitung; Moujaes, Samir [Department of Mechanical Engineering, University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas NV, 89154-4027 (United States)

2002-07-01

444

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

445

Microstructures and mechanical properties of a directionally solidified NiAl-Mo eutectic alloy  

SciTech Connect

A NiAl-Mo ternary eutectic alloy, having the nominal composition Ni-45.5Al-9Mo (at.%), was directionally solidified in a high-temperature optical floating zone furnace. Well-aligned rod-like microstructures were obtained, consisting of NiAl matrix and 14% (by volume) continuous Mo fibers having a square cross-section. With increasing growth rate (from 20 to 80 mm/h), the spacing and size of the Mo fibers decreased, from {approx}2 to 1 {mu}m (fiber spacing) and 800 to 400 nm (fiber size). X-ray microprobe analyses revealed that the NiAl matrix contained essentially no Mo (<0.1 at.%) and had the composition Ni-45.2Al (at.%), while the composition of the Mo fibers was Mo-10.1Al-3.9Ni (at.%). From electron backscatter diffraction patterns, the following orientation relationships were obtained: <1 0 0>{sub NiAl}//<1 0 0>{sub Mo}, and (0 1 1){sub NiAl}//(0 1 1){sub Mo}. The growth directions and Mo/NiAl interface boundaries were found to be parallel to <1 0 0> and (0 1 1), respectively, in both Mo and NiAl. Nanoindentation was used to probe the mechanical properties of the individual phases in the eutectic microstructure and the modulus and hardness of the NiAl matrix were determined to be 180 and 2.9 GPa, respectively, and those of the Mo fibers 270 and 4.8 GPa. Tensile tests were used to investigate the temperature dependence of the strength and ductility of the composite. Its ductile-to-brittle transition temperature was found to be {approx}675 deg C, and its yield strength about 25-30% higher than that of <1 0 0> NiAl single crystals over the temperature range 600-1000 deg C.

Bei, H. [Department of Materials Science and Engineering, University of Tennessee, 434 Dougherty Hall, Knoxville, TN 37996-2200 (United States) and Oak Ridge National Laboratory, Metals and Ceramics Division, 1 Bethel Valley Road, Oak Ridge, TN 37831-6093 (United States)]. E-mail: Hbei1@utk.edu; George, E.P. [Department of Materials Science and Engineering, University of Tennessee, 434 Dougherty Hall, Knoxville, TN 37996-2200 (United States) and Oak Ridge National Laboratory, Metals and Ceramics Division, 1 Bethel Valley Road, Oak Ridge, TN 37831-6093 (United States)]. E-mail: georgeep@ornl.gov

2005-01-03

446

Microstructure of Y 2O 3 doped Al 2O 3\\/ZrO 2 eutectic fibers grown by the micro-pulling-down method  

Microsoft Academic Search

Al2O3\\/ZrO2 eutectic crystal fibers containing various amounts of Y2O3 were grown by the micro-pulling-down method. The eutectic microstructures and some mechanical properties were investigated as a function of growth rate and doping amount of Y2O3. Doped with Y2O3, Al2O3\\/ZrO2 eutectic fibers 0.3–2mm in diameter and 500mm in length have been grown over the range of pulling rate 0.1–15mm\\/min. The dominant

J. H. Lee; A. Yoshikawa; H. Kaiden; K. Lebbou; T. Fukuda; D. H. Yoon; Y. Waku

2001-01-01

447

Direct correlation between microstructure and mechanical tensile properties in Pb-free solders and eutectic SnPb solder for flip chip technology  

NASA Astrophysics Data System (ADS)

The relationship between the microstructure and the mechanical tensile properties of lead-free solders and eutectic SnPb solders is presented for flip chip scale interconnects. Eutectic Sn-37Pb and Sn-0.7Cu solder (in wt %) exhibited a ductile fracture after tensile testing. Eutectic Sn-3.5Ag solder (in wt %) had greater strength and exhibited a brittle fracture at the interface. The different fracture behavior of the lead-free solders was attributed to the grain size and configuration of the intermetallics. Minor additions of alloying elements to the high Sn lead-free solder dramatically affected the microstructure and mechanical properties.

Jang, J. W.; de Silva, A. P.; Lee, T. Y.; Lin, J. K.; Frear, D. R.

2001-07-01

448

Combustion of solvent refined coal  

SciTech Connect

Successful laboratory study of Solvent Refined Coal, both solid (SRC I) and liquid fuel oil (SRC II), led into full-scale utility boiler tests with the intent of demonstrating the suitability of solvent refined coal as a potential utility boiler fuel. In general, no major operational problems or adverse boiler performance effects were encountered due to the combustion of SRC. No equipment problems were experienced with either Babcock and Wilcox's Type E pulverizers or water-cooled dual register burners during the SRC I combustion tests. Some differences were noted between coal and SRC I with respect to the combustion efficiency and heat absorption patterns within the boiler. Both SO/sub 2/ and NOx emissions were within EPA limits.

Ghassemzadeh, M.R.

1983-01-01

449

Firing of pulverized solvent refined coal  

DOEpatents

An air-purged burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired without the coking thereof on the burner components. The air-purged burner is designed for the firing of pulverized solvent refined coal in a tangentially fired boiler.

Derbidge, T. Craig (Sunnyvale, CA); Mulholland, James A. (Chapel Hill, NC); Foster, Edward P. (Macungie, PA)

1986-01-01

450

Solvent radical mediated hydrogenolysis in coal liquefaction  

SciTech Connect

In the conventional model for coal liquefaction the role of the solvents is merely to stabilize radicals generated by thermolysis of coal structures. We have previously presented a model in which the solvent radicals play an active part in engendering bond scission by transferring hydrogen to ipso postions. In this paper we present experimental evidence in support of solvent radical mediated hydrogenolysis. 9 refs.

McMillen, D.F.; Malhotra, R.; Chang, S.J.; Nigenda, S.E.

1985-01-01

451

Reduction of solvent use through fluxless soldering  

Microsoft Academic Search

Conventional soldering typically requires fluxing to promote wetting. Halogenated solvents must then be used to remove the flux residues. While such practice has been routinely accepted throughout the DOE weapons complex, new environmental laws and agreements will eventually phaseout the use of these solvents. Solvent substitution or alternative technologies must be developed to meet these restrictions. SNL, Albuquerque is characterizing

Hosking

1990-01-01

452

Solvent pretreatment of feed coal for briquetting  

SciTech Connect

Solvent pretreating of coal fines prior to briquetting results in coal briquettes which have no added binder and which will withstand weathering conditions better than binder containing briquettes. The solvents are generally described as organic Lewis base solvents which are capable of electron donor action, and include among others, acetone, methyl ethyl ketone, and ethylene diamine.

Martin, D.M.; Miller, M.R.

1980-11-25

453

Solvent substitution for electronic products  

Microsoft Academic Search

Allied-Signal Inc., Kansas City Division (KCD), manufactures the electrical, electrochemical, mechanical, and plastic components for nuclear weapons. The KCD has made a commitment to eliminate the use of chlorohydrocarbon (CHC) and chlorofluorocarbon (CFC) solvents to the greatest technical extent possible consistent with nuclear safety and stockpile reliability requirements. Current cleaning processes in the production departments use trichloroethylene, 1,1,1-trichloroethane, and various

Benkovich

1992-01-01

454

Solvent cleaning system and method for removing contaminants from solvent used in resin recycling  

DOEpatents

A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

Bohnert, George W. (Harrisonville, MO); Hand, Thomas E. (Lee' s Summit, MO); DeLaurentiis, Gary M. (Jamestown, CA)

2009-01-06

455

Cause of Deep Moonquakes  

NASA Astrophysics Data System (ADS)

It is well known that the occurrence of deep moonquakes is highly correlated with the solid tides raised by Earth and the Sun. However, it has long been debated whether the tides are simply acting as a triggering mechanism for a release of accumulated tectonic stresses in the Moon's interior or the tides themselves are responsible for their generation, releasing tidally dissipated energy in the form of moonquakes. One way to test which of these two hypotheses is correct is to see when deep moonquakes occur relative to the long- term tidal amplitude variations caused by the changing position of the Sun relative to the eccentric orbit of the Moon around Earth. If the tides are simply acting as a trigger mechanism, deep moonquakes are more likely to occur when the tidal stress amplitudes are increasing, while if the tides are the main cause of deep moonquakes, they are more likely to occur shortly after the peaks in tidal stress amplitudes. We thus examined the frequency of deep moonquake occurrence as reported in the recently updated lunar event catalog relative to the difference between the anomalistic and synodic phases. Tidal stress amplitude reaches maxima when this phase difference is 0°, i.e., a new moon coincides with a perigee crossing, and when it is 180°, i.e., a full moon coincides with a perigee crossing. The result shows a general trend of maximum activity shortly following each of the tidal amplitude maxima, supporting the tidal generation hypothesis. However, an additional peak activity is found shortly before the tidal amplitude maximum at phase difference of 180°, also supporting the tidal triggering hypothesis in certain restricted cases. This secondary peak is limited only to some, but not all, deep moonquake nests. These trends are independent of whether the deep moonquake epicenters are located in either of the E-W hemispheres and in which of the tidal stress regimes as determined by the distance to the sub-earth point. Thus it appears that deep moonquakes generally represent release of tidally dissipated energy with additional triggered release of accumulated tectonic stress at a limited number of specific locations. However, this conclusion is provisional because the Apollo data did not cover the entire 18-year tidal cycle of the Moon.

Nakamura, Y.; Frohlich, C.

2008-12-01

456

Mysteries of the Deep  

NSDL National Science Digital Library

This Scientific American Frontiers website contains videos from the television episode Mysteries of the Deep, as well as related articles and student activities. The videos explore the technology that has opened up the farthest reaches of the ocean and made it possible to lift shipwrecks from the ocean floor. The videos total to approximately one hour in length. The articles explore evidence in support of the flood in the biblical story of Noah; what deep-ocean research has revealed about continental drift, plate tectonics, and the formation of the Earth; and how shipwrecks are lifted from the ocean floor.

457

Foaming properties of solvents for use in air-assisted solvent extraction  

Microsoft Academic Search

The air-assisted solvent extraction (AASX) concept uses a solvent-coated bubble to contact the organic and aqueous phases. Compared to conventional solvent extraction, a high contact area can be created using less solvent and the buoyancy provided by the air core promotes phase separation. Solvent-coated bubbles are produced by forming a foam. The foam is injected through a capillary and a

H. M. Tarkan; J. A. Finch

2005-01-01

458

Effect of impurities on the microhardness of eutectic alloys of the systems A/sup III/B/sup V/-Ge(Si)  

SciTech Connect

It is believed, based on the Hall-Petch law, that the toughness of multiphase alloys increases as the size of the crystallites in the ingot decreases. This assertion, however, is not always applicable to modified eutectic alloys, when their strength and dispersity change simultaneously. This paper is devoted to clarifying this difference. We investigated the effect of the form and concentration of impurities on the integral microhardness of eutectic alloys of the systems InSb-Ge, GaSb-Ge, GaAs-Ge, and GaAs-Si. It is shown that the Hall-Petch law does not hold for doped eutectic alloys. The change in the microhardness of the eutectic alloy accompanying doping is determined by the change in the microhardness of the phases.

Leonov, V.V.

1988-07-01

459

On the Impurity Parameters for Impurities Detected in the Eutectics Co-C and Pt-C and Their Role in the Estimate of the Uncertainty in the Eutectic Temperatures  

NASA Astrophysics Data System (ADS)

In this paper, impurity parameters m i and k i have been calculated for a range of impurities I as detected in the eutectics Co-C and Pt-C, by means of the software package Thermo-Calc within the ternary phase spaces Co-C- I and Pt-C- I. The choice of the impurities is based upon a selection out of the results of impurity analyses performed for a representative set of samples for each of the eutectics in study. The analyses in question are glow discharge mass spectrometry (GDMS) or inductively coupled plasma mass spectrometry (ICP-mass). Tables and plots of the impurity parameters against the atomic number Z i of the impurities will be presented, as well as plots demonstrating the validity of van't Hoff's law, the cornerstone to this study, for both eutectics. For the eutectics in question, the uncertainty u( T E - T liq ) in the correction T E - T liq will be derived, where T E and T liq refer to the transition temperature of the pure system and to the liquidus temperature in the limit of zero growth rate of the solid phase during solidification of the actual system, respectively. Uncertainty estimates based upon the current scheme SIE-OME, combining the sum of individual estimates (SIE) and the overall maximum estimate (OME) are compared with two alternative schemes proposed in this paper, designated as IE-IRE, combining individual estimates (IE) and individual random estimates (IRE), and the hybrid scheme SIE-IE-IRE, combining SIE, IE, and IRE.

Bloembergen, Pieter; Dong, Wei; Bai, Cheng-Yu; Wang, Tie-Jun

2011-12-01

460

Radiometric observation of melting and freezing plateaus for a series of metal-carbon eutectic points in the range 1330 °C to 1950 °C  

Microsoft Academic Search

Melting and freezing plateaus were radiometrically observed for the metal-carbon eutectics Ni-C, Pd-C, Pt-C, and Ru-C, using graphite crucibles and black-body cavities. The graphite crucibles were able to withstand heat cycles without breaking. Since the crucible material is a component of the eutectic fixed-point material, the latter is inherently free of contamination from the crucible. The temperature differences between the

Y. Yamada; H. Sakate; F. Sakuma; A. Ono

1999-01-01

461

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

Microsoft Academic Search

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,

Shigesaburo Ogawa; Shuichi Osanai

2007-01-01

462

Vacuum distillation of a mixture of LiCl–KCl 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 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

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

2008-01-01

463

UV–vis absorption spectroscopic study for on-line monitoring of uranium concentration in LiCl–KCl eutectic salt  

Microsoft Academic Search

UV–vis absorption spectroscopy of uranium in LiCl–KCl eutectic salt at 773K was studied for the on-site use in pyrochemical process. Uranium(III) chloride was electrochemically prepared from uranium metal in LiCl–KCl 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

464

Roles of imposed cyclic strain amplitude and cyclic strain rate on the stress relaxation behaviour of pre-strained eutectic Sn3.5Ag solder joints  

Microsoft Academic Search

Purpose – To understand the roles of service-related parameters, such as imposed cyclic strain amplitude and cyclic strain rate, on the stress relaxation behaviour of eutectic Sn-Ag solder joints. Design\\/methodology\\/approach – Cyclic shear straining with associated stress relaxation at the shear strain extremes imposed was carried out on pre-strained eutectic Sn-Ag solder joints with various cyclic shear straining conditions. Results

H. Rhee; K. N. Subramanian

2006-01-01

465

High-temperature mechanical properties of porous NaMgF 3 derived from directionally solidified NaMgF 3–NaF eutectics  

Microsoft Academic Search

Porous NaMgF3 ceramics have been fabricated by leaching a NaF–NaMgF3 eutectic in distilled water, producing NaMgF3 with 53% of connected porosity. The eutectic was fabricated using the Bridgman technique at growth rates of 8, 10 and 15mm\\/h. The microstructure and composition of the resulting material has been studied by means of X-ray diffraction and SEM. Compression mechanical tests have been

J. Ramírez-Rico; A. R. de Arellano-López; J. Martínez-Fernández; A. Larrea; V. M. Orera

2008-01-01

466

Microstructure investigation of NiAl–Cr(Mo) interface in a directionally solidified NiAl–Cr(Mo) eutectic alloyed with refractory metal  

Microsoft Academic Search

The microstructure of a directionally solidified NiAl–Cr(Mo) eutectic alloyed with refractory metal in as-processed and heat-treated states has been studied by means of scanning electron microscopy and high resolution electron microscopy (HREM). The microstructure of the NiAl–Cr(Mo) eutectic was characterized by lamellar Cr(Mo) phases embedded within NiAl matrix with common growth direction of ?111?. The interface between NiAl and lamellar

Y. X Chen; C. Y Cui; J. T Guo; D. X Li

2004-01-01

467

The solidification and mechanical properties of chill-cast AI-AI 3 IMi and AI-AI 2 Cu eutectic alloys  

Microsoft Academic Search

This paper describes the effect of chill-casting on the solidification behaviour and mechanical properties of the AI-AI3Ni and AI-AI2Cu eutectic alloys. Cellular microstructures were obtained by casting the eutectic alloys into preheated split-steel moulds mounted on either a water-cooled or plain copper chill, to promote growth along the length of the ingot and not radially from the mould wall. This

F. S. J. Jabczynski; B. Cantor

1981-01-01

468

Cause of Deep Moonquakes  

Microsoft Academic Search

It is well known that the occurrence of deep moonquakes is highly correlated with the solid tides raised by Earth and the Sun. However, it has long been debated whether the tides are simply acting as a triggering mechanism for a release of accumulated tectonic stresses in the Moon's interior or the tides themselves are responsible for their generation, releasing

Y. Nakamura; C. Frohlich

2008-01-01

469

Deep Ocean Ambient Noise.  

National Technical Information Service (NTIS)

The objective of this report is to provide information on deep ocean ambient noise which can be used in sonar system design and analysis. Guidelines are given for estimating wind-generated noise, oceanic ship traffic noise, biological noise levels, and th...

A. A. Barrios

1967-01-01

470

Project DEEP STEAM  

Microsoft Academic Search

Development of technology for thermally efficient downhole delivery of surface generated steam and for downhole steam generators are the major elements of Project DEEP STEAM. Specific activities include development of advanced concept thermal packers, evaluation of the thermal performance of insulated tubing designs in a test tower and in a field environment, and development of downhole steam generator concepts. Field

B. W. Marshall

1982-01-01

471

Identification of Deep Earthquakes.  

National Technical Information Service (NTIS)

The objective of this project is to identify and apply seismic event discriminants that will reliably separate small crustal earthquakes (magnitudes less than about 4 and depths less than about 40 to 50 km) from small, deep earthquakes (depths between abo...

G. E. Randall H. E. Hartse

2010-01-01

472

Teaching for Deep Learning  

ERIC Educational Resources Information Center

The authors have been engaged in research focused on students' depth of learning as well as teachers' efforts to foster deep learning. Findings from a study examining the teaching practices and student learning outcomes of sixty-four teachers in seventeen different states (Smith et al. 2005) indicated that most of the learning in these classrooms…

Smith, Tracy Wilson; Colby, Susan A.

2007-01-01

473

Oceanography: Deep ocean freshening  

NASA Astrophysics Data System (ADS)

The traditional view of the open ocean is that surface waters should change faster and that the deep waters should be relatively stable. Now research shows that the depths of the Southern Ocean are also rapidly freshening and warming, and that these changes are spreading towards the Equator.

Bindoff, Nathaniel L.; Hobbs, William R.

2013-10-01

474

Deep Submergence Vehicle Alvin  

NSDL National Science Digital Library

This is the site to go to for information about Alvin, the deep submergence vehicle. Describes the history of Alvin, dive statistics, dive logs, dive site viewer, publication, and photos. Students will love the interactive Alvin simulator. Also available are a user manual, observer information, and cruise planning tips. An excellent marine technology resource.

475

Deep brain stimulation  

Microsoft Academic Search

During the last decade deep brain stimulation (DBS) has become a routine method for the treatment of advanced Parkinson’s disease (PD), leading to striking improvements in motor function and quality of life of PD patients. It is associated with minimal morbidity. The rationale of targeting specific structures within basal ganglia such as the subthalamic nucleus (STN) or the internal segment

Sorin Breit; Jörg B. Schulz; Alim-Louis Benabid

2004-01-01

476

Solvent cavitation under solvophobic confinement.  

PubMed

The stability of liquids under solvophobic confinement can tip in favor of the vapor phase, nucleating a liquid-to-vapor phase transition that induces attractive forces between confining surfaces. In the case of water adjacent to hydrophobic surfaces, experimental and theoretical evidence support confinement-mediated evaporation stabilization of biomolecular and colloidal assemblies. The macroscopic thermodynamic theory of cavitation under confinement establishes the connection between the size of the confining surfaces, interfacial free energies, and bulk solvent pressure with the critical evaporation separation and interfacial forces. While molecular simulations have confirmed the broad theoretical trends, a quantitative comparison based on independent measurements of the interfacial free energies and liquid-vapor coexistence properties has, to the best of our knowledge, not yet been performed. To overcome the challenges of simulating a large number of systems to validate scaling predictions for a three-dimensional fluid, we simulate both the forces and liquid-vapor coexistence properties of a two-dimensional Lennard-Jones fluid confined between solvophobic plates over a range of plate sizes and reservoir pressures. Our simulations quantitatively agree with theoretical predictions for solvent-mediated forces and critical evaporation separations once the length dependence of the solvation free energy of an individual confining plate is taken into account. The effective solid-liquid line tension length dependence results from molecular scale correlations for solvating microscopic plates and asymptotically decays to the macroscopic value for plates longer than 150 solvent diameters. The success of the macroscopic thermodynamic theory at describing two-dimensional liquids suggests application to surfactant monolayers to experimentally confirm confinement-mediated cavitation. PMID:23947875

Ashbaugh, Henry S

2013-08-14

477

Investigation of differently designed Pd-C eutectic fixed-point cells for the calibration of thermocouples  

NASA Astrophysics Data System (ADS)

An interlaboratory comparison of the melting temperatures of three palladium-carbon (Pd-C) eutectic fixed-point cells of different designs and usable for the calibration of thermocouples was performed at NIM. Two Pt/Pd thermocouples were constructed for this particular purpose. One of the Pd-C eutectic cells is of conventional design and size; the two other cells are miniature fixed-point cells of different designs. The melting temperature of the conventional cell, PdC1-NIM, was slightly higher than the melting temperatures of the miniature cells by about 160 mK (PdCM2 of PTB) and 290 mK (PdC2-NIM). The melting temperatures of the two miniature Pd-C cells agree within their measurement uncertainties for k = 2 of about 135 mK. Furthermore, a new aspect of leakage effects often observed in the use of Pd-C cells is presented.

Edler, F.; Zheng, W.

2011-10-01

478

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

479

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

480

Nucleation Control and Thermal Aging Resistance of Near-Eutectic Sn-Ag-Cu-X Solder Joints by Alloy Design  

NASA Astrophysics Data System (ADS)

Elemental (X) additions to Sn-3.5Ag-0.95Cu (SAC3595) solder were developed with minimal (<0.25 wt.%) concentration to avoid pro-eutectic Ag3Sn blades by reducing undercooling (? T) and to eliminate thermal-aging-induced embrittlement. Calorimetry and microstructure results on simple Cu/Cu joints identified 0.21Zn, 0.10Mn, and 0.05Al as sufficient to reduce undercooling below that for SAC3595 and to eliminate Ag3Sn blades. A 211°C melting onset for the X = Mn alloys also suggested the discovery of a new quaternary eutectic. Shear testing and microstructure analysis of larger joints showed that 0.05Al and 0.21Zn additions resulted in reduced as-soldered strength (30 MPa), like Sn-0.95Cu, but all joints showed ductile failure at about 30 MPa after 1000 h at 150°C.

Anderson, Iver E.; Walleser, Jason W.; Harringa, Joel L.; Laabs, Fran; Kracher, Alfred

2009-12-01

481

Self-calibration of a W/Re thermocouple using a miniature Ru-C (1954 °C) eutectic cell  

NASA Astrophysics Data System (ADS)

Previous successful investigations of miniature cobalt-carbon (Co-C, 1324 °C) and palladium-carbon (Pd-C, 1492 °C) high temperature fixed-point cells for thermocouple self-calibration have been reported [1-2]. In the present work, we describe a series of measurements of a miniature ruthenium-carbon (Ru-C) eutectic cell (melting point 1954 °C) to evaluate the repeatability and stability of a W/Re thermocouple (type C) by means of in-situ calibration. A miniature Ru-C eutectic fixed-point cell with outside diameter 14 mm and length 30 mm was fabricated to be used as a self-calibrating device. The performance of the miniature Ru-C cell and the type C thermocouple is presented, including characterization of the stability, repeatability, thermal environment influence, ITS-90 temperature realization and measurement uncertainty.

Ongrai, O.; Pearce, J. V.; Machin, G.; Sweeney, S. J.

2013-09-01

482

Effect of microalloying on the creep strength and microstructure of an eutectic Sn-Pb solder alloy  

SciTech Connect

The present research aims to improve the creep strength of Sn-Pb eutectic solder by the addition of small amount of effective elements, such as Sb, Ag, Cu, and Ga, which are selected by preliminary experiments and analysis. Creep tests were conducted at the stress and temperature range of 5 N/m to 15 N/m m{sup 2} and 313 K to 378 K, respectively. The microalloying treatment increased significantly the creep-rupture time by one order at the same condition of creep stress and temperature, comparing with that of the regular Sn-Pb eutectic solder alloy. Microstructural observation indicated that the excellent creep properties are obtained by the particles dispersion hardening due to the combined addition of the microalloying elements.

Wade, Noboru; Akuzawa, Tatsuo; Yamada, Seiji; Sugiyama, Daigo; Kim, I.S.; Miyahara, Kazuya

1999-11-01