WorldWideScience

Sample records for eutectics moas cras

  1. MOAS

    International Nuclear Information System (INIS)

    Kim, I.S.; Modarres, M.

    1987-01-01

    A real-time knowledge-based operator advisory system (Maryland Operator Advisory System; MOAS) is being developed at the University of Maryland using PICON (real-time expert system shell for process control). MOAS is an expert system designed to assist the plant operators during transient conditions initiated by the Condensate and Feed Water System (CFWS) of a pressurized water reactor. The MOAS performs (1) intelligent prealarming and alarming, (2) real-time sensor validation and sensor conflict resolution, (3) real-time hardware failure diagnosis, and (4) real-time corrective measure synthesis. The core of the MOAS knowledge base is constructed using an integrated deep-knowledge approach called Coal Tree-Success Tree (GTST). The process domain knowledge of the CFWS is completely and rigorously modeled in the GTST format, which is then used to build up the knowledge base of the expert system. This paper briefly describes the GTST model, design of the current MOAS and ongoing and future efforts

  2. Stardust Blazes MOA Trail

    Science.gov (United States)

    Faris, Grant B.; Bryant, Larry W.

    2010-01-01

    Mission Operations Assurance (MOA) started at the Jet Propulsion Laboratory (JPL) with the Magellan and Galileo missions of the late 80's. It continued to develop and received a significant impetus with the failures of two successive missions to Mars in the late 90's. MOA continued to evolve with each successive project at JPL achieving its current maturity with the Stardust sample return to Earth.

  3. Credit Rating Agencies (CRAs) : The EU Regulatory Framework Assessment

    OpenAIRE

    Boehm, Kristina

    2013-01-01

    Credit Rating Agencies (CRAs) can provide a valuable service for the capital markets if they deliver a credible assessment of the relative probability of default of credit financial instruments that enables investors to reduce the information asymmetry. CRAs have had an indisputable role in accentuating the crisis, and preventative regulation of CRAs has emerged as crucial and necessary, becoming a priority in all high-level policy decisions in Europe and worldwide. This thesis will first pre...

  4. Mobile Objects and Agents (MOA)

    Science.gov (United States)

    Milojicic, Dejan S.; LaForge, William; Chauhan, Deepika

    1998-12-01

    This paper describes the design and implementation of the Mobile Objects and Agents (MOA) project at the Open Group Research Institute. MOA was designed to support migration, communication and control of agents. It was implemented on top of the Java Virtual Machine, without any modifications to it. The initial project goals were to support communication across agent migration, as a means for collaborative work; and to provide extensive resource control, as a basic support for countering denial of service attacks. In the course of the project we added two further goals: compliance with the Java Beans component model, which provides for additional configurability and customization of agent system and agent applications; and interoperability, which allows cooperation with other agent systems. This paper analyses the architecture of MOA, in particular the support for mobility, naming and locating, communication, and resource management. Object and component models of MOA are discussed and some implementation details described. We summarize the lessons learned while developing and implementing MOA and compare it with related work.

  5. Defining the period of moa extinction

    International Nuclear Information System (INIS)

    Anderson, A.

    2000-01-01

    Few aspects of New Zealand's prehistory have engaged scientific and public attention so consistently as two interlinked questions of moa extinction; when did moas become extinct and why? Answers offered over the last 160 years have run the gamut from chronological antiquity by evolutionary senescence, to within the 19th century Maori and European disturbance. (author)

  6. Pressure-induced electronic phase separation of magnetism and superconductivity in CrAs.

    Science.gov (United States)

    Khasanov, Rustem; Guguchia, Zurab; Eremin, Ilya; Luetkens, Hubertus; Amato, Alex; Biswas, Pabitra K; Rüegg, Christian; Susner, Michael A; Sefat, Athena S; Zhigadlo, Nikolai D; Morenzoni, Elvezio

    2015-09-08

    The recent discovery of pressure (p) induced superconductivity in the binary helimagnet CrAs has raised questions on how superconductivity emerges from the magnetic state and on the mechanism of the superconducting pairing. In the present work the suppression of magnetism and the occurrence of superconductivity in CrAs were studied by means of muon spin rotation. The magnetism remains bulk up to p ≃ 3.5 kbar while its volume fraction gradually decreases with increasing pressure until it vanishes at p ≃ 7 kbar. At 3.5 kbar superconductivity abruptly appears with its maximum Tc ≃ 1.2 K which decreases upon increasing the pressure. In the intermediate pressure region (3.5 magnetic volume fractions are spatially phase separated and compete for phase volume. Our results indicate that the less conductive magnetic phase provides additional carriers (doping) to the superconducting parts of the CrAs sample thus leading to an increase of the transition temperature (Tc) and of the superfluid density (ρs). A scaling of ρs with Tc(3.2) as well as the phase separation between magnetism and superconductivity point to a conventional mechanism of the Cooper-pairing in CrAs.

  7. Affective maps use as possibility of territorial reading in Social Assistence Reference Center - CRAS

    Directory of Open Access Journals (Sweden)

    Diego Menezes Augusto

    2016-07-01

    Full Text Available Based on surveys and our professional experience, we feel impelled to seek ways to work in CRAS in the territorialization process. Our proposal aims to overcome the mere division of the territory and identification of facilities and beneficiaries of income transfer governmental programs as from the discussion of methodologies involving professionals and users, supported on ethical and political commitment to the community. Thus, we find in Environmental Psychology relevant strategies to this endeavor. We aim to present the Affective Maps Generator Instrument as a method able to assist the CRAS’ Psychologist in the territorialization process. In CRAS, the Affective Maps provide a design of the studied area in its entirety, enables user-environment relationship visualization, as from the ways in which community subjects imply with their residence places.

  8. Determinant of Household Business Scale of Moa Buffaloes at Moa Island Southwest Maluku Regency

    Science.gov (United States)

    Lainsamputty, J.; Roessali, W.; Santosa, S. I.; Eddy, B. T.

    2018-02-01

    The objective of this research was to analyze factors that affect the business scale of Moa buffaloes at Moa Island, Regency of Southwest Maluku. The research used a survey method with multistage random sampling. The location chosen was the District of Moa Lakor at Moa Island based on its largest buffalo population. Respondents were randomly drawn in a total of 120 respondents. The variables measured were years of experience in rearing animals, costs of production, farmer’s participation in group activities, animal housing systems, farmer’s income and farmer’s age. The statistical test used was the multiple linear regressions. The results showed that the mean of business scale in the area of high density of buffaloes population was 12.6 AU, in the moderate was 12.4 AU and in the low was 11.0 AU. The average of production cost was IDR 1.893.536.00/year, the average of revenue was IDR14.083.333.00/year, while the average of income was IDR 12.189.797.00/year. The independent variables simultaneously influence the business scale (Pcosts of production, participation and housing systems had highly significant influences on the business scale (P<0.01).

  9. Superconductivity in the vicinity of antiferromagnetic order in CrAs.

    Science.gov (United States)

    Wu, Wei; Cheng, Jinguang; Matsubayashi, Kazuyuki; Kong, Panpan; Lin, Fukun; Jin, Changqing; Wang, Nanlin; Uwatoko, Yoshiya; Luo, Jianlin

    2014-11-19

    One of the common features of unconventional superconducting systems such as the heavy-fermion, high transition-temperature cuprate and iron-pnictide superconductors is that the superconductivity emerges in the vicinity of long-range antiferromagnetically ordered state. In addition to doping charge carriers, the application of external pressure is an effective and clean approach to induce unconventional superconductivity near a magnetic quantum critical point. Here we report on the discovery of superconductivity on the verge of antiferromagnetic order in CrAs via the application of external pressure. Bulk superconductivity with Tc≈2 K emerges at the critical pressure Pc≈8 kbar, where the first-order antiferromagnetic transition at T(N)≈265 K under ambient pressure is completely suppressed. The close proximity of superconductivity to an antiferromagnetic order suggests an unconventional pairing mechanism for CrAs. The present finding opens a new avenue for searching novel superconductors in the Cr and other transition metal-based systems.

  10. Pedagogia Social nos CRAS: Novos Entrecruzamentos Identitários para os/as Pedagogos/as (Social Pedagogy in the CRAS: New Identity Intercrossings for...

    Directory of Open Access Journals (Sweden)

    Berenice dos Anjos Miranda

    2017-10-01

    Full Text Available Resumo: A partir da institucionalização do Sistema Único de Assistência Social (SUAS no Brasil, a proteção social assume um caráter interdisciplinar sobre intervenções com famílias e seus/suas membros em situações de riscos e vulnerabilidades sociais. Este estudo é proveniente de Trabalho de Conclusão de Curso de Licenciatura em Pedagogia, abordada pela perspectiva qualitativa com recursos da pesquisa documental e com a aplicação de um questionário para dar suporte ao estudo de caso em um dos onze municípios pesquisados na microrregião de Andradina, situados no Oeste do Estado de São Paulo. Os apontamentos conclusivos nos retornaram possíveis truncamentos entre aquilo que é especificidade da Pedagogia e as práticas que são direcionadas pelas Orientações técnicas do CRAS para ações dos/das Técnicos/as de Referência das famílias.Palavras-chave: Pedagogia Social. Educação Não-Formal. Assistência Social.Abstract: From the institutionalization of the Unified System of Social Assistance (SUAS in Brazil, social protection assumes an interdisciplinary character in the interventions with families and their members in situations of risks and social vulnerabilities. This study is a work of conclusion of course of Degree in Pedagogy, approached by the qualitative perspective with documentary research resources and with the application of a questionnaire to support the case study in one of the eleven municipalities surveyed in the Andradina microregion, located in the west of the São Paulo State. The concluding remarks have given us possible truncations between what is specificity of Pedagogy and the practices that are directed by the CRAS Technical Guidelines for actions of the Reference Technician of families. Keywords: Social Pedagogy. Non-formal Education. Social Assistence.

  11. Where Have the Moas Gone? A Case Study of Animal Extinction.

    Science.gov (United States)

    Lang, Anna J.

    1979-01-01

    Discusses systematics, ecology, and distribution of New Zealand's moas (flightless birds). Presents two theories of extinction: environmental catastrophe and human impact. Concludes that some moa species survived the Pleistocene epoch and primitive man completed the extinction process. (CK)

  12. A megafauna's microfauna: gastrointestinal parasites of New Zealand's extinct moa (Aves: Dinornithiformes.

    Directory of Open Access Journals (Sweden)

    Jamie R Wood

    Full Text Available WE PERFORM THE FIRST MULTIDISCIPLINARY STUDY OF PARASITES FROM AN EXTINCT MEGAFAUNAL CLADE USING COPROLITES FROM THE NEW ZEALAND MOA (AVES: Dinornithiformes. Ancient DNA and microscopic analyses of 84 coprolites deposited by four moa species (South Island giant moa, Dinornis robustus; little bush moa, Anomalopteryx didiformis; heavy-footed moa, Pachyornis elephantopus; and upland moa, Megalapteryx didinus reveal an array of gastrointestinal parasites including coccidians (Cryptosporidium and members of the suborder Eimeriorina, nematodes (Heterakoidea, Trichostrongylidae, Trichinellidae and a trematode (Echinostomida. Parasite eggs were most prevalent and diverse in coprolites from lowland sites, where multiple sympatric moa species occurred and host density was therefore probably higher. Morphological and phylogenetic evidence supports a possible vicariant Gondwanan origin for some of the moa parasites. The discovery of apparently host-specific parasite taxa suggests paleoparasitological studies of megafauna coprolites may provide useful case-studies of coextinction.

  13. Rod and lamellar growth of eutectic

    Directory of Open Access Journals (Sweden)

    M. Trepczyńska-Łent

    2010-04-01

    Full Text Available The paper presents adaptation problem of lamellar growth of eutectic. The formation of rod eutectic microstructure was investigated systematically. A new rod eutectic configuration was observed in which the rods form with elliptical cylindrical shape. A new interpretation of the eutectic growth theory was proposed.

  14. Representando as práticas e praticando as representações nos CRAS de Sergipe

    Directory of Open Access Journals (Sweden)

    Marcela Flores Cardoso Sobral

    Full Text Available Este trabalho analisa as relações entre representações sociais e práticas sociais, enfocando a atividade profissional do psicólogo em um contexto de atuação específico e de inserção recente, os Centros de Referência de Assistência Social (CRAS. Investigamos as representações sociais que os usuários têm dos psicólogos e suas relações com as práticas desses profissionais nos CRAS de Sergipe. Para tanto, foram realizados dois estudos: um com 27 psicólogos que atuam em CRAS e outro com 20 usuários desse serviço. Os resultados revelaram, no primeiro estudo, a existência de uma dissociação entre as práticas declaradas pelos profissionais e a percepção das práticas de outros psicólogos. No segundo estudo, foi possível evidenciar que a representação social do psicólogo ainda está mais vinculada à atuação na área clínica, que tem como prática fundamental a conversa e o conselho. Tais representações apresentam relação tanto com a percepção dos usuários sobre as práticas dos psicólogos como com a prática real adotada pelos psicólogos no CRAS.

  15. Highly informative ancient DNA 'snippets' for New Zealand moa.

    Directory of Open Access Journals (Sweden)

    Jonathan McCallum

    Full Text Available BACKGROUND: Analysis of ancient DNA has provided invaluable information on past ecologies, ancient populations, and extinct species. We used a short snippet of highly variable mitochondrial control region sequence from New Zealand's moa to characterise a large number of bones previously intractable to DNA analysis as well as bone fragments from swamps to gain information about the haplotype diversity and phylogeography that existed in five moa species. METHODOLOGY/PRINCIPAL FINDINGS: By targeting such 'snippets', we show that moa populations differed substantially in geographic structure that is likely to be related to population mobility and history. We show that populations of Pachyornis geranoides, Dinornis novaezealandiae, and Dinornis robustus were highly structured and some appear to have occupied the same geographic location for hundreds of thousands of years. In contrast, populations of the moa Anomalopteryx didiformis and Euryapteryx curtus were widespread, with specific populations of the latter occupying both the North and South Islands of New Zealand. We further show that for a specific area, in this case a North Island swamp, complete haplotype diversity and even sex can be recovered from collections of small, often discarded, bone fragments. CONCLUSIONS/SIGNIFICANCE: Short highly variable mitochondrial 'snippets' allow successful typing of environmentally damaged and fragmented skeletal material, and can provide useful information about ancient population diversity and structure without the need to sample valuable, whole bones often held by museums.

  16. Eutectic Composite Turbine Blade Development

    Science.gov (United States)

    1976-11-01

    Eutectic alloys evaluated included MC (metallic carbide ) fiber reinforced nickel- and cobalt -base eutectics (NiTaC and CoTaC) and NisCb lamella reinforced...blade superalloy . The results in Figure 68 indicated that carbide defect structures tend to decrease 1500CHCF strength somewhat, but all...Surface finishes were in the range of 5 to 15 AA. Drilling - Parallel tests were made with carbide and cobalt H.S.S. drills under conditions listed in

  17. Structure-property relationships in eutectic composites

    Science.gov (United States)

    Hertzberg, R. W.

    1976-01-01

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

  18. Structural and magnetic phase diagram of CrAs and its relationship with pressure-induced superconductivity

    Science.gov (United States)

    Shen, Yao; Wang, Qisi; Hao, Yiqing; Pan, Bingying; Feng, Yu; Huang, Qingzhen; Harriger, L. W.; Leao, J. B.; Zhao, Yang; Chisnell, R. M.; Lynn, J. W.; Cao, Huibo; Hu, Jiangping; Zhao, Jun

    2016-02-01

    We use neutron diffraction to study the structure and magnetic phase diagram of the newly discovered pressure-induced superconductor CrAs. Unlike most magnetic unconventional superconductors where the magnetic moment direction barely changes upon doping, here we show that CrAs exhibits a spin reorientation from the a b plane to the a c plane, along with an abrupt drop of the magnetic propagation vector at a critical pressure (Pc≈0.6 GPa). This magnetic phase transition, accompanied by a lattice anomaly, coincides with the emergence of bulk superconductivity. With further increasing pressure, the magnetic order completely disappears near the optimal Tc regime (P ≈0.94 GPa). Moreover, the Cr magnetic moments tend to be aligned antiparallel between nearest neighbors with increasing pressure toward the optimal superconductivity regime. Our findings suggest that the noncollinear helimagnetic order is strongly coupled to structural and electronic degrees of freedom, and that the antiferromagnetic correlations between nearest neighbors might be essential for superconductivity.

  19. Mode of Action (MOA) Assignment Classifications for Ecotoxicology: An Evaluation of approaches

    Science.gov (United States)

    The mode of toxic action (MOA) is recognized as a key determinant of chemical toxicity and as an alternative to chemical class-based predictive toxicity modeling. However, MOA classification has never been standardized in ecotoxicology, and a comprehensive comparison of classific...

  20. Evaporation Behavior and Characterization of Eutectic Solvent and Ibuprofen Eutectic Solution.

    Science.gov (United States)

    Phaechamud, Thawatchai; Tuntarawongsa, Sarun; Charoensuksai, Purin

    2016-10-01

    Liquid eutectic system of menthol and camphor has been reported as solvent and co-solvent for some drug delivery systems. However, surprisingly, the phase diagram of menthol-camphor eutectic has not been reported previously. The evaporation behavior, physicochemical, and thermal properties of this liquid eutectic and ibuprofen eutectic solution were characterized in this study. Differential scanning calorimetry (DSC) analysis indicated that a eutectic point of this system was near to 1:1 menthol/camphor and its eutectic temperature was -1°C. The solubility of ibuprofen in this eutectic was 282.11 ± 6.67 mg mL(-1) and increased the drug aqueous solubility fourfold. The shift of wave number from Fourier transform infrared spectroscopy (FTIR) indicated the hydrogen bonding of each compound in eutectic mixture. The weight loss from thermogravimetric analysis of menthol and camphor related to the evaporation and sublimation, respectively. Menthol demonstrated a lower apparent sublimation rate than camphor, and the evaporation rate of eutectic solvent was lower than the sublimation rate of camphor but higher than the evaporation of menthol. The evaporation rate of the ibuprofen eutectic solution was lower than that of the eutectic solvent because ibuprofen did not sublimate. This eutectic solvent prolonged the ibuprofen release with diffusion control. Thus, the beneficial information for thermal behavior and related properties of eutectic solvent comprising menthol-camphor and ibuprofen eutectic solution was attained successfully. The rather low evaporation of eutectic mixture will be beneficial for investigation and tracking the mechanism of transformation from nanoemulsion into nanosuspension in the further study using eutectic as oil phase.

  1. Initial stages of solidification of eutectic alloys

    International Nuclear Information System (INIS)

    Lemaignan, Clement

    1980-01-01

    The study of the various initial stages of eutectic solidification - i.e. primary nucleation, eutectic structure formation and stable growth conditions - was undertaken with various techniques including low angle neutron diffusion, in-situ electron microscopy on solidifying alloys and classical metallography. The results obtained allow to discuss the effect of metastable states during primary nucleation, of surface dendrite during eutectic nucleation and also of the crystallographic anisotropy during growth. (author) [fr

  2. Scaling-Up Eutectic Freeze Crystallization

    NARCIS (Netherlands)

    Genceli, F.E.

    2008-01-01

    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)

  3. Determining eutectic composition in metal alloys

    Science.gov (United States)

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

    1977-01-01

    Tube crucible and furnace are used to separate eutectic mixture from trial-melt ingot. As ingot is a slowly heated to melting point, initial surface meeting will be eutectic mixture. Molten metal is collected at bottom of crucible, where it is solidified.

  4. Examination of Clustering in Eutectic Microstrcture

    Directory of Open Access Journals (Sweden)

    Bortnyik K.

    2017-06-01

    Full Text Available The eutectic microstructures are complex microstructures and a hard work to describe it with few numbers. The eutectics builds up eutectic cells. In the cells the phases are clustered. With the development of big databases the data mining also develops, and produces a lot of method to handling the large datasets, and earns information from the sets. One typical method is the clustering, which finds the groups in the datasets. In this article a partitioning and a hierarchical clustering is applied to eutectic structures to find the clusters. In the case of AlMn alloy the K-means algorithm work well, and find the eutectic cells. In the case of ductile cast iron the hierarchical clustering works better. With the combination of the partitioning and hierarchical clustering with the image transformation, an effective method is developed for clustering the objects in the microstructures.

  5. Big birds and their brains: paleoneurology of the New Zealand moa.

    Science.gov (United States)

    Ashwell, K W S; Scofield, R P

    2008-01-01

    The moa (Dinornithiformes: Aves) are an extinct group of ratites from the North and South Islands of New Zealand. The ancestors of both the moa and the kiwi were isolated from other Gondwanan fauna as much as 80 million years ago and evolved in the absence of large mammalian predators. As such they represent a natural experiment in the removal of mammalian predation pressure on the encephalization of these two groups of ratites. We have used endocranial and skull morphometry in conjunction with high resolution CT scanning of the skulls of 8 species of moa to assess encephalization and brain morphology in moa and compare these features with extant ratites. Absolute brain size among the moa ranged from 17.0 ml for Euryapteryx curtus to 60.0 ml for female Dinornis giganteus. Values for encephalization quotients (EQ) of moa ranged from 0.205 for Euryapteryx gravis of the southern North Island to a mean (+/- SD) of 0.475 (+/- 0.026) for Anomalopteryx didiformis, partially overlapping values for extant non-New Zealand ratites (emu: 0.402 +/- 0.042; rhea: 0.496 +/- 0.016; ostrich: 0.474 +/- 0.084). Nevertheless, mean +/- SD EQ for all moa examined (0.379 +/- 0.065) was significantly lower than EQ for extant non-New Zealand ratites (0.539 +/- 0.141). Bending of the endocranial axis was much less among moa than either the kiwi or non-New Zealand ratites, consistent with the caudal position of the foramen magnum and the horizontal carriage of the head and upper neck during life. Endocranial morphology of the moa species examined was similar to that for non-New Zealand ratites, with proportionally similar sizes of the olfactory bulb, Wulst, vagal and maxillomandibular foramina, suggesting that the moa occupied similar diurnal niches with comparable sensory specializations to the emu, rhea and ostrich. No evidence of olfactory specialization (i.e., enlarged olfactory bulbs and increased surface area of the olfactory nasal cavity or cribriform plate) was evident in any of the

  6. Raman mapping in the elucidation of solid salt eutectic and near eutectic structures

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Kerridge, D. H.

    2002-01-01

    The distribution of the different components of solidified eutectic or near-eutectic salt mixtures (eutectics) was examined by use of Raman microscope mapping of the structures formed when these melts were slowly cooled. Seven binary and one ternary system were investigated. In most cases...... and the composition. When unidirectional cooling was applied it was possible for the system (KCl-Na2SO4, 60:40 mol/mol) to observe lamellar arrangements of the component phases, in an arrangement closely similar to what is frequently found among metallic or ceramic eutectics. Each area, conglomerate or lamellar, did...

  7. Cargas actuantes en túneles de Moa

    Directory of Open Access Journals (Sweden)

    Roberto Blanco-Torrens

    2000-03-01

    Full Text Available Para la confección del presente trabajo se realizó un estudio que abarcó 2 km de túneles del municipio Moa a los que se les hizo un análisis detallado del macizo rocoso que los circunda, y se determinaron las propiedades físico-mecánica de las rocas, agrietamiento, afluencia de agua y sus consecuencias, etc. Se valoró la estabilidad por varias metodologías (Barton, Bieniawsky, Bulichev y otras y fueron usados, por sus resultados, los valores obtenidos del empleo de la de Barton. Se estableció el mecanismo de acción de la presión minera y se caracterizó en dos casos típicos, a partir de los cuales se determinan los valores de las cargas estáticas que se pueden producir. Se consideró el macizo como un cuerpo elástico, homogéneo e isotrópico para establecer el estado tensional inicial y así calcular las cargas dinámicas que pueden actuar. Además se puntualizan los valores de las cargas considerados como críticos.

  8. Modelling Eutectic Growth in Unmodified and Modified Near-Eutectic Al-Si Alloy

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat; Hattel, Jesper Henri; Taylor, John A.

    2013-01-01

    A numerical model that describes solidification of primary aluminium grains and nucleation and growth of eutectic cells is used to analyse the solidification of an Al-12.5wt% Si alloy. Nucleation of eutectic cells is modelled using an Oldfield-type nucleation model where the number of nuclei in t...... in the liquid and the growth velocity of the eutectic cells to determine the size and distribution of eutectic cells in the solidified material.......A numerical model that describes solidification of primary aluminium grains and nucleation and growth of eutectic cells is used to analyse the solidification of an Al-12.5wt% Si alloy. Nucleation of eutectic cells is modelled using an Oldfield-type nucleation model where the number of nuclei...... in the melt is determined by the amount of active nuclei and the local undercooling from the surface to the centre of a plate casting. Eutectic grains are modelled as spheres growing between the dendrites. The growth velocity of the eutectic cells is a function of undercooling. Experimentally determined...

  9. A high-precision chronology for the rapid extinction of New Zealand moa (Aves, Dinornithiformes)

    Science.gov (United States)

    Perry, George L. W.; Wheeler, Andrew B.; Wood, Jamie R.; Wilmshurst, Janet M.

    2014-12-01

    Megafaunal extinction followed the prehistoric human settlement of islands across the globe, but the exact duration and dynamics of the extinction processes are difficult to determine. The New Zealand moa (Aves, Dinornithiformes) are a prime example, where, despite an extensive fossil and archaeological record, debate continues about their extinction chronology and how extinction timings varied among regions and species. We apply probabilistic sightings methods to 111 high-quality radiocarbon dates (from a pool of 653 dates) on moa remains from natural and archaeological sites to provide a high-resolution spatio-temporal chronology of moa extinction. We interpret this alongside an estimated time for the onset of hunting pressure, obtained by applying the same methods to the most reliable proxies for initial human settlement of New Zealand: coprolites of and seeds gnawed by the commensal Pacific rat (Rattus exulans). By comparing local and national extinction times, we discriminate between the point at which hunting stopped (economic extinction) and the total extinction of moa (ca 150 and 200 years after settlement, respectively). Extinction occurred contemporaneously at sites separated by hundreds of kilometres. There was little difference between the extinction times of the smallest (20-50 kg) and largest (200+ kg) moa species. Our results demonstrate how rapidly megafauna were exterminated from even large, topographically- and ecologically-diverse islands such as New Zealand, and highlight the fragility of such ecosystems in the face of human impacts.

  10. Growth and Morphology of Rod Eutectics

    Energy Technology Data Exchange (ETDEWEB)

    Jing Teng; Shan Liu; R. Trivedi

    2008-03-17

    The formation of rod eutectic microstructure is investigated systematically in a succinonitrile-camphor alloy of eutectic composition by using the directional solidification technique. A new rod eutectic configuration is observed in which the rods form with elliptical cylindrical shape. Two different orientations of the ellipse are observed that differ by a 90{sup o} rotation such that the major and the minor axes are interchanged. Critical experiments in thin samples, where a single layer of rods forms, show that the spacing and orientation of the elliptic rods are governed by the growth rate and the sample thickness. In thicker samples, multi layers of rods form with circular cross-section and the scaling law between the spacing and velocity predicted by the Jackson and Hunt model is validated. A theoretical model is developed for a two-dimensional array of elliptical rods that are arranged in a hexagonal or a square array, and the results are shown to be consistent with the experimental observations. The model of elliptic rods is also shown to reduce to that for the circular rod eutectic when the lengths of the two axes are equal, and to the lamellar eutectic model when one of the axes is much larger than the other one.

  11. Identification of microsatellites from an extinct moa species using high-throughput (454) sequence data

    DEFF Research Database (Denmark)

    Allentoft, Morten Erik; Schuster, Stephan C.; Holdaway, Richard N.

    2009-01-01

    Genetic variation in microsatellites is rarely examined in the field of ancient DNA (aDNA) due to the low quantity of nuclear DNA in the fossil record together with the lack of characterized nuclear markers in extinct species. 454 sequencing platforms provide a new high-throughput technology...... capable of generating up to 1 gigabases per run as short (200-400-bp) read lengths. 454 data were generated from the fossil bone of an extinct New Zealand moa (Aves: Dinornithiformes). We identified numerous short tandem repeat (STR) motifs, and here present the successful isolation and characterization...... of one polymorphic microsatellite (Moa_MS2). Primers designed to flank this locus amplified all three moa species tested here. The presented method proved to be a fast and efficient way of identifying microsatellite markers in ancient DNA templates and, depending on biomolecule preservation, has...

  12. Youngest reported radiocarbon age of a moa (Aves : Dinornithiformes) dated from a natural site in New Zealand

    International Nuclear Information System (INIS)

    Rawlence, N.J.; Cooper, A.

    2013-01-01

    The extinction date of the giant flightless New Zealand ratite bird, the crested moa (Pachyornis australis), is of considerable interest because the youngest verified remains are dated to the Pleistocene–Holocene transition c. 10,000 yr BP, which was characterised by severe climatic and habitat change, and are considerably earlier than the late Holocene extinctions of the other eight moa species. Analysis of a partial crested moa skeleton (NMNZ S23569) from Castle Keep Entrance, Bulmer Cave System, Mount Owen, South Island, generated a radiocarbon date of 564±26 yr BP (544-508 cal yr BP; 95.4% AD 1396-1442). As a result the Bulmer Cave specimen represents the youngest moa yet found from a natural site in New Zealand. Combined with additional crested moa remains dated to the late Holocene from Cheops Cave (Mount Arthur) and Magnesite Quarry (Cobb Valley), this indicates that crested moa did not go extinct during the Pleistocene–Holocene transition but survived until after Polynesian colonisation in c. AD 1280. The new radiocarbon dates reported here have important implications for the timing of moa extinction and the late survival of moa in alpine areas of New Zealand. (author). 47 refs., 2 figs., 1 tab.

  13. Moa diet fits the bill: virtual reconstruction incorporating mummified remains and prediction of biomechanical performance in avian giants.

    Science.gov (United States)

    Attard, Marie R G; Wilson, Laura A B; Worthy, Trevor H; Scofield, Paul; Johnston, Peter; Parr, William C H; Wroe, Stephen

    2016-01-13

    The moa (Dinornithiformes) are large to gigantic extinct terrestrial birds of New Zealand. Knowledge about niche partitioning, feeding mode and preference among moa species is limited, hampering palaeoecological reconstruction and evaluation of the impacts of their extinction on remnant native biota, or the viability of exotic species as proposed ecological 'surrogates'. Here we apply three-dimensional finite-element analysis to compare the biomechanical performance of skulls from five of the six moa genera, and two extant ratites, to predict the range of moa feeding behaviours relative to each other and to living relatives. Mechanical performance during biting was compared using simulations of the birds clipping twigs based on muscle reconstruction of mummified moa remains. Other simulated food acquisition strategies included lateral shaking, pullback and dorsoventral movement of the skull. We found evidence for limited overlap in biomechanical performance between the extant emu (Dromaius novaehollandiae) and extinct upland moa (Megalapteryx didinus) based on similarities in mandibular stress distribution in two loading cases, but overall our findings suggest that moa species exploited their habitats in different ways, relative to both each other and extant ratites. The broad range of feeding strategies used by moa, as inferred from interspecific differences in biomechanical performance of the skull, provides insight into mechanisms that facilitated high diversities of these avian herbivores in prehistoric New Zealand. © 2016 The Author(s).

  14. Finite Element Analysis of Eutectic Structures

    Science.gov (United States)

    2014-03-12

    controlled by an optical pyrometer . Boron nitride (BN) (Momentive Performance Materials, Albany, NY) and fused silica (SiO2) (Momentive Performance...characterization Optical micrographs of LaB6-y(TixZr1-x)B2 cross sections displayed the typical morphology of boride eutectics obtained by...compositions determined by EPMA;  eutectic compositions in binary systems: LaB6-ZrB2 [3] and LaB6-TiB2 [16]. (insert: optical microscope image

  15. Moa (Aves : Dinornithiformes) nesting material from rockshelters in the semi-arid interior of South Island, New Zealand

    International Nuclear Information System (INIS)

    Wood, J.R.

    2008-01-01

    The first descriptions of plant remains from the nests of extinct moa (Aves: Dinornithiformes) are presented. The samples of desiccated nesting material were collected during excavation of Holocene sediments within five rockshelters in semi-arid regions of southern South Island, New Zealand, between 1964 and 2006. The nesting materials were attributed to moa on the basis of associated moa coprolites, feathers and eggshell fragments. The nesting material includes short, clipped twigs from a range of locally available tree, shrub and liane species. These twig clippings show a size distribution similar to those recorded from moa gizzard content samples. Other nesting material from the sites includes longer twigs and fragments of bark. The plant materials suggest general similarities between the nests of moa and those of the extant Australasian ratites, emu (Dromaius novaehollandiae) and cassowary (Casuarius spp.). (author). 37 refs., 7 figs., 1 tab

  16. Structural basis of thermal stability of the tungsten cofactor synthesis protein MoaB from Pyrococcus furiosus.

    Directory of Open Access Journals (Sweden)

    Nastassia Havarushka

    Full Text Available Molybdenum and tungsten cofactors share a similar pterin-based scaffold, which hosts an ene-dithiolate function being essential for the coordination of either molybdenum or tungsten. The biosynthesis of both cofactors involves a multistep pathway, which ends with the activation of the metal binding pterin (MPT by adenylylation before the respective metal is incorporated. In the hyperthermophilic organism Pyrococcus furiosus, the hexameric protein MoaB (PfuMoaB has been shown to catalyse MPT-adenylylation. Here we determined the crystal structure of PfuMoaB at 2.5 Å resolution and identified key residues of α3-helix mediating hexamer formation. Given that PfuMoaB homologues from mesophilic organisms form trimers, we investigated the impact on PfuMoaB hexamerization on thermal stability and activity. Using structure-guided mutagenesis, we successfully disrupted the hexamer interface in PfuMoaB. The resulting PfuMoaB-H3 variant formed monomers, dimers and trimers as determined by size exclusion chromatography. Circular dichroism spectroscopy as well as chemical cross-linking coupled to mass spectrometry confirmed a wild-type-like fold of the protomers as well as inter-subunits contacts. The melting temperature of PfuMoaB-H3 was found to be reduced by more than 15 °C as determined by differential scanning calorimetry, thus demonstrating hexamerization as key determinant for PfuMoaB thermal stability. Remarkably, while a loss of activity at temperatures higher than 50 °C was observed in the PfuMoaB-H3 variant, at lower temperatures, we determined a significantly increased catalytic activity. The latter suggests a gain in conformational flexibility caused by the disruption of the hexamerization interface.

  17. Raman mapping in the elucidation of solid salt eutectic and near eutectic structures

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Kerridge, D. H.

    2002-01-01

    The distribution of the different components of solidified eutectic or near-eutectic salt mixtures (eutectics) was examined by use of Raman microscope mapping of the structures formed when these melts were slowly cooled. Seven binary and one ternary system were investigated. In most cases...... the component crystallized phases consisted of roughly rounded areas of about 0.5-5 mum across, the areas alternating in all directions across the sections. These three-dimensional structures may best be described by the terns 'conglomerate.' The size of these areas depended on the cooling rate...... and the composition. When unidirectional cooling was applied it was possible for the system (KCl-Na2SO4, 60:40 mol/mol) to observe lamellar arrangements of the component phases, in an arrangement closely similar to what is frequently found among metallic or ceramic eutectics. Each area, conglomerate or lamellar, did...

  18. Microstructure Of MnBi/Bi Eutectic Alloy

    Science.gov (United States)

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

    1988-01-01

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

  19. Mode of Action (MOA) Assignment Classifications for Ecotoxicology: Evaluation of Available Methods

    Science.gov (United States)

    There are various structure-based classification schemes to categorize chemicals based on mode of action (MOA) which have been applied for both eco and human toxicology. With increasing calls to assess 1000s of chemicals, some of which have little available information other tha...

  20. A Critical Review of Mode of Action (MOA) Assignment Classifications for Ecotoxicology

    Science.gov (United States)

    There are various structure-based classification schemes to categorize chemicals based on mode of action (MOA) which have been applied for both eco and human health toxicology. With increasing calls to assess thousands of chemicals, some of which have little available informatio...

  1. MOA-2009-BLG-387Lb: a massive planet orbiting an M dwarf

    DEFF Research Database (Denmark)

    Batista, V.; Gould, A.; Dieters, S.

    2011-01-01

    We report the discovery of a planet with a high planet-to-star mass ratio in the microlensing event MOA-2009-BLG-387, which exhibited pronounced deviations over a 12-day interval, one of the longest for any planetary event. The host is an M dwarf, with a mass in the range 0.07 M_sun < M_host < 0....

  2. Hodie mihi, cras tibi

    Czech Academy of Sciences Publication Activity Database

    Roháček, Jiří

    -, č. 1 (2011), s. 31 ISSN 1210-9525 Institutional research plan: CEZ:AV0Z80330511 Keywords : sepulcral monuments * sculpture * epigraphy * history of art Subject RIV: AL - Art , Architecture, Cultural Heritage

  3. Age of North Island giant moa (Dinornis novaezealandiae) bones found on the forest floor in the Ruahine Range

    International Nuclear Information System (INIS)

    Wood, J.R.; Wilmshurst, J.M.

    2013-01-01

    During the nineteenth century, multiple discoveries of moa bones lying on the ground surface in exposed situations generated debate about the recentness of moa extinction. Subsequently, clearance of land for agricultural purposes has probably resulted in the destruction of many surface moa bones and such finds are now rare. The recent discovery of a pair of tibiotarsi from a North Island giant moa (Dinornis novaezealandiae) lying on the forest floor at Aorangi Awarua, Ruahine Range, has allowed the age of two surface moa bones to be tested. Both tibiotarsi were AMS radiocarbon dated and returned ages of 681±28 and 721±29 14C years BP. The 2σ calibrated ranges are statistically the same age and suggest that the bones are from one bird that died sometime between AD 1286 and 1390. Although the bones post-date human settlement of New Zealand, they are not anomalously recent. The results show that, given favourable environmental conditions, moa bones can persist in exposed situations for long periods, and do not necessarily reflect survival of moa into relatively recent times. (author)

  4. The algal flora of two distinct habitats along the Moa River in the state of Acre, Brazil

    OpenAIRE

    Archibald, Patricia A.; King, Joe M.

    1985-01-01

    Twenty-eoght algal samples were collected in September-October, 1984, from two distinct habitats in the state of Acre, Brazil. Eleven were from the Moa River, and 17 were from a sulfur water spring which flows into the Moa River. A total of 74 species, representing 48 genera of algae, were identified from these samples. Forty-nine species were found in the Moa River and 67 in the sulfur water spring. Both coolection site had rich assemblages of cyanophycean algae, chlorophycean algae, and dia...

  5. OUTROS ESPAÇOS, NOVOS SABERES: a atuação do pedagogo no Centro de Referência e Assistência Social – CRAS, em Imperatriz-MA

    Directory of Open Access Journals (Sweden)

    Keyla Cardoso Tavares

    2017-03-01

    Este estudio tuvo como objetivo conocer la contribución del pedagogo en los Centros de Referencia y Asistencia Social en la ciudad de Imperatriz-MA. Con un enfoque cualitativo para la recolección de datos se llevó a cabo en un período de un mes del tiempo total de dos semanas se dedicaron a observar la rutina de actividades en CRAS y las otras dos semanas para las entrevistas con los maestros que trabajan en unidades para averiguar cómo funcionan y cuáles son las contribuciones de estos profesionales al CRAS. Con base en la observación y análisis de los datos, se observó que los profesores participantes en el equipo técnico que se encarga de supervisar las familias inscritas en el CRAS, conferencias, los grupos de servicio y la convivencia y conexiones para fortalecer Servicio, y llevar a cabo la planificación de las actividades y proyectos a ser ejecutados por la unidad junto con los otros profesionales que conforman el equipo de CRAS. Palabras clave: Pedagogos; El Bienestar Social; Los Derechos; La Planificación.

  6. Crystallography of Alumina-YAG-Eutectic

    Science.gov (United States)

    Farmer, Serene C.; Sayir, Ali; Dickerson, Robert M.; Matson, Lawrence E.

    2000-01-01

    Multiple descriptions of the alumina-YAG eutectic crystallography appear in the ceramic literature. The orientation between two phases in a eutectic system has direct impact on residual stress, morphology, microstructural stability, and high temperature mechanical properties. A study to demonstrate that the different crystallographic relationships can be correlated with different growth constraints was undertaken. Fibers produced by Laser-Heated Float Zone (LHFZ) and Edge-defined Film-fed Growth (EFG) were examined. A map of the orientation relationship between Al2O3 and Y3Al5O12 and their relationship to the fiber growth axis as a function of pull rate are presented. Regions in which a single orientation predominates are identified.

  7. A psicologia nos centros de referência de assistência social (CRAS: um panorama das publicações científicas brasileiras de 2004 a 2014 / Psychology in social assistance reference centers (CRAS: a review in brazilian scientific publications between 2004 and 2014

    Directory of Open Access Journals (Sweden)

    Roberta Fin Motta

    2015-12-01

    Full Text Available RESUMO O artigo apresenta uma revisão narrativa de estudos sobre a publicação em periódicos da área da Psicologia a respeito da presença dos (as psicólogos (as no campo da Assistência Social, com ênfase na sua relação com Centros de Referências de Assistência Social (CRAS. A pesquisa realizou-se entre os meses de Agosto de 2014 a Maio de 2015, com consulta às bases de dados bibliográficos eletrônicos da BVS - Psi e da CAPES, no período de 2004 a 2014. Usou-se as palavras-chave: «Centro de Referência de Assistência Social», associadas ao descritor psicologia, totalizando 20 textos selecionados. Percebe-se o envolvimento e o investimento que têm sido feitos na área em relação a esta temática nos últimos anos. Além disso, a Assistência Social tem colaborado para a expansão e interiorização da profissão e o desenvolvimento de diferentes práticas das tradicionais, contudo, a clínica tradicional responde a demandas que extrapolam as atribuições do CRAS.ABSTRACT The article presents a narrative review of studies about publications in psychology journals with regard to the presence of psychologists in the Social Assistance field, with emphasis on its relationship with the Social Assistance Reference Centers (CRAS. The research was conducted between the months of August 2014 to May 2015, consulting electronic bibliographic databases from BVS-Psi and CAPES, during the period 2004-2014. We used the keywords «Social Assistance Reference Center», associated with the psychology descriptor – in total 20 selected texts. Development and investment that has been made in recent years is perceived in the area related to this topic. In addition, social assistance has contributed to the expansion and assimilation of the profession, and the development of different traditional practices; however, the traditional clinic responds to the demands that extrapolates the powers of the CRAS.

  8. Trabalho Interdisciplinar nos CRAS: um novo enfoque e trato à pobreza? = Interdisciplinary work in RCSA: a new approach in dealing with poverty?

    Directory of Open Access Journals (Sweden)

    Teixeira, Solange Maria

    2010-01-01

    Full Text Available Este artigo discute parte dos resultados de uma pesquisa realizada com os membros técnicos da equipe interdisciplinar dos Centros de Referência de Assistência Social (CRAS, no município de Teresina, com o objetivo de analisar as tendências do trabalho social e suas inovações no trato à pobreza. Mediante uso de metodologia qualitativa, a pesquisa abordou, através de entrevistas semiestruturadas, dez profissionais, entre eles assistentes sociais e psicólogos. Os resultados apontam inovações conceituais relativas à abordagem da pobreza, todavia, o trabalho social ainda carece de aportes teóricos e metodológicos para um novo trato à pobreza que supere a psicologização dos problemas sociais, ou o seu contrário, as visões objetivistas sem soluções práticas para o cotidiano

  9. Were moas really hunted to extinction in less than 100 years?

    International Nuclear Information System (INIS)

    Wilkes, O.

    2000-01-01

    Three months ago New Zealand archaeologists were surprised to read in their daily newspapers that moas had been eaten to extinction by Maori moahunters in less than 100 years. The claim had been made in the US journal 'Science' by Richard Holdaway, formerly with Canterbury University, and Chris Jacomb of Canterbury Museum. It seems to me there are a number of weaknesses in the original paper, which should have been thrashed out locally before going for prestigious exposure overseas. The rapid extinction claim is based first of all on a 'Leslie matrix model' of moa population dynamics, and secondly on some recent carbon dates of a single archaeological site, Monck's Cave, near Christchurch. 21 refs

  10. The evolutionary history of the extinct ratite moa and New Zealand Neogene paleogeography

    DEFF Research Database (Denmark)

    Bunce, M; Worthy, T H; Phillips, M J

    2009-01-01

    The ratite moa (Aves: Dinornithiformes) were a speciose group of massive graviportal avian herbivores that dominated the New Zealand (NZ) ecosystem until their extinction approximately 600 years ago. The phylogeny and evolutionary history of this morphologically diverse order has remained...... controversial since their initial description in 1839. We synthesize mitochondrial phylogenetic information from 263 subfossil moa specimens from across NZ with morphological, ecological, and new geological data to create the first comprehensive phylogeny, taxonomy, and evolutionary timeframe for all...... of the species of an extinct order. We also present an important new geological/paleogeographical model of late Cenozoic NZ, which suggests that terrestrial biota on the North and South Island landmasses were isolated for most of the past 20-30 Ma. The data reveal that the patterns of genetic diversity within...

  11. Evaluación y cartografiado del peligro por deslizamientos en el municipio de Moa

    Directory of Open Access Journals (Sweden)

    Yexenia Viltres-Milán

    2014-10-01

    Full Text Available La ocurrencia de deslizamientos en el municipio de Moa genera situaciones de amenaza a la industria, las comunidades, las actividades socio-económicas y al medio ambiente. El presente trabajo tuvo el propósito de evaluar y cartografiar, aplicando los Sistemas de Información Geográfica (SIG, el peligro por deslizamiento en el municipio. Como basamento metodológico se utilizó la guía para el estudio de peligro, vulnerabilidad y riesgo por deslizamientos del terreno, elaborada por el Grupo Nacional de Gestión de Riesgos, del año 2012. El resultado fue el mapa de peligrosidad total por deslizamiento del municipio de Moa, a escala 1: 100 000, el cual constituye una herramienta más de gestión y reducción del riesgo en el ordenamiento territorial

  12. Implementation of an integrated on-line process surveillance and diagnostic system at the Halden reactor project: MOAS

    International Nuclear Information System (INIS)

    Kim, I.S.; Grini, R.-E.; Nilsen, S.

    2001-01-01

    MOAS is an integrated on-line process surveillance and diagnostic system that uses several different models for knowledge acquisition and diagnostic reasoning, such as goal-tree success-tree model, process monitor trees, and sensor failure diagnosis trees. Within these models, the knowledge of the process and its operation, including deep knowledge, like mass balance or controller algorithm, is incorporated. During an extensive review, made as part of the integrated diagnosis system project of the Halden reactor project, MOAS (Maryland Operator Advisory System) was identified as one of the most thorough systems developed thus far. MOAS encompasses diverse functional aspects that are required for an effective process disturbance management: (1) intelligent process monitoring and alarming, (2) on-line sensor data validation and sensor failure diagnosis, (3) on-line hardware (besides sensors) failure diagnosis, and (4) real-time corrective measure synthesis. The MOAS methodology was used for the NORS (Nokia Research Simulator) process at the Halden man-machine laboratory HAMMLAB of the OECD Halden reactor project. The performance tests of MOAS, implemented in G2 real-time expert system shell, show that MOAS successfully carries out its intended functions, i.e. quickly recognizing an occurring disturbance, correctly diagnosing its cause, and presenting advice on its control to the operator. The lessons learned and insights gained during the implementation and performance tests also are discussed

  13. High-resolution coproecology: using coprolites to reconstruct the habits and habitats of New Zealand's extinct upland moa (Megalapteryx didinus.

    Directory of Open Access Journals (Sweden)

    Jamie R Wood

    Full Text Available Knowledge about the diet and ecology of extinct herbivores has important implications for understanding the evolution of plant defence structures, establishing the influences of herbivory on past plant community structure and composition, and identifying pollination and seed dispersal syndromes. The flightless ratite moa (Aves: Dinornithiformes were New Zealand's largest herbivores prior to their extinction soon after initial human settlement. Here we contribute to the knowledge of moa diet and ecology by reporting the results of a multidisciplinary study of 35 coprolites from a subalpine cave (Euphrates Cave on the South Island of New Zealand. Ancient DNA analysis and radiocarbon dating revealed the coprolites were deposited by the extinct upland moa (Megalapteryx didinus, and span from at least 6,368±31 until 694±30 (14C years BP; the approximate time of their extinction. Using pollen, plant macrofossil, and ancient DNA analyses, we identified at least 67 plant taxa from the coprolites, including the first evidence that moa fed on the nectar-rich flowers of New Zealand flax (Phormium and tree fuchsia (Fuchsia excorticata. The plant assemblage from the coprolites reflects a highly-generalist feeding ecology for upland moa, including browsing and grazing across the full range of locally available habitats (spanning southern beech (Nothofagus forest to tussock (Chionochloa grassland. Intact seeds in the coprolites indicate that upland moa may have been important dispersal agents for several plant taxa. Plant taxa with putative anti-browse adaptations were also identified in the coprolites. Clusters of coprolites (based on pollen assemblages, moa haplotypes, and radiocarbon dates, probably reflect specimens deposited at the same time by individual birds, and reveal the necessity of suitably large sample sizes in coprolite studies to overcome potential biases in diet interpretation.

  14. The crystal structure of escherichia coli MoaB suggests a probable role in molybdenum cofactor synthesis

    International Nuclear Information System (INIS)

    Sanishvili, R.; Beasley, S.; Skarina, T; Glesne, D; Joachimiak, A; Edwards, A; Savchenko, A.; Univ. Health Network; Univ. of Toronto

    2004-01-01

    The crystal structure of Escherichia coli MoaB was determined by multiwavelength anomalous diffraction phasing and refined at 1.6 Angstrom resolution. The molecule displayed a modified Rossman fold. MoaB is assembled into a hexamer composed of two trimers. The monomers have high structural similarity with two proteins, MogA and MoeA, from the molybdenum cofactor synthesis pathway in E. Coli, as well as with domains of mammalian gephyrin and plant Cnx1, which are also involved in molybdopterin synthesis. Structural comparison between these proteins and the amino acid conservation patterns revealed a putative active site in MoaB. The structural analysis of this site allowed to advance several hypothesis which can be tested in further studies

  15. Polymerisation of activated RNA in eutectic ice phases

    DEFF Research Database (Denmark)

    Dörr, Mark; Maurer, Sarah Elisabeth; Monnard, Pierre-Alain

    The non enzymatic elongation of RNA oligomers by activated RNA dimers and other oligomers in eutectic ice phases is investigated. Eutectic salt-ice mixtures contain channels of liquid aqueous solutions with a high molecule concentration or brines, which form an environment conductive to spontaneous...... (“cooperative sequences”) or degrading (“parasitic sequences”) the RNA population. These eutectic phases in water-ice are plausible prebiotic micro-environments that should help to overcome the dilution problem in origin of life scenarios. They might have supported the production of libraries....../populations of longer RNA chains rising the potential to produce (auto-)catalytic active molecular species (e.g. ribozymes)....

  16. Eutectic propeties of primitive Earth's magma ocean

    Science.gov (United States)

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

    2009-04-01

    It is widely accepted that the early Earth was partially molten (if not completely) due to the high energy dissipated by terrestrial accretion [1]. After core formation, subsequent cooling of the magma ocean has led to fractional crystallization of the primitive mantle. The residual liquid corresponds to what is now called the fertile mantle or pyrolite. Melting relations of silicates have been extensively investigated using the multi-anvil press, for pressures between 3 and 25 GPa [2,3]. Using the quench technique, it has been shown that the pressure affects significantly the solidus and liquidus curves, and most probably the composition of the eutectic liquid. At higher pressures, up to 65 GPa, melting studies were performed on pyrolite starting material using the laser-heated diamond anvil cell (LH-DAC) technique [4]. However, the quench technique is not ideal to define melting criteria, and furthermore these studies were limited in pressure range of investigation. Finally, the use of pyrolite may not be relevant to study the melting eutectic temperature. At the core-mantle boundary conditions, melting temperature is documented by a single data point on (Mg,Fe)2SiO4 olivine, provided by shock wave experiments at around 130-140 GPa [5]. These previous results present large uncertainties of ~1000 K. The aim of this study is to determine the eutectic melting temperature in the chemically simplified system composed of the two major lower mantle phases, the MgSiO3 perovskite and MgO periclase. We investigated melting in-situ using the laser-heated diamond anvil cell coupled with angle dispersive X-ray diffraction at the ID27 beamline of the ESRF [6]. Melting relations were investigated in an extended P-T range comparable to those found in the Earth's lower mantle, i.e. from 25 to 120 GPa and up to more than 5000 K. Melting was evidenced from (a) disappearance of one of the two phases in the diffraction pattern, (b) drastic changes of the diffraction image itself, and

  17. Radiocarbon dates on desiccated moa (Dinornithiformes) flesh from inland Otago, New Zealand

    International Nuclear Information System (INIS)

    Anderson, A.; Rowe, L.; Petchey, F.; White, M.

    2010-01-01

    Remains of soft tissues from extinct moa (Dinornithiformes), mainly desiccated sinew, muscle, skin, and feathers have been recovered rather seldom but their distribution is distinctive. Of 22 records of such finds accumulated between 1864 and 1987, 15 came from inland Otago, west of Dunedin in the southern South Island. Most were found in the late nineteenth century in rockshelters, clefts or alluvial sediments and were regarded at the time as ev dence of the survival of moa up to about AD 1800. Improbable as this latter point is, it has not been tested by radiocarbon dating until now. Our particular impetus to do so, however, arises in another way. It is from research, again largely within inland Otago, on Maori artefacts which have also been made from various other kinds of soft tissues (flax, grasses, dog skin, bird skin, feathers etc.). A series of accelerator mass spectrometry (AMS) radiocarbon dates on these shows that they are exclusively late, post-AD 1650, which begs the question of why the age range does not extend across the full prehistoric period, beginning about AD 1300. (author). 6 refs., 2 figs., 1 tab.

  18. The creep behavior of In-Ag eutectic solder joints

    International Nuclear Information System (INIS)

    Reynolds, H.L.; Kang, S.H.; Morris, J.W. Jr.; Univ. of California, Berkeley, CA

    1999-01-01

    The addition of 3 wt.% Ag to In results in a eutectic composition with improved mechanical properties while only slightly lowering the melting temperature. Steady-state creep properties of In-Ag eutectic solder joints have been measured using constant load tests at 0, 30, 60, and 90 C. Constitutive equations are derived to describe the creep behavior. The data are well represented by an equation of the form proposed by Dorn: a power-law equation applies to each independent creep mechanism. Two parallel mechanisms were observed for the In-Ag eutectic joints. The high-stress mechanism is a bulk mechanism with a thermal dependence dominated by the thermal dependence of creep in the In-rich matrix. The low-stress mechanism is a grain boundary mechanism. Results of this work are discussed with regard to creep behavior of typical eutectic systems

  19. Characterization of CoQ 10-lauric acid eutectic system

    Energy Technology Data Exchange (ETDEWEB)

    Tarate, Bapurao; Bansal, Arvind K., E-mail: akbansal@niper.ac.in

    2015-04-10

    Highlights: • Two polymorphic forms of CoQ 10. • CoQ 10 forms eutectic mixture with LA. • Experimental and predicted values of eutectic points are 70% CoQ 10 at 37.93 °C and 87.7% CoQ 10 at 38.98 °C, respectively. • Attraction exists between CoQ 10 and LA molecules. - Abstract: Solid state characterization of coenzyme Q10 (CoQ 10) was carried out using differential scanning calorimetry (DSC), variable temperature X-ray diffractometry (VT-XRD) and hot/cold stage microscopy (H/CSM). It revealed that CoQ 10 exists in two polymorphic forms. The recrystallized samples of CoQ 10 melted at different temperatures either due to the wide crystal size variation or change in crystallinity. Further, the binary mixture of CoQ 10 and lauric acid (LA) formed eutectic mixture in the ratio 70:30 melting at 37.93 °C, which was close to the predicted eutectic composition of 87.7:12.3 melting at 38.98 °C. The values of actual liquidus temperatures for CoQ 10 are higher than the predicted liquidus temperatures. The experimental heat of fusion at eutectic point was less than the calculated heat of fusion. Activity coefficient of CoQ 10 in the binary mixture was less than unity, which indicates the attraction between the components of eutectic mixture.

  20. Mechanism of eutectic formation upon compaction and its effects on tablet properties

    International Nuclear Information System (INIS)

    Bi, Mingda; Hwang, Sung-Joo; Morris, Kenneth R.

    2003-01-01

    The unique property of a eutectic mixture is a lower melting temperature than that of any of its pure components. What differentiates a eutectic mixture from a simple physical mixture is less well understood. This impedes the ability to anticipate and/or detect unintentional eutectic formation during pharmaceutical tablet manufacturing and any potential negative impact. In this study, a thermodynamic/heat transfer approach was used to explain the mechanism of eutectic formation upon exposure to a physical stress, i.e. compaction, and a differential scanning calorimetric (DSC) method was developed to detect and quantify the amount of eutectic formed in the compacts. Furthermore, the mechanism of eutectic formation upon compaction was tested experimentally by correlating the amount of eutectic formed in tablets with the particle size, compaction force, the estimated intimate contact area between the eutectic-forming materials, calculated tablet tensile strength, and tablet porosity. The effect of the presence of eutectics on tablet properties was also investigated. The results show that intimate contact and mutual solubility between eutectic-forming materials are the necessary and sufficient criteria for eutectic formation upon compaction. The systems of acetaminophen (APAP)/caffeine and APAP/propylphenazone were both shown to exhibit eutectic behavior upon compaction and the extent of formation was dependent upon the amount of intimate contact between eutectic-forming materials. Finally, it was found that eutectic had no negative effect on tablet hardness

  1. HISTÓRIAS DE MORTE E LUTO: UM ESTUDO SÓCIOANTROPOLÓGICO DA VIVÊNCIA DA MORTE EM UM GRUPO OPERATIVO NO CRAS

    Directory of Open Access Journals (Sweden)

    Andréia Santiago Sobreira Santos Souza

    2016-03-01

    Full Text Available O  presente  artigo  inicia  apresentando  uma  reflexão  sócioantropológica  sobre  a  relação  saúde  e  doença,  demonstrando  a  partir desses indicadores que a morte e luto, os quais queremos destacar, podem ser lidos através de múltiplos impulsionadores e bases epistemológicas. Aqui escolhemos a Antropologia e a Sociologia. Através da exposição de análises de textos dentro da abordagem sócio-antropológica  gostaríamos  de  reforçar  a  necessidade  desse  olhar  multidisciplinar,  destacando  seu  caráter  enriquecedor  e clareador para o estudo da morte e do luto. Para tanto, nos propomos a narrar uma vivência em um grupo operativo numa unidade de Centro de Referência em Assistência Social (CRAS, onde o assunto “morte” surgiu como fator disparador de experiências passadas, relacionadas a perdas e luto. A observação desse fenômeno coletivo nos instigou a refletir sobre a morte como uma construção social ainda atrelada a aspectos negativos e de superação (luto desafiadora, fora do âmbito de trabalho em saúde, necessariamente.

  2. Ubiquitin-like prokaryotic MoaD as a fusion tag for expression of heterologous proteins in Escherichia coli.

    Science.gov (United States)

    Yuan, Sujuan; Wang, Xin; Xu, Jian; Yan, Zheng; Wang, Nan

    2014-01-21

    Eukaryotic ubiquitin and SUMO are frequently used as tags to enhance the fusion protein expression in microbial host. They increase the solubility and stability, and protect the peptides from proteolytic degradation due to their stable and highly conserved structures. Few of prokaryotic ubiquitin-like proteins was used as fusion tags except ThiS, which enhances the fusion expression, however, reduces the solubility and stability of the expressed peptides in E. coli. Hence, we investigated if MoaD, a conserved small sulfur carrier in prokaryotes with the similar structure of ubiquitin, could also be used as fusion tag in heterologous expression in E. coli. Fusion of MoaD to either end of EGFP enhanced the expression yield of EGFP with a similar efficacy of ThiS. However, the major parts of the fusion proteins were expressed in the aggregated form, which was associated with the retarded folding of EGFP, similar to ThiS fusions. Fusion of MoaD to insulin chain A or B did not boost their expression as efficiently as ThiS tag did, probably due to a less efficient aggregation of products. Interestingly, fusion of MoaD to the murine ribonuclease inhibitor enhanced protein expression by completely protecting the protein from intracellular degradation in contrast to ThiS fusion, which enhanced degradation of this unstable protein when expressed in E. coli. Prokaryotic ubiquitin-like protein MoaD can act as a fusion tag to promote the fusion expression with varying mechanisms, which enriches the arsenal of fusion tags in the category of insoluble expression.

  3. Sensitive Amino Acid Composition and Chirality Analysis with the Mars Organic Analyzer (MOA)

    Science.gov (United States)

    Skelley, A. M.; Scherer, J. R.; Aubrey, A. D.; Ivester, R. H.; Ehrenfreund, P.; Grunthaner, F. J.; Bada, J. L.; Mathies, R. A.

    2004-12-01

    Detection of life on Mars requires definition of a suitable biomarker and development of sensitive yet compact instrumentation capable of performing in situ analyses. Our studies are focused on amino acid analysis because amino acids are more resistant to decomposition than other biomolecules, and because amino acid chirality is a well-defined biomarker. Amino acid composition and chirality analysis has been previously demonstrated in the lab on microfabricated capillary electrophoresis (CE) chips (1, 2). To analyze amino acids in situ, we have developed the Mars Organic Analyzer (MOA), a portable analysis system that consists of a compact instrument and a novel multi-layer CE microchip. The heart of the MOA is the microchip that contains the CE separation channels as well as microfabricated valves and pumps (3) for sample handling. The pneumatic microfabricated valves are created by combining an etched displacement chamber, an actuated PDMS membrane layer, and a discontinuous fluidic channel structure. A microfabricated pump is created by combining three individually-addressable valves in series. These membrane valves and pumps are integrated with the glass separation channel using a novel multilayer design in which sample enters the top fluidic layer for routing and is directed to the bottom glass layers for CE separation and analysis. The microfabricated device is operated by the portable instrument which contains solenoids for controlling fluidic valves, electronics, a 15 mW 400 nm diode laser, confocal detection optics, and a fiber-optic coupled photomultiplier for fluorescence detection. Limits of detection of fluorescamine-labeled amino acids are in the nM to pM range corresponding to part-per-trillion sensitivities in soil samples (4). The portable CE instrument, in combination with the Mars Organic Detector (MOD) (5), was recently successfully field tested on soil samples rich in jarosite from Panoche Valley, CA. Jarosite has recently been detected on Mars

  4. Environmental impact of the minero-metallurgic industry on the marine ecosystem in Moa, Cuba

    International Nuclear Information System (INIS)

    Martinez Canals, M.; Pedro Garcia, L.

    1999-01-01

    One of the biggest nickel mineral deposits of the world is located in Moa; therefore two plants are installed for the extraction of this metal in the region, and another is in its construction phase. During the technological processes, residuals that contain great quantity of metallic elements, and high acidity level are discharged into the environment. The objectives of this research were to establish the levels of pollution of eleven metals, Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in the superficial bottom sediments, sea water and organisms of the marine aquatorium (green and white sea urchins, blue crabs, oysters and mangrove leaves). The dynamics of pollution in superficial sediments was also determined in the course of a 9-year study. As complementary analyses, pH and salinity were determined for the supradjacent water to the marine bottom, as well as the content of organic carbon, and granulometry of the sediment

  5. Il museo di antropologia come museo culturale: il caso del MOA di Vancouver

    Directory of Open Access Journals (Sweden)

    Claudia Gualtieri

    2011-03-01

    Full Text Available This essay will examine anthropology museums as cultural museums from the methodological approach of Cultural Studies. Within this frame, the museum acts as a mode of conservation of material culture thus revealing its immaterial consequences. In the museum, historical memories are preserved and re-enacted to articulate cultural identities in the present, to shed light on the past, and to illuminate future communal practices. After a brief survey on collections in the epoch of European geographical discoveries and on the birth of anthropology as a science in colonial times, the essay will consider the exhibition of cultural artefacts belonging to the First Nations of British Columbia in the Museum of Anthropology (MOA in Vancouver. References to native land claims will help to understand the links between time and place, history and geography, cultural memory and land that are central to native re-constructions of identity. Through a critical reading of conventional ethnographic and anthropological criteria in museum displays, the codes of conservation and repatriation will be introduced in relation to the notion of native title and cultural property. The MOA will be used as a case in point to explore practices of negotiation with native peoples. The indigenous worldview regarding the use of objects and the performance of a living culture will be presented as opposed to the conventional aesthetic appreciation and exhibition of cultural objects. The essay will then illustrate how museums are produced and organised according to ideologically relevant standpoints in specific times and places, and how visitor-oriented practices should address a critical reading of dynamics of power and knowledge control in contemporary societies.

  6. Development of eutectic free cladding materials for metallic fuel

    Energy Technology Data Exchange (ETDEWEB)

    Tokiwai, Moriyasu; Yuda, Ryoichi [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan); Ohuchi, Atsushi [Nippon Nuclear Fuel Development Co. Ltd., Oarai, Ibaraki (Japan); Amaya, Masaki [Global Nuclear Fuel-Japan Co., Ltd, Oarai, Ibaraki (Japan)

    2002-11-01

    Historically, it is well known that U base metallic fuel has a lower eutectic temperature with stainless steel cladding. In the phase diagram for the U-Fe binary system, the eutectic temperature is 998K. The eutectic reaction is a limiting factor for raising reactor operation temperature. For the purpose of development of eutectic-free cladding materials, three kinds of diffusion-couple tests with 10 mass%Zr alloy were conducted at a temperature of 1027K for 2250 hrs. We selected the following materials: (a) nitrogen charged zirconium foils, (b) vanadium foils of commercial grade, and (c) nitrogen charged ferritic stainless steel (HT-9). The results showed that typical Zr with layer was observed in all of these materials. Zr with layer appeared to act as a barrier against inter-diffusion of U, Fe. The barrier provided immunity to the eutectic reaction. Discussion was made on C-14 problems in relation to another desirable thermodynamic characteristics of Zr such as carbon-14 immobilization. EPMA analysis indicated relatively high nitrogen concentration at the barrier. The barrier is probably composed of ZrN. (author)

  7. On the Nonequilibrium Interface Kinetics of Rapid Coupled Eutectic Growth

    Science.gov (United States)

    Dong, H.; Chen, Y. Z.; Shan, G. B.; Zhang, Z. R.; Liu, F.

    2017-08-01

    Nonequilibrium interface kinetics (NEIK) is expected to play an important role in coupled growth of eutectic alloys, when solidification velocity is high and intermetallic compound or topologically complex phases form in the crystallized product. In order to quantitatively evaluate the effect of NEIK on the rapid coupled eutectic growth, in this work, two nonequilibrium interface kinetic effects, i.e., atom attachment and solute trapping at the solid-liquid interface, were incorporated into the analyses of the coupled eutectic growth under the rapid solidification condition. First, a coupled growth model incorporating the preceding two nonequilibrium kinetic effects was derived. On this basis, an expression of kinetic undercooling (Δ T k), which is used to characterize the NEIK, was defined. The calculations based on the as-derived couple growth model show good agreement with the reported experimental results achieved in rapidly solidified eutectic Al-Sm alloys consisting of a solid solution phase ( α-Al) and an intermetallic compound phase (Al11Sm3). In terms of the definition of Δ T k defined in this work, the role of NEIK in the coupled growth of the Al-Sm eutectic system was analyzed. The results show that with increasing the coupled growth velocity, Δ T k increases continuously, and its ratio to the total undercooling reaches 0.32 at the maximum growth velocity for coupled eutectic growth. Parametric analyses on two key alloy parameters that influence Δ T k, i.e., interface kinetic parameter ( μ i ) and solute distribution coefficient ( k e ), indicate that both μ i and k e influence the NEIK significantly and the decrease of either these two parameters enhances the NEIK effect.

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

    Science.gov (United States)

    Terheggen, Logan; Cosby, Tyler; Sangoro, Joshua

    2015-03-01

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

  9. Moa fossils and chronology of a Pleistocene terrace sequence, Tauweru, Wairarapa, New Zealand

    International Nuclear Information System (INIS)

    Collen, J.D.; Grapes, R.H.; Eager, S.H.

    2000-01-01

    The fortuitous preservation of bones of the medium-sized moa Euryapteryx geranoides (Owen) in Pleistocene colluvial sediments near Tauweru, Wairarapa, has allowed radiocarbon dating of a terrace sequence along the lower Tauweru River. The bones were in a shelly, conglomeratic sandstone on an erosion surface cut into mid-Pliocene (Waipipian) siltstone, and were overlain by loess and situated immediately adjacent to onlapping fluvial gravels. Most of the bones are from a single skeleton buried articulated and apparently nearly complete, and there is also a single left tibiotarsus from a slightly larger bird. Bone from the right femur gave a radiocarbon age of 14 262 +/- 87 yr BP by accelerator mass spectrometry. The material was slightly chalky and had a low collagen yield with a relatively large amount of humic material; contamination which would lower the measured age is thus possible. However, an amino acid profile characteristic of collagen makes it unlikely that high contaminant levels are present. The radiocarbon age for the bone is likely to be 14-18 ka (16-22 000 cal. yr) or possibly older, with the lower limit being set by the radiocarbon age and the upper limit inferred from the amount of humic contamination. This is thus the oldest moa skeleton reported from Wairarapa. Loess overlying the bones contains disseminated shards of clear rhyolitic glass with a composition identical to that of the 22.6 ka (24 500 cal. yr) Kawakawa Tephra, and gave an age by optical dating of 26 +/- 2 ka. A thicker tephra deposit within loess on a higher, deeply dissected surface may also be partly reworked; optical dating of a sample of loess from 2 m beneath it gave an age of 22 +/- 2 ka. Thermoluminescence dating of two samples of the conglomeratic deposits surrounding the bones gave ages of 52 +/- 13.2 and 102 +/- 18 ka, respectively, indicating redeposition of these sediments without resetting of the thermoluminescence signal. One of these samples was also dated by optical

  10. Catalytic Gasification of Coal using Eutectic Salt Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Atul Sheth; Pradeep Agrawal; Yaw D. Yeboah

    1998-12-04

    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

  11. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon [Univ. of California, Berkeley, CA (United States)

    2002-05-01

    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.

  12. Creep in directionally solidified NiAl-Mo eutectics

    Czech Academy of Sciences Publication Activity Database

    Dudová, Marie; Kuchařová, Květa; Barták, Tomáš; Bei, H.; George, E.P.; Somsen, Ch.; Dlouhý, Antonín

    2011-01-01

    Roč. 65, č. 8 (2011), s. 699-702 ISSN 1359-6462 R&D Projects: GA ČR GA202/09/2073 Institutional research plan: CEZ:AV0Z20410507 Keywords : high - temperature creep * NiAl - Mo eutectic * Mo fibres Subject RIV: JG - Metallurgy Impact factor: 2.699, year: 2011

  13. Effect of titanium on the near eutectic grey iron

    DEFF Research Database (Denmark)

    Moumeni, Elham; Tiedje, Niels Skat; Hattel, Jesper Henri

    The effect of Titanium on the microstructure of grey iron was investigated experimentally in this work. Tensile test bars of grey cast iron of near eutectic alloys containing 0.01, 0.1, 0.26 and 0.35% Ti, respectively were made in green sand moulds. Chemical analysis, metallographic investigation...

  14. Directional solidification of eutectic composites in space environment

    Science.gov (United States)

    Yue, A. S.

    1972-01-01

    The Ni-Ni3Ta eutectic and a nickel-base alloy containing 30 wt pct Ta were solidified unidirectionally in an electron beam floating zone melting apparatus. It was found that the volume fraction of the Ni3Ta phase in the Ni-Ni3Ta eutectic mixture was increased from 7.6 to 36 volume pct in agreement with the theory as predicted. Tensile properties of the randomly solidified and unidirectionally solidified Ni-Ni3Ta eutectic were determined as function of solidification rate and temperature. It was found that the ultimate tensile strength decreased as both the test temperature and solidification rate increased. An elongation of 40 pct was obtained for a nickelbase alloy containing 30 wt at room temperature. This unusually large elongation was attributed to the superplastic behavior of the alloy. The critical currents versus the external fields at 2.5, 3.0, 3.5 and 4.2 deg for the unidirectionally solidified Pb-Sn eutectic were measured. The values of critical fields at zero critical currents were obtained by extrapolation.

  15. Solidification with back-diffusion of irregular eutectics

    Directory of Open Access Journals (Sweden)

    M. Trepczyńska-Łent

    2008-10-01

    Full Text Available The definition of the α - parameter back-diffusion has been introduced in the work. The alternative models of solidification were describedtaking into consideration back-diffusion process. The possibility of using those models for eutectic alloys solidification is worthyof interest.

  16. 4'-Methyl derivatives of 5-MOP and 5-MOA: synthesis, photoreactivity, and photobiological activity.

    Science.gov (United States)

    Gia, O; Anselmo, A; Conconi, M T; Antonello, C; Uriarte, E; Caffieri, S

    1996-10-25

    The synthesis and photobiological activity of four new 4'-methyl derivatives of 5-MOP (5-methoxypsoralen) and 5-MOA (5-methoxyangelicin), i.e., 4,4'-dimethyl-5-methoxypsoralen, 3,4'-dimethyl-5-methoxypsoralen, 4,4'-dimethyl-5-methoxyangelicin, and 3,4'-dimethyl-5-methoxyangelicin, are described. All these compounds photobind efficiently to DNA. The DNA-photobinding process was investigated using various nucleic acid structures such as double-helix DNA, bacterial DNA, and synthetic polydeoxyribonucleotides. Photoreaction experiments showed that, unlike 8-MOP (8-methoxypsoralen) and 5-MOP, both angular derivatives bind thymine and cytosine with the same efficiency. The principal nucleoside-psoralen monoadducts were isolated and characterized after enzymatic digestion or acid hydrolysis. Biological activity studies revealed a good correlation with the extent of covalent photoaddition. Moreover, the two angular derivatives and the 4,4'-dimethyl-5-methoxypsoralen were unable to induce skin erythema, in striking contrast with the reference drugs, 8-MOP and 5-MOP; only the 3,4'-dimethyl-5-methoxypsoralen caused erythema, although to a substantially lower extent than that induced by the two parent compounds.

  17. Modeling of aluminum-silicon irregular eutectic growth by cellular automaton model

    Directory of Open Access Journals (Sweden)

    Rui Chen

    2016-03-01

    Full Text Available Due to the extensive application of Al-Si alloys in the automotive and aerospace industries as structural components, an understanding of their microstructural formation, such as dendrite and (Al+Si eutectic, is of great importance to control the desirable microstructure, so as to modify the performance of castings. Since previous major themes of microstructural simulation are dendrite and regular eutectic growth, few efforts have been paid to simulate the irregular eutectic growth. Therefore, a multiphase cellular automaton (CA model is developed and applied to simulate the time-dependent Al-Si irregular eutectic growth. Prior to model establishment, related experiments were carried out to investigate the influence of cooling rate and Sr modification on the growth of eutectic Si. This CA model incorporates several aspects, including growth algorithms and nucleation criterion, to achieve the competitive and cooperative growth mechanism for nonfaceted-faceted Al-Si irregular eutectic. The growth kinetics considers thermal undercooling, constitutional undercooling, and curvature undercooling, as well as the anisotropic characteristic of eutectic Si growth. The capturing rule takes into account the effects of modification on the silicon growth behaviors. The simulated results indicate that for unmodified alloy, the higher eutectic undercooling results in the higher eutectic growth velocity, and a more refined eutectic microstructure as well as narrower eutectic lamellar spacing. For modified alloy, the eutectic silicon tends to be obvious fibrous morphology and the morphology of eutectic Si is determined by both chemical modifier and cooling rate. The predicted microstructure of Al-7Si alloy under different solidification conditions shows that this proposed model can successfully reproduce both dendrite and eutectic microstructures.

  18. On the stable eutectic solidification of iron–carbon–silicon alloys

    International Nuclear Information System (INIS)

    Stefanescu, Doru M.; Alonso, Gorka; Larrañaga, Pello; Suarez, Ramon

    2016-01-01

    Extensive effort was expanded to elucidate the growth and morphology of the stable eutectic grains during early solidification of continuous cooled Fe–C–Si alloys. To this purpose, quenching experiments at successive stages during solidification have been carried out on five cast irons with various magnesium and titanium levels designed to produce graphite morphologies ranging from lamellar to mixed compacted–spheroidal. The graphite shape factors were measured on the metallographic samples, and their evolution as a function of the chemical composition and the solid fraction was analyzed. Extensive scanning electron microscopy was carried on to evaluate the change in graphite shape during early solidification, to establish the fraction of solid at which the transition from spheroidal-to-compacted-to-lamellar graphite occurs, and to outline the early morphology of the eutectic grains. It was confirmed that solidification of Mg containing irons started with the development of spheroidal graphite even at Mg levels as low as 0.013 mass%. Then, as solidification proceeds, when some spheroids developed one or more tails (tadpole graphite), the spheroidal-to-compacted graphite transition occurs. The new findings were then integrated in previous knowledge to produce an understanding of the eutectic solidification of these materials. It was concluded that in hypoeutectic lamellar graphite iron austenite/graphite eutectic grains can nucleate at the austenite/liquid interface or in the bulk of the liquid, depending on the sulfur content and on the cooling rate. When graphite nucleation occurs on the primary austenite, several eutectic grains can nucleate and grow on the same dendrite. The primary austenite continues growing as eutectic austenite and therefore the two have the same crystallographic orientation. Thus, a final austenite grain may include several eutectic grains. In eutectic irons the eutectic grains nucleate and grow mostly in the liquid. The eutectic

  19. Coatings for directional eutectics. [for corrosion and oxidation resistance

    Science.gov (United States)

    Felten, E. J.; Strangman, T. E.; Ulion, N. E.

    1974-01-01

    Eleven coating systems based on MCrAlY overlay and diffusion aluminide prototypes were evaluated to determine their capability for protecting the gamma/gamma prime-delta directionally solidified eutectic alloy (Ni-20Cb-6Cr-2.5Al) in gas turbine engine applications. Furnace oxidation and hot corrosion, Mach 0.37 burner-rig, tensile ductility, stress-rupture and thermomechanical fatigue tests were used to evaluate the coated gamma/gamma prime-delta alloy. The diffusion aluminide coatings provided adequate oxidation resistance at 1144 K (1600 F) but offered very limited protection in 114 K (1600 F) hot corrosion and 1366 K (2000 F) oxidation tests. A platinum modified NiCrAlY overlay coating exhibited excellent performance in oxidation testing and had no adverse effects upon the eutectic alloy.

  20. Electrochemical method of producing eutectic uranium alloy and apparatus

    Science.gov (United States)

    Horton, James A.; Hayden, H. Wayne

    1995-01-01

    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.

  1. Eutectic solidification mode of spheroidal graphite cast iron and graphitization

    Directory of Open Access Journals (Sweden)

    Hideo Nakae

    2007-02-01

    Full Text Available The shrinkage and chilling tendency of spheroidal graphite (abbreviated SG cast iron is much greater than that of the flake graphite cast iron in spite of its higher amount of C and Si contents. Why? The main reason should be the difference in their graphitization during the eutectic solidification. In this paper, we discuss the difference in the solidification mechanism of both cast irons for solving these problems using unidirectional solidification and the cooling curves of the spheroidal graphite cast iron. The eutectic solidification rate of the SG cast iron is controlled by the diffusion of carbon through the austenite shell, and the final thickness is 1.4 times the radius of the SG, therefore, the reduction of the SG size, namely, the increase in the number, is the main solution of these problems.

  2. ALFIN-ORG: Sitio web para el desarrollo de habilidades informacionales en el Instituto Superior Metalúrgico de Moa

    Directory of Open Access Journals (Sweden)

    MSc. Miguel Ángel Fernández Marín

    2016-04-01

    Full Text Available En el Instituto Superior Minero Metalúrgico de Moa, no existe acceso pleno a todas las fuentes de información, no se le da el uso adecuado a las tecnologías, no hay cultura infor­macional de cómo aprovecharla y a la hora de determinar que es útil, no se toma la decisión correcta. Debido a esto, existe un cúmulo de información que no es aprovechada y tras el avance tecnológico crece cada día. Por estas ra­zones, es necesario que se pueda trabajar y asimilar toda la información de manera correcta, basado en el desarro­llo de estrategias de búsqueda mediante la utilización de los medios digitales. Para darle solución a la problemática anterior, se proyecta el objetivo de crear un sitio web que contribuya al desarrollo de habilidades informacionales en el Instituto Superior Minero Metalúrgico de Moa. Para la con­fección del sitio web se utilizó Hot Potatoes 6.3.0.3 para di­señar los sistemas de ejercicios de autoevaluación en el sitio web. Joomla 1.6.0 para el desarrollo del sitio web. Como len­guaje de programación PHP Script Language versión 5.2.6. Como gestor de Bases de Datos MySQL Database versión 5.0.51b. El resultado del trabajo constituye un sitio web que posee una estructura informativa-evaluativa para lograr las habilidades informacionales en el Instituto Superior Minero Metalúrgico de Moa.

  3. The preferential orientation and lattice misfit of the directionally solidified Fe-Al-Ta eutectic composite

    Science.gov (United States)

    Cui, Chunjuan; Wang, Pei; Yang, Meng; Wen, Yagang; Ren, Chiqiang; Wang, Songyuan

    2018-01-01

    Fe-Al intermetallic compound has been paid more attentions recently in many fields such as aeronautic, aerospace, automobile, energy and chemical engineering, and so on. In this paper Fe-Al-Ta eutectic was prepared by a modified Bridgman directional solidification technique, and it is found that microstructure of the Fe-Al-Ta eutectic alloy transforms from the broken-lamellar eutectic to cellular eutectic with the increase of the solidification rate. In the cellular eutectic structure, the fibers are parallel to each other within the same grain, but some fibers are deviated from the original orientation at the grain boundaries. To study the crystallographic orientation relationship (OR) between the two phases, the preferential orientation of the Fe-Al-Ta eutectic alloy at the different solidification rates was studied by Selected Area Electron Diffraction (SAED). Moreover, the lattice misfit between Fe2Ta(Al) Laves phase and Fe(Al,Ta) matrix phase was calculated.

  4. Application of SEM/EBSD and FEG-TEM/CBED to determine eutectic solidification mechanisms

    International Nuclear Information System (INIS)

    Nogita, K.; Dahle, A.K.; Drennan, J.

    2002-01-01

    Full text: This study shows the application of electron backscatter diffraction (EBSD) in SEM and convergent beam electron diffraction (CBED) in FEG-TEM to determine eutectic nucleation and growth in hypoeutectic Al-Si foundry alloys. Because the eutectic reaction is often the final stage of solidification it can be expected to have a significant impact on the formation of casting defects, particularly porosity. Previous EBSD work by Nogita and Dahle (2001), Dahle et al (2001), has shown that the eutectic nucleates on the primary phase in the unmodified alloy, and eutectic grains are nucleated in the intergranular liquid, instead of filling the dendrite envelopes, when Sr or Sb is added. However, the orientation relationship between silicon and aluminium in the eutectic has so far not been determined because of difficulties with sample preparation for EBSD and also detection limitations of Kikuchi refraction of silicon and aluminium, particularly in modified alloys with a refined eutectic. The combination of the EBSD technique in SEM and CBED in TEM analyses can provide crystallographic orientation relationships between primary aluminium dendrites, eutectic aluminium and silicon, which are important to explicitly define the solidification mode of the eutectic in hypoeutectic Al-Si alloys. These relationships are influenced, and altered, by the addition of certain elements. This paper also describes the sample preparation techniques for SEM and TEM for samples with different eutectic structures. The advantages the techniques are discussed. Copyright (2002) Australian Society for Electron Microscopy Inc

  5. Divorced Eutectic Solidification of Mg-Al Alloys

    Science.gov (United States)

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

    2015-08-01

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

  6. Pattern Formation and Growth Kinetics in Eutectic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Jing [Iowa State Univ., Ames, IA (United States)

    2007-01-01

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

  7. Structural models of faceted-faceted eutectic system vanillin-acenaphthene

    International Nuclear Information System (INIS)

    Sharma, B.L.

    2003-01-01

    Thermodynamic model for the eutectic system vanillin-acenaphthene has been developed by analysing the excess functions computed from its experimentally determined solidus-liquidus equilibrium data. Spontaneous nucleation model has been explored from the maximum limit of undercooling of the system and verified by the experimental evidences of dislocation mechanism governing the anisotropic velocity of crystallisation determined at different undercoolings. Viscosity measurements of eutectic and non-eutectic melts at different temperatures revealed the essence of peculiar structural changes and specific energy interactions in the eutectic melt in the temperature range near its melting temperature. The rheological activation energy, E vis for eutectic and non-eutectic melts is found to be a function of temperature. Crystalline faceted structure of the system has been furnished with morphological evidences obtained from microscopic studies at different growth rates, whereas whisker reinforced structural model has been accomplished with mechanical properties computed for both isotropic and anisotropic modes of growth. Of greater interest is the special reference of moderate anisotropic growth, since experimental confirmation was obtained for the theoretical shape of parabolic variation in the mechanical properties of eutectic composite material with growth velocity. Direct evidence of three- to four-fold increase in strength properties of the eutectic material at its moderate anisotropic growth velocity (3.11x10 -7 m 3 s -1 ) in comparison with its isotropic growth in an ice bath (∼273 K), confirms a complete composite microstructure with whiskers in equilibrium with the matrix, embedded parallel to the growth direction

  8. Phase equilibrium, crystallization behavior and thermodynamic studies of (m-dinitrobenzene + vanillin) eutectic system

    International Nuclear Information System (INIS)

    Singh, Jayram; Singh, N.B.

    2015-01-01

    Graphical abstract: The phase diagram of (m-dinitrobenzene + vanillin) system. - Highlights: • (Thaw + melt) method has shown that (m-dinitrobenzene + vanillin) system forms simple eutectic type phase diagram. • Excess thermodynamic functions showed that eutectic mixture is non-ideal. • The flexural strength measurements have shown that in eutectic mixture, crystallization occurs in an ordered way. - Abstract: The phase diagram of (m-dinitrobenzene + vanillin) system has been studied by the thaw melt method and an eutectic type phase diagram was obtained. The linear velocities of crystallization of the parent components and the eutectic mixture were determined. The enthalpy of fusion of the components and the eutectic mixture were determined using the differential scanning calorimetric technique. Excess Gibbs energy, excess entropy, excess enthalpy of mixing, and interfacial energy have been calculated. FTIR spectroscopic studies and flexural strength measurements were also made. The results have shown that the eutectic is a non-ideal mixture of the two components. On the basis of Jackson’s roughness parameter, it is predicted that the eutectic has faceted morphology

  9. Natural deep eutectic solvents and their application in natural product research and development

    NARCIS (Netherlands)

    Dai, yuntao

    2013-01-01

    Natural deep eutectic solvents (NADES) ionic liquids (ILs) and deep eutectic solvents (DES) were proposed by our group to extend the range of ILs and DES, particularly to develop cheap, nontoxic, and low viscosity green solvents, and to apply them in health-related fields. They are liquid

  10. Interest and difficulties of O-g studies of the mechanisms of eutectic growth

    International Nuclear Information System (INIS)

    Lemaignan, Clement; Malmejac, Yves.

    1976-01-01

    The possible modifications of the very diverse mechanisms involved in a typical eutectic solidification due to the effects of O-g conditions are described. The convection effects, eutectic solidification, nucleation and relations between interlamellar spacing and growth rate are studied [fr

  11. Effects of a novel magnetic orthopedic appliance (MOA-III) on the dentofacial complex in mild to moderate skeletal class III children.

    Science.gov (United States)

    Zhao, Ning; Feng, Jing; Hu, Zheng; Chen, Rongjing; Shen, Gang

    2015-10-14

    The objective of this study was to evaluate the changes of skeletal and dental structures in mild to moderate skeletal Class III children following the use of a new magnetic orthopedic appliance (MOA-III). A total of 36 patients (14 boys and 22 girls, mean age 9 years and 5 months) who presented with a mild to moderate skeletal Class III jaw discrepancy were treated with MOA-III. Another group of 20 untreated patients (9 boys and 11 girls, mean age 9 years and 2 months) with the same level of deformity served as the control group. The average treatment time was 6.6 months. Radiographs were taken at the same time intervals for both groups. A paired t test was used to determine the significant differences before and after treatment, and a two-sample t test was used to analyze the differences between the treatment and control groups. The anterior crossbite in all subjects was corrected after MOA-III therapy. The maxillomandibular relationship showed favorable changes (ANB, Wits, overjet increased significantly, P  0.05). Significant upper incisor proclination and lower incisor retroclination were observed (UI-NA increased, P III appliance compared to the untreated group. The MOA-III was effective for the early treatment of a mild to moderate Class III malocclusion in children.

  12. Directionally solidified pseudo-binary eutectics of Ni-Cr-/Hf,Zr/

    Science.gov (United States)

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

    1975-01-01

    This report is concerned with the experimental determination of pseudo binary eutectic compositions and the directional solidification of the Ni-Cr-Hf,Zr, and Ni-Cr-Zr eutectic alloys. To determine unknown eutectics, chemical analyses were made of material bled from near eutectic ingots during incipient melting. Nominal compositions in weight per cent of Ni-18.6Cr-24.0Hf, Ni-19.6Cr-12.8Zr-2.8Hf, and Ni-19.2Cr-14.8Zr formed aligned pseudo-binary eutectic structures. The melting points were about 1270 C. The reinforcing intermetallic phases were identified as noncubic (Ni,Cr)7Hf2 and (Ni,Cr)7(Hf,Zr)2, and face centered cubic (Ni,Cr)5Zr. The volume fraction of the reinforcing phases were about 0.5.

  13. Antimony Influence on Shape of Eutectic Silicium in Al-Si Based Alloys

    Directory of Open Access Journals (Sweden)

    Bolibruchová D.

    2017-12-01

    Full Text Available Liquid AI-Si alloys are usually given special treatments before they are cast to obtain finer or modified matrix and eutectic structures, leading to improved properties. For many years, sodium additions to hypoeutectic and eutectic AI-Si melts have been recognized as the most effective method of modifying the eutectic morphology, although most of the group IA or IIA elements have significant effects on the eutectic structure. Unfortunately, many of these approaches also have associated several founding difficulties, such as fading, forming dross in presence of certain alloying elements, reduced fluidity, etc. ln recent years, antimony additions to AI-Si castings have attracted considerable attention as an alternative method of refining the eutectic structure. Such additions eliminate many of the difficulties listed above and provide permanent (i.e. non-fading refining ability. In this paper, the authors summarize work on antimony treatment of Al-Si based alloys.

  14. The novel eutectic microstructures of Si-Mn-P ternary alloy

    International Nuclear Information System (INIS)

    Wu Yaping; Liu Xiangfa

    2010-01-01

    The microstructures of Si-Mn-P alloy manufactured by the technique of combining phosphorus transportation and alloy melting were investigated using electron probe micro-analyzer (EPMA). The phase compositions were determined by energy spectrum and the varieties of eutectic morphologies were discussed. It is found that there is no ternary compound but Si, MnP and MnSi 1.75-x could appear when the Si-Mn-P alloy's composition is proper. Microstructure is greatly refined by rapid solidification technique and the amount of eutectic phases change with faster cooling rates. Moreover, primary Si or MnP are surrounded firstly by the binary eutectic (Si + MnP) and then the ternary eutectic (Si + MnSi 1.75-x + MnP) which also exhibit binary structures due to divorced eutectic determined by the particularity of some Si-Mn-P alloys.

  15. Variación de la dinámica erosiva y acumulativa en Cayo Moa Grande, Bahía de Moa, Cuba. Período 1972–2007

    Directory of Open Access Journals (Sweden)

    Hans-Juergen Gursky

    2009-03-01

    Full Text Available Esta investigación tuvo el propósito de comprobar cambios en la dinámica erosiva–acumulativa en Cayo Moa Grande, con base en un análisis fotogeológico temporal. Se usaron fotos aéreas, correspondientes al proyecto K-10 del año 1972, a escala aproximada 1:36 000, e imágenes obtenidas de Google Earth en el año 2007. Para la valoración espacial de los cambios se implementó como herramienta de trabajo un sistema de información geográfica que permitió sectorizar las fotos aéreas; mediante la superposición de la línea de costa para los diferentes años analizados y calculando la tasa de punto final, se determinan las principales transformaciones geodinámicas del cayo en un periodo de 35 años. Los procesos de erosión y sedimentación en Cayo Moa Grande se manifiestan de forma rápida y se registran principalmente en los últimos 50 años, alcanzando un avance máximo en las últimas tres décadas. Tales procesos han modificado la configuración de la línea de costa con la acumulación de sedimentos en la parte occidental y central del cayo y un intenso proceso erosivo en la porción oriental del mismo.

  16. Deep eutectic-solvothermal synthesis of nanostructured ceria

    Science.gov (United States)

    Hammond, Oliver S.; Edler, Karen J.; Bowron, Daniel T.; Torrente-Murciano, Laura

    2017-01-01

    Ceria is a technologically important material with applications in catalysis, emissions control and solid-oxide fuel cells. Nanostructured ceria becomes profoundly more active due to its enhanced surface area to volume ratio, reactive surface oxygen vacancy concentration and superior oxygen storage capacity. Here we report the synthesis of nanostructured ceria using the green Deep Eutectic Solvent reline, which allows morphology and porosity control in one of the less energy-intensive routes reported to date. Using wide Q-range liquid-phase neutron diffraction, we elucidate the mechanism of reaction at a molecular scale at considerably milder conditions than the conventional hydrothermal synthetic routes. The reline solvent plays the role of a latent supramolecular catalyst where the increase in reaction rate from solvent-driven pre-organization of the reactants is most significant. This fundamental understanding of deep eutectic-solvothermal methodology will enable future developments in low-temperature synthesis of nanostructured ceria, facilitating its large-scale manufacturing using green, economic, non-toxic solvents.

  17. Divorced eutectic in a HPDC magnesium-aluminum alloy

    International Nuclear Information System (INIS)

    Barbagallo, S.; Laukli, H.I.; Lohne, O.; Cerri, E.

    2004-01-01

    The morphology of the eutectic in a thin-wall high pressure die cast (HPDC) U-shape AM60 magnesium box was investigated by light microscope, SEM, TEM and EPMA. The extremely fast cooling rate taking place in the solidification process produces a highly segregated zone near the boundaries of small grains and a fine distribution of β particles, which is typical of a completely divorced eutectic. It was shown that the segregated zone is coherent with the primary α-Mg grain core even if the increased aluminium content produces a deformation of the hexagonal crystal lattice, which was estimated through diffraction patterns (SADP). The variation of the alloying elements content through the grain boundaries was shown by means of EPMA line scanning. The β particle composition was quantitatively investigated and the results show that, in comparison with the equilibrium phase diagram, the non-equilibrium phase boundary of the Mg 17 Al 12 region is moved some percent towards the lower aluminium content, at the high cooling rate that occurs in high pressure die castings. The cubic structure of the β phase was revealed by diffraction pattern. The presence of small Al-Mn particles both inside the grain and in the boundary region was also put in evidence by TEM

  18. Agrobiodiversity in riparian backyards and rural cutover lands in the Boca do Moa community – Acre, Brazil

    Directory of Open Access Journals (Sweden)

    Williane Maria de Oliveira Martins

    2012-09-01

    Full Text Available The riparian rural cutover lands and backyards represent a sustainable alternative for the production of food and medicinal drugs to the traditional communities from the Amazon, especially with regard to products diversity and income generation. Considering the ecological and social functions of these spaces, this paper aims at analyzing the agrobiodiversity of these environments in the Boca Moa community, in the town of Cruzeiro do Sul, Acre, Brazil. Data collection was carried out through participative, formal, and inductive interviews following a semi-structured questionnaire with open questions, besides in loco visits. The rural cutover lands present many species at the same area, and manioc is the main product cultivated. The backyards have spatial arrangements of food species, with emphasis on fruits and vegetables, besides medicinal plants. Thus, both the backyards and rural cutover lands participate in the subsistence and income of riparian families from this community.

  19. Reactive transport model of the formation of oxide-type Ni-laterite profiles (Punta Gorda, Moa Bay, Cuba)

    Science.gov (United States)

    Domènech, Cristina; Galí, Salvador; Villanova-de-Benavent, Cristina; Soler, Josep M.; Proenza, Joaquín A.

    2017-10-01

    Oxide-type Ni-laterite deposits are characterized by a dominant limonite zone with goethite as the economically most important Ni ore mineral and a thin zone of hydrous Mg silicate-rich saprolite beneath the magnesium discontinuity. Fe, less soluble, is mainly retained forming goethite, while Ni is redeposited at greater depth in a Fe(III) and Ni-rich serpentine (serpentine II) or in goethite, where it adsorbs or substitutes for Fe in the mineral structure. Here, a 1D reactive transport model, using CrunchFlow, of Punta Gorda oxide-type Ni-laterite deposit (Moa Bay, Cuba) formation is presented. The model reproduces the formation of the different laterite horizons in the profile from an initial, partially serpentinized peridotite, in 106 years, validating the conceptual model of the formation of this kind of deposits in which a narrow saprolite horizon rich in Ni-bearing serpentine is formed above peridotite parent rock and a thick limonite horizon is formed over saprolite. Results also confirm that sorption of Ni onto goethite can explain the weight percent of Ni found in the Moa goethite. Sensitivity analyses accounting for the effect of key parameters (composition, dissolution rate, carbonate concentration, quartz precipitation) on the model results are also presented. It is found that aqueous carbonate concentration and quartz precipitation significantly affects the laterization process rate, while the effect of the composition of secondary serpentine or of mineral dissolution rates is minor. The results of this reactive transport modeling have proven useful to validate the conceptual models derived from field observations.

  20. Thermal energy storage using chloride salts and their eutectics

    International Nuclear Information System (INIS)

    Myers, Philip D.; Goswami, D. Yogi

    2016-01-01

    Achieving the goals of the U.S. Department of Energy (DOE) Sunshot initiative requires (1) higher operating temperatures for concentrating solar power (CSP) plants to increase theoretical efficiency, and (2) effective thermal energy storage (TES) strategies to ensure dispatchability. Current inorganic salt-based TES systems in large-scale CSP plants generally employ molten nitrate salts for energy storage, but nitrate salts are limited in application to lower temperatures—generally, below 600 °C. These materials are sufficient for parabolic trough power plants, but they are inadequate for use at higher temperatures. At the higher operating temperatures achievable in solar power tower-type CSP plants, chloride salts are promising candidates for application as TES materials, owing to their thermal stability and generally lower cost compared to nitrate salts. In light of this, a recent study was conducted, which included a preliminary survey of chloride salts and binary eutectic systems that show promise as high temperature TES media. This study provided some basic information about the salts, including phase equilibria data and estimates of latent heat of fusion for some of the eutectics. Cost estimates were obtained through a review of bulk pricing for the pure salts among various vendors. This review paper updates that prior study, adding data for additional salt eutectic systems obtained from the literature. Where possible, data are obtained from the thermodynamic database software, FactSage. Radiative properties are presented, as well, since at higher temperatures, thermal radiation becomes a significant mode of heat transfer. Material compatibility for inorganic salts is another important consideration (e.g., with regard to piping and/or containment), so a summary of corrosion studies with various materials is also presented. Lastly, cost data for these systems are presented, allowing for meaningful comparison among these systems and other materials for TES

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

    International Nuclear Information System (INIS)

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

    1978-01-01

    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 2 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 gas mixture for oxide--metal eutectic composite growth. The Cr 2 O 3 --Mo--Cr systems was used to verify certain aspects of the proposed criteria

  2. CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES; FINAL

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  3. CATALYTIC GASIFICATION OF COAL USING EUTECTIC SALT MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-12-01

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

  4. Unique parasite aDNA in moa coprolites from New Zealand suggests mass parasite extinctions followed human-induced megafauna extinctions

    Science.gov (United States)

    Lafferty, Kevin D.; Hopkins, Skylar R.

    2018-01-01

    Having split early from Gondwana, Zealandia (now modern New Zealand) escaped discovery until the late 13th century, and therefore remains an important glimpse into a human-free world. Without humans or other land mammals, diverse and peculiar birds evolved in isolation, including several flightless moa species, the giant pouakai eagle (Harpagornis moorei), the kiwi (Apteryx mantelli), and the kakapo parrot (Strigops habroptila). This unique community has fascinated paleoecologists, who have spent almost two centuries devising new ways to glean information from ancient bird remains. In PNAS, Boast et al. (1) apply one recent technological advance, ancient DNA (aDNA) metabarcoding, to confirm previous discoveries and report new details about moa and kakapo diets, parasites, and niches. Their efforts confirm Zealandia was a lot different before humans arrived.

  5. Meloxicam transdermal delivery: effect of eutectic point on the rate and extent of skin permeation

    Directory of Open Access Journals (Sweden)

    Soliman Mohammadi-Samani

    2014-02-01

    Conclusion: This study set out to determine that thymol plays as a skin permeation enhancer and increases the meloxicam skin absorption and this enhancement is significant at the eutectic point of drug-enhancer mixture.

  6. Eutectic Formation During Solidification of Ni-Based Single-Crystal Superalloys with Additional Carbon

    Science.gov (United States)

    Wang, Fu; Ma, Dexin; Bührig-Polaczek, Andreas

    2017-11-01

    γ/ γ' eutectics' nucleation behavior during the solidification of a single-crystal superalloy with additional carbon was investigated by using directional solidification quenching method. The results show that the nucleation of the γ/ γ' eutectics can directly occur on the existing γ dendrites, directly in the remaining liquid, or on the primary MC-type carbides. The γ/γ' eutectics formed through the latter two mechanisms have different crystal orientations than that of the γ matrix. This suggests that the conventional Ni-based single-crystal superalloy castings with additional carbon only guarantee the monocrystallinity of the γ matrix and some γ/ γ' eutectics and, in addition to the carbides, there are other misoriented polycrystalline microstructures existing in macroscopically considered "single-crystal" superalloy castings.

  7. Data supporting the prediction of the properties of eutectic organic phase change materials

    Directory of Open Access Journals (Sweden)

    Samer Kahwaji

    2018-04-01

    Full Text Available The data presented in this article include the molar masses, melting temperatures, latent heats of fusion and temperature-dependent heat capacities of fifteen fatty acid phase change materials (PCMs. The data are used in conjunction with the thermodynamic models discussed in Kahwaji and White (2018 [1] to develop a computational tool that calculates the eutectic compositions and thermal properties of eutectic mixtures of PCMs. The computational tool is part of this article and consists of a Microsoft Excel® file available in Mendeley Data repository [2]. A description of the computational tool along with the properties of nearly 100 binary mixtures of fatty acid PCMs calculated using this tool are also included in the present article. The Excel® file is designed such that it can be easily modified or expanded by users to calculate the properties of eutectic mixtures of other classes of PCMs. Keywords: Phase change materials, PCM, Eutectic, Thermal properties, Thermal energy storage

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

    Energy Technology Data Exchange (ETDEWEB)

    Hu, S C; De Jonghe, L C

    1982-04-01

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

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

    Science.gov (United States)

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

    2014-05-01

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

  10. The effect of the solidification mode on eutectic structure in Fe-C-V alloys

    International Nuclear Information System (INIS)

    Fras, E.; Guzik, E.

    1980-01-01

    The aim of the study was to determine such a chemical composition of Fe-C-V alloys which would ensure the formation of perfectly eutectic structures as well as to investigate the eutectic morphology of these alloys when undergoing bulk and directional solidification. Attempts have been done to get in situ composites from Fe-C-V alloys. The adopted testing methods as well as obtained results are described in detail. (H.M.)

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  12. The Exoplanet Mass-Ratio Function From the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass

    Science.gov (United States)

    Suzuki, D.; Bennett, D. P.; Sumi, T.; Bond, I. A.; Rogers, L. A.; Abe, F.; Asakura, Y.; Bhattacharya, A.; Donachie, M.; Freeman, M.; hide

    2016-01-01

    We report the results of the statistical analysis of planetary signals discovered in MOA-II microlensing survey alert system events from 2007 to 2012. We determine the survey sensitivity as a function of planet star mass ratio, q, and projected planet star separation, s, in Einstein radius units. We find that the mass-ratio function is not a single power law, but has a change in slope at q approx.10(exp -4), corresponding to approx. 20 Stellar Mass for the median host-star mass of approx. 0.6 M. We find significant planetary signals in 23 of the 1474 alert events that are well-characterized by the MOA-II survey data alone. Data from other groups are used only to characterize planetary signals that have been identified in the MOA data alone. The distribution of mass ratios and separations of the planets found in our sample are well fit by a broken power-law model. We also combine this analysis with the previous analyses of Gould et al. and Cassan et al., bringing the total sample to 30 planets. The unbroken power-law model is disfavored with a p-value of 0.0022, which corresponds to a Bayes factor of 27 favoring the broken power-law model. These results imply that cold Neptunes are likely to be the most common type of planets beyond the snow line.

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

    Science.gov (United States)

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

    1975-01-01

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

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

    Science.gov (United States)

    Baird, Jared A; Taylor, Lynne S

    2011-06-01

    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.

  15. The formation mechanism of eutectic microstructures in NiAl-Cr composites.

    Science.gov (United States)

    Tang, Bin; Cogswell, Daniel A; Xu, Guanglong; Milenkovic, Srdjan; Cui, Yuwen

    2016-07-20

    NiAl-based eutectic alloys, consisting of an ordered bcc matrix (B2) and disordered bcc fibers (A2), have been a subject of intensive efforts aimed at tailoring the properties of many of the currently used nickel-based superalloys. A thermodynamic phase field model was developed on a thermodynamic foundation and fully integrated with a thermo-kinetic database of the Ni-Al-Cr ternary system to elucidate the resulting peculiar eutectic microstructure. Invoking a variation of the liquid/solid interfacial thickness with temperature, we simulated the characteristic sunflower-like eutectic microstructures in the NiAl-Cr composites, consistent with experimental observations. The mechanism that governs the formation of the peculiar eutectic morphology was envisioned from the modeled evolutions associated with six sequential steps. Our calculations show that the conditional spinodal decomposition occurring in sequence could further trim and revise the microstructure of the eutectics by generating fine-domain structures, thereby providing an additional method to explore the novel NiAl-based eutectic composites with tunable properties at elevated temperatures.

  16. Phase transformation and deformation behavior of NiTi-Nb eutectic joined NiTi wires.

    Science.gov (United States)

    Wang, Liqiang; Wang, Cong; Zhang, Lai-Chang; Chen, Liangyu; Lu, Weijie; Zhang, Di

    2016-04-06

    NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19' martensite transformation are induced by plastic deformation. R phase transformation, which significantly contributes to superelasticity, preferentially occurs at the interfaces between NiTi and eutectic region. Round-shaped Nb-rich phase with rod-like and lamellar-type eutectics are observed in eutectic regions. These phases appear to affect the deformation behavior of the brazed NiTi-Nb region via five distinct stages in stress-strain curves: (I) R phase reorientation, (II) R phase transformation from parent phase, (III) elastic deformation of reoriented martensite accompanied by the plastic deformation of Nb-rich phase and lamellar NiTi-Nb eutectic, (IV) B19' martensitic transformation, and (V) plastic deformation of the specimen.

  17. The Frequency of Snowline-Region Planets from Four Years of OGLE-MOA-Wise Second-Generation Microlensing

    Science.gov (United States)

    Shvartzvald, Y.; Maoz, D.; Udalski, A.; Sumi, T.; Friedmann, M.; Kaspi, S.; Poleski, R.; Szymanski, M. K.; Skowron, J.; Kozlowski, S.; hide

    2016-01-01

    We present a statistical analysis of the first four seasons from a second-generation microlensing survey for extrasolar planets, consisting of near-continuous time coverage of 8 deg to the 2nd power of the Galactic bulge by the Optical Gravitational Lens Experiment (OGLE), Microlensing Observations in Astrophysics (MOA), and Wise microlensing surveys. During this period, 224 microlensing events were observed by all three groups. Over 12% of the events showed a deviation from single-lens microlensing, and for approx. 1/3 of those the anomaly is likely caused by a planetary companion. For each of the 224 events, we have performed numerical ray-tracing simulations to calculate the detection efficiency of possible companions as a function of companion-to-host mass ratio and separation. Accounting for the detection efficiency, we find that 55 +34 -22%of microlensed stars host a snowline planet. Moreover, we find that Neptune-mass planets are approx.10 times more common than Jupiter-mass planets. The companion-to-host mass-ratio distribution shows a deficit at q approx. 10 (exp -2), separating the distribution into two companion populations, analogous to the stellar-companion and planet populations, seen in radial-velocity surveys around solar-like stars. Our survey, however, which probes mainly lower mass stars, suggests a minimum in the distribution in the super-Jupiter mass range, and a relatively high occurrence of brown-dwarf companions.

  18. Microstructural evolution and thermal stability of aluminum-cerium-nickel ternary eutectic

    Science.gov (United States)

    Fodran, Eric John

    The engineering community has identified several applications in which the use of a lightweight alloy for elevated temperature service, in substitution for current heavier and more costly alloys, would have a substantial benefit. This need for structural materials to perform at elevated temperatures has driven researchers to develop novel alloys as well as processing routes to manufacture them and obtain optimum microstructures. Previous studies on aluminum based binary eutectic systems have proven that the aluminum alloy system shows promising potential for satisfying this need. This has motivated the investigation of the solidification and thermal stability of the Al-12 wt% Ce-5 wt% Ni ternary eutectic performed in this investigation. The solidification behavior of the Al-Ce-Ni ternary eutectic was conducted via solidification of various compositions at and above the eutectic composition in a copper chill mold, thus allowing the observation of various solidification rates on a single ingot. Directional solidification of the ternary eutectic was also conducted to further study the unique microstructures forms. After casting the ingots were analyzed for the composition of phases in the microstructure via X-ray diffraction, and the distribution of the phases determined by scanning electron microscopy. The solidification of the ternary eutectic was found to occur much like that of a faceted/non-faceted binary couples growth. The thermal stability of the microstructure was also studied. Ternary eutectic microstructures were heat treated at various temperatures for time intervals up to 100 hours. The coupled growth microstructures were found to coarsen at temperature above 400°C, which was associated with a loss in hardness. Coarsening of the microstructures at elevated temperatures was also observed to occur by multiple mechanisms: an Ostwald ripening within the eutectic cell, and an accelerated coarsening at the cell boundaries due to increased diffusion at

  19. Directional solidification of Al2-Cu-Al and Al3-Ni-Al eutectics during TEXUS rocket flight

    Science.gov (United States)

    Favier, J. J.; Degoer, J.

    1984-01-01

    One lamellar eutectic sample and one fiber-like eutectic sample were solidified directionally during the TEXUS-6 rocket flight. The microstructures and the results of the thermal analysis, obtained from the temperatures recorded on the cartridge skin, are compared. No appreciable modifications of the regularity of the eutectic structures were observed by passing from 1 g to 0.0001 g in these experiments. No steady state growth conditions were achieved in these experiments.

  20. Deep eutectic solvent-based valorization of spent coffee grounds.

    Science.gov (United States)

    Yoo, Da Eun; Jeong, Kyung Min; Han, Se Young; Kim, Eun Mi; Jin, Yan; Lee, Jeongmi

    2018-07-30

    Spent coffee grounds (SCGs) are viewed as a valuable resource for useful bioactive compounds, such as chlorogenic acids and flavonoids, and we suggest an eco-friendly and efficient valorization method. A series of choline chloride-based deep eutectic solvents (DESs) were tested as green extraction solvents for use with ultrasound-assisted extraction. Extraction efficiency was evaluated based on total phenolic content (TPC), total flavonoid content, total chlorogenic acids, and/or anti-oxidant activity. A binary DES named HC-6, which was composed of 1,6-hexanediol:choline chloride (molar ratio 7:1) was designed to produce the highest efficiency. Experimental conditions were screened and optimized for maximized efficiency using a two-level fractional factorial design and a central composite design, respectively. As a result, the proposed method presented significantly enhanced TPC and anti-oxidant activity. In addition, phenolic compounds could be easily recovered from extracts at high recovery yields (>90%) by adsorption chromatography. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Synthesis of Barium Titanate Using Deep Eutectic Solvents.

    Science.gov (United States)

    Boston, Rebecca; Foeller, Philip Y; Sinclair, Derek C; Reaney, Ian M

    2017-01-03

    Novel synthetic routes to prepare functional oxides at lower temperatures are an increasingly important area of research. Many of these synthetic routes, however, use water as the solvent and rely on dissolution of the precursors, precluding their use with, for example, titanates. Here we present a low-cost solvent system as a means to rapidly create phase-pure ferroelectric barium titanate using a choline chloride-malonic acid deep eutectic solvent. This solvent is compatible with alkoxide precursors and allows for the rapid synthesis of nanoscale barium titanate powders at 950 °C. The phase and morphology were determined, along with investigation of the synthetic pathway, with the reaction proceeding via BaCl 2 and TiO 2 intermediates. The powders were also used to create sintered ceramics, which exhibit a permittivity maximum corresponding to a tetragonal-cubic transition at 112 °C, as opposed to the more conventional temperature of ∼120 °C. The lower-than-expected value for the ferro- to para-electric phase transition is likely due to undetectable levels of contaminants.

  2. Purification of biodiesel by choline chloride based deep eutectic solvent

    Science.gov (United States)

    Niawanti, Helda; Zullaikah, Siti; Rachimoellah, M.

    2017-05-01

    Purification is a crucial step in biodiesel production to meet the biodiesel standard. This study purified biodiesel using choline chloride based deep eutectic solvent (DES). DES was used to reduce unreacted oil and unsaponifiable matter in rice bran oil based biodiesel. The objective of this work was to study the effect of extraction time using DES on the content and yield of fatty acid methyl ester (FAME). Rice bran used in this work contains 16.49 % of oil with initial free fatty acids (FFA) of 44.75 %. Acid catalyzed methanolysis was employed to convert rice bran oil (RBO) into biodiesel under following operation conditions: T = 60 °C, t = 8 h, molar ratio of oil to methanol = 1/10, H2SO4 = 1% w/w of oil. Rice bran oil based biodiesel obtained contain 89.05 % of FAME with very low FFA content (0.05 %). DES was made from a mixture of choline chloride and ethylene glycol with molar ratio of 1/2. Molar ratio of crude biodiesel to DES were 1/2 and 1/4. Extraction time was varied from 15 minutes to 240 minutes at 30 °C. The highest FAME content was obtained after purification for 240 min. at molar ratio crude biodiesel to DES 1/4 was 96.60 %. This work shows that DES has potential to purify biodiesel from non-edible raw material, such as RBO.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Yuntao [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Spronsen, Jaap van; Witkamp, Geert-Jan [Laboratory for Process Equipment, Delft University of Technology, Delft (Netherlands); Verpoorte, Robert [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands); Choi, Young Hae, E-mail: y.choi@chem.leidenuniv.nl [Natural Products Laboratory, Institute of Biology, Leiden University, 2300 RA Leiden (Netherlands)

    2013-03-05

    Highlights: ► Natural products were used as a source for deep eutectic solvents and ionic liquids. ► We define own chemical and physical properties of natural deep eutectic solvents. ► Interaction between natural deep eutectic solvents and solutes was confirmed by NMR. ► The developed natural deep eutectic solvents were applied as green media. - Abstract: 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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    Highlights: ► Natural products were used as a source for deep eutectic solvents and ionic liquids. ► We define own chemical and physical properties of natural deep eutectic solvents. ► Interaction between natural deep eutectic solvents and solutes was confirmed by NMR. ► The developed natural deep eutectic solvents were applied as green media. - Abstract: 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

  5. Stable carbon and nitrogen isotope signatures indicate recovery of marine biota from sewage pollution at Moa Point, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Karyne M

    2003-07-01

    Stable carbon and nitrogen isotopes have been used to assess sewage contamination of a sewage outfall, discharging milli-screened effluent into Moa Point Bay, New Zealand, and monitor the recovery of flora and fauna after the outfall's closure. An initial study characterising the extent of the discharge and the effects on seaweed (Ulva lactuca L.), blue mussels (Mytilus galloprovincialis) and limpets (Cellana denticulata) from the area, showed effects of the sewage discharge on flora and fauna were localised within in the bay. The immediate area surrounding the discharge area was found to contain limited biodiversity, with an abundance of Ulva lactuca, a bright green lettuce-like seaweed, typically found in areas with high nutrient input, limpets and small blue mussels. The nitrogen isotopic signature ({delta}{sup 15}N) is shown to be a good tracer of sewage pollution in seaweed and associated grazers (i.e. limpets) as a result of the increased contribution of urea and ammonia to seawater nitrogen derived from the effluent. The carbon isotopic signature ({delta}{sup 13}C) is suggested as a more appropriate sewage tracer for mussels, which filter feed the effluent's particulate organic matter from the water. Lower carbon:nitrogen ratios were found in Ulva lactuca sampled from around the outfall region compared to uncontaminated control sites. However carbon:nitrogen ratios do not vary significantly amongst shellfish species. After closure, monitoring continued for 9 months and showed that the carbon and nitrogen isotopic signatures of algae (Ulva lactuca L.) returned to similar control site levels within 3 months. Limpet and blue mussels (Cellana denticulata and Mytilus galloprovincialis) showed slower recovery times than the Ulva lactuca, with detectable levels of the sewage-derived carbon and nitrogen remaining in the animal's tissue for up to 9 months.

  6. Stable carbon and nitrogen isotope signatures indicate recovery of marine biota from sewage pollution at Moa Point, New Zealand

    International Nuclear Information System (INIS)

    Rogers, Karyne M.

    2003-01-01

    Stable carbon and nitrogen isotopes have been used to assess sewage contamination of a sewage outfall, discharging milli-screened effluent into Moa Point Bay, New Zealand, and monitor the recovery of flora and fauna after the outfall's closure. An initial study characterising the extent of the discharge and the effects on seaweed (Ulva lactuca L.), blue mussels (Mytilus galloprovincialis) and limpets (Cellana denticulata) from the area, showed effects of the sewage discharge on flora and fauna were localised within in the bay. The immediate area surrounding the discharge area was found to contain limited biodiversity, with an abundance of Ulva lactuca, a bright green lettuce-like seaweed, typically found in areas with high nutrient input, limpets and small blue mussels. The nitrogen isotopic signature (δ 15 N) is shown to be a good tracer of sewage pollution in seaweed and associated grazers (i.e. limpets) as a result of the increased contribution of urea and ammonia to seawater nitrogen derived from the effluent. The carbon isotopic signature (δ 13 C) is suggested as a more appropriate sewage tracer for mussels, which filter feed the effluent's particulate organic matter from the water. Lower carbon:nitrogen ratios were found in Ulva lactuca sampled from around the outfall region compared to uncontaminated control sites. However carbon:nitrogen ratios do not vary significantly amongst shellfish species. After closure, monitoring continued for 9 months and showed that the carbon and nitrogen isotopic signatures of algae (Ulva lactuca L.) returned to similar control site levels within 3 months. Limpet and blue mussels (Cellana denticulata and Mytilus galloprovincialis) showed slower recovery times than the Ulva lactuca, with detectable levels of the sewage-derived carbon and nitrogen remaining in the animal's tissue for up to 9 months

  7. Directional growth and characterization of Fe?Al?Nb eutectic alloys

    Science.gov (United States)

    Mota, M. A.; Coelho, A. A.; Bejarano, J. M. Z.; Gama, S.; Caram, R.

    1999-03-01

    The manufacturing of components for operation at high temperatures requires the use of metallic materials which can keep satisfactory mechanical and chemical properties, even at temperatures beyond 1000°C. An interesting alternative to solve such a problem is the use of directionally solidified eutectic alloys. A potentially promising system for the manufacture of structural materials, and so far not totally studied, is the eutectic based on the Fe-Al-Nb system, which involves the (FeAl) 2Nb phase and the FeAl solid solution. Eutectic samples from this system were directionally solidified in a vertical Bridgman crystal growth unit. The objective of the experiments was to determine the influence of the growth rate on the eutectic microstructure. The ingots obtained were investigated by using optical and electron scanning microscopy. At low growth rate, the eutectic microstructure remained regular, even though it showed several types of microstructure defects. As the growth rate was increased, a transition from lamellar to fibrous morphology was observed.

  8. Molecular interactions in the betaine monohydrate-polyol deep eutectic solvents: Experimental and computational studies

    Science.gov (United States)

    Zahrina, Ida; Mulia, Kamarza; Yanuar, Arry; Nasikin, Mohammad

    2018-04-01

    DES (deep eutectic solvents) are a new class of ionic liquids that have excellent properties. The strength of interaction between molecules in the DES affects their properties and applications. In this work, the strength of molecular interactions between components in the betaine monohydrate salt and polyol (glycerol or/and propylene glycol) eutectic mixtures was studied by experimental and computational studies. The melting point and fusion enthalpy of the mixtures were measured using STA (Simultaneous Thermal Analyzer). The nature and strength of intermolecular interactions were observed by FT-IR and NMR spectroscopy. The molecular dynamics simulation was used to determine the number of H-bonds, percent occupancy, and radial distribution functions in the eutectic mixtures. The interaction between betaine monohydrate and polyol is following order: betaine monohydrate-glycerol-propylene glycol > betaine monohydrate-glycerol > betaine monohydrate-propylene glycol, where the latter is the eutectic mixture with the lowest stability, strength and extent of the hydrogen bonding interactions between component molecules. The presence of intra-molecular hydrogen bonding interactions, the inter-molecular hydrogen bonding interactions between betaine molecule and polyol, and also interactions between polyol and H2O of betaine monohydrate in the eutectic mixtures.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, N.

    2012-03-26

    In a radioactive material (RAM) packaging, the formation of eutectic at the Pu/SS (plutonium/stainless steel) interface is a serious concern and must be avoided to prevent of leakage of fissile material to the environment. The eutectic temperature for the Pu/SS is rather low (410 C) and could seriously impact the structural integrity of the containment vessel under accident conditions involving fire. The 9975 packaging is used for long term storage of Pu bearing materials in the DOE complex where the Pu comes in contact with the stainless steel containment vessel. Due to the serious consequences of the containment breach at the eutectic site, the Pu/SS interface temperature is kept well below the eutectic formation temperature of 410 C. This paper discusses the thermal models and the results for the extended fire conditions (1500 F for 86 minutes) that exist in a long term storage facility and concludes that the 9975 packaging Pu/SS interface temperature is well below the eutectic temperature.

  10. Deep Eutectic Solvents pretreatment of agro-industrial food waste.

    Science.gov (United States)

    Procentese, Alessandra; Raganati, Francesca; Olivieri, Giuseppe; Russo, Maria Elena; Rehmann, Lars; Marzocchella, Antonio

    2018-01-01

    Waste biomass from agro-food industries are a reliable and readily exploitable resource. From the circular economy point of view, direct residues from these industries exploited for production of fuel/chemicals is a winning issue, because it reduces the environmental/cost impact and improves the eco-sustainability of productions. The present paper reports recent results of deep eutectic solvent (DES) pretreatment on a selected group of the agro-industrial food wastes (AFWs) produced in Europe. In particular, apple residues, potato peels, coffee silverskin, and brewer's spent grains were pretreated with two DESs, (choline chloride-glycerol and choline chloride-ethylene glycol) for fermentable sugar production. Pretreated biomass was enzymatic digested by commercial enzymes to produce fermentable sugars. Operating conditions of the DES pretreatment were changed in wide intervals. The solid to solvent ratio ranged between 1:8 and 1:32, and the temperature between 60 and 150 °C. The DES reaction time was set at 3 h. Optimal operating conditions were: 3 h pretreatment with choline chloride-glycerol at 1:16 biomass to solvent ratio and 115 °C. Moreover, to assess the expected European amount of fermentable sugars from the investigated AFWs, a market analysis was carried out. The overall sugar production was about 217 kt yr -1 , whose main fraction was from the hydrolysis of BSGs pretreated with choline chloride-glycerol DES at the optimal conditions. The reported results boost deep investigation on lignocellulosic biomass using DES. This investigated new class of solvents is easy to prepare, biodegradable and cheaper than ionic liquid. Moreover, they reported good results in terms of sugars' release at mild operating conditions (time, temperature and pressure).

  11. Lead-Bismuth-Eutectic Spallation Neutron Source for Nuclear Transmuter

    International Nuclear Information System (INIS)

    Gohar, Y.; Herceg, J.; Krajtl, L.; Micklich, B.; Pointer, D.; Saiveau, J.; Sofu, T.; Finck, P.

    2002-01-01

    A lead-bismuth eutectic (LBE) spallation target design concept has been developed for the subcritical multiplier (SCM) design of the accelerator-driven test facility (ADTF). The design is based on a coaxial geometrical configuration, which has been carefully analyzed and designed to achieve an optimum performance. The target design description, the results from the parametric studies, and the design analyses including neutronics, heat transfer, and hydraulics analyses are given in this paper. A detailed MCNPX geometrical model for the target has been developed to generate heating rates and nuclear responses in the structural material for the design process. The beam has a uniform distribution of 600 MeV protons and 5-MW total power. A small LBE buffer is optimized to reduce the irradiation damage in the SCM fuel elements from the scatter protons and the high-energy neutrons, to maximize the neutron yield to the SCM operation, and to provide inlet and outlet manifolds for the LBE coolant. A special attention has been given to the target window design to enhance its lifetime. The window volumetric heating is 766 W/cm 3 relative to 750 W/cm 3 in LBE for a 40-μA/cm 2 current density. The results show that the nuclear heating from the proton beam diminishes at about 32 cm along the beam axis in the LBE target material. The neutron contribution to the atomic displacement is in the range of 94 to ∼100% for the structure material outside the proton beam path. In the beam window, the neutron contribution is ∼74% and the proton beam is responsible for more than 95% of the total gas production. The proton contribution to the gas production vanishes outside the beam path. The LBE average velocity is ∼2 m/s. The heat transfer and the hydraulics analyses have been iterated to reduce the maximum temperature and the thermal stress level in the target window to enhance its operating life. (authors)

  12. Identification of moaA3 gene in patient isolates of Mycobacterium tuberculosis in Kerala, which is absent in M. tuberculosis H37Rv and H37Ra

    Directory of Open Access Journals (Sweden)

    Radhakrishnan Indulakshmi

    2005-10-01

    Full Text Available Abstract Background Tuberculosis is endemic to developing countries like India. Though the whole genome sequences of the type strain M. tuberculosis H37Rv and the clinical strain M. tuberculosis CDC1551 are available, the clinical isolates from India have not been studied extensively at the genome level. This study was carried out in order to have a better understanding of isolates from Kerala, a state in southern India. Results A PCR based strategy was followed making use of the deletion region primers to understand the genome level differences between the type strain H37Rv and the clinical isolates of M. tuberculosis from Kerala. PCR analysis of patient isolates using RD1 region primers revealed the amplification of a 386 bp region, in addition to the expected 652 bp amplicon. Southern hybridization of genomic DNA with the 386 bp amplicon confirmed the presence of this new region in a majority of the patient isolates from Kerala. Sequence comparison of this amplicon showed close homology with the moaA3 gene of M. bovis. In M. bovis this gene is present in the RvD5 region, an IS6110 mediated deletion that is absent in M. tuberculosis H37Rv. Conclusion This study demonstrates the presence of moaA3 gene, that is absent in M. tuberculosis H37Rv and H37Ra, in a large number of local isolates. Whether the moaA3 gene provides any specific advantage to the field isolates of the pathogen is unclear. Field strains from Kerala have fewer IS6110 sequences and therefore are likely to have fewer IS6110 dependent rearrangements. But as deletions and insertions account for much of the genomic diversity of M. tuberculosis, the mechanisms of formation of sequence polymorphisms in the local isolates should be further examined. These results suggest that studies should focus on strains from endemic areas to understand the complexities of this pathogen.

  13. Behavior of radioisotope in liquid neutron irradiated Pb-17Li eutectic

    International Nuclear Information System (INIS)

    Tebus, V.N.; Aksenov, B.S.; Klabukov, U.G.

    1994-01-01

    Investigation of radioisotope 210 Po evaporation from liquid neutron irradiated Pb- 17 Li eutectic has been performed by Knudsen method. Equilibrium 210 Po vapor pressures at temperatures 250-700 degrees C were found about 3-4 orders of magnitude less than that for pure Po and were closed to equilibrium vapor pressures of Po-Pb compound. It was proposed Po forms stable Po-Pb compounds in eutectic at temperatures up to 750-800 degrees C. But disintegrates during long storage owing to self irradiation. It was determined Po aerosol transfer with radio gases takes place at the melting period. Contamination is happened also under irradiated eutectic storage at room temperature owing to aggregate recoil characteristic of Po

  14. Estimating the Eutectic Composition of Simple Binary Alloy System Using Linear Geometry

    Directory of Open Access Journals (Sweden)

    Muhammed Olawale Hakeem AMUDA

    2008-06-01

    Full Text Available A simple linear equation was developed and applied to a hypothetical binary equilibrium diagram to evaluate the eutectic composition of the binary alloy system. Solution of the equations revealed that the eutectic composition of the case study Pb – Sn, Bi – Cd and Al – Si alloys are 39.89% Pb, 60.11% Sn, 58.01% Bi, 41.99% Cd and 90.94% Al, 9.06% Si respectively. These values are very close to experimental values. The percent deviation of analytical values from experimental values ranged between 2.87 and 5% for the three binary systems considered, except for Si – Al alloy in which the percent deviation for the silicon element was 22%.It is concluded that equation of straight line could be used to predict the eutectic composition of simple binary alloys within tolerable experimental deviation range of 2.5%.

  15. RETRACTED ARTICLE: Comparison on grain refinement efficiency of peritectic and eutectic alloying elements on pure aluminium

    Science.gov (United States)

    Haghayeghi, R.; Kapranos, P.

    2014-07-01

    The work investigated the grain refining efficiency of peritectic forming solutes as well as eutectic solutes on pure Al. Significant grain refinement for peritectic and small refinement for the eutectic elements were achieved and the mechanisms of refinement were studied. In order to investigate the grain structure and solidification phenomena for each set of alloys, a TP-1 test, as well as thermal analysis, was performed and back scattered images were used to analyze the phases that may contribute to the grain refinement. It appears that the significant grain refinement of peritectic elements is due to the formation of in-situ properitectic particles and their appropriate constitutional undercooling. The results suggest that the availability of potent nuclei and exogenous particles play major roles in the grain refinement efficiency. However, in the case of eutectic elements only segregation power contributes to refinement whilst the availability of potent nuclei is of paramount importance.

  16. Data supporting the prediction of the properties of eutectic organic phase change materials.

    Science.gov (United States)

    Kahwaji, Samer; White, Mary Anne

    2018-04-01

    The data presented in this article include the molar masses, melting temperatures, latent heats of fusion and temperature-dependent heat capacities of fifteen fatty acid phase change materials (PCMs). The data are used in conjunction with the thermodynamic models discussed in Kahwaji and White (2018) [1] to develop a computational tool that calculates the eutectic compositions and thermal properties of eutectic mixtures of PCMs. The computational tool is part of this article and consists of a Microsoft Excel® file available in Mendeley Data repository [2]. A description of the computational tool along with the properties of nearly 100 binary mixtures of fatty acid PCMs calculated using this tool are also included in the present article. The Excel® file is designed such that it can be easily modified or expanded by users to calculate the properties of eutectic mixtures of other classes of PCMs.

  17. Metales traza en sedimentos de la Bahía de Cayo Moa (Cuba). Una evaluación de la contaminación

    OpenAIRE

    Yosbanis M. Cervantes-Guerra; Yuri Almaguer-Carmenates; Allan Pierra-Conde; Gerardo Orozco-Melgar; Hans-Juergen Gursky

    2011-01-01

    En este artículo se evalúan los niveles de cuatro elementos traza: arsénico (As), cobre (Cu), plomo (Pb) y zinc (Zn) en sedimentos superficiales de la bahía de Cayo Moa, en la cual la actividad humana ha incidido desde mediados del pasado siglo, paralelamente al desarrollo de una de las regiones mineras más importante de Cuba. Para evaluar el grado de contaminación de los sedimentos se utilizaron tres métodos fundamentales: la comparación con otros ecosistemas marinos, la determinación del ni...

  18. Structural and phonon transmission study of Ge-Au-Ge eutectically bonded interfaces

    International Nuclear Information System (INIS)

    Knowlton, W.B.; Lawrence Berkeley Lab., CA

    1995-07-01

    This thesis presents a structural analysis and phonon transparency investigation of the Ge-Au-Ge eutectic bond interface. Interface development was intended to maximize the interfacial ballistic phonon transparency to enhance the detection of the dark matter candidate WIMPs. The process which was developed provides an interface which produces minimal stress, low amounts of impurities, and insures Ge lattice continuity through the interface. For initial Au thicknesses of greater than 1,000 angstrom Au per substrate side, eutectic epitaxial growth resulted in a Au dendritic structure with 95% cross sectional and 90% planar Au interfacial area coverages. In sections in which Ge bridged the interface, lattice continuity across the interface was apparent. Epitaxial solidification of the eutectic interface with initial Au thicknesses < 500 A per substrate side produced Au agglomerations thereby reducing the Au planar interfacial area coverage to as little as 30%. The mechanism for Au coalescence was attributed to lateral diffusion of Ge and Au in the liquid phase during solidification. Phonon transmission studies were performed on eutectic interfaces with initial Au thicknesses of 1,000 angstrom, 500 angstrom, and 300 angstrom per substrate side. Phonon imaging of eutectically bonded samples with initial Au thicknesses of 300 angstrom/side revealed reproducible interfacial percent phonon transmissions from 60% to 70%. Line scan phonon imaging verified the results. Phonon propagation TOF spectra distinctly showed the predominant phonon propagation mode was ballistic. This was substantiated by phonon focusing effects apparent in the phonon imaging data. The degree of interface transparency to phonons and resulting phonon propagation modes correlate with the structure of the interface following eutectic solidification. Structural studies of samples with initial Au thickness of 1,000 angstrom/side appear to correspond with the phonon transmission study

  19. Transformation of eutectic emulsion to nanosuspension fabricating with solvent evaporation and ultrasonication technique.

    Science.gov (United States)

    Phaechamud, Thawatchai; Tuntarawongsa, Sarun

    2016-01-01

    Eutectic solvent can solubilize high amount of some therapeutic compounds. Volatile eutectic solvent is interesting to be used as solvent in the preparation of nanosuspension with emulsion solvent evaporation technique. The mechanism of transformation from the eutectic emulsion to nanosuspension was investigated in this study. The 30% w/w ibuprofen eutectic solution was used as the internal phase, and the external phase is composed of Tween 80 as emulsifier. Ibuprofen nanosuspension was prepared by eutectic emulsion solvent evaporating method followed with ultrasonication. During evaporation process, the ibuprofen concentration in emulsion droplets was increased leading to a drug supersaturation but did not immediately recrystallize because of low glass transition temperature (T g) of ibuprofen. The contact angle of the internal phase on ibuprofen was apparently lower than that of the external phase at all times of evaporation, indicating that the ibuprofen crystals were preferentially wetted by the internal phase than the external phase. From calculated dewetting value ibuprofen crystallization occurred in the droplet. Crystallization of the drug was initiated with external mechanical force, and the particle size of the drug was larger due to Ostwald ripening. Cavitation force from ultrasonication minimized the ibuprofen crystals to the nanoscale. Particle size and zeta potential of formulated ibuprofen nanosuspension were 330.87±51.49 nm and -31.1±1.6 mV, respectively, and exhibited a fast dissolution. Therefore, the combination of eutectic emulsion solvent evaporation method with ultrasonication was favorable for fabricating an ibuprofen nanosuspension, and the transformation mechanism was attained successfully.

  20. DSC study and calculation of metronidazole and clarithromycin thermodynamic melting parameters for individual substances and for eutectic mixture

    International Nuclear Information System (INIS)

    Agafonova, Evgeniia V.; Moshchenskiy, Yuriy V.; Tkachenko, Mikhail L.

    2014-01-01

    Highlights: • The system clarithromycin–metronidazole is a system with a simple eutectic. • The eutectic melting temperature for the system clarithromycin–metronidazole is 155.2 ± 0.5 °C and it is not changed by varying the composition of the system. • The DSC curve for the composition of 89:11 mol or 64.9:35.1 wt% corresponds to the eutectic (or the invariant) composition for the system clarithromycin–metronidazole. - Abstract: In this study melting thermodynamic characteristics of clarithromycin and metronidazole as individual substances were investigated by DSC method. It was found that the binary system of clarithromycin and metronidazole is a system with simple eutectic. Composition, melting temperature and the heat of fusion of the eutectic were determined by calculation and experimental methods

  1. A potentiostatic and galvanostatic study of the selective dissolution of Cd/Pb eutectic alloy

    International Nuclear Information System (INIS)

    Sokharev, N.P.; Rabdel, A.A.; Zhadanov, V.V.

    1986-01-01

    The authors consider the selective dissolution (SD) of the electronegative component of a two-phase, eutectic alloy (Cd/Pb) under galvanostatic conditions. Treating this process as the extraction of a solid substance from a porous matrix, the distribution of the concentration of EC ions, c(x, t), can be described by a differential equation (presented). Experimental data are presented in two equations which are applicable for the description of the selective dissolution process of the electronegative component of a eutectic alloy under conditions of concentration polarization

  2. Eutectic reaction analysis between TRU-50%Zr alloy fuel and HT-9 cladding, and temperature prediction of eutectic reaction under steady-state

    International Nuclear Information System (INIS)

    Hwang, Woan; Lee, Byoung Oon; Lee, Bong Sang; Park, Won Seok

    2001-02-01

    Blanket fuel assembly for HYPER contains a bundle of pins arrayed in triangular pitch, which has hexagonal bundle structure. The reference blanket fuel pin consists of the fuel slug of TRU-50wt%Zr alloy and the cladding material of ferritic martensite steel, HT-9. Chemical interaction between fuel slug and cladding is one of the major concerns in metallic fuel rod design. The contact of metallic fuel slug and stainless steel cladding in a fuel rod forms a complex multi-component diffusion couple at elevated temperatures. The potential problem of inter-diffusion of fuel and cladding components is essentially two-fold weakening of cladding mechanical strength due to the formation of diffusion zones in the cladding, and the formation of comparatively low melting point phases in the fuel/cladding interface to develop eutectic reaction. The main components of fuel slug are composed of zirconium alloying element in plutonium matrix, including neptunium, americium and uranium additionally. Therefore basic eutectic reaction change of Pu-Fe binary system can be assessed, while it is estimated how much other elements zirconium, uranium, americium and neptunium influence on plutonium phase stability. Afterwards it is needed that eutectic reaction is verified through experimental necessarily

  3. Eutectic reaction analysis between TRU-50%Zr alloy fuel and HT-9 cladding, and temperature prediction of eutectic reaction under steady-state

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Woan; Lee, Byoung Oon; Lee, Bong Sang; Park, Won Seok

    2001-02-01

    Blanket fuel assembly for HYPER contains a bundle of pins arrayed in triangular pitch, which has hexagonal bundle structure. The reference blanket fuel pin consists of the fuel slug of TRU-50wt%Zr alloy and the cladding material of ferritic martensite steel, HT-9. Chemical interaction between fuel slug and cladding is one of the major concerns in metallic fuel rod design. The contact of metallic fuel slug and stainless steel cladding in a fuel rod forms a complex multi-component diffusion couple at elevated temperatures. The potential problem of inter-diffusion of fuel and cladding components is essentially two-fold weakening of cladding mechanical strength due to the formation of diffusion zones in the cladding, and the formation of comparatively low melting point phases in the fuel/cladding interface to develop eutectic reaction. The main components of fuel slug are composed of zirconium alloying element in plutonium matrix, including neptunium, americium and uranium additionally. Therefore basic eutectic reaction change of Pu-Fe binary system can be assessed, while it is estimated how much other elements zirconium, uranium, americium and neptunium influence on plutonium phase stability. Afterwards it is needed that eutectic reaction is verified through experimental necessarily.

  4. Dimethylurea/citric acid as a highly efficient deep eutectic solvent

    Indian Academy of Sciences (India)

    Dimethylurea/citric acid deep eutectic solvent was used as a dual catalyst and a green reaction medium for the efficient synthesis of bis(indolyl)methanes, quinolines and aryl-4, 5-diphenyl-1H-imidazoles. Ease of recovery and reusability of DES with high activity makes this method efficient and eco-friendly.

  5. Consolidation of B4C-TaB2 eutectic composites by spark plasma sintering

    Directory of Open Access Journals (Sweden)

    Dmytro Demirskyi

    2015-12-01

    Full Text Available The in situ synthesis/consolidation of B4C-TaB2 eutectic composites by spark plasma sintering (SPS is reported. The microstructure–property relations were determined for composites with the B4C-TaB2 eutectic composition as functions of TaB2 content, and TaB2-TaB2 interlamellar spacing. A clear maximum in fracture toughness was identified (∼4.5 MPa m1/2 for eutectic composites with interlamellar spacing between 0.9 and 1.1 μm. The composites with the hypereutectic composition of 40 mol.% TaB2 obtained by SPS exhibited lower Vickers hardness (25–26 GPa but higher indentation fracture toughness (up to 4.9 MPa m1/2 than eutectic composites with 30–35 mol.% of TaB2.

  6. The binary eutectic of NSAIDS and two-phase liquid system for enhanced membrane permeation.

    Science.gov (United States)

    Yuan, Xudong; Capomacchia, A C

    2005-01-01

    The eutectic properties of binary mixtures of some nonsteroidal anti-inflammatory drugs (NSAIDs) with ibuprofen were studied using differential scanning calorimetry (DSC) and phase equilibrium diagrams. The melting points of selected NSAIDs were significantly depressed due to binary eutectic formation with ibuprofen. Ketoprofen and ibuprofen were selected to study the effect of eutectic formation on membrane permeation using Franz diffusion cells and snake skin as the model membrane. The presence of aqueous isopropyl alcohol (IPA) was necessary to completely transform the solid drugs into an oily state at ambient temperature. As much as the 99.6% of ibuprofen and the 88.8% of ketoprofen added were found in the oily phase of the two-phase liquid system formed when aqueous IPA was added to the eutectic mixture. Due to the high drug concentration in the oily phase, and maximum thermodynamic activity, the two-phase liquid system showed enhanced membrane permeation rates of ibuprofen (37.5 microg/cm2/hr) and ketoprofen (33.4 microg/cm2/hr) compared to other reference preparations used.

  7. Optical, Electrochemical and Thermal Studies of Conjugated Polymers Synthesized by Eutectic Melt Reaction.

    Science.gov (United States)

    Bathula, Chinna; Buruga, Kezia; Kang, Youngjong; Khazi, Imtiyaz Ahmed M

    2017-05-01

    This paper reports on the synthesis of a novel donor-acceptor conjugated polymers, P1 and P2 by solvent free eutectic melt polymerization reaction. Triisopropylsilylethynyl(TIPS) substituted benzo[1,2-b:4,5-b']dithiophene(BDT) is used as donor, thienithiophene(TT) and thienopyrroledione(TPD) are utilized as acceptors for demonstrating eutectic polymerization. The most important fact in the solvent-free reaction between solid reactants actually proceeds through bulk liquid phases. Such liquid phases are possible due to the formation of eutectics between the reactants and product(s) and any evolution of heat. Naphthalene is explored in this reaction for forming eutectics with the reactants, resulting in desired polymers. Thermal stability, optical and electrochemical properties of these polymers were determined. Optical band gaps of the polymers were found to be 1.58 and 1.65 eV. Electrochemical studies by cyclic voltametry experiment revealed HOMO and LUMO energy levels to be -5.22, -5.60 eV, and -3.76, -4.16 eV, respectively. The polymers were thermally stable up to 285-400 °C. Thermal, optical and electrochemical studies indicated these materials to be promising candidates in organic electronic applications.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kadir Tuncbilek; Ahmet Sari [Gaziosmanpasa University, Tokat (Turkey). Dept. of Chemistry; Sefa Tarhan; Gazanfer Ergunes [Gaziosmanpasa University, Tokat (Turkey). Dept. of Agricultural Machinery; Kamil Kaygusuz [Karadeniz University, Trabzon (Turkey). Dept. of Chemistry

    2005-04-01

    Palmitic acid (PA, 59.8{sup o}C) and lauric acid (LA, 42.6{sup o}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 the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of 69.0 wt% LA and 31 wt% PA forms a eutectic mixture having melting temperature of 35.2 {sup o}C and the latent heat of fusion of 166.3 J g{sup -1}. This study also considers the experimental determination of the thermal characteristics of the eutectic mixture during the heat charging and discharging processes. Radial and axial temperature distribution, heat transfer coefficient between the heat transfer fluid (HTF) pipe and the PCM, heat recovery rate and heat charging and discharging fractions were experimentally established employing a vertical concentric pipe-in-pipe energy storage system. The changes of these characteristics were evaluated with respect to the effect of inlet HTF temperature and mass flow rate. The DSC thermal analysis and the experimental results indicate that the LA-PA eutectic mixture can be a potential material for low temperature thermal energy storage applications in terms of its thermo-physical and thermal characteristics. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Tuncbilek, K.; Sari, A. [Gaziosmanpasa Univ., Tokat (Turkey). Dept. of Chemistry; Tarhan, S.; Erguenes, G. [Gaziosmanpasa Univ., Tokat (Turkey). Dept. of Agricultural Machinery; Kaygusuz, K. [Karadeniz Technical Univ., Trabzon (Turkey). Dept. of Chemistry

    2005-04-01

    Palmitic acid (PA, 59.8 {sup o}C) and lauric acid (LA, 42.6 {sup o}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 the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of 69.0 wt% LA and 31 wt% PA forms a eutectic mixture having melting temperature of 35.2 {sup o}C and the latent heat of fusion of 166.3 J g{sup -1}. This study also considers the experimental determination of the thermal characteristics of the eutectic mixture during the heat charging and discharging processes. Radial and axial temperature distribution, heat transfer coefficient between the heat transfer fluid (HTF) pipe and the PCM, heat recovery rate and heat charging and discharging fractions were experimentally established employing a vertical concentric pipe-in-pipe energy storage system. The changes of these characteristics were evaluated with respect to the effect of inlet HTF temperature and mass flow rate. The DSC thermal analysis and the experimental results indicate that the LA-PA eutectic mixture can be a potential material for low temperature thermal energy storage applications in terms of its thermo-physical and thermal characteristics. (author)

  10. Dimethylurea/citric acid as a highly efficient deep eutectic solvent for ...

    Indian Academy of Sciences (India)

    Dimethylurea/citric acid deep eutectic solvent was used as a dual catalyst and a green reaction medium for the efficient synthesis of bis(indolyl)methanes, quinolines and aryl-4, 5-diphenyl-1H-imidazoles. Ease of recovery and reusability of DES with high activity makes this method efficient and eco-friendly.

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

    International Nuclear Information System (INIS)

    Townsend, A.B.

    1980-10-01

    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

  12. Lauric and myristic acids eutectic mixture as phase change material for low-temperature heating applications

    Energy Technology Data Exchange (ETDEWEB)

    Keles, Sadat; Kaygusuz, Kamil [Karadeniz Technical Univ., Dept. of Chemistry, Trabzon (Turkey); Sari, Ahmet [Gaziosmanpasa Univ., Dept. of Chemistry, Tokat (Turkey)

    2005-07-01

    Lauric acid (m.p.: 42.6 deg C) and myristic acid (m.p.: 52.2 deg C) are phase change materials (PCM) having quite high melting points 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 lauric acid (LA) and myristic acid (MA). In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of 66.0 wt% LA forms a eutectic mixture having melting temperature of 34.2 deg C and the latent heat of fusion of 166.8 J g{sup -1} . This study also considers the experimental establishment of thermal characteristics of the eutectic PCM in a vertical concentric pipe-in-pipe heat storage system. Thermal performance of the PCM was evaluated with respect to the effect of inlet temperature and mass flow rate of the heat transfer fluid on those characteristics during the heat charging and discharging processes. The DSC thermal analysis and the experimental results indicate that the LA-MA eutectic PCM can be potential material for low-temperature solar energy storage applications in terms of its thermo-physical and thermal characteristics. (Author)

  13. Phase Evolution in and Creep Properties of Nb-Rich Nb-Si-Cr Eutectics

    Science.gov (United States)

    Gang, Florian; Kauffmann, Alexander; Heilmaier, Martin

    2018-03-01

    In this work, the Nb-rich ternary eutectic in the Nb-Si-Cr system has been experimentally determined to be Nb-10.9Si-28.4Cr (in at. pct). The eutectic is composed of three main phases: Nb solid solution (Nbss), β-Cr2Nb, and Nb9(Si,Cr)5. The ternary eutectic microstructure remains stable for several hundred hours at a temperature up to 1473 K (1200 °C). At 1573 K (1300 °C) and above, the silicide phase Nb9(Si,Cr)5 decomposes into α-Nb5Si3, Nbss, and β-Cr2Nb. Under creep conditions at 1473 K (1200 °C), the alloy deforms by dislocation creep while the major creep resistance is provided by the silicide matrix. If the silicide phase is fragmented and, thus, its matrix character is destroyed by prior heat treatment [ e.g., at 1773 K (1500 °C) for 100 hours], creep is mainly controlled by the Laves phase β-Cr2Nb, resulting in increased minimum strain rates. Compared to state of the art Ni-based superalloys, the creep resistance of this three-phase eutectic alloy is significantly higher.

  14. Dimethylurea/citric acid as a highly efficient deep eutectic solvent for ...

    Indian Academy of Sciences (India)

    Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, 76169, Iran e-mail: hkhabazzadeh@uk.ac.ir. MS received 27 October 2013; revised 13 January 2014; accepted 17 January 2014. Abstract. Dimethylurea/citric acid deep eutectic solvent was used as a dual catalyst and a green reaction medium for ...

  15. Free energy change of off-eutectic binary alloys on solidification

    Science.gov (United States)

    Ohsaka, K.; Trinh, E. H.; Lin, J.-C.; Perepezko, J. H.

    1991-01-01

    A formula for the free energy difference between the undercooled liquid phase and the stable solid phase is derived for off-eutectic binary alloys in which the equilibrium solid/liquid transition takes place over a certain temperature range. The free energy change is then evaluated numerically for a Bi-25 at. pct Cd alloy modeled as a sub-subregular solution.

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

    DEFF Research Database (Denmark)

    Lewis, Alison E.; Nathoo, J.; Thomsen, Kaj

    2010-01-01

    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...

  17. Review of possible experiments in the eutectic growth and thermodiffusion fields

    International Nuclear Information System (INIS)

    Malmejac, Yves.

    1976-01-01

    The results now available from the SKYLAB and ASTP programmes give a clearer indication of the lines of the research to pursue in the years to come. The criteria necessary for the choice of experiments are analysed in the fields of eutectic solidification and diffusion along a temperature gradient in liquid alloys [fr

  18. Luminescence and scintillation properties of Ce dope SrHfO.sub.3./sub. based eutectics

    Czech Academy of Sciences Publication Activity Database

    Kamada, K.; Kurosawa, S.; Shoji, Y.; Pejchal, Jan; Ohashi, Y.; Yokota, Y.; Yoshikawa, A.

    2015-01-01

    Roč. 41, Mar SI (2015), s. 41-44 ISSN 0925- 3467 R&D Projects: GA MŠk(CZ) LH14266 EU Projects: European Commission(XE) 316906 - LUMINET Institutional support: RVO:68378271 Keywords : scintillator * eutectic * micro pulling down method * Ce 3+ Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2015

  19. Coupled growth of Al-Al2Cu eutectics in Al-Cu-Ag alloys

    International Nuclear Information System (INIS)

    Hecht, U; Witusiewicz, V; Drevermann, A

    2012-01-01

    Coupled eutectic growth of Al and Al 2 Cu was investigated in univariant Al-Cu-Ag alloys during solidification with planar and cellular morphology. Experiments reveal the dynamic selection of small spacings, below the minimum undercooling spacing and show that distinct morphological features pertain to nearly isotropic or anisotropic Al-Al 2 Cu interfaces.

  20. Synthesis and characterization of novel binary organic monotectic and eutectic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, K.P. [Department of Chemistry, Center of Advanced Study, Banaras Hindu University, Varanasi 221 005 (India); Rai, R.N., E-mail: rn_rai@yahoo.co.in [Department of Chemistry, Center of Advanced Study, Banaras Hindu University, Varanasi 221 005 (India)

    2012-05-10

    Highlights: Black-Right-Pointing-Pointer The two novel phase diagrams of binary organic systems were studied. Black-Right-Pointing-Pointer The various thermodynamic functions have been calculated. Black-Right-Pointing-Pointer The optical microphotograph of monotectic shows lamellar structure. Black-Right-Pointing-Pointer Growth kinetics of binary materials at different under cooling were studied. Black-Right-Pointing-Pointer The relations between interfacial energies satisfy the Cahn's wetting condition. - Abstract: The phase diagram of biphenyl - 3-hydroxybenzaldehyde (BP-HB) shows the formation of a eutectic with HB-0.935 mole% BP and 4-bromochlorobenzene -m-aminophenol (BCB-AP) show the formation of a monotectic (AP-0.150 mole% BCB) and a eutectic (AP-0.996 mole% BCB). The BCB-AP shows large miscibility gap where the consolute temperature is 12.5 Degree-Sign C above the monotectic horizontal. Growth kinetics of pure components, the eutectics and the monotectic were studied by measuring the rate of movement of the solid-liquid interface which suggests the applicability of Hillig-Turnbull's equation. The thermodynamic functions such as heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions were calculated from the enthalpy of fusion values, determined by the DSC method. The relation between interfacial energies of monotectic system satisfies the Cahn's wetting condition. The optical microphotograph of monotectic shows lamellar structure whereas eutectics show broken lamellar and lamellar pearlite structures.

  1. Eutectic melting temperature of the lowermost Earth's mantle

    Science.gov (United States)

    Andrault, D.; Lo Nigro, G.; Bolfan-Casanova, N.; Bouhifd, M.; Garbarino, G.; Mezouar, M.

    2009-12-01

    Partial melting of the Earth's deep mantle probably occurred at different stages of its formation as a consequence of meteoritic impacts and seismology suggests that it even continues today at the core-mantle boundary. Melts are important because they dominate the chemical evolution of the different Earth's reservoirs and more generally the dynamics of the whole planet. Unfortunately, the most critical parameter, that is the temperature profile inside the deep Earth, remains poorly constrained accross the planet history. Experimental investigations of the melting properties of materials representative of the deep Earth at relevant P-T conditions can provide anchor points to refine past and present temperature profiles and consequently determine the degree of melting at the different geological periods. Previous works report melting relations in the uppermost lower mantle region, using the multi-anvil press [1,2]. On the other hand, the pyrolite solidus was determined up to 65 GPa using optical observations in the laser-heated diamond anvil cell (LH-DAC) [3]. Finally, the melting temperature of (Mg,Fe)2SiO4 olivine is documented at core-mantle boundary (CMB) conditions by shock wave experiments [4]. Solely based on these reports, experimental data remain too sparse to draw a definite melting curve for the lower mantle in the relevant 25-135 GPa pressure range. We reinvestigated melting properties of lower mantle materials by means of in-situ angle dispersive X-ray diffraction measurements in the LH-DAC at the ESRF [5]. Experiments were performed in an extended P-T range for two starting materials: forsterite and a glass with chondrite composition. In both cases, the aim was to determine the onset of melting, and thus the eutectic melting temperatures as a function of pressure. Melting was evidenced from drastic changes of diffraction peak shape on the image plate, major changes in diffraction intensities in the integrated pattern, disappearance of diffraction rings

  2. Deep eutectic solvents: sustainable media for nanoscale and functional materials.

    Science.gov (United States)

    Wagle, Durgesh V; Zhao, Hua; Baker, Gary A

    2014-08-19

    Deep eutectic solvents (DESs) represent an alternative class of ionic fluids closely resembling room-temperature ionic liquids (RTILs), although, strictly speaking, they are distinguished by the fact that they also contain an organic molecular component (typically, a hydrogen bond donor like a urea, amide, acid, or polyol), frequently as the predominant constituent. Practically speaking, DESs are attractive alternatives to RTILs, sharing most of their remarkable qualities (e.g., tolerance to humidity, negligible vapor pressure, thermostability, wide electrochemical potential windows, tunability) while overcoming several limitations associated with their RTIL cousins. Particularly, DESs are typically, less expensive, more synthetically accessible (typically, from bulk commodity chemicals using solvent/waste-free processes), nontoxic, and biodegradable. In this Account, we provide an overview of DESs as designer solvents to create well-defined nanomaterials including shape-controlled nanoparticles, electrodeposited films, metal-organic frameworks, colloidal assemblies, hierarchically porous carbons, and DNA/RNA architectures. These breakthroughs illustrate how DESs can fulfill multiple roles in directing chemistry at the nanoscale: acting as supramolecular template, metal/carbon source, sacrificial agent (e.g., ammonia release from urea), and/or redox agent, all in the absence of formal stabilizing ligand (here, solvent and stabilizer are one and the same). The ability to tailor the physicochemical properties of DESs is central to controlling their interfacial behavior. The preorganized "supramolecular" nature of DESs provides a soft template to guide the formation of bimodal porous carbon networks or the evolution of electrodeposits. A number of essential parameters (viscosity, polarity, surface tension, hydrogen bonding), plus coordination with solutes/surfaces, all play significant roles in modulating species reactivity and mass transport properties governing the

  3. Sustainable Poly(Ionic Liquids) for CO2 Capture Based on Deep Eutectic Monomers

    KAUST Repository

    Isik, Mehmet

    2016-10-05

    The design of high performance solid sorbent materials for CO2 capture is a technology which has been employed to mitigate global warming. However, the covalent incorporation of functionalities into polymeric supports usually involves multistep energy-intensive chemical processes. This fact makes the net CO2 balance of the materials negative even though they possess good properties as CO2 sorbents. Here we show a new family of polymers which are based on amines, amidoximes, and natural carboxylic acids and can be obtained using sustainable low energy processes. Thus, deep eutectic monomers based on natural carboxylic acids, amidoximes, and amines have been prepared by just mixing with cholinium type methacrylic ammonium monomer. The formation of deep eutectic monomers was confirmed by differential scanning calorimetry measurements. In all cases, the monomers displayed glass transition temperatures well below room temperature. Computational studies revealed that the formation of eutectic complexes lengthens the distance between the cation and the anion causing charge delocalization. The liquid nature of the resulting deep eutectic monomers (DEMs) made it possible to conduct a fast photopolymerization process to obtain the corresponding poly(ionic liquids). Materials were characterized by means of nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction to evaluate the properties of the polymers. The polymers were then used as solid sorbents for CO2 capture. It has been shown that the polymers prepared with citric acid displayed better performance both experimentally and computationally. The current endeavor showed that sustainable poly(ionic liquids) based on deep eutectic monomers can be easily prepared to produce low-energy-cost alternatives to the materials currently being researched for CO2 capture. © 2016 American Chemical Society.

  4. Metales traza en sedimentos de la Bahía de Cayo Moa (Cuba. Una evaluación de la contaminación

    Directory of Open Access Journals (Sweden)

    Yosbanis M. Cervantes-Guerra

    2011-12-01

    Full Text Available En este artículo se evalúan los niveles de cuatro elementos traza: arsénico (As, cobre (Cu, plomo (Pb y zinc (Zn en sedimentos superficiales de la bahía de Cayo Moa, en la cual la actividad humana ha incidido desde mediados del pasado siglo, paralelamente al desarrollo de una de las regiones mineras más importante de Cuba. Para evaluar el grado de contaminación de los sedimentos se utilizaron tres métodos fundamentales: la comparación con otros ecosistemas marinos, la determinación del nivel de enriquecimiento metálico mediante el cálculo del Factor de Contaminación, y la interpretación de los datos obtenidos con base en criterios de calidad. El rango de concentraciones varió entre 7-153 µgg-1 para As, 18-175 µgg-1 para Cu, 5-62 µgg-1 para Pb y de 46-527 µgg-1 para el Zn. La distribución espacial de las concentraciones mostró valores altos en toda la bahía y zonas aledañas, con variaciones según el elemento analizado; los mayores niveles de As se encontraron en las desembocaduras de los ríos Moa y Cayo Guam. El Cu, Pb y Zn están en mayor proporción en el interior de la bahía, específicamente en el punto P5, aunque en los puntos ubicados en el sur de Cayo Moa Grande los valores de estos contaminantes fueron también elevados. Los resultados muestran una elevada concentración de As, Cu, Pb y Zn; los niveles de contaminación revelados en este estudio permiten clasificar algunos puntos analizados como altamente contaminados o con un potencial de riesgo biológico alto.

  5. THE INFLUENCE OF HEAT TREATMENT WITH THE LIQUID PHASE ON FORMATION OF A MICROSTRUCTURE OF EUTECTIC Al-Si-ALLOY

    Directory of Open Access Journals (Sweden)

    A. Anikin

    2015-01-01

    Full Text Available The effect of heat treatment on the structure of the eutectic Al-Si-alloy, a theoretical substantiation process based on thermal analyzer and cooked microstructures was presented in this paper.

  6. Growth and scintillation properties of Eu doped BaCl.sub.2./sub./LiF eutectic scintillator

    Czech Academy of Sciences Publication Activity Database

    Kamada, K.; Hishinuma, K.; Kurosawa, S.; Yamaji, A.; Shoji, Y.; Pejchal, Jan; Yokota, Y.; Ohashi, Y.; Yoshikawa, A.

    2015-01-01

    Roč. 50, Dec (2015), 76-80 ISSN 0925- 3467 Institutional support: RVO:68378271 Keywords : scintillator * eutectic * micro-pulling down Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2015

  7. Particularidades geológicas del complejo ofiolítico de Moa a partir de los datos aeromagnéticos 1:50 000

    Directory of Open Access Journals (Sweden)

    Alina Rodríguez-Infante

    2000-03-01

    Full Text Available En este artículo se presentan los resultados obtenidos de la interpretación de los datos aeromagnéticos a escala 1:50000 de la secuencia ofiolítica de la región de Moa.Los datos fueron reducidos al polo, lo que permitió obtener un mapa de anomalías magnéticas más sencillo y representativo de las heterogeneidades geológicas presentes en el área de estudio. A partir de esta interpretación se ubicaron las zonas de posible desarrollo de alteraciones hidrotermales, se establecieron las variaciones espaciales de los diferentes tipos litológicos y de los espesores de las rocas ultrabásicas serpentinizadas, se delimitaron los posibles frentes de escamas de cabalgamientos y se aportaron nuevos elementos a considerar durante la prospección de cromita.

  8. Effects of sewage contamination on macro-algae and shellfish at Moa Point, New Zealand, using stable carbon and nitrogen isotopes

    International Nuclear Information System (INIS)

    Rogers, K.M.

    1999-01-01

    Stable carbon and nitrogen isotopes have been used to characterise sewage discharge and effects on seaweed (Ulva lactuca L.), blue mussels (Mytilus galloprovincialis), and limpets (Cellana denticulata) from Moa Point Bay, New Zealand. The nitrogen ( 15 N / 14 N) ratio is shown to be a good tracer of sewage pollution in Ulva lactuca and associated grazers (Cellana denticulata) as a result of the increased contribution of urea and ammonia to the surrounding marine environment from the sewage outfall. The carbon ( 13 C / 12 C) ratio is suggested as a more appropriate sewer tracer for mussels (Mytilus galloprovincialis), which filter feed the particulate organic matter from the effluent. Lower carbon : nitrogen ratios were found in U. lactuca sampled from the outfall region, compared to uncontaminated control sites, however carbon : nitrogen ratios do not vary significantly amongst shellfish species. (author). 18 refs., 4 figs., 2 tabs

  9. On the performance of a novel grain refiner in hyper-eutectic Al-Si cast alloys

    OpenAIRE

    Bolzoni, L; Nowak, M; Hari Babu, N

    2014-01-01

    The stringent requirements for pollution reduction are pushing the automotive industry towards the employment of lightweight structures and, therefore, aluminium and its alloys play a remarkable role. Al-Si casting alloy with eutectic or hyper- eutectic compositions are, normally, employed for the production of high performance automotive products such as pistons and engine blocks which have to withstand critical loading conditions (i.e. high temperature, high pressure and corrosive exhaust g...

  10. Flux flow and proximity effects in aligned Pb--Cd eutectic lamellar structures

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, C. R.

    1977-09-01

    A high speed directional solidification technique was used to fabricate lamellar Pb-Cd and (Pb-Mg)--(Cd-Mg) superconductor-normal metal composites in which all the lamellae are oriented perpendicular to the broad surface of the sample. These lamellar composites are found to behave like a large number (approximately 1000) of superconducting-normal-superconducting junctions. For the Pb-Cd eutectic system, the critical current densities and critical fields have shown no dependence upon the lamellar periods between 1.0 and 3.1 microns. The critical current density of the aligned lamellar Pb-Cd structures was enhanced approximately 50% when compared to quenched eutectic alloy and to pure Pb. The superconducting transition temperature, T/sub c/, varies inversely with the square of the thickness of the superconducting material as expected from Ginzburg-Landau theory. Upon annealing, the Pb lamellae change from type II to type I superconductivity.

  11. Filtration of aluminum alloys and its influence on mechanical properties and shape of eutectical silicium

    Directory of Open Access Journals (Sweden)

    M. Brůna

    2008-07-01

    Full Text Available Filtration during casting of high quality aluminum alloys belongs to main refining methods. Even when there are many years of experiences and experimental works on this subject, there are still some specific anomalies. While using ceramic filtration media during casting of aluminum alloys, almost in all experiments occurred increase of strength limit and atypical increase of extension. This anomaly was not explained with classical metallurgical methods, black-white contrast after surface etching neither with color surface etching. For that reason was used deep etching on REM. By using pressed ceramic filters, by studying morphology eutectical silicon was observed modification morphology of eutectical silicon, this explains increase extension after filtration. Pressed ceramic filters were used on experimental works. Casting was executed on hardenable alloy AlSi10MgMn.

  12. Flux flow and proximity effects in aligned Pb--Cd eutectic lamellar structures

    International Nuclear Information System (INIS)

    Spencer, C.R.

    1977-09-01

    A high speed directional solidification technique was used to fabricate lamellar Pb-Cd and (Pb-Mg)--(Cd-Mg) superconductor-normal metal composites in which all the lamellae are oriented perpendicular to the broad surface of the sample. These lamellar composites are found to behave like a large number (approximately 1000) of superconducting-normal-superconducting junctions. For the Pb-Cd eutectic system, the critical current densities and critical fields have shown no dependence upon the lamellar periods between 1.0 and 3.1 microns. The critical current density of the aligned lamellar Pb-Cd structures was enhanced approximately 50% when compared to quenched eutectic alloy and to pure Pb. The superconducting transition temperature, T/sub c/, varies inversely with the square of the thickness of the superconducting material as expected from Ginzburg-Landau theory. Upon annealing, the Pb lamellae change from type II to type I superconductivity

  13. Kinetic and thermophysical studies of acetamide-sodium bromide eutectic for low temperature storage applications

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K.; Sethi, B.P.S.; Chopra, Suneeta (Panjab Univ., Chandigarh (IN). Energy Research Centre)

    1992-02-01

    The kinetics of thermal decomposition of acetamide-sodium bromide using a Differential Scanning Calorimeter and a Differential Thermogravimetric Analyser have been reported. The kinetic parameters have been evaluated using Zsako's method using 10 different mechanisms, such as nucleation, nuclei growth and diffusion. The thermophysical properties, such as density and viscosity, which have a profound effect on the design of the heat exchanger and crystallization have been evaluated and reported. The results show that the eutectic has favourable characteristics, namely low volume change, high energy storage density, high heat of fusion, good thermal stability and favourable crystallization characteristics. The eutectic could find use in thermal energy storage applications for commercial and laundry water heating, process heating hot water, process heating hot air, crop drying and food warming in the hotel industry. (Author).

  14. Chip bonding of low-melting eutectic alloys by transmitted laser radiation

    Science.gov (United States)

    Hoff, Christian; Venkatesh, Arjun; Schneider, Friedrich; Hermsdorf, Jörg; Bengsch, Sebastian; Wurz, Marc C.; Kaierle, Stefan; Overmeyer, Ludger

    2017-06-01

    Present-day thermode bond systems for the assembly of radio-frequency identification (RFID) chips are mechanically inflexible, difficult to control, and will not meet future manufacturing challenges sufficiently. Chip bonding, one of the key processes in the production of integrated circuits (ICs), has a high potential for optimization with respect to process duration and process flexibility. For this purpose, the technologies used, so far, are supposed to be replaced by a transmission laser-bonding process using low-melting eutectic alloys. In this study, successful bonding investigations of mock silicon chips and of RFID chips on flexible polymer substrates are presented using the low-melting eutectic alloy, 52In48Sn, and a laser with a wavelength of 2 μm.

  15. Phase-field-lattice Boltzmann study for lamellar eutectic growth in a natural convection melt

    Directory of Open Access Journals (Sweden)

    Ang Zhang

    2017-11-01

    Full Text Available In the present study, the influence of natural convection on the lamellar eutectic growth is determined by a phase-field-lattice Boltzmann study for Al-Cu eutectic alloy. The mass difference resulting from concentration difference led to the fluid flow, and a robust parallel and adaptive mesh refinement algorithm was employed to improve the computational efficiency without any compromising accuracy. Results show that the existence of natural convection would affect the growth undercooling and thus control the interface shape by adjusting the lamellar width. In particular, by alternating the magnitude of the solute expansion coefficient, the strength of the natural convection is changed. Corresponding microstructure patterns are discussed and compared with those under no-convection conditions.

  16. Directional solidification of Zn-Al-Cu eutectic alloy by the vertical Bridgman method

    Directory of Open Access Journals (Sweden)

    Büyük U.

    2015-01-01

    Full Text Available In the present work, the effect of growth rate and temperature gradient on microstructure and mechanical properties of Zn-7wt.%Al-4wt.%Cu eutectic alloy has been investigated. Alloys prepared under steady-state conditions by vacuumed hot filing furnace. Then, the alloys were directionally solidified upward with different growth rates (V=11.62-230.77 mm/s at a constant temperature gradient (G=7.17 K/mm and with different temperature gradients (G=7.17-11.04 K/mm at a constant growth rate (V=11.62 mm/s by a Bridgman furnace. The microstructures were observed to be lamellae of Zn, Al and broken lamellae CuZn4 phases from quenched samples. The values of eutectic spacing, microhardness and ultimate tensile strength of alloys were measured. The dependency of the microstructure and mechanical properties on growth rate and temperature gradient were investigated using regression analysis.

  17. Eutectic phases in water-ice : an efficient medium for biopolymerization

    DEFF Research Database (Denmark)

    Monnard, Pierre-Alain; Dörr, Mark; Löffler, Philipp M. G.

    2011-01-01

    bodies might therefore hint at either emerging, or extant, or past life. The non-enzymatic synthesis of such polymeric materials or their precursors likely had to rely on a supply of monomers dissolved at low concentrations in an aqueous medium. This environment represents a clear hurdle to the synthesis...... of long polymers as it tends to inhibit polymerization due to entropic effects and favors the reverse reaction (decomposition by hydrolysis). It was therefore proposed that polymerization could occur in a distinct micro- or nanostructured environment that would permit a local increase in the monomer...... concentration, reduce water activity and protect monomers as well as polymers from hydrolysis. Several types of micro- or nanostructured environments, among them the eutectic phase in water-ice have been proposed to promote RNA and peptide oligomer formation. The eutectic phase might be of particular interest...

  18. The effect of the electrode material on the electrodeposition of zinc from deep eutectic solvents

    International Nuclear Information System (INIS)

    Vieira, L.; Schennach, R.; Gollas, B.

    2016-01-01

    Highlights: • Mechanistic insight into zinc electrodeposition from deep eutectic solvents. • Overpotential for hydrogen evolution affects the electrodeposition of zinc. • Electrodeposited zinc forms surface alloys on Cu, Au, and Pt. • In situ PM-IRRAS of a ZnCl 2 containing deep eutectic solvent on glassy carbon. - Abstract: The voltammetric behaviour of the ZnCl 2 containing deep eutectic solvent choline chloride/ethylene glycol 1:2 was investigated on glassy carbon, stainless steel, Au, Pt, Cu, and Zn electrodes. While cyclic voltammetry on glassy carbon and stainless steel showed a cathodic peak for zinc electrodeposition only in the anodic reverse sweep, a cathodic peak was found also in the cathodic forward sweep on Au, Pt, Cu, and Zn. This behaviour is in agreement with the proposed mechanism of zinc deposition from an intermediate species Z, whose formation depends on the cathodic reduction potential of the solvent. The voltammetric reduction of the electrolyte involves hydrogen evolution and as a result the formation of Z and its reduction to zinc depend on the hydrogen overpotential for each electrode material. On Au, Pt, and Cu also the anodic stripping was different from that on glassy carbon and steel due to the formation of surface zinc alloys with the three former metals. The morphology of the zinc layers on Cu has been characterised by scanning electron microscopy and focussed ion beam. X-ray diffraction confirmed the presence of crystalline zinc and a Cu 4 Zn phase. Spectroelectrochemistry by means of polarization modulation reflection-absorption spectroscopy (PM-IRRAS) on a glassy carbon electrode in the ZnCl 2 containing deep eutectic solvent showed characteristic potential dependent changes. The variation of band intensities at different applied potentials correlate with the voltammetry and suggest the formation of a compact blocking layer on the electrode surface, which inhibits the electrodeposition of zinc at sufficiently negative

  19. High-Operating-Temperature Direct Ink Writing of Mesoscale Eutectic Architectures.

    Science.gov (United States)

    Boley, J William; Chaudhary, Kundan; Ober, Thomas J; Khorasaninejad, Mohammadreza; Chen, Wei Ting; Hanson, Erik; Kulkarni, Ashish; Oh, Jaewon; Kim, Jinwoo; Aagesen, Larry K; Zhu, Alexander Y; Capasso, Federico; Thornton, Katsuyo; Braun, Paul V; Lewis, Jennifer A

    2017-02-01

    High-operating-temperature direct ink writing (HOT-DIW) of mesoscale architectures that are composed of eutectic silver chloride-potassium chloride. The molten ink undergoes directional solidification upon printing on a cold substrate. The lamellar spacing of the printed features can be varied between approximately 100 nm and 2 µm, enabling the manipulation of light in the visible and infrared range. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Temperature-dependent viscosities of eutectic Al-Si alloys modified with Sr and P

    Energy Technology Data Exchange (ETDEWEB)

    Song Xigui [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China)], E-mail: sxglm@126.com; Bian Xiufang; Zhang Jingxiang; Zhang Jie [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan, 250061 (China)

    2009-06-24

    The viscosities of eutectic Al-12 wt.%Si alloy and those modified with Sr and P were investigated using high-temperature torsional oscillation viscometer. Strontium decreased melt's viscosity, while phosphorus increased viscosity. Both additional level and means of addition affected the variation of viscosity. The activation energy of viscous flow was strengthened after modification, but the influence of modification on the molar volume was perplexing.

  1. Experimental investigation of thermophysical properties of eutectic Re-C at high temperatures

    Science.gov (United States)

    Belikov, R. S.; Senchenko, V. N.; Sulyanov, S. N.

    2018-01-01

    Using the previously described experimental setup for investigation of thermophysical properties of refractory materials under high pressures and temperatures a few experiments with samples of cast eutectic Re-C were carried out. The experimental technique was extended for millisecond electrical heating of the samples under the high static pressure of inert gas. First experimental data on the specific enthalpy, specific heat capacity and linear thermal expansion of ReC0.3 were obtained.

  2. Chemical and electrochemical properties in the molten lithium chloride-potassium chloride eutectic

    International Nuclear Information System (INIS)

    Delarue, G.

    1960-12-01

    We have studied the behaviour of several chemical species in the molten LiCI-KCI eutectic. The solubility of certain oxides and sulphides has made it possible for us to show the existence of O 2- and S 2- ions. We have been able to show the existence of a certain number of chemical reactions: oxido-reduction precipitation, complex formation; we have studied, amongst others, the oxidation of O 2- and of S 2- . (author) [fr

  3. Continuous sodium modification of nearly-eutectic aluminium alloys. Part I. Theoretical backgrounds of the process

    Directory of Open Access Journals (Sweden)

    Białobrzeski A.

    2007-01-01

    Full Text Available One of the possible techniques of continuous sodium modification of nearly-eutectic alloys is continuous electrolysis of sodium compounds (salts, taking place directly in metal bath (in crucible. For this process it is necessary to use a solid electrolyte conducting sodium ions. The main properties and methods to obtain solid electrolyte of „beta alumina” were highlighted, along with the possibilities of its application in foundry metallurgical processes.

  4. A comparative study on the compatibility of liquid lead–gold eutectic and liquid lead–bismuth eutectic with T91 and SS 316LN steels

    International Nuclear Information System (INIS)

    Dai, Y.; Gao, W.; Zhang, T.; Platacis, E.; Heinitz, S.; Thomsen, K.

    2012-01-01

    Liquid lead–gold eutectic (LGE) is considered as a potential target material for high power spallation sources. In the present work, the corrosion effects of LGE on T91 and SS 316LN steels have been investigated in comparison with that of liquid lead–bismuth eutectic (LBE) under the same testing conditions. Two tests were conducted at 400 °C for 1800 h and at 450 °C for 1300 h, in which specimens of the two steels were exposed to 1 m/s flowing LGE and LBE. Surface inspections showed that the specimens underwent a mixed corrosion mode of dissolution and oxidation. The results obtained from the SS 316LN specimens are very interesting. Firstly, EDX (electron energy dispersion X-ray spectrometry) analyses revealed that Ni, Cr and Mn have a higher dissolution rate in LGE than in LBE. Secondly, it was observed that LBE attacked strongly on grain-boundaries (GBs) and twin-boundaries (TBs), while LGE did not preferentially attack GBs and TBs. Further, the diffusion or penetration paths of LBE look straight, while those of LGE look like a complex network. In the attacked regions the chemical composition of the steel did not change much in the LBE case, but changed greatly in the LGE case. The T91 specimens exhibited considerably weaker corrosion effects under the present testing conditions.

  5. Experimental specifications for eutectic reaction between metallic fuel and HT-9

    International Nuclear Information System (INIS)

    Hwang, Woan; Nam, Cheol; Lee, Byoung Oon; Ryu, Woo Seog

    1998-10-01

    The chemical interaction between metallic fuel and cladding is important in designing the fuel pin of the KALIMER. When metal fuel and cladding are contacted, the elements in fuel and cladding are inter-diffuse each other, forming the reaction layers at interface. The reaction layers may cause two important factors in aspects of fuel pin integrity. Firstly, it degrades cladding strength by reducing effective cladding thickness. Secondly, these layers accelerate eutectic reaction at transient conditions. To evaluate these phenomena, the diffusion couple experiment is planned by using metal fuels with various zirconium contents and HT-9 steel. The U-Zr fuel alloys will be used for the experiment with the different zirconium contents, these are 8, 10 and 12 weight %. This experiment aims to evaluate the effects of zirconium content on the chemical reaction. Furthermore, the reaction rate and threshold temperature of the eutectic melting will be determined as a function of the zirconium content. This document describes the detail experimental specifications for the eutectic reaction such as test setup, test requirements and test procedure. (author). 10 refs

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

    Science.gov (United States)

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

    2012-01-01

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

  7. Development of sunlight-driven eutectic phase change material nanocomposite for applications in solar water heating

    Directory of Open Access Journals (Sweden)

    S. Shankara Narayanan

    2017-09-01

    Full Text Available Organic phase change materials (PCMs have been utilized as latent heat energy storage medium for effective thermal management. In this work, a PCM nanocomposite, consisting of a mixture of two organic PCMs (referred to as eutectic gel PCM and minimal amount (0.5 wt% of nanographite (NG as a supporting material, was prepared. Differential scanning calorimeter was used to determine the melting temperature and latent heat of pristine PCM, paraffin (61.5 °C and 161.5 J/g, eutectic gel PCM (54 °C and 158 J/g and eutectic gel PCM nanocomposite (53.5 °C and 155 J/g. The prepared PCM nanocomposites exhibited enhanced thermal conductivity and ultrafast thermal charging characteristics. The nanocomposites were employed for two different applications: (i providing hot water using an indigenously fabricated solar water heating (SWH system and (ii solar rechargeable glove that can be rapidly warmed and used. Experimental results on SWH system show that the use of PCM nanocomposites helps to increase the charging rate of PCM while reducing the discharging rate of heat by PCM to water, thus enhancing the maximum utilization of solar energy and hence improving the efficiency of the SWH system. The experimental results on solar rechargeable glove revealed that the glove has the ability to retain the temperature up to 3 hours.

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

    Energy Technology Data Exchange (ETDEWEB)

    Shilei, L.; Neng, Z. [School of Environment Science and Technology, Tianjin University, Tianjin (China); Guohui, F. [Shenyang Jianzhu University, Shenyang (China)

    2006-07-01

    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 thermal cycle tests were conducted to study the changes in latent heat of fusion and melting temperature of phase change wallboards combined with the eutectic mixtures of CA and LA. Differential scanning calorimetry (DSC) tested the transition temperature and latent heat. The results showed that the melting temperature and latent heat of these phase change wallboards with eutectic mixtures have no obvious variations after repeated 360 thermal cycles, which proved that these phase change wallboards have good thermal stability for melting temperature and variations in latent heat of fusion for long time application. Therefore, they can be used for latent heat storage in the field of building energy conservation. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Lv Shilei; Zhu Neng [Tianjin University (China). School of Environmental Science and Technology; Feng Guohui [Shenyang Jianzhu University, Shenyang (China)

    2006-06-15

    Capric acid (CA) and lauric acid (LA), as phase change materials (PCM), can be applied for energy storage in low temperature. The phase transitions 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 thermal cycle tests were conducted to study the changes in latent heat of fusion and melting temperature of phase change wallboards combined with the eutectic mixtures of CA and LA. Differential scanning calorimetry (DSC) tested the transition temperature and latent heat. The results showed that the melting temperature and latent heat of these phase change wallboards with eutectic mixtures have not obvious variations after repeated 360 thermal cycles, which proved that these phase change wallboards have good thermal stability for melting temperature and variations in latent heat of fusion for long time application. Therefore, they can be used for latent heat storage in the field of building energy conservation. (author)

  10. The effect of deep eutectic solvents on catalytic function and structure of bovine liver catalase.

    Science.gov (United States)

    Harifi-Mood, Ali Reza; Ghobadi, Roohollah; Divsalar, Adeleh

    2017-02-01

    Aqueous solutions of reline and glyceline, the most common deep eutectic solvents, were used as a medium for Catalase reaction. By some spectroscopic methods such as UV-vis, fluorescence and circular dichroism (CD) function and structure of Catalase were investigated in aqueous solutions of reline and glyceline. These studies showed that the binding affinity of the substrate to the enzyme increased in the presence of 100mM glyceline solution, which contrasts with reline solution that probably relates to instructive changes in secondary structure of protein. Meanwhile, enzyme remained nearly 70% and 80% active in this concentration of glyceline and reline solutions respectively. In the high concentration of DES solutions, enzyme became mainly inactive but surprisingly stayed in nearly 40% active in choline chloride solution, which is the common ion species in reline and glyceline solvents. It is proposed that the chaotropic nature of choline cation might stop the reducing trend of activity in concentrated choline chloride solutions but this instructive effect is lost in aqueous deep eutectic solvents. In this regard, the presence of various concentrations of deep eutectic solvents in the aqueous media of human cells would be an activity adjuster for this important enzyme in its different operation conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Potential Process for the Decontamination of Pyro-electrometallurgical LiCl-KCl Eutectic Salt Electrolyte

    International Nuclear Information System (INIS)

    Griffith, Christopher S.; Sizgek, Erden; Sizgek, Devlet; Luca, Vittorio

    2008-01-01

    Presented here is a potential option with experimental validation for the decontamination of LiCl-KCl eutectic salt electrolyte from a pyro-electrometallurgical process by employing already developed inorganic ion exchange materials. Adsorbent materials considered include titano-silicates and molybdo- and tungstophosphates for Cs extraction, Si-doped antimony pyrochlore for Sr extraction and hexagonal tungsten bronzes for lanthanide (LN) and minor actinide (MA) polishing. Encouraging results from recent investigations on the removal of target elements (Cs, Sr and LN) from aqueous solutions containing varying concentrations of alkali and alkali metal contaminants which would be akin to a solution formed from the dissolution of spent LiCl-KCl eutectic salt electrolyte are presented. Further investigations have also shown that the saturated adsorbents can be treated at relatively low temperatures to afford potential waste forms for the adsorbed elements. Efficient evaporation and drying of a solution of dissolved LiCl-KCl eutectic salt electrolyte (50 L, 5 L.h -1 ) has been demonstrated using a Microwave-Heated Mechanical Fluidized Bed (MWMFB) apparatus. (authors)

  12. Electrochemical behaviour of ThF4 in LiCl-KCl eutectic

    International Nuclear Information System (INIS)

    Agarwal, Renu; Mukerjee, S.K.; Ramakumar, K.L.

    2016-01-01

    Pyrochemical processing of nuclear fuels is an integral part of molten salt reactor technology. Thorium containing molten salt reactors are relevant for transmutation of minor actinides and utilizations of vast thorium resources. Understanding chemical and electrochemical behavior of actinide and lanthanide ions in chloride melts is an important task in this process. A eutectic of lithium and potassium chloride is found to be the most suitable salt for this study due to its low melting, high reduction potential and significant solubility of most of the actinide and lanthanide salts. However, electrochemistry of thorium in chloride melt is inconsistent due to dispute over the presence of Th(II) cation along with Th(IV). In the present experiments, cyclic-voltammograms of ThF 4 in LiCl-KCl eutectic salt were measured using three electrodes cell, where all the electrodes were 1 mm molybdenum wires and counter electrode wire was twisted into a spiral shape to increase surface area and was used for mixing the salts in molten state. Cyclic-voltammograms of pure eutectic melt and with ThF 4 were measured at scanning rates 50-300 mV/s, at 648 K and 723 K. Diffusion coefficient of Th 4+ was calculated using Delahay equation

  13. The role of trace element segregation in the eutectic modification of hypoeutectic Al-Si alloys

    Energy Technology Data Exchange (ETDEWEB)

    Nogita, K., E-mail: k.nogita@uq.edu.a [Department of Materials Engineering, University of Queensland, Brisbane, QLD 4072 (Australia); Department of Adaptive Machine Systems, Osaka University, Suita, Osaka, 565-0871 (Japan); Yasuda, H.; Yoshiya, M. [Department of Adaptive Machine Systems, Osaka University, Suita, Osaka, 565-0871 (Japan); McDonald, S.D. [Department of Materials Engineering, University of Queensland, Brisbane, QLD 4072 (Australia); CRC for Alloy and Solidification Technology (CAST), Brisbane, QLD 4072 (Australia); Uesugi, K.; Takeuchi, A.; Suzuki, Y. [Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo, 679-5198 (Japan)

    2010-01-21

    Modification of the eutectic silicon in hypoeutectic Al-Si alloys causes a structural transformation of the silicon phase from a needle-like to a fine fibrous morphology and is carried out extensively in industry to improve mechanical properties. It has been documented that the fibrous silicon phase in chemically modified alloys is heavily twinned. It has been proposed that this increased density of twinning results from the adsorption of impurity-elements at the solid-liquid interface perpetuating further growth according to a twin plane re-entrant edge (TPRE) model. In this paper, we discuss this mechanism of eutectic modification in light of experimental data obtained by synchrotron radiation and predictions based on theoretical calculations. This research utilizes a {mu}-XRF (X-ray fluorescence) technique at the SPring-8 synchrotron radiation facility X-ray source and reveals that different elements which theoretically satisfy the geometric requirements of the impurity-induced TPRE model do not have the same effect on the growth of silicon during solidification. Europium for instance is distributed relatively homogeneously in the silicon phase while ytterbium was not found in the silicon phase at all. This has important implications for the fundamental mechanisms of eutectic modification in hypoeutectic aluminium-silicon alloys.

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

    Science.gov (United States)

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

    2011-03-21

    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.

  15. The Influence of Cr on the Solidification Behavior of Polycrystalline γ(Ni)/ γ'(Ni3Al)- δ(Ni3Nb) Eutectic Ni-Base Superalloys

    Science.gov (United States)

    Xie, Mengtao; Helmink, Randolph; Tin, Sammy

    2012-04-01

    In the current investigation, the effect of Cr on the solidification characteristics and as-cast microstructure of pseudobinary γ- δ 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 γ- δ eutectic microstructure in the interdendritic region. Increasing levels of Cr also triggered morphological changes in the γ- δ eutectic and the formation of γ- γ'- δ 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 γ' precipitation temperature of these γ/ γ'- δ eutectic alloys. A comparison of the experimental results with thermodynamic calculations using the CompuTherm Pandat database (CompuTherm LLC, Madison, WI) showed qualitative agreement.

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

    Science.gov (United States)

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

    2013-06-01

    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.

  17. Investigation on drug solubility enhancement using deep eutectic solvents and their derivatives.

    Science.gov (United States)

    Li, Zheng; Lee, Ping I

    2016-05-30

    Deep eutectic solvent (DES) is a room temperature liquid typically formed by mixing two solid compounds, such as a quaternary ammonium salt (QAS) (e.g. choline chloride) and a hydrogen bond donor (HBD) (e.g. urea or a carboxylic acid) at their eutectic composition. Very often, a range of room temperature liquids can also be obtained near the eutectic composition. Hence, it is more convenient to introduce a more general term deep eutectic solvent derivatives (DESDs) to describe a wide range of DES-like derivatives including those derived from ternary mixtures. The melting point of the mixture is lowered because the hydrogen bonding between DESD components reduces the lattice energy of components of the eutectic system. Based on the analysis of available data for 22 such choline chloride-based DES pairs, we found that the observed melting point depression can be statistically correlated with the difference between the hydrogen bonding contribution (δh) and the polar contribution (δp) to the solubility parameter of the hydrogen bond donor (HBD) component. The correlation was validated with a new DESD based on glycolic acid and choline chloride, which form DESDs at a molar ratio between 1:1 and 1:4 with DES-like properties. As a room temperature liquid, this DESD exhibits a wide range of solubility enhancement on several weakly basic poorly water-soluble drugs. For example, the solubility of itraconazole, piroxicam, lidocaine, and posaconazole has been observed to increase by 6700, 430, 28, and 6400-fold, respectively as compared to their aqueous solubility at room temperature. Furthermore, another new ternary DESD based on choline chloride, glycolic acid, and oxalic acid at a molar ratio of 1:1.6:0.4 is shown to further increase the solubility of itraconazole to a remarkable level of 5.36mg/mL (a 53,600-fold increase!). Because the components of such DESDs can include those biodegradable ones that had previously been used in formulated human products, the potential

  18. Thermo-physical stability of fatty acid eutectic mixtures subjected to accelerated aging for thermal energy storage (TES) application

    International Nuclear Information System (INIS)

    Fauzi, Hadi; Metselaar, Hendrik S.C.; Mahlia, T.M.I.; Silakhori, Mahyar

    2014-01-01

    The thermo-physical stability of fatty acids eutectic mixtures subjected to accelerated number of melting/solidification processes has been identified using thermal cycling test in this study. Myristic acid/palmitic acid (MA/PA) (70/30, wt.%) and myristic acid/palmitic acid/sodium stearate (MA/PA/SS) (70/30/5, wt.%) were selected as eutectic phase change materials (PCMs) to evaluate their stability of phase transition temperature, latent heat of fusion, chemical structure, and volume changes after 200, 500, 1000, and 1500 thermal cycles. The thermal properties of each eutectic PCMs measured by differential scanning calorimetric (DSC) indicated the phase transition temperature and latent heat of fusion values of MA/PA/SS has a smallest changes after 1500 thermal cycles than MA/PA eutectic mixture. MA/PA/SS also has a better chemical structure stability and smaller volume change which is 1.2%, compared to MA/PA with a volume change of 1.6% after 1500 cycles. Therefore, it is concluded that the MA/PA/SS eutectic mixture is suitable for use as a phase change material in thermal energy storage (TES) such as solar water heating and solar space heating applications. - Highlights: •The prepared MA/PA and MA/PA/SS were used as eutectic phase change materials (PCM). •Thermo-physical reliability of eutectic PCMs evaluated using a thermal cycling test. •MA/PA/SS has a great thermo-physical stability than MA/PA after 1500 thermal cycles

  19. Las nuevas casas de la Inquisición en Santiago de Compostela: del palacio de Monterrey a la sede de Porta da Mámoa

    Directory of Open Access Journals (Sweden)

    Pita Galán, Paula

    2012-12-01

    Full Text Available In 1726 the Inquisition decided to rebuild its building: the Palace of Monterrey, in Santiago de Compostela. This intervention should have been made according to a project of Fernando de Casas but caused the moving of the Santo Oficio to a new building known as Casa Grande del Horreo or de Calo, in front of Porta da Mámoa. Thanks to unknown documents and the collection of plates of the Inquisition conserved at Archivo Histórico Universitario de Santiago, we will analized the circumstances that caused the change of building as well as propose an hypothetical reconstruction of the Casa de Calo from the testimonies of those who knew it before of the deep removal, directed by the master mason of San Martín Pinario fray Francisco Velasco that transform it into a Palace of the Inquisition.

    En 1726 el Tribunal de la Inquisición se propuso remodelar sus instalaciones en el Palacio de Monterrey, en Santiago de Compostela. Dicha intervención, que debía realizarse según un proyecto de Fernando de Casas, determinó el traslado del Santo Oficio a un nuevo inmueble: la Casa Grande del Hórreo o de Calo, frente a la Porta da Mámoa. A partir de documentación inédita y del estudio de la colección de planos de la Inquisición que conserva el Archivo Histórico Universitario de Santiago, analizaremos las circunstancias que motivaron el cambio de sede, y reconstruiremos la Casa de Calo según los testimonios de quienes la conocieron antes de que una profunda remoción dirigida por fray Francisco Velasco, maestro de obras de San Martín Pinario, la transformase en un palacio de la Inquisición. [gl] En 1726 o Tribunal da Inquisición propúxose remodelar a súas instalacións no Pazo de Monterrey, en Santiago de Compostela. Dita intervención, que debíase realizar seguindo un proxecto de Fernando de Casas, determinou o traslado do Santo Ofi cio a un novo inmoble: a Casa Grande do Hórreo ou de Calo, frente a Porta da Mámoa. A partir de

  20. Toxicological studies for adults and children of insecticide residues with common mode of action (MoA) in pome, stone, berries and other small fruit

    International Nuclear Information System (INIS)

    Lozowicka, B.; Mojsak, P.; Jankowska, M.; Kaczynski, P.; Hrynko, I.; Rutkowska, E.; Szabunko, J.; Borusiewicz, A.

    2016-01-01

    The presence of pesticide residues in fruit is a serious health concern. This paper for the first time demonstrated the Hazard Index (HI) method to carry out acute, chronic and cumulative health risk assessment to the 14 groups of insecticides for three subpopulations. The challenge of this study was to present results from a long period of research (years 2005–2014) with toxicological aspects, especially in multiresidue samples. Near 1000 fresh pome, stone, berries and small fruit were prepared by two accredited MSPD and QuEChERS methods followed by liquid and gas chromatography analyses with various systems of detection ECD/NPD/MS/MS. Twenty percent of the fruit samples contained 16 insecticide residues in the range of 0.01–0.81 mg/kg and 3% over MRL. The class of pesticide with the highest contribution to the ADI was found to be OPPs: dimethoate and diazinon for adults 48% and 66% of the ADI whereas for infants 144% and 294% of the ADI. The highest contributions of the cHQ to common MoA pesticides were AChE inhibitors: 135% for adults and 528% for infants, sodium channel modulators 4.9% and 20%, nicotic acetylocholine receptor < 2.9% and < 10.6% for adults and infants, respectively. The fruit with the highest contribution to the ADI were found to be apples (316%, 58%), cherries (96%, 37%) and pears (129%, 33%) for infants and adults. The study findings indicated that dietary exposures to insecticide residues in fruit would be unlikely to pose unacceptable health risks for the infants, toddlers and adults. - Highlights: • Health risk assessment of insecticide via dietary intake of fruit was estimated. • Sixteen residues in pome, stone, berries and small fruit ranged from 0.01 to 0.8 mg/kg. • Organophosphates were the most frequently occurring group with common MoA. • Dietary exposures for adults and children were below the safety reference values. • Toxicological study provided important date of human health.

  1. Toxicological studies for adults and children of insecticide residues with common mode of action (MoA) in pome, stone, berries and other small fruit

    Energy Technology Data Exchange (ETDEWEB)

    Lozowicka, B., E-mail: B.Lozowicka@iorpib.poznan.pl [Plant Protection Institute - National Research Institute, Laboratory of Pesticide Residues, Chelmonskiego 22, 15-195 Bialystok (Poland); Mojsak, P.; Jankowska, M.; Kaczynski, P.; Hrynko, I.; Rutkowska, E.; Szabunko, J. [Plant Protection Institute - National Research Institute, Laboratory of Pesticide Residues, Chelmonskiego 22, 15-195 Bialystok (Poland); Borusiewicz, A. [Department of Agronomy, The Academy of Agrobusiness in Łomza (Poland)

    2016-10-01

    The presence of pesticide residues in fruit is a serious health concern. This paper for the first time demonstrated the Hazard Index (HI) method to carry out acute, chronic and cumulative health risk assessment to the 14 groups of insecticides for three subpopulations. The challenge of this study was to present results from a long period of research (years 2005–2014) with toxicological aspects, especially in multiresidue samples. Near 1000 fresh pome, stone, berries and small fruit were prepared by two accredited MSPD and QuEChERS methods followed by liquid and gas chromatography analyses with various systems of detection ECD/NPD/MS/MS. Twenty percent of the fruit samples contained 16 insecticide residues in the range of 0.01–0.81 mg/kg and 3% over MRL. The class of pesticide with the highest contribution to the ADI was found to be OPPs: dimethoate and diazinon for adults 48% and 66% of the ADI whereas for infants 144% and 294% of the ADI. The highest contributions of the cHQ to common MoA pesticides were AChE inhibitors: 135% for adults and 528% for infants, sodium channel modulators 4.9% and 20%, nicotic acetylocholine receptor < 2.9% and < 10.6% for adults and infants, respectively. The fruit with the highest contribution to the ADI were found to be apples (316%, 58%), cherries (96%, 37%) and pears (129%, 33%) for infants and adults. The study findings indicated that dietary exposures to insecticide residues in fruit would be unlikely to pose unacceptable health risks for the infants, toddlers and adults. - Highlights: • Health risk assessment of insecticide via dietary intake of fruit was estimated. • Sixteen residues in pome, stone, berries and small fruit ranged from 0.01 to 0.8 mg/kg. • Organophosphates were the most frequently occurring group with common MoA. • Dietary exposures for adults and children were below the safety reference values. • Toxicological study provided important date of human health.

  2. Eutectic mixtures of some fatty acids for latent heat storage: Thermal properties and thermal reliability with respect to thermal cycling

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey)]. E-mail: asari@gop.edu.tr

    2006-06-15

    Accelerated thermal cycle tests have been conducted to study the change in melting temperatures and latent heats of fusion of the eutectic mixtures of lauric acid (LA)-myristic acid (MA), lauric acid (LA)-palmitic acid (PA) and myristic acid (MA)-stearic acid (SA) as latent heat storage materials. The thermal properties of these materials were determined by the differential scanning calorimetry (DSC) analysis method. The thermal reliability of the eutectic mixtures after melt/freeze cycles of 720, 1080 and 1460 was also evaluated using the DSC curves. The accelerated thermal cycle tests indicate that the melting temperatures usually tend to decrease, and the variations in the latent heats of fusion are irregular with increasing number of thermal cycles. Moreover, the probable reasons for the change in thermal properties of the eutectic mixtures after repeated thermal cycles were investigated. Fourier Transform Infrared (FT-IR) spectroscopic analysis indicates that the accelerated melt/freeze processes do not cause any degradation in the chemical structure of the mixtures. The change in thermal properties of the eutectic mixtures with increasing number of thermal cycles is only because of the presence of certain amounts of impurities in the fatty acids used in their preparation. It is concluded that the tested eutectic mixtures have reasonable thermal properties and thermal reliability as phase change materials (PCMs) for latent heat storage in any solar heating applications that include a four year utilization period.

  3. Eutectic mixtures of some fatty acids for latent heat storage: Thermal properties and thermal reliability with respect to thermal cycling

    International Nuclear Information System (INIS)

    Sari, Ahmet

    2006-01-01

    Accelerated thermal cycle tests have been conducted to study the change in melting temperatures and latent heats of fusion of the eutectic mixtures of lauric acid (LA)-myristic acid (MA), lauric acid (LA)-palmitic acid (PA) and myristic acid (MA)-stearic acid (SA) as latent heat storage materials. The thermal properties of these materials were determined by the differential scanning calorimetry (DSC) analysis method. The thermal reliability of the eutectic mixtures after melt/freeze cycles of 720, 1080 and 1460 was also evaluated using the DSC curves. The accelerated thermal cycle tests indicate that the melting temperatures usually tend to decrease, and the variations in the latent heats of fusion are irregular with increasing number of thermal cycles. Moreover, the probable reasons for the change in thermal properties of the eutectic mixtures after repeated thermal cycles were investigated. Fourier Transform Infrared (FT-IR) spectroscopic analysis indicates that the accelerated melt/freeze processes do not cause any degradation in the chemical structure of the mixtures. The change in thermal properties of the eutectic mixtures with increasing number of thermal cycles is only because of the presence of certain amounts of impurities in the fatty acids used in their preparation. It is concluded that the tested eutectic mixtures have reasonable thermal properties and thermal reliability as phase change materials (PCMs) for latent heat storage in any solar heating applications that include a four year utilization period

  4. Formation of Al2O3-HfO2 Eutectic EBC Film on Silicon Carbide Substrate

    Directory of Open Access Journals (Sweden)

    Kyosuke Seya

    2015-01-01

    Full Text Available The formation mechanism of Al2O3-HfO2 eutectic structure, the preparation method, and the formation mechanism of the eutectic EBC layer on the silicon carbide substrate are summarized. Al2O3-HfO2 eutectic EBC film is prepared by optical zone melting method on the silicon carbide substrate. At high temperature, a small amount of silicon carbide decomposed into silicon and carbon. The components of Al2O3 and HfO2 in molten phase also react with the free carbon. The Al2O3 phase reacts with free carbon and vapor species of AlO phase is formed. The composition of the molten phase becomes HfO2 rich from the eutectic composition. HfO2 phase also reacts with the free carbon and HfC phase is formed on the silicon carbide substrate; then a high density intermediate layer is formed. The adhesion between the intermediate layer and the substrate is excellent by an anchor effect. When the solidification process finished before all of HfO2 phase is reduced to HfC phase, HfC-HfO2 functionally graded layer is formed on the silicon carbide substrate and the Al2O3-HfO2 eutectic structure grows from the top of the intermediate layer.

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

    International Nuclear Information System (INIS)

    Bahadori, Laleh; Chakrabarti, Mohammed Harun; Mjalli, Farouq Sabri; AlNashef, Inas Muen; Manan, Ninie Suhana Abdul; Hashim, Mohd Ali

    2013-01-01

    Highlights: • Physicochemical properties of seven deep eutectic solvents as electrolytes measured. • Walden plot showed ideal ammonium-based deep eutectic solvents. • Potential windows of all deep eutectic solvents determined. • Diffusion coefficients and rate constants of organometallic redox couples measured. • Rate constants of deep eutectic solvents were lower than those of ionic liquids. -- Abstract: Seven deep eutectic solvents (DESs) containing ammonium based salts are prepared by means of hydrogen bonding with acid, amine, amide and nitrate based compounds. The major physicochemical properties of the DESs in terms of density, viscosity, electrical conductivity, molar conductivity and pH are investigated prior to ascertaining their electrochemical characteristics by means of cyclic voltammetry and chronoamperometry. Nitrate based DESs exhibit higher conductivities but lower viscosities than other DESs, whereas the amide based DES displays the widest electrochemical potential window. Diffusion coefficient, D, of two organometallic redox couples, Fc/Fc + (ferrocene/ferrocenium) and Cc/Cc + (cobaltocene/cobaltocenium) is found to be of the order of 10 −9 to 10 −8 cm 2 s −1 in all studied DESs while the heterogeneous rate constant for electron transfer across the electrode/DES interface is of the order of 10 −4 cm s −1 . The Stokes–Einstein products of Fc and Cc + in the DESs have also been determined

  6. The Au/Si eutectic bonding compatibility with KOH etching for 3D devices fabrication

    Science.gov (United States)

    Liang, Hengmao; Liu, Mifeng; Liu, Song; Xu, Dehui; Xiong, Bin

    2018-01-01

    KOH etching and Au/Si eutectic bonding are cost-efficient technologies for 3D device fabrication. Aimed at investigating the process compatibility of KOH etching and Au/Si bonding, KOH etching tests have been carried out for Au/bulk Si and Au/amorphous Si (a-Si) bonding wafers in this paper. For the Au/bulk Si bonding wafer, a serious underetch phenomenon occurring on the damage layer in KOH etching definitely results in packaging failure. In the microstructure analysis, it is found that the formation of the damage layer between the bonded layer and bulk Si is attributed to the destruction of crystal Si lattices in Au/bulk Si eutectic reaction. Considering the occurrence of underetch for Au/Si bonding must meet two requirements: the superfluous Si and the defective layer near the bonded layer, the Au/a-Si bonding by regulating the a-Si/Au thickness ratio is presented in this study. Only when the a-Si/Au thickness ratio is relatively low are there not underetch phenomena, of which the reason is the full reaction of the a-Si layer avoiding the formation of the damage layer for easy underetch. Obviously, the Au/a-Si bonding via choosing a moderate a-Si/Au thickness ratio (⩽1.5:1 is suggested) could be reliably compatible with KOH etching, which provides an available and low-cost approach for 3D device fabrication. More importantly, the theory of the damage layer proposed in this study can be naturally applied to relevant analyses on the eutectic reaction of other metals and single crystal materials.

  7. Biodiesel production from ethanolysis of palm oil using deep eutectic solvent (DES) as co-solvent

    Science.gov (United States)

    Manurung, R.; Winarta, A.; Taslim; Indra, L.

    2017-06-01

    Biodiesel produced from ethanolysis is more renewable and have better properties (higher oxidation stability, lower cloud and pour point) compared to methanolysis, but it has a disadvantage such as complicated purification. To improve ethanolysis process, deep eutectic solvent (DES) can be prepared from choline chloride and glycerol and used as co-solvent in ethanolysis. The deep eutectic solvent is formed from a quaternary ammonium salt (choline chloride) and a hydrogen bond donor (Glycerol), it is a non-toxic, biodegradable solvent compared to a conventional volatile organic solvent such as hexane. The deep eutectic solvent is prepared by mixing choline chloride and glycerol with molar ratio 1:2 at temperature 80 °C, stirring speed 300 rpm for 1 hour. The DES is characterized by its density and viscosity. The ethanolysis is performed at a reaction temperature of 70 °C, ethanol to oil molar ratio of 9:1, potassium hydroxide as catalyst concentration of 1.2 wt. DES as co-solvent with concentration 0.5 to 3 wt. stirring speed 400 rpm, and a reaction time 1 hour. The obtained biodiesel is then characterized by its density, viscosity, and ester content. The oil - ethanol phase condition is observed in the reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to without DES, showed that oil and ethanol become more slightly miscible, which favors the reaction. Using DES as co-solvent in ethanolysis showed increasing in yield and easier purification. The esters properties meet the international standards ASTM D6751, with the highest yield achieved 83,67 with 99,77 conversion at DES concentration 2 . Increasing DES concentration above 2 in ethanolysis decrease the conversion and yield, because of the excessive glycerol in the systems makes the reaction equilibrium moves to the reactant side.

  8. Magnetic deep eutectic solvents molecularly imprinted polymers for the selective recognition and separation of protein

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanjin [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Dai, Qingzhou [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Zhou, Yigang [Department of Microbiology, College of Basic Medicine, Central South University, Changsha, 410083 (China)

    2016-09-14

    A novel and facile magnetic deep eutectic solvents (DES) molecularly imprinted polymers (MIPs) for the selective recognition and separation of Bovine hemoglobin (BHb) was prepared. The new-type DES was adopted as the functional monomer which would bring molecular imprinted technology to a new direction. The amounts of DES were optimized. The obtained magnetic DES-MIPs were characterized with fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), dynamic light scattering (DLS), elemental analysis and vibrating sample magnetometer (VSM). The results suggested that the imprinted polymers were successfully formed and possessed a charming magnetism. The maximum adsorption capability (Q{sub max}) and dissociation constant (K{sub L}) were analyzed by Langmuir isotherms (R{sup 2} = 0.9983) and the value were estimated to be 175.44 mg/g and 0.035 mg/mL for the imprinted particles. And the imprinted particles showed a high imprinting factor of 4.77. In addition, the magnetic DES-MIPs presented outstanding recognition specificity and selectivity so that it can be utilized to separate template protein from the mixture of proteins and real samples. Last but not least, the combination of deep eutectic solvents and molecular imprinted technology in this paper provides a new perspective for the recognition and separation of proteins. - Highlights: • Combined green deep eutectic solvents (DES) and molecular imprinted technology in recognition and separation of proteins. • DES was adopted as a new-type functional monomer. • The obtained magnetic DES-MIPs can separate proteins rapidly by an external magnetic field. • Adsorption and selectivity properties were discussed.

  9. Spatial profile of thermoelectric effects during Peltier pulsing in Bi and Bi/MnBi eutectic

    Science.gov (United States)

    Silberstein, R. P.; Larson, D. J., Jr.

    1987-01-01

    The spatial profile of the thermal transients that occur during and following the current pulsing associated with Peltier Interface Demarcation during directional solidification is studied. Results for pure Bi are presented in detail and compared with corresponding results for the Bi/MnBi eutectic. Significant thermal transients occur throughout the sample that can be accounted for by the Peltier effect, the Thomson effect, and Joule heating. These effects are separated and their behavior is studied as a function of time, current density, and position with respect to the solid/liquid interface.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-02-29

    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.

  11. Resistance of a gamma/gamma prime - delta directionally solidified eutectic alloy to recrystallization

    Science.gov (United States)

    Tewari, S. N.; Scheuermann, C. M.; Andrews, C. W.

    1975-01-01

    The lamellar directionally solidified nickel-base eutectic alloy gamma/gamma prime-delta has potential as an advanced turbine blade material. The microstructural stability of this alloy was investigated. Specimens were plastically deformed by uniform compression or Brinell indentation, then annealed between 705 and 1120 C. Microstructural changes observed after annealing included gamma prime coarsening, pinch-off and spheroidization of delta lamellae, and the appearance of an unidentified blocky phase in surface layers. All but the first of these was localized in severely deformed regions, suggesting that microstructural instability is not a serious problem in the use of this alloy.

  12. Chemical properties of some elements in a molten lithium chloride, potassium chloride eutectic (1962)

    International Nuclear Information System (INIS)

    Molina, R.

    1961-12-01

    The increasing use of molten media especially in chemical preparations and for certain technological applications, has made it more necessary to have a knowledge of the chemical properties of elements in these solvents. Structural studies on molten solutions show the existence of certain species such as ions and complexes known to exist in aqueous solutions. This fact, together with certain experiments on chemical reactions in molten media has led us to establish a comparison between these media and aqueous solutions. We wish to show that the same fundamental phenomena occur in these media as are found in the chemistry of aqueous solutions and that this makes it possible to predict certain reactions. We have taken as examples the chemical properties of vanadium, uranium and sulphur in a LiCl-KCl eutectic melted at 480 deg. C. The first problem is to identify the various degrees of oxidation of these elements existing in the solvent chosen. We have tried to resolve it by comparing the absorption spectra obtained in aqueous solution and in the molten eutectic. We consider the possibilities of this method in a chapter on absorption spectrophotometry in the LiCl-KCl eutectic. During the study of the chemical properties we stress the various methods of displacing the equilibria: complex formation, variation of the oxidation-reduction properties with complex formation. The complexes of the O 2- ion are considered in particular. The study of the exchange of this particle is facilitated by the use of a classification of some of its complexes which we call the pO 2- scale by analogy with the pH scale; the value pO 2- is defined by the relationship: pO 2- = log O 2- Similarly, the use of apparent potential diagrams pO 2- makes it possible to predict and to interpret reactions involving the simultaneous exchange of electrons and O 2- ions between the various degrees of oxidation of the same element. It is possible, by studying some reactions of this type between two elements

  13. Pressure-induced structural change in liquid GaIn eutectic alloy

    DEFF Research Database (Denmark)

    Yu, Q.; Ahmad, A. S.; Ståhl, Kenny

    2017-01-01

    Synchrotron x-ray diffraction reveals a pressure induced crystallization at about 3.4 GPa and a polymorphic transition near 10.3 GPa when compressed a liquid GaIn eutectic alloy up to ~13 GPa at room temperature in a diamond anvil cell. Upon decompression, the high pressure crystalline phase...... remains almost unchanged until it transforms to the liquid state at around 2.3 GPa. The ab initio molecular dynamics calculations can reproduce the low pressure crystallization and give some hints on the understanding of the transition between the liquid and the crystalline phase on the atomic level...

  14. Directional solidification of filamentary shapes of Pb--Cd and Pb--Sn eutectic alloys

    International Nuclear Information System (INIS)

    Dhindaw, B.K.; Verhoeven, J.D.; Spencer, C.R.; Gibson, E.D.

    1978-01-01

    Eutectic alloys of Pb--Cd and Pb--Sn were directionally solidified as thin filamentary strips contained in stainless steel and quartz capillaries. As the solidification rate increased the filament width, w, had to be reduced to maintain complete alignment of the lamellae clear across the filament. It was determined that in order to achieve complete alignment the ratio of filament width to lamellar spacing, w/lambda had to be less than about 30. Experiments were carried out at rates of 2-400 μm/s and at temperature gradients of 130 and 320 0 C/cm

  15. Study on corrosion test techniques in lead bismuth eutectic flow. Joint research report in JFY2002

    International Nuclear Information System (INIS)

    Takahashi, Minoru; Sekimoto, Hiroshi

    2003-03-01

    The evaluation of corrosion behaviors of core and structural materials in lead bismuth eutectic is one of the key issues for the utilization of lead bismuth eutectic as a coolant of the primary loops of lead bismuth cooled fast breeder reactors (FBRs) and the intermediate heat transport media of new-type steam generators of the sodium cooled FBRs. The purpose of the present study is to establish corrosion test techniques in lead bismuth eutectic flow. The techniques of steel corrosion test and oxygen control in flowing lead bismuth eutectic, and the technologies of a lead bismuth flow test at high temperature and high velocity were developed through corrosion test using a lead bismuth flow test loop of the Tokyo Institute of Technology in JFY2002. The major results are summarized as follows: (1) Techniques of fabrication, mount and rinse of corrosion specimens, measurement method of weight loss, and SEM/EDX analysis method have been established through lead bismuth corrosion test. (2) Weight losses were measured, corrosion and lead bismuth-adhered layers and eroded parts were observed in two 1000 hr-corrosion tests, and the results were compared with each other for twelve existing steels including ODS, F82H and SUH-3. (3) An oxygen sensor made of zirconia electrolyte structurally resistant to thermal stress and thermal shock was developed and tested in the lead bismuth flow loop. Good performance has been obtained. (4) An oxygen control method by injecting argon and hydrogen mixture gas containing steam into lead bismuth was applied to the lead bismuth flow loop, and technical issues for the development of the oxygen control method were extracted. (5) Technical measures for freezing and leakage of lead bismuth in the flow loop were accumulated. (6) Technical measures for flow rate decrease/blockage due to precipitation of oxide and corrosion products in a low temperature section of the lead bismuth flow loop were accumulated. (7) Electromagnetic flow meters with MI

  16. Fundamental study on the salt distillation from the mixtures of rare earth precipitates and LiCl-KCl eutectic salt

    International Nuclear Information System (INIS)

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

    2008-01-01

    An electrorefining process of spent nuclear fuel generates waste salt containing some radioactive metal chlorides. The most effective method to reduce salt waste volume is to separate radioactive metals from non-radioactive salts. A promising approach is to change radioactive metal chlorides into salt-insoluble oxides by an oxygen sparging. Following this, salt distillation process is available to effectively separate the precipitated particulate metal oxides from salt. This study investigated the distillation rates of LiCl-KCl eutectic salt under different vacuums at elevated temperatures. The first part study investigated distillation rates of eutectic salt under different vacuums at high temperatures by using thermo-gravimetric furnace system. In the second part, we tested the removal of eutectic salt from the RE precipitates by using the laboratory vacuum distillation furnace system. Investigated variables were the temperature of mixture, the degree of vacuum and the time

  17. Thermal properties and stabilities of the eutectic mixture: 1,6-hexanediol/lauric acid as a phase change material for thermal energy storage

    International Nuclear Information System (INIS)

    Han, Lipeng; Ma, Guixiang; Xie, Shaolei; Sun, Jinhe; Jia, Yongzhong; Jing, Yan

    2017-01-01

    Highlights: • The eutectic mixture of 1,6-hexanediol/lauric acid was studied as a phase change material. • The mass fraction of 1,6-hexanediol in eutectic point is 70%. • The melting point and latent heat are measured to be 36.92 °C and 177.11 J g −1 . • The eutectic mixture showed good thermal and cyclic stabilities. - Abstract: Thermal properties and stabilities of the eutectic mixture: 1,6-hexanediol (HE) and lauric acid (LA) as a new phase change material (PCM) for latent heat thermal energy storage (TES) were investigated. Differential scanning calorimetry (DSC) results indicated that the aforementioned HE/LA mixture with eutectic composition (70/30 wt.%) was a suitable PCM in terms of melting point (T peak = 36.92 ± 0.71 °C) and latent heat of fusion (ΔH m = 177.11 ± 7.93 J g −1 ). After 1000 thermal cycles, the change in melting point for the eutectic mixture was in the range of −0.49% to −1.19%, and the change in latent heat of fusion was in the range of −0.22% to −3.24%. The eutectic mixture was thermally and chemically stable according to results of thermogravimetric analysis (TGA), volatile test and Fourier Transform Infrared (FT-IR) spectroscopic analysis. Therefore, the HE/LA eutectic mixture is an effective TES material to reduce energy consumption.

  18. Evaluación del desgaste de la banda transportadora en las minas de níquel de Moa y Nicaro

    Directory of Open Access Journals (Sweden)

    Lorenzo Velazquez

    2009-03-01

    Full Text Available Las bandas trasportadoras en las minas de níquel de las empresas Ernesto Che Guevara, de Moa y Rene Ramos Latour, de Nicaro, sufren desgaste y destrucción paulatina por la acción de los impactos de la mena al caer, y por el desplazamiento de estas partículas sobre la banda. Para evaluar el desgaste de la banda se experimentó, dejando caer sobre ella, desde diferentes alturas, partículas de diversos tamaños y formas, variando la velocidad de movimiento de la banda, con el fin de establecer el desplazamiento de las partículas de forma experimental y teórica en función de la velocidad de movimiento. Esto permite determinar la longitud del área de suministro del transportador y la resistencia al movimiento en esa zona. Como resultado se obtuvo un modelo teórico que permite evaluar la variación de la velocidad de deformación de la banda al verter el mineral desde alturas diferentes. Se concluye que el desgaste de la banda en los puntos de carga puede reducirse disminuyendo la altura de caída y se recomienda emplear velocidades de banda mayores de 3 m/s independientemente del tamaño y forma de las partículas.

  19. Structure and mechanical properties of a eutectic high-temperature Nb-Si alloy grown by directional solidification

    Science.gov (United States)

    Karpov, M. I.; Vnukov, V. I.; Korzhov, V. P.; Stroganova, T. S.; Zheltyakova, I. S.; Prokhorov, D. V.; Gnesin, I. B.; Kiiko, V. M.; Kolobov, Yu. R.; Golosov, E. V.; Nekrasov, A. N.

    2014-04-01

    The structure and the short-term high-temperature strength of Ni-18.7 at % Si (Nb-Nb3Si eutectic) alloys fabricated by vacuum electron-beam zone melting and induction melting in an argon atmosphere are studied. The structure of the samples prepared by vacuum electron-beam zone melting is characterized by the presence of primary Nb5Si3 intermetallic precipitates and the absence of its secondary precipitates. The structure of the samples prepared by induction melting in an argon atmosphere has two characteristic zones, namely, eutectic and eutectoid ones.

  20. Effects of phase fraction on superconductivity of low-valence eutectic titanate films

    Science.gov (United States)

    Kurokawa, Hikaru; Yoshimatsu, Kohei; Sakata, Osami; Ohtomo, Akira

    2017-08-01

    Creation and characterization of mixed valence states in transition-metal oxides are a fundamental approach to search for the unprecedented electronic and magnetic properties. In contrast to complex oxides, mixed-valence simple oxides tend to form binary or ternary phases, and turning a valence from one to next must be accompanied by structural transformations owing to a lower tolerance for oxygen non-stoichiometry. In this paper, epitaxial growth and transport properties of low-valence titanate thin films are reported to shed light on recently discovered superconducting γ-phase Ti3O5 (γ-Ti3O5). Single-phase TiO and Ti2O3 films and eutectic films including TiO, Ti2O3, and γ-Ti3O5 phases were independently grown on α-Al2O3 (0001) substrates by using pulsed-laser deposition. The X-ray diffraction measurements revealed clear epitaxial relationships with substrates and among three eutectic phases. Temperature dependence of the resistivity revealed that the γ-Ti3O5-rich films exhibited superconductivity with a maximum of transition temperature (TC) of 6.3 K. Distinct effects of the phase fraction on TC are found between TiO- and Ti2O3-enriched samples, suggesting the complex mechanisms of the superconducting proximity effect.

  1. Eutectic superalloys strengthened by delta Ni3Cb lamellae, and gamma prime, Ni3Al precipitates.

    Science.gov (United States)

    Lemkey, F. D.; Thompson, E. R.

    1972-01-01

    Bivariant eutectic alloys, located on a liquidus surface within the Ni-Cb-Cr-Al quaternary, were identified which permitted the production of aligned delta Ni3Cb lamellae within a nichrome matrix containing the fcc precipitate gamma prime Ni3Al. The volume fraction of delta and gamma prime could be varied significantly by compositional changes. After directional solidification certain alloys possessed improved ductility and corrosion resistance with respect to the Ni3Al-Ni3Cb eutectic, while their values of tensile and creep strength approached or exceeded those for the Ni3Al-Ni3Cb pseudobinary system. The mechanical properties of the directionally solidified alloy, Ni-19.7 wt % Cb-6.0 wt % Cr-2.5 wt % Al, were evaluated. Its longitudinal strength in tension and creep was found to be superior to all advanced nickel base superalloys. It is thus demonstrated that useful properties for gas turbine airfoil applications can be achieved by reinforcing a strong and tough gamma nichrome matrix containing precipitated gamma prime by a strong lamellar intermetallic compound having greater strength at elevated temperature.

  2. Thermodynamic properties and equation of state of liquid lead and lead bismuth eutectic

    Science.gov (United States)

    Sobolev, V. P.; Schuurmans, P.; Benamati, G.

    2008-06-01

    Since the 1950s, liquid lead (Pb) and lead-bismuth eutectic (Pb-Bi) have been studied in the USA, Canada and in the former-USSR as potential coolants for nuclear installations due to their very attractive thermophysical and neutronic properties. However, experimental data on the thermal properties of these coolants in the temperature range of interest are still incomplete and often contradictory. This makes it very difficult to perform design calculations and to analyse the normal and abnormal behaviour of nuclear installations where these coolants are expected to be used. Recently, a compilation of heavy liquid metal (HLM) properties along with recommendations for its use was prepared by the OECD/NEA Working Party on Fuel Cycle (WPFC) Expert Group on Lead-Bismuth Eutectic Technology. A brief review of this compilation and some new data are presented in this article. A set of correlations for the temperature dependence of the main thermodynamic properties of Pb and Pb-Bi(e) at normal pressure, and a set of simplified thermal and caloric equations of state for the liquid phase are proposed.

  3. Electrochemical study in the molten sodium acid sulphate - potassium acid sulphate eutectic

    International Nuclear Information System (INIS)

    Le Ber, F.

    1964-01-01

    The general properties of the NaHSO 4 - KHSO 4 molten eutectic resemble those of neutral sulphates and those of concentrated H 2 SO 4 . We have been able to show the existence in solution of the ions HSO - 4 SO 2- 4 , and H 3 O + , these last being formed by the action of the HSO - 4 ions on dissolved H 2 O. The electro-active zone with a polished platinum electrode is limited in oxidation by the ions H 3 O + and SO 2- 4 , and in reduction by the protons of HSO - 4 . We have compared the electro-active zones obtained with different electrodes (Ag-Au-graphite-mercury). We have considered the dissolution of a few metallic oxides and halides. This work shows the role as O 2- ion acceptors of HSO - 4 ions. We have undertaken an electro-chemical study of a few oxido-reduction Systems: H + / H 2 , Ag↓ / Ag (1), the vanadium and uranium Systems, those of mercury Hg↓ / Hg 2- 2 and of gold Au/Au 3+ , then of the attack by the solvent of a few common metals such as aluminium, iron, copper and nickel. The study of silver Systems has made it possible to obtain the solubility products of AgCl and AgBr and to consider the possibility of coulometric titration Cl - ions with Ag + ions. We have shown the existence of various chemical species of vanadium which may exist in the molten eutectic. (author) [fr

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

    Energy Technology Data Exchange (ETDEWEB)

    Nishita, H.

    1980-10-01

    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.

  5. A eutectic-alloy-infused soft actuator with sensing, tunable degrees of freedom, and stiffness properties

    Science.gov (United States)

    Hao, Yufei; Wang, Tianmiao; Xie, Zhexin; Sun, Wenguang; Liu, Zemin; Fang, Xi; Yang, Minxuan; Wen, Li

    2018-02-01

    This paper presents a soft actuator embedded with two types of eutectic alloys which enable sensing, tunable mechanical degrees of freedom (DOF), and variable stiffness properties. To modulate the stiffness of the actuator, we embedded a low melting point alloy (LMPA) in the bottom portion of the soft actuator. Different sections of the LMPA could be selectively melted by the Ni-Cr wires twined underneath. To acquire the curvature information, EGaIn (eutectic gallium indium) was infused into a microchannel surrounding the chambers of the soft actuator. Systematic experiments were performed to characterize the stiffness, tunable DOF, and sensing the bending curvature. We found that the average bending force and elasticity modulus could be increased about 35 and 4000 times, respectively, with the LMPA in a solid state. The entire LMPA could be melted from a solid to a liquid state within 12 s. In particular, up to six different motion patterns could be achieved under each pneumatic pressure of the soft actuator. Furthermore, the kinematics of the actuator under different motion patterns could be obtained by a mathematical model whose input was provided by the EGaIn sensor. For demonstration purposes, a two-fingered gripper was fabricated to grasp various objects by adjusting the DOF and mechanical stiffness.

  6. Green Processing of Lignocellulosic Biomass and Its Derivatives in Deep Eutectic Solvents.

    Science.gov (United States)

    Tang, Xing; Zuo, Miao; Li, Zheng; Liu, Huai; Xiong, Caixia; Zeng, Xianhai; Sun, Yong; Hu, Lei; Liu, Shijie; Lei, Tingzhou; Lin, Lu

    2017-07-10

    The scientific community has been seeking cost-competitive and green solvents with good dissolving capacity for the valorization of lignocellulosic biomass. At this point, deep eutectic solvents (DESs) are currently emerging as a new class of promising solvents that are generally liquid eutectic mixtures formed by self-association (or hydrogen-bonding interaction) of two or three components. DESs are attractive solvents for the fractionation (or pretreatment) of lignocellulose and the valorization of lignin, owing to the high solubility of lignin in DESs. DESs are also employed as effective media for the modification of cellulose to afford functionalized cellulosic materials, such as cellulose nanocrystals. More interestingly, biomassderived carbohydrates, such as fructose, can be used as one of the constituents of DESs and then dehydrated to 5-hydroxymethylfurfural in high yield. In this review, a comprehensive summary of recent contribution of DESs to the processing of lignocellulosic biomass and its derivatives is provided. Moreover, further discussion about the challenges of the application of DESs in biomass processing is presented. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Crystallization behavior of Ge-doped eutectic Sb70Te30 films in optical disks

    Science.gov (United States)

    Khulbe, Pramod K.; Hurst, Terril; Horie, Michikazu; Mansuripur, Masud

    2002-10-01

    We report laser-induced crystallization behavior of binary Sb-Te and ternary Ge-doped eutectic Sb70Te30 thin film samples in a typical quadrilayer stack as used in phase-change optical disk data storage. Several experiments have been conducted on a two-laser static tester in which one laser operating in pulse mode writes crystalline marks on amorphous film or amorphous marks on crystalline film, while the second laser operating at low-power cw mode simultaneously monitors the progress of the crystalline or amorphous mark formation in real time in terms of the reflectivity variation. The results of this study show that the crystallization kinetics of this class of film is strongly growth dominant, which is significantly different from the crystallization kinetics of stochiometric Ge-Sb-Te compositions. In Sb-Te and Ge-doped eutectic Sb70Te30 thin-film samples, the crystallization behavior of the two forms of amorphous states, namely, as-deposited amorphous state and melt-quenched amorphous state, remains approximately same. We have also presented experiments showing the effect of the variation of the Sb/Te ratio and Ge doping on the crystallization behavior of these films.

  8. Evolution of eutectic spacing during unidirectional solidification of Al-Ni alloys

    Directory of Open Access Journals (Sweden)

    Igor Jefferson Cabral Araujo

    2011-01-01

    Full Text Available Hypoeutectic Al-Ni alloys show a ductile phase α distributed with a β phase Al3Ni fragile where β serves as reinforcement of the structure of the material. The eutectic composition alloys obey the relationship: λ2.v = C, where λ is the eutectic spacing, v is a tip growth rate and C is a constant. The aim of this study is to establish correlations between λ and v for hypoeutectic Al-1%, 3% and 5% Ni alloys. Unsteady-state upward directional solidification experiments were performed, as well as metallography, dissolution of the aluminum matrix and scanning electron microscopy (SEM. The interphase spacing of the three Al-Ni alloys decreased with increasing tip growth rate, with a predominance of a rod-like morphology on intermetallic. It was observed that parameters such as tip growth rate, cooling rate and temperature gradient decreases as the solidification front advances. It was further observed that a single experimental law λ = 1.2 v-0, 5 illustrates the evolution of the interphase spacing for any examined alloy.

  9. Thermal Characterization of Lauric-Stearic Acid/Expanded Graphite Eutectic Mixture as Phase Change Materials.

    Science.gov (United States)

    Zhu, Hua; Zhang, Peng; Meng, Zhaonan; Li, Ming

    2015-04-01

    The eutectic mixture of lauric acid (LA) and stearic acid (SA) is a desirable phase change material (PCM) due to the constant melting temperature and large latent heat. However, its poor thermal conductivity has hampered its broad utilization. In the present study, pure LA, SA and the mixtures with various mass fractions of LA-SA were used as the basic PCMs, and 10 wt% expanded graphite (EG) was added to enhance the thermal conductivities. The phase change behaviors, microstructural analysis, thermal conductivities and thermal stabilities of the mixtures of PCMs were investigated by differential scanning calorimetry (DSC), scanning electronic microscope (SEM), transient plane source (TPS) and thermogravimetric analysis (TGA), respectively. The results show that the LA-SA binary mixture of mixture ratio of 76.3 wt%: 23.7 wt% forms an eutectic mixture, which melts at 38.99 °C and has a latent heat of 159.94 J/g. The melted fatty acids are well absorbed by the porous network of EG and they have a good thermal stability. Furthermore, poor thermal conductivities can be well enhanced by the addition of EG.

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

    Science.gov (United States)

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

    2005-01-01

    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-Gd 7Pd 3, Gd-GdZn, Gd-GdCd).

  11. Lattice relations and solidification of the complex regular eutectic (Cr,Fe)-(Cr,Fe)23C6

    Science.gov (United States)

    Lai, Hsuan-Han; Hsieh, Chih-Chun; Lin, Chi-Ming; Wu, Weite

    2017-05-01

    The eutectic (Cr,Fe)-(Cr,Fe)23C6 showed a triaxial fishbone structure and could be categorized as a "complex regular structure". In this study, the lattice relations of the fishbone (Cr,Fe)23C6 were examined and the solidification process was observed using a transmission electron microscope and a confocal laser scanning microscope. For one of the three fish bones in a eutectic cell, parallel (Cr,Fe)23C6 lamellas at one side of the spine had the same lattice direction, as did those in the (Cr,Fe) phase. The lattices of neighboring (Cr,Fe)23C6 and (Cr,Fe) phases were not coherent. Lamellar (Cr,Fe)23C6 on opposite sides of a spine had different lattice directions, and their lattice boundary was in the spine. By using the confocal laser scanning microscope, the solidification of lamellar eutectic structure could be observed. At the low cooling rate of 5 o C·min-1, parallel lamellas would grow thick blocks instead of thin plates. To obtain a thin lamellar eutectic structure, the cooling rate should be higher, like the rate in welding.

  12. Assessing the thermal performance of three cold energy storage materials with low eutectic temperature for food cold chain

    International Nuclear Information System (INIS)

    Li, Yu-Chu M.; Chen, Yen-Hong A.

    2016-01-01

    Development a novel inorganic salt eutectic solution for cold energy storage material (ESM) have succeeded conducted in this study. The eutectic solutions shows a low melting temperature and high latent heat of fusion value as effect of addition nano copper powder into the eutectic solution. We report a new simulation technique of thermal property as well as test results of three inorganic salts. The thermal property of three inorganic salts were simulated using the differential scanning calorimetry (DSC) method with the help of three binary phase diagrams. The simulation shows the liquidus temperature of each binary phase diagram conforming nicely to the theoretical prediction of the Gibbs-Duhem equation. In order to predict cold storage keeping time, we derived a heat transfer model based on energy conservation law. Three ESMs were tested for their cold energy storage performance and thermal properties aging for durability. The empirical results indicate that, for food cold chain, the melting point rule is superior with less deviation. With this information, one can pre-estimate the basic design parameters with great accuracy; the cost of design and development for a new cold storage logistics system can be dramatically reduced. - Highlights: • For these three ESMs, their modified values of melting point and latent heat are presented in Table 2. • But, TC is usually not a constant like TE. • The freezing time underwent a drop ∼10% in the binary eutectic region.

  13. Quantitative Comparison of Ternary Eutectic Phase-Field Simulations with Analytical 3D Jackson-Hunt Approaches

    Science.gov (United States)

    Steinmetz, Philipp; Kellner, Michael; Hötzer, Johannes; Nestler, Britta

    2018-02-01

    For the analytical description of the relationship between undercoolings, lamellar spacings and growth velocities during the directional solidification of ternary eutectics in 2D and 3D, different extensions based on the theory of Jackson and Hunt are reported in the literature. Besides analytical approaches, the phase-field method has been established to study the spatially complex microstructure evolution during the solidification of eutectic alloys. The understanding of the fundamental mechanisms controlling the morphology development in multiphase, multicomponent systems is of high interest. For this purpose, a comparison is made between the analytical extensions and three-dimensional phase-field simulations of directional solidification in an ideal ternary eutectic system. Based on the observed accordance in two-dimensional validation cases, the experimentally reported, inherently three-dimensional chain-like pattern is investigated in extensive simulation studies. The results are quantitatively compared with the analytical results reported in the literature, and with a newly derived approach which uses equal undercoolings. A good accordance of the undercooling-spacing characteristics between simulations and the analytical Jackson-Hunt apporaches are found. The results show that the applied phase-field model, which is based on the Grand potential approach, is able to describe the analytically predicted relationship between the undercooling and the lamellar arrangements during the directional solidification of a ternary eutectic system in 3D.

  14. Thermal characteristic investigation of eutectic composite fatty acid as heat storage material for solar heating and cooling application

    Science.gov (United States)

    Thaib, R.; Fauzi, H.; Ong, H. C.; Rizal, S.; Mahlia, T. M. I.; Riza, M.

    2018-03-01

    A composite phase change material (CPCM) of myristic acid/palmitic acid/sodium myristate (MA/PA/SM) and of myristic acid/palmitic acid/sodium laurate (MA/PA/SL) were impregnated with purified damar gum as called Shorea Javanica (SJ) to improve the thermal conductivity of CPCM. The thermal properties, thermal conductivity, and thermal stability of both CPCM have investigated by using a Differential Scanning Calorimetry (DSC) thermal analysis, hot disc thermal conductivity analyzer, and Simultaneous Thermal Analyzer (STA), simultaneously. However, a chemical compatibility between both fatty acid eutectic mixtures and SJ in composite mixtures measured by Fourier Transform Infra-Red (FT-IR) spectrophotometer. The results were obtained that the thermal conductivity of MA/PA/SM/SJ and MA/PA/SL/SJ eutectic composite phase change material (CPCM) were improved by addition 3 wt.% and 2 wt.% of Shorea javanica (SJ), respectively, without occur a significant change on thermal properties of CPCM. Moreover, the absorbance spectrum of FT-IR shows the good compatibility of SJ with both MA/PA/SM and MA/PA/SL eutectic mixtures, the composite PCM also present good thermal performance and good thermal stability. Therefore, it can be noted that the purified Shorea Javanica proposed, the as high conductive material in this study was able to improve the thermal conductivity of eutectic PCM without any significant reduction on its thermo-physical and chemical properties and can be recommended as novelty composite phase change material for thermal energy storage application.

  15. Optimization of deep eutectic solvent-based ultrasound-assisted extraction of polysaccharides from Dioscorea opposita Thunb.

    Science.gov (United States)

    Zhang, Lijin; Wang, Maoshan

    2017-02-01

    In this study, deep eutectic solvents were proposed for the ultrasound-assisted extraction of polysaccharides from Dioscorea opposita Thunb. Several deep eutectic solvents were prepared for the extraction of polysaccharides, among which the deep eutectic solvent composed of choline chloride and 1,4-butanediol was proved to be suitable for the extraction. Based on the screening of single-factor experiment design and orthogonal experiment design, three experimental factors were optimized for the Box-Behnken experimental design combined with response surface methodology, which gave the optimal extraction conditions: water content of 32.89%(v/v), extraction temperature of 94.00°C, and the extraction time of 44.74min. The optimal extraction conditions could supply higher extraction yield than those of hot water extraction and water-based ultrasound-assisted extraction. Therefore, deep eutectic solvents were an excellent extraction solvent alternative to the extraction of polysaccharides from sample matrices. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. LiF/CaF.sub.2./sub./LiBaF.sub.3./sub. ternary fluoride eutectic scintillator

    Czech Academy of Sciences Publication Activity Database

    Hishinuma, K.; Kamada, K.; Kurosawa, S.; Yamaji, A.; Pejchal, Jan; Yokota, Y.; Ohashi, Y.; Yoshikawa, A.

    2015-01-01

    Roč. 54, č. 4 (2015), "04DH04-1"-"04DH04-4" ISSN 0021-4922 Institutional support: RVO:68378271 Keywords : scintillator * eutectics * fluorides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.122, year: 2015

  17. Presencia de rodingitas en las rocas de dique asociadas a gabros de la zona de Yaguaneque, Moa, Holguín

    Directory of Open Access Journals (Sweden)

    Alianna Corona Rodríguez

    2014-07-01

    Full Text Available En la zona de Yaguaneque abundan las rocas ofiolíticas como parte del macizo Moa-Baracoa. En el interior de los cuerpos básicos (gabros afloran rocas de diques con tremolita-actinolita, clorita, epidota, clinocloro y zoisita, pertenecientes a la facies de esquistos verdes, indicadores de la existencia de procesos metasomáticos en las rocas básicas y metamorfismo retrógrado. Asociadas a los gabros se reportan rodingitas, en forma de lentes o como diques de color claro, con espesores que varían entre 30 cm y 70 cm y longitud de hasta un metro. La composición mineralógica es: clinocloro, anfíboles cálcicos (tremolita actinolita, zoisita, epidota y clorita. Se interpreta que estas rocas son producto de un metasomatismo cálcico, contemporáneo a la serpentinización de las rocas ultrabásicas en dos eventos: el primero asociado a un metamorfismo hidrotermal evidenciado por la preservación de texturas magmáticas; el segundo, durante el emplazamiento tectónico, bajo condiciones de P-T correspondientes a la facies esquistos verdes, que dio lugar a un metamorfismo retrógrado que supuestamente transformó los granates en cloritas. Los gabros constituyen la roca de caja y su composición mineralógica es: plagioclasa (anortita, clinopiroxenos (diópsido y, subordinadamente,olivino en forma de granos relícticos con un borde de alteración a clorita

  18. Stable, low-cost phase change material for building applications: The eutectic mixture of decanoic acid and tetradecanoic acid

    International Nuclear Information System (INIS)

    Kahwaji, Samer; Johnson, Michel B.; Kheirabadi, Ali C.; Groulx, Dominic; White, Mary Anne

    2016-01-01

    Highlights: • Decanoic/tetradecanoic acid eutectic at 0.82 ± 0.02 mole fraction (78 ± 2 mass%) decanoic acid. • Melting of eutectic at 20.5 ± 1.5 °C, useful for building applications. • High enthalpy change, 153 ± 15 J g −1 , is promising. • Negligible change in stability after 3000 melt–freeze cycles. - Abstract: We present a thorough characterization of the thermal properties and thermal reliability of the eutectic mixture of decanoic acid with tetradecanoic acid, as a phase change material (PCM) of potential interest for passive temperature control in buildings. From the temperature-composition binary phase diagram we found that the eutectic composition is 0.82 ± 0.02 mole fraction (78 ± 2 mass%) decanoic acid. We thoroughly characterized the thermal properties of the eutectic mixture. The eutectic composition has a high latent heat of fusion Δ fus H = 153 ± 15 J g −1 and a melting temperature T onset = 20.5 ± 1.5 °C. The heat capacity measured as a function of temperature for the solid and liquid phases just below and above the melting point is 1.9 and 2.1 ± 0.2 J K −1 g −1 , respectively. The average value of the thermal conductivity of the solid phase measured between −33 and 9 °C is κ s = 0.20 ± 0.02 W m −1 K −1 and for the liquid phase, the thermal conductivity is κ l = 0.23 ± 0.03 W m −1 K −1 for 28 and 38 °C. The mixture has a good long-term thermal stability as indicated by negligible changes in Δ fus H and T onset after 3000 melt–freeze cycles. The parameters determined in this work allow more accurate modeling and optimization of the behavior of the eutectic mixture in preparation for implementation as a thermal energy storage PCM.

  19. The solid-liquid separation characteristics of pure LiCl-KCl eutectic salt using different types of crucibles

    International Nuclear Information System (INIS)

    Ki-Min Park; Sang-Woon Kwon; Jeong-Guk Kim; Choon-Ho Cho

    2013-01-01

    Uranium deposits were recovered at the solid cathode of an electrorefining system, and deposited uranium dendrite normally contains about 30-40 wt% LiCl-KCl eutectic salts. Therefore, a separation of the eutectic salts from deposited uranium is essential for reusing these salts and uranium. A process such as distillation was employed for cathode processing due to the advantages of a minimal generation of secondary waste, a compact unit process, and simple and low-cost equipment. However, the realization of a wide evaporation area or high distillation temperature is limited by various factors such as the material or structure of a distiller. Also, the electrical energy flow from outside has a lot of consumption to maintain the high temperature. Hence, in this study, solid-liquid separation experiments are proposed to increase the throughput of the salt removal process by the separation of the liquid salt prior to the distillation of the LiCl-KCl eutectic salt. The solid-liquid separation of salt was carried out in a vertical type distiller. The behavior of the solid-liquid separation of pure eutectic salt was investigated as a function of temperature, pressure, sieve size, and crucible shape. From the experimental results using pure eutectic salts, the amount of salt separation was achieved at more than 94 wt%. The rate of solid-liquid separation of salt using 600 deg C is higher than that of 500 deg C under the same condition. The influence of a vacuum for solid-liquid separation can be disregarded, and the separation rate of a 100 mesh was higher than that of a 150 mesh. In addition, the rate of separation for salts using a porous crucible is higher than that in a non-porous crucible. (author)

  20. Thermal properties and reliability of eutectic mixture of stearic acid-acetamide as phase change material for latent heat storage

    International Nuclear Information System (INIS)

    Ma, Guixiang; Han, Lipeng; Sun, Jinhe; Jia, Yongzhong

    2017-01-01

    Highlights: • The system of stearic acid-acetamide binary mixtures were studied as phase change material. • The eutectic mixtures featured low melting temperatures and high latent heats of fusion for latent heat storage. • Solid-liquid phase diagrams for the system were constructed. • Negligible change in stability after 500 heating/cooling cycles. - Abstract: The thermal properties and reliability of the stearic acid (SA) with acetamide (AC) binary mixture were characterized using differential scanning calorimetry (DSC), powder X-ray diffraction (XRD), thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FT-IR). The phase diagrams for the SA-AC binary mixture with AC in the metastable and the stable form were constructed. The eutectic system with stable AC is 0.604 mol fraction SA, and displayed a melting temperature (T m ) of 64.55 °C and latent heat of melting (ΔH m ) of 193.87 J·g −1 . The eutectic systems with metastable AC are 0.397 and 0.604 mol fraction SA. The melting temperatures are 62.23 °C and 62.54 °C, and latent heats of fusion are 222.10 J·g −1 and 194.28 J·g −1 , respectively. Following accelerated thermal cycling tests, TG and FT-IR analysis indicate that the eutectic mixture (χ SA = 0.397) with the metastable AC has good cyclic and thermal stability. The results show that the SA-AC eutectic mixture use as phase change material (PCM) possess good prospect for low temperature thermal energy storage (TES) applications.

  1. Separation of rare earths and other valuable metals from deep-eutectic solvents: a new alternative for the recycling of used NdFeB magnets

    OpenAIRE

    Riano, Sofia; Petranikova, Martina; Onghena, Bieke; Vander Hoogerstraete, Tom; Banerjee, Dipanjan; Foreman, Mark R. St J.; ekberg, christian; BINNEMANS, Koen

    2017-01-01

    International audience; Deep-eutectic solvents (DESs) are used as a promising alternative to aqueous solutions for the recovery of valuable metals from NdFeB magnets. A deep-eutectic solvent based on choline chloride and lactic acid (molar ratio 1 : 2) was used for the leaching of rare earths and other metals from NdFeB magnets. A process for the separation of Fe, B and Co from Nd and Dy in the deep-eutectic solvent was developed by using the ionic liquid tricaprylmethylammonium thiocyanate (...

  2. Voltammetry of uranyl chloride in the LiCl - KCl eutectic

    International Nuclear Information System (INIS)

    Fondanaiche, J.C.

    1965-01-01

    Spent UO 2 - PuO 2 fuels can be reprocessed in a molten salt media. Uranium dioxide can easily be dissolved as UO 2 Cl 2 in a molten salt bath using chlorine gas. A study of quantitative analysis of an uranyl chloride solution in the LiCl-KCl eutectic at 400 C has been performed here using voltammetry (a large area-graphite indicator electrode has been employed). The precision which is obtained is around 6 per cent for concentrations below 10 -2 M. Precision decreases slightly for more concentrated solutions. The study of polarization curves allowed to give a reduction mechanism for the UO 2 ++ ion. For dilute solutions, this reduction proceeds through the UO 2 + ion. But interpretation of current-potential curves is made difficult by the dismutation reaction of the UO 2 ion and by the fact that the surface of the indicator electrode is not renewed. (author) [fr

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

    Science.gov (United States)

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

    2004-07-28

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

  4. Low-energy biomass pretreatment with deep eutectic solvents for bio-butanol production.

    Science.gov (United States)

    Procentese, Alessandra; Raganati, Francesca; Olivieri, Giuseppe; Russo, Maria Elena; Rehmann, Lars; Marzocchella, Antonio

    2017-11-01

    Waste lettuce leaves - from the "fresh cut vegetable" industry - were pretreated with the deep eutectic solvent (DES) made of choline chloride - glycerol. Reaction time (3-16h) and the operation temperature (80-150°C) were investigated. Enzymatic glucose and xylose yields of 94.9% and 75.0%, respectively were obtained when the biomass was pretreated at 150°C for 16h. Sugars contained in the biomass hydrolysate were fermented in batch cultures of Clostridium acetobutylicum DSMZ 792. The energy consumption and the energy efficiency related to the DES pretreatment were calculated and compared to the most common lignocellulosic pretreatment processes reported in the literature. The DES pretreatment process was characterized by lower energy required (about 28% decrease and 72% decrease) than the NAOH pretreatment and steam explosion process respectively. The Net Energy Ratio (NER) value related to butanol production via DES biomass pretreatment was assessed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Study of thermodynamic properties of Np-Al alloys in molten LiCl-KCl eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, E.; Soucek, P.; Malmbeck, R.; Glatz, J. P. [Institute for Transuranium Elements, Karlsruhe (Germany); Caravaca, C. [CIEMAT, DE/DFN/URAA, Madrid (Spain)

    2008-08-15

    This work is focused on chemical characterisation and determination of thermodynamic properties of Np-Al alloys. The alloys are formed on a solid Al electrode during Np electrodeposition in molten LiCl-KCl Eutectic. Open circuit potential measurements, after small depositions of Np metal onto the Al electrode were used to determine thermodynamic properties of the Np-Al alloys formed (G, H, S, activity of Np in Al) by an e.m.f. method. Galvanostatic electrolyses were carried out on an Al plates. Stable Np-Al deposit was obtained and identified, by XRD analysis, as a mixture NpAl{sub 3} and NpAl{sub 4} alloys.

  6. Thermoelectric and morphological effects of Peltier pulsing on directional solidification of eutectic Bi-Mn

    Science.gov (United States)

    Silberstein, R. P.; Larson, D. J., Jr.; Dressler, B.

    1984-01-01

    Extensive in situ thermal measurements using Peltier Interface Demarcation (PID) during directional solidification of eutectic Bi/MnBi were carried out. Observations indicate that significant thermal transients occur throughout the sample as a result of the Peltier pulsing. The contributions of the Peltier, Thomson, and Joule heats were separated and studied as a function of pulse intensity and polarity. The Joule and the combined Peltier and Thomson thermal contributions were determined as a function of time during and after the current pulses, close to the solid/liquid interface. Variations of the Bi/MnBi particle morphology clearly reveal the interface shape, changes in interface velocity, meltback, and temporary loss of cooperative growth, as a result of the pulsing.

  7. MYRRHA ADS DATABASE: Part I. Thermophysical properties of molten lead-bismuth eutectic. Version 1

    International Nuclear Information System (INIS)

    Sobolev, V.

    2005-11-01

    This report is an update of the internal SCK-CEN report IR-18 'Database of thermal properties for the melted lead-bismuth eutectic' issued in 2002. This compilation takes into account larger amount of original sources and, partially, the work performed in the framework of the preparation of a 'zero' version of the HLMC Handbook by the OECD/NEA Working Group on LBE Technology. An analysis is performed of the previous recommendations using some general physical laws and referencing to the properties of lead and bismuth. The updated and extended version of the molten LBE thermal properties database is developed and the correlations are proposed for the design calculations of ADS MYRRHA. (author)

  8. Tensile behavior of an eutectic Pb–Sn alloy processed by ECAP and rolling

    Directory of Open Access Journals (Sweden)

    Livia Ponzo Lugon

    2014-10-01

    Full Text Available A eutectic lead–tin alloy was prepared by melting the commercially pure metals and cast in cylindrical molds with 10 mm diameter. The billets were processed by 4 passes of ECAP using a die with 90° between channels through route A and rolled to a final thickness of ∼1 mm. The microstructure was determined by optical microscopy. Tensile tests were carried out at room temperature in the strain rate range between 10−4 and 10−2 s−1. The results show the elongation to failure increases at low strain-rates. The strain-rate sensitivity parameter was determined and a maximum value of ∼0.4 was observed at the lowest strain-rate.

  9. Effect of Chemical Composition on Number of Eutectic Colonies in Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    Janus A.

    2013-03-01

    Full Text Available Determined were direction and intensity of influence of alloying additions on the number of eutectic graphite colonies in austenitic cast iron Ni-Mn-Cu. Chemical composition of the cast iron was 1.7 to 3.3% C, 1.4 to 3.1% Si, 2.8 to 9.9% Ni, 0.4 to 7.7% Mn, 0 to 4.6% Cu, 0.14 to 0.16% P and 0.03 to 0.04% S. Analysed were structures of mottled (20 castings and grey (20 castings cast iron. Obtained were regression equations determining influence intensity of individual components on the number of graphite colonies per 1 cm2 (LK. It was found that, in spite of high total content of alloying elements in the examined cast iron, the element that mainly decides the LK value is carbon, like in a plain cast iron.

  10. Self-organized Sr leads to solid state twinning in nano-scaled eutectic Si phase.

    Science.gov (United States)

    Albu, M; Pal, A; Gspan, C; Picu, R C; Hofer, F; Kothleitner, G

    2016-08-16

    A new mechanism for twin nucleation in the eutectic Al-Si alloy with trace Sr impurities is proposed. Observations made by sub-angstrom resolution scanning transmission electron microscopy and X-ray probing proved the presence of Sr columns located preferentially at twin boundaries. Density functional theory simulations indicate that Sr atoms bind in the Si lattice only along the direction, with preferential positions at first and second nearest neighbors for interstitial and substitutional Sr, respectively. Density functional theory total energy calculations confirm that twin nucleation at Sr columns is energetically favorable. Hence, twins may nucleate in Si precipitates after solidification, which provides a different perspective to the currently accepted mechanism which suggests twin formation during precipitate growth.

  11. Oxygen measurements in stagnant lead-bismuth eutectic using electrochemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Konys, J. [Forschungszentrum Karlsruhe GmbH, Institute for Materials Research III, 76021 Karlsruhe (Germany); Muscher, H. [Forschungszentrum Karlsruhe GmbH, Institute for Materials Research III, 76021 Karlsruhe (Germany)]. E-mail: heinrich.muscher@imf.fzk.de; Voss, Z. [Forschungszentrum Karlsruhe GmbH, Institute for Materials Research III, 76021 Karlsruhe (Germany); Wedemeyer, O. [Forschungszentrum Karlsruhe GmbH, Institute for Materials Research III, 76021 Karlsruhe (Germany)

    2004-11-01

    Sensors are the major part of an active oxygen control system (OCS) to be used in ADS reactors employing lead bismuth eutectic (LBE). We tested Pt/air and Bi/Bi{sub 2}O{sub 3} probes based on yttria-stabilized zirconia (YSZ) solid electrolytes. The sensors were calibrated by evaluating the electromotive force (EMF) - temperature dependencies in oxygen un-/saturated stagnant LBE compared to the van't-Hoff's isotherm. Also, probe kinetics while changing the H{sub 2}/H{sub 2}O ratio was studied. Typical, reproducible curves are presented confirming attainment of oxygen equilibrium between the fluids. The sensor outputs are deterministic, predictable. Exceptional small drifts were due to interfacial kinetics, not to the sensors behavior. Simultaneous testing of several probes in one melt was performed. The sensors seemed to be qualified for large scale use.

  12. Thermophoresis research of nanoparticles in liquid lead-bismuth eutectic alloy

    International Nuclear Information System (INIS)

    Yang Xu; Zhou Tao; Liu Liang; Fang Xiaolu; Lin Daping

    2015-01-01

    Thermophoresis theory of solid particles in liquid are selected to research thermophoresis phenomenon in liquid Lead-Bismuth Eutectic (LBE). Thermophoretic velocity of different particles in LBE and stainless steel particles in different fluid are calculated. The results showed that, thermophoretic velocity of particles in LBE increase with the increase of temperature gradient and the decrease of particle radius. And the thermophoretic velocity of stainless steel particles two orders of magnitude lower than the Carbon Nanotubes (CNT) particles, at the same time, it is similar to copper particles in LBE. What's more, the thermophoretic velocity of stainless steel particles in LBE would one order of magnitude lower than that in water and R134a. Of course, it is still faster than that in Engine Oil and Ethyl Glycol two orders of magnitude. (author)

  13. Fabrication of capacitive absolute pressure sensor using Si-Au eutectic bonding in SOI wafer

    International Nuclear Information System (INIS)

    Lee, Kang Ryeol; Kim, Kunnyun; Park, Hyo-Derk; Kim, Yong Kook; Choi, Seung-Woo; Choi, Woo-Beom

    2006-01-01

    A capacitive absolute pressure sensor was fabricated using a large deflected diaphragm with a sealed vacuum cavity formed by removing handling silicon wafer and oxide layers from a SOI wafer after eutectic bonding of a silicon wafer to the SOI wafer. The deflected displacements of the diaphragm formed by the vacuum cavity in the fabricated sensor were similar to simulation results. Initial capacitance values were about 2.18pF and 3.65pF under normal atmosphere, where the thicknesses of the diaphragm used to fabricate the vacuum cavity were 20 μm and 30 μm, respectively. Also, it was confirmed that the differences of capacitance value from 1000hPa to 5hPa were about 2.57pF and 5.35pF, respectively

  14. Electrochemical study of actinide nitrides in LiCl-KCl eutectic melts

    International Nuclear Information System (INIS)

    Shirai, Osamu; Iwai, Takashi; Arai, Yasuo; Kato, Tetsuya

    2003-01-01

    Nitride fuels for advanced fast breeder reactors, transmutation of minor actinides and Pu burning fast reactors have been contemplated because of their high thermal conductivity and high melting point. Research on the pyro-chemical reprocessing of nitride fuels has been conducted at the JAERI based on chlorine molten salt electro-refining to obtain fundamental data of redox reactions and pyro-chemistry for minor actinides such as NpN, AmN, CmN and their solid solutions. Experiments on anodic dissolution of UN, PuN and NpN in LiCl-KCl eutectic melts were made with cyclic voltamogram measurements and redox reactions of each actinide nitride were analyzed to show mechanisms of chlorine nitrides formation and establish optimum conditions of actinide metal recovery onto solid cathode. (T. Tanaka)

  15. Direct construction of diverse metallophthalocyanines by manifold substrates in a deep eutectic solvent

    Science.gov (United States)

    Shaabani, Ahmad; Hooshmand, Seyyed Emad; Afshari, Ronak; Shaabani, Shabnam; Ghasemi, Vahid; Atharnezhad, Mojtaba; Akbari, Masoud

    2018-02-01

    Direct access to a wide range of metal-free phthalocyanines and metallophthalocyanines in deep eutectic solvents (DESs), is reported. Substituted and unsubstituted phthalocyanines of Mn, Fe, Co, Ni, Cu, Zn, Pd, In, and Pt with various raw materials such as phthalonitriles, phthalimides, phthalic anhydrides and phthalic acids are successfully prepared in the DES based on choline chloride and urea in a very short reaction time with appropriate yields. It has been shown that DES as a green and rapidly degraded reaction medium in the environment plays a triple role as a solvent, organocatalyst, and reactant in this process. Moreover, the DES system could be separated and reused in four consecutive reaction runs with no considerable loss in catalytic activity.

  16. Towards the development of continuous, organocatalytic, and stereoselective reactions in deep eutectic solvents

    Directory of Open Access Journals (Sweden)

    Davide Brenna

    2016-12-01

    Full Text Available Different deep eutectic solvent (DES mixtures were studied as reaction media for the continuous synthesis of enantiomerically enriched products by testing different experimental set-ups. L-Proline-catalysed cross-aldol reactions were efficiently performed in continuo, with high yield (99%, anti-stereoselectivity, and enantioselectivity (up to 97% ee. Moreover, using two different DES mixtures, the diastereoselectivity of the process could be tuned, thereby leading to the formation, under different experimental conditions, to both the syn- and the anti-isomer with very high enantioselectivity. The excess of cyclohexanone was recovered and reused, and the reaction could be run and the product isolated without the use of any organic solvent by a proper choice of DES components. The dramatic influence of the reaction media on the reaction rate and stereoselectivity of the process suggests that the intimate architecture of DESs deeply influences the reactivity of different species involved in the catalytic cycle.

  17. Template Directed Oligomer Ligation in Eutectic Phases in Water-Ice

    DEFF Research Database (Denmark)

    Dörr, Mark; Löffler, Philipp M. G.; Wieczorek, Rafal

    2011-01-01

    achieved, if small, activated, oligonucleotides are ligated on a template. A template directed ligation can lead to autocatalytic or cross- catalytic replication and thus maintain a certain pool of catalyitc species. Important for these processes is a destabilization of the formed douplex....../multiplex to overcome product inhibition. The latest results of our template directed ligation experiments in the eutectic ice phase are presented. Different activation strategies are compared and an outlook towards applications in molecular evolution and artifical cell systems (« protocells ») will be given. Figure 1....... (a) Reaction scheme of the condensation reaction of two oligoribonucleotides : The leaving group in this example is imidazole. (b) Illustration of a possible spatial arrangement of a template (15nt) directed ligation. The 7-mer is activated with imidazole at the 5' phosphate (apical moiety...

  18. The buoyancy convection during directional solidification of AlZn eutectic

    International Nuclear Information System (INIS)

    Prazak, M.; Procio, M.; Holecek, S.

    1993-01-01

    A study has been made of the effect of buoyancy convection during the directional solidification of AlZn eutectic alloy. Experiments have been conducted using a Bridgman-Stockbarger arrangement with the furnace moving along the specimen. The apparatus rotated around the horizontal axis, which made it possible to carry out measurements at different angles β contained by the gravity and temperature gradient vectors in the specimen. The anisotropy of both the linear thermal expansion coefficient a and the hardness HK measured by the Knoop method has been studied. The dilatation measurements confirmed the expected anisotropy of the linear thermal expansion of directionally solidified specimens. The values of HK correspond with the lamellar spacing measured in the metallographic study. (orig.)

  19. Superconductivity in filamentary eutectic composites. Progress report, June 1, 1980-May 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Zaitlin, M P

    1980-01-01

    Measurements of electrical resistivity and magnetic susceptibility have been performed as a function of temperature on samples of Nb-Th eutectic composite. Samples with Nb filament radii as small as 38A were used which is considerably less than the coherence length xi in Nb of approx. 380A. Surprisingly, measurements of all samples showed a drop in electrical resistance near the transition temperature of bulk Nb and an unmeasurably small resistance by approx. 8K. The magnetic susceptibility showed essentially perfect diamagnetism below approx. 7 to 9K even for samples with the smallest of filament radii. This is in contradiction to theories of the proximity effect which predict a sharp decrease in the transition temperature for samples with a radius smaller than xi. Some measurements in a static magnetic field have also been made.

  20. Towards eco-friendly crop protection: natural deep eutectic solvents and defensive secondary metabolites.

    Science.gov (United States)

    Mouden, Sanae; Klinkhamer, Peter G L; Choi, Young Hae; Leiss, Kirsten A

    2017-01-01

    With mounting concerns over health and environmental effects of pesticides, the search for environmentally acceptable substitutes has amplified. Plant secondary metabolites appear in the horizon as an attractive solution for green crop protection. This paper reviews the need for changes in the techniques and compounds that, until recently, have been the mainstay for dealing with pest insects. Here we describe and discuss main strategies for selecting plant-derived metabolites as candidates for sustainable agriculture. The second part surveys ten important insecticidal compounds, with special emphasis on those involved in human health. Many of these insecticidal metabolites, however, are crystalline solids with limited solubility which might potentially hamper commercial formulation. As such, we introduce the concept of natural deep eutectic solvents for enhancing solubility and stability of such compounds. The concept, principles and examples of green pest control discussed here offer a new suite of environmental-friendly tools designed to promote and adopt sustainable agriculture.

  1. Continuous sodium modification of nearly-eutectic aluminium alloys. Part II. Experimental studiem

    Directory of Open Access Journals (Sweden)

    Białobrzeski A.

    2007-01-01

    Full Text Available One of the possible means of continuous sodium modification of nearly-eutectic alloys may be continuous electrolysis of sodium compounds (salts, taking place directly in metal bath (in the crucible. For this process it is necessary to use a solid electrolyte conducting sodium ions. Under the effect of the applied direct current voltage, sodium salt placed in a retort made from the solid electrolyte undergoes dissociation, and next - electrolysis. The retort is immersed in liquid metal. The anode is sodium salt, at that temperature occurring in liquid state, connected to the direct current source through, e.g. a graphite electrode, while cathode is the liquid metal. Sodium ions formed during the sodium salt dissociation and electrolysis are transported through the wall of the solid electrolyte (the material of the retort and in contact with liquid alloy acting as a cathode, they are passing into atomic state, modifying the metal bath.

  2. Preparing of LiCl-KCl-UCl3 eutectic salt by a chlorination of Cd

    International Nuclear Information System (INIS)

    Kang, Hee Seok; Woo, Moon Sik; Lee, Han Soo

    2008-01-01

    Uranium trichloride salt(UCl 3 ) is supplied with the initial U in to the LiCl-KCl eutectic salt for a stabilization of the initial cell voltage during an electrorefining process in a reactor. The apparatus for producing UCl 3 consists of a chlorine gas generator, a chlorinator, and an off-gas wet scrubber. Gaseous chlorine in the chlorine gas generator was injected into a lower layer of liquid Cd where CdCl 2 formed. The CdCl 2 reacts with the uranium to form uranium trichloride and Cd. The throughput of the UCl 3 chlorinator is about. 1.4Kg UCl 3 /batch. During a production the temperature of the reactants are maintained at about 600 .deg. C

  3. Meloxicam transdermal delivery: effect of eutectic point on the rate and extent of skin permeation.

    Science.gov (United States)

    Mohammadi-Samani, Soliman; Yousefi, Gholamhossein; Mohammadi, Farhad; Ahmadi, Fatemeh

    2014-02-01

    Drug delivery through the skin can transfer therapeutic levels of drugs for pharmacological effects. Analgesics such as NSAIDs have gastrointestinal side effects and topical dosage forms of these drugs are mainly preferred, especially for local pains. Meloxicam is one of NSAIDs with no topical form in the market. In this research, we attempted to quantify the skin permeation of a meloxicam topical preparation and to show how permeation would be increased by using thymol as an enhancer. The effect of eutectic point of drug and thymol mixture on rate and extent of skin permeation was also studied. Different mixtures of thymol and meloxicam (2:8, 4:6, 5:5, 6:4, 8:2) were prepared and their melting point were obtained by differential scanning calorimetry. Then drug permeation was measured using diffusion cells and the Guinea pig skin. Mixtures in ratios 5:5 and 4:6 of meloxicam / thymol showed a new endotherm at 149 and 140°C in DSC thermograms. The permeability of meloxicam from the creams containing 6:4, 5:5 and 4:6 ratios of meloxicam to thymol were 4.71, 15.2, 22.06 µg/cm(2) respectively. This was significantly different from the cream of pure meloxicam (3.76 µg/cm(2)). This study set out to determine that thymol plays as a skin permeation enhancer and increases the meloxicam skin absorption and this enhancement is significant at the eutectic point of drug-enhancer mixture.

  4. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Science.gov (United States)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan

    2015-09-01

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, 1H-NMR and 13C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  5. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  6. Electrochemical behaviour of dysprosium in the eutectic LiCl-KCl at W and Al electrodes

    International Nuclear Information System (INIS)

    Castrillejo, Y.; Bermejo, M.R.; Barrado, A.I.; Pardo, R.; Barrado, E.; Martinez, A.M.

    2005-01-01

    The electrochemical behaviour of DyCl 3 was studied in the eutectic LiCl-KCl at different temperatures. The cathodic reaction can be written:Dy(III)+3e-bar Dy(0)which can be divided in two very close cathodic steps:Dy(III)+1e-bar Dy(II)andDy(II)+2e-bar Dy(0)Transient electrochemical techniques, such as cyclic voltammetry, chronopotentiometry, and chronoamperometry were used in order to study the reaction mechanism and the transport parameters of electroactive species at a tungsten electrode. The results showed that in the eutectic LiCl-KCl, electrocrystallization of dysprosium seems to be the controlling electrochemical step. Chronoamperometric studies indicated instantaneous nucleation of dysprosium with three dimensional growth of the nuclei whatever the applied overpotential.Mass transport towards the electrode is a simple diffusion process, and the diffusion coefficient of the electroactive species, i.e. Dy(III), has been calculated. The validity of the Arrhenius law was also verified by plotting the variation of the logarithm of the diffusion coefficient versus 1/T.In addition, the electrode reactions of the LiCl-KCl-DyCl 3 solutions at an Al wire were also investigated by cyclic voltammetry and open circuit chronopotentiometry. The redox potential of the Dy(III)/Dy couple at the Al electrode was observed at more positive potentials values than those at the inert electrode. This potential shift was thermodynamically analyzed by a lowering of activity of Dy in the metal phase due to the formation of intermetallic compounds

  7. Características físico-químicas de las dunitas serpentinizadas de la región de Moa-Baracoa (zonas Amores y Miraflores)

    OpenAIRE

    María C. Ramírez-Pérez; Gleurides Rodríguez-Martínez; Carlos A. Leyva-Rodríguez; José A. Pons-Herrera

    2000-01-01

    Los principales resultados de la caracterización físico-química y mineralógica de las dunitas serpentinizadas de las zonas de Amores y Miraflores en la región de Moa-Baracoa, se exponen en este trabajo. Se demuestra la presencia de minerales del grupo de la serpentina, principalmente antigorita, debido al proceso de serpentinización que ha afectado a estas rocas, y su transformación en fase forsterita luego de su calentamiento. Estos aspectos revisten especial importancia para las investigaci...

  8. Fatty acid eutectic/polymethyl methacrylate composite as form-stable phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lijiu; Meng, Duo [School of Civil Engineering, Dalian University of Technology, Dalian 116024 (China)

    2010-08-15

    This work is focused on the preparation and characterization of fatty acid eutectic/polymethyl methacrylate (PMMA) form-stable phase change material (PCM). Capric acid (CA), lauric acid (LA), myristic acid (MA) and stearic acid (SA) were selected to prepare binary fatty acid eutectic for the sake of decreasing the phase change temperature. Using the method of self-polymerization, CA-LA, CA-MA, CA-SA and LA-MA eutectics acting as the heat-absorbing materials and PMMA serving as the supporting material were compounded in the ratio of 50/50 wt.%. The relations between mass fraction of LA-MA eutectic and latent heat and compressive strength of LA-MA/PMMA composite were discussed, and the feasible maximum mass fraction of LA-MA eutectic was determined to be 70%. CA-LA/PMMA, CA-MA/PMMA, CA-SA/PMMA and LA-MA/PMMA composites were examined to investigate their potential application in building energy conservation. Scanning electron microscope and polarizing optical microscope observations showed that fatty acid eutectic was coated by PMMA thus the composite remained solid when the sample was heated above the melted point of the fatty acid. Fourier-transform infrared results indicated that fatty acid and PMMA had no chemical reaction and exhibited good compatibility with each other. According to the differential scanning calorimetry results, phase change temperatures of CA-LA/PMMA, CA-MA/PMMA, CA-SA/PMMA and LA-MA/PMMA composites were 21.11 C, 25.16 C, 26.38 C and 34.81 C and their latent heat values were determined to be 76.3 kJ/kg, 69.32 kJ/kg, 59.29 kJ/kg and 80.75 kJ/kg, respectively. Moreover, thermal stability and expansibility of the form-stable PCMs were characterized by thermogravimetric analysis and volume expansion coefficient respectively, and the results indicated that the composites were available for building energy conservation. (author)

  9. Directionally solidified Eu doped CaF.sub.2./sub./Li.sub.3./sub.AlF.sub.6./sub. eutectic scintillator for neutron detection

    Czech Academy of Sciences Publication Activity Database

    Kamada, K.; Hishinuma, K.; Kurosawa, S.; Shoji, Y.; Pejchal, Jan; Ohashi, Y.; Yokota, Y.; Yoshikawa, A.

    2015-01-01

    Roč. 50, Dec (2015), 71-75 ISSN 0925-3467 Institutional support: RVO:68378271 Keywords : scintillator * eutectic * micro-pulling down Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2015

  10. Reply to "On Vaporization of liquid Pb-Li eutectic alloy from 1000 K to 1200 K- A high temperature mass spectrometric study"

    Science.gov (United States)

    Jain, Uttam; Mukherjee, Abhishek

    2018-03-01

    This communication is in response to a letter to editor commenting on the authors' earlier paper "Vaporization of liquid Pb-Li eutectic alloy from 1000 K to 1200 K - A high temperature mass spectrometric study".

  11. Fe-Al-Nb phase diagram investigation and directional growth of the (Fe, Al){sub 2}Nb-(Fe, Al, Nb){sub ss} eutectic system

    Energy Technology Data Exchange (ETDEWEB)

    Mota, M.A. [State University of Campinas, C.P. 6122, 13083-970 Campinas, SP (Brazil); Coelho, A.A. [State University of Campinas, C.P. 6122, 13083-970 Campinas, SP (Brazil); Bejarano, J.M.Z. [State University of Campinas, C.P. 6122, 13083-970 Campinas, SP (Brazil); Gama, S. [State University of Campinas, C.P. 6122, 13083-970 Campinas, SP (Brazil); Caram, R. [State University of Campinas, C.P. 6122, 13083-970 Campinas, SP (Brazil)]. E-mail: rcaram@fem.unicamp.br

    2005-08-16

    An attractive alternative method for the manufacture of high temperature structural materials may be achieved from a eutectic transformation found in the Fe-Al-Nb system, which generates the (Fe, Al){sub 2}Nb and (Fe, Al, Nb){sub ss} solid phases. Eutectic and off-eutectic samples from the Fe-Al-Nb system were prepared by arc melting under argon atmosphere, which were subsequently directionally solidified using a vertical Bridgman crystal growth unit. The ingots obtained were investigated using optical and electron scanning microscopy with the purpose to evaluate the effect of the growth condition on the microstructure. Primarily, the growth mode of the (Fe, Al){sub 2}Nb/(Fe, Al, Nb) eutectic was considered by examining off-eutectic samples. The solidification experiments carried out under different conditions revealed that the microstructure of this system is very sensitive to a growth rate variation. At a low growth rate, the eutectic microstructure was regular, even though several types of defects were found. As the growth rate was increased, a transition from lamellar to fibrous morphology was observed. Some aspects of this transition were also evaluated.

  12. Initial Stages of GaAs/Au Eutectic Alloy Formation for the Growth of GaAs Nano wires

    International Nuclear Information System (INIS)

    Rosnita, M.; Yussof, W.; Zuhairi, I.; Zulkafli, O.; Samsudi, S.

    2012-01-01

    Annealing temperature plays an important role in the formation of an Au-Ga eutectic alloy. The effects of the annealing temperature on gold nanoparticles colloid and substrate surface were studied using AFM, FE-SEM and TEM. At 600 degree Celsius, the layer of gold colloids particle formed an island in the state of molten eutectic alloy and absorbed evaporated metal-organics to formed nano wire (NW) underneath the alloy. Pit formed on the substrate surface due to the chemical reactions during the annealing process have an impact on the direction of growth of the NW. Without annealing, the NW formed vertically on the GaAs (100) surface. The growth direction depends on the original nucleation facets and surface energy when annealed. When annealed, the wire base is large and curved due to the migration of Ga atoms on the substrate surface towards the tip of the wire and the line tension between the substrate surface and gold particle. (author)

  13. Following the electroreduction of uranium dioxide to uranium in LiCl–KCl eutectic in situ using synchrotron radiation

    OpenAIRE

    Brown, L.D.; Abdulaziz, R.; Jervis, R.; Bharath, V.J.; Atwood, R.C.; Reinhard, C.; Connor, L.D.; Simons, S.J.R.; Inman, D.; Brett, D.J.L.; Shearing, P.R.

    2015-01-01

    The electrochemical reduction of uranium dioxide to metallic uranium has been investigated in lithium chloride–potassium chloride eutectic molten salt. Laboratory based electrochemical studies have been coupled with in situ energy dispersive X-ray diffraction, for the first time, to deduce the reduction pathway. No intermediate phases were identified using the X-ray diffraction before, during or after electroreduction to form α-uranium. This suggests that the electrochemical reduction occurs ...

  14. Thermal properties and thermal reliability of eutectic mixtures of some fatty acids as latent heat storage materials

    International Nuclear Information System (INIS)

    Sari, Ahmet; Sari, Hayati; Oenal, Adem

    2004-01-01

    The present study deals with two subjects. The first one is to determine the thermal properties of lauric acid (LA)-stearic acid (SA), myristic acid (MA)-palmitic acid (PA) and palmitic acid (PA)-stearic acid (SA) eutectic mixtures as latent heat storage material. The properties were measured by the differential scanning calorimetry (DSC) analysis technique. The second one is to study the thermal reliability of these materials in view of the change in their melting temperatures and latent heats of fusion with respect to repeated thermal cycles. For this aim, the eutectic mixtures were subjected to 360 repeated melt/freeze cycles, and their thermal properties were measured after 0, 90,180 and 360 thermal cycles by the technique of DSC analysis. The DSC thermal analysis results show that the binary systems of LA-SA in the ratio of 75.5:24.5 wt.%, MA-PA in the ratio of 58:42 wt.% and PA-SA in the ratio of 64.2:35.8 wt.% form eutectic mixtures with melting temperatures of 37.0, 42.60 and 52.30 deg. C and with latent heats of fusion of 182.7, 169.7 and 181.7 J g -1 , respectively. These thermal properties make them possible for heat storage in passive solar heating applications with respect to climate conditions. The accelerated thermal cycle tests indicate that the changes in the melting temperatures and latent heats of fusion of the studied eutectic mixtures are not regular with increasing number of thermal cycles. However, these materials, latent heat energy storage materials, have good thermal reliability in terms of the change in their thermal properties with respect to thermal cycling for about a one year utility period

  15. Growth of LiF/LiBaF.sub.3./sub. eutectic scintillator crystals and their optical properties

    Czech Academy of Sciences Publication Activity Database

    Kurosawa, S.; Yamaji, A.; Pejchal, Jan; Yokota, Y.; Ohashi, Y.; Kamada, K.; Yoshikawa, A.

    2017-01-01

    Roč. 52, č. 10 (2017), s. 5531-5536 ISSN 0022-2461 Grant - others:AV ČR(CZ) JSPS-17-18 Program:Bilaterální spolupráce Institutional support: RVO:68378271 Keywords : scintillators * eutectics * crystal growth Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.599, year: 2016

  16. Capture and Solidification of Rare Earth Nuclide (Nd) in LiCl-KCl Eutectic Salt Using a Synthetic Inorganic Composite

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Na-Young; Eun, Hee-Chul; Park, Hwan-Seo; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    In this study, neodymium (Nd) nuclides in LiCl-KCl eutectic salts were captured and solidified using a synthetic inorganic composite (Li{sub 2}O-SiO{sub 2}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}), a process that allows the selective capture of Nd and fabrication of a composite with Nd captured from waste, without additional additives or mixing. The Nd nuclides in the LiCl-KCl eutectic salt were mainly captured in the form of LiNdSiO{sub 4}, and it was confirmed that NdSiO{sub 3} can be formed in the composite with captured Nd when the content of Nd in the composite is increased. The capture efficiency was higher than about 98 wt%. It was thought that the salt recovered from the Nd capture test was a renewable form could be reused in the pyroprocessing of used nuclear fuel, because the composite has high chemical durability in a LiCl-KCl eutectic salt at 900 ℃. The composite captured Nd was fabricated into a homogeneous glass form and a stable ceramic form.

  17. Long-Term Stability Evaluation of a Sn-Doped Ni-C Eutectic Cell Suitable for Radiation Thermometry

    Science.gov (United States)

    Teixeira, R. N.; Machin, G.

    2017-07-01

    Metal carbon eutectic cells (high-temperature fixed points, HTFPs) (Machin in AIP Conf Proc 1552:305, 2013) are being considered for use as reliable high-temperature references for non-contact thermometry above the copper point (1084.62°C). Recent studies have demonstrated the concept of using doped metal carbon eutectic cells as artefacts suitable for temperature scale comparisons (Teixeira et al. in AIP Conf Proc 1552:363, 2013; Teixeira et al. in Int J Thermophys 35:467-474, 2014; Machin et al. in Int J Thermophys 36:327-335, 2015). When using such artefacts, the participating institutes do not know the realization temperature of the doped HTFP cell, because it has been modified by the addition of a selected dopant at a definite concentration. The use of such fixed points can critically evaluate the real measurement capability of the institutes in any comparison. The pyrometry laboratory of Inmetro developed a set of doped Ni-C eutectic cells in 2012 and 2013. This paper describes the long-term stability of a Sn-doped Ni-C cell constructed in 2012, which accumulated more than 220 h above 1300°C amounting to more than 50 cycles of melts and freezes. The cell remained stable, well within the measurement uncertainty, throughout the evaluation period demonstrating the utility of such cells for scale comparison purposes.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jhong, Huei-Ru; Wong, David Shan-Hill; Wan, Chi-Chao; Wang, Yung-Yun [Department of Chemical Engineering, National Tsing-Hua University, 101 Guang Fu Road, Section 2, Hsin-chu, Taiwan 30013 (China); Wei, Tzu-Chien [Tripod Technology Corporation, Hsin-chu, Taiwan 30013 (China)

    2009-01-15

    We utilize a quaternary ammonium salt-derivative ionic liquid called G.CI which is a eutectic mixture of glycerol and choline iodide as electrolyte for dye-sensitized solar cells. Such eutectic compound belongs to a new series of ionic liquid called deep eutectic solvents (DES), which possess many outstanding features compared to the traditional imidazolium-based ionic liquids including cheap raw materials, simple preparation procedures and better biocompatibility. Current-voltage characteristics of the G.CI/PMII-based binary electrolytes stand at 0.533 V on V{sub oc}, 12.0 mA cm{sup -2} on J{sub sc}, 0.582 on fill factor, and 3.88% cell efficiency under AM 1.5, 100 mW/cm{sup 2} illuminations. The comparable cell performance together with all the above advantages makes G.CI as a strong candidate for future electrolyte development for dye-sensitized solar cells (DSSCs). (author)

  19. Surfactant-Solvent Interaction Effects on the Micellization of Cationic Surfactants in a Carboxylic Acid-Based Deep Eutectic Solvent.

    Science.gov (United States)

    Sanchez-Fernandez, Adrian; Hammond, Oliver S; Jackson, Andrew J; Arnold, Thomas; Doutch, James; Edler, Karen J

    2017-12-19

    Deep eutectic solvents have been demonstrated to support amphiphile self-assembly, providing potential alternatives as structure-directing agents in the synthesis of nanostructures, and drug delivery. Here we have expanded on this recent research to investigate the self-assembly of alkyltrimethylammonium bromide surfactants in choline chloride:malonic acid deep eutectic solvent and mixtures of the solvent with water. Surface tension and small-angle neutron scattering were used to determine the behavior of the amphiphiles. Surfactants were found to remain active in the solvent, and surface tension measurements revealed changes in the behavior of the surfactants with different levels of hydration. Small-angle neutron scattering shows that in this solvent the micelle shape depends on the surfactant chain length, varying from globular micelles (aspect ratio ∼2) for short chain surfactants to elongated micelles (aspect ratio ∼14) for long chain surfactants even at low surfactant concentration. We suggest that the formation of elongated micelles can be explained through the interaction of the solvent with the surfactant headgroup, since ion-ion interactions between surfactant headgroups and solvent may modify the morphology of the micelles. The presence of water in the deep eutectic solvents promotes an increase in the charge density at the micelle interface and therefore the formation of less elongated, globular micelles.

  20. Highly Simple Deep Eutectic Solvent Extraction of Manganese in Vegetable Samples Prior to Its ICP-OES Analysis.

    Science.gov (United States)

    Bağda, Esra; Altundağ, Hüseyin; Soylak, Mustafa

    2017-10-01

    In the present work, simple and sensitive extraction methods for selective determination of manganese have been successfully developed. The methods were based on solubilization of manganese in deep eutectic solvent medium. Three deep eutectic solvents with choline chloride (vitamin B4) and tartaric/oxalic/citric acids have been prepared. Extraction parameters were optimized with using standard reference material (1573a tomato leaves). The quantitative recovery values were obtained with 1.25 g/L sample to deep eutectic solvent (DES) volume, at 95 °C for 2 h. The limit of detection was found as 0.50, 0.34, and 1.23 μg/L for DES/tartaric, DES/oxalic, and DES/citric acid, respectively. At optimum conditions, the analytical signal was linear for the range of 10-3000 μg/L for all studied DESs with the correlation coefficient >0.99. The extraction methods were applied to different real samples such as basil herb, spinach, dill, and cucumber barks. The known amount of manganese was spiked to samples, and good recovery results were obtained.

  1. Identification of Flavonoids (Quercetin, Gallic acid and Rutin from Catharanthus roseus Plant Parts using Deep Eutectic Solvent

    Directory of Open Access Journals (Sweden)

    Asma Nisar

    2017-02-01

    Full Text Available Green technology is the most important topic in the pharmaceutical field because it reduces the cost of medicines and minimizes the environmental impact of the field and is better for human health and safety. Green chemistry emphasizes that the solvent should be nontoxic, safe, cheap, green, readily available, recyclable, and biodegradable. Deep eutectic solvents, a new type of green solvent, have some renowned properties—for instance, high thermal stability, low vapor pressure, low cost, biodegradability, and high viscosity. In this study, deep eutectic solvents made up of choline chloride-glycerol (1:2 were used for the extraction and isolation of flavonoid (rutin, gallic acid, and quercetin from Catharanthus roseus plant parts, flower petal, leaves, stem, and root. The amounts of rutin and quercetin in flower petal are 29.46 and 6.51%, respectively, whereas, rutin, gallic acid, and quercetin amounts in leaves are 25.16, 8.57, and 10.47%, respectively. In stem the amounts of rutin, gallic acid, and quercetin are 13.02, 5.89, and 7.47%, respectively. In root, only quercetin has been obtained that is 13.49%. The HPLC is an analytical method, which was found to be an excellent technique for determination of rutin, gallic acid, and quercetin using deep eutectic solvent extraction from plant parts of Catharanthus roseus.

  2. Scintillation properties of LiF–SrF2 and LiF–CaF2 eutectic

    International Nuclear Information System (INIS)

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

    2013-01-01

    Dopant free eutectic scintillators 6 LiF–SrF 2 and 6 LiF–CaF 2 were developed by the vertical Bridgeman method for the purpose of thermal neutron detection. The molar ratio of LiF and Ca/SrF 2 was 4:1 on its eutectic composition. The α-ray induced radioluminescence spectra of the scintillators showed intense emission peak at 300 nm due to the emission from the self-trapped exciton in Ca/SrF 2 layers. When the samples were irradiated with 252 Cf neutrons, 6 LiF–SrF 2 and 6 LiF–CaF 2 exhibited the light yields of 4700 and 9400 ph/n, respectively. Scintillation decay times of 6 LiF–SrF 2 and 6 LiF–CaF 2 were accepted for scintillation detectors, 90 and 250 ns, respectively. -- Highlights: • Nondoped LiF–CaF 2 and LiF–SrF 2 eutectic scinitillators are reported for the first time. • Two sample showed self-trapped exciton emission. • LiF–SrF 2 sample exhibited the light yield of 9400 ph/n and this value was comparable to conventional materials doped with rare earth ions. • Scintillation decay times of LiF–CaF 2 and LiF–SrF 2 were 250 and 90 ns, respectively

  3. Compatibility of different stainless steels in molten Pb-Bi eutectic at high temperatures

    International Nuclear Information System (INIS)

    Chandra, K.; Kain, Vivekanand; Laik, A.; Sharma, B.P.; Bhattacharya, S.; Debnath, A.K.

    2005-10-01

    Advanced nuclear reactors and the accelerator driven subcritical (ADS) system require the structural materials to be in contact with the molten metals/lead-bismuth eutectic at 400 degC and higher temperatures. One of the primary concerns in using the molten lead-bismuth eutectic (LBE) as a coolant in the primary circuit of these systems is the degradation of structural materials in contact with LBE. An experimental setup has been fabricated to expose the materials in the molten LBE at high temperatures in stagnant condition under inert atmosphere. Samples from five different stainless steels (types 304L, 316L, 403, duplex SS SAF 2205 and super austenitic SS 2RK65) were exposed in this setup at 450 degC for 200h and at 500 degC for 600 and 2100 h under argon atmosphere. A different setup was prepared in which type 316L SS tube in the as-welded condition was exposed in molten LBE at 500 degC for 1200 h in rotating condition. All the samples showed formation of oxide on their surfaces. The thickness and compositional profiles of these oxides analyzed by EPMA confirmed formation of a double layer oxide on type 316L SS. The oxide thickness was highest on SS 403, while it was lowest on 304L and 316L SS. SEM results showed dissolution of materials at the surface in Sandvik 2RK65 and preferential dissolution of austenite phase in duplex SS. None of the stainless steels, except the duplex and the super austenitic stainless steels, showed any localized or selective corrosion. The composition of LBE before and after the exposure tests was analyzed by XRF technique. The result showed presence of Fe, Cr and Ni in the used LBE but these elements were not present in the virgin Pb-Ei alloy. This showed that the corrosion of stainless steels in LBE at temperatures upto 500 degC is due to oxidation and dissolution of alloying elements through the oxide on stainless steels. (author)

  4. Bulk and interfacial structures of reline deep eutectic solvent: A molecular dynamics study

    Science.gov (United States)

    Kaur, Supreet; Sharma, Shobha; Kashyap, Hemant K.

    2017-11-01

    We apply all-atom molecular dynamics simulations to describe the bulk morphology and interfacial structure of reline, a deep eutectic solvent comprising choline chloride and urea in 1:2 molar ratio, near neutral and charged graphene electrodes. For the bulk phase structural investigation, we analyze the simulated real-space radial distribution functions, X-ray/neutron scattering structure functions, and their partial components. Our study shows that both hydrogen-bonding and long-range correlations between different constituents of reline play a crucial role to lay out the bulk structure of reline. Further, we examine the variation of number density profiles, orientational order parameters, and electrostatic potentials near the neutral and charged graphene electrodes with varying electrode charge density. The present study reveals the presence of profound structural layering of not only the ionic components of reline but also urea near the electrodes. In addition, depending on the electrode charge density, the choline ions and urea molecules render different orientations near the electrodes. The simulated number density and electrostatic potential profiles for reline clearly show the presence of multilayer structures up to a distance of 1.2 nm from the respective electrodes. The observation of positive values of the surface potential at zero charge indicates the presence of significant nonelectrostatic attraction between the choline cation and graphene electrode. The computed differential capacitance (Cd) for reline exhibits an asymmetric bell-shaped curve, signifying different variation of Cd with positive and negative surface potentials.

  5. Uniaxial tensile and shear deformation tests of gold–tin eutectic solder film

    Directory of Open Access Journals (Sweden)

    Takahiro Namazu, Hideki Takemoto, Hiroshi Fujita and Shozo Inoue

    2007-01-01

    Full Text Available This paper describes a novel experimental technique for measuring mechanical properties of gold-tin (Au–Sn eutectic solder film used for soldering package in microelectromechanical systems (MEMS. Dual-source DC magnetron sputtering was employed to deposit Au-20 weight % (wt% Sn film. The tensile test with in situ X-ray diffraction (XRD measurement evaluates the Young's modulus and Poisson's ratio at intermediate temperatures. The Young's modulus and Poisson's ratio at room temperature were found to be 51.3 GPa and 0.288, lower than bulk values. The Young's modulus decreased with increasing temperature, whereas the Poisson's ratio did not depend on temperature. The XRD tensile test also showed creep deformation behavior of Au–Sn film. We have developed a shear deformation test technique, which is performed by using Au–Sn film sandwiched by two single crystal silicon (Si cantilever structures, to characterize the shear properties of the film. The shear moduli obtained from the shear deformation tests ranged from 11.5 to 13.3 GPa, about 38% lower than those from the XRD tensile tests. The measured shear strength from 12 to 17 MPa exhibited a temperature dependency. Information about the tensile and shear characteristics would likely to be of great use in designing Au–Sn soldering packages for MEMS.

  6. Enhancing cellulose accessibility of corn stover by deep eutectic solvent pretreatment for butanol fermentation.

    Science.gov (United States)

    Xu, Guo-Chao; Ding, Ji-Cai; Han, Rui-Zhi; Dong, Jin-Jun; Ni, Ye

    2016-03-01

    In this study, an effective corn stover (CS) pretreatment method was developed for biobutanol fermentation. Deep eutectic solvents (DESs), consisted of quaternary ammonium salts and hydrogen donors, display similar properties to room temperature ionic liquid. Seven DESs with different hydrogen donors were facilely synthesized. Choline chloride:formic acid (ChCl:formic acid), an acidic DES, displayed excellent performance in the pretreatment of corn stover by removal of hemicellulose and lignin as confirmed by SEM, FTIR and XRD analysis. After optimization, glucose released from pretreated CS reached 17.0 g L(-1) and yield of 99%. The CS hydrolysate was successfully utilized in butanol fermentation by Clostridium saccharobutylicum DSM 13864, achieving butanol titer of 5.63 g L(-1) with a yield of 0.17 g g(-1) total sugar and productivity of 0.12 g L(-1)h(-1). This study demonstrates DES could be used as a promising and biocompatible pretreatment method for the conversion of lignocellulosic biomass into biofuel. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Explosive hazards analysis of the eutectic solution NaK and KO2

    International Nuclear Information System (INIS)

    Commander, J.C.

    1975-06-01

    Planning, preparation, conductance, and evaluation of field tests are reported to determine the explosive hazards associated with the combining of the sodium-potassium eutectic alloy (NaK) with the superoxide of potassium (KO 2 ) under various conditions of state, contamination, and detonation initiation. The planning and preparation was conducted by Aerojet Nuclear Company (ANC) at the Idaho National Engineering Laboratory, and the explosive hazards testing was done by Cook Associates, Inc., at IRECO Chemicals Pelican Point Research and Development facility in Utah. The test results showed that binary combinations of pure NaK and KO 2 could not be made to detonate, although the mixtures will spontaneously ignite and burn. However, tertiary combinations of NaK, KO 2 plus a water or hydrocarbon contaminant produced explosive hazards under a variety of conditions. The work was performed as part of the Decontamination and Decommissioning (D and D) of the first Experimental Breeder Reactor (EBR-I) and was funded by 189c I-215. (U.S.)

  8. Carbon Dioxide Capture by Deep Eutectic Solvent Impregnated Sea Mango Activated Carbon

    Science.gov (United States)

    Zulkurnai, N. Z.; Ali, U. F. Md.; Ibrahim, N.; Manan, N. S. Abdul

    2018-03-01

    The increment amount of the CO2 emission by years has become a major concern worldwide due to the global warming issue. However, the influence modification of activated carbon (AC) has given a huge revolution in CO2 adsorption capture compare to the unmodified AC. In the present study, the Deep Eutectic Solvent (DES) modified surface AC was used for Carbon Dioxide (CO2) capture in the fixed-bed column. The AC underwent pre-carbonization and carbonization processes at 519.8 °C, respectively, with flowing of CO2 gas and then followed by impregnation with 53.75% phosphoric acid (H3PO4) at 1:2 precursor-to-activant ratios. The prepared AC known as sea mango activated carbon (SMAC) was impregnated with DES at 1:2 solid-to-liquid ratio. The DES is composing of choline chloride and urea with ratio 1:2 choline chloride to urea. The optimum adsorption capacity of SMAC was 33.46 mgco2/gsol and 39.40 mgco2/gsol for DES modified AC (DESAC).

  9. Mechanistic Selection and Growth of Twinned Bicrystalline Primary Si in Near Eutectic Al-Si Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Choonho [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    Morphological evolution and selection of angular primary silicon is investigated in near-eutectic Al-Si alloys. Angular silicon arrays are grown directionally in a Bridgman furnace at velocities in the regime of 10-3 m/sec and with a temperature gradient of 7.5 x 103 K/m. Under these conditions, the primary Si phase grows as an array of twinned bicrystalline dendrites, where the twinning gives rise to a characteristic 8-pointed star-shaped primary morphology. While this primary Si remains largely faceted at the growth front, a complex structure of coherent symmetric twin boundaries enables various adjustment mechanisms which operate to optimize the characteristic spacings within the primary array. In the work presented here, this primary silicon growth morphology is examined in detail. In particular, this thesis describes the investigation of: (1) morphological selection of the twinned bicrystalline primary starshape morphology; (2) primary array behavior, including the lateral propagation of the starshape grains and the associated evolution of a strong <100> texture; (3) the detailed structure of the 8-pointed star-shaped primary morphology, including the twin boundary configuration within the central core; (4) the mechanisms of lateral propagation and spacing adjustment during array evolution; and (5) the thermosolutal conditions (i.e. operating state) at the primary growth front, including composition and phase fraction in the vicinity of the primary tip.

  10. Investigation of enthalpy and specific heat of the gallium-indium-tin eutectic alloy

    International Nuclear Information System (INIS)

    Roshchupkin, V.V.; Migaj, L.L.; Fordeeva, L.K.; Perlova, N.L.

    1978-01-01

    Enthalpy and specific heat of the fusible (melting point is 10.6 deg C) eutectic alloy (67% Ga - 20.5% In - 12.5% Sn according to mass) are determined by the mixing method. The determination was carried out in vacuum at the residual pressure of >= 1x10 -5 torr in the temperature range from 59.3 to 437.0 deg C. It is established that temperature dependence of alloy enthalpy is described by the equation: Hsub(t) - Hsub(0degC)=1.014+0.0879t-0.0000129 t 2 , where (Hsub(t) - Hsub(0degC)) is enthalpy, cal/g; t-temperature, deg C. Mean-square dispersion is +-0.6%. Temperature dependence of alloy specific heat in the temperature range under study was determined by differentiation of the equation obtained for enthalpy: Csub(p)=0.0879-0.000026t, where Csub(p)-specific heat, cal/gx deg. It is supposed that temperature increase makes it possible to decrease slightly specific heat

  11. Molecular dynamics simulation of metallic impurity diffusion in liquid lead-bismuth eutectic (LBE)

    Science.gov (United States)

    Gao, Yun; Takahashi, Minoru; Cavallotti, Carlo; Raos, Guido

    2018-04-01

    Corrosion of stainless steels by lead-bismuth eutectic (LBE) is an important problem which depends, amongst other things, on the diffusion of the steel components inside this liquid alloy. Here we present the results of classical molecular dynamics simulations of the diffusion of Fe and Ni within LBE. The simulations complement experimental studies of impurity diffusion by our group and provide an atomic-level understanding of the relevant diffusion phenomena. They are based on the embedded atom method (EAM) to represent many-body interactions among atoms. The EAM potentials employed in our simulations have been validated against ab initio density functional calculations. We show that the experimental and simulation results for the temperature-dependent viscosity of LBE and the impurity diffusion coefficients can be reconciled by assuming that the Ni and Fe diffuse mainly as nanoscopic clusters below 1300 K. The average Fe and Ni cluster sizes decrease with increasing the temperature and there is essentially single-atom diffusion at higher temperatures.

  12. Deacidification of palm oil using betaine monohydrate-based natural deep eutectic solvents.

    Science.gov (United States)

    Zahrina, Ida; Nasikin, Mohammad; Krisanti, Elsa; Mulia, Kamarza

    2018-02-01

    In the palm oil industry, the deacidification process is performed by steam stripping which causes the loss of most of palm oil's natural antioxidants due to high temperature. The liquid-liquid extraction process which is carried out at low temperature is preferable in order to preserve these compounds. The use of hydrated ethanol can reduce the losses of antioxidants, but the ability of this solvent to extract free fatty acids also decreases. Betaine monohydrate-based natural deep eutectic solvents (NADES) have extensive potential for this process. The selectivity of these NADES was determined to select a preferable solvent. The betaine monohydrate-glycerol NADES in a molar ratio of 1:8 was determined to be the preferred solvent with the highest selectivity. This solvent has an efficiency of palmitic acid extraction of 34.14%, and the amount of antioxidants can be preserved in the refined palm oil up to 99%. The compounds are stable during extraction. Copyright © 2017. Published by Elsevier Ltd.

  13. On the formation of U-Al alloys in the molten LiCl-KCl eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Cassayre, L. [Laboratoire de Genie Chimique (LGC), Universite Paul Sabatier, UMR CNRS 5503, 31062 Toulouse cedex 9 (France); Caravaca, C. [CIEMAT, DE/DFN/URAA, Avda. Complutense, 22, Madrid 28040 (Spain); Jardin, R. [European Commission, JRC, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Malmbeck, R. [European Commission, JRC, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany)], E-mail: rikard.malmbeck@ec.europa.eu; Masset, P.; Mendes, E.; Serp, J.; Soucek, P.; Glatz, J.-P. [European Commission, JRC, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany)

    2008-08-15

    U-Al alloy formation has been studied in the temperature range of 400-550 deg. C by electrochemical techniques in the molten LiCl-KCl eutectic. Cyclic voltammetry showed that underpotential reduction of U(III) onto solid Al occurs at a potential about 0.35 V more anodic than pure U deposition. Open circuit potential measurements, recorded after small depositions of U metal onto the Al electrode, did not allow the distinction between potentials associated with UAl{sub x} alloys and the Al rest potential, as they were found to be practically identical. As a consequence, a spontaneous chemical reaction between dissolved UCl{sub 3} and Al is thermodynamically possible and was experimentally observed. Galvanostatic electrolyses were carried out both on Al rods and Al plates. Stable and dense U-Al deposits were obtained with high faradic yields, and the possibility to load the whole bulk of a thin Al plate was demonstrated. The analyses (by SEM-EDX and XRD) of the deposits indicated the formation of different intermetallic phases (UAl{sub 2}, UAl{sub 3} and UAl{sub 4}) depending on the experimental conditions.

  14. Equilibrium evaporation behavior of polonium and its homologue tellurium in liquid lead-bismuth eutectic

    International Nuclear Information System (INIS)

    Ohno, Shuji; Miyahara, Shinya; Kurata, Yuji; Katsura, Ryoei; Yoshida, Shigeru

    2006-01-01

    Experimental study using the transpiration method investigates equilibrium evaporation behavior of radionuclide polonium ( 210 Po) generated and accumulated in liquid lead-bismuth eutectic (LBE) cooled nuclear systems. The experiment consists of two series of tests: preliminary evaporation tests for homologue element tellurium (Te) in LBE, and evaporation tests for 210 Po-accumulated LBE in which test specimens are prepared by neutron irradiation. The evaporation tests of Te in LBE provide the suggestion that Te exists in a chemical form of PbTe as well as the information for confirming the validity of technique and conditions of Po test. From the evaporation tests of 210 Po in LBE, we obtain fundamental data and empirical equations such as 210 Po vapor concentration in the gas phase, 210 Po partial vapor pressure, thermodynamic activity coefficients, and gas-liquid equilibrium partition coefficient of 210 Po in LBE in the temperature range from 450 to 750degC. Additionally, radioactivity concentration of 210 Po and 210m Bi vapor in a cover gas region of a typical LBE-cooled nuclear system is specifically estimated based on the obtained experimental results, and the importance of 210 Po evaporation behavior is quantitatively demonstrated. (author)

  15. Lead-Bismuth Eutectic cooled experimental Accelerator Driven System. Windowless target unit thermal-hydraulic analysis

    International Nuclear Information System (INIS)

    Bianchi, F.; Ferri, R.; Moreau, V.

    2004-01-01

    A main concern related to the peaceful use of nuclear energy is the safe management of nuclear wastes, with particular attention to long-lived fission products. An increasing attention has recently been addressed to transmutation systems (Accelerator Driven System: ADS) able to 'burn' the actinides and some of the long-lived fission products (High-Level Waste: HLW), transforming them in short or medium-lived wastes that may be easier managed and stored in the geological disposal, with the consequent easier acceptability by population. An ADS consists of a subcritical-core coupled with an accelerator by means of a target. This paper deals with the thermal-hydraulic analysis, performed with STAR-CD and RELAP5 codes for the windowless target unit of Lead-Bismuth Eutectic (LBE) cooled experimental ADS (XADS), both to assess its behaviour during operational and accident sequences and to provide input data for the thermal-mechanical analyses. It also reports a description of modifications properly implemented in the codes used for the assessment of this kind of plants. (author)

  16. Analysis of heavy eutectic loop for investigation of operability and safety

    International Nuclear Information System (INIS)

    Kim, C.S.; Jeong, S.H.; Suh, K.Y.; Kim, C.H.; Hwang, I.S.; Lee, I.S.

    2003-01-01

    It is proposed that challenges of managing long-lived spent nuclear fuel wastes be technically resolved by a partitioning and transmutation system named as PEACER. The PEACER design goals include proliferation resistance, environmental friendliness, accident tolerance, continuable energy, and economical reactor. In an earlier study, the conceptual design for the PEACER was developed to meet the aforementioned goals. The PEACER is being designed at the Seoul National University with the metallic type U-TRU (TRansUranic)-Zr fuel and the Pb-Bi coolant, but without an intermediate loop. It not only produces power but also transmutes long-term radioactive materials. A PEACER can transmute the minor actinides of two commercial-sized pressurized water reactors. The project has been initiated in which Seoul National University, Korea Advanced Institute of Science and Technology, and Kyunghee University will develop the nuclear transmutation power reactor based on the PEACER conceptual design. The objectives of this project are divided into the nuclear transmutation power reactor design optimization, three-dimensional visualization, and large-scale Pb-Bi thermal hydraulic and materials test loop called HELIOS (Heavy Eutectic Loop for Investigation of Operability and Safety). (author)

  17. Irradiation of structural materials in contact with lead bismuth eutectic in the high flux reactor

    Energy Technology Data Exchange (ETDEWEB)

    Magielsen, A.J., E-mail: magielsen@nrg.eu [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands); Jong, M.; Bakker, T.; Luzginova, N.V.; Mutnuru, R.K.; Ketema, D.J.; Fedorov, A.V. [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands)

    2011-08-31

    In the framework of the materials domain DEMETRA in the European Transmutation research and development project EUROTRANS, irradiation experiment IBIS has been performed in the High Flux Reactor in Petten. The objective was to investigate the synergystic effects of irradiation and lead bismuth eutectic exposure on the mechanical properties of structural materials and welds. In this experiment ferritic martensitic 9 Cr steel, austenitic 316L stainless steel and their welds have been irradiated for 250 Full Power Days up to a dose level of 2 dpa. Irradiation temperatures have been kept constant at 300 deg. C and 500 deg. C. During the post-irradiation test phase, tensile tests performed on the specimens irradiated at 300 deg. C have shown that the irradiation hardening of ferritic martensitic 9 Cr steel at 1.3 dpa is 254 MPa, which is in line with the irradiation hardening obtained for ferritic martensitic Eurofer97 steel investigated in the fusion program. This result indicates that no LBE interaction at this irradiation temperature is present. A visual inspection is performed on the specimens irradiated in contact with LBE at 500 deg. C and have shown blackening on the surface of the specimens and remains of LBE that makes a special cleaning procedure necessary before post-irradiation mechanical testing.

  18. Topical amethocaine (Ametop) is superior to EMLA for intravenous cannulation. Eutectic mixture of local anesthetics.

    LENUS (Irish Health Repository)

    Browne, J

    2012-02-03

    PURPOSE: A eutectic mixture of local anesthetics (EMLA) is commonly used to provide topical anesthesia for intravenous (i.v.) cannulation. One of its side effects is vasoconstriction, which may render cannulation more difficult. A gel formulation of amethocaine (Ametop) is now commercially available. The aim of this study was to compare EMLA and Ametop with regard to the degree of topical anesthesia afforded, the incidence of vasoconstriction and the ease of i.v. cannulation. METHODS: Thirty two ASA I adult volunteers had a #16 gauge i.v. cannula inserted on two separate occasions using EMLA and Ametop applied in a double blind fashion for topical anesthesia. Parameters that were recorded after each cannulation included visual analogue pain scores (VAPS), the presence of vasoconstriction and the ease of cannulation, graded as: 1 = easy, 2 = moderately difficult, 3 = difficult and 4 = failed. RESULTS: The mean VAPS +\\/- SD after cannulation with Ametop M was 12+\\/-9.9 and with EMLA was 25.3+\\/-16.6 (P = 0.002). Vasoconstriction occurred after EMLA application on 17 occasions and twice after Ametop (P = 0.001). The grade of difficulty of cannulation was 1.44+\\/-0.88 following EMLA and 1.06+\\/-0.25 with Ametop (P = 0.023). CONCLUSIONS: Intravenous cannulation was less painful following application of Ametop than EMLA. In addition, Ametop caused less vasoconstriction and facilitated easier cannulation. Its use as a topical anesthetic agent is recommended, especially when i.v. access may be problematic.

  19. Countercurrent assisted quantitative recovery of metabolites from plant-associated natural deep eutectic solvents

    Science.gov (United States)

    Friesen, J. Brent; Zhang, Yu; McAlpine, James B.; Lankin, David C.; Chen, Shao-Nong; Pauli, Guido F.

    2016-01-01

    NAtural Deep Eutectic Solvents (NADES) are chemically simple but physiologically important plant constituents that exhibit unique solubilizing properties of other metabolites, including bioactive constituents. The high polarity of NADES introduces a challenge in the ability of conventional solid-support based chromatography to recover potential bioactive metabolites. This complicates the systematic explanation of the NADES’ functions in botanical extracts. The present study utilizes countercurrent separation (CCS) methodology to overcome the recovery challenge. To demonstrate its feasibility, Glucose-Choline chloride-Water (GCWat, 2:5:5, mole/mole) served as a model NADES, and four widely used marker flavonoids with different polarities (rutin, quercetin, kaempferol, and daidzein) were chosen as model target analytes. In order to prepare GCWat with high consistency, a water drying study was performed. The unique capabilities of the recently introduced CherryOne system, offering volumetric phase metering, were used to monitor the CCS operations. The collected fractions were analyzed using UHPLC and NMR/quantitative NMR. CCS was able to recover the analytes from the NADES matrix with quantitative recoveries of 95.7%, 94.6%, 97.0%, and 96.7% for rutin, quercetin, kaempferol, and daidzein respectively. The CCS strategy enables recovery of target metabolites from NADES-containing crude extracts as well as from other chemical mixtures, and moreover offers a means of using NADES as environmentally friendly extraction solvents. PMID:27118320

  20. Orientation relationship and interfaces in Ni and Co-YSZ cermets prepared from directionally solidified eutectics

    Science.gov (United States)

    Larrea, Angel; Laguna-Bercero, Miguel A.; Peña, José I.; Merino, Rosa I.; Orera, Víctor M.

    2009-06-01

    Textured Ni-YSZ and Co-YSZ (YSZ: cubic yttria stabilized zirconia) cermets prepared by reduction of directionally solidified NiO-YSZ and CoO-YSZ oxide eutectics respectively display a self-organized microstucture formed by ∼400 nm wide alternating lamellae of YSZ and porous metal suitable for electrochemical applications. The electrochemical properties of the cermets depend on their microstructure. We have analyzed the orientation relationships and interfaces both of the oxide composites and cermets using Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray pole figures and Electron Back-Scattering Diffraction. In spite of the similar crystal structure, growth habits and orientation relationships of NiO-YSZ and CoO-YSZ are different. Also the crystallographic behaviour, when cermets are produced, differs. However the metal-YSZ interfaces are about the most stable ones giving good metal-ceramic adhesion. Due to their lamellar microstructure and good metal-ceramic adhesion these composites present long-term stability at working conditions, which makes them good candidates to be used as anodes in solid oxide fuel cells or electrolyzers.

  1. Adsorbed Eutectic GaIn Structures on a Neoprene Foam for Stretchable MRI Coils.

    Science.gov (United States)

    Varga, Matija; Mehmann, Andreas; Marjanovic, Josip; Reber, Jonas; Vogt, Christian; Pruessmann, Klaas Paul; Tröster, Gerhard

    2017-11-01

    Stretchable conductors based on eutectic gallium-indium (eGaIn) alloy are patterned on a polychloroprene substrate (neoprene foam) using stencil printing. By tuning the amount of eGaIn on the neoprene substrate, different strain-sensitivity of electrical resistance is achieved. Conductors with a layer of eGaIn, which adsorbs to the walls of 60-100 µm wide neoprene cells, change their electrical resistance for 5% at 100% strain. When the amount of eGaIn is increased, the cells are filled with eGaIn and the strain-sensitivity of the electrical resistance rises to 300% at 100% strain. The developed conductors are patterned as stretchable on-body coils for receiving magnetic signals in a clinical magnetic resonance imaging setup. First images with a stretchable coil are acquired on an orange and compared to the images that are recorded using a rigid copper coil of the same size. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Extraction of Illegal Dyes from Red Chili Peppers with Cholinium-Based Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Shuqiang Zhu

    2017-01-01

    Full Text Available Deep eutectic solvents (DESs as a new kind of green solvents have been used to extract bioactive compounds but there are few applications in extracting chrysoidine dyes. In this study, we developed an ultrasonic-assisted extraction method with choline chloride/hydrogen bond donor (ChCl/HBD DES for the extraction of chrysoidine G (COG, astrazon orange G (AOG, and astrazon orange R (AOR in food samples. Some experimental parameters, such as extraction time, raw material/solvent ratio, and temperature, were evaluated and optimized as follows: the ratio of ChCl/HBD, 1 : 2 (v/v; the ratio of sample/DES, 1 : 10 (g/mL; extraction time, 20 min; extraction temperature, 50°C. Under the optimized conditions, the limits of detection (μg/mL were 0.10 for COG and 0.06 for AOG and AOR. The relative standard deviations were in the range of 1.2–2.1%. The recoveries of the three dyes were in the range of 80.2–105.0%. By comparing with other commonly used solvents for extracting chrysoidine dyes, the advantages of DESs proved them to be potential extraction solvents for chrysoidine G, astrazon orange G, and astrazon orange R in foods.

  3. Potential containment materials for liquid-lead and lead-bismuth eutectic spallation neutron source

    International Nuclear Information System (INIS)

    Park, J.J.; Butt, D.P.; Beard, C.A.

    1997-11-01

    Lead (Pb) and lead-bismuth eutectic (44Pb-56Bi) have been the two primary candidate liquid-metal target materials for the production of spallation neutrons. Selection of a container material for the liquid-metal target will greatly affect the lifetime and safety of the target subsystem. For the lead target, niobium-1 (wt%) zirconium (Nb-1Zr) is a candidate containment material for liquid lead, but its poor oxidation resistance has been a major concern. The oxidation rate of Nb-1Zr was studied based on the calculations of thickness loss due to oxidation. According to these calculations, it appeared that uncoated Nb-1Zr may be used for a one-year operation at 900 C at P O 2 = 1 x 10 -6 torr, but the same material may not be used in argon with 5-ppm oxygen. Coating technologies to reduce the oxidation of Nb-1Zr are reviewed, as are other candidate refractory metals such as molybdenum, tantalum, and tungsten. For the Pb-Bi target, three candidate containment materials are suggested based on a literature survey of the materials compatibility and proton irradiation tests: Croloy 2-1/4, modified 9Cr-1Mo, and 12Cr-1Mo (HT-9) steel. These materials seem to be used only if the lead-bismuth is thoroughly deoxidized and treated with zirconium and magnesium

  4. Removal of polonium contamination by lead-bismuth eutectic in nuclear systems

    International Nuclear Information System (INIS)

    Miura, Terumitsu; Obara, Toru; Sekimoto, Hiroshi

    2003-01-01

    Lead-Bismuth eutectic (LBE) is considered as a promising candidate of the coolant of liquid metal cooled fast reactor, and the coolant and/or target of accelerator driven system. LBE has various good characters for coolant, but it has also some problems such as polonium production. It is necessary to take polonium contamination into consideration, when LBE is used as the coolant. In the present paper, the removal of contaminating polonium from material surface is studied. Baking method is investigated for polonium removal from contaminated quartz glass plate in vacuum. Before and after baking, the mass of the contaminants on the surface and alpha particle counts from contaminated surface is measured. When the contaminated quartz glass plates are baked at more than 400degC for a few minutes, alpha particle counts from the surface decreases by more than 99.7%, and the mass of contaminants decreases by more than 50%. When the baking was performed at 300degC for 15 minutes and more, alpha particle count decreases by more than 80%, and the mass decreases in little. When, the baking temperature is lower than 200degC, alpha particle counts and mass do not decrease. (author)

  5. Preparation and Thermal Properties of Eutectic Hydrate Salt Phase Change Thermal Energy Storage Material

    Directory of Open Access Journals (Sweden)

    Lin Liang

    2018-01-01

    Full Text Available In this study, a new cold storage phase change material eutectic hydrate salt (K2HPO4·3H2O–NaH2PO4·2H2O–Na2S2O3·5H2O was prepared, modified, and tested. The modification was performed by adding a nucleating agent and thickener. The physical properties such as viscosity, surface tension, cold storage characteristics, supercooling, and the stability during freeze-thaw cycles were studied. Results show that the use of nucleating agents, such as sodium tetraborate, sodium fluoride, and nanoparticles, are effective. The solidification temperature and latent heat of these materials which was added with 0, 3, and 5 wt% thickeners were −11.9, −10.6, and −14.8°C and 127.2, 118.6, 82.56 J/g, respectively. Adding a nucleating agent can effectively improve the nucleation rate and nucleation stability. Furthermore, increasing viscosity has a positive impact on the solidification rate, supercooling, and the stability during freeze-thaw cycles.

  6. An Expeditious and Greener Synthesis of 2-Aminoimidazoles in Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Martina Capua

    2016-07-01

    Full Text Available A high-yield one-pot two-step synthesis of 2-aminoimidazoles (2-AI, exploiting an under-air heterocyclodehydration process between α-chloroketones and guanidine derivatives, and using deep eutectic solvents (DESs as nonconventional, “green” and “innocent” reaction media, has been accomplished successfully. The combination of either glycerol or urea with choline chloride (ChCl proved to be effective for decreasing the reaction time to about 4–6 h in contrast to the 10–12 h usually required for the same reaction run in toxic and volatile organic solvents and under an argon atmosphere. In addition, the use of the ChCl–urea as a DES also enables the direct isolation of triaryl-substituted 2-AI derivatives by means of a simple work-up procedure consisting in filtration and crystallization, and allows the recycle of the DES mixture. A plausible mechanism highlighting the potential role played by hydrogen bonding catalysis has also been illustrated.

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

    Science.gov (United States)

    Domínguez de María, Pablo; Maugeri, Zaira

    2011-04-01

    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. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    International Nuclear Information System (INIS)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie

    2015-01-01

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  9. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  10. Supported Silver Nanoparticle and Near-Interface Solution Dynamics in a Deep Eutectic Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Hammons, Joshua A.; Ustarroz, Jon; Muselle, Thibault; Torriero, Angel A. J.; Terryn, Herman; Suthar, Kamlesh; Ilavsky, Jan

    2016-01-28

    Type III deep eutectic solvents (DES) have attracted significant interest as both environmentally friendly and functional solvents that are, in some ways, advantageous to traditional aqueous systems. While these solvents continue to produce remarkable thin films and nanoparticle assemblies, their interactions with metallic surfaces are complex and difficult to manipulate. In this study, the near-surface region (2–600 nm) of a carbon surface is investigated immediately following silver nanoparticle nucleation and growth. This is accomplished, in situ, using a novel grazing transmission small-angle X-ray scattering approach with simultaneous voltammetry and electrochemical impedance spectroscopy. With this physical and electrochemical approach, the time evolution of three distinct surface interaction phenomena is observed: aggregation and coalescence of Ag nanoparticles, multilayer perturbations induced by nonaggregated Ag nanoparticles, and a stepwise transport of dissolved Ag species from the carbon surface. The multilayer perturbations contain charge-separated regions of positively charged choline-ethylene and negatively charged Ag and Cl species. Both aggregation-coalescence and the stepwise decrease in Ag precursor near the surface are observed to be very slow (~2 h) processes, as both ion and particle transport are significantly impeded in a DES as compared to aqueous electrolytes. Finally, altogether, this study shows how the unique chemistry of the DES changes near the surface and in the presence of nanoparticles that adsorb the constituent species.

  11. Liquid eutectic GaIn as an alternative electrode for PTB7:PCBM organic solar cells

    Science.gov (United States)

    Thanh Hau Pham, Viet; Kieu Trinh, Thanh; Tam Nguyen Truong, Nguyen; Park, Chinho

    2017-04-01

    Conventional vacuum deposition process of aluminum (Al) is costly, time-consuming and difficult to apply to the large-scale production of organic photovoltaic devices (OPV). This paper reports a vacuum-free fabrication process of poly[[4,8-bis(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b‧]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thienophenediyl]:[6,6]-phenyl C71 butyric acid methyl ester (PTB7:PCBM) bulk heterojunction organic solar cell with liquid eutectic gallium-indium (EGaIn) electrode as an alternative to the common Al electrode. The insertion of a thin poly(ethylene oxide) (PEO) layer after depositing organic photoactive layer could help prevent the diffusion of liquid EGaIn into the active layer and allow the deposition of the EGaIn electrode. The PEO interfacial layer was formed by spin-coating from a mixed solvent of alcohol and water. Among different alcohol+water (methanol, ethanol, ethylene glycol, n-propanol, isopropanol, and isobutanol) mixed solvent tested, the n-propanol+water mixed solvent showed the greatest enhancement to the performance of OPVs. The improved device performance was attributed to the reactivity of mixed solvent n-propanol+water toward the surface of PTB7:PCBM active layer, which could help optimize surface morphology.

  12. Bifunctionalized ordered mesoporous organosilica synthesized in deep eutectic solvent for extraction of triazine herbicides from watermelon.

    Science.gov (United States)

    Li, Zan; Jia, Jun; Wang, Mingwei; Zhang, Hua; Yan, Hongyuan; Qiao, Fengxia

    2017-12-22

    A C 8 -and-amino-bifunctionalized ordered mesoporous organosilica (C 8 -AMS) was prepared in a deep eutectic solvent-a green solvent-that was used as the reaction medium for this procedure instead of organic solvents or other catalyst for the first time. This method provided a nontoxic way for C 8 grafting and obtaining an ordered mesoporous organosilica material with both hydrophilic and hydrophobic groups. Besides advantages such as its large surface area, regular and uniform pore size, and hydrothermal stability, the obtained bifunctionalized C 8 -AMS also have two main functional groups in the obtained structure, C 8 and amino, which enriched the adsorption mechanism of the material and as a result improved the adsorption selectivity of C 8 -AMS. Its performance as an adsorbent was estimated in extracting trace triazine herbicides from watermelon using solid-phase extraction (SPE) followed by high-performance liquid chromatography (HPLC). The proposed method provided satisfactory features in terms of linearity (0.01-2.00μgg -1 ), limits of detection (2.9-5.1ngg -1 ), accuracy (recovery: 85.7-101.7%), and precision (intra-day and inter-day RSDs: 1.68-2.60% and 3.05-4.01%). Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Food-Grade Synthesis of Maillard-Type Taste Enhancers Using Natural Deep Eutectic Solvents (NADES

    Directory of Open Access Journals (Sweden)

    Maximilian Kranz

    2018-01-01

    Full Text Available The increasing demand for healthier food products, with reduced levels of table salt, sugar, and mono sodium glutamate, reinforce the need for novel taste enhancers prepared by means of food-grade kitchen-type chemistry. Although several taste modulating compounds have been discovered in processed foods, their Maillard-type ex food production is usually not exploited by industrial process reactions as the yields of target compounds typically do not exceed 1–2%. Natural deep eutectic solvents (NADES are reported for the first time to significantly increase the yields of the taste enhancers 1-deoxy-ᴅ-fructosyl-N-β-alanyl-ʟ-histidine (49% yield, N-(1-methyl-4-oxoimidazolidin-2-ylidene aminopropionic acid (54% yield and N2-(1-carboxyethyl guanosine 5′-monophosphate (22% yield at low temperature (80–100 °C within a maximum reaction time of 2 h. Therefore, NADES open new avenues to a “next-generation culinary chemistry” overcoming the yield limitations of traditional Maillard chemistry approaches and enable a food-grade Maillard-type generation of flavor modulators.

  14. XRD and EBSD Measurements of Directional Solidification Fe-C Eutectic Alloy

    Directory of Open Access Journals (Sweden)

    Trepczyńska-Łent M.

    2016-12-01

    Full Text Available In a vacuum Bridgman-type furnace, under an argon atmosphere, directionally solidified sample of Fe - C alloy was produced. The pulling rate was v = 83 μm/s (300 mm/h and constant temperature gradient G = 33,5 K/mm. The microstructure of the sample was examined on the longitudinal section using an Optical Microscope and Scanning Electron Microscope. The X-ray diffraction and electron backscatter diffraction technique (EBSD have been used for the crystallographic analysis of carbide particles in carbide eutectic. The X-ray diffraction was made parallel and perpendicular to the axis of the goniometer. The EBSD shows the existence of iron carbide Fe3C with orthorhombic and hexagonal structure. Rapid solidification may cause a deformation of the lattice plane which is indicated by different values of the lattice parameters. Such deformation could also be the result of directional solidification. Not all of the peaks in X–ray diffractograms were identified. They may come from other iron carbides. These unrecognized peaks may also be a result of the residual impurity of alloy.

  15. Evaluation of the effect of Bi, Sb, Sr and cooling condition on eutectic phases in an Al–Si–Cu alloy (ADC12) by in situ thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Farahany, S., E-mail: saeedfarahany@gmail.com [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Johor Bahru (Malaysia); Ourdjini, A.; Idrsi, M.H. [Department of Materials Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Johor Bahru (Malaysia); Shabestari, S.G. [Center of Excellence for High Strength Alloys Technology (CEHSAT), School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), 16846-13114 Tehran (Iran, Islamic Republic of)

    2013-05-10

    Highlights: • Combined effect of Bi, Sb and Sr additions, and cooling condition was evaluated. • Two different scenarios of recalecense in response to cooling rate were observed. • Fraction solid increased in the order of Sr > Bi > Sb, corresponds to Si morphologies. • Only Bi decreased the nucleation temperature of Al{sub 2}Cu eutectic phase. - Abstract: Al–Si and Al–Cu eutectic phases strongly affect the properties of Al–Si–Cu cast alloys. The characteristic parameters of these two eutectic phases with addition of bismuth, antimony and strontium under different cooling rates (0.6–2 °C/s) were investigated in ADC12 alloy using in situ thermal analysis. Results show that additives affect the Al–Si phase more than the Al–Cu (Al{sub 2}Cu) phase. Addition elements showed two different scenarios in response to cooling rate in terms of recalescence of the Al–Si eutectic phase. Both Bi and Sb caused an increase in recalescence with increased cooling rate but Sr addition reduced the recalescence. Additions of Sb and Sr increased the nucleation temperature of Al{sub 2}Cu, but addition of Bi produced an opposite effect. There seems to be relationship between the solidification temperature range and fraction solid of Al–Si and Al{sub 2}Cu eutectic phases. As the cooling rate increases the fraction solid of Al–Si decreased and that of Al{sub 2}Cu increased.

  16. Carbon Dioxide Capture with Ionic Liquids and Deep Eutectic Solvents: A New Generation of Sorbents.

    Science.gov (United States)

    Sarmad, Shokat; Mikkola, Jyri-Pekka; Ji, Xiaoyan

    2017-01-20

    High cost and high energy penalty for CO 2 uptake from flue gases are important obstacles in large-scale industrial applications, and developing efficient technology for CO 2 capture from technical and economic points is crucial. Ionic liquids (ILs) show the potential for CO 2 separation owing to their inherent advantages, and have been proposed as alternatives to overcome the drawbacks of conventional sorbents. Chemical modification of ILs to improve their performance in CO 2 absorption has received more attention. Deep eutectic solvents (DESs) as a new generation of ILs are considered as more economical alternatives to cope with the deficiencies of high cost and high viscosity of conventional ILs. This Review discusses the potential of functionalized ILs and DESs as CO 2 sorbents. Incorporation of CO 2 -philic functional groups, such as amine, in cation and/or anion moiety of ILs can promot their absorption capacity. In general, the functionalization of the anion part of ILs is more effective than the cation part. DESs represent favorable solvent properties and are capable of capturing CO 2 , but the research work is scarce and undeveloped compared to the studies conducted on ILs. It is possible to develop novel DESs with promising absorption capacity. However, more investigation needs to be carried out on the mechanism of CO 2 sorption of DESs to clarify how these novel sorbents can be adjusted and fine-tuned to be best tailored as optimized media for CO 2 capture. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Science.gov (United States)

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

    2014-11-18

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

  18. Study on extraction of cellulose from corn cobs by deep eutectic solvents

    Directory of Open Access Journals (Sweden)

    Hongjie LIU

    2017-12-01

    Full Text Available In order to explore a new method for the separation and extraction of cellulose, cellulose is extracted from waste biomass corn cobs by deep eutectic solvent(DES, in which 1,4-butanediol (BDO and choline chloride (ChCl are used as the donor and the acceptor of hydrogen bonds, respectively. The influence of the molar ration of ChCl to BDO, the treatment temperature, the interaction time and liquid-solid ratio to fiber material yield and cellulose content under ordinary pressure is investigated through experiment. The structures of raw materials and the products are characterized by using infrared spectroscopy (FT-IR, thermogravimetric (TG/DTG, X-ray diffraction (XRD and scanning electron microscopy (SEM. The result shows that the fiber material yield and cellulose content are 44.6% and 77.8%, respectively under the optimum conditions which are ChCl-BDO molar ration of 1∶3, treatment temperature of 180 ℃, reaction time of 4 h and liquid-solid ration of 20∶1(g∶g, and under the condition, the removal rate of lignin and hemicellulose are 95% and 75%, respectively, with only losing a little cellulose. The FT-IR, TG/DTG, XRD and SEM results show that the lignin and hemicellulose in the corn cobs are greatly removed after DES treatment. The fiber material internal is more loose and the structure of the cellulose is barely damaged. The result shows that DES has a good prospect in the field of cellulose separation and extraction.

  19. PC-SAFT Modeling of CO2 Solubilities in Deep Eutectic Solvents.

    Science.gov (United States)

    Zubeir, Lawien F; Held, Christoph; Sadowski, Gabriele; Kroon, Maaike C

    2016-03-10

    Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT), a physically based model that accounts for different molecular interactions explicitly, was applied to describe for the first time the phase behavior of deep eutectic solvents (DESs) with CO2 at temperatures from 298.15 to 318.15 K and pressures up to 2 MPa. DESs are mixtures of two solid compounds, a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA), which form liquids upon mixing with melting points far below that of the individual compounds. In this work, the HBD is lactic acid and the HBAs are tetramethylammonium chloride, tetraethylammonium chloride, and tetrabutylammonium chloride. Two different modeling strategies were considered for the PC-SAFT modeling. In the first strategy, the so-called pseudo-pure component approach, a DES was considered as a pseudo-pure compound, and its pure-component parameters were obtained by fitting to pure DES density data. In the second strategy, the so-called individual-component approach, a DES was considered to consist of two individual components (HBA and HBD), and the pure-component parameters of the HBA and HBD were obtained by fitting to the density of aqueous solutions containing only the individual compounds of the DES. In order to model vapor-liquid equilibria (VLE) of DES + CO2 systems, binary interaction parameters were adjusted to experimental data from the literature and to new data measured in this work. It was concluded that the individual-component strategy allows quantitative prediction of the phase behavior of DES + CO2 systems containing those HBD:HBA molar ratios that were not used for k(ij) fitting. In contrast, applying the pseudo-pure component strategy required DES-composition specific k(ij) parameters.

  20. Nucleation and growth of lead oxide particles in liquid lead-bismuth eutectic.

    Science.gov (United States)

    Gladinez, Kristof; Rosseel, Kris; Lim, Jun; Marino, Alessandro; Heynderickx, Geraldine; Aerts, Alexander

    2017-10-18

    Liquid lead-bismuth eutectic (LBE) is an important candidate to become the primary coolant of future, generation IV, nuclear fast reactors and Accelerator Driven System (ADS) concepts. One of the main challenges with the use of LBE as a coolant is to avoid its oxidation which results in solid lead oxide (PbO) precipitation. The chemical equilibria governing PbO formation are well understood. However, insufficient kinetic information is currently available for the development of LBE-based nuclear technology. Here, we report the results of experiments in which the nucleation, growth and dissolution of PbO in LBE during temperature cycling are measured by monitoring dissolved oxygen using potentiometric oxygen sensors. The metastable region, above which PbO nucleation can occur, has been determined under conditions relevant for the operation of LBE cooled nuclear systems and was found to be independent of setup geometry and thus thought to be widely applicable. A kinetic model to describe formation and dissolution of PbO particles in LBE is proposed, based on Classical Nucleation Theory (CNT) combined with mass transfer limited growth and dissolution. This model can accurately predict the experimentally observed changes in oxygen concentration due to nucleation, growth and dissolution of PbO, using the effective interfacial energy of a PbO nucleus in LBE as a fitting parameter. The results are invaluable to evaluate the consequences of oxygen ingress in LBE cooled nuclear systems under normal operating and accidental conditions and form the basis for the development of cold trap technology to avoid PbO formation in the primary reactor circuit.

  1. Co-C and Pd-C Eutectic Fixed Points for Radiation Thermometry and Thermocouple Thermometry

    Science.gov (United States)

    Wang, L.

    2017-12-01

    Two Co-C and Pd-C eutectic fixed point cells for both radiation thermometry and thermocouple thermometry were constructed at NMC. This paper describes details of the cell design, materials used, and fabrication of the cells. The melting curves of the Co-C and Pd-C cells were measured with a reference radiation thermometer realized in both a single-zone furnace and a three-zone furnace in order to investigate furnace effect. The transition temperatures in terms of ITS-90 were determined to be 1324.18 {°}C and 1491.61 {°}C with the corresponding combined standard uncertainty of 0.44 {°}C and 0.31 {°}C for Co-C and Pd-C, respectively, taking into account of the differences of two different types of furnaces used. The determined ITS-90 temperatures are also compared with that of INRIM cells obtained using the same reference radiation thermometer and the same furnaces with the same settings during a previous bilateral comparison exercise (Battuello et al. in Int J Thermophys 35:535-546, 2014). The agreements are within k=1 uncertainty for Co-C cell and k = 2 uncertainty for Pd-C cell. Shapes of the plateaus of NMC cells and INRIM cells are compared too and furnace effects are analyzed as well. The melting curves of the Co-C and Pd-C cells realized in the single-zone furnace are also measured by a Pt/Pd thermocouple, and the preliminary results are presented as well.

  2. Chemical compatibility of Eurofer steel with sodium-potassium NaK-78 eutectic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Sena, A., E-mail: ali.abou-sena@kit.edu [Institute for Neutron Physics and Reactor Technology (INR), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Arbeiter, F. [Institute for Neutron Physics and Reactor Technology (INR), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Baumgaertner, S. [Institute for Applied Materials – Applied Materials Physics (IAM-AWP), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Boettcher, T. [Institute for Neutron Physics and Reactor Technology (INR), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Heinzel, A. [Institute for Pulsed Power and Microwave Technology (IHM), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Piecha, H. [Institute for Nuclear and Energy Technologies (IKET), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Zinn, K. [Institute for Neutron Physics and Reactor Technology (INR), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)

    2016-02-15

    Highlights: • Eurofer SSTT specimens were immersed in static NaK-78 for 6 months at 480–500 °C. • The Eurofer steel did not suffer any degradation in its mechanical properties. • The chemical interaction between Eurofer specimens and NaK-78 was minimal. • Using NaK-78, with low oxygen content, is feasible for the IFMIF HFTM capsules. - Abstract: In the high flux area of the International Fusion Materials Irradiation Facility (IFMIF) neutron source, the capsules of the High Flux Test Module (HFTM) contain SSTT Eurofer specimens for fusion relevant irradiation at temperature up to 550 °C. Using the sodium potassium eutectic alloy NaK-78 to fill the gaps among the Eurofer specimens stacked inside the HFTM capsules was introduced in order to improve the thermal conduction among all specimens and have uniform and predictable temperature distribution. Therefore the objective of this study is to investigate the chemical compatibility between Eurofer steel and NaK-78 to evaluate the applicability of this concept. In the present experiment, the SSTT Eurofer specimens were immersed in static NaK-78 inside a capsule made of Eurofer and kept under IFMIF HFTM-relevant conditions including high temperature (cycling between 480 °C and 500 °C) and duration of six months. Following the experiment, mechanical tests (tensile and Charpy impact) of the Eurofer specimens were performed in addition to surface and microstructure analyses to detect any relevant corrosion or degradation. The mechanical tests revealed that the Eurofer specimens did not show any degradation in their mechanical properties. Also, the surface and microstructure analyses showed that the chemical interaction between the Eurofer steel and NaK-78 was minimal after six month of exposure at cyclic temperature between 480 and 500 °C.

  3. Ligand-Mediated Stabilization of Low Temperature Metal Eutectics and Their Use in Composite Systems

    Science.gov (United States)

    Finkenauer, Lauren R.

    The objective of this thesis is to contribute to the understanding of the behavior of the liquid metal eutectic gallium/indium (EGaIn) in composite systems and provide a platform for the development of functional hybrid nanocomposites. Contributions are regarding (i) the investigation of the electromechanical coupling performance of EGaIn as electrodes in a soft electrostatic transducer and (ii) the effectiveness of organic surfactants to stabilize EGaIn nanoparticles in organic solvents. For the first portion, a completely soft dielectric elastomer actuator (DEA) using EGaIn electrodes was fabricated and evaluated. Experimental actuation of the DEA showed high agreement with a generalized NeoHookean constitutive law, assuming uniaxial pre-stretch and considering the device saddle deformation. The expected conductive behavior of the liquid alloy was confirmed, and further efforts have focused on the development and stabilization of EGaIn nanodroplets, which do not exhibit the problems associated with larger pools of EGaIn (such as leakage) and can be applied to soft multifunctional materials. A computational procedure was developed for calculating suspended EGaIn nanoparticle mass in order to determine reaction yields using applied Mie theory and optical characterization techniques (dynamic light scattering and UV/Vis spectrophotometry). This method calculated total mass to within 20% when applied to a known system. A systematic study evaluating particle yield as a function of aliphatic surfactant composition and concentration (and solvent type) revealed a pronounced dependence of nanodroplet formation on the solvent type as well as surfactant structure. Ethanol (EtOH) was found to be the most effective solvent for the formation and stabilization of EGaIn nanodroplets, in which only thiol-based surfactants were found to improve nanodroplet yield. Results suggest a stabilization mechanism other than the expected self-assembled monolayer (SAM) formation. The research

  4. The physicochemical and thermodynamic properties of the choline chloride-based deep eutectic solvents

    Directory of Open Access Journals (Sweden)

    Troter Dragan Z.

    2017-01-01

    Full Text Available This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity properties of several choline chloride (ChCl based deep eutectic solvents (DESs, with 1:2 mole ratio, respectively: ChCl:propylene glycol, ChCl:1,3-dimethylurea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15–363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio. Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel–Tamman–Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity of ChCl:1,3-dimethylurea and ChCl: :thiourea DESs were inferior to those of the ChCl:urea DES. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 45001

  5. Micro-IBA analysis of Au/Si eutectic “crop-circles”

    Energy Technology Data Exchange (ETDEWEB)

    Amato, Giampiero [The Quantum Research Lab, INRiM, Strada delle Cacce 91, 10135 Torino (Italy); Battiato, Alfio [Physics Department, NIS Research Centre and CNISM, University of Torino, via P. Giuria 1, 10125 Torino (Italy); Croin, Luca [The Quantum Research Lab, INRiM, Strada delle Cacce 91, 10135 Torino (Italy); Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Jaksic, Milko; Siketic, Zdravko [Department for Experimental Physics, Ruđer Bošković Institute, P.O. Box 180, 10002 Zagreb (Croatia); Vignolo, Umberto [Physics Department, NIS Research Centre and CNISM, University of Torino, via P. Giuria 1, 10125 Torino (Italy); Vittone, Ettore, E-mail: ettore.vittone@unito.it [Physics Department, NIS Research Centre and CNISM, University of Torino, via P. Giuria 1, 10125 Torino (Italy)

    2015-04-01

    Highlights: •Gold “crop circles” after annealing Au thin films deposited onto native silicon oxide. •Morphological and IBA analysis confirms the model proposed by Matthews et al. [1]. •The shape of the Au central polygon is determined by the Si orientation. -- Abstract: When a thin gold layer is deposited onto the native oxide of a silicon wafer and is annealed at temperatures greater than 600 °C, peculiar circular features, few micrometers in diameter, with a regular polygon at the centre of each circle, reminiscent of so called “alien” crop circles, can be observed. A model has been recently proposed in Matthews et al. [1], where the formation of such circular structures is attributed to the interdiffusion of gold and silicon through holes in the native oxide induced by the weakening of the amorphous silica matrix occurring during the annealing process. The rupture of the liquid Au/Si eutectic disc surrounding the pinhole in the oxide causes the debris to be pulled to the edges of the disk, forming Au droplets around it and leaving an empty zone of bare silicon oxide. In this paper, we present a morphological study and a RBS/PIXE analyses of these circular structures, carried out by scanning electron microscopy and by 4 MeV C microbeam, respectively. The results confirm the depletion of gold in the denuded circular zones, and the presence of gold droplets in the centers, which can be attributed to the Au segregation occurring during the cooling stage.

  6. Basic principles of lead and lead-bismuth eutectic application in blanket of fusion reactors

    International Nuclear Information System (INIS)

    Beznosov, A.V.; Pinaev, S.S.; Muraviev, E.V.; Romanov, P.V.

    2005-01-01

    High magnetohydrodynamic pressure drop is an important issue for liquid metal blanket concepts. To decrease magnetohydrodynamic resistance authors propose to form insulating coatings on internal surface of blanket ducts at any moment of fusion reactor exploitation. It may be achieved easily if lead or lead-bismuth eutectic is used and technology of oxidative potential handling is applied. A number of experiments carried out in NNSTU show the availability of the proposed technology. It bases on formation of the insulating coatings that consist of the oxides of components of the structural materials and of the coolant components. In-situ value of the insulating coatings characteristics ρδ is ∼ 10 -5 Ohm·m 2 for steels and 5,0x10 -6 - 5,0x10 -5 Ohm·m 2 for vanadium alloys. Thermal cycling is possible during exploitation of a blanket. The experimental research of the insulating coatings properties during thermal cycling have shown that the coatings formed into the lead and lead-bismuth coolants save there insulating properties. Experience of many years is an undoubted advantage of the lead-bismuth coolant and less of the lead coolant in comparison with lithium. Russian Federation possesses of experience of exploitation of the research and industrial facilities, of experience of creation of the pumps, steamgenerators and equipment with heavy liquid metal coolants. The unique experience of designing, assembling and exploitation of the fission reactors with lead-bismuth coolant is also available. The problem of technology of lead and lead-bismuth coolants for power high temperature radioactive facilities has been solved. Accidents, emergency situations such as leakage of steamgenerators or depressurization of gas system in facilities with lead and lead-bismuth coolants have been explored and suppressed. (author)

  7. Eutectic-based wafer-level-packaging technique for piezoresistive MEMS accelerometers and bond characterization using molecular dynamics simulations

    Science.gov (United States)

    Aono, T.; Kazama, A.; Okada, R.; Iwasaki, T.; Isono, Y.

    2018-03-01

    We developed a eutectic-based wafer-level-packaging (WLP) technique for piezoresistive micro-electromechanical systems (MEMS) accelerometers on the basis of molecular dynamics analyses and shear tests of WLP accelerometers. The bonding conditions were experimentally and analytically determined to realize a high shear strength without solder material atoms diffusing to adhesion layers. Molecular dynamics (MD) simulations and energy dispersive x-ray (EDX) spectrometry done after the shear tests clarified the eutectic reaction of the solder materials used in this research. Energy relaxation calculations in MD showed that the diffusion of solder material atoms into the adhesive layer was promoted at a higher temperature. Tensile creep MD simulations also suggested that the local potential energy in a solder material model determined the fracture points of the model. These numerical results were supported by the shear tests and EDX analyses for WLP accelerometers. Consequently, a bonding load of 9.8 kN and temperature of 300 °C were found to be rational conditions because the shear strength was sufficient to endure the polishing process after the WLP process and there was little diffusion of solder material atoms to the adhesion layer. Also, eutectic-bonding-based WLP was effective for controlling the attenuation of the accelerometers by determining the thickness of electroplated solder materials that played the role of a cavity between the accelerometers and lids. If the gap distance between the two was less than 6.2 µm, the signal gains for x- and z-axis acceleration were less than 20 dB even at the resonance frequency due to air-damping.

  8. Scintillation properties of LiF–SrF{sub 2} and LiF–CaF{sub 2} eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Yanagida, Takayuki, E-mail: yanagida@lsse.kyutech.ac.jp [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196 (Japan); Kawaguchi, Noriaki [Tokuyama Corporation, 1-1 Mikage-cho, Shunan-shi, Yamaguchi 745-8648 (Japan); Fujimoto, Yutaka [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196 (Japan); Fukuda, Kentaro [Tokuyama Corporation, 1-1 Mikage-cho, Shunan-shi, Yamaguchi 745-8648 (Japan); Watanabe, Kenichi; Yamazaki, Atsushi; Uritani, Akira [Quantum Science and Energy Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2013-12-15

    Dopant free eutectic scintillators {sup 6}LiF–SrF{sub 2} and {sup 6}LiF–CaF{sub 2} were developed by the vertical Bridgeman method for the purpose of thermal neutron detection. The molar ratio of LiF and Ca/SrF{sub 2} was 4:1 on its eutectic composition. The α-ray induced radioluminescence spectra of the scintillators showed intense emission peak at 300 nm due to the emission from the self-trapped exciton in Ca/SrF{sub 2} layers. When the samples were irradiated with {sup 252}Cf neutrons, {sup 6}LiF–SrF{sub 2} and {sup 6}LiF–CaF{sub 2} exhibited the light yields of 4700 and 9400 ph/n, respectively. Scintillation decay times of {sup 6}LiF–SrF{sub 2} and {sup 6}LiF–CaF{sub 2} were accepted for scintillation detectors, 90 and 250 ns, respectively. -- Highlights: • Nondoped LiF–CaF{sub 2} and LiF–SrF{sub 2} eutectic scinitillators are reported for the first time. • Two sample showed self-trapped exciton emission. • LiF–SrF{sub 2} sample exhibited the light yield of 9400 ph/n and this value was comparable to conventional materials doped with rare earth ions. • Scintillation decay times of LiF–CaF{sub 2} and LiF–SrF{sub 2} were 250 and 90 ns, respectively.

  9. Design studies of hydraulic verification test section of windowless target of liquid lead-bismuth eutectic experimental platform

    International Nuclear Information System (INIS)

    Zhu Linglin; Bai Yunqing; Chen Zhao

    2010-01-01

    As one of the key components of the accelerator driven system (ADS), the formation and control of the free surface is one of the key issues in the design of the windowless target which needs the theoretical analysis and experimental verification. FDS team is launching the conceptual design of ADS reactor and is developing the integrative experimental platform of liquid lead-bismuth eutectic technology. The hydraulic verification facility for windowless spallation target is an important part of the platform. In this paper, the aim of the design and major parameters of the facility were described, and the major components and experimental schemes were presented. (authors)

  10. Dynamic viscosities of pure tin and Sn-Ag, Sn-Cu, and Sn-Ag-Cu eutectic melts

    Science.gov (United States)

    Rozhitsina, E. V.; Gruner, S.; Kaban, I.; Hoyer, W.; Sidorov, V. E.; Popel', P. S.

    2011-02-01

    The dynamic viscosities of the melts of pure tin and eutectic Sn-Ag, Sn-Cu, and Sn-Ag-Cu alloys are studied in heating followed by cooling, and the maximum heating temperature was 1200°C. An irreversible decrease in the viscosity is found in the temperature range 800-1000°C in the polytherms of all melts. This finding is related to the loss of a local order in a melt and can be used to develop temperature regimes for the production of lead-free solders.

  11. RAMAN/Cr3+ FLUORESCENCE MAPPING OF MELT-GROWN Al2O3/GdAlO3 EUTECTICS

    OpenAIRE

    Gouadec , Gwénael; Colomban , Philippe; Piquet , Nicolas; Trichet , Marie-France; Mazerolles , Léo

    2005-01-01

    International audience; The paper reports on the Raman/fluorescence study of melt-grown Al2O3/GdAlO3 eutectic composites. Raman bands from the Α-alumina and gadolinium perovskite phases identified by X-ray diffraction were systematically observed together in the domains optically visible, even when the latter were much larger than the Raman probe. This suggests a more complex interlocking pattern than appearing on SEM or optical microscopy images. The polarization of alumina and GdAlO3 Raman ...

  12. Preparation and characterization of the Li(17)Pb(83) eutectic alloy and the LiPb intermetallic compound

    International Nuclear Information System (INIS)

    Jauch, U.; Karcher, V.; Schulz, B.

    1986-01-01

    Li(17)Pb(83) and LiPb were prepared from the pure elements in amounts of several hundred grams. The resolidified samples were characterized by melting points (eutectic temperature), chemical analysis and metallography. Using differential thermal analysis the heats of fusion were determined and the behaviour of the intermetallic phase LiPb in vacuum and high purified He was studied. The results from these investigations were applied to characterize Li(17)Pb(83) prepared in high amounts for technical application as a potential liquid breeder material. (orig.)

  13. Unconventional transport characteristics of p-wave superconducting junctions in Sr2RuO4-Ru eutectic system

    International Nuclear Information System (INIS)

    Kambara, H.; Kashiwaya, S.; Yaguchi, H.; Asano, Y.; Tanaka, Y.; Maeno, Y.

    2010-01-01

    We report on novel local transport characteristics of naturally formed p-wave superconducting junctions of Sr 2 RuO 4 -Ru eutectic system by using microfabrication technique. We observed quite anomalous voltage-current (differential resistance-current) characteristics for both I//ab and I//c directions, which are not seen in conventional Josephson junctions. The anomalous features suggest the internal degrees of freedom of the superconducting state, possibly due to chiral p-wave domain. The dc current acts as a driving force to move chiral p-wave domain walls and form larger critical current path to cause the anomalous hysteresis.

  14. Effect of Strontium and Phosphorus on Eutectic Al-Si Nucleation and Formation of β-Al5FeSi in Hypoeutectic Al-Si Foundry Alloys

    Science.gov (United States)

    Cho, Y. H.; Lee, H.-C.; Oh, K. H.; Dahle, A. K.

    2008-10-01

    The present investigation was carried out on hypoeutectic Al-Si alloys containing two levels of Fe, 0.5 and 1.1 wt pct, and Sr in the range of 30 to 500 ppm. The addition of Sr in excess of 100 ppm significantly reduced the number of eutectic grains and also resulted in the formation of polygonal-shaped Al2Si2Sr intermetallics. Transmission electron microscopy studies revealed that the Al2Si2Sr phase surrounded the P-rich particles. This may suggest that the otherwise potent nuclei for the Al-Si eutectic, aluminum phosphide (AlP), become poisoned or deactivated by the formation of the Al2Si2Sr phase around the particles. At the high-Fe level (1.1 wt pct Fe), pre-eutectic formation of β-Al5FeSi platelets further reduced the number of eutectic Al-Si nucleation events. It is proposed that both eutectic silicon and β-Al5FeSi are preferentially nucleated on AlP particles. Nucleation of eutectic silicon, therefore, becomes more difficult when it is preceded by the formation of Al2Si2Sr or β-Al5FeSi, because fewer nuclei are available to nucleate silicon. Addition of up to 60 ppm P to the alloys increased the formation temperature of the β-Al5FeSi platelets but did not significantly alter the size, whereas the addition of Sr decreased the β-Al5FeSi nucleation temperature by reducing the potency of the AlP particles.

  15. Fabrication and characterization of large size {sup 6}LiF/CaF{sub 2}:Eu eutectic composites with the ordered lamellar structure

    Energy Technology Data Exchange (ETDEWEB)

    Kawaguchi, Noriaki [Tokuyama Corporation, 3-3-1 Shibuya, Shibuya-ku, Tokyo 150-8383 (Japan); Fukuda, Kentaro, E-mail: ken-fukuda@tokuyama.co.jp [Tokuyama Corporation, 3-3-1 Shibuya, Shibuya-ku, Tokyo 150-8383 (Japan); Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Suyama, Toshihisa [Tokuyama Corporation, 3-3-1 Shibuya, Shibuya-ku, Tokyo 150-8383 (Japan); Watanabe, Kenichi; Yamazaki, Atsushi [Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Yoshikawa, Akira [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

    2011-10-01

    As alternative candidates for the {sup 3}He neutron detectors, {sup 6}LiF/CaF{sub 2}:Eu eutectic composites were fabricated and their scintillation properties were evaluated. Large size LiF/CaF{sub 2}:Eu eutectic composites of 58 mm diameter and 50 mm thickness were produced by Bridgman method. The composites had a finely ordered lamellar structure along the solidification direction. The lamellar structure was controlled by the direction and the rate of solidification, and it was optimized to improve the scintillation properties. Better results were achieved when thinner lamellar layers were aligned along the scintillation light path.

  16. Fabrication and characterization of large size 6LiF/CaF2:Eu eutectic composites with the ordered lamellar structure

    International Nuclear Information System (INIS)

    Kawaguchi, Noriaki; Fukuda, Kentaro; Yanagida, Takayuki; Fujimoto, Yutaka; Yokota, Yuui; Suyama, Toshihisa; Watanabe, Kenichi; Yamazaki, Atsushi; Yoshikawa, Akira

    2011-01-01

    As alternative candidates for the 3 He neutron detectors, 6 LiF/CaF 2 :Eu eutectic composites were fabricated and their scintillation properties were evaluated. Large size LiF/CaF 2 :Eu eutectic composites of 58 mm diameter and 50 mm thickness were produced by Bridgman method. The composites had a finely ordered lamellar structure along the solidification direction. The lamellar structure was controlled by the direction and the rate of solidification, and it was optimized to improve the scintillation properties. Better results were achieved when thinner lamellar layers were aligned along the scintillation light path.

  17. Parametric Study for Devulcanization of Waste Tire Rubber Utilizing Deep Eutectic Solvent (DES

    Directory of Open Access Journals (Sweden)

    Walvekar Rashmi

    2018-01-01

    Full Text Available Waste rubber is a polymeric material containing 50% of rubber and is generally referred to as waste tyre rubber. The main purpose of this research is to study ultrasonic devulcanisation of waste rubber utilising deep eutectic solvent (DES of ZnCl2:Urea by improving process parameters such as sonication time, reaction temperature and rubber: DES mass ratio by effectively cleaving cross-link sulphur bonds. DES was created and prepared by mixing ZnCl2 with urea at 2:7 and 1:4 molar ratios respectively. Physicochemical properties of the prepared DES was measured using DSC, KFT and TGA analysis to find the freezing point, moisture content and degradation temperature, whereby their freezing point below 60°C, moisture content lower than 3.0 wt.% and 200°C degradation temperature average. Rubber to DES mass ratio was varied at 1:20, 1:30 and 1:40 and sonicated for 15 minutes inside ultrasonic water-bath. Samples were placed onto hot plate whereby heating temperature was varied at room temperature, 130°C, 150°C, and 180°C for 15 minutes. Samples were filtered, washed with distilled water and dried in oven for 24 hours. Once dried, samples were taken for analysis using TGA, EDX, FESEM, FTIR and Gel content. Under TGA analysis, most samples have an average degradation temperature of 200°C, hence justifying a successful devulcanisation. EDX analysis shows two occurrences during devulcanisation process which is bond reformation and cleavage. Furthermore, it is determined that heating temperature of 130°C is an important parameter as it is the optimum temperature for ZnCl2:Urea. Under FTIR analysis, it shows that disulphide bond, S-S is the only bond that is being broken while the rest still remains the same. Gel content analysis showed that samples have a lower soluble fraction after devulcanisation process. Finally, FESEM proves that at 130°C and 15 minutes is the optimum temperature and time which is illustrated by the smooth surface at that

  18. Coupling Fluid Dynamics and Multiphase Disequilibria: Applications to Eutectic and Peritectic Systems

    Science.gov (United States)

    Tweed, L. E. L.; Spiegelman, M. W.; Kelemen, P. B.

    2017-12-01

    Computational thermodynamics has yielded great insights into petrological processes. However, on its own it cannot capture the inherently dynamic nature of many of these processes which depend on the interaction between time-dependent processes including advection, diffusion and chemical reaction. To understand this interplay, and to move away from a purely equilibrium view, requires the integration of computational thermodynamics and fluid mechanics. A key aspect of doing this is the treatment of chemical reactions as time-dependent, irreversible processes. Such a development is integral to understanding a host of petrological questions from the open system evolution of magma chambers to the dynamics of melt migration beneath mid-ocean ridges and flux melting of the mantle wedge in subduction zones. A simple thermodynamically consistent reactive model is developed that can be integrated with conservation equations for mass, momentum and energy. The model rests on the thermodynamic characterization of an independent set of reactions and has the advantage of being completely general and easily extensible to systems comprising multiple solid and liquid phases. The underlying theory is described in detail in another contribution in this session. Here we apply the framework to experimentally constrained simple systems of petrological interest including the fo-qz binary and the fo-qz-k2o ternary. These systems contain a variety of phase topologies including eutectic and peritectic reactions. As the model allows for the seamless exhaustion and stabilization of phases, we can explore the effect that these discontinuous changes have on the compositional and dynamic evolution of the system. To do this we track how the systems respond to sudden changes in intensive variables that perturb them from equilibrium. Such changes are rife in crustal magmatic systems. Simulations for decompression melting are also run to explore the interplay between reactive and advective fluxes

  19. Dissolution mechanism of austenitic stainless steels in lead-bismuth eutectic at 500 deg. C

    International Nuclear Information System (INIS)

    Roy, M.

    2012-01-01

    In the framework of the future nuclear power plants studies, lead-bismuth eutectic (LBE) is foreseen as a coolant in the primary or the secondary circuit in three nuclear systems. The use of this liquid alloy induces corrosion issues for structural steels. In liquid lead alloys, steels can undergo two corrosion phenomena: dissolution or oxidation depending on the temperature and the dissolved oxygen content in LBE. The goal of this study is to identify the dissolution mechanisms of austenitic steels in LBE at 500 deg. C. Four Fe-Cr-Ni model austenitic steels, the 316L steel and five other industrial steels were corroded in LBE up to, respectively, 3000, 6000 and 200 h. The dissolution mechanism is identical for all steels: it starts by a preferential dissolution of chromium and nickel. This dissolution leads to the formation of a ferritic corrosion layer penetrated by LBE and containing between 5 and 10 at% of chromium and almost no nickel. This study demonstrates that dissolutions of nickel and chromium are linked. Otherwise, the corrosion kinetics is linear whatever the tested austenitic steel. The controlling steps of the austenitic steels' corrosion rates have been identified. Natural convection in the LBE bath leads to the formation of a diffusion boundary layer at the steel surface. Chromium diffusion in this diffusion boundary layer seems to control the corrosion rates of the model and industrial austenitic steels except the 316L steel. Indeed, the corrosion rate of the 316L steel is controlled by an interfacial reaction which is either the simultaneous dissolution of nickel and chromium in Ni, Cr compounds or the nickel and chromium dissolution catalyzed by the dissolved oxygen in LBE. This study has permitted to highlight the major role of chromium on the corrosion mechanisms and the corrosion rates of austenitic steels: the corrosion rate increases when chromium activity increases. Finally, the impact of the dissolved oxygen and the minor alloying

  20. Incorporation of antibacterial agent derived deep eutectic solvent into an active dental composite.

    Science.gov (United States)

    Wang, Jing; Dong, Xiaoqing; Yu, Qingsong; Baker, Sheila N; Li, Hao; Larm, Nathaniel E; Baker, Gary A; Chen, Liang; Tan, Jingwen; Chen, Meng

    2017-12-01

    To incorporate an antibacterial agent derived deep eutectic solvent (DES) into a dental resin composite, and investigate the resulting mechanical properties and antibacterial effects. The DES was derived from benzalkonium chloride (BC) and acrylic acid (AA) and was incorporated into the dental resin composite through rapid mixing. A three-point bending test was employed to measure the flexural strength of the composite. An agar diffusion test was used to investigate antibacterial activity. Artificial (accelerated) aging was undertaken by immersing the composites in buffer solutions at an elevated temperature for up to 4 weeks. UV-vis spectrophotometry and NMR analysis were conducted to study BC release from the composite. Finally, the biocompatibility of the composite materials was evaluated using osteoblast cell culture for 7 days. Results were compared to those of a control composite which contained no BC. The DES-incorporated composite (DES-C) displayed higher flexural strength than a similar BC-incorporated composite BC (BC-C) for the same level of BC. The inclusion of BC conferred antibacterial activity to both BC-containing composites, although BC-C produced larger inhibition halos than DES-C at the same loading of BC. Control composites which contained no BC showed negligible antibacterial activity. After artificial aging, the DES-C composite showed better maintenance of the mechanical properties of the control compared with BC-C, although a decrease was observed during the three-point bending test, particularly upon storage at elevated temperatures. No BC release was detected in the aged solutions of DES-C, whereas the BC-C showed a linear increase in BC release with storage time. Significantly, cell viability results indicated that DES-C has better biocompatibility than BC-C. The incorporation of a BC-based DES into a dental resin composite provides a new strategy to develop antibacterial dental materials with better biocompatibility and longer effective

  1. Stability of the lamellar structure in Mo-TiC eutectic composite under a low vacuum at high temperatures

    International Nuclear Information System (INIS)

    Goto, Shoji; Nishijima, Yuzo; Yoshinaga, Hideo

    1986-01-01

    Thermal stability of the lamellar structure in a Mo-TiC eutectic composite has been investigated through the heat-treatment at 1523 - 2223 K for 5.76 x 10 4 - 3.6 x 10 5 s under a low vacuum pressure of 13 mPa. It was found that the TiC phase in the eutectic lamellar disappeared above the critical temperature of about 1750 K, but below the critical temperature the disappearance of TiC phase was hardly observed and TiO film was formed on the surface. The Mo matrix phase was not oxidized and was stable at all test temperatures, since its affinity for oxygen is lower than that for carbon and titanium. It is presumed that at higer temperatures the disappearance process of TiC phase is controlled by the diffusion of carbon atoms through the matrix to the surface, and carbon and titanium atoms on the surface are removed by CO gas formation and TiO evaporation, respectively, but at lower temperatures the evaporation of TiO is so slow that the TiO film is formed on the surface. (author)

  2. Palm ethyl ester purification by using Choline Chloride – 1,2 propanediol as deep eutectic solvent

    Science.gov (United States)

    Manurung, R.; Alhamdi, M. A.; Syahputra, A.

    2018-02-01

    Deep eutectic solvent (DES) has gained more attention for using in biodiesel production because of environmental benefits and process improvements. This study was aimed to test the potency and effectiveness of Deep Eutectic Solvent (DES) based choline chloride: 1.2-propanediol as co-solvent in biodiesel purification. The method used in preparing DES synthesis process was conducted by mixing choline chloride: 1.2-propanediol with mole ratio variation such as: 1:2 ; 1:2.5 ; 1:3 ; and 1:3.5 (mole/mole). The temperature of DES synthesis was at 80 °C with 300 rpm stirring speed for 60 minutes. Variation of DES concentration base on percentage palm oil used: 1, 3, and 5 %. DES possible to increase the ethyl ester yield of biodiesel in the purification process. The best result of yield was 89.95% with the 9:1 molar ratio ethanol: oil and 5% of DES. The operation condition was at 70 °C of temperature reaction, 400 rpm of stirring speed, and 90 minutes of reaction time.

  3. Preparation of eutectic superalloys by EFG. [Edge-defined Film-fed Growth for directional solidification in airfoil structures

    Science.gov (United States)

    Hurley, G. F.; Marr, N. W.

    1975-01-01

    An attempt was made to produce airfoil shaped bars of three different eutectic superalloys by means of the edge-defined, film-fed growth (EFG) method. The alloys used were a gamma + delta Ni-Cb alloy, a gamma/gamma prime + delta Ni-Cb-Al alloy and a Co-TaC alloy containing Ni and Cr. The development of a new die material was essential in the investigation since these alloys are reactive toward known die materials. Tantalum carbide was selected as a die material because it exhibited spontaneous capillary rise and slow rate of degradation in the liquid metals. Eutectic bars up to 1 mm thick and 6 mm wide were grown from TaC dies in order to determine the growth characteristics and the thermal gradient. Large bars of the gamma/gamma prime + delta alloy were grown and tensile tested. A die with a blind central cavity was designed and several hollow, tear-shaped bars were grown.

  4. Following the electroreduction of uranium dioxide to uranium in LiCl–KCl eutectic in situ using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.D.; Abdulaziz, R.; Jervis, R.; Bharath, V.J. [Electrochemical Innovation Lab, Dept. Chemical Engineering, UCL, London WC1E 7JE (United Kingdom); Atwood, R.C.; Reinhard, C.; Connor, L.D. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Simons, S.J.R.; Inman, D.; Brett, D.J.L. [Electrochemical Innovation Lab, Dept. Chemical Engineering, UCL, London WC1E 7JE (United Kingdom); Shearing, P.R., E-mail: p.shearing@ucl.ac.uk [Electrochemical Innovation Lab, Dept. Chemical Engineering, UCL, London WC1E 7JE (United Kingdom)

    2015-09-15

    Highlights: • We investigated the electroreduction of UO{sub 2} to U in LiCl/KCL eutectic molten salt. • Combined electrochemical measurement and in situ XRD is utilised. • The electroreduction appears to occur in a single, 4-electron-step, process. • No intermediate compounds were observed. - Abstract: The electrochemical reduction of uranium dioxide to metallic uranium has been investigated in lithium chloride–potassium chloride eutectic molten salt. Laboratory based electrochemical studies have been coupled with in situ energy dispersive X-ray diffraction, for the first time, to deduce the reduction pathway. No intermediate phases were identified using the X-ray diffraction before, during or after electroreduction to form α-uranium. This suggests that the electrochemical reduction occurs via a single, 4-electron-step, process. The rate of formation of α-uranium is seen to decrease during electrolysis and could be a result of a build-up of oxygen anions in the molten salt. Slow transport of O{sup 2−} ions away from the UO{sub 2} working electrode could impede the electrochemical reduction.

  5. Green synthesis of mesoporous molecular sieve incorporated monoliths using room temperature ionic liquid and deep eutectic solvents.

    Science.gov (United States)

    Zhang, Li-Shun; Zhao, Qing-Li; Li, Xin-Xin; Li, Xi-Xi; Huang, Yan-Ping; Liu, Zhao-Sheng

    2016-12-01

    A hybrid monolith incorporated with mesoporous molecular sieve MCM-41 of uniform pore structure and high surface area was prepared with binary green porogens in the first time. With a mixture of room temperature ionic liquids and deep eutectic solvents as porogens, MCM-41 was modified with 3-(trimethoxysilyl) propyl methacrylate (γ-MPS) and the resulting MCM-41-MPS was incorporated into poly (BMA-co-EDMA) monoliths covalently. Because of good dispersibility of MCM-41-MPS in the green solvent-based polymerization system, high permeability and homogeneity for the resultant hybrid monolithic columns was achieved. The MCM-41-MPS grafted monolith was characterized by scanning electron microscopy, energy dispersive spectrometer area scanning, transmission electron microscopy, FT-IR spectra and nitrogen adsorption tests. Chromatographic performance of MCM-41-MPS grafted monolith was characterized by separating small molecules in capillary electrochromatography, including phenol series, naphthyl substitutes, aniline series and alkyl benzenes. The maximum column efficiency of MCM-41-MPS grafted monolith reached 209,000 plates/m, which was twice higher than the corresponding MCM-41-MPS free monolith. Moreover, successful separation of non-steroidal anti-inflammatory drugs and polycyclic aromatic hydrocarbons demonstrated the capacity in broad-spectrum application of the MCM-41-MPS incorporated monolith. The results indicated that green synthesis using room temperature ionic liquid and deep eutectic solvents is an effective method to prepare molecular sieve-incorporated monolithic column. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Vibration Monitoring Using Fiber Optic Sensors in a Lead-Bismuth Eutectic Cooled Nuclear Fuel Assembly †

    Science.gov (United States)

    De Pauw, Ben; Lamberti, Alfredo; Ertveldt, Julien; Rezayat, Ali; van Tichelen, Katrien; Vanlanduit, Steve; Berghmans, Francis

    2016-01-01

    Excessive fuel assembly vibrations in nuclear reactor cores should be avoided in order not to compromise the lifetime of the assembly and in order to prevent the occurrence of safety hazards. This issue is particularly relevant to new reactor designs that use liquid metal coolants, such as, for example, a molten lead-bismuth eutectic. The flow of molten heavy metal around and through the fuel assembly may cause the latter to vibrate and hence suffer degradation as a result of, for example, fretting wear or mechanical fatigue. In this paper, we demonstrate the use of optical fiber sensors to measure the fuel assembly vibration in a lead-bismuth eutectic cooled installation which can be used as input to assess vibration-related safety hazards. We show that the vibration characteristics of the fuel pins in the fuel assembly can be experimentally determined with minimal intrusiveness and with high precision owing to the small dimensions and properties of the sensors. In particular, we were able to record local strain level differences of about 0.2 μϵ allowing us to reliably estimate the vibration amplitudes and modal parameters of the fuel assembly based on optical fiber sensor readings during different stages of the operation of the facility, including the onset of the coolant circulation and steady-state operation. PMID:27110782

  7. Study of the Formation of Eutectic Melt of Uranium and Thermal Analysis for the Salt Distillation of Uranium Deposits

    International Nuclear Information System (INIS)

    Park, Sung Bin; Hwang, Sung Chan; Kang, Young Ho; Park, Ki Min; Jun, Wan Gi; Lee, Han Soo; Cho, Dong Wook

    2010-01-01

    Uranium deposits from an electrorefining process contain about 30% salt. In order to recover pure uranium and transform it into an ingot, the salts have to be removed from the uranium deposits. Major process variables for the salt distillation process of the uranium deposits are hold temperature and vacuum pressure. Effects of the variables on the salt removal efficiency were studied in the previous study 1. By applying the Hertz-Langmuir relation to the salt evaporation of the uranium deposits, the evaporation coefficients were obtained at the various conditions. The operational conditions for achieving above 99% salt removal were deduced. The salt distilled uranium deposits tend to form the eutectic melt with iron, nickel, chromium for structural material of salt evaporator. In this study, we investigated the hold temperature limitation in order to prevent the formation of the eutectic melt between uranium and other metals. The reactions between the uranium metal and stainless steel were tested at various conditions. And for enhancing the evaporation rate of the salt and the efficient recovery of the distilled salt, the thermal analysis of the salt distiller was conducted by using commercial CFX software. From the thermal analysis, the effect of Ar gas flow on the evaporation of the salt was studied.

  8. Handbook on Lead-bismuth Eutectic Alloy and Lead Properties, Materials Compatibility, Thermal-hydraulics and Technologies - 2015 Edition

    International Nuclear Information System (INIS)

    Fazio, Concetta; Sobolev, V.P.; Aerts, A.; Gavrilov, S.; Lambrinou, K.; Schuurmans, P.; Gessi, A.; Agostini, P.; Ciampichetti, A.; Martinelli, L.; Gosse, S.; Balbaud-Celerier, F.; Courouau, J.L.; Terlain, A.; Li, N.; Glasbrenner, H.; Neuhausen, J.; Heinitz, S.; Zanini, L.; Dai, Y.; Jolkkonen, M.; Kurata, Y.; Obara, T.; Thiolliere, N.; Martin-Munoz, F.J.; Heinzel, A.; Weisenburger, A.; Mueller, G.; Schumacher, G.; Jianu, A.; Pacio, J.; Marocco, L.; Stieglitz, R.; Wetzel, T.; Daubner, M.; Litfin, K.; Vogt, J.B.; Proriol-Serre, I.; Gorse, D.; Eckert, S.; Stefani, F.; Buchenau, D.; Wondrak, T.; Hwang, I.S.

    2015-01-01

    Heavy liquid metals such as lead or lead-bismuth have been proposed and investigated as coolants for fast reactors since the 1950's. More recently, there has been renewed interest worldwide in the use of these materials to support the development of systems for the transmutation of radioactive waste. Heavy liquid metals are also under evaluation as a reactor core coolant and accelerator-driven system neutron spallation source. Several national and international R and D programmes are ongoing for the development of liquid lead-alloy technology and the design of liquid lead-alloy-cooled reactor systems. In 2007, a first edition of the handbook was published to provide deeper insight into the properties and experimental results in relation to lead and lead-bismuth eutectic technology and to establish a common database. This handbook remains a reference in the field and is a valuable tool for designers and researchers with an interest in heavy liquid metals. The 2015 edition includes updated data resulting from various national and international R and D programmes and contains new experimental data to help understand some important phenomena such as liquid metal embrittlement and turbulent heat transfer in a fuel bundle. The handbook provides an overview of liquid lead and lead-bismuth eutectic properties, materials compatibility and testing issues, key aspects of thermal-hydraulics and existing facilities, as well as perspectives for future R and D. (authors)

  9. Electrochemically shape-controlled synthesis in deep eutectic solvents of Pt nanoflowers with enhanced activity for ethanol oxidation

    International Nuclear Information System (INIS)

    Wei Lu; Fan Youjun; Wang Honghui; Tian Na; Zhou Zhiyou; Sun Shigang

    2012-01-01

    Highlights: ► The electrochemically shape-controlled synthesis in deep eutectic solvents (DESs) has been applied to produce the uniform Pt nanoflowers with sharp single crystal petals and high density of atomic steps. ► The as-prepared Pt nanoflowers exhibit higher electrocatalytic activity and stability than commercial Pt black catalyst toward ethanol electrooxidation. ► The growth of Pt nanoflowers in DESs by the simple electrochemical route is straightforward and controllable in terms of nanoflowers’ shape and size. - Abstract: The electrochemically shape-controlled synthesis in deep eutectic solvents (DESs) has been applied to produce the electrocatalyst of Pt nanoflowers. The uniform Pt nanoflowers with sharp single crystal petals and high density of atomic steps were characterized by SEM, TEM, XRD, XPS and electrochemical tests. The results illustrated that the as-prepared Pt nanoflowers exhibit higher electrocatalytic activity and stability than commercial Pt black catalyst toward ethanol electrooxidation. The growth of Pt nanoflowers in DESs by the simple electrochemical route is straightforward and controllable in terms of nanoflowers’ shape and size, which can be applied in shape-controlled synthesis of other noble metal nanoparticles with high catalytic activity.

  10. Eutectics Me5Si3-MeSi2 in a triple system Mo-W-Si

    International Nuclear Information System (INIS)

    Gnesin, B.A.; Gurjiyants, P.A.; Borisenko, E.B.

    2001-01-01

    Refractory metals silicides high-melting point eutectics are of great interest for different high temperature applications: production of composite materials with silicon carbide skeleton, antioxidant protective coatings on carbon materials, brazing of carbon, silicon carbide and refractory metals alloys materials. Phase diagrams Mo-Si and W-Si are compared: diagrams are similar but not in all significant details. Number of possible crystal structures for molybdenum silicides is at least twice more, than for tungsten and this difference is manifested distinctly for composite samples with different W-Mo ratio air high-temperature tests. In tests of new silicon carbide-refractory metal silicides composites materials (REFSIC) with 10-20 seconds heating time up to 1700 o C and 20-40 seconds time of cooling silicides with molybdenum prevalence were not so steady as tungsten based silicides. Experimental data concerning eutectic temperature dependence on W-Mo ratio, X-ray diffraction data, scanning electron and optical microscopy structure investigations results and some properties are discussed. (author)

  11. Application of the rotating cylinder electrode in molten LiCl-KCl eutectic containing uranium(III)- and magnesium(II)-chloride

    Science.gov (United States)

    Rappleye, Devin; Simpson, Michael F.

    2017-04-01

    The application of the rotating cylinder electrode (RCE) to molten LiCl-KCl eutectic mixtures for electroanalytical measurements is presented. This enabled the measurement of the limiting current which was observed to follow a linear trend with the rotational rate raised to 0.64-0.65 power on average, which closely agrees with existing RCE mass-transfer correlations. This is the first publication of electroanalytical RCE measurements in LiCl-KCl eutectic based molten salt mixtures, to our knowledge. These measurements were made in mixtures of molten LiCl-KCl eutectic containing UCl3 and MgCl2. Kinetic parameters were calculated for Mg2+ in LiCl-KCl eutectic. The exchange current density (io) of Mg2+ deposition varied with mole fraction (x) according to io(A cm-2) = 1.64x0.689. The parameters from RCE measurements were also applied in an electrochemical co-deposition model entitled DREP to detect and predict the deposition rate of U and Mg. DREP succeeded in detecting the co-deposition of U and Mg, even when Mg constituted less than 0.5 wt% of the deposit.

  12. Air-assisted dispersive liquid-liquid microextraction based on a new hydrophobic deep eutectic solvent for the preconcentration of benzophenone-type UV filters from aqueous samples.

    Science.gov (United States)

    Ge, Dandan; Zhang, Yi; Dai, Yixiu; Yang, Shumin

    2017-12-28

    Deep eutectic solvents are considered as new and green solvents that can be widely used in analytical chemistry such as microextraction. In the present work, a new dl-menthol-based hydrophobic deep eutectic solvent was synthesized and used as extraction solvents in an air-assisted dispersive liquid-liquid microextraction method for preconcentration and extraction of benzophenone-type UV filters from aqueous samples followed by high-performance liquid chromatography with diode array detection. In an experiment, the deep eutectic solvent formed by dl-menthol and decanoic acid was added to an aqueous solution containing the UV filters, and then the mixture was sucked up and injected five times by using a glass syringe, and a cloudy state was achieved. After extraction, the solution was centrifuged and the upper phase was subjected to high-performance liquid chromatography for analysis. Various parameters such as the type and volume of the deep eutectic solvent, number of pulling, and pushing cycles, solution pH and salt concentration were investigated and optimized. Under the optimum conditions, the developed method exhibited low limits of detection and limits of quantitation, good linearity, and precision. Finally, the proposed method was successfully applied to determine the benzophenone-type filters in environmental water samples with relative recoveries of 88.8-105.9%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Nano-eutectic growth in Co-17.8 wt%Gd alloy ribbons and the magnetostrictive properties at different wheel speeds.

    Science.gov (United States)

    Yao, Wen-Jing; Sun, Wen; Wang, Nan; Han, Seung Zeon; Lee, Je-Hyun

    2014-11-01

    Under near-equilibrium solidification conditions, the Co-17.8 wt%Gd eutectic alloy forms rod-like eutectic microstructure of (αCo) solid solution and Co17Gd2 compound. When the solidification condition is far from the equilibrium, the rapid growth of nano-eutectic in Co-17.8 wt%Gd alloy ribbons is realized by the single-roller techniques. The average granular size (d) of nano-eutectic in the center of ribbons varies with the increase of wheel speed (V), d = 510.36-25.51 V+0.44 V2. XRD results of ribbons at different wheel speeds indicate that, with the rise of wheel speed, the main peak of Co17Gd2 compound becomes more and more notable, whereas the main peak of (αCo) solid solution tends to reduce. Along the length direction, the Co-17.8 wt%Gd alloy ribbons have the negative magnetostrictive strain. The magnetostrictive strain enhances with the increase of wheel speed. At the wheel speed of 40 m/s, the magnetostrictive coefficient of ribbons is measured to be - 733 ppm at the magnetic field of 6 kOe. The influence of the wheel speed and the magnetic field on the maanetostrictive coefficient is discussed.

  14. Growth and luminescence properties of Eu-doped HfO.sub.2./sub./α-Al.sub.2./sub.O.sub.3./sub. eutectic scintillator

    Czech Academy of Sciences Publication Activity Database

    Kamada, K.; Hishinuma, K.; Kurosawa, S.; Yamaji, A.; Shoji, Y.; Pejchal, Jan; Ohashi, Y.; Yokota, Y.; Yoshikawa, A.

    2016-01-01

    Roč. 34, č. 8 (2016), s. 796-801 ISSN 1002-0721 Institutional support: RVO:68378271 Keywords : eutectic * scintillator * micro-pulling down method * rare earths Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.429, year: 2016

  15. Preparation and properties of shape-stabilized phase change materials based on fatty acid eutectics and cellulose composites for thermal energy storage

    International Nuclear Information System (INIS)

    Cao, Lei; Tang, Yaojie; Fang, Guiyin

    2015-01-01

    Shape-stabilized fatty acid eutectics/carboxy methyl cellulose-1 composites as phase change materials (PCMs) were synthesized by absorbing liquid eutectics into the carboxy methyl cellulose-1 fibers. The chemical structure, crystalloid phase and morphology were determined by the Fourier transformation infrared spectroscope, X-ray diffractometer and scanning electronic microscope. The thermal properties and thermal stability were measured by the differential scanning calorimeter, thermogravimetric analyzer and the thermal cycling test, respectively. The results indicate that the eutectics are well adsorbed in the porous structure of the carboxy methyl cellulose-1. According to the DSC (differential scanning calorimeter) results, the composites melt at 32.2 °C with latent heat of 114.6 kJ/kg and solidify at 29.2 °C with latent heat of 106.8 kJ/kg. The thermal cycling test proves that the composites have good thermal reliability. It is envisioned that the prepared shape-stabilized PCMs have considerable potential for developing their roles in thermal energy storage. - Highlights: • The fatty acid eutectic/carboxy methyl cellulose-1 composites as PCMs were prepared. • Chemical structure and microstructure of composites were determined by FT-IR and SEM. • Thermal properties and stabilities were investigated by DSC and TGA. • The thermal cycling test confirmed that the composite has good thermal reliability

  16. Eutectic Gallium-Indium (EGaIn) : A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature

    NARCIS (Netherlands)

    Dickey, Michael D.; Chiechi, Ryan C.; Larsen, Ryan J.; Weiss, Emily A.; Weitz, David A.; Whitesides, George M.

    2008-01-01

    This paper describes the rheological behavior of the liquid metal eutectic gallium-indium (EGaIn) as it is injected into microfluidic channels to form stable microstructures of liquid metal. EGaIn is well-suited for this application because of its rheological properties at room temperature: it

  17. Preliminary study on nano- and micro-composite sol-gel based alumina coatings on structural components of lead-bismuth eutectic cooled fast breeder reactors

    International Nuclear Information System (INIS)

    Dou, Peng; Kasada, Ryuta

    2011-01-01

    In order to protect the structural components of lead-bismuth eutectic cooled fast breeder reactors from liquid metal corrosion, Al 2 O 3 nano- and micro-composite coatings were developed using an improved sol-gel process, which includes dipping specimens in a sol-gel solution dispersed with fine α-Al 2 O 3 powders prepared by mechanical milling. Accelerated corrosion tests were conducted on coated specimens in liquid lead-bismuth eutectic at 500 o C under dynamic conditions. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses revealed that the coatings are composed of α-Al 2 O 3 and they are about 10 μm thick. After the corrosion tests, no spallation occurred on the coatings, and neither Pb nor Bi penetrated into the coatings, which indicates that the coatings possess an enhanced dynamic LBE corrosion resistance to lead-bismuth eutectic corrosion. The nano-structured composite particles integrated into the coatings play an important role in achieving such superior lead-bismuth eutectic corrosion resistance.

  18. Efficient absorption of SO{sub 2} with low-partial pressures by environmentally benign functional deep eutectic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai; Ren, Shuhang [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 (China); Hou, Yucui [Department of Chemistry, Taiyuan Normal University, Taiyuan, 030031 (China); Wu, Weize, E-mail: wzwu@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 (China)

    2017-02-15

    Graphical abstract: Environmentally benign deep eutectic solvents (DESs) based on betaine or L-carnitine with ethylene glycol were designed with a function and used to efficiently capture SO{sub 2} with low partial pressures. - Highlights: • Deep eutectic solvents (DESs) were designed with a function to absorb low-conc. SO{sub 2}. • Betaine(Bet) and L-carnitine(L-car) with a functional group were used as H-bond acceptor. • Bet + ethylene glycol (EG) DES and L-car + EG DES are environmentally benign. • L-car + EG DES can absorb 0.644 mol SO{sub 2} per mole L-car (0.37% SO{sub 2}). • L-car + EG DES is a promising absorbent for SO{sub 2} capture. - Abstract: Sulfur dioxide (SO{sub 2}) emitted from the burning of fossil fuels is one of the main air contaminants. In this work, we found that environmentally benign solvents, deep eutectic solvents (DESs) could be designed with a function to absorb low-partial pressure SO{sub 2} from simulated flue gas. Two kinds of biodegradable functional DESs based on betaine (Bet) and L-carnitine (L-car) as hydrogen bond accepters (HBA) and ethylene glycol (EG) as a hydrogen bond donor (HBD) were prepared with mole ratios of HBA to HBD from 1:3 to 1:5, and they were investigated to absorb SO{sub 2} with different partial pressures at various temperatures. The results showed that the two DESs could absorb low-partial pressure SO{sub 2} efficiently. SO{sub 2} absorption capacities of the DESs with HBA/HBD mole ratio of 1:3 were 0.332 mol SO{sub 2}/mol HBA for Bet + EG DES and 0.820 mol SO{sub 2}/mol HBA for L-car + EG DES at 40 °C with a SO{sub 2} partial pressure of 0.02 atm. In addition, the regeneration experiments demonstrated that the absorption capacities of DESs did not change after five absorption and desorption cycles. Furthermore, the absorption mechanism of SO{sub 2} by DESs was studied by FT-IR, {sup 1}H NMR and {sup 13}C NMR spectra. It was found that there are strong acid–base interactions between SO{sub 2} and

  19. Computational Evaluation of Mixtures of Hydrofluorocarbons and Deep Eutectic Solvents for Absorption Refrigeration Systems.

    Science.gov (United States)

    Abedin, Rubaiyet; Heidarian, Sharareh; Flake, John C; Hung, Francisco R

    2017-10-24

    We used computational tools to evaluate three working fluid mixtures for single-effect absorption refrigeration systems, where the generator (desorber) is powered by waste or solar heat. The mixtures studied here resulted from combining a widely used hydrofluorocarbon (HFC) refrigerant, R134a, with three common deep eutectic solvents (DESs) formed by mixing choline chloride (hydrogen bond acceptor, HBA) with urea, glycerol, or ethylene glycol as the hydrogen bond donor (HBD) species. The COSMOtherm/TmoleX software package was used in combination with refrigerant data from NIST/REFPROP, to perform a thermodynamic evaluation of absorption refrigeration cycles using the proposed working fluid mixtures. Afterward, classical MD simulations of the three mixtures were performed to gain insight on these systems at the molecular level. Larger cycle efficiencies are obtained when R134a is combined with choline chloride and ethylene glycol, followed by the system where glycerol is the HBD, and finally that where the HBD is urea. MD simulations indicate that the local density profiles of all species exhibit very sharp variations in systems containing glycerol or urea; furthermore, the Henry's law constants of R134a in these two systems are larger than those observed for the HFC in choline chloride and ethylene glycol, indicating that R134a is more soluble in the latter DES. Interaction energies indicate that the R134a-R134a interactions are weaker in the system where ethylene glycol is the HBD, as compared to in the other DES. Radial distribution functions confirm that in all systems, the DES species do not form strong directional interactions (e.g., hydrogen bonds) with the R134a molecules. Relatively strong interactions are observed between the Cl anions and the hydrogen atoms in R134a; however, the atom-atom interactions between R134a and the cation and HBD species are weaker and do not play a significant role in the solvation of the refrigerant. In all systems, R134a has

  20. High electrical resistivity Nd-Fe-B die-upset magnet doped with eutectic DyF3–LiF salt mixture

    Directory of Open Access Journals (Sweden)

    K. M. Kim

    2017-05-01

    Full Text Available Nd-Fe-B-type die-upset magnet with high electrical resistivity was prepared by doping of eutectic DyF3–LiF salt mixture. Mixture of melt-spun Nd-Fe-B flakes (MQU-F: Nd13.6Fe73.6Co6.6Ga0.6B5.6 and eutectic binary (DyF3–LiF salt (25 mol% DyF3 – 75 mol% LiF was hot-pressed and then die-upset. By adding the eutectic salt mixture (> 4 wt%, electrical resistivity of the die-upset magnet was enhanced to over 400 μΩ.cm compared to 190 μΩ.cm of the un-doped magnet. Remarkable enhancement of the electrical resistivity was attributed to homogeneous and continuous coverage of the interface between flakes by the easily melted eutectic salt dielectric mixture. It was revealed that active substitution of the Nd atoms in neighboring flakes by the Dy atoms from the added (DyF3–LiF salt mixture had occurred during such a quick thermal processing of hot-pressing and die-upsetting. This Dy substitution led to coercivity enhancement in the die-upset magnet doped with the eutectic (DyF3–LiF salt mixture. Coercivity and remanence of the die-upset magnet doped with (DyF3–LiF salt mixture was as good as those of the DyF3-doped magnet.

  1. Magnetic anisotropy induced by crystallographic orientation and morphological alignment in directionally-solidified eutectic Mn-Sb alloy

    International Nuclear Information System (INIS)

    Lou, Chang-Sheng; Liu, Tie; Dong, Meng; Wu, Chun; Shao, Jian-Guo; Wang, Qiang

    2017-01-01

    The influences of the crystallographic orientation and morphological alignment upon the magnetic anisotropic behavior of polycrystalline materials were investigated. Microstructures obtained in eutectic Mn-Sb alloys via directional solidification simultaneously displayed crystallographic orientation and morphological alignment. Both the crystallographic orientation and the morphological alignment were able to induce magnetic anisotropy in the alloys, wherein the influence of the crystallographic orientation and the morphological alignment upon the magnetic anisotropic behavior of the alloys strongly depended upon their directions and exhibited either mutual promotion or competition. These findings may provide useful guidance for the fabrication design of functional magnetic materials. - Highlights: • We study effects of orientation in crystal and morphology on magnetic anisotropy. • Both orientation in crystal and morphology can induce magnetic anisotropy. • Their effects depend on direction and exhibit either mutual promotion or competition.

  2. Progress towards a process for the recycling of nickel metal hydride electric cells using a deep eutectic solvent

    Directory of Open Access Journals (Sweden)

    Mark R.StJ. Foreman

    2016-12-01

    Full Text Available Solvent extraction experiments relating to the recycling of the transition metals and lanthanides in nickel metal hydride cells are presented. The metal extraction is occurring from a deep eutectic solvent which is formed from chemicals suitable for use in food and related products. While it has been shown that the water content of the DES has a large effect on the extraction of transition metals by a mixture of chloride ionic liquid (Aliquat 336 and an aromatic solvent, the water content has a smaller effect on the solvent extraction of lanthanides with a solution of di(2-ethylhexyl hydrogen phosphate (DEHPA in a saturated aliphatic hydrocarbon. This study suggests that an industrial scale solvent extraction process for the recycling of metals from nickel hydride electrical cells will be feasible.

  3. Following the electroreduction of uranium dioxide to uranium in LiCl-KCl eutectic in situ using synchrotron radiation

    Science.gov (United States)

    Brown, L. D.; Abdulaziz, R.; Jervis, R.; Bharath, V. J.; Atwood, R. C.; Reinhard, C.; Connor, L. D.; Simons, S. J. R.; Inman, D.; Brett, D. J. L.; Shearing, P. R.

    2015-09-01

    The electrochemical reduction of uranium dioxide to metallic uranium has been investigated in lithium chloride-potassium chloride eutectic molten salt. Laboratory based electrochemical studies have been coupled with in situ energy dispersive X-ray diffraction, for the first time, to deduce the reduction pathway. No intermediate phases were identified using the X-ray diffraction before, during or after electroreduction to form α-uranium. This suggests that the electrochemical reduction occurs via a single, 4-electron-step, process. The rate of formation of α-uranium is seen to decrease during electrolysis and could be a result of a build-up of oxygen anions in the molten salt. Slow transport of O2- ions away from the UO2 working electrode could impede the electrochemical reduction.

  4. Preparation of YBa2Cu3O7-x precursors from a fused eutectic of sodium and potassium hydroxides

    International Nuclear Information System (INIS)

    Coppa, N.; Nichols, D.H.; Schwegler, J.W.; Crow, J.E.; Myer, G.H.; Salamon, R.E.

    1989-01-01

    A method for preparing YBa 2 Cu 3 O 7-x from the simultaneous thermal decomposition of the nitrates of yttrium, barium, and copper in an anhydrous fused eutectic of sodium and potassium hydroxide is described. This method eliminates the need for any mechanical grinding or the introduction of carbon containing anions. Products formed are fine powders (∼1 μm) having mole ratios 1.00 Y:2.00 Ba:3.06 Cu. X-ray diffraction analysis reveal that the initial products are Y(OH) 3 , BaO 2 , and CuO, which when air calcinated/ oxygen annealed at 900--950 degree C form the superconducting YBa 2 Cu 3 O 7-x . A mechanism is postulated for product formation as a function of reaction conditions

  5. Results of Long-Term Stability Tests Performed for the Eutectics Co-C and Pt-C

    Science.gov (United States)

    Wang, T.; Bai, C.; Dong, W.; Yuan, Z.; Bloembergen, P.; Liu, F.

    2011-08-01

    The stability of the Co-C and Pt-C eutectic fixed points is investigated in this article. Six cells were employed for the testing. Two existing cells, a Co-C cell with a C/C sheet incorporated and a Pt-C cell equipped with a graphite sleeve that had been previously aged, were studied to determine the presence of anomalous drifts or degrading robustness that may possibly appear when the testing period is extended. The stability of four cells of a new design, a Co-C cell and three Pt-C cells, which were constructed in a hybrid manner, to include a sleeve, foil lining, and two of them with a cavity support, were likewise tested. Results show that different designs of Pt-C cells can exhibit good stability. However, for Co-C cells, the cavity rift remains a problem. The possible reasons for this rift and methods for increasing cell life are discussed.

  6. Laser Machining and In Vitro Assessment of Wollastonite-Tricalcium Phosphate Eutectic Glasses and Glass-Ceramics.

    Science.gov (United States)

    Sola, Daniel; Grima, Lorena

    2018-01-13

    Bioactivity and ingrowth of ceramic implants is commonly enhanced by a suitable interconnected porous network. In this work, the laser machining of CaSiO₃‒Ca₃(PO₄)₂ biocompatible eutectic glass-ceramics and glasses was studied. For this purpose, 300 µm diameter craters were machined by using pulsed laser radiation at 532 nm with a pulsewidth in the nanosecond range. Machined samples were soaked in simulated body fluid for 2 months to assess the formation of a hydroxyapatite layer on the surface of the laser machined areas. The samples were manufactured by the laser floating zone technique using a CO₂ laser. Morphology, composition and microstructure of the machined samples were described by Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and micro-Raman Spectroscopy.

  7. Effect of sintering temperature on microstructure and compressive strength of B4C-AlSi eutectic alloy

    International Nuclear Information System (INIS)

    Liu Jinyun; Zha Wusheng; Liu Gaihua; Lan Jun; Feng Quanhe; Zou Congpei

    2008-01-01

    The block neutron absorber of B 4 C based on Al-Si eutectic alloy has been prepared by powder-metallurgy method. The effects of sinter temperature on microstructure, compressive strength, and ductility of sintered billets have been investigated. It has been shown that the sintering temperature decides sensitively the compressive strength and ductility of sintered billets. Sintered under 550, 555, 560, and 565 degree C, the billet shows different states, such as sub-sintered, best-sintered, over-sintered, and molten. Sintered under 550 degree C, the powder have not been metallurgically combined with each other. Beyond 560 degree C, the billets are molten. The 555 degree C is the best sintering temperature, under which the powder have been partly melted and the metallurgical combination has been occurred, then the billets have a better ductility. (authors)

  8. Dynamic Analysis of Recalescence Process and Interface Growth of Eutectic Fe82B17Si1 Alloy

    Science.gov (United States)

    Fan, Y.; Liu, A. M.; Chen, Z.; Li, P. Z.; Zhang, C. H.

    2018-03-01

    By employing the glass fluxing technique in combination with cyclical superheating, the microstructural evolution of the undercooled Fe82B17Si1 alloy in the obtained undercooling range was studied. With increase in undercooling, a transition of cooling curves was detected from one recalescence to two recalescences, followed by one recalescence. The two types of cooling curves were fitted by the break equation and the Johnson-Mehl-Avrami-Kolmogorov model. Based on the cooling curves at different undercoolings, the recalescence rate was calculated by the multi-logistic growth model and the Boettinger-Coriel-Trivedi model. Both the recalescence features and the interface growth kinetics of the eutectic Fe82B17Si1 alloy were explored. The fitting results that were obtained using TEM (SAED), SEM and XRD were consistent with the changing rule of microstructures. Finally, the relationship between the microstructure and hardness was also investigated.

  9. The interfacial free energy of solid Sn on the boundary interface with liquid Cd-Sn eutectic solution

    International Nuclear Information System (INIS)

    Saatci, B; Cimen, S; Pamuk, H; Guenduez, M

    2007-01-01

    Equilibrated grain boundary groove shapes for solid Sn in equilibrium with Cd-Sn liquid were directly observed after annealing a sample at the eutectic temperature for about 8 days. The thermal conductivities of the solid phase, K S , and the liquid phase, K L , for the groove shapes were measured. From the observed groove shapes, the Gibbs-Thomson coefficients were obtained with a numerical method, using the measured G, K S and K L values. The solid-liquid interfacial energy of solid Sn in equilibrium with Cd-Sn liquid was determined from the Gibbs-Thomson equation. The grain boundary energy for solid Sn was also calculated from the observed groove shapes

  10. Eutectic crystallization behavior of new Zr48Cu36Al8Ag8 alloy with high glass-forming ability

    International Nuclear Information System (INIS)

    Zhang, Q S; Zhang, W; Xie, G Q; Inoue, A

    2009-01-01

    A water quenching method is used to produce as-cast Zr 48 Cu 36 Al 8 Ag 8 rods with diameters from 20 mm to 25 mm. The microstructures of the as-cast samples were investigated by X-ray diffraction, optical microscopy and scanning electron microscopy. Furthermore, the crystallization behavior of the Zr 48 Cu 36 Al 8 Ag 8 glassy alloy was examined by XRD and transmission electron microscopy. Based on the results obtained one can assume that the simultaneous precipitation of the Zr 2 Cu+AlCu 2 Zr eutectic phases is the possible reason for the high stabilization of the quaternary Zr 48 Cu 36 Al 8 Ag 8 supercooled liquid.

  11. Electronic absorption spectra of rare earth (III) species in NaCl-2CsCl eutectic based melts

    Science.gov (United States)

    Volkovich, V. A.; Ivanov, A. B.; Yakimov, S. M.; Tsarevskii, D. V.; Golovanova, O. A.; Sukhikh, V. V.; Griffiths, T. R.

    2016-09-01

    Electronic absorption spectra of ions of trivalent rare earth elements were measured in the melts based on NaCl-2CsCl eutectic in the wavelength ranges of 190-1350 and 1450-1700 nm. The measurements were performed at 550-850 °C. The EAS of Y, La, Ce and Lu containing melts have no absorption bands in the studied regions. For the remaining REEs (Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) the absorption bands in the EAS were assigned to the corresponding f-f electron transitions. The Stark effect was observed for Yb(III) F5/2 excited state. Increasing temperature leads to decreasing intensity of the absorption bands, except for the bands resulting from hypersensitive transitions. Beer's law was confirmed up to 0.4 M solutions of REE.

  12. Ultrafast crystallization and thermal stability of In-Ge doped eutectic Sb70Te30 phase change material

    International Nuclear Information System (INIS)

    Lee Meiling; Miao Xiangshui; Ting Leehou; Shi Luping

    2008-01-01

    Effect of In and Ge doping in the form of In 2 Ge 8 Sb 85 Te 5 on optical and thermal properties of eutectic Sb 70 Te 30 alloys was investigated. Crystalline structure of In 2 Ge 8 Sb 85 Te 5 phase change material consists of a mixture of phases. Thermal analysis shows higher crystallization temperature and activation energy for crystallization. Isothermal reflectivity-time measurement shows a growth-dominated crystallization mechanism. Ultrafast crystallization speed of 30 ns is realized upon irradiation by blue laser beam. The use of ultrafast and thermally stable In 2 Ge 8 Sb 85 Te 5 phase change material as mask layer in aperture-type super-resolution near-field phase change disk is realized to increase the carrier-to-noise ratio and thermal stability

  13. Tensile behaviour at room and high temperatures of novel metal matrix composites based on hyper eutectic Al-Si alloys

    International Nuclear Information System (INIS)

    Valer, J.; Rodriguez, J.M.; Urcola, J.J.

    1997-01-01

    This work shows the improvement obtained on tensile stress at room and high temperatures of hyper eutectic Al-Si alloys. These alloys are produced by a combination of spray-forming, extrusion and thixoforming process, in comparison with conventional casting alloys.Al-25% Si-5%Cu. Al-25%Si-5%Cu-2%Mg and Al-30%Si-5%Cu alloys have been studied relating their microstructural parameters with tensile stress obtained and comparing them with conventional Al-20%Si. Al-36%Si and Al-50%Si alloys. Al-25%Si-5%Cu alloy-was tested before and after semi-solid forming, in order to distinguish the different behaviour of this alloy due to the different microstructure. The properties obtained with these alloys were also related to Al-SiC composites formed by similar processes. (Author) 20 refs

  14. Physical properties of the eutectic NaF-LiF-LaF3 melt ionic liquid system

    Directory of Open Access Journals (Sweden)

    Yu. O. Plevachuk

    2012-06-01

    Full Text Available Results of experimental studies on electrical conductivity, viscosity and thermo-electromotive force temperature dependencies of eutectic NaF-LiF-LaF3 melt ionic liquid mixture in the temperature range of (580 ÷ 800 °C are presented. It has been found, that at the temperature of (675 ± 5 °C the ionic mixture thermo-electromotive force changes its sing to reverse, with this change being correlated with viscosity temperature dependence type readjustment occurring at the same temperature. It has been shown that the maximum value of liquid ionic mixture electrical conductivity is achieved at the temperature of (750 ± 5 °C. Obtained results could help in the molten salt reactor blanket design.

  15. A Novel Selective Deep Eutectic Solvent Extraction Method for Versatile Determination of Copper in Sediment Samples by ICP-OES.

    Science.gov (United States)

    Bağda, Esra; Altundağ, Huseyin; Tüzen, Mustafa; Soylak, Mustafa

    2017-08-01

    In the present study, a simple, mono step deep eutectic solvent (DES) extraction was developed for selective extraction of copper from sediment samples. The optimization of all experimental parameters, e.g. DES type, sample/DES ratio, contact time and temperature were performed with using BCR-280 R (lake sediment certified reference material). The limit of detection (LOD) and the limit of quantification (LOQ) were found as 1.2 and 3.97 µg L -1 , respectively. The RSD of the procedure was 7.5%. The proposed extraction method was applied to river and lake sediments sampled from Serpincik, Çeltek, Kızılırmak (Fadl and Tecer region of the river), Sivas-Turkey.

  16. Development of a low tritium partial pressure permeation system for mass transport measurement in lead lithium eutectic

    International Nuclear Information System (INIS)

    Pawelko, R.; Shimada, M.; Katayama, K.; Fukada, S.; Terai, T.

    2014-01-01

    A new experimental system designed to investigate tritium mass transfer properties in materials important to fusion technology is operational at the Safety and Tritium Applied Research (STAR) facility located at the Idaho National Laboratory (INL). The tritium permeation measurement system was developed as part of the Japan/US TITAN collaboration to investigate tritium mass transfer properties in liquid lead lithium eutectic (LLE) alloy. The system is similar to a hydrogen/deuterium permeation measurement system developed at Kyushu University and also incorporates lessons learned from previous tritium permeation experiments conducted at the STAR facility. This paper describes the experimental system that is configured specifically to measure tritium mass transfer properties at low tritium partial pressures. We present preliminary tritium permeation results for α-Fe and α-Fe/LLE samples at 600degC and at tritium partial pressures between 1.0E-3 and 2.4 Pain helium. The preliminary results are compared with literature data. (author)

  17. Effect of thermal cycling on the microstructure of a directionally solidified Fe, Cr, Al-TaC eutectic alloy

    Science.gov (United States)

    Harf, F. H.; Tewari, S. N.

    1977-01-01

    Cylindrical bars (1.2 cm diameter) of Fe-13.6Cr-3.7Al-9TaC (wt %) eutectic alloy were directionally solidified in a modified Bridgman type furnace at 1 cm/h. The alloy microstructure consisted of aligned TaC fibers imbedded in a bcc Fe-Cr-Al matrix. Specimens of the alloy were thermally cycled from 1100 to 425 C in a burner rig. The effects of 1800 thermal cycles on the microstructure was examined by scanning electron microscopy, revealing a zig-zag shape of TaC fibers aligned parallel to the growth direction. The mechanism of carbide solution and reprecipitation on the (111) easy growth planes, suggested previously to account for the development of irregular serrations in Co-Cr-Ni matrix alloys, is believed to be responsible for these zig-zag surfaces.

  18. Galvanic reduction of uranium(III) chloride from LiCl-KCl eutectic salt using gadolinium metal

    Science.gov (United States)

    Bagri, Prashant; Zhang, Chao; Simpson, Michael F.

    2017-09-01

    The drawdown of actinides is an important unit operation to enable the recycling of electrorefiner salt and minimization of waste. A new method for the drawdown of actinide chlorides from LiCl-KCl molten salt has been demonstrated here. Using the galvanic interaction between the Gd/Gd(III) and U/U(III) redox reactions, it is shown that UCl3 concentration in eutectic LiCl-KCl can be reduced from 8.06 wt.% (1.39 mol %) to 0.72 wt.% (0.12 mol %) in about an hour via plating U metal onto a steel basket. This is a simple process for returning actinides to the electrorefiner and minimizing their loss to the salt waste stream.

  19. Petrología de las rocas plutónicas de afinidad ofiolítica presentes en la zona de Cayo Grande (macizo ofiolítico Moa-Baracoa, Cuba Oriental

    Directory of Open Access Journals (Sweden)

    Gerardo Orozco-Melgar

    2001-03-01

    Full Text Available La zona de Cayo Grande es parte del Macizo Moa-Baracoa, localizado en la parte más oriental de la faja Mayarí-Baracoa. En este trabajo se presentan y se discuten las características texturales, petrográficas, de quimismo mineral, de geotermometría catiónica, así como las implicaciones petrogenéticas de las rocas de afinidad ofiolítica presentes en la zona de Cayo Grande. Las características microestructurales de las dunitas impregnadas en la zona de estudio, indican condiciones de desequilibrio entre el olivino y la asociación plagioclasa+clinopiroxeno, y no presentan correlación entre los contenidos de forsterita y los de Ni en los olivinos. Esto es indicativo de la existencia de circulación magmática mediante flujo poroso en la zona. El orden de cristalización de los clinopiroxenos anterior a la plagioclasa, y la composición de las plagioclasas en las gabronoritas estudiadas en la zona de Cayo Grande, son indicativos de secuencias de acumulados en ofiolitas de zonas de suprasubducción, lo que sugiere un ambiente geodinámico en una zona de expansión de una cuenca de trasarco para las gabronoritas de la zona de Cayo Grande

  20. Caracterización físico-química y mineralógica de la escoria de fundición de ferroníquel de Moa

    Directory of Open Access Journals (Sweden)

    Yaritza Ramírez-Cruz

    2013-12-01

    Full Text Available La escoria de fundición de ferroníquel obtenida a escala piloto a partir del mineral saprolítico del yacimiento Moa Occidental, se caracterizó desde el punto de vista físico, químico y mineralógico con el objetivo de evaluar sus posibilidades de utilización industrial. Mediante Espectrometría por Fluorescencia de Rayos X y Difracción de Rayos X se constató que en su composición existen fundamentalmente óxidos de silicio y magnesio, con valores promedios de 46% el primero y 37 % el segundo. El olivino, la forsterita y la clinoenstatita se identificaron como sus fases mineralógicas principales. La densidad es de 3,20 g/cm 3 ; temperatura de fusión de 1 650ºC y viscosidad de 6,5 poises. Estos resultados evidenciaron similitud con escorias de ferroníquel obtenidas en otras partes del mundo, que son usadas como material abrasivo, material de construcción y refractario

  1. Evaluación de la calidad físico-química y bacteriológica del agua subterránea en pozos criollos del municipio de Moa

    Directory of Open Access Journals (Sweden)

    Osvaldo Fernández-Urgellés

    2007-03-01

    Full Text Available Los pobladores de los repartos Las Coloradas y La Playa (municipio de Moa utilizan para el consumo humano agua subterránea procedente de pozos criollos cuando falla la distribución de agua potable a través de la red hidrológica. Para conocer los componentes generales, mayoritarios y no deseables se evaluó la calidad físico-química y bacteriológica de estas aguas. Se emplearon las técnicas analíticas convencionales así como métodos gráficos. Los resultados reflejaron la presencia de elementos no deseables, indicadores de contaminación, que sobrepasan los índices establecidos para el consumo humano como agua potable. Los resultados del análisis bacteriológico evidenciaron la presencia de bacilos de colis y colifecales, siendo fundamentalmente su composición fecal lo que determina su estado sanitario. Se concluye que las aguas de los pozos criollos estudiados no responden a los requisitos establecidos en las normas para consumo humano.

  2. Eutectic mixtures of some fatty acids for low temperature solar heating applications: Thermal properties and thermal reliability

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey)]. E-mail: asari@gop.edu.tr

    2005-10-01

    The thermal properties and thermal reliability of the eutectic mixtures of lauric acid-myristic acid (LA-MA), lauric acid-palmitic acid (LA-PA), myristic acid-stearic acid (MA-SA) as phase change material (PCM) were determined after repeated melt/freeze cycles by the method of differential scanning calorimeter (DSC). The DSC thermal analysis results indicate that the binary systems of LA-MA in ratio of 66.0:34.0 wt.%, LA-PA in ratio of 69.0:31.0 wt.% and MA-SA in ratio of 64.0:36.0 wt.% form eutectic mixture with a melting temperature of 34.2 deg. C, 35.2 deg. C and 44.1 deg. C, and with a latent heat of fusion of 166.8 J g{sup -1}, 166.3 J g{sup -1} and 182.4 J g{sup -1}, respectively. The changes in the melting temperatures and the latent heats of fusion are in the range of -0.31 deg. C-0.14 deg. C and 0.9%-2.4% for LA-MA, -0.40 deg. C-0.23 deg. C and 1.5%-3.0% for LA-PA, and 1.11 deg. C-0.26 deg. C and -1.10%-2.2% for MA-SA during the 1460 thermal cycles. Based on the results, it can be concluded that the studied PCMs have good thermal properties and thermal reliability for a four-year energy storage period, which corresponds to 1460 thermal cycles, in terms of the change in their melting temperatures and latent heats of fusion.

  3. Response Surface Optimization of Rotenone Using Natural Alcohol-Based Deep Eutectic Solvent as Additive in the Extraction Medium Cocktail

    Directory of Open Access Journals (Sweden)

    Zetty Shafiqa Othman

    2017-01-01

    Full Text Available Rotenone is a biopesticide with an amazing effect on aquatic life and insect pests. In Asia, it can be isolated from Derris species roots (Derris elliptica and Derris malaccensis. The previous study revealed the comparable efficiency of alcohol-based deep eutectic solvent (DES in extracting a high yield of rotenone (isoflavonoid to binary ionic liquid solvent system ([BMIM]OTf and organic solvent (acetone. Therefore, this study intends to analyze the optimum parameters (solvent ratio, extraction time, and agitation rate in extracting the highest yield of rotenone extract at a much lower cost and in a more environmental friendly method by using response surface methodology (RSM based on central composite rotatable design (CCRD. By using RSM, linear polynomial equations were obtained for predicting the concentration and yield of rotenone extracted. The verification experiment confirmed the validity of both of the predicted models. The results revealed that the optimum conditions for solvent ratio, extraction time, and agitation rate were 2 : 8 (DES : acetonitrile, 19.34 hours, and 199.32 rpm, respectively. At the optimum condition of the rotenone extraction process using DES binary solvent system, this resulted in a 3.5-fold increase in a rotenone concentration of 0.49 ± 0.07 mg/ml and yield of 0.35 ± 0.06 (%, w/w as compared to the control extract (acetonitrile only. In fact, the rotenone concentration and yield were significantly influenced by binary solvent ratio and extraction time (P<0.05 but not by means of agitation rate. For that reason, the optimal extraction condition using alcohol-based deep eutectic solvent (DES as a green additive in the extraction medium cocktail has increased the potential of enhancing the rotenone concentration and yield extracted.

  4. Investigation of the antimicrobial effect of natural deep eutectic solvents (NADES) as solvents in antimicrobial photodynamic therapy.

    Science.gov (United States)

    Wikene, Kristine Opsvik; Rukke, Håkon Valen; Bruzell, Ellen; Tønnesen, Hanne Hjorth

    2017-06-01

    Natural deep eutectic solvents (NADES) are a third class of liquids, separate from water and lipids. Some NADES, especially those containing organic acids, have been suggested to possess antimicrobial properties. Such properties may be advantageous when NADES are used as solvents in e.g. antimicrobial photodynamic therapy. However, to control the toxicity of acid-containing NADES, they must retain their specific qualities upon dilution. Hence, the aims of this study were to investigate the effect of dilution on the acid-containing NADES network, their antimicrobial activity on different planktonic microorganisms, and their influence on phototoxicity when used as solvents for a photosensitiser. Four bacteria and one fungus were exposed to the NADES, CS (citric acid:sucrose) and MFG (malic acid:fructose:glucose) (molar ratios 1:1 and 1:1:1, respectively), at ≤1:200 dilution. Additionally, the antimicrobial properties of the NADES were studied in Escherichia coli in terms of pH and chelating effects. In investigations of phototoxicity, the microorganisms were exposed to the photosensitiser meso-tetra(p-hydroxyphenyl)porphine (THPP; 1nM) dissolved in diluted NADES combined with blue light (27J/cm 2 ). The eutectic network appeared to remain upon dilution ≤1:200. CS (1:200) was less toxic than an equal concentration of citric acid in the Gram-negative bacteria Klebsiella pneumoniae and E. coli (p<0.05). A higher degree of phototoxicity was induced in E. coli (~1% survival) when THPP was dissolved in CS or MFG than in phosphate buffer (~61% survival; p<0.05). No conclusion could be drawn as to whether the observed toxicity in E. coli exposed to NADES was due to the pH of the solutions or chelation of outer membrane-bound cations. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Development of High-Strength High-Temperature Cast Al-Ni-Cr Alloys Through Evolution of a Novel Composite Eutectic Structure

    Science.gov (United States)

    Pandey, P.; Kashyap, S.; Tiwary, C. S.; Chattopadhyay, K.

    2017-12-01

    Aiming to develop high-strength Al-based alloys with high material index (strength/density) for structural application, this article reports a new class of multiphase Al alloys in the Al-Ni-Cr system that possess impressive room temperature and elevated temperature (≥ 200 °C) mechanical properties. The ternary eutectic and near eutectic alloys display a complex microstructure containing intermetallic phases displaying hierarchically arranged plate and rod morphologies that exhibit extraordinary mechanical properties. The yield strengths achieved at room temperatures are in excess of 350 MPa with compressive plastic strains of more than 30 pct (without fracturing) for these alloys. The stability of the complex microstructure also leads to a yield stress of 191 ± 8 to 232 ± 5 MPa at 250 °C. It is argued that the alloys derive their high strength and impressive plasticity through synergic effects of refined nanoeutectics of two different morphologies forming a core shell type of architecture.

  6. Low temperature diffusion process using rare earth-Cu eutectic alloys for hot-deformed Nd-Fe-B bulk magnets

    Energy Technology Data Exchange (ETDEWEB)

    Akiya, T., E-mail: akiya.takahiro@nims.go.jp; Sepehri-Amin, H.; Ohkubo, T. [Elements Strategy Initiative Center for Magnetic Materials, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Liu, J.; Hono, K. [Elements Strategy Initiative Center for Magnetic Materials, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8577 (Japan); Hioki, K.; Hattori, A. [Daido Steel Co., LTD, Nagoya 457-8545 (Japan)

    2014-05-07

    The low temperature grain boundary diffusion process using RE{sub 70}Cu{sub 30} (RE = Pr, Nd) eutectic alloy powders was applied to sintered and hot-deformed Nd-Fe-B bulk magnets. Although only marginal coercivity increase was observed in sintered magnets, a substantial enhancement in coercivity was observed when the process was applied to hot-deformed anisotropic bulk magnets. Using Pr{sub 70}Cu{sub 30} eutectic alloy as a diffusion source, the coercivity was enhanced from 1.65 T to 2.56 T. The hot-deformed sample expanded along c-axis direction only after the diffusion process as RE rich intergranular layers parallel to the broad surface of the Nd{sub 2}Fe{sub 14}B are thickened in the c-axis direction.

  7. Bonding of Cf/SiC composite to Invar alloy using an active cement, Ag-Cu eutectic and Cu interlayer

    Science.gov (United States)

    Lei, Zhao; Xiaohong, Li; Jinbao, Hou; Qiang, Sun; Fuli, Zhang

    2012-10-01

    The interfacial microstructures and mechanical properties of the joints formed by active cement added brazing in vacuum of Cf/SiC composite to Invar alloy, using Ag-Cu eutectic alloy and pure copper foil as braze alloy and interlayer respectively, were investigated. CuTi, Cu4Ti3, Fe2Ti and the reaction layer of TiC and Si were the predominant components at the joint interface. The maximum shear strength of the joint was 77 MPa for brazing at 850 °C for 15 min. The results show that active cement added brazing in vacuum using Ag-Cu eutectic alloy and Cu interlayer can be used successfully for joining Cf/SiC composites to Invar alloy.

  8. Effects of Microalloying on the Microstructures and Mechanical Properties of Directionally Solidified Ni-33(at.%)Al-31Cr-3Mo Eutectic Alloys Investigated

    Science.gov (United States)

    Whittenberger, J. Daniel; Raj, Sai V.; Locci, Ivan E.; Salem, Jonathan A.

    2002-01-01

    Despite nickel aluminide (NiAl) alloys' attractive combination of oxidation and thermophysical properties, their development as replacements for superalloy airfoils in gas turbine engines has been largely limited by difficulties in developing alloys with an optimum combination of elevated-temperature creep resistance and room-temperature fracture toughness. Alternatively, research has focused on developing directionally solidified NiAl-based in situ eutectic composites composed of NiAl and (Cr,Mo) phases in order to obtain a desirable combination of properties a systematic investigation was undertaken at the NASA Glenn Research Center to examine the effects of small additions of 11 alloying elements (Co, Cu, Fe, Hf, Mn, Nb, Re, Si, Ta, Ti, and Zr) in amounts varying from 0.25 to 1.0 at.% on the elevated-temperature strength and room-temperature fracture toughness of directionally solidified Ni-33Al-31Cr-3Mo eutectic alloy. The alloys were grown at 12.7 mm/hr, where the unalloyed eutectic base alloy exhibited a planar eutectic microstructure. The different microstructures that formed because of these fifth-element additions are included in the table. The additions of these elements even in small amounts resulted in the formation of cellular microstructures, and in some cases, dendrites and third phases were observed. Most of these elemental additions did not improve either the elevated-temperature strength or the room-temperature fracture toughness over that of the base alloy. However, small improvements in the compression strength were observed between 1200 and 1400 K when 0.5 at.% Hf and 0.25 at.% Ti were added to the base alloy. The results of this study suggest that the microalloying of Ni-33Al-31Cr-3Mo will not significantly improve either its elevatedtemperature strength or its room-temperature fracture toughness. Thus, any improvements in these properties must be acquired by changing the processing conditions.

  9. Modeling the dynamics of the lead bismuth eutectic experimental accelerator driven system by an infinite impulse response locally recurrent neural network

    International Nuclear Information System (INIS)

    Zio, Enrico; Pedroni, Nicola; Broggi, Matteo; Golea, Lucia Roxana

    2009-01-01

    In this paper, an infinite impulse response locally recurrent neural network (IIR-LRNN) is employed for modelling the dynamics of the Lead Bismuth Eutectic eXperimental Accelerator Driven System (LBE-XADS). The network is trained by recursive back-propagation (RBP) and its ability in estimating transients is tested under various conditions. The results demonstrate the robustness of the locally recurrent scheme in the reconstruction of complex nonlinear dynamic relationships

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

    International Nuclear Information System (INIS)

    Baran, Guelseren; Sari, Ahmet

    2003-01-01

    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 stearic acid (SA) binary system and measurement of its thermophysical properties by differential scanning calorimetry (DSC). Second is establishment of the phase transition characteristics of the mixture, such as the total melting and solidification temperatures and times, the heat transfer modes in the melted and solidified PCM and the effect of Reynolds and Stefan numbers as initial heat transfer fluid (HTF) conditions on the phase transition behaviors. Third is calculation of the heat transfer coefficients between the outside wall of the HTF pipe and the PCM, the heat recovery rates and heat fractions during the phase change processes of the mixture and also discussion of the effect of the inlet HTF parameters on these characteristics. The DSC results showed that the PA-SA binary system in the mixture ratio of 64.2:35.8 wt% forms a eutectic, which melts at 52.3 deg. C and has a latent heat of 181.7 J g -1 , and thus, these properties make it a suitable PCM for passive solar space heating and domestic water heating applications with respect to climate conditions. The experimental results also indicated that the eutectic mixture of PA-SA encapsulated in the annulus of concentric double pipes has good phase change and heat transfer characteristics during the melting and solidification processes, and it is an attractive candidate as a potential PCM for heat storage in latent heat thermal energy storage systems

  11. Evaluation of damage induced by high irradiation levels on α-Ni-Ni3Si eutectic structure

    Science.gov (United States)

    Camacho Olguin, Carlos Alberto; Garcia-Borquez, Arturo; González-Rodríguez, Carlos Alberto; Loran-Juanico, Jose Antonio; Cruz-Mejía, Hector

    2015-06-01

    Diluted alloys of the binary system Ni-Si have been used as target of beam of ions, electrons, neutrons and so on because in this kind of alloy occurs transformations order-disorder, when the temperature is raised. This fact has permitted to evaluate the phenomena associated with the damage induced by irradiation (DII). The results of these works have been employed to understand the behavior under irradiation of complex alloys and to evaluate the reliability of the results of mathematical simulation of the evolution of the DII. The interest in the alloy system Ni-Si has been reborn due to the necessity of developing materials, which have better resistance against the corrosion on more aggressive environments such as those generated on the nuclear power plants or those that exist out of the Earth's atmosphere. Now, a growing interest to use concentrated alloys of this binary system on diverse fields of the materials science has been taking place because up to determined concentration of silicon, a regular eutectic is formed, and this fact opens the possibility to develop lamellar composite material by directional solidification. However, nowadays, there is a lack of fundamental knowledge about the behavior of this type of lamellar structure under aggressive environments, like those mentioned before. Hence, the task of this work is to evaluate the effect that has the irradiation over the microstructure of the concentrated alloy Ni22at%Si. The dendritic region of the hypereutectic alloy consists of an intermetallic phase Ni3Si, whereas the interdendritic region is formed by the alternation of lamellas of solid solution α-Ni and intermetallic phase Ni3Si. Such kind of microstructure has the advantage to get information of the DII over different phases individually, and at the same time, about of the microstructure influence over the global damage in the alloy. The hypereutectic Ni22at%Si alloy was irradiated perpendicularly to its surface, with 3.66 MeV - Ni ions up

  12. Utilización de datos aerogamma espectrométricos para la localización de zonas de alteración hidrotermal en la región Sagua-Moa, Cuba Oriental

    Directory of Open Access Journals (Sweden)

    Leduar Ramayo-Cortés

    2000-03-01

    Full Text Available En la región de Moa están presentes yacimientos minerales de cromitas y de lateritas ferroniquelíferas-cobaltíferas. Los yacimientos de cromitas se localizan en la zona de transición manto-corteza, y las lateritas ricas en Ni y Co se desarrollan como producto del intemperismo de las rocas ultramáficas. Estos yacimientos históricamente han constituido el soporte económico de la región. En los últimos años, en sedimentos fluviales y en placeres de playas de minerales pesados, se han establecido altas concentraciones de metales preciosos de origen hidrotermal. El objetivo de este trabajo es localizar áreas de alteración hidrotermal y aportar nuevos elementos que permitan orientar la prospección geológica a partir de la interpretación de los datos aerogamma espectrométricos. Para la identificación de tales áreas se analizó la información geológica disponible y los resultados del análisis combinado de los parámetros aerogamma espectrométricos siguientes: 1 anomalías de potasio; 2 bajos valores de eTh/K y eU/K; 3 altos valores de eU/eTh, y 4 valores anómalos de F: K.eU/eTh. Como resultado, se logró localizar las principales zonas de alteración hidrotermal y establecer las condiciones aerogamma espectrométricas para detectarlas

  13. Caracterización ingeniero geológica del perfil de meteorización de rocas ultrabásicas serpentinizadas en el territorio de Moa, Cuba

    Directory of Open Access Journals (Sweden)

    Rafael Guardado-Lacaba

    2005-03-01

    Full Text Available Las cortezas de meteorización desarrollada sobre rocas ultrabásicas serpentinizadas en la región de Moa han sido ampliamente caracterizadas desde el punto de vista mineralógico y geoquímico, no siendo así respecto a su comportamiento ingeniero geológico, el cual constituye un elemento fundamental para emprender cualquier evaluación de riesgos asociados a movimientos de masas. La presente investigación abarcó las cortezas de tipo residual sobre las cuales se aplicaron los métodos geomecánicos tradicionalmente utilizados para caracterizar el comportamiento ingeniero geológico de un macizo. Se realizó la descripción visual de los diferentes horizontes lateríticos, y se aplicaron índices relacionados con las propiedades físico- mecánicas, estructurales y texturales tales como el índice de microfractura y micropetrográfico, índice de calidad del macizo rocoso (RQD e índice de alteración unificado. Como resultado se presenta una propuesta de clasificación ingeniero geológica del perfil en función del grado de meteorización, el cuál se definió en una escala de I a V a partir de los valores típicos de las propiedades físico mecánicas, RQD, relación porcentual roca/suelo y otros dos elementos relacionados con el modo de rotura de taludes y laderas y la tipología de deslizamiento

  14. Investigation of Elastic Deformation Mechanism in As-Cast and Annealed Eutectic and Hypoeutectic Zr–Cu–Al Metallic Glasses by Multiscale Strain Analysis

    Directory of Open Access Journals (Sweden)

    Hiroshi Suzuki

    2016-01-01

    Full Text Available Elastic deformation behaviors of as-cast and annealed eutectic and hypoeutectic Zr–Cu–Al bulk metallic glasses (BMG were investigated on a basis of different strain-scales, determined by X-ray scattering and the strain gauge. The microscopic strains determined by Direct-space method and Reciprocal-space method were compared with the macroscopic strain measured by the strain gauge, and the difference in the deformation mechanism between eutectic and hypoeutectic Zr–Cu–Al BMGs was investigated by their correlation. The eutectic Zr50Cu40Al10 BMG obtains more homogeneous microstructure by free-volume annihilation after annealing, improving a resistance to deformation but degrading ductility because of a decrease in the volume fraction of weakly-bonded regions with relatively high mobility. On the other hand, the as-cast hypoeutectic Zr60Cu30Al10 BMG originally has homogeneous microstructure but loses its structural and elastic homogeneities because of nanocluster formation after annealing. Such structural changes by annealing might develop unique mechanical properties showing no degradations of ductility and toughness for the structural-relaxed hypoeutectic Zr60Cu30Al10 BMGs.

  15. Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis.

    Science.gov (United States)

    Huang, Jingyu; Lu, Shilei; Kong, Xiangfei; Liu, Shangbao; Li, Yiran

    2013-10-22

    This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs), based on eutectic mixtures as phase change materials (PCMs) for thermal energy storage and high-density polyethylene (HDPE)-ethylene-vinyl acetate (EVA) polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD)-capric acid (CA), TD-lauric acid (LA), and TD-myristic acid (MA), which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC). The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD-CA PCM), 24.53 °C/24.92 °C (FS TD-LA PCM), and 33.15 °C/30.72 °C (FS TD-MA PCM), respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP). It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties.

  16. Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis

    Directory of Open Access Journals (Sweden)

    Yiran li

    2013-10-01

    Full Text Available This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs, based on eutectic mixtures as phase change materials (PCMs for thermal energy storage and high-density polyethylene (HDPE-ethylene-vinyl acetate (EVA polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD–capric acid (CA, TD–lauric acid (LA, and TD–myristic acid (MA, which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC. The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD–CA PCM, 24.53 °C/24.92 °C (FS TD–LA PCM, and 33.15 °C/30.72 °C (FS TD–MA PCM, respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM and Fourier-transform infrared (FT-IR spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP. It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties.

  17. Form-Stable Phase Change Materials Based on Eutectic Mixture of Tetradecanol and Fatty Acids for Building Energy Storage: Preparation and Performance Analysis

    Science.gov (United States)

    Huang, Jingyu; Lu, Shilei; Kong, Xiangfei; Liu, Shangbao; li, Yiran

    2013-01-01

    This paper is focused on preparation and performance analysis of a series of form-stable phase change materials (FSPCMs), based on eutectic mixtures as phase change materials (PCMs) for thermal energy storage and high-density polyethylene (HDPE)-ethylene-vinyl acetate (EVA) polymer as supporting materials. The PCMs were eutectic mixtures of tetradecanol (TD)–capric acid (CA), TD–lauric acid (LA), and TD–myristic acid (MA), which were rarely explored before. Thermal properties of eutectic mixtures and FSPCMs were measured by differential scanning calorimeter (DSC). The onset melting/solidification temperatures of form-stable PCMs were 19.13 °C/13.32 °C (FS TD–CA PCM), 24.53 °C/24.92 °C (FS TD–LA PCM), and 33.15 °C/30.72 °C (FS TD–MA PCM), respectively, and latent heats were almost greater than 90 J/g. The surface morphologies and chemical stability of form-stable PCM were surveyed by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy, respectively. The thermal cycling test revealed that the thermal reliability of these three form-stable PCMs was good. Thermal storage/release experiment indicated melting/solidification time was shortened by introducing 10 wt % aluminum powder (AP). It is concluded that these FSPCMs can act as potential building thermal storage materials in terms of their satisfactory thermal properties. PMID:28788358

  18. Reduction behavior of UO22+ in molten LiCl–RbCl and LiCl–KCl eutectics by using tungsten

    International Nuclear Information System (INIS)

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

    2013-01-01

    The reduction of uranium from UO 2 2+ to UO 2 + or U 4+ in molten LiCl–RbCl and LiCl–KCl eutectics was examined by using tungsten and chlorine gas. Spectrophotometric technique was adopted to determine the concentration of uranium species. When tungsten was immersed into the LiCl–RbCl eutectic melt at 400 °C without supplying chlorine gas, 36% of the total weight of the hexavalent of UO 2 2+ was reduced to the pentavalent of UO 2 + . Under purging chlorine gas into the melt, 96% of UO 2 2+ was reduced to the tetravalent of U 4+ . Tungsten oxy-chloride of WOCl 4 was produced via the reductions of UO 2 2+ , which was volatized from the melt and adsorbed on the upper part of experimental cell. On the other hand, 84% of UO 2 2+ in the LiCl–KCl eutectic melt at 500 °C was reduced to U 4+ by using tungsten and chlorine gas

  19. Reduction behavior of UO22+ in molten LiCl-RbCl and LiCl-KCl eutectics by using tungsten

    Science.gov (United States)

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

    2013-08-01

    The reduction of uranium from UO22+ to UO2+ or U4+ in molten LiCl-RbCl and LiCl-KCl eutectics was examined by using tungsten and chlorine gas. Spectrophotometric technique was adopted to determine the concentration of uranium species. When tungsten was immersed into the LiCl-RbCl eutectic melt at 400 °C without supplying chlorine gas, 36% of the total weight of the hexavalent of UO22+ was reduced to the pentavalent of UO2+. Under purging chlorine gas into the melt, 96% of UO22+ was reduced to the tetravalent of U4+. Tungsten oxy-chloride of WOCl4 was produced via the reductions of UO22+, which was volatized from the melt and adsorbed on the upper part of experimental cell. On the other hand, 84% of UO22+ in the LiCl-KCl eutectic melt at 500 °C was reduced to U4+ by using tungsten and chlorine gas.

  20. A novel poly(deep eutectic solvent)-based magnetic silica composite for solid-phase extraction of trypsin

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kaijia [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Li, Yixue; Lin, Yunxuan; Zhang, Haibao [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082 (China); Zhou, Yigang [Department of Microbiology, College of Basic Medicine, Central South University, Changsha, 410083 (China)

    2016-11-23

    Novel poly(deep eutectic solvent) grafted silica-coated magnetic microspheres (Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES) were prepared by polymerization of choline chloride-itaconic acid (ChCl-IA) and γ-MPS-modified magnetic silica composites, and were characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectra (XPS), thermal gravimetric analysis (TGA) and transmission electron microscope (TEM). Then the synthetic Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES microspheres were applied for the magnetic solid-phase extraction (MSPE) of trypsin for the first time. After extraction, the concentration of trypsin in the supernatant was determined by a UV–vis spectrophotometer. Single factor experiments were carried out to investigate the effects of the extraction process, including the concentration of trypsin, the ionic strength, the pH value, the extraction time and the temperature. Experimental results showed the extraction capacity could reach up to 287.5 mg/g under optimized conditions. In comparison with Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS, Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES displayed higher extraction capacity and selectivity for trypsin. According to the regeneration studies, Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES microspheres can be recycled six times without significant loss of its extraction capacity, and retained a high extraction capacity of 233 mg/g after eight cycles. Besides, the activity studies also demonstrated that the activity of the extracted trypsin was well retained. Furthermore, the analysis of real sample revealed that the prepared magnetic microspheres can be used to purify trypsin in crude bovine pancreas extract. These results highlight the potential of the proposed Fe{sub 3}O{sub 4}@SiO{sub 2}-MPS@PDES-MSPE method in separation of biomolecules. - Highlights: • A strategy for solid-phase extraction of trypsin based on poly(deep eutectic solvent) modified magnetic silica

  1. Deep eutectic solvent (DES) as a pretreatment for oil palm empty fruit bunch (OPEFB) in production of sugar

    Science.gov (United States)

    Nor, Nur Atikah Md; Mustapha, Wan Aida Wan; Hassan, Osman

    2015-09-01

    Oil Palm Empty Fruit Bunch (OPEFB) was pretreated using Deep Eutectic Solvent (DES) at different parameters to enable a highest yield of sugar. DES is a combination of two or more cheap and safe components to form a eutectic mixture through hydrogen bond interaction, which has a melting point lower than that of each component. DES can be used to replace ionic liquids (ILs), which are more expensive and toxic. In this study, OPEFB was pretreated with DES mixture of choline chloride: urea in 1:2 molar ratio. The pretreatment was performed at temperature 110°C and 80°C for 4 hours and 1 hour. Pretreatment A (110°C, 4 hours), B (110°C, 1 hour), C (80°C, 4 hours) and D (80°C, 1 hour). Enzymatic hydrolysis was done by using the combination of two enzymes, namely, Cellic Ctec2 and Cellic Htec2. The treated fiber is tested for crystallinity using XRD and functional group analysis using FTIR, to check the effect of the pretreatment on the fiber and compared it with the untreated fiber. From XRD analysis, DES successfully gave an effect towards degree of crystallinity of cellulose. Pretreatment A (110°C, 4 hours) and B (110°C, 1 hour) successfully reduce the percentage of crystallinity while pretreatment C (80°C, 4 hours) and D (80°C, 1 hour) increased the percentage of crystallinity. From FTIR analysis, DES cannot remove the functional group of lignin and hemicellulose but it is believed that DES can expose the structure of cellulose. Upon enzymatic hydrolysis, DES-treated fiber successfully produced sugar but not significantly when compared with raw. Pretreatment A (110°C, 4 hours), B (110°C, 1 hour), C (80°C, 4 hours) and D (80°C, 1 hour) produced glucose at the amount of 60.47 mg/ml, 66.33 mg/ml, 61.96 mg/ml and 59.12 mg/ml respectively. However, pretreatment C gave the highest xylose (70.01 mg/ml) production compared to other DES pretreatments.

  2. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanhua; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-02

    Highlights: • A strategy for extraction of protein based on DES-coated magnetic graphene oxide. • The deep eutectic solvents were based on choline chloride. • Bovine serum albumin was used as the analyte. • The material prepared works for the acidic but not the basic or the neutral proteins. - Abstract: Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe{sub 3}O{sub 4}@GO) to form Fe{sub 3}O{sub 4}@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe{sub 3}O{sub 4}@GO-DES, and the results indicated the successful preparation of Fe{sub 3}O{sub 4}@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe{sub 3}O{sub 4}@GO-DES. Comparison of Fe{sub 3}O{sub 4}@GO and Fe{sub 3}O{sub 4}@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe{sub 3}O{sub 4}@GO-DES performs better than Fe{sub 3}O{sub 4}@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L{sup −1} Na{sub 2}HPO{sub 4} contained 1 mol L{sup −1} NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled.

  3. Electrochemical measurements of diffusion coefficients and activity coefficients for MnCl2 in molten eutectic LiCl-KCl

    Science.gov (United States)

    Horvath, D.; Rappleye, D.; Bagri, P.; Simpson, M. F.

    2017-09-01

    An electrochemical study of manganese chloride in molten salt mixtures of eutectic LiCl-KCl was carried out using a variety of electrochemical methods in a high temperature cell including cyclic voltammetry (CV), chronopotentiometry (CP), chronoamperometry (CA), and open circuit potentiometry. Single step reduction from Mn2+ to Mn(0) was observed on both W and Mo working electrodes. Using a combination of these methods, measurements were made of activity coefficient and diffusion coefficient for MnCl2 in LiCl-KCl as a function of concentration (3.54 × 10-4 to 3.60 × 10-3 mol fraction of MnCl2) at 773K. From OCP measurements, values for activity coefficient varied from 0.014 to 0.0071. Diffusion coefficients varied with concentration and differed based on measurement method (CV, CA, or CP). Based on cyclic Mn(II) ranged from 1.1 to 2.8 × 10-5 cm2/s depending on concentration.

  4. Theoretical evidence of charge transfer interaction between SO₂ and deep eutectic solvents formed by choline chloride and glycerol.

    Science.gov (United States)

    Li, Hongping; Chang, Yonghui; Zhu, Wenshuai; Wang, Changwei; Wang, Chao; Yin, Sheng; Zhang, Ming; Li, Huaming

    2015-11-21

    The nature of the interaction between deep eutectic solvents (DESs), formed by ChCl and glycerol, and SO2 has been systematically investigated using the M06-2X density functional combined with cluster models. Block-localized wave function energy decomposition (BLW-ED) analysis shows that the interaction between SO2 and DESs is dominated by a charge transfer interaction. After this interaction, the SO2 molecule becomes negatively charged, whereas the ChCl-glycerol molecule is positively charged, which is the result of Lewis acid-base interaction. The current result affords a theoretical proof that it is highly useful and efficient to manipulate the Lewis acidity of absorbents for SO2 capture. Moreover, hydrogen bonding as well as electrostatic interactions may also contribute to the stability of the complex. Structure analysis shows that solvent molecules will adjust their geometries to interact with SO2. In addition, the structure of SO2 is barely changed after interaction. The interaction energy between different cluster models and SO2 ranges from -6.8 to -14.4 kcal mol(-1). It is found that the interaction energy is very sensitive to the solvent structure. The moderate interaction between ChCl-glycerol and SO2 is consistent with the concept that highly efficient solvents for SO2 absorption should not only be solvable but also regenerable.

  5. Deep Eutectic Solvents as Novel and Effective Extraction Media for Quantitative Determination of Ochratoxin A in Wheat and Derived Products

    Directory of Open Access Journals (Sweden)

    Luca Piemontese

    2017-01-01

    Full Text Available An unprecedented, environmentally friendly, and faster method for the determination of Ochratoxin A (OTA (a mycotoxin produced by several species of Aspergillus and Penicillium and largely widespread in nature, in wheat and derived products has, for the first time, been set up and validated using choline chloride (ChCl-based deep eutectic solvents (DESs (e.g., ChCl/glycerol (1:2 and ChCl/ urea (1:2 up to 40% (w/w water as privileged, green, and biodegradable extraction solvents. This also reduces worker exposure to toxic chemicals. Results are comparable to those obtained using conventional, hazardous and volatile organic solvents (VOCs typical of the standard and official methods. OTA recovery from spiked durum wheat samples, in particular, was to up to 89% versus 93% using the traditional acetonitrile-water mixture with a repeatability of the results (RSDr of 7%. Compatibility of the DES mixture with the antibodies of the immunoaffinity column was excellent as it was able to retain up to 96% of the OTA. Recovery and repeatability for durum wheat, bread crumbs, and biscuits proved to be within the specifications required by the current European Commission (EC regulation. Good results in terms of accuracy and precision were achieved with mean recoveries between 70% (durum wheat and 88% (bread crumbs and an RSDr between 2% (biscuits and 7% (bread.

  6. Oxidation mechanism of T91 steel in liquid lead-bismuth eutectic: with consideration of internal oxidation

    Science.gov (United States)

    Ye, Zhongfei; Wang, Pei; Dong, Hong; Li, Dianzhong; Zhang, Yutuo; Li, Yiyi

    2016-01-01

    Clarification of the microscopic events that occur during oxidation is of great importance for understanding and consequently controlling the oxidation process. In this study the oxidation product formed on T91 ferritic/martensitic steel in oxygen saturated liquid lead-bismuth eutectic (LBE) at 823 K was characterized at the nanoscale using focused-ion beam and transmission electron microscope. An internal oxidation zone (IOZ) under the duplex oxide scale has been confirmed and characterized systematically. Through the microscopic characterization of the IOZ and the inner oxide layer, the micron-scale and nano-scale diffusion of Cr during the oxidation in LBE has been determined for the first time. The micron-scale diffusion of Cr ensures the continuous advancement of IOZ and inner oxide layer, and nano-scale diffusion of Cr gives rise to the typical appearance of the IOZ. Finally, a refined oxidation mechanism including the internal oxidation and the transformation of IOZ to inner oxide layer is proposed based on the discussion. The proposed oxidation mechanism succeeds in bridging the gap between the existing models and experimental observations. PMID:27734928

  7. Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

    KAUST Repository

    Wu, Hongjun

    2017-07-13

    Over-reliance on non-renewable fossil fuel leads to steadily increasing concentration of atmospheric CO2, which has been implicated as a critical factor contributing to global warming. The efficient conversion of CO2 into useful product is highly sought after both in academic and industry. Herein, a novel conversion strategy is proposed to one-step transform CO2/H2O into syngas (CO/H2) in molten salt with electrolysis method. All the energy consumption in this system are contributed from sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized syngas contains very desirable content of H2 and CO, with tuneable molar ratios (H2/CO) from 0.6 to 7.8, and with an efficient faradaic efficiency of ∼94.5%. The synthesis of syngas from CO2 with renewable energy at a such low electrolytic temperature not only alleviates heat loss, mitigates system corrosion, and heightens operational safety, but also decreases the generation of methane, thus increases the yield of syngas, which is a remarkable technological breakthrough and this work thus represents a stride in sustainable conversion of CO2 to value-added product.

  8. Enzymatic Synthesis of Glucose-Based Fatty Acid Esters in Bisolvent Systems Containing Ionic Liquids or Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Kai-Hua Zhao

    2016-09-01

    Full Text Available Sugar fatty acid esters (SFAEs are biocompatible nonionic surfactants with broad applications in food, cosmetic, and pharmaceutical industries. They can be synthesized enzymatically with many advantages over their chemical synthesis. In this study, SFAE synthesis was investigated by using two reactions: (1 transesterification of glucose with fatty acid vinyl esters and (2 esterification of methyl glucoside with fatty acids, catalyzed by Lipozyme TLIM and Novozym 435 respectively. Fourteen ionic liquids (ILs and 14 deep eutectic solvents (DESs were screened as solvents, and the bisolvent system composed of 1-hexyl-3-methylimidazolium trifluoromethylsulfonate ([HMIm][TfO] and 2-methyl-2-butanol (2M2B was the best for both reactions, yielding optimal productivities (769.6 and 397.5 µmol/h/g, respectively which are superior to those reported in the literature. Impacts of different reaction conditions were studied for both reactions. Response surface methodology (RSM was employed to optimize the transesterification reaction. Results also demonstrated that as co-substrate, methyl glucoside yielded higher conversions than glucose, and that conversions increased with an increase in the chain length of the fatty acid moieties. DESs were poor solvents for the above reactions presumably due to their high viscosity and high polarity.

  9. Fundamental Study on a Distillation Separation of a LiCl-KCl Eutectic Salt from Rare Earth Precipitates

    International Nuclear Information System (INIS)

    Yang, Hee Chul; Eun, Hee Chul; Kim, In Tae

    2010-01-01

    The distillation rate on LiCl-KCl eutectic salt under different vacuums from 0.5-50 mmHg was first investigated by using both a non-isothermal and a isothermal thermogravimetric (TG) analysis. Based on the non-isothermal TG data, distillation rate equations as a function of the temperature could be derived. Calculated flux by these model flux equations was in agreement with the distillation rate obtained from isothermal TG analysis. A distillation rate of 10 -4 -10 -5 mole cm -2 sec -1 is obtainable at temperatures less than 1300 K and vacuums of 0.5-50 mmHg. About a 99% salt distillation efficiency was obtained after an hour at a temperature above 1150 K under 50 mmHg in a small scale distillation test system. An increase in the vaporizing surface area is relatively effective for removing residual salt in the remaining particles, when compared to that for the vaporizing time. Over 99.95% of total distillation efficiency was obtained for a 1-h distillation operation by increasing the inner surface area from 4.52 cm 2 to 12.56 cm 2 .

  10. Absorption spectra and cyclic voltammograms of uranium species in molten lithium molybdate-sodium molybdate eutectic at 550 C

    International Nuclear Information System (INIS)

    Nagai, T.; Fukushima, M.; Myochin, M.; Uehara, A.; Fujii, T.; Yamana, H.; Sato, N.

    2011-01-01

    Absorption spectra of uranium species dissolved in molten lithium molybdate.sodium molybdate eutectic of 0.51Li 2 MoO 4 -0.49Na 2 MoO 4 mixture at 550 C were measured by UV/Vis/NIR spectrophotometry, and their redox reactions were investigated by cyclic voltammetry. We found that the major ions of uranium species dissolved in the melt were uranyl penta-valent. After purging dry oxygen gas into the melt, pentavalent species were oxidized to the uranyl hexa-valent. In the cyclic voltammetry of the melt without uranium species, it was confirmed that the lithium-sodium molybdenum oxide compounds were deposited on the working electrode at the negative potential and the lithium molybdenum oxide compounds were deposited on the counter electrode at positive potential. When UO 2 was dissolved into the melt, the reductive reaction of the uranium species was observed at the reductive potential of the pure melt. This suggests that the uranium species dissolved in the melts could be recovered as mixed uranium-molybdenum oxides by electrolysis. (orig.)

  11. Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

    Science.gov (United States)

    Wu, Hongjun; Liu, Yue; Ji, Deqiang; Li, Zhida; Yi, Guanlin; Yuan, Dandan; Wang, Baohui; Zhang, Zhonghai; Wang, Peng

    2017-09-01

    Over-reliance on non-renewable fossil fuel leads to steadily increasing concentration of atmospheric CO2, which has been implicated as a critical factor contributing to global warming. The efficient conversion of CO2 into useful product is highly sought after both in academic and industry. Herein, a novel conversion strategy is proposed to one-step transform CO2/H2O into syngas (CO/H2) in molten salt with electrolysis method. All the energy consumption in this system are contributed from sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (decreases the generation of methane, thus increases the yield of syngas, which is a remarkable technological breakthrough and this work thus represents a stride in sustainable conversion of CO2 to value-added product.

  12. Choline and Geranate Deep Eutectic Solvent as a Broad-Spectrum Antiseptic Agent for Preventive and Therapeutic Applications.

    Science.gov (United States)

    Zakrewsky, Michael; Banerjee, Amrita; Apte, Sanjana; Kern, Theresa L; Jones, Mattie R; Sesto, Rico E Del; Koppisch, Andrew T; Fox, David T; Mitragotri, Samir

    2016-06-01

    Antiseptic agents are the primary arsenal to disinfect skin and prevent pathogens spreading within the host as well as into the surroundings; however the Food and Drug Administration published a report in 2015 requiring additional validation of nearly all current antiseptic agents before their continued use can be allowed. This vulnerable position calls for urgent identification of novel antiseptic agents. Recently, the ability of a deep eutectic, Choline And Geranate (CAGE), to treat biofilms of Pseudomonas aeruginosa and Salmonella enterica was demonstrated. Here it is reported that CAGE exhibits broad-spectrum antimicrobial activity against a number of drug-resistant bacteria, fungi, and viruses including clinical isolates of Mycobacterium tuberculosis, Staphylococcus aureus, and Candida albicans as well as laboratory strains of Herpes Simplex Virus. Studies in human keratinocytes and mice show that CAGE affords negligible local or systemic toxicity, and an ≈180-14 000-fold improved efficacy/toxicity ratio over currently used antiseptic agents. Further, CAGE penetrates deep into the dermis and treats pathogens located in deep skin layers as confirmed by the ability of CAGE in vivo to treat Propionibacterium acnes infection. In combination, the results clearly demonstrate CAGE holds promise as a transformative platform antiseptic agent for preventive as well as therapeutic applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. The modelling of lead removal from water by deep eutectic solvents functionalized CNTs: artificial neural network (ANN) approach.

    Science.gov (United States)

    Fiyadh, Seef Saadi; AlSaadi, Mohammed Abdulhakim; AlOmar, Mohamed Khalid; Fayaed, Sabah Saadi; Hama, Ako R; Bee, Sharifah; El-Shafie, Ahmed

    2017-11-01

    The main challenge in the lead removal simulation is the behaviour of non-linearity relationships between the process parameters. The conventional modelling technique usually deals with this problem by a linear method. The substitute modelling technique is an artificial neural network (ANN) system, and it is selected to reflect the non-linearity in the interaction among the variables in the function. Herein, synthesized deep eutectic solvents were used as a functionalized agent with carbon nanotubes as adsorbents of Pb 2+ . Different parameters were used in the adsorption study including pH (2.7 to 7), adsorbent dosage (5 to 20 mg), contact time (3 to 900 min) and Pb 2+ initial concentration (3 to 60 mg/l). The number of experimental trials to feed and train the system was 158 runs conveyed in laboratory scale. Two ANN types were designed in this work, the feed-forward back-propagation and layer recurrent; both methods are compared based on their predictive proficiency in terms of the mean square error (MSE), root mean square error, relative root mean square error, mean absolute percentage error and determination coefficient (R 2 ) based on the testing dataset. The ANN model of lead removal was subjected to accuracy determination and the results showed R 2 of 0.9956 with MSE of 1.66 × 10 -4 . The maximum relative error is 14.93% for the feed-forward back-propagation neural network model.

  14. Impregnated-electrode-type liquid metal ion source (IV): Extraction of Si, Ge, Sb by using eutectic alloy

    International Nuclear Information System (INIS)

    Chen, G.; Gotoh, Y.; Tsuji, H.; Ishikawa, J.; Takagi, T.

    1985-01-01

    An impregnated-electrode-type liquid metal ion source has been developed in which a sintered porous tungsten tip is used. There has been an increasing interest in liquid metal ion source to obtain focused ion beams. The focused ion beam can perform three useful process steps: direct-write ion implantation to semiconductor, ion sputtering to make thin films and ion exposure to define resist. It is necessary to extract various ions for this purpose. It is possible to extract ions of Ga, Au, and Ag with impregnated-electrode-type liquid metal ion source. For micro-electronic application, ions of Si, Ge and Sb are desirable for doping, but their high melting points or high vapour pressures prohibit their use in elemental form. The purpose of the present investigation is to fabricate eutectic alloys which can be used in impregnated-electrode-type liquid metal ion source. The authors have been successful to obtain ions of Si, Ge and Sb, and revealed relevant basic ion source parameters such as current-voltage characteristics, mass spectra and life time

  15. Pencil graphite electrodes for improved electrochemical detection of oleuropein by the combination of Natural Deep Eutectic Solvents and graphene oxide.

    Science.gov (United States)

    Gomez, Federico J V; Spisso, Adrian; Fernanda Silva, María

    2017-11-01

    A novel methodology is presented for the enhanced electrochemical detection of oleuropein in complex plant matrices by Graphene Oxide Pencil Grahite Electrode (GOPGE) in combination with a buffer modified with a Natural Deep Eutectic Solvent, containing 10% (v/v) of Lactic acid, Glucose and H 2 O (LGH). The electrochemical behavior of oleuropein in the modified-working buffer was examined using differential pulse voltammetry. The combination of both modifications, NADES modified buffer and nanomaterial modified electrode, LGH-GOPGE, resulted on a signal enhancement of 5.3 times higher than the bare electrode with unmodified buffer. A calibration curve of oleuropein was performed between 0.10 to 37 μM and a good linearity was obtained with a correlation coefficient of 0.989. Detection and quantification limits of the method were obtained as 30 and 102 nM, respectively. In addition, precision studies indicated that the voltammetric method was sufficiently repeatable, %RSD 0.01 and 3.16 (n = 5) for potential and intensity, respectively. Finally, the proposed electrochemical sensor was successfully applied to the determination of oleuropein in an olive leaf extract prepared by ultrasound-assisted extraction. The results obtained with the proposed electrochemical sensor were compared with Capillary Zone Electrophoresis analysis with satisfactory results. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Numerical simulation of heat-transfer and insoluble corrosion product deposition in lead-bismuth eutectic alloy

    International Nuclear Information System (INIS)

    Yang Xu; Zhou Tao; Fang Xiaolu; Lin Daping; Ru Xiaolong

    2015-01-01

    As the primary coolant of ADS (accelerator driven sub-critical system), the safety of reactor will be threatened and the lifetime of the reactor will be shortened by appearing of the tiny particles in LBE (lead-bismuth eutectic) alloy. To this end, numerical simulation with the code of FLUENT was used to research the deposition distribution of insoluble corrosion products in rectangular channel. The standard k-ε model was selected to predict the turbulence variation in the rectangular channel. The discrete phase model (DPM) was used to track the trajectory of the particles. It is found that the deposition efficiency is positively correlated with the temperature difference between the fluid and cold wall. The near wall region with a high concentration of particulate matter and low temperature is in favor of particulate matter deposition on the wall. At the same time, the high turbulence kinetic near wall region is not conducive to the deposition of particulate matter. A secondary flow phenomenon occurs under the influence of boundary wall, namely that there are eight symmetrical regions in the radial direction. (authors)

  17. Synthesis and application of magnetic deep eutectic solvents: Novel solvents for ultrasound assisted liquid-liquid microextraction of thiophene.

    Science.gov (United States)

    Khezeli, Tahere; Daneshfar, Ali

    2017-09-01

    Two novel magnetic deep eutectic solvents (MDESs), comprised of cheap and simple components named [choline chloride/phenol] [FeCl 4 ] and [choline chloride/ethylene glycol] [FeCl 4 ] were prepared and characterized by CHN elemental analysis, proton nuclear magnetic resonance ( 1 H NMR), vibrating sample magnetometery (VSM), Raman, Fourier transform-infrared (FT-IR) and UV-Vis spectrometery. The extraction efficiency of the prepared MDESs has been investigated in ultrasound assisted liquid-liquid microextraction based MDES (UALLME-MDES). Briefly, MDESs were added to n-heptan containing thiophene. Then, MDESs were dispersed in n-heptane by sonication. After that, microdroplets of MDESs were collected by a magnet and the remained concentration of thiophene in n-heptane phase was analyzed by GC-FID. The results indicated that [choline chloride/phenol] [FeCl 4 ] has higher extraction efficiency than [choline chloride/ethylene glycol] [FeCl 4 ]. This work opens a new way to the application of MDESs. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents.

    Directory of Open Access Journals (Sweden)

    Laleh Bahadori

    Full Text Available The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs containing ammonium-based salts and hydrogen bond donvnors (polyol type are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+ and reduction of cobaltocenium (Cc+/Cc at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5 appears suitable for further testing in electrochemical energy storage devices.

  19. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents.

    Science.gov (United States)

    Bahadori, Laleh; Chakrabarti, Mohammed Harun; Manan, Ninie Suhana Abdul; Hashim, Mohd Ali; Mjalli, Farouq Sabri; AlNashef, Inas Muen; Brandon, Nigel

    2015-01-01

    The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs) containing ammonium-based salts and hydrogen bond donvnors (polyol type) are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+) and reduction of cobaltocenium (Cc+/Cc) at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5) appears suitable for further testing in electrochemical energy storage devices.

  20. Mechanical and barrier properties of starch-based films plasticized with two- or three component deep eutectic solvents.

    Science.gov (United States)

    Zdanowicz, Magdalena; Johansson, Caisa

    2016-10-20

    The aim of this work was to prepare two- and three-components deep eutectic solvents (DES) and investigate their potential as starch plasticizers. Starch/DES films were prepared via casting method. Mechanical properties, water vapor- and oxygen transmission rates were measured; additionally contact angle and moisture sorption were determined and FTIR analysis was applied on the films. Native potato starch and hydroxypropylated and oxidized starch (HOPS) with common plasticizers (e.g. polyols, urea) and DES were studied. Moreover, influence of three methods of DES introduction and concentration of plasticizer on the films properties were compared. HOPS films were prepared by two methods: as non-cured and cured samples. Some of DESs containing citrate anion exhibited crosslinking ability of polysaccharide matrix. Non-cured HOPS/DES films exhibited more favourable mechanical and barrier properties than cured analogue films. Samples prepared with unmodified potato starch had higher mechanical and barrier properties than films made with HOPS. Starch-based films plasticized with novel DESs with parallel crosslinking activity exhibited satisfactory mechanical and barrier properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Application of novel ternary deep eutectic solvents as a functional monomer in molecularly imprinted polymers for purification of levofloxacin.

    Science.gov (United States)

    Li, Xiaoxia; Row, Kyung Ho

    2017-11-15

    A series of ecofriendly ternary deep eutectic solvents (DESs) with different molar ratios were prepared as candidate functional monomers. Three of the optimal ternary DESs as functional monomers were applied to the preparation of molecularly imprinted polymers (MIPs). After synthesis, the proposed polymers were characterized by elemental analysis (EA), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller surface area measurements (BET) and Fourier transform infrared spectroscopy (FT-IR). These MIPs based on ternary DESs with different molar ratios exhibited different absorption capacities of levofloxacin. A sample of levofloxacin (500ng) was dissolved in a millet extractive (10mL). All MIPs were used as SPE adsorbents to purify the extracts. According to characterization result, the ternary DES-3 (1:3:1.5) was joined in the synthetic process of MIP-1. The green ternary DES-3-based MIPs had the best selectivity recovery for levofloxacin (91.4%) from the millet extractive. The best selectivity of MIP-1 was attributed to the novel monomer (ternary DES) in the preparation of the materials. Overall, ternary DES-based MIPs have potential applications as media in many research areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Small angle neutron scattering study of the conformation of poly(ethylene oxide) dissolved in deep eutectic solvents.

    Science.gov (United States)

    Chen, Zhengfei; McDonald, Samila; FitzGerald, Paul; Warr, Gregory G; Atkin, Rob

    2017-11-15

    The conformation of poly(ethylene oxide) (PEO) in deep eutectic solvents (DESs) is determined by the polymer-solvent interactions, especially hydrogen bonding interactions. The hypothesis for this work is that the hydrogen bonding environment of a DES can be varied via changing the cation or hydrogen bond donor (HBD), and therefore the solvent quality for PEO; the anion species will also effect hydrogen bonding, but this is not examined here. Small angle neutron scattering (SANS) is used to probe the concentration dependent conformation of 36kDa PEO dissolved in DESs formed by mixing ethyl or butyl ammonium bromide with a molecular HBD (glycerol or ethylene glycol) in a 1:2 molar ratio. The radius of gyration (R g ), Flory exponent and crossover concentration (c * ) from the dilute to the semi-dilute regime of PEO in the DESs revealed by SANS and Zimm plot analysis show that these DESs are moderately good solvents for PEO. When the ammonium alkyl chain length is increased, the hydrogen bond density per unit volume decreases, and with it the solvent quality for PEO. The solvent quality is improved when the HBD is changed from glycerol to ethylene glycol due to differences in the hydrogen bonding environment for PEO. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Thermodynamic Investigation of the Effect of Interface Curvature on the Solid-Liquid Equilibrium and Eutectic Point of Binary Mixtures.

    Science.gov (United States)

    Liu, Fanghui; Zargarzadeh, Leila; Chung, Hyun-Joong; Elliott, Janet A W

    2017-10-12

    Thermodynamic phase behavior is affected by curved interfaces in micro- and nanoscale systems. For example, capillary freezing point depression is associated with the pressure difference between the solid and liquid phases caused by interface curvature. In this study, the thermal, mechanical, and chemical equilibrium conditions are derived for binary solid-liquid equilibrium with a curved solid-liquid interface due to confinement in a capillary. This derivation shows the equivalence of the most general forms of the Gibbs-Thomson and Ostwald-Freundlich equations. As an example, the effect of curvature on solid-liquid equilibrium is explained quantitatively for the water/glycerol system. Considering the effect of a curved solid-liquid interface, a complete solid-liquid phase diagram is developed over a range of concentrations for the water/glycerol system (including the freezing of pure water or precipitation of pure glycerol depending on the concentration of the solution). This phase diagram is compared with the traditional phase diagram in which the assumption of a flat solid-liquid interface is made. We show the extent to which nanoscale interface curvature can affect the composition-dependent freezing and precipitating processes, as well as the change in the eutectic point temperature and concentration with interface curvature. Understanding the effect of curvature on solid-liquid equilibrium in nanoscale capillaries has applications in the food industry, soil science, cryobiology, nanoporous materials, and various nanoscience fields.

  4. Bright metal coatings from sustainable electrolytes: the effect of molecular additives on electrodeposition of nickel from a deep eutectic solvent.

    Science.gov (United States)

    Abbott, Andrew P; Ballantyne, Andrew; Harris, Robert C; Juma, Jamil A; Ryder, Karl S

    2017-01-25

    Organic and inorganic additives are often added to nickel electroplating solutions to improve surface finish, reduce roughness and promote uniform surface morphology of the coatings. Such additives are usually small molecules and often referred to as brighteners or levellers. However, there have been limited investigations into the effect of such additives on electrodeposition from ionic liquids (ILs) and deep eutectic solvents (DESs). Here we study the effect of four additives on electrolytic nickel plating from an ethyleneglycol based DES; these are nicotinic acid (NA), methylnicotinate (MN), 5,5-dimethylhydantoin (DMH) and boric acid (BA). The additives show limited influence on the bulk Ni(ii) speciation but have significant influence on the electrochemical behaviour of Ni deposition. Small concentrations (ca. 15 mM) of NA and MN show inhibition of Ni(ii) reduction whereas high concentrations of DMH and BA are required for a modest difference in behaviour from the additive free system. NA and MN also show that they significantly alter the nucleation and growth mechanism when compared to the additive free system and those with DMH and BA. Each of the additive systems had the effect of producing brighter and flatter bulk electrodeposits with increased coating hardness but XRD shows that NA and MN direct crystal growth to the [111] orientation whereas DMH and BA direct crystal growth to the [220] orientation.

  5. The contact heat conductance at diamond-OFHC copper interface with GaIn eutectic as a heat transfer medium

    International Nuclear Information System (INIS)

    Assoufid, L.; Khounsary, A.M.

    1996-01-01

    Results of an experimental study of the contact heat conductance across a single diamond crystal interface with OFHC copper (Cu) are reported. Gallium-indium (GaIn) eutectic was used as an interstitial material. Contact conductance data are important in the design and the prediction of the performance of x-ray diamond monochromators under high-heat-load conditions. Two sets of experiments were carried out. In one, the copper surface in contact with diamond was polished and then electroless plated with 1 μm of nickel, while in the other, the copper contact surface was left as machined. Measured average interface heat conductances are 44.7 ±8 W/cm 2 -K for nonplated copper and 23.0 ±3 W/cm 2 -K for nickel-plated copper. For reference, the thermal contact conductances at a copper-copper interface (without diamond) were also measured, and the results are reported. A typical diamond monochromator, 0.2 mm thick, will absorb about 44 W under a standard undulator beam at the Advanced Photon Source. The measured conductance for nickel-plated copper suggests that the temperature drop across the interface of diamond and nickel-plated copper, with a 20 mm 2 contact area, will be about 10 degree C. Therefore temperature rises are rather modest, and the accuracy of the measured contact conductances presented here are sufficient for design purposes

  6. Investigation of the Vortex States of Sr2RuO4-Ru Eutectic Microplates Using DC-SQUIDs

    Science.gov (United States)

    Sakuma, Daisuke; Nago, Yusuke; Ishiguro, Ryosuke; Kashiwaya, Satoshi; Nomura, Shintaro; Kono, Kimitoshi; Maeno, Yoshiteru; Takayanagi, Hideaki

    2017-11-01

    We investigated the magnetic properties of a Sr2RuO4-Ru eutectic microplate containing a single Ru-inclusion using micrometer-sized DC-SQUIDs (direct-current superconducting quantum interference devices). A phase frustration at the interface between chiral p-wave superconducting Sr2RuO4 and s-wave superconducting Ru is expected to cause novel magnetic vortex states such as the spontaneous Ru-center vortex under zero magnetic field [as reported by H. Kaneyasu and M. Sigrist, https://doi.org/10.1143/JPSJ.79.053706" xlink:type="simple">J. Phys. Soc. Jpn. 79, 053706 (2010)]. Our experimental results show no positive evidence for such a spontaneous vortex state. However, in an applied field, an abrupt change in the magnetic flux distribution was observed at a superconducting transition of Ru. The flux distribution is clarified by comparing our experimental results with electromagnetic field simulations in our sample geometry. We discuss the transition of the vortex states and the superconducting coupling at the Sr2RuO4/Ru interface.

  7. Fundamental study on reaction of lead-bismuth eutectic and sodium. Identification of reaction products and examination of reaction behavior

    International Nuclear Information System (INIS)

    Saito, Jun-ichi; Hirakawa, Yasushi

    2003-09-01

    A simplified secondary sodium cooling system utilizing lead-bismuth eutectic as an intermediate coolant has been selected as one of candidate systems for the 'Feasibility Studies on Commercialized Fast Reactor System'. In this study, fundamental reaction experiments have been performed to understand a reaction behavior between sodium and lead-bismuth. In order to identify the reaction products and to elucidate a reaction process, sampling and X-ray diffraction analysis of the reaction products are carried out. Following results are obtained. (1) The principal reaction products which formed in sodium and lead-bismuth ternary system are BiNa 3 and Pb 4 Na 15 intermetallic compounds. These two reaction products are identified irrespective of either primary sample content or sampling temperature. (2) Pb 3 Na intermetallic compound is identified in the reaction products for the first time. (3) The principal reaction product which formed in sodium and bismuth binary system is BiNa 3 intermetallic compound. (4) The reaction products which formed in sodium and lead binary system consist of various intermetallic compounds of sodium and lead system. Single phase of an intermetallic compound can not be obtained in this system. Based on these X-ray diffraction analyses, reaction process models of formation and dissolution are proposed. (author)

  8. Analysis of the Deformability of Two-Layer Materials AZ31/Eutectic / Analiza Możliwości Odkształcania Plastycznego Materiału Dwuwarstwowego AZ31/Eutektyka

    Directory of Open Access Journals (Sweden)

    Mola R.

    2015-12-01

    Full Text Available The paper present the results of physical simulation of the deformation of the two-layered AZ31/eutectic material using the Gleeble 3800 metallurgical processes simulator. The eutectic layer was produced on the AZ31 substrate using thermochemical treatment. The specimens of AZ31 alloy were heat treated in contact with aluminium powder at 445°C in a vacuum furnace. Depending on the heating time, Al-enriched surface layers with a thickness of 400, 700 and 1100 μm were fabricated on a substrate which was characterized by an eutectic structure composed of the Mg17Al12 phase and a solid solution of aluminium in magnesium. In the study, physical simulation of the fabricated two-layered specimens with a varying thickness of the eutectic layer were deformed using the plane strain compression test at various values of strain rates. The testing results have revealed that it is possible to deform the two-layered AZ31/eutectic material at low strain rates and small deformation values.

  9. Enhanced and green extraction polyphenols and furanocoumarins from Fig (Ficus carica L.) leaves using deep eutectic solvents.

    Science.gov (United States)

    Wang, Tong; Jiao, Jiao; Gai, Qing-Yan; Wang, Peng; Guo, Na; Niu, Li-Li; Fu, Yu-Jie

    2017-10-25

    Nowadays, green extraction of bioactive compounds from medicinal plants has gained increasing attention. As green solvent, deep eutectic solvent (DES) have been highly rated to replace toxic organic solvents in extraction process. In present study, to simultaneous extraction five main bioactive compounds from fig leaves, DES was tailor-made. The tailor-made DES composed of a 3:3:3 molar ratio of glycerol, xylitol and D-(-)-Fructose showed enhanced extraction yields for five target compounds simultaneously compared with traditional methanol and non-tailor DESs. Then, the tailor-made DES based extraction methods have compared and microwave-assisted extraction was selected and optimized due to its high extraction yields with lower time consumption. The influencing parameters including extraction temperature, liquid-solid ratio, and extraction time were optimized using response surface methodology (RSM). Under optimal conditions the extraction yield of caffeoylmalic acid, psoralic acid-glucoside, rutin, psoralen and bergapten was 6.482mg/g, 16.34mg/g, 5.207mg/g, 15.22mg/g and 2.475mg/g, respectively. Macroporous resin D101 has been used to recovery target compounds with recovery yields of 79.2%, 83.4%, 85.5%, 81.2% and 75.3% for caffeoylmalic acid, psoralic acid-glucoside, rutin, psoralen and bergapten, respectively. The present study suggests that DESs are truly designer and efficient solvents and the method we developed was efficient and sustainable for extraction main compounds from Fig leaves.mg/g. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Electrochemical studies and analysis of 1-10 wt% UCl3 concentrations in molten LiCl-KCl eutectic

    Science.gov (United States)

    Hoover, Robert O.; Shaltry, Michael R.; Martin, Sean; Sridharan, Kumar; Phongikaroon, Supathorn

    2014-09-01

    Three electrochemical methods - cyclic voltammetry (CV), chronopotentiometry (CP), and anodic stripping voltammetry (ASV) - were applied to solutions of up to 10 wt% UCl3 in the molten LiCl-KCl eutectic salt at 500 °C to determine electrochemical properties and behaviors and to help provide a scientific basis for the development of an in situ electrochemical probe for determining the concentration of uranium in a used nuclear fuel electrorefiner. Diffusion coefficients of UCl4 and UCl3 were calculated to be (6.72 ± 0.360) × 10-6 cm2/s and (1.04 ± 0.17) × 10-5 cm2/s, respectively. Apparent standard reduction potentials were determined to be (-0.381 ± 0.013) V and (-1.502 ± 0.076) V vs. 5 mol% Ag/AgCl or (-1.448 ± 0.013) V and (-2.568 ± 0.076) V vs. Cl2/Cl- for the U(IV)/U(III) and U(III)/U redox couples, respectively. In comparing this data with supercooled thermodynamic data to determine activity coefficients, the thermodynamic database used was important with resulting activity coefficients ranging from 2.34 × 10-3 to 1.08 × 10-2 for UCl4 and 4.94 × 10-5 to 4.50 × 10-4 for UCl3. Of anodic stripping voltammetry and cyclic voltammetry anodic or cathodic peaks, the CV cathodic peak height divided by square root of scan rate was shown to be the most reliable method of determining UCl3 concentration in the molten salt.

  11. Electrochemical studies and analysis of 1–10 wt% UCl3 concentrations in molten LiCl–KCl eutectic

    International Nuclear Information System (INIS)

    Hoover, Robert O.; Shaltry, Michael R.; Martin, Sean; Sridharan, Kumar; Phongikaroon, Supathorn

    2014-01-01

    Three electrochemical methods – cyclic voltammetry (CV), chronopotentiometry (CP), and anodic stripping voltammetry (ASV) – were applied to solutions of up to 10 wt% UCl 3 in the molten LiCl–KCl eutectic salt at 500 °C to determine electrochemical properties and behaviors and to help provide a scientific basis for the development of an in situ electrochemical probe for determining the concentration of uranium in a used nuclear fuel electrorefiner. Diffusion coefficients of UCl 4 and UCl 3 were calculated to be (6.72 ± 0.360) × 10 −6 cm 2 /s and (1.04 ± 0.17) × 10 −5 cm 2 /s, respectively. Apparent standard reduction potentials were determined to be (−0.381 ± 0.013) V and (−1.502 ± 0.076) V vs. 5 mol% Ag/AgCl or (−1.448 ± 0.013) V and (−2.568 ± 0.076) V vs. Cl 2 /Cl − for the U(IV)/U(III) and U(III)/U redox couples, respectively. In comparing this data with supercooled thermodynamic data to determine activity coefficients, the thermodynamic database used was important with resulting activity coefficients ranging from 2.34 × 10 −3 to 1.08 × 10 −2 for UCl 4 and 4.94 × 10 −5 to 4.50 × 10 −4 for UCl 3 . Of anodic stripping voltammetry and cyclic voltammetry anodic or cathodic peaks, the CV cathodic peak height divided by square root of scan rate was shown to be the most reliable method of determining UCl 3 concentration in the molten salt

  12. Identification of Major Flavone C-Glycosides and Their Optimized Extraction from Cymbidium kanran Using Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Kyung Min Jeong

    2017-11-01

    Full Text Available Cymbidium kanran, an orchid exclusively distributed in Northeast Asia, has been highly valued as a decorative plant and traditional herbal medicine. Here, C. kanran extracts were prepared in 70% aqueous methanol using ultrasound-assisted extraction (UAE and subjected to liquid chromatography-photodiode array detection and ultra-high performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry analysis, which were used for quantitative and qualitative analysis, respectively. It was found that the extracts were rich in flavone C-glycosides including vicenin-2, vicenin-3, schaftoside, vitexin, and isovitexin. Ten deep eutectic solvents (DESs were synthesized by combining choline chloride (hydrogen bond acceptor with various polyols and diols (hydrogen bond donors and were tested as a medium for the efficient production of extracts enriched with potentially bioactive flavone C-glycosides from C. kanran. A DES named ChCl:DPG, composed of choline chloride and dipropylene glycol at a 1:4 molar ratio, exhibited the best extraction yields. Then, the effects of extraction conditions on the extraction efficiency were investigated by response surface methodology. Lower water content in the extraction solvent and longer extraction time during UAE were desirable for higher extraction yields. Under the statistically optimized conditions, in which 100 mg of C. kanran powder were extracted in 0.53 mL of a mixture of ChCl:DPG and water (74:26, w/w for 86 min, a total of 3.441 mg g−1 flavone C-glycosides including 1.933 mg g−1 vicenin-2 was obtained. This total yield was 196%, 131%, and 71% more than those obtained using 100% methanol, water, and 70% methanol, respectively.

  13. Interaction and dynamics of (alkylamide + electrolyte) deep eutectics: Dependence on alkyl chain-length, temperature, and anion identity

    International Nuclear Information System (INIS)

    Guchhait, Biswajit; Das, Suman; Daschakraborty, Snehasis; Biswas, Ranjit

    2014-01-01

    Here we investigate the solute-medium interaction and solute-centered dynamics in (RCONH 2 + LiX) deep eutectics (DEs) via carrying out time-resolved fluorescence measurements and all-atom molecular dynamics simulations at various temperatures. Alkylamides (RCONH 2 ) considered are acetamide (CH 3 CONH 2 ), propionamide (CH 3 CH 2 CONH 2 ), and butyramide (CH 3 CH 2 CH 2 CONH 2 ); the electrolytes (LiX) are lithium perchlorate (LiClO 4 ), lithium bromide (LiBr), and lithium nitrate (LiNO 3 ). Differential scanning calorimetric measurements reveal glass transition temperatures (T g ) of these DEs are ∼195 K and show a very weak dependence on alkyl chain-length and electrolyte identity. Time-resolved and steady state fluorescence measurements with these DEs have been carried out at six-to-nine different temperatures that are ∼100–150 K above their individual T g s. Four different solute probes providing a good spread of fluorescence lifetimes have been employed in steady state measurements, revealing strong excitation wavelength dependence of probe fluorescence emission peak frequencies. Extent of this dependence, which shows sensitivity to anion identity, has been found to increase with increase of amide chain-length and decrease of probe lifetime. Time-resolved measurements reveal strong fractional power dependence of average rates for solute solvation and rotation with fraction power being relatively smaller (stronger viscosity decoupling) for DEs containing longer amide and larger (weaker decoupling) for DEs containing perchlorate anion. Representative all-atom molecular dynamics simulations of (CH 3 CONH 2 + LiX) DEs at different temperatures reveal strongly stretched exponential relaxation of wavevector dependent acetamide self dynamic structure factor with time constants dependent both on ion identity and temperature, providing justification for explaining the fluorescence results in terms of temporal heterogeneity and amide clustering in these multi

  14. Stearic–capric acid eutectic/activated-attapulgiate composite as form-stable phase change material for thermal energy storage

    International Nuclear Information System (INIS)

    Song, Shaokun; Dong, Lijie; Chen, Shun; Xie, Haian; Xiong, Chuanxi

    2014-01-01

    Highlights: • S–C/a-ATP form-stable PCM was prepared by vacuum fusion method. • Maximum mass fraction of S–C in composite without leakage is as high as 50 wt%. • The phase change temperature and latent heat is measured to be 21.8 °C and 72.6 J/g. • Thermal and chemical reliable with respect to a large number of thermal cycling. • The S–C/a-ATP has great potential in building energy conservation. - Abstract: The aim of this research was to prepare a novel form-stable PCMs (FSPCM) for latent heat thermal energy storage (LHTES) in low temperature, by incorporating eutectic mixture of stearic-capric acid (S–C) into activated-attapulgite (a-ATP) which acted as supporting material in the composite. The a-ATP is open-ended tubular capillary with large specific surface area, which is beneficial for the adsorption of PCMs. The maximum mass fraction of stearic-capric binary fatty acid loaded in a-ATP is determined as high as 50 wt% without melted S–C seepage from the composite. The phase change temperatures and latent heats of FSPCM are measured to be 21.8 °C and 72.6 J/g for melting process, and 20.3 °C and 71.9 J/g for freezing process, respectively, indicating it has suitable phase change temperature and high latent heat storage capacity. Moreover, the S–C/a-ATP FSPCM shows good thermal and chemical reliability after 1000 times thermal cycling test, which is identified by differential scanning calorimetry (DSC) and Fourier transformation infrared (FTIR). Therefore, the S–C/a-ATP FSPCM is an effective LHTES building material to reduce energy consumption

  15. Effect of Electric Field on the Wetting Behavior of Eutectic Gallium-Indium Alloys in Aqueous Environment

    Science.gov (United States)

    Yuan, Bo; He, Zhi-Zhu; Liu, Jing

    2018-02-01

    Room-temperature liquid metals have many intriguing properties that have not previously been fully understood. Among them, surface tension behaviors of such metals are especially critical in a group of newly emerging areas such as printed electronics, functional materials and soft machines, etc. This study is dedicated to clarifying the wettability of liquid metals on various substrate surfaces with varied roughness immersed in solutions when subject to an electric field. The contact angles of Ga75.5In24.5 in several typical liquids were comprehensively measured and interpreted, and were revealed to be affected by the components and concentration of the environmental solution. Meanwhile, the roughness of the substrates is also revealed to be an important parameter dominating the process. The dynamic wetting behaviors of liquid metal in aqueous environment under an electric field were quantified. The contact angle values of eutectic gallium-indium alloys (eGaIn) on titanium substrates with different roughness would lead to better electrowetting performances on rougher surfaces. In particular, using an electrical field to control the wetting status of liquid metal with the matching substrate have been illustrated, which would offer a practical way to flexibly control liquid metal-based functional devices working in an aqueous environment. Furthermore, Lippmann-Young's equation reveals the relationship between contact angle and applied voltage, explaining the excellent electrowetting property of eGaIn. The power law, R = αt β , was adopted to characterize the two-stage wetting process of eGaIn under different voltages. In the initial process, β ≈ 1/2 represents the complete wetting law, while the later one, β ≈ 1/10, meets with Tanner's law of a drop spontaneously spreading on a smooth surface.

  16. Corrosion mechanism of T91 steel by Pb-Bi eutectic used as spallation target: importance for accelerator driven system

    International Nuclear Information System (INIS)

    Martinelli, L.

    2005-10-01

    The aim of this work has been to determine the oxidation mechanism of the martensitic steel T91 in the Pb-Bi liquid eutectic alloy, saturated in oxygen, at 470 C, in order to develop a long-term predictive model of the oxidation kinetics of the steel. This work enters in the framework of the lifetime studies of the spallation module demonstrator: MEGAPIE for the researches on hybrid reactors. An experimental characterization of the oxide layers has been carried out as well as the oxidation kinetics of the T91 steel. An oxidation mechanism has been elaborated from these experimental results and then simulated. The oxide layer formed at the T91 surface presents a duplex structure constituted by a magnetite external layer and a spinel Fe-Cr internal layer. A growth mechanism of the oxide layers has been proposed: the growth of the magnetite layer seems to be limited by the iron diffusion in the lattice of the duplex oxide layer. In parallel, an auto-regulation mechanism seems to govern the growth of the Fe-Cr spinel layer. This mechanism includes a non-limiting step of the oxygen diffusion in the oxide layer (by liquid way in the nano-channels of lead), as well as a limiting step of iron diffusion in the lattice of the oxide layer. In considering the proposed oxidation mechanisms, a simulation of the growth of the two oxide layers is carried out and compared to the long-time oxidation growth kinetics. The good agreement between the experimental results allows, finally, to strengthen the proposition of a long-term growth kinetic oxidation mechanism of the oxide layers. (O.M.)

  17. Study of the wettability of fusion relevant steels by the sodium potassium eutectic alloy NaK-78

    Directory of Open Access Journals (Sweden)

    Ali Abou-Sena

    2016-12-01

    Full Text Available Several validation activities were dedicated to the High Flux Test Module (HFTM of the International Fusion Materials Irradiation Facility (IFMIF at the Karlsruhe Institute of Technology (KIT in Germany. The HFTM contains 24 capsules packed densely with Eurofer specimens to facilitate their irradiation in the high flux zone directly behind the IFMIF neutron source. The small gaps among the Eurofer specimens are filled by the sodium potassium eutectic alloy NaK-78 to improve the thermal conduction among the specimens and achieve uniform and predictable temperature distribution. As a result of first trials, the filling process of NaK-78 into the specimens’ capsule had been identified as an issue worth further investigations. Therefore, the wettability of the steels Eurofer and SS 316 by NaK-78 is experimentally investigated to evaluate the applicability of this concept and identify the favorable conditions. In the experiment, the capillary rise of NaK-78 in a two-parallel-plates channel (gap is investigated versus the following: (i temperature of both NaK-78 and the parallel plates from 50°C to 350°C, (ii machining techniques used for the parallel plates, (iii thickness of the gap between the plates, and (iv material of the parallel plates including Eurofer and SS 316. The present experimental results will help in defining the working conditions required to achieve an optimal filling of the IFMIF HFTM capsules with NaK-78 and a complete wetting of the capsules’ specimens.

  18. Microstructural Characterization of a Directionally-Solidified Ni-33 (at. %)Al-31Cr-3Mo Eutectic Alloy as a Function of Withdrawal Rate

    Science.gov (United States)

    Raj, S. V.; Locci, I. E.; Whittenberger, J. D.; Salem, J. A.

    2000-01-01

    The Ni-33 (at. %)Al-3lCr-3Mo eutectic alloy was directionally-solidified (DS) at different rates, V(sub I), varying between 2.5 to 508 mm/ h. Detailed qualitative and quantitative metallographic and chemical analyses were conducted on the directionally-solidified rods. The microstructures consisted of eutectic colonies with parallel lamellar NiAl/(Cr,Mo) plates for solidification rates at and below 12.7 mm/ h. Cellular eutectic microstructures were observed at higher solidification rates, where the plates exhibited a radial pattern. The microstructures were demonstrated to be fairly uniform throughout a 100 mm length of the DS zone by quantitative metallography. The average cell size, bar-d, decreased with increasing growth rate to a value of 125 microns at 508 mm/ h according to the relation bar-d (microns) approx. = 465 V(sup -0.22, sub I), where V(sub I) is in mm/ h. Both the average NiAl plate thickness, bar-Delta(sub NiAl), and the interlamellar spacing, bar-lambda, were observed to be constant for V(sub I) less than or = 50.8 mm/ h but decreased with increasing growth rate above this value as 0.93 bar-Delta(sub NiAl)(microns) = 61.2 V(sup -0.93, sub I) and bar-lambda (microns) = 47.7 V(sup -0.64, sub I), respectively. The present results are detailed on a microstructural map. Keywords Optical microscopy, microstructure, compounds intermetallic, directional solidification

  19. Thermal stability and oxidizing properties of mixed alkaline earth-alkali molten carbonates: A focus on the lithium-sodium carbonate eutectic system with magnesium additions

    International Nuclear Information System (INIS)

    Frangini, Stefano; Scaccia, Silvera

    2013-01-01

    Highlights: • TG/DSC analysis was conducted on magnesium-containing eutectic Li/Na eutectic carbonates. • Magnesium influence on the oxygen solubility properties of carbonate was also experimentally determined at 600 °C and 650 °C. • A reproducible partial decarbonation process in premelting region caused formation of magnesium oxycarbonate-like phases. • The acidobase buffering action of magnesium oxycarbonate species could explain the high basic/oxidizing properties of such carbonate melts. • A general correlation between thermal instability in premelting region and basic/oxidizing melt properties was established. - Abstract: A comparative study on thermal behavior and oxygen solubility properties of eutectic 52/48 lithium/sodium carbonate salt containing minor additions of magnesium up to 10 mol% has been made in order to determine whether a general correlation between these two properties can be found or not. Consecutive TG/DSC heating/cooling thermal cycles carried out under alternating CO 2 and N 2 gas flows allowed to assign thermal events observed in the premelting region to a partial decarbonation process of the magnesium-alkali mixed carbonates. The observed decarbonation process at 460 °C is believed to come from initial stage of thermal decomposition of magnesium carbonate resulting in the metastable formation of magnesium oxycarbonate-like phases MgO·2MgCO 3 , in a similar manner as previously reported for lanthanum. Reversible formation and decomposition of the magnesium carbonate phase has been observed under a CO 2 gas atmosphere. The intensity of the decomposition process shows a maximum for a 3 mol% MgO addition that gives also the highest oxygen solubility, suggesting therefore that instability thermal analysis in the premelting region can be considered as providing an effective measure of the basicity/oxidizing properties of alkali carbonate melts with magnesium or, in more general terms, with cations that are strong modifiers of

  20. Do carboximide–carboxylic acid combinations form co-crystals? The role of hydroxyl substitution on the formation of co-crystals and eutectics

    Directory of Open Access Journals (Sweden)

    Ramanpreet Kaur

    2015-05-01

    Full Text Available Carboxylic acids, amides and imides are key organic systems which provide understanding of molecular recognition and binding phenomena important in biological and pharmaceutical settings. In this context, studies of their mutual interactions and compatibility through co-crystallization may pave the way for greater understanding and new applications of their combinations. Extensive co-crystallization studies are available for carboxylic acid/amide combinations, but only a few examples of carboxylic acid/imide co-crystals are currently observed in the literature. The non-formation of co-crystals for carboxylic acid/imide combinations has previously been rationalized, based on steric and computed stability factors. In the light of the growing awareness of eutectic mixtures as an alternative outcome in co-crystallization experiments, the nature of various benzoic acid/cyclic imide combinations is established in this paper. Since an additional functional group can provide sites for new intermolecular interactions and, potentially, promote supramolecular growth into a co-crystal, benzoic acids decorated with one or more hydroxyl groups have been systematically screened for co-crystallization with one unsaturated and two saturated cyclic imides. The facile formation of an abundant number of hydroxybenzoic acid/cyclic carboximide co-crystals is reported, including polymorphic and variable stoichiometry co-crystals. In the cases where co-crystals did not form, the combinations are shown invariably to result in eutectics. The presence or absence and geometric disposition of hydroxyl functionality on benzoic acid is thus found to drive the formation of co-crystals or eutectics for the studied carboxylic acid/imide combinations.

  1. Do carboximide-carboxylic acid combinations form co-crystals? The role of hydroxyl substitution on the formation of co-crystals and eutectics.

    Science.gov (United States)

    Kaur, Ramanpreet; Gautam, Raj; Cherukuvada, Suryanarayan; Guru Row, Tayur N

    2015-05-01

    Carboxylic acids, amides and imides are key organic systems which provide understanding of molecular recognition and binding phenomena important in biological and pharmaceutical settings. In this context, studies of their mutual interactions and compatibility through co-crystallization may pave the way for greater understanding and new applications of their combinations. Extensive co-crystallization studies are available for carboxylic acid/amide combinations, but only a few examples of carboxylic acid/imide co-crystals are currently observed in the literature. The non-formation of co-crystals for carboxylic acid/imide combinations has previously been rationalized, based on steric and computed stability factors. In the light of the growing awareness of eutectic mixtures as an alternative outcome in co-crystallization experiments, the nature of various benzoic acid/cyclic imide combinations is established in this paper. Since an additional functional group can provide sites for new intermolecular inter-actions and, potentially, promote supramolecular growth into a co-crystal, benzoic acids decorated with one or more hydroxyl groups have been systematically screened for co-crystallization with one unsaturated and two saturated cyclic imides. The facile formation of an abundant number of hydroxybenzoic acid/cyclic carboximide co-crystals is reported, including polymorphic and variable stoichiometry co-crystals. In the cases where co-crystals did not form, the combinations are shown invariably to result in eutectics. The presence or absence and geometric disposition of hydroxyl functionality on benzoic acid is thus found to drive the formation of co-crystals or eutectics for the studied carboxylic acid/imide combinations.

  2. Cu Nanoparticles Improved Thermal Property of Form-Stable Phase Change Materials Made with Carbon Nanofibers and LA-MA-SA Eutectic Mixture.

    Science.gov (United States)

    Song, Xiaofei; Cai, Yibing; Huang, Cong; Gu, Ying; Zhang, Junhao; Qiao, Hui; Wei, Qufu

    2018-04-01

    A novel form-stable phase change materials (FSPCMs) was fabricated by incorporating fatty acid eutectics with electrospun carbon nanofibers (CNFs) surface-attached with copper (Cu) nanoparticles. Three different Cu/CNFs mats were made through combining the technique and principle of electrospinning, pre-oxidation/carbonization and in-situ reduction, while lauric-myristic-stearic acid (LA-MA-SA) ternary eutectic mixture was prepared as the model PCM. The morphology and crystal structure of Cu/CNFs were characterized by Fourier transfer infrared (FT-IR) spectra, Scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray energy dispersive spectroscopy (EDS), respectively. The results showed that Cu nanoparticles dispersed uniformly on the surface of CNFs mats without agglomeration, and Cu/CNFs mats could provide the mechanical support for FSPCMs and effectively prevent the flow/leakage of molten fatty acid. Morphological structures, as well as the properties of thermal energy storage and thermal energy storage/retrieval rates, of the resulting FSPCMs were investigated by SEM, Differential scanning calorimetry (DSC), and measurement of melting/freezing times, respectively. The results indicated that the fabricated FSPCMs exhibited desired structural morphology, and LA-MA-SA well dispersed in three-dimensional porous structure of Cu/CNFs mats. The melting and crystallization enthalpies of the fabricated FSPCMs were in the range of 117.1-140.7 kJ/kg and 117.2-142.4 kJ/kg, respectively. In comparison with melting/freezing times of LA-MA-SA ternary eutectic mixture, the melting/freezing times of fabricated FSPCMs were respectively decreased ~27.0-49.2% and ~44.1-63.0%. The fabricated FSPCMs possessed good thermal energy storage/retrieval property, and might have great potential for renewable energy storage applications.

  3. Temperature effect on fluorescence and UV-vis absorption spectroscopic properties of Dy(III) in molten LiCl-KCl eutectic salt

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Young [Department of Nuclear and Quantum Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Yun, Jong-Il, E-mail: jiyun@kaist.ac.kr [Department of Nuclear and Quantum Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2012-11-15

    The spectroscopic properties of Dy(III) in molten LiCl-KCl eutectic salt at high temperature were investigated by time-resolved laser fluorescence spectroscopy (TRLFS) and UV-vis absorption spectroscopy. For the first time, a visible fluorescence of Dy(III) in high-temperature LiCl-KCl eutectic salt was measured due to the electronic transitions from {sup 4}I{sub 13/2} and {sup 4}F{sub 9/2} to {sup 6}H{sub J/2} (J=7, Horizontal-Ellipsis ,15). The effect of temperature on hypersensitivity for the electronic transitions from the {sup 4}I{sub 13/2} excited state ({approx}25700 cm{sup -1}) of Dy(III) was confirmed by altering temperature in chloride eutectic salt in accord with optical absorption measurements. The molar absorptivity of {sup 4}I{sub 13/2} Leftwards-Arrow {sup 6}H{sub 15/2} was enhanced with increasing temperature. The fluorescence intensity of Dy(III) followed a simple mono-exponential decay curve, suggesting the formation of a single chemical species in high-temperature LiCl-KCl molten salt. - Highlights: Black-Right-Pointing-Pointer Spectroscopic characteristics of Dy(III) in the high-temperature LiCl-KCl salt. Black-Right-Pointing-Pointer In-situ chemical analysis of Dy(III) by fluorescence and absorbance measurement. Black-Right-Pointing-Pointer Temperature effect on hypersensitivity for electronic transitions from {sup 4}I{sub 13/2} excited state. Black-Right-Pointing-Pointer Single chemical species of Dy(III) exists in high-temperature LiCl-KCl salt.

  4. Rheological Analysis of Binary Eutectic Mixture of Sodium and Potassium Nitrate and the Effect of Low Concentration CuO Nanoparticle Addition to Its Viscosity

    Directory of Open Access Journals (Sweden)

    Mathieu Lasfargues

    2015-08-01

    Full Text Available This paper is focused on the characterisation and demonstration of Newtonian behaviour of salt at both high and low shear rate for sodium and potassium nitrate eutectic mixture (60/40 ranging from 250 °C to 500 °C. Analysis of published and experimental data was carried out to correlate all the numbers into one meaningful 4th order polynomial equation. Addition of a low amount of copper oxide nanoparticles to the mixture increased viscosity of 5.0%–18.0% compared to the latter equation.

  5. Construction and analysis of dynamic solidification curves for non-equilibrium solidification process in lost-foam casting hypo-eutectic gray cast iron

    Directory of Open Access Journals (Sweden)

    Ming-guo Xie

    2017-05-01

    Full Text Available Most lost-foam casting processes involve non-equilibrium solidification dominated by kinetic factors, while construction of a common dynamic solidification curve is based on pure thermodynamics, not applicable for analyses and research of non-equilibrium macro-solidification processes, and the construction mode can not be applied to non-equilibrium solidification process. In this study, the construction of the dynamic solidification curve (DSC for the non-equilibrium macro-solidification process included: a modified method to determine the start temperature of primary austenite precipitation (TAL and the start temperature of eutectic solidification (TES; double curves method to determine the temperature of the dendrite coherency point of primary austenite (TAC and the temperature of eutectic cells collision point (TEC; the “technical solidus” method to determine the end temperature of eutectic reaction (TEN. For this purpose, a comparative testing of the non-equilibrium solidification temperature fields in lost-foam casting and green sand mold casting hypoeutectic gray iron was carried out. The thermal analysis results were used to construct the DSCs of both these casting methods under non-equilibrium solidification conditions. The results show that the transformation rate of non-equilibrium solidification in hypoeutectic gray cast iron is greater than that of equilibrium solidification. The eutectic solidification region presents a typical mushy solidification mode. The results also indicate that the primary austenite precipitation zone of lost-foam casting is slightly larger than that of green sand casting. At the same time, the solid fraction (fs of the dendrite coherency points in lost-foam casting is greater than that in the green sand casting. Therefore, from these two points, lost-foam casting is more preferable for reduction of shrinkage and mechanical burnt-in sand tendency of the hypoeutectic gray cast iron. Due to the fact that

  6. Rheological Analysis of Binary Eutectic Mixture of Sodium and Potassium Nitrate and the Effect of Low Concentration CuO Nanoparticle Addition to Its Viscosity.

    Science.gov (United States)

    Lasfargues, Mathieu; Cao, Hui; Geng, Qiao; Ding, Yulong

    2015-08-11

    This paper is focused on the characterisation and demonstration of Newtonian behaviour of salt at both high and low shear rate for sodium and potassium nitrate eutectic mixture (60/40) ranging from 250 °C to 500 °C. Analysis of published and experimental data was carried out to correlate all the numbers into one meaningful 4th order polynomial equation. Addition of a low amount of copper oxide nanoparticles to the mixture increased viscosity of 5.0%-18.0% compared to the latter equation.

  7. Idaho National Laboratory Lead or Lead-Bismuth Eutectic (LBE) Test Facility - R&D Requirements, Design Criteria, Design Concept, and Concept Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Eric P. Loewen; Paul Demkowicz

    2005-05-01

    The Idaho National Laboratory Lead-Bismuth Eutectic Test Facility will advance the state of nuclear technology relative to heavy-metal coolants (primarily Pb and Pb-Bi), thereby allowing the U.S. to maintain the pre-eminent position in overseas markets and a future domestic market. The end results will be a better qualitative understanding and quantitative measure of the thermal physics and chemistry conditions in the molten metal systems for varied flow conditions (single and multiphase), flow regime transitions, heat input methods, pumping requirements for varied conditions and geometries, and corrosion performance. Furthering INL knowledge in these areas is crucial to sustaining a competitive global position. This fundamental heavy-metal research supports the National Energy Policy Development Group’s stated need for energy systems to support electrical generation.1 The project will also assist the Department of Energy in achieving goals outlined in the Nuclear Energy Research Advisory Committee Long Term Nuclear Technology Research and Development Plan,2 the Generation IV Roadmap for Lead Fast Reactor development, and Advanced Fuel Cycle Initiative research and development. This multi-unit Lead-Bismuth Eutectic Test Facility with its flexible and reconfigurable apparatus will maintain and extend the U.S. nuclear knowledge base, while educating young scientists and engineers. The uniqueness of the Lead-Bismuth Eutectic Test Facility is its integrated Pool Unit and Storage Unit. This combination will support large-scale investigation of structural and fuel cladding material compatibility issues with heavy-metal coolants, oxygen chemistry control, and thermal hydraulic physics properties. Its ability to reconfigure flow conditions and piping configurations to more accurately approximate prototypical reactor designs will provide a key resource for Lead Fast Reactor research and development. The other principal elements of the Lead-Bismuth Eutectic Test Facility

  8. Double freezing of (NH(4))(2)SO(4)/H(2)O droplets below the eutectic point and the crystallization of (NH(4))(2)SO(4) to the ferroelectric phase.

    Science.gov (United States)

    Bogdan, A

    2010-09-23

    This paper presents the differential scanning calorimetry (DSC) results obtained from measurements of single droplets of different subeutectic concentrations (freezing of the droplets takes place below the eutectic temperature of Te ≈ 254.5 K, a phase separation into ice and a residual freeze-concentrated solution occurs. The residual solution is formed by the expulsion of NH4+ and SO42- ions from the ice lattice during the nucleation and growth of ice and may possess the eutectic concentration of 40 wt % (NH4)2SO4. On further cooling, the residual solution freezes to the eutectic solid mixture of ice/(NH4)2SO4 at a temperature that is either above or below the ferroelectric "Curie" temperature of Tc ≈ 223 K. If the freezing of the residual solution takes place below the Tc, then (NH4)2SO4 crystallizes directly into the ferroelectric phase.

  9. Uranium hexafluoride liquid thermal expansion, elusive eutectic with hydrogen fluoride, and very first production using chlorine trifluoride

    Energy Technology Data Exchange (ETDEWEB)

    Rutledge, G.P. [Central Environmental, Inc., Anchorage, AK (United States)

    1991-12-31

    Three unusual incidents and case histories involving uranium hexafluoride in the enrichment facilities of the USA in the late 1940`s and early 1950`s are presented. The history of the measurements of the thermal expansion of liquids containing fluorine atoms within the molecule is reviewed with special emphasis upon uranium hexafluoride. A comparison is made between fluorinated esters, fluorocarbons, and uranium hexafluoride. The quantitative relationship between the thermal expansion coefficient, a, of liquids and the critical temperature, T{sub c} is presented. Uranium hexafluoride has an a that is very high in a temperature range that is used by laboratory and production workers - much higher than any other liquid measured. This physical property of UF{sub 6} has resulted in accidents involving filling the UF{sub 6} containers too full and then heating with a resulting rupture of the container. Such an incident at a uranium gaseous diffusion plant is presented. Production workers seldom {open_quotes}see{close_quotes} uranium hexafluoride. The movement of UF{sub 6} from one container to another is usually trailed by weight, not sight. Even laboratory scientists seldom {open_quotes}see{close_quotes} solid or liquid UF{sub 6} and this can be a problem at times. This inability to {open_quotes}see{close_quotes} the UF{sub 6}-HF mixtures in the 61.2{degrees}C to 101{degrees}C temperature range caused a delay in the understanding of the phase diagram of UF{sub 6}-HF which has a liquid - liquid immiscible region that made the eutectic composition somewhat elusive. Transparent fluorothene tubes solved the problem both for the UF{sub 6}-HF phase diagram as well as the UF{sub 6}-HF-CIF{sub 3} phase diagram with a miscibility gap starting at 53{degrees}C. The historical background leading to the first use of CIF{sub 3} to produce UF{sub 6} in both the laboratory and plant at K-25 is presented.

  10. Environmentally friendly and non-polluting solvent pretreatment of palm samples for polyphenol analysis using choline chloride deep eutectic solvents.

    Science.gov (United States)

    Fu, Najing; Lv, Runqiu; Guo, Zhixin; Guo, Yiwei; You, Xiaoyu; Tang, Baokun; Han, Dandan; Yan, Hongyuan; Row, Kyung Ho

    2017-04-07

    In this work, choline chloride (ChCl) deep eutectic solvents (DESs) were evaluated for the pretreatment of palm samples in the analysis of polyphenols, such as protocatechuic acid, catechins, epicatechin, and caffeic acid. During the enrichment step of the pretreatment, eight DESs comprising ChCl with ethylene glycol (EG), glycerol (Gly), xylitol (Xyl), phenol (Ph), formic acid (FA), citric acid (CiA), oxalic acid (OA), or malonic acid (MA), were prepared and applied to the reflux extraction of polyphenols from palm samples. All the DESs exhibited higher polyphenol extraction efficiency than methanol, and the highest extraction efficiency was obtained using ChCl-FA (1:1, mole ratio). For the purification step of the pretreatment, eight ChCl DES-modified adsorbents were prepared by hydrothermal polymerization and packed into solid-phase extraction (SPE) cartridges, and ChCl-Urea, ChCl-Gly, ChCl-FA, and water, were used as eluents. The ChCl DES-modified adsorbents were characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy, and Brunauer-Emmett-Teller surface analysis, and the polyphenols were analyzed by mass spectrometry and high-performance liquid chromatograph-ultraviolet detection. The highest purification efficiency was obtained using the ChCl-Ph DES-modified adsorbent as the SPE packing material and ChCl-Urea-H 2 O (1:1:5, mole ratio), ChCl-Gly (1:1, mole ratio), ChCl-FA-H 2 O (1:1:5, mole ratio), and H 2 O as the eluents. Compared to conventional purification processes that employ commercial C 18 or C 8 SPE columns with organic solvents as eluents, the ChCl DES-based SPE purification process successfully avoided the use of expensive commercial SPE columns and organic solvents. Furthermore, it isolated a larger amount of the target compounds under the same experimental conditions, and could be applied over five cycles with good reversibility. This work indicates that DESs as green solvents have great

  11. Liquidus projection of the Nb-Cr-Al system near the Al3(Nb,Cr) + Cr(Al,Nb) eutectic region

    International Nuclear Information System (INIS)

    Souza, S.A.; Ferrandini, P.L.; Nunes, C.A.; Coelho, A.A.; Caram, R.

    2006-01-01

    The system Nb-Cr-Al was investigated in the region near the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic and the liquidus projection of that region was determined based on the microstructural characterization of arc melted alloys. The characterization utilized scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential thermal analysis (DTA) and X-ray diffraction (XRD). The results allowed one to determine three primary solidification liquidus surfaces ((Cr,Al) 2 Nb, Cr(Al,Nb) and Al 3 (Nb,Cr)), that are originated from the binary systems Cr-Nb, Cr-Al and Al-Nb. It is proposed the occurrence of the invariant reaction L + (Cr,Al) 2 Nb ↔ Al 3 (Nb,Cr) + Cr(Al,Nb) and of a point of minimum, which involves a three phase reaction, L ↔ Al 3 (Nb,Cr) + Cr(Al,Nb). All alloys studied showed formation of the Al 3 (Nb,Cr) + Cr(Al,Nb) eutectic as the last solidification step with Al(Nb)Cr 2 precipitating from Cr(Al,Nb)

  12. Optimization of Controllable Factors in the Aluminum Silicon Eutectic Paste and Rear Silicon Nitride Mono-Passivation Layer of PERC Solar Cells

    Science.gov (United States)

    Park, Sungeun; Park, Hyomin; Kim, Dongseop; Yang, JungYup; Lee, Dongho; Kim, Young-Su; Kim, Hyun-Jong; Suh, Dongchul; Min, Byoung Koun; Kim, Kyung Nam; Park, Se Jin; Kim, Donghwan; Lee, Hae-Seok; Nam, Junggyu; Kang, Yoonmook

    2018-03-01

    Passivated emitter and rear contact (PERC) is a promising technology owing to high efficiency can be achieved with p-type wafer and their easily applicable to existing lines. In case of using p-type mono wafer, 0.5-1% efficiency increase is expected with PERC technologies compared to existing Al BSF solar cells, while for multi-wafer solar cells it is 0.5-0.8%. We addressed the optimization of PERC solar cells using the Al paste. The paste was prepared from the aluminum-silicon alloy with eutectic composition to avoid the formation of voids that degrade the open-circuit voltage. The glass frit of the paste was changed to improve adhesion. Scanning electron microscopy revealed voids and local back surface field between the aluminum electrode and silicon base. We confirmed the conditions on the SiNx passivation layer for achieving higher efficiency and better adhesion for long-term stability. The cell characteristics were compared across cells containing different pastes. PERC solar cells with the Al/Si eutectic paste exhibited the efficiency of 19.6%.

  13. Vortex assisted deep eutectic solvent (DES)-emulsification liquid-liquid microextraction of trace curcumin in food and herbal tea samples.

    Science.gov (United States)

    Aydin, Funda; Yilmaz, Erkan; Soylak, Mustafa

    2018-03-15

    We developed a new microextraction method for separation and preconcentration of curcumin using deep eutectic solvent known as green solvent. Deep eutectic solvent (DES) formed by mixing of choline chloride and phenol was used as an extraction solvent in microextraction study to extract the curcumin at pH 4.0. The curcumin concentration in enriched DES phase was analyzed by UV-Visible spectrophotometer. The effect of parameters such as pH, mol ratio of DES composition, volume of DES, volume of tetrahydrofuran (THF) and sample volume were examined. Interference effects of matrix components were investigated. The preconcentration factor was 12.5. The detection limit of method (n = 10) was 2.86 µg L -1 and the relative standard deviation (RSD, n = 8) was 1.8%. The method was successfully applied to determination of curcumin in food and herbal tea samples. The mean recoveries were between 96% and 102% and standard deviations were found in the range of 1-6%. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2004-01-01

    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 . The interface between NiAl and lamellar Cr(Mo) did not have any transition layers. Misfit dislocations were observed at the NiAl-Cr(Mo) interface. In addition to lamellar Cr(Mo) phases, coherent Cr(Mo, Ni, Al) precipitates and NiAl precipitates were also observed in the NiAl matrix and lamellar Cr(Mo) phases, respectively. After hot isostatic pressing and heat treatment, the NiAl-Cr(Mo) interfaces became smooth and straight. Square array of misfit dislocations was directly observed at the (0 0 1) interface between NiAl and Cr(Mo, Ni, Al) precipitate. The configuration of misfit dislocation network showed a generally good agreement with prediction based on the geometric O-lattice model

  15. First principles study of the thermodynamic and kinetic properties of U in an electrorefining system using molybdenum cathode and LiCl-KCl eutectic molten salt

    International Nuclear Information System (INIS)

    Kwon, Choah; Kang, Joonhee; Kang, Woojong; Kwak, Dohyun; Han, Byungchan

    2016-01-01

    Using first principles density functional theory (DFT) calculations we obtain thermodynamic and kinetic properties of U in an electrorefining process for spent nuclear fuels using a LiCl-KCl eutectic molten salt and Mo as a cathode. The thermodynamic stability of electrodeposited U from the molten salt onto the Mo(110) surface electrode is evaluated by activity coefficients as function of surface coverages of U and Cl. Additionally, ab-initio molecular dynamic simulations combined with the Stokes-Einstein-Sutherland relation enables us to calculate the viscosity of the LiCl-KCl eutectic molten salt. Our results well agree with previously reported experimental data endorsing the credibility. Based on our atomic-level mechanical understanding we propose that an accurate computational model system incorporating the electrochemical conditions of the electrorefining process essential for the purpose of establishing thermodynamic and kinetic database of U, otherwise critical deviations are inevitable. More interestingly, the effect of coadsorption of Cl with U on the Mo(110) surface plays a key role in stabilizing electrodeposited U on the cathode. Our approach can be useful for validating published experimental database and for identifying key factors guiding a rational design of highly efficient electrorefining system for spent nuclear fuels, and thus reducing high-level radioactive nuclear wastes.

  16. Spectroscopic and thermal investigations of the fluoroaluminate complex formation in NaF-KF and LiF-NaF-KF eutectics.

    Science.gov (United States)

    von Barner, J H; Bessada, C; Berg, R W

    2003-03-24

    The dissolution and complex formation of fluoroaluminates in two eutectic alkalifluoride mixtures, NaF-KF (FNAK) and LiF-NaF-KF (FLINAK), have been investigated by Raman, NMR, and thermal analysis. Melting and dissolution took place stepwise. The eutectic alkalifluoride mixtures with minor amounts of dissolved fluoroaluminate salts started melting at around 460 and 740 degrees C for FLINAK and FNAK mixtures, respectively. Total melting/dissolution of mixtures with 9-11 mol % aluminum fluoro salts added took place near 780 degrees C in the FLINAK solvent and at approximately 900 degrees C for FNAK solutions. The solidified melts were characterized by Raman bands at 561 (nu(1)), 391 (nu(2)), and 328 cm(-1) (nu(5)) and a (27)Al NMR chemical shift near 0 ppm originating from isolated AlF(6)(3-) octahedral ions. The Raman and NMR signals due to AlF(6)(3-) were also observed at temperatures where the samples were only partly melted. Upon total melting, a pronounced dissociation of AlF(6)(3-) into AlF(5)(2-) and fluoride ions took place. At even higher temperatures, the equilibrium was displaced in favor of AlF(5)(2-) in the FNAK solvent. The AlF(5)(2-) ion was characterized by an intensive Raman band at 558 cm(-1) and an increasingly positive (27)Al chemical shift with raising temperature, e.g., of 16 ppm at 935 degrees C.

  17. Preparation of porous lead from shape-controlled PbO bulk by in situ electrochemical reduction in ChCl-EG deep eutectic solvent

    Science.gov (United States)

    Ru, Juanjian; Hua, Yixin; Xu, Cunying; Li, Jian; Li, Yan; Wang, Ding; Zhou, Zhongren; Gong, Kai

    2015-12-01

    Porous lead with different shapes was firstly prepared from controlled geometries of solid PbO bulk by in situ electrochemical reduction in choline chloride-ethylene glycol deep eutectic solvents at cell voltage 2.5 V and 353 K. The electrochemical behavior of PbO powders on cavity microelectrode was investigated by cyclic voltammetry. It is indicated that solid PbO can be directly reduced to metal in the solvent and a nucleation loop is apparent. Constant voltage electrolysis demonstrates that PbO pellet can be completely converted to metal for 13 h, and the current efficiency and specific energy consumption are about 87.79% and 736.82 kWh t-1, respectively. With the electro-deoxidation progress on the pellet surface, the reduction rate reaches the fastest and decreases along the distance from surface to inner center. The morphologies of metallic products are porous and mainly consisted of uniform particles which connect with each other by finer strip-shaped grains to remain the geometry and macro size constant perfectly. In addition, an empirical model of the electro-deoxidation process from spherical PbO bulk to porous lead is also proposed. These findings provide a novel and simple route for the preparation of porous metals from oxide precursors in deep eutectic solvents at room temperature.

  18. A cellular automaton - finite volume method for the simulation of dendritic and eutectic growth in binary alloys using an adaptive mesh refinement

    Science.gov (United States)

    Dobravec, Tadej; Mavrič, Boštjan; Šarler, Božidar

    2017-11-01

    A two-dimensional model to simulate the dendritic and eutectic growth in binary alloys is developed. A cellular automaton method is adopted to track the movement of the solid-liquid interface. The diffusion equation is solved in the solid and liquid phases by using an explicit finite volume method. The computational domain is divided into square cells that can be hierarchically refined or coarsened using an adaptive mesh based on the quadtree algorithm. Such a mesh refines the regions of the domain near the solid-liquid interface, where the highest concentration gradients are observed. In the regions where the lowest concentration gradients are observed the cells are coarsened. The originality of the work is in the novel, adaptive approach to the efficient and accurate solution of the posed multiscale problem. The model is verified and assessed by comparison with the analytical results of the Lipton-Glicksman-Kurz model for the steady growth of a dendrite tip and the Jackson-Hunt model for regular eutectic growth. Several examples of typical microstructures are simulated and the features of the method as well as further developments are discussed.

  19. Photo- and radio-excited luminescence properties of Eu-doped La2O3–Al2O3 based eutectics

    International Nuclear Information System (INIS)

    Fujimoto, Yutaka; Kamada, Kei; Yanagida, Takayuki; Wakahara, Shingo; Suzuki, Shotaro; Kurosawa, Shunsuke; Yoshikawa, Akira

    2013-01-01

    Eutectic crystal of 0.5% Eu-doped 30LaAlO 3 –70Al 2 O 3 (vol %) was prepared by micro-pulling down (μ-PD) technique under nitrogen atmosphere. Being excited at a wavelength of 320 nm, the crystal exhibited intense emission band with a maximum at 450 nm which is corresponding to 4f 6 5d-4f 7 ( 8 S 7/2 ) transitions of Eu 2+ . The decay time and fluorescence quantum efficiency (QE) were determined to be about 475 ns and 60%, respectively. When alpha-ray excited the crystal, both Eu 2+ 4f 6 5d-4f 7 ( 8 S 7/2 ) and Eu 3+ 4f 6 -4f 6 ( 5 D 0 - 7 F 1,2 ) emission peaks were observed at 435 nm and 600 nm. By the pulse height spectra, the relative scintillation light yield of the crystal was about 4% compared with that of BGO commercial scintillator. -- Highlights: •0.5% Eu-doped 30LaAlO 3 –70Al 2 O 3 eutectic crystal was grown by μ-PD technique. •The crystal showed intense Eu 2+ 5d-4f emission at 450 nm under excited at 320 nm. •The fluorescence quantum efficiency was calculated to be about 60%. •The scintillation light yield was about 4% compared with that of BGO scintillator

  20. A new approach to obtain strip-structured biepitaxial YBa2Cu3O7-δ films by using Ca-stabilized zirconia-CaZrO3 eutectic substrates

    International Nuclear Information System (INIS)

    Santiso, J.; Doudkowsky, M.; Garcia, G.; Figueras, A.; Laukhin, V.; Angurel, L.A.; Merino, R.I.; Pena, J.I.; Sanjuan, M.L.; Orera, V.M.

    2000-01-01

    Biepitaxial thin films of the superconductor YBa 2 Cu 3 O 7-δ (YBCO) have been prepared in a single deposition step using structured eutectic crystals as substrates. A regular alternating strip pattern of grain boundary junctions can be observed that reproduces the substrate pattern. The films show an anisotropy of transport properties in the superconducting and normal states. (orig.)

  1. Eutectic gamma (Nickel)/gamma vprime(Nickel Aluminide) delta (Nickel Niobium) polycrystalline nickel-base superalloys: Chemistry, processing, microstructure and properties

    Science.gov (United States)

    Xie, Mengtao

    Directionally solidified (D.S.) gamma(Ni)/gamma'(Ni 3A1)-delta(Ni3Nb) eutectic alloys were considered as candidate turbine blade materials. Currently, the properties of polycrystalline gamma/gamma'-delta alloys are of interest as they inherit many advantageous attributes from the D.S. gamma/gamma'-delta alloys. This thesis is therefore dedicated towards the development of a fundamental understanding of these novel eutectic alloys from several important perspectives. This thesis will first be focused on quantifying the effect of several elements. A set of Ni-Cr-Al-Nb alloy compositions with increasing levels of Cr was designed to investigate the influence of Cr on the primary phase formation, solidus and liquidus temperatures and g-d eutectic morphology. A matrix of complex gamma/gamma'-delta alloy compositions with the same (Ta+Nb) content but varying Ta/Nb ratios was designed to study the influence of Ta on elemental segregation and solid state partitioning behaviors. Thermodynamic predicaitons using the Computherm Pandat database (PanNi7) were compared to experimental results in these investigations. The second part of this thesis will provide a more general understanding of the effects of common elements. A large number of experimental alloys covering a broad range of compositions were selected for the analysis. Important alloy attributes were characterized as a function of element concentration. Linear regression analysis was performed to reveal the relative effectiveness of different elements. An extensive comparison between the experimental observations and Pandat predictions was provided to critically evaluate the strength and weakness of existing thermodynamic database model in this novel alloy system. The last part of this thesis emphasizes the development of cast and wrought processes for cast gamma/gamma'-delta alloys as a cost effective alternative to the powder metallurgy route. Hot rolling of workpieces encapsulated within a steel can was performed on

  2. Eutectic Nano-Droplet Template Injection into Bulk Silicon to Construct Porous Frameworks with Concomitant Conformal Coating as Anodes for Li-Ion Batteries

    Science.gov (United States)

    Qu, Fei; Li, Chilin; Wang, Zumin; Wen, Yuren; Richter, Gunther; Strunk, Horst P.

    2015-05-01

    Building porosity in monolithic materials is highly desired to design 3D electrodes, however ex-situ introduction or in-situ generation of nano-scale sacrificial template is still a great challenge. Here Al-Si eutectic droplet templates are uniformly injected into bulk Si through Al-induced solid-solid convection to construct a highly porous Si framework. This process is concomitant with process-inherent conformal coating of ion-conductive oxide. Such an all-in-one method has generated a (continuously processed) high-capacity Si anode integrating longevity and stable electrolyte-anode diaphragm for Li-ion batteries (e.g. a reversible capacity as large as ~1800 mAh/g or ~350 μAh/cm2-μm with a CE of ~99% at 0.1 C after long-term 400 cycles).

  3. Density of molten salt Mixtures of eutectic LiCl-KCl containing UCl{sub 3}, CeCl{sub 3}, or LaCl{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, C.; Simpson, M. F. [Dept. of Metallurgical Engineering, University of Utah, Salt Lake City (United States)

    2017-06-15

    Densities of molten salt mixtures of eutectic LiCl-KCl with UCl{sub 3}, CeCl{sub 3}, or LaCl{sub 3} at various concentrations (up to 13 wt%) were measured using a liquid surface displacement probe. Linear relationships between the mixture density and the concentration of the added salt were observed. For LaCl{sub 3} and CeCl{sub 3}, the measured densities were signifcantly higher than those previously reported from Archimedes’ method. In the case of LiCl-KCl-UCl{sub 3}, the data ft the ideal mixture density model very well. For the other salts, the measured densities exceeded the ideal model prediction by about 2%.

  4. An Electrochemical Study of Lanthanide Elements in LiCl-KCl Eutectic Molten Salt to Convert All The Spent Nuclear Fuel into Low and Intermediate Level Waste

    International Nuclear Information System (INIS)

    Bae, Judong; Hwang, Il Soon; Park, Byung Gi; Hong, Kwang

    2010-01-01

    An additional unit step for the residual actinide recovery, designated as 'Pyro-Reisodex', was proposed to convert all the spent nuclear waste into low and intermediated level water by achieving high decontamination factor for TRH elements. The measurement of basic material properties of lanthanide elements in LiCl-KCl eutectic molten salt is necessary to evaluate the performance of the step. Thus, standard potential, activity coefficient, and diffusion coefficient of lanthanide elements is being tried to determine using conventional electrochemical methods. The cycle voltammetry was measured for LiCl-KCl-SmCl 3 mixture and the standard potential, activity coefficient, and diffusion coefficient of this system was determined from the voltammogram data. The calculated data was well-agreed with reference. Based on this results, another techniques for other lanthanide elements will be applied for better understanding of LiCl-KCl-LnCl n system

  5. Effects of neutron irradiation on mechanical properties of silicon carbide composites fabricated by nano-infiltration and transient eutectic-phase process

    International Nuclear Information System (INIS)

    Koyanagi, T.; Hinoki, T.; Shimoda, K.; Ozawa, K.; Katoh, Y.

    2014-01-01

    Unidirectional silicon carbide (SiC)-fiber-reinforced SiC matrix (SiC/SiC) composites fabricated by a nano-infiltration and transient eutectic-phase (NITE) process were irradiated with neutrons at 830°C to 5.9 dpa, and at 1270°C to 5.8 dpa. The in-plane and trans-thickness tensile and the inter-laminar shear properties were evaluated at ambient temperature. The mechanical characteristics, including the quasi-ductile behavior, the proportional limit stress, and the ultimate tensile strength, were retained subsequent to irradiation. Analysis of the stress–strain hysteresis loop indicated the increased fiber/matrix interface friction and the decreased residual stresses. The inter-laminar shear strength exhibited a significant decrease following irradiation. (author)

  6. Thermal shock and thermal fatigue resistant ZrO2/Al2O3 ceramics in the eutectic composition range. Pt. 1

    International Nuclear Information System (INIS)

    Liu, T.; Dorfschmidt, K.; Oberacker, R.

    1992-01-01

    Thermal shock and thermal fatigue resistant ZrO 2 /Al 2 O 3 ceramics in the eutectic composition range have been prepared and characterized in this work. The microstructures such as chemical composition (Al 2 O 3 -content), stabilizer (Y 2 O 3 , CeO 2 ), porosity, grain size and crack configuration (duplex, dendrite microstructure) have been varied systematically by different processing techniques. Mechanical properties such as Youngs modulus, bending strength, fracture toughness and R-curve behaviour have been investigated. Interrelations between the above microstructures and the mechanical properties have been established. Optimized combination of high toughness and high strength has been reached in crack free, fine-grained Ce-stabilized ZA-materials. On the other hand pronounced inelastic behaviour has been measured by optimization of the crack configuration in the duplex and dendrite microstructures. 6 refs., 1 tab., 10 figs

  7. Unique low-molecular-weight lignin with high purity extracted from wood by deep eutectic solvents (DES): a source of lignin for valorization

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Vasco, Carlos; Ma, Ruoshui; Quintero, Melissa; Guo, Mond; Geleynse, Scott; Ramasamy, Karthikeyan K.; Wolcott, Michael; Zhang, Xiao

    2016-01-01

    This paper reports a new method of applying Deep Eutectic Solvents (DES) for extracting lignin from woody biomass with high yield and high purity. DES mixtures prepared from Choline Chloride (ChCl) and four hydrogen-bond donors–acetic acid, lactic acid, levulinic acid and glycerol–were evaluated for treatment of hardwood (poplar) and softwood (D. fir). It was found that these DES treatments can selectively extract a significant amount of lignin from wood with high yields: 78% from poplar and 58% from D. fir. The extracted lignin has high purity (95%) with unique structural properties. We discover that DES can selectively cleave ether linkages in wood lignin and facilitate lignin removal from wood. The mechanism of DES cleavage of ether bonds between phenylpropane units was investigated. The results from this study demonstrate that DES is a promising solvent for wood delignification and the production of a new source of lignin with promising potential applications.

  8. Investigating microstructural evolution during the electroreduction of UO{sub 2} to U in LiCl-KCl eutectic using focused ion beam tomography

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.D.; Abdulaziz, R.; Tjaden, B.; Inman, D.; Brett, D.J.L.; Shearing, P.R., E-mail: p.shearing@ucl.ac.uk

    2016-11-15

    Reprocessing of spent nuclear fuels using molten salt media is an attractive alternative to liquid-liquid extraction techniques. Pyroelectrochemical processing utilizes direct, selective, electrochemical reduction of uranium dioxide, followed by selective electroplating of a uranium metal. Thermodynamic prediction of the electrochemical reduction of UO{sub 2} to U in LiCl-KCl eutectic has shown to be a function of the oxide ion activity. The pO{sup 2−} of the salt may be affected by the microstructure of the UO{sub 2} electrode. A uranium dioxide filled “micro-bucket” electrode has been partially electroreduced to uranium metal in molten lithium chloride-potassium chloride eutectic. This partial electroreduction resulted in two distinct microstructures: a dense UO{sub 2} and a porous U metal structure were characterised by energy dispersive X-ray spectroscopy. Focused ion beam tomography was performed on five regions of this electrode which revealed an overall porosity ranging from 17.36% at the outer edge to 3.91% towards the centre, commensurate with the expected extent of reaction in each location. The pore connectivity was also seen to reduce from 88.32% to 17.86% in the same regions and the tortuosity through the sample was modelled along the axis of propagation of the electroreduction, which was seen to increase from a value of 4.42 to a value of infinity (disconnected pores). These microstructural characteristics could impede the transport of O{sup 2−} ions resulting in a change in the local pO{sup 2−} which could result in the inability to perform the electroreduction. - Highlights: • The microstructural evolution of the reduction from UO{sub 2} to U has been investigated. • The porosity and tortuosity is seen to change significantly during electroreduction. • Low porosity and high tortuosity associated with the UO{sub 2} phase may impede O{sup 2−} transport.

  9. Investigating microstructural evolution during the electroreduction of UO2 to U in LiCl-KCl eutectic using focused ion beam tomography

    Science.gov (United States)

    Brown, L. D.; Abdulaziz, R.; Tjaden, B.; Inman, D.; Brett, D. J. L.; Shearing, P. R.

    2016-11-01

    Reprocessing of spent nuclear fuels using molten salt media is an attractive alternative to liquid-liquid extraction techniques. Pyroelectrochemical processing utilizes direct, selective, electrochemical reduction of uranium dioxide, followed by selective electroplating of a uranium metal. Thermodynamic prediction of the electrochemical reduction of UO2 to U in LiCl-KCl eutectic has shown to be a function of the oxide ion activity. The pO2- of the salt may be affected by the microstructure of the UO2 electrode. A uranium dioxide filled "micro-bucket" electrode has been partially electroreduced to uranium metal in molten lithium chloride-potassium chloride eutectic. This partial electroreduction resulted in two distinct microstructures: a dense UO2 and a porous U metal structure were characterised by energy dispersive X-ray spectroscopy. Focused ion beam tomography was performed on five regions of this electrode which revealed an overall porosity ranging from 17.36% at the outer edge to 3.91% towards the centre, commensurate with the expected extent of reaction in each location. The pore connectivity was also seen to reduce from 88.32% to 17.86% in the same regions and the tortuosity through the sample was modelled along the axis of propagation of the electroreduction, which was seen to increase from a value of 4.42 to a value of infinity (disconnected pores). These microstructural characteristics could impede the transport of O2- ions resulting in a change in the local pO2- which could result in the inability to perform the electroreduction.

  10. Collective dynamic dipole moment and orientation fluctuations, cooperative hydrogen bond relaxations, and their connections to dielectric relaxation in ionic acetamide deep eutectics: Microscopic insight from simulations

    Science.gov (United States)

    Das, Suman; Biswas, Ranjit; Mukherjee, Biswaroop

    2016-08-01

    The paper reports a detailed simulation study on collective reorientational relaxation, cooperative hydrogen bond (H-bond) fluctuations, and their connections to dielectric relaxation (DR) in deep eutectic solvents made of acetamide and three uni-univalent electrolytes, lithium nitrate (LiNO3), lithium bromide (LiBr), and lithium perchlorate (LiClO4). Because cooperative H-bond fluctuations and ion migration complicate the straightforward interpretation of measured DR timescales in terms of molecular dipolar rotations for these conducting media which support extensive intra- and inter-species H-bonding, one needs to separate out the individual components from the overall relaxation for examining the microscopic origin of various timescales. The present study does so and finds that reorientation of ion-complexed acetamide molecules generates relaxation timescales that are in sub-nanosecond to nanosecond range. This explains in molecular terms the nanosecond timescales reported by recent giga-Hertz DR measurements. Interestingly, the simulated survival timescale for the acetamide-Li+ complex has been found to be a few tens of nanosecond, suggesting such a cation-complexed species may be responsible for a similar timescale reported by mega-Hertz DR measurements of acetamide/potassium thiocyanate deep eutectics near room temperature. The issue of collective versus single particle relaxation is discussed, and jump waiting time distributions are determined. Dependence on anion-identity in each of the cases has been examined. In short, the present study demonstrates that assumption of nano-sized domain formation is not required for explaining the DR detected nanosecond and longer timescales in these media.

  11. A liquid-based eutectic system: LiBH4·NH 3-nNH3BH3 with high dehydrogenation capacity at moderate temperature

    KAUST Repository

    Tan, Yingbin

    2011-01-01

    A novel eutectic hydrogen storage system, LiBH4·NH 3-nNH3BH3, which exists in a liquid state at room temperature, was synthesized through a simple mixing of LiBH 4·NH3 and NH3BH3 (AB). In the temperature range of 90-110 °C, the eutectic system showed significantly improved dehydrogenation properties compared to the neat AB and LiBH 4·NH3 alone. For example, in the case of the LiBH4·NH3/AB with a mole ratio of 1:3, over 8 wt.% hydrogen could be released at 90 °C within 4 h, while only 5 wt.% hydrogen released from the neat AB at the same conditions. Through a series of experiments it has been demonstrated that the hydrogen release of the new system is resulted from an interaction of AB and the NH3 group in the LiBH4·NH3, in which LiBH4 works as a carrier of ammonia and plays a crucial role in promoting the interaction between the NH3 group and AB. The enhanced dehydrogenation of LiBH 4·NH3/AB may result from the polar liquid state reaction environments and the initially promoted formation of the diammoniate of diborane, which will facilitate the B-H⋯H-N interaction between LiBH4·NH3 and AB. Kinetics analysis revealed that the rate-controlling steps of the dehydrogenation process are three-dimensional diffusion of hydrogen at temperatures ranging from 90 to 110 °C. This journal is © The Royal Society of Chemistry.

  12. A basic study on capture and solidification of rare earth nuclide (Nd) in LiCl-KCl eutectic salt using an inorganic composite with Li{sub 2}OAl{sub 2}O{sub 3}- SiO{sub 2}-B{sub 2}O{sub 3} systems

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Na Young; Eum, Hee Chul; Park, Hwan Seo; Ahn, Do Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-03-15

    The pyroprocessing of spent nuclear fuel generates LiCl-KCl eutectic waste salt containing radioactive rare earth nuclides. It is necessary to develop a simple process for the treatment of LiCl-KCl eutectic waste in a hot-cell facility. In this study, capture and solidification of a rare earth nuclide (Nd) in LiCl-KCl eutectic salt using an inorganic composite with a Li{sub 2}OAl{sub 2}O{sub 3}- SiO{sub 2}-B{sub 2}O{sub 3} system was conducted to simplify the existing separation and solidification process of rare earth nuclides in LiCl-KCl eutectic waste salt from the pyroprocessing of spent nuclear fuel. More than 98wt% of Nd in LiCl-KCl eutectic salt was captured when the mass ratio of the composite was 0.67 over NdCl3 in the eutectic salt. The content of Nd{sub 2}O{sub 3} in the Nd captured-composite reached about 50wt%, and this composite was directly fabricated into a homogeneous and chemical resistant glass waste in a monolithic form. These results will be utilized in designing a process to simplify the existing separation and solidification process.

  13. Electrochemical study of Tm (III) ions on W and oxo acidity reactions in the LiCI-KCI eutectic; Estudio electroquimico de disoluciones de Tm (III) sobre W y reacciones de oxoacidez en el eutectico LiCI.-KCl

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Requejo, P.

    2010-07-01

    Study of the electrochemical behaviour of Tm (III) dissolutions in the LiCI-KCI eutectic mixture using inert electrodes (W) and reagent electrodes (Al). On W, TM (III) ions are reduced in two consecutives stages sufficiently separated. The TM electro-reduction on Al makes room for the formation of intermetallic compounds so the use of an Ai electrode is appropriate to decontamination operations.

  14. The influence of Ta on the solidification microstructure and segregation behavior of γ(Ni)/γ′(Ni3Al)–δ(Ni3Nb) eutectic Ni-base superalloys

    International Nuclear Information System (INIS)

    Xie, M.; Helmink, R.; Tin, S.

    2013-01-01

    Highlights: ► Ta and Nb have a nominally identical influence on equilibrium δ volume fraction. ► Ta and Nb impact the sequence and segregation differently during solidification. ► Microstructure varies with both overall Ta + Nb level and Ta/Nb ratio. ► Pandat (PanNi7) is unable to predict trends quantitatively in this system. -- Abstract: Polycrystalline γ/γ′–δ eutectic Ni-base superalloys based on the Ni–Al–Nb alloy system were recently demonstrated to possess excellent high temperature strength and creep resistance. Investigations aimed to establish the fundamental relationships between alloy chemistry, solidification behavior and cast microstructure in these novel Ni–Al–Nb γ/γ′–δ alloy systems are currently underway. This particular study is focused on understanding the influence of Ta additions on the solidification sequence, phase volume fraction, distribution coefficient and solid state partitioning parameter of this eutectic alloy system by systematically investigating a series of experimental alloys with nominally constant overall levels of Ta + Nb content but varying Ta/Nb ratios. Although many of the tendencies observed in these multi-component γ/γ′–δ eutectic alloys are in agreement with trends observed in lower order model alloy systems, Ta additions were found to significantly modify solidification characteristics of the alloys. The experimental observations were also used to critically assess the predictive capability of thermodynamic database calculations. Despite the qualitative agreement observed between the experimental results and predictions for relatively simple quaternary and quinary model alloys, comparison of the results for higher order, multi-component γ/γ′–δ eutectic alloys reveals notable differences

  15. Part I: Virtual laboratory versus traditional laboratory: Which is more effective for teaching electrochemistry? Part II: The green synthesis of aurones using a deep eutectic solvent

    Science.gov (United States)

    Hawkins, Ian C.

    The role of the teaching laboratory in science education has been debated over the last century. The goals and purposes of the laboratory are still debated and while most science educators consider laboratory a vital part of the education process, they differ widely on the purposes for laboratory and what methods should be used to teach laboratory. One method of instruction, virtual labs, has become popular among some as a possible way of capitalizing on the benefits of lab in a less costly and more time flexible format. The research regarding the use of virtual labs is limited and the few studies that have been done on General Chemistry labs do not use the virtual labs as a substitute for hands-on experiences, but rather as a supplement to a traditional laboratory program. This research seeks to determine the possible viability of a virtual simulation to replace a traditional hands-on electrochemistry lab in the General Chemistry II course sequence. The data indicate that for both content knowledge and the development of hands-on skills the virtual lab showed no significant difference in overall scores on the assessments, but that an individual item related to the physical set-up of a battery showed better scores for the hands-on labs over the virtual labs. Further research should be done to determine if these results are similar in other settings with the use of different virtual labs and how the virtual labs compare to other laboratories using different learning styles and learning goals. One often cited purpose of laboratory experiences in the context of preparing chemists is to simulate the experiences common in chemical research so graduate experience in a research laboratory was a necessary part of my education in the field of laboratory instruction. This research experience provided me the opportunity, to complete an organic synthesis of aurones using a deep eutectic solvent. These solvents show unique properties that make them a viable alternative to ionic

  16. The influence of natural deep eutectic solvents on bioactive natural products: Studying interactions between a hydrogel model and Schisandra chinensis metabolites.

    Science.gov (United States)

    Liu, Yang; Zhang, Yu; Chen, Shao-Nong; Brent Friesen, J; Nikolić, Dejan; Choules, Mary P; McAlpine, James B; Lankin, David C; Gemeinhart, Richard A; Pauli, Guido F

    2018-02-20

    Natural Deep Eutectic Solvent (NADES) species can exhibit unexpected solubilizing power for lipophilic molecules despite their simple composition, hydrophilic organic molecules and water. In the present study, the unique properties of NADES species were applied in combination with a model polymer system: a hydrophilic chitosan/alginate hydrogel. Briefly, NADES species (e.g., mannose-dimethylurea-water, 2:5:5, mole/mole) formed matrices to 1) dissolve lipophilic molecules (e.g., curcumin), 2) load lipophilic molecule(s) into the hydrogel, and 3) spontaneously vacate from the system. NADES species ubiquitously occur in natural sources, and a crude extract is a mixture of the NADES species and bioactive metabolites. Based on these ideas, we hypothesized that the crude extract may also allow the loading of natural bioactive molecules from a natural NADES species into (bio)hydrogel systems. To evaluate this hypothesis in vitro, Schisandra chinensis fruit extract was chosen as a representative mixture of lipophilic botanical molecules and hydrophilic NADES species. The results showed that the NADES matrix of S. chinensis was capable of loading at least three bioactive lignans (i.e., gomisin A, gomisin J, and angeloylgomisin H) into the polymer system. The lipophilic metabolites can subsequently be released from the hydrogel. The outcomes suggest that a unique drug delivery mechanism may exist in nature, thereby potentially improving the bioavailability of lipophilic metabolites through physicochemical interactions with the NADESs. Copyright © 2017. Published by Elsevier B.V.

  17. Determination of the E-pO{sup 2-} stability diagram of plutonium in the molten LiCl-KCl eutectic at 450 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, Concha [CIEMAT, DE/DFN/URR, Avda. Complutense 22, Madrid 28040 (Spain)], E-mail: c.caravaca@ciemat.es; Laplace, Annabelle; Vermeulen, Jackie; Lacquement, Jerome [Commissariat a l' Energie Atomique, Site de Marcoule, DEN/DRCP/SCPS/LPP, Batiment 399, BP 17171, 30207 Bagnols sur Ceze (France)

    2008-07-01

    Plutonium trichloride solution in the molten LiCl-KCl eutectic was prepared by carbochlorination of plutonium oxide. Kinetics of this reaction was compared in different conditions in the range of 443-550 deg. C. Using this molten salt solution, the redox potential of the Pu(III)/Pu couple at inert tungsten electrode was measured at 450 deg. C by electromotive force measurement and was found to be E'{sup o} = -2.76 V vs. the Cl{sub 2(g)}(1 atm)/Cl{sup -} reference electrode (molar fraction scale). Reaction between plutonium trichloride and oxide ions was studied by potentiometric titration, using yttria stabilized electrodes. In our experimental conditions, the titration curves indicate the precipitation of the sesquioxide Pu{sub 2}O{sub 3}. The solubility product cologarithm calculated from these curves is found to be pK{sub s}(Pu{sub 2}O{sub 3}) = 22.8 {+-} 1.1 (molality scale). Using the experimentally obtained values for E'{sup o}, activity coefficient and pK{sub s} joined to the published thermodynamic data, the stability phase diagram of the Pu-O species was then drawn.

  18. Low temperature synthesis of CaZrO3 nanoceramics from CaCl2–NaCl molten eutectic salt

    Directory of Open Access Journals (Sweden)

    Rahman Fazli

    2015-06-01

    Full Text Available CaZrO3 nanoceramics were successfully synthesized at 700 C using the molten salt method, and the effects of processing parameters, such as temperature, holding time, and amount of salt on the crystallization of CaZrO3 were investigated. CaCl2, Na2CO3, and nano-ZrO2 were used as starting materials. On heating, CaCl2–NaCl molten eutectic salt provided a liquid medium for the reaction of CaCO3 and ZrO2 to form CaZrO3. The results demonstrated that CaZrO3 started to form at about 600C and that, after the temperature was increased to 1,000C, the amounts of CaZrO3 in the resultant powders increased with a concomitant decrease in CaCO3and ZrO2 contents. After washing with hot distilled water, the samples heated for 3 h at 700C were single-phase CaZrO3 with 90–95 nm particle size. Furthermore, the synthesized CaZrO3 particles retained the size and morphology of the ZrO2 powders which indicated that a template mechanism dominated the formation of CaZrO3 by molten-salt method.

  19. The influence of a eutectic mixture of lidocaine and prilocaine on minor surgical procedures: a randomized controlled double-blind trial.

    LENUS (Irish Health Repository)

    Shaikh, Faisal M

    2012-01-31

    BACKGROUND: A eutectic mixture of lidocaine and prilocaine (EMLA) has been shown to be effective in reducing pain from needle sticks, including those associated with blood sampling and intravenous insertion. OBJECTIVE: To evaluate the effectiveness of EMLA cream applied before needle puncture for local anesthetic administration before minor surgical procedures in this double-blind, randomized, controlled, parallel-group study. MATERIALS AND METHODS: Patients were randomly assigned to receive EMLA or placebo cream (Aqueous) applied under an occlusive dressing. After the procedure, patients were asked to rate the needle prick and procedure pain on a visual analog scale (0=no pain; 10=maximum pain). RESULTS: A total of 94 minor surgical procedures (49 in EMLA and 45 in control) were performed. The mean needle-stick pain score in the EMLA group was significantly lower than in the control group (2.7 vs. 5.7, p<.001, Mann-Whitney U-test). There was also significantly lower procedure pain in the EMLA group than in the control group (0.83 vs. 1.86, p=.009). There were no complications associated with the use of EMLA. CONCLUSION: EMLA effectively reduces the preprocedural needle-stick pain and procedural pain associated with minor surgical procedures.

  20. Die-cast of a hypo-eutectic AL-SI alloy: influence of injection temperature on microstructure and mechanical properties

    International Nuclear Information System (INIS)

    Santos, Silvano Leal dos; Santos, Sydney Ferreira

    2014-01-01

    Die-casting is widely used for manufacturing light alloy components for automotive industry. Among others, hypo-eutectic Al-Si alloys are currently processed by die-casting. To obtain high quality die-cast components, a better understanding on the correlations between processing parameters, microstructures, and mechanical properties are of utmost importance. In this study, we investigate the effect of injection temperature of liquid metal on the microstructure and mechanical properties of Al-Si alloy EN AC 46000 (DIN designation). The injection temperatures were 579, 589, 643, and 709 deg C. As-cast components had their microstructures analyzed by X-ray diffraction, optical and scanning electron microscopy, and X-ray energy dispersive spectroscopy. The mechanical properties were examined by micro-hardness and tensile tests. It was observed that the ultimate tensile strength slightly increased with the increase of injection temperature. The same trend was observed for micro-hardness. The amount of porosity in the samples varies in a small amount for different injection temperatures. On the other hand, the microstructure of the alloys seems more refined for higher temperatures of injection. This refinement in microstructure might play a major role on the mechanical properties of the Al-Si die-cast alloy. (author)

  1. Glass transition dynamics and conductivity scaling in ionic deep eutectic solvents: The case of (acetamide + lithium nitrate/sodium thiocyanate) melts

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, Satya N., E-mail: satyanarayantripathy@gmail.com; Wojnarowska, Zaneta; Knapik, Justyna; Paluch, Marian [Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Silesian Center for Education and Interdisciplinary Research, 75 Pulku Piechoty 1A, 41-500 Chorzow (Poland); Shirota, Hideaki [Department of Nanomaterial Science and Department of Chemistry, Chiba University, 1-33 Yayoi, Inage-ku, Chiba 263-8522 (Japan); Biswas, Ranjit [Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata 700098 (India)

    2015-05-14

    A detailed investigation on the molecular dynamics of ionic deep eutectic solvents (acetamide + lithium nitrate/sodium thiocyanate) is reported. The study was carried out employing dielectric relaxation spectroscopy covering seven decades in frequency (10{sup −1}-10{sup 6} Hz) and in a wide temperature range from 373 K down to 173 K, accessing the dynamic observables both in liquid and glassy state. The dielectric response of the ionic system has been presented in the dynamic window of modulus formalism to understand the conductivity relaxation and its possible connection to the origin of localized motion. Two secondary relaxation processes appear below glass transition temperature. Our findings provide suitable interpretation on the nature of secondary Johari-Goldstein process describing the ion translation and orientation of dipoles in a combined approach using Ngai’s coupling model. A nearly constant loss feature is witnessed at shorter times/lower temperatures. We also discuss the ac conductivity scaling behavior using Summerfield approach and random free energy barrier model which establish the time-temperature superposition principle. These experimental observations have fundamental importance on theoretical elucidation of the conductivity relaxation and glass transition phenomena in molten ionic conductors.

  2. Combined NMR and molecular dynamics modeling study of transport properties in sulfonamide based deep eutectic lithium electrolytes: LiTFSI based binary systems.

    Science.gov (United States)

    Pauric, Allen D; Halalay, Ion C; Goward, Gillian R

    2016-03-07

    The trend toward Li-ion batteries operating at increased (>4.3 V vs. Li/Li(+)) voltages requires the development of novel classes of lithium electrolytes with electrochemical stability windows exceeding those of LiPF6/carbonate electrolyte solutions. Several new classes of electrolytes have been synthesized and investigated over the past decade, in the search for LIB electrolytes with improved properties (increased hydrolytic stability, improved thermal abuse tolerance, higher oxidation voltages, etc.) compared with the present state-of-the-art LiPF6 and organic carbonates-based formulations. Among these are deep eutectic electrolytes (DEEs), which share many beneficial characteristics with ionic liquids, such as low vapor pressure and large electrochemical stability windows, with the added advantage of a significantly higher lithium transference number. The present work presents the pulsed field gradient NMR characterization of the transport properties (diffusion coefficients and cation transport numbers) of binary DEEs consisting of a sulfonamide solvent and lithium bis(trifluoromethanesulfonyl)imide salt. Insights into the structural and dynamical properties, which enable one to rationalize the observed ionic conductivity behavior were obtained from a combination of NMR data and MD simulations. The insights thus gained should assist the formulation of novel DEEs with improved properties for LIB applications.

  3. A Double-Blind, Randomised, Placebo-Controlled Trial of EMLA® Cream (Eutectic Lidocaine/Prilocaine Cream) for Analgesia Prior to Cryotherapy of Plantar Warts in Adults.

    Science.gov (United States)

    Lee, Siew Hui; Pakdeethai, Janthorn; Toh, Matthias P H S; Aw, Derrick C W

    2014-10-01

    Cryotherapy with liquid nitrogen is an effective, safe and convenient form of treatment for plantar warts. EMLA® cream (eutectic mixture of lidocaine 2.5% and prilocaine 2.5%) is a topical local anaesthetic agent that has proven to be effective and well tolerated in the relief of pain associated with various minor interventions in numerous clinical settings. In a single-centre, double-blind, randomised placebo-controlled study, 64 subjects were randomised into 2 groups. The subjects had a thick layer of EMLA® cream or placebo cream applied to pared plantar wart(s) and onto the surrounding margin of 1 mm to 2 mm under occlusion for 60 minutes prior to receiving cryotherapy. The pain of cryotherapy was evaluated by the subjects using a self-administered Visual Analogue Scale (VAS) immediately after the cryotherapy. There was no statistical difference between the mean VAS score for EMLA® cream (47.0 ± 21.4 mm) and placebo (48.9 ± 22.0 mm). Those with more than 1 wart had a significantly higher VAS score than those with only 1 wart (59.1 ± 21.8 vs. 44.3 ± 20.4, P cryotherapy. We conclude that the application of EMLA® cream prior to cryotherapy does not reduce the pain associated with cryotherapy.

  4. Electrowinning of U-Pu onto inert solid cathode in LiCl-KCl eutectic melts containing UCl3 and PuCl3

    Science.gov (United States)

    Sakamura, Yoshiharu; Murakami, Tsuyoshi; Tada, Kohei; Kitawaki, Shinichi

    2018-04-01

    Electrowinning process was investigated for extracting actinides from molten salts used for the pyrochemical reprocessing of spent nuclear fuels. The separation of actinides from lanthanides is expected to be enhanced by employing inert solid cathodes due to larger potential differences on these cathodes. In this study, the co-deposition behavior of Pu and U metals onto an inert solid cathode made of tungsten was examined in LiCl-KCl eutectic melts containing UCl3 and PuCl3 at 773 K. The standard potential of U3+/U is 0.31 V more positive than that of Pu3+/Pu. The U3+ concentration was varied in the range of 0.11-0.66 wt%, while the Pu3+ concentration was maintained at approximately 2.9 wt%. When the U3+ concentration was not sufficiently low, the deposited U metal readily grew outward from the electrode surface and the electrode surface area rapidly increased, which facilitated only the deposition of U metal. It was estimated that metallic Pu can be efficiently collected along with U at U3+ concentrations lower than ∼0.2 wt%.

  5. Analysis by numerical calculations of the depth and dynamics of the penetration of ordered cellular structure made by casting from AlSi10Mg eutectic alloy

    Directory of Open Access Journals (Sweden)

    M. Małysza

    2011-07-01

    Full Text Available Owing to high plastic deformability while maintaining stress values constant and relatively low, ordered cellular structures arecharacterised by excellent properties and the ability to dissipate the impact energy. Due to the low weight, structures of this type can beused, among others, for different parts of motor vehicles. For tests, a trapezoidal ordered cellular structure of 50.8 x 50.8 x 25.4 (mmoverall dimensions was selected. It was made as an investment casting from AlSi9Mg eutectic alloy by the method of Rapid Prototyping(RP. During FEM computations using an Abaqus programme, it was assumed that the material is isotropic and exhibits the features of anelastic – plastic body, introducing to calculations the, listed in a table, values of the stress-strain curve obtained in tensile tests performedon a MTS testing machine (10T. The computations used Johnson - Cook model, which is usually sufficiently accurate when modelling thephenomena of penetration of an element by an object of high initial velocity. The performed numerical calculations allowed identification

  6. Efficient Cleavage of Lignin-Carbohydrate Complexes and Ultrafast Extraction of Lignin Oligomers from Wood Biomass by Microwave-Assisted Treatment with Deep Eutectic Solvent.

    Science.gov (United States)

    Liu, Yongzhuang; Chen, Wenshuai; Xia, Qinqin; Guo, Bingtuo; Wang, Qingwen; Liu, Shouxin; Liu, Yixing; Li, Jian; Yu, Haipeng

    2017-04-22

    Lignocellulosic biomass is an abundant and renewable resource for the production of biobased value-added fuels, chemicals, and materials, but its effective exploitation by an energy-efficient and environmentally friendly strategy remains a challenge. Herein, a facile approach for efficiently cleaving lignin-carbohydrate complexes and ultrafast fractionation of components from wood by microwave-assisted treatment with deep eutectic solvent is reported. The solvent was composed of sustainable choline chloride and oxalic acid dihydrate, and showed a hydrogen-bond acidity of 1.31. Efficient fractionation of lignocellulose with the solvent was realized by heating at 80 °C under 800 W microwave irradiation for 3 min. The extracted lignin showed a low molecular weight of 913, a low polydispersity of 1.25, and consisted of lignin oligomers with high purity (ca. 96 %), and thus shows potential in downstream production of aromatic chemicals. The other dissolved matter mainly comprised glucose, xylose, and hydroxymethylfurfural. The undissolved material was cellulose with crystal I structure and a crystallinity of approximately 75 %, which can be used for fabricating nanocellulose. Therefore, this work promotes an ultrafast lignin-first biorefinery approach while simultaneously keeping the undissolved cellulose available for further utilization. This work is expected to contribute to improving the economics of overall biorefining of lignocellulosic biomass. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  7. First-time success with needle procedures was higher with a warm lidocaine and tetracaine patch than an eutectic mixture of lidocaine and prilocaine cream.

    Science.gov (United States)

    Cozzi, Giorgio; Borrometi, Fabio; Benini, Franca; Neri, Elena; Rusalen, Francesca; Celentano, Loredana; Zanon, Davide; Schreiber, Silvana; Ronfani, Luca; Barbi, Egidio

    2017-05-01

    More than 50% of children report apian during venepuncture or intravenous cannulation and using local anaesthetics before needle procedures can lead to different success rates. This study examined how many needle procedures were successful at the first attempt when children received either a warm lidocaine and tetracaine patch or an eutectic mixture of lidocaine and prilocaine (EMLA) cream. We conducted this multicentre randomised controlled trial at three tertiary-level children's hospitals in Italy in 2015. Children aged three to 10 years were enrolled in an emergency department, paediatric day hospital and paediatric ward and randomly allocated to receive a warm lidocaine and tetracaine patch or EMLA cream. The primary outcome was the success rate at the first attempt. The analysis included 172 children who received a warm lidocaine and tetracaine patch and 167 who received an EMLA cream. The needle procedure was successful at the first attempt in 158 children (92.4%) who received the warm patch and in 142 children (85.0%) who received the cream (p = 0.03). The pain scores were similar in both groups. This study showed that the first-time needle procedure success was 7.4% higher in children receiving a warm lidocaine and tetracaine patch than EMLA cream. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  8. Electrochemical characterisation of CaCl2 deficient LiCl-KCl-CaCl2 eutectic melt and electro-deoxidation of solid UO2

    Science.gov (United States)

    Sri Maha Vishnu, D.; Sanil, N.; Mohandas, K. S.; Nagarajan, K.

    2016-03-01

    The CaCl2 deficient ternary eutectic melt LiCl-KCl-CaCl2 (50.5: 44.2: 5.3 mol %) was electrochemically characterised by cyclic voltammetry and polarization techniques in the context of its probable use as the electrolyte in the electrochemical reduction of solid UO2 to uranium metal. Tungsten (cathodic polarization) and graphite (anodic polarization) working electrodes were used in these studies carried out in the temperature range 623 K-923 K. The cathodic limit of the melt was observed to be set by the deposition of Ca2+ ions followed by Li+ ions on the tungsten electrode and the anodic limit by oxidation of chloride ions on the graphite electrode (chlorine evolution). The difference between the onset potential of deposition of Ca2+ and Li+ was found to be 0.241 V at a scan rate of 20 mV/s at 623 K and the difference decreased with increase in temperature and vanished at 923 K. Polarization measurements with stainless steel (SS) cathode and graphite anode at 673 K showed the possibility of low-energy reactions occurring on the UO2 electrode in the melt. UO2 pellets were cathodically polarized at 3.9 V for 25 h to test the feasibility of electro-reduction to uranium in the melt. The surface of the pellets was found reduced to U metal.

  9. Observation of an Aligned Gas - Solid "Eutectic" during Controlled Directional Solidification Aboard the International Space Station - Comparison with Ground-based Studies

    Science.gov (United States)

    Grugel, R. N.; Anilkumar, A.

    2005-01-01

    Direct observation of the controlled melting and solidification of succinonitrile was conducted in the glovebox facility of the International Space Station (ISS). The experimental samples were prepared on ground by filling glass tubes, 1 cm ID and approximately 30 cm in length, with pure succinonitrile (SCN) in an atmosphere of nitrogen at 450 millibar pressure for eventual processing in the Pore Formation and Mobility Investigation (PFMI) apparatus in the glovebox facility (GBX) on board the ISS. Real time visualization during controlled directional melt back of the sample showed nitrogen bubbles emerging from the interface and moving through the liquid up the imposed temperature gradient. Over a period of time these bubbles disappear by dissolving into the melt. Translation is stopped after melting back of about 9 cm of the sample, with an equilibrium solid-liquid interface established. During controlled re-solidification, aligned tubes of gas were seen growing perpendicular to the planar solid/liquid interface, inferring that the nitrogen previously dissolved into the liquid SCN was now coming out at the solid/liquid interface and forming the little studied liquid = solid + gas eutectic-type reaction. The observed structure is evaluated in terms of spacing dimensions, interface undercooling, and mechanisms for spacing adjustments. Finally, the significance of processing in a microgravity environment is ascertained in view of ground-based results.

  10. Ultrasonic cavitation erosion of 316L steel weld joint in liquid Pb-Bi eutectic alloy at 550°C.

    Science.gov (United States)

    Lei, Yucheng; Chang, Hongxia; Guo, Xiaokai; Li, Tianqing; Xiao, Longren

    2017-11-01

    Liquid lead-bismuth eutectic alloy (LBE) is applied in the Accelerator Driven transmutation System (ADS) as the high-power spallation neutron targets and coolant. A 19.2kHz ultrasonic device was deployed in liquid LBE at 550°C to induce short and long period cavitation erosion damage on the surface of weld joint, SEM and Atomic force microscopy (AFM) were used to map out the surface properties, and Energy Dispersive Spectrometer (EDS) was applied to the qualitative and quantitative analysis of elements in the micro region of the surface. The erosion mechanism for how the cavitation erosion evolved by studying the element changes, their morphology evolution, the surface hardness and the roughness evolution, was proposed. The results showed that the pits, caters and cracks appeared gradually on the erode surface after a period of cavitation. The surface roughness increased along with exposure time. Work hardening by the bubbles impact in the incubation stage strengthened the cavitation resistance efficiently. The dissolution and oxidation corrosion and cavitation erosion that simultaneously happened in liquid LBE accelerated corrosion-erosion process, and these two processes combined to cause more serious damage on the material surface. Contrast to the performance of weld metal, base metal exhibited a much better cavitation resistance. Copyright © 2017. Published by Elsevier B.V.

  11. Graphene and graphene oxide modified by deep eutectic solvents and ionic liquids supported on silica as adsorbents for solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoqin; Li, Guizhen; Row, Kyung Ho [Dept. of Chemistry and Chemical Engineering, Inha University, Incheon (Korea, Republic of)

    2017-02-15

    A novel deep eutectic solvent (DES) and ionic liquid (IL)-modified graphene (G) and graphene oxide (GO) were synthesized and used as effective adsorbents for the preconcentration of three chlorophenols (CPs), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP), in environmental water samples prior to high-performance liquid chromatography (HPLC). The new materials were characterized by scanning electron microscopy (S-4200) and Fourier-transform infrared spectrometry. The prepared functionalized GO@silica shows remarkable adsorption capacity toward CPs. When used as solid-phase extraction (SPE) sorbents, a superior recovery (88.49–89.70%) could be obtained compared to commercial sorbents, such as silica and aminosilica. Based on this, a method for the analysis of CPs in water samples was established by coupling SPE with HPLC. These results highlight the potential new role of DES and IL-modified GO in the preparation of analytical samples.

  12. Micro/nano encapsulation of some paraffin eutectic mixtures with poly(methyl methacrylate) shell: Preparation, characterization and latent heat thermal energy storage properties

    International Nuclear Information System (INIS)

    Sarı, Ahmet; Alkan, Cemil; Bilgin, Cahit

    2014-01-01

    Graphical abstract: Four kinds of micro/nano capsules, PMMA/(C17-C24), PMMA/(C19-C18), PMMA/(C19-C24) and PMMA/(C20-C24), were synthesized successfully as novel encapsulated phase change materials (PCMs) for the different monomer/PEM ratios via emulsion polymerization. The FTIR spectroscopy analysis confirmed the polymerization reaction occurred around the PEMs to be used as core materials. The POM, SEM and PSD analysis results showed that the synthesized PMMA/PEM micro/nano capsules had spherical shape appearance and micro/nano sizes. DSC analysis measurements revealed that the prepared micro/nano capsules containing the highest PEM content had a melting temperature range of about 20–36 °C and latent heat capacities in the range of about 86–169 J/g. TGA findings demonstrated that the encapsulated PEMs had good thermal reliability and chemical stability even after subjecting them to 5000 melting/freezing cycles. Furthermore, the prepared micro/nano capsules had reasonable thermal conductivity values and fine melting–freezing reversibility. - Highlights: • PSD analysis results showed that the encapsulated PEMs had micro/nano sized-spheres. • The encapsulated PEMs melt in the temperature range of about 20–36 °C. • The encapsulated PEMs had latent heat capacities of in the range of about 86–169 J/g. • TGA results demonstrated that they had good thermal stability. • The encapsulated PEMs had good thermal conductivity and phase change reversibility. - Abstract: This work is aimed to prepare, characterize and determine the latent heat thermal energy storage properties of micro/nano encapsulated paraffin eutectic mixtures (PEMs) with polymethylmethacrylate (PMMA) shell. The eutectic combination ratios and optimum melting temperatures of C17-C24, C19-C18, C19-C24 and C20-C24 mixtures were find out prior to the encapsulation processes. Four kinds of micro/nano capsules, PMMA/(C17-C24), PMMA/(C19-C18), PMMA/(C19-C24) and PMMA/(C20-C24), were synthesized

  13. Natural deep eutectic solvent mediated pretreatment of rice straw: bioanalytical characterization of lignin extract and enzymatic hydrolysis of pretreated biomass residue.

    Science.gov (United States)

    Kumar, Adepu K; Parikh, Bhumika S; Pravakar, Mohanty

    2016-05-01

    The present investigation demonstrated pretreatment of lignocellulosic biomass rice straw using natural deep eutectic solvents (NADESs), and separation of high-quality lignin and holocellulose in a single step. Qualitative analysis of the NADES extract showed that the extracted lignin was of high purity (>90 %), and quantitative analysis showed that nearly 60 ± 5 % (w/w) of total lignin was separated from the lignocellulosic biomass. Addition of 5.0 % (v/v) water during pretreatment significantly enhanced the total lignin extraction, and nearly 22 ± 3 % more lignin was released from the residual biomass into the NADES extract. X-ray diffraction studies of the untreated and pretreated rice straw biomass showed that the crystallinity index ratio was marginally decreased from 46.4 to 44.3 %, indicating subtle structural alterations in the crystalline and amorphous regions of the cellulosic fractions. Thermogravimetric analysis of the pretreated biomass residue revealed a slightly higher T dcp (295 °C) compared to the T dcp (285 °C) of untreated biomass. Among the tested NADES reagents, lactic acid/choline chloride at molar ratio of 5:1 extracted maximum lignin of 68 ± 4 mg g(-1) from the rice straw biomass, and subsequent enzymatic hydrolysis of the residual holocellulose enriched biomass showed maximum reducing sugars of 333 ± 11 mg g(-1) with a saccharification efficiency of 36.0 ± 3.2 % in 24 h at 10 % solids loading.

  14. Lab-Scale Electrodeposition Behaviors of Pr(III) with Use of Quartz Cell in Molten LiCl-KCl Eutectic

    Energy Technology Data Exchange (ETDEWEB)

    Jee, Young Taek; Yun, Jong-Il [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    As electrorefining is proceeded, all actinides and lanthanides in metallic form are electrochemically oxidized and dissolved into the salt, while UCl{sub 3} in the salt is reduced and forms U-metal at solid cathodes. Since this unit process includes diverse actinides and recovers most of uranium, information on stream of nuclear materials and electrochemical condition inside of electrorefiner must continuously be notified not only for its performance assessment and process prediction but also for its safeguards. Currently, there are several computational models for electrorefiner (REFIN, ERAD, and etc.). However, the absence of model which reflects the change in surface area of cathode due to electrodeposition of UCl{sub 3} critically disturbs the precision of simulation. The change in surface area leads the change in current density, diffusion layer, potential and current gradient, and thus changes the entire electrochemical conditions in electrorefiner. In this paper, as a beginning step of investigating electrodeposition behavior of lanthanides and actinides, lab-scale electrodeposition experiments and methodological evaluation on the use of quartz cell are performed. In the lab-scale electrodeposition, sizes of quartz cell and deposited material became crucial factors for precise analysis of experiments. In a typical stabilized electrodeposition, CA diagram showed large plateau with reasonably increased magnitude of current due to the increase in surface area of working electrode. The amount of charge transferred (-61.55 C) can be utilized for concentration balance. According to ICP-OES, the decreased amount of bulk was 0.301 wt. % which was close to the expected decrease from the information of charge flow (0.29 wt. %). However, deposited material in contact with quartz wall in molten LiCl-KCl eutectic led a spontaneous reaction between each other. As an indicator of this undesired reaction, the cell became black, and enormous amount of charge was consumed. In

  15. Novel binary deep eutectic electrolytes for rechargeable Li-ion batteries based on mixtures of alkyl sulfonamides and lithium perfluoroalkylsulfonimide salts

    Science.gov (United States)

    Geiculescu, O. E.; DesMarteau, D. D.; Creager, S. E.; Haik, O.; Hirshberg, D.; Shilina, Y.; Zinigrad, E.; Levi, M. D.; Aurbach, D.; Halalay, I. C.

    2016-03-01

    Ionic liquids (IL's) were proposed for use in Li-ion batteries (LIBs), in order to mitigate some of the well-known drawbacks of LiPF6/mixed organic carbonates solutions. However, their large cations seriously decrease lithium transference numbers and block lithium insertion sites at electrode-electrolyte interfaces, leading to poor LIB rate performance. Deep eutectic electrolytes (DEEs) (which share some of the advantages of ILs but possess only one cation, Li+), were then proposed, in order to overcome the difficulties associated with ILs. We report herein on the preparation, thermal properties (melting, crystallization, and glass transition temperatures), transport properties (specific conductivity and viscosity) and thermal stability of binary DEEs based on mixtures of lithium bis(trifluoromethane)sulfonimide or lithium bis(fluoro)sulfonimide salts with an alkyl sulfonamide solvent. Promise for LIB applications is demonstrated by chronoamperometry on Al current collectors, and cycling behavior of negative and positive electrodes. Residual current densities of 12 and 45 nA cm-2 were observed at 5 V vs. Li/Li+ on aluminum, 1.5 and 16 nA cm-2 at 4.5 V vs. Li/Li+, respectively for LiFSI and LiTFSI based DEEs. Capacities of 220, 130, and 175 mAh· g-1 were observed at low (C/13 or C/10) rates, respectively for petroleum coke, LiMn1/3Ni1/3Co1/3O2 (a.k.a. NMC 111) and LiAl0.05Co0.15Ni0.8O2 (a.k.a. NCA).

  16. Electrochemical behavior of lanthanum and yttrium ions in two molten chlorides with different oxoacidic properties: The eutectic LiCl-KCl and the equimolar mixture CaCl2-NaCl

    Directory of Open Access Journals (Sweden)

    Castrillejo Y.

    2003-01-01

    Full Text Available The electrochemical behavior of LaCl3 and YCl3 was studied in two molten chloride mixtures with different oxoacidic properties, the eutectic LiCl-KCl and the equimolar CaCl2-NaCl melt at different temperatures. The stable oxidation states of both elements have been found to be (III and (0 in both melts, and it was found that both La(III and Y(III cations were less solvated by the chloride ions in the calcium-based melt, which was explained by the stability of CaCl4 2- ions in that melt. Transient electrochemical techniques, such as cyclic voltammetry, chronopotentiometry and chronoamperometry were used in order to study the reaction mechanism and the transport parameters of electro active species at a tungsten electrode. The results showed that in the eutectic LiCl-KCl, the electro crystallization of lanthanum and yttrium seems to be the controlling electrochemical step while in CaCl2-NaCl this phenomenon has not been observed. That was explained in terms of the differences in the physicochemical properties of the systems, especially interfacial tensions. In the eutectic LiCl-KCl chronoamperometric studies indicated instantaneous and three dimensional nucleation and crystal growth of lanthanum and yttrium whatever the applied over potential of the rare earth metal is, whereas in the equimolar mixture CaCl2-NaCl, the corresponding electrochemical exchanges were found to be quasi-reversible, and the values of the kinetic parameters, K0 and α,were obtained for both reactions. Mass transport towards the electrode is a simple diffusion process, and the diffusion coefficients have been calculated. The validity of the Arrhenius law was also verified by plotting the variation of the logarithm of the diffusion coefficient versus 1/T.

  17. Texturas de los minerales del grupo de la sílice de la manifestación epitermal El Rifle-Hato Viejo, región de Moa: clasificación, descripción e implicaciones genéticas

    Directory of Open Access Journals (Sweden)

    Leduar Ramayo-Cortés

    2001-03-01

    Full Text Available En el marco de la región de Moa, Cuba oriental, se localizan varias manifestaciones hidrotermales. Se trata de sistemas vetiformes y brechas hidrotermales con contenidos significativos de metales nobles. La manifestación hidrotermal El Rifle-Hato Viejo se destaca por su extensión, y está formada por brechas y vetas de cuarzo mineralizadas, vinculadas preferentemente a fracturas correspondientes al sistema de fallas NW-SE y se hospeda en rocas sedimentarias del Campaniense Tardío-Daniense. El estudio textural de los minerales del grupo de la sílice permitió el reconocimiento de varias texturas, las cuales fueron clasificadas en tres grupos: 1 texturas de crecimiento primario (calcedonia maciza, costriforme, en peine, cristales zonados, y maciza, 2 texturas de recristalización (mosaico, plumosa y llameante, y 3 texturas de reemplazo (en enrejado, paralelo y radiado. Sobre la base de este análisis se estableció la secuencia deposicional de los diferentes minerales del grupo de la sílice y se reveló la presencia de la paragénesis de alteración adularia-sericita, lo cual indicaría el desarrollo de un sistema epitermal de baja sulfuración. Estas texturas también se usaron para indicar el nivel de emplazamiento dentro del sistema epitermal; en este caso, el emplazamiento de la manifestación El Rifle-Hato Viejo se corresponde con el nivel intermedio o coloiforme-costriforme, el cual se encuentra por encima de la zona propicia para la deposición del oro, por lo que podría esperarse la presencia de contenidos más elevados en profundidad.

  18. Study of directionally solidified eutectic Al2O3-ZrO2(3%Y2O3 doped with TiO2

    Directory of Open Access Journals (Sweden)

    Peña, J. I.

    2007-06-01

    Full Text Available An study of directionally grown samples of the eutectic composition in the Al2O3-ZrO2 (3 mol% Y2O3 system, with small TiO2 additions (1 wt%, is presented. The microstructural changes induced by this addition are analysed using SEM (EDX techniques. The mechanical changes, when TiO2 is added, are studied by measuring the flexural strength by three point bending. Also, the toughness is determined by Vickers indentation method. When slow growth rates (10 mm/h are used, interpenetratred and homogeneous microstructure is obtained, independently of the TiO2 doping. When growth rates are higher (300 and 1000 mm/h the structure changes and the phases are organized in form of colonies or cells, which have smaller size when TiO2 is present. This size reduction is accompanied with an increase of the toughness.Este trabajo presenta un estudio de muestras crecidas direccionalmente del sistema Al2O3-ZrO2 (3 mol% Y2O3 en su composición eutéctica con pequeñas adiciones de óxido de titanio (1% de TiO2 en peso. Se analizan los cambios microestructurales inducidos por esta adición mediante SEM (EDX y se estudian los cambios en su comportamiento mecánico medido por flexión en tres puntos, así como la tenacidad de fractura mediante indentación Vickers. Con velocidades lentas de solidificación (10 mm/h se obtiene en ambos casos una microestructura homogénea e interpenetrada, mientras que a velocidades mayores, 300 y 1000 mm/h, se forma una estructura en las que las fases se organizan en forma de colonias o células, siendo éstas de menor tamaño en las muestras dopadas. Esta disminución en el tamaño viene acompañada de un aumento de la tenacidad de fractura medida por indentación.

  19. Dissolution and oxidation behaviour of various austenitic steels and Ni rich alloys in lead-bismuth eutectic at 520 °C

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Marion, E-mail: marion.roy@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d’Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France); Martinelli, Laure, E-mail: laure.martinelli@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d’Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France); Ginestar, Kevin, E-mail: kevin.ginestar@cea.fr [CEA, DEN, DPC, SCCME, Laboratoire d’Etude de la Corrosion Non Aqueuse, F-91191 Gif-sur-Yvette (France); Favergeon, Jérôme, E-mail: jerome.favergeon@utc.fr [Laboratoire Roberval, UMR 7337, Université de Technologie de Compiègne, Centre de Recherche de Royallieu, CS 60319, 60203 Compiègne Cedex (France); Moulin, Gérard [Laboratoire Roberval, UMR 7337, Université de Technologie de Compiègne, Centre de Recherche de Royallieu, CS 60319, 60203 Compiègne Cedex (France)

    2016-01-15

    Ten austenitic steels and Ni rich alloys were tested in static lead-bismuth eutectic (LBE) at 520 °C in order to obtain a selection of austenitic steels having promising corrosion behaviour in LBE. A test of 1850 h was carried out with a dissolved oxygen concentration between 10{sup −9} and 5 10{sup −4} g kg{sup −1}. The combination of thermodynamic of the studied system and literature results leads to the determination of an expression of the dissolved oxygen content in LBE as a function of temperature: RT(K)ln[O](wt%) = −57584/T(K) −55.876T(K) + 254546 (R is the gas constant in J mol{sup −1} K{sup −1}). This relation can be considered as a threshold of oxygen content above which only oxidation is observed on the AISI 316L and AISI 304L austenitic alloys in static LBE between 400 °C and 600 °C. The oxygen content during the test leads to both dissolution and oxidation of the samples during the first 190 h and leads to pure oxidation for the rest of the test. Results of mixed oxidation and dissolution test showed that only four types of corrosion behaviour were observed: usual austenitic steels and Ni rich alloys behaviour including the reference alloy 17Cr-12Ni-2.5Mo (AISI 316LN), the 20Cr-31Ni alloy one, the Si containing alloy one and the Al containing alloy one. According to the proposed criteria of oxidation and dissolution kinetics, silicon rich alloys and aluminum rich alloy presented a promising corrosion behaviour. - Highlights: • 10 austenitic steels and Ni rich alloys were tested in LBE at 520 °C with dissolved oxygen content between 10{sup -9} and 5 10{sup -4} wt%. • It is shown that only thermodynamics cannot explain the Ni rich alloys corrosion behaviour in LBE. • The role of oxygen on corrosion behaviour in LBE was highlighted. • An equilibrium line was defined above which only oxidation has occurred on 316L: RTln[O](wt%) = -57584/T(K)-55.876T(K)+254546. • 18Cr-15Ni-3.7Si, 21Cr-11Ni-1.6Si and 14Cr-25Ni-3.5Al

  20. Preparation and properties of palmitic-stearic acid eutectic mixture/expanded graphite composite as phase change material for energy storage

    International Nuclear Information System (INIS)

    Zhang, Nan; Yuan, Yanping; Du, Yanxia; Cao, Xiaoling; Yuan, Yaguang

    2014-01-01

    A novel composite PCM (phase change material) with PA-SA (palmitic-stearic acid) eutectic mixture as PCM and EG (expanded graphite) as supporting material was prepared. The optimum absorption ratio of PA-SA/EG (Palmitic-stearic acid/expanded graphite) composite PCM was determined as PA-SA:EG = 13:1 (by mass). Scanning electron microscope and Fourier transformation infrared spectroscopy results show that PA-SA was uniformly distributed in the porous network structure of EG due to the physical action. Thermal property and thermal stability of the PA-SA/EG composite PCM were characterized by DSC (differential scanning calorimetry) and TGA (thermogravimetric analysis). DSC results indicated that the melting and freezing temperatures and latent heats of PA-SA/EG were measured as 53.89 °C and 54.37 °C, and 166.27 J/g and 166.13 J/g. TGA test results revealed that PA-SA/EG had a good thermal stability in working temperature range. Thermal cycling test results showed PA-SA/EG had a good thermal reliability after 720 thermal cycles. Thermal conductivity of the composite PCM was measured as 2.51 W/m K, much higher than that of PA-SA. The thermal energy storage and release rates of PA-SA/EG were also increased due to the high thermal conductivity of EG. In conclusion, the prepared PA-SA/EG composite PCM can be acted as a potential material for thermal energy storage due to the acceptable thermal properties, good thermal reliability and stability, high thermal conductivity. - Highlights: • PA-SA/EG (Palmitic-stearic acid/expanded graphite) composite PCM was prepared. • Optimum absorption ratio of PA-SA in EG was obtained as 13:1 (by mass). • Thermal conductivity and performance of PA-SA/EG have been significate improved. • PA-SA/EG has a good thermal reliability and thermal stability