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Sample records for volatile elements mn

  1. Volatile elements in Allende inclusions. [Mn, Na and Cl relation to meteorite evolution

    Science.gov (United States)

    Grossman, L.; Ganapathy, R.

    1975-01-01

    New data are presented on the relatively volatile elements (Mn, Na, and Cl) in coarse- and fine-grained Ca/Al-rich inclusions of different textures and mineralogy in the Allende meteorite. It is shown that the coarse-grained inclusions condensed from the solar nebula at high temperature and contained vanishingly small quantities of volatile elements at that time. Later, volatiles were added to these during the metamorphism of the Allende parent body. The fine-grained inclusions were also affected by the addition of volatiles during this metamorphism but, unlike the coarse-grained ones, they incorporated large amounts of volatiles when they condensed from the solar nebula, accounting for their higher volatile element contents.

  2. Chondritic Mn/Na ratio and limited post-nebular volatile loss of the Earth

    Science.gov (United States)

    Siebert, Julien; Sossi, Paolo A.; Blanchard, Ingrid; Mahan, Brandon; Badro, James; Moynier, Frédéric

    2018-03-01

    The depletion pattern of volatile elements on Earth and other differentiated terrestrial bodies provides a unique insight as to the nature and origin of planetary building blocks. The processes responsible for the depletion of volatile elements range from the early incomplete condensation in the solar nebula to the late de-volatilization induced by heating and impacting during planetary accretion after the dispersion of the H2-rich nebular gas. Furthermore, as many volatile elements are also siderophile (metal-loving), it is often difficult to deconvolve the effect of volatility from core formation. With the notable exception of the Earth, all the differentiated terrestrial bodies for which we have samples have non-chondritic Mn/Na ratios, taken as a signature of post-nebular volatilization. The bulk silicate Earth (BSE) is unique in that its Mn/Na ratio is chondritic, which points to a nebular origin for the depletion; unless the Mn/Na in the BSE is not that of the bulk Earth (BE), and has been affected by core formation through the partitioning of Mn in Earth's core. Here we quantify the metal-silicate partitioning behavior of Mn at deep magma ocean pressure and temperature conditions directly applicable to core formation. The experiments show that Mn becomes more siderophile with increasing pressure and temperature. Modeling the partitioning of Mn during core formation by combining our results with previous data at lower P-T conditions, we show that the core likely contains a significant fraction (20 to 35%) of Earth's Mn budget. However, we show that the derived Mn/Na value of the bulk Earth still lies on the volatile-depleted end of a trend defined by chondritic meteorites in a Mn/Na vs Mn/Mg plot, which tend to higher Mn/Na with increasing volatile depletion. This suggests that the material that formed the Earth recorded similar chemical fractionation processes for moderately volatile elements as chondrites in the solar nebula, and experienced limited post

  3. Siderophile Volatile Element Partitioning during Core Formation.

    Science.gov (United States)

    Loroch, D. C.; Hackler, S.; Rohrbach, A.; Klemme, S.

    2017-12-01

    Since the nineteen sixties it is known, that the Earth's mantle is depleted relative to CI chondrite in numerous elements as a result of accretion and core-mantle differentiation. Additionally, if we take the chondritic composition as the initial solar nebular element abundances, the Earth lacks 85 % of K and up to 98 % of other volatiles. However one potentially very important group of elements has received considerably less attention in this context and these elements are the siderophile but volatile elements (SVEs). SVEs perhaps provide important information regarding the timing of volatile delivery to Earth. Especially for the SVEs the partitioning between metal melt and silicate melt (Dmetal/silicate) at core formation conditions is poorly constrained, never the less they are very important for most of the core formation models. This study is producing new metal-silicate partitioning data for a wide range of SVEs (S, Se, Te, Tl, Ag, As, Au, Cd, Bi, Pb, Sn, Cu, Ge, Zn, In and Ga) with a focus on the P, T and fO2dependencies. The initial hypothesis that we are aiming to test uses the accretion of major portions of volatile elements while the core formation was still active. The key points of this study are: - What are the effects of P, T and fO2 on SVE metal-silicate partioning? - What is the effect of compositional complexity on SVE metal-silicate partioning? - How can SVE's D-values fit into current models of core formation? The partitioning experiments will be performed using a Walker type multi anvil apparatus in a pressure range between 10 and 20 GPa and temperatures of 1700 up to 2100 °C. To determine the Dmetal/silicate values we are using a field emission high-resolution JEOL JXA-8530F EPMA for major elements and a Photon Machines Analyte G2 Excimer laser (193 nm) ablation system coupled to a Thermo Fisher Element 2 single-collector ICP-MS (LA-ICP-MS) for the trace elements. We recently finished the first sets of experiments and can provide the

  4. Stability and `volatility ` of element 104 oxychloride

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, B.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The formation enthalpies {Delta}H{sup *} of solid and gaseous oxychlorides of element 104 from free atoms were estimated by extrapolation. Stability and volatility of these compounds are compared to those of the homologous and neighbouring elements in the periodic system. It can be supposed that in a gas adsorption chromatographic process with oxygen containing chlorinating carrier gas the transport with the carrier gas flow occurs in the chemical state 104Cl{sub 4}. Only in the absorbed state the compound 104OCl{sub 2} is formed. (author) 1 fig., 3 refs.

  5. Volatile characteristic of trace elements during microwave pyrolysis of oil shale

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Jing-ru; Wang, Qing; Kong, Ling-wen; Bai, Zhang [Northeast Dianli Univ., Jilin (China). Engineering Research Centre

    2013-07-01

    Oil shale is abundant in the world. Today, the industry of oil shale retorting for producing shale oil is developing owing to high price of oil in the world. In order to study migratory behavior of trace elements in oil shale at microwave pyrolysis, tests were performed in laboratory with oil shale of the Huadian deposit of China at different powers from 400 to 700 W. The trace elements As, Cd, Hg, Mo, Pb, Se, Cr, Cu, Ni, V, Zn, Ba, Co, Mn present in oil shale and shale char were determined by the inductively coupled plasma-mass spectrometry (ICP-MS). By comparing the content of trace elements in oil shale and shale char, distribution characteristics of trace elements at retorting were studied. The overall trends of volatile ratio of trace elements are ascending with higher microwave power and higher than the conventional pyrolysis. The differences in the volatile ratio indicate that the trace elements investigated are bound with the oil shale kerogen and its mineral matter in different manner. So Float-sink experiments (FSE) were performed on oil shale. Huadian oil shale has more included mineral. The volatilization of organic matter is not the main reason for the volatilization of trace elements in oil shale. The trace elements combined with the mineral elements may be also certain volatility.

  6. Elemental volatility of HT-9 fusion reactor alloy

    International Nuclear Information System (INIS)

    Henslee, S.P.; Neilson, R.M. Jr.

    1985-01-01

    The volatility of elemental constituents from HT-9, a ferritic steel, proposed for fusion reactor structures, was investigated. Tests were conducted in flowing air at temperatures from 800 to 1200 0 C for durations of 1 to 20 h. Elemental volatility was calculated in terms of the weight fraction of the element volatilized from the initial alloy; molybdenum, manganese, and nickel were the primary constituents volatilized. Comparisons with elemental volatilities observed for another candidate fusion reactor materials. Primary Candidate Alloy (PCA), an austenitic stainless steel, indicate significant differences between the volatilities of these steels that may impact fusion reactor safety analysis and alloy selection. Scanning electron microscopy and energy dispersive spectrometry were used to investigate the oxide layers formed on HT-9 and to measure elemental contents within these layers

  7. Core-Mantle Partitioning of Volatile Elements and the Origin of Volatile Elements in Earth and Moon

    Science.gov (United States)

    Righter, K.; Pando, K.; Danielson, L.; Nickodem, K.

    2014-01-01

    Depletions of siderophile elements in mantles have placed constraints on the conditions on core segregation and differentiation in bodies such as Earth, Earth's Moon, Mars, and asteroid 4 Vesta. Among the siderophile elements there are a sub-set that are also volatile (volatile siderophile elements or VSE; Ga, Ge, In, As, Sb, Sn, Bi, Zn, Cu, Cd), and thus can help to constrain the origin of volatile elements in these bodies, and in particular the Earth and Moon. One of the fundamental observations of the geochemistry of the Moon is the overall depletion of volatile elements relative to the Earth, but a satisfactory explanation has remained elusive. Hypotheses for Earth include addition during accretion and core formation and mobilized into the metallic core, multiple stage origin, or addition after the core formed. Any explanation for volatile elements in the Earth's mantle must also be linked to an explanation of these elements in the lunar mantle. New metal-silicate partitioning data will be applied to the origin of volatile elements in both the Earth and Moon, and will evaluate theories for exogenous versus endogenous origin of volatile elements.

  8. Origin of Volatiles in Earth: Indigenous Versus Exogenous Sources Based on Highly Siderophile, Volatile Siderophile, and Light Volatile Elements

    Science.gov (United States)

    Righter, K.; Danielson, L.; Pando, K. M.; Marin, N.; Nickodem, K.

    2015-01-01

    Origin of Earth's volatiles has traditionally been ascribed to late accretion of material after major differentiation events - chondrites, comets, ice or other exogenous sources. A competing theory is that the Earth accreted its volatiles as it was built, thus water and other building blocks were present early and during differentiation and core formation (indigenous). Here we discuss geochemical evidence from three groups of elements that suggests Earth's volatiles were acquired during accretion and did not require additional sources after differentiation.

  9. Volatile element trends in gas-rich meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Bart, G; Lipschutz, M E [Purdue Univ., Lafayette, IN (USA). Dept. of Chemistry

    1979-09-01

    Study of 10 volatile elements (and non-volatile Co) in co-existing light and dark portions of 5 gas-rich chondrites indicates patterns of distinct but non-uniform enrichment of volatile elements. Only Cs is enriched in all samples; Bi and Tl enrichments covary. The observed enrichments are inconsistent with prior suggestions of admixture of C1 or C2 chondritic matter, whether pristine or partly devolatilized, but suggest that both light and dark portions of each chondrite represents a compositionally more extended sampling of parental nebular material than hitherto known.

  10. Volatile elements - water, carbon, nitrogen, noble gases - on Earth

    Science.gov (United States)

    Marty, B.

    2017-12-01

    Understanding the origin and evolution of life-bearing volatile elements (water, carbon, nitrogen) on Earth is a fruitful and debated area of research. In his pioneering work, W.W. Rubey inferred that the terrestrial atmosphere and the oceans formed from degassing of the mantle through geological periods of time. Early works on noble gas isotopes were consistent with this view and proposed a catastrophic event of mantle degassing early in Earth's history. We now have evidence, mainly from noble gas isotopes, that several cosmochemical sources contributed water and other volatiles at different stages of Earth's accretion. Potential contributors include the protosolar nebula gas that equilibrated with magma oceans, inner solar system bodies now represented by chondrites, and comets. Stable isotope ratios suggest volatiles where primarily sourced by planetary bodies from the inner solar system. However, recent measurements by the European Space Agency Rosetta probe on the coma of Comet 67P/Churyumov-Gerasimenko permit to set quantitative constraints on the cometary contribution to the surface of our planet. The surface and mantle reservoirs volatile elements exchanged volatile elements through time, with rates that are still uncertain. Some mantle regions remained isolated from whole mantle convection within the first tens to hundreds million years after start of solar system formation. These regions, now sampled by some mantle plumes (e.g., Iceland, Eifel) preserved their volatile load, as indicated by extinct and extant radioactivity systems. The abundance of volatile elements in the mantle is still not well known. Different approaches, such as high pressure experimental petrology, noble gas geochemistry, modelling, resulted in somewhat contrasted estimates, varying over one order of magnitude for water. Comparative planetology, that is, the study of volatiles on the Moon, Venus, Mars, Vesta, will shed light on the sources and strengths of these elements in the

  11. Volatile Element Fluxes at Copahue Volcano, Argentina

    Science.gov (United States)

    Varekamp, J. C.

    2002-05-01

    Copahue volcano has a crater lake and acid hot springs that discharge into the Rio Agrio river system. These fluids are very concentrated (up to 6 % sulfate), rich in rock-forming elements (up to 2000 ppm Mg) and small spheres of native sulfur float in the crater lake. The stable isotope composition of the waters (delta 18O =-2.1 to + 3.6 per mille; delta D = -49 to -26 per mille) indicates that the hot spring waters are at their most concentrated about 70% volcanic brine and 30 % glacial meltwater. The crater lake waters have similar mixing proportions but added isotope effects from intense evaporation. Further dilution of the waters in the Rio Agrio gives values closer to local meteoric waters (delta 18O = -11 per mille; delta D = -77 per mille), whereas evaporation in closed ponds led to very heavy water (up to delta 18O = +12 per mille). The delta 34S value of dissolved sulfate is +14.2 per mille, whereas the native sulfur has values of -8.2 to -10.5 per mille. The heavy sulfate probably formed when SO2 disproportionated into bisulfate and native sulfur at about 300 C. We measured the sulfate fluxes in the Rio Agrio, which ranged from 20-40 kilotons S/year. The whole system was releasing sulfur at an equivalent rate of about 250-650 tons SO2/day. From the river flux sulfur values and the stochiometry of the disproportionation reaction we calculated the rate of liquid sulfur storage inside the volcano (6000 m3/year). During the eruptions of 1995/2000, large amounts of that stored liquid sulfur were ejected as pyroclastic sulfur. The calculated rate of rock dissolution (from rock- forming element fluxes in the Rio Agrio) suggests that the void space generated by rock dissolution is largely filled by native sulfur and silica. The S/Cl ratio in the hydrothermal fluids is about 2, whereas glass inclusions have S/Cl = 0.2, indicating the strong preferential degassing of sulfur.

  12. Volatile element loss during planetary magma ocean phases

    Science.gov (United States)

    Dhaliwal, Jasmeet K.; Day, James M. D.; Moynier, Frédéric

    2018-01-01

    Moderately volatile elements (MVE) are key tracers of volatile depletion in planetary bodies. Zinc is an especially useful MVE because of its generally elevated abundances in planetary basalts, relative to other MVE, and limited evidence for mass-dependent isotopic fractionation under high-temperature igneous processes. Compared with terrestrial basalts, which have δ66Zn values (per mille deviation of the 66Zn/64Zn ratio from the JMC-Lyon standard) similar to some chondrite meteorites (∼+0.3‰), lunar mare basalts yield a mean δ66Zn value of +1.4 ± 0.5‰ (2 st. dev.). Furthermore, mare basalts have average Zn concentrations ∼50 times lower than in typical terrestrial basaltic rocks. Late-stage lunar magmatic products, including ferroan anorthosite, Mg- and Alkali-suite rocks have even higher δ66Zn values (+3 to +6‰). Differences in Zn abundance and isotopic compositions between lunar and terrestrial rocks have previously been interpreted to reflect evaporative loss of Zn, either during the Earth-Moon forming Giant Impact, or in a lunar magma ocean (LMO) phase. To explore the mechanisms and processes under which volatile element loss may have occurred during a LMO phase, we developed models of Zn isotopic fractionation that are generally applicable to planetary magma oceans. Our objective was to identify conditions that would yield a δ66Zn signature of ∼+1.4‰ within the lunar mantle. For the sake of simplicity, we neglect possible Zn isotopic fractionation during the Giant Impact, and assumed a starting composition equal to the composition of the present-day terrestrial mantle, assuming both the Earth and Moon had zinc 'consanguinity' following their formation. We developed two models: the first simulates evaporative fractionation of Zn only prior to LMO mixing and crystallization; the second simulates continued evaporative fractionation of Zn that persists until ∼75% LMO crystallization. The first model yields a relatively homogenous bulk solid

  13. Efficient growth of HTS films with volatile elements

    Energy Technology Data Exchange (ETDEWEB)

    Siegal, M.P.; Overmyer, D.L.; Dominguez, F.

    1998-12-22

    A system is disclosed for applying a volatile element-HTS layer, such as Tl-HTS, to a substrate in a multiple zone furnace, said method includes heating at higher temperature, in one zone of the furnace, a substrate and adjacent first source of Tl-HTS material, to sublimate Tl-oxide from the source to the substrate; and heating at lower temperature, in a separate zone of the furnace, a second source of Tl-oxide to replenish the first source of Tl-oxide from the second source. 3 figs.

  14. TWO EXTRASOLAR ASTEROIDS WITH LOW VOLATILE-ELEMENT MASS FRACTIONS

    International Nuclear Information System (INIS)

    Jura, M.; Xu, S.; Klein, B.; Zuckerman, B.; Koester, D.

    2012-01-01

    Using ultraviolet spectra obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope, we extend our previous ground-based optical determinations of the composition of the extrasolar asteroids accreted onto two white dwarfs, GD 40 and G241-6. Combining optical and ultraviolet spectra of these stars with He-dominated atmospheres, 13 and 12 polluting elements are confidently detected in GD 40 and G241-6, respectively. For the material accreted onto GD 40, the volatile elements C and S are deficient by more than a factor of 10 and N by at least a factor of 5 compared to their mass fractions in primitive CI chondrites and approach what is inferred for bulk Earth. A similar pattern is found for G241-6 except that S is undepleted. We have also newly detected or placed meaningful upper limits for the amount of Cl, Al, P, Ni, and Cu in the accreted matter. Extending results from optical studies, the mass fractions of refractory elements in the accreted parent bodies are similar to what is measured for bulk Earth and chondrites. Thermal processing, perhaps interior to a snow line, appears to be of central importance in determining the elemental compositions of these particular extrasolar asteroids.

  15. High salinity volatile phases in magmatic Ni-Cu-platinum group element deposits

    Science.gov (United States)

    Hanley, J. J.; Mungall, J. E.

    2004-12-01

    The role of "deuteric" fluids (exsolved magmatic volatile phases) in the development of Ni-Cu-PGE (platinum group element) deposits in mafic-ultramafic igneous systems is poorly understood. Although considerable field evidence demonstrates unambiguously that fluids modified most large primary Ni-Cu-PGE concentrations, models which hypothesize that fluids alone were largely responsible for the economic concentration of the base and precious metals are not widely accepted. Determination of the trace element composition of magmatic volatile phases in such ore-forming systems can offer considerable insight into the origin of potentially mineralizing fluids in such igneous environments. Laser ablation ICP-MS microanalysis allows researchers to confirm the original metal budget of magmatic volatile phases and quantify the behavior of trace ore metals in the fluid phase in the absence of well-constrained theoretical or experimental predictions of ore metal solubility. In this study, we present new evidence from major deposits (Sudbury, Ontario, Canada; Stillwater Complex, Montana, U.S.A.) that compositionally distinct magmatic brines and halide melt phases were exsolved from crystallizing residual silicate melt and trapped within high-T fluid conduits now comprised of evolved rock compositions (albite-quartz graphic granite, orthoclase-quartz granophyre). Petrographic evidence demonstrates that brines and halide melts coexisted with immiscible carbonic phases at the time of entrapment (light aliphatic hydrocarbons, CO2). Brine and halide melt inclusions are rich in Na, Fe, Mn, K, Pb, Zn, Ba, Sr, Al and Cl, and homogenize by either halite dissolution at high T ( ˜450-700° C) or by melting of the salt phase (700-800° C). LA-ICPMS analyses of single inclusions demonstrate that high salinity volatile phases contained abundant base metals (Cu, Fe, Sn, Bi) and precious metals (Pt, Pd, Au, Ag) at the time of entrapment. Notably, precious metal concentrations in the inclusions

  16. A volatile topic: Parsing out the details of Earth's formation through experimental metal-silicate partitioning of volatile and moderately volatile elements

    Science.gov (United States)

    Mahan, B. M.; Siebert, J.; Blanchard, I.; Badro, J.; Sossi, P.; Moynier, F.

    2017-12-01

    Volatile and moderately volatile elements display different volatilities and siderophilities, as well as varying sensitivity to thermodynamic controls (X, P, T, fO2) during metal-silicate differentiation. The experimental determination of the metal-silicate partitioning of these elements permits us to evaluate processes controlling the distribution of these elements in Earth. In this work, we have combined metal-silicate partitioning data and results for S, Sn, Zn and Cu, and input these characterizations into Earth formation models. Model parameters such as source material, timing of volatile delivery, fO2 path, and degree of impactor equilibration were varied to encompass an array of possible formation scenarios. These models were then assessed to discern plausible sets of conditions that can produce current observed element-to-element ratios (e.g. S/Zn) in the Earth's present-day mantle, while also satisfying current estimates on the S content of the core, at no more than 2 wt%. The results of our models indicate two modes of accretion that can maintain chondritic element-to-element ratios for the bulk Earth and can arrive at present-day mantle abundances of these elements. The first mode requires the late addition of Earth's entire inventory of these elements (assuming a CI-chondritic composition) and late-stage accretion that is marked by partial equilibration of large impactors. The second, possibly more intuitive mode, requires that Earth accreted - at least initially - from volatile poor material preferentially depleted in S relative to Sn, Zn, and Cu. From a chemical standpoint, this source material is most similar to type I chondrule rich (and S poor) materials (Hewins and Herzberg, 1996; Mahan et al., 2017; Amsellem et al., 2017), such as the metal-bearing carbonaceous chondrites.

  17. Ferroelectric polymer gates for non-volatile field effect control of ferromagnetism in (Ga, Mn)As layers

    International Nuclear Information System (INIS)

    Stolichnov, I; Riester, S W E; Mikheev, E; Setter, N; Rushforth, A W; Edmonds, K W; Campion, R P; Foxon, C T; Gallagher, B L; Jungwirth, T; Trodahl, H J

    2011-01-01

    (Ga, Mn)As and other diluted magnetic semiconductors (DMS) attract a great deal of attention for potential spintronic applications because of the possibility of controlling the magnetic properties via electrical gating. Integration of a ferroelectric gate on the DMS channel adds to the system a non-volatile memory functionality and permits nanopatterning via the polarization domain engineering. This topical review is focused on the multiferroic system, where the ferromagnetism in the (Ga, Mn)As DMS channel is controlled by the non-volatile field effect of the spontaneous polarization. Use of ferroelectric polymer gates in such heterostructures offers a viable alternative to the traditional oxide ferroelectrics generally incompatible with DMS. Here we review the proof-of-concept experiments demonstrating the ferroelectric control of ferromagnetism, analyze the performance issues of the ferroelectric gates and discuss prospects for further development of the ferroelectric/DMS heterostructures toward the multiferroic field effect transistor. (topical review)

  18. Early accretion of water and volatile elements to the inner Solar System: evidence from angrites.

    Science.gov (United States)

    Sarafian, Adam R; Hauri, Erik H; McCubbin, Francis M; Lapen, Thomas J; Berger, Eve L; Nielsen, Sune G; Marschall, Horst R; Gaetani, Glenn A; Righter, Kevin; Sarafian, Emily

    2017-05-28

    Inner Solar System bodies are depleted in volatile elements relative to chondrite meteorites, yet the source(s) and mechanism(s) of volatile-element depletion and/or enrichment are poorly constrained. The timing, mechanisms and quantities of volatile elements present in the early inner Solar System have vast implications for diverse processes, from planetary differentiation to the emergence of life. We report major, trace and volatile-element contents of a glass bead derived from the D'Orbigny angrite, the hydrogen isotopic composition of this glass bead and that of coexisting olivine and silicophosphates, and the 207 Pb- 206 Pb age of the silicophosphates, 4568 ± 20 Ma. We use volatile saturation models to demonstrate that the angrite parent body must have been a major body in the early inner Solar System. We further show via mixing calculations that all inner Solar System bodies accreted volatile elements with carbonaceous chondrite H and N isotope signatures extremely early in Solar System history. Only a small portion (if any) of comets and gaseous nebular H species contributed to the volatile content of the inner Solar System bodies.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

  19. Composition of the earth's upper mantle. II - Volatile trace elements in ultramafic xenoliths

    Science.gov (United States)

    Morgan, J. W.; Wandless, G. A.; Petrie, R. K.; Irving, A. J.

    1980-01-01

    Radiochemical neutron activation analysis was used to determine the nine volatile elements Ag, Bi, Cd, In, Sb, Se, Te, Tl, and Zn in 19 ultramafic rocks, consisting mainly of spinel and garnet lherzolites. A sheared garnet lherzolite, PHN 1611, may approximate undepleted mantle material and tends to have a higher volatile element content than the depleted mantle material represented by spinel lherzolites. Comparisons of continental basalts with PHN 1611 and of oceanic ridge basalts with spinel lherzolites show similar basalt: source material partition factors for eight of the nine volatile elements, Sb being the exception. The strong depletion of Te and Se in the mantle, relative to lithophile elements of similar volatility, suggests that 97% of the earth's S, Se and Te may be in the outer core.

  20. Organic and volatile elements in the solar system

    Directory of Open Access Journals (Sweden)

    Remusat L.

    2012-01-01

    Full Text Available Chondrites and comets have accreted primitive materials from the early solar system. Those materials include organics, water and other volatile components. The most primitive chondrites and comets have undergone few modifications on their respective parent bodies and can deliver to laboratories components that were present at the origin of the protosolar nebula. Here I present a review of the organic material and volatile components that have been studied in the most primitive chondrites, and the last data from the stardust mission about the cometary record. This paper focuses on materials that can be studied in laboratories, by mass spectrometry, ion probes or organic chemistry techniques.

  1. Distribution, movement, and evolution of the volatile elements in the lunar regolith

    International Nuclear Information System (INIS)

    Gibson, E.K. Jr.

    1975-01-01

    The abundances and distributions of carbon, nitrogen, and sulfur in lunar soils are reviewed. Carbon and nitrogen have a predominantly extra-lunar origin in lunar soils and breccias, while sulfur is mostly indigeneous to the Moon. The lunar processes which effect the movement, distribution, and evolution of carbon, nitrogen, and sulfur, along with the volatile alkali elements sodium, potassium, and rubidium during regolith processes are discussed. Possible mechanisms which may result in the addition to or loss from the Moon of these volatile elements are considered. (Auth.)

  2. Distribution, movement, and evolution of the volatile elements in the lunar regolith

    Science.gov (United States)

    Gibson, E. K., Jr.

    1975-01-01

    The abundances and distributions of carbon, nitrogen, and sulfur in lunar soils are reviewed. Carbon and nitrogen have a predominantly extra-lunar origin in lunar soils and breccias, while sulfur is mostly indigeneous to the moon. The lunar processes which effect the movement, distribution, and evolution of carbon, nitrogen, and sulfur, along with the volatile alkali elements sodium, potassium, and rubidium during regolith processes are discussed. Possible mechanisms which may result in the addition to or loss from the moon of these volatile elements are considered.

  3. The lunar core can be a major reservoir for volatile elements S, Se, Te and Sb.

    Science.gov (United States)

    Steenstra, Edgar S; Lin, Yanhao; Dankers, Dian; Rai, Nachiketa; Berndt, Jasper; Matveev, Sergei; van Westrenen, Wim

    2017-11-06

    The Moon bears a striking compositional and isotopic resemblance to the bulk silicate Earth (BSE) for many elements, but is considered highly depleted in many volatile elements compared to BSE due to high-temperature volatile loss from Moon-forming materials in the Moon-forming giant impact and/or due to evaporative loss during subsequent magmatism on the Moon. Here, we use high-pressure metal-silicate partitioning experiments to show that the observed low concentrations of volatile elements sulfur (S), selenium (Se), tellurium (Te), and antimony (Sb) in the silicate Moon can instead reflect core-mantle equilibration in a largely to fully molten Moon. When incorporating the core as a reservoir for these elements, their bulk Moon concentrations are similar to those in the present-day bulk silicate Earth. This suggests that Moon formation was not accompanied by major loss of S, Se, Te, Sb from Moon-forming materials, consistent with recent indications from lunar carbon and S isotopic compositions of primitive lunar materials. This is in marked contrast with the losses of other volatile elements (e.g., K, Zn) during the Moon-forming event. This discrepancy may be related to distinctly different cosmochemical behavior of S, Se, Te and Sb within the proto-lunar disk, which is as of yet virtually unconstrained.

  4. Distribution of volatile and non volatile elements in grain-size fractions of Apollo 17 drive tube 74001/2

    International Nuclear Information System (INIS)

    Kraehenbuehl, U.

    1980-01-01

    A study of four samples of double drive tube 74001/2 originating from 12, 25, 38, and 58 cm depths indicates that the concentrations of major and nonvolatile elements are fairly uniform for the four layers and the individual size fractions, while volatile elements as well as Au and Ir are enriched in the smaller grain-size fractions. It is concluded from the measured Au/Ir ratios and from the absence of a surface enrichment of Co that the material in the drive tube 74001/2 is not the result of an impact of an iron meteorite into a lava lake, but originated in at least three volcanic eruptions. No indication of a later disturbance of the stratigraphy of the layers is observed. Exposure ages of 345,000 and 225,000 years result from Ir deposits for the two layers of 74002

  5. Effect of alloying elements on σ phase formation in Fe-Cr-Mn alloys

    International Nuclear Information System (INIS)

    Okazaki, Yoshimitsu; Miyahara, Kazuya; Hosoi, Yuzo; Tanino, Mitsuru; Komatsu, Hazime.

    1989-01-01

    Alloys of Fe-(8∼12%) Cr-(5∼30%) Mn were solution-treated at 1373 K for 3.6 ks, followed by cold-working of 50% reduction. Both solution-treated and 50% cold-worked materials were aged in the temperature range from 773 to 973 K for 3.6 x 10 3 ks. The identification of σ phase formation was made by using X-ray diffraction from the electrolytically extracted residues of the aged specimens. The region of σ phase formation determined by the present work is wider than that on the phase diagram already reported. It is to be noted that Mn promotes markedly the σ phase formation, and that three different types of σ phase formation are observed depending on Mn content: α→γ + α→γ + α + σ in 10% Mn, α→γ + σ in 15 to 20% Mn alloys, α→χ(Chi) →χ + σ + γ in 25 to 30% Mn alloys. An average electron concentration (e/a) in the σ phase was estimated by quantitative analysis of alloying elements using EPMA. The e/a value in the σ phase formed in Fe-(12∼16%) Cr-Mn alloys aged at 873 K for 3.6 x 10 3 ks is about 7.3, which is independent of Mn content. In order to prevent σ phase formation in Fe-12% Cr-15% Mn alloy, the value of Ni * eq of 11 (Ni * eq = Ni + 30(C) + 25(N)) is required. (author)

  6. Rust and schreibersite in Apollo 16 highland rocks - Manifestations of volatile-element mobility

    Science.gov (United States)

    Hunter, R. H.; Taylor, L. A.

    Rust is a manifestation of halogen and volatile-metal mobility in the lunar environment. Schreibersite is stable as the primary phosphorus-bearing phase in the highland rocks, a consequence of the inherently low oxygen fugacity within impact-generated melts. Apatite and whitlockite are subordinate in these rocks. The partitioning of P into phosphide in impact-generated melts, and the failure of phosphate to crystallize, effects a decoupling of the halogens and phosphorus. Of the Apollo 16 rocks, 63% contain rust, 70% contain schreibersite, and 52% contain both phases, thereby establishing the pervasiveness of volatile-elements throughout the highland rocks. The major portion of these volatile-bearing phases occur in impact melt-rocks or in breccia matrices. Rhabdites of schreibersite in some of the FeNi grains indicate that there is a meteoritic contribution to the phosphorus in these rocks. Cl/P2O5 ratios in lunar highland rocks are a function of secondary effects, with any apparent Cl-P correlations being coincidential. The present observations preclude the validity of models based on such elemental ratios in these rocks. The presence of rust in the clast laden matrices of pristine rocks indicates fugitive element localization. Pristine clasts may have been contaminated. The basis for a pristine volatile chemistry is questioned.

  7. Determination of refractive and volatile elements in sediment using laser ablation inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Duodu, Godfred Odame; Goonetilleke, Ashantha; Allen, Charlotte; Ayoko, Godwin A

    2015-10-22

    Wet-milling protocol was employed to produce pressed powder tablets with excellent cohesion and homogeneity suitable for laser ablation (LA) analysis of volatile and refractive elements in sediment. The influence of sample preparation on analytical performance was also investigated, including sample homogeneity, accuracy and limit of detection. Milling in volatile solvent for 40 min ensured sample is well mixed and could reasonably recover both volatile (Hg) and refractive (Zr) elements. With the exception of Cr (-52%) and Nb (+26%) major, minor and trace elements in STSD-1 and MESS-3 could be analysed within ±20% of the certified values. Comparison of the method with total digestion method using HF was tested by analysing 10 different sediment samples. The laser method recovers significantly higher amounts of analytes such as Ag, Cd, Sn and Sn than the total digestion method making it a more robust method for elements across the periodic table. LA-ICP-MS also eliminates the interferences from chemical reagents as well as the health and safety risks associated with digestion processes. Therefore, it can be considered as an enhanced method for the analysis of heterogeneous matrices such as river sediments. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Effect of alloying elements on the shape memory properties of ductile Cu-Al-Mn alloys

    International Nuclear Information System (INIS)

    Sutou, Y.; Kainuma, R.; Ishida, K.

    1999-01-01

    The effect of alloying elements on the M s temperature, ductility and the shape memory properties of Cu-Al-Mn ductile shape memory (SM) alloys was investigated by differential scanning calorimetry, cold-rolling and tensile test techniques. It was found that the addition of Au, Si and Zn to the Cu 73 -Al 17 -Mn 10 alloy stabilized the martensite (6M) phase increasing the M s temperature, while the addition of Ag, Co, Cr, Fe, Ni, Sn and Ti decreased the stability of the martensite phase, decreasing the M s temperature. The SM properties were improved by the addition of Co, Ni, Cr and Ti. (orig.)

  9. Volatility

    Directory of Open Access Journals (Sweden)

    María Sánchez

    2016-11-01

    Full Text Available The action consists of moving with small kicks a tin of cola refresh -without Brand-from a point of the city up to other one. During the path I avoid bollards, the slope differences between sidewalks, pedestrians, parked motorcycles, etc. Volatility wants to say exactly that the money is getting lost. That the money is losing by gentlemen and by ladies who are neither financial sharks, nor big businessmen… or similarly, but ingenuous people, as you or as me, who walk down the street.

  10. Quantitative microanalysis of Mn, Zn and other elements in mature wheat seed

    International Nuclear Information System (INIS)

    Mazzolini, A.P.; Pallaghy, C.K.; Legge, G.J.F.

    1984-01-01

    A scanning proton microprobe has been used to determine quantitatively the distribution of Mn,Zn and other elements in the mature wheat seed. Both X-ray and nuclear scattered proton data were collected during the irradiation of a 40 μ-thick longitudinal section, and these were used to calculate absolute elemental concentrations for the various features of interest in the embryo region. In the embryo, Mn was highest in the radicle (1400 +- 200 ppm) and lowest in the coleorhiza (200 +- 30 ppm), whereas Zn was highest in the scutellum (600 +- 100 ppm) and lowest in the leaf primordium (410 +- 70 ppm). Comparisons with direct bulk chemical analysis of excised embryos showed agreement. The possible biological significance of the distribution of elements is discussed

  11. Determination of refractive and volatile elements in sediment using laser ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Duodu, Godfred Odame [School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology (QUT), 2 George St, 4001, QLD (Australia); Goonetilleke, Ashantha [School of Civil Engineering and Built Environment, Science and Engineering Faculty, Queensland University of Technology (QUT), 2 George St, 4001, QLD (Australia); Allen, Charlotte [Institute for Future Environments, Queensland University of Technology (QUT), 2 George St, 4001, QLD (Australia); Ayoko, Godwin A., E-mail: g.ayoko@qut.edu.au [School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology (QUT), 2 George St, 4001, QLD (Australia)

    2015-10-22

    Wet-milling protocol was employed to produce pressed powder tablets with excellent cohesion and homogeneity suitable for laser ablation (LA) analysis of volatile and refractive elements in sediment. The influence of sample preparation on analytical performance was also investigated, including sample homogeneity, accuracy and limit of detection. Milling in volatile solvent for 40 min ensured sample is well mixed and could reasonably recover both volatile (Hg) and refractive (Zr) elements. With the exception of Cr (−52%) and Nb (+26%) major, minor and trace elements in STSD-1 and MESS-3 could be analysed within ±20% of the certified values. Comparison of the method with total digestion method using HF was tested by analysing 10 different sediment samples. The laser method recovers significantly higher amounts of analytes such as Ag, Cd, Sn and Sn than the total digestion method making it a more robust method for elements across the periodic table. LA-ICP-MS also eliminates the interferences from chemical reagents as well as the health and safety risks associated with digestion processes. Therefore, it can be considered as an enhanced method for the analysis of heterogeneous matrices such as river sediments. - Highlights: • Wet milling was used to produce pressed tablet sediment for LA-ICP-MS analysis. • Milling was effective for refractive elements with narrow range of particle size. • This is the first use of LA-ICP-MS for Hg analysis in sediment samples. • Acceptable accuracy and precision were obtained for most of the elements studied. • Detection limits down to parts per trillion were observed for some elements.

  12. Origin of the earth's moon: constraints from alkali volatile trace elements

    International Nuclear Information System (INIS)

    Kreutzberger, M.E.; Drake, M.J.; Jones, J.H.

    1986-01-01

    Although the Moon is depleted in volatile elements compared to the Earth, these depletions are not in accord with simple volatility. For example, the Cs/Rb ratios of the Earth and Moon inferred from basalts are approximately one seventh and one half of the CI ratio, respectively. Volatility considerations alone predict that the lunar Cs/Rb ratio should be equal to or lower than the terrestrial ratio if the Moon was derived entirely from Earth mantle material. Thus hypotheses such as rotational fission which invoke derivation of lunar material entirely from the Earth's mantle may be excluded. The collisional ejection hypothesis of lunar origin requires at least 18% of lunar material to be derived from a projectile with dehydrated CI composition to match the lunar Cs/Rb ratio, and 25% to 50% to match both the lunar Cs/Rb ratio and absolute concentrations of Cs and Rb. It remains to be demonstrated that this relatively large contribution of projectile material is consistent with other elemental abundances and element ratios in the Moon. (author)

  13. Agricultural management, season and trace elements effects on volatile oil production from Melissa officinalis L. (Lemon balm)

    International Nuclear Information System (INIS)

    Sussa, Fabio Vitorio; Duarte, Celina Lopes; Silva, Paulo Sergio Cardoso da; Furlan, Marcos Roberto

    2016-01-01

    The objective of this study was to provide information about organic and mineral fertilization, season and trace elements effects on volatile oil production by the species Melissa officinalis. Elemental concentration was determined by instrumental neutron activation analysis and atomic absorption spectrometry. The volatile oil was extracted by hydrodistillation and analyzed by gas chromatography coupled to a mass spectrometer. The elemental content and the main compounds vary according to agricultural management and season. The results indicate that the production of volatile oil main compounds from M. officinalis is correlated with the concentrations of Na, Co, Rb, Cd, Cs, La, Sm and Hf. (author)

  14. Evolution of Mg-5Al-0.4Mn microstructure after rare earth elements addition

    Directory of Open Access Journals (Sweden)

    A. Żydek

    2011-04-01

    Full Text Available Mg-5Al-0.4Mn-xRE (x = 0, 1, 2, 3 wt.% magnesium alloys were prepared successfully by casting method. The microstructure wasinvestigated by light microscopy. The influence of rare earth (RE elements on the area fraction of eutectic was analysed. The obtainedresults revealed that the as-cast Mg-5Al-0.4Mn alloy consist of α - Mg matrix and eutectic α + γ (where γ is Mg17Al12. However, whilerare earth elements were added to the Mg-Al type alloy, Al11RE3 precipitates were formed. The amount of the Al11RE3 precipitatesincreased with increasing addition of RE, but the amount of γ - Mg17Al12 decreased.

  15. Determination of Trace and Volatile Element Abundance Systematics of Lunar Pyroclastic Glasses 74220 and 15426 Using LA-ICP-MS

    Science.gov (United States)

    McIntosh, E. Carrie; Porrachia, Magali; McCubbin, Francis M.; Day, James M. D.

    2017-01-01

    Since their recognition as pyroclastic glasses generated by volcanic fire fountaining on the Moon, 74220 and 15426 have garnered significant scientific interest. Early studies recognized that the glasses were particularly enriched in volatile elements on their surfaces. More recently, detailed analyses of the interiors of the glasses, as well as of melt inclusions within olivine grains associated with the 74220 glass beads, have determined high H2O, F, Cl and S contents. Such elevated volatile contents seem at odds with evidence from moderately volatile elements (MVE), such as Zn and K, for a volatile- depleted Moon. In this study, we present initial results from an analytical campaign to study trace element abundances within the pyroclastic glass beads. We report trace element data determined by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for 15426 and 74220.

  16. Meteoritic Constraints on Models of the Solar Nebula: The Abundances of Moderately Volatile Elements

    Science.gov (United States)

    Cassen, Patrick; Cuzzi, Jeff (Technical Monitor)

    1994-01-01

    The "moderately volatile" elements are those which condense (or evaporate) in the temperature range 650 - 1350 K, as a mix of material with solar abundances is cooled (or heated) tinder equilibrium conditions. Their relative abundances in chondritic meteorites are solar (or "cosmic", as defined by the composition of Cl meteorites) to within a factor of several, but vary within that range in a way that correlates remarkably well with condensation temperature, independent of chemical affinity. It has been argued that this correlation reflects a systematically selective process which favored the accretion of refractory material over volatile material from a cooling nebula. Wasson and Chou (Meteoritics 9, 69-94, 1974, and Wasson and co-authors in subsequent papers) suggested that condensation and settling of solids contemporaneously with the cooling and removal of nebular gas could produce the observed abundance patterns, but a quantitative model has been lacking. We show that the abundance patterns of the moderately volatile elements in chondritic meteorites can be produced, in some degree of quantitative detail, by models of the solar nebula that are designed to conform to observations of T Tauri stars and the global conservation laws. For example, even if the local surface density of the nebula is not decreasing, condensation and accretion of solids from radially inflowing gas in a cooling nebula can result in depletions of volatiles, relative to refractories, like those observed, The details of the calculated abundance patterns depend on (but are not especially sensitive to) model parameters, and can exhibit the variations that distinguish the meteorite classes. Thus it appears that nebula characteristics such as cooling rates, radial flow velocities, and particle accumulation rates can be quantitatively constrained by demanding that they conform to meteoritic data; and the models, in turn, can produce testable hypotheses regarding the time and location of the

  17. The Development of the Low-Cost Titanium Alloy Containing Cr and Mn Alloying Elements

    Science.gov (United States)

    Zhu, Kailiang; Gui, Na; Jiang, Tao; Zhu, Ming; Lu, Xionggang; Zhang, Jieyu; Li, Chonghe

    2014-04-01

    The α + β-type Ti-4.5Al-6.9Cr-2.3Mn alloy has been theoretically designed on the basis of assessment of the Ti-Al-Cr-Mn thermodynamic system and the relationship between the molybdenum equivalent and mechanical properties of titanium alloys. The alloy is successfully prepared by the split water-cooled copper crucible, and its microstructures and mechanical properties at room temperature are investigated using the OM, SEM, and the universal testing machine. The results show that the Ti-4.5Al-6.9Cr-2.3Mn alloy is an α + β-type alloy which is consistent with the expectation, and its fracture strength, yield strength, and elongation reach 1191.3, 928.4 MPa, and 10.7 pct, respectively. Although there is no strong segregation of alloying elements under the condition of as-cast, the segregation of Cr and Mn is obvious at the grain boundary after thermomechanical treatment.

  18. Dynamic measurement of coal thermal properties and elemental composition of volatile matter during coal pyrolysis

    Directory of Open Access Journals (Sweden)

    Rohan Stanger

    2014-01-01

    Full Text Available A new technique that allows dynamic measurement of thermal properties, expansion and the elemental chemistry of the volatile matter being evolved as coal is pyrolysed is described. The thermal and other properties are measured dynamically as a function of temperature of the coal without the need for equilibration at temperature. In particular, the technique allows for continuous elemental characterisation of tars as they are evolved during pyrolysis and afterwards as a function of boiling point. The technique is demonstrated by measuring the properties of maceral concentrates from a coal. The variation in heats of reaction, thermal conductivity and expansion as a function of maceral composition is described. Combined with the elemental analysis, the results aid in the interpretation of the chemical processes contributing to the physical and thermal behaviour of the coal during pyrolysis. Potential applications in cokemaking studies are discussed.

  19. Erosion of volatile elemental condensed gases by keV electron and light-ion bombardment

    International Nuclear Information System (INIS)

    Schou, J.

    1991-11-01

    Erosion of the most volatile elemental gases by keV electron and light-ion bombardment has been studied at the experimental setup at Risoe. The present work includes frozen neon, argon, krypton, nitrogen, oxygen and three hydrogen isotopes, deuterium, hydrogen deuteride and hydrogen. The yield of these condensed gases has been measured as a function of film thickness and primary energy for almost all combinations of primary particles (1-3 keV electrons, 5-10 keV hydrogen- and helium ions) and ices. These and other existing results show that there are substantial common features for the sputtering of frozen elemental gases. Within the two groups, the solid rare gases and the solid molecular gases, the similarity is striking. The hydrogenic solids deviate in some respects from the other elements. The processes that liberate kinetic energy for the particle ejection in sputtering are characteristic of the specific gas. (au) 3 tabs., 12 ills., 159 refs

  20. Effect of alloying elements on solidification of primary austenite in Ni-Mn-Cu cast iron

    Directory of Open Access Journals (Sweden)

    A. Janus

    2011-04-01

    Full Text Available Within the research, determined were direction and intensity of alloying elements influence on solidification way (directional orvolumetric of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu. 50 cast shafts dia. 20 mm were analysed.Chemical composition of the alloy was as follows: 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 to0.16 % P and 0.03 to 0.04 % S. The discriminant analysis revealed that carbon influences solidification of primary austenite dendrites most intensively. It clearly increases the tendency to volumetric solidification. Influence of the other elements is much weaker. This means that the solidification way of primary austenite dendrites in hypoeutectic austenitic cast iron Ni-Mn-Cu does not differ from that in an unalloyed cast iron.

  1. Low-activation Mn-Cr austenitic stainless steel with further reduced content of long-lived radioactive elements

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M.; Saida, T.; Hirai, S. [Mitsubishi Heavy Ind. Ltd., Yokohama (Japan); Kusuhashi, M.; Sato, I.; Hatakeyama, T. [The Japan Steel Works Ltd., Chatsu-machi 4, Muroran 051-8505 (Japan)

    1998-06-01

    Low-activation austenitic stainless steel based on Mn-Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn-Cr austenitic stainless steel, 24.5Mn-13.5Cr-0.02C-0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and characteristics of corrosion resistance, are presented. It was found that the alloy has excellent material properties virtually equivalent to those of 316SS. In this study, the applicability of the Schaeffler, DeLong and Hull constitution diagrams for the stainless steels with low Ni and high Mn contents was also examined. The boundary conditions distinguishing the single austenite phase from the others have been identified for the Mn-Cr steels. (orig.) 22 refs.

  2. Low-activation Mn Cr austenitic stainless steel with further reduced content of long-lived radioactive elements

    Science.gov (United States)

    Onozuka, Masanori; Saida, Tomikane; Hirai, Shouzou; Kusuhashi, Mikio; Sato, Ikuo; Hatakeyama, Tsuyoshi

    1998-06-01

    Low-activation austenitic stainless steel based on Mn-Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn-Cr austenitic stainless steel, 24.5Mn-13.5Cr-0.02C-0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and characteristics of corrosion resistance, are presented. It was found that the alloy has excellent material properties virtually equivalent to those of 316SS. In this study, the applicability of the Schaeffler, DeLong and Hull constitution diagrams for the stainless steels with low Ni and high Mn contents was also examined. The boundary conditions distinguishing the single austenite phase from the others have been identified for the Mn-Cr steels.

  3. The Fe/Mn constraint on precursors of basaltic achondrites

    Science.gov (United States)

    Delaney, Jeremy S.; Boesenberg, Joseph S.

    1993-01-01

    Most achondritic meteorites have Fe/Mn ratios that are lower than those of carbonaceous chondrites and of course are lower than the solar system abundance ratio of these elements. Models of the origin of achondritic assemblages must, therefore, account for these ratios. Fe/Mn ratios are suggested to be distinctive for samples from each achondrite parent body and for the Earth and Moon, but the correspondence between the Fe/Mn systematics of achondrites and chondritic precursors is unclear. Most models of achondrite genesis involve magmatic differentiation of chondritic precursors. The Fe/Mn difference between achondrites and chondrites is particularly significant since Fe and Mn are geochemically similar elements with similar partitioning behavior in familiar magmatic systems and are generally coupled during crystal-liquid fractionation. In contrast, however, Mn is more volatile than Fe in a nebular setting. Variation of Fe/Mn ratios based on the relative volatility of these elements in the early nebula provides a constraint for models by which the basaltic achondrites (with Fe/Mn ratios approximately = 25-50) are derived from mixtures of nebular components that were enriched in volatile components such as Mn. However, such volatile enriched components have not been identified in chondrites. When the abundance in achondrites of elements of similar volatility is examined, anomalies appear. For example, Na is massively depleted in basaltic achondrites when compared to Mn. These anomalies might be explained using current models but the alternative hypothesis, that Fe/Mn ratio is controlled not by nebular volatility constraints, but by planetary differentiation should be explored.

  4. First principles study of elemental mercury (Hg0) adsorption on low index CoMnO3 surfaces

    International Nuclear Information System (INIS)

    Ji, Wenchao; Su, Pingru; Tang, Qingli; Cheng, Zhiwen; Shen, Zhemin; Fan, Maohong

    2017-01-01

    Highlights: • Hg 0 adsorption on low index CoMnO 3 surface was predicted by DFT method. • Hg 0 is adsorbed on the CoMnO 3 surface with chemisorption interaction. • Hg 0 has highest adsorption energy on CoMnO 3 (1 0 0) surface with Hg-Mn mechanism. • The electron transfer of Hg 0 has positive relationship with adsorption energy. - Abstract: The density functional theory (DFT) is applied to predict elemental mercury (Hg 0 ) adsorption on CoMnO 3 surface for the first time. GGA/PBE functional were selected to determine the potential Hg 0 capture mechanisms. The results show that Hg 0 has good affinity with CoMnO 3 surfaces with chemical adsorption. The adsorption energy of Hg 0 -CoMnO 3 (1 0 0), Hg 0 -CoMnO 3 (1 0 1) and Hg 0 -CoMnO 3 (1 1 0) are −85.225, −72.305 and −70.729 kJ/mol, respectively. The Hg-Mn and Hg-Co mechanisms were revealed on low index surfaces. Hg 0 was oxidized to its valence state of 0.236 on Mn site in CoMnO 3 (1 0 0) surface. The Hg-Co interaction mechanism occurred on Hg 0 -CoMnO 3 (1 0 1) and Hg 0 -CoMnO 3 (1 1 0) with 0.209e − and 0.189e − transformation, respectively. The PDOS analysis shows that Hg-Mn interaction depends on the hybridization of Hg(s- and d-orbitals) and Mn (s-, p- and d- orbitals). However, Hg-Co interaction stems from s- and d- orbitals of Hg, which only overlapping with d- and p- orbital of Co. Both the adsorption energy and electronic structure analysis indicated that CoMnO 3 catalyst performed excellent in Hg 0 oxidation. Exposing CoMnO 3 (1 0 0) is most favorable in Hg 0 control, which provides theoretical instruction on certain crystal plane synthesis in experiment.

  5. Volatile and light lithophile elements in high-anorthite plagioclase-hosted melt inclusions from Iceland

    Science.gov (United States)

    Neave, David A.; Hartley, Margaret E.; Maclennan, John; Edmonds, Marie; Thordarson, Thorvaldur

    2017-05-01

    Melt inclusions formed during the early stages of magmatic evolution trap primitive melt compositions and enable the volatile contents of primary melts and the mantle to be estimated. However, the syn- and post-entrapment behaviour of volatiles in primitive high-anorthite plagioclase-hosted melt inclusions from oceanic basalts remains poorly constrained. To address this deficit, we present volatile and light lithophile element analyses from a well-characterised suite of nine matrix glasses and 102 melt inclusions from the 10 ka Grímsvötn tephra series (i.e., Saksunarvatn ash) of Iceland's Eastern Volcanic Zone (EVZ). High matrix glass H2O and S contents indicate that eruption-related exsolution was arrested by quenching in a phreatomagmatic setting; Li, B, F and Cl did not exsolve during eruption. The almost uniformly low CO2 content of plagioclase-hosted melt inclusions cannot be explained by either shallow entrapment or the sequestration of CO2 into shrinkage bubbles, suggesting that inclusion CO2 contents were controlled by decrepitation instead. High H2O/Ce values in primitive plagioclase-hosted inclusions (182-823) generally exceed values expected for EVZ primary melts (∼ 180), and can be accounted for by diffusive H2O gain following the entrainment of primitive macrocrysts into evolved and H2O-rich melts a few days before eruption. A strong positive correlation between H2O and Li in plagioclase-hosted inclusions suggests that diffusive Li gain may also have occurred. Extreme F enrichments in primitive plagioclase-hosted inclusions (F/Nd = 51-216 versus ∼15 in matrix glasses) possibly reflect the entrapment of inclusions from high-Al/(Al + Si) melt pools formed by dissolution-crystallisation processes (as indicated by HFSE depletions in some inclusions), and into which F was concentrated by uphill diffusion since F is highly soluble in Al-rich melts. The high S/Dy of primitive inclusions (∼300) indicates that primary melts were S-rich in comparison

  6. Modelling of Equilibrium Between Mantle and Core: Refractory, Volatile, and Highly Siderophile Elements

    Science.gov (United States)

    Righter, K.; Danielson, L.; Pando, K.; Shofner, G.; Lee, C. -T.

    2013-01-01

    Siderophile elements have been used to constrain conditions of core formation and differentiation for the Earth, Mars and other differentiated bodies [1]. Recent models for the Earth have concluded that the mantle and core did not fully equilibrate and the siderophile element contents of the mantle can only be explained under conditions where the oxygen fugacity changes from low to high during accretion and the mantle and core do not fully equilibrate [2,3]. However these conclusions go against several physical and chemical constraints. First, calculations suggest that even with the composition of accreting material changing from reduced to oxidized over time, the fO2 defined by metal-silicate equilibrium does not change substantially, only by approximately 1 logfO2 unit [4]. An increase of more than 2 logfO2 units in mantle oxidation are required in models of [2,3]. Secondly, calculations also show that metallic impacting material will become deformed and sheared during accretion to a large body, such that it becomes emulsified to a fine scale that allows equilibrium at nearly all conditions except for possibly the length scale for giant impacts [5] (contrary to conclusions of [6]). Using new data for D(Mo) metal/silicate at high pressures, together with updated partitioning expressions for many other elements, we will show that metal-silicate equilibrium across a long span of Earth s accretion history may explain the concentrations of many siderophile elements in Earth's mantle. The modeling includes refractory elements Ni, Co, Mo, and W, as well as highly siderophile elements Au, Pd and Pt, and volatile elements Cd, In, Bi, Sb, Ge and As.

  7. Spectrographic determination of impurities in ammonium bifluoride. IV.Study of the processes of vaporization, transport and excitation of the elements Fe, Mn, Mo, Ni, Pb and Si

    International Nuclear Information System (INIS)

    Alduan, F.A.; Capdevila, C.; Roca, M.

    1981-01-01

    The influences of the processes of vaporization, transport and excitation on the shape of the volatilization-excitation curves and on the values of the spectra-line intensities have been investigated in a method for the spectrographic determination of Fe, Mn, Mo, Ni, Pb and Si in ammonium bifluoride samples by direct current arc Ga 2 O 3 , GeO 2 , MgO and ZnO. The reaction products in the electrode cavity have been identified by X-ray powder diffraction analysis and the porcentages of vaporized and diffused element evaluated through analysis by total-burning spectrographic methods. In addition, the values of both the number of particles entering the discharge column and the transport efficiencies have been calculated. Thus, the origin of most observed differences has been explained. (author)

  8. Volatile Constituents, Inorganic Elements and Primary Screening of Bioactivity of Black Coral Cigarette Holders

    Directory of Open Access Journals (Sweden)

    Ganggang Shi

    2011-05-01

    Full Text Available Black corals (BC have been used for a long time in Chinese medicine, and may have some pharmaceutical functions when used as material for cigarette holders in southeast China. This study is aimed to investigate the bioactivities of volatile constituents in BC and to explore the folklore behind the use of BC cigarette holders (BCCHs. We extracted the volatile constituents of BC by supercritical fluid extraction (SFE with carbon dioxide (CO2-SFE, then identified and analyzed the constituents by gas chromatography-mass spectrometry (GC-MS. In total, 15 components were reliably identified in BC and found to be biologically active. These included triethyl phosphate, butylated hydroxytoluene, cedrol, n-hexadecanoic acid, squalene, and cholesterol. Meanwhile 13 inorganic elements (P, Ca, Mg, S, B, Si, Fe, Cu, Zn, Ba, etc. were determined by inductively coupled plasma spectrometer (ICPS. In the bioactivity tests, the BC extract (BCE showed a scavenging activity of 2,2-diphenyl-1-picrylhydrazyl free radicals and hydroxyl radicals by phenanthroline-Fe (II oxidation and moderate inhibition of Gram-positive microorganisms. The antioxidant and antimicrobial activities of BC, which are related to the active chemical composition, may explain the perceived benefit for cigarette smokers who use BCCHs.

  9. Tuning glass formation and brittle behaviors by similar solvent element substitution in (Mn,Fe)-based bulk metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tao [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Li, Ran, E-mail: liran@buaa.edu.cn [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Xiao, Ruijuan [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Gang [State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Wang, Jianfeng [School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); Zhang, Tao, E-mail: zhangtao@buaa.edu.cn [Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191 (China)

    2015-02-25

    A family of Mn-rich bulk metallic glasses (BMGs) was developed through the similar solvent elements (SSE) substitution of Mn for Fe in (Mn{sub x}Fe{sub 80−x})P{sub 10}B{sub 7}C{sub 3} alloys. The effect of the SSE substitution on glass formation, thermal stability, elastic constants, mechanical properties, fracture morphologies, Weibull modulus and indentation fracture toughness was discussed. A thermodynamics analysis provided by Battezzati et al. (L. Battezzati, E. Garrone, Z. Metallkd. 75 (1984) 305–310) was adopted to explain the compositional dependence of the glass-forming ability (GFA). The elastic moduli follow roughly linear correlations with the substitution concentration of Mn in (Mn{sub x}Fe{sub 80−x})P{sub 10}B{sub 7}C{sub 3} BMGs. The introduction of Mn to replace Fe significantly decreases the plasticity of the resulting BMGs and the Weibull modulus of the fracture strength. A super-brittle Mn-based BMGs of (Mn{sub 55}Fe{sub 25})P{sub 10}B{sub 7}C{sub 3} BMGs were found with the indentation fracture toughness (K{sub c}) of 1.91±0.04 MPa m{sup 1/2}, the lowest value among all kinds of BMGs so far. The atomic and electronic structure of the selected BMGs were simulated by the first principles molecular dynamics calculations based on density functional theory, which provided a possible understanding of the brittleness caused by the similar chemical element replacement of Mn for Fe.

  10. APXS of First Rocks Encountered by Curiosity in Gale Crater: Geochemical Diversity and Volatile Element (K and ZN) Enrichment

    Science.gov (United States)

    Schmidt, M. E.; King, P. L.; Gellert, R.; Elliott, B.; Thompson, L.; Berger, J.; Bridges, J.; Campbell, J. L; Grotzinger, J.; Hurowitz, J.; hide

    2013-01-01

    The Alpha Particle X-ray spectrometer (APXS) on the Curiosity rover in Gale Crater [1] is the 4th such instrument to have landed on Mars [2]. Along the rover's traverse down-section toward Glenelg (through sol 102), the APXS has examined four rocks and one soil [3]. Gale rocks are geochemically diverse and expand the range of Martian rock compositions to include high volatile and alkali contents (up to 3.0 wt% K2O) with high Fe and Mn (up to 29.2% FeO*).

  11. Measurement of Gas and Volatile Elements Production Cross Section in a Molten Lead-Bismuth Target

    CERN Multimedia

    2002-01-01

    MEGAPIE is a project for a 1 MW liquid PbBi spallation source, to be built at the SINQ facility at the Paul Scherrer Institut, which will be an important step in the roadmap towards the demonstration of the ADS concept and high power molten metal targets in general. In the design and construction of such a challenging project it is extremely important to evaluate the amount and type of gas and volatile elements which will be produced, for a reliable and safe operation of the experiment. Both stable (H, $^{4}$He and other noble gases) and radioactive isotopes are of interest. Currently, different design options are under consideration to deal with the gas produced during operation. \\\\ For a correct estimation of the production cross sections, a measurement with a liquid PbBi target and a proton beam of energy close to the one of MEGAPIE (575 MeV) is necessary. We would like to use the ISOLDE facility, which offers the unique opportunity via its mass spectrometric analysis of the elements present in the gas pha...

  12. Volatilization behavior of semivolatile elements in vitrification of high-level liquid waste

    International Nuclear Information System (INIS)

    Igarashi, Hiroshi; Kato, Koh; Takahashi, Takeshi

    1991-11-01

    The effect of temperature on the volatilization of ruthenium, technetium, and selenium was observed in calcination experiments with simulated high-level liquid waste. Technetium and selenium were more volatile as calcining temperature increased. Ruthenium was less volatile when temperature exceeded 300degC. More than 80% of ruthenium that volatilized from room temperature to 500degC occurred between 200 and 300degC. A small amount of ruthenium volatilized above 300degC as well as below 135degC. (author)

  13. Effects of Alloying Elements (Cr, Mn) on Corrosion Properties of Carbon Steel in Synthetic Seawater

    International Nuclear Information System (INIS)

    Hyun, Youngmin; Kim, Heesan

    2016-01-01

    Effects of alloying elements, manganese and chromium, on corrosion resistance of carbon steel were examined using weight loss test and electrochemical tests (polarization test and electrochemical impedance spectroscopy (EIS)) in synthetic seawater at 60 ℃. The results from the weight loss test showed that chromium effectively improved corrosion resistance of carbon steel during the entire immersion time, but manganese improved corrosion resistance after the lowered corrosion resistance at the beginnings of immersion. Unlike the weight loss test, the electrochemical tests showed that the corrosion resistance did not increase with immersion time, in all the specimens. This disagreement is explained by the presence of rust involved in electrochemical reaction during electrochemical tests. The analysis of rust with transmission electron microscopy (TEM)−energy dispersive spectroscopy (EDS) showed that the amorphous-like rust layer located at the metal/rust interface with enriched alloying element (Cr, Mn) prevents diffusion of corrosive species into a metal/rust interface effectively, which leads to increased corrosion resistance. The initial corrosion behaviour is also affected by the rust types. In other words, manganese accelerated the formation of spinel oxides, negatively affecting corrosion resistance. Meanwhile, chromium accelerated the formation of goethite but impeded the formation of spinel oxides, positively affecting the corrosion resistance. From the above results, the corrosion resistance of steel is closely related with a rust type.

  14. Effects of Alloying Elements (Cr, Mn) on Corrosion Properties of Carbon Steel in Synthetic Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, Youngmin; Kim, Heesan [Hongik University, Sejong (Korea, Republic of)

    2016-02-15

    Effects of alloying elements, manganese and chromium, on corrosion resistance of carbon steel were examined using weight loss test and electrochemical tests (polarization test and electrochemical impedance spectroscopy (EIS)) in synthetic seawater at 60 ℃. The results from the weight loss test showed that chromium effectively improved corrosion resistance of carbon steel during the entire immersion time, but manganese improved corrosion resistance after the lowered corrosion resistance at the beginnings of immersion. Unlike the weight loss test, the electrochemical tests showed that the corrosion resistance did not increase with immersion time, in all the specimens. This disagreement is explained by the presence of rust involved in electrochemical reaction during electrochemical tests. The analysis of rust with transmission electron microscopy (TEM)−energy dispersive spectroscopy (EDS) showed that the amorphous-like rust layer located at the metal/rust interface with enriched alloying element (Cr, Mn) prevents diffusion of corrosive species into a metal/rust interface effectively, which leads to increased corrosion resistance. The initial corrosion behaviour is also affected by the rust types. In other words, manganese accelerated the formation of spinel oxides, negatively affecting corrosion resistance. Meanwhile, chromium accelerated the formation of goethite but impeded the formation of spinel oxides, positively affecting the corrosion resistance. From the above results, the corrosion resistance of steel is closely related with a rust type.

  15. Volatile and non-volatile elements in grain-size separated samples of Apollo 17 lunar soils

    International Nuclear Information System (INIS)

    Giovanoli, R.; Gunten, H.R. von; Kraehenbuehl, U.; Meyer, G.; Wegmueller, F.; Gruetter, A.; Wyttenbach, A.

    1977-01-01

    Three samples of Apollo 17 lunar soils (75081, 72501 and 72461) were separated into 9 grain-size fractions between 540 and 1 μm mean diameter. In order to detect mineral fractionations caused during the separation procedures major elements were determined by instrumental neutron activation analyses performed on small aliquots of the separated samples. Twenty elements were measured in each size fraction using instrumental and radiochemical neutron activation techniques. The concentration of the main elements in sample 75081 does not change with the grain-size. Exceptions are Fe and Ti which decrease slightly and Al which increases slightly with the decrease in the grain-size. These changes in the composition in main elements suggest a decrease in Ilmenite and an increase in Anorthite with decreasing grain-size. However, it can be concluded that the mineral composition of the fractions changes less than a factor of 2. Samples 72501 and 72461 are not yet analyzed for the main elements. (Auth.)

  16. Mechanisms of chemical generation of volatile hydrides for trace element determination (IUPAC Technical Report)

    Czech Academy of Sciences Publication Activity Database

    D'Ulivo, A.; Dědina, Jiří; Mester, Z.; Sturgeon, R. E.; Wang, Q.; Welz, B.

    2011-01-01

    Roč. 83, č. 6 (2011), s. 1283-1340 ISSN 0033-4545 Institutional research plan: CEZ:AV0Z40310501 Keywords : borane complexes * chemical generation of volatile hydrides (CHG) * volatile hydrides Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.789, year: 2011

  17. The study of major, trace and rare earth elements geochemistry in Shahrestanak Mn deposit, south of Qom: Implications for genesis

    Directory of Open Access Journals (Sweden)

    Mohammad Maanijou

    2015-04-01

    Full Text Available Introduction The Shahrestanak Mn deposit is located in southern Qom province, 12 km southwest of the city of Kahak. Based on geological-structural divisions of Iran, the deposit belongs to central volcanic belt or Urumieh-Dokhtar zone. The Venarch deposit is one the most important known manganese deposits in Iran. The Sharestanak and Venarch deposits are spatially and temporally related to each other, and have similar geology, mineral texture and structure, host rocks, relationships with faults, and depositional environment. So, their magmatism and deposition conditions can be related to each other. Since no systematic study on the Shahrestanak deposit had been performed before discussing its geological and geochemical characteristics, here it is being attempted to study the geology, petrography, geochemistry of major, minor and trace elements, and Rare Earth Elements (REE of ore, to distinguish the depositional environments and genesis of this deposit and to compare REE of ore in this deposit with other deposits. Sampling and method of study Fourteen samples of manganese ore were selected for geochemical study and analyzing of major, minor, trace elements and REE by ICP-AES and ICP-MS and were sent to SGS Co., Toronto. Detection limits for major elements and trace elements are 0.01% and 0.05ppm, respectively. Result and discussion The deposit is characterized by various lithology and stratigraphy units, consist of: 1 Middle to -Upper Eocene volcano-sedimentary rocks, 2 Oligocene lower red conglomerate and sandstone, 3 Oligo-Miocene limestone and marl (Qom Formation, and 4 Eocene and Lower Miocene basic to intermediate dykes. The most abundant minerals of the deposit are braunite, hausmannite, pyrolusite, and manganite. Evidences such as high Mn/Fe (11.33 and Si/Al (4.86 ratios, low contents of trace elements specially Co (11.40 ppm, Ni (24 ppm, Cu (81.85 ppm, and Ce, with high amounts of SiO2, Mn, Fe, Ba, Zn, As and Sr, all represent

  18. Study of polyoxide catalysts of methane combustion on Mn, Cu, Ni, rare earth elements, alkaline earth elements base by the X-ray fluorescence analysis method

    International Nuclear Information System (INIS)

    Grigor'eva, V.P.; Popova, N.M.; Zheksenbaeva, Z.T.; Sass, A.S.; Salakhova, R.Kh.; Dosumov, K.D.

    2002-01-01

    The results of X-ray fluorescence analysis of polyoxide catalysts on of Mn, Cu, Ni, rare earth elements, alkaline earth elements base supported on 2 % Ce/θ-Al 2 O 3 are presented. This polyoxide catalysts are using for deep methane oxidation. DRON-4-7 X-ray diffractometers was applied for the analysis. It was found, that oxides in Ni-Cu-Cr catalysts after long time heating up to 1200 deg. C have been interacted with catalyst supports with Ni(Cu)Al 2 O 3 aluminates formation and due to its decomposition transformation degree of CH 4 to CO 2 are reduced. Activity of MnBaSrCeLa catalysts after heating up to 1200 deg. C does not changed

  19. A history of violence: Insights into post-accretionary heating in carbonaceous chondrites from volatile element abundances, Zn isotopes and water contents

    Science.gov (United States)

    Mahan, Brandon; Moynier, Frédéric; Beck, Pierre; Pringle, Emily A.; Siebert, Julien

    2018-01-01

    Carbonaceous chondrites (CCs) may have been the carriers of water, volatile and moderately volatile elements to Earth. Investigating the abundances of these elements, their relative volatility, and isotopes of state-change tracer elements such as Zn, and linking these observations to water contents, provide vital information on the processes that govern the abundances and isotopic signatures of these species in CCs and other planetary bodies. Here we report Zn isotopic data for 28 CCs (20 CM, 6 CR, 1 C2-ung, and 1 CV3), as well as trace element data for Zn, In, Sn, Tl, Pb, and Bi in 16 samples (8 CM, 6 CR, 1 C2-ung, and 1 CV3), that display a range of elemental abundances from case-normative to intensely depleted. We use these data, water content data from literature and Zn isotopes to investigate volatile depletions and to discern between closed and open system heating. Trace element data have been used to construct relative volatility scales among the elements for the CM and CR chondrites. From least volatile to most, the scale in CM chondrites is Pb-Sn-Bi-In-Zn-Tl, and for CR chondrites it is Tl-Zn-Sn-Pb-Bi-In. These observations suggest that heated CM and CR chondrites underwent volatile loss under different conditions to one another and to that of the solar nebula, e.g. differing oxygen fugacities. Furthermore, the most water and volatile depleted samples are highly enriched in the heavy isotopes of Zn. Taken together, these lines of evidence strongly indicate that heated CM and CR chondrites incurred open system heating, stripping them of water and volatiles concomitantly, during post-accretionary shock impact(s).

  20. Effects of flue gas components on removal of elemental mercury over Ce–MnO_x/Ti-PILCs

    International Nuclear Information System (INIS)

    He, Chuan; Shen, Boxiong; Li, Fukuan

    2016-01-01

    Highlights: • Ce–MnO_x/Ti-PILC exhibited high Hg"0 removal activity. • SO_2 restrained Hg"0 oxidation and adsorption due to the formation of SO_4"2"−. • The formation of NH_3 to NH_4"+ restrained the Hg"0 adsorption and oxidation. - Abstract: The adsorption and oxidation of elemental mercury (Hg"0) under various flue gas components were investigated over a series of Ce–MnO_x/Ti-PILC catalysts, which were synthesized by an impregnation method. To discuss the mechanism, the catalysts were characterized by various techniques such as N_2 adsorption–desorption, scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) analysis and X-ray photoelectron spectroscopy (XPS). The results indicated that the presence of 500 ppm SO_2 in the flue gas significantly restrained the Hg"0 adsorption and oxidation over 6%Ce–6%MnO_x/Ti-PILC due to the formation of SO_4"2"− species. Hg"0 could be oxidized to HgCl_2 in the presence of HCl, because the Deacon process occurred. NO would react with active oxygen to form NO_2-containing species, which facilitated Hg"0 oxidation. While the presence of NO limited the Hg"0 adsorption on 6%Ce–6%MnO_x/Ti-PILC due to the competitive adsorption of NO with Hg"0. The addition of NH_3 in the flue gas significantly restrained Hg"0 adsorption and oxidation, because the formed NH_4"+ species covered the active adsorption sites on the surfaces, and further limited Hg"0 oxidation. However, when NO and NH_3 were simultaneously added into the flue gas, the Hg"0 oxidation efficiency of 6%Ce–6%MnO_x/Ti-PILC exhibited a relatively high value (72%) at 250 °C, which indicated the practicability to use Ce–MnO_x/Ti-PILC for Hg"0 removal under SCR conditions.

  1. Irradiation behavior of U 6Mn-Al dispersion fuel elements

    Science.gov (United States)

    Meyer, M. K.; Wiencek, T. C.; Hayes, S. L.; Hofman, G. L.

    2000-02-01

    Irradiation testing of U 6Mn-Al dispersion fuel miniplates was conducted in the Oak Ridge Research Reactor (ORR). Post-irradiation examination showed that U 6Mn in an unrestrained plate configuration performs similarly to U 6Fe under irradiation, forming extensive and interlinked fission gas bubbles at a fission density of approximately 3×10 27 m-3. Fuel plate failure occurs by fission gas pressure driven `pillowing' on continued irradiation.

  2. Metal-Silicate-Sulfide Partitioning of U, Th, and K: Implications for the Budget of Volatile Elements in Mercury

    Science.gov (United States)

    Habermann, M.; Boujibar, A.; Righter, K.; Danielson, L.; Rapp, J.; Righter, M.; Pando, K.; Ross, D. K.; Andreasen, R.

    2016-01-01

    During formation of the solar system, the Sun produced strong solar winds, which stripped away a portion of the volatile elements from the forming planets. Hence, it was expected that planets closest to the sun, such as Mercury, are more depleted in volatile elements in comparison to other terrestrial planets. However, the MESSENGER mission detected higher than expected K/U and K/Th ratios on Mercury's surface, indicating a volatile content between that of Mars and Earth. Our experiments aim to resolve this discrepancy by experimentally determining the partition coefficients (D(sup met/sil)) of K, U, and Th between metal and silicate at varying pressure (1 to 5 GPa), temperature (1500 to 1900 C), oxygen fugacity (IW-2.5 to IW-6.5) and sulfur-content in the metal (0 to 33 wt%). Our data show that U, Th, and K become more siderophile with decreasing fO2 and increasing sulfur-content, with a stronger effect for U and Th in comparison to K. Using these results, the concentrations of U, Th, and K in the bulk planet were calculated for different scenarios, where the planet equilibrated at a fO2 between IW-4 and IW-7, assuming the existence of a FeS layer, between the core and mantle, with variable thickness. These models show that significant amounts of U and Th are partitioned into Mercury's core. The elevated superficial K/U and K/Th values are therefore only a consequence of the sequestration of U and Th into the core, not evidence of the overall volatile content of Mercury.

  3. Essential trace (Zn, Cu, Mn and toxic (Cd, Pb, Cr elements in the liver of birds from Eastern Poland

    Directory of Open Access Journals (Sweden)

    Komosa A.

    2012-01-01

    Full Text Available We have focused our study on the concentrations of essential heavy metals (Zn, Cu and Mn and non-essential trace metals (Pb, Cd and Cr in the livers of birds from Eastern Poland. The largest mean amount of Zn - as much as 279 mg/kg dry mass (d.m. - was found in mute swans. However, only in one of the analysed buzzard specimens the concentration of Zn, found to be 664 mg/kg d.m., exceeded the level indicative of poisoning for this element. Birds specializing in catching rodents accumulated Mn in their livers in a very narrow range of concentrations, around 5.0 mg/kg d.m. on average. The range of mean Mn concentrations (around 6.5 mg/kg d.m. was also found to be narrow for piscivorous birds. The highest mean levels of Pb were found in mute swans (2.7 mg/kg d.m., and the highest levels of Cd (2.0 mg/kg d.m. for rooks. Concentrations of total Cr above detection level were found in 22 specimens (53.7%, and concentration values were highest for rooks. Analyses showed that the concentrations of biogenic elements did not exceed the levels indicative of poisoning (except in one specimen. The study demonstrated that lead shots remain a hazard to water ecosystems. Pb, Cd and Cr levels in the livers of omnivorous and piscivorous species indicate the permanent presence of these elements in the environment and may confirm the thesis about the growing role of electronic waste, including metallic e-waste, in the emission of the total amount of contamination with these elements.

  4. The origin of volatile element depletion in early solar system material: Clues from Zn isotopes in chondrules

    Science.gov (United States)

    Pringle, Emily A.; Moynier, Frédéric; Beck, Pierre; Paniello, Randal; Hezel, Dominik C.

    2017-06-01

    Volatile lithophile elements are depleted in the different planetary materials to various degrees, but the origin of these depletions is still debated. Stable isotopes of moderately volatile elements such as Zn can be used to understand the origin of volatile element depletions. Samples with significant volatile element depletions, including the Moon and terrestrial tektites, display heavy Zn isotope compositions (i.e. enrichment of 66Zn vs. 64Zn), consistent with kinetic Zn isotope fractionation during evaporation. However, Luck et al. (2005) found a negative correlation between δ66Zn and 1/[Zn] between CI, CM, CO, and CV chondrites, opposite to what would be expected if evaporation caused the Zn abundance variations among chondrite groups. We have analyzed the Zn isotope composition of multiple samples of the major carbonaceous chondrite classes: CI (1), CM (4), CV (2), CO (4), CB (2), CH (2), CK (4), and CK/CR (1). The bulk chondrites define a negative correlation in a plot of δ66Zn vs 1/[Zn], confirming earlier results that Zn abundance variations among carbonaceous chondrites cannot be explained by evaporation. Exceptions are CB and CH chondrites, which display Zn systematics consistent with a collisional formation mechanism that created enrichment in heavy Zn isotopes relative to the trend defined by CI-CK. We further report Zn isotope analyses of chondrite components, including chondrules from Allende (CV3) and Mokoia (CV3), as well as an aliquot of Allende matrix. All chondrules are enriched in light Zn isotopes (∼500 ppm on 66Zn/64Zn) relative to the bulk, contrary to what would be expected if Zn were depleted during evaporation, on the other hand the matrix has a complementary heavy isotope composition. We report sequential leaching experiments in un-equilibrated ordinary chondrites, which show sulfides are isotopically heavy compared to silicates and the bulk meteorite by ca. +0.65 per mil on 66Zn/64Zn. We suggest isotopically heavy sulfides were

  5. Irradiation behavior of U{sub 6}Mn-Al dispersion fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, M.K. E-mail: mitchell.meyer@anl.gov; Wiencek, T.C.; Hayes, S.L.; Hofman, G.L

    2000-04-01

    Irradiation testing of U{sub 6}Mn-Al dispersion fuel miniplates was conducted in the Oak Ridge Research Reactor (ORR). Post-irradiation examination showed that U{sub 6}Mn in an unrestrained plate configuration performs similarly to U{sub 6}Fe under irradiation, forming extensive and interlinked fission gas bubbles at a fission density of approximately 3x10{sup 27} m{sup -3}. Fuel plate failure occurs by fission gas pressure driven 'pillowing' on continued irradiation.

  6. First principles study of elemental mercury (Hg{sup 0}) adsorption on low index CoMnO{sub 3} surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Wenchao; Su, Pingru; Tang, Qingli; Cheng, Zhiwen [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240 (China); Shen, Zhemin, E-mail: zmshen@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240 (China); Fan, Maohong [Department of Chemical and Petroleum Engineering, University of Wyoming, Laramie, Wyoming, 82071 (United States); School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, 30332 (United States)

    2017-06-30

    Highlights: • Hg{sup 0} adsorption on low index CoMnO{sub 3} surface was predicted by DFT method. • Hg{sup 0} is adsorbed on the CoMnO{sub 3} surface with chemisorption interaction. • Hg{sup 0} has highest adsorption energy on CoMnO{sub 3} (1 0 0) surface with Hg-Mn mechanism. • The electron transfer of Hg{sup 0} has positive relationship with adsorption energy. - Abstract: The density functional theory (DFT) is applied to predict elemental mercury (Hg{sup 0}) adsorption on CoMnO{sub 3} surface for the first time. GGA/PBE functional were selected to determine the potential Hg{sup 0} capture mechanisms. The results show that Hg{sup 0} has good affinity with CoMnO{sub 3} surfaces with chemical adsorption. The adsorption energy of Hg{sup 0}-CoMnO{sub 3} (1 0 0), Hg{sup 0}-CoMnO{sub 3} (1 0 1) and Hg{sup 0}-CoMnO{sub 3} (1 1 0) are −85.225, −72.305 and −70.729 kJ/mol, respectively. The Hg-Mn and Hg-Co mechanisms were revealed on low index surfaces. Hg{sup 0} was oxidized to its valence state of 0.236 on Mn site in CoMnO{sub 3} (1 0 0) surface. The Hg-Co interaction mechanism occurred on Hg{sup 0}-CoMnO{sub 3} (1 0 1) and Hg{sup 0}-CoMnO{sub 3} (1 1 0) with 0.209e{sup −} and 0.189e{sup −} transformation, respectively. The PDOS analysis shows that Hg-Mn interaction depends on the hybridization of Hg(s- and d-orbitals) and Mn (s-, p- and d- orbitals). However, Hg-Co interaction stems from s- and d- orbitals of Hg, which only overlapping with d- and p- orbital of Co. Both the adsorption energy and electronic structure analysis indicated that CoMnO{sub 3} catalyst performed excellent in Hg{sup 0} oxidation. Exposing CoMnO{sub 3} (1 0 0) is most favorable in Hg{sup 0} control, which provides theoretical instruction on certain crystal plane synthesis in experiment.

  7. Validation of FNAA method for testing the elements of Mn, Cr and Mg on the Gajahwong river sediment sample

    International Nuclear Information System (INIS)

    Wisjachudin Faisal; Elin Nuraini

    2010-01-01

    Validation of elements of Mn, Cr and Mg by using FNAA method has been performed. NBS SRM 8704 (Bufallo River Sediment), was used as the standard reference material, with the neutrons generator operating condition at the optimum voltage of 110 kV. Energy and channel number of calibration lines obtained with the standard equation as y = 1.034 x + 151.21. From the analysis of SRM, the results show that only Mg can be analyzed, because Cr and Mn are located at the same peak point (interferences), so that they can not be analyzed. From the analysis for Mg element (SRM), the precision and the accuration obtained are 95.53 % and 94.88%, while the average price of expanded uncertainty for the various locations is 0.233 ± 0.012. Mg content analysis result at various locations along the river Gajahwong ranging from 85.41 – 103.55 ppm. When compared with previous studies showing the elements content of Fe, Al and Si is much higher than Mg content. (author)

  8. Study of new technique of solid combustible materials to determination of volatile elements by flame atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Campos, R.C. de.

    1988-01-01

    A new technique for direct trace element analysis of solid combustible materials is described. The samples (up to 10 mg) are weighed on a graphite platform wich is then placed in a quartz tube, at the focal point of three infrared lamps. When the lamps are turned on, the sample burns in a stream of air, and the resulting dry aerosol containing volatile elements such as Hg, Cd, Bi, Tl, Zn, Pb and Cu is carried into the mixing chamber and thence into the flame, where the atomic absorption measurement is carried out. This technique overcomes chemical sample preparation steps, avoiding contaminations of losses associated with these steps. A ''furnace in flame'' system where the aerosol is transported to a flame heated T-tube is also described. The influence of flame stoichiometry, observation height, platform material and air flux intensity was studied inorder to determine optimal analytical conditions. (author) [pt

  9. Autonomous generator based on Ni-Mn-Ga microactuator as a frequency selective element

    Directory of Open Access Journals (Sweden)

    Barandiaran J.M.

    2013-01-01

    Full Text Available In this work, we suggest the temperature-induced resistivity change at the martensitic transformation in the Ni-Mn-Ga ferromagnetic shape memory alloy as a driving mechanism enabling periodic signal generation. We demonstrated its practical importance by a design of the prototype of a low-frequency autonomous generator. A prominent feature of this new generator is a control of its frequency by the external magnetic field.

  10. The magnetic field and the evolution of element spots on the surface of the HgMn eclipsing binary ARAur

    Science.gov (United States)

    Hubrig, S.; Savanov, I.; Ilyin, I.; González, J. F.; Korhonen, H.; Lehmann, H.; Schöller, M.; Granzer, T.; Weber, M.; Strassmeier, K. G.; Hartmann, M.; Tkachenko, A.

    2010-10-01

    The system ARAur is a young late B-type double-lined eclipsing binary with a primary star of HgMn peculiarity. We applied the Doppler imaging method to reconstruct the distribution of Fe and Y over the surface of the primary using spectroscopic time series obtained in 2005 and from 2008 October to 2009 February. The results show a remarkable evolution of the element distribution and overabundances. Measurements of the magnetic field with the moment technique using several elements reveal the presence of a longitudinal magnetic field of the order of a few hundred gauss in both stellar components and a quadratic field of the order of 8kG on the surface of the primary star. Based on observations obtained at the 2.56-m Nordic Optical Telescope on La Palma, the Karl-Schwarzschild-Observatorium in Tautenburg and the STELLA robotic telescope on Tenerife. E-mail: shubrig@aip.de

  11. The synthetic evaluation of CuO-MnOx-modified pinecone biochar for simultaneous removal formaldehyde and elemental mercury from simulated flue gas.

    Science.gov (United States)

    Yi, Yaoyao; Li, Caiting; Zhao, Lingkui; Du, Xueyu; Gao, Lei; Chen, Jiaqiang; Zhai, Yunbo; Zeng, Guangming

    2018-02-01

    A series of low-cost Cu-Mn-mixed oxides supported on biochar (CuMn/HBC) synthesized by an impregnation method were applied to study the simultaneous removal of formaldehyde (HCHO) and elemental mercury (Hg 0 ) at 100-300° C from simulated flue gas. The metal loading value, Cu/Mn molar ratio, flue gas components, reaction mechanism, and interrelationship between HCHO removal and Hg 0 removal were also investigated. Results suggested that 12%CuMn/HBC showed the highest removal efficiency of HCHO and Hg 0 at 175° C corresponding to 89%and 83%, respectively. The addition of NO and SO 2 exhibited inhibitive influence on HCHO removal. For the removal of Hg 0 , NO showed slightly positive influence and SO 2 had an inhibitive effect. Meanwhile, O 2 had positive impact on the removal of HCHO and Hg 0 . The samples were characterized by SEM, XRD, BET, XPS, ICP-AES, FTIR, and H 2 -TPR. The sample characterization illustrated that CuMn/HBC possessed the high pore volume and specific surface area. The chemisorbed oxygen (O β ) and the lattice oxygen (O α ) which took part in the removal reaction largely existed in CuMn/HBC. What is more, MnO 2 and CuO (or Cu 2 O) were highly dispersed on the CuMn/HBC surface. The strong synergistic effect between Cu-Mn mixed oxides was critical to the removal reaction of HCHO and Hg 0 via the redox equilibrium of Mn 4+ + Cu + ↔ Mn 3+ + Cu 2+ .

  12. Elemental moment variation of bcc Fe{sub x}Mn{sub 1−x} on MgO(001)

    Energy Technology Data Exchange (ETDEWEB)

    Bhatkar, H.; Snow, R.J. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Arenholz, E. [Advanced Light Source, Lawrence Berkeley National Laboratories, Berkeley, CA 94720 (United States); Idzerda, Y.U., E-mail: idzerda@montana.edu [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2017-02-01

    We report the growth, structural characterization, and electronic structure evolution of epitaxially grown bcc Fe{sub x}Mn{sub 1−x} on MgO(001). It is observed that the 20 nm thick Fe{sub x}Mn{sub 1−x} alloy films remained bcc from 0.65≤x≤1, much beyond the bulk stability range of 0.88≤x≤1. X-ray absorption spectroscopy and X-ray magnetic circular dichroism show that both the Fe and Mn L{sub 3} binding energies slightly increase with Mn incorporation and that the elemental moment of Fe in the 20 nm crystalline bcc alloy film remain nearly constant, then shows a dramatic collapse near x~0.84. The Mn MCD intensity is found to be small at all compositions that exhibit ferromagnetism - Highlights: • Bcc Fe{sub x}Mn{sub 1−x} films were stabilized beyond bulk range by epitaxial growth on MgO. • XMCD shows negligible moment in Mn regardless of composition. • Fe moment stays constant until 84% Mn concentration. • Magnetic moment suddenly collapses before any structural change seen in RHEED.

  13. Investigation of the impact of trace elements on anaerobic volatile fatty acid degradation using a fractional factorial experimental design.

    Science.gov (United States)

    Jiang, Ying; Zhang, Yue; Banks, Charles; Heaven, Sonia; Longhurst, Philip

    2017-11-15

    The requirement of trace elements (TE) in anaerobic digestion process is widely documented. However, little is understood regarding the specific requirement of elements and their critical concentrations under different operating conditions such as substrate characterisation and temperature. In this study, a flask batch trial using fractional factorial design is conducted to investigate volatile fatty acids (VFA) anaerobic degradation rate under the influence of the individual and combined effect of six TEs (Co, Ni, Mo, Se, Fe and W). The experiment inoculated with food waste digestate, spiked with sodium acetate and sodium propionate both to 10 g/l. This is followed by the addition of a selection of the six elements in accordance with a 2 6-2 fractional factorial principle. The experiment is conducted in duplicate and the degradation of VFA is regularly monitored. Factorial effect analysis on the experimental results reveals that within these experimental conditions, Se has a key role in promoting the degradation rates of both acetic and propionic acids; Mo and Co are found to have a modest effect on increasing propionic acid degradation rate. It is also revealed that Ni shows some inhibitory effects on VFA degradation, possibly due to its toxicity. Additionally, regression coefficients for the main and second order effects are calculated to establish regression models for VFA degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Phase transformation and magnetic properties of MnAl powders prepared by elemental-doping and salt-assisted ball milling

    Science.gov (United States)

    Qian, Hui-Dong; Si, Ping-Zhan; Choi, Chul-Jin; Park, Jihoon; Cho, Kyung Mox

    2018-05-01

    The effects of elemental doping of Si and Fe on the ɛ→τ phase transformation and the magnetic properties of MnAl were studied. The magnetic powders of Si- and Fe-doped MnAl were prepared by using induction melting followed by water-quenching, annealing, and salt-assisted ball-milling. The Fe-doped MnAl powders are mainly composed of the L10-structured τ-phase, while the Si-doped MnAl are composed of τ-phase and a small fraction of γ2- and β-phases. A unique thin leaves-like morphology with thickness of several tens of nanometers and diameter size up to 500 nm were observed in the Si-doped MnAl powders. The Fe-doped MnAl powders show irregular shape with much larger dimensions in the range from several to 10 μm. The morphology difference of the samples was ascribed to the variation of the mechanical properties affected by different doping elements. The phase transformation temperatures of the ɛ-phase of the samples were measured. The doping of Fe decreases the onset temperature of the massive phase transformation in MnAl, while the Si-doping increases the massive phase transformation temperature. Both Fe and Si increase the Curie temperature of MnAl. A substantially enhanced coercivity up to 0.45 T and 0.42 T were observed in the ball-milled MnAl powders doped with Si and Fe, respectively.

  15. Determination of volatile trace elements in terrestrial minerals and lunar soils by RNAA

    International Nuclear Information System (INIS)

    Kraehenbuehl, U.; Wegmueller, F.

    1978-01-01

    A procedure is reported for the simultaneous determination of Au, Cd, Ge, Hg, In, Sb, Te and Zn in 5-50 mg aliquots of minerals and lunar soils. After irradiation with thermal neutrons the samples are dissolved in digestion bombs by HF/HClO 4 . Sulfide precipitates provide the necessary group separations. The purified elements are measured on Ge(Li) detectors. Accuracy and precision are generally better than 10%. (author)

  16. [Removal Characteristics of Elemental Mercury by Mn-Ce/molecular Sieve].

    Science.gov (United States)

    Tan, Zeng-qiang; Niu, Guo-ping; Chen, Xiao-wen; An, Zhen

    2015-06-01

    The impregnation method was used to support molecular sieve with active manganese and cerium components to obtain a composite molecular sieve catalyst. The mercury removal performance of the catalyst was studied with a bench-scale setup. XPS analysis was used to characterize the sample before and after the modification in order to study the changes in the active components of the catalyst prepared. The results showed that the catalyst carrying manganese and cerium components had higher oxidation ability of elemental mercury in the temperature range of 300 degrees C - 450 degrees C, especially at 450 degrees C, the oxidation efficiency of elemental mercury was kept above 80%. The catalyst had more functional groups that were conducive to the oxidation of elemental mercury, and the mercury removal mainly depended on the chemical adsorption. The SO2 and NO in flue gas could inhibit the oxidation of elemental mercury to certain extent.

  17. Trace and rare earth elements fractionation in volcanic- and sediment-hosted Mn ores: a study case of Sardinia (western Italy).

    Science.gov (United States)

    Sinisi, Rosa

    2015-04-01

    It is widely accepted that, regardless of the geological environment (continental, marine or hydrothermal), the occurrences of clay minerals and/or mineral phases with clay-type crystal structure (as zeolites and Mn-oxides), play a key role in the trace elements and REEs uptake processes. The REE resources are produced mostly from ion-adsorption type REE deposits of southern China that are formed by weathering of granitic rocks and subsequent chemical adsorption of REE on clay minerals. A significant group of minerals with a high metal uptake capacity is represented by Mn oxides. Their "tunnel" structure, in fact, allows both the absorption (inside the minerals) and adsorption (outside the minerals) of cations and anions producing metal accumulations with economic and environmental significance. However, the ores, mainly that forming within sedimentary environment, often have impurities due to presence of minerals unrelated to mineralization. These minerals can significantly alter the compositional features of the ores and suggest misleading conclusions. In Sardinia (Italy, western Mediterranean), Mn-oxide mineralizations occur and recently their origin has been discussed and identified (Sinisi et al. 2012). In this study the mineralogical and chemical compositions of the Sardinian sediment-hosted and volcanic-hosted Mn-ore are exhibit exploring the possibility that they can represent exploitable trace and REE mineralizations. High contents of metals characterize these Mn deposits. Besides some trace elements (Ni, Cr, Zn, Cu, As, Pb, and U) that commonly typify the Mn oxi-hydroxide ores, all rare earth elements showed high concentrations in the Sardinian deposits, comparable to those of the main actually exploited REE sinks. For this reason, a simple statistical data treatment (R-mode Factor Analysis) was performed on fifteen and nineteen samples of sediment-hosted and volcanic-hosted Mn ore respectively, in order to identify both the mineral phases trapping trace

  18. Brain regional distributions of the minor and trace elements, Na, Mg, Cl, K, Mn, Zn, Rb and Br, in young and aged mice

    International Nuclear Information System (INIS)

    Amano, R.; Oishi, S.; Ishie, M.; Kimura, M.

    2001-01-01

    Brain regional cerebral concentrations of minor and trace elements, Na, Mg, Cl, K, Mn, Zn, Rb and Br were determined in young and aged mice, by instrumental neutron activation analysis for small amounts of regional (corpus striatum, cerebellum, cerebral cortex, hippocampus, midbrain, pons and medulla olfactory bulb) samples. Significant age-related differences were found for Mn concentration in all brain regions: The Mn concentration of the young brain was higher than those of aged brain, in addition, Zn was distributed heterogeneously, and highly concentrated in cerebral cortex and hippocampus regions in both young and aged mice. These results suggest that, in the aged brain, Mn is required less than in the young brain, on the other hand, Zn is required equally in both young and aged brains. (author)

  19. Volatile elements production rates in a 1.4 Gev proton-irradiated molten lead-bismuth target

    CERN Document Server

    Zanini, L; Everaerts, P; Fallot, M; Franberg, H; Gröschel, F; Jost, C; Kirchner, T; Kojima, Y; Köster, U; Lebenhaft, J; Manfrina, E; Pitcher, E J; Ravn, H L; Tall, Y; Wagner, W; Wohlmuther, M

    2005-01-01

    Production rates of volatile elements following spallation reaction of 1.4 GeV protons on a liquid Pb/Bi target have been measured. The experiment was performed at the ISOLDE facility at CERN. These data are of interest for the developments of targets for accelerator driven systems such as MEGAPIE. Additional data have been taken on a liquid Pb target. Calculations were performed using the FLUKA and MCNPX Monte Carlo codes coupled with the evolution codes ORIHET3 and FISPACT using different options for the intra-nuclear cascades and evaporation models. Preliminary results from the data analysis show good comparison with calculations for Hg and for noble gases. For other elements such as I it is apparent that only a fraction of the produced isotopes is released. The agreement with the experimental data varies depending on the model combination used. The best results are obtained using MCNPX with the INCL4/ABLA models and with FLUKA. Discrepancies are found for some isotopes produced by fission using the MCNPX ...

  20. Survey of trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) in retail samples of flavoured and bottled waters.

    Science.gov (United States)

    Barroso, M F; Ramos, S; Oliva-Teles, M T; Delerue-Matos, C; Sales, M G F; Oliveira, M B P P

    2009-01-01

    Concentrations of eleven trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) were measured in 39 (natural and flavoured) water samples. Determinations were performed using graphite furnace electrothermetry for almost all elements (Al, As, Cd, Cr, Co, Mn, Ni, Pb, and Si). For Se determination hydride generation was used, and cold vapour generation for Hg. These techniques were coupled to atomic absorption spectrophotometry. The trace element content of still or sparkling natural waters changed from brand to brand. Significant differences between natural still and natural sparkling waters (p element was compared with the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. It was shown that flavoured waters generally increase the trace element content. The addition of preservatives and acidifying regulators had a significant influence on Mn, Co, As and Si contents (p < 0.05). Fruit juice can also be correlated to the increase of Co and As. Sweeteners did not provide any significant difference in Mn, Co, Se and Si content.

  1. Volatile (Cl, F and S) and major element constraints on subduction-related mantle metasomatism along the alkaline basaltic backarc, Payenia, Argentina

    DEFF Research Database (Denmark)

    Brandt, Frederik Ejvang; Holm, Paul Martin; Hansteen, Thor H.

    2017-01-01

    We present data on volatile (S, F and Cl) and major element contents in olivine-hosted melt inclusions (MIs) from alkaline basaltic tephras along the Quaternary Payenia backarc volcanic province (~34°S–38°S) of the Andean Southern Volcanic Zone (SVZ). The composition of Cr-spinel inclusions and h...

  2. Major, Trace, and Volatile (CO2, H2O, S, F, and Cl) Elements from 1000+ Hawaiian Olivine-hosted Melt Inclusions Reveal the Dynamics of Crustal Recycling

    Science.gov (United States)

    Marske, J. P.; Hauri, E. H.; Trusdell, F.; Garcia, M. O.; Pietruszka, A. J.

    2015-12-01

    Global cycling of volatile elements (H2O, CO2, F, S, Cl) via subduction to deep mantle followed by entrainment and melting within ascending mantle plumes is an enigmatic process that controls key aspects of hot spot volcanism (i.e. melting rate, magma supply, degassing, eruptive style). Variations in radiogenic isotope ratios (e.g.187Os/188Os) at hot spots such as Hawaii reveal magmatic processes within deep-seated mantle plumes (e.g. mantle heterogeneity, lithology, and melt transport). Shield-stage lavas from Hawaii likely originate from a mixed plume source containing peridotite and recycled oceanic crust (pyroxenite) based on variations of radiogenic isotopes. Hawaiian lavas display correlations among isotopes, major and trace elements [1] that might be expected to have an expression in the volatile elements. To investigate this link, we present Os isotopic ratios (n=51), and major, trace, and volatile elements from 1003 olivine-hosted melt inclusions (MI) and their host minerals from tephra from Koolau, Mauna Loa, Hualalai, Kilauea, and Loihi volcanoes. The data show a strong correlation between MI volatile contents and incompatible trace element ratios (La/Yb) with Os isotopes of the same host olivines and reveal large-scale volatile heterogeneity and zonation exists within the Hawaiian plume. 'Loa' chain lavas, which are thought to originate from greater proportions of recycled oceanic crust/pyroxenite, have MIs with lower H2O, S, F, and Cl contents compared to 'Kea' chain lavas that were derived from more peridotite-rich sources. The depletion of volatile elements in the 'Loa' volcano MIs can be explained if they tapped an ancient dehydrated oceanic crust component within the Hawaiian plume. Higher extents of melting beneath 'Loa' volcanoes can also explain these depletions. The presence of dehydrated recycled mafic material in the plume source suggests that subduction effectively devolatilizes part of the oceanic crust. These results are similar to the

  3. Seasonal variation of major elements (Ca, Mg) and trace metals (Fe, Cu, Zn, Mn) and cultured mussel Perna viridis L. and seawater in the Dona Paula Bay, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Rivonker, C.U.; Parulekar, A.H.

    The major elements and trace metals were analysed from nussel tissue and the seawater taken from three depths (0, 5 and 9 meters) from the culture site. Range of variation in Ca, Mg, Fe, Cu, Zn and Mn were 226-399; 708-1329; 0.005-0.084; BDL-0...

  4. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Boyce, J. W.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Magna, T.; Ni, P.; Tartese, R.; hide

    2017-01-01

    The chapter will begin with an introduction that defines magmatic volatiles (e.g., H, F, Cl, S) versus geochemical volatiles (e.g., K, Rb, Zn). We will discuss our approach of understanding both types of volatiles in lunar samples and lay the ground work for how we will determine the overall volatile budget of the Moon. We will then discuss the importance of endogenous volatiles in shaping the "Newer Views of the Moon", specifically how endogenous volatiles feed forward into processes such as the origin of the Moon, magmatic differentiation, volcanism, and secondary processes during surface and crustal interactions. After the introduction, we will include a re-view/synthesis on the current state of 1) apatite compositions (volatile abundances and isotopic compositions); 2) nominally anhydrous mineral phases (moderately to highly volatile); 3) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar pyroclastic glass beads; 4) volatile (moderately to highly volatile) abundances in and isotopic compositions of lunar basalts; 5) volatile (moderately to highly volatile) abundances in and isotopic compositions of melt inclusions; and finally 6) experimental constraints on mineral-melt partitioning of moderately to highly volatile elements under lunar conditions. We anticipate that each section will summarize results since 2007 and focus on new results published since the 2015 Am Min review paper on lunar volatiles [9]. The next section will discuss how to use sample abundances of volatiles to understand the source region and potential caveats in estimating source abundances of volatiles. The following section will include our best estimates of volatile abundances and isotopic compositions (where permitted by available data) for each volatile element of interest in a number of important lunar reservoirs, including the crust, mantle, KREEP, and bulk Moon. The final section of the chapter will focus upon future work, outstanding questions

  5. Metallic elements (Ca, Hg, Fe, K, Mg, Mn, Na, Zn) in the fruiting bodies of Boletus badius.

    Science.gov (United States)

    Kojta, Anna K; Falandysz, Jerzy

    2016-06-01

    The aim of this study was to investigate and compare the levels of eight metallic elements in the fruiting bodies of Bay Bolete (Boletus badius; current name Imleria badia) collected from ten sites in Poland to understand better the value of this popular mushroom as an organic food. Bay Bolete fruiting bodies were collected from the forest area near the towns and villages of Kętrzyn, Poniatowa, Bydgoszcz, Pelplin, Włocławek, Żuromin, Chełmno, Ełk and Wilków communities, as well as in the Augustów Primeval Forest. Elements such as Ca, Fe, K, Mg, Mn, Na and Zn were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-OES), and mercury by cold vapor atomic absorption spectrometry (CV-AAS). This made it possible to assess the nutritional value of the mushroom, as well as possible toxicological risks associated with its consumption. The results were subjected to statistical analysis (Kruskal-Wallis test, cluster analysis, principal component analysis). Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Trace elements partitioning during coal combustion in fluidized bed under O{sub 2}/CO{sub 2} atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Li, Haixin; Zhao, Changsui; Liang, Cai; Duan, Lunbo; Chen, Huichao [Southeast Univ., Nanjing (China). School of Energy and Environment

    2013-07-01

    Experiments were conducted to investigate the effects of temperature and O{sub 2}/CO{sub 2} atmosphere on trace elements (Cr, Mn, Co, Ni, Cd, Pb, Hg, As, Se) partitioning during combustion of Xuzhou bituminous coal in a 6 kWth fluidized bed. Inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectrometry (AFS) were used to determine trace elements contents in raw coal, bottom ash, fly ash and flue gas. The results indicate that with bed temperature increase, the relative enrichment of all the trace elements except Cr in bottom ash decreases suggesting that their volatility is enhanced. The relative enrichments of hardly volatile elements, like Cr and Mn in fly ash increase with bed temperature increase while those of partially volatile and highly volatile elements in fly ash are opposite. The relative enrichments of trace elements except Cr and Mn in fly ash are higher than those in bottom ash. Increasing bed temperature promotes elements like As, Se and Hg to migrate to vapor phase, Mn to migrate to fly ash and Cr to migrate to both bottom ash and fly ash. 21%O{sub 2}/79%CO{sub 2} atmosphere improves the volatility of Cr, Mn, Co, Se and their migration to fly ash, while restrains the volatility of As, Ni, Pb. It has little effect on the volatility of Hg but improves its migration to fly ash. Mass balance ratio was also calculated to observe trace elements distribution in bottom ash, fly ash and flue gas. There is no much difference in trace elements distribution between the two atmospheres. It can be seen that the trace elements proportion in fly ash is much greater, and more than 40% of Hg is distributed in the gas phase. Most of Hg and Se volatilize during combustion. The mass balance ratios are 87 {proportional_to} 129% which is considered acceptable.

  7. Tuning of the magneto-caloric effects in MnFe(P,As) by substitution of elements

    International Nuclear Information System (INIS)

    Tegus, O.; Brueck, E.; Li, X.W.; Zhang, L.; Dagula, W.; Boer, F.R. de; Buschow, K.H.J.

    2004-01-01

    MnFe(P,As) displays a large magnetocaloric effect around room temperature. Substitution of Cr for Fe results in a reduction of both the ordering temperature and the magnetocaloric effect. Substitution of Co for Fe leads to a decrease of the ordering temperature, whereas 10% extra Fe substituted for Mn leads to an increase of the ordering temperature. Finally, 10% extra Mn substituted for Fe results in an enhanced magnetocaloric effect with hardly any change of ordering temperature

  8. Influence of elemental diffusion on low temperature formation of MgH2 in TiMn1.3T0.2-Mg (T = 3d-transition elements)

    International Nuclear Information System (INIS)

    Yamamoto, K.; Tanioka, S.; Tsushio, Y.; Shimizu, T.; Morishita, T.; Orimo, S.; Fujii, H.

    1996-01-01

    In order to examine the influence of the elemental diffusion from the host compound into the Mg region on low temperature formation of MgH 2 , we have investigated the hydriding properties and the microstructures of the composite materials TiMn 1.3 T 0.2 -Mg (T = V, Cr, Mn, Fe, Co, Ni and Cu). MgH 2 is formed at 353 K in all composite materials. Of all the substitutions, the amount of MgH 2 is the largest in the case of the Cu substitution, which originates from the existence of the Mg-Mg 2 Cu eutectic formed by Cu diffusion from the host compound TiMn 1.3 Cu 0.2 into the Mg region during the liquid phase sintering. In addition, the hydrogen capacity of TiMn 1.3 Cu 0.2 -Mg (that is TiMn 1.3 Cu 0.1 -(Mg+Mg 2 Cu) after the sintering) easily saturates in comparison with TiMn 1.5 -(Mg+Mg 2 Cu) without Cu diffusion. It is concluded that Cu diffusion promotes the mobility of hydrogen atoms at the complex interface between the host compound and the Mg region. (orig.)

  9. Magnetically induced electrical transport and dielectric properties of 3d transition elemental substitution at the Mn-site in Nd0.67Ba0.33MnO3 manganites

    Science.gov (United States)

    Sudakshina, B.; Arun, B.; Chandrasekhar, K. Devi; Yang, H. D.; Vasundhara, M.

    2018-05-01

    We have investigated the temperature dependence of electrical transport and dielectric properties along with magnetoresistance and magneto dielectric behavior in Nd0.67Ba0.33Mn0.9TR0.1O3 (TR= Cr, Fe, Co, Ni, Cu) manganites. All the compounds crystallized into an orthorhombic structure with Imma space group. Nd0.67Ba0.33MnO3 shows insulating to metallic behavior at intermediate temperatures, but, with the substitution of transitional elements it shows insulating in nature, down to lowest temperature measured for all the compounds. Dielectric measurement shows the intrinsic behavior of these lossy materials. A large value of magneto resistance is obtained for all the compounds and considerable amount of magneto-dielectric effect is shown for all the substituted compounds at lower temperatures.

  10. The effect of a fourth element (Co, Cu, Fe, Pd) on the standard enthalpy of formation of the Heusler compound Ni{sub 2}MnSn

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Ming, E-mail: myin1@hawk.iit.edu; Nash, Philip

    2016-05-15

    The standard enthalpies of formation of quaternary Heusler compounds (X, Ni){sub 2}MnSn (X = Co, Cu, Fe, Pd) were investigated experimentally using high temperature direct reaction calorimetry. Lattice parameters of these compounds were determined using X-ray diffraction analysis. Microstructures were identified using scanning electron microscopy and energy dispersive spectroscopy. The effect of an additional X element on the standard enthalpy of formation of the Heusler compound Ni{sub 2}MnSn is discussed. - Highlights: • Enthalpies of formation of (X,Ni){sub 2}YZ (X = Co, Cu, Fe, Pd) were measured by drop calorimeters. • Magnetic contribution to enthalpy of formation plays an important role. • Introducing a fourth element could stabilize an unstable Heusler structure. • Lattice parameters do not necessarily obey the Vegard's law. • It is possible to tailor properties of Heusler compounds with enough background information.

  11. The centralized control of elemental mercury emission from the flue gas by a magnetic rengenerable Fe-Ti-Mn spinel.

    Science.gov (United States)

    Liao, Yong; Xiong, Shangchao; Dang, Hao; Xiao, Xin; Yang, Shijian; Wong, Po Keung

    2015-12-15

    A magnetic Fe-Ti-Mn spinel was developed to adsorb gaseous Hg(0) in our previous study. However, it is currently extremely restricted in the control of Hg(0) emission from the flue gas for at least three reasons: sorbent recovery, sorbent regeneration and the interference of the chemical composition in the flue gas. Therefore, the effect of SO2 and H2O on the adsorption of gaseous Hg(0) on the Fe-Ti-Mn spinel and the regeneration of spent Fe-Ti-Mn spinel were investigated in this study. Meanwhile, the procedure of the centralized control of Hg(0) emission from the flue gas by the magnetic Fe-Ti-Mn spinel has been analyzed for industrial application. The spent Fe-Ti-Mn spinel can be regenerated by water washing followed by the thermal treatment at 450 °C with no obvious decrease of its ability for Hg(0) capture. Meanwhile, gaseous Hg(0) in the flue gas can be remarkably concentrated during the regeneration, facilitating its safe disposal. Initial pilot test demonstrated that gaseous Hg(0) in the real flue gas can be concentrated at least 100 times by the Fe-Ti-Mn spinel. Therefore, Fe-Ti-Mn spinel was a novel magnetic regenerable sorbent, which can be used for the centralized control of Hg(0) emission from the flue gas. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Trace elements determination in human hair

    International Nuclear Information System (INIS)

    Carrion, Jose

    1995-01-01

    Concentrations of Cu, Zn, Pb, Mg, Ca, Na, K, Mn, Cr, Ni, Co, V, Cd and Al, in human hair sampled from 23 young men during 24 months were determined by atomic absorption spectroscopy. Additional determination of mercury and volatile elements were made by using accessory MHS-10. Statistical treatment of data is presented for each person and element. The pre-treatment of hair carried out with an organic solvent to remove the superficial pollutants is explained. (The author)

  13. Rare earth elements (REE) and yttrium in stream waters, stream sediments, and Fe Mn oxyhydroxides: Fractionation, speciation, and controls over REE + Y patterns in the surface environment

    Science.gov (United States)

    Leybourne, Matthew I.; Johannesson, Karen H.

    2008-12-01

    We have collected ˜500 stream waters and associated bed-load sediments over an ˜400 km 2 region of Eastern Canada and analyzed these samples for Fe, Mn, and the rare earth elements (REE + Y). In addition to analyzing the stream sediments by total digestion (multi-acid dissolution with metaborate fusion), we also leached the sediments with 0.25 M hydroxylamine hydrochloride (in 0.05 M HCl), to determine the REE + Y associated with amorphous Fe- and Mn-oxyhydroxide phases. We are thus able to partition the REE into "dissolved" (primary sources, the host lithologies (i.e., mechanical dispersion) and hydromorphically transported (the labile fraction). Furthermore, Eu appears to be more mobile than the other REE, whereas Ce is preferentially removed from solution and accumulates in the stream sediments in a less labile form than the other REEs + Y. Despite poor statistical correlations between the REEs + Y and Mn in either the total sediment or partial extractions, based on apparent distribution coefficients and the pH of the stream waters, we suggest that either sediment organic matter and/or possibly δ-MnO 2/FeOOH are likely the predominant sinks for Ce, and to a lesser extent the other REE, in the stream sediments.

  14. A preliminary study of the effect of phytoadditive carvacrol on the trace elements (Cu, Mn and Zn content in fish tissues

    Directory of Open Access Journals (Sweden)

    EBRU YILMAZ

    2014-04-01

    Full Text Available Phytoadditives have gained increasing interest as feed additives for fish. The aim of the present study was to determine whether selected dietary phytoadditive can influence the bioavailability of several trace elements (Cu, Mn and Zn, which play an important role in the physiological processes. The experiments were carried out at a commercial trout farm. A total of 420 juvenile rainbow trout (mean weight ± SD = 10.79±0.57, Oncorhynchus mykiss, were randomly allocated into four different treatments with three replicates each. Fish were kept in raceways (3X0.8X0.4 m at 10±1°C with a natural photoperiod. Proper amount of carvacrol was sprayed on 1 kg of commercial trout diet to prepare four diets with 0 (Control, C0, 1 (C1, 3 (C3 and 5 (C5 carvacrol g/kg diet. Fish were fed to apparent satiation three times per day. The feeding trial lasted four weeks. Then, in different type of fish tissues (muscle, liver and pyloric caeca from fish fed with diets enriched in carvacrol, beneficial elements (Cu, Mn and Zn were analysed by atomic adsorption spectrophotometer. Results showed that the levels of Cu, Zn and Mn were especially significantly increase by C1 diet in all tissues (muscle, liver and pyloric caeca except muscle and pyloric caeca Zn. The results of this experiment indicate that the carvacrol had the ability to potentiate the trace element retention. Although bioaccumulations of Cu, Zn and Mn in the muscle, liver and pyloric caeca are well demonstrated, the exact mechanisms of phytoadditives are still only partially understood. More investigations are required to detail the mechanisms involved in phytoadditives this enhancement.

  15. Effects of alloying elements (Mn, Co, Al, W, Sn, B, C and S) on biodegradability and in vitro biocompatibility of pure iron.

    Science.gov (United States)

    Liu, B; Zheng, Y F

    2011-03-01

    Pure iron was determined to be a valid candidate material for biodegradable metallic stents in recent animal tests; however, a much faster degradation rate in physiological environments was desired. C, Mn, Si, P, S, B, Cr, Ni, Pb, Mo, Al, Ti, Cu, Co, V and W are common alloying elements in industrial steels, with Cr, Ni, Mo, Cu, Ti, V and Si being acknowledged as beneficial in enhancing the corrosion resistance of iron. The purpose of the present work (using Fe-X binary alloy models) is to explore the effect of the remaining alloying elements (Mn, Co, Al, W, B, C and S) and one detrimental impurity element Sn on the biodegradability and biocompatibility of pure iron by scanning electron microscopy, X-ray diffraction, metallographic observation, tensile testing, microhardness testing, electrochemical testing, static (for 6 months) and dynamic (for 1 month with various dissolved oxygen concentrations) immersion testing, cytotoxicity testing, hemolysis and platelet adhesion testing. The results showed that the addition of all alloying elements except for Sn improved the mechanical properties of iron after rolling. Localized corrosion of Fe-X binary alloys was observed in both static and dynamic immersion tests. Except for the Fe-Mn alloy, which showed a significant decrease in corrosion rate, the other Fe-X binary alloy corrosion rates were close to that of pure iron. It was found that compared with pure iron all Fe-X binary alloys decreased the viability of the L929 cell line, none of experimental alloying elements significantly reduced the viability of vascular smooth muscle cells and all the elements except for Mn increased the viability of the ECV304 cell line. The hemolysis percentage of all Fe-X binary alloy models were less than 5%, and no sign of thrombogenicity was observed. In vitro corrosion and the biological behavior of these Fe-X binary alloys are discussed and a corresponding mechanism of corrosion of Fe-X binary alloys in Hank's solution proposed. As a

  16. Determination of the potential and coherent scattering cross-sections of the elements Si, Ca, Cr, Mn, Co, Zn, Zr, Sb and Ta

    International Nuclear Information System (INIS)

    Adib, M.; Abdel-Kawy, A.; Hamouda, I.

    1976-01-01

    The potential scattering cross-sections for slow neutrons have been measured for Si, Ca, Cr, Mn, Co, Zn, Zr, Sb and Ta in order to determine the nuclear potential radius and to investigate the prediction of nuclear optical model. The coherent scattering cross-sections for these elements have been measured from the obtained values of the Bragg cut-offs observed in the behaviour of the total cross-sections at cold neutron energies. The measurements were based on the total neutron cross-sections resulting from transmission experiments performed with the neutron chopper at ET-RR-1 reactor

  17. Certification of trace element contents (As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn) in a fly ash obtained from the combustion of pulverised coal

    International Nuclear Information System (INIS)

    Griepink, B.; Colinet, E.; Guzzi, G.; Haemers, L.; Muntau, H.

    1983-01-01

    The element contents of As, Cd, Co, Cu, Fe, Mn, Hg, Na, Pb and Zn of a fly ash from pulverised coal are certified. The procedures and their results for the homogenisation, the contamination and homogeneity checks and the analytical campaign are reported. The certified mass fractions and indicative values for Cr, Ni, Th, V and water soluble sulphate are given. The work was carried out within the framework of the activities of the Community Bureau of Reference (BCR) of the Commission of the European Communities. (orig.) [de

  18. Vapor-phase elemental mercury adsorption by Ca(OH){sub 2} impregnated with MnO{sub 2} and Ag in fixed-bed system

    Energy Technology Data Exchange (ETDEWEB)

    Y.J. Wang; Y.F. Duan; Z.J. Huang; S.L. Meng; L.G. Yang; C.S. Zhao [Southeast University, Nanjing (China). School of Energy and Environment

    2010-05-15

    The ability of three sorbents (untreated Ca(OH){sub 2}, MnO{sub 2}-impregnated Ca(OH){sub 2} and Ag-impregnated Ca(OH){sub 2}) removing the elemental mercury had been studied using a laboratory-scale fixed-bed reactor at 80{sup o}C under simulated fuel gas conditions. The adsorption performance of the three sorbents was compared by mercury removal efficiency and adsorption capacity. The effect of acid gases such as HCl and SO{sub 2} on the mercury removal was investigated and presented in this article. The results showed that the mercury removal by Ca(OH){sub 2} was mainly controlled by physical mechanisms. In the case of Ca(OH){sub 2}, the presence of both SO{sub 2} and HCl promoted the Hg{sup 0} removal, and compared HCl with SO{sub 2}, HCl had a higher mercury removal than SO{sub 2}. Ca(OH){sub 2} impregnated with MnO{sub 2} had a slightly higher mercury removal than the original Ca(OH){sub 2}, but it was beneficial for mercury speciation. The presence of both SO{sub 2} and HCl promotes the Hg0 removal greatly, which was adsorbed by Ca(OH){sub 2} impregnated with MnO{sub 2}. The Ca(OH){sub 2} impregnated with MnO{sub 2} adsorbed more than 50% total Hg due to the occurrence of chemisorptions. The mercury removal by Ca(OH){sub 2} impregnated with Ag was the highest. This may be because mercury integrated with silver easily that could produce silver amalgam alloy.

  19. Trace elements in land plants: concentration ranges and accumulators of rare earths, Ba, Ra, Mn, Fe, Co and heavy halogens

    International Nuclear Information System (INIS)

    Koyama, M.; Shirakawa, M.; Takada, J.; Katayama, Y.; Matsubara, T.

    1987-01-01

    More than 2000 samples of land plant leaves, mostly of tree, were analyzed by neutron activation analysis in order to find out macroscopic relations between distributions of chemical elements in plants and soil characteristics. The distributions of the elements in plants were also examined from the view point of botanical taxonomy or phylogeny. New species which accumulate Co, rare earths, Ba, Ra, heavy halogens and some other elements were found. Capability or potentiality for accumulating elements could be related to higher ranks of taxonomy, that is, genus or family. The nature of soil is also found to have profound effects on the extent of accumulation of elements in plants. (author)

  20. Addition of granular activated carbon and trace elements to favor volatile fatty acid consumption during anaerobic digestion of food waste.

    Science.gov (United States)

    Capson-Tojo, Gabriel; Moscoviz, Roman; Ruiz, Diane; Santa-Catalina, Gaëlle; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Bernet, Nicolas; Delgenès, Jean-Philippe; Escudié, Renaud

    2018-07-01

    The effect of supplementing granular activated carbon and trace elements on the anaerobic digestion performance of consecutive batch reactors treating food waste was investigated. The results from the first batch suggest that addition of activated carbon favored biomass acclimation, improving acetic acid consumption and enhancing methane production. Adding trace elements allowed a faster consumption of propionic acid. A second batch proved that a synergy existed when activated carbon and trace elements were supplemented simultaneously. The degradation kinetics of propionate oxidation were particularly improved, reducing significantly the batch duration and improving the average methane productivities. Addition of activated carbon favored the growth of archaea and syntrophic bacteria, suggesting that interactions between these microorganisms were enhanced. Interestingly, microbial analyses showed that hydrogenotrophic methanogens were predominant. This study shows for the first time that addition of granular activated carbon and trace elements may be a feasible solution to stabilize food waste anaerobic digestion. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Volatilization mechanism of certain elements in a method of semiquantitative spectrographic analysis; Mecanismo de volatilizacion de ciertos elementos en un metodo de analisis espectrografico semicuantitativo

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Guerra, J P

    1972-07-01

    The efficiency of the compounds GeO{sub 2}, Li{sub 2}B{sub 4}O{sub 7}, Li{sub 2}CO{sub 3}, SiO{sub 2} and SrCO{sub 3} as spectrochemical buffers, in the development of a semiquantitative spectrographic method of analysis, that can be applied to the determination of 47 elements in different matrices, has been tested. It has been shown that trough the use of Li{sub 2}B{sub 4}O{sub 7} or Geo{sub 2} adequate accuracy is obtained, attaining with the latter the detection of much lower concentrations, specially for the elements Mo. Ti, V and W. In order to account for the different behaviour of these elements their volatilization mechanism has been studied. MoB{sub 2}, TiB{sub 2}, VB{sub 2}.{delta}WB and {epsilon}-WB were found, by x-ray diffraction analysis, to be reaction products in the case of mixtures with Li{sub 2}B{sub 4}O{sub 7}. (Author)

  2. Trace elements in land plants: concentration ranges and accumulators of rare earths, Ba, Ra, Mn, Fe, Co, and heavy halogens

    International Nuclear Information System (INIS)

    Koyama, Mutsuo; Shirakawa, Masahiro; Takada, Jitsuya; Katayama, Yukio; Matsubara, Takashi

    1986-01-01

    More than 2000 samples of land plant leaves, mostly of tree, have been analysed by neutron activation analysis in order to find out macroscopic relations between distributions of chemical elements in plants and soil characteristics. The distributions of the elements in plants were also examined from the view point of botanical taxonomy or phylogeny. New species which accumulate Co, rare earths, Ba, Ra, heavy halogens and other elements have been found. Capability or potentiality for accumulating elements could be related to primarily to species. In several cases, however, it is related to higher ranks of taxonomy, that is, genus or family. The nature of soil is also found to have profound effects on the extent of accumulation of elements in plants. (author)

  3. Volatile and siderophile trace elements in anorthositic rocks from Fiskenaesset, West Greenland: comparison with lunar and meteoritic analogues

    International Nuclear Information System (INIS)

    Morgan, J.W.; Ganapathy, R.; Higuchi, H.; Kraehenbuehl, U.

    1976-01-01

    Seventeen trace elements (Ag, Au, Bi, Br, Cd, Cs, Ge, Ir, Ni, Rb, Re, Sb, Se, Te, Tl, U, Zn) were analysed by radiochemical neutron activation and 13 other elements (Ce, Co, Cr, Eu, Fe, Hf, La, Lu, Na, Sc, Sm, Tb, Yb) by instrumental neutron activation in a total of 12 rocks from the layered anorthositic complex at Fiskenaesset, West Greenland, and in the plagioclase-rich unbrecciated eucrite, Serra de Mage. The results are discussed and compared with lunar and meteoritic analogues. (author)

  4. Carbonatite and silicate melt metasomatism of the mantle surrounding the Hawaiian plume: Evidence from volatiles, trace elements, and radiogenic isotopes in rejuvenated-stage lavas from Niihau, Hawaii

    Science.gov (United States)

    Dixon, Jacqueline; Clague, David A.; Cousens, Brian; Monsalve, Maria Luisa; Uhl, Jessika

    2008-09-01

    We present new volatile, trace element, and radiogenic isotopic compositions for rejuvenated-stage lavas erupted on Niihau and its submarine northwest flank. Niihau rejuvenated-stage Kiekie Basalt lavas are mildly alkalic and are isotopically similar to, though shifted to higher 87Sr/86Sr and lower 206Pb/204Pb than, rejuvenated-stage lavas erupted on other islands and marginal seafloor settings. Kiekie lavas display trace element heterogeneity greater than that of other rejuvenated-stage lavas, with enrichments in Ba, Sr, and light-rare earth elements resulting in high and highly variable Ba/Th and Sr/Ce. The high Ba/Th lavas are among the least silica-undersaturated of the rejuvenated-stage suite, implying that the greatest enrichments are associated with the largest extents of melting. Kiekie lavas also have high and variable H2O/Ce and Cl/La, up to 620 and 39, respectively. We model the trace element concentrations of most rejuvenated-stage lavas by small degrees (˜1% to 9%) of melting of depleted peridotite recently metasomatized by a few percent of an enriched incipient melt (0.5% melting) of the Hawaiian plume. Kiekie lavas are best explained by 4% to 13% partial melting of a peridotite source metasomatized by up to 0.2% carbonatite, similar in composition to oceanic carbonatites from the Canary and Cape Verde Islands, with lower proportion of incipient melt than that for other rejuvenated-stage lavas. Primary H2O and Cl of the carbonatite component must be high, but variability in the volatile data may be caused by heterogeneity in the carbonatite composition and/or interaction with seawater. Our model is consistent with predictions based on carbonated eclogite and peridotite melting experiments in which (1) carbonated eclogite and peridotite within the Hawaiian plume are the first to melt during plume ascent; (2) carbonatite melt metasomatizes plume and surrounding depleted peridotite; (3) as the plume rises, silica-undersaturated silicate melts are also

  5. Novel carbon fiber cathode membrane with Fe/Mn/C/F/O elements in bio-electrochemical system (BES) to enhance wastewater treatment

    Science.gov (United States)

    Gao, Changfei; Liu, Lifen; Yang, Fenglin

    2018-03-01

    A novel conductive membrane with Fe/Mn/C/F/O elements is developed, it functions as the catalytic cathode of MFC and the antifouling filter of MBR simultaneously, in a newly designed integrated wastewater treatment system, without proton exchange membrane (PEM). The optimal conductive membrane is characterized using SEM-EDX, XRD and XPS. BET and porous structure analysis of the grounded membrane material indicate a narrow and small pore size (2-7 nm). The membrane surface is rich in Fe species (Fe - Fe2O3- Fe3O4) and manganese oxide (MnO2). Its characteristics such as excellent electro-chemical oxygen reduction reaction (ORR) activity, high clear water flux (>240 L/(m2·h)) and better antifouling filtration performance are further confirmed. The new system features bio-electrochemical system (BES) and integrates bio-filtration (trickling filter and air contact oxidation bed) and proton transfer through quartz sand chamber (QSC) which eliminates the use of expensive proton exchange membrane. The system removes chemical oxygen demand (>97.4%), ammonia nitrogen (>96.7%), total phosphorus (>98.0%) effectively, and it simultaneously generates electricity (446 mW/m3). The low cost and high performances, economic and advantageous system has good compatibility with existing wastewater treatment facilities and a wide application prospect.

  6. Geochemical dispersion of Si, Al, Fe, Mn, Na, K, Cu and Zn elements in soils and their use for characterization areas geochemically homogeneous

    International Nuclear Information System (INIS)

    Silva, W.R.L. da.

    1982-01-01

    Variations in the chemical composition of soils are used to characterize sub-areas geochemically - homogenous. The application of this methodology in a tropical humid region of accentuated topography constitute the principal objective of the present research. Samples of red latosols (Horizon B) developed over granite, sandstone and basalt occurring in the Central Granite Region of the Serra dos Carajas, Para State, Brazil were analized for the elements Si, Al, Fe, Mn, Na, K, Cu e Zn, by atomic absorption spectrophotometry. Based on the criterion of similarity in the chemical composition (Cluster Analysis, Factor Analysis) the soils were separeted in to different groups. The geographical distribution of the different groups permit the establishment of a close relationship between the different parent lithologies and their corresponding soils. (author)

  7. The crystallization of amorphous Fe2MnGe powder prepared by ball milling

    International Nuclear Information System (INIS)

    Zhang, L.; Brueck, E.; Tegus, O.; Buschow, K.H.J.; Boer, F.R. de

    2003-01-01

    We synthesized for the first time the intermetallic compound Fe 2 MnGe. To avoid preferential evaporation of volatile components we exploited mechanical alloying. Amorphous Fe 2 MnGe alloy powder was prepared by planetary ball milling elemental starting materials. The amorphous-to-crystalline transition was studied by means of differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A cubic D0 3 phase is formed at low temperature and transforms to a high-temperature hexagonal D0 19 phase. The apparent activation energy was determined by means of the Kissinger method

  8. Effect of microalloying elements (Nb, V and Ti) on the hot flow behavior of high-Mn austenitic twinning induced plasticity (TWIP) steel

    International Nuclear Information System (INIS)

    Reyes-Calderón, F.; Mejía, I.; Boulaajaj, A.; Cabrera, J.M.

    2013-01-01

    This research work studies the effect of microalloying elements such as Nb, V and Ti on the hot flow behavior of high-Mn austenitic TWIP steel. For this purpose, isothermal uniaxial hot compression tests were carried out at three temperatures (900, 1000 and 1100 °C) and four constant strain rates (10 −1 , 10 −2 , 10 −3 and 10 −4 s −1 ). Experimental results revealed that hot flow curves of microalloyed TWIP steels show single peak curves for all test conditions. Results are discussed in terms of the peak stress (σ p ) and peak strain (ε p ) and its dependence on the strain rate (ε) and temperature. The addition of microalloying elements such as Nb, V and Ti in TWIP steels generates a slight increase in the σ p value, and Ti microalloyed TWIP steel exhibits the highest σ p value. Hot deformed microstructures were analyzed by the Electron Back-Scattering Diffraction Technique (EBSD). The most important results of the austenitic recrystallized grain refinement were obtained for V and Ti microalloyed TWIP steels.

  9. Volatility Discovery

    DEFF Research Database (Denmark)

    Dias, Gustavo Fruet; Scherrer, Cristina; Papailias, Fotis

    The price discovery literature investigates how homogenous securities traded on different markets incorporate information into prices. We take this literature one step further and investigate how these markets contribute to stochastic volatility (volatility discovery). We formally show...... that the realized measures from homogenous securities share a fractional stochastic trend, which is a combination of the price and volatility discovery measures. Furthermore, we show that volatility discovery is associated with the way that market participants process information arrival (market sensitivity......). Finally, we compute volatility discovery for 30 actively traded stocks in the U.S. and report that Nyse and Arca dominate Nasdaq....

  10. An Overview of the Effects of Alloying Elements on the Properties of Lightweight Fe-(15-35) Mn-(5-12) Al-(0.3-1.2) C Steel

    Science.gov (United States)

    Xing, Jia; Wei, Yinghui; Hou, Lifeng

    2018-04-01

    In this review, the influences of alloying elements on the phase constitution, density, and stacking fault energy of Fe-(15-35) Mn-(5-12) Al-(0.3-1.2) C lightweight steel are discussed. The mechanical properties of austenite single-phase and austenite-ferrite dual-phase Fe-Mn-Al-C steels processed by different procedures are also statistically analyzed. The austenite single-phase steel was found to possess superior strength and plasticity. Three reasonable explanations for the mechanism of plastic deformation are presented, namely, shear band-induced plasticity, microband-induced plasticity, and slip band refinement-induced plasticity.

  11. Trace element emissions from coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

    Trace elements are emitted during coal combustion. The quantity, in general, depends on the physical and chemical properties of the element itself, the concentration of the element in the coal, the combustion conditions and the type of particulate control device used, and its collection efficiency as a function of particle size. Some trace elements become concentrated in certain particle streams following combustion such as bottom ash, fly ash, and flue gas particulate matter, while others do not. Various classification schemes have been developed to describe this partitioning behaviour. These classification schemes generally distinguish between: Class 1: elements that are approximately equally concentrated in the fly ash and bottom ash, or show little or no fine particle enrichment, examples include Mn, Be, Co and Cr; Class 2: elements that are enriched in the fly ash relative to bottom ash, or show increasing enrichment with decreasing particle size, examples include As, Cd, Pb and Sb; Class 3: elements which are emitted in the gas phase (primarily Hg (not discussed in this review), and in some cases, Se). Control of class 1 trace elements is directly related to control of total particulate matter emissions, while control of the class 2 elements depends on collection of fine particulates. Due to the variability in particulate control device efficiencies, emission rates of these elements can vary substantially. The volatility of class 3 elements means that particulate controls have only a limited impact on the emissions of these elements.

  12. Virtual volatility

    Science.gov (United States)

    Silva, A. Christian; Prange, Richard E.

    2007-03-01

    We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.

  13. The finite element analysis of austenite decomposition during continuous cooling in 22MnB5 steel

    International Nuclear Information System (INIS)

    Chen, Xiangjun; Li, Guangyao; Sun, Guangyong; Xiao, Namin; Li, Dianzhong

    2014-01-01

    The hot stamping process has been increasingly used in newly designed vehicles to improve crash worthiness and fuel efficiency. In this study, a finite element model based on a subroutine of the commercial software ABAQUS is developed to predict the interactive influence of temperature field and phase transformation on high-strength boron steel. JMAK-type equations with the incubation time and additivity hypothesis are adopted to describe the austenite decomposition into ferrite, pearlite and bainite, while the Koistinen and Marburger (K–M) model is used to describe the displacive transformation of matensite. The simulation results show that the introduction of incubation time into a JMAK equation can provide a more reasonable prediction of the transformation kinetics than if the equation is unmodified. A comparison between the simulation and the standard Jominy end-quenching test demonstrates the capability of the present model for the prediction of transformation kinetics, microstructure distribution and mechanical properties. Furthermore, the adoption of experimentally measured microhardness values for the individual phase constituent can produce improved accuracy of the hardness predictions compared to the empirical hardness equations. (paper)

  14. Iodine volatility

    International Nuclear Information System (INIS)

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany

  15. Discrimination and risk assessment due to the volatile compounds and the inorganic elements present in the Greek marc distillates Tsipouro and Tsikoudia

    Directory of Open Access Journals (Sweden)

    Evangelos H. Soufleros

    2005-03-01

    Full Text Available Tsipouro and Tsikoudia are two denominations with geographic indications of the traditional Greek marc distillate, which is produced in continental Greece and in the island of Crete respectively. It is produced by the Greek winegrowers as well as by the professional distillers. To provide data on the safety of domestic Tsipouro and Tsikoudia distillates for human consumption and to draw conclusions from any essential results, which might have an impact on the quality of this product, 23 samples were analysed for: (a Volatile compounds by the use of gas chromatography, (b Inorganic elements, using atomic absorption spectrometry and (c the pH values through-out using standard methods. Data revealed differences between these two denominations, which have been confirmed by the application of a statistic analysis and a PCA. Thus, Tsikoudia was found to contain statistically higher amounts of acetalde-hyde. However, the levels that have been observed did not exceed the official limits. Most of the Tsipouro and Tsikoudia samples also contained low concentrations of estragol, an anise compound, lead and copper, which do not represent a risk to consumer health due to their toxicity. On the other hand, the total concentration of higher alcohols was higher than the official minimum limit (140 g.hl-1 Absolute Alcohol-AA, while the amylic alcohols rarely exceeded 300 g.hl-1 AA. The high concentrations of ethyl acetate (>300 g.hl-1 AA and ethyl lactate in a few samples showed the necessity of limiting unwanted fermentations in the grape pomace. The analytical study showed that the quality of the marc distillate is, generally, satisfactory. However, it revealed great differences between Tsipouro and Tsikoudia even among the samples of each denomination and, con-sequently, these domestic distillates need standardization and a more systematic production.

  16. Implications for behavior of volatile elements during impacts—Zinc and copper systematics in sediments from the Ries impact structure and central European tektites

    Science.gov (United States)

    Rodovská, Zuzana; Magna, TomáÅ.¡; Žák, Karel; Kato, Chizu; Savage, Paul S.; Moynier, Frédéric; Skála, Roman; Ježek, Josef

    2017-10-01

    Moldavites are tektites genetically related to the Ries impact structure, located in Central Europe, but the source materials and the processes related to the chemical fractionation of moldavites are not fully constrained. To further understand moldavite genesis, the Cu and Zn abundances and isotope compositions were measured in a suite of tektites from four different substrewn fields (South Bohemia, Moravia, Cheb Basin, Lusatia) and chemically diverse sediments from the surroundings of the Ries impact structure. Moldavites are slightly depleted in Zn ( 10-20%) and distinctly depleted in Cu (>90%) relative to supposed sedimentary precursors. Moreover, the moldavites show a wide range in δ66Zn values between 1.7 and 3.7‰ (relative to JMC 3-0749 Lyon) and δ65Cu values between 1.6 and 12.5‰ (relative to NIST SRM 976) and are thus enriched in heavy isotopes relative to their possible parent sedimentary sources (δ66Zn = -0.07 to +0.64‰; δ65Cu = -0.4 to +0.7‰). In particular, the Cheb Basin moldavites show some of the highest δ65Cu values (up to 12.5‰) ever observed in natural samples. The relative magnitude of isotope fractionation for Cu and Zn seen here is opposite to oxygen-poor environments such as the Moon where Zn is significantly more isotopically fractionated than Cu. One possibility is that monovalent Cu diffuses faster than divalent Zn in the reduced melt and diffusion will not affect the extent of Zn isotope fractionation. These observations imply that the capability of forming a redox environment may aid in volatilizing some elements, accompanied by isotope fractionation, during the impact process. The greater extent of elemental depletion, coupled with isotope fractionation of more refractory Cu relative to Zn, may also hinge on the presence of carbonyl species of transition metals and electromagnetic charge, which could exist in the impact-induced high-velocity jet of vapor and melts.

  17. Measurements of gas and volatile element production rates from an irradiated molten lead and lead-bismuth spallation target with proton beams of 1 and 1.4 GeV

    International Nuclear Information System (INIS)

    Tall, Y.

    2008-03-01

    The integrated project EUROTRANS (European Research Programme for the Transmutation of High Level Nuclear Waste in an Accelerator Driven System) of the 6. EURATOM Framework Programme aims to demonstrate the transmutation of radioactive waste in ADS (Accelerator Driven Sub-critical system). It will carry out a first advanced design of an experimental facility to demonstrate the technical feasibility of transmutation, and will produce a conceptual design of an industrial facility dedicated to transmutation. An ADS consists of three fundamental elements: the accelerator of protons, the sub-critical core and the spallation target. SUBATECH (physique Sub-Atomique et des Technologies associees) laboratory is involved to the study of the chosen liquid lead-bismuth as a spallation ADS target. The irradiation of liquid lead-bismuth target with energetic proton beam generates in addition to neutrons, volatile and radioactive residues. In order to determine experimentally the production rates of gas and volatile elements following a spallation reaction in a lead-bismuth target, the experiment IS419 was performed at the ISOLDE facility at CERN (Centre Europeen de la Recherche Nucleaire). This experiment constitutes the frame of the thesis whose main objective is to assess and study the production and release rates of many gas and volatile element from the irradiated lead-bismuth target with an energetic proton beam. The obtained data are compared to Monte Carlo simulation code (MCNPX) results in order to test the intranuclear cascade model of Bertini and of Cugnon, and the evaporation options of Dresner and Schmidt. (author)

  18. Partitioning of elements during coal combustion and leaching experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wen-feng; Qin Yong; Song Dang-yu; Wang Jun-yi [China University of Mining & Technology, Xuzhou (China). School of Resources and Earth Science

    2009-04-15

    The mineral component and content of sulfur and 42 major and trace elements of the feed coal, fly and bottom ashes collected from Shizuishan coal-fired power plant, Ningxia, China were analyzed using AFS, INAA, ICP-MS, ICP-AES, XRD. Based on the coal combustion and leaching experiments, the partitioning of these elements during coal combustion and the leaching behavior of the 11 potentially hazardous elements, including As, Cd, Co, Cr, Hg, Mo, Ni, Pb, Se, Th and U were investigated. The results show that the distribution of elements in the fly and bottom ashes is controlled by their volatilities and modes of occurrence in the coal. The degree of volatilization of elements may be mainly associated with boiling/melting points of these elements and their compounds. The elements easily volatilized, organically bound or associated with sub-micrometer and nano minerals (e.g. Al and Na) tend to be enriched in the fine fractions of fly ash, and most elements do not vaporize which are approximately equally partitioned in the fly and bottom ashes. The emission rates of As, Cr, K, Mg, Mn, Mo, Pb, Sb, and Zn are notably influenced by the temperature ranging from 877 to 1300{sup o}C. The leaching behavior of elements depend significantly on their geochemical properties and modes of occurrence. The elements with a low degree of volatilization are not easily leached, while volatile elements easily leached under the acid conditions. Arsenic, B Br, Cd, Cu, Hg, Pb, S, Sb and Se show a higher emission rate during coal combustion, and the leached concentrations of Cd, Co, Mo, Ni and U in the acid media exceed their limited concentrations recommended in relevant environment quality standards for water, which will harm the environment. 32 refs., 4 figs., 4 tabs.

  19. Measurements of gas and volatile element production rates from an irradiated molten lead and lead-bismuth spallation target with proton beams of 1 and 1.4 GeV; Mesures de taux de production d'elements gazeux et volatiles lors de reactions induites par des protons de 1 et 1,4 GeV sur des cibles epaisses de plomb et plomb-bismuth liquides

    Energy Technology Data Exchange (ETDEWEB)

    Tall, Y

    2008-03-15

    The integrated project EUROTRANS (European Research Programme for the Transmutation of High Level Nuclear Waste in an Accelerator Driven System) of the 6. EURATOM Framework Programme aims to demonstrate the transmutation of radioactive waste in ADS (Accelerator Driven Sub-critical system). It will carry out a first advanced design of an experimental facility to demonstrate the technical feasibility of transmutation, and will produce a conceptual design of an industrial facility dedicated to transmutation. An ADS consists of three fundamental elements: the accelerator of protons, the sub-critical core and the spallation target. SUBATECH (physique Sub-Atomique et des Technologies associees) laboratory is involved to the study of the chosen liquid lead-bismuth as a spallation ADS target. The irradiation of liquid lead-bismuth target with energetic proton beam generates in addition to neutrons, volatile and radioactive residues. In order to determine experimentally the production rates of gas and volatile elements following a spallation reaction in a lead-bismuth target, the experiment IS419 was performed at the ISOLDE facility at CERN (Centre Europeen de la Recherche Nucleaire). This experiment constitutes the frame of the thesis whose main objective is to assess and study the production and release rates of many gas and volatile element from the irradiated lead-bismuth target with an energetic proton beam. The obtained data are compared to Monte Carlo simulation code (MCNPX) results in order to test the intranuclear cascade model of Bertini and of Cugnon, and the evaporation options of Dresner and Schmidt. (author)

  20. Unstable volatility

    DEFF Research Database (Denmark)

    Casas, Isabel; Gijbels, Irène

    2012-01-01

    The objective of this paper is to introduce the break-preserving local linear (BPLL) estimator for the estimation of unstable volatility functions for independent and asymptotically independent processes. Breaks in the structure of the conditional mean and/or the volatility functions are common...... in Finance. Nonparametric estimators are well suited for these events due to the flexibility of their functional form and their good asymptotic properties. However, the local polynomial kernel estimators are not consistent at points where the volatility function has a break. The estimator presented...

  1. Effects of alloying elements on the Snoek-type relaxation in Ti–Nb–X–O alloys (X = Al, Sn, Cr, and Mn)

    International Nuclear Information System (INIS)

    Lu, H.; Li, C.X.; Yin, F.X.; Fang, Q.F.; Umezawa, O.

    2012-01-01

    Highlights: ► The O Snoek-type relaxation in the Ti–Nb–X–O alloys was investigated. ► The dipole shape factor (δλ) and critical temperature T c were deduced from the peak. ► The δλ and T c were analyzed in terms of the d-orbital energy level (Md). ► With decreasing Md, the δλ increases and saturates at last while the T c decreases. ► The Md can be taken as a key parameter in designing high damping β-Ti alloys. - Abstract: The effect of alloying elements on the oxygen Snoek-type relaxation in the Ti–24Nb–X–1.7O alloys (X = 1Al, 2Al, 1Sn, 2Sn, 2Cr, 2Mn) was investigated in order to develop high damping materials based on point defect relaxation process. The relaxation strength of the Ti–Nb–Al–O and Ti–Nb–Sn–O alloys is the highest while that of the Ti–Nb–Mn–O and Ti–Nb–Cr–O alloys is the lowest. The dipole shape factor (δλ) and critical temperature T c , which are intrinsic to the Snoek-type relaxation, were figured out and analyzed in terms of the d-orbital energy level (Md) for each alloy based on the measured damping peak. With the decreasing Md, the δλ increases and saturates at last when the Md decreases to a certain value (about 2.435 eV), while the critical temperature T c decreases linearly. The parameter Md can be taken as a key parameter in designing high damping β-Ti alloys, that is, to design an intermediate value of Md at which the values of both δλ and T c are as high as possible.

  2. Chasing volatility

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification, the condi......The realized volatility of financial returns is characterized by persistence and occurrence of unpreditable large increments. To capture those features, we introduce the Multiplicative Error Model with jumps (MEM-J). When a jump component is included in the multiplicative specification...... estimate alternative specifications of the model using a set of daily bipower measures for 7 stock indexes and 16 individual NYSE stocks. The estimates of the jump component confirm that the probability of jumps dramatically increases during the financial crisis. Compared to other realized volatility...... models, the introduction of the jump component provides a sensible improvement in the fit, as well as for in-sample and out-of-sample volatility tail forecasts....

  3. Volatility in energy prices

    International Nuclear Information System (INIS)

    Duffie, D.

    1999-01-01

    This chapter with 58 references reviews the modelling and empirical behaviour of volatility in energy prices. Constant volatility and stochastic volatility are discussed. Markovian models of stochastic volatility are described and the different classes of Markovian stochastic volatility model are examined including auto-regressive volatility, option implied and forecasted volatility, Garch volatility, Egarch volatility, multivariate Garch volatility, and stochastic volatility and dynamic hedging policies. Other volatility models and option hedging are considered. The performance of several stochastic volatility models as applied to heating oil, light oil, natural gas, electricity and light crude oil are compared

  4. Stochastic volatility of volatility in continuous time

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Veraart, Almut

    This paper introduces the concept of stochastic volatility of volatility in continuous time and, hence, extends standard stochastic volatility (SV) models to allow for an additional source of randomness associated with greater variability in the data. We discuss how stochastic volatility...... of volatility can be defined both non-parametrically, where we link it to the quadratic variation of the stochastic variance process, and parametrically, where we propose two new SV models which allow for stochastic volatility of volatility. In addition, we show that volatility of volatility can be estimated...

  5. Magnetic properties and local structure of the binary elements codoped Bi1−xLaxFe0.95Mn0.05O3

    International Nuclear Information System (INIS)

    Li, Yongtao; Zhang, Hongguang; Liu, Hao; Dong, Xueguang; Li, Qi; Chen, Wei; Mao, Weiwei; Li, Xing’ao; Dong, Chenglin; Ren, Shanling

    2014-01-01

    Highlights: • For the samples Bi 1−x La x (Fe 0.95 Mn 0.05 )O 3 (x = 0, 0.10, 0.15, 0.20), the magnetization changes nonmonotonously with La doping. • Doping La ions affects the local structures of Mn atoms instead of those of Fe atoms by analyzing XAFS data. • The changes of magnetic property result from the changes of the Mn–O bond length. - Abstract: Polycrystalline Bi 1−x La x Fe 0.95 Mn 0.05 O 3 (x = 0, 0.10, 0.15, 0.20) samples were successfully synthesized via sol–gel method. The magnetic properties and local structures of all these samples are investigated. By increasing lanthanum content from 0 to 0.15, the magnetization increases, while it decreases by further La doping. The results of local structures of Fe atoms and Mn atoms which were measured using X-ray absorption fine structure (XAFS) spectra of Fe and Mn K-edge demonstrate that the former has no change, whereas the latter exhibits systematical change of the Mn–O bond length, resulting from doped La ions. We demonstrate that doped La ions affect the local structures of Mn atoms, whereas it has no influence on the local structures of Fe atoms. Finally, to explain the magnetization phenomenon, we analyze interrelation between magnetic property and the Mn–O bond length on the basis of the local structure distortion of the samples

  6. Effect of trace elements (ZnSO/sub 4/, MnSO/sub 4//sub /and Al/sub 2/(SO/sub 4/)/sub 3/) on soil Ph, Zinc and manganese concentrations in case of mature teat bushes

    International Nuclear Information System (INIS)

    Nosheen, M.; Riaz, A.K.

    2005-01-01

    A field experiment was conducted to study the effect of trace elements on growth and yield of mature tea bushes, at National Tea Research Inst., Shinkiari, Mansehra, Pakistan, during 2003. The treatments included control (no fertilizer), recommended dose of NPK (432:111:74 kg ha/sup -1/ alone and NPK in combination with either two doses of (5.5 and 11 kg ha/sup -1/) ZnSO/sub 4/ or (2.0 and 4.0 kg ha/sup -1/)MnSO/sub 4/ or (0.225 and 0.45 kg ha/sup -1/) Al/sub 2/(SO/sub 4/)/sub 3/ to soil and one dose of each (11 kg ha/sup -1/) ZnSO/sub 4/, (4.0 kg ha/sup -1) MnSO/sub 4/ and (0.45 kg ha/sup -1/) Al/sub 2/(SO/sub 4/)/sub 3/ applied as spray solution. Treatments including soil application of NPK alone and NPK + either ZnSO/sub 4/, MnSO/sub 4/ or Al/sub 2/(SO/sub 4/)/sub 3/ significantly (P < 0.001) increased tea yield (fresh weight of three leaves + bud), shoot height and tissue Zn and Mn concentrations with significant interactions (T x t) on tissue Zn and Mn levels. As compared to control the yield increased by 7.0,30,.37,42,37 and 34% with NPK alone, NPK + 5.5, + 11.0 ZnSO/sub 4/, + 2.0, + 4.0 MnSO/sub 4/, + 0.225, + 0.45 kg ha/sup -1/ Al/sub 2/(SO/sub 4/)/sub 3/, respectively during fist three months while the yield of six months plucking showed similar response to treatments but was significantly lower than the first three months. Soil pH, Zn and Mn concentrations were significantly affected by treatments, time of sampling, and depth of sampling. Except ZnSO/sub 4/, lower doses of MnSO/sub 4/ (2.0 kg ha-l) and Al/sub 2/(SO/sub 4/)/sub 3/ (0.225 kg ha/sup -1/), were more effective as compared to their higher doses when applied to soil, regarding tea yield and shoot height. Foliar application of 11 kg ha-l ZnSO/sub 4/ significantly increased yield as compared to its both levels when applied to soil. It is concluded that MnSO/sub 4/ and Al/sub 2/(SO/sub 4/)/sub 3/ should be applied at the rate of 2.0 and 0.225 kg ha/sup -l/. (author)

  7. Influence of addition elements on the stacking-fault energy and mechanical properties of an austenitic Fe-Mn-C steel

    International Nuclear Information System (INIS)

    Dumay, A.; Chateau, J.-P.; Allain, S.; Migot, S.; Bouaziz, O.

    2008-01-01

    We present a thermochemical model of the stacking-fault energy (SFE) in the Fe-Mn-C system with few percent of Cu, Cr, Al and Si in addition. Aluminium strongly increases the SFE, contrary to chromium, while the effect of silicon is more complex. Copper also increases the SFE, but strongly decreases the Neel temperature. The SFE is the relevant parameter that controls mechanical twinning, which is known to be at the origin of the excellent mechanical properties of these steels. Using this model, copper containing Fe-Mn-C grades were elaborated with SFE below 18 mJ/m 2 , in the range where ε-martensite platelets form instead of microtwins during plastic deformation. This substitution of deformation modes, confirmed by X-ray diffraction, does not significantly damage the mechanical properties, as long as the SFE is greater than 12 mJ/m 2 , which avoids the formation of α'-martensite

  8. V, Cr, and Mn in the Earth, Moon, EPB, and SPB and the origin of the Moon: Experimental studies

    International Nuclear Information System (INIS)

    Drake, M.J.; Capobianco, C.J.; Newsom, H.E.

    1989-01-01

    The abundances of V, Cr, and Mn inferred for the mantles of the Earth and Moon decrease in that order and are similar, but are distinct from those inferred for the mantles of the Eucrite Parent Body (EPB) and Shergottite Parent Body (SPB). This similarity between Earth and Moon has been used to suggest that the Moon is derived substantially or entirely from Earth mantle material following terrestrial core formation. To test this hypothesis, the authors have determined the partitioning of V, Cr, and Mn between solid iron metal, S-rich metallic liquid, and synthetic basaltic silicate liquid at 1,260 degree C and one bar pressure. The sequence of compatibility in the metallic phases is Cr > V > Mn at high oxygen fugacity and V > Cr > Mn at low oxygen fugacities. Solubilities in liquid metal always exceed solubilities in solid metal. These partition coefficients suggest that the abundances of V, Cr, and Mn do not reflect core formation in the Earth. Rather, they are consistent with the relative volatilities of these elements. The similarity in the depletion patterns of V, Cr, and Mn inferred for the mantles of the Earth and Moon is a necessary, but not sufficient, condition for the Moon to have been derived wholly or in part from the Earth's mantle

  9. Volatile accretion history of the Earth.

    Science.gov (United States)

    Wood, B J; Halliday, A N; Rehkämper, M

    2010-10-28

    It has long been thought that the Earth had a protracted and complex history of volatile accretion and loss. Albarède paints a different picture, proposing that the Earth first formed as a dry planet which, like the Moon, was devoid of volatile constituents. He suggests that the Earth's complement of volatile elements was only established later, by the addition of a small veneer of volatile-rich material at ∼100 Myr (here and elsewhere, ages are relative to the origin of the Solar System). Here we argue that the Earth's mass balance of moderately volatile elements is inconsistent with Albarède's hypothesis but is well explained by the standard model of accretion from partially volatile-depleted material, accompanied by core formation.

  10. Effect of impurity elements Al, Mn, and N2 on the corrosion resistance of zircaloy-2 in high temperature water and steam

    International Nuclear Information System (INIS)

    Gadiyar, H.S.

    1978-01-01

    Although the impurity limits are specified in standard zircaloy-2, it is possible that during its manufacture some of the impurities may exceed by a few ppm than the normally set values. It is necessary to understand the corrosion behaviour of such zircaloy-2 which contain a small amount of excessive impurities. This report summarizes some such data of the impurities aluminium, manganese and nitrogen. It is seen that the common impurities which can affect the corrosion of zircaloy-2 significantly are Al and N 2 and to a lesser extent Mn. (author)

  11. OPTIMIZATION OF STEEL SATURATION PROCESSES USING CARBIDE-FORMING ELEMENTS IN SYSTEMS BASED ON Cr-Ti-V AND Cr-Ti-Mn

    Directory of Open Access Journals (Sweden)

    A. A. Shmatov

    2007-01-01

    Full Text Available Optimization of saturating mixture compositions has been carried out in two three-component systems, namely: Cr-Ti-V and Cr-Ti-Mn in respect of micro-hardness and wear resistance of carbide coatings obtained by thermo-chemical treatment of high carbon steel. «Composition - properties» diagrams have been plotted using mathematical models. Treatment with optimum compositions of powder media permits to increase wear resistance of steel by factor of 30-70 as compared with untreated steel. 

  12. Enhancement of magnetic and ferroelectric properties of BiFeO3 by Er and transition element (Mn, Co) co-doping

    International Nuclear Information System (INIS)

    Han, Yumin; Mao, Weiwei; Quan, Chuye; Wang, Xingfu; Yang, Jianping; Yang, Tao; Li, Xing’ao

    2014-01-01

    Highlights: • BiFeO 3 , Bi 0.8 Er 0.2 FeO 3 , Bi 0.8 Er 0.2 Fe 0.9 Mn 0.1 O 3 and Bi 0.8 Er 0.2 Fe 0.9 Co 0.1 O 3 nanoparticles were prepared by sol–gel method. • The introduction of Er and Mn, Co into BiFeO 3 leads into a phase transition with reduced grain size. • The phase transformation combined with size reduction has significantly increased saturated polarization (Ps), remanent polarization (Pr) and saturated magnetization (Ms), remanent magnetization (Mr) behaviors of the doped samples with the same variation trend. • The formation of dipolar defect complexes (DDCs) in the doped samples may also contribute to the improved ferroelectric property. • Bi 0.8 Er 0.2 Fe 0.9 Mn 0.1 O 3 exhibits significantly improved ferroelectric and ferromagnetic properties. - Abstract: BiFeO 3 (BFO), Bi 0.8 Er 0.2 FeO 3 (BEFO), Bi 0.8 Er 0.2 Fe 0.9 Mn 0.1 O 3 (BEFMO) and Bi 0.8 Er 0.2 Fe 0.9 Co 0.1 O 3 (BEFCO) nanoparticles were prepared by sol–gel method having an average size of 200 nm for BFO, under100 nm for BEFO and under 60 nm for BEFMO and BEFCO. Phase transition from a rhombohedral symmetry (R3c) for BFO to an orthorhombic symmetry (Ibmm) for BEFO, BEFMO and BEFCO has been observed. The phase transformation combined with size reduction has significantly improved both ferroelectric and ferromagnetic behaviors of the doped samples in a similar way. The formation of dipolar defect complexes (DDCs) in the doped samples also contributes to the improved ferroelectric property with saturated polarization (Ps) of 0.375 μC/cm 2 and remanent polarization (Pr) of 0.244 μC/cm 2 for BEFMO. Size effect may also impact the simultaneously developed Pr for BEFMO and BEFCO. Owning to the interactions between the ferromagnetic and antiferromagnetic microdomains, improved saturated magnetization (Ms) and remanent magnetization (Mr) are also observed in BEFMO

  13. Apatite/Melt Partitioning Experiments Reveal Redox Sensitivity to Cr, V, Mn, Ni, Eu, W, Th, and U

    Science.gov (United States)

    Righter, K.; Yang, S.; Humayun, M.

    2016-01-01

    Apatite is a common mineral in terrestrial, planetary, and asteroidal materials. It is commonly used for geochronology (U-Pb), sensing volatiles (H, F, Cl, S), and can concentrate rare earth elements (REE) during magmatic fractionation and in general. Some recent studies have shown that some kinds of phosphate may fractionate Hf and W and that Mn may be redox sensitive. Experimental studies have focused on REE and other lithophile elements and at simplified or not specified oxygen fugacities. There is a dearth of partitioning data for chalcophile, siderophile and other elements between apatite and melt. Here we carry out several experiments at variable fO2 to study the partitioning of a broad range of trace elements. We compare to existing data and then focus on several elements that exhibit redox dependent partitioning behavior.

  14. Pricing Volatility Referenced Assets

    Directory of Open Access Journals (Sweden)

    Alan De Genaro Dario

    2006-12-01

    Full Text Available Volatility swaps are contingent claims on future realized volatility. Variance swaps are similar instruments on future realized variance, the square of future realized volatility. Unlike a plain vanilla option, whose volatility exposure is contaminated by its asset price dependence, volatility and variance swaps provide a pure exposure to volatility alone. This article discusses the risk-neutral valuation of volatility and variance swaps based on the framework outlined in the Heston (1993 stochastic volatility model. Additionally, the Heston (1993 model is calibrated for foreign currency options traded at BMF and its parameters are used to price swaps on volatility and variance of the BRL / USD exchange rate.

  15. New procedure of quantitative mapping of Ti and Al released from dental implant and Mg, Ca, Fe, Zn, Cu, Mn as physiological elements in oral mucosa by LA-ICP-MS.

    Science.gov (United States)

    Sajnóg, Adam; Hanć, Anetta; Koczorowski, Ryszard; Barałkiewicz, Danuta

    2017-12-01

    A new procedure for determination of elements derived from titanium implants and physiological elements in soft tissues by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is presented. The analytical procedure was developed which involved preparation of in-house matrix matched solid standards with analyte addition based on certified reference material (CRM) MODAS-4 Cormorant Tissue. Addition of gelatin, serving as a binding agent, essentially improved physical properties of standards. Performance of the analytical method was assayed and validated by calculating parameters like precision, detection limits, trueness and recovery of analyte addition using additional CRM - ERM-BB184 Bovine Muscle. Analyte addition was additionally confirmed by microwave digestion of solid standards and analysis by solution nebulization ICP-MS. The detection limits are in range 1.8μgg -1 to 450μgg -1 for Mn and Ca respectively. The precision values range from 7.3% to 42% for Al and Zn respectively. The estimated recoveries of analyte addition line within scope of 83%-153% for Mn and Cu respectively. Oral mucosa samples taken from patients treated with titanium dental implants were examined using developed analytical method. Standards and tissue samples were cryocut into 30µm thin sections. LA-ICP-MS allowed to obtain two-dimensional maps of distribution of elements in tested samples which revealed high content of Ti and Al derived from implants. Photographs from optical microscope displayed numerous particles with µm size in oral mucosa samples which suggests that they are residues from implantation procedure. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Transport of volatile fission products in the fuel-to-sheath gap of defective fuel elements during normal and reactor accident conditions

    International Nuclear Information System (INIS)

    Lewis, B.J.; Bonin, H.W.

    1995-01-01

    An analytical treatment has been used to model the vapour transport of radioactive fission products released into the fuel-to-sheath gap of defective nuclear fuel elements. The model accounts for both diffusive and bulk-convective transport. Convective transport becomes important as a result of a significant release of gaseous fission products into the gap during a high-temperature reactor accident. However, during normal reactor operation, diffusion is shown to be the dominant process of transport. The model is based on an analysis of several in-reactor tests with operating defective fuel elements, and high-temperature annealing experiments with irradiated fuel specimens. ((orig.))

  17. Stock return, seasonality and asymmetric conditional volatility in steel & iron subsector

    Directory of Open Access Journals (Sweden)

    V. Chirila

    2015-01-01

    Full Text Available This paper presents the results obtained following the testing of five hypotheses regarding conditional return and volatility of the most listed European stocks in the steel & iron subsector. The following elements of the stocks are analysed: time variation of volatility, seasonality of return and volatility, relationship between return and volatility and volatility asymmetry. The results obtained confirm for all the analyzed stocks the existence of volatility variation in time, the lack of correlation between return and volatility, the existence of asymmetry phenomenon of volatility and the presence in some stocks of the seasonality effect both for return and volatility.

  18. Volatility in GARCH Models of Business Tendency Index

    Science.gov (United States)

    Wahyuni, Dwi A. S.; Wage, Sutarman; Hartono, Ateng

    2018-01-01

    This paper aims to obtain a model of business tendency index by considering volatility factor. Volatility factor detected by ARCH (Autoregressive Conditional Heteroscedasticity). The ARCH checking was performed using the Lagrange multiplier test. The modeling is Generalized Autoregressive Conditional Heteroscedasticity (GARCH) are able to overcome volatility problems by incorporating past residual elements and residual variants.

  19. Distribution of P, K, Ca, Mg, Cd, Cu, Fe, Mn, Pb and Zn in wood and bark age classes of willows and poplars used for phytoextraction on soils contaminated by risk elements.

    Science.gov (United States)

    Zárubová, Pavla; Hejcman, Michal; Vondráčková, Stanislava; Mrnka, Libor; Száková, Jiřina; Tlustoš, Pavel

    2015-12-01

    Fast-growing clones of Salix and Populus have been studied for remediation of soils contaminated by risk elements (RE) using short-rotation coppice plantations. Our aim was to assess biomass yield and distributions of elements in wood and bark of highly productive willow (S1--[Salix schwerinii × Salix viminalis] × S. viminalis, S2--Salix × smithiana clone S-218) and poplar (P1--Populus maximowiczii × Populus nigra, P2--P. nigra) clones with respect to aging. The field experiment was established in April 2008 on moderately Cd-, Pb- and Zn- contaminated soil. Shoots were harvested after four seasons (February 2012) and separated into annual classes of wood and bark. All tested clones grew on contaminated soils, with highest biomass production and lowest mortality exhibited by P1 and S2. Concentrations of elements, with exception of Ca and Pb, decreased with age and were higher in bark than in wood. The Salix clones were characterised by higher removal of Cd, Mn and Zn compared to the Populus clones. Despite generally higher RE content in young shoots, partly due to lower wood/bark ratios and higher RE concentrations in bark, the overall removal of RE was higher in older wood classes due to higher biomass yield. Thus, longer rotations seem to be more effective when phytoextraction strategy is considered. Of the four selected clones, S1 exhibited the best removal of Cd and Zn and is a good candidate for phytoextraction.

  20. Electric-field controlled ferromagnetism in MnGe magnetic quantum dots

    Directory of Open Access Journals (Sweden)

    Faxian Xiu

    2011-03-01

    Full Text Available Electric-field control of ferromagnetism in magnetic semiconductors at room temperature has been actively pursued as one of the important approaches to realize practical spintronics and non-volatile logic devices. While Mn-doped III-V semiconductors were considered as potential candidates for achieving this controllability, the search for an ideal material with high Curie temperature (Tc>300 K and controllable ferromagnetism at room temperature has continued for nearly a decade. Among various dilute magnetic semiconductors (DMSs, materials derived from group IV elements such as Si and Ge are the ideal candidates for such materials due to their excellent compatibility with the conventional complementary metal-oxide-semiconductor (CMOS technology. Here, we review recent reports on the development of high-Curie temperature Mn0.05Ge0.95 quantum dots (QDs and successfully demonstrate electric-field control of ferromagnetism in the Mn0.05Ge0.95 quantum dots up to 300 K. Upon the application of gate-bias to a metal-oxide-semiconductor (MOS capacitor, the ferromagnetism of the channel layer (i.e. the Mn0.05Ge0.95 quantum dots was modulated as a function of the hole concentration. Finally, a theoretical model based upon the formation of magnetic polarons has been proposed to explain the observed field controlled ferromagnetism.

  1. Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al–5Mg–Mn Alloys Solidified Under Near-Rapid Cooling

    Science.gov (United States)

    Liu, Yulin; Huang, Gaoren; Sun, Yimeng; Zhang, Li; Huang, Zhenwei; Wang, Jijie; Liu, Chunzhong

    2016-01-01

    Mn was an important alloying element used in Al–Mg–Mn alloys. However, it had to be limited to a low level (Al–5Mg–Mn alloy with low Fe content (Al6(Fe,Mn) was small in size and amount. With increasing Mn content, intermetallic Al6(Fe,Mn) increased, but in limited amount. In high-Fe-containing Al–5Mg–Mn alloys (0.5 wt % Fe), intermetallic Al6(Fe,Mn) became the dominant phase, even in the alloy with low Mn content (0.39 wt %). Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al6(Fe,Mn) was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al6(Fe,Mn) phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al6(Fe,Mn) to become the primary phase at a lower Mn content. PMID:28787888

  2. Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al-5Mg-Mn Alloys Solidified Under Near-Rapid Cooling.

    Science.gov (United States)

    Liu, Yulin; Huang, Gaoren; Sun, Yimeng; Zhang, Li; Huang, Zhenwei; Wang, Jijie; Liu, Chunzhong

    2016-01-29

    Mn was an important alloying element used in Al-Mg-Mn alloys. However, it had to be limited to a low level (Al-5Mg-Mn alloy with low Fe content (Al₆(Fe,Mn) was small in size and amount. With increasing Mn content, intermetallic Al₆(Fe,Mn) increased, but in limited amount. In high-Fe-containing Al-5Mg-Mn alloys (0.5 wt % Fe), intermetallic Al₆(Fe,Mn) became the dominant phase, even in the alloy with low Mn content (0.39 wt %). Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al₆(Fe,Mn) was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al₆(Fe,Mn) phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al₆(Fe,Mn) to become the primary phase at a lower Mn content.

  3. Effect of Mn and Fe on the Formation of Fe- and Mn-Rich Intermetallics in Al–5Mg–Mn Alloys Solidified Under Near-Rapid Cooling

    Directory of Open Access Journals (Sweden)

    Yulin Liu

    2016-01-01

    Full Text Available Mn was an important alloying element used in Al–Mg–Mn alloys. However, it had to be limited to a low level (<1.0 wt % to avoid the formation of coarse intermetallics. In order to take full advantage of the benefits of Mn, research was carried out to investigate the possibility of increasing the content of Mn by studying the effect of cooling rate on the formation of Fe- and Mn-rich intermetallics at different content levels of Mn and Fe. The results indicated that in Al–5Mg–Mn alloy with low Fe content (<0.1 wt %, intermetallic Al6(Fe,Mn was small in size and amount. With increasing Mn content, intermetallic Al6(Fe,Mn increased, but in limited amount. In high-Fe-containing Al–5Mg–Mn alloys (0.5 wt % Fe, intermetallic Al6(Fe,Mn became the dominant phase, even in the alloy with low Mn content (0.39 wt %. Cooling rate played a critical role in the refinement of the intermetallics. Under near-rapid cooling, intermetallic Al6(Fe,Mn was extremely refined. Even in the high Mn and/or high-Fe-containing alloys, it still demonstrated fine Chinese script structures. However, once the alloy composition passed beyond the eutectic point, the primary intermetallic Al6(Fe,Mn phase displayed extremely coarse platelet-like morphology. Increasing the content of Fe caused intermetallic Al6(Fe,Mn to become the primary phase at a lower Mn content.

  4. Evaluation of pyrolysis curves for volatile elements in aqueous standards and carbon-containing matrices in electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Silva, A.F. [Delft University of Technology, Faculty of Applied Sciences, DelftChemTech, Julianalaan 136, 2628 BL Delft (Netherlands); Universidade Federal de Santa Catarina, Departamento de Quimica, 88040-900 Florianopolis, SC (Brazil); Welz, B. [Universidade Federal de Santa Catarina, Departamento de Quimica, 88040-900 Florianopolis, SC (Brazil); Loos-Vollebregt, M.T.C. de [Delft University of Technology, Faculty of Applied Sciences, DelftChemTech, Julianalaan 136, 2628 BL Delft (Netherlands)], E-mail: m.t.c.deloos-vollebregt@tudelft.nl

    2008-07-15

    Pyrolysis curves in electrothermal atomic absorption spectrometry (ET AAS) and electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) have been compared for As, Se and Pb in lobster hepatopancreas certified reference material using Pd/Mg as the modifier. The ET AAS pyrolysis curves confirm that the analytes are not lost from the graphite furnace up to a pyrolysis temperature of 800 deg. C. Nevertheless, a downward slope of the pyrolysis curve was observed for these elements in the biological material using ETV-ICP-MS. This could be related to a gain of sensitivity at low pyrolysis temperatures due to the matrix, which can act as carrier and/or promote changes in the plasma ionization equilibrium. Experiments with the addition of ascorbic acid to the aqueous standards confirmed that the higher intensities obtained in ETV-ICP-MS are related to the presence of organic compounds in the slurry. Pyrolysis curves for As, Se and Pb in coal and coal fly ash were also investigated using the same Pd/Mg modifier. Carbon intensities were measured in all samples using different pyrolysis temperatures. It was observed that pyrolysis curves for the three analytes in all slurry samples were similar to the corresponding graphs that show the carbon intensity for the same slurries for pyrolysis temperatures from 200 deg. C up to 1000 deg. C.

  5. Asymmetric Realized Volatility Risk

    Directory of Open Access Journals (Sweden)

    David E. Allen

    2014-06-01

    Full Text Available In this paper, we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive. Even though returns standardized by ex post quadratic variation measures are nearly Gaussian, this unpredictability brings considerably more uncertainty to the empirically relevant ex ante distribution of returns. Explicitly modeling this volatility risk is fundamental. We propose a dually asymmetric realized volatility model, which incorporates the fact that realized volatility series are systematically more volatile in high volatility periods. Returns in this framework display time varying volatility, skewness and kurtosis. We provide a detailed account of the empirical advantages of the model using data on the S&P 500 index and eight other indexes and stocks.

  6. Mn(II,III) oxidation and MnO2 mineralization by an expressed bacterial multicopper oxidase

    Science.gov (United States)

    Butterfield, Cristina N.; Soldatova, Alexandra V.; Lee, Sung-Woo; Spiro, Thomas G.; Tebo, Bradley M.

    2013-01-01

    Reactive Mn(IV) oxide minerals are ubiquitous in the environment and control the bioavailability and distribution of many toxic and essential elements and organic compounds. Their formation is thought to be dependent on microbial enzymes, because spontaneous Mn(II) to Mn(IV) oxidation is slow. Several species of marine Bacillus spores oxidize Mn(II) on their exosporium, the outermost layer of the spore, encrusting them with Mn(IV) oxides. Molecular studies have identified the mnx (Mn oxidation) genes, including mnxG, encoding a putative multicopper oxidase (MCO), as responsible for this two-electron oxidation, a surprising finding because MCOs only catalyze single-electron transfer reactions. Characterization of the enzymatic mechanism has been hindered by the lack of purified protein. By purifying active protein from the mnxDEFG expression construct, we found that the resulting enzyme is a blue (absorption maximum 590 nm) complex containing MnxE, MnxF, and MnxG proteins. Further, by analyzing the Mn(II)- and (III)-oxidizing activity in the presence of a Mn(III) chelator, pyrophosphate, we found that the complex facilitates both electron transfers from Mn(II) to Mn(III) and from Mn(III) to Mn(IV). X-ray absorption spectroscopy of the Mn mineral product confirmed its similarity to Mn(IV) oxides generated by whole spores. Our results demonstrate that Mn oxidation from soluble Mn(II) to Mn(IV) oxides is a two-step reaction catalyzed by an MCO-containing complex. With the purification of active Mn oxidase, we will be able to uncover its mechanism, broadening our understanding of Mn mineral formation and the bioinorganic capabilities of MCOs. PMID:23818588

  7. Study of mobilization and speciation of trace elements in coal pyrolysis

    International Nuclear Information System (INIS)

    Ting, B.T.G.

    1979-01-01

    Various types of coal contain high levels of a number of trace elements. Little is known of the fates of these trace elements during the conversion of coal to liquid and gaseous products. Studies were undertaken of mobilization and speciation of trace elements in coal pyrolysis, one of the major coal conversion processes. The bituminous coal was pyrolyzed to produce liquid and gaseous products. The pyrolysis products were collected in traps in an inert gas stream. In addition mildly hydrogenated coal was prepared by mixing with tetralin, a hydrogen donor solvent, at boiling temperature. In order to characterize each element specifically during pyrolysis, base samples of coal and mildly hydrogenated coal (H-coal) were spiked with heavy metal sulfides, trace metals bound to partially oxidized coal (coal humates), and halide salts prior to carrying out pyrolysis. Eight elements were investigated in this research. They are As, Br, Cl, Co, Cr, Mn, Se, and V. Pre-spiked hydrogenated coal, i.e., pulverized coal spiked with halide salts and heavy metal sulfides then hydrogenated with tetralin, was prepared and studied for the fates of these elements during pyrolysis. Chlorinated and brominated coals were also prepared to compare the volatility differences between organically and inorganically bound halogens during the pyrolysis reaction. These products and the coal char residues were analyzed for the spiked elements mainly by neutron activation analysis for the spiked elements to determine their degree of volatility. Volatility and recovery (mass balance) will be discussed for those elements that appeared highly volatile during pyrolysis. In order to understand the halogenated compounds in the pyrolysis products, gas chromatograms were taken to the collected pyrolysis products of coal, hydrogenated coal, NaCl spiked coal, NaBr spiked coal, chlorinated coal, and brominated coal

  8. Thermochromatography study of volatile polonium species in various gas atmospheres

    CERN Document Server

    Maugeri, Emilio Andrea; Eichler, Robert; Piguet,David; Mendonça, Tania Melo; Stora, Thierry; Schumann, Dorothea

    2014-01-01

    Phenomena related to the volatilization of polonium and its compounds are critical issues for the safety assessment of the innovative lead–bismuth cooled type of nuclear reactor or accelerator driven systems. The formation and volatilization of different species of polonium and their interaction with fused silica was studied by thermochromatography using carrier gases with varied redox potential. The obtained results show that under inert and reducing conditions in the absence of moisture, elemental polonium is formed. Polonium compounds more volatile than elemental polonium can be formed if traces of moisture are present in both inert and reducing carrier gas. The use of dried oxygen as carrier gas leads to the formation of polonium oxides, which are less volatile than elemental polonium. It was also found that the volatility of polonium oxides increases with increasing oxidation state. In the presence of moisture in an oxidizing carrier gas, species are formed that are more volatile than the oxides and le...

  9. Endogenous Lunar Volatiles

    Science.gov (United States)

    McCubbin, F. M.; Liu, Y.; Barnes, J. J.; Anand, M.; Boyce, J. W.; Burney, D.; Day, J. M. D.; Elardo, S. M.; Hui, H.; Klima, R. L.; Magna, T.; Ni, P.; Steenstra, E.; Tartèse, R.; Vander Kaaden, K. E.

    2018-04-01

    This abstract discusses numerous outstanding questions on the topic of endogenous lunar volatiles that will need to be addressed in the coming years. Although substantial insights into endogenous lunar volatiles have been gained, more work remains.

  10. Current status of fluoride volatility method development

    Energy Technology Data Exchange (ETDEWEB)

    Uhlir, J.; Marecek, M.; Skarohlid, J. [UJV - Nuclear Research Institute, Research Centre Rez, CZ-250 68 Husinec - Rez 130 (Czech Republic)

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  11. Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

    Science.gov (United States)

    Võ, Uyên-Uyén T; Morris, Michael P

    2014-06-01

    Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

  12. Normalization for Implied Volatility

    OpenAIRE

    Fukasawa, Masaaki

    2010-01-01

    We study specific nonlinear transformations of the Black-Scholes implied volatility to show remarkable properties of the volatility surface. Model-free bounds on the implied volatility skew are given. Pricing formulas for the European options which are written in terms of the implied volatility are given. In particular, we prove elegant formulas for the fair strikes of the variance swap and the gamma swap.

  13. Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2013-01-01

    textabstractIn this paper we document that realized variation measures constructed from highfrequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive.

  14. Assessment of Energetic Compounds, Semi-volatile Organic Compounds, and Trace Elements in Streambed Sediment and Stream Water from Streams Draining Munitions Firing Points and Impact Areas, Fort Riley, Kansas, 2007-08

    Science.gov (United States)

    Coiner, R.L.; Pope, L.M.; Mehl, H.E.

    2010-01-01

    An assessment of energetic compounds (explosive and propellant residues) and associated semi-volatile organic compounds (SVOCs) and trace elements in streambed sediment and stream water from streams draining munitions firing points and impact areas at Fort Riley, northeast Kansas, was performed during 2007-08 by the U.S. Geological Survey (USGS) in cooperation with the U.S. Army. Streambed sediment from 16 sampling sites and stream-water samples from 5 sites were collected at or near Fort Riley and analyzed for as many as 17 energetic compounds, 65 SVOCs, and 27 trace elements. None of the energetic compounds or SVOCs were detected in streambed sediment collected from sites within the Fort Riley Military Reservation. This may indicate that these compounds either are not transported from dispersal areas or that analytical methods are not sensitive enough to detect the small concentrations that may be transported. Concentrations of munitions-associated trace elements did not exceed sediment-quality guidelines recommended by the U.S. Environmental Protection Agency (USEPA) and are not indicative of contamination of streambed sediment at selected streambed sampling sites, at least in regards to movement from dispersal areas. Analytical results of stream-water samples provided little evidence of contamination by energetic compounds, SVOCs, or associated trace elements. Perchlorate was detected in 19 of 20 stream-water samples at concentrations ranging from an estimated 0.057 to an estimated 0.236 ug/L (micrograms per liter) with a median concentration of an estimated 0.114 ug/L, substantially less than the USEPA Interim Health Advisory criterion (15 ug/L), and is in the range of documented background concentrations. Because of these small concentrations and possible natural sources (precipitation and groundwater), it is likely that the occurrence of perchlorate in stream water is naturally occurring, although a definitive identification of the source of perchlorate in

  15. Crystal structures and thermal decomposition of permanganates AE[MnO_4]_2 . n H_2O with the heavy alkaline earth elements (AE=Ca, Sr and Ba)

    International Nuclear Information System (INIS)

    Henning, Harald; Bauchert, Joerg M.; Conrad, Maurice; Schleid, Thomas

    2017-01-01

    Reexamination of the syntheses and crystal structures as well as studies of the thermal decomposition of the heavy alkaline earth metal permanganates Ca[MnO_4]_2 . 4 H_2O, Sr[MnO_4]_2 . 3 H_2O and Ba[MnO_4]_2 are the focus of this work. As an alternative to the very inelegant Muthmann method, established for the synthesis of Ba[MnO_4]_2 a long time ago, we employed a cation-exchange column loaded with Ba"2"+ cations and passed through an aqueous potassium-permanganate solution. We later used this alternative also with strontium- and calcium-loaded columns and all the compounds synthesized this way were indistinguishable from the products of the established methods. Ca[MnO_4]_2 . 4 H_2O exhibiting [CaO_8] polyhedra crystallizes in the orthorhombic space group Pccn with the lattice parameters a=1397.15(9), b=554.06(4) and c=1338.97(9) pm with Z=4, whereas Sr[MnO_4]_2 . 3 H_2O with [SrO_1_0] polyhedra adopts the cubic space group P2_13 with a=964.19(7) pm and Z=4. So the harder the AE"2"+ cation, the higher its demand for hydration in aqueous solution. Consequently, the crystal structure of Ba[MnO_4]_2 in the orthorhombic space group Fddd with a=742.36(5), b=1191.23(7) and c=1477.14(9) pm with Z=8 lacks any crystal water, but contains [BaO_1_2] polyhedra. During the thermal decomposition of Ca[MnO_4]_2 . 4 H_2O, the compound expels up to two water molecules of hydration, before the crystal structure collapses after the loss of the third H_2O molecule at 157 C. The crystal structure of Sr[MnO_4]_2 . 3 H_2O breaks down after the expulsion of the third water molecule as well, but this already occurs at 148 C. For both the calcium and the strontium permanganate samples, orthobixbyite-type α-Mn_2O_3 and the oxomanganates(III,IV) AEMn_3O_6 (AE=Ca and Sr) remain as final decomposition products at 800 C next to amorphous phases. On the other hand, the already anhydrous Ba[MnO_4]_2 thermally decomposes to hollandite-type BaMn_8O_1_6 and BaMnO_3 at 800 C.

  16. Silicon isotopes in angrites and volatile loss in planetesimals

    Science.gov (United States)

    Moynier, Frédéric; Savage, Paul S.; Badro, James; Barrat, Jean-Alix

    2014-01-01

    Inner solar system bodies, including the Earth, Moon, and asteroids, are depleted in volatile elements relative to chondrites. Hypotheses for this volatile element depletion include incomplete condensation from the solar nebula and volatile loss during energetic impacts. These processes are expected to each produce characteristic stable isotope signatures. However, processes of planetary differentiation may also modify the isotopic composition of geochemical reservoirs. Angrites are rare meteorites that crystallized only a few million years after calcium–aluminum-rich inclusions and exhibit extreme depletions in volatile elements relative to chondrites, making them ideal samples with which to study volatile element depletion in the early solar system. Here we present high-precision Si isotope data that show angrites are enriched in the heavy isotopes of Si relative to chondritic meteorites by 50–100 ppm/amu. Silicon is sufficiently volatile such that it may be isotopically fractionated during incomplete condensation or evaporative mass loss, but theoretical calculations and experimental results also predict isotope fractionation under specific conditions of metal–silicate differentiation. We show that the Si isotope composition of angrites cannot be explained by any plausible core formation scenario, but rather reflects isotope fractionation during impact-induced evaporation. Our results indicate planetesimals initially formed from volatile-rich material and were subsequently depleted in volatile elements during accretion. PMID:25404309

  17. Major and trace element and volatile constraints on magma systematics of seamounts and axial ridge glasses from the East Pacific Rise between 8°N and 12°N

    Science.gov (United States)

    Lytle, M. L.; Kelley, K. A.; Wanless, V. D.; Hauri, E. H.

    2017-12-01

    The East Pacific Rise is a fast spreading mid-ocean ridge system (6-16cm/yr) consisting of many spreading ridges and transform faults. Focusing on a well-studied segment between 8-12°N, we present new SIMS measurements of magmatic volatiles (H2O, CO2, S, Cl, F) and new LA-ICP-MS trace element data in both on-axis and off-axis glasses, coupled with previously published data and use these data to relate melt composition to crystallization and melting processes. The seamounts range in composition from evolved (MgO = 5.54 wt%) to fairly primitive (MgO = 9.70 wt%), whereas on-axis samples have a narrower range of MgO (5.85 - 8.83 wt%). Seamounts span a wide range of enrichment in trace element compositions (La/Sm 0.45 - 4.63; Th/La 0.02 - 0.14; K/Ti 0.02 - 0.66), whereas on-axis glasses reflect NMORB compositions (La/Sm 0.5 - 1; Th/La 0.035 - 0.07; K/Ti 0.05 - 0.15). Light rare earth elements in the seamounts vary from depleted to enriched and have variable Eu anomalies (0.79 - 1.10), while on-axis samples have NMORB patterns with more negative Eu anomalies (0.74 - 1.00). The H2O content of the seamounts ranges from dry (0.05 wt%) to fairly wet (0.96 wt%), whereas on-axis samples have a narrower range (0.15 - 0.31 wt%). Cl contents show variable mixing between seawater and a magmatic component, with seamounts assimilating more seawater. Magmatic liquid lines of descent (LLD), recorded in glass, reflect fractional crystallization of olivine, plagioclase, and clinopyroxene, consistent with modal phenocryst abundances of the rocks. A multi-element approach (e.g., MgO vs. Al2O3, CaO, CaO/Al2O3), constrains LLDs, providing fractionation slopes, allowing mafic basalt compositions to be accurately corrected back to primary melts in equilibrium with Fo90. Using these melts, pressures and temperatures of melt equilibration can be constrained using melt thermobarometry. On-axis samples reflect higher PT conditions (1371°C; 1.37 GPa), although within error of seamounts (1340

  18. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast i......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  19. Large Magnetic Anisotropy in HfMnP

    Science.gov (United States)

    Parker, David; Lamichhane, Tej; Taufour, Valentin; Masters, Morgan; Thimmaiah, Srinivasa; Bud'Ko, Ser'gey; Canfield, Paul

    We present a theoretical and experimental study of two little-studied manganese phosphide ferromagnets, HfMnP and ZrMnP, with Curie temperatures above room temperature. We find an anisotropy field in HfMnP approaching 10 T - larger than that of the permanent magnet workhorse NdFeB magnets. From theory we determine the source of this anisotropy. Our results show the potential of 3d-element-based magnetic materials for magnetic applications.

  20. Effect of Ce addition on microstructure of Al20Cu2Mn3 twin phase in an Al–Cu–Mn casting alloy

    International Nuclear Information System (INIS)

    Chen Zhongwei; Chen Pei; Li Shishun

    2012-01-01

    Highlights: ► Rare earth element Ce can retard the formation of the Al 20 Cu 2 Mn 3 twin phase in an Al–Cu–Mn casting alloy. ► Patterns of the particles of the Al 20 Cu 2 Mn 3 phase in Al–Cu–Mn free Ce alloy are more diverse. ► The symmetry of neighboring components of twins is characterized by glide reflection and reflection. ► The twins of Al 20 Cu 2 Mn 3 phase can enhance the mechanical properties of the Al–Cu–Mn casting alloys. - Abstract: Effects of Ce addition on microstructure of Al 20 Cu 2 Mn 3 twin phase and mechanical properties of an Al–Cu–Mn casting alloy were investigated by transmission electron microscopy, selected area electron diffraction, high resolution transmission electron microscopy and tensile test. The results show that rare earth element Ce can retard the formation of the Al 20 Cu 2 Mn 3 phase in the Al–Cu–Mn alloy. Compared with the Ce containing alloy, patterns of particles of the Al 20 Cu 2 Mn 3 phase in the Al–Cu–Mn free Ce alloy are more diverse. The symmetry of neighboring components of twins is characterized by glide reflection and reflection. In addition, twins of the Al 20 Cu 2 Mn 3 phase can enhance the mechanical properties of the Al–Cu–Mn alloy.

  1. Understanding Financial Market Volatility

    NARCIS (Netherlands)

    A. Opschoor (Anne)

    2014-01-01

    markdownabstract__Abstract__ Volatility has been one of the most active and successful areas of research in time series econometrics and economic forecasting in recent decades. Loosely speaking, volatility is defined as the average magnitude of fluctuations observed in some phenomenon over

  2. Improving Garch Volatility Forecasts

    NARCIS (Netherlands)

    Klaassen, F.J.G.M.

    1998-01-01

    Many researchers use GARCH models to generate volatility forecasts. We show, however, that such forecasts are too variable. To correct for this, we extend the GARCH model by distinguishing two regimes with different volatility levels. GARCH effects are allowed within each regime, so that our model

  3. Asymmetric Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2014-01-01

    markdownabstract__Abstract__ In this paper we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized

  4. The volatility of HOL

    International Nuclear Information System (INIS)

    Wren, D.J.; Sanipelli, G.

    1985-01-01

    The volatility of HOI has been measured using a mass spectrometer to analyze the gas phase above an aqueous solution. The HOI in solution was generated continuously in a flow reactor that combined I/sup -/ and OCl/sup -/ solutions. The analysis has resulted in a lower limit of 6X10/sup 3/ mol . dm/sup -3/ . atm/sup -1/ for the equilibrium constant for the reaction HOI(g)/equilibrium/HOI(aq). This value is a factor 30 greater than the best previous estimate. This new limit for HOI volatility results in higher total iodine partition coefficients, particularly for solutions with pH>8. The upper limit for the equilibrium constant is consistent with essentially zero volatility for HOI. The effect of HOI volatility on total iodine volatility is briefly discussed as a function of solution chemistry and kinetics

  5. Volatilization of iodine from soils and plants

    International Nuclear Information System (INIS)

    Wildung, R.E.; Cataldo, D.A.; Garland, T.R.

    1985-04-01

    Elevated levels of 129 I, a long-lived fission product, are present in the environment as a result of nuclear weapons testing and fuel reprocessing. To aid in understanding the anomalous behavior of this element, relative to natural I ( 127 I), in the vicinity of nuclear fuel reprocessing plants, preliminary laboratory-growth chamber studies were undertaken to examine the possible formation of volatile inorganic and organic I species in soil and plant systems. Inorganic 129 I added to soil was volatilized from both the soil and plant during plant growth, at average ratios of 2 x 10 -3 %/day soil and 9 x 10 -3 %/day foliage, respectively. Volatilization rates from soil were an order of magnitude less in the absence of growing roots. Less than 2% of soil or plant volatiles was subsequently retained by plant canopies. Volatile I, chemically characterized by selective sorption methods, consisted principally of alkyl iodides formed by both soil and plant processes. However, plants and soils containing actively growing roots produced a larger fraction of volatile inorganic I than soil alone. 14 refs., 1 fig., 3 tabs

  6. Crystal structures and thermal decomposition of permanganates AE[MnO{sub 4}]{sub 2} . n H{sub 2}O with the heavy alkaline earth elements (AE=Ca, Sr and Ba)

    Energy Technology Data Exchange (ETDEWEB)

    Henning, Harald; Bauchert, Joerg M.; Conrad, Maurice; Schleid, Thomas [Stuttgart Univ. (Germany). Inst. fuer Anorganische Chemie

    2017-10-01

    Reexamination of the syntheses and crystal structures as well as studies of the thermal decomposition of the heavy alkaline earth metal permanganates Ca[MnO{sub 4}]{sub 2} . 4 H{sub 2}O, Sr[MnO{sub 4}]{sub 2} . 3 H{sub 2}O and Ba[MnO{sub 4}]{sub 2} are the focus of this work. As an alternative to the very inelegant Muthmann method, established for the synthesis of Ba[MnO{sub 4}]{sub 2} a long time ago, we employed a cation-exchange column loaded with Ba{sup 2+} cations and passed through an aqueous potassium-permanganate solution. We later used this alternative also with strontium- and calcium-loaded columns and all the compounds synthesized this way were indistinguishable from the products of the established methods. Ca[MnO{sub 4}]{sub 2} . 4 H{sub 2}O exhibiting [CaO{sub 8}] polyhedra crystallizes in the orthorhombic space group Pccn with the lattice parameters a=1397.15(9), b=554.06(4) and c=1338.97(9) pm with Z=4, whereas Sr[MnO{sub 4}]{sub 2} . 3 H{sub 2}O with [SrO{sub 10}] polyhedra adopts the cubic space group P2{sub 1}3 with a=964.19(7) pm and Z=4. So the harder the AE{sup 2+} cation, the higher its demand for hydration in aqueous solution. Consequently, the crystal structure of Ba[MnO{sub 4}]{sub 2} in the orthorhombic space group Fddd with a=742.36(5), b=1191.23(7) and c=1477.14(9) pm with Z=8 lacks any crystal water, but contains [BaO{sub 12}] polyhedra. During the thermal decomposition of Ca[MnO{sub 4}]{sub 2} . 4 H{sub 2}O, the compound expels up to two water molecules of hydration, before the crystal structure collapses after the loss of the third H{sub 2}O molecule at 157 C. The crystal structure of Sr[MnO{sub 4}]{sub 2} . 3 H{sub 2}O breaks down after the expulsion of the third water molecule as well, but this already occurs at 148 C. For both the calcium and the strontium permanganate samples, orthobixbyite-type α-Mn{sub 2}O{sub 3} and the oxomanganates(III,IV) AEMn{sub 3}O{sub 6} (AE=Ca and Sr) remain as final decomposition products at 800 C

  7. Study on the application of magnesium oxide adsorptive compound to preconcentrate trace elements (As, Cu, Co, Cr, Hg, Mn, Sb and Zn) in high salt water and neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Giang, Nguyen; Tam, Nguyen Thanh; Phuong Mai, Truong Thi; Ho Tran The Huu [Center for Analytical Techniques, Nuclear Research Institute, Dalat (Viet Nam)

    2007-12-15

    The project presents preconcentration neutron activation analysis techniques for determination of trace metals (As, Co, Cr Cu, Hg, Mn, Sb and Zn) in high salt water by adsorption of trace metals on magnesium oxide. Precipitate is collected on 0.45 {mu}m membrane filters and irradiated in pneumatic rabit system and Lazy Susan facility at flux 5.10{sup 12} n/cm{sup 2}.sec for As, Cu, Mn and 2.10{sup 12} n/cm{sup 2}.sec for Hg, Sb, Cr, Co and Zn. The radioactivities of {sup 76}As, {sup 60}Co, {sup 64}Cu, {sup 51}Cr, {sup 203}Hg, {sup 56}Mn, {sup 124}Sb and {sup 65}Zn were measured. {sup 76}As, {sup 60}Co, {sup 64}Cu, {sup 51}Cr, {sup 203}Hg, {sup 56}Mn, {sup 124}Sb and {sup 65}Zn radio traces were used to establish optimum conditions and to evaluate the chemical yield. Detection limits of this method are 0.019, 0.006, 0.044, 0.058, 0.021, 0.027, 0.012 and 0.094 {mu}g of As, Co, Cr, Cu, Hg, Mn, Sb and Zn respectively. (author)

  8. Mn induced ferromagnetism spin fluctuation enhancement in Sr{sub 2}Ru{sub 1−x}Mn{sub x}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Long; Cai, Jinzhu; Xie, Qiyun; Lv, Bin [Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Mao, Z.Q. [Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118 (United States); Wu, X.S., E-mail: xswu@nju.edu.cn [Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)

    2013-09-15

    We establish that Sr{sub 2}RuO{sub 4} is extremely close to incommensurate spin density wave instability. With increasing Mn content, the RuO{sub 6} octahedron in the unit cell varies. The octahedron of RuO{sub 6} contracts along c-axis for x<0.20, Mn element mainly showing the +3 chemical valence (Mn{sup 3+}), and it expands along c-axis with further increasing Mn content (x>0.20), and Mn element shows the +4 chemical valence (Mn{sup 4+}). Spin-glass-related ferromagnetism enhancement is observed for x>0.20, which indicates the critical ferromagnetic spin fluctuation due to Mn doping in Sr{sub 2}Ru{sub 1−x}Mn{sub x}O{sub 4}. - Highlights: • The chemical valence of Mn ions changed from Mn{sup 3+} to Mn{sup 4+} with the increase of Mn content. • Spin-glass-related ferromagnetism enhancement behavior is observed. • The electrical resistivity can be fitted using Mott's variable-range hopping model. • The evolution of octahedron with increase of Mn content is given. • The spin fluctuation effect plays an important role in the magnetic property.

  9. Interior Volatile Reservoirs in Mercury

    Science.gov (United States)

    Anzures, B. A.; Parman, S. W.; Milliken, R. E.; Head, J. W.

    2018-05-01

    More measurements of 1) surface volatiles, and 2) pyroclastic deposits paired with experimental volatile analyses in silicate minerals can constrain conditions of melting and subsequent eruption on Mercury.

  10. Fe-Mn-Si based shape memory alloys

    International Nuclear Information System (INIS)

    Hsu, T.Y.

    2000-01-01

    Characteristics of martensitic transformation fcc(γ)→hcp(ε) in Fe-Mn-Si based alloys are briefly reviewed. By analyzing the influences of constituents and treatments on shape memory effect (SME) in Fe-Mn-Si, the main factors controlling SME are summarized as austenite strengthening, stacking fault energy (probability) and antiferromagnetic temperature. Contribution of thermomechanical training to SME is introduced. The Fe-Mn-Si-RE (rare earth elements) and Fe-Mn-Si-Cr-N alloys are recommended as two novel shape memory alloys with superior SME. (orig.)

  11. Pluto's Volatile Transport

    Science.gov (United States)

    Young, Leslie

    2012-10-01

    Pluto's varying subsolar latitude and heliocentric distance leads to large variations in the surface volatile distribution and surface pressure. I present results of new volatile transport models (Young 2012a, b). The models include insolation, thermal emission, subsurface conduction, heating of a volatile slab, internal heat flux, latent heat of sublimation, and strict global mass balance. Numeric advances include initial conditions that allow for rapid convergence, efficient computation with matrix arithmetic, and stable Crank-Nicholson timesteps for both bare and volatile-covered areas. Runs of the model show six distinct seasons on Pluto. (1) As Pluto approaches perihelion, the volatiles on the old winter pole (the Rotational North Pole, RNP) becomes more directly illuminated , and the pressure and albedo rise rapidly. (2) When a new ice cap forms on the Rotational South Pole, RSP, volatiles are exchanged between poles. The pressure and albedo change more slowly. (3) When all volatiles have sublimed from the RNP, the albedo and pressure drop rapidly. (4-6) A similar pattern is repeated near aphelion with a reversal of the roles and the poles. I will compare results with earlier Pluto models of Hansen and Paige (1996), show the dependence on parameters such as substrate inertia, and make predictions for the New Horizons flyby of Pluto in 2015. This work was supported, in part, by funding from NASA Planetary Atmospheres Grant NNG06GF32G and the Spitzer project (JPL research support Agreement 1368573). Hansen, C. J. and D. A. Paige 1996. Seasonal Nitrogen Cycles on Pluto. Icarus 120, 247-265. Young, L. A. 2012a. Volatile transport on inhomogeneous surfaces: I - Analytic expressions, with application to Pluto’s day. Icarus, in press Young, L. A. 2012b. Volatile transport on inhomogeneous surfaces: II. Numerical calculations, with application to Pluto's season. In preparation.

  12. 23 Elemental Composition of Suspended Particulate Matter ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    The samples were analysed by energy dispersive x-ray fluorescence. (EDXRF) and atomic absorption spectroscopy (AAS) for up to 10 elements. It was found that 66% of the ..... coefficients between the various crustal elements Ca, Ti, Mn, ...

  13. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  14. Spatiotemporal distribution of airborne elements monitored with the moss bags technique in the Greater Thriasion Plain, Attica, Greece.

    Science.gov (United States)

    Saitanis, C J; Frontasyeva, M V; Steinnes, E; Palmer, M W; Ostrovnaya, T M; Gundorina, S F

    2013-01-01

    The well-known moss bags technique was applied in the heavily polluted Thriasion Plain region, Attica, Greece, in order to study the spatiotemporal distribution, in the atmosphere, of the following 32 elements: Na, Al, Cl, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Co, Zn, As, Se, Br, Sr, Mo, Sb, I, Ba, La, Ce, Sm, Tb, Dy, Yb, Hf, Ta, Hg, Th, and U. The moss bags were constituted of Sphagnum girgensohnii materials. The bags were exposed to ambient air in a network of 12 monitoring stations scattered throughout the monitoring area. In order to explore the temporal variation of the pollutants, four sets of moss bags were exposed for 3, 6, 9, and 12 months. Instrumental neutral activation analysis was used for the determinations of the elements. The data were analyzed using the Pearson correlations, the partial redundancy analysis, and the biplot statistical methods. Some pairs of elements were highly correlated indicating a probable common source of origin. The levels of the measured pollutants were unevenly distributed throughout the area and different pollutants exhibited different spatial patterns. In general, higher loads were observed in the stations close to and within the industrial zone. Most of the measured elements (e.g., Al, Ca, Ni, I, Zn, Cr, and As) exhibited a monotonic accumulation trend over time. Some elements exhibited different dynamics. The elements Mn, Mo, and Hg showed a decreasing trend, probably due to leaching and/or volatilization processes over time. Na and Br initially showed an increasing trend during the winter and early spring periods but decreased drastically during the late warm period. The results further suggest that the moss bags technique would be considered valuable for the majority of elements but should be used with caution in the cases of elements vulnerable to leaching and/or volatilization. It also suggests that the timing and the duration of the exposure of moss materials should be considered in the interpretation of the results.

  15. American options under stochastic volatility

    NARCIS (Netherlands)

    Chockalingam, A.; Muthuraman, K.

    2011-01-01

    The problem of pricing an American option written on an underlying asset with constant price volatility has been studied extensively in literature. Real-world data, however, demonstrate that volatility is not constant, and stochastic volatility models are used to account for dynamic volatility

  16. Foliar Mn accumulation in eastern Australian herbarium specimens: prospecting for 'new' Mn hyperaccumulators and potential applications in taxonomy.

    Science.gov (United States)

    Fernando, Denise R; Guymer, Gordon; Reeves, Roger D; Woodrow, Ian E; Baker, Alan J; Batianoff, George N

    2009-04-01

    The analysis of herbarium specimens has previously been used to prospect for 'new' hyperaccumulators, while the use of foliar manganese (Mn) concentrations as a taxonomic tool has been suggested. On the basis of their geographic and taxonomic affiliations to known Mn hyperaccumulators, six eastern Australian genera from the Queensland Herbarium collection were sampled for leaf tissue analyses. ICP-OES was used to measure Mn and other elemental concentrations in 47 species within the genera Austromyrtus, Lenwebbia, Gossia (Myrtaceae), Macadamia (Proteaceae), Maytenus and Denhamia (Celastraceae). The resulting data demonstrated (a) up to seven 'new' Mn hyperaccumulators, mostly tropical rainforest species; (b) that one of these 'new' Mn hyperaccumulators also had notably elevated foliar Ni concentrations; (c) evidence of an interrelationship between foliar Mn and Al uptake among the Macadamias; (d) considerable variability of Mn hyperaccumulation within Gossia; and (e) the possibility that Maytenus cunninghamii may include subspecies. Gossia bamagensis, G. fragrantissima, G. sankowsiorum, G. gonoclada and Maytenus cunninghamii were identified as 'new' Mn hyperaccumulators, while Gossia lucida and G. shepherdii are possible 'new' Mn hyperaccumulators. Of the three Myrtaceae genera examined, Mn hyperaccumulation appears restricted to Gossia, supporting its recent taxonomic revision. In the context of this present investigation and existing information, a reassesment of the general definition of Mn hyperaccumulation may be warranted. Morphological variation of Maytenus cunninghamii at two extremities was consistent with variation in Mn accumulation, indicating two possible 'new' subspecies. Although caution should be exercised in interpreting the data, surveying herbarium specimens by chemical analysis has provided an effective means of assessing foliar Mn accumulation. These findings should be followed up by field studies.

  17. Foliar Mn accumulation in eastern Australian herbarium specimens: prospecting for ‘new’ Mn hyperaccumulators and potential applications in taxonomy

    Science.gov (United States)

    Fernando, Denise R.; Guymer, Gordon; Reeves, Roger D.; Woodrow, Ian E.; Baker, Alan J.; Batianoff, George N.

    2009-01-01

    Background and Aims The analysis of herbarium specimens has previously been used to prospect for ‘new’ hyperaccumulators, while the use of foliar manganese (Mn) concentrations as a taxonomic tool has been suggested. On the basis of their geographic and taxonomic affiliations to known Mn hyperaccumulators, six eastern Australian genera from the Queensland Herbarium collection were sampled for leaf tissue analyses. Methods ICP-OES was used to measure Mn and other elemental concentrations in 47 species within the genera Austromyrtus, Lenwebbia, Gossia (Myrtaceae), Macadamia (Proteaceae), Maytenus and Denhamia (Celastraceae). Key Results The resulting data demonstrated (a) up to seven ‘new’ Mn hyperaccumulators, mostly tropical rainforest species; (b) that one of these ‘new’ Mn hyperaccumulators also had notably elevated foliar Ni concentrations; (c) evidence of an interrelationship between foliar Mn and Al uptake among the Macadamias; (d) considerable variability of Mn hyperaccumulation within Gossia; and (e) the possibility that Maytenus cunninghamii may include subspecies. Conclusions Gossia bamagensis, G. fragrantissima, G. sankowsiorum, G. gonoclada and Maytenus cunninghamii were identified as ‘new’ Mn hyperaccumulators, while Gossia lucida and G. shepherdii are possible ‘new’ Mn hyperaccumulators. Of the three Myrtaceae genera examined, Mn hyperaccumulation appears restricted to Gossia, supporting its recent taxonomic revision. In the context of this present investigation and existing information, a reassesment of the general definition of Mn hyperaccumulation may be warranted. Morphological variation of Maytenus cunninghamii at two extremities was consistent with variation in Mn accumulation, indicating two possible ‘new’ subspecies. Although caution should be exercised in interpreting the data, surveying herbarium specimens by chemical analysis has provided an effective means of assessing foliar Mn accumulation. These findings should be

  18. Oil and stock market volatility: A multivariate stochastic volatility perspective

    International Nuclear Information System (INIS)

    Vo, Minh

    2011-01-01

    This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility structure in an attempt to extract information intertwined in both markets for risk prediction. It offers four major findings. First, the stock and oil futures prices are inter-related. Their correlation follows a time-varying dynamic process and tends to increase when the markets are more volatile. Second, conditioned on the past information, the volatility in each market is very persistent, i.e., it varies in a predictable manner. Third, there is inter-market dependence in volatility. Innovations that hit either market can affect the volatility in the other market. In other words, conditioned on the persistence and the past volatility in their respective markets, the past volatility of the stock (oil futures) market also has predictive power over the future volatility of the oil futures (stock) market. Finally, the model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry. - Research Highlights: → This paper models the volatility of stock and oil futures markets using the multivariate stochastic volatility model. → The correlation between the two markets follows a time-varying dynamic process which tends to increase when the markets are more volatile. → The volatility in each market is very persistent. → Innovations that hit either market can affect the volatility in the other market. → The model produces more accurate Value-at-Risk estimates than other benchmarks commonly used in the financial industry.

  19. Tensile and high cycle fatigue behaviors of high-Mn steels at 298 and 110 K

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Wongyu; Jeong, Daeho; Sung, Hyokyung; Kim, Sangshik, E-mail: sang@gnu.ac.kr

    2017-02-15

    Tensile and high cycle fatigue behaviors of high-Mn austenitic steels, including 25Mn, 25Mn0.2Al, 25Mn0.5Cu, 24Mn4Cr, 22Mn3Cr and 16Mn2Al specimens, were investigated at 298 and 110 K. Depending on the alloying elements, tensile ductility of high-Mn steels either increased or decreased with decreasing temperature from 298 to 110 K. Reasonable correlation between the tendency for martensitic tranformation, the critical twinning stress and the percent change in tensile elongation suggested that tensile deformation of high-Mn steels was strongly influenced by SFE determining TRIP and TWIP effects. Tensile strength was the most important parameter in determining the resistance to high cycle fatigue of high-Mn steels with an exceptional work hardening capability at room and cryogenic temperatures. The fatigue crack nucleation mechanism in high-Mn steels did not vary with decreasing tempertature, except Cr-added specimens with grain boundary cracking at 298 K and slip band cracking at 110 K. The EBSD (electron backscatter diffraction) analyses suggested that the deformation mechanism under fatigue loading was significantly different from tensile deformation which could be affected by TRIP and TWIP effects. - Highlights: •The resistances to HCF of various high-Mn steels were measured. •The variables affecting tensile and HCF behaviors of high-Mn steels were assessed. •The relationship between tensile and the HCF behaviors of high-Mn steels was established.

  20. Volatile liquid storage system

    International Nuclear Information System (INIS)

    Laverman, R.J.; Winters, P.J.; Rinehart, J.K.

    1992-01-01

    This patent describes a method of collecting and abating emission from a volatile liquid in an above ground storage tank. It comprises the liquid storage tank having a bottom, a vertical cylindrical circular wall having a lower edge portion joined to the bottom, and an external fixed roof, the tank having an internal floating roof floating on a volatile liquid stored in the tank, and air vent means in the tank in communication with a vapor space in the tank constituting at least the space above the floating roof when the floating roof floats on a predetermined maximum volume of volatile liquid in the tank; permitting ambient air; pumping emission laden air from the tank vapor space above the floating roof; and by means of the emissions abatement apparatus eliminating most of the emission from the emissions laden air with formation of a gaseous effluent and then discharging the resulting gaseous effluent to the atmosphere

  1. Understanding Interest Rate Volatility

    DEFF Research Database (Denmark)

    Volker, Desi

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty...... and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochastic Volatility" (co-authored with Sebastian Fux), investigates the ability of the class of regime switching models...... with and without stochastic volatility to capture the main stylized features of U.S. interest rates. The third essay, \\Variance Risk Premia in the Interest Rate Swap Market", investigates the time-series and cross-sectional properties of the compensation demanded for holding interest rate variance risk. The essays...

  2. Magnetism in Mn-nanowires and -clusters as δ-doped layers in group IV semiconductors (Si, Ge)

    Science.gov (United States)

    Simov, K. R.; Glans, P.-A.; Jenkins, C. A.; Liberati, M.; Reinke, P.

    2018-01-01

    Mn doping of group-IV semiconductors (Si/Ge) is achieved by embedding nanostructured Mn-layers in group-IV matrix. The Mn-nanostructures are monoatomic Mn-wires or Mn-clusters and capped with an amorphous Si or Ge layer. The precise fabrication of δ-doped Mn-layers is combined with element-specific detection of the magnetic signature with x-ray magnetic circular dichroism. The largest moment (2.5 μB/Mn) is measured for Mn-wires with ionic bonding character and a-Ge overlayer cap; a-Si capping reduces the moment due to variations of bonding in agreement with theoretical predictions. The moments in δ-doped layers dominated by clusters is quenched with an antiferromagnetic component from Mn-Mn bonding.

  3. Volatile and Isotopic Imprints of Ancient Mars

    Science.gov (United States)

    Mahaffy, Paul R.; Conrad, Pamela G.

    2015-01-01

    The science investigations enabled by Curiosity rover's instruments focus on identifying and exploring the habitability of the Martian environment. Measurements of noble gases, organic and inorganic compounds, and the isotopes of light elements permit the study of the physical and chemical processes that have transformed Mars throughout its history. Samples of the atmosphere, volatiles released from soils, and rocks from the floor of Gale Crater have provided a wealth of new data and a window into conditions on ancient Mars.

  4. Theoretical predictions of properties and volatility of chlorides and oxychlorides of group-4 elements. II. Adsorption of tetrachlorides and oxydichlorides of Zr, Hf, and Rf on neutral and modified surfaces

    Science.gov (United States)

    Pershina, V.; Borschevsky, A.; Iliaš, M.; Türler, A.

    2014-08-01

    With the aim to interpret results of gas-phase chromatography experiments on volatility of group-4 tetrachlorides and oxychlorides including those of Rf, adsorption enthalpies of these species on neutral, and modified quartz surfaces were estimated on the basis of relativistic, two-component Density Functional Theory calculations of MCl4, MOCl2, MCl6-, and MOCl42 with the use of adsorption models. Several mechanisms of adsorption were considered. In the case of physisorption of MCl4, the trend in the adsorption energy in the group should be Zr > Hf > Rf, so that the volatility should change in the opposite direction. The latter trend complies with the one in the sublimation enthalpies, ΔHsub, of the Zr and Hf tetrachlorides, i.e., Zr Hf > Rf, as defined by the complex formation energies. In the case of adsorption of MCl4 on a chlorinated quartz surface, formation of the MCl62- surface complexes can occur, so that the trend in the adsorption strength should be Zr ≤ Hf < Rf. All the predicted sequences, showing a smooth change of the adsorption energy in the group, are in disagreement with the reversed trend Zr ≈ Rf < Hf, observed in the "one-atom-at-a-time" gas-phase chromatography experiments. Thus, currently no theoretical explanation can be found for the experimental observations.

  5. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    2009-01-01

    This paper introduces a two-component volatility model based on first moments of both components to describe the dynamics of speculative return volatility. The two components capture the volatile and the persistent part of volatility, respectively. The model is applied to 10 Asia-Pacific stock ma...... markets. A positive or risk-premium effect exists between the return and the volatile component, yet the persistent component is not significantly priced for the return dynamic process....... markets. Their in-mean effects on returns are tested. The empirical results show that the persistent component is much more important for the volatility dynamic process than is the volatile component. However, the volatile component is found to be a significant pricing factor of asset returns for most...

  6. Pricing Volatility of Stock Returns with Volatile and Persistent Components

    DEFF Research Database (Denmark)

    Zhu, Jie

    In this paper a two-component volatility model based on the component's first moment is introduced to describe the dynamic of speculative return volatility. The two components capture the volatile and persistent part of volatility respectively. Then the model is applied to 10 Asia-Pacific stock m......, a positive or risk-premium effect exists between return and the volatile component, yet the persistent component is not significantly priced for return dynamic process....... markets. Their in-mean effects on return are also tested. The empirical results show that the persistent component accounts much more for volatility dynamic process than the volatile component. However the volatile component is found to be a significant pricing factor of asset returns for most markets...

  7. Stabilization of mercury over Mn-based oxides: Speciation and reactivity by temperature programmed desorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Haomiao [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Ma, Yongpeng [Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, No. 136, Science Avenue, Zhengzhou 450001 (China); Huang, Wenjun; Mei, Jian; Zhao, Songjian; Qu, Zan [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Yan, Naiqiang, E-mail: nqyan@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2017-01-05

    Highlights: • Hg-TPD method was used for speciation of mercury species. • Different elements modified MnO{sub x} have different mercury binding state. • Understanding mercury existed state was beneficial for designing novel materials. - Abstract: Mercury temperature-programmed desorption (Hg-TPD) method was employed to clarify mercury species over Mn-based oxides. The elemental mercury (Hg{sup 0}) removal mechanism over MnO{sub x} was ascribed to chemical-adsorption. HgO was the primary mercury chemical compound adsorbed on the surface of MnO{sub x}. Rare earth element (Ce), main group element (Sn) and transition metal elements (Zr and Fe) were chosen for the modification of MnO{sub x}. Hg-TPD results indicated that the binding strength of mercury on these binary oxides followed the order of Sn-MnO{sub x} < Ce-MnO{sub x} ∼ MnO{sub x} < Fe-MnO{sub x} < Zr-MnO{sub x}. The activation energies for desorption were calculated and they were 64.34, 101.85, 46.32, 117.14, and 106.92 eV corresponding to MnO{sub x}, Ce-MnO{sub x}, Sn-MnO{sub x}, Zr-MnO{sub x} and Fe-MnO{sub x}, respectively. Sn-MnO{sub x} had a weak bond of mercury (Hg-O), while Zr-MnO{sub x} had a strong bond (Hg≡O). Ce-MnO{sub x} and Fe-MnO{sub x} had similar bonds compared with pure MnO{sub x}. Moreover, the effects of SO{sub 2} and NO were investigated based on Hg-TPD analysis. SO{sub 2} had a poison effect on Hg{sup 0} removal, and the weak bond of mercury can be easily destroyed by SO{sub 2}. NO was favorable for Hg{sup 0} removal, and the bond strength of mercury was enhanced.

  8. Volatilization: a soil degassing coefficient for iodine

    International Nuclear Information System (INIS)

    Sheppard, M.I.; Thibault, D.H.; Smith, P.A.; Hawkins, J.L.

    1994-01-01

    Iodine, an element essential to some animals, is ubiquitous in the biosphere. Unlike other metallic elements, molecular I is volatile, and other inorganic species present in aerated soils, such as I - and IO 3 - , may also volatilize as hydrides, hydrogen iodide (HI), or hydrogen iodates (HIO 3 , HIO 4 ). Methyl iodide has been measured in soils, and it is likely evolved from soils and plants. The long-lived radioisotope 129 I is abundant in nuclear wastes, and its high solubility in groundwater makes it an important element in the performance assessment of underground disposal facilities. Overestimates of soil I residence half-times by traditional foodchain models may be due to underestimation of volatilization. Field and lysimeter experiments over a 3-year period, and direct trapping experiments in the laboratory are reported. The results, combined with values from the literature, indicate the soil I degassing coefficient for a wide range of soil types, vegetated and bare, wet and dry, is lognormally distributed with a geometric mean of 2.1 x 10 -2 year -1 , a range of 1.8 x 10 -4 to 3.1 year -1 and a geometric standard deviation of 3.0. The results of a biosphere model simulation including degassing reduces soil I concentrations fivefold and increases air concentrations 25-fold at steady state, compared to simulations without degassing. (author)

  9. Fourier transform imaging of impurities in the unit cells of crystals: Mn in GaAs

    Science.gov (United States)

    Lee, T.-L.; Bihler, C.; Schoch, W.; Limmer, W.; Daeubler, J.; Thieß, S.; Brandt, M. S.; Zegenhagen, J.

    2010-06-01

    The lattice sites of Mn in ferromagnetic (Ga,Mn)As thin films were imaged using the x-ray standing wave technique. The model-free images, obtained straightforwardly by Fourier inversion, disclose immediately that the Mn mostly substitutes the Ga with a small fraction residing on minority sites. The images further reveal variations in the Mn concentrations of the different sites upon post-growth treatments. Subsequent model refinement based on the directly reconstructed images resolves with high precision the complete Mn site distributions. It is found that post-growth annealing increases the fraction of substitutional Mn at the expense of interstitial Mn whereas hydrogenation has little influence on the Mn site distribution. Our study offers an element-specific high-resolution imaging approach for accurately determining the detailed site distributions of dilute concentrations of atoms in crystals.

  10. 2-22 Study of Oxidation/reduction Volatilization Technology

    Institute of Scientific and Technical Information of China (English)

    Tan; Cunmin[1; Cao; Shiwei[1; Tian; Yuan[1; Qin; Zhi[1

    2015-01-01

    As an advanced dry head-end processing of spent fuel reprocessing, the oxidation-reduction volatilization technology will use for pulverizing uranium oxide ceramic pellets, decladding, and removal of most of volatile and semi-volatile fission elements, 3H, 14C, Kr, Xe, I, Cs, Ru and Tc, from fuel prior to main treatment process. The AIROX and ORIOX process, including circulation of oxidation in oxygen atmosphere and reduction in hydrogen atmosphere, researched on international at present, is considered to be the first choice for head-end processing.

  11. Silicon isotopes in angrites and volatile loss in planetesimals

    OpenAIRE

    Pringle, Emily A.; Moynier, Frédéric; Savage, Paul S.; Badro, James; Barrat, Jean-Alix

    2014-01-01

    Understanding volatile elements in the early solar system is a key step toward understanding the processes of planetary formation and the composition of Earth, but the origin of volatiles on Earth is not well understood. In this article, we present measurements of silicon isotope ratios in angrites, a class of meteorites dating from the first few million years after condensation of solids from the solar nebula. We show that the silicon isotope composition of angrites is consistent with a depl...

  12. Quantifying requirements volatility effects

    NARCIS (Netherlands)

    Kulk, G.P.; Verhoef, C.

    2008-01-01

    In an organization operating in the bancassurance sector we identified a low-risk IT subportfolio of 84 IT projects comprising together 16,500 function points, each project varying in size and duration, for which we were able to quantify its requirements volatility. This representative portfolio

  13. Idiosyncratic Volatility Puzzle

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Lambertides, Neophytos

    from a large pool of macroeconomic and Önancial variables. Cleaning for macro-Önance e§ects reverses the puzzling negative relation between returns and idiosyncratic volatility documented previously. Portfolio analysis shows that the e§ects from macro-Önance factors are economically strong...

  14. Manure application and ammonia volatilization

    NARCIS (Netherlands)

    Huijsmans, J.F.M.

    2003-01-01

    Keywords: manure application, ammonia volatilization, environmental conditions, application technique, incorporation technique, draught force, work organization, costs Livestock manure applied on farmland is an important source of ammonia (NH3) volatilization, and NH3 is a major atmospheric

  15. Facile synthesis and Li-ion storage properties of porous Mn-based oxides microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xiaojuan, E-mail: houxiaojuan@nuc.edu.cn [Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education, School of Instrument and Electronics, North University of China, Taiyuan, Shanxi Province 030051 (China); Zhu, Jie [Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education, School of Instrument and Electronics, North University of China, Taiyuan, Shanxi Province 030051 (China); School of Computer and Remote Sensing Information Technology, North China Institute of Aerospace Engineering, Langfang, Hebei Province 065000 (China); Shi, Shuzheng [School of Mechanical Engineering, Hebei University of Architecture, Zhangjiakou, Hebei Province 075000 (China); He, Jian; Mu, Jiliang; Geng, Wenping; Chou, Xiujian; Xue, Chenyang [Key Laboratory of Instrumentation Science & Dynamic Measurement of Ministry of Education, School of Instrument and Electronics, North University of China, Taiyuan, Shanxi Province 030051 (China)

    2017-05-15

    Highlights: • The Mn{sub 2}O{sub 3}, MnCo{sub 2}O{sub 4} and CoMn{sub 2}O{sub 4} microspheres were fabricated with the same method. • Capacities present an increasing trend as with the increasing percentage of Co element. • Plateaus present a lower trend as with the increasing percentage of Mn element. • Mn{sub 2}O{sub 3} microspheres present the most excellent cycling stability. - Abstract: Porous nanosheets assembled Mn-based oxides (Mn{sub 2}O{sub 3}, MnCo{sub 2}O{sub 4} and CoMn{sub 2}O{sub 4}) microspheres of diameters about 3–6 μm and pore size distribution mainly around 10 nm have been synthesized by the same facile solvothermal route without any surfactant followed by a calcination process. In virtue of the porous nanosheets constructed microspheres, the Mn-based oxides microspheres Mn{sub 2}O{sub 3} present specific capacities of 650 mAh/g after 100 charge and discharge cycles. Additionally among the three Mn-based oxides the representative specific capacities present an increasing trend as with the increasing percentage of Co element, the plateau of charge and discharge present a lower trend as with the increasing percentage of Mn element which is more suitable as anode materials in high output full batteries. Then the oxides with different components could be applied in different conditions such as the need for high specific capacity or high output lithium-ion batteries. Consequently the easy fabrication of microspheres and excellent electrochemical performances demonstrate Mn-based oxides’ great potential in lithium-ion batteries.

  16. Impact of environmental chemistry on mycogenic Mn oxide minerals

    Science.gov (United States)

    Santelli, C. M.; Farfan, G. A.; Post, A.; Post, J. E.

    2012-12-01

    Manganese (Mn) oxide minerals are ubiquitous in aquatic and terrestrial environments and their presence can have broad environmental consequences. In particular, Mn oxides scavenge nutrients and metals, degrade complex organics, and oxidize a variety of inorganic contaminants. The "reactivity" of Mn oxides, however, is highly dependent upon crystallite size, composition, and structure, which are largely determined by environmental factors such as solution chemistry. It is has been suggested that most Mn oxides in terrestrial and aquatic environments are formed by microbial activity; indeed, a diversity of Mn(II)-oxidizing bacteria and fungi have been isolated and their mineral byproducts are consistent with those observed in natural systems. Previous studies showed that Mn(II)-oxidizing Ascomycete fungi produce highly-disordered, nanocrystalline Mn oxides that are structurally similar to synthetic δ-MnO2 or natural vernadite. Unlike related studies with Mn-oxidizing bacteria, Mn oxides produced by these fungi did not "age" or transform to more crystalline mineral phases with time. We hypothesize that fungal growth conditions, in particular the low concentration of cations, are inhibiting secondary mineral formation. The overall goal of this research is to examine the structure and speciation of fungally-precipitated Mn oxides with respect to fungal species, time, and concentration of soluble Mn(II), Na, and Ca - three environmentally relevant cations that promote the transformation of δ-MnO2 to more crystalline mineral phases such as feitknechtite, birnessite, or ranciéite. For this study, we examined the Mn oxides formed by different species of Mn(II)-oxidizing fungi (Pyrenochaeta sp., Stagonospora sp., Plectosphaerella cucumerina., and Acremonium strictum). Isolates were grown for 8 or 16 days in a nutrient lean media consisting of yeast extract, trace elements and 0.2 mM MnCl2 supplemented with varying concentrations of Na, Ca, or Mn(II) compounds. The

  17. Mn-substituted perovskites RECoxMn1-xO3: a comparison between magnetic properties of LaCoxMn1-xO3 and GdCoxMn1-xO3

    Directory of Open Access Journals (Sweden)

    Barahona, P.

    2008-08-01

    Full Text Available Cooperative phenomena constitute important mechanisms to explain the magnetic properties of the perovskite manganites REMnO3, in which the rare-earth and/or Mn is partially replaced by divalent elements. In this way, the manganese ion changes its valence state (Mn3+ Mn4+, triggering strong magnetic interactions. In this work we describe the case of GdCoxMn1-xO3 (0.0 ≤ x ≤ 1.0 for which the antiferromagnetic interaction between the Gd sublattice and the Mn/Co network leads to a reversal of the magnetic moment at low temperature. No inversion is observed for the LaCoxMn1-xO3 series, in which the ordering temperature may attain a maximum of 235 K for LaCo0.50Mn0.50O3, while it is only 120 K for similar Co/Mn ratio in the case of GdCo0.50Mn0.50O3. Magnetic properties are described in terms of two regimes: one, for x 3 manganite and another one, for x > 0.5, when Mn substitutes Co in the GdCoO3 cobaltite, while the magnetic interactions are maximized at x(Co = 0.50. This hypothesis is discussed in terms of the respective oxidation states of both manganese (Mn3+ / Mn4+ and cobalt (Co2+ / Co3+.El fenómeno cooperativo constituye un importante mecanismo para explicar las propiedades magnéticas de las perovskitas manganitas TRMnO3, en las que el catión de tierra rara, TR, y/o el catión Mn3+ son parcialmente reemplazados por cationes divalentes. Por esta vía el ión de manganeso cambia de estado de valencia (Mn3+ Mn4+, generando fuertes interacciones magnéticas. En el presente trabajo se describe el caso de las soluciones sólidas GdCoxMn1-xO3 (0.0 ≤ x ≤ 1.0 para las que la interacción antiferromagnética entre la subred del Gd3+ y la red Mn/Co lleva a una inversión del momento magnético a baja temperatura. No se ha observado inversión para la serie LaCoxMn1-xO3, en que la temperatura de orden puede alcanzar un máximo de 235K para LaCo0.50Mn0.50O3, mientras que en el caso de GdCo0.50Mn0.50O3, en que sí se observa inversión, la

  18. The effect of H2O gas on volatilities of planet-forming major elements. I - Experimental determination of thermodynamic properties of Ca-, Al-, and Si-hydroxide gas molecules and its application to the solar nebula

    Science.gov (United States)

    Hashimoto, Akihiko

    1992-01-01

    The vapor pressures of Ca(OH)2(g), Al(OH)3(g), and Si(OH)4(g) molecules in equilibrium with solid calcium-, aluminum, and silicon-oxides, respectively, were determined, and were used to derive the heats of formation and entropies of these species, which are expected to be abundant under the currently postulated physical conditions in the primordial solar nebula. These data, in conjunction with thermodynamic data from literature, were used to calculate the relative abundances of M, MO(x), and M(OH)n gas species and relative volatilities of Fe, Mg, Si, Ca, and Al for ranges of temperature, total pressure, and H/O abundance ratio corresponding to the plausible ranges of physical conditions in the solar nebula. The results are used to explain how Ca and Al could have evaporated from Ca,Al-rich inclusions in carbonaceous chondrites, while Si, Mg, and Fe condensed onto them during the preaccretion alteration of CAIs.

  19. Theoretical predictions of properties and volatility of chlorides and oxychlorides of group-4 elements. II. Adsorption of tetrachlorides and oxydichlorides of Zr, Hf, and Rf on neutral and modified surfaces

    International Nuclear Information System (INIS)

    Pershina, V.; Borschevsky, A.; Iliaš, M.; Türler, A.

    2014-01-01

    With the aim to interpret results of gas-phase chromatography experiments on volatility of group-4 tetrachlorides and oxychlorides including those of Rf, adsorption enthalpies of these species on neutral, and modified quartz surfaces were estimated on the basis of relativistic, two-component Density Functional Theory calculations of MCl 4 , MOCl 2 , MCl 6 − , and MOCl 4 2 with the use of adsorption models. Several mechanisms of adsorption were considered. In the case of physisorption of MCl 4 , the trend in the adsorption energy in the group should be Zr > Hf > Rf, so that the volatility should change in the opposite direction. The latter trend complies with the one in the sublimation enthalpies, ΔH sub , of the Zr and Hf tetrachlorides, i.e., Zr < Hf. On the basis of a correlation between these quantities, ΔH sub (RfCl 4 ) was predicted as 104.2 kJ/mol. The energy of physisorption of MOCl 2 on quartz should increase in the group, Zr < Hf < Rf, as defined by increasing dipole moments of these molecules along the series. In the case of adsorption of MCl 4 on quartz by chemical forces, formation of the MOCl 2 or MOCl 4 2− complexes on the surface can take place, so that the sequence in the adsorption energy should be Zr > Hf > Rf, as defined by the complex formation energies. In the case of adsorption of MCl 4 on a chlorinated quartz surface, formation of the MCl 6 2− surface complexes can occur, so that the trend in the adsorption strength should be Zr ≤ Hf < Rf. All the predicted sequences, showing a smooth change of the adsorption energy in the group, are in disagreement with the reversed trend Zr ≈ Rf < Hf, observed in the “one-atom-at-a-time” gas-phase chromatography experiments. Thus, currently no theoretical explanation can be found for the experimental observations

  20. Composition of volatile aromatic compounds and minerals of tarhana enriched with cherry laurel (Laurocerasus officinalis).

    Science.gov (United States)

    Temiz, Hasan; Tarakçı, Zekai

    2017-03-01

    Different concentrations of cherry laurel pulp (0, 5, 10, 15 and 20%) were used to produce tarhana samples. Volatile aromatic compounds and minor mineral content were investigated. Volatile aromatic compounds were analyzed by using GC-MS with SPME fiber and minor mineral values were evaluated with inductively coupled plasma optical emission spectrometer. The statistical analysis showed that addition of pulp affected volatile aromatic compounds and minor mineral content significantly. Thirty five volatile aromatic compounds were found in tarhana samples. The octanoic acid from acids, benzaldehyde (CAS) phenylmethanal from aldehydes, 6-methyl-5-hepten-2-one from ketones, octadecane (CAS) n -octadecane form terpenes, ethyl caprylate from esters and benzenemethanol (CAS) benzyl alcohol from alcohols had the highest percentage of volatile aromatic compounds. Tarhana samples were rich source of Mn, Cu and Fe content.

  1. The exploitation of volatile oil

    Institute of Scientific and Technical Information of China (English)

    MENG Teng; ZHANG Da; TENG Xiangjin; LINing; HAO Zaibin

    2007-01-01

    Rose is a kind of favorite ornamental plant. This article briefly introduced the cultivation and the use of rose around the world both in ancient time and nowadays. Today, volatile oil becomes the mainstream of the rose industry. People pay attention to the effect of volatile oil; meanwhile, they speed up their research on extracting volatile oil and the ingredients.

  2. Alternative Asymmetric Stochastic Volatility Models

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  3. Essays on nonparametric econometrics of stochastic volatility

    NARCIS (Netherlands)

    Zu, Y.

    2012-01-01

    Volatility is a concept that describes the variation of financial returns. Measuring and modelling volatility dynamics is an important aspect of financial econometrics. This thesis is concerned with nonparametric approaches to volatility measurement and volatility model validation.

  4. Behaviour, capture and inertization of some trace elements during combustion of refuse-derived char from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Vassilev, S.V.; Braekman-Danheux, C.; Laurent, P.; Thiemann, T.; Fontana, A. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Central Lab. of Mineralogy and Crystallography

    1999-08-01

    An investigation of refuse-derived char (RDC) generated by thermolysis of municipal solid waste (MSW) was undertaken to elucidate the behaviour of some toxic and potentially toxic trace elements (Cr, Cu, Mn, Ni, Pb, Sb and Zn) plus Fe during combustion of RDC. About 87% of Sb, 66% of Pb, 60% of Cu and significant parts of Fe{gt}Zn{gt}Ni{gt}Mn{gt}Cr from the RDC are volatile at 1200{degree}C, and their behaviour in the temperature interval 500-1200{degree}C is characterized. The use of sorbents (zeolite, kaolinite, montmorillonite, coals enriched in kaolinite and calcite, and lime plus portlandite) for capture, solidification and inertization of the most volatile elements during combustion of RDC is also described. Perspective sorbents and inertants for a retention of the most volatile Pb, Sb and Cu in RDC ash are kaolinite and montmorillonite or coals enriched in these minerals. In addition, when there is an effective RDC washing (dechlorination and desulphurization), the use of sorbents for capture of some metals could be reduced or even avoided. Recommendations are given for RDC utilization and improvisation of the collection, separation procedures and removal efficiency of some heavy-metal, chloride and sulphate compounds from MSW and RDC prior to their use. The results show that a long-term strategy based on detailed understanding of the source, formation, behaviour and fate of the elements and their modes of occurrence in MSW, RDC and combustion waste residues is required in order to validate a perspective waste pyrolytic processes development. 55 refs., 3 figs., 6 tabs.

  5. Ammonia volatilization from coated urea forms

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Costa do Nascimento

    2013-08-01

    Full Text Available Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N volatilization losses in sugar cane harvested after stubble burning. The sources urea, sulfur-coated urea, urea coated with boric acid and copper sulfate, as well as nitrate and ammonium sulfate, were tested at amounts containing N rates of 120 kg ha-1 N. The integration of new technologies in urea fertilization can reduce N losses by volatilization. These losses were most reduced when using nitrate and ammonium sulfate. The application of a readily acidified substance (boric acid to urea was more efficient in reducing volatilization losses and nutrient removal by sugar cane than that of a substance with gradual acidification (elemental sulfur.

  6. Determination of trace elements in biological material by neutron activation analysis. [As,Au,Br,Cd,Cl,Co,Cr,Fe,Hg,K,Mn,Na,Ni,Rb,Sb,Sc,Se,Zn

    Energy Technology Data Exchange (ETDEWEB)

    Tran Van, L; Teherani, D K

    1989-04-10

    Eighteen trace elements in biological materials (grass (Imperata cylindrica), mimosa plant (Mimosa pudica), rice) by neutron activation method were determined. In the comparative analysis the content of the same element was different in each material, although they were collected at the same place and the same sampling method was applied. (author) 4 refs.; 1 fig.; 1 tab.

  7. Discovery of ferromagnetism with large magnetic anisotropy in ZrMnP and HfMnP

    Energy Technology Data Exchange (ETDEWEB)

    Lamichhane, Tej N.; Taufour, Valentin; Kaluarachchi, Udhara S.; Bud' ko, Sergey L.; Canfield, Paul C. [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); The Ames Laboratory, US Department of Energy, Iowa State University, Ames, Iowa 50011 (United States); Masters, Morgan W. [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Parker, David S. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Thimmaiah, Srinivasa [The Ames Laboratory, US Department of Energy, Iowa State University, Ames, Iowa 50011 (United States)

    2016-08-29

    ZrMnP and HfMnP single crystals are grown by a self-flux growth technique, and structural as well as temperature dependent magnetic and transport properties are studied. Both compounds have an orthorhombic crystal structure. ZrMnP and HfMnP are ferromagnetic with Curie temperatures around 370 K and 320 K, respectively. The spontaneous magnetizations of ZrMnP and HfMnP are determined to be 1.9 μ{sub B}/f.u. and 2.1 μ{sub B}/f.u., respectively, at 50 K. The magnetocaloric effect of ZrMnP in terms of entropy change (ΔS) is estimated to be −6.7 kJ m{sup −3} K{sup −1} around 369 K. The easy axis of magnetization is [100] for both compounds, with a small anisotropy relative to the [010] axis. At 50 K, the anisotropy field along the [001] axis is ∼4.6 T for ZrMnP and ∼10 T for HfMnP. Such large magnetic anisotropy is remarkable considering the absence of rare-earth elements in these compounds. The first principle calculation correctly predicts the magnetization and hard axis orientation for both compounds, and predicts the experimental HfMnP anisotropy field within 25%. More importantly, our calculations suggest that the large magnetic anisotropy comes primarily from the Mn atoms, suggesting that similarly large anisotropies may be found in other 3d transition metal compounds.

  8. Discovery of ferromagnetism with large magnetic anisotropy in ZrMnP and HfMnP

    International Nuclear Information System (INIS)

    Lamichhane, Tej N.; Taufour, Valentin; Kaluarachchi, Udhara S.; Bud'ko, Sergey L.; Canfield, Paul C.; Masters, Morgan W.; Parker, David S.; Thimmaiah, Srinivasa

    2016-01-01

    ZrMnP and HfMnP single crystals are grown by a self-flux growth technique, and structural as well as temperature dependent magnetic and transport properties are studied. Both compounds have an orthorhombic crystal structure. ZrMnP and HfMnP are ferromagnetic with Curie temperatures around 370 K and 320 K, respectively. The spontaneous magnetizations of ZrMnP and HfMnP are determined to be 1.9 μ_B/f.u. and 2.1 μ_B/f.u., respectively, at 50 K. The magnetocaloric effect of ZrMnP in terms of entropy change (ΔS) is estimated to be −6.7 kJ m"−"3 K"−"1 around 369 K. The easy axis of magnetization is [100] for both compounds, with a small anisotropy relative to the [010] axis. At 50 K, the anisotropy field along the [001] axis is ∼4.6 T for ZrMnP and ∼10 T for HfMnP. Such large magnetic anisotropy is remarkable considering the absence of rare-earth elements in these compounds. The first principle calculation correctly predicts the magnetization and hard axis orientation for both compounds, and predicts the experimental HfMnP anisotropy field within 25%. More importantly, our calculations suggest that the large magnetic anisotropy comes primarily from the Mn atoms, suggesting that similarly large anisotropies may be found in other 3d transition metal compounds.

  9. Volatile metabolites from actinomycetes

    DEFF Research Database (Denmark)

    Scholler, C.E.G.; Gurtler, H.; Pedersen, R.

    2002-01-01

    Twenty-six Streptomyces spp. were screened for their volatile production capacity on yeast starch agar. The volatile organic compounds (VOCs) were concentrated on a porous polymer throughout an 8-day growth period. VOCs were analyzed by gas chromatography with flame ionization detection...... and identified or characterized by gas chromatography-mass spectrometry. A total of 120 VOCs were characterized by retention index and mass spectra. Fifty-three compounds were characterized as terpenoid compounds, among which 18 could be identified. Among the VOCs were alkanes, alkenes, alcohols, esters, ketones....... The relationship between the excretion of geosmin and the production of spores was examined for one isolate. A good correlation between headspace geosmin and the number of spores was observed, suggesting that VOCs could be used to indicate the activity of these microorganisms in heterogeneous substrates....

  10. Theoretical predictions of properties and volatility of chlorides and oxychlorides of group-4 elements. II. Adsorption of tetrachlorides and oxydichlorides of Zr, Hf, and Rf on neutral and modified surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pershina, V., E-mail: V.Pershina@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt D-64291 (Germany); Borschevsky, A. [Helmholtz Institute Mainz, Mainz D-55128, Germany and Centre for Theoretical Chemistry and Physics, New Zealand Institute for Advanced Study, Massey University, Private Bag 102904, 0745 North Shore MSC, Auckland (New Zealand); Iliaš, M. [Department of Chemistry, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, SK-974 00 Banská Bystrica (Slovakia); Türler, A. [Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland and Laboratory for Radiochemistry and Environmental Chemistry, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

    2014-08-14

    With the aim to interpret results of gas-phase chromatography experiments on volatility of group-4 tetrachlorides and oxychlorides including those of Rf, adsorption enthalpies of these species on neutral, and modified quartz surfaces were estimated on the basis of relativistic, two-component Density Functional Theory calculations of MCl{sub 4}, MOCl{sub 2}, MCl{sub 6}{sup −}, and MOCl{sub 4}{sup 2} with the use of adsorption models. Several mechanisms of adsorption were considered. In the case of physisorption of MCl{sub 4}, the trend in the adsorption energy in the group should be Zr > Hf > Rf, so that the volatility should change in the opposite direction. The latter trend complies with the one in the sublimation enthalpies, ΔH{sub sub}, of the Zr and Hf tetrachlorides, i.e., Zr < Hf. On the basis of a correlation between these quantities, ΔH{sub sub}(RfCl{sub 4}) was predicted as 104.2 kJ/mol. The energy of physisorption of MOCl{sub 2} on quartz should increase in the group, Zr < Hf < Rf, as defined by increasing dipole moments of these molecules along the series. In the case of adsorption of MCl{sub 4} on quartz by chemical forces, formation of the MOCl{sub 2} or MOCl{sub 4}{sup 2−} complexes on the surface can take place, so that the sequence in the adsorption energy should be Zr > Hf > Rf, as defined by the complex formation energies. In the case of adsorption of MCl{sub 4} on a chlorinated quartz surface, formation of the MCl{sub 6}{sup 2−} surface complexes can occur, so that the trend in the adsorption strength should be Zr ≤ Hf < Rf. All the predicted sequences, showing a smooth change of the adsorption energy in the group, are in disagreement with the reversed trend Zr ≈ Rf < Hf, observed in the “one-atom-at-a-time” gas-phase chromatography experiments. Thus, currently no theoretical explanation can be found for the experimental observations.

  11. Minimum Tracking Error Volatility

    OpenAIRE

    Luca RICCETTI

    2010-01-01

    Investors assign part of their funds to asset managers that are given the task of beating a benchmark. The risk management department usually imposes a maximum value of the tracking error volatility (TEV) in order to keep the risk of the portfolio near to that of the selected benchmark. However, risk management does not establish a rule on TEV which enables us to understand whether the asset manager is really active or not and, in practice, asset managers sometimes follow passively the corres...

  12. Recovering volatile liquids

    Energy Technology Data Exchange (ETDEWEB)

    Bregeat, J H

    1925-07-30

    The products of hydrogenation of alicyclic compounds, such as terpenes, for example, pinene or oil of turpentine, are used as washing liquids for absorbing vapours of volatile liquids from gases, such as natural gases from petroliferous regions, gases from the distillation of coal, lignite, schist, peat, etc. or from the cracking of heavy oils. Other liquids such as tar oils vaseline oils, cresols, etc. may be added.

  13. Understanding Interest Rate Volatility

    OpenAIRE

    Volker, Desi

    2016-01-01

    This thesis is the result of my Ph.D. studies at the Department of Finance of the Copenhagen Business School. It consists of three essays covering topics related to the term structure of interest rates, monetary policy and interest rate volatility. The rst essay, \\Monetary Policy Uncertainty and Interest Rates", examines the role of monetary policy uncertainty on the term structure of interest rates. The second essay, \\A Regime-Switching A ne Term Structure Model with Stochast...

  14. Measurements of non-volatile aerosols with a VTDMA and their correlations with carbonaceous aerosols in Guangzhou, China

    Science.gov (United States)

    Cheung, Heidi H. Y.; Tan, Haobo; Xu, Hanbing; Li, Fei; Wu, Cheng; Yu, Jian Z.; Chan, Chak K.

    2016-07-01

    Simultaneous measurements of aerosol volatility and carbonaceous matters were conducted at a suburban site in Guangzhou, China, in February and March 2014 using a volatility tandem differential mobility analyzer (VTDMA) and an organic carbon/elemental carbon (OC / EC) analyzer. Low volatility (LV) particles, with a volatility shrink factor (VSF) at 300 °C exceeding 0.9, contributed 5 % of number concentrations of the 40 nm particles and 11-15 % of the 80-300 nm particles. They were composed of non-volatile material externally mixed with volatile material, and therefore did not evaporate significantly at 300 °C. Non-volatile material mixed internally with the volatile material was referred to as medium volatility (MV, 0.4 transported at low altitudes (below 1500 m) for over 40 h before arrival. Further comparison with the diurnal variations in the mass fractions of EC and the non-volatile OC in PM2.5 suggests that the non-volatile residuals may be related to both EC and non-volatile OC in the afternoon, during which the concentration of aged organics increased. A closure analysis of the total mass of LV and MV residuals and the mass of EC or the sum of EC and non-volatile OC was conducted. It suggests that non-volatile OC, in addition to EC, was one of the components of the non-volatile residuals measured by the VTDMA in this study.

  15. The memory of volatility

    Directory of Open Access Journals (Sweden)

    Kai R. Wenger

    2018-03-01

    Full Text Available The focus of the volatility literature on forecasting and the predominance of theconceptually simpler HAR model over long memory stochastic volatility models has led to the factthat the actual degree of memory estimates has rarely been considered. Estimates in the literaturerange roughly between 0.4 and 0.6 - that is from the higher stationary to the lower non-stationaryregion. This difference, however, has important practical implications - such as the existence or nonexistenceof the fourth moment of the return distribution. Inference on the memory order is complicatedby the presence of measurement error in realized volatility and the potential of spurious long memory.In this paper we provide a comprehensive analysis of the memory in variances of international stockindices and exchange rates. On the one hand, we find that the variance of exchange rates is subject tospurious long memory and the true memory parameter is in the higher stationary range. Stock indexvariances, on the other hand, are free of low frequency contaminations and the memory is in the lowernon-stationary range. These results are obtained using state of the art local Whittle methods that allowconsistent estimation in presence of perturbations or low frequency contaminations.

  16. Magnetism in Mn-nanowires and -clusters as δ-doped layers in group IV semiconductors (Si, Ge

    Directory of Open Access Journals (Sweden)

    K. R. Simov

    2018-01-01

    Full Text Available Mn doping of group-IV semiconductors (Si/Ge is achieved by embedding nanostructured Mn-layers in group-IV matrix. The Mn-nanostructures are monoatomic Mn-wires or Mn-clusters and capped with an amorphous Si or Ge layer. The precise fabrication of δ-doped Mn-layers is combined with element-specific detection of the magnetic signature with x-ray magnetic circular dichroism. The largest moment (2.5 μB/Mn is measured for Mn-wires with ionic bonding character and a-Ge overlayer cap; a-Si capping reduces the moment due to variations of bonding in agreement with theoretical predictions. The moments in δ-doped layers dominated by clusters is quenched with an antiferromagnetic component from Mn–Mn bonding.

  17. Beryllium abundances in Hg-Mn stars

    International Nuclear Information System (INIS)

    Boesgaard, A.M.; Heacox, W.D.; Wolff, S.C.; Borsenberger, J.; Praderie, F.

    1982-01-01

    The Hg-Mn stars show anomalous line strengths of many chemical elements including Be. We have observed the Be ii resonance doublet at lambdalambda 3130, 3131 at 6.7 A mm -1 in 43 Hg-Mn stars and 10 normal stars in the same temperature range with the coude spectrograph of the 2.24 m University of Hawaii telescope at Mauna Kea. Measured equivalent widths of the two lines and/or the blend of the doublet have been compared with predictions from (1) LTE model atmospheres and (2) non-LTE line formation on non-LTE model atmospheres. (For strong Be ii lines, the LTE calculations result in more Be by factors of 2 to 4 than do the non-LTE calculations.) Overabundances of factors of 20--2 x 10 4 relative to solar have been found for 75% of the Hg-Mn stars. The 25% with little or no Be are typically among the cooler Hg-Mn stars, but for the stars with Be excesses, there is only marginal evidence for a correlationi of the size of the overabundance and temperature. It is suggested that diffusion driven by radiation pressure is responsible for the observed Be abundance anomalies

  18. Exploring heterogeneous market hypothesis using realized volatility

    Science.gov (United States)

    Chin, Wen Cheong; Isa, Zaidi; Mohd Nor, Abu Hassan Shaari

    2013-04-01

    This study investigates the heterogeneous market hypothesis using high frequency data. The cascaded heterogeneous trading activities with different time durations are modelled by the heterogeneous autoregressive framework. The empirical study indicated the presence of long memory behaviour and predictability elements in the financial time series which supported heterogeneous market hypothesis. Besides the common sum-of-square intraday realized volatility, we also advocated two power variation realized volatilities in forecast evaluation and risk measurement in order to overcome the possible abrupt jumps during the credit crisis. Finally, the empirical results are used in determining the market risk using the value-at-risk approach. The findings of this study have implications for informationally market efficiency analysis, portfolio strategies and risk managements.

  19. Energy levels of 56Mn

    DEFF Research Database (Denmark)

    Van Assche, P. H. M.; Baader, H. A.; Koch, H. R.

    1971-01-01

    The low-energy spectrum of the 55Mn(n,γ)56 Mn reaction has been studied with a γ-diffraction spectrometer. These data allowed the construction of a level scheme for 56Mn with two previously unobserved doublets. High-energy γ-transitions to the low-energy states have been measured for different...

  20. Volatility of V15Cr5Ti fusion reactor alloy

    International Nuclear Information System (INIS)

    Neilson, R.M. Jr.

    1986-01-01

    One potential hazard from the presence of activation products in fusion facilities is accidental oxidation-driven volatility of those activation products. Scoping experiments were conducted to investigate the oxidation and elemental volatility of candidate fusion reactor alloy V15Cr5Ti as a function of time, temperature, and test atmosphere. Experiments in air and in argon carrier gases containing 10 4 to 10 1 Pa (10 -1 to 10 -4 atm) oxygen were conducted to investigate the lower oxygen partial pressure limit for the formation of a low melting point (approximately 650 0 C), high volatility, oxide layer and its formation rate. Experiments to determine the elemental volatility of alloy constituents in air at temperatures of 700 0 C to greater than 1600 0 C. Some of these volatility experiments used V15Cr5Ti that was arc-remelted to incorporate small quantities (<0.1 wt. %) of Sc and Ca. Incorporation of Sc and Ca in test specimens permitted volatility measurement of radioactive constituents present only after activation of V15Cr5Ti

  1. Assessment of heavy metals (Cd and Pb) and micronutrients (Cu, Mn, and Zn) of paddy (Oryza sativa L.) field surface soil and water in a predominantly paddy-cultivated area at Puducherry (Pondicherry, India), and effects of the agricultural runoff on the elemental concentrations of a receiving rivulet.

    Science.gov (United States)

    Reddy, M Vikram; Satpathy, Deepmala; Dhiviya, K Shyamala

    2013-08-01

    The concentrations of toxic heavy metals-Cd and Pb and micronutrients-Cu, Mn, and Zn were assessed in the surface soil and water of three different stages of paddy (Oryza sativa L.) fields, the stage I-the first stage in the field soon after transplantation of the paddy seedlings, holding adequate amount of water on soil surface, stage II-the middle stage with paddy plants of stem of about 40 cm length, with sufficient amount of water on the soil surface, and stage III-the final stage with fully grown rice plants and very little amount of water in the field at Bahour, a predominantly paddy cultivating area in Puducherry located on the southeast Coast of India. Comparison of the heavy metal and micronutrient concentrations of the soil and water across the three stages of paddy field showed their concentrations were significantly higher in soil compared with that of water (p soil. The elemental concentrations in paddy soil as well as water was in the ranking order of Cd > Mn > Zn > Cu > Pb indicating concentration of Cd was maximum and Pb was minimum. The elemental concentrations in both soil and water across the three stages showed a ranking order of stage II > stage III > stage I. The runoff from the paddy fields has affected the elemental concentrations of the water and sediment of an adjacent receiving rivulet.

  2. Trace Elements and Minerals in Fumarolic Sulfur: The Case of Ebeko Volcano, Kuriles

    Directory of Open Access Journals (Sweden)

    E. P. Shevko

    2018-01-01

    Full Text Available Native sulfur deposits on fumarolic fields at Ebeko volcano (Northern Kuriles, Russia are enriched in chalcophile elements (As-Sb-Se-Te-Hg-Cu and contain rare heavy metal sulfides (Ag2S, HgS, and CuS, native metal alloys (Au2Pd, and some other low-solubility minerals (CaWO4, BaSO4. Sulfur incrustations are impregnated with numerous particles of fresh and altered andesite groundmass and phenocrysts (pyroxene, magnetite as well as secondary minerals, such as opal, alunite, and abundant octahedral pyrite crystals. The comparison of elemental abundances in sulfur and unaltered rocks (andesite demonstrated that rock-forming elements (Ca, K, Fe, Mn, and Ti and other lithophile and chalcophile elements are mainly transported by fumarolic gas as aerosol particles, whereas semimetals (As, Sb, Se, and Te, halogens (Br and I, and Hg are likely transported as volatile species, even at temperatures slightly above 100°C. The presence of rare sulfides (Ag2S, CuS, and HgS together with abundant FeS2 in low-temperature fumarolic environments can be explained by the hydrochloric leaching of rock particles followed by the precipitation of low-solubility sulfides induced by the reaction of acid solutions with H2S at ambient temperatures. The elemental composition of native sulfur can be used to qualitatively estimate elemental abundances in low-temperature fumarolic gases.

  3. Monitoring volatile anaesthetic agents

    International Nuclear Information System (INIS)

    Russell, W.J.

    2000-01-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  4. Monitoring volatile anaesthetic agents

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W J [Royal Adelaide Hospital, SA (Australia). Department of Anaesthesia and Intensive Care

    2000-12-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  5. Lewis acid catalysis and Green oxidations: sequential tandem oxidation processes induced by Mn-hyperaccumulating plants.

    Science.gov (United States)

    Escande, Vincent; Renard, Brice-Loïc; Grison, Claude

    2015-04-01

    Among the phytotechnologies used for the reclamation of degraded mining sites, phytoextraction aims to diminish the concentration of polluting elements in contaminated soils. However, the biomass resulting from the phytoextraction processes (highly enriched in polluting elements) is too often considered as a problematic waste. The manganese-enriched biomass derived from native Mn-hyperaccumulating plants of New Caledonia was presented here as a valuable source of metallic elements of high interest in chemical catalysis. The preparation of the catalyst Eco-Mn1 and reagent Eco-Mn2 derived from Grevillea exul exul and Grevillea exul rubiginosa was investigated. Their unusual polymetallic compositions allowed to explore new reactivity of low oxidative state of manganese-Mn(II) for Eco-Mn1 and Mn(IV) for Eco-Mn2. Eco-Mn1 was used as a Lewis acid to catalyze the acetalization/elimination of aldehydes into enol ethers with high yields; a new green and stereoselective synthesis of (-)-isopulegol via the carbonyl-ene cyclization of (+)-citronellal was also performed with Eco-Mn1. Eco-Mn2 was used as a mild oxidative reagent and controlled the oxidation of aliphatic alcohols into aldehydes with quantitative yields. Oxidative cleavage was interestingly noticed when Eco-Mn2 was used in the presence of a polyol. Eco-Mn2 allowed direct oxidative iodination of ketones without using iodine, which is strongly discouraged by new environmental legislations. Finally, the combination of the properties in the Eco-Mn catalysts and reagents gave them an unprecedented potential to perform sequential tandem oxidation processes through new green syntheses of p-cymene from (-)-isopulegol and (+)-citronellal; and a new green synthesis of functionalized pyridines by in situ oxidation of 1,4-dihydropyridines.

  6. Magnetic anisotropies of (Ga,Mn)As films and nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Frank

    2011-02-02

    In this work the magnetic anisotropies of the diluted magnetic semiconductor (Ga,Mn)As were investigated experimentally. (Ga,Mn)As films show a superposition of various magnetic anisotropies which depend sensitively on various parameters such as temperature, carrier concentration or lattice strain. However, the anisotropies of lithographically prepared (Ga,Mn)As elements differ significantly from an unpatterned (Ga,Mn)As film. In stripe-shaped structures this behaviour is caused by anisotropic relaxation of the compressive lattice strain. In order to determine the magnetic anisotropies of individual (Ga,Mn)As nanostructures a combination of ferromagnetic resonance and time-resolved scanning Kerr microscopy was employed in this thesis. In addition, local changes of the magnetic anisotropy in circular and rectangular structures were visualized by making use of spatially resolved measurements. Finally, also the influence of the laterally inhomogeneous magnetic anisotropies on the static magnetic properties, such as coercive fields, was investigated employing spatially resolved static MOKE measurements on individual (Ga,Mn)As elements. (orig.)

  7. Ambient Volatility of Triethyl Phosphate

    Science.gov (United States)

    2017-08-01

    of materials is predictable using Raoult’s law. This report details the measurement of the effect of water vapor partial pressure on the volatility...empirical correlation taking into account nonideal behavior was developed to enable estimation of TEPO volatility at any combination of ambient...of the second component is expected to be one-half as much as in the absence of water vapor. Similarly, the measured volatility of the second

  8. Geochemistry of the Nsuta Mn deposit in Ghana: Implications for the Paleoproterozoic atmosphere and ocean chemistry

    Science.gov (United States)

    Goto, K. T.; Ito, T.; Suzuki, K.; Kashiwabara, T.; Takaya, Y.; Shimoda, G.; Nozaki, T.; Kiyokawa, S.; Tetteh, G. M.; Nyame, F. K.

    2013-12-01

    Oxygenation of the atmosphere and oceans has influenced the evolution of ocean chemistry and diversification of early life. A number of large manganese (Mn) deposits are distributed in the Paleoproterozoic sedimentary successions that were formed during the great oxidation event (GOE) around 2.4-2.2 Ga (Meynard, 2010). Due to the high redox potential of Mn, occurrences of Mn deposits have been regarded as important evidence for a highly oxidized environment during the Paleoproterozoic (Kirschvink et al., 2000). Furthermore, because Mn oxides strongly adsorb various elements, including bioessential elements such as Mo, formation of large Mn deposits may have affected the seawater chemical composition and ecology during the Paleoproterozoic. However, the genesis of each Mn deposit is poorly constrained, and the relationships among the formation of Mn deposits, the evolution of atmospheric and ocean chemistry, and the diversification of early life are still ambiguous. In this study, we report the Re-Os isotope compositions, rare earth element (REE) compositions, and abundance of manganophile elements in the Mn carbonate ore and host sedimentary rock samples collected from the Nsuta Mn deposit of the Birimian Supergroup, Ghana. The Nsuta deposit is one of the largest Paleoproterozoic Mn deposits, although its genesis remains controversial (Melcher et al., 1995; Mucke et al., 1999). The composite Re-Os isochron age (2149 × 130 Ma) of the Mn carbonate and sedimentary rock samples was consistent with the depositional age of the sedimentary rocks (~2.2 Ga) presumed from the U-Pb zircon age of volcanic rocks (Hirdes and Davis, 1998), suggesting that the timing of Mn ore deposition was almost equivalent to the host rock sedimentation. The PAAS-normalized REE pattern showed a positive Eu anomaly in all samples and a positive Ce anomaly only in the Mn carbonate ore. These REE patterns indicate the possible contribution of Eu-enriched fluids derived from hydrothermal activity

  9. Volatiles from solids

    Energy Technology Data Exchange (ETDEWEB)

    Loughrey, C T

    1939-08-24

    To remove volatiles from solids, such as oil shale, gases, and/or vapours are passed through a mass of the materials, the vapours and gases separated, and the vapours condensed. The volatile-containing solid materials are fed to a retort, and a shaft is driven to rotate an impeller so as to displace the liquid and create a vortex tube, which draws in gas from the atmosphere through an intake, twyer, interstices in the material in the retort, a conduit, chamber, tubes, another chamber and cylinder. This gas is carried outwardly and upwardly by the vortices in the liquid and is carried to discharge through three conduits. The vapours entrained by the gas are part condensed in the liquid and the remainder directed to a condenser. Steam may be delivered to the twyer through a nozzle of a pipe, with or without air, and combustible hydrocarbon fuel may be fed through the burner nozzle or solid fuel may be directed from feeder and combusted in the twyer.

  10. Molecular plant volatile communication.

    Science.gov (United States)

    Holopainen, Jarmo K; Blande, James D

    2012-01-01

    Plants produce a wide array of volatile organic compounds (VOCs) which have multiple functions as internal plant hormones (e.g., ethylene, methyl jasmonate and methyl salicylate), in communication with conspecific and heterospecific plants and in communication with organisms of second (herbivores and pollinators) and third (enemies of herbivores) trophic levels. Species specific VOCs normally repel polyphagous herbivores and those specialised on other plant species, but may attract specialist herbivores and their natural enemies, which use VOCs as host location cues. Attraction of predators and parasitoids by VOCs is considered an evolved indirect defence, whereby plants are able to indirectly reduce biotic stress caused by damaging herbivores. In this chapter we review these interactions where VOCs are known to play a crucial role. We then discuss the importance of volatile communication in self and nonself detection. VOCs are suggested to appear in soil ecosystems where distinction of own roots from neighbours roots is essential to optimise root growth, but limited evidence of above-ground plant self-recognition is available.

  11. (BS-Mn) nanocomposite

    African Journals Online (AJOL)

    Bamboo supported manganese (BS-Mn) nanocomposite was prepared in a single pot system via bottom-up approach using a chemical reduction method. Langmuir surface area, BET surface area, and Single pore surface area were 349.70 m2/g, 218.90 m2/g, and 213.50 m2/g, respectively. The pore size (24.34 Ȧ); pore ...

  12. A Method for Software Requirement Volatility Analysis Using QFD

    Directory of Open Access Journals (Sweden)

    Yunarso Anang

    2016-10-01

    Full Text Available Changes of software requirements are inevitable during the development life cycle. Rather than avoiding the circumstance, it is easier to just accept it and find a way to anticipate those changes. This paper proposes a method to analyze the volatility of requirement by using the Quality Function Deployment (QFD method and the introduced degree of volatility. Customer requirements are deployed to software functions and subsequently to architectural design elements. And then, after determining the potential for changes of the design elements, the degree of volatility of the software requirements is calculated. In this paper the method is described using a flow diagram and illustrated using a simple example, and is evaluated using a case study.

  13. Synthesis, structure, magnetic, electrical and electrochemical properties of Al, Cu and Mg doped MnO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, Ahmed M., E-mail: ahmedh242@yahoo.com [National Research Centre, Inorganic Chemistry Department, Behoes St., Dokki, Cairo (Egypt); Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Abuzeid, Hanaa M. [National Research Centre, Inorganic Chemistry Department, Behoes St., Dokki, Cairo (Egypt); Narayanan, N. [Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Ehrenberg, Helmut [Institute for Complex Materials, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Materials Science, Technische Universitaet Darmstadt, Petersenstr. 23, D-64287 Darmstadt (Germany); Julien, C.M. [Universite Pierre et Marie Curie, Physicochimie des Electrolytes, Colloides et Sciences Analytiques (PECSA), 4 place Jussieu, 75005 Paris (France)

    2011-10-17

    Highlights: {yields} Al, Mg and Cu doped MnO{sub 2} as cathode in Li-ion batteries. {yields} Pure phase MnO{sub 2} for virgin and doped MnO{sub 2} were obtained. {yields} Doping elements improve the electrical conductivity of MnO{sub 2}. {yields} Electrochemical behaviour of MnO{sub 2} improved after doping by Al, Mg and Cu. - Abstract: Pure and doped manganese dioxides were prepared by wet-chemical method using fumaric acid and potassium permanganate as raw materials. X-ray diffraction patterns show that pure and Al, Cu and Mg doped manganese dioxides (d-MnO{sub 2}) crystallized in the cryptomelane-MnO{sub 2} structure. Thermal analysis show that, with the assistance of potassium ions inside the 2 x 2 tunnel, the presence of Al, Cu and Mg doping elements increases the thermal stability of d-MnO{sub 2}. The electrical conductivity of d-MnO{sub 2} increases in comparison with pure MnO{sub 2}, while Al-doped MnO{sub 2} exhibits the lower resistivity. As shown in the magnetic measurements, the value of the experimental effective magnetic moment of Mn ions decreases with introduction of dopants, which is attributed to the presence of a mixed valency of high-spin state Mn{sup 4+}/Mn{sup 3+}. Doped MnO{sub 2} materials show good capacity retention in comparison with virgin MnO{sub 2}. Al-doped MnO{sub 2} shows the best electrochemical results in terms of capacity retention and recharge efficiency.

  14. Volatility Mean Reversion and the Market Price of Volatility Risk

    NARCIS (Netherlands)

    Boswijk, H.P.

    2001-01-01

    This paper analyzes sources of derivative pricing errors in a stochastic volatility model estimated on stock return data. It is shown that such pricing errors may reflect the existence of a market price of volatility risk, but also may be caused by estimation errors due to a slow mean reversion in

  15. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    The persistent nature of equity volatility is investigated by means of a multi-factor stochastic volatility model with time varying parameters. The parameters are estimated by means of a sequential matching procedure which adopts as auxiliary model a time-varying generalization of the HAR model f...

  16. Mn bioavailability by polarized Caco-2 cells: comparison between Mn gluconate and Mn oxyprolinate

    Directory of Open Access Journals (Sweden)

    Fulgenzi Alessandro

    2011-07-01

    Full Text Available Abstract Background Micronutrient inadequate intake is responsible of pathological deficiencies and there is a need of assessing the effectiveness of metal supplementation, frequently proposed to rebalance poor diets. Manganese (Mn is present in many enzymatic intracellular systems crucial for the regulation of cell metabolism, and is contained in commercially available metal supplements. Methods We compared the effects of two different commercial Mn forms, gluconate (MnGluc and oxyprolinate (MnOxP. For this purpose we used the polarized Caco-2 cells cultured on transwell filters, an established in vitro model of intestinal epithelium. Since micronutrient deficiency may accelerate mitochondrial efficiency, the mitochondrial response of these cells, in the presence of MnGluc and MnOxP, by microscopy methods and by ATP luminescence assay was used. Results In the presence of both MnOxP and MnGluc a sustained mitochondrial activity was shown by mitoTraker labeling (indicative of mitochondrial respiration, but ATP intracellular content remained comparable to untreated cells only in the presence of MnOxP. In addition MnOxP transiently up-regulated the antioxidant enzyme Mn superoxide dismutase more efficiently than MnGluc. Both metal treatments preserved NADH and βNADPH diaphorase oxidative activity, avoided mitochondrial dysfunction, as assessed by the absence of a sustained phosphoERK activation, and were able to maintain cell viability. Conclusions Collectively, our data indicate that MnOxP and MnGluc, and primarily the former, produce a moderate and safe modification of Caco-2 cell metabolism, by activating positive enzymatic mechanisms, thus could contribute to long-term maintenance of cell homeostasis.

  17. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    We examine the effect of political 'institutions' on economic growth volatility, using data from more than 100 countries over the period 1960 to 2005, taking into account various control variables as suggested in previous studies. Our indicator of volatility is the relative standard deviation of the

  18. Fundamental volatility is regime specific

    NARCIS (Netherlands)

    Arnold, I.J.M.; MacDonald, R.; Vries, de C.G.

    2006-01-01

    A widely held notion holds that freely floating exchange rates are excessively volatile when judged against fundamentals and when moving from fixed to floating exchange rates. We re-examine the data and conclude that the disparity between the fundamentals and exchange rate volatility is more

  19. Investigation on trace elements in crude oil and organic matter extracted from rocks with instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Ding Zuguo; Chai Zhifang

    1990-01-01

    Solvent extraction, column chromatography and instrumental neutron activation analysis(INAA) have been used to investigate the trace elements in crude oil, organic matter extracted from rocks and their related fractions. With these methods, about 70 crude oil samples from eight different oil fields in China and 6 extracted asphaltene samples of the lower paleozoic from the upper Yangtze region have been analyzed, and about 40 elements of interest have been determined. Those elements include Al, As, Au, Ba, Br, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, Ir, Mg, Mn, Mo, Na, Ni, Rb, Re, S, Sb, Sc, Se, Sr, Th, Zn, V and parts of REE. The experimental results show that the method possesses several advantages, i.e. non-destructive, multi-elements, sensitive, precise and accurate. Without ashing samples, the loss of volatile elements such as Cl, S, Se and Sb are avoided. The column chromatography makes it possible to study the distributions of trace elements in different fractions of crude oil and organic matter extracted. Meanwhile, the characters of trace elements in them have also been discussed

  20. Volatile organic compounds

    International Nuclear Information System (INIS)

    Silseth, May Liss

    1998-01-01

    The goal is: Not more emission of volatile organic compounds (VOCs) than necessary. The items discussed in this presentation are the VOCs, how to calculate emission of VOCs, how to reduce or avoid them, and different recovery processes. The largest source of Norwegian emissions of non methane VOCs (NMVOCs) is offshore loading of raw petroleum. Emissions of VOCs should be reduced mainly for two reasons: (1) on sunny days NMVOCs may react with NOx to form ozon and smog close to the surface, (2) ozone and smog close to the surface may be harmful to plants and animals, and they are hazardous to human health. As for the calculation of VOC emissions, the VOCON project will release the calculation program HCGASS in 1999. This project is a cooperative project headed by SINTEF/Marintek

  1. Governmentally amplified output volatility

    Science.gov (United States)

    Funashima, Yoshito

    2016-11-01

    Predominant government behavior is decomposed by frequency into several periodic components: updating cycles of infrastructure, Kuznets cycles, fiscal policy over business cycles, and election cycles. Little is known, however, about the theoretical impact of such cyclical behavior in public finance on output fluctuations. Based on a standard neoclassical growth model, this study intends to examine the frequency at which public investment cycles are relevant to output fluctuations. We find an inverted U-shaped relationship between output volatility and length of cycle in public investment. This implies that periodic behavior in public investment at a certain frequency range can cause aggravated output resonance. Moreover, we present an empirical analysis to test the theoretical implication, using the U.S. data in the period from 1968 to 2015. The empirical results suggest that such resonance phenomena change from low to high frequency.

  2. Jakartans, Institutionally Volatile

    Directory of Open Access Journals (Sweden)

    Masaaki OKAMOTO

    2014-01-01

    Full Text Available Jakarta recently has gained even more central political attention in Indonesia since Joko Widodo (Jokowi and Basuki Purnama (Ahok became, respectively, the province’s governor and vice-governor in 2012. They started a series of eye-catching and populist programmes, drawing popular support from not only the people of Jakarta, but also among Indonesians in general. Jokowi is now even the most popular candidate for the presidential election in 2014. Their rise is phenomenal in this sense, but it is understandable if we look at Jakartan voters’ behaviour and the institutional arrangement that leads to it. Jakarta, as the national capital, has a unique arrangement in that the province has no autonomous regency or city. This paper argues that this arrangement causes Jakartans to be more politically volatile and describes how this institutional arrangement was created by analysing the minutes of the meeting to discuss the laws concerning Jakarta Province.

  3. Emerging non-volatile memories

    CERN Document Server

    Hong, Seungbum; Wouters, Dirk

    2014-01-01

    This book is an introduction to the fundamentals of emerging non-volatile memories and provides an overview of future trends in the field. Readers will find coverage of seven important memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), Multiferroic RAM (MFRAM), Phase-Change Memories (PCM), Oxide-based Resistive RAM (RRAM), Probe Storage, and Polymer Memories. Chapters are structured to reflect diffusions and clashes between different topics. Emerging Non-Volatile Memories is an ideal book for graduate students, faculty, and professionals working in the area of non-volatile memory. This book also: Covers key memory technologies, including Ferroelectric Random Access Memory (FeRAM), Ferromagnetic RAM (FMRAM), and Multiferroic RAM (MFRAM), among others. Provides an overview of non-volatile memory fundamentals. Broadens readers' understanding of future trends in non-volatile memories.

  4. Nonparametric methods for volatility density estimation

    NARCIS (Netherlands)

    Es, van Bert; Spreij, P.J.C.; Zanten, van J.H.

    2009-01-01

    Stochastic volatility modelling of financial processes has become increasingly popular. The proposed models usually contain a stationary volatility process. We will motivate and review several nonparametric methods for estimation of the density of the volatility process. Both models based on

  5. Volatility Exposure for Strategic Asset Allocation

    OpenAIRE

    Briere, Marie; Burgues, Alexandre; Signori, Ombretta

    2008-01-01

    This paper examines the advantages of incorporating strategic exposure to equity volatility into the investment-opportunity set of a long-term equity investor. We consider two standard volatility investments: implied volatility and volatility risk premium strategies. To calibrate and assess the risk/return profile of the portfolio, we present an analytical framework offering pragmatic solutions for long-term investors seeking exposure to volatility. The benefit of volatility exposure for a co...

  6. Latent Integrated Stochastic Volatility, Realized Volatility, and Implied Volatility: A State Space Approach

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    process is downward biased. Implied volatility performs better than any of the alternative realized measures when forecasting future integrated volatility. The results are largely similar across the stock market (S&P 500), bond market (30-year U.S. T-bond), and foreign currency exchange market ($/£ )....

  7. Dynamic VaR Measurement of Gold Market with SV-T-MN Model

    Directory of Open Access Journals (Sweden)

    Fenglan Li

    2017-01-01

    Full Text Available VaR (Value at Risk in the gold market was measured and predicted by combining stochastic volatility (SV model with extreme value theory. Firstly, for the fat tail and volatility persistence characteristics in gold market return series, the gold price return volatility was modeled by SV-T-MN (SV-T with Mixture-of-Normal distribution model based on state space. Secondly, future sample volatility prediction was realized by using approximate filtering algorithm. Finally, extreme value theory based on generalized Pareto distribution was applied to measure dynamic risk value (VaR of gold market return. Through the proposed model on the price of gold, empirical analysis was investigated; the results show that presented combined model can measure and predict Value at Risk of the gold market reasonably and effectively and enable investors to further understand the extreme risk of gold market and take coping strategies actively.

  8. The Phase Transformations in Hypoeutectoid Steels Mn-Cr-Ni

    Directory of Open Access Journals (Sweden)

    RoŻniata E.

    2015-04-01

    Full Text Available The results of a microstructure and hardness investigations of the hypoeutectoid steels Mn-Cr-Ni, imitating by its chemical composition toughening steels, are presented in the paper. The analysis of the kinetics of phase transformations of undercooled austenite of steels containing different amounts of alloying elements in their chemical composition, constitutes the aim of investigations.

  9. Elemental balance in soy sauce

    International Nuclear Information System (INIS)

    Haruyama, Yoichi; Saito, Manabu; Yoshida, Koji.

    1996-01-01

    We have measured the elemental concentrations of soy sauce and its actual raw materials which are used in a certain soy sauce factory. In the present measurement, we measured de-fatted soybean, wheat and salt as raw materials and soy sauce and soy sauce waste as final products. Five kinds of elements, such as Mn, Fe, Cu, Zn and Br, were detected. We obtained elemental concentrations of them except for Mn in each materials. The measured elemental concentration in soy sauce agreed well each other with the calculated one within the experimental errors using the measured concentration in the raw materials and their weight in actual producing process. Contrary to our expectation, it was found that wheat contributes to soy sauce bromine concentration dominantly in the present case. (author)

  10. Trace elements in brazilian soils

    International Nuclear Information System (INIS)

    Rocha, Geraldo Cesar

    1995-01-01

    A literature revision on trace elements (Zn, B, Mn, Mo, Cu, Fe, and Cl) in Brazilian soils was prepared, with special attention to the chemical form and range in the soil, extraction methods and correlation of the amount in soils with soil properties

  11. Parallel Prediction of Stock Volatility

    Directory of Open Access Journals (Sweden)

    Priscilla Jenq

    2017-10-01

    Full Text Available Volatility is a measurement of the risk of financial products. A stock will hit new highs and lows over time and if these highs and lows fluctuate wildly, then it is considered a high volatile stock. Such a stock is considered riskier than a stock whose volatility is low. Although highly volatile stocks are riskier, the returns that they generate for investors can be quite high. Of course, with a riskier stock also comes the chance of losing money and yielding negative returns. In this project, we will use historic stock data to help us forecast volatility. Since the financial industry usually uses S&P 500 as the indicator of the market, we will use S&P 500 as a benchmark to compute the risk. We will also use artificial neural networks as a tool to predict volatilities for a specific time frame that will be set when we configure this neural network. There have been reports that neural networks with different numbers of layers and different numbers of hidden nodes may generate varying results. In fact, we may be able to find the best configuration of a neural network to compute volatilities. We will implement this system using the parallel approach. The system can be used as a tool for investors to allocating and hedging assets.

  12. Increasing Mn substitution in magnetic semiconductors through controlled ambient annealing processes

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, J. [Materials Science Program, Department of Mechanical and Aerospace Engineering, UC San Diego, La Jolla, CA 92093-0411 (United States); Bandaru, P.R. [Materials Science Program, Department of Mechanical and Aerospace Engineering, UC San Diego, La Jolla, CA 92093-0411 (United States)], E-mail: pbandaru@ucsd.edu

    2008-06-25

    We report on a controlled ambient annealing technique aimed at increasing the amount of Mn incorporation in III-V semiconductors. The aim is to reduce the number of hole carrier and magnetic element compensating entities, such as Mn interstitials and anti-site defects, to increase the magnetic Curie temperature. The idea is (a) to increase the number of Group III vacancies through annealing in Group V vapor rich conditions and (b) judicious use of crystal field theory to reduce/stabilize Mn interstitials. Our experimental results constitute the highest reportedT{sub c} ({approx}130 K) in Mn doped InSb and Mn doped InP. The possibility of ferrimagnetism in Mn and Cr incorporated GaAs, was noted.

  13. Volatiles in the Martian regolith

    International Nuclear Information System (INIS)

    Clark, B.C.; Baird, A.K.

    1979-01-01

    An inventory of released volatiles on Mars has been derived based upon Viking measurements of atmospheric and surface chemical composition, and upon the inferred mineralogy of a ubiquitous regolith, assumed to average 200m in depth. This model is consistent with the relative abundances of volatiles (except for S) on the Earth's surface, but implies one-fifteenth of the volatile release of Earth if starting materials were comparable. All constituents are accommodated as chemical components of, or absorbed phases on, regolith materials--without the necessity of invoking unobservable deposits of carbonates, nitrates, or permafrost ice

  14. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    We show that the empirical ranking of volatility models can be inconsistent for the true ranking if the evaluation is based on a proxy for the population measure of volatility. For example, the substitution of a squared return for the conditional variance in the evaluation of ARCH-type models can...... variance in out-of-sample evaluations rather than the squared return. We derive the theoretical results in a general framework that is not specific to the comparison of volatility models. Similar problems can arise in comparisons of forecasting models whenever the predicted variable is a latent variable....

  15. The Impact of Environmental Mn Exposure on Insect Biology

    Directory of Open Access Journals (Sweden)

    Yehuda Ben-Shahar

    2018-03-01

    Full Text Available Manganese (Mn is an essential trace element that acts as a metal co-factor in diverse biochemical and cellular functions. However, chronic environmental exposure to high levels of Mn is a well-established risk factor for the etiology of severe, atypical parkinsonian syndrome (manganism via its accumulation in the basal ganglia, pallidum, and striatum brain regions, which is often associated with abnormal dopamine, GABA, and glutamate neural signaling. Recent studies have indicated that chronic Mn exposure at levels that are below the risk for manganism can still cause behavioral, cognitive, and motor dysfunctions via poorly understood mechanisms at the molecular and cellular levels. Furthermore, in spite of significant advances in understanding Mn-induced behavioral and neuronal pathologies, available data are primarily for human and rodents. In contrast, the possible impact of environmental Mn exposure on brain functions and behavior of other animal species, especially insects and other invertebrates, remains mostly unknown both in the laboratory and natural habitats. Yet, the effects of environmental exposure to metals such as Mn on insect development, physiology, and behavior could also have major indirect impacts on human health via the long-term disruptions of food webs, as well as direct impact on the economy because of the important role insects play in crop pollination. Indeed, laboratory and field studies indicate that chronic exposures to metals such as Mn, even at levels that are below what is currently considered toxic, affect the dopaminergic signaling pathway in the insect brain, and have a major impact on the behavior of insects, including foraging activity of important pollinators such as the honey bee. Together, these studies highlight the need for a better understanding of the neuronal, molecular, and genetic processes that underlie the toxicity of Mn and other metal pollutants in diverse animal species, including insects.

  16. Stochastic volatility and stochastic leverage

    DEFF Research Database (Denmark)

    Veraart, Almut; Veraart, Luitgard A. M.

    This paper proposes the new concept of stochastic leverage in stochastic volatility models. Stochastic leverage refers to a stochastic process which replaces the classical constant correlation parameter between the asset return and the stochastic volatility process. We provide a systematic...... treatment of stochastic leverage and propose to model the stochastic leverage effect explicitly, e.g. by means of a linear transformation of a Jacobi process. Such models are both analytically tractable and allow for a direct economic interpretation. In particular, we propose two new stochastic volatility...... models which allow for a stochastic leverage effect: the generalised Heston model and the generalised Barndorff-Nielsen & Shephard model. We investigate the impact of a stochastic leverage effect in the risk neutral world by focusing on implied volatilities generated by option prices derived from our new...

  17. Solvent Refined Coal (SRC) process: trace elements. Research and development report No. 53, interim report No. 30. Volume III. Pilot plant development work. Part 6. The fate of trace elements in the SRC process

    International Nuclear Information System (INIS)

    Khalil, S.R.

    1980-02-01

    Instrumental neutron activation analysis was used to study the distribution and fate of up to 36 elements in the Solvent Refined Coal Process Pilot Plant located at Fort Lewis, Washington. The elements Ti, V, Mg, Ca, Al, Cl, Mn, As, Br, Na, K, Sm, La, Ga, Cu, Sb, Se, Hg, Ni, Co, Cr, Fe, Rb, Cs, Sc, Tb, Eu, Ce, Sr, Ba, Th, U, Hf, Ta, Zr and Zn were measured in feed coal, insoluble residues, process solvent, process and effluent waters, by-product sulfur, SRC-I solid product, liquid-liquid separator oils and SRC-II liquid products. The material balance was calculated for each element from the concentration data and yields of each process fraction for both the SRC-I and SRC-II processes. Except for Ti, Cl and Br in the SRC-I mode and Hg in the SRC-II mode, each element was substantially lower in the SRC products than in the original feed coal. Residues from the process contained more than 80% of the trace element content found in the coal, except for Hg. More than 98.5% of the total contents of K and Fe in coal were retained in the insoluble residues. Elements such as Hg, Se, As and Sb can form volatile compounds (such as Hg 0 , H 2 Se, AsH 3 and SbH 3 ) stable under the process conditions. The high enhancement factors of Se (957), As (202) and Sb (27.4) in the aqueous phase of the separator water compared to that of the oil are evidence for the formation of volatile species which are more soluble in water than in the oil phase

  18. Volatility from copper and tungsten alloys for fusion reactor applications

    International Nuclear Information System (INIS)

    Smolik, G.R.; Neilson, R.M. Jr.; Piet, S.J.

    1989-01-01

    Accident scenarios for fusion power plants present the potential for release and transport of activated constituents volatilized from first wall and structural materials. The extent of possible mobilization and transport of these activated species, many of which are ''oxidation driven'', is being addressed by the Fusion Safety Program at the Idaho National Engineering Laboratory (INEL). This report presents experimental measurements of volatilization from a copper alloy in air and steam and from a tungsten alloy in air. The major elements released included zinc from the copper alloy and rhenium and tungsten from the tungsten alloy. Volatilization rates of several constituents of these alloys over temperatures ranging from 400 to 1200 degree C are presented. These values represent release rates recommended for use in accident assessment calculations. 8 refs., 3 figs., 5 tabs

  19. The origin of volatiles in the Earth's mantle

    Science.gov (United States)

    Hier-Majumder, Saswata; Hirschmann, Marc M.

    2017-08-01

    The Earth's deep interior contains significant reservoirs of volatiles such as H, C, and N. Due to the incompatible nature of these volatile species, it has been difficult to reconcile their storage in the residual mantle immediately following crystallization of the terrestrial magma ocean (MO). As the magma ocean freezes, it is commonly assumed that very small amounts of melt are retained in the residual mantle, limiting the trapped volatile concentration in the primordial mantle. In this article, we show that inefficient melt drainage out of the freezing front can retain large amounts of volatiles hosted in the trapped melt in the residual mantle while creating a thick early atmosphere. Using a two-phase flow model, we demonstrate that compaction within the moving freezing front is inefficient over time scales characteristic of magma ocean solidification. We employ a scaling relation between the trapped melt fraction, the rate of compaction, and the rate of freezing in our magma ocean evolution model. For cosmochemically plausible fractions of volatiles delivered during the later stages of accretion, our calculations suggest that up to 77% of total H2O and 12% of CO2 could have been trapped in the mantle during magma ocean crystallization. The assumption of a constant trapped melt fraction underestimates the mass of volatiles in the residual mantle by more than an order of magnitude.Plain Language SummaryThe Earth's deep interior contains substantial amounts of volatile elements like C, H, and N. How these elements got sequestered in the Earth's interior has long been a topic of debate. It is generally assumed that most of these elements escaped the interior of the Earth during the first few hundred thousand years to create a primitive atmosphere, leaving the mantle reservoir nearly empty. In this work, we show that the key to this paradox involves the very early stages of crystallization of the mantle from a global magma ocean. Using numerical models, we show

  20. The Release of Trace Elements in the Process of Coal Coking

    Directory of Open Access Journals (Sweden)

    Jan Konieczyński

    2012-01-01

    Full Text Available In order to assess the penetration of individual trace elements into the air through their release in the coal coking process, it is necessary to determine the loss of these elements by comparing their contents in the charge coal and in coke obtained. The present research covered four coke oven batteries differing in age, technology, and technical equipment. By using mercury analyzer MA-2 and the method of ICP MS As, Be, Cd, Co, Hg, Mn, Ni, Se, Sr, Tl, V, and Zn were determined in samples of charge coal and yielded coke. Basing on the analyses results, the release coefficients of selected elements were determined. Their values ranged from 0.5 to 94%. High volatility of cadmium, mercury, and thallium was confirmed. The tests have shown that although the results refer to the selected case studies, it may be concluded that the air purity is affected by controlled emission occurring when coke oven batteries are fired by crude coke oven gas. Fugitive emission of the trace elements investigated, occurring due to coke oven leaks and openings, is small and, is not a real threat to the environment except mercury.

  1. Trace element analysis of soy sauce

    International Nuclear Information System (INIS)

    Tomita, Michio; Haruyama, Yoichi; Saito, Manabu

    1994-01-01

    Trace elements in soy sauce have been measured by means of in-air PIXE. Six kinds of trace elements were detected, such as Mu, Fe, Ni, Zn, Cu and Br. Concentrations of Mn, Fe, Zn and Br which were observed in all samples, have been determined. Each analyzed sample contained considerable amount of bromine about 160 ppm. (author)

  2. Volatility Properties of Polonium

    International Nuclear Information System (INIS)

    Eichler, B.

    2002-06-01

    Thermodynamical constants to describe evaporation processes of polonium are summarized and critically discussed. Additionally, systematic changes of the properties of the chalcogenes are analyzed, empirical correlations are proofed and cyclic processes are balanced. Accordingly, the existing values of entropies for polonium are acceptable. Questionable, however, are those values of enthalpies, which have been deduced from results of the experimental investigations of the vapor pressure temperature dependency, of the melting point, and of the boiling temperatures. Technical difficulties and possible error sources of the measurements resulting from the radioactive decay properties of 210 Po are discussed. Using extrapolative standard enthalpies and entropies as well as their temperature dependency, the equilibrium partial pressure of the monomeric and dimeric polonium above the pure condensed phase and the equilibrium constant of the dimerization reaction in the gas phase are calculated: log p/pa Po (g) = (11.797 ± 0.024) -(9883.4 ± 9.5)/T (for T = 298-600 K); = (10.661 ± 0.057) - (9328.4 ± 4.9)/T (for T = 500-1300 K); log p/pa Po 2 (g) = (13.698 ± 0.049) - (8592.3 ± 19.6)/T (for T = 298-600 K); = (11.424 ± 0.124) - (7584.1 ± 98.1)/T (for T = 500-1300 K); log K (dim) = (-4.895 ± 0.012) + (11071 ± 6)/T. According to these calculations and in contrast to other works, polonium evaporates in the entire temperature range between 298 and 1300 K in the dimeric state. Hence, 'latent heats' of the volatilization processes are clearly larger compared to literature data. Especially in the temperature range of the solid polonium the calculated vapor pressure curve shifts significantly to lower values, whereas the boiling point was almost reproduced by the calculation. The results of the extrapolation for the standard enthalpy of the gaseous monomeric polonium and the dimerization enthalpy ΔH 0 298 Po (g) = 188.9 kJ/mol and ΔH 0 298 (form) Po 2 (g) = 211.5 kJ/mol are

  3. Sub-micrometer scale minor element mapping in interplanetary dust particles: a test for stratospheric contamination

    International Nuclear Information System (INIS)

    Flynn, G.J.; Keller, L.P.; Sutton, S.R.

    2006-01-01

    We mapped the spatial distribution of minor elements including K, Mn, and Zn in 3 IDPs and found no evidence for the surface coatings (rims) of these elements that would be expected if the enrichments previously reported were due to contamination. Combined X-ray microprobe (XRM), energy dispersive x-ray fluorescence using a Transmission Electron Microscope (TEM), and electron microprobe measurements have determined that the average bulk chemical composition of the interplanetary dust particles (IDPs) collected from the Earth's stratosphere is enriched relative to the CI meteorite composition by a factor of 2 to 4 for carbon and for the moderately volatile elements Na, K, P, Mn, Cu, Zn, Ga, Ge, and Se, and enriched to ∼30 times CI for Br. However, Jessberger et al., who have reported similar bulk enrichments using Proton Induced X-ray Emission (PIXE), attribute the enrichments to contamination by meteor-derived atmospheric aerosols during the several weeks these IDPs reside in the Earth's atmosphere prior to collection. Using scanning Auger spectroscopy, a very sensitive surface analysis technique, Mackinnon and Mogk have observed S contamination on the surface of IDPs, presumably due to the accretion of sulfate aerosols during stratospheric residence. But the S-rich layer they detected was so thin (∼100 angstroms thick) that the total amount of S on the surface was too small to significantly perturb the bulk S-content of a chondritic IDP. Stephan et al. provide support for the contamination hypothesis by reporting the enrichment of Br on the edges of the IDPs using Time-of-Flight Secondary-Ion Mass-Spectrometry (TOF-SIMS), but TOF-SIMS is notorious for producing false edge-effects, particularly on irregularly-shaped samples like IDPs. Sutton et al. mapped the spatial distribution of Fe, Ni, Zn, Br, and Sr, at the ∼2 (micro)m scale, in four IDPs using element-specific x-ray fluorescence (XRF) computed microtomography. They found the moderately volatile

  4. Magnetic properties of doped Mn-Ga alloys made by mechanical milling and heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Daniel R. [Department of Material Science and Engineering, Florida State University, Tallahassee, FL 32304 (United States); National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Han, Ke; Niu, Rongmei [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Siegrist, Theo; Besara, Tiglet [Department of Material Science and Engineering, Florida State University, Tallahassee, FL 32304 (United States); Department of Chemical Engineering, Florida Agricultural and Mechanical University-Florida State University, Tallahassee, FL 32304 (United States)

    2016-05-15

    Mn-Ga alloys have shown hard magnetic properties, even though these alloys contain no rare-earth metals. However, much work is needed before rare-earth magnets can be replaced. We have examined the magnetic properties of bulk alloys made with partial replacement of both the Mn and Ga elements in the Mn{sub 0.8}Ga{sub 0.2} system. Bulk samples of Mn-Ga-Bi, Mn-Ga-Al, Mn-Fe-Ga and Mn-(FeB)-Ga alloys were fabricated and studied using mechanically milling and heat treatments while altering the atomic percentage of the third element between 2.5 and 20 at%. The ternary alloy exhibits all hard magnetic properties at room temperature with large coercivity. Annealed Mn-Ga-X bulk composites exhibit high coercivities up to 16.6 kOe and remanence up to 9.8 emu/g, that is increased by 115% over the binary system.

  5. Fabrication and Magnetic Properties of Co₂MnAl Heusler Alloys by Mechanical Alloying.

    Science.gov (United States)

    Lee, Chung-Hyo

    2018-02-01

    We have applied mechanical alloying (MA) to produce nanocrystalline Co2MnAl Heusler alloys using a mixture of elemental Co50Mn25Al25 powders. An optimal milling and heat treatment conditions to obtain a Co2MnAl Heusler phase with fine microstructure were investigated by X-ray diffraction, differential scanning calorimeter and vibrating sample magnetometer measurements. α-(Co, Mn, Al) FCC phases coupled with amorphous phase are obtained after 3 hours of MA without any evidence for the formation of Co2MnAl alloys. On the other hand, a Co2MnAl Heusler alloys can be obtained by the heat treatment of all MA samples up to 650 °C. X-ray diffraction result shows that the average grain size of Co2MnAl Heusler alloys prepared by MA for 5 h and heat treatment is in the range of 95 nm. The saturation magnetization of MA powders decreases with MA time due to the magnetic dilution by alloying with nonmagnetic Mn and Al elements. The magnetic hardening due to the reduction of the grain size with ball milling is also observed. However, the saturation magnetization of MA powders after heat treatment increases with MA time and reaches to a maximum value of 105 emu/g after 5 h of MA. It can be also seen that the coercivity of 5 h MA sample annealed at 650 °C is fairly low value of 25 Oe.

  6. Magnetic properties of doped Mn-Ga alloys made by mechanical milling and heat treatment

    Directory of Open Access Journals (Sweden)

    Daniel R. Brown

    2016-05-01

    Full Text Available Mn-Ga alloys have shown hard magnetic properties, even though these alloys contain no rare-earth metals. However, much work is needed before rare-earth magnets can be replaced. We have examined the magnetic properties of bulk alloys made with partial replacement of both the Mn and Ga elements in the Mn0.8Ga0.2 system. Bulk samples of Mn-Ga-Bi, Mn-Ga-Al, Mn-Fe-Ga and Mn-(FeB-Ga alloys were fabricated and studied using mechanically milling and heat treatments while altering the atomic percentage of the third element between 2.5 and 20 at%. The ternary alloy exhibits all hard magnetic properties at room temperature with large coercivity. Annealed Mn-Ga-X bulk composites exhibit high coercivities up to 16.6 kOe and remanence up to 9.8 emu/g, that is increased by 115% over the binary system.

  7. Solid state synthesis of Mn{sub 5}Ge{sub 3} in Ge/Ag/Mn trilayers: Structural and magnetic studies

    Energy Technology Data Exchange (ETDEWEB)

    Myagkov, V.G.; Bykova, L.E.; Matsynin, A.A.; Volochaev, M.N.; Zhigalov, V.S.; Tambasov, I.A. [Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Mikhlin, Yu L. [Institute of Chemistry and Chemical Technology, SB RAS, Krasnoyarsk 660049 (Russian Federation); Velikanov, D.A. [Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Bondarenko, G.N. [Institute of Chemistry and Chemical Technology, SB RAS, Krasnoyarsk 660049 (Russian Federation)

    2017-02-15

    The thin-film solid-state reaction between elemental Ge and Mn across chemically inert Ag layers with thicknesses of (0, 0.3, 1 and 2.2 µm) in Ge/Ag/Mn trilayers was studied for the first time. The initial samples were annealed at temperatures between 50 and 500 °C at 50 °C intervals for 1 h. The initiation temperature of the reaction for Ge/Mn (without a Ag barrier layer) was ~ 120 °C and increased slightly up to ~ 250 °C when the Ag barrier layer thickness increased up to 2.2 µm. In spite of the Ag layer, only the ferromagnetic Mn{sub 5}Ge{sub 3} compound and the Nowotny phase were observed in the initial stage of the reaction after annealing at 500 °C. The cross-sectional studies show that during Mn{sub 5}Ge{sub 3} formation the Ge is the sole diffusing species. The magnetic and cross-sectional transmission electron microscopy (TEM) studies show an almost complete transfer of Ge atoms from the Ge film, via a 2.2 µm Ag barrier layer, into the Mn layer. We attribute the driving force of the long-range transfer to the long-range chemical interactions between reacting Mn and Ge atoms. - Graphical abstract: The direct visualization of the solid state reaction between Mn and Ge across a Ag buffer layer at 500 °C. - Highlights: • The migration of Ge, via an inert 2.2 µm Ag barrier, into a Mn layer. • The first Mn{sub 5}Ge{sub 3} phase was observed in reactions with different Ag layers. • The Ge is the sole diffusing species during Mn{sub 5}Ge{sub 3} formation • The long-range chemical interactions control the Ge atomic transfer.

  8. Effect of trace element addition and increasing organic loading rates on the anaerobic digestion of cattle slaughterhouse wastewater.

    Science.gov (United States)

    Schmidt, Thomas; McCabe, Bernadette K; Harris, Peter W; Lee, Seonmi

    2018-05-18

    In this study, anaerobic digestion of slaughterhouse wastewater with the addition of trace elements was monitored for biogas quantity, quality and process stability using CSTR digesters operated at mesophilic temperature. The determination of trace element concentrations was shown to be deficient in Fe, Ni, Co, Mn and Mo compared to recommendations given in the literature. Addition of these trace elements resulted in enhanced degradation efficiency, higher biogas production and improved process stability. Higher organic loading rates and lower hydraulic retention times were achieved in comparison to the control digesters. A critical accumulation of volatile fatty acids was observed at an organic loading rate of 1.82 g L -1  d -1 in the control compared to 2.36 g L -1  d -1 in the digesters with trace element addition. The improved process stability was evident in the final weeks of experimentation, in which control reactors produced 84% less biogas per day compared to the reactors containing trace elements. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    OpenAIRE

    Chen, Jinghui; Kobayashi, Masahito; McAleer, Michael

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The proposed test is a stochastic volatility version of the co-movement test proposed by Engle and Susmel (1993), who investigated whether international equity markets have volatility co-movement using t...

  10. The price of fixed income market volatility

    CERN Document Server

    Mele, Antonio

    2015-01-01

    Fixed income volatility and equity volatility evolve heterogeneously over time, co-moving disproportionately during periods of global imbalances and each reacting to events of different nature. While the methodology for options-based "model-free" pricing of equity volatility has been known for some time, little is known about analogous methodologies for pricing various fixed income volatilities. This book fills this gap and provides a unified evaluation framework of fixed income volatility while dealing with disparate markets such as interest-rate swaps, government bonds, time-deposits and credit. It develops model-free, forward looking indexes of fixed-income volatility that match different quoting conventions across various markets, and uncovers subtle yet important pitfalls arising from naïve superimpositions of the standard equity volatility methodology when pricing various fixed income volatilities. The ultimate goal of the authors´ efforts is to make interest rate volatility standardization a valuable...

  11. Bimetallic Co-Mn Perovskite Fluorides as Highly-Stable Electrode Materials for Supercapacitors.

    Science.gov (United States)

    Shi, Wei; Ding, Rui; Li, Xudong; Xu, Qilei; Ying, Danfeng; Huang, Yongfa; Liu, Enhui

    2017-11-02

    Bimetallic Co-Mn perovskite fluorides (KCo x Mn 1-x F 3 , denoted as K-Co-Mn-F) with various Co/Mn ratios (1:0, 12:1, 6:1, 3:1, 1:1, 1:3, 0:1) were prepared through a one-pot solvothermal strategy and further used as electrode materials for supercapacitors. The optimal K-Co-Mn-F candidate (Co/Mn=6:1) showed a size range of 0.1-1 μm and uniform elemental distribution; exhibiting small changes in XRD peaks and XPS binding energy in comparison to the bare K-Co-F and K-Mn-F, due to the structural/electronic effects. Owing to the stronger synergistic effect of Co/Mn redox species, the K-Co-Mn-F (Co/Mn=6:1) electrode exhibited superior specific capacity and rate behavior (113-100 C g -1 at 1-16 Ag -1 ) together with excellent cycling stability (118 % for 5000 cycles at 8 Ag -1 ), and the activated carbon (AC)//K-Co-Mn-F (Co/Mn=6:1) asymmetric capacitor showed superior energy and power densities (8.0-2.4 Wh kg -1 at 0.14-8.7 kW kg -1 ) along with high cycling stability (90 % for 10 000 cycles at 5 Ag -1 ). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Observability of market daily volatility

    Science.gov (United States)

    Petroni, Filippo; Serva, Maurizio

    2016-02-01

    We study the price dynamics of 65 stocks from the Dow Jones Composite Average from 1973 to 2014. We show that it is possible to define a Daily Market Volatility σ(t) which is directly observable from data. This quantity is usually indirectly defined by r(t) = σ(t) ω(t) where the r(t) are the daily returns of the market index and the ω(t) are i.i.d. random variables with vanishing average and unitary variance. The relation r(t) = σ(t) ω(t) alone is unable to give an operative definition of the index volatility, which remains unobservable. On the contrary, we show that using the whole information available in the market, the index volatility can be operatively defined and detected.

  13. Multiscaling and clustering of volatility

    Science.gov (United States)

    Pasquini, Michele; Serva, Maurizio

    1999-07-01

    The dynamics of prices in stock markets has been studied intensively both experimentally (data analysis) and theoretically (models). Nevertheless, while the distribution of returns of the most important indices is known to be a truncated Lévy, the behaviour of volatility correlations is still poorly understood. What is well known is that absolute returns have memory on a long time range, this phenomenon is known in financial literature as clustering of volatility. In this paper we show that volatility correlations are power laws with a non-unique scaling exponent. This kind of multiscale phenomenology is known to be relevant in fully developed turbulence and in disordered systems and it is pointed out here for the first time for a financial series. In our study we consider the New York Stock Exchange (NYSE) daily index, from January 1966 to June 1998, for a total of 8180 working days.

  14. Distribution of Alkalis (Na, Cs, Rb) Between Silicate and Sulfide: Implications for Planetary Volatile Depletion

    Science.gov (United States)

    Boujibar, A.; Fei, Y.; Righter, K.; Du, Z.; Bullock, E.

    2018-01-01

    The abundances of volatile elements in the Earth's mantle are correlated with their temperatures of condensation. This depletion can be due to either incomplete condensation of the elements during the nebula condensation or evaporation processes during planetary growth. Elements that have affinities with metals (siderophile) and sulfides (chalcophile) are additionally depleted due to their segregation into the core. Therefore, study of lithophile elements could be useful to isolate processes of volatilization and their effect on the abundance of the elements in the Earth's mantle. However, the correlation of these lithophile elements including alkali elements, with their temperatures of condensation shows a significant scatter, which is difficult to reconcile with a depletion by vaporization or incomplete condensation alone.

  15. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    After the financialization of commodity futures markets in 2004-05 oil volatility has become a strong predictor of returns and volatility of the overall stock market. Furthermore, stocks' exposure to oil volatility risk now drives the cross-section of expected returns. The difference in average...... return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  16. Standard elements; Elements standards

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Following his own experience the author recalls the various advantages, especially in the laboratory, of having pre-fabricated vacuum-line components at his disposal. (author) [French] A la suite de sa propre experience, l'auteur veut rappeler les divers avantages que presente, tout particulierement en laboratoire, le fait d'avoir a sa disposition des elements pre-fabriques de canalisations a vide. (auteur)

  17. Oxidation/volatilization rates in air for candidate fusion reactor blanket materials, PCA and HT-9

    International Nuclear Information System (INIS)

    Piet, S.J.; Kraus, H.G.; Neilson, R.M. Jr.; Jones, J.L.

    1986-01-01

    Large uncertainties exist in the quantity of neutron-induced activation products that can be mobilized in potential fusion accidents. The accidental combination of high temperatures and oxidizing conditions might lead to mobilization of a significant amount of activation products from structural materials. Here, the volatilization of constituents of PCA and HT-9 resulting from oxidation in air was investigated. Tests were conducted in flowing air at temperatures from 600 to 1300 0 C for 1, 5, or 20 hours. Elemental volatility was calculated in terms of the weight fraction of the element volatilized from the initial alloy. Molybdenum and manganese were the radiologically significant primary constituents most volatilized, suggesting that molybdenum and manganese should be minimized in fusion steel compositions. Higher chromium content appears beneficial in reducing hazards from mobile activation products. Scanning electron microscopy and energy dispersive spectroscopy were used to study the oxide layer on samples

  18. Structural and Magnetic Properties of Co-Mn-Sb Thin films

    Energy Technology Data Exchange (ETDEWEB)

    Meinert, M.; Schmalhorst, J.-M.; Ebke, D.; Liu, N. N.; Thomas, A.; Reiss, G.; Kanak, J.; Stobiecki, T.; Arenholz, E.

    2009-12-17

    Thin Co-Mn-Sb films of different compositions were investigated and utilized as electrodes in alumina based magnetic tunnel junctions with CoFe counterelectrode. The preparation conditions were optimized with respect to magnetic and structural properties. The Co-Mn-Sb/Al-O interface was analyzed by x-ray absorption spectroscopy and magnetic circular dichroism with particular focus on the element-specific magnetic moments. Co-Mn-Sb crystallizes in different complex cubic structures depending on its composition. The magnetic moments of Co and Mn are ferromagnetically coupled in all cases. A tunnel magnetoresistance ratio of up to 24% at 13 K was found and indicates that Co-Mn-Sb is not a ferromagnetic half-metal. These results are compared to recent works on the structure and predictions of the electronic properties.

  19. DOES ENERGY CONSUMPTION VOLATILITY AFFECT REAL GDP VOLATILITY? AN EMPIRICAL ANALYSIS FOR THE UK

    Directory of Open Access Journals (Sweden)

    Abdul Rashid

    2013-10-01

    Full Text Available This paper empirically examines the relation between energy consumption volatility and unpredictable variations in real gross domestic product (GDP in the UK. Estimating the Markov switching ARCH model we find a significant regime switching in the behavior of both energy consumption and GDP volatility. The results from the Markov regime-switching model show that the variability of energy consumption has a significant role to play in determining the behavior of GDP volatilities. Moreover, the results suggest that the impacts of unpredictable variations in energy consumption on GDP volatility are asymmetric, depending on the intensity of volatility. In particular, we find that while there is no significant contemporaneous relationship between energy consumption volatility and GDP volatility in the first (low-volatility regime, GDP volatility is significantly positively related to the volatility of energy utilization in the second (high-volatility regime.

  20. The Mn site in Mn-doped GaAs nanowires: an EXAFS study

    International Nuclear Information System (INIS)

    D’Acapito, F; Rovezzi, M; Boscherini, F; Jabeen, F; Bais, G; Piccin, M; Rubini, S; Martelli, F

    2012-01-01

    We present an EXAFS study of the Mn atomic environment in Mn-doped GaAs nanowires. Mn doping has been obtained either via the diffusion of the Mn used as seed for the nanowire growth or by providing Mn during the growth of Au-induced wires. As a general finding, we observe that Mn forms chemical bonds with As but is not incorporated in a substitutional site. In Mn-induced GaAs wires, Mn is mostly found bonded to As in a rather disordered environment and with a stretched bond length, reminiscent of that exhibited by MnAs phases. In Au-seeded nanowires, along with stretched MnAs coordination, we have found the presence of Mn in a MnAu intermetallic compound. (paper)

  1. Autoradiographic methods for studying marked volatile substances (1961)

    International Nuclear Information System (INIS)

    Cohen, Y.; Wepierre, J.

    1961-01-01

    The autoradiographic methods for animals used up to the present do not make it possible to localise exactly the distribution of marked volatile molecules. The Ullberg method (1954) which we have modified (Cohen, Delassue, 1959) involves cold desiccant. The method due to Pellerin (1957) avoids this desiccant but the histological comparison of the autoradiography with the biological document itself is difficult, if not impossible. Nevertheless, we have adopted certain points in the two methods and propose the following technique for the autoradiographic study of marked volatile molecules: 1- The surface of the frozen sample to be studied is prepared using a freezing microtome. 2- The last section, which is 20 μ thick and whose histological elements are parallel to those of the block, is dried by cooling and is used as the biological reference document for the autoradiography obtained, as is indicated in 3; 3- The radiography films are applied to the frozen block at -30 deg. C. The autoradiographs correspond to the radioactivity of the volatile molecule and of its non-volatile degradation products. 4- The radiographic film is also applied to the 20 μ section previously dried at -20 deg. C. This autoradiography corresponds to the radioactivity of the non-volatile degradation products of the molecule. 5- We confirmed the absence of diffusion of the volatile molecule and of pseudo-radiographic effects (photochemical and others). This method, which has enabled us to study the distribution of a carbide, para-cymene (C 14 ) 7, macroscopically in the case of a whole mouse and microscopically on the skin of a dog, can find general applications. (authors) [fr

  2. Superheavy Elements Challenge Experimental and Theoretical Chemistry

    CERN Document Server

    Zvára, I

    2003-01-01

    When reflecting on the story of superheavy elements, the an experimenter, acknowledges the role, which the predictions of nuclear and chemical theories have played in ongoing studies. Today, the problems of major interest for experimental chemistry are the studies of elements 112 and 114 including their chemical identification. Advanced quantum chemistry calculations of atoms and molecules would be of much help. First experiments with element 112 evidence that the metal is much more volatile and inert than mercury.

  3. assessment of toxic elements in selected nigeria broiler feeds using

    African Journals Online (AJOL)

    User

    2015-12-02

    Dec 2, 2015 ... toxic elements Mn, Cr, Zn, Fe, Co, Sr, La, Sm, Th and Se in some selected ... However, the results shows the Fe concentration in sample B ..... activation analysis” Applied Radiation and ... Neutron Activation Analysis of Soil.

  4. Autoradiographic methods for studying marked volatile substances (1961); Methode.d'etude autoradiographique de substances marquees volatiles (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Y; Wepierre, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The autoradiographic methods for animals used up to the present do not make it possible to localise exactly the distribution of marked volatile molecules. The Ullberg method (1954) which we have modified (Cohen, Delassue, 1959) involves cold desiccant. The method due to Pellerin (1957) avoids this desiccant but the histological comparison of the autoradiography with the biological document itself is difficult, if not impossible. Nevertheless, we have adopted certain points in the two methods and propose the following technique for the autoradiographic study of marked volatile molecules: 1- The surface of the frozen sample to be studied is prepared using a freezing microtome. 2- The last section, which is 20 {mu} thick and whose histological elements are parallel to those of the block, is dried by cooling and is used as the biological reference document for the autoradiography obtained, as is indicated in 3; 3- The radiography films are applied to the frozen block at -30 deg. C. The autoradiographs correspond to the radioactivity of the volatile molecule and of its non-volatile degradation products. 4- The radiographic film is also applied to the 20 {mu} section previously dried at -20 deg. C. This autoradiography corresponds to the radioactivity of the non-volatile degradation products of the molecule. 5- We confirmed the absence of diffusion of the volatile molecule and of pseudo-radiographic effects (photochemical and others). This method, which has enabled us to study the distribution of a carbide, para-cymene (C{sup 14}) 7, macroscopically in the case of a whole mouse and microscopically on the skin of a dog, can find general applications. (authors) [French] Les methodes d'autoradiographies sur l'animal, proposees jusqu'a present, ne permettent pas de localiser de facon precise la distribution de molecules marquees volatiles. En effet, la methode de Ullberg (1954) que nous avons modifiee (Cohen, Delassue, 1959) necessite la dessiccation par le froid. La methode

  5. Universal scaling behaviors of meteorological variables’ volatility and relations with original records

    Science.gov (United States)

    Lu, Feiyu; Yuan, Naiming; Fu, Zuntao; Mao, Jiangyu

    2012-10-01

    Volatility series (defined as the magnitude of the increments between successive elements) of five different meteorological variables over China are analyzed by means of detrended fluctuation analysis (DFA for short). Universal scaling behaviors are found in all volatility records, whose scaling exponents take similar distributions with similar mean values and standard deviations. To reconfirm the relation between long-range correlations in volatility and nonlinearity in original series, DFA is also applied to the magnitude records (defined as the absolute values of the original records). The results clearly indicate that the nonlinearity of the original series is more pronounced in the magnitude series.

  6. Role of Non-Volatile Memories in Automotive and IoT Markets

    Science.gov (United States)

    2017-03-01

    Standard Manufacturing Supply Long Term Short to Medium Term Density Up to 16MB Up to 2MB IO Configuration Up to x128 Up to x32 Design for Test...Role of Non-Volatile Memories in Automotive and IoT Markets Vipin Tiwari Director, Business Development and Product Marketing SST – A Wholly Own...microcontrollers (MCU) and certainly one of the most challenging elements to master. This paper addresses the role of non-volatile memories for

  7. Volatility Spillovers Across Petroleum Markets

    Czech Academy of Sciences Publication Activity Database

    Baruník, Jozef; Kočenda, Evžen; Vácha, Lukáš

    2015-01-01

    Roč. 36, č. 3 (2015), s. 309-329 ISSN 0195-6574 R&D Projects: GA ČR GA14-24129S Keywords : Volatility spillovers * Asymmetry * Petroleum markets Subject RIV: AH - Economics Impact factor: 1.662, year: 2015 http://library.utia.cas.cz/separaty/2014/E/barunik-0438407.pdf

  8. Stochastic Volatility and DSGE Models

    DEFF Research Database (Denmark)

    Andreasen, Martin Møller

    This paper argues that a specification of stochastic volatility commonly used to analyze the Great Moderation in DSGE models may not be appropriate, because the level of a process with this specification does not have conditional or unconditional moments. This is unfortunate because agents may...

  9. Characterisation of selected volatile organic compounds in ...

    African Journals Online (AJOL)

    GCMS), was used to identify volatile compounds at three different temperatures. Fifty volatile compounds, inclusive of 14 acids, 14 alcohols, and 22 esters were identified and quantified in the two brands of indigenous banana beer samples. Only 12 ...

  10. Time-Varying Periodicity in Intraday Volatility

    DEFF Research Database (Denmark)

    Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor

    We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...

  11. A Fractionally Integrated Wishart Stochastic Volatility Model

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2013-01-01

    textabstractThere has recently been growing interest in modeling and estimating alternative continuous time multivariate stochastic volatility models. We propose a continuous time fractionally integrated Wishart stochastic volatility (FIWSV) process. We derive the conditional Laplace transform of

  12. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    We present and test a model relating a firm's idiosyncratic cost, its exporting status, and the volatilities of its domestic and export sales. In prior models of trade, supply costs for domestic and exports were linear and thus additively separable. We introduce a nonlinear cost function in order...... to link the domestic and export supply costs. This theoretical contribution has two new implications for the exporting firm. First, the demand volatility in the foreign market now directly affects the firm's domestic sales volatility. Second, firms hedge domestic demand volatility with exports. The model...... has several testable predictions. First, larger firms have lower total and domestic sales volatilities. Second, foreign market volatility increases domestic sales volatilities for exporters. Third, exporters allocate output across both markets in order to reduce total sales volatility. We find...

  13. Fluctuation behaviors of financial return volatility duration

    Science.gov (United States)

    Niu, Hongli; Wang, Jun; Lu, Yunfan

    2016-04-01

    It is of significantly crucial to understand the return volatility of financial markets because it helps to quantify the investment risk, optimize the portfolio, and provide a key input of option pricing models. The characteristics of isolated high volatility events above certain threshold in price fluctuations and the distributions of return intervals between these events arouse great interest in financial research. In the present work, we introduce a new concept of daily return volatility duration, which is defined as the shortest passage time when the future volatility intensity is above or below the current volatility intensity (without predefining a threshold). The statistical properties of the daily return volatility durations for seven representative stock indices from the world financial markets are investigated. Some useful and interesting empirical results of these volatility duration series about the probability distributions, memory effects and multifractal properties are obtained. These results also show that the proposed stock volatility series analysis is a meaningful and beneficial trial.

  14. Pyrolysis and volatilization of cocaine

    International Nuclear Information System (INIS)

    Martin, B.R.; Lue, L.P.; Boni, J.P.

    1989-01-01

    The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time

  15. Trace element analysis in soy sauce

    International Nuclear Information System (INIS)

    Haruyama, Yoichi; Saito, Manabu; Tomiya, Michio

    1993-01-01

    Trace elements in soy sauce have been measured by means of in-air PIXE. Six kinds of trace elements were detected, such as Mn, Fe, Ni, Zn, Cu and Br. Concentrations of Mn, Fe, Zn and Br which were observed in all samples, have been determined. Each analyzed sample contained considerable amount of Br about 160 ppm. Comparison of Br content of the imported raw materials with those of the domestic ones suggested that the large amount of Br was the residual fumigation chemicals in the imported raw materials. (author)

  16. A nonparametric approach to forecasting realized volatility

    OpenAIRE

    Adam Clements; Ralf Becker

    2009-01-01

    A well developed literature exists in relation to modeling and forecasting asset return volatility. Much of this relate to the development of time series models of volatility. This paper proposes an alternative method for forecasting volatility that does not involve such a model. Under this approach a forecast is a weighted average of historical volatility. The greatest weight is given to periods that exhibit the most similar market conditions to the time at which the forecast is being formed...

  17. Volatilization and reaction of fission products in flowing steam

    International Nuclear Information System (INIS)

    Johnson, I.; Steidl, D.V.; Johnson, C.E.

    1985-01-01

    The principal risk to the public from nuclear power plants derives from the highly radioactive atoms (fission products) generated as energy is produced in the nuclear fuel. The revolatilization of fission products from reactor system surfaces due to self-heating by radioactive decay has become a complicating factor in the source-term redefinition effort. It has had a major impact on calculations of fission product distributions in accident safety analyses. The focus of this research effort was to investigate the volatilization and transport of fission products and control rod materials in a flowing gaseous steam-hydrogen mixture. Fission product and control rod materials in various combinations were studied including CsI, CsOH, TeO 2 , SrO, Ag, In, Cd and Mn. The vaporization behavior of the deposits were characterized with respect to vaporization rates, chemical species and downstream transport behavior

  18. Gas phase chromatography of halides of elements 104 and 105

    International Nuclear Information System (INIS)

    Tuerler, A.; Gregorich, K.E.; Czerwinski, K.R.; Hannink, N.J.; Henderson, R.A.; Hoffman, D.C.; Kacher, C.D.; Kadkhodayan, B.; Kreek, S.A.; Lee, D.M.; Leyba, J.D.; Nurmia, M.J.; Gaeggeler, H.W.; Jost, D.T.; Kovacs, J.; Scherer, U.W.; Vermeulen, D.; Weber, A.; Barth, H.; Gober, M.K.; Kratz, J.V.; Bruechle, W.; Schaedel, M.; Schimpf, E.; Gober, M.K.; Kratz, J.V.; Zimmermann, H.P.

    1991-04-01

    On-line isothermal gas phase chromatography was used to study halides of 261 104 (T 1/2 = 65 s) and 262,263 105 (T 1/2 = 34 s and 27 s) produced an atom-at-a time via the reactions 248 Cm( 18 O, 5n) and 249 Bk( 18 O, 5n, 4n), respectively. Using HBr and HCl gas as halogenating agents, we were able to produce volatile bromides and chlorides of the above mentioned elements and study their behavior compared to their lighter homologs in Groups 4 or 5 of the periodic table. Element 104 formed more volatile bromides than its homolog Hf. In contrast, element 105 bromides were found to be less volatile than the bromides of the group 5 elements Nb and Ta. Both 104 and Hf chlorides were observed to be more volatile than their respective bromides. 31 refs., 8 figs

  19. Boron-doped MnO{sub 2}/carbon fiber composite electrode for supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Hong Zhong, E-mail: hzchi@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Zhu, Hongjie [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Gao, Linhui [Center of Materials Engineering, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2015-10-05

    Highlights: • Interstitial ion in MnO{sub 2} lattice. • Porous film composed by interlocking worm-like nanostructure. • Boron-doped birnessite-type MnO{sub 2}/carbon fiber composite electrode. • Enhanced capacitive properties through nonmetal element doping. - Abstract: The boron-doped MnO{sub 2}/carbon fiber composite electrode has been prepared via in situ redox reaction between potassium permanganate and carbon fibers in the presence of boric acid. The addition of boron as dopant results in the increase of growth-rate of MnO{sub 2} crystal and the formation of worm-like nanostructure. Based on the analysis of binding energy, element boron incorporates into the MnO{sub 2} lattice through interstitial mode. The doped electrode with porous framework is beneficial to pseudocapacitive reaction and surface charge storage, leading to higher specific capacitance and superior rate capability. After experienced 1000 cycles, the boron-doped MnO{sub 2} still retain a higher specific capacitance by about 80% of its initial value. The fall in capacitance is blamed to be the combination of the formation of soluble Mn{sup 2+} and the absence of active site on the outer surface.

  20. Testing for Volatility Co-movement in Bivariate Stochastic Volatility Models

    NARCIS (Netherlands)

    J. Chen (Jinghui); M. Kobayashi (Masahito); M.J. McAleer (Michael)

    2017-01-01

    markdownabstractThe paper considers the problem of volatility co-movement, namely as to whether two financial returns have perfectly correlated common volatility process, in the framework of multivariate stochastic volatility models and proposes a test which checks the volatility co-movement. The

  1. Systematic study on surface and magnetostructural changes in Mn-substituted dysprosium ferrite by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Rekha, G. [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Tholkappiyan, R. [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Department of Physics, College of Science, UAE University, Al-Ain 15551 (United Arab Emirates); Vishista, K., E-mail: raovishista@gmail.com [Department of Physics, College of Engineering Guindy, Anna University, Sardar Patel Road, Chennai 600025 (India); Hamed, Fathalla [Department of Physics, College of Science, UAE University, Al-Ain 15551 (United Arab Emirates)

    2016-11-01

    Highlights: • Garnet type Dy{sub 3}Fe{sub 5-x}Mn{sub x}O{sub 12} (x = 0–0.06) nanoparticles of 88.4–86.8 nm were synthesized by hydrothermal method. • The Dy, Mn, Fe and O elements in the ferrites were confirmed from XPS. • The multiple oxidation states of Fe and Mn ions, bonding energy and cationic distributions of the samples were examined by XPS. • The magnetic property shows ferromagnetic behavior from VSM technique. • The results from these studies are correlated with respect to Mn dopant. - Abstract: Dysprosium iron garnets are of scientific importance because of the wide range of magnetic properties that can be obtained in substituting dysprosium by a rare earth metal. In the present work, the effect of Mn substitution on magnetostructural changes in dysprosium ferrite nanoparticles is studied. Highly crystalline pure and Mn doped dysprosium ferrite nanoparticles were synthesized by hydrothermal method. The samples were calcined at 1100 °C for 2 h in air atmosphere which is followed by characterization using XRD, FT-IR analysis, SEM, XPS and VSM. The average crystallite size of synthesized samples were calculated by X-ray diffraction falls in the range of 88.4–86.8 nm and was found to be in cubic garnet structure. For further investigation of the structure and corresponding changes in the tetrahedral and octahedral stretching vibrational bonds, FT-IR was used. The synthesized samples consist of multiple oxidation (Fe{sup 3+} and Fe{sup 2+}) states for Fe ions and (Mn{sup 3+} and Mn{sup 2+}) Mn ions analyzed in three ways of Fe 2p and Mn 2p spectra from the XPS analysis. With respect to Mn dopant in Dy{sub 3}Fe{sub 5}O{sub 12}, the cationic distributions of elements were discussed from high resolution XPS spectra by peak position and shift, area, width. To find out the porous/void surface morphology of the sample, scanning electron microscopy was used. From XPS analysis, the presence of elements (Dy, Mn, Fe and O) and their composition in the

  2. Oil Volatility Risk and Expected Stock Returns

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Pan, Xuhui (Nick)

    return between the quintile of stocks with low exposure and high exposure to oil volatility is significant at 0.66% per month, and oil volatility risk carries a significant risk premium of -0.60% per month. In the post-financialization period, oil volatility risk is strongly related with various measures...

  3. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...

  4. Sources of Magmatic Volatiles Discharging from Subduction Zone Volcanoes

    Science.gov (United States)

    Fischer, T.

    2001-05-01

    Subduction zones are locations of extensive element transfer from the Earth's mantle to the atmosphere and hydrosphere. This element transfer is significant because it can, in some fashion, instigate melt production in the mantle wedge. Aqueous fluids are thought to be the major agent of element transfer during the subduction zone process. Volatile discharges from passively degassing subduction zone volcanoes should in principle, provide some information on the ultimate source of magmatic volatiles in terms of the mantle, the crust and the subducting slab. The overall flux of volatiles from degassing volcanoes should be balanced by the amount of volatiles released from the mantle wedge, the slab and the crust. Kudryavy Volcano, Kurile Islands, has been passively degassing at 900C fumarole temperatures for at least 40 years. Extensive gas sampling at this basaltic andesite cone and application of CO2/3He, N2/3He systematics in combination with C and N- isotopes indicates that 80% of the CO2 and approximately 60% of the N 2 are contributed from a sedimentary source. The mantle wedge contribution for both volatiles is, with 12% and 17% less significant. Direct volatile flux measurements from the volcano using the COSPEC technique in combination with direct gas sampling allows for the calculation of the 3He flux from the volcano. Since 3He is mainly released from the astenospheric mantle, the amount of mantle supplying the 3He flux can be determined if initial He concentrations of the mantle melts are known. The non-mantle flux of CO2 and N2 can be calculated in similar fashion. The amount of non-mantle CO2 and N2 discharging from Kudryavy is balanced by the amount of CO2 and N2 subducted below Kudryavy assuming a zone of melting constrained by the average spacing of the volcanoes along the Kurile arc. The volatile budget for Kudryavy is balanced because the volatile flux from the volcano is relatively small (75 t/day (416 Mmol/a) SO2, 360 Mmol/a of non-mantle CO2 and

  5. Exchange anisotropy and micromagnetic properties of PtMn/NiFe bilayers

    International Nuclear Information System (INIS)

    Pokhil, Taras; Linville, Eric; Mao, Sining

    2001-01-01

    Magnetic microstructure, exchange induced uniaxial and unidirectional anisotropy and structural transformation have been studied in PtMn/NiFe bilayer films and small elements as a function of annealing time. The relationship between the fcc-fct ordering phase transformation in PtMn and the development of exchange induced magnetic properties in PtMn/NiFe bilayers is complicated by the fact that the transformation occurs throughout the entire volume of the PtMn film, while the exchange between the layers is predominantly an interface effect. Consequently, the development of the exchange anisotropy should depend primarily on the character of the structural transformation at the interface between PtMn and NiFe. The purpose of this article is to correlate the volume phase transformation in PtMn to the development of exchange anisotropy and micromagnetic behavior in PtMn/NiFe bilayers. The interface structure can be inferred from the anisotropy and micromagnetic measurements, leading to a model that explains the relationship between the volume and interface transformation structures in PtMn, and magnetic properties of the bilayers. The structure and magnetic properties were characterized by x-ray diffraction, vibrating sample magnetometry, and magnetic force microscopy. [copyright] 2001 American Institute of Physics

  6. Four-state non-volatile memory in a multiferroic spin filter tunnel junction

    Science.gov (United States)

    Ruan, Jieji; Li, Chen; Yuan, Zhoushen; Wang, Peng; Li, Aidong; Wu, Di

    2016-12-01

    We report a spin filter type multiferroic tunnel junction with a ferromagnetic/ferroelectric bilayer barrier. Memory functions of a spin filter magnetic tunnel junction and a ferroelectric tunnel junction are combined in this single device, producing four non-volatile resistive states that can be read out in a non-destructive manner. This concept is demonstrated in a LaNiO3/Pr0.8Ca0.2MnO3/BaTiO3/La0.7Sr0.3MnO3 all-oxide tunnel junction. The ferromagnetic insulator Pr0.8Ca0.2MnO3 serves as the spin filter and the ferromagnetic metal La0.7Sr0.3MnO3 is the spin analyzer. The ferroelectric polarization reversal in the BaTiO3 barrier switches the tunneling barrier height to produce a tunneling electroresistance. The ferroelectric switching also modulates the spin polarization and the spin filtering efficiency in Pr0.8Ca0.2MnO3.

  7. An experimental and thermodynamic equilibrium investigation of the Pb, Zn, Cr, Cu, Mn and Ni partitioning during sewage sludge incineration.

    Science.gov (United States)

    Liu, Jingyong; Fu, Jiewen; Ning, Xun'an; Sun, Shuiyu; Wang, Yujie; Xie, Wuming; Huang, Shaosong; Zhong, Sheng

    2015-09-01

    The effects of different chlorides and operational conditions on the distribution and speciation of six heavy metals (Pb, Zn, Cr, Cu, Mn and Ni) during sludge incineration were investigated using a simulated laboratory tubular-furnace reactor. A thermodynamic equilibrium investigation using the FactSage software was performed to compare the experimental results. The results indicate that the volatility of the target metals was enhanced as the chlorine concentration increased. Inorganic-Cl influenced the volatilization of heavy metals in the order of Pb>Zn>Cr>Cu>Mn>Ni. However, the effects of organic-Cl on the volatility of Mn, Pb and Cu were greater than the effects on Zn, Cr and Ni. With increasing combustion temperature, the presence of organic-Cl (PVC) and inorganic-Cl (NaCl) improved the transfer of Pb and Zn from bottom ash to fly ash or fuse gas. However, the presence of chloride had no obvious influence on Mn, Cu and Ni. Increased retention time could increase the volatilization rate of heavy metals; however, this effect was insignificant. During the incineration process, Pb readily formed PbSiO4 and remained in the bottom ash. Different Pb compounds, primarily the volatile PbCl2, were found in the gas phase after the addition of NaCl; the dominant Pb compounds in the gas phase after the addition of PVC were PbCl2, Pb(ClO4)2 and PbCl2O4. Copyright © 2015. Published by Elsevier B.V.

  8. Local Structure of Mn in (La1-xHox)2/3Ca1/3MnO3 Studied by X-ray Absorption Fine Structure

    International Nuclear Information System (INIS)

    Pietnoczka, A.; Bacewicz, R.; Antonowicz, J.; Zalewski, W.; Pekala, M.; Drozd, V.; Fagnard, J.F.; Vanderbemden, P.

    2010-01-01

    Results of X-ray absorption fine structure measurements in manganites (La 1-x Ho x ) 2/3 Ca 1/3 MnO 3 with 0.15 3 is doped with a divalent element such as Ca 2+ , substituting for La 3+ , holes are induced in the filled Mn d orbitals. This leads to a strong ferromagnetic coupling between Mn sites. Ca ions in La 1-x Ca x MnO 3 introduce a distortion of the crystal lattice and mixed valence Mn ions (Mn 3+ and Mn 4+ ). On the other hand, in manganites (La 1-x Ho x ) 2/3 Ca 1/3 MnO 3 the substitution of La for Ho causes a lattice distortion and induces a disorder, which reduces a magnetic interaction. The ferromagnetic transition temperature and conductivity decrease very quickly with increasing x. The magnetic and transport properties of compounds depend on the local atomic structure around Mn ions. The information on the bond lengths and Debye-Waller factor are obtained from the extended X-ray absorption fine structure (EXAFS) data analysis. The charge state of Mn is determined from the position of the absorption edge in X-ray absorption near edge structure (XANES) data. XAFS results are in good agreement with magnetic characteristics of the studied materials. (authors)

  9. Galvanic element. Galvanisches Element

    Energy Technology Data Exchange (ETDEWEB)

    Sprengel, D.; Haelbig, H.

    1980-01-03

    The invention concerns a gas-tight sealed accumulator with positive and negative electrode plates and an auxillary electrode electroconductively bound to the latter for suppressing oxygen pressure. The auxillary electrode is an intermediate film electrode. The film catalysing oxygen reduction is hydrophilic in character and the other film is hydrophobic. A double coated foil has proved to be advantageous, the hydrophilic film being formed from polymer-bound activated carbon and the hydrophrobic film from porous polytetrafluoroethylene. A metallic network of silver or nickel is rolled into the outer side of the activated carbon film. This auxillary electrode can be used to advantage in all galvanic elements. Even primary cells fall within the scope of application for auxillary electrodes because many of these contain a highly oxidized electrodic material which tends to give off oxygen.

  10. Phase relations in the pseudobinary systems RAO3-R2Ti2O7 (R: rare earth element and Y, A: Fe, Ga, Al, Cr and Mn) and syntheses of new compounds R(A1-xTix)O3+x/2 (2/3≤x≤3/4) at elevated temperatures in air

    Science.gov (United States)

    Brown, Francisco; Jacobo-Herrera, Ivan; Alvarez-Montaño, Victor; Kimizuka, Noboru; Kurashina, Keiji; Michiue, Yuichi; Matsuo, Yoji; Mori, Shigeo; Ikeda, Naoshi; Medrano, Felipe

    2017-07-01

    Phase relations in the pseudo-binary systems RFeO3-R2Ti2O7 (R: Lu, Ho and Dy), RGaO3-R2Ti2O7 (R: Lu and Er), LuAlO3-Lu2Ti2O7 and RAO3-R2Ti2O7 (R: Lu and Yb. A: Cr and Mn) at elevated temperatures in air were determined by means of a classic quenching method. There exist Lu(Fe1-xTix)O3+x/2, R(Ga1-xTix)O3+x/2 (R: Lu and Er) and Lu(Al1-xTix)O3+x/2 (2/3≤ x≤3/4) having the Yb(Fe1-xTix)O3+x/2-type of crystal structure (x=0.72, space group: R3m, a(Å)=17.9773 and c(Å)=16.978 as a hexagonal setting) in these pseudo binary systems. Eighteen compounds R(A1-xTix)O3+x/2 (R: Lu-Sm and Y, A: Fe, Ga and Al) were newly synthesized and their lattice constants as a hexagonal setting were measured by means of the X-ray powder diffraction method. The R occupies the octahedral site and both A and Ti does the trigonalbipyramidal one in these compounds. Relation between lattice constants for the rhombic R(A1-xTix)O3+x/2 and the monoclinic In(A1-xTix)O3+x/2 are as follows, ah≈5 x bm, ch≈3 x cm x sin β and am=31/2 x bm, where ah and ch are the lattice constants as a hexagonal setting for R(A1-xTix)O3+x/2 and am, bm, cm and β are those of the monoclinic In(A1-xTix)O3+x/2. Crystal structural relationships among α-InGaO3 (hexagonal, high pressure form, space group: P63/mmc), InGaO3 (rhombic, hypothetical), (RAO3)n(BO)m and RAO3(ZnO)m (R: Lu-Ho, Y and In, A: Fe, Ga, and Al, B: divalent cation element, m, n: natural number), the orthorhombic-and monoclinic In(A1-xTix)O3+x/2 (A: Fe, Ga, Al, Cr and Mn) and the hexagonal-and rhombic R(A1-xTix)O3+x/2 (R: Lu-Sm and Y, A: Fe, Ga and Al) are schematically presented. We concluded that the crystal structures of both the α-InGaO3 (high pressure form, hexagonal, space group: P63/mmc) and the hypothetical InGaO3 (rhombic) are the key structures for constructing the crystal structures of these compounds having the cations with CN=5.

  11. Money growth volatility and the demand for money in Germany: Friedman's volatility hypothesis revisited

    OpenAIRE

    Brüggemann, Imke; Nautz, Dieter

    1997-01-01

    Recently, the Bundesbank claimed that monetary targeting has become considerably more diffcult by the increased volatility of short-term money growth. The present paper investigates the impact of German money growth volatility on income velocity and money demand in view of Friedman's money growth volatility hypothesis. Granger-causality tests provide some evidence for a velocity-volatility linkage. However the estimation of volatility-augmented money demand functions reveals that - in contras...

  12. Impact of microorganism on polonium volatilization

    International Nuclear Information System (INIS)

    Momoshima, N.; Ishida, A.; Fukuda, A.; Yoshinaga, C.

    2007-01-01

    Volatilization of polonium by microorganisms, Chromobacterium violaceum, Escherichia coli and Bacillus subtilis was examined for pure cultures in LB medium at 30 deg C, showing relative Po emission intensity 100, 10 and 1, respectively. Chromobacterium violaceum pre-cultured in LB medium without Po and suspended in water with Po showed high Po volatilization in spite of poor nutriment condition. Antibiotics inhibit volatilization of Po and cultivation at low temperature greatly reduced volatilization. The results strongly support the biological effects on Po volatilization. (author)

  13. Visualizing elemental deposition patterns on carbonaceous anodes from lithium ion batteries: A laser ablation-inductively coupled plasma-mass spectrometry study on factors influencing the deposition of lithium, nickel, manganese and cobalt after dissolution and migration from the Li1[Ni1/3Mn1/3Co1/3]O2 and LiMn1.5 Ni0.5O4 cathode

    Science.gov (United States)

    Schwieters, Timo; Evertz, Marco; Fengler, Alexander; Börner, Markus; Dagger, Tim; Stenzel, Yannick; Harte, Patrick; Winter, Martin; Nowak, Sascha

    2018-03-01

    In this study, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is applied to previously aged carbonaceous anodes from lithium ion batteries (LIBs). These electrodes are treated by cyclic aging in a lithium ion cell set-up against Li1[Ni1/3Mn 1/3Co1/3]O2 = NMC111 to elucidate factors that influence transition metal dissolution (TMD) of the cathode and subsequent deposition on the anode. The investigations are carried out by qualitatively visualizing the 7Li and TM patterns (60Ni, 55Mn and 59Co) of whole coin and pouch-bag electrodes. The lithium, as well as the TM amount, found on the anode, is directly correlated to the applied upper cut-off voltage (4.6, 4.7, 4.8 and 4.9 V) showing more deposition of Li and TMs at elevated voltages. While 7Li shows a more homogeneous pattern, the TM distribution is inhomogeneous but showing a similar pattern for all TMs of the same sample. An unequal pressure distribution, resulting in a nonparallel electrode alignment, on the electrode stack is identified to be responsible for the inhomogeneous TM deposition pattern. This uneven electrode orientation results in different diffusion pathways for the TM migration with regard to the spatial distances.

  14. Volatile constituents of Trichothecium roseum.

    Science.gov (United States)

    Vanhaelen, M; Vanhaelen-Fastre, R; Geeraerts, J

    1978-06-01

    In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.

  15. Chirospecific analysis of plant volatiles

    International Nuclear Information System (INIS)

    Tkachev, A V

    2007-01-01

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  16. Chirospecific analysis of plant volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Tkachev, A V [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-10-31

    Characteristic features of the analysis of plant volatiles by enantioselective gas (gas-liquid) chromatography and gas chromatography/mass spectrometry are discussed. The most recent advances in the design of enantioselective stationary phases are surveyed. Examples of the preparation of the most efficient phases based on modified cyclodextrins are given. Current knowledge on the successful analytical resolution of different types of plant volatiles (aliphatic and aromatic compounds and mono-, sesqui- and diterpene derivatives) into optical antipodes is systematically described. Chiral stationary phases used for these purposes, temperature conditions and enantiomer separation factors are summarised. Examples of the enantiomeric resolution of fragrance compounds and components of plant extracts, wines and essential oils are given.

  17. Forecasting volatility of crude oil markets

    International Nuclear Information System (INIS)

    Kang, Sang Hoon; Kang, Sang-Mok; Yoon, Seong-Min

    2009-01-01

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  18. Forecasting volatility of crude oil markets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sang Hoon [Department of Business Administration, Gyeongsang National University, Jinju, 660-701 (Korea); Kang, Sang-Mok; Yoon, Seong-Min [Department of Economics, Pusan National University, Busan, 609-735 (Korea)

    2009-01-15

    This article investigates the efficacy of a volatility model for three crude oil markets - Brent, Dubai, and West Texas Intermediate (WTI) - with regard to its ability to forecast and identify volatility stylized facts, in particular volatility persistence or long memory. In this context, we assess persistence in the volatility of the three crude oil prices using conditional volatility models. The CGARCH and FIGARCH models are better equipped to capture persistence than are the GARCH and IGARCH models. The CGARCH and FIGARCH models also provide superior performance in out-of-sample volatility forecasts. We conclude that the CGARCH and FIGARCH models are useful for modeling and forecasting persistence in the volatility of crude oil prices. (author)

  19. Money, banks and endogenous volatility

    OpenAIRE

    Pere Gomis-Porqueras

    2000-01-01

    In this paper I consider a monetary growth model in which banks provide liquidity, and the government fixes a constant rate of money creation. There are two underlying assets in the economy, money and capital. Money is dominated in rate of return. In contrast to other papers with a larger set of government liabilities, I find a unique equilibrium when agents' risk aversion is moderate. However, indeterminacies and endogenous volatility can be observed when agents are relatively risk averse.

  20. Forecasting volatility for options valuation

    International Nuclear Information System (INIS)

    Belaifa, M.; Morimune, K.

    2006-01-01

    The petroleum sector plays a neuralgic role in the basement of world economies, and market actors (producers, intermediates, as well as consumers) are continuously subjected to the dynamics of unstable oil market. Huge amounts are being invested along the production chain to make one barrel of crude oil available to the end user. Adding to that are the effect of geopolitical dynamics as well as geological risks as expressed in terms of low chances of successful discoveries. In addition, fiscal regimes and regulations, technology and environmental concerns are also among some of the major factors that contribute to the substantial risk in the oil industry and render the market structure vulnerable to crises. The management of these vulnerabilities require modern tools to reduce risk to a certain level, which unfortunately is a non-zero value. The aim of this paper is, therefore, to provide a modern technique to capture the oil price stochastic volatility that can be implemented to value the exposure of an investor, a company, a corporate or a Government. The paper first analyses the regional dependence on oil prices, through a historical perspective and then looks at the evolution of pricing environment since the large price jumps of the 1970s. The main causes of oil prices volatility are treated in the third part of the paper. The rest of the article deals with volatility models and forecasts used in risk management, with an implication for pricing derivatives. (author)

  1. Human skin volatiles: a review.

    Science.gov (United States)

    Dormont, Laurent; Bessière, Jean-Marie; Cohuet, Anna

    2013-05-01

    Odors emitted by human skin are of great interest to biologists in many fields; applications range from forensic studies to diagnostic tools, the design of perfumes and deodorants, and the ecology of blood-sucking insect vectors of human disease. Numerous studies have investigated the chemical composition of skin odors, and various sampling methods have been used for this purpose. The literature shows that the chemical profile of skin volatiles varies greatly among studies, and the use of different sampling procedures is probably responsible for some of these variations. To our knowledge, this is the first review focused on human skin volatile compounds. We detail the different sampling techniques, each with its own set of advantages and disadvantages, which have been used for the collection of skin odors from different parts of the human body. We present the main skin volatile compounds found in these studies, with particular emphasis on the most frequently studied body regions, axillae, hands, and feet. We propose future directions for promising experimental studies on odors from human skin, particularly in relation to the chemical ecology of blood-sucking insects.

  2. Volatilization of gasoline from soil

    International Nuclear Information System (INIS)

    Arthus, P.

    1993-05-01

    Gasoline contaminated soil threatens water resources and air quality. The extent of the threat depends on gasoline behavior in soil, which is affected by various mechanisms such as volatilization. To quantify volatilization, gasoline spills were simulated in the laboratory using a synthetic gasoline and three dry soils. Total gasoline and individual gasoline compound concentrations in soil were monitored as a function of depth and time. The time to reduce overall gasoline concentration in coarse sand, sandy loam, and silt loam to 40% of initial concentration, averaged between surface and a 200-mm depth, ranged from 0.25 d to 10 d. A wicking phenomenon which contributed to gasoline flux toward the atmosphere was indicated by behavior of a low-volatility gasoline compound. Based on separate wicking experiments, this bulk immiscible movement was estimated at an upward velocity of 0.09 m/d for Delhi sandy loam and 0.05 m/d for Elora silt loam. 70 refs., 24 figs., 34 tabs

  3. Calix[4]arene supported clusters: a dimer of [Mn(III)Mn(II)] dimers

    DEFF Research Database (Denmark)

    Taylor, Stephanie M; McIntosh, Ruaraidh D; Beavers, Christine M

    2011-01-01

    Phosphinate ligands allow for the transformation of a calix[4]arene supported [Mn(III)(2)Mn(II)(2)] tetramer cluster motif into an unusual [Mn(III)Mn(II)](2) dimer of dimers; the clusters self-assemble in the crystal to form bi-layer arrays reminiscent of the typical packing of calixarene solvates....

  4. Influence of Mn-Co Spinel Coating on Oxidation Behavior of Ferritic SS Alloys for SOFC Interconnect Applications

    DEFF Research Database (Denmark)

    Venkatachalam, Vinothini; Molin, Sebastian; Kiebach, Wolff-Ragnar

    2014-01-01

    Chromia forming ferritic stainless steels (SS) are being considered for intermediate temperature solid oxide fuel cell interconnect applications. However, protective coatings are in general needed to avoid chromium volatilization and poisoning of cathodes from chromium species. Mn-Co spinel is one...... of the promising candidates to prevent chromium outward diffusion, improve oxidation resistance and ensure high electrical conductivity over the lifetime of interconnects. In the present study, uniform and well adherent Mn-Co spinel coatings were produced on Crofer 22APU using electrophoretic deposition (EPD...

  5. Engineering helimagnetism in MnSi thin films

    Science.gov (United States)

    Zhang, S. L.; Chalasani, R.; Baker, A. A.; Steinke, N.-J.; Figueroa, A. I.; Kohn, A.; van der Laan, G.; Hesjedal, T.

    2016-01-01

    Magnetic skyrmion materials have the great advantage of a robust topological magnetic structure, which makes them stable against the superparamagnetic effect and therefore a candidate for the next-generation of spintronic memory devices. Bulk MnSi, with an ordering temperature of 29.5 K, is a typical skyrmion system with a propagation vector periodicity of ˜18 nm. One crucial prerequisite for any kind of application, however, is the observation and precise control of skyrmions in thin films at room-temperature. Strain in epitaxial MnSi thin films is known to raise the transition temperature to 43 K. Here we show, using magnetometry and x-ray spectroscopy, that the transition temperature can be raised further through proximity coupling to a ferromagnetic layer. Similarly, the external field required to stabilize the helimagnetic phase is lowered. Transmission electron microscopy with element-sensitive detection is used to explore the structural origin of ferromagnetism in these Mn-doped substrates. Our work suggests that an artificial pinning layer, not limited to the MnSi/Si system, may enable room temperature, zero-field skyrmion thin-film systems, thereby opening the door to device applications.

  6. Engineering helimagnetism in MnSi thin films

    Directory of Open Access Journals (Sweden)

    S. L. Zhang

    2016-01-01

    Full Text Available Magnetic skyrmion materials have the great advantage of a robust topological magnetic structure, which makes them stable against the superparamagnetic effect and therefore a candidate for the next-generation of spintronic memory devices. Bulk MnSi, with an ordering temperature of 29.5 K, is a typical skyrmion system with a propagation vector periodicity of ∼18 nm. One crucial prerequisite for any kind of application, however, is the observation and precise control of skyrmions in thin films at room-temperature. Strain in epitaxial MnSi thin films is known to raise the transition temperature to 43 K. Here we show, using magnetometry and x-ray spectroscopy, that the transition temperature can be raised further through proximity coupling to a ferromagnetic layer. Similarly, the external field required to stabilize the helimagnetic phase is lowered. Transmission electron microscopy with element-sensitive detection is used to explore the structural origin of ferromagnetism in these Mn-doped substrates. Our work suggests that an artificial pinning layer, not limited to the MnSi/Si system, may enable room temperature, zero-field skyrmion thin-film systems, thereby opening the door to device applications.

  7. Engineering helimagnetism in MnSi thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. L.; Hesjedal, T., E-mail: Thorsten.Hesjedal@physics.ox.ac.uk [Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU (United Kingdom); Chalasani, R.; Kohn, A. [Department of Materials Science and Engineering, Tel Aviv University, Ramat Aviv 6997801, Tel Aviv (Israel); Baker, A. A. [Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, OX1 3PU (United Kingdom); Magnetic Spectroscopy Group, Diamond Light Source, Didcot, OX11 0DE (United Kingdom); Steinke, N.-J. [ISIS, Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0QX (United Kingdom); Figueroa, A. I.; Laan, G. van der [Magnetic Spectroscopy Group, Diamond Light Source, Didcot, OX11 0DE (United Kingdom)

    2016-01-15

    Magnetic skyrmion materials have the great advantage of a robust topological magnetic structure, which makes them stable against the superparamagnetic effect and therefore a candidate for the next-generation of spintronic memory devices. Bulk MnSi, with an ordering temperature of 29.5 K, is a typical skyrmion system with a propagation vector periodicity of ∼18 nm. One crucial prerequisite for any kind of application, however, is the observation and precise control of skyrmions in thin films at room-temperature. Strain in epitaxial MnSi thin films is known to raise the transition temperature to 43 K. Here we show, using magnetometry and x-ray spectroscopy, that the transition temperature can be raised further through proximity coupling to a ferromagnetic layer. Similarly, the external field required to stabilize the helimagnetic phase is lowered. Transmission electron microscopy with element-sensitive detection is used to explore the structural origin of ferromagnetism in these Mn-doped substrates. Our work suggests that an artificial pinning layer, not limited to the MnSi/Si system, may enable room temperature, zero-field skyrmion thin-film systems, thereby opening the door to device applications.

  8. Accumulation of Heavy Metals in Ricinus communis L. from Mn Contaminated Area

    Directory of Open Access Journals (Sweden)

    YI Xin-yu

    2014-02-01

    Full Text Available Xiangbi No. 1 and Zibi No. 7 were planted in the Mn contaminated soils to explore its potential of ecological remediation and ener-gy utilization in the areas of Mn contaminated site. The major nutrient elements and the concentrations of heavy metals(Mn, Pb, Zn, Cu and Cr in different parts(root, branch and leaf and topsoil samples were detected after entering into the period of reproductive growth.The results showed that the average content of Mn was as high as 7 884.96 mg·kg-1,which exceeded 6.5 times of national soil environmental quality standard(level 2.The mean level of Mn in tissues of Xiangbi No. 1 was found to be in the sequence of root>leaf>branch,whereas,the mean level of Mn in different parts of Zibi No. 7 was found to be in the order of leaf>fruit>branchroot respectively. The average concentration of Mn in the leaf reached the peak value(765.43 mg·kg-1,which was higher than Xiangbi No.1 about 79.53%.The leaf/root ratios of Pb, Cu, Cr contents in Zibi No. 7 were higher than those of Xiangbi No. 1 samples.The accumulation and translocation in plants was affect-ed by different heavy metal elements in soils.The results demonstrated that Zibi No. 7 had a better uptake and translocation capacity of Mn,Pb,Cu and Cr, meanwhile,plants of two species had differences in accumulation and translocation ability and were proved to possess good Mn-tolerance ability for remediation of heavy metal contaminated soils.

  9. Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

    Science.gov (United States)

    Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

    2017-04-01

    Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Identification of the interstitial Mn site in ferromagnetic (Ga,Mn)As

    CERN Document Server

    AUTHOR|(CDS)2093111; Wahl, Ulrich; Augustyns, Valerie; Silva, Daniel; Granadeiro Costa, Angelo Rafael; Houben, K; Edmonds, Kevin W; Gallagher, BL; Campion, RP; Van Bael, MJ; Castro Ribeiro Da Silva, Manuel; Martins Correia, Joao; Esteves De Araujo, Araujo Joao Pedro; Temst, Kristiaan; Vantomme, André; Da Costa Pereira, Lino Miguel

    2015-01-01

    We determined the lattice location of Mn in ferromagnetic (Ga,Mn)As using the electron emission channeling technique. We show that interstitial Mn occupies the tetrahedral site with As nearest neighbors (TAs) both before and after thermal annealing at 200 °C, whereas the occupancy of the tetrahedral site with Ga nearest neighbors (TGa) is negligible. TAs is therefore the energetically favorable site for interstitial Mn in isolated form as well as when forming complexes with substitutional Mn. These results shed new light on the long standing controversy regarding TAs versus TGa occupancy of interstitial Mn in (Ga,Mn)As.

  11. Hot char-catalytic reforming of volatiles from MSW pyrolysis

    International Nuclear Information System (INIS)

    Wang, Na; Chen, Dezhen; Arena, Umberto; He, Pinjing

    2017-01-01

    Highlights: • Volatile from MSW pyrolysis is reformed with hot char from the same pyrolysis process. • The yields of syngas increase evidently with H 2 being the main contributor and the major component of the syngas. • Pyrolysis oil becomes light and its composition distribution is narrowed. • The HHV, volatile elements and alkali metals contents in the char decrease. • The emissions including SO 2 , NO, NO 2 and HCN changed after reforming process. - Abstract: Volatile products obtained from pyrolysis of municipal solid waste (MSW), including syngas and pyrolysis oil, were forced to contact the hot char from the same pyrolysis process at 500–600 °C in a fixed bed reactor to be reformed. The yields and properties of syngas, char and pyrolysis liquid were investigated; and the energy re-distribution among the products due to char reforming was quantified. The preliminary investigation at lab scale showed that hot char-catalytic reforming of the volatiles leads to an increase in the dry syngas yield from 0.25 to 0.37 N m 3 kg −1 MSW at 550 °C. Accordingly, the carbon conversion ratio into syngas increases from 29.6% to 35.0%; and the MSW chemical energy transferred into syngas increased from 41.8% to 47.4%. The yield of pyrolysis liquid products, including pyrolysis oil and water, decreased from 27.3 to 16.5 wt%, and the molecular weight of the oil becoming lighter. Approximately 60% of the water vapour contained in the volatiles converted into syngas. After reforming, the concentrations of SO 2 and HCN in the syngas decreases, while those of NO and NO 2 increase. The char concentrations of N, H, C and alkali metal species decreased and its higher heating value decreased too.

  12. Measurements of non-volatile aerosols with a VTDMA and their correlations with carbonaceous aerosols in Guangzhou, China

    Directory of Open Access Journals (Sweden)

    H. H. Y. Cheung

    2016-07-01

    Full Text Available Simultaneous measurements of aerosol volatility and carbonaceous matters were conducted at a suburban site in Guangzhou, China, in February and March 2014 using a volatility tandem differential mobility analyzer (VTDMA and an organic carbon/elemental carbon (OC ∕ EC analyzer. Low volatility (LV particles, with a volatility shrink factor (VSF at 300 °C exceeding 0.9, contributed 5 % of number concentrations of the 40 nm particles and 11–15 % of the 80–300 nm particles. They were composed of non-volatile material externally mixed with volatile material, and therefore did not evaporate significantly at 300 °C. Non-volatile material mixed internally with the volatile material was referred to as medium volatility (MV, 0.4  <  VSF  <  0.9 and high volatility (HV, VSF  <  0.4 particles. The MV and HV particles contributed 57–71 % of number concentration for the particles between 40 and 300 nm in size. The average EC and OC concentrations measured by the OC ∕ EC analyzer were 3.4 ± 3.0 and 9.0 ± 6.0 µg m−3, respectively. Non-volatile OC evaporating at 475 °C or above, together with EC, contributed 67 % of the total carbon mass. In spite of the daily maximum and minimum, the diurnal variations in the volume fractions of the volatile material, HV, MV and LV residuals were less than 15 % for the 80–300 nm particles. Back trajectory analysis also suggests that over 90 % of the air masses influencing the sampling site were well aged as they were transported at low altitudes (below 1500 m for over 40 h before arrival. Further comparison with the diurnal variations in the mass fractions of EC and the non-volatile OC in PM2.5 suggests that the non-volatile residuals may be related to both EC and non-volatile OC in the afternoon, during which the concentration of aged organics increased. A closure analysis of the total mass of LV and MV residuals and the mass of EC or the

  13. Method for refreshing a non-volatile memory

    Science.gov (United States)

    Riekels, James E.; Schlesinger, Samuel

    2008-11-04

    A non-volatile memory and a method of refreshing a memory are described. The method includes allowing an external system to control refreshing operations within the memory. The memory may generate a refresh request signal and transmit the refresh request signal to the external system. When the external system finds an available time to process the refresh request, the external system acknowledges the refresh request and transmits a refresh acknowledge signal to the memory. The memory may also comprise a page register for reading and rewriting a data state back to the memory. The page register may comprise latches in lieu of supplemental non-volatile storage elements, thereby conserving real estate within the memory.

  14. [Effect of vesicular-arbuscular mycorrhizal fungi on growth, nutrient uptake and synthesis of volatile oil in Schizonepeta tenuifolia briq].

    Science.gov (United States)

    Wei, G; Wang, H

    1991-03-01

    Inoculating Schizonepeta tenuifolia with VA mycorrhizal fungi can significantly improve the plant growth and uptake of P and S, and influence the absorption of K, Na, Fe, Mo, Mn, Zn, Co, Ba, Ni and Pb. It is interesting to note that VA mycorrhiza can also increase the synthesis of volatile oil in the shoots of S. tenuifolia. The efficiency of VA mycorrhiza varies with the fungal species.

  15. Stochastic volatility models and Kelvin waves

    Energy Technology Data Exchange (ETDEWEB)

    Lipton, Alex [Merrill Lynch, Mlfc Main, 2 King Edward Street, London EC1A 1HQ (United Kingdom); Sepp, Artur [Merrill Lynch, 4 World Financial Center, New York, NY 10080 (United States)], E-mail: Alex_Lipton@ml.com, E-mail: Artur_Sepp@ml.com

    2008-08-29

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  16. Stochastic volatility models and Kelvin waves

    Science.gov (United States)

    Lipton, Alex; Sepp, Artur

    2008-08-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  17. Stochastic volatility models and Kelvin waves

    International Nuclear Information System (INIS)

    Lipton, Alex; Sepp, Artur

    2008-01-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics

  18. Uncertainty of Volatility Estimates from Heston Greeks

    Directory of Open Access Journals (Sweden)

    Oliver Pfante

    2018-01-01

    Full Text Available Volatility is a widely recognized measure of market risk. As volatility is not observed it has to be estimated from market prices, i.e., as the implied volatility from option prices. The volatility index VIX making volatility a tradeable asset in its own right is computed from near- and next-term put and call options on the S&P 500 with more than 23 days and less than 37 days to expiration and non-vanishing bid. In the present paper we quantify the information content of the constituents of the VIX about the volatility of the S&P 500 in terms of the Fisher information matrix. Assuming that observed option prices are centered on the theoretical price provided by Heston's model perturbed by additive Gaussian noise we relate their Fisher information matrix to the Greeks in the Heston model. We find that the prices of options contained in the VIX basket allow for reliable estimates of the volatility of the S&P 500 with negligible uncertainty as long as volatility is large enough. Interestingly, if volatility drops below a critical value of roughly 3%, inferences from option prices become imprecise because Vega, the derivative of a European option w.r.t. volatility, and thereby the Fisher information nearly vanishes.

  19. Elemental Concentration of Inhalable and Respirable Particulate ...

    African Journals Online (AJOL)

    20537 and respirable foam for I.O.M sampler. The elemental composition (Co, Ni, Zn, Cu, Fe, Pb, Cr, Mn and Cd) were analyzed by using Atomic Absorption Spectrophotometric (AAS). The data generated were subjected to descriptive analysis. In inhalable fraction,the enrichment factor ranged from 1-73.3 while in respirable ...

  20. Atmospheric wet deposition of mercury and other trace elements in Pensacola, Florida

    Directory of Open Access Journals (Sweden)

    W. M. Landing

    2010-05-01

    Full Text Available In an effort to understand and quantify the impact of local, regional, and far-distant atmospheric mercury sources to rainfall mercury deposition in the Pensacola, Florida watershed, a program of event-based rainfall sampling was started in late 2004. Modified Aerochem-Metrics wet/dry rainfall samplers were deployed at three sites in the region around the Crist coal-fired power plant and event-based samples were collected continuously for three years. Samples were analyzed for total Hg and a suite of trace elements including Al, As, Ba, Bi, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, La, Li, Mg, Mn, Na, Nb, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Th, U, V, and Zn. Nutrients (ammonia and nitrate and major anions (chloride and sulfate were also measured on each sample. Multivariate statistical methods were used to sort these tracers into factors that represent potential source categories contributing to the rainfall chemistry. As, Hg, Sb, Se, Sn, and non sea-salt sulfate were all significantly correlated (R>0.6 with one factor which we interpret as an anthropogenic source term reflecting input from coal combustion throughout the southeastern US. Using ratios of total Hg to volatile elements, we estimate that 22–33% of the rainfall Hg results from coal combustion in the southeastern US with the majority coming from the global background.

  1. Tissue distribution, subcellular localization and endocrine disruption patterns induced by Cr and Mn in the crab Ucides cordatus

    International Nuclear Information System (INIS)

    Correa, Jose Dias; Ramos da Silva, Miguel; Bastos da Silva, Antonio Carlos; Araujo de Lima, Silene Maria; Malm, Olaf; Allodi, Silvana

    2005-01-01

    The essential trace elements Cr and Mn are toxic at high concentrations and information about low concentration is insufficient in the literature. In polluted mangroves, the crab Ucides cordatus can represent a useful tool to assess information on the potential impact of trace elements like Cr and Mn on the environment, since this species is comestible and thus, commercially negotiated. Therefore, U. cordatus crabs were exposed in vivo to different concentrations of Cr and Mn solved in seawater and had their tissue distribution and subcellular deposits evaluated. The gill, hepatopancreas and muscle concentrations were determined by atomic absorption spectroscopy and the results showed that Cr and Mn presented the highest values in the gills rather than in the hepatopancreas and muscular tissue. Electron microscopy and analytical X-ray microanalysis revealed Cr precipitates on the gill surface, co-localized with epiphyte bacteria. In addition, since Cr and Mn did not equally accumulate in most of the tissues studied, glycemic rate of animals, which received injections of extracts of eyestalks of the contaminated crabs, were measured in order to evaluate whether the studied concentrations of Cr and Mn could produce any metabolic alteration. The results indicated that extracts of the eyestalks of crabs submitted to Cr and Mn salts and injected into normal crabs markedly influenced crustacean hyperglycemic hormone synthesis and/or release. The results are discussed with respect to sensitivity of the employed methods and the possible significance of the concentrations of Cr and Mn in the organisms

  2. NMR relaxation studies with MnDPDP

    International Nuclear Information System (INIS)

    Southon, T.E.; Grant, D.; Bjoernerud, A.; Moen, O.M.; Spilling, B.; Martinsen, I.; Refsum, H.

    1997-01-01

    Purpose: Our studies were designed to compare the efficacy of mangafodipir trisodium (MnDPDP, Teslascan) as a tissue-specific MR agent with that of manganese chloride (MnCl 2 ), to compare the efficacy of different doses and rates of administration of MnDPDP, and to collect the data needed for predicting optimum pulse sequences. Material and Methods: The dose response for the relaxation rates R1 and R2 at 0.47 T, and the manganese (Mn) concentrations in rat liver and in the liver, pancreas, heart and adrenals of pigs was determined for both MnDPDP and MnCl 2 administered i.v. Computer simulations were carried out to model the effects of different tissue Mn concentrations and TR on signal intensities and contrast-to-noise ratios. Results: In rat liver and pig organs both compounds produced a positive dose-response in R1 and tissue Mn concentration, and only small or no response in R2. The Mn concentration in rat liver was positively correlated with R1, regardless of the form in which Mn was given, or the rate of administration. Optimal imaging parametes are therefore expected to be different pre- and post-MnDPDP administration. (orig./AJ)

  3. Effect of Fertilizers and Irrigation on Distribution of Mobile Forms of Mn, Zn and Cu in Typical Chernozems of the Republic of Moldova

    Directory of Open Access Journals (Sweden)

    Leah T. Gh.

    2013-04-01

    Full Text Available The paper presents the study results of mobile forms of Mn, Zn and Cu in irrigated fertilized and unfertilized chernozems typical. Irrigation affects the content and distribution of mobile forms of trace elements, increasing their removal beyond the 150 cm of soil layer. The fertilization increase the migration of Cu until 130 cm, fixed Mn and Zn in 0-60 cm of the irrigated soils. During irrigation constitutes a danger of soil contamination with Mn, Cu and Zn.

  4. Inflation Volatility and the Inflation-Growth Tradeoff in India

    OpenAIRE

    Raghbendra Jha; Varsha S. Kulkarni

    2012-01-01

    This paper amends the New Keynesian Phillips curve model to include inflation volatility and tests the determinants of such volatility for India. It provides results on the determinants of inflation volatility and expected inflation volatility for OLS and ARDL (1,1) models and for change in inflation volatility and change in expected inflation volatility using ECM models. Output gap affects change in expected inflation volatility along (in the ECM model) and not in the other models. Major det...

  5. Temperature dependence of the Faraday rotation for CdMnCoTe films

    International Nuclear Information System (INIS)

    Ahn, J. Y.; Tanaka, M.; Imamura, M.

    2001-01-01

    The temperature dependence of magneto-optical property in the visible wavelength region has been studied on four-element semimagnetic semiconductor CdMnCoTe films deposited on quartz glass substrates by using MBE equipment. A large dispersion of Faraday rotation was observed, and the peak of the Faraday rotation was shifted to the higher photon energies with increasing Mn concentration at low temperatures. At 180 K, the value of the Faraday rotation observed for the Cd 0.647 Mn 0.34 Co 0.013 Te film on quartz glass was -0.36 deg/cmG at 630 nm. It is equivalent to the value of -0.36 deg/cmG observed at 77 K for the Cd 0.52 Mn 0.48 Te film on quartz glass. At 77 K, the Faraday rotation observed for the Cd 0.647 Mn 0.34 Co 0.013 Te film on quartz glass was -0.49 deg/cmG at 610 nm. The value is approximately two times larger than that of the Cd 0.52 Mn 0.48 Te film deposited on the same quartz glass substrate. The origin of the enhancement of Faraday rotation in CdMnCoTe films has been discussed in terms of the magnetic susceptibility χ. [copyright] 2001 American Institute of Physics

  6. Volatile communication in plant-aphid interactions.

    Science.gov (United States)

    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release. Copyright 2010 Elsevier Ltd. All rights reserved.

  7. Tuning the magnetic properties of GaAs:Mn/MnAs hybrids via the MnAs cluster shape

    International Nuclear Information System (INIS)

    Nidda, H-A Krug von; Kurz, T; Loidl, A; Hartmann, Th; Klar, P J; Heimbrodt, W; Lampalzer, M; Volz, K; Stolz, W

    2006-01-01

    We report a systematic study of ferromagnetic resonance in granular GaAs:Mn/MnAs hybrids grown on GaAs(001) substrates by metal-organic vapour-phase epitaxy. The ferromagnetic resonance of the MnAs clusters can be resolved at all temperatures below T c . An additional broad absorption is observed below 60 K and is ascribed to localized charge carriers of the GaAs:Mn matrix. The anisotropy of the MnAs ferromagnetic resonance field originates from the magneto-crystalline field and demagnetization effects of the ferromagnetic MnAs clusters embedded in the GaAs:Mn matrix. Its temperature dependence basically scales with magnetization. Comparison of the observed angular dependence of the resonance field with model calculations yields the preferential orientation and shape of the clusters formed in hybrid layers of different thickness (150-1000 nm) grown otherwise at the same growth conditions. The hexagonal axes of the MnAs clusters are oriented along the four cubic GaAs space diagonals. Thin layers contain lens-shaped MnAs clusters close to the surface, whereas thick layers also contain spherical clusters in the bulk of the layer. The magnetic properties of the hexagonal MnAs clusters can be tuned by a controlled variation of the cluster shape

  8. Macroeconomic Volatility and Welfare in Developing Countries

    OpenAIRE

    Loayza, Norman V.; Rancière, Romain; Servén, Luis; Ventura, Jaume

    2007-01-01

    Macroeconomic Volatility and Welfare in Developing Countries: An Introduction Norman V. Loayza, Romain Ranciere, Luis Serven, ` and Jaume Ventura Macroeconomic volatility, both a source and a reflection of underdevelopment, is a fundamental concern for developing countries. This article provides a brief overview of the recent literature on macroeconomic volatility in developing countries, highlighting its causes, consequences, and possible remedies. to reduce domestic policy-induced macroecon...

  9. Identify and Manage the Software Requirements Volatility

    OpenAIRE

    Khloud Abd Elwahab; Mahmoud Abd EL Latif; Sherif Kholeif

    2016-01-01

    Management of software requirements volatility through development of life cycle is a very important stage. It helps the team to control significant impact all over the project (cost, time and effort), and also it keeps the project on track, to finally satisfy the user which is the main success criteria for the software project. In this research paper, we have analysed the root causes of requirements volatility through a proposed framework presenting the requirements volatility causes and how...

  10. Labour Demand and Exchange Rate Volatility

    OpenAIRE

    Udo Broll; Sabine Hansen

    2004-01-01

    The purpose of this paper is to assess under what conditions exchange rate volatility exerts a positive effect on a firm's labour demand. As the exchange rate volatility increases, so does the value of the export option provided the firm under study is flexible. Flexibility is important because it gives the firm option value. Higher volatility increases the potential gains from trade and may increase the demand for labour. This may explain part of the mixed empirical findings regarding the ef...

  11. Equity Volatility and Corporate Bond Yields

    OpenAIRE

    John Y. Campbell; Glen B. Taksler

    2002-01-01

    This paper explores the effect of equity volatility on corporate bond yields. Panel data for the late 1990s show that idiosyncratic firm-level volatility can explain as much cross-sectional variation in yields as can credit ratings. This finding, together with the upward trend in idiosyncratic equity volatility documented by Campbell, Lettau, Malkiel, and Xu (2001), helps to explain recent increases in corporate bond yields. The definitive version is available at www.blackwell-synergy.com.

  12. Free-Standing GaMnAs Nanomachined Sheets for van der Pauw Magnetotransport Measurements

    Directory of Open Access Journals (Sweden)

    Jae-Hyun Lee

    2016-12-01

    Full Text Available We report on the realization of free-standing GaMnAs epilayer sheets using nanomachining techniques. By optimizing the growth conditions of the sacrificial Al0.75Ga0.25As layer, free-standing metallic GaMnAs (with ~6% Mn microsheets (with TC ~85 K with integrated electrical probes are realized for magnetotransport measurements in the van der Pauw geometry. GaMnAs epilayer needs to be physically isolated to avoid buckling effects stemming from the release of lattice mismatch strain during the removal of the AlGaAs sacrificial layer. From finite element analysis, symmetrically placed and serpentine-shaped electrical leads induce minimal thermal stress at low temperatures. From magnetotransport measurements, changes in magnetic anisotropy are readily observed.

  13. The effects of Ni, Mo, Ti and Si on the mechanical properties of Cr free Mn steel (Fe-25Mn-5Al-2C)

    International Nuclear Information System (INIS)

    Schuon, S.R.

    1982-01-01

    The FeMnAlC alloys may hold potential as Cr-free replacements for high strategic material iron base superalloys, but little is known about their intermediate temperature (650 C to 870 C) mechanical properties. The effects of alloying elements on the mechanical properties of model FeMnAlC alloys were studied. Results showed that modified FeMnAlC alloys had promising short term, intermediate temperature properties but had relatively poor stress rupture lives at 172 MPa and 788 C. Room temperature and 788 C tensile strength of FeMnAlC alloys were better than common cast stainless steels. Changes in room temperature tensile and 788 C tensile strength and ductility, and 788 C stress rupture life were correlated with changes in Ni, Mo, Ti, and Si levels due to alloying effects on interstitial carbon levels and carbide morphology. Fe-25Mn-5Al-2C had a very poor stress rupture life at 172 MPa and 788 C. Addition of carbide-forming elements improved the stress rupture life

  14. Production Function of Outgassed Volatiles on Mercury: Implications for Polar Volatiles on Mercury and the Moon

    Science.gov (United States)

    Deutsch, A. N.; Head, J. W.

    2018-05-01

    We are interested in the flux of volatiles delivered to the polar regions of Mercury and the Moon through time. We integrate the production functions for volatile delivery from impacts, solar wind, and volcanism, which we focus on initially.

  15. [Solidification of volatile oil with graphene oxide].

    Science.gov (United States)

    Yan, Hong-Mei; Jia, Xiao-Bin; Zhang, Zhen-Hai; Sun, E; Xu, Yi-Hao

    2015-02-01

    To evaluate the properties of solidifying volatile oil with graphene oxide, clove oil and zedoary turmeric oil were solidified by graphene oxide. The amount of graphene oxide was optimized with the eugenol yield and curcumol yield as criteria. Curing powder was characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The effects of graphene oxide on dissolution in vitro and thermal stability of active components were studied. The optimum solidification ratio of graphene oxide to volatile oil was 1:1. Dissolution rate of active components had rare influence while their thermal stability improved after volatile oil was solidified. Solidifying herbal volatile oil with graphene oxide deserves further study.

  16. [Chemical components of Vetiveria zizanioides volatiles].

    Science.gov (United States)

    Huang, Jinghua; Li, Huashou; Yang, Jun; Chen, Yufen; Liu, Yinghu; Li, Ning; Nie, Chengrong

    2004-01-01

    The chemical components of the volatiles from Vetiveria zizanioides were analyzed by SPME and GC-MS. In the roots, the main component was valencene (30.36%), while in the shoots and leaves, they were 9-octadecenamide (33.50%), 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene (27.46%), and 1,2-benzendicarboxylic acid, diisooctyl ester(18.29%). The results showed that there were many terpenoids in the volatils. In shoot volatiles, there existed 3 monoterpenes, 2 sequiterpenes and 1 triterpene. Most of the volatiles in roots were sesquiterpenes.

  17. CAM Stochastic Volatility Model for Option Pricing

    Directory of Open Access Journals (Sweden)

    Wanwan Huang

    2016-01-01

    Full Text Available The coupled additive and multiplicative (CAM noises model is a stochastic volatility model for derivative pricing. Unlike the other stochastic volatility models in the literature, the CAM model uses two Brownian motions, one multiplicative and one additive, to model the volatility process. We provide empirical evidence that suggests a nontrivial relationship between the kurtosis and skewness of asset prices and that the CAM model is able to capture this relationship, whereas the traditional stochastic volatility models cannot. We introduce a control variate method and Monte Carlo estimators for some of the sensitivities (Greeks of the model. We also derive an approximation for the characteristic function of the model.

  18. The effect of volatility on percutaneous absorption.

    Science.gov (United States)

    Rouse, Nicole C; Maibach, Howard I

    2016-01-01

    Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy. A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption. A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs. Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.

  19. Element Content Analysis of Edible Insect of Ghana (Curculionidae: Sitophilus zeamais) Using EDXRF Spectrometer

    OpenAIRE

    AYDOĞAN, Zeynep; GÜROL, Ali; İNCEKARA, Ümit; TAHİDU, Osman Damba

    2016-01-01

    The overall study objective was to develop baseline information on the heavy elements concentration in edible insect Sitophilus zeamais (Coleoptera: Curculionidae) and to evaluate the contamination levels of this insect. Twelve heavy elements (V, Mn, Fe, Cu, Zn, Br, Sn, Sb, I, La, Ce, Pb) were analysed by energy dispersive X-ray fluorescence (EDXRF). The element concentration showed trend of Cu>Zn>Sn>Sb>Mn>Fe>I=La>Ce>Br>V>P...

  20. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has a metal liner disposed between the cladding and the nuclear fuel material and a high lubricity material in the form of a coating disposed between the liner and the cladding. The liner preferably has a thickness greater than the longest fission product recoil distance and is composed of a low neutron capture cross-section material. The liner is preferably composed of zirconium, an alloy of zirconium, niobium or an alloy of niobium. The liner serves as a preferential reaction site for volatile impurities and fission products and protects the cladding from contact and reaction with such impurities and fission products. The high lubricity material acts as an interface between the liner and the cladding and reduces localized stresses on the cladding due to fuel expansion and cracking of the fuel

  1. Oxidation/volatilization rates in air for candidate fusion reactor blanket materials, PCA and HT-9

    International Nuclear Information System (INIS)

    Piet, S.J.; Kraus, H.G.; Neilson, R.M. Jr.; Jones, J.L.

    1986-01-01

    Large uncertainties exist in the quantity of neutron-induced activation products that can be mobilized in potential fusion accidents. The accidental combination of high temperatures and oxidizing conditions might lead to mobilization of a significant amount of activation products from structural materials. Here, the volatilization of constituents of PCA and HT-9 resulting from oxidation in air was investigated. Tests were conducted in flowing air at temperatures from 600 to 1300 0 C for 1, 5, or 20 h. Elemental volatility was calculated in terms of the weight fraction of the element volatilized from the initial alloy. Molybdenum and manganese were the radiologically significant primary constituents most volatilizized, suggesting that molybdenum and manganese should be minimized in fusion steel compositions. Higher chromium content appears beneficial in reducing hazards from mobile activation products. Scanning electron microscopy and energy dispersive spectroscopy were used to study the oxide layer on samples. (orig.)

  2. Oil price volatility, financial regulation and energy policy

    International Nuclear Information System (INIS)

    Chevalier, J.M.

    2010-01-01

    In October of 2009, the French Ministry of Economy asked the author to chair a work group on oil price volatility. The report resulting from that work was submitted to the minister on February 9, 2010. Based on the report, this article focuses on three major elements: (i) the operation of the oil market, with interacting physical basics and financial basics (ii) financial market regulation, more specifically commodities-derived product markets and current work in that area and (iii) the lessons one can draw from that exercise in terms of energy policy. Significant projects have been initiated on global, European and national levels. (author)

  3. Effects of Mn Ion Implantation on XPS Spectroscopy of GaN Thin Films

    Science.gov (United States)

    Majid, Abdul; Ahmad, Naeem; Rizwan, Muhammad; Khan, Salah Ud-Din; Ali, Fekri Abdulraqeb Ahmed; Zhu, Jianjun

    2018-02-01

    Gallium nitride (GaN) thin film was deposited onto a sapphire substrate and then implanted with 250 keV Mn ions at two different doses of 2 × 1016 ions/cm2 and 5 × 1016 ions/cm2. The as-grown and post-implantation-thermally-annealed samples were studied in detail using x-ray photoelectron spectroscopy (XPS). The XPS peaks of Ga 3 d, Ga 2 p, N 1 s, Mn 2 p and C 1 s were recorded in addition to a full survey of the samples. The doublet peaks of Ga 2 p for pure GaN were observed blue-shifted when compared with elemental Ga, and appeared further shifted to higher energies for the implanted samples. These observations point to changes in the bonds and the chemical environment of the host as a result of ion implantation. The results revealed broadening of the N 1 s peak after implantation, which is interpreted in terms of the presence of N-Mn bonds in addition to N-Ga bonds. The XPS spectra of Mn 2 p recorded for ion-implanted samples indicated splitting of Mn 2 p 1/2 and Mn 2 p 3/2 peaks higher than that for metallic Mn, which helps rule out the possibility of clustering and points to substitutional doping of Mn. These observations provide a framework that sheds light on the local environment of the material for understanding the mechanism of magnetic exchange interactions in Mn:GaN based diluted magnetic semiconductors.

  4. Mineralogical characteristics of Mn coatings from different weathering environments in China: clues on their formation

    Science.gov (United States)

    Xu, Xiaoming; Ding, Hongrui; Li, Yan; Lu, Anhuai; Li, Yan; Wang, Changqiu

    2018-03-01

    Identification of Mn oxides in natural Mn coatings is very difficult due to their poor crystallinity, fine grains, complex chemistry and tiny amounts. In this work, we investigated three types of Mn coatings including rock varnish, dendrite and soil Fe-Mn cutan from different weathering environments in China. Optical microscope, scanning electron microscope, energy dispersive X-ray spectroscopy and micro-Raman spectrometer were employed to achieve non-destructive, sensitive, in-situ and micro analysis on their mineral assemblages, micromorphological features and elemental distribution characteristics. The observed results suggest that rock varnish and soil cutan comprise birnessite, while dendrite is mainly composed of hollandite. Rock varnish with a layered structure has a clear boundary with its substrate, and microlaminations which arise from the fluctuations in Mn content (6.42-17.07 wt%) within the sample profile are obvious on closer inspection. Branch-like dendrite is rich in Mn (32.53-42.96 wt%) but poor in Si and Al, which shows a pilotaxitic texture with its substrate. Soil Fe-Mn cutan can be further divided into an outer black Mn-rich (8.26-13.58 wt%) belt and an inner yellowish-brown Fe-rich (2.06-4.85 wt%) belt, and a clear border can be identified between these two belts. Mn in the substrate of rock varnish and soil cutan is below detection limit while it can be detected in the substrate of dendrite (1.43-7.83 wt%). Our in-situ analysis provides more precise results than traditional powder test. These mineralogical characteristics indicate that dendrite is most likely endogenic, while rock varnish and soil cutan are external accretion formed under different weathering environments.

  5. Mn-based nanostructured building blocks: Synthesis, characterization and applications

    Science.gov (United States)

    Beltran Huarac, Juan

    The quest for smaller functional elements of devices has stimulated increased interest in charge-transfer phenomena at the nanoscale. Mn-based nanostructured building blocks are particularly appealing given that the excited states of high-spin Mn2+ ions induce unusual d-d energy transfer processes, which is critical for better understanding the performance of electronic and spintronic devices. These nanostructures also exhibit unique properties superior to those of common Fe- and Co-based nanomaterials, including: excellent structural flexibility, enhanced electrochemical energy storage, effective ion-exchange dynamics, more comprehensive transport mechanisms, strong quantum yield, and they act as effective luminescent centers for more efficient visible light emitters. Moreover, Mn-based nanostructures (MBNs) are crucial for the design and assembly of inexpensive nanodevices in diluted magnetic semiconductors (DMS), optoelectronics, magneto-optics, and field-effect transistors, owing to the great abundance and low-cost of Mn. Nonetheless, the paucity of original methods and techniques to fabricate new multifunctional MBNs that fulfill industrial demands limits the sustainable development of innovative technology in materials sciences. In order to meet this critical need, in this thesis we develop and implement novel methods and techniques to fabricate zero- and one-dimensional highly-crystalline new-generation MBNs conducive to the generation of new technology, and provide alternative and feasible miniaturization strategies to control and devise at nanometric precision their size, shape, structure and composition. Herein, we also establish the experimental conditions to grow Mn-based nanowires (NWs), nanotubes (NTs), nanoribbons (NRs), nanosaws (NSs), nanoparticles (NPs) and nanocomposites (NCs) via chemical/physical deposition and co-precipitation chemical routes, and determine the pertinent arrangements to our experimental schemes in order to extend our bottom

  6. A successive ionic layer adsorption and reaction (SILAR) method to fabricate a layer-by-layer (LbL) MnO2-reduced graphene oxide assembly for supercapacitor application

    Science.gov (United States)

    Jana, Milan; Saha, Sanjit; Samanta, Pranab; Murmu, Naresh Chandra; Kim, Nam Hoon; Kuila, Tapas; Lee, Joong Hee

    2017-02-01

    A facile, cost effective and additive-free successive ionic layer adsorption and reaction (SILAR) technique is demonstrated to develop layer-by-layer (LbL) assembly of reduced graphene oxide (RGO) and MnO2 (MnO2-RGOSILAR) on a stainless steel current collector, for designing light-weight and small size supercapacitor electrode. The transmission electron microscopy and field emission scanning electron microscopy images shows uniform distribution of RGO and MnO2 in the MnO2-RGOSILAR. The LbL (MnO2-RGOSILAR) demonstrates improved physical and electrochemical properties over the hydrothermally prepared MnO2-RGO (MnO2-RGOHydro). The electrochemical environment of MnO2-RGOSILAR is explained by constant phase element in the high frequency region, and a Warburg element in the low frequency region in the Z-View fitted Nyquist plot. The equivalent circuit of the MnO2-RGOHydro, displays the co-existence of EDL and constant phase element, indicating inhomogeneous distribution of MnO2 and RGO by the hydrothermal technique. An asymmetric supercapacitor device is designed with MnO2-RGOSILAR as positive electrode, and thermally reduced GO (TRGO) as negative electrode. The designed cell exhibits high energy density of ∼88 Wh kg-1, elevated power density of ∼23,200 W kg-1, and ∼79% retention in capacitance after 10,000 charge-discharge cycles.

  7. Accumulative capabilities of essential nutrient elements in organs of ...

    African Journals Online (AJOL)

    use

    2011-11-23

    Nov 23, 2011 ... Cu > Mn > Zn > B. In conclusion, the ACs for essential nutrient elements differed, with the ... and Fe were quantified using Perkin Elmer Atomic Absorption .... vitamin C, protein and fat ranging from 249.6 to 266 .... Boron determination in plant tissues by ... Accumulation of cadmium and selected elements.

  8. Removal of trace element by isolates of Aspergillus brasiliensis ...

    African Journals Online (AJOL)

    Coffee beans processing generates a large volume of wastewater composed of trace elements which can be detrimental to human health. The present study aimed at evaluating the capacity of strains of Aspergillus brasiliensis and Penicillium citrinum in tolerating and removing trace elements namely: Cu, Mn and Zn from ...

  9. Kinetic Investigations of SiMn Slags From Different Mn Sources

    Science.gov (United States)

    Kim, Pyunghwa Peace; Tangstad, Merete

    2018-03-01

    The kinetics of MnO and SiO2 reduction were investigated for Silicomanganese (SiMn) slags using a Thermogravimetric analysis (TGA) between 1773 K and 1923 K (1500 °C and 1650 °C) under CO atmospheric pressure. The charge materials were based on Assmang ore and HC FeMn Slag. Rate models for MnO and SiO2 reduction were applied to describe the metal-producing rates, as shown by the following equations: r_{MnO} = k_{MnO} × A × ( {a_{MnO} - {a_{Mn} }/{K_{T }}} ) r_{{{SiO}2 }} = k_{SiO2} × A × ( {a_{{{SiO}2 }} - {a_{Si} }/{K_{T }}} ). The results show that the choice of raw materials in the charge considerably affected the reduction rate of MnO and SiO2. The highest reduction rate was found to be from charges using HC FeMn slag. The difference in the driving forces was insignificant among the SiMn slags, and the similar slag viscosities could not explain the different reduction rates. Instead, the difference is attributed to small amounts of sulfur and the amount of iron in the charge. In addition, the rate models were applicable to describe the reduction of MnO and SiO2 in SiMn slags.

  10. Large reversible magnetostrictive effect of MnCoSi-based compounds prepared by high-magnetic-field solidification

    Science.gov (United States)

    Hu, Q. B.; Hu, Y.; Zhang, S.; Tang, W.; He, X. J.; Li, Z.; Cao, Q. Q.; Wang, D. H.; Du, Y. W.

    2018-01-01

    The MnCoSi compound is a potential magnetostriction material since the magnetic field can drive a metamagnetic transition from an antiferromagnetic phase to a high magnetization phase in it, which accompanies a large lattice distortion. However, a large driving magnetic field, magnetic hysteresis, and poor mechanical properties seriously hinder its application for magnetostriction. By substituting Fe for Mn and introducing vacancies of the Mn element, textured and dense Mn0.97Fe0.03CoSi and Mn0.88CoSi compounds are prepared through a high-magnetic-field solidification approach. As a result, large room-temperature and reversible magnetostriction effects are observed in these compounds at a low magnetic field. The origin of this large magnetostriction effect and potential applications are discussed.

  11. Transplutonium elements

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishnan, C. K.; Jadhav, A. V.; Reghuraman, K.; Mathew, K. A.; Nair, P. S.; Ramaniah, M. V.

    1973-07-01

    Research progress is reported on studies of the transplutonium elements including recovery and purification of americium, preparation of /sup 238/Pu, extraction studies using diethylhexyl phosphate. (DHM)

  12. Behavior of volatiles in arc volcanism : geochemical and petrologic evidence from active volcanoes in Indonesia

    NARCIS (Netherlands)

    Hoog, J.C.M. de

    2001-01-01

    Large amounts of material are recycled along subduction zones by uprising magmas, of which volcanoes are the surface expression. This thesis focuses on the behavior of volatiles elements (S, Cl, H) during these recycling processes. The study area is the Indonesian arc system, which

  13. Segregation Behaviour of Third Generation Advanced High-Strength Mn-Al Steels

    Directory of Open Access Journals (Sweden)

    A. Grajcar

    2012-04-01

    Full Text Available The paper addresses the macro- and microsegregation of alloying elements in the new-developed Mn-Al TRIP steels, which belong to the third generation of advanced high-strength steels (AHSS used in the automotive industry. The segregation behaviour both in the as-cast state and after hot forging was assessed in the macro scale by OES and by EDS measurements in different structural constituents. The structural investigations were carried out using light and scanning electron microscopy. A special attention was paid to the effect of Nb microaddition on the structure and the segregation of alloying elements. The tendency of Mn and Al to macrosegregation was found. It is difficult to remove in Nb-free steels. Microsegregation of Mn and Al between austenite and ferritic structural constituents can be removed.

  14. Marine oligotrophy and element biogeochemistry

    International Nuclear Information System (INIS)

    Jeffree, R.A.; Szymczak, R.

    1999-01-01

    A biogeochemical model has been developed that explains the inverse and non-linear relationship between Po-210 concentration in zooplankton and their biomass, under oligotrophic conditions in French Polynesia. This study identified other elements with comparable accumulatory behaviours to Po-210 in phytoplankton, seston and zooplankton, that are proposed to be critical to its enhanced environmental levels under oligotrophy. Field investigation in the Gulf of Papua showed that four of these a priori identified elements viz Cd, Co, Pb and Mn, as well as Cr and Ni, showed elevated water concentrations with reduced biological productivity, results that are consistent with those previously obtained for Po-210 and the proposed explanatory model. These findings point to the enhanced susceptibility of oligotrophic systems to contamination from particle-reactive elements. (author)

  15. Investigation of Vertical Migration of Pollutants through the Unsaturated Zone Using Stable Isotopes and Trace Elements

    International Nuclear Information System (INIS)

    Ahmed, M.A.

    2012-01-01

    Vertical migration of pollutants through unsaturated zone is a complicated process and is affected by a number of factors like type of soil, its chemical properties, or organic matter content, in addition to climatic conditions and biological activity of microorganisms in soil. Soil properties that influence water movement through unsaturated zone are important for determining flow paths, reactions between soil and pollutants and the ultimate destination of these pollutants, and may improve the diagnosis of the potential pollution risk. Three soil cores were sampled to a depth up to 100 cm from cultivated clayey soil, sewage irrigated sandy soil and fertilized sandy soil. The samples were collected at intervals of 5 or 10 cm. The δ 13 C signature of the soil shifted significantly towards that of C 3 -type vegetation in soil cores. The general trend toward heavier 13 C enrichment with depth could be due to isotopic fractionation occurring during decomposition of soil organic matters. Increased δ 15 N with depth in the soil cores suggests that microbial mineralization, denitrification, or volatilization processes caused the enriched δ 15 N signatures. Decreasing nitrogen percent and nitrate values with depth also help support the idea of microbiological processes. The results indicate that concentrations of major and trace elements varied widely among the different soil types and decreased with depths in the studied soil profile. The accumulation pattern for these elements in the soil profiles follows the order: Co < Ni < Mo < Ag < Sr < V < Cu < Cr < Zn < Mn < B < Mg < Al < Fe. The relationships between element concentrations against ph and organic matter contents show antithetical relationships and suggest evidence that these elements arise from anthropogenic input. The results of this study show that there exists risk for the environment due to notable migration of pollutants through the unsaturated zone and that the migrations were also observed to be highly

  16. Fundamental uncertainty and stock market volatility

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2008-01-01

    We provide empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from participants in the Survey of Professional Forecasters over the period 1969 to 1996.

  17. Effects of Idiosyncratic Volatility in Asset Pricing

    Directory of Open Access Journals (Sweden)

    André Luís Leite

    2016-04-01

    Full Text Available This paper aims to evaluate the effects of the aggregate market volatility components - average volatility and average correlation - on the pricing of portfolios sorted by idiosyncratic volatility, using Brazilian data. The study investigates whether portfolios with high and low idiosyncratic volatility - in relation to the Fama and French model (1996 - have different exposures to innovations in average market volatility, and consequently, different expectations for return. The results are in line with those found for US data, although they portray the Brazilian reality. Decomposition of volatility allows the average volatility component, without the disturbance generated by the average correlation component, to better price the effects of a worsening or an improvement in the investment environment. This result is also identical to that found for US data. Average variance should thus command a risk premium. For US data, this premium is negative. According to Chen and Petkova (2012, the main reason for this negative sign is the high level of investment in research and development recorded by companies with high idiosyncratic volatility. As in Brazil this type of investment is significantly lower than in the US, it was expected that a result with the opposite sign would be found, which is in fact what occurred.

  18. Decomposing European bond and equity volatility

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditio...

  19. Volatility transmission and patterns in Bund futures

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); R. van Ieperen; A.J. Menkveld (Bert); P. Kofman (Paul); M.P.E. Martens (Martin)

    1997-01-01

    textabstractWe analyze intraday volatility behavior for the Bund futures contract that is traded simultaneously at two competing exchanges. We investigate the transmission of volatility between the exchanges. We find that the lead/lag relations are restricted to a few minutes and do not reveal a

  20. Stock market volatility and macroeconomic uncertainty

    NARCIS (Netherlands)

    Arnold, I.J.M.; Vrugt, E.B.

    2006-01-01

    This paper provides empirical evidence on the link between stock market volatility and macroeconomic uncertainty. We show that US stock market volatility is significantly related to the dispersion in economic forecasts from SPF survey participants over the period from 1969 to 1996. This link is much

  1. CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS ...

    African Journals Online (AJOL)

    CHEMICAL INVESTIGATION OF THE VOLATILE CONSTITUENTS OF CLEOME VISCOSA FROM NIGERIA. Gabriel Olatunji, Peter Weyerstahl, Stephen Oguntoye. Abstract. The major volatile constituents of the oils from the integral parts of Cleome viscosa L. from Nigeria have been identified by GC, GC/MS and 1H NMR.

  2. The economic value of realized volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jacobs, Kris

    2014-01-01

    Many studies have documented that daily realized volatility estimates based on intraday returns provide volatility forecasts that are superior to forecasts constructed from daily returns only. We investigate whether these forecasting improvements translate into economic value added. To do so, we ...

  3. Firm-level volatility and exports

    NARCIS (Netherlands)

    Vannoorenberghe, G.C.L.

    2012-01-01

    This paper shows that the share of exports in the total sales of a firm has a positive and substantial impact on the volatility of its sales. Decomposing the volatility of sales of exporters between their domestic and export markets, I show using an identification strategy based on a firm-specific

  4. American option pricing with stochastic volatility processes

    Directory of Open Access Journals (Sweden)

    Ping LI

    2017-12-01

    Full Text Available In order to solve the problem of option pricing more perfectly, the option pricing problem with Heston stochastic volatility model is considered. The optimal implementation boundary of American option and the conditions for its early execution are analyzed and discussed. In view of the fact that there is no analytical American option pricing formula, through the space discretization parameters, the stochastic partial differential equation satisfied by American options with Heston stochastic volatility is transformed into the corresponding differential equations, and then using high order compact finite difference method, numerical solutions are obtained for the option price. The numerical experiments are carried out to verify the theoretical results and simulation. The two kinds of optimal exercise boundaries under the conditions of the constant volatility and the stochastic volatility are compared, and the results show that the optimal exercise boundary also has stochastic volatility. Under the setting of parameters, the behavior and the nature of volatility are analyzed, the volatility curve is simulated, the calculation results of high order compact difference method are compared, and the numerical option solution is obtained, so that the method is verified. The research result provides reference for solving the problems of option pricing under stochastic volatility such as multiple underlying asset option pricing and barrier option pricing.

  5. Mutual fund volatility timing and management fees

    NARCIS (Netherlands)

    Giambona, E.; Golec, J.

    2009-01-01

    This paper shows that compensation incentives partly drive fund managers’ market volatility timing strategies. Larger incentive management fees lead to less counter-cyclical or more pro-cyclical volatility timing. But fund styles or aggregate fund flows could also account for this relation;

  6. Some recent developments in stochastic volatility modelling

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Nicolato, Elisa; Shephard, N.

    2002-01-01

    This paper reviews and puts in context some of our recent work on stochastic volatility (SV) modelling for financial economics. Here our main focus is on: (i) the relationship between subordination and SV, (ii) OU based volatility models, (iii) exact option pricing, (iv) realized power variation...

  7. Volatility Determination in an Ambit Process Setting

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole; Graversen, Svend-Erik

    The probability limit behaviour of normalised quadratic variation is studied for a simple tempo-spatial ambit process, with particular regard to the question of volatility memorylessness.......The probability limit behaviour of normalised quadratic variation is studied for a simple tempo-spatial ambit process, with particular regard to the question of volatility memorylessness....

  8. Order flow and volatility: An empirical investigation

    NARCIS (Netherlands)

    Opschoor, A.; Taylor, N.; van der Wel, M.; van Dijk, D.

    2014-01-01

    We study the relationship between order flow and volatility. To this end we develop a comprehensive framework that simultaneously controls for the effects of macro announcements and order flow on prices and the effect of macro announcements on volatility. Using high-frequency 30-year U.S. Treasury

  9. Volatile organometallic and semiconductor materials

    International Nuclear Information System (INIS)

    Dickson, R.S.

    1991-01-01

    This article reports on a project concerned with the metal organic chemical vapour deposition (MOCVD) of mercury-cadmium telluride (MCT) undertaken by a research consortium based in the Clayton area involving Monash University Chemistry Department, Telecom Research Laboratories, and CSIRO Division of Material Sciences and Technology. An M.R. Semicon 226 MOCVD reactor, operating near atmospheric presure with hydrogen carrier gas has been used. Most applications of MCT are direct consequence of its responsiveness to radiation in infrared region spectrum. The main aims of the project were to prepare and assess a range of volatile organometallics that might find use as a dopant sources for MCT, to prepare and study the properties of a range of different lanthanide complexes for MOCVD applications and to fully characterize the semiconductor wafers after growth. 19 refs., 3 figs

  10. Volatility smile as relativistic effect

    Science.gov (United States)

    Kakushadze, Zura

    2017-06-01

    We give an explicit formula for the probability distribution based on a relativistic extension of Brownian motion. The distribution (1) is properly normalized and (2) obeys the tower law (semigroup property), so we can construct martingales and self-financing hedging strategies and price claims (options). This model is a 1-constant-parameter extension of the Black-Scholes-Merton model. The new parameter is the analog of the speed of light in Special Relativity. However, in the financial context there is no ;speed limit; and the new parameter has the meaning of a characteristic diffusion speed at which relativistic effects become important and lead to a much softer asymptotic behavior, i.e., fat tails, giving rise to volatility smiles. We argue that a nonlocal stochastic description of such (Lévy) processes is inadequate and discuss a local description from physics. The presentation is intended to be pedagogical.

  11. Fuel element tomography by gammametry

    International Nuclear Information System (INIS)

    Simonet, G.; Pineira, T.

    1982-03-01

    As from transversal gamma determinations of a cylindrical fuel element, the TOMOGAM program reconstitutes the distribution of fission products in a section. This direct, fast and non destructive method, makes it possible to have access to the behaviour of the fuel at any time: - the soluble fission products in the matrix represent the fuel itself and the distribution of the fissions, - the migrating elements inform on the temperature reached in accordance with the permitted powers, - the volatile nuclides build up in particular points where physical-chemical phenomena of fuel-cladding interaction are liable to corrode the latter. Hence, gamma spectrometry extends its possibilities of analysis relative to the performance of reactor elements [fr

  12. Paramagnetic resonance of Mn4+ and Mn2+ centers in lanthanum gallate single crystals

    Science.gov (United States)

    Vazhenin, V. A.; Potapov, A. P.; Guseva, V. B.; Artyomov, M. Yu.

    2010-03-01

    An increase in the manganese concentration in lanthanum gallate in the range 0.5-5.0% has been found to result in a complete replacement of individual Mn4+ ions by Mn2+ ions. The relative concentrations and binding energies of individual Mn4+, Mn3+, and Mn2+ ions have been determined. The spin Hamiltonians of the Mn2+ and Mn4+ centers in the rhombohedral and orthorhombic phases, respectively, have been constructed and the orientation of the principal axes of the fine-structure tensor of Mn4+ at room temperature has been found. The possibility of using electron paramagnetic resonance for determining the rotation angles of oxygen octahedra of lanthanum gallate with respect to the perovskite structure has been discussed.

  13. Metamorphic Perspectives of Subduction Zone Volatiles Cycling

    Science.gov (United States)

    Bebout, G. E.

    2008-12-01

    Field study of HP/UHP metamorphic rocks provides "ground-truthing" for experimental and theoretical petrologic studies estimating extents of deep volatiles subduction, and provides information regarding devolatilization and deep subduction-zone fluid flow that can be used to reconcile estimates of subduction inputs and arc volcanic outputs for volatiles such as H2O, N, and C. Considerable attention has been paid to H2O subduction in various bulk compositions, and, based on calculated phase assemblages, it is thought that a large fraction of the initially structurally bound H2O is subducted to, and beyond, subarc regions in most modern subduction zones (Hacker, 2008, G-cubed). Field studies of HP/UHP mafic and sedimentary rocks demonstrate the impressive retention of volatiles (and fluid-mobile elements) to depths approaching those beneath arcs. At the slab-mantle interface, high-variance lithologies containing hydrous phases such as mica, amphibole, talc, and chlorite could further stabilize H2O to great depth. Trench hydration in sub-crustal parts of oceanic lithosphere could profoundly increase subduction inputs of particularly H2O, and massive flux of H2O-rich fluids from these regions into the slab-mantle interface could lead to extensive metasomatism. Consideration of sedimentary N concentrations and δ15N at ODP Site 1039 (Li and Bebout, 2005, JGR), together with estimates of the N concentration of subducting altered oceanic crust (AOC), indicates that ~42% of the N subducting beneath Nicaragua is returned in the corresponding volcanic arc (Elkins et al., 2006, GCA). Study of N in HP/UHP sedimentary and basaltic rocks indicates that much of the N initially subducted in these lithologies would be retained to depths approaching 100 km and thus available for addition to arcs. The more altered upper part of subducting oceanic crust most likely to contribute to arcs has sediment-like δ15NAir (0 to +10 per mil; Li et al., 2007, GCA), and study of HP/UHP eclogites

  14. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors to h...

  15. Hygroscopicity and ammonia volatilization losses from nitrogen sources in coated urea

    Directory of Open Access Journals (Sweden)

    Letícia de Abreu Faria

    2014-06-01

    Full Text Available Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; and by stabilized fertilizers, which prolong the period during which N remains in the amide or ammonia forms by urease inhibitors. This study evaluated the hygroscopicity of and ammonia volatilization from urea coated with boric acid and copper sulfate or with sulfur. The hygroscopicity of the sources was evaluated over time after exposure to five levels of relative humidity (RH and volatilization evaluated after application to the soil surface covered with sugarcane trash. Ammonium nitrate has a low potential for volatilization losses, but is highly hygroscopic. Although coating with boric acid and copper sulfate or elemental sulfur reduced the critical humidity level of urea, the delay in the volatilization process is a potential positive factor.

  16. Switchable Polarization in Mn Embedded Graphene.

    Science.gov (United States)

    Noor-A-Alam, Mohammad; Ullah, Hamid; Shin, Young-Han

    2018-03-14

    Graphene, despite its many unique properties, is neither intrinsically polar due to inversion symmetry nor magnetic. However, based on density functional theory, we find that Mn, one of transition metals, embedded in single or double vacancy (Mn@SV and Mn@DV) in a graphene monolayer induces a dipole moment perpendicular to the sheet, which can be switched from up to down by Mn penetration through the graphene. Such switching could be realized by an external stimuli introduced through the tip of a scanning probe microscope, as already utilized in the studies of molecular switches. We estimate the energy barriers for dipole switching, which are found to be 2.60 eV and 0.28 eV for Mn@SV and Mn@DV, respectively. However, by applying biaxial tensile strain, we propose a mechanism for tuning the barrier. We find that 10% biaxial tensile strain, which is already experimentally achievable in graphene-like two-dimensional materials, can significantly reduce the barrier to 0.16 eV in Mn@SV. Moreover, in agreement with previous studies, we find a high magnetic moment of 3 μ B for both Mn@SV and Mn@DV, promising the potential of these structures in spintronics as well as in nanoscale electro-mechanical or memory devices.

  17. Study of γ Pav and its implications in the Mn abundance in the near stars

    International Nuclear Information System (INIS)

    Scheid, P.L.

    1975-05-01

    The spectrum of the star γ Pav has been investigated at high dispersion. A differential curve of growth analysis of this star relative to the sun has been performed to find with good accuracy the abundances of the various elements in the atmosphere of γ Pav. It is found that this star is deficient by a factor of five in relation to the sun. Mn proved to be more underabundant than the other iron group elements as we do not consider the hyperfine structure of its lines. This effect practically disappears as we take into account the wide hyperfine structure of the Mn lines. The abundances of the s-process elements suggest that the material from which γ Pav has been formed has undergone a neutron exposure analogous to the one that originated the s-elements in the solar system (Author) [pt

  18. Synthesis and Characterization of Multimetallic Fe(II) and Mn(II ...

    African Journals Online (AJOL)

    Iron(II) and Manganese(II) complexes of the resulting ligand were obtained from its reactions with Fe(II) and Mn(II) salts in absolute methanol for the metal to ligand ratio 2:3. These complexes were characterized by Solubility, Conductivity, IR and UV-VIS spectrometry, elemental analysis and mass spectrometry. Keywords: ...

  19. Synthesis of Li-Mn-O mesocrystals with controlled crystal phases through topotactic transformation of MnCO₃.

    Science.gov (United States)

    Dang, Feng; Hoshino, Tatsuhiko; Oaki, Yuya; Hosono, Eiji; Zhou, Haoshen; Imai, Hiroaki

    2013-03-21

    Mesocrystals of Li-Mn-O compounds, such as LiMn2O4, Li2MnO3, and LiMnO2-Li2MnO3, consisting of oriented nanoscale units were selectively produced under hydrothermal conditions from biomimetically prepared MnCO3 mesocrystals. Topotactic transformation through the intermediate phase of Mn5O8 inheriting a hierarchical structure of the MnCO3 precursor was essential for the formation of the mesocrystal compounds. The crystal phases were successfully controlled by varying the conditions for the hydrothermal reactions. The Li-Mn-O mesocrystals have considerable potential as cathodes of Li-ion batteries.

  20. Trace element analysis in soy sauce. 2

    International Nuclear Information System (INIS)

    Haruyama, Yoichi; Saito, Manabu; Tomita, Michio; Yoshida, Koji.

    1994-01-01

    Trace elements in four kinds of soybean and three kinds of salt have been measured by means of in-air PIXE. In soybeans, which were made in Japan, America, Canada and China, six kinds of trace elements were detected, such as Mn, Fe, Ni, Cu, Zn and Br. The concentration of these elements varied depending on the place they were made. American soybean showed characteristic feature compared with other soybeans. As to the bromine concentration, American soybean contains ten times as much as Japanese one. In salts Br and Sr were detected. (author)

  1. Trace elements in wild and orchard honeys

    Energy Technology Data Exchange (ETDEWEB)

    Almeida-Silva, M.; Canha, N.; Galinha, C.; Dung, H.M. [Instituto Tecnologico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Freitas, M.C., E-mail: cfreitas@itn.pt [Instituto Tecnologico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Sitoe, T. [Instituto Tecnologico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal)

    2011-11-15

    The present study aims the identification and quantification of trace elements in two types of honey samples: Orchard honey and Wild honey from mainland Portugal. Chemical elements content was assessed by Instrumental Neutron Activation Analysis (INAA). Concentrations were determinated for Ag, As, Br, Ca, Cl, Cs, Cu, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, U, V and Zn. The nutritional values of both honey types were evaluated since this product contains some elements that are essential dietary nutrients for humans. Physical properties of the honey samples, such as electrical conductivy and pH, were assessed as well.

  2. Trace elements in sera from patients with visceral leishmaniasis

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, R.; Bhattacharya, A. [Department of Zoology, Calcutta University, Calcutta (India); Chakraborty, A.; Sudarshan, M.; Jal, P.K.; Chintalapudi, S.N. [Inter University Consortium for DAE Facilities, Calcutta Centre 3/LB-8, Bidhan Nagar, Calcutta (India); Dutta, R.K. [Schonland Research Centre for Nuclear Sciences, University of Witwatersrand, Johannesburg (South Africa)

    2000-07-01

    Trace elements are known to have pivotal role in human health and disease. Present investigation employed PIXE analysis to probe into the elemental profile of patients suffering from visceral Leishmaniasis. Remarkable alternations were observed in concentration of elements like Cl, K, Ca, Mn, Fe, Cu, Zn. The pattern of enhancement of elemental concentration corresponds to the progression of the disease. Additionally, our present data reflect probable correlation between alteration in trace elemental status and other pathological syndromes associated with Leishmaniasis. The possibility of considering trace elements as a diagnostic marker for a better understanding of the disease is discussed. (author)

  3. Trace elements in sera from patients with visceral leishmaniasis

    International Nuclear Information System (INIS)

    Mukhopadhyay, R.; Bhattacharya, A.; Chakraborty, A.; Sudarshan, M.; Jal, P.K.; Chintalapudi, S.N.; Dutta, R.K.

    2000-01-01

    Trace elements are known to have pivotal role in human health and disease. Present investigation employed PIXE analysis to probe into the elemental profile of patients suffering from visceral Leishmaniasis. Remarkable alternations were observed in concentration of elements like Cl, K, Ca, Mn, Fe, Cu, Zn. The pattern of enhancement of elemental concentration corresponds to the progression of the disease. Additionally, our present data reflect probable correlation between alteration in trace elemental status and other pathological syndromes associated with Leishmaniasis. The possibility of considering trace elements as a diagnostic marker for a better understanding of the disease is discussed. (author)

  4. Arsenic and Mn levels in Isaza (Gymnogobius isaza) during the mass mortality event in Lake Biwa, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Sawako Horai; Hayase, Daisuke; Eguchi, Akifumi; Itai, Takaaki; Nomiyama, Kei; Isobe, Tomohiko; Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Ishikawa, Toshiyuki [Department of Environmental Education, Faculty of Education, Shiga University, 2-5-1 Hiratsu, Otsu, Shiga 520-0862 (Japan); Kumagai, Michio [Lake Biwa Environmental Research Institute, 5-34 Yanagasaki, Otsu, Shiga 520-0022 (Japan); Tanabe, Shinsuke, E-mail: shinsuke@agr.ehime-u.ac.jp [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)

    2011-10-15

    The present study measured the concentrations of 25 elements (Li, Mg, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) in the whole body of Isaza which is an endemic fish species to Lake Biwa, Japan, and compared the values in the specimens from the mass mortality Isaza (MMI) and normal fresh Isaza (NFI). The mean levels of Mn and total As (T-As) were relatively higher in MMI than in NFI. In the T-As, highly toxic inorganic As was detected in MMI. Moreover we found Mn and As concentrations in surface sediment were extremely high and temporally increased. From all these results, we could infer that the dissolution of Mn and As from surface sediment of Lake Biwa might have been one of the cause for the mass mortality of Isaza. - Highlights: > Mn and As levels were significantly higher in MMI than in NFI. > The number of chemical species of As detected from MMI was less than that from NFI. > Mn and As levels were highest in surface sediment, and sharply decreased with depth. > Mn and As levels in surface sediment temporally increased. - As and Mn levels in dead Isaza caused by mass mortality.

  5. Influences of graphene oxide support on the electrochemical performances of graphene oxide-MnO2 nanocomposites

    Directory of Open Access Journals (Sweden)

    Xi Lifei

    2011-01-01

    Full Text Available Abstract MnO2 supported on graphene oxide (GO made from different graphite materials has been synthesized and further investigated as electrode materials for supercapacitors. The structure and morphology of MnO2-GO nanocomposites are characterized by X-ray diffraction, X-ray photoemission spectroscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and Nitrogen adsorption-desorption. As demonstrated, the GO fabricated from commercial expanded graphite (denoted as GO(1 possesses more functional groups and larger interplane gap compared to the GO from commercial graphite powder (denoted as GO(2. The surface area and functionalities of GO have significant effects on the morphology and electrochemical activity of MnO2, which lead to the fact that the loading amount of MnO2 on GO(1 is much higher than that on GO(2. Elemental analysis performed via inductively coupled plasma optical emission spectroscopy confirmed higher amounts of MnO2 loading on GO(1. As the electrode of supercapacitor, MnO2-GO(1 nanocomposites show larger capacitance (307.7 F g-1 and better electrochemical activity than MnO2-GO(2 possibly due to the high loading, good uniformity, and homogeneous distribution of MnO2 on GO(1 support.

  6. Determination of trace elements in chicken feeds in Khartoum state

    International Nuclear Information System (INIS)

    Hassan, Salma Yahya Mohammed

    2017-03-01

    Trace elements are very important for chicken because thy contribute in biochemical processes required for normal growth, development and formation of the eggshell. The deficiency or the elevation of these trace elements may affect the normal physiological activity and biochemical process of their bodies. In this study the concentrations of trace elements in chicken feed samples were determined by X RF spectrometry. The results showed that there were 9 trace elements in sample ( K, Ca Mn, Fe Cu Zn, Pb, Rb, Sr) the mean concentration were K ( 2.12 x 10 4 ), Ca (2.22x10 4 ), Mn (48.1). Fe (191), Cu(9.81), Zn (24.6), Pb (1.63), Rb (7.79), Sr(4.09) ppm. Comparing the trace elements concentrations obtained in this study with the recommended values showed that some of them e.g Mn, Cu, Zn, Fe were found higher concentration than the recommended values, which stipulated by national research council NRC European Union. While lead concentration was in the permissible limit (5mg/kg). However, the statistical Alan's revealed than there were no significant difference between all concentrations of trace elements in the two types of chicken feeds i.e layer and broiler. The pearson correlation test displayed a strong correlation between K-Rb (0.885), Mn-Zn (0.874). The negative correlation between Mn-Rb (0.680), K-Mn (0.6000), K-Ca (0.565), Zn-Rb (-0.541). Ca-Rb (0.458) were found . Further investigations were performed using the principal component analysis (PCA) which involved the extraction of principal factor to study the total variance in the feed samples in terms of the trace elements concentrations in each. The obtained results revealed that the first principal component have a positive correlation with the elements Ca, Mn, Pb, and Zn, while K and Rb showed negative correlation with it. Similarly, the second principal compound showed positive correlation with the elements Mn, PB and Zn, while Ca and Sr showed negative, on the perth hand the third component was found to

  7. Highly stabilized and photoluminescence enhancement of ZnS:Mn2+ nanoparticles in biotin matrix

    International Nuclear Information System (INIS)

    Keshari, Ashish K.; Pandey, Avinash C.

    2009-01-01

    We synthesized the ZnS:Mn 2+ nanoparticles passivated by biocompatible layer, namely, biotin by chemical precipitation route and studied their temporal evolution for size, structure, optical, and photoluminescence stability. To monitor the structural and optoelectronic properties of the nanoparticles with time, we have characterized the grown product by x-ray diffraction, small angle x-ray scattering, UV visible, and photoluminescence spectroscopic techniques at a regular interval for a period of three months. Results showed that the properties of nanophosphors capped with biotin are remaining the same even after 3 months. Energy dispersive x-ray analysis of 3 month aged sample shows long time compatibility between ZnS:Mn 2+ nanoparticles and the biotin. This is also confirmed by electron microscopy that the growth of the nanoparticles is strongly arrested by the biotin. X-ray photoelectron spectra were also recorded to show the chemical state of the elements. Enhanced ratio of Zn 2p to Mn 2p peaks in the x-ray photoelectron spectra of ZnS:Mn 2+ nanoparticles shows that the Mn 2+ ions are incorporated within ZnS host matrix. We found that biotin capping will enhance the luminescence from ZnS:Mn 2+ nanoparticles as compared to without capped particles. Absence of biotin will gradually degrade the luminescence upon aging while drastic degradation in luminescence intensity was observed after annealing. Properties show that biotin also protected the nanoparticles from any environmental attack

  8. Recent advances on Fe- and Mn-based cathode materials for lithium and sodium ion batteries

    Science.gov (United States)

    Zhu, Xiaobo; Lin, Tongen; Manning, Eric; Zhang, Yuancheng; Yu, Mengmeng; Zuo, Bin; Wang, Lianzhou

    2018-06-01

    The ever-growing market of electrochemical energy storage impels the advances on cost-effective and environmentally friendly battery chemistries. Lithium-ion batteries (LIBs) are currently the most critical energy storage devices for a variety of applications, while sodium-ion batteries (SIBs) are expected to complement LIBs in large-scale applications. In respect to their constituent components, the cathode part is the most significant sector regarding weight fraction and cost. Therefore, the development of cathode materials based on Earth's abundant elements (Fe and Mn) largely determines the prospects of the batteries. Herein, we offer a comprehensive review of the up-to-date advances on Fe- and Mn-based cathode materials for LIBs and SIBs, highlighting some promising candidates, such as Li- and Mn-rich layered oxides, LiNi0.5Mn1.5O4, LiFe1-xMnxPO4, NaxFeyMn1-yO2, Na4MnFe2(PO4)(P2O7), and Prussian blue analogs. Also, challenges and prospects are discussed to direct the possible development of cost-effective and high-performance cathode materials for future rechargeable batteries.

  9. Fabrication of Mg-X-O (X = Fe, Co, Ni, Cr, Mn, Ti, V, and Zn) barriers for magnetic tunnel junctions

    Science.gov (United States)

    Yakushiji, K.; Kitagawa, E.; Ochiai, T.; Kubota, H.; Shimomura, N.; Ito, J.; Yoda, H.; Yuasa, S.

    2018-05-01

    We fabricated magnetic tunnel junctions with a 3d-transition material(X)-doped MgO (Mg-X-O) barrier, and evaluated the effect of the doping on magnetoresistance (MR) and microstructure. Among the variations of X (X = Fe, Co, Ni, Cr, Mn, Ti, V, and Zn), X = Fe and Mn showed a high MR ratio of more than 100%, even at a low resistance-area product of 3 Ωμm2. The microstructure analysis revealed that (001) textured orientation formed for X = Fe and Mn despite substantial doping (about 10 at%). The elemental mappings indicated that Fe atoms in the Mg-Fe-O barrier were segregated at the interfaces, while Mn atoms were evenly involved in the Mg-Mn-O barrier. This suggests that MgO has high adaptability for Fe and Mn dopants in terms of high MR ratio.

  10. Characterization of Danio rerio Mn2+-dependent ADP-ribose/CDP-alcohol diphosphatase, the structural prototype of the ADPRibase-Mn-like protein family.

    Directory of Open Access Journals (Sweden)

    Joaquim Rui Rodrigues

    Full Text Available The ADPRibase-Mn-like protein family, that belongs to the metallo-dependent phosphatase superfamily, has different functional and structural prototypes. The functional one is the Mn(2+-dependent ADP-ribose/CDP-alcohol diphosphatase from Rattus norvegicus, which is essentially inactive with Mg(2+ and active with low micromolar Mn(2+ in the hydrolysis of the phosphoanhydride linkages of ADP-ribose, CDP-alcohols and cyclic ADP-ribose (cADPR in order of decreasing efficiency. The structural prototype of the family is a Danio rerio protein with a known crystallographic structure but functionally uncharacterized. To estimate the structure-function correlation with the same protein, the activities of zebrafish ADPRibase-Mn were studied. Differences between zebrafish and rat enzymes are highlighted. The former showed a complex activity dependence on Mn(2+, significant (≈25% Mg(2+-dependent activity, but was almost inactive on cADPR (150-fold less efficient than the rat counterpart. The low cADPR hydrolase activity agreed with the zebrafish genome lacking genes coding for proteins with significant homology with cADPR-forming enzymes. Substrate-docking to zebrafish wild-type protein, and characterization of the ADPRibase-Mn H97A mutant pointed to a role of His-97 in catalysis by orientation, and to a bidentate water bridging the dinuclear metal center as the potential nucleophile. Finally, three structural elements that delimit the active site entrance in the zebrafish protein were identified as unique to the ADPRibase-Mn-like family within the metallo-dependent phosphatase superfamily.

  11. Flower volatiles, crop varieties and bee responses.

    Directory of Open Access Journals (Sweden)

    Björn K Klatt

    Full Text Available Pollination contributes to an estimated one third of global food production, through both the improvement of the yield and the quality of crops. Volatile compounds emitted by crop flowers mediate plant-pollinator interactions, but differences between crop varieties are still little explored. We investigated whether the visitation of crop flowers is determined by variety-specific flower volatiles using strawberry varieties (Fragaria x ananassa Duchesne and how this affects the pollination services of the wild bee Osmia bicornis L. Flower volatile compounds of three strawberry varieties were measured via headspace collection. Gas chromatography showed that the three strawberry varieties produced the same volatile compounds but with quantitative differences of the total amount of volatiles and between distinct compounds. Electroantennographic recordings showed that inexperienced females of Osmia bicornis had higher antennal responses to all volatile compounds than to controls of air and paraffin oil, however responses differed between compounds. The variety Sonata was found to emit a total higher level of volatiles and also higher levels of most of the compounds that evoked antennal responses compared with the other varieties Honeoye and Darselect. Sonata also received more flower visits from Osmia bicornis females under field conditions, compared with Honeoye. Our results suggest that differences in the emission of flower volatile compounds among strawberry varieties mediate their attractiveness to females of Osmia bicornis. Since quality and quantity of marketable fruits depend on optimal pollination, a better understanding of the role of flower volatiles in crop production is required and should be considered more closely in crop-variety breeding.

  12. Volatility persistence in crude oil markets

    International Nuclear Information System (INIS)

    Charles, Amélie; Darné, Olivier

    2014-01-01

    Financial market participants and policy-makers can benefit from a better understanding of how shocks can affect volatility over time. This study assesses the impact of structural changes and outliers on volatility persistence of three crude oil markets – Brent, West Texas Intermediate (WTI) and Organization of Petroleum Exporting Countries (OPEC) – between January 2, 1985 and June 17, 2011. We identify outliers using a new semi-parametric test based on conditional heteroscedasticity models. These large shocks can be associated with particular event patterns, such as the invasion of Kuwait by Iraq, the Operation Desert Storm, the Operation Desert Fox, and the Global Financial Crisis as well as OPEC announcements on production reduction or US announcements on crude inventories. We show that outliers can bias (i) the estimates of the parameters of the equation governing volatility dynamics; (ii) the regularity and non-negativity conditions of GARCH-type models (GARCH, IGARCH, FIGARCH and HYGARCH); and (iii) the detection of structural breaks in volatility, and thus the estimation of the persistence of the volatility. Therefore, taking into account the outliers on the volatility modelling process may improve the understanding of volatility in crude oil markets. - Highlights: • We study the impact of outliers on volatility persistence of crude oil markets. • We identify outliers and patches of outliers due to specific events. • We show that outliers can bias (i) the estimates of the parameters of GARCH models, (ii) the regularity and non-negativity conditions of GARCH-type models, (iii) the detection of structural breaks in volatility of crude oil markets

  13. Magnetic properties and EXAFS study of nanocrystalline Fe2Mn0.5Cu0.5Al synthesized using mechanical alloying technique

    International Nuclear Information System (INIS)

    Nanto, Dwi; Yang, Dong-Seok; Yu, Seong-Cho

    2014-01-01

    Nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al has been synthesized by the mechanical alloying technique and studied as a function of milling time. Alloy nature of Fe 2 Mn 0.5 Cu 0.5 Al was observed in a sample milled for 96 h. The magnetic saturation is 4.0 μ B /f.u., which coincidently follows Slater–Pauling rule at 5 K. Nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al has enhanced saturate magnetization compared to any other fabrication of Fe 2 MnAl reported. Cu element plays an important role in site competes with other elements and may result in the enhancement of saturate magnetization. In accordance to the magnetic results and EXAFS pattern, it was revealed that the dynamics of magnetic properties were confirmed as structural changes of nanocrystalline Fe 2 Mn 0.5 Cu 0.5 Al

  14. ENHANCED ANAEROBIC DIGESTION OF FOOD WASTE BY SUPPLEMENTING TRACE ELEMENTS: ROLE OF SELENIUM (VI AND IRON (II

    Directory of Open Access Journals (Sweden)

    Javkhlan eAriunbaatar

    2016-02-01

    Full Text Available This paper discusses the potential to enhance the anaerobic digestion of food waste FW by supplementing trace elements (Fe, Co, Ni, Zn, Mn, Cu, Se, and Mo individually as well as in cocktails. A series of batch experiments on the biomethane potential of synthetic food waste were performed with low (FW-A and high (FW-B trace element background concentrations prepared in, respectively, Delft (The Netherlands and Tampa (Florida, USA. The most effective trace elements for FW-A were Fe with an increase of 39.2 (± 0.6 % of biomethane production, followed by Se (34.1 ± 5.6 % increase, Ni (26.4 ± 0.2 % increase and Co (23.8 ± 0.2 % increase. For FW-B supplementing these trace elements did not result in enhancement of the biomethane production, except for Se. FW-B had a Se concentration of 1.3 (± 0. 5 µg/gTS, while it was below the detection limit for FW-A. Regardless of the FW source, Se resulted in 30 – 35% increase of biomethane production at a concentration range of 25-50 µg/L (0.32 – 0.63 µM. Volatile fatty acids analysis revealed that TE supplementation enhances their consumption, thus yielding a higher biomethane production. Moreover, additional experiments on sulfide inhibition showed the enhancing effects of trace elements on the anaerobic digestion of food waste were not related with sulfide toxicity, but with the enzymatic reactions and/or microbial biomass aggregation.

  15. Recovering the Elemental Composition of Comet Wild 2 Dust in Five Stardust Impact Tracks and Terminal Particles in Aerogel

    International Nuclear Information System (INIS)

    Ishii, H A; Brennan, S; Bradley, J P; Luening, K; Ignatyev, K; Pianetta, P

    2007-01-01

    The elemental (non-volatile) composition of five Stardust impact tracks and terminal particles left from capture of Comet 81P/Wild 2 dust were mapped in a synchrotron x-ray scanning microprobe with full fluorescence spectra at each pixel. Because aerogel includes background levels of several elements of interest, we employ a novel 'dual threshold' approach to discriminate against background contaminants: an upper threshold, above which a spectrum contains cometary material plus aerogel and a lower threshold below which it contains only aerogel. The difference between normalized cometary-plus-background and background-only spectra is attributable to cometary material. The few spectra in between are discarded since misallocation is detrimental: cometary material incorrectly placed in the background spectrum is later subtracted from the cometary spectrum, doubling the loss of reportable cometary material. This approach improves precision of composition quantification. We present the refined whole impact track and terminal particle elemental abundances for the five impact tracks. One track shows mass increases in Cr and Mn (1.4x), Cu, As and K (2x), Zn (4x) and total mass (13%) by dual thresholds compared to a single threshold. Major elements Fe and Ni are not significantly affected. The additional Cr arises from cometary material containing little Fe. We exclude Au intermixed with cometary material because it is found to be a localized surface contaminant carried by comet dust into an impact track. The dual threshold technique can be used in other situations where elements of interest in a small sample embedded in a matrix are also present in the matrix itself

  16. Fuel element

    International Nuclear Information System (INIS)

    Armijo, J.S.

    1976-01-01

    A fuel element for nuclear reactors is proposed which has a higher corrosion resisting quality in reactor operations. The zirconium alloy coating around the fuel element (uranium or plutonium compound) has on its inside a protection layer of metal which is metallurgically bound to the substance of the coating. As materials are namned: Alluminium, copper, niobium, stainless steel, and iron. This protective metallic layer has another inner layer, also metallurgically bound to its surface, which consists usually of a zirconium alloy. (UWI) [de

  17. Linking waterlogging tolerance with Mn²⁺ toxicity: a case study for barley.

    Science.gov (United States)

    Huang, X; Shabala, S; Shabala, L; Rengel, Z; Wu, X; Zhang, G; Zhou, M

    2015-01-01

    Vast agricultural areas are affected by flooding, causing up to 80% yield reduction and resulting in multibillion dollar losses. Up to now, the focus of plant breeders was predominantly on detrimental effects of anoxia, while other (potentially equally important) traits were essentially neglected; one of these is soil elemental toxicity. Excess water triggers a progressive decrease in soil redox potential, thus increasing the concentration of Mn(2+) that can be toxic to plants if above a specific threshold. This work aimed to quantify the relative contribution of Mn(2+) toxicity to waterlogging stress tolerance, using barley as a case study. Twenty barley (Hordeum vulgare) genotypes contrasting in waterlogging stress tolerance were studied for their ability to cope with toxic (1 mm) amounts of Mn(2+) in the root rhizosphere. Under Mn(2+) toxicity, chlorophyll content of most waterlogging-tolerant genotypes (TX9425, Yerong, CPI-71284-48 and CM72) remained above 60% of the control value, whereas sensitive genotypes (Franklin and Naso Nijo) had 35% less chlorophyll than 35% of controls. Manganese concentration in leaves was not related to visual Mn(2+) toxicity symptoms, suggesting that various Mn(2+) tolerance mechanisms might operate in different tolerant genotypes, i.e. avoidance versus tissue tolerance. The overall significant (r = 0.60) correlation between tolerance to Mn(2+) toxicity and waterlogging in barley suggests that plant breeding for tolerance to waterlogging traits may be advanced by targeting mechanisms conferring tolerance to Mn(2+) toxicity, at least in this species. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  18. Effects of reactive Mn(III)-oxalate complexes on structurally intact plant cell walls

    Science.gov (United States)

    Summering, J. A.; Keiluweit, M.; Goni, M. A.; Nico, P. S.; Kleber, M.

    2011-12-01

    Lignin components in the in plant litter are commonly assumed to have longer residence times in soil than many other compounds, which are supposedly, more easily degradable. The supposed resistance of lignin compounds to decomposition is generally attributed to the complex chain of biochemical steps required to create footholds in the non-porous structure of ligno-cellulose in cell walls. Interestingly, Mn(III) complexes have shown the ability to degrade ligno-cellulose. Mn(III) chelated by ligands such as oxalate are soluble oxidizers with a high affinity for lignin structures. Here we determined (i) the formation and decay kinetics of the Mn(III)-oxalate complexes in aqueous solution and (ii) the effects that these complexes have on intact ligno-cellulose. UV/vis spectroscopy and iodometric titrations confirmed the transient nature of Mn(III)-oxalate complexes with decay rates being in the order of hours. Zinnia elegans tracheary elements - a model ligno-cellulose substrate - were treated with Mn(III)-oxalate complexes in a newly developed flow-through reactor. Soluble decomposition products released during the treatment were analyzed by GC/MS and the degree of cell integrity was measured by cell counts, pre- and post-treatment counts indicate a decrease in intact Zinnia elegans as a result of Mn(III)-treatment. GC/MS results showed the release of a multitude of solubilized lignin breakdown products from plant cell walls. We conclude that Mn(III)-oxalate complexes have the ability to lyse intact plant cells and solubilize lignin. Lignin decomposition may thus be seen as resource dependent, with Mn(III) a powerful resource that should be abundant in terrestrial characterized by frequent redox fluctuations.

  19. Modelling of volatility in monetary transmission mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel [Department of Statistics and Operation Analysis, Faculty of Business and Economics, Mendel University in Brno, Zemědělská 1, 61300, Brno (Czech Republic); Bednářová, Petra [Institute of Technology and Business, Okružní 517/10, 370 01, České Budějovice (Czech Republic)

    2015-03-10

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches.

  20. Modelling of volatility in monetary transmission mechanism

    International Nuclear Information System (INIS)

    Dobešová, Anna; Klepáč, Václav; Kolman, Pavel; Bednářová, Petra

    2015-01-01

    The aim of this paper is to compare different approaches to modeling of volatility in monetary transmission mechanism. For this purpose we built time-varying parameter VAR (TVP-VAR) model with stochastic volatility and VAR-DCC-GARCH model with conditional variance. The data from three European countries are included in the analysis: the Czech Republic, Germany and Slovakia. Results show that VAR-DCC-GARCH system captures higher volatility of observed variables but main trends and detected breaks are generally identical in both approaches

  1. Volatility Forecast in Crises and Expansions

    Directory of Open Access Journals (Sweden)

    Sergii Pypko

    2015-08-01

    Full Text Available We build a discrete-time non-linear model for volatility forecasting purposes. This model belongs to the class of threshold-autoregressive models, where changes in regimes are governed by past returns. The ability to capture changes in volatility regimes and using more accurate volatility measures allow outperforming other benchmark models, such as linear heterogeneous autoregressive model and GARCH specifications. Finally, we show how to derive closed-form expression for multiple-step-ahead forecasting by exploiting information about the conditional distribution of returns.

  2. Metabolomic and elemental profiling of melon fruit quality as affected by genotype and environment

    NARCIS (Netherlands)

    Bernillon, S.; Biais, B.; Deborde, C.; Maucort, M.; Cabasson, C.; Gibon, Y.; Hansen, T.; Husted, S.; Vos, de R.C.H.; Mumm, R.; Jonker, H.; Ward, J.L.; Miller, S.J.; Baker, J.M.; Burger, J.; Tadmor, Y.; Beale, M.H.; Schjoerring, J.K.; Schaffer, A.; Rolin, D.; Hall, R.D.; Moing, A.

    2013-01-01

    Melon (Cucumis melo L.) is a global crop in terms of economic importance and nutritional quality. The aim of this study was to explore the variability in metabolite and elemental composition of several commercial varieties of melon in various environmental conditions. Volatile and non-volatile

  3. Effect of storage on the yield and the elemental composition of the ...

    African Journals Online (AJOL)

    The yield of the volatile oils of Eucalyptus citrodora and lemon grass obtained from a locally constructed apparatus is presented. Hydro distillation of the fresh and dried leaves at room temperature (25°C) gave a better yield with dried leaves. Elemental composition of the crude and rectified volatile oils of the predominant ...

  4. Valence state of Mn in Ca-doped LaMnO3 studied by high-resolution Mn K ß emission spectroscopy

    NARCIS (Netherlands)

    Tyson, T.A.; Qian, Q.; Kao, C.-C.; Rueff, J.-P.; Groot, F.M.F. de; Croft, M.; Cheong, S.-W.; Greenblatt, M.; Subramanian, M.A.

    1999-01-01

    Mn K ß x-ray emission spectra provide a direct method to probe the effective spin state and charge density on the Mn atom and is used in an experimental study of a class of Mn oxides. Specifically, the Mn K ß line positions and detailed spectral shapes depend on the oxidation and the spin state of

  5. Mn induced 1 × 2 reconstruction in the τ-MnAl(0 0 1) surface

    Science.gov (United States)

    Guerrero-Sánchez, J.; Takeuchi, Noboru

    2018-05-01

    We report on first principles total energy calculations to describe the structural, electronic and magnetic properties of MnAl(0 0 1) surfaces. We have concentrated in structural models having 1 × 1 and 1 × 2 periodicities, since recent experiments of the similar MnGa(0 0 1) surface have found 1 × 1 and 1 × 2 reconstructions. Our calculations show the existence of two stable structures for different ranges of chemical potential. A 1 × 1 surface is stable for Al-rich conditions, whereas a Mn-induced 1 × 2 reconstruction appears after increasing the Mn chemical potential up to Mn-rich conditions. It is important to notice that experimentally, Mn rich conditions are important for improved magnetic properties. The Mn layers in both structures have ferromagnetic arrangements, but they are aligned antiferromagnetically with the almost no magnetic Al atoms. Moreover, the on top Mn atoms, which produce the 1 × 2 reconstruction, align antiferromagnetically with the second layer Mn atoms. These findings are similar to those obtained experimentally in MnGa thin films grown by molecular beam epitaxy. Therefore, this method could also be used to grow the proposed MnAl films.

  6. Aerosol volatility in a boreal forest environment

    Science.gov (United States)

    Häkkinen, S. A. K.; ńijälä, M.; Lehtipalo, K.; Junninen, H.; Virkkula, A.; Worsnop, D. R.; Kulmala, M.; Petäjä, T.; Riipinen, I.

    2012-04-01

    Climate and health effects of atmospheric aerosols are determined by their properties such as their chemical composition. Aerosol chemical composition can be studied indirectly by measuring volatility of aerosol particles. The volatility of submicron aerosol particles (20-500 nm) was studied in a boreal forest site at SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations II) station (Vesala et al., 1998) in Hyytiälä, Finland, during 01/2008-05/2010. The instrument used for the measurements was VDMPS (Volatility Differential Mobility Particle Sizer), which consists of two separate instruments: DMPS (Differential Mobility Particle Sizer, Aalto et al., 2001) and TD (Thermodenuder, Wehner et al., 2002). Aerosol evaporation was examined by heating the aerosol and comparing the total aerosol mass before and after heating. In the VDMPS system ambient aerosol sample was heated up to temperatures ranging from 80 °C to 280 °C. The higher the heating temperature was the more aerosol material was evaporated. There was a non-volatile residual present in aerosol particles when heated up to 280 °C. This residual explained (20±8)% of the total aerosol mass. Aerosol non-volatile mass fraction was highest during winter and smallest during summer months. The role of black carbon in the observed non-volatile residual was determined. Black carbon explained 40 to 90% of the non-volatile mass. Especially during colder seasons noticeable amount of non-volatile material, something else than black carbon, was observed. According to Kalberer et al. (2004) some atmospheric organic species can form polymers that have high evaporation temperatures. Also low-volatile organic salts may contribute to the non-volatile aerosol (Smith et al., 2010). Aerosol mass composition measured directly with AMS (Aerosol Mass Spectrometer, Jayne et al., 2000) was analyzed in order to examine the properties of the non-volatile material (other than black carbon). The AMS measurements were performed

  7. Role of Reactive Mn Complexes in a Litter Decomposition Model System

    Science.gov (United States)

    Nico, P. S.; Keiluweit, M.; Bougoure, J.; Kleber, M.; Summering, J. A.; Maynard, J. J.; Johnson, M.; Pett-Ridge, J.

    2012-12-01

    The search for controls on litter decomposition rates and pathways has yet to return definitive characteristics that are both statistically robust and can be understood as part of a mechanistic or numerical model. Herein we focus on Mn, an element present in all litter that is likely an active chemical agent of decomposition. Berg and co-workers (2010) found a strong correlation between Mn concentration in litter and the magnitude of litter degradation in boreal forests, suggesting that litter decomposition proceeds more efficiently in the presence of Mn. Although there is much circumstantial evidence for the potential role of Mn in lignin decomposition, few reports exist on mechanistic details of this process. For the current work, we are guided by the hypothesis that the dependence of decomposition on Mn is due to Mn (III)-oxalate complexes act as a 'pretreatment' for structurally intact ligno-carbohydrate complexes (LCC) in fresh plant cell walls (e.g. in litter, root and wood). Manganese (III)-ligand complexes such as Mn (III)-oxalate are known to be potent oxidizers of many different organic and inorganic compounds. In the litter system, the unique property of these complexes may be that they are much smaller than exo-enzymes and therefore more easily able to penetrate LCC complexes in plant cell walls. By acting as 'diffusible oxidizers' and reacting with the organic matrix of the cell wall, these compounds can increase the porosity of fresh litter thereby facilitating access of more specific lignin- and cellulose decomposing enzymes. This possibility was investigated by reacting cell walls of single Zinnia elegans tracheary elements with Mn (III)-oxalate complexes in a continuous flow reactor. The uniformity of these individual plant cells allowed us to examine Mn (III)-induced changes in cell wall chemistry and ultrastructure on the micro-scale using fluorescence and electron microscopy as well as IR and X-ray spectromicroscopy. This presentation will

  8. Multi-elemental characterization of Cuban natural zeolites

    International Nuclear Information System (INIS)

    Rizo, O.D.; Peraza, E.F.H.

    1997-01-01

    Concentration of 38 elements in samples from four important Cuban zeolite beds have been obtained by Instrumental Neutron Activation (INAA) and X-ray Fluorescence analyses (XRFA). In comparison with other analytical techniques good agreement was reached. The concentration values of minor element Ba, Sr, Zn and Mn and 25 trace element (including 9 REE) are at the first time reported in Cuban zeolite. It is important for the zeolite evaluation in different industrial uses. (author)

  9. Trace elements levels in centenarian ‘dodgers’

    OpenAIRE

    Alis, Rafael; Santos-Lozano, Alejandro; Sanchís-Gomar, Fabián; Pareja Galeano, Helios; Fiuza Luces, María del Carmen; Garatachea, Nuria; Lucía Mulas, Alejandro; Emanuele, Enzo

    2016-01-01

    Trace element bioavailability can play a role in several metabolic and physiological pathways known to be altered during the aging process. We aimed to explore the association of trace elements with increased lifespan by analyzing the circulating levels of seven trace elements (Cr, Cu, Fe, Mn, Mo, Se and Zn) in a cohort of healthy centenarians or ‘dodgers’ (≥100 years, free of major age-related diseases) in comparison with sex-matched younger elderly controls. Centenarians showed significant ...

  10. Multi-elemental characterization of Cuban natural zeolites

    International Nuclear Information System (INIS)

    Diaz Rizo, O.; Herrera Peraza, E.F.

    1996-01-01

    Concentrations of 38 elements in samples from four important Cuban zeolite bed have beam obtained by Instrumental Neutron Activation (INAA) and X-Ray Fluorescence Analysis (XRFA). In comparison with other analytical techniques good agreement was achieved. The concentration values of minor element Ba, Sr, Zn, and Mn, and 25 trace element (including 9 REE) are at the first time reported in Cuban zeolite. It is important for the zeolite evaluation in different industrial uses

  11. Strong correlation and ferromagnetism in (Ga,Mn)As and (Ga,Mn)N

    International Nuclear Information System (INIS)

    Filippetti, A.; Spaldin, N.A.; Sanvito, S.

    2005-01-01

    The band energies of the ferromagnetic diluted magnetic semiconductors (Ga,Mn)As and (Ga,Mn)N are calculated using a self-interaction-free approach which describes covalent and strongly correlated electrons without adjustable parameters. Both materials are half-metallic, although the contribution of Mn-derived d states to the bands around the Fermi energy is very different in the two cases. In (Ga,Mn)As the bands are strongly p-d hybridized, with a dominance of As p states. In contrast in (Ga,Mn)N the Fermi energy lies within three flat bands of mainly d character that are occupied by two electrons. Thus the Mn ion in (Ga,Mn)N behaves as a deep trap acceptor, with the hole at 1.39 eV above the GaN valence band top, and is in excellent agreement with the experimental data

  12. Partitioning behaviour of trace elements in a stoker-fired combustion unit : An example using bituminous coals from the Greymouth coalfield (Cretaceous), New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.; Moore, T.A.; Weaver, S.D. [University of Canterbury, Department of Geological Science, Christchurch (New Zealand); Clemens, A.H.; Gong, D. [CRL Energy Ltd, PO Box 31 244, Lower Hutt (New Zealand); Eby, N. [Department of Environmental, Earth and Atmospheric Sciences, University of Massachusetts, Lowell, MA 01854 (United States)

    2005-07-20

    In order to understand trace element behaviour during combustion of coals from the Greymouth coalfield, combustion tests were performed on three seam composite samples. The major and trace elements from sub-samples of feed coal, bottom ash, fly ash, and flue gas were analysed by different techniques including inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), wavelength dispersive X-ray fluorescence (WD-XRF), and scanning electron microscopy with energy-dispersive X-ray analyser (SEM-EDXA). To help better understand trace element partitioning in combustion ash, float-sink and sequential leaching experiments were also employed to determine the association of trace elements with mineral matter or organic matter. Instrumental Neutron Activation Analysis (INAA) was also employed to determine trace element content in float and sink fractions of fly ash as well as in three major phases in the bottom ash. The partitioning behaviour of trace elements, including some that are environmentally sensitive, was also investigated through the use of float-sink tests and direct determination of trace elements in different combustion ash types and phases. Mass balance and partitioning of major and trace elements have been studied to determine the fate of trace elements after combustion. The partitioning of trace elements, especially hazardous air pollutants (HAPs), in different combustion ashes can be summarised as follows:1.Most trace elements, especially As, Ba, Co, Cr, Mn, Ni, are partitioned in the glassy and refractory bottom ash fractions. 2.A significant proportion of trace elements of As, Se, and Pb are partitioned into fly ash fractions. 3.Some volatile elements (e.g. > 90% of S and Hg and up to 64% of Cl) and, to a lesser extent, B (up to 44%) and Cd (up to 50%) are partitioned in the flue gas fraction. 4.Although the low ash yield of Greymouth coal seams have the advantage of generating less solid

  13. Altruism in a volatile world.

    Science.gov (United States)

    Kennedy, Patrick; Higginson, Andrew D; Radford, Andrew N; Sumner, Seirian

    2018-03-15

    The evolution of altruism-costly self-sacrifice in the service of others-has puzzled biologists since The Origin of Species. For half a century, attempts to understand altruism have developed around the concept that altruists may help relatives to have extra offspring in order to spread shared genes. This theory-known as inclusive fitness-is founded on a simple inequality termed Hamilton's rule. However, explanations of altruism have typically not considered the stochasticity of natural environments, which will not necessarily favour genotypes that produce the greatest average reproductive success. Moreover, empirical data across many taxa reveal associations between altruism and environmental stochasticity, a pattern not predicted by standard interpretations of Hamilton's rule. Here we derive Hamilton's rule with explicit stochasticity, leading to new predictions about the evolution of altruism. We show that altruists can increase the long-term success of their genotype by reducing the temporal variability in the number of offspring produced by their relatives. Consequently, costly altruism can evolve even if it has a net negative effect on the average reproductive success of related recipients. The selective pressure on volatility-suppressing altruism is proportional to the coefficient of variation in population fitness, and is therefore diminished by its own success. Our results formalize the hitherto elusive link between bet-hedging and altruism, and reveal missing fitness effects in the evolution of animal societies.

  14. Nano-sized Mn3O4 and β-MnOOH from the decomposition of β-cyclodextrin-Mn: 2. The water-oxidizing activities.

    Science.gov (United States)

    Najafpour, Mohammad Mahdi; Mostafalu, Ramin; Hołyńska, Małgorzata; Ebrahimi, Foad; Kaboudin, Babak

    2015-11-01

    Nano-sized Mn oxides contain Mn3O4, β-MnOOH and Mn2O3 have been prepared by a previously reported method using thermal decomposition of β-cyclodextrin-Mn complexes. In the next step, the water-oxidizing activities of these Mn oxides using cerium(IV) ammonium nitrate as a chemical oxidant are studied. The turnover frequencies for β-MnO(OH) and Mn3O4 are 0.24 and 0.01-0.17 (mmol O2/mol Mns), respectively. Subsequently, water-oxidizing activities of these compounds are compared to the other previously reported Mn oxides. Important factors affecting water oxidation by these Mn oxides are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Theoretical investigation of the reaction of Mn+ with ethylene oxide.

    Science.gov (United States)

    Li, Yuanyuan; Guo, Wenyue; Zhao, Lianming; Liu, Zhaochun; Lu, Xiaoqing; Shan, Honghong

    2012-01-12

    The potential energy surfaces of Mn(+) reaction with ethylene oxide in both the septet and quintet states are investigated at the B3LYP/DZVP level of theory. The reaction paths leading to the products of MnO(+), MnO, MnCH(2)(+), MnCH(3), and MnH(+) are described in detail. Two types of encounter complexes of Mn(+) with ethylene oxide are formed because of attachments of the metal at different sites of ethylene oxide, i.e., the O atom and the CC bond. Mn(+) would insert into a C-O bond or the C-C bond of ethylene oxide to form two different intermediates prior to forming various products. MnO(+)/MnO and MnH(+) are formed in the C-O activation mechanism, while both C-O and C-C activations account for the MnCH(2)(+)/MnCH(3) formation. Products MnO(+), MnCH(2)(+), and MnH(+) could be formed adiabatically on the quintet surface, while formation of MnO and MnCH(3) is endothermic on the PESs with both spins. In agreement with the experimental observations, the excited state a(5)D is calculated to be more reactive than the ground state a(7)S. This theoretical work sheds new light on the experimental observations and provides fundamental understanding of the reaction mechanism of ethylene oxide with transition metal cations.

  16. Realized volatility and absolute return volatility: a comparison indicating market risk.

    Science.gov (United States)

    Zheng, Zeyu; Qiao, Zhi; Takaishi, Tetsuya; Stanley, H Eugene; Li, Baowen

    2014-01-01

    Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods.

  17. International Coordination of Lunar Polar Volatiles Exploration

    Science.gov (United States)

    Gruener, J. E.; Suzuki, N. H.; Carpenter, J. D.

    2015-10-01

    The International Space Exploration Coordination Group (ISECG) has established a study team to coordinate the worldwide interest in lunar polar volatiles, and in particular water ice, in an effort to stimulate cooperation and collaboration.

  18. Release of volatile mercury from vascular plants

    Science.gov (United States)

    Siegel, S. M.; Puerner, N. J.; Speitel, T. W.

    1974-01-01

    Volatile, organic solvent soluble mercury has been found in leaves and seeds of several angiosperms. Leaves of garlic vine, avocado, and haole-koa release mercury in volatile form rapidly at room temperature. In garlic vine, the most active release is temperature dependent, but does not parallel the vapor-pressure temperature relationship for mercury. Mercury can be trapped in nitric-perchloric acid digestion fluid, or n-hexane, but is lost from the hexane unless the acid mixture is present. Seeds of haole-koa also contain extractable mercury but volatility declines in the series n-hexane (90%), methanol (50%), water (10%). This suggests that reduced volatility may accompany solvolysis in the more polar media.

  19. International trade and exchange rate volatility

    NARCIS (Netherlands)

    J.M.A. Viaene (Jean-Marie); C.G. de Vries (Casper)

    1992-01-01

    textabstractFor currencies with well developed forward markets several papers have investigated the conjectured negative relationship between trade and short term exchange rate volatility, without being very successful. A theoretical explanation for the empirical anomalies is provided by solving

  20. Volatility estimation using a rational GARCH model

    Directory of Open Access Journals (Sweden)

    Tetsuya Takaishi

    2018-03-01

    Full Text Available The rational GARCH (RGARCH model has been proposed as an alternative GARCHmodel that captures the asymmetric property of volatility. In addition to the previously proposedRGARCH model, we propose an alternative RGARCH model called the RGARCH-Exp model thatis more stable when dealing with outliers. We measure the performance of the volatility estimationby a loss function calculated using realized volatility as a proxy for true volatility and compare theRGARCH-type models with other asymmetric type models such as the EGARCH and GJR models.We conduct empirical studies of six stocks on the Tokyo Stock Exchange and find that a volatilityestimation using the RGARCH-type models outperforms the GARCH model and is comparable toother asymmetric GARCH models.

  1. Characterisation of selected volatile organic compounds in ...

    African Journals Online (AJOL)

    kshale

    2013-05-15

    May 15, 2013 ... have entered the commercial market, both in rural areas ... nation of volatile compounds include: gas chromate- graphy (GC) ... prior to the actual analysis, various extraction methods ..... traditional and industrial 'orujo' spirits.

  2. Reducing ammonia volatilization from compound fertilizers ...

    African Journals Online (AJOL)

    Paul

    2012-09-13

    Sep 13, 2012 ... Ammonia volatilization is a direct loss of available nitrogen in agriculture. The objective of this ... precautions in handling and storage. Zeolites can be ..... Humic and Fulvic Acids isolated from Palm Oil Mill Effluent Sludge.

  3. Volatile Organic Compunds (Environmental Health Student Portal)

    Science.gov (United States)

    ... Weather Health Effects Take Action Water Pollution Water Pollution Home Chemicals and Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Videos Games Experiments For Teachers Home Chemicals Volatile ...

  4. Reactive flash volatilization of fluid fuels

    Science.gov (United States)

    Schmidt, Lanny D.; Dauenhauer, Paul J.; Dreyer, Bradon J.; Salge, James R.

    2013-01-08

    The invention provides methods for the production of synthesis gas. More particularly, various embodiments of the invention relate to systems and methods for volatilizing fluid fuel to produce synthesis gas by using a metal catalyst on a solid support matrix.

  5. Volatile compounds in meat and meat products

    Directory of Open Access Journals (Sweden)

    Monika KOSOWSKA

    Full Text Available Abstract Meaty flavor is composed of a few hundreds of volatile compounds, only minor part of which are responsible for the characteristic odor. It is developed as a result of multi-directional reactions proceeding between non-volatile precursors contained in raw meat under the influence of temperature. The volatile compounds are generated upon: Maillard reactions, lipid oxidation, interactions between Maillard reaction products and lipid oxidation products as well as upon thiamine degradation. The developed flavor is determined by many factors associated with: raw material (breed, sex, diet and age of animal, conditions and process of slaughter, duration and conditions of meat storage, type of muscle, additives applied and the course of the technological process. The objective of this review article is to draw attention to the issue of volatile compounds characteristic for meat products and factors that affect their synthesis.

  6. Hammerstein system represention of financial volatility processes

    Science.gov (United States)

    Capobianco, E.

    2002-05-01

    We show new modeling aspects of stock return volatility processes, by first representing them through Hammerstein Systems, and by then approximating the observed and transformed dynamics with wavelet-based atomic dictionaries. We thus propose an hybrid statistical methodology for volatility approximation and non-parametric estimation, and aim to use the information embedded in a bank of volatility sources obtained by decomposing the observed signal with multiresolution techniques. Scale dependent information refers both to market activity inherent to different temporally aggregated trading horizons, and to a variable degree of sparsity in representing the signal. A decomposition of the expansion coefficients in least dependent coordinates is then implemented through Independent Component Analysis. Based on the described steps, the features of volatility can be more effectively detected through global and greedy algorithms.

  7. Defect Structure of High-Temperature-Grown GaMnSb/GaSb

    International Nuclear Information System (INIS)

    Romanowski, P.; Bak-Misiuk, J.; Dynowska, E.; Domagala, J.Z.; Wojciechowski, T.; Jakiela, R.; Sadowski, J.; Barcz, A.; Caliebe, W.

    2010-01-01

    GaMnSb/GaSb(100) layers with embedded MnSb inclusions have been grown at 720 K using MBE technique. This paper presents the investigation of the defect structure of Ga1-xMnxSb layers with different content of manganese (up to x = 0.07). X-ray diffraction method using conventional and synchrotron radiation was applied. Dimensions and shapes of inclusions were detected by scanning electron microscopy. Depth profiles of elements were measured using secondary ion mass spectroscopy technique. (authors)

  8. Chemical effect on total mass attenuation coefficients of V, Cr, Mn, Co and Ni

    International Nuclear Information System (INIS)

    Soeguet, Oe.; Colak, S.; Bueyuekkasap, E.; Kuecuekoender, A.

    2002-01-01

    Detailed interpretation of data obtained from X-ray transmission measurements usually depends on the assumption that the contribution of each element is additive. This assumption yields the mixture rule for X-ray attenuation coefficients which is valid if molecular and chemical effects are negligible. Total mass attenuation coefficients of V, Cr, Mn, Co and Ni in various their compounds was measured. Absorption corrections were carried on data for ligands in the compounds. It was found that V, Cr, Mn, Co and Ni had different total mass attenuation coefficients in the different compounds. Results were compared with theoretical values of HUBBELL and SELTZER. (author)

  9. Ferromagnetic (Ga,Mn)As layers and nanostructures: control of magnetic anisotropy by strain engineering

    Energy Technology Data Exchange (ETDEWEB)

    Wenisch, Jan

    2008-07-01

    This work studies the fundamental connection between lattice strain and magnetic anisotropy in the ferromagnetic semiconductor (Ga,Mn)As. The first chapters provide a general introduction into the material system and a detailed description of the growth process by molecular beam epitaxy. A finite element simulation formalism is developed to model the strain distribution in (Ga,Mn)As nanostructures is introduced and its predictions verified by high-resolution X-ray diffraction methods. The influence of lattice strain on the magnetic anisotropy is explained by an magnetostatic model. A possible device application is described in the closing chapter. (orig.)

  10. Trace elements in magnetite from massive iron oxide-apatite deposits indicate a combined formation by igneous and magmatic-hydrothermal processes

    Science.gov (United States)

    Knipping, Jaayke L.; Bilenker, Laura D.; Simon, Adam C.; Reich, Martin; Barra, Fernando; Deditius, Artur P.; Wälle, Markus; Heinrich, Christoph A.; Holtz, François; Munizaga, Rodrigo

    2015-12-01

    Iron oxide-apatite (IOA) deposits are an important source of iron and other elements (e.g., REE, P, U, Ag and Co) vital to modern society. However, their formation, including the namesake Kiruna-type IOA deposit (Sweden), remains controversial. Working hypotheses include a purely magmatic origin involving separation of an Fe-, P-rich, volatile-rich oxide melt from a Si-rich silicate melt, and precipitation of magnetite from an aqueous ore fluid, which is either of magmatic-hydrothermal or non-magmatic surface or metamorphic origin. In this study, we focus on the geochemistry of magnetite from the Cretaceous Kiruna-type Los Colorados IOA deposit (∼350 Mt Fe) located in the northern Chilean Iron Belt. Los Colorados has experienced minimal hydrothermal alteration that commonly obscures primary features in IOA deposits. Laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) transects and electron probe micro-analyzer (EPMA) wavelength-dispersive X-ray (WDX) spectrometry mapping demonstrate distinct chemical zoning in magnetite grains, wherein cores are enriched in Ti, Al, Mn and Mg. The concentrations of these trace elements in magnetite cores are consistent with igneous magnetite crystallized from a silicate melt, whereas magnetite rims show a pronounced depletion in these elements, consistent with magnetite grown from an Fe-rich magmatic-hydrothermal aqueous fluid. Further, magnetite grains contain polycrystalline inclusions that re-homogenize at magmatic temperatures (>850 °C). Smaller inclusions (500 ppm) concentrations.

  11. The geochemical profile of Mn, Co, Cu and Fe in Kerteh Mangrove Forest, Terengganu

    International Nuclear Information System (INIS)

    Kamaruzzaman, B.Y.; Antotina, A.; Airiza, Z.; Syalindran, S.; Ong, M.C.

    2007-01-01

    The geochemical profile of Kerteh mangrove sediments was analyzed for the vertical and horizontal distribution. The 100 cm core sediment sample and 15 surface sediments samples were taken from the field. The geochemical elements of Mn, Co, Cu and Fe of the sediments were analyzed. Geochemical proxy of Mn, Co, Cu and Fe were analyzed by using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The mean concentrations of Mn, Co, Cu and Fe for the vertical distribution were 210.18 μg/ g, 15.55 μg/ g, 43.65 μg/ g and 1.88 μg/ g respectively. on the other hand, the mean concentrations of the geochemical elements for horizontal distributions were 230.50 μg/ g for Mn, 17.57 μg/ g for Co, 43.381 μg/ g for Cu and 2.93 μg/ g for Fe. Enrichment factor and normalization was used to point out the level of pollution. The EF and the normalization indicated that all the geochemical elements were from the natural sources. (author)

  12. Investor attention and FX market volatility

    OpenAIRE

    Goddard, John; Kita, Arben; Wang, Qingwei

    2015-01-01

    We study the relationship between investors’ active attention, measured by a Google search volume index (SVI), and the dynamics of currency prices. Investor attention is correlated with the trading activities of large FX market participants. Investor attention comoves with comtemporaneous FX market volatility and predicts subsequent FX market volatility, after controlling for macroeconomic fundamentals. In addition, investor attention is related to the currency risk premium. Our results sugge...

  13. Implied Volatility Surface: Construction Methodologies and Characteristics

    OpenAIRE

    Cristian Homescu

    2011-01-01

    The implied volatility surface (IVS) is a fundamental building block in computational finance. We provide a survey of methodologies for constructing such surfaces. We also discuss various topics which can influence the successful construction of IVS in practice: arbitrage-free conditions in both strike and time, how to perform extrapolation outside the core region, choice of calibrating functional and selection of numerical optimization algorithms, volatility surface dynamics and asymptotics.

  14. Essays on Economic Volatility and Financial Frictions

    OpenAIRE

    Zhao, Hongyan

    2012-01-01

    This dissertation consists of three essays in macroeconomics. The first one essay discusses the reasons of Chinese huge foreign reserves holdings. It contributes to the literature of sudden stops, precautionary saving and foreign assets holdings. In the second essay, I study the price volatility of commodities and manufactured goods. I measure the price volatility of each individual goods but not on the aggregated level and therefore the results complete the related study. The third essay exp...

  15. News Impact Curve for Stochastic Volatility Models

    OpenAIRE

    Makoto Takahashi; Yasuhiro Omori; Toshiaki Watanabe

    2012-01-01

    This paper proposes a new method to compute the news impact curve for stochastic volatility (SV) models. The new method incorporates the joint movement of return and volatility, which has been ignored by the extant literature, by simply adding a couple of steps to the Bayesian MCMC estimation procedures for SV models. This simple procedure is versatile and applicable to various SV type models. Contrary to the monotonic news impact functions in the extant literature, the new method gives a U-s...

  16. Ammonia volatilization from sows on grassland

    Science.gov (United States)

    Sommer, S. G.; Søgaard, H. T.; Møller, H. B.; Morsing, S.

    According to regulations, sows with piglets on organic farms must graze on pastures. Volatilization of ammonia (NH 3) from urine patches may represent a significant source of nitrogen (N) loss from these farms. Inputs of N are low on organic farms and losses may reduce crop production. This study examined spatial variations in NH 3 volatilization using a movable dynamic chamber, and the pH and total ammoniacal nitrogen (TAN) content in the topsoil of pastures with grazing sows was measured during five periods between June 1998 and May 1999. Gross NH 3 volatilization from the pastures was also measured with an atmospheric mass balance technique during seven periods from September 1997 until June 1999. The dynamic chamber study showed a high variation in NH 3 volatilization because of the distribution of urine; losses were between 0 and 2.8 g NH 3-N m -2 day -1. Volatilization was highest near the feeding area and the huts, where the sows tended to urinate. Ammonia volatilization rate was linearly related to the product of NH 3 concentration in the boundary layer and wind speed. The NH 3 in the boundary layer was in equilibrium with NH 3 in soil solution. Gross NH 3 volatilization was in the range 0.07-2.1 kg NH 3-N ha -1 day -1 from a pasture with 24 sows ha -1. Ammonia volatilization was related to the amount of feed given to the sows, incident solar radiation and air temperature during measuring periods, and also to temperature, incident solar radiation and rain 1-2 days before measurements. Annual ammonia loss was 4.8 kg NH 3-N sow -1.

  17. Decomposing European bond and equity volatility

    OpenAIRE

    Christiansen, Charlotte

    2004-01-01

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditional variance of e.g. the unexpected German stock return is divided into separate effects from the contemporaneous idiosyncratic variance of US bonds, US stocks, European bonds, European stocks, German...

  18. Range-based volatility, expected stock returns, and the low volatility anomaly

    Science.gov (United States)

    2017-01-01

    One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics. PMID:29190652

  19. Level Shifts in Volatility and the Implied-Realized Volatility Relation

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; de Magistris, Paolo Santucci

    We propose a simple model in which realized stock market return volatility and implied volatility backed out of option prices are subject to common level shifts corresponding to movements between bull and bear markets. The model is estimated using the Kalman filter in a generalization to the mult......We propose a simple model in which realized stock market return volatility and implied volatility backed out of option prices are subject to common level shifts corresponding to movements between bull and bear markets. The model is estimated using the Kalman filter in a generalization...... to the multivariate case of the univariate level shift technique by Lu and Perron (2008). An application to the S&P500 index and a simulation experiment show that the recently documented empirical properties of strong persistence in volatility and forecastability of future realized volatility from current implied...... volatility, which have been interpreted as long memory (or fractional integration) in volatility and fractional cointegration between implied and realized volatility, are accounted for by occasional common level shifts....

  20. Range-based volatility, expected stock returns, and the low volatility anomaly.

    Science.gov (United States)

    Blau, Benjamin M; Whitby, Ryan J

    2017-01-01

    One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics.

  1. Range-based volatility, expected stock returns, and the low volatility anomaly.

    Directory of Open Access Journals (Sweden)

    Benjamin M Blau

    Full Text Available One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility, which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics.

  2. Bias correction in the realized stochastic volatility model for daily volatility on the Tokyo Stock Exchange

    Science.gov (United States)

    Takaishi, Tetsuya

    2018-06-01

    The realized stochastic volatility model has been introduced to estimate more accurate volatility by using both daily returns and realized volatility. The main advantage of the model is that no special bias-correction factor for the realized volatility is required a priori. Instead, the model introduces a bias-correction parameter responsible for the bias hidden in realized volatility. We empirically investigate the bias-correction parameter for realized volatilities calculated at various sampling frequencies for six stocks on the Tokyo Stock Exchange, and then show that the dynamic behavior of the bias-correction parameter as a function of sampling frequency is qualitatively similar to that of the Hansen-Lunde bias-correction factor although their values are substantially different. Under the stochastic diffusion assumption of the return dynamics, we investigate the accuracy of estimated volatilities by examining the standardized returns. We find that while the moments of the standardized returns from low-frequency realized volatilities are consistent with the expectation from the Gaussian variables, the deviation from the expectation becomes considerably large at high frequencies. This indicates that the realized stochastic volatility model itself cannot completely remove bias at high frequencies.

  3. Synthesis of Li-Mn-O mesocrystals with controlled crystal phases through topotactic transformation of MnCO3

    Science.gov (United States)

    Dang, Feng; Hoshino, Tatsuhiko; Oaki, Yuya; Hosono, Eiji; Zhou, Haoshen; Imai, Hiroaki

    2013-02-01

    Mesocrystals of Li-Mn-O compounds, such as LiMn2O4, Li2MnO3, and LiMnO2-Li2MnO3, consisting of oriented nanoscale units were selectively produced under hydrothermal conditions from biomimetically prepared MnCO3 mesocrystals. Topotactic transformation through the intermediate phase of Mn5O8 inheriting a hierarchical structure of the MnCO3 precursor was essential for the formation of the mesocrystal compounds. The crystal phases were successfully controlled by varying the conditions for the hydrothermal reactions. The Li-Mn-O mesocrystals have considerable potential as cathodes of Li-ion batteries.Mesocrystals of Li-Mn-O compounds, such as LiMn2O4, Li2MnO3, and LiMnO2-Li2MnO3, consisting of oriented nanoscale units were selectively produced under hydrothermal conditions from biomimetically prepared MnCO3 mesocrystals. Topotactic transformation through the intermediate phase of Mn5O8 inheriting a hierarchical structure of the MnCO3 precursor was essential for the formation of the mesocrystal compounds. The crystal phases were successfully controlled by varying the conditions for the hydrothermal reactions. The Li-Mn-O mesocrystals have considerable potential as cathodes of Li-ion batteries. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr33767g

  4. PELTIER ELEMENTS

    CERN Document Server

    Tani, Laurits

    2015-01-01

    To control Peltier elements, temperature controller was used. I used TEC-1091 that was manufactured my Meerstetter Engineering. To gain control with the temperature controller, software had to be intalled on a controlling PC. There were different modes to control the Peltier: Tempererature controller to control temperature, Static current/voltage to control voltage and current and LIVE ON/OFF to auto-tune the controller respectively to the system. Also, since near the collision pipe there is much radiation, radiation-proof Peltier elements have to be used. To gain the best results, I had to find the most efficient Peltier elements and try to get their cold side to -40 degrees Celsius.

  5. Volatile flavor compounds in yogurt: a review.

    Science.gov (United States)

    Cheng, Hefa

    2010-11-01

    Considerable knowledge has been accumulated on the volatile compounds contributing to the aroma and flavor of yogurt. This review outlines the production of the major flavor compounds in yogurt fermentation and the analysis techniques, both instrumental and sensory, for quantifying the volatile compounds in yogurt. The volatile compounds that have been identified in plain yogurt are summarized, with the few key aroma compounds described in detail. Most flavor compounds in yogurt are produced from lipolysis of milkfat and microbiological transformations of lactose and citrate. More than 100 volatiles, including carbonyl compounds, alcohols, acids, esters, hydrocarbons, aromatic compounds, sulfur-containing compounds, and heterocyclic compounds, are found in yogurt at low to trace concentrations. Besides lactic acid, acetaldehyde, diacetyl, acetoin, acetone, and 2-butanone contribute most to the typical aroma and flavor of yogurt. Extended storage of yogurt causes off-flavor development, which is mainly attributed to the production of undesired aldehydes and fatty acids during lipid oxidation. Further work on studying the volatile flavor compounds-matrix interactions, flavor release mechanisms, and the synergistic effect of flavor compounds, and on correlating the sensory properties of yogurt with the compositions of volatile flavor compounds are needed to fully elucidate yogurt aroma and flavor.

  6. Analysis of volatiles from irradiated yeast extract

    International Nuclear Information System (INIS)

    Liao Tao; Li Xin; Zu Xiaoyan; Chen Yuxia; Geng Shengrong

    2013-01-01

    The method for determination volatiles from irradiated yeast extract (YE) using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed in this paper. The extraction conditions were optimized with reference to the peak area and number of volatiles as aldehyde, ketone, alcohol, acid, ester and sulfur compounds. The optimized conditions of HS-SPME for volatiles in irradiated YE were: divinyl benzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber, extration time 40 min, extraction temperature 40℃. The volatiles from YE irradiated by 0-19.8 kGy were detected using HS-SPME coupled with GC-MS. The results showed that only 15 volatiles were detected from no irradiated YE and main compounds were acetic acid, 2, 3-butanediol and 1-hexanol, 2-ethyl-. There were 40 volatiles detected from irradiated YE and the main compounds were acetic acid, phenylethyl alcohol, heptanal and nonanal. Compare to no irradiated yeast extract, the aldehyde, ketone, alkene and disulfide, dimethyl were produced by irradiating process. (authors)

  7. Financial Development, Financial Structure, and Macroeconomic Volatility: Evidence from China

    Directory of Open Access Journals (Sweden)

    Feng Wei

    2016-11-01

    Full Text Available Using annual data from 1997–2014 of 30 provinces, municipalities, and autonomous regions, subdividing trended and cyclical volatility of macroeconomics and inflation, considering different indicators of financial development and financial structure, this paper investigated the impact of financial development and financial structure on macroeconomic volatility. The empirical results found that (1 the trended and cyclical volatility of the previous macroeconomic period had a significantly positive impact on that of the current period, and the impact of trended volatility was greater than that of cyclical volatility; (2 financial development had a significantly negative impact on macroeconomic cyclical volatility through inflation cyclical volatility, but inflation trended volatility would amplify macroeconomic volatility; financial markets have no significant effect on macroeconomic volatility; financial structure measured with the ratio of stock market turnover and the efficiency of the financial development had a significant positive impact on macroeconomic cyclical volatility; and (3 inflation trended volatility had a significantly negative impact on macroeconomic cyclical volatility and trended volatility, while inflation cyclical volatility had a significantly positive impact on macroeconomic cyclical volatility.

  8. Long memory and tail dependence in trading volume and volatility

    DEFF Research Database (Denmark)

    Rossi, Eduardo; Santucci de Magistris, Paolo

    2013-01-01

    We investigate the relationship between volatility, measured by realized volatility, and trading volume for 25 NYSE stocks. We show that volume and volatility are long memory but not fractionally cointegrated in most cases. We also find right tail dependence in the volatility and volume innovations...

  9. Characterization of elements in marine organisms

    International Nuclear Information System (INIS)

    Ishii, Toshiaki

    1993-01-01

    Characterization of elements in marine organisms was carried out to estimate the behavior of radionuclides in marine ecosystem or to clarify the physiological roles of elements in marine organisms. The concentrations of 238 U in fifty-five species of marine organisms were measured by inductively coupled plasma mass spectrometry. The concentrations of 238 U in soft tissues of marine animals ranged from 0.076 to 5000ng/g wet wt. Especially, the branchial heart of octopus vulgaris showed the specific accumulation of 238 U. The kidney granules of bivalve molluscs showed very high concentrations of Mn, Zn, 210 Pb, 210 Po etc. The XAFS study for the granules of Cyclosunetta menstrualis indicated that the chemical form of metals in the granules was phosphate (e. g. Mn 3 (PO 4 ) 2 · 4H 2 O). (author)

  10. The suitability of the simplified method of the analysis of coffee infusions on the content of Ca, Cu, Fe, Mg, Mn and Zn and the study of the effect of preparation conditions on the leachability of elements into the coffee brew.

    Science.gov (United States)

    Stelmach, Ewelina; Pohl, Pawel; Szymczycha-Madeja, Anna

    2013-12-01

    A fast and straightforward method of the analysis of coffee infusions was developed for measurements of total concentrations of Ca, Cu, Fe, Mg, Mn and Zn by flame atomic absorption spectrometry. Its validity was proved by the analysis of spiked samples; recoveries of added metals were found to be within 98-104% while the precision was better than 4%. The method devised was used for the analysis of re-distilled water infusions of six popular ground coffees available in the Polish market. Using the mud coffee preparation it was established that percentages of metals leached in these conditions varied a lot among analysed coffees, especially for Ca (14-42%), Mg (6-25%) and Zn (1-24%). For remaining metals, the highest extractabilities were assessed for Mn (30-52%) while the lowest for Fe (4-16%) and Cu (2-12%). In addition, it was found that the water type and the coffee brewing preparation method influence the concentration of studied metals in coffee infusions the most. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Metallic elements fractionation in municipal solid waste incineration residues

    Science.gov (United States)

    Kowalski, Piotr R.; Kasina, Monika; Michalik, Marek

    2016-04-01

    Municipal solid waste incineration (MSWI) residues are represented by three main materials: bottom ash, fly ash and air pollution control (APC) residues. Among them ˜80 wt% is bottom ash. All of that materials are products of high temperature (>1000° C) treatment of waste. Incineration process allows to obtain significant reduction of waste mass (up to 70%) and volume (up to 90%) what is commonly used in waste management to reduce the amount need to be landfilled or managed in other way. Incineration promote accumulation non-combustible fraction of waste, which part are metallic elements. That type of concentration is object of concerns about the incineration residues impact on the environment and also gives the possibility of attempts to recover them. Metallic elements are not equally distributed among the materials. Several factors influence the process: melting points, volatility and place and forms of metallic occurrence in the incinerated waste. To investigate metallic elements distribution in MSWI residues samples from one of the biggest MSW incineration plant in Poland were collected in 2015. Chemical analysis with emphasis on the metallic elements content were performed using inductively coupled plasma optical emission (ICP-OES) and mass spectrometry (ICP-MS). The bottom ash was a SiO2-CaO-Al2O3-Fe2O3-Na2O rich material, whereas fly ash and APC residues were mostly composed of CaO and SiO2. All of the materials were rich in amorphous phase occurring together with various, mostly silicate crystalline phases. In a mass of bottom ash 11 wt% were metallic elements but also in ashes 8.5 wt% (fly ash) and ˜4.5 wt% (APC residues) of them were present. Among the metallic elements equal distribution between bottom and fly ash was observed for Al (˜3.85 wt%), Mn (770 ppm) and Ni (˜65 ppm). In bottom ash Fe (5.5 wt%), Cr (590 ppm) and Cu (1250 ppm) were concentrated. These values in comparison to fly ash were 5-fold higher for Fe, 3-fold for Cu and 1.5-fold for

  12. Brain trace elements and aging

    International Nuclear Information System (INIS)

    Hebbrecht, Geert; Maenhaut, Willy; Reuck, Jacques de

    1999-01-01

    Degenerative mechanisms involved in the aging process of the brain are to a certain extent counteracted by repair mechanisms. In both degenerative and recovery processes, trace elements are involved. The present study focused on the role of two minor (i.e., K and Ca) and six trace elements (i.e., Mn, Fe, Cu, Zn, Se and Rb) in the aging process. The elements were determined by PIXE in cerebral cortex and white matter, basal ganglia, brainstem and cerebellar cortex of 18 postmortem human brains, from persons without a history of neurologic or psychiatric disease who deceased between the age of 7 and 79. This age range allowed us to study the relationship between elemental concentrations and age. The most prominent findings were a concentration decrease for K and Rb and a concentration increase for the elements Ca, Fe, Zn and Se. The study supports recent findings that Ca and Fe are involved in brain degenerative processes initiated by oxygen free radicals, whereas Zn and Se are involved in immunological reactions counteracting the aging process

  13. Concentration of stable elements in food products

    International Nuclear Information System (INIS)

    Montford, M.A.; Shank, K.E.; Hendricks, C.; Oakes, T.W.

    1980-01-01

    Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentration of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed

  14. Assessment of elemental contamination in road dust using EDXRF

    International Nuclear Information System (INIS)

    Saradhi, I.V.; Sandeep, P.; Pandit, G.G.

    2014-01-01

    Road dust samples were collected in different locations of heavy traffic, medium traffic, express way and industrial areas of Mumbai. The concentrations of various elements (Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn and Pb) in road dust samples were analyzed using EDXRF. The average elemental profile of road dust in Mumbai was comparable with studies carried out in other countries with slight variations. The estimated geo accumulation indices and enrichment factors indicated moderate elemental contamination and enrichment of anthropogenic elements in road dust samples. Factor analysis of elemental data resolved four sources namely crustal, tyre wear, vehicular/industrial emissions and break wear. (author)

  15. Heavy element affinities in Apollo 17 samples

    International Nuclear Information System (INIS)

    Allen, R.O. Jr.; Jovanovic, S.; Reed, G.W. Jr.

    1975-01-01

    204 Pb, Bi, Tl and Zn in samples from Apollo 17 exhibit relationships not found in samples from other sites. 204 Pb, Tl and Zn in residues remaining after dilute acid leaching are correlated with one another. Orange soil 74220, which is enriched in 204 Pb, Tl and Zn, is included in these relationships. In addition the submicron metallic phase generally associated with agglutinate formation is correlated with all three of these elements; this relationship has already been reported for 204 Pb in other samples. Thus, orange soil and agglutinates appear to be involved in concentrating heavy volatile metals. A process other than mixing is required to account for this. As a consequence of the isolation of the landing site by the surrounding massifs, local supply and recycling of volatile trace elements in soils may account for some of the interelement relations. (Auth.)

  16. Fuel element

    International Nuclear Information System (INIS)

    Kennedy, S.T.

    1982-01-01

    A nuclear reactor fuel element wherein a stack of nuclear fuel is prevented from displacement within its sheath by a retainer comprising a tube member which is radially expanded into frictional contact with the sheath by means of a captive ball within a tapered bore. (author)

  17. Transactinide elements

    International Nuclear Information System (INIS)

    Hemingway, J.D.

    1975-01-01

    The review is covered in sections, entitled: predicted nuclear properties - including closed shells, decay characteristics; predicted chemical properties - including electronic structure and calculated properties, X-radiation, extrapolated chemical properties, separation chemistry; methods of synthesis; the natural occurrence of superheavy elements. (U.K.)

  18. Can Internet search queries help to predict stock market volatility?

    OpenAIRE

    Dimpfl, Thomas; Jank, Stephan

    2011-01-01

    This paper studies the dynamics of stock market volatility and retail investor attention measured by internet search queries. We find a strong co-movement of stock market indices’ realized volatility and the search queries for their names. Furthermore, Granger causality is bi-directional: high searches follow high volatility, and high volatility follows high searches. Using the latter feedback effect to predict volatility we find that search queries contain additional information about market...

  19. Synthesis and Electrochemistry of Li3MnO4: Mn in the +5 OxidationState

    Energy Technology Data Exchange (ETDEWEB)

    Saint, Juliette.A.; Doeff, Marca M.; Reed, John

    2007-06-19

    Computational and experimental work directed at exploringthe electrochemical properties of tetrahedrally coordinated Mn in the +5oxidation state is presented. Specific capacities of nearly 700 mAh/g arepredicted for the redox processes of LixMnO4 complexes based on twotwo-phase reactions. One is topotactic extractionof Li from Li3MnO4 toform LiMnO4 and the second is topotactic insertion of Li into Li3MnO4 toform Li5MnO4. In experiments, it is found that the redox behavior ofLi3MnO4 is complicated by disproportionation of Mn5+ in solution to formMn4+ and Mn7+ and byother irreversible processes; although an initialcapacity of about 275 mAh/g in lithiumcells was achieved. Strategiesbased on structural considerations to improve the electrochemicalproperties of MnO4n- complexes are given.

  20. Synthesis and structural stability of Cr-doped Li2MnSiO4/C cathode materials by solid-state method

    Science.gov (United States)

    Cheng, Hong-Mei; Zhao, Shi-Xi; Wu, Xia; Zhao, Jian-Wei; Wei, Lei; Nan, Ce-Wen

    2018-03-01

    The crystal structure of the Li2MnSiO4 cathode material would collapse during the charge and discharge process because of that the Mn-O coordination polyhedron changed from [MnO4] into [MnO6] in the process of Mn+2 to Mn+4, but the Cr element could remain [CrO4] crystal ligand from Cr+2 to Cr+4, so Cr element substitution was used to improve the structural stability of the Li2MnSiO4 cathode material. In this work, Li2Mn1-xCrxSiO4/C nanocomposites were synthesized by solid-state method. XRD, SEM and TEM observations show that the as-prepared Li2Mn1-xCrxSiO4/C materials presents an orthorhombic crystal structure (S.G. Pmn21), the particle size of Li2Mn1-xCrxSiO4/C powder ranges from 50 to 100 nm. The XRD and XPS results indicate that Cr+2 is successfully doped into Li2MnSiO4 lattice and has well compatibility with Li2MnSiO4. The electrochemical results display that Li2Mn92.5%Cr7.5%SiO4/C exhibits significantly enhanced cycle stability and discharge capability. The initial discharge capacity of the Li2Mn92.5%Cr7.5%SiO4/C sample is 255 mAh g-1, and the discharge capacity was still about 60 mAh g-1 after 50 cycles. Furthermore, the XRD patterns, TEM images and Raman analysis reveal that the Cr doping enhances the structural stability of Li2Mn1-xCrxSiO4/C and improves the electrochemical activity of the cathode. Thus, the Li2Mn92.5%Cr7.5%SiO4/C have shown potential applications for lithium ion batteries.

  1. Microstructure and corrosion resistance of Sm-containing Al-Mn-Si-Fe-Cu alloy

    Directory of Open Access Journals (Sweden)

    Han Yuyin

    2017-12-01

    Full Text Available Optimizing alloy composition is an effective way to improve physical and chemical properties of automobile heat exchanger materials.A Sm-containing Al-Mn-Si-Fe-Cu alloy was investigated through transmission electron microscopy,scanning electron microscopy,and electrochemical measurement.Experimental results indicated that main phases distributed in the alloy wereα-Al(Mn,FeSi,Al2Sm and Al10Cu7Sm2.Alloying with Sm element could refine the precipitated α-Al(Mn,FeSi phase.Polarization testing results indicated that the corrosion surfacewas mainly composed of pitting pits and corrosion products.Sea water acetic acid test(SWAAT showed that corrosion loss increased first and then slowed downwith increase of the corrosion time.

  2. Reversibility in martensitic transformation and shape memory in high Mn ferrous alloys

    International Nuclear Information System (INIS)

    Tomota, Y.

    2000-01-01

    The reversibility of austenite (γ : fcc) epsilon (ε : hcp) martensitic transformation and shape memory effect in high Mn ferrous alloys are discussed. A particular emphasis is put on the ε → γ reverse transformation behavior in two poly-crystalline alloys, Fe-24Mn and Fe-24Mn-6Si, where the latter exhibits excellent shape memory while the former shows poor memory although their forward γ → ε transformation behavior is quite similar. TEM in situ observations have revealed that the motion of Shockley partial dislocations during ε → γ reverse transformation is different from each other in these two alloys. The influence of alloying elements on the shape memory effect can be related to solid solution hardening of austenite, suggesting an important role of internal stress. The effect of training on enhancing the shape memory is explained by such an internal stress distribution associated with the formation of very thin, i.e., nano-scale ε/γ lamellae. (orig.)

  3. Synthesis and characterization of Mn(III) chloro complexes with salen-type ligands

    International Nuclear Information System (INIS)

    Byun, Jong Chul; Han, Chung Hun; Lee, Nam Ho; Baik, Jong Seok; Park, Yu Chul

    2002-01-01

    A series of novel salen-type complexes ((Mn(III)(L acn )Cl): n=1∼11) containing Cl - ion were obtained by reactions of the Mn(CH 3 COO) 2 ·4H 2 O with the potentially tetradentate compartmental ligand (H 2 L acn ), prepared by condensation the of one mole of diamine (ethylenediamine, 1,3-propanediamine, o-phenylenediamine, and 2,2-dimethyl-1,3-propanediamine) with two moles of aldehyde (salicylaldehyde, 5-chloro- salicylaldehyde, 3,5-dichlorosalicylal-dehyde, and 3,5-di-tert-butyl-2-hydroxy-benzaldehyde) in a methanol solution . The resulting salen-type ligands and their Mn(III) complexes were identified and characterized by elemental analysis, conductivity, thermogravimetry and UV-VIS, IR, and NMR spectroscopy

  4. Hydrogenation properties and microstructure of Ti-Mn-based alloys for hybrid hydrogen storage vessel

    International Nuclear Information System (INIS)

    Shibuya, Masachika; Nakamura, Jin; Akiba, Etsuo

    2008-01-01

    Ti-Mn-based AB 2 -type alloys which are suitable for a hybrid hydrogen storage vessel have been synthesized and evaluated hydrogenation properties. As the third element V was added to Ti-Mn binary alloys. All the alloys synthesized in this work mainly consist of the C14 Laves and BCC phase. In the case of Ti0.5V0.5Mn alloy, the amounts of hydrogen absorption was 1.8 wt.% at 243 K under the atmosphere of 7 MPa H 2 , and the hydrogen desorption pressure was in the range of 0.2-0.4 MPa at 243 K. The hydrogen capacity of this alloy did not saturate under 7 MPa H 2 and seems to increase with hydrogen pressure up to 35 MPa that is estimated working pressure of the hybrid hydrogen storage vessel

  5. Electrochemical properties of LiMn2O4 cathode material doped with an actinide

    International Nuclear Information System (INIS)

    Eftekhari, Ali; Moghaddam, Abdolmajid Bayandori; Solati-Hashjin, Mehran

    2006-01-01

    Metal substation as an efficient approach for improvement of battery performance of LiMn 2 O 4 was performed by an actinide dopant. Uranium as the last natural element and most common actinide was employed for this purpose. Cyclic voltammetric studies revealed that incorporation of uranium into LiMn 2 O 4 spinel significantly improves electrochemical performance. It also strengthens the spinel stability to exhibit better cycleability. Surprisingly, the capacity increases upon cycling of LiU 0.01 Mn 1.99 O 4 cathode. This inverse behavior is attributed to uniform distribution of dopant during insertion/extraction process. In other words, this is an electrochemical refinement of the nanostructure which is not detectable in microscale morphology, as rearrangement of dopant in nanoscale occurs and this is an unexceptional nanostructural ordering. In addition, uranium doping strengthens the Li diffusion, particularly at redox potentials

  6. Volatility and variance swaps : A comparison of quantitative models to calculate the fair volatility and variance strike

    OpenAIRE

    Röring, Johan

    2017-01-01

    Volatility is a common risk measure in the field of finance that describes the magnitude of an asset’s up and down movement. From only being a risk measure, volatility has become an asset class of its own and volatility derivatives enable traders to get an isolated exposure to an asset’s volatility. Two kinds of volatility derivatives are volatility swaps and variance swaps. The problem with volatility swaps and variance swaps is that they require estimations of the future variance and volati...

  7. Volatile organic compounds in the unsaturated zone from radioactive wastes

    Science.gov (United States)

    Baker, Ronald J.; Andraski, Brian J.; Stonestrom, David A.; Luo, Wentai

    2012-01-01

    Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0–2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m-2 yr-1. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere.

  8. EMP and SIMS studies on Mn/Ca and Fe/Ca systematics in benthic foraminifera from the Peruvian OMZ: a contribution to the identification of potential redox proxies and the impact of cleaning protocols

    OpenAIRE

    Glock, N.; Eisenhauer, A.; Liebetrau, V.; Wiedenbeck, M.; Hensen, C.; Nehrke, G.

    2012-01-01

    In this study we present an initial dataset of Mn/Ca and Fe/Ca ratios in tests of benthic foraminifera from the Peruvian oxygen minimum zone (OMZ) determined with SIMS. These results are a contribution to a better understanding of the proxy potential of these elemental ratios for ambient redox conditions. Foraminiferal tests are often contaminated by diagenetic coatings, like Mn rich carbonate- or Fe and Mn rich (oxyhydr)oxide coatings. Thus, it is substantial to assure that...

  9. Non-Metallic Inclusions and Hot-Working Behaviour of Advanced High-Strength Medium-Mn Steels

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2016-06-01

    Full Text Available The work addresses the production of medium-Mn steels with an increased Al content. The special attention is focused on the identification of non-metallic inclusions and their modification using rare earth elements. The conditions of the thermomechanical treatment using the metallurgical Gleeble simulator and the semi-industrial hot rolling line were designed for steels containing 3 and 5% Mn. Hot-working conditions and controlled cooling strategies with the isothermal holding of steel at 400°C were selected. The effect of Mn content on the hot-working behaviour and microstructure of steel was addressed. The force-energetic parameters of hot rolling were determined. The identification of structural constituents was performed using light microscopy and scanning electron microscopy methods. The addition of rare earth elements led to the total modification of non-metallic inclusions, i.e., they replaced Mn and Al forming complex oxysulphides. The Mn content in a range between 3 and 5% does not affect the inclusion type and the hot-working behaviour. In contrast, it was found that Mn has a significant effect on a microstructure.

  10. Transfer factors of some selected radionuclides (radioactive Cs, Sr, Mn, Co and Zn) from soil to leaf vegetables

    International Nuclear Information System (INIS)

    Ban-nai, Tadaaki; Muramatsu, Yasuyuki; Yanagisawa, Kei

    1995-01-01

    Transfer factors of radionuclides from soil to leaf vegetables (cabbage, Chinese cabbage, komatsuna, spinach and lettuce) have been studied by radiotracer experiments using Andosol as a representative of Japanese soils. The transfer factors of radioactive Cs, Sr, Mn, Co and Zn for edible parts of vegetables (average of five vegetables) were 0.11, 0.24, 0.61, 0.05 and 0.52, respectively. These values should be used in safety assessment for Japanese agricultural environment. The transfer factors of Mn, Co and Zn for spinach were higher than those for the other vegetables. The transfer factors of Cs for different organs of the leaf vegetables were rather homogeneous. The transfer factors of Sr and Mn were higher for older (outer) leaves than younger (inner) ones. In contrast to Sr and Mn, transfer factors of Zn for younger leaves were higher than those for older ones. The distribution ratios of the elements between soil-solution and soil were in the order Sr>Mn>Cs>Co>Zn, whereas the distribution ratios of the elements between plant and soil-solution were in the order Zn>Cs>Mn>Co>Sr. These results indicate that the selectivity for Sr by plants from the soil-solution was low and that for Zn was very high. (author)

  11. Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J., E-mail: jun.cui@pnnl.gov; Choi, J. P.; Li, G.; Polikarpov, E.; Darsell, J. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354 (United States); Kramer, M. J.; Zarkevich, N. A.; Wang, L. L.; Johnson, D. D. [Materials Sciences and Engineering Division, Ames Laboratory, Ames, Iowa 50011 (United States); Marinescu, M. [Electron Energy Corporation, Landisville, Pennsylvania 17538 (United States); Huang, Q. Z.; Wu, H. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102 (United States); Vuong, N. V.; Liu, J. P. [Department of Physics, University of Texas at Arlington, Arlington, Texas 76019 (United States)

    2014-05-07

    MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 μ{sub B} at 50 K and 300 K, respectively.

  12. Magnetic structures of Er6Mn23 and Dy6Mn23

    International Nuclear Information System (INIS)

    Ouladdiaf, B.; Deportes, J.; Rodriguez-Carvajal, J.

    1995-01-01

    The R 6 Mn 23 (R=rare earth) compounds crystallize in the cubic Th 6 Mn 23 -type structure with space group Fm3m. Powder neutron-diffraction experiments were performed on Dy 6 Mn 23 and Er 6 Mn 23 . The magnetic unit cell coincides with the chemical one. The R moments have a ferromagnetic non-collinear arrangement, whereas the Mn moments are parallel to the [1 1 1] direction. The magnetic structures belong to the three-dimensional Γ 5g irreducible representation of Fm3m associated with the wave vector K=[0 0 0]. The spin configurations in both compounds result from the competition between the R-R, R-Mn magnetic interactions and the crystal electric field on the R ions. (orig.)

  13. Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

    Energy Technology Data Exchange (ETDEWEB)

    Cui, J; Choi, JP; Li, G; Polikarpov, E; Darsell, J; Kramer, MJ; Zarkevich, NA; Wang, LL; Johnson, DD; Marinescu, M; Huang, QZ; Wu, H; Vuong, NV; Liu, JP

    2014-05-07

    MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 mu(B) at 50 K and 300 K, respectively. (C) 2014 AIP Publishing LLC.

  14. Solvent Extraction of Co, Ni and Mn from NCM Sulfate Leaching Solution of Li(NCMO2 Secondary Battery Scraps

    Directory of Open Access Journals (Sweden)

    Hong Hyun Seon

    2017-06-01

    Full Text Available As a part of the study on recycling Li(NCMO2 lithium-ion battery scraps, solvent extraction experiments were performed using different extraction agents such as PC88A, Cyanex272 and D2EHPA to separate Co, Ni and Mn from the leaching solution. When the ratio of Mn to Ni was about 0.4 in the leaching solution, the separation factor for Co and Mn was found to be less than 10 so that the separation of Co and Ni was insufficient. When solvent extraction was done using the solution with the lower Mn/Ni ratio of 0.05 where Mn was removed by potassium permanganate and chlorine dioxide, more than 99% of Mn could be extracted through five courses of extraction using 30vol% D2EHPA while the extraction rates of Co and Ni were around 17% and 11%, respectively. In the case that Mn was removed from the solution, the extraction rate of Co was higher than 99% whereas less than 7% Ni was extracted using Cyanex272 suggesting that Co and Ni elements were effectively separated.

  15. Sodium channels as targets for volatile anesthetics

    Directory of Open Access Journals (Sweden)

    Karl F. Herold

    2012-03-01

    Full Text Available The molecular mechanisms of modern inhaled anesthetics although widely used in clinical settings are still poorly understood. Considerable evidence supports effects on membrane proteins such as ligand- and voltage-gated ion channels of excitable cells. Na+ channels are crucial to action potential initiation and propagation, and represent potential targets for volatile anesthetics. Inhibition of presynaptic Na+ channels leads to reduced neurotransmitter release at the synapse and could therefore contribute to the mechanisms by which volatile anesthetics produce their characteristic effects: amnesia, unconsciousness, and immobility. Early studies on crayfish and squid giant axon showed inhibition of Na+ currents by volatile anesthetics. Subsequent studies using native neuronal preparations and heterologous expression systems with various mammalian Na+ channel isoforms implicated inhibition of presynaptic Na+ channels in anesthetic actions. Volatile anesthetics reduce peak Na+ current and shift the voltage of half-maximal steady-state inactivation towards more negative potentials, thus stabilizing the fast-inactivated state. Furthermore recovery from fast-inactivation is slowed together with an enhanced use-dependent block during pulse train protocols. These effects can reduce neurotransmitter release by depressing presynaptic excitability, depolarization and Ca entry, and ultimately transmitter release. This reduction in transmitter release is more portent for glutamatergic vs. GABAergic terminals. Involvement of Na+ channel inhibition in mediating the immobility caused by volatile anesthetics has been demonstrated in animal studies, in which intrathecal infusion of the Na+ channel blocker tetrodotoxin increases volatile anesthetic potency, whereas infusion of the Na+ channels agonist veratridine reduces anesthetic potency. These studies indicate that inhibition of presynaptic Na+ channels by volatile anesthetics is involved in mediating some of

  16. Realized Beta GARCH: A Multivariate GARCH Model with Realized Measures of Volatility and CoVolatility

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri

    We introduce a multivariate GARCH model that utilizes and models realized measures of volatility and covolatility. The realized measures extract information contained in high-frequency data that is particularly beneficial during periods with variation in volatility and covolatility. Applying the ...

  17. Circadian rhythm in concentrations of Mg, K, Ca and Mn in Japanese morning glory during flowering process

    International Nuclear Information System (INIS)

    Ikeue, Natsuko; Tanoi, Keitaro; Furukawa, Jun; Yokota, Harumi; Okuni, Yoko; Nakanishi, Tomoko M.

    2001-01-01

    Concentrations of 4 trace elements, Mg, K, Ca and Mn, in each tissues of Japanese morning glory were analyzed during the flower development. To determine the element amount, neutron activation analysis with gamma-ray spectroscopy was performed. In this study, we focused on the movement of the trace elements especially with short-day treatment. Each element showed its specific distribution in the parts of a plant. The concentration of each element was changed rhythmically within a day. It was noted that, in the apical bud, concentrations of Mg, Ca and Mn were decreased from 5 h (2 h before light was on) to 7 h and increased again after 9 h. (author)

  18. Circadian rhythm in concentrations of Mg, K, Ca and Mn in Japanese morning glory during flowering process

    Energy Technology Data Exchange (ETDEWEB)

    Ikeue, Natsuko; Tanoi, Keitaro; Furukawa, Jun; Yokota, Harumi; Okuni, Yoko; Nakanishi, Tomoko M. [Tokyo Univ. (Japan). Graduate School of Agricultural and Life Sciences

    2001-06-01

    Concentrations of 4 trace elements, Mg, K, Ca and Mn, in each tissues of Japanese morning glory were analyzed during the flower development. To determine the element amount, neutron activation analysis with gamma-ray spectroscopy was performed. In this study, we focused on the movement of the trace elements especially with short-day treatment. Each element showed its specific distribution in the parts of a plant. The concentration of each element was changed rhythmically within a day. It was noted that, in the apical bud, concentrations of Mg, Ca and Mn were decreased from 5 h (2 h before light was on) to 7 h and increased again after 9 h. (author)

  19. Effect of Mn content on structural, optical, opto-thermal and electrical properties of ZnO:Mn sprayed thin films compounds

    International Nuclear Information System (INIS)

    Mimouni, R.; Kamoun, O.; Yumak, A.; Mhamdi, A.; Boubaker, K.; Petkova, P.; Amlouk, M.

    2015-01-01

    Highlights: • Proposing an original explanation to the difference between manganese-doped zinc oxide and undoped behavior. • Presenting an original effective electrical and fluorescence-related calculation scheme. • Outlining original AC–DC investigation protocol. - Abstract: Manganese-doped zinc oxide thin films (ZnO:Mn) at different percentages (0–3%) were deposited on glass substrates using a chemical spray technique. The effects of manganese element content on structural, optical, opto-thermal and electrical conductivity of ZnO:Mn thin films were investigated by means of X-ray diffraction, optical measurement, Photoluminescence spectroscopy and impedance spectroscopy. XRD analysis revealed that all films consist of single phase ZnO and were well crystallized in würtzite phase with the crystallites preferentially oriented towards (0 0 2) direction parallel to c-axis. Doping manganese resulted in a slight decrease in the optical band gap energy of the films and a noticeably change in optical constants. The UV peak positions for ZnO:Mn samples slightly red shift to the longer wavelength in comparison with the pure ZnO which can be attributed to the change in the acceptor level induced by the substitutional Mn 2+ and the band-gap narrowing of ZnO with the Mn dopant. We have performed original AC and DC conductivity studies inspired from Jonscher and small polaron models. These studies helped establishing significant correlation between temperature and activation energy and Mn content. From the spectroscopy impedance analysis we investigated the frequency relaxation phenomenon and the circuit equivalent circuit of such thin films. Finally, all results have been discussed, as an objective of the actual work, in terms of the manganese doping concentration

  20. Interplay between magnetic order at Mn and Tm sites alongside the structural distortion in multiferroic films of o -TmMn O3

    Science.gov (United States)

    Windsor, Y. W.; Ramakrishnan, M.; Rettig, L.; Alberca, A.; Bothschafter, E. M.; Staub, U.; Shimamoto, K.; Hu, Y.; Lippert, T.; Schneider, C. W.

    2015-06-01

    We employ resonant soft x-ray diffraction to individually study the magnetic ordering of the Mn and the Tm sublattices in single-crystalline films of orthorhombic (o -) TmMn O3 . The same magnetic ordering wave vector of (0 q 0 ) with q ≈0.46 is found for both ionic species, suggesting that the familiar antiferromagnetic order of the Mn ions induces a magnetic order on the Tm unpaired 4 f electrons. Indeed, intensity variations of magnetic reflections with temperature corroborate this scenario. Calculated magnetic fields at the Tm sites are used as a model magnetic structure for the Tm, which correctly predicts intensity variations at the Tm resonance upon azimuthal rotation of the sample. The model allows ruling out a b c -cycloid modulation of the Mn ions as the cause for the incommensurate ordering, as found in TbMn O3 . The structural distortion, which occurs in the ferroelectric phase below TC, was followed through nonresonant diffraction of structural reflections forbidden by the high-temperature crystal symmetry. The (0 q 0 ) magnetic reflection appears at the Mn resonance well above TC, indicating that this reflection is sensitive also to the intermediate sinusoidal magnetic phase. The model presented suggests that the Tm 4 f electrons are polarized well above the ferroelectric transition and are possibly not affected by the transition at TC. The successful description of the induced order observed at the Tm resonance is a promising example for future element-selective studies in which "spectator" ions may allow access to previously unobtainable information about other constituent ions.