WorldWideScience

Sample records for volatile elements na

  1. Mars Accreted a Volatile Element-Depleted Late Veneer Indicating Early Delivery of Martian Volatiles

    Science.gov (United States)

    Becker, H.; Wang, Z.

    2016-08-01

    Chalcophile elements in SNC meteorites are used to constrain abundances in the Martian mantle. Strong depletion of Te relative to highly siderophile elements suggests a volatile element-depleted late veneer, requiring that volatiles arrived earlier.

  2. 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.

  3. 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.

  4. 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.

  5. Core-Mantle Partitioning of Volatile Siderophile Elements and the Origin of Volatile Elements in the Earth

    Science.gov (United States)

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

    2012-01-01

    There are currently several hypotheses on the origin of volatile siderophile elements in the Earth. One hypothesis is that they were added during Earth s accretion and core formation and mobilized into the metallic core [1], others claim multiple stage origin [2], while some hypothesize that volatiles were added after the core already formed [3]. Several volatile siderophile elements are depleted in Earth s mantle relative to the chondrites, something which continues to puzzle many scientists. This depletion is likely due to a combination of volatility and core formation. The Earth s core is composed of Fe and some lighter constituents, although the abundances of these lighter elements are unknown [4]. Si is one of these potential light elements [5] although few studies have analyzed the effect of Si on metal-silicate partitioning, in particular the volatile elements. As, In, Ge, and Sb are trace volatile siderophile elements which are depleted in the mantle but have yet to be extensively studied. The metal-silicate partition coefficients of these elements will be measured to determine the effect of Si. Partition coefficients depend on temperature, pressure, oxygen fugacity, and metal and silicate composition and can constrain the concentrations of volatile, siderophile elements found in the mantle. Reported here are the results from 13 experiments examining the partitioning of As, In, Ge, and Sb between metallic and silicate liquid. These experiments will examine the effect of temperature, and metal-composition (i.e., Si content) on these elements in or-der to gain a greater understanding of the core-mantle separation which occurred during the Earth s early stages. The data can then be applied to the origin of volatile elements in the Earth.

  6. Effect of volatile elements on porosity formation in solidifying alloys

    Science.gov (United States)

    Couturier, G.; Rappaz, M.

    2006-03-01

    Besides dissolved gases such as hydrogen, the partial vapour pressure of volatile solute elements, such as zinc, has been accounted for in equations governing the nucleation and growth of pores in solidifying alloys. In particular, a simple analytical solution giving the porosity fraction as a function of the fraction of solid is proposed. This solution is then used to study the influence of zinc on porosity formation in aluminium- and copper-base alloys. It is shown that the zinc vapour pressure is too low to increase the porosity of aluminium-base alloys, whereas it has a significant effect in brasses. Implementing this contribution into an existing software which calculates the pressure drop in the mushy zone and the segregation of dissolved gases, simulations have been performed in order to assess in more realistic situations the influence of volatile solute elements on porosity.

  7. The Volatility and condensation behaviour of elements in dependence of T and fO2: a novel experimental approach

    Science.gov (United States)

    Ertel-Ingrisch, Werner; Dingwell, Don B.

    2010-05-01

    The volatility of elements is one of the most important variables during geological processes on Earth: its impact ranges from daily out gassing of volcanic vents to catastrophic emissions during volcanic eruptions which might scale up to global impacts on our climate. Volatility played, however, already a major role during the formation of our solar system: the nebular gases and their element budget passed through an elemental fractionation process based on differences in the evaporation and condensation behaviour of matter within the solar nebula - the origin of all the planets within our solar system. Precise knowledge of the parameters controlling volatility as well as condensation of elements is still lacking. Whether an element behaves volatile or refractory depends highly on the temperature and oxygen fugacity (fO2) conditions prevailing. To address this issue, we initiated a systematic study of the volatility of 18 volatile elements in respect to fO2 and temperature applying a modified mechanically assisted equilibration technique (MAE): Approx. 60 g of a haplobasaltic starting composition (An-Di) doped with up to 5000 ppm of volatile elements (Li, K, Na, Ti, Cr, Mn, Co, Cu, Cu, Zn, Ga, Rb, Cd, In, Sn, Sb, Cs, Tl) was heated to run temperatures. To investigate the fO2 dependence 2 experiments at logfO2 = -11.3 (~ IW -0.5) and - 0,7 (pure air) at a constant temperature of 1300 °C were performed, while T dependence was investigated at 1300 and 1500 °C at constant fO2 in pure air. The original MAE technique was modified by two Al2O3 plates extending from the hot spot region up to the upper, cooler regions of the muffle tube. These plates function as condensation traps. The temperature profile of the entire setup including the Al2O3 plates under run conditions was calibrated prior to any run. Experiments lasted for up two weeks while experimental conditions were kept strictly constant and were monitored. Up to 46 samples were taken from the melt by time

  8. Zinc and volatile element loss during planetary magma ocean phases

    Science.gov (United States)

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

    2016-10-01

    Zinc is a moderately volatile element and a key tracer of volatile depletion on planetary bodies due to lack of significant isotopic fractionation under high-temperature processes. Terrestrial basalts have δ66Zn values similar to some chondrites (+ 0.15 to 0.3‰ where [{66Zn/64Znsample/66Zn/64ZnJMC-Lyon-1} × 1000]) and elevated Zn concentrations (100 ppm). Lunar mare basalts yield a mean δ66Zn value of +1.4 ± 0.5‰ and have low Zn concentrations (~2 ppm). Late-stage lunar magmatic products, such as ferroan anorthosite, Mg-suite and Alkali suite rocks exhibit heavier δ66Zn values (+3 to +6‰). The heavy δ66Zn lunar signature is thought to reflect evaporative loss and fractionation of zinc, either during a giant impact or in a magma ocean phase.We explore conditions of volatile element loss within a lunar magma ocean (LMO) using models of Zn isotopic fractionation that are widely applicable to planetary magma oceans. For the Moon, our objective was to identify conditions that would yield a δ66Zn signature of ~ +1.4‰ within the mantle, assuming a terrestrial mantle zinc starting composition.We examine two cases of zinc evaporative fractionation: (1) lunar surface zinc fractionation that was completed prior to LMO crystallization and (2) lunar surface zinc fractionation that was concurrent with LMO crystallization. The first case resulted in a homogeneous lunar mantle and the second case yielded a stratified lunar mantle, with the greatest zinc isotopic enrichment in late-stage crystallization products. This latter case reproduces the distribution of zinc isotope compositions in lunar materials quite well.We find that hydrodynamic escape was not a dominant process in losing Zn, but that erosion of a nascent lunar atmosphere, or separation of condensates into a proto-lunar crust are possible. While lunar volatile depletion is still possible as a consequence of the giant impact, this process cannot reproduce the variable δ66Zn found in the Moon. Outgassing

  9. Two Extrasolar Asteroids with Low Volatile-Element Mass Fractions

    CERN Document Server

    Jura, M; Klein, B; Koester, D; Zuckerman, B

    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 ...

  10. Distribution of moderately volatile trace elements in fine-grained chondrule rims in the unequilibrated CO3 chondrite, ALH A77307.

    Science.gov (United States)

    Brearley, A J; Bajt, S; Sutton, S R

    1995-10-01

    The concentrations of Ni, Cu, Zn, Ga, Ge, and Se in five, fine-grained chondrule rims in the highly unequilibrated CO3 chondrite ALH A77307 (3.0) have been determined for the first time by synchrotron X-ray fluorescence (SXRF) microprobe at Brookhaven National Laboratory. These elements are especially useful for tracing the role of condensation and evaporation processes which occurred at moderate temperatures in the solar nebula. Understanding the distribution of moderately volatile elements between matrix and chondrules is extremely important for evaluating the different models for the volatile depletions in chondritic meteorites. The data show that the trace element chemistry of rims on different chondrules is remarkably similar, consistent with data obtained for the major and minor elements by electron microprobe. These results support the idea that rims are not genetically related to individual chondrules, but all sampled the same reservoir of homogeneously mixed dust. Of the trace elements analyzed, Zn and Ga show depletions relative to CI chondrite values, but in comparison with bulk CO chondrites all the elements are enriched by approximately 1.5 to 3.5 x CO. The abundance patterns for moderately volatile elements in ALH A77307 chondrule rims closely mimic those observed in the bulk chondrite, indicating that matrix is the major reservoir for these elements. The close matching of the patterns for the volatile depleted bulk chondrite and enriched matrix is especially striking for Na, which is anomalously depleted in ALH A77307 in comparison with average CO chondrite abundances. The depletion in Na is probably attributable to the effects of leaching in Antarctica. With the exception of Na, the volatile elements show a relatively smooth decrease in abundance as a function of condensation temperature, indicating that their behavior is largely controlled by their volatility.

  11. Earth's moderately volatile element composition may not be chondritic: Evidence from In, Cd and Zn

    Science.gov (United States)

    Wang, Zaicong; Laurenz, Vera; Petitgirard, Sylvain; Becker, Harry

    2016-02-01

    Current models assume that siderophile volatile elements (SVE) are depleted in bulk Earth to the same extent as lithophile elements of similar volatility. The observed additional depletion of many SVE relative to lithophile elements in the bulk silicate Earth (BSE) is ascribed to partitioning of SVE into Earth's core. However, the assumption of similar volatility of moderately volatile elements during Earth formation processes as in solar gas is quite uncertain. Here, these assumptions will be tested by assessing abundances and ratios of indium and cadmium in the BSE using new data on mantle rocks, and the application of high- and low-pressure-temperature metal-silicate partitioning data. New bulk rock abundance data of In and Cd obtained on bulk rocks of peridotite tectonites and xenoliths by isotope dilution refine previous results inferred from basalts and in-situ analyses of silicate minerals in peridotite xenoliths. The CI chondrite-normalized abundance of In in the BSE is similar to zinc and is 3-4 times higher than Cd. New and published low- and high-P-T metal-silicate partitioning data indicate that, during core formation at a range of conditions, In is always more siderophile than Zn and Cd. Adding the fraction of these elements in Earth's core to the BSE results in bulk Earth compositions that yield higher CI chondrite normalized abundances of In in the bulk Earth compared to Zn and Cd. Because In is more volatile than Zn and Cd in gas of solar composition, suprachondritic In/Zn and In/Cd in the bulk Earth suggest that during formation of Earth or its building materials, the volatilities of these elements and perhaps other volatile elements likely have changed significantly (i.e. In became less volatile). The results also suggest that known carbonaceous chondrites likely did not deliver the main volatile element-rich fraction of the Earth. Various arguments suggest that the loss of moderately volatile elements during planetary accretion should be limited

  12. 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

    2017-04-01

    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 207Pb-206Pb 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'.

  13. 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).

  14. 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.

  15. Occurrence and volatility of several trace elements in pulverized coal boiler

    Institute of Scientific and Technical Information of China (English)

    HUANG Ya-ji; JIN Bao-sheng; ZHONG Zhao-ping; XIAO Rui; TANG Zhi-yong; REN Hui-feng

    2004-01-01

    The contents of eight trace elements(Mn, Cr, Pb, As, Se, Zn, Cd, Hg) in raw coal, bottom ash and flyash were measured in a 220 t/h pulverized coal boiler. Factors affecting distribution of trace elements wereinvestigated, including fly ash diameter, furnace temperature, oxygen content and trace elements' characters. Onecoefficient of Meij was also improved to more directly show element enrichment in combustion products. Theseelements may be classified into three groups according to their distribution: Group 1: Hg, which is very volatile.Group 2: Pb, Zn, Cd, which are partially volatile. Group 3: Mn, which is hardly volatile. Se may be locatedbetween groups 1 and 2. Cr has properties of both group 1 and 3. In addition, the smaller diameter of fly ash, themore relative enrichment of trace elements( except Mn). The fly ash showed different adsorption mechanisms oftrace elements and the volatilization of trace elements rises with furnace temperature. Relative enrichments of traceelements(except Mn and Cr) in fly ash are larger than that in bottom ash. Low oxygen content can not alwaysimprove the volatilization of trace elements. Pb is easier to form chloride than Cd during coal combustion. Traceelements should be classified in accordance with factors.

  16. Bioindication of volatile elements emission by the Puyehue-Cordón Caulle (North Patagonia) volcanic event in 2011.

    Science.gov (United States)

    Bubach, Débora; Pérez Catán, Soledad; Arribére, María; Guevara, Sergio Ribeiro

    2012-07-01

    The emission of volatile pollutants from the volcanic eruption of the Puyehue-Cordón Caulle complex (North Patagonia Andean Range) that started in June 4th, 2011, was investigated by bioindication means with the epyphytic fruticose lichen Usnea sp. The elemental composition of pooled samples made up with 10 lichen thalli were analysed by Instrumental Neutron Activation Analysis. Eleven sampling sites were selected within the impacted region at different distance from the volcanic source. Five sites were selected as they were already sampled in a previous study prior to the eruption. Two other new sampling sites were selected from outside the impacted zone to provide non-impacted baseline sites. The elements associated with the lichen incorporation of particulate matter (PM) of geological origin were identified by linear correlation with a geochemical tracer (Sm concentrations). The elements associated with PM uptake were Ce, Eu, Fe, Hf, La, Lu, Na, Nd, Sb, Sc, Se, Ta, Tb, Th, U, and Yb. Arsenic and Cs concentrations showed contributions exceeding the PM fraction in sites near the volcanic centre, also higher than the baseline concentrations, which could be associated with permanent emissions from the geothermal system of the Puyehue-Cordón Caulle complex. The lichen concentrations of Ba, Ca, Co, Hg, K, Rb, Sr, and Zn were not associated with the PM, not showing higher concentrations in the sites nearby the volcanic source or respect to the baseline values either. Therefore, there is no indication of the emission of volatile forms of these elements in the lichen records. The lichen records only identified Br volatile emissions associated with the Puyehue-Cordón Caulle complex eruption in 2011.

  17. Rubidium isotopes in primitive chondrites: Constraints on Earth's volatile element depletion and lead isotope evolution

    Science.gov (United States)

    Nebel, O.; Mezger, K.; van Westrenen, W.

    2011-05-01

    The bulk silicate Earth (BSE) shows substantial deficits in volatile elements compared to CI-chondrites and solar abundances. These deficits could be caused by pre-accretionary depletion in the solar nebula during condensation of solids, or by later heat-driven evaporation during collision of small bodies that later accreted to form the Earth. The latter is considered to result in isotope fractionation for elements with low condensation temperatures that correlates with the degree of depletion. Here, we report first high-precision isotope ratio measurements of the moderately volatile and lithophile trace element Rb. Data from seventeen chondrite meteorites show that their Rb isotope abundances are nearly indistinguishable from Earth, not deviating more than 1 per mil in their 87Rb/85Rb. The almost uniform solar system Rb isotope pool suggests incomplete condensation or evaporation in a single stage is unlikely to be the cause of the volatile element deficit of the Earth. As Rb and Pb have similar condensation temperatures, we use their different degrees of depletion in the BSE to address the mechanisms and timing of terrestrial volatile depletion. The Rb isotope data are consistent with a scenario in which the volatile budget of the Earth was generated by a mixture of a highly volatile-element depleted early Proto-Earth with undepleted material in the course of terrestrial accretion. Observed Pb and Rb abundances and U-Pb and Rb-Sr isotope systematics suggest that volatile addition occurred at approximately the same time at which last core-mantle equilibration was achieved. In line with previous suggestions, this last equilibration involved a second stage of Pb (but not Rb) depletion from the BSE. The timing of this second Pb loss event can be constrained to ~ 110 Ma after the start of the solar system. This model supports a scenario with core storage of Pb in the aftermath of a putative Moon forming giant impact that also delivered the bulk of the volatile

  18. DISTRIBUTION OF MAJOR ELEMENTS (Na, K, Ca, Mg) IN THE ...

    African Journals Online (AJOL)

    a

    the elements with all values falling within 1-10 showing that the degree of accumulation was intensive. ... ionized water added and filtered into 50 mL standard flask. ... Distribution of Na, K, Ca, Mg in Fadama crops in Ekiti State, Nigeria. Bull.

  19. 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.

  20. 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.

  1. The role of chondrules in nebular fractionations of volatiles and other elements

    Science.gov (United States)

    Grossman, J. N.

    1994-01-01

    For at least 30 years, cosmochemists have been grappling with the question of how and why groups of geochemically and volatility related elements became fractionated in the major chondrite groups. At least five relatively independent fractionations are known. Virtually everyone who has thought about these facts has been attempted to attribute at least some of the fractionations to the physical separation or mixing of the visible components. By far the most abundant of these components in meteorites is chondrules, and indeed chondrules have long been suspected of playing a direct role in fractionation of volatile elements. The question addressed here is whether chondrules formed before or after chemical components became separated is of fundamental importance to our understanding of the early solar system, as the answer constrains how, when, where, and from what chondrules formed, and tells us about how materials were processed in the nebula.

  2. Origin of the earth's moon - Constraints from alkali volatile trace elements

    Science.gov (United States)

    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 basalt 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 percent of lunar material to be derived from a projectile with dehydrated CI composition to match the lunar Cs/Rb ratio, and 25-50 percent 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.

  3. 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.

  4. Photospheric Abundances of Volatile and Refractory Elements in Planet-Harboring Stars

    CERN Document Server

    Takeda, Y; Kambe, E; Aoki, W; Honda, S; Kawanomoto, S; Masuda, S; Izumiura, H; Watanabe, E; Koyano, H; Maehara, H; Norimoto, Y; Okada, T; Shimizu, Y; Uraguchi, F; Yanagisawa, K; Yoshida, M; Miyama, S; Ando, H

    2001-01-01

    By using the high-dispersion spectra of 14 bright planet-harboring stars (along with 4 reference stars) observed with the new coude echelle spectrograph at Okayama Astrophysical Observatory, we investigated the abundances of volatile elements (C, N, O, S, Zn; low condensation temperature Tc) in order to examine whether these show any significant difference compared to the abundances of other refractory elements (Si, Ti, V, Fe, Co, Ni; high Tc) which are known to be generally overabundant in those stars with planets, since a Tc-dependence is expected if the cause of such a metal-richness is due to the accretion of solid planetesimals onto the host star. We found, however, that all elements we studied behave themselves quite similarly to Fe (i.e., [X/Fe]~0) even for the case of volatile elements, which may suggest that the enhanced metallicity in those planet-bearing stars is not so much an acquired character (by accretion of rocky material) as rather primordial.

  5. 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.

  6. Volatile Elements Retention During Injection Casting of Metallic Fuel Slug for a Recycling Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Hwan; Song, Hoon; Kim, Hyung-Tae; Oh, Seok-Jin; Kuk, Seoung-Woo; Keum, Chang-Woon; Lee, Jung-Won; Kim, Ki-Hwan; Lee, Chan-Bock [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The as-cast fuels prepared by injection casting were sound and the internal integrities were found to be satisfactory through gamma-ray radiography. U and Zr were uniform throughout the matrix of the slug, and the impurities, i.e., oxygen, carbon, and nitrogen, satisfied the specification of the total impurities of less than 2000 ppm. The losses of the volatile Mn were effectively controlled using argon over pressures, and dynamic pumping for a period of time before injection showed no detrimental effect on the Mn loss by vaporization. This result suggests that volatile minor actinide-bearing fuels for SFRs can be prepared by improved injection methods. A practical process of metallic fuel fabrication for an SFR needs to be cost efficient, suitable for remote operation, and capable of mass production while reducing the amount of radioactive waste. Injection casting was chosen as the most promising technique, and this technique has been applied to fuel slug fabrication for the Experimental Breeder Reactor-II (EBR-II) driver and the Fast Flux Test Facility (FFTF) fuel pins. Because of the simplistic nature of the process and equipment, compared to other processes examined, this process has been successfully used in a remote operation environment for fueling of the EBR-II reactor. In this study, several injection casting methods were applied in order to prepare metallic fuel for an fast reactor that control the transport of volatile elements during fuel melting and casting. Mn was selected as a surrogate alloy since it possesses a total vapor pressure equivalent to that of a volatile minor actinide-bearing fuel. U.10Zr and U.10Zr.5Mn (wt%) metallic fuels were injection cast under various casting conditions and their soundness was characterized.

  7. Semi-volatile organic compounds and trace elements in the Yangtze River source of drinking water.

    Science.gov (United States)

    Wu, Bing; Zhang, Xuxiang; Zhang, Xiaolin; Yasun, Aishangjiang; Zhang, Yan; Zhao, Dayong; Ford, Tim; Cheng, Shupei

    2009-08-01

    Determination of 24 semi-volatile organic compounds (SVOCs) and 24 trace elements in water samples was conducted in order to investigate the quality of the Nanjing source of drinking water taken from Yangtze River. The total concentrations of SVOCs and trace elements were in the range of 1,951-11,098 ng/l and 51,274-72,384 microg/l, respectively. No significant seasonal changes were found for the pollutants' concentrations. A primary health risk assessment was carried out to evaluate potential health effects. Risk quotients involving carcinogenic effects for benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, dibenz(a,h)anthracene, bis(2-ethylhexyl)phthalate and arsenic were >1 under the worst-case scenario. The results of this study demonstrate the importance of further studies on the environmental health effects of exposure to the source water.

  8. Chemical fractionations in meteorites. V - Volatile and siderophile elements in achondrites and ocean ridge basalts.

    Science.gov (United States)

    Laul, J. C.; Keays, R. R.; Ganapathy, R.; Anders, E.; Morgan, J. W.

    1972-01-01

    Eighteen achondrites and 4 terrestrial basalts (3 ocean ridge, 1 continental) were analyzed by radiochemical neutron activation analysis for Ag, Au, Bi, Br, Cd, Co, Cs, Cu, Ga, In, Ir, Rb, Se, Tl and Zn. Samples included 7 eucrites, 5 howardites, 2 nakhlites, 2 shergottites, an angrite, and an aubrite. Light and dark portions of the gas-rich meteorites Kapoeta and Pesyanoe were analyzed separately. Nakhlites and shergottites have volatile element abundances similar to those in ocean ridge basalts; eucrites, howardites, and angrites show greater depletions by an order of magnitude and less similar abundance patterns. In terms of a two-component model of planetary accretion, the parent planets contained the following percentages of low-temperature material: eucrites 0.8, nakhlites 38, shergottites 28. Shergottites may be genetically related to L-chondrites. The siderophile element pattern of achondrites resembles that of the moon, but with less extreme depletions.

  9. 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.

  10. A Synthesis of Experimental Data Describing the Partitioning of Moderately Volatile Elements in Major Rock Forming Minerals: Implications for the Moon

    Science.gov (United States)

    Vander Kaaden, Kathleen E.; Draper, David S.; McCubbin, Francis M.; Neal, Clive R.; Taylor, G. Jeffrey

    2017-01-01

    Highly volatile elements [condensation temperatures below about 700 K] and water are highly informative about lunar bulk composition (hence origin), differentiation and magmatic evolution, and the role of impacts in delivering volatiles to the Moon. Fractionation of volatile elements compared to moderately volatile and refractory elements are informative about high-temperature conditions that operated in the proto-lunar disk. Existing data show clearly that the Moon is depleted in volatile elements compared to the bulk silicate Earth. For example, K/Th is 400-700 in the Moon compared to 2800-3000 in Earth. A complicating factor is that the abundances of the highly volatile elements in major lunar lithologies vary by approximately two orders of magnitude. Perhaps most interesting, H2O is not correlated with the concentration of volatile elements, indicating a decoupling of highly volatile elements from the even more volatile H2O. We contend that this decoupling could be a significant tracer of processes operating during lunar formation, differentiation, and bombardment, and the combination of analyzing both volatile elements and water is likely to provide significant insight into lunar geochemical history. This variation and lack of correlation raises the question: what were the relative contributions of crystallization in the magma ocean, subsequent mantle overturn, production of secondary magmas, and addition of volatiles by large impacts in producing this apparently large range in volatile abundances? This current study will produce new partitioning data relevant to the role and distribution of the volatile and non-volatile, yet geochemically significant elements (Co, Ni, Zn, Se, Rb, Sr, Mo, Ag, Cd, In, Sb, Ce, Yb, Tl, Pb, Bi) during the thermal and magmatic evolution of the Moon.

  11. The isotope composition of selenium in chondrites constrains the depletion mechanism of volatile elements in solar system materials

    Science.gov (United States)

    Vollstaedt, Hauke; Mezger, Klaus; Leya, Ingo

    2016-09-01

    Solar nebula processes led to a depletion of volatile elements in different chondrite groups when compared to the bulk chemical composition of the solar system deduced from the Sun's photosphere. For moderately-volatile elements, this depletion primarily correlates with the element condensation temperature and is possibly caused by incomplete condensation from a hot solar nebula, evaporative loss from the precursor dust, and/or inherited from the interstellar medium. Element concentrations and interelement ratios of volatile elements do not provide a clear picture about responsible mechanisms. Here, the abundance and stable isotope composition of the moderately- to highly-volatile element Se are investigated in carbonaceous, ordinary, and enstatite chondrites to constrain the mechanism responsible for the depletion of volatile elements in planetary bodies of the inner solar system and to define a δ 82 / 78 Se value for the bulk solar system. The δ 82 / 78 Se of the studied chondrite falls are identical within their measurement uncertainties with a mean of - 0.20 ± 0.26 ‰ (2 s.d., n = 14, relative to NIST SRM 3149) despite Se abundance depletions of up to a factor of 2.5 with respect to the CI group. The absence of resolvable Se isotope fractionation rules out a kinetic Rayleigh-type incomplete condensation of Se from the hot solar nebula or partial kinetic evaporative loss on the precursor material and/or the parent bodies. The Se depletion, if acquired during partial condensation or evaporative loss, therefore must have occurred under near equilibrium conditions to prevent measurable isotope fractionation. Alternatively, the depletion and cooling of the nebula could have occurred simultaneously due to the continuous removal of gas and fine particles by the solar wind accompanied by the quantitative condensation of elements from the pre-depleted gas. In this scenario the condensation of elements does not require equilibrium conditions to avoid isotope

  12. 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.

  13. Radial Transport in the Solar Nebula: Implications for Moderately Volatile Element Depletions in Chondritic Meteorites

    CERN Document Server

    Ciesla, F J

    2007-01-01

    In this paper, the possibility that the moderately volatile element depletions observed in chondritic meteorites are the results of planetesimals accreting in a solar nebula that cooled from an initially hot state (temperatures > 1350 K out to ~2-4 AU) is explored. A model is developed to track the chemical inventory of planetesimals that accrete in a viscously evolving protoplanetary disk, accounting for the redistribution of solids and vapor by advection, diffusion, and gas drag. It is found that depletion trends similar to those observed in the chondritic meteorites can be reproduced for a small range of model parameters. However, the necessary range of parameters is inconsistent with observations of disks around young stars and other constraints on meteorite parent body formation. Thus, counter to previous work, it is concluded that the global scale evolution of the solar nebula is not the cause for the observed depletion trends.

  14. The elemental composition of the Sun I. The intermediate mass elements Na to Ca

    CERN Document Server

    Scott, Pat; Asplund, Martin; Sauval, A Jacques; Lind, Karin; Takeda, Yoichi; Collet, Remo; Trampedach, Regner; Hayek, Wolfgang

    2014-01-01

    The composition of the Sun is an essential piece of reference data for astronomy, cosmology, astroparticle, space and geo-physics. This article, dealing with the intermediate-mass elements Na to Ca, is the first in a series describing the comprehensive re-determination of the solar composition. In this series we severely scrutinise all ingredients of the analysis across all elements, to obtain the most accurate, homogeneous and reliable results possible. We employ a highly realistic 3D hydrodynamic solar photospheric model, which has successfully passed an arsenal of observational diagnostics. To quantify systematic errors, we repeat the analysis with three 1D hydrostatic model atmospheres (MARCS, MISS and Holweger & M\\"uller 1974) and a horizontally and temporally-averaged version of the 3D model ($\\langle$3D$\\rangle$). We account for departures from LTE wherever possible. We have scoured the literature for the best transition probabilities, partition functions, hyperfine and other data, and stringently ...

  15. Some refractory and volatile element chemistry of CaS in enstatite chondrites

    Institute of Scientific and Technical Information of China (English)

    陈永亨; Paul H.Benoit

    1996-01-01

    INAA data for REE, Sc, Se, Br and Zn in CaS extracted from 5 enstatite chondrites (Qingzhen EH3, St. Marks EH5, Atlanta EL6, Hvittis EL6 and Pillistfer EL6) are reported. The results indicate that the REE abundances in CaS from unequilibrated enstatite chondrite, Qingzhen, are much higher than that from equilibrated ones. Similarly, the abundances of Sc, Se, Br and Zn in CaS from Qingzhen are higher than that in CaS grains from equilibrated chondrites, revealing that CaS is a previous condensate and is not simple residues of an evaporative process. Secondly, metamorphism has caused the redistribution of the trace elements among the minerals in enstatite chondrites, and this metamorphic fractionation reflects the differences from element volatilities and chemical properties. The REE patterns of CaS of enstatite chondrites and aubrites could not explain that aubrites were derived from known enstatite chondrites by igneous processing. And depleted europium in metamorphism and igneous process may be carried

  16. 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...

  17. Influence of partial replacement of NaCl with KCl on profiles of volatile compounds in dry-cured bacon during processing

    Science.gov (United States)

    This study investigated the influence of partial substitution of NaCl with KCl on the formation of volatile compounds in bacons during processing using a purge and trap dynamic headspace GC/MS system. Three substitutions were 0% KCl (I), 40% KCl (II), and 70% KCl (III). The profiles of the volatile ...

  18. The elemental composition of the Sun. I. The intermediate mass elements Na to Ca

    Science.gov (United States)

    Scott, Pat; Grevesse, Nicolas; Asplund, Martin; Sauval, A. Jacques; Lind, Karin; Takeda, Yoichi; Collet, Remo; Trampedach, Regner; Hayek, Wolfgang

    2015-01-01

    The chemical composition of the Sun is an essential piece of reference data for astronomy, cosmology, astroparticle, space and geo-physics: elemental abundances of essentially all astronomical objects are referenced to the solar composition, and basically every process involving the Sun depends on its composition. This article, dealing with the intermediate-mass elements Na to Ca, is the first in a series describing the comprehensive re-determination of the solar composition. In this series we severely scrutinise all ingredients of the analysis across all elements, to obtain the most accurate, homogeneous and reliable results possible. We employ a highly realistic 3D hydrodynamic model of the solar photosphere, which has successfully passed an arsenal of observational diagnostics. For comparison, and to quantify remaining systematic errors, we repeat the analysis using three different 1D hydrostatic model atmospheres (marcs, miss and Holweger & Müller 1974, Sol. Phys., 39, 19) and a horizontally and temporally-averaged version of the 3D model (⟨ 3D ⟩). We account for departures from local thermodynamic equilibrium (LTE) wherever possible. We have scoured the literature for the best possible input data, carefully assessing transition probabilities, hyperfine splitting, partition functions and other data for inclusion in the analysis. We have put the lines we use through a very stringent quality check in terms of their observed profiles and atomic data, and discarded all that we suspect to be blended. Our final recommended 3D+NLTE abundances are: log ɛNa = 6.21 ± 0.04, log ɛMg = 7.59 ± 0.04, log ɛAl = 6.43 ± 0.04, log ɛSi = 7.51 ± 0.03, log ɛP = 5.41 ± 0.03, log ɛS = 7.13 ± 0.03, log ɛK = 5.04 ± 0.05 and log ɛCa = 6.32 ± 0.03. The uncertainties include both statistical and systematic errors. Our results are systematically smaller than most previous ones with the 1D semi-empirical Holweger & Müller model, whereas the ⟨ 3D ⟩ model returns

  19. Characterisation of inorganic elements and volatile organic compounds in the dried sea cucumber Stichopus japonicus.

    Science.gov (United States)

    Lee, Hae-Won; Lim, Na-Lae; Cho, Kichul; Yang, Hye Young; Yim, Kyung June; Kim, Mi-Ju; Lee, Myunglip; Kim, Dong Hyeun; Koh, Hyoung Bum; Jung, Won-Kyo; Roh, Seong Woon; Kim, Daekyung

    2014-03-15

    The sea cucumber Stichopus japonicus lives in a variety of marine habitats and is an important cultivated edible aquatic species in East Asia. In this study, S. japonicus, collected from the sea near Jeju Island of Korea, was lyophilised or vacuum-dried and then analysed by gas chromatography-mass spectrometry (GC-MS) or inductively coupled plasma mass spectrometry (ICP-MS). The GC-MS profiles of vacuum-dried and lyophilised samples differed. Based on direct injection and static headspace analysis, 37 volatile organic compounds (VOCs) were identified in vacuum-dried samples and 33 VOCs were identified in lyophilised samples. Therefore, the odour of vacuum-dried sea cucumber is thought to be due to the presence of various VOCs that are absent in lyophilised sea cucumber. According to ICP-MS analysis, the levels of 15 inorganic elements were slightly higher in lyophilised samples than in vacuum-dried samples. The results of the inorganic and organic chemical analyses provide information about the composition of dried sea cucumber. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. On the volatile enrichments and heavy element content in HD 189733b

    CERN Document Server

    Mousis, O; Petit, J -M; Zahnle, K; Biennier, L; Picaud, S; Johnson, T V; Mitchell, J B A; Boudon, V; Cordier, D; Devel, M; Georges, R; Griffith, C; Iro, N; Marley, M S; Marboeuf, U

    2010-01-01

    Favored theories of giant planet formation center around two main paradigms, namely the core accretion model and the gravitational instability model. These two formation scenarios support the hypothesis that the giant planet metallicities should be higher or equal to that of the parent star. Meanwhile, spectra of the transiting hot Jupiter HD189733b suggest that carbon and oxygen abundances range from depleted to enriched with respect to the star. Here, using a model describing the formation sequence and composition of planetesimals in the protoplanetary disk, we determine the range of volatile abundances in the envelope of HD189733b that is consistent with the 20--80 Earth-masses of heavy elements estimated to be present in the planet's envelope. We then compare the inferred carbon and oxygen abundances to those retrieved from spectroscopy and we find a range of supersolar values that directly fit both spectra and internal structure models. In some cases, we find that the apparent contradiction between the s...

  1. Optical Attenuation in MoNA and LISA Detector Elements

    Science.gov (United States)

    Rice, Logan; Wong, Jonathan; MoNA Collaboration

    2011-10-01

    The MoNA collaboration is a research group of students and faculty from 13 primarily undergraduate institutions, with detectors at the NSCL: MoNA (Modular Neutron Array) and the newly-built LISA (Large multi-Institutional Scintillating Array). These arrays each have 144 plastic scintillating bars. When a neutron collides with a hydrogen nucleus within the plastic, photomultiplier tubes at either end of the bar detect the scintillation photons. Their arrival times are used to determine the position of the event, but as the light travels through the detector it loses intensity exponentially. How dramatic this loss is can be described by a parameter called the attenuation length, with larger attenuation lengths corresponding to lower loss. Recently the MoNA collaboration conducted its LISA commissioning experiment investigating two-neutron decay states of 25O. As a part of LISA's commissioning, we measured the attenuation lengths of the individual detector bars that make up the LISA array and compared these lengths with those of the older MoNA array. We found that the LISA bars had a larger attenuation length on average with impacts on detector efficiency and effective threshold. The authors wish to acknowledge the contributions of the members of the MoNA Collaboration.

  2. Volatile Metabolites

    Directory of Open Access Journals (Sweden)

    Daryl D. Rowan

    2011-11-01

    Full Text Available Volatile organic compounds (volatiles comprise a chemically diverse class of low molecular weight organic compounds having an appreciable vapor pressure under ambient conditions. Volatiles produced by plants attract pollinators and seed dispersers, and provide defense against pests and pathogens. For insects, volatiles may act as pheromones directing social behavior or as cues for finding hosts or prey. For humans, volatiles are important as flavorants and as possible disease biomarkers. The marine environment is also a major source of halogenated and sulfur-containing volatiles which participate in the global cycling of these elements. While volatile analysis commonly measures a rather restricted set of analytes, the diverse and extreme physical properties of volatiles provide unique analytical challenges. Volatiles constitute only a small proportion of the total number of metabolites produced by living organisms, however, because of their roles as signaling molecules (semiochemicals both within and between organisms, accurately measuring and determining the roles of these compounds is crucial to an integrated understanding of living systems. This review summarizes recent developments in volatile research from a metabolomics perspective with a focus on the role of recent technical innovation in developing new areas of volatile research and expanding the range of ecological interactions which may be mediated by volatile organic metabolites.

  3. Effect of the partial NaCl substitution by other chloride salts on the volatile profile during the ripening of dry-cured lacón

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, R.; Munekata, P.E.; Cittadini, A.; Lorenzo, J.M.

    2016-07-01

    The influence of three salting treatments (treatment II: 50% NaCl-50% KCl; III: 45% NaCl-25% KCl-20% CaCl2-10% MgCl2; IV: 30% NaCl-50% KCl-15% CaCl2-5% MgCl2) on the formation of volatile compounds throughout the process was studied and compared to those of a control “lacón” (treatment I: 100% NaCl). There was an intense formation of volatile compounds throughout the processing, particularly during the dry-ripening stage. The most abundant chemical family in all the formulations, in the final product was hydrocarbons followed by aldehydes. The total volatile compound release was more intense in the control “lacóns” (1164 AU×106 ·g–1dry matter) than in “lacóns” from formulations II, III and IV (817–891 AU×106 ·g−1dry matter). The “lacóns” from formulation I showed the highest amounts of aldehydes. The “lacóns” from formulations I and II presented the highest amounts of hydrocarbons. The main conclusion is that the replacement of NaCl produces changes in the volatile profile and could be affect the aroma of “lacón”. (Author)

  4. Volatilization of elemental mercury from fresh blast furnace sludge mixed with basic oxygen furnace sludge under different temperatures.

    Science.gov (United States)

    Földi, Corinna; Dohrmann, Reiner; Mansfeldt, Tim

    2015-11-01

    Blast furnace sludge (BFS) is a waste with elevated mercury (Hg) content due to enrichment during the production process of pig iron. To investigate the volatilization potential of Hg, fresh samples of BFS mixed with basic oxygen furnace sludge (BOFS; a residue of gas purification from steel making, processed simultaneously in the cleaning devices of BFS and hence mixed with BFS) were studied in sealed column experiments at different temperatures (15, 25, and 35 °C) for four weeks (total Hg: 0.178 mg kg(-1)). The systems were regularly flushed with ambient air (every 24 h for the first 100 h, followed by every 72 h) for 20 min at a flow rate of 0.25 ± 0.03 L min(-1) and elemental Hg vapor was trapped on gold coated sand. Volatilization was 0.276 ± 0.065 ng (x m: 0.284 ng) at 15 °C, 5.55 ± 2.83 ng (x m: 5.09 ng) at 25 °C, and 2.37 ± 0.514 ng (x m: 2.34 ng) at 35 °C. Surprisingly, Hg fluxes were lower at 35 than 25 °C. For all temperature variants, an elevated Hg flux was observed within the first 100 h followed by a decrease of volatilization thereafter. However, the background level of ambient air was not achieved at the end of the experiments indicating that BFS mixed with BOFS still possessed Hg volatilization potential.

  5. Chlorine distribution and its isotopic composition in “rusty rock” 66095. Implications for volatile element enrichments of “rusty rock” and lunar soils, origin of “rusty” alteration, and volatile element behavior on the Moon

    Science.gov (United States)

    Shearer, C. K.; Sharp, Z. D.; Burger, P. V.; McCubbin, F. M.; Provencio, P. P.; Brearley, A. J.; Steele, A.

    2014-08-01

    An interesting characteristic of the pyroclastic glass bead deposits, select impact produced lithologies such as the “rusty rock” 66095, and unique lunar soils from the Apollo 16 landing site, is their unusual enrichments in 204Pb, Cd, Bi, Br, I, Ge, Sb, Tl, Zn, and Cl which indicates that portions of these sample contain a substantial volatile component. Sample 66095, a fine-grained, subophitic to ophitic polymict melt breccia, also hosts a pervasive low-temperature, volatile-rich, oxyhydrated mineral assemblage. The volatile element enrichments in these assorted lunar lithologies have been attributed to a variety of extra-lunar and lunar processes, whereas the oxyhydration in 66095 has long been thought to represent either terrestrial alteration of lunar chlorides and Fe-Ni metal to βFeO(OH,Cl) or indigenous lunar processes. In 66095, Cl is accommodated in FeO(OH,Cl), phosphates, and chlorides and is heterogeneously distributed. The low-temperature alteration occurs as rims around Fe-Ni metal and sulfide grains, and as dispersed grains in the adjacent matrix. Micro-Raman and transmission electron microscope (TEM) imaging indicate that akaganéite (βFeO(OH,Cl)) is the dominant FeO(OH) polymorph and is intergrown with goethite (αFeO(OH)) and hematite (αFe2O3). TEM observations indicate a well-defined “nanometer-scale” stratigraphy” to the alteration. For example, kamacite (body centered cubic) → face-centered cubic (fcc) Fe-Ni alloy → lawrencite (FeCl2) → akaganéite. The lunar lawrencite (Fe,Ni)Cl2 in 66095 does not react directly to akaganéite on Earth. Rather, lawrencite exposed to terrestrial conditions reacts to form an amorphous Fe- and Cl-bearing phase, nano-crystalline goethite, and hematite. The morphology of these terrestrial alteration products is significantly different than that of the akaganéite occurring in 66095. The chlorine isotopic compositions of these volatile-rich samples are enriched in heavy Cl. For 66095, the δ37Cl

  6. Determination of elemental composition of volatile organic compounds from Chinese rose oil by spectral accuracy and mass accuracy.

    Science.gov (United States)

    Zhou, Wei; Zhang, Yaheng; Xu, Hongliang; Gu, Ming

    2011-10-30

    Elemental composition determination of volatile organic compounds through high mass accuracy and isotope pattern matching could not be routinely achieved with a unit-mass resolution mass spectrometer until the recent development of the comprehensive instrument line-shape calibration technology. Through this unique technology, both m/z values and mass spectral peak shapes are calibrated simultaneously. Of fundamental importance is that calibrated mass spectra have symmetric and mathematically known peak shapes, which makes it possible to deconvolute overlapped monoisotopes and their (13)C-isotope peaks and achieve accurate mass measurements. The key experimental requirements for the measurements are to acquire true raw data in a profile or continuum mode with the acquisition threshold set to zero. A total of 13 ions from Chinese rose oil were analyzed with internal calibration. Most of the ions produced high mass accuracy of better than 5 mDa and high spectral accuracy of better than 99%. These results allow five tested ions to be identified with unique elemental compositions and the other eight ions to be determined as a top match from multiple candidates based on spectral accuracy. One of them, a coeluted component (Nerol) with m/z 154, could not be identified by conventional GC/MS (gas chromatography/mass spectrometry) and library search. Such effective determination for elemental compositions of the volatile organic compounds with a unit-mass resolution quadrupole system is obviously attributed to the significant improvement of mass accuracy. More importantly, high spectral accuracy available through the instrument line-shape calibration enables highly accurate isotope pattern recognition for unknown identification.

  7. Assimetria na volatilidade dos retornos revisitada: Ibovespa, merval e inmex Asymmetry of return volatility revisited: ibovespa, merval, and inmex

    Directory of Open Access Journals (Sweden)

    Thiago Fleith Otuki

    2008-12-01

    Full Text Available Este artigo procura, por meio de modelos da classe ARCH, evidências do efeito assimétrico na volatilidade das séries de retornos dos índices de ações da Argentina (Merval, Brasil (Ibovespa e México (Inmex durante o período de janeiro de 2000 a dezembro de 2005. Os resultados mostraram maior influência de eventos negativos do que positivos, de mesma intensidade, sobre a volatilidade das séries analisadas, e verificou-se que choques nas séries de retornos têm efeito por vários períodos. Esses resultados são semelhantes aos encontrados por Ceretta e Costa Jr. (1999 para o período da segunda metade da década de 1990, quando houve uma série de crises sistêmicas no mercado financeiro internacional. Esta comparação permite conjecturar que esse efeito assimétrico é prevalente em séries de índices de ações, independentemente de o período analisado ser conturbado ou não.This paper searched, for evidence of the asymmetric effect on volatility in the stock index return series of Argentina (Merval, Brazil (Ibovespa, and Mexico (Inmex from January 2000 to December 2005 using ARCH modeling. Results showed a greater influence of negative events on volatility than positive ones of the same intensity, and that shocks on the return series persisted for some time. This is similar to findings of Ceretta and Costa Jr. (1999 during the second half of the 1990 decade, a period with many financial crises. This comparison permits conjecture that this asymmetric effect does not depend upon whether the period in question was one with economic shocks or not.

  8. Effect of additives on the volatility of elements in a DC arc during the atomic emission analysis of nickel(II) oxide

    Energy Technology Data Exchange (ETDEWEB)

    Zolotareva, N.I.; Kuzyakov, Yu.Ya.; Khlystova, A.D.; Chernova, N.A.

    1986-10-20

    The authors have studied the effect of traditional halogenating additives, AgCl, CdF/sub 2/, PTFE and that of an effective additive they have selected, ZnF/sub 2/, on the volatility of impurity elements, viz. tungsten, molybdenum, titanium, and zirconium from nickel (II) oxide, and determined the constants for the average relative volatility of the elements by the method of Kantor and Pungor. The results have been used to lower the limits of detection of the impurities cited in nickel(II) oxide.

  9. Importance of Relativistic Effects for Intermediate-Z Elements:Photoionization Process of Excited Na

    Institute of Scientific and Technical Information of China (English)

    HAN Xiao-Ying; WANG Xiao-Lu; VOKY Lan; FEAUTRIER Nicole; LI Jia-Ming

    2007-01-01

    Using a modified R-matrix code,the fine-structure-resolved partial photoionization cross sections of excited Na (Z=11)are calculated within the Breit-Pauli approximation.Our calculated energy levels of Na+ and Na are in good agreement with the experimental values within 1% and the branching ratios of the J-resolved partial cross sections are consistent with the recent measurements within the experimental uncertainties.The agreements are impossible to be obtained without adequately taking into account the relativistic effects and the electron correlations together.Therefore,even for the intermediate-Z elements(e.g.Na with Z=11),the relativistic effects(mainly the spjn-orbit interactions)should not be neglected.

  10. Gas composition of major volatile elements in protoplanetary discs and its implication for planet formation

    CERN Document Server

    Amaury, Thiabaud; Yann, Alibert; Ingo, Leya; Klaus, Mezger

    2014-01-01

    Direct observations of gaseous exoplanets reveals that their gas envelope is commonly enriched in C/O ratio compared to that of the host star. This has been explained by considering that the gas phase of the disc could be inhomogeneous, exceeding the stellar C/O ratio in regions where these planets formed; but few studies have considered the drift of the gas and the migration of planets. We aim to derive the gas composition in planets to evaluate if the formation of giant planets with an enriched C/O ratio is possible. The study focusses on the effects of different processes on the C/O ratio like the disc evolution, the drift of gas, and the migration of the planet. We used our previous models for computation of the chemical composition together with the planet formation model of Alibert et al. (2013), to which we added the composition and drift of the gas phase of the disc composed of major volatile species, H2 and He. The study focusses on the region where ice lines are present and influence the C/O ratio o...

  11. Volatile metabolites produced from agro-industrial wastes by Na-alginate entrapped Kluyveromyces marxianus

    Directory of Open Access Journals (Sweden)

    Onur Güneşer

    Full Text Available Abstract The aim of this study was to evaluate the effects of alginate entrapment on fermentation metabolites of Kluyveromyces marxianus grown in agrowastes that served as the liquid culture media. K. marxianus cells entrapped in Na-alginate were prepared using the traditional liquid-droplet-forming method. Whey and pomaces from processed tomatoes, peppers, and grapes were used as the culture media. The changes in the concentrations of sugar, alcohol, organic acids, and flavor compounds were analyzed using gas chromatography-mass spectrometry (GC-MS and high pressure liquid chromatography (HPLC. Both free and entrapped, K. marxianus were used individually to metabolize sugars, organic acids, alcohols, and flavor compounds in the tomato, pepper, grape, and acid whey based media. Marked changes in the fermentation behaviors of entrapped and free K. marxianus were observed in each culture. A 1.45-log increase was observed in the cell numbers of free K. marxianus during fermentation. On the contrary, the cell numbers of entrapped K. marxianus remained the same. Both free and entrapped K. marxianus brought about the fermentation of sugars such as glucose, fructose, and lactose in the agrowaste cultures. The highest volume of ethanol was produced by K. marxianus in the whey based media. The concentrations of flavor compounds such as ethyl acetate, isoamyl alcohol, isoamyl acetate, 2-phenylethyl isobutyrate, phenylethyl acetate, and phenylethyl alcohol were higher in fermented agrowaste based media compared to the control.

  12. 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 ...

  13. 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...

  14. 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

  15. Olivine-Wadsleyite-Pyroxene Epitaxy: Element and Volatile Distributions at the 410km Discontinuity

    Science.gov (United States)

    Smyth, J. R.; Miyajima, N.; Huss, G. R.; Hellebrand, E.; Rubie, D. C.; Frost, D. J.

    2010-12-01

    We have synthesized hydrous peridotite-composition samples at 13GPa and 1400C with co-existing coarse grains (~100 micrometer) of olivine, wadsleyite, clinoenstatite, and melt in a multi-anvil press. The olivine grains contain fine-scale lamellae of wadsleyite and clinoenstatite that likely resulted from small temperature fluctuations during the four-hour experiment. Major-element compositions were determined by electron microprobe and H contents by secondary ion mass spectroscopy (SIMS). The olivine is about Fo93 in composition and contains about 650 ppm by weight H2O. The wadsleyite is about Fo87 in composition and contains about 1650 weight percent H2O. The clinoenstatite is about En96 in composition and about 440 ppm H2O. High resolution transmission electron microscopy of the lamellae and host show that the olivine and wadsleyite share their close-packed oxygen planes so that the wadsleyite lamellae are nearly planar and perpendicular to the [1 0 0] of olivine. The wadsleyite lamellae thus have their [1 0 1] and [1 0 -1] directions parallel to the [1 0 0] of olivine. Additionally, a second orientation relation with the [001] of olivine parallel to [100] of wadsleyite is also found as are incoherent blebs of wadsleyite in olivine. The coexisting melt phase quenched to a feathery mass of mostly wadsleyite crystals. Neither a quenched glass phase nor a nominally hydrous phase was observed. The lamellae indicate that the olivine-wadsleyite transformation can proceed effectively by coherent mechanisms that could potentially preserve lattice preferred orientation. The observed rapid coherent inversion from olivine to wadsleyite means that a metastable preservation of olivine below 410 km is unlikely under slightly hydrous conditions. The distribution of H among the nominally anhydrous phases implies that dehydration of peridotites by partial melting is inefficient so that complete dehydration of subducting slabs is unlikely. SEM-BSE image of wadsleyite (W) blebs and

  16. Historic activity of mt. Vesuvius: major elements and volatile constituents of primary melts

    Science.gov (United States)

    Cecchetti, A.; Marianelli, P.; Metrich, N.; Sbrana, A.

    2003-04-01

    Mt. Vesuvius experienced a three-century long period of semi-persistent activity, after the 1631 eruption and is presently in a phase of rest. During this period, several eruptions displayed composite style since they started with lava effusions and evolved towards explosive activity (lava fountains, phreatomagmatic explosions and occasionally steady columns). The tephrostratigraphic sequence of post-1631 activity is well reconstructed [1] on the basis of historical chronicles and field investigations, whereas information about the feeding system is still weak. We have selected samples related to energetic lava fountain activity that occurred during the 1794, 1822 and 1872 composite-style eruptions for investigating the deep feeding systems of Mt. Vesuvius, during the 1631--1944 period. We present data on melt inclusions and their host olivines. Major elements, S, Cl and F were obtained using the electron microprobe (SX50, Camparis), CO_2 and H_2O by Fourier Transform InfraRed spectroscopy. Carbon was also analysed by nuclear reaction 12C(d,p)13C. The magma batches emitted during the 1794, 1822 and 1872 eruptions brought to the surface primitive olivines (Fo90.4-88.5) containing spinel (Cr/(Cr+Al) = 0.77--0.75). Their inclusions attest of crystallization at high pressure from K-rich (HK) parental magmas with K_2O varying from 4.3 to 6.0, high K_2O/H_2O (up to 2.4), Cl/H_2O (up to 0.25), Cl/F (up to 3) ratios, and H_2O content systematically high and variable from 2.3 to 4.9 wt.%. The most primitive compositions are recorded in melt inclusions from the oldest samples (1794 and 1822 eruptions). We propose a rather rapid transfer of HK-melts carrying olivine crystals from depth. This process is only detectable by the means of melt inclusions in Fo-rich olivines phenocrysts occurring only in the deposits related to the most powerful episodes of lava fountains while the whole rocks are cumulative with respect to clinopyroxene (± leucite). These new data, in addition to

  17. The effect of easily ionized elements Na and K on the performance of pulsed plasma thruster using water propellant

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In view of the low thrust power ratio caused by the high resistance of pulsed plasma thruster using water propellant,the paper argues that the easily ionized elements Na and K with low ionic potentials are added in the water propellant to improve its performance. The measurement of the discharging current and plasma emission spectrographic analysis prove the improvement. The experiments show that the elements Na and K have certain effect on the improvement of the performance of pulsed plasma thruster: In comparison with water propellant,the NaCl and KCl water propellant has a lower total resistance and a higher ratio of thruster power and specific impulse,and the NaCl water propellant has a slightly stronger effect on pulsed plasma thruster than the KCl. The plasma emission spectrographic analysis is in consistent with the experiment of measuring the discharging current: The elements Na and K can intensify the plasma emission spectrographic signal.

  18. The Volatile Element Evolution of Intra-plate Alkaline Rocks as Recorded by Apatite: An Example from the Hegau Volcanic Field (Southwest Germany)

    Science.gov (United States)

    Von Der Handt, A.; Rahn, M. K. W.; Wang, L. X.; Marks, M. A. W.

    2014-12-01

    The role of volatiles in the petrogenesis of alkaline intra-plate magmas has been the subject of an increasing number of experimental studies. The study of naturally occurring rocks and their volatile contents is often complicated by syn- and post-eruptive degassing and alteration processes. Minerals that incorporate volatiles into their structure such as apatites are often more faithful recorders of the pre-eruptive volatile budget. The Hegau volcanic field in Southwest Germany is part of the Central European Volcanic Province, lies around 60-70 km to the east of the Upper Rhine graben and of Miocene age. Three main lithological units can be distinguished (1) olivine melilites (2) phonolites and (3) the "Deckentuff" series referring to a series of diatreme-filling pipe breccias and lapilli tuff layers. Carbonatites occur subordinately in the Hegau province. Earlier radiometric age dating suggested distinct phases of volcanic activity of Deckentuffs, melilites and phonolites with little overlap, but new apatite fission-track and (U-Th)/He age data suggest a synchronous activity. Apatite is an abundant accessory phase in the Deckentuff and phonolite series and we investigated its major, trace and volatile element composition by EPMA, SIMS and cathodoluminescence imaging. Pronounced core-rim zoning of apatite in places attests that diffusional equilibration was very limited and they likely retained their primary compositions. This allows us to trace the entire magmatic evolution of the Hegau province from its most primitive to most evolved products as well as resolve it in time by combining age dating with compositional analysis. Apatite compositions fall along the OH-F join with low Cl-contents (<0.5 wt%). Volatile contents (Cl, OH, S) are highest in most primitive compositions and decrease with further evolution while F increases. Multiple magmatic cycles can be discerned with a general trend to the more evolved phonolite compositions toward the end of volcanic

  19. Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements

    Directory of Open Access Journals (Sweden)

    ChunMei Liu

    2015-01-01

    Full Text Available This research applied sodium hydroxide (NaOH pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production.

  20. Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements.

    Science.gov (United States)

    Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

    2015-01-01

    This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L(-1)·d(-1) of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%-62.2% higher than with NaOH-pretreatment alone and 22.2%-56.3% higher than with untreated corn stover. The best combination was obtained 5-9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production.

  1. Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements

    Science.gov (United States)

    Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

    2015-01-01

    This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469

  2. Ammonia volatilization of urea in the out-of-season corn Volatilização de amônia da ureia na cultura do milho safrinha

    Directory of Open Access Journals (Sweden)

    Hamilton Seron Pereira

    2009-12-01

    Full Text Available The aim of this study was to evaluate the N losses due to volatilization at different rates of common urea, polymer coated urea and urease inhibitor-treated urea in the out-of-season corn, using semi-open static collectors. The treatments consisted of N levels on side-dressing fertilization with urea in different treatments: (a control (without N, (b urea 40 kg ha-1 N, (c urea 80 kg ha-1 N, (d polymer coated urea 40 kg ha-1 N, (e polymer coated urea 80 kg ha-1 N and (f urea with the urease inhibitor (UI N 80 kg ha-1 N. The results showed that the treatments with polymer coated urea and with urease inhibitor-treated urea reduced the volatilization of N around 50 % compared to common urea, either in the first and the second N side-dressing fertilizations. Thus, they demonstrate that the polymer coat and the urease inhibitors were effective in reducing the volatilization of urea N applied in coverage, which resulted in higher productivity. There was also increasing urease activity in the treatments with application of common urea.O objetivo deste estudo foi avaliar as perdas por volatilização doN em diferentes doses de ureia comum, revestida com polímeros e tratada com inibidores de urease na cultura do milho safrinha, utilizando coletores semiabertos estáticos. O N, na forma de ureia, foi aplicado em cobertura nas seguintes doses: milho safrinha solteiro (sem N; ureia - 40 kg ha-1 de N; ureia - 80 kg ha-1 de N; ureia revestida com polímeros - 40 kg ha-1 de N; ureia revestida com polímeros 80 kg ha-1 de N; e ureia com inibidor de urease (UI - 80 kg ha-1 de N. Os resultados mostraram que os tratamentos com ureia revestida e ureia com inibidor de urease reduziram a volatilização de N em torno de 50 % em relação à ureia comum, tanto na primeira quanto na segunda cobertura nitrogenada. Foi demonstrado que o revestimento da ureia e o inibidor da urease foram eficientes na redução da volatilização do N da ureia aplicados em cobertura, o

  3. Emissions control of volatile organic compounds in petroleum industry; Controle de emissoes de compostos organicos volateis na industria do petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Gutierres, Ricardo; Moreira, Andrea Cristina de Castro Araujo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES). P e D de Energia e Desenvolvimento Sustentavel (PDEDS)

    2004-07-01

    Volatile organic compounds are among the most common pollutants emitted by refining processes. The sources of these emissions should be controlled for preserving the ambient air quality. This article outlines the main factors to be considered for defining an effective emissions control strategy and compares the major characteristics of the available control technologies. (author)

  4. Origins of volatile elements (H, C, N, noble gases) on Earth and Mars in light of recent results from the ROSETTA cometary mission

    Science.gov (United States)

    Marty, Bernard; Avice, Guillaume; Sano, Yuji; Altwegg, Kathrin; Balsiger, Hans; Hässig, Myrtha; Morbidelli, Alessandro; Mousis, Olivier; Rubin, Martin

    2016-05-01

    Recent measurements of the volatile composition of the coma of Comet 67P/Churyumov-Gerasimenko (hereafter 67P) allow constraints to be set on the origin of volatile elements (water, carbon, nitrogen, noble gases) in inner planets' atmospheres. Analyses by the ROSINA mass spectrometry system onboard the Rosetta spacecraft indicate that 67P ice has a D/H ratio three times that of the ocean value (Altwegg et al., 2015) and contains significant amounts of N2, CO, CO2, and importantly, argon (Balsiger et al., 2015). Here we establish a model of cometary composition based on literature data and the ROSINA measurements. From mass balance calculations, and provided that 67P is representative of the cometary ice reservoir, we conclude that the contribution of cometary volatiles to the Earth's inventory was minor for water (≤1%), carbon (≤1%), and nitrogen species (a few % at most). However, cometary contributions to the terrestrial atmosphere may have been significant for the noble gases. They could have taken place towards the end of the main building stages of the Earth, after the Moon-forming impact and during either a late veneer episode or, more probably, the Terrestrial Late Heavy Bombardment around 4.0-3.8 billion years (Ga) ago. Contributions from the outer solar system via cometary bodies could account for the dichotomy of the noble gas isotope compositions, in particular xenon, between the mantle and the atmosphere. A mass balance based on 36Ar and organics suggests that the amount of prebiotic material delivered by comets could have been quite considerable - equivalent to the present-day mass of the biosphere. On Mars, several of the isotopic signatures of surface volatiles (notably the high D/H ratios) are clearly indicative of atmospheric escape processes. Nevertheless, we suggest that cometary contributions after the major atmospheric escape events, e.g., during a Martian Late Heavy Bombardment towards the end of the Noachian era, could account for the

  5. 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.; Leshin, L.; Lewis, K. W.; McLennan, S. M.; Ming, D. W.; Perrett, G.; Pradler, I.; Stolper, E. M.; Squyres, S. W.; Greiman, A. H.

    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*).

  6. Possible Sources of Polar Volatiles

    Science.gov (United States)

    Schultz, P. H.

    2011-12-01

    : surface layer of atomic/molecules over a regolith containing an assortment of cold-trapped elements (Na/Ca/Mg/K/Ag/Hg) and compounds (OH, CO, H2). In addition to the solar flux, cometary dust dominates the impact flux for particles less than 1g and dominates impact flashes observed telescopically (Cooke, pers. comm.). While large, volatile-rich impactors may be less frequent, they have the potential for injecting significant quantities (10-15%) into impact melts (Harris and Schultz, 2011). In addition, laboratory impact experiments at the NASA Ames Vertical Gun Range used high-speed spectroscopy to illustrate the capture of volatile fractions below the surface during hypervelocity impacts. On the Moon, melt-trapped volatiles comprising the regolith would be gradually recycled during each lunation during impact gardening, thereby titrating the supply of volatiles to the polar deep freeze. Consequently, diverse sources likely contributed this potpourri of trapped cold-trapped volatile

  7. Slab-derived halogens and noble gases illuminate closed system processes controlling volatile element transport into the mantle wedge

    Science.gov (United States)

    Kobayashi, Masahiro; Sumino, Hirochika; Nagao, Keisuke; Ishimaru, Satoko; Arai, Shoji; Yoshikawa, Masako; Kawamoto, Tatsuhiko; Kumagai, Yoshitaka; Kobayashi, Tetsuo; Burgess, Ray; Ballentine, Chris J.

    2017-01-01

    Halogen and noble gas systematics are powerful tracers of volatile recycling in subduction zones. We present halogen and noble gas compositions of mantle peridotites containing H2O-rich fluid inclusions collected at volcanic fronts from two contrasting subduction zones (the Avacha volcano of Kamchatka arc and the Pinatubo volcano of Luzon arcs) and orogenic peridotites from a peridotite massif (the Horoman massif, Hokkaido, Japan) which represents an exhumed portion of the mantle wedge. The aims are to determine how volatiles are carried into the mantle wedge and how the subducted fluids modify halogen and noble gas compositions in the mantle. The halogen and noble gas signatures in the H2O-rich fluids are similar to those of marine sedimentary pore fluids and forearc and seafloor serpentinites. This suggests that marine pore fluids in deep-sea sediments are carried by serpentine and supplied to the mantle wedge, preserving their original halogen and noble gas compositions. We suggest that the sedimentary pore fluid-derived water is incorporated into serpentine through hydration in a closed system along faults at the outer rise of the oceanic, preserving Cl/H2O and 36Ar/H2O values of sedimentary pore fluids. Dehydration-hydration process within the oceanic lithospheric mantle maintains the closed system until the final stage of serpentine dehydration. The sedimentary pore fluid-like halogen and noble gas signatures in fluids released at the final stage of serpentine dehydration are preserved due to highly channelized flow, whereas the original Cl/H2O and 36Ar/H2O ratios are fractionated by the higher incompatibility of halogens and noble gases in hydrous minerals.

  8. 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)

  9. The occurrence of hazardous volatile elements and nanoparticles in Bulgarian coal fly ashes and the effect on human health exposure

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis F.O., E-mail: lfsoliveira@univates.br [Centro Universitario Univates, Pro Reitoria de Pesquisa Estensao e Pos Graduacao, Programa de Pos Graduacao Ambiente e Desenvolvimento (Brazil); Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina (Brazil); DaBoit, Katia [Department of Environmental Medicine, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Sampaio, Carlos H. [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Goncalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre - RS (Brazil); Jasper, Andre [Centro Universitario Univates, Pro Reitoria de Pesquisa Estensao e Pos Graduacao, Programa de Pos Graduacao Ambiente e Desenvolvimento (Brazil); Andrade, Maria L. [Department of Plant Biology and Soil Science, University of Vigo, 36310 Vigo (Spain); Kostova, Irena J. [Sofia University ' St. Kliment Ohridski' , Department of Geology, Paleontology and Fossil Fuels, 15, Tzar Osvoboditel Blvd., 1000 Sofia (Bulgaria); and others

    2012-02-01

    Low-rank, high-mineral matter Bulgarian coals were studied using a variety of chemical, optical, and electron beam methods. The larger fly ash carbon phases include charred carbons in contrast to coked carbons present in the fly ashes of bituminous-coal-derived fly ashes. Nanoscale carbons include multi-walled carbon nanotubes (MWCNTs) encapsulating Hg, Se, and As, among other elements. In addition to the glass which dominates the fly ash, relatively coarse 'rock fragments', consisting of an unmelted to partially melted core surrounded by a glassy rim, are present in the fly ash. Nano-scale minerals can contain hazardous elements and, along with metal-bearing multiwalled nanotubes, can be a path for the entry of hazardous particles into the lungs and other organs. Highlights: Black-Right-Pointing-Pointer We model Bulgarian power plants which have regulated minerals nanoparticles can contain hazardous elements. Black-Right-Pointing-Pointer We study changes in the level of information about nanominerals importance and the effect on human health exposure. Black-Right-Pointing-Pointer Increasing information will increase quality if power plants procedures are similar.

  10. P2-type Na(x)[Fe(1/2)Mn(1/2)]O2 made from earth-abundant elements for rechargeable Na batteries.

    Science.gov (United States)

    Yabuuchi, Naoaki; Kajiyama, Masataka; Iwatate, Junichi; Nishikawa, Heisuke; Hitomi, Shuji; Okuyama, Ryoichi; Usui, Ryo; Yamada, Yasuhiro; Komaba, Shinichi

    2012-04-29

    Rechargeable lithium batteries have risen to prominence as key devices for green and sustainable energy development. Electric vehicles, which are not equipped with an internal combustion engine, have been launched in the market. Manganese- and iron-based positive-electrode materials, such as LiMn(2)O(4) and LiFePO(4), are used in large-scale batteries for electric vehicles. Manganese and iron are abundant elements in the Earth's crust, but lithium is not. In contrast to lithium, sodium is an attractive charge carrier on the basis of elemental abundance. Recently, some layered materials, where sodium can be electrochemically and reversibly extracted/inserted, have been reported. However, their reversible capacity is typically limited to 100 mAh g(-1). Herein, we report a new electrode material, P2-Na(2/3)[Fe(1/2)Mn(1/2)]O(2), that delivers 190 mAh g(-1) of reversible capacity in the sodium cells with the electrochemically active Fe(3+)/Fe(4+) redox. These results will contribute to the development of rechargeable batteries from the earth-abundant elements operable at room temperature.

  11. Volatile (sulphur and chlorine), major, and trace element geochemistry of mafic to intermediate tephras from the Chilean Southern Volcanic Zone (33-43°S)

    Science.gov (United States)

    Wehrmann, Heidi; Hoernle, Kaj; Jacques, Guillaume; Garbe-Schönberg, Dieter; Schumann, Kai; Mahlke, Julia; Lara, Luis E.

    2014-10-01

    Here we present the first systematic investigation of volatile geochemistry along the Southern Volcanic Zone (SVZ) of Chile. Holocene olivine-hosted melt inclusions in the most mafic tephras sampled from 16 volcanoes along the volcanic front of the SVZ between 33°S and 43°S were analysed for pre-eruptive sulphur, chlorine, and major element contents. These results are combined with trace element compositions of the host whole rocks. The highest fractionation-corrected gas contents occur in the least-degassed melt inclusions from small monogenetic cones of Los Hornitos, Cabeza de Vaca, and Apagado from both the transitional and the southern-central SVZ, reaching ~3,000 μg/g S and 1,400 μg/g Cl, while the lowest abundances of ~1,100 μg/g S and ~600 μg/g Cl were found in the central SVZ at Volcán Lonquimay, Volcán Llaima, and Volcán Villarrica. Chlorine co-varies with trace element indicators for the degree of melting and/or source enrichment, such that the lowest Cl contents are found in high-degree melts from the most depleted mantle sources. The size of the volcanic edifices correlates inversely with Cl abundances in the melt. This could reflect more extensive degassing during ascent through the complex magma plumbing systems beneath the stratovolcanoes or greater dilution during larger degrees of melting of more depleted sources, or a combination of these factors. Compared to other subduction zones, the SVZ melt inclusions exhibit Cl and S abundances in the same range as most of those from the Central American and those from the Marianas arcs.

  12. 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...

  13. Ionizing radiation effects on volatiles formation in Camellia sinensis (L) teas; Efeito da radiacao ionizante na formacao de volateis em chas da planta Camellia sinensis (L)

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, Gustavo Bernardes

    2009-07-01

    The aim of this study was to evaluate the effects of radiation on volatile formation in white, green, oolong and black teas. Samples were irradiated in room temperature at {sup 60}Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20 kGy. The volatiles organic compound was extracted by hydro distillation and the extract was separated and identified by gas chromatography mass spectrometry (GCMS) analysis. The results show that the volatiles formations are directly proportional to the increase of radiation dose. The white tea showed less influence of ionizing radiation, as 37.86% of the compounds were stable at all doses of radiation and formed 47.53% of new compounds after irradiation. The green tea was the tea that has the greatest influence of radiation effects, increasing 66.12% of volatiles identified in relation to the control sample and only 21.77% of volatiles found naturally were resistant to all doses of radiation. The oolong tea, despite suffering a partial enzymatic treatment, was the second tea that has least interference of radiation in increasing the formation of new volatile. >From this tea, was able to detect 49.59% of new compounds after irradiation and 30.08% of the compounds found naturally were also found after irradiation. The black tea has the second greatest influence of radiation on formation of new volatile (60.94%) and only 17.97% of all identified compounds were not degraded after radiation. (author)

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

    Science.gov (United States)

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

    2017-07-01

    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 host olivines in Payenia are also included to constrain any variations in oxygen fugacity. The variation of potassium, fluorine and chlorine in MIs in Payenia can be modelled by partial melting (1-10%) of a variously metasomatised mantle. The high chlorine contents in MIs (up to 3200 ppm) from Northern Payenia require addition of subduction-related fluids to a mantle wedge, whereas volatile signatures in the southern Payenia are consistent with derivation from an enriched OIB source. Cl and Cl/K ratios define positive correlations with host olivine fosterite content (Fo80-90) that cannot be explained by olivine fractionation, degassing and/or degree of mantle melting. Neither can the correlation between SiO2 and TiO2 in the MIs and host olivine Fo-content be explained by magmatic differentiation processes. Instead these correlations essentially require a south to north mantle source transition from a low Mg# pyroxenite (from recycled eclogite) to a high Mg# fluid metasomatised peridotite. The Cl/K and S/K ratios in Payenia MIs extend from enriched OIB-like signatures (south) to Andean SVZ arc like signatures (north). We show that the northward increase in S, Cl and S/K is coupled to a northward increase in melt oxidation states and thus in Fe3+/Fetot ratios in the magmas. The increase in oxidation state also correlates with an increase of Mn/Fe (olivine) ratios. We calculate that 25% of the apparent north-south pyroxenite-peridotite source variation in Payenia (based on olivine Mn/Fe ratios) can be explained by the south to north variation in melt oxidation states.

  15. Volatiles in protoplanetary disks

    CERN Document Server

    Pontoppidan, Klaus M; Bergin, Edwin A; Brittain, Sean; Marty, Bernard; Mousis, Olvier; Oberg, Karin L

    2014-01-01

    Volatiles are compounds with low sublimation temperatures, and they make up most of the condensible mass in typical planet-forming environments. They consist of relatively small, often hydrogenated, molecules based on the abundant elements carbon, nitrogen and oxygen. Volatiles are central to the process of planet formation, forming the backbone of a rich chemistry that sets the initial conditions for the formation of planetary atmospheres, and act as a solid mass reservoir catalyzing the formation of planets and planetesimals. This growth has been driven by rapid advances in observations and models of protoplanetary disks, and by a deepening understanding of the cosmochemistry of the solar system. Indeed, it is only in the past few years that representative samples of molecules have been discovered in great abundance throughout protoplanetary disks - enough to begin building a complete budget for the most abundant elements after hydrogen and helium. The spatial distributions of key volatiles are being mapped...

  16. 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.

  17. Virtual volatility

    OpenAIRE

    A. Christian Silva; Prange, Richard E.

    2006-01-01

    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 st...

  18. Plant volatiles.

    Science.gov (United States)

    Baldwin, Ian T

    2010-05-11

    Plant volatiles are the metabolites that plants release into the air. The quantities released are not trivial. Almost one-fifth of the atmospheric CO2 fixed by land plants is released back into the air each day as volatiles. Plants are champion synthetic chemists; they take advantage of their anabolic prowess to produce volatiles, which they use to protect themselves against biotic and abiotic stresses and to provide information - and potentially disinformation - to mutualists and competitors alike. As transferors of information, volatiles have provided plants with solutions to the challenges associated with being rooted in the ground and immobile.

  19. 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...

  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 i...

  1. 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 i...

  2. 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)

  3. Rare Earth Chalcogels NaLnSnS4 (Ln = Y, Gd, Tb) for Selective Adsorption of Volatile Hydrocarbons and Gases

    KAUST Repository

    Edhaim, Fatimah

    2017-06-28

    The synthesis and characterization of the rare earth chalcogenide aerogels NaYSnS4, NaGdSnS4, and NaTbSnS4 is reported. Rare earth metal ions like Y3+, Gd3+, and Tb3+ react with the chalcogenide clusters [SnS4]4– in aqueous formamide solution forming extended polymeric networks by gelation. Aerogels obtained after supercritical drying have BET surface areas of 649 m2·g–1 (NaYSnS4), 479 m2·g–1 (NaGdSnS4), and 354 m2·g–1 (NaTbSnS4). Electron microscopy and physisorption studies reveal that the new materials have pores in the macro (above 50 nm) and meso (2–50 nm) regions. These aerogels show higher adsorption of toluene vapor over cyclohexane vapor and CO2 over CH4 or H2. The notable adsorption capacity for toluene (NaYSnS4: 1108 mg·g–1; NaGdSnS4: 921 mg·g–1; and NaTbSnS4: 645 mg·g–1) and high selectivity for gases (CO2/H2: 172 and CO2/CH4: 50 for NaYSnS4, CO2/H2: 155 and CO2/CH4: 37 for NaGdSnS4, and CO2/H2: 75 and CO2/CH4: 28 for NaTbSnS4) indicate potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes.

  4. 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...... 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....

  5. Volatility Risk

    OpenAIRE

    Zhiguang Wang

    2009-01-01

    Classical capital asset pricing theory tells us that riskaverse investors would require higher returns to compensate for higher risk on an investment. One type of risk is price (return) risk, which reflects uncertainty in the price level and is measured by the volatility (standard deviation) of asset returns. Volatility itself is also known to be random and hence is perceived as another type of risk. Investors can bear price risk in exchange for a higher return. But are investors willing to p...

  6. Volatility and mobility of some trace elements in coal from Shizuishan Power Plant%石嘴山电厂煤中微量元素的迁移释放行为

    Institute of Scientific and Technical Information of China (English)

    宋党育; 麻银娟; 秦勇; 王文峰; 郑楚光

    2011-01-01

    应用电感耦合等离子体质谱(ICP-MS)和原子荧光光谱(AFS)对中国西北部石嘴山电厂的原煤、底灰和飞灰中Hg、As、Se、Pb、Cr、Cd、Mo、Ni、Co、U和Th 11种微量元素的含量进行了测定.根据底灰和飞灰的产率,结合微量元素在底灰和飞灰中的含量计算了电厂燃煤过程中微量元素的挥发性.结果表明,Hg、Cd、Se、As四种元素在燃煤过程的挥发率均在50%以上,最高可达70%.通过对底灰和飞灰在酸性介质下的柱淋滤实验研究了底灰和飞灰中微量元素在60h内的迁移释放行为.Mn、Ni、Co、As四种元素的最大淋出率均超过2.0%,最高接近10.0%,并且还未达到淋滤平衡.根据微量元素的挥发和淋滤释放特性建立了电厂煤中有害微量元素在燃烧和淋滤过程中的释放分配模型.结果显示,燃煤过程中的挥发是微量元素释放的主要形式,部分元素的淋滤释放也可对周围水环境造成污染.%The volatility and mobility of eleven trace elements (Hg, As, Se, Ph, Cr, Cd, Mo, Ni, Co, U and Th) in coal from Shizuishan Power Plant were investigated.Column leaching tests on bottom ash and fly ash by sulfuric acid for 60 h were conducted.The contents of trace elements in input coal, bottom ash, fly ash and leaching solutions were determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic fluorescence spectroscopy (AFS).The volatility of trace elements during coal combustion was calculated based on the trace elements concentration in coal, ash and the ash yield of the raw coal.The results demonstrate that over 50% of As, Pb, and Hg volatilize to the atmosphere, leaching test results indicate that the maximum leaching proportion of As, Cd, Ni, and Mo is 1.8% ~ 6.2%.Based on the volatility and leaching characteristics, the volatilization and migration model of trace elements in the process of combustion and leaching was established.The results show that volatility of trace

  7. Determination of acrolein, ethanol, volatile acidity, and copper in different samples of sugarcane spirits Determinação de acroleína, etanol, acidez volátil e cobre em diferentes amostras de aguardentes de cana

    Directory of Open Access Journals (Sweden)

    José Masson

    2012-09-01

    Full Text Available Seventy-one samples of sugarcane spirits from small and average size stills produced in the northern and southern Minas Gerais (Brazil were analyzed for acrolein using HPLC (High Performance Liquid Chromatography. Ethanol and copper concentrations and volatile acidity were also determined according to methods established by the Ministry of Agriculture, Livestock and Supply (MAPA. A total of 9.85% of the samples tested showed levels of acrolein above the legal limits, while the copper concentrations of 21.00% of the samples and the volatile acidity of 8.85% of the samples were higher than the limits established by the Brazilian legislation. The concentration of acrolein varied from 0 to 21.97 mg.100 mL-1 of ethanol. However, no significant difference at 5% of significance was observed between the samples produced in the northern and southern Minas Gerais. The method used for determination of acrolein in sugarcane spirits involved the formation of a derivative with 2,4-dinitrophenylhydrazine (2,4-DNPH and subsequent analysis by HPLC.As setenta e uma amostras de aguardentes de cana coletadas em alambiques de pequeno e médio porte, provenientes das regiões norte e sul de Minas Gerais, foram avaliadas por CLAE (Cromatografia Líquida de Alta Eficiência quanto ao teor de acroleína. Avaliaram-se também as concentrações de etanol, acidez volátil e cobre, utilizando-se as metodologias estabelecidas pelo Ministério da Agricultura, Pecuária e Abastecimento (MAPA. Do total de amostras, 9,85% apresentaram níveis de acroleína acima do limite legal, 21,00% apresentaram teores de cobre e 8,85% de acidez volátil acima dos limites estabelecidos pela legislação brasileira. Os teores de acroleína variaram de 0 a 21,97 mg.100 mL-1 de etanol. Entretanto, não ocorreu diferença significativa no nível de 5% de significância entre as amostras do norte e as do sul de Minas Gerais. O método aplicado para a determinação de acroleína em aguardente de

  8. Alelopatia de extratos voláteis na germinação de sementes e no comprimento da raiz de alface Allelopathy of plant volatile extracts on seed germination and radicle length of lettuce

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Sampaio Alves

    2004-11-01

    Full Text Available O objetivo deste trabalho foi identificar possíveis efeitos alelopáticos de extratos voláteis de óleos essenciais na germinação e no comprimento da raiz de plântulas de alface. Foram utilizadas cinco concentrações de cada óleo (0,0, 0,001, 0,01, 0,1 e 1,0%, v/v, em delineamento inteiramente casualizado, com quatro repetições de 25 sementes de alface. Os extratos voláteis de óleos essenciais de canela, alecrim-pimenta, capim-citronela e alfavaca-cravo evidenciaram potencialidades alelopáticas na germinação e comprimento das raízes de plântulas de alface, efeitos que variaram de acordo com a concentração do óleo. O extrato volátil de óleo de jaborandi estimula o crescimento da radícula e não provoca inibição da germinação de sementes de alface, caracterizando-se como de efeito alelopático benéfico.The objective of this work was to identify allelopathic effects of volatile extracts of essential oils on germination and radicle length of lettuce seedlings. Five concentrations were utilized for each oil (0.0, 0.001, 0.01, 0.1 and 1.0%, v/v arranged into a completely randomized design with four replicates of 25 seeds. The volatile extracts of essential oils of cinnamon, alecrim-pimenta, capim-citronela and alfavaca-cravo revealed allelopathic potentialities on lettuce seed germination and radicle growth, effect which varied according to the oil concentration. The volatile extract of Jaborandi essential oil stimulates radicle growth and does not inhibit lettuce seeds germination, which is characterized as a beneficial allelopathic effect.

  9. Volatile profile of the headspace fraction of "assa-peixe" (Vernonia sp. honeys Perfil dos compostos voláteis presentes na fração "headspace" de méis de assa-peixe

    Directory of Open Access Journals (Sweden)

    Mariana Carvalho Ribeiro

    2008-03-01

    Full Text Available The volatile compounds were isolated from the headspace fraction of "assa-peixe" honeys by adsorptive column chromatography, eluted with acetone and analysed by GC-FID and GC-MS. Volatile compounds were separated using a polar phase column. Low- and medium-boiling point volatile compounds predominated in the headspace. A large proportion of 3-penten-2-one (80.5 ± 13.9 µg.kg-1 and benzaldehyde (25.9 ± 4.2 µg.kg-1 was found in the headspace fraction, while 2-penten-1-ol, 3-hexenyl butanoate, octadecane and hexanoic acid (Os compostos voláteis da fração "Headspace" de méis de assa-peixe foram adsorvidos pela técnica de cromatografia de adsorção, eluídos com acetona e analisados através da CG/DIC e CG/EM usando coluna polar de sílica fundida. Os compostos voláteis de baixo e médio ponto de ebulição predominaram na fração "headspace". Foi achada uma grande proporção de 3-penten-2-ona (80,5 ± 13,9 µg.kg-1 e benzaldeído (25,9 ± 4,2 µg.kg-1, enquanto o 2-penten-1-ol, o hexanoato de 3-hexenila, o octadecano e o ácido hexanóico (<0,01 µg.kg-1 foram compostos minoritários. Um total de doze compostos voláteis foi identificado, sendo cinco descritos pela primeira vez no mel de assa-peixe. Destes cinco, a 3-penten-2-ona, o dodecano, o tridecano e o benzaldeído foram definitivamente identificados na fração "headspace" dos méis de assa-peixe brasileiro.

  10. 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.

  11. NaCl 和 Zn 对棉花生长及营养元素吸收的影响%Effects of NaCl and Zn on Growth and Nutrient Elements Uptake of Cotton

    Institute of Scientific and Technical Information of China (English)

    陈文岭; 靳孟贵; 朱永惠; 王在敏

    2015-01-01

    微咸水在西北干旱区广泛分布,越来越多地被运用于灌溉棉花(Gossypiumhirsutum L .)等作物.微咸水中 NaCl 和微量元素含量比淡水高,有关 NaCl 和微量元素各自对棉花生长的影响已有大量研究,而他们对棉花生长的相互作用研究比较缺乏.选取对棉花生长作用敏感的 NaCl 和微量元素 Zn,开展不同 NaCl 和 Zn 浓度灌溉水盆栽试验.结果表明,缺 Zn 环境下,在灌溉水电导率为2.90~3.95 dS/m 的范围内,随着电导率增大,NaCl 促进棉花根和地上部生长及皮棉产量增加.富 Zn 环境下,灌溉水电导率大于5.04 dS/m时,随着电导率增大皮棉产量明显下降.在灌溉水中 Zn 浓度为0.1920~3.0680μmol/L 的范围内,Zn 浓度越大棉花营养生长越快;大于0.7676μmol/L 时,随着 Zn 浓度增大皮棉产量下降.灌溉水中 NaCl 和 Zn 对棉花生长和产量的影响作用,表现为相互拮抗作用关系.棉花叶的 Ca、K、Mg、B 和 Fe 含量以及铃的 Cu 和 Zn 含量高于其他组织,Na 和 Mn 不易迁移,易富集在棉花根部.Zn 在盐胁迫条件下影响棉花对营养元素的吸收,使棉花体内相关营养元素含量发生变化,进而影响棉花生长及产量.%Brackish water distributes widely in arid area of Northwest China and the NaCl and trace element contents in brackish water are higher than those in fresh water.Cotton (Gossypium hirsutum L .)is likely to be affected by simultaneous NaCl and manganese toxicity stress when irrigated with brackish water.The crop yields including cotton (Gossypium hirsutum L .)are usually reduced by poor quality of irrigation water or the low contents of nutrient elements in soil.Many experiments indicate that some salinities in irrigation water or soil will affect the cotton growth and yield,and the predominant salt damage to cotton plant is from sodium (Na+).Meanwhile proper nutrient supply for

  12. Estudos dos compostos orgânicos voláteis precursores de ozônio na cidade de São Paulo Studies of the volatile organic compounds precursors of ozone in São Paulo city

    Directory of Open Access Journals (Sweden)

    Débora Souza Alvim

    2011-06-01

    Full Text Available O ozônio é o principal problema de poluição do ar na cidade de São Paulo. Este estudo, que foi realizado em uma estação de monitoramento da qualidade do ar da Companhia de Tecnologia de Saneamento Ambiental (CETESB, enfoca a elucidação dos principais compostos orgânicos voláteis precursores de ozônio na atmosfera paulistana. Foram coletadas 36 amostras nos meses de agosto e setembro de 2006, nos quais o consumo de etanol era de aproximadamente 50% nesta época. Foram quantificadas 69 espécies de compostos orgânicos voláteis, nos quais os dez compostos mais importantes na formação de O3 foram: 1-buteno (6,8%, eteno (6,5%, formaldeído (6,1%, acetaldeído (5,5%, tolueno (4,8%, 1-etil-4-metilbenzeno (3,7%, trans-2-penteno (3,7%, propeno (3,7%, trans-2-buteno (3,5% e 1-metilciclopenteno (3,5%. As classes mais abundantes em concentração no ar foram: alcanos (45%, alcenos (26%, aromáticos (14%, aldeídos (13% e alcadienos (2%.Ozone is the main problem of air pollution in the city of São Paulo. This study, which was carried out in the Brazilian Basic Sanitation Engineering Company (CETESB, acronym in Portuguese monitoring station of air quality, focused on the elucidation of the main volatile organic compounds ozone precursors in São Paulo atmosphere. Thirty-six samples were collected in August and September 2006, when the consumption of ethanol was about 50%, 69 species of volatile organic compounds were quantified, the ten major urban pollutants compounds in the formation of O3 were: 1-butene (6.8%, ethylene (6.5%, formaldehyde (6.1%, acetaldehyde (5.5%, toluene (4.8%, 1-ethyl-4-methylbenzene (3.7%, trans-2-pentene (3.7%, propylene (3.7%, trans-2-butene (3.5%, and 1-methylcyclopentene (3.5%. The most abundant classes of air concentration were: alkanes (45%, alkenes (26%, aromatics (14%, aldehydes (13%, and alkadyenes (2%.

  13. Synthesis and structure of NaNbO3 ceramic powders in ultrahigh pressure field

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The NaNbO3 powders were synthesized and their crystal structure changes were analyzed by ultrahigh pressure up to 6 GPa. The results indicate that the pure NaNbO3 powders can be synthesized at 300℃ under a pressure of 4 GPa, to significantly restrain the Na element volatilization compared with the traditional synthesis method. It is found that the crystal structure of synthesized NaNbO3 changes from low symmetry to high symmetry with the increase of the pressure.

  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. 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.

  16. Influence of relativistic effect on chemical properties of element 104; Wplyw efektu relatywistycznego na wlasnosci chemiczne pierwiastka 104

    Energy Technology Data Exchange (ETDEWEB)

    Bilewicz, A.

    1997-12-31

    The influence of relativistic effect upon chemical properties of element 104 is discussed. An original method of measurements of adsorption on the surface of thin film of cobalt ferrocyanate was developed and applied for the studies of 104{sup 4+} hydrolysis. Results of this experiments indicate that in the Group 4 tendency to hydrolysis decreases in the order 104{sup 4+}>Zr{sup 4+}>Hf{sup 4+}. The results were explained on the basis of relativistic effect. Unexpected chemical properties of element 104 in aqueous solutions indicate, that due to relativistic effect element 104 differs distinctly from its congeners - Zr and Hf. In contrary it becomes similar to the lightest element in the Group, Ti, through atomic mass of latter is 213 unit less. (author). 119 refs, 22 figs, 7 tabs.

  17. Phase composition and elemental partitioning in glass-ceramics containing high-Na/Al high level waste

    Energy Technology Data Exchange (ETDEWEB)

    Stefanovsky, S.V., E-mail: profstef@mtu-net.ru [SIA Radon, 7th Rostovskii lane 2/14, Moscow 119121 (Russian Federation); Sorokaletova, A.N. [SIA Radon, 7th Rostovskii lane 2/14, Moscow 119121 (Russian Federation); Nikonov, B.S. [Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS, Staromonetniy lane 35, Moscow 109017 (Russian Federation)

    2012-05-15

    Mixtures of surrogates of high level waste with high sodium and aluminum contents and sodium-lithium borosilicate frit were melted in alumina crucibles in a resistive furnace followed by quenching of one portion of the melt and annealing of the residual material in a turned-off furnace. The annealed materials with waste loading of up to 45 wt.% contained minor spinel type phase and trace of nepheline (Na,K)AlSiO{sub 4}. In the annealed materials contained waste oxides in amount of 50 wt.% and more nepheline and spinel were found to be major and minor phases, respectively. At high waste loadings two extra phases: Cs-aluminosilicate (CsAlSiO{sub 4}) and mixed Na/Cs-aluminosilicate were found in amount of 3-5 vol.% each. The latter phase contains of up to {approx}5.7 wt.% SO{sub 3} or 0.13 formula units S (Na{sub 0.75}K{sub 0.05}Cs{sub 0.29}Ca{sub 0.02}Sr{sub 0.02}Al{sub 0.99}Fe{sub 0.03}Si{sub 0.76}S{sub 0.13}O{sub 4}). Sulfur incorporation as S{sup 6+} or SO{sub 4}{sup 2-} ions into crystal lattice may be facilitated in the presence of large-size Cs{sup +} cations. Simplified suggested formula of this phase may be represented as Na{sub 0.8}Cs{sub 0.3}AlSi{sub 0.8}S{sub 0.1}O{sub 3.95}. It was also synthesized by sintering of mixture of chemicals at 1300 Degree-Sign C and found to be instable at temperatures higher than 1300 Degree-Sign C.

  18. P2-type Nax[Fe1/2Mn1/2]O2 made from earth-abundant elements for rechargeable Na batteries

    Science.gov (United States)

    Yabuuchi, Naoaki; Kajiyama, Masataka; Iwatate, Junichi; Nishikawa, Heisuke; Hitomi, Shuji; Okuyama, Ryoichi; Usui, Ryo; Yamada, Yasuhiro; Komaba, Shinichi

    2012-06-01

    Rechargeable lithium batteries have risen to prominence as key devices for green and sustainable energy development. Electric vehicles, which are not equipped with an internal combustion engine, have been launched in the market. Manganese- and iron-based positive-electrode materials, such as LiMn2O4 and LiFePO4, are used in large-scale batteries for electric vehicles. Manganese and iron are abundant elements in the Earth’s crust, but lithium is not. In contrast to lithium, sodium is an attractive charge carrier on the basis of elemental abundance. Recently, some layered materials, where sodium can be electrochemically and reversibly extracted/inserted, have been reported. However, their reversible capacity is typically limited to 100 mAh g-1. Herein, we report a new electrode material, P2-Na2/3[Fe1/2Mn1/2]O2, that delivers 190 mAh g-1 of reversible capacity in the sodium cells with the electrochemically active Fe3+/Fe4+ redox. These results will contribute to the development of rechargeable batteries from the earth-abundant elements operable at room temperature.

  19. 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.

  20. Volatile Exsolution Experiments: Sampling Exsolved Magmatic Fluids

    Science.gov (United States)

    Tattitch, B.; Blundy, J. D.

    2015-12-01

    In magmatic arcs the conditions of volatile exsolution exert a direct control on the composition of exsolved magmatic volatiles phases (MVPs), as well as on their parental magmas. The ability to accurately assess the exchange of major and trace elements between MVPs and magmas is key to understanding the evolution of arc magmas. The trace element signatures measured in arc volcanoes, fumaroles, and hydrothermal ore deposits are greatly influenced by the role of MVPs. In order to investigate the interplay and evolution of melts and MVPs we need experimental methods to simulate MVP exsolution that impose minimal external constraints on their equilibration. Previous experiments have focused on evaluating the exchange of elements between aqueous fluids and silicate melts under equilibrium conditions[1,2]. However, the large mass proportion of fluid to melt in these experiment designs is unrealistic. As a result, the idealized compositions of the aqueous fluids may exert a strong control on melt compositions for which they are out of equilibrium, especially at low melt fractions. In contrast, other experiments have focused on the melt during crystallization but must calculate MVP compositions by mass balance[3]. In order to investigate MVPs and magmas during this critical period of MVP exsolution, we present a new two-stage fluid-melt experimental design. Stage one experiments generate super-liquidus hydrous melts using Laguna del Maule rhyolites and dactites, as analogues for ascending arc magmas. Stage two experiments allow aliquots of stage one melt/glass to crystallize and exsolve MVPs. The design then uses pressure cycling to promote infiltration of in-situ fractured quartz[4] and traps the MVPs as synthetic fluid inclusions. We present results from trial stage 2 experiments, which produced synthetic fluid inclusions consistent with literature values of fluid-melt Cl partitioning[5] and of sufficient size for LA-ICPMS analysis. Trace element partitioning for Li, Na

  1. Transfer of volatiles and metals from mafic to felsic magmas in composite magma chambers: An experimental study

    Science.gov (United States)

    Guo, Haihao; Audétat, Andreas

    2017-02-01

    In order to determine the behavior of metals and volatiles during intrusion of mafic magma into the base of silicic, upper crustal magma chambers, fluid-rock partition coefficients (Dfluid/rock) of Li, B, Na, S, Cl, K, Mn, Fe, Rb, Sr, Ba, Ce, Cu, Zn, Ag, Cd, Mo, As, Se, Sb, Te, W, Tl, Pb and Bi were determined experimentally at 2 kbar and 850 °C close to the solidus of mafic magma. In a first step, volatile-bearing mafic glasses were prepared by melting a natural basaltic trachyandesite in the presence of volatile-bearing fluids at 1200 °C/10 kbar in piston cylinder presses. The hydrous glasses were then equilibrated in subsequent experiments at 850 °C/2 kbar in cold-seal pressure vessels, which caused 80-90% of the melt to crystallize. After 0.5-2.0 days of equilibration, the exsolved fluid was trapped by means of in-situ fracturing in the form of synthetic fluid inclusions in quartz. Both the mafic rock residue and the fluid inclusions were subsequently analyzed by laser-ablation ICP-MS for major and trace elements. Reverse experiments were conducted by equilibrating metal-bearing aqueous solutions with rock powder and then trapping the fluid. In two additional experiments, information on relative element mobilities were obtained by reacting fluids that exsolved from crystallizing mafic magma with overlying silicic melts. The combined results suggest that under the studied conditions S, Cl, Cu, Se, Br, Cd and Te are most volatile (Dfluid/rock >10), followed by Li, B, Zn, As, Ag, Sb, Cs, W, Tl, Pb and Bi (Dfluid/rock = 1-10). Less volatile are Na, Mg, K, Ca, Mn, Fe, Rb, Sr, Mo and Rb (Dfluid/rock 0.1-1), and the least fluid-mobile elements are Al, Si, Ti, Zr, Ba and Ce (Dfluid/rock <0.1). This trend is broadly consistent with relative element volatilities determined on natural high-temperature fumarole gases, although some differences exist. Based on the volatility data and measured mineral-melt and sulfide-melt partition coefficients, volatile fluxing in

  2. Volatile organic compounds and trace metal level in some beers collected from Romanian market

    Science.gov (United States)

    Voica, Cezara; Kovacs, Melinda; Vadan, Marius

    2013-11-01

    Beer is one of the most popular beverages at worldwide level. Through this study fifteen different types of beer collected from Romanian market were analysed in order to evaluate their mineral, trace element as well the their organic content. Importance of such characterization of beer samples is supported by the fact that their chemical composition can affect both taste and stability of beer, as well the consumer health. Minerals and trace elements analysis were performed on ICP-MS while organic compounds analysis was done through GC-MS. Through ICP-MS analysis, elements as Ca, Na, K and Mg were evidenced at mgṡkg-1 order while elements as Cr, Ba, Co, Ni were detected at lower level. After GC-MS analysis the major volatile compounds that were detected belong to alcohols namely ethanol, propanol, isobutanol, isoamyl alcohol and linalool. Selected fatty acids and esters were evidenced also in the studied beer samples.

  3. The use of decision trees and naïve Bayes algorithms and trace element patterns for controlling the authenticity of free-range-pastured hens' eggs.

    Science.gov (United States)

    Barbosa, Rommel Melgaço; Nacano, Letícia Ramos; Freitas, Rodolfo; Batista, Bruno Lemos; Barbosa, Fernando

    2014-09-01

    This article aims to evaluate 2 machine learning algorithms, decision trees and naïve Bayes (NB), for egg classification (free-range eggs compared with battery eggs). The database used for the study consisted of 15 chemical elements (As, Ba, Cd, Co, Cs, Cu, Fe, Mg, Mn, Mo, Pb, Se, Sr, V, and Zn) determined in 52 eggs samples (20 free-range and 32 battery eggs) by inductively coupled plasma mass spectrometry. Our results demonstrated that decision trees and NB associated with the mineral contents of eggs provide a high level of accuracy (above 80% and 90%, respectively) for classification between free-range and battery eggs and can be used as an alternative method for adulteration evaluation.

  4. 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...

  5. Modeling and Forecasting the Volatility of Eastern European Emerging Markets

    Directory of Open Access Journals (Sweden)

    Sang Hoon Kang

    2009-06-01

    Full Text Available This study has attempted to seek a volatility forecasting model that can reflect sufficiently the long memory characteristic in the volatility of four Eastern European emerging stock markets, naThis study has attempted to seek a volatility forecasting model that can reflect sufficiently the long memory characteristic in the volatility of four Eastern European emerging stock markets, namely, Hungary, Poland, Russia, and Slovakia. From the results of our empirical analysis, we found that the FIGARCH model is better equipped to capture the long memory property in the volatility of these markets than the GARCH and IGARCH models. More importantly, the FIGARCH model is found to provide superior performance in one-day-ahead volatility forecasts. Thus, this study recommends researchers, portfolio managers, and traders to use the long memory FIGARCH model in analyzing and forecasting the volatility dynamics of Eastern European emerging markets.

  6. 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.

  7. Volatiles Which Increase Magma Viscosity

    Science.gov (United States)

    Webb, S.

    2015-12-01

    The standard model of an erupting volcano is one in which the viscosity of a decompressing magma increases as the volatiles leave the melt structure to form bubbles. It has now been observed that the addition of the "volatiles" P, Cl and F result in an increase in silicate melt viscosity. This observation would mean that the viscosity of selected degassing magmas would decrease rather than increase. Here we look at P, Cl and F as three volatiles which increase viscosity through different structural mechanisms. In all three cases the volatiles increase the viscosity of peralkaline composition melts, but appear to always decrease the viscosity of peraluminous melts. Phosphorus causes the melt to unmix into a Na-P rich phase and a Na-poor silicate phase. Thus as the network modifying Na (or Ca) are removed to the phosphorus-rich melt, the matrix melt viscosity increases. With increasing amounts of added phosphorus (at network modifying Na ~ P) the addition of further phosphorus causes a decrease in viscosity. The addition of chlorine to Fe-free aluminosilicate melts results in an increase in viscosity. NMR data on these glass indicates that the chlorine sits in salt-like structures surrounded by Na and/or Ca. Such structures would remove network-modifying atoms from the melt structure and thus result in an increase in viscosity. The NMR spectra of fluorine-bearing glasses shows that F takes up at least 5 different structural positions in peralkaline composition melts. Three of these positions should result in a decrease in viscosity due to the removal of bridging oxygens. Two of the structural positons of F, however, should result in an increase in viscosity as they require the removal of network-modifying atoms from the melt structure (with one of the structures being that observed for Cl). This would imply that increasing amounts of F might result in an increase in viscosity. This proposed increase in viscosity with increasing F has now been experimentally confirmed.

  8. Volatile Organic Compounds (VOCs)

    Science.gov (United States)

    ... Contact Us Share Volatile Organic Compounds' Impact on Indoor Air Quality On this page: Introduction Sources Health Effects Levels in Homes Steps to Reduce Exposure Standards or Guidelines Additional Resources Introduction Volatile organic compounds ( ...

  9. Influência do dióxido de enxofre e cultivares de videira na formação de alguns compostos voláteis e na qualidade sensorial do destilado de vinho Influence of sulfur dioxide and grape varieties at the formation of some volatile compounds and at the sensory quality of the wine distillate

    Directory of Open Access Journals (Sweden)

    Marco Antonio SALTON

    2000-12-01

    Full Text Available Com o objetivo de estudar o efeito do SO2 e das cultivares de videira - Herbemont, Couderc 13, Trebbiano e Isabel - na composição química e na qualidade sensorial do destilado de vinho, efetuaram-se microvinificações e posterior destilação dos vinhos na safra de 1996. As análises dos compostos voláteis foram feitas através de cromatografia gasosa e a avaliação sensorial dos destilados foi efetuada pelo grupo de degustação da Embrapa Uva e Vinho. Os resultados mostraram que o SO2 favoreceu a formação de etanal nas cultivares estudadas. Observou-se também um aumento na soma dos álcoois superiores em função do SO2, exceto para o destilado da cv. Isabel. Constatou-se que o destilado de Isabel se caracterizou por apresentar teor mais elevado de metanol e mais baixo de 1-propanol, possivelmente devido ao sistema de vinificação. O destilado de Isabel, juntamente com o de Couderc 13, apresentou teores mais baixos de 2-metil-1-propanol, 3-metil-1-butanol e da soma dos álcoois superiores. O destilado de Trebbiano apresentou teor mais elevado de 2-metil-1-propanol e juntamente com o de Herbemont teores mais elevados de 1-propanol, 2-metil-1-butanol, 3-metil-1-butanol e na soma dos álcoois superiores. A avaliação sensorial evidenciou que o SO2 influenciou na qualidade de aroma, no gosto agradável e na qualidade geral dos destilados das cultivares Herbemont e Trebbiano. O de Herbemont se caracterizou por apresentar menor qualidade de aroma, gosto agradável, tipicidade e qualidade geral. Apresentou, ainda, nota mais elevada para aroma e gosto indesejáveis.With the aim of studying the influence of SO2 and grape varieties - Herbemont, Couderc 13, Trebbiano and Isabella, on the chemical composition and sensory quality of wine distillates, some microvinification and posterior distillation of wines were made, at the harvest of 1996. The analyses of volatile components were made through gas chromatography and the sensory evaluation of

  10. Volatile Evolution of Magma Associated with the Solchiaro Eruption in the Phlegrean Volcanic District (Italy)

    Science.gov (United States)

    Esposito, R.; Bodnar, R. J.; de Vivo, B.; Lima, A.; Fedele, L.; Shimizu, N.; Hunter, J.

    2009-12-01

    The Phlegrean volcanic district (PVD) in southern Italy is one of the best known volcanic hazard areas in the world. More than 1.5 million people live in close proximity to the volcanic centers. The PVD comprises three volcanic fields: the Campi Flegrei caldera and the islands of Ischia and Procida. We studied volatiles plus major and trace elements in the magma associated with the Solchiaro eruption on the Island of Procida, Italy, to gain a better understanding of the relationship between pre-eruptive volatiles and magmatic evolution. The Solchiaro eruption is one of the more primitive products erupted in the PVD and provides information on the source of later more evolved magmas associated with this volcanic system. The composition of the magma before eruption was determined by analyzing 104 melt inclusions (MIs) in forsteritic olivine, glass embayment plus rim glasses, and high vesciculated glasses selected from 4 representative samples. The composition of MIs was recalculated and ranges from basaltic to trachy-basaltic. Among major elements potassium shows the highest variability, from 0.5 to 6 wt%. MI define a continuous trend based on major and minor element compositions. Embayments matrix glass and high vesciculated glasses define a field that suggests a discontinuous process. Compatible to incompatible trace element ratios in early melts are highly variable and represent the melt phase before or at the very beginning of assimilation-fractional crystallization (FCA) processes. Intermediate melt compositions reflect continuing FCA processes, late melt compositions suggest that the FCA process was aborted before eruption. Volatile contents of early melt are highly variable and reflect source heterogeneities, and the melts are interpreted to be undersaturated. Intermediate melts were volatile saturated and H2O-CO2 contents define a degassing path. Depths of trapping of MI range from 4.4 to 2.2 km, and are calculated based on Newman and Lowenstern (2002) and

  11. Effects of Pulp and Na-Bentonite Amendments on the Mobility of Trace Elements, Soil Enzymes Activity and Microbial Parameters under Ex Situ Aided Phytostabilization

    Science.gov (United States)

    Wasilkowski, Daniel; Mrozik, Agnieszka

    2017-01-01

    The objective of this study was to explore the potential use of pulp (by-product) from coffee processing and Na-bentonite (commercial product) for minimizing the environmental risk of Zn, Pb and Cd in soil collected from a former mine and zinc-lead smelter. The effects of soil amendments on the physicochemical properties of soil, the structural and functional diversity of the soil microbiome as well as soil enzymes were investigated. Moreover, biomass of Festuca arundinacea Schreb. (cultivar Asterix) and the uptake of trace elements in plant tissues were studied. The outdoor pot set contained the following soils: control soil (initial), untreated soil (without additives) with grass cultivation and soils treated (with additives) with and without plant development. All of the selected parameters were measured at the beginning of the experiment (t0), after 2 months of chemical stabilization (t2) and at the end of the aided phytostabilization process (t14). The obtained results indicated that both amendments efficiently immobilized the bioavailable fractions of Zn (87–91%) and Cd (70–83%) at t14; however, they were characterized by a lower ability to bind Pb (33–50%). Pulp and Na-bentonite drastically increased the activity of dehydrogenase (70- and 12-fold, respectively) at t14, while the activities of urease, acid and alkaline phosphatases differed significantly depending on the type of material that was added into the soil. Generally, the activities of these enzymes increased; however, the increase was greater for pulp (3.5-6-fold) than for the Na-bentonite treatment (1.3–2.2-fold) as compared to the control. Soil additives significantly influenced the composition and dynamics of the soil microbial biomass over the experiment. At the end, the contribution of microbial groups could be ordered as follows: gram negative bacteria, fungi, gram positive bacteria, actinomycetes regardless of the type of soil enrichment. Conversely, the shift in the functional

  12. Forming Chondrules in Impact Splashes II Volatile Retention

    Science.gov (United States)

    Dullemond, Cornelis Petrus; Harsono, Daniel; Stammler, Sebastian Markus; Johansen, Anders

    2016-11-01

    Solving the mystery of the origin of chondrules is one of the most elusive goals in the field of meteoritics. Recently, the idea of planet(esimal) collisions releasing splashes of lava droplets, long considered out of favor, has been reconsidered as a possible origin of chondrules by several papers. One of the main problems with this idea is the lack of quantitative and simple models that can be used to test this scenario by directly comparing to the many known observables of chondrules. In Paper I of this series, we presented a simple thermal evolution model of a spherically symmetric expanding cloud of molten lava droplets that is assumed to emerge from a collision between two planetesimals. The production of lava could be either because the two planetesimals were already in a largely molten (or almost molten) state due to heating by 26Al, or due to impact jetting at higher impact velocities. In the present paper, number II of this series, we use this model to calculate whether or not volatile elements such as Na and K will remain abundant in these droplets or whether they will get depleted due to evaporation. The high density of the droplet cloud (e.g., small distance between adjacent droplets) causes the vapor to quickly reach saturation pressure and thus shuts down further evaporation. We show to what extent, and under which conditions, this keeps the abundances of these elements high, as is seen in chondrules. We find that for most parameters of our model (cloud mass, expansion velocity, initial temperature) the volatile elements Mg, Si, and Fe remain entirely in the chondrules. The Na and K abundances inside the droplets will initially stay mostly at their initial values due to the saturation of the vapor pressure, but at some point start to drop due to the cloud expansion. However, as soon as the temperature starts to decrease, most or all of the vapor recondenses again. At the end, the Na and K elements retain most of their initial abundances, albeit

  13. 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

  14. Silicon isotopes in angrites and volatile loss in planetesimals.

    Science.gov (United States)

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

    2014-12-02

    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.

  15. Evaporative fractionation of volatile stable isotopes and their bearing on the origin of the Moon.

    Science.gov (United States)

    Day, James M D; Moynier, Frederic

    2014-09-13

    The Moon is depleted in volatile elements relative to the Earth and Mars. Low abundances of volatile elements, fractionated stable isotope ratios of S, Cl, K and Zn, high μ ((238)U/(204)Pb) and long-term Rb/Sr depletion are distinguishing features of the Moon, relative to the Earth. These geochemical characteristics indicate both inheritance of volatile-depleted materials that formed the Moon and planets and subsequent evaporative loss of volatile elements that occurred during lunar formation and differentiation. Models of volatile loss through localized eruptive degassing are not consistent with the available S, Cl, Zn and K isotopes and abundance data for the Moon. The most probable cause of volatile depletion is global-scale evaporation resulting from a giant impact or a magma ocean phase where inefficient volatile loss during magmatic convection led to the present distribution of volatile elements within mantle and crustal reservoirs. Problems exist for models of planetary volatile depletion following giant impact. Most critically, in this model, the volatile loss requires preferential delivery and retention of late-accreted volatiles to the Earth compared with the Moon. Different proportions of late-accreted mass are computed to explain present-day distributions of volatile and moderately volatile elements (e.g. Pb, Zn; 5 to >10%) relative to highly siderophile elements (approx. 0.5%) for the Earth. Models of early magma ocean phases may be more effective in explaining the volatile loss. Basaltic materials (e.g. eucrites and angrites) from highly differentiated airless asteroids are volatile-depleted, like the Moon, whereas the Earth and Mars have proportionally greater volatile contents. Parent-body size and the existence of early atmospheres are therefore likely to represent fundamental controls on planetary volatile retention or loss.

  16. p-capture reaction cycles in rotating massive stars and their impact on elemental abundances in globular cluster stars: A case study of O, Na and Al

    Science.gov (United States)

    Mahanta, Upakul; Goswami, Aruna; Duorah, Hiralal; Duorah, Kalpana

    2017-08-01

    Elemental abundance patterns of globular cluster stars can provide important clues for understanding cluster formation and early chemical evolution. The origin of the abundance patterns, however, still remains poorly understood. We have studied the impact of p-capture reaction cycles on the abundances of oxygen, sodium and aluminium considering nuclear reaction cycles of carbon-nitrogen-oxygen-fluorine, neon-sodium and magnesium-aluminium in massive stars in stellar conditions of temperature range 2×107 to 10×107 K and typical density of 102 gm cc-1. We have estimated abundances of oxygen, sodium and aluminium with respect to Fe, which are then assumed to be ejected from those stars because of rotation reaching a critical limit. These ejected abundances of elements are then compared with their counterparts that have been observed in some metal-poor evolved stars, mainly giants and red giants, of globular clusters M3, M4, M13 and NGC 6752. We observe an excellent agreement with [O/Fe] between the estimated and observed abundance values for globular clusters M3 and M4 with a correlation coefficient above 0.9 and a strong linear correlation for the remaining two clusters with a correlation coefficient above 0.7. The estimated [Na/Fe] is found to have a correlation coefficient above 0.7, thus implying a strong correlation for all four globular clusters. As far as [Al/Fe] is concerned, it also shows a strong correlation between the estimated abundance and the observed abundance for globular clusters M13 and NGC 6752, since here also the correlation coefficient is above 0.7 whereas for globular cluster M4 there is a moderate correlation found with a correlation coefficient above 0.6. Possible sources of these discrepancies are discussed.

  17. Elemental and radionuclides distribution in the production and use of phosphate fertilizers in Brazil; Distribuicao elementar e de radionuclideos na producao e uso de fertilizantes fosfatados no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Saueia, Catia Heloisa Rosignoli

    2006-07-01

    Fertilizer is considered an essential component for agriculture, because its use increases the natural soil nutrients, which are lost slow waste or erosion. The Brazilian phosphate fertilizer is obtained by wet reaction of igneous phosphate rock with concentrated sulphuric acid, giving as final product, phosphoric acid and dihydrated calcium sulphate (phosphogypsum) as by-product. Phosphoric acid is the starting material for triple superphosphate (TSP), single superphosphate (SSP), monoammonium phosphate (MAP) and diammonium phosphate (DAP). The phosphate rock used as raw material presents in its composition, radionuclides of the U and Th natural series in. During the chemical attack of the phosphate rock, this equilibrium is disrupted and the radionuclides and the elements migrate to intermediate, final products and byproducts, according to their solubility and chemical properties. While the fertilizers are commercialized, the phosphogypsum is disposed in stack piles and can cause an impact in the environment. In order to evaluate the radionuclides and the elements distribution in the industrial process of phosphate fertilizer production, samples of concentrated rock, fertilizers (SSP, TSP, MAP and DAP) and phosphogypsum from three national industries (A, B and C), were analyzed. The characterization of the elements Ba, Co, Cr, Fe, Hf, Na, Sc, Ta, Th, U, Zn and Zr, and the rare earths La, Ce, Nd, Sm, Eu, Tb, Yb and Lu, were performed by instrumental neutron activation analysis. The results obtained showed that, in general, the rare earth elements are distributed uniformly in the fertilizers and phosphogypsum, except for Lu. The elemental concentration present in the fertilizers SSP and TSP are of the same order of magnitude of the source rock. The same behavior was observed in the fertilizers MAP and DAP, except for the elements Co, Sc and U. The radionuclides of the U series ({sup 238}U, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 210}Pb) and of the Th series

  18. Analiza niskofrekventnog spektra vibracija na elementima strukture helikoptera 'Gazela' / Analysis of low frequency vibrations on the structural connection elements of the Gazelle helicopter

    Directory of Open Access Journals (Sweden)

    Miroslav M. Jovanović

    2010-10-01

    Full Text Available U radu je prikazan postupak i metodologija ispitivanja vibracija na helikopteru 'gazela' radi definisanja efikasnosti prigušenja vibracija na vezi struktura - sedište pilota. Posebna pažnja posvećena je teorijskim osnovama vibracija na helikopteru, određivanju radnih frekvencija, definisanju režima rada i profila leta helikoptera u toku ispitivanja. Na kraju rada prikazani su rezultati merenja vibracija u frekventnom domenu. / In this paper the procedure and methodology of vibration testing on a Gazelle helicopter are presented with the aim to define efficiency of vibration damping at the structure-pilot seat connection. A particular attention is paid to the theoretical basis of helicopter vibrations, definition of working frequency, regime and profile of flight during the test. The results of the vibration measurement are shown in the frequency domain. Introduction Nowadays, possibility of defining loads and vibrations is one of the most important requests in the design and modification of processes on helicopters. The loads occuring on the main rotor during flight are the basic source of vibrations on the helicopter. Possibilities to satisfy international standards in the area of structural and human vibrations are based on continuous and adequate measurement and analysis of the vibration levels on all elements of helicopters. This paper shows the procedures of vibration measuring and analyzing in order to define efficiency of vibration damping using a modern acquisition system NetdB 12 and its software dBFA Suite. Theoretical analysis of vibration sources on the helicopter main rotor The helicopter rotor operates in a complex aerodynamic flow field. The aerodynamic loads on the rotor blade vary considerably as it moves around the rotor disc, and in steady flight these loads are periodic. A particular attention is paid to a theoretical basis of vibration sources on a helicopter. A complex aerodynamic field in the plane of the helicopter

  19. Dança na Educação: a busca de elementos na arte e na estétia Dance in Education: the Search for Elements in Art and in Aesthetics Danza en la Educación: la Búsqueda de Elementos en el Arte y la Estética

    Directory of Open Access Journals (Sweden)

    2006-11-01

    Full Text Available Nesta pesquisa tivemos o intuito de desenvolver uma fundamentação teórica para a dança na educação, com base em elementos da arte e da estética. Temos como pressuposto metodológico a realização de uma pesquisa teórica baseada na hermenêutica. Na arte identificamos como primordiais a criatividade e a expressividade, e na estética, a sensibilidade. Acreditamos que esses elementos formam o tripé básico para o trabalho com a dança tanto na educação formal quanto na educação informal. PALAVRAS-CHAVE: Dança - Educação - Arte - Estética. In this research work we aimed at developoing a theoretical basis for dance in education. Thus, we searched for elements in Art and in Aesthetics that could contribute to this aim. Therefore, in Art we identified creativity and expressiveness as important elements; and in Aesthetics, sensitivity came out as an important element. We believe these elements form the basic tripod for the work with dance in formal as well as in informal education. The main aim of this study is to develop a theoretical basis for dance in education with elements taken from Art and Aesthetics. The methodological approach chosen for this study was a theoretical research based on hermeneutics. The reflections developed here are by no means final; however, we believe this research work brings its contribution to all who are interested in this field and it also shows the way to other possible studies in the area. KEY WORDS: Dance - Education - Art - Aesthetics. En esta investigación tuvimos el propósito de desarrollar una fundamentación teórica para la danza en la educación. De este modo, buscamos en el arte y en la estética elementos que pudieran contribuir para este hecho. Entonces, en el arte identificamos como primordiales la creatividad y la expresividad, y en la estética, la sensibilidad. Elementos que creemos formar el trípode básico para el trabajo con la danza tanto en la educación formal como

  20. Volatilização de amônia com aplicação de uréia na superfície do solo, no sistema plantio direto Ammonia volatilization after urea surface applied in corn no-tillage

    Directory of Open Access Journals (Sweden)

    Clovis Orlando Da Ros

    2005-08-01

    Full Text Available Com o objetivo de avaliar o efeito dos resíduos culturais de aveia preta (Avena strigosa, dispostos na superfície do solo, nas perdas de N por volatilização de amônia, conduziu-se um experimento a campo, em 2002/03, na UFSM (RS, em um Argissolo Vermelho distrófico arênico. O delineamento experimental foi o inteiramente casualizado, com três repetições. Os tratamentos constituíram da aplicação de uréia no milho, na presença e na ausência de resíduos culturais de aveia, em três épocas (pré-semeadura, semeadura e em cobertura. A uréia foi aplicada a lanço, sem incorporação ao solo, na dose equivalente a 50kg ha-1 de N, em cada época. Os resíduos culturais diminuíram os fluxos de volatilização de amônia quando eles proporcionaram maior umidade do solo no momento da aplicação da uréia, em relação ao solo descoberto. Em condições semelhantes de umidade de solo, entre os tratamentos com e sem resíduos culturais, houve maior volatilização de amônia, quando a uréia foi aplicada sobre os resíduos culturais. Quando ocorreu chuva no dia posterior a aplicação da uréia, não houve efeito dos resíduos culturais na volatilização de amônia. Na soma das três épocas de aplicação de uréia na cultura do milho, a quantidade de amônia volatilizada não diferiu entre os tratamentos com e sem resíduos culturais, com média de 17 % de perda do N-uréia aplicado.The experiment was carried out in 2002/03, the Federal University of Santa Maria, State of Rio Grande do Sul, Brasil, in a typic Haoludal under six years of no-tillage to evaluate the effects of black oat residues left at soil surface on ammonia volatilization. The experiment was in a completely randomized design with three replications. The treatments were urea applied with and without surface residue in three times: before seeding; seeding and; topdressing. The urea was spread at a rate of 50kg ha-1 de N each time. The residues reduced the ammonia fluxes

  1. Mantle Volatiles - Distribution and Consequences

    Science.gov (United States)

    Luth, R. W.

    2003-12-01

    Volatiles in the mantle have, for many years, been the subject of intensive study from a number of perspectives. They are of interest because of their potential effects on melting relationships, on transport of major and trace elements, and on the rheological and other physical properties of the mantle. By convention, "volatiles" in this context are constituents that are liquid or gaseous at normal Earth surface conditions. This review will look at the behavior of C-O-H-S-halogen volatiles, beginning with H2O and C-O volatiles.There have been tremendous strides made recently towards understanding how volatiles in general and water in particular is transported and stored in the mantle. This progress is based on research on a number of fronts: studies of mantle-derived samples have provided insight into the nature and occurrence of hydrous phases such as amphibole, mica, and chlorite, and have provided constraints on the capacity of nominally anhydrous minerals (NAMs) such as olivine, pyroxenes, and garnet to contain "water" by a variety of substitution mechanisms. Experimental studies on mantle-derived magmas have provided constraints on volatile contents in their source regions. Other studies have constrained the pressure, temperature, and composition conditions over which hydrous phases are stable in the mantle.Fundamental questions remain about the geochemical cycling of volatiles in the mantle, and between the mantle and the surface. Much attention has focused on the capability of hydrous phases such as amphibole, mica, serpentine, chlorite, and a family of "dense hydrous magnesian silicates" (DHMSs) to act as carriers of water in subducting slabs back into the mantle. It has been clear since the work of Ito et al. (1983) that there is a discrepancy between the amount of volatiles subducted into the mantle and those returned to the surface by arc magmatism. A recent overview of volatile cycling in subduction systems by Bebout (1996) suggests that 5-15% of the H2

  2. Removal Of Volatile Impurities From Copper Concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, L.; Schuler, A.; Frei, A.; Sturzenegger, M.

    2005-03-01

    To study the removal of volatile impurities from two different copper concentrates they have been heated on a thermo balance to temperatures between 900 and 1500 C. This sample treatment revealed that both concentrates undergo strong weight losses at 500 and 700 C. They were attributed to the removal of sulfur. Elemental analyses of the residues by ICP spectrometry have shown that the thermal treatment efficiently removes the volatile impurities. Already below 900 C most of the arsenic is removed by evaporation, the largest fraction of lead and zinc is removed in the temperature interval of 1300-1500 C. It was observed that quartz in the concentrate leads to the formation of a silicon-enriched phase besides a metal rich sulfide phase. The former is interpreted as an early stage of a silicate slag. Elemental analysis showed that the formation of this distinct slag phase does not hinder the efficient removal of volatile impurities. (author)

  3. Emerging Equity Market Volatility

    OpenAIRE

    Geert Bekaert; Harvey, Campbell R.

    1995-01-01

    Returns in emerging capital markets are very different from returns in developed markets. While most previous research has focused on average returns, we analyze the volatility of the returns in emerging equity markets. We characterize the time-series of volatility in emerging markets and explore the distributional foundations of the variance process. Of particular interest is evidence of asymmetries in volatility and the evolution of the variance process after periods of capital market refor...

  4. 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......, 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....

  5. Origin of Na in glass inclusions hosted in olivine from Allende CV3 and Jbilet Winselwan CM2: Implications for chondrule formation

    Science.gov (United States)

    Florentin, L.; Faure, F.; Deloule, E.; Tissandier, L.; Gurenko, A.; Lequin, D.

    2017-09-01

    Glass inclusions trapped in Mg-rich olivines within type I chondrules from the Allende (CV3) and Jbilet Winselwan (CM2) chondrites were analyzed by EPMA (Electron Probe Microanalysis) for major elements and by SIMS (Secondary Ion Mass Spectrometry) for Cl and S (analyzed here for the first time in chondrule-hosted glass inclusions). The inclusions from Jbilet Winselwan are poor in Na2O, whereas those from Allende are Na-rich, displaying up to 8 wt.% Na2O. The source of Na is a central issue in terms of chondrule origins because of the volatility of Na at high temperature. The wide scatter in Na2O contents of olivine-hosted glass inclusions from chondrules has led the community to propose that Na2O came from late interactions of chondrules with a Si/Na-rich gas. To gain new insights into the origins of the Na2O recorded in glass inclusions, heating experiments (up to 1810 °C) were performed on Allende inclusions in an effort to constrain the initial composition of the trapped melts. Our results demonstrate that sodium (although volatile) does not escape from inclusions during heating, thus confirming that glass inclusions behave as closed systems. Furthermore, heated olivines still bear inclusions containing up to 7.2 wt.% of Na2O. Olivines are thought to form at temperatures at which Na is volatile. This implies that (1) Na from glass inclusions cannot come from condensation but rather results from trapping in a Na-rich environment, which implies a high pressure, as in a melting planetasimal (2) there may be two distinct origins for the sodium: an indigenous origin for the sodium trapped inside glass inclusions and a gaseous origin for the sodium recorded in mesostasis from chondrules. Consequently, these results are in favor of a planetesimal origin for olivine from chondrules.

  6. 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 time. Wi

  7. 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

  8. 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

  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 ident...

  10. Analiza niskofrekventnog spektra vibracija na elementima strukture helikoptera 'Gazela' / Analysis of low frequency vibrations on the structural connection elements of the Gazelle helicopter

    OpenAIRE

    Jovanović, Miroslav M.

    2010-01-01

    U radu je prikazan postupak i metodologija ispitivanja vibracija na helikopteru 'gazela' radi definisanja efikasnosti prigušenja vibracija na vezi struktura - sedište pilota. Posebna pažnja posvećena je teorijskim osnovama vibracija na helikopteru, određivanju radnih frekvencija, definisanju režima rada i profila leta helikoptera u toku ispitivanja. Na kraju rada prikazani su rezultati merenja vibracija u frekventnom domenu. / In this paper the procedure and methodology of vibration testing o...

  11. Examining Moderate Volatile Loss through Lunar History

    Science.gov (United States)

    Saxena, Prabal; Killen, Rosemary M.; Airapetian, Vladimir; Petro, Noah; Mandell, Avi

    2017-06-01

    While the Moon and bulk silicate earth (BSE) share many compositional similarities, a notable difference is the apparent depletion of moderate volatiles in lunar samples. Depletion of elements such as sodium and potassium relative to BSE composition has been observed in Apollo samples. The source of these depletions is poorly understood but may be a result of preferential accretion of volatile-rich melt in the inner disk to the Earth during Moon formation.However, recent Kepler data has indicated that stellar analogues to our Sun experience enhanced flare activity early in their evolution. This implies that the Sun may have had a higher frequency and energy of flares and associated Coronal Mass Ejections (CME) in its distant past. We examine the potential impacts of this increased activity on lunar exosphere generation and specifically on potential loss of moderate volatiles including sodium and potassium.We use a surface bounded exosphere model that incorporates multiple processes including photon stimulated desorption, kinetic sputtering and impact vaporization in order to study potential moderate volatile loss under a variety of different conditions. This model is informed by appropriate solar wind and CME properties, which includes CMEs of different energies. We also incorporate regolith overturn to determine ranges of potential bulk depletion of moderate volatiles from the lunar regolith.Our work is aimed at determining the potential impact of solar activity on the depletion of moderate volatiles in the lunar regolith. Such a contribution is important to ascertain in order to isolate the depletion of volatiles due to disk processes and may thus help constrain details of the Moon's formation. Finally, we also examine the potential of lunar abundances of moderate volatiles as an observational tracer of past solar activity.

  12. Natural wetland emissions of methylated trace elements

    NARCIS (Netherlands)

    Vriens, B.; Lenz, M.; Charlet, L.; Berg, M.; Winkel, L.H.E.

    2014-01-01

    Natural wetlands are well known for their significant methane emissions. However, trace element emissions via biomethylation and subsequent volatilization from pristine wetlands are virtually unstudied, even though wetlands constitute large reservoirs for trace elements. Here we show that the averag

  13. Water Vapor-Mediated Volatilization of High-Temperature Materials

    Science.gov (United States)

    Meschter, Peter J.; Opila, Elizabeth J.; Jacobson, Nathan S.

    2013-07-01

    Volatilization in water vapor-containing atmospheres is an important and often unexpected mechanism of degradation of high-temperature materials during processing and in service. Thermodynamic properties data sets for key (oxy)hydroxide vapor product species that are responsible for material transport and damage are often uncertain or unavailable. Estimation, quantum chemistry calculation, and measurement methods for thermodynamic properties of these species are reviewed, and data judged to be reliable are tabulated and referenced. Applications of water vapor-mediated volatilization include component and coating recession in turbine engines, oxidation/volatilization of ferritic steels in steam boilers, chromium poisoning in solid-oxide fuel cells, vanadium transport in hot corrosion and degradation of hydrocracking catalysts, Na loss from Na β"-Al2O3 tubes, and environmental release of radioactive isotopes in a nuclear reactor accident or waste incineration. The significance of water vapor-mediated volatilization in these applications is described.

  14. A adição de diferentes produtos químicos e o efeito da umidade na volatilização de amônia em cama de frango Addition of chemical additives and the effect of moisture in the volatilization of ammonia in poultry litter

    Directory of Open Access Journals (Sweden)

    Rangel Medeiros

    2008-11-01

    Full Text Available Foi avaliada a redução da volatilização de amônia em cama de frangos por meio da adição de aditivos químicos em três experimentos. No primeiro experimento foram estudadas diferentes doses de fosfato: testemunha; 5, 10, 15, 20 e 25%, adicionado à cama No segundo, foi estudado o efeito da umidade, para os mesmos tratamentos realizados no primeiro experimento. No terceiro experimento, foram testados diferentes aditivos na cama de frango (testemunha, Sal de Glauber, Enxofre, Sulfato de cobre, Fosfato, Sulfato de alumínio e Carbonato de sódio, nos níveis de concentração de: 1,2,3,4 e 5%. Como resultado, obteve-se que a dose de 15% de superfosfatosimples foi a mais eficiente (PThe effect of additives to reduce volatilization of ammonia in poultry litter was evaluated in three experiments. In experiment one, different doses of phosphate, in the form of simple superphosphate, were studied by means of six treatments: 5, 10, 15, 20 and 25% added to the poultry litter. In the second experiment, the effect of humidity was verified by using the same treatments carried out in the previous experiment. In experiment three, different additives were tested in the poultry litter, following seven treatments: Glauber’s salt; sulphur; copper sulphate, phosphate, aluminium sulphate; and sodium carbonate. In treatment one, the dose of 15% of simple superphosphate added to the poultry litter showed to be more effective than the other additives, for it has inhibited 95% of the volatilization. As to experiment two, a strong inhibiting influence of water in the volatilization of ammonia could be detected. As to experiment three, the copper sulphate was the best additive (P>0.05 to inhibit the poultry litter’s volatilization of ammonia (62%, followed by both the aluminium sulphate (53% and the simple superphosphate (43%. The use of carbonate has promoted an increase of 41% in the levels of ammonia volatilization.

  15. Elementos biológicos na configuração do território do rio Doce Biological elements in the River Doce's territory configuration

    Directory of Open Access Journals (Sweden)

    Haruf Salmen Espindola

    2008-06-01

    Full Text Available No médio rio Doce, entre 1930 e 1960, as terras de floresta foram ocupadas pela agricultura e pecuária. No início as culturas agrícolas encontraram condições favoráveis para se expandir, mas não suficientes para se consolidar, antes de dar lugar à pecuária, como é comum na história da agricultura brasileira. As terras cobertas pela floresta foram tomadas pelo capim-colonião (Panicum maximum Jacq. var. maximum num ritmo maior que o avanço da atividade humana. A gramínea africana encontrou condições excepcionais para se alastrar, dadas pelo relevo, pelo clima e pelo manejo praticado por agricultores e fazendeiros. As suas características biológicas favoreceram o avanço das pastagens. O capim-colonião não diminui a força dos elementos socioeconômicos, marcados por relações de poder em que o fazendeiro levava nítida vantagem, mas entender sua biologia contribui para a compreensão da configuração do território do rio Doce.At the middle Doce river , between 1930 and 1960, the forest lands had been occupied by agriculture and cattle raising. First, the agricultural cultures had found favorable conditions to enlargement, but not enough for consolidating itself, before giving place to cattle, as it is common in the history of Brazilian agriculture. The lands covered by the forest had been invaded by the capim-colonião (Panicum maximum Jacq. var. maximum in a bigger rhythm than the advance of the human activity. The African grassy found very good conditions to spreading (the relief, the climate and the practices of the farmers. Its biological characteristics had favored the advance of the grass. The capim-colonião does not diminished the force of the socioeconomics elements, marked for power relations where the farmer took clear advantage, but understand its biological aspects contributes for the understanding of the configuration of the territory of the river Doce.

  16. 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......In this paper, we scrutinize the cross-sectional relation between idiosyncratic volatility and stock returns. As a novelty, the idiosyncratic volatility is obtained by conditioning upon macro-Önance factors as well as upon traditional asset pricing factors. The macro-Önance factors are constructed...

  17. Composition, volatile components, and trace elements in andesitic melts of the Kurile-Kamchatka region%俄罗斯Kurile-Kamchatka地区安山质熔体的成分、挥发分组成和微量元素

    Institute of Scientific and Technical Information of China (English)

    M.L.Tolstykh; V.B.Naumov; A.D.Babansky

    2007-01-01

    Melt inclusions in minerals from some volcanoes of the Kurile-Kamchatka region were examined. The studied basaltic andesites and andesites were sampled from volcanoes of the Central Kamchatka depression ( Shiveluch and Bezymyannyi), Eastern Kamchatka volcanic belt (Avachinskii and Karymskii), and Iturup Island, Southern Kuriles (Kudryavyi). Basalts of the 1996 eruption of the Karymskii volcanic center and dacites of Dikii Greben' volcano, Southern Kamchatka were also studied. More than 260 melt inclusions from 31 rock samples were homogenized, and quenched glasses were analyzed using electron and ion microprobes. The compositions of melt inclusions in andesitic phenocrysts vary in silica contents from 56 to 80wt%. Al2O3 , FeO, MgO, CaO decrease and Na2O and K2O increase with increasing SiO2. Many inclusions ( about 80% ) are dacitic or rhyolitic. However, the compositions of silicic glasses ( >65wt% SiO2 ) in andesites significantly differ in TiO2 , FeO, MgO, CaO, and K2O contents from those in dacites and rhyolites. High-potassium melts (K2O 3.8 ~6.8wt% ) with various SiO2 from 51.4 to 77.2wt% were found in minerals of all volcanoes studied. This indicates a contribution of a component selectively enriched in potassium to magmas of the whole region. A great compositional diversity of melt inclusions in plagioclase phenocrysts from the Bezymyannyi andesites suggests a complex history of plagioclase crystallization and magma evolution in the andesite formation. Melts from different volcanoes strongly vary in volatile contents. The highest H2O contents are found in the melts from Shiveluch (3.0 ~7.2wt%, 4.7wt% on average) and Avachinskii (4.7 ~4.8wt% ); while those are lower in melts of Kudryavyi (0.1 ~ 2.6wt% ), Dikii Greben' (0.4 ~ 1.8wt% ), and Bezymyannyi ( < 1wt% ). Chlorine contents are also variable. The lowest values are found in the Bezymyannyi melts (0.09wt% on average), the highest Cl contents are typical of melt inclusions in minerals from

  18. On guidance and volatility

    NARCIS (Netherlands)

    Billings, M.B.; Jennings, R.; Lev, B.

    2013-01-01

    Survey evidence suggests that managers voluntarily disclose information, particularly earnings guidance, with an aim toward dampening share price volatility. Yet, consultants and influential institutions advise against providing guidance — citing fears of litigation and market penalties associated w

  19. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    profit on well-developed markets. Dynamic participation features on cross asset portfolios are at rst sight a remedy to that dilemma. Based on volatility thresholds and portfolio re-balancing, the fund engineers try to create a "volatility guaranteed" investment opportunity by surfing on the unusual high...... concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex......, interest rates and commodities. If an investor positions himself on the (volatility) market within a long/short trading framework, he typically bets on a traditional mispricing arbitrage. However as this corresponds to a call spread with equal exercise prices, this strategy alone would not generate enough...

  20. It’s all about volatility of volatility

    DEFF Research Database (Denmark)

    Grassi, Stefano; Santucci de Magistris, Paolo

    2015-01-01

    for the realized volatility series. It emerges that during the recent financial crisis the relative weight of the daily component dominates over the monthly term. The estimates of the two factor stochastic volatility model suggest that the change in the dynamic structure of the realized volatility during...... the financial crisis is due to the increase in the volatility of the persistent volatility term. A set of Monte Carlo simulations highlights the robustness of the methodology adopted in tracking the dynamics of the parameters....

  1. 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.

  2. Effects of minerals in ferric bauxite on sodium carbonate decomposition and volatilization

    Institute of Scientific and Technical Information of China (English)

    胡文韬; 王化军; 刘欣伟; 孙传尧

    2015-01-01

    Direct reduction is an emerging technology for ferric bauxite utilization. However, because of sodium volatilization, its sodium carbonate consumption is considerably higher than that in ordinary bauxite processing technology. TG-DSC and XRD were applied to detecting phase transformation and mass loss in direct reduction to reveal the mechanism on sodium volatilization. The results show that the most significant influence factor of ferric bauxite on sodium volatilization in direct reduction system is its iron content. Sodium volatilization is probably ascribed to the instability of amorphous substances structure. Amorphous substances are the intermediate-products of the reaction, and the volatilization rate of sodium increases with its generating rate. These amorphous substances are volatile, thus, more sodium is volatilized with its generation. A small amount of amorphous substances are generated in the reaction between Na2CO3and Al2O3; thus, only 3.15% of sodium is volatilized. Similarly, the volatilization rate is 1.87% in the reaction between Na2CO3and SiO2. However, the volatilization rate reaches 7.64% in the reaction between Na2CO3 and Fe2O3 because of the generation of a large amount of amorphous substances.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vo, Minh, E-mail: minh.vo@metrostate.edu

    2011-09-15

    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.

  4. Effect of exogenous 2,4-epibrassinolide on trace element absorption and chlorophyll fluorescence of Medicago sativa L. seedlings under NaCl stress%外源 EBR 对 NaCl 胁迫下紫花苜蓿幼苗微量元素吸收及叶绿素荧光动力学参数的影响

    Institute of Scientific and Technical Information of China (English)

    寇江涛; 康文娟; 苗阳阳; 师尚礼

    2016-01-01

    North China. Brassinosteroid (BR) has been globally recognized as a new plant growth hormone with high and broad spectrum activity, which could regulate plant growth and development and mitigate a series of abiotic stresses due to high salinity, heavy metal contamination, high temperatures, low temperatures, drought and hypoxia. It also plays an important role in regulating the photosynthesis and absorption of trace element of plants. Given the importance of the study of the effects of BR on trace element absorption and fluorescence kinetics parameters in Medicago sativa L. seedlings under salt stress, we investigated salt resistance and possible physiological regulation mechanism of M. sativa seedlings induced by exogenous 2,4-Epibrassinolide (EBR). The effects of EBR on the absorption, transportation and allocation of trace elements, leaf PSⅡ function, electron transport rate and light allocation in seedlings of M. sativa cv. Zhongmu No.3 and M. sativa cv. Longzhong under NaCl stress were determined using the hydroponics method. Four treatments were conducted in the experiment ― CK (distilled water), 150 mmol·L-1 NaCl, 0.1 μmol·L-1 EBR and 150 mmol·L-1 NaCl +0.1 μmol·L-1 EBR. The results showed that Cu2+ content increased significantly in different organs (leave, stem and root) of the seedlings, also Fe2+, Mn2+ and Zn2+ contents significantly decreased and then Fe2+/Na+, Mn2+/Na+, Cu2+/Na+ and Zn2+/Na+declined markedly under 150 mmol·L-1 NaCl stress. The metabolic process of the uptake, transportation and distribution of inorganic ions was disordered and PSⅡ reaction center damaged. Concurrently, there was a drop in the transportation ratio of photosynthetic electrons (ETR) and photochemical reaction energy. NaCl stress facilitated antenna dissipated energy and reaction center dissipated energy, which resulted in a drop in photosynthetic capacity. This condition was reversed by the addition of 0.1 μmol·L-1 EBR under NaCl stress. Addition of EBR

  5. 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.

  6. 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...

  7. Stochastic volatility selected readings

    CERN Document Server

    Shephard, Neil

    2005-01-01

    Neil Shephard has brought together a set of classic and central papers that have contributed to our understanding of financial volatility. They cover stocks, bonds and currencies and range from 1973 up to 2001. Shephard, a leading researcher in the field, provides a substantial introduction in which he discusses all major issues involved. General Introduction N. Shephard. Part I: Model Building. 1. A Subordinated Stochastic Process Model with Finite Variance for Speculative Prices, (P. K. Clark). 2. Financial Returns Modelled by the Product of Two Stochastic Processes: A Study of Daily Sugar Prices, 1961-7, S. J. Taylor. 3. The Behavior of Random Variables with Nonstationary Variance and the Distribution of Security Prices, B. Rosenberg. 4. The Pricing of Options on Assets with Stochastic Volatilities, J. Hull and A. White. 5. The Dynamics of Exchange Rate Volatility: A Multivariate Latent Factor ARCH Model, F. X. Diebold and M. Nerlove. 6. Multivariate Stochastic Variance Models. 7. Stochastic Autoregressive...

  8. Application of different methodologies in the preparation of organic matrices for determination of trace elements by differential pulse anodic stripping voltammetry; Aplicacao de diferentes metodologias na preparacao de matrizes organicas para a determinacao voltametrica de elementos traco

    Energy Technology Data Exchange (ETDEWEB)

    Sisti, Cristina

    2001-07-01

    The determination of trace elements in food samples is of great importance for the human health, considering the factors of essentiality and toxicity. On the other hand, the chemical analysis is largely affected for the steps of sample preparation; laboratory contamination of the sample and the reagents or still volatilization and losses of the elements. If these parameters are not controlled the achieved precision and accuracy could be low. In this work, the content of zinc, cadmium, lead and copper was determined in adults diet samples collected by duplicate portion technique and bovine liver, applying the differential pulse anodic stripping voltametry - (DP-ASV) technique. In the digestion of the matrices in acid medium, conventional methodologies were used, conductive heating in open recipients and equipment with microwaves source in open and closed vessels. The best procedure was the sample digestion by microwaves, in closed vessels and the other treatments made in controlled atmosphere with hood laminar-airflow class 100. The established methodology was validated with the use of a certified sample as reference (NIST - bovine liver 1577b). (author)

  9. 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...... 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...... 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....

  10. Analysis of breath volatile organic compounds as a screening tool for detection of Tuberculosis in cattle

    Science.gov (United States)

    • Keywords: bovine tuberculosis; Mycobacterium bovis; breath analysis; volatile organic compound; gas chromatography; mass spectrometry; NaNose • Introduction: This presentation describes two studies exploring the use of breath VOCs to identify Mycobacterium bovis infection in cattle. • Methods: ...

  11. 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.......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...... 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...

  12. Dynamic Volatility Arbitrage

    DEFF Research Database (Denmark)

    Dorn, Jochen

    concepts, next to nothing is known about position reverting strategies and how, and -even more important- in which context they are applied in practice. In the recent market downturn only one sector generated signicant profits for the leading investment banks: Volatility trading activities, namely on Forex...

  13. Stock markets liberalization affects volatility?

    OpenAIRE

    Ioan Alin NISTOR; Maria-Lenuţa CIUPAC-ULICI; GHERMAN Mircea-Cristian

    2012-01-01

    Regarding the impact of liberalization, the results show that, in general, market opening is accompanied by a significant increase in market volatility. In particular, volatility tends to decrease due to large capital inflows and domestic growth.The study analyzes the impact of stock market liberalization on volatility in six emerging stock markets by using GARCH methodology. Theory on the effects of financial liberalization on volatility has been ambiguous, and empirical work has yielded con...

  14. Elementos traço e complicações obstétricas na gestação na adolescência Trace elements and obstetric complications in teenage pregnancy

    Directory of Open Access Journals (Sweden)

    Milena Lima de Moraes

    2010-08-01

    Full Text Available Minerais estão relacionados com todas as etapas de crescimento e diferenciação celular. Quando a gestação coincide com a adolescência a demanda nutricional necessária para ótimo desenvolvimento e crescimento materno e fetal aumenta consideravelmente. Apesar de existirem muitos estudos sobre as funções destes micronutrientes, pouco se sabe sobre suas atuações no resultado da gestação. Este trabalho objetivou revisar na literatura o papel do cobre, ferro, e zinco no resultado da gestação, em especial de gestantes adolescentes, focando intercorrências como baixo peso ao nascer, partos pré-termo, pré-eclampsia, abortos, dentre outras complicações associadas à gestação na adolescência. Os estudos já realizados são limitados, há a necessidade de promovê-los em países em desenvolvimento, onde a deficiência de micronutrientes e intercorrências possuem altos índices. Os benefícios da suplementação de minerais na redução da prevalência de déficits e na melhora dos estoques maternos têm sido demonstrados, mas dados sobre os benefícios potenciais para o feto são pouco conclusivos.Minerals are associated with all stages of growth and cellular differentiation. When gestation coincides with adolescence, the nutritional requirements for optimal development of the mother and fetus increase significantly. Although there are many studies on the function of micronutrients, little is known about their influence on pregnancy outcome. This work aimed to review studies that investigated the influence of copper, iron and zinc on pregnancy outcome, especially in teenagers, focusing on intercurrences such as low birth weight, preterm births, pre-eclampsia, miscarriages and other complications associated with teenage pregnancy. There are only a few studies on this topic and a need to promote them in developing countries, where high rates of micronutrient deficiencies and intercurrences are common. The efficacy of mineral

  15. 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.

  16. 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.

  17. Plant volatiles and the environment

    NARCIS (Netherlands)

    Loreto, F.; Dicke, M.; Schnitzler, J.P.; Turlings, T.C.J.

    2014-01-01

    Volatile organic compounds emitted by plants represent the largest part of biogenic volatile organic compounds (BVOCs) released into our atmosphere. Plant volatiles are formed through many biochemical pathways, constitutively and after stress induction. In recent years, our understanding of the func

  18. Comparative study for essential elements determination in milk products samples by INAA and ICP-AES; Estudo comparativo na determinacao de elementos essenciais em amostras de produtos lacteos por AANI e ICP-AES

    Energy Technology Data Exchange (ETDEWEB)

    Kira, Carmen S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Equipamentos Especializados; Maihara, Vera A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2002-07-01

    The mineral elements Ca, Fe, K, Mg, Na and Zn were analyzed in milk products by using instrumental neutron activation analysis (INAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The study included four types of cheese (mozzarella, minas, prato, parmesan), chocolate milk and yogurt. The samples were purchased from the local markets. Average concentrations ranged from 3668 (chocolate milk) to 16558 (parmesan cheese) mg/kg for Ca; from 2.61 (parmesan cheese) to 28.9 (chocolate milk) mg/kg for Fe; from 673 (mozzarella cheese) to 10492 (chocolate milk) mg/kg for K; from 398 (yogurt) to 2280 (minas cheese) mg/kg for Mg; from 1681 (yogurt) to 15248 (parmesan cheese) mg/kg for Na; from 12.1 (chocolate milk) to 71.8 (parmesan cheese) mg/kg for Zn. Two National Institute of Standards and Technology (NIST) standard reference materials (SRM 8435 Whole Milk Powder and SRM 1549 Non Fat Milk Powder) were analyzed to verify method accuracy. The statistic test used to determine the significance of the difference between the techniques was based on Unpaired t-Student test. Statistical test revealed no significance differences (P< 0,05) between the average values provided by the two methods for the most of determined elements. (author)

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

    DEFF Research Database (Denmark)

    Bach, Christian; Christensen, Bent Jesper

    We include simultaneously both realized volatility measures based on high-frequency asset returns and implied volatilities backed out of individual traded at the money option prices in a state space approach to the analysis of true underlying volatility. We model integrated volatility as a latent...... fi…rst order Markov process and show that our model is closely related to the CEV and Barndorff-Nielsen & Shephard (2001) models for local volatility. We show that if measurement noise in the observable volatility proxies is not accounted for, then the estimated autoregressive parameter in the latent...... 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 ($/£ )....

  20. Forming chondrules in impact splashes - II Volatile retention

    CERN Document Server

    Dullemond, Cornelis Petrus; Stammler, Sebastian Markus; Johansen, Anders

    2016-01-01

    Solving the mystery of the origin of chondrules is one of the most elusive goals in the field of meteoritics. Recently the idea of planet(esimal) collisions releasing splashes of lava droplets, long considered out of favor, has been reconsidered as a possible origin of chondrules by several papers. One of the main problems with this idea is the lack of quantitative and simple models that can be used to test this scenario by directly comparing to the many known observables of chondrules. In Paper I of this series we presented a simple thermal evolution model of a spherically symmetric expanding cloud of molten lava droplets that is assumed to emerge from a collision between two planetesimals. In the present paper, number II of this series, we use this model to calculate whether or not volatile elements such as Na and K will remain abundant in these droplets or whether they will get depleted due to evaporation. The high density of the droplet cloud (e.g. small distance between adjacent droplets) causes the vapo...

  1. Electrochemical detection of volatile organic compounds using a Na{sub 3}Zr{sub 2}Si{sub 2}PO{sub 12}/Bi{sub 2}Cu{sub 0.1}V{sub 0.9}O{sub 5.35} heterojunction device

    Energy Technology Data Exchange (ETDEWEB)

    Kida, Tetsuya, E-mail: kida@mm.kyushu-u.ac.jp [Department of Energy and Material Sciences, Faculty of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan); Morinaga, Naoki; Kishi, Shotaro [Department of Molecular and Material Sciences, Interdisciplinary Graduate School of Engineering Science, Kyushu University, Kasuga-Koen 6-1, Kasuga, Fukuoka 816-8580 (Japan); An, Ki-Mun; Sim, Kyoung-Won; Chae, Bu-Young [Department of Materials Science and Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Kim, Jung-kwan [Education Center for Green Industry-friendly Fusion Technology (GIFT), Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Ryu, Bong-Ki [Department of Materials Science and Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Shimanoe, Kengo [Department of Energy and Material Sciences, Faculty of Engineering Sciences, Kyushu University, Kasuga-koen, Kasuga, Fukuoka 816-8580 (Japan)

    2011-09-01

    Highlights: > A device combining a sodium ion conductor of NASICON (Na{sub 3}Zr{sub 2}Si{sub 2}PO{sub 12}) with an oxygen ion conductor of BiCuVOx (Bi{sub 2}Cu{sub 0.1}V{sub 0.9}O{sub 5.35}) was fabricated. > The device can electrochemically detect volatile organic compounds (VOCs). > The electrochemical oxidation of VOCs with oxide ions occurred as the sensing reaction. > The formation of an oxygen ion-conductive layer at the interface between NASICON and BiCuVOx was suggested. - Abstract: A fast sodium ion conductor, NASICON (Na{sub 3}Zr{sub 2}Si{sub 2}PO{sub 12}), has been widely used for gas sensor applications. In this study, we demonstrate that a device combining NASICON with an oxygen-ion conductor of BiCuVOx (Bi{sub 2}Cu{sub 0.1}V{sub 0.9}O{sub 5.35}) can electrochemically detect volatile organic compounds (VOCs), such as ethanol, formaldehyde, and toluene. The sensing electrode made of BiCuVOx was attached onto a sintered NASICON disk at high temperature to produce an interfacial layer that had a different morphology and composition from those of NASICON and BiCuVOx, as observed by scanning electron microscopy-energy dispersive X-ray spectroscopy analysis. The device in which NASICON was fitted with the BiCuVOx-based electrode was found to efficiently detect VOCs in ppm concentrations. The sensor signal (electromotive force) exceeded 100 mV in response to 10 ppm HCOH at 400 deg. C, demonstrating the high sensitivity of the device. It also exhibited a relatively quick response, reproducible and stable sensor signals, and high selectivity to VOCs. The sensor responses followed behavior typical for mixed-potential-type gas sensors based on oxygen-ion conductors. It was thus suggested that the electrochemical oxidation of VOCs with oxide ions took place at the interfacial oxygen ion-conductive layer that was formed by the reaction of NASICON with BiCuVOx.

  2. Discontinuous finite elements applied to solution of problems about heat transfer in heterogeneous media; Elementos finitos descontinuos na solucao de problemas envolvendo transferencia de calor em meios heterogeneos

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Monica Barcellos Jansen; Carmo, Eduardo Gomes Dutra do [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear. E-mail: monica@lmn.con.ufrj.br; carmo@lmn.com.ufrj.br

    2000-07-01

    Heat transfer problems in heterogenous media with large variation of thermal conductivity are notorious for the difficulties in obtaining good numerical results. In this work it is proposed an application of a new mixed discontinuous finite element formulation to this class of problems, which produces good results without the need of high mesh refinement. Stability and consistency aspects are considered and numerical results are presented to show the efficacy of the method. (author)

  3. Scaling Foreign Exchange Volatility

    OpenAIRE

    Jonathan Batten; Craig Ellis

    2001-01-01

    When asset returns are normally distributed the risk of an asset over a long return interval may be estimated by scaling the risk from shorter return intervals. While it is well known that asset returns are not normally distributed a key empirical question concerns the effect that scaling the volatility of dependent processes will have on the pricing of related financial assets. This study provides an insight into this issue by investigating the return properties of the most important currenc...

  4. Comparison of Hygroscopicity, Volatility, and Mixing State of Submicrometer Particles between Cruises over the Arctic Ocean and the Pacific Ocean.

    Science.gov (United States)

    Kim, Gibaek; Cho, Hee-Joo; Seo, Arom; Kim, Dohyung; Gim, Yeontae; Lee, Bang Yong; Yoon, Young Jun; Park, Kihong

    2015-10-20

    Ship-borne measurements of ambient aerosols were conducted during an 11 937 km cruise over the Arctic Ocean (cruise 1) and the Pacific Ocean (cruise 2). A frequent nucleation event was observed during cruise 1 under marine influence, and the abundant organic matter resulting from the strong biological activity in the ocean could contribute to the formation of new particles and their growth to a detectable size. Concentrations of particle mass and black carbon increased with increasing continental influence from polluted areas. During cruise 1, multiple peaks of hygroscopic growth factor (HGF) of 1.1-1.2, 1.4, and 1.6 were found, and higher amounts of volatile organic species existed in the particles compared to that during cruise 2, which is consistent with the greater availability of volatile organic species caused by the strong oceanic biological activity (cruise 1). Internal mixtures of volatile and nonhygroscopic organic species, nonvolatile and less-hygroscopic organic species, and nonvolatile and hygroscopic nss-sulfate with varying fractions can be assumed to constitute the submicrometer particles. On the basis of elemental composition and morphology, the submicrometer particles were classified into C-rich mixture, S-rich mixture, C/S-rich mixture, Na-rich mixture, C/P-rich mixture, and mineral-rich mixture. Consistently, the fraction of biological particles (i.e., P-containing particles) increased when the ship traveled along a strongly biologically active area.

  5. 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.

  6. An Intelligent Analysis Model for Multisource Volatile Memory

    Directory of Open Access Journals (Sweden)

    Xiaolu Zhang

    2013-09-01

    Full Text Available For the rapidly development of network and distributed computing environment, it make researchers harder to do analysis examines only from one or few pieces of data source in persistent data-oriented approaches, so as the volatile memory analysis either. Therefore, mass data automatically analysis and action modeling needs to be considered for reporting entire network attack process. To model multiple volatile data sources situation can help understand and describe both thinking process of investigator and possible action step for attacker. This paper presents a Game model for multisource volatile data and applies it to main memory images analysis with the definition of space-time feature for volatile element information. Abstract modeling allows the lessons gleaned in performing intelligent analysis, evidence filing and automating presentation. Finally, a test demo based on the model is also present to illustrate the whole procedure

  7. Volatile Concentrations and H-Isotope Composition of Unequilibrated Eucrites

    Science.gov (United States)

    Sarafian, Adam R.; Nielsen, Sune G.; Marschall, Horst R.; Gaetani, Glenn A.; Hauri, Erik H.; Righter, Kevin; Berger, Eve L.

    2017-01-01

    Eucrites are among the oldest and best studied asteroidal basalts (1). They represent magmatism that occurred on their parent asteroid, likely 4-Vesta, starting at 4563 Ma and continuing for approx. 30 Myr. Two hypotheses are debated for the genesis of eucrites, a magma ocean model (2), and a mantle partial melting model. In general, volatiles (H, C, F, Cl) have been ignored for eucrites and 4-Vesta, but solubility of wt% levels of H2O are possible at Vestan interior PT conditions. Targeted measurements on samples could aid our understanding considerably. Recent studies have found evidence of volatile elements in eucrites, but quantifying the abundance of volatiles remains problematic (6). Volatile elements have a disproportionately large effect on melt properties and phase stability, relative to their low abundance. The source of volatile elements can be elucidated by examining the hydrogen isotope ratio (D/H), as different H reservoirs have drastically different H isotope compositions. Recent studies of apatite in eucrites have shown that the D/H of 4-Vesta matches that of Earth and carbonaceous chondrites, however, the D/H of apatites may not represent the D/H of a primitive 4-Vesta melt due to the possibility of degassing prior to the crystallization of apatite. Therefore, the D/H of early crystallizing phases must be measured to determine if the D/H of 4-Vesta is equal to that of the Earth and carbonaceous chondrites.

  8. Ammonia volatilization in no-till system in the south-central region of the State of Paraná, Brazil Volatilização de amônia em plantio direto na região centro-sul do Paraná

    Directory of Open Access Journals (Sweden)

    Sandra Mara Vieira Fontoura

    2010-10-01

    Full Text Available Ammonia (NH3 volatilization can reduce the efficiency of urea applied to the surface of no-till (NT soils. Thus, the objectives of this study were to evaluate the magnitude of NH3 losses from surface-applied urea and to determine if this loss justifies the urea incorporation in soil or its substitution for other N sources under the subtropical climatic conditions of South-Central region of Paraná State, Brazil. The experiment, performed over four harvesting seasons in a clayey Hapludox followed a randomized block design with four replicates. A single dose of N (150 kg ha-1 to V5 growth stage of corn cultivated under NT system was applied and seven treatments were evaluated, including surface-applied urea, ammonium sulfate, ammonium nitrate, urea with urease inhibitor, controlled-release N source, a liquid N source, incorporated urea, and a control treatment with no N application. Ammonia volatilization was evaluated for 20 days after N application using a semi-open static system. The average cumulative NH3 loss due to the superficial application of urea was low (12.5 % of the applied N compared to the losses observed in warmer regions of Southeastern Brazil (greater than 50 %. The greatest NH3 losses were observed in dry years (up to 25.4 % of the applied N, and losses decreased exponentially as the amount of rainfall after N application increased. Incorporated urea and alternative N sources, with the exception of controlled-release N source, decreased NH3 volatilization in comparison with surface-applied urea. Urea incorporation is advantageous for the reduction of NH3 volatilization; however, other aspects as its low operating efficiency should be considered before this practice is adopted. In the South-Central region of Paraná, the low NH3 losses from the surface-applied urea in NT system due to wet springs and mild temperatures do not justify its replacement for other N sources.A volatilização de amônia (NH3 pode resultar em baixa efici

  9. Effect and Predictive Elements for 52 Weeks’ Telbivudine Treatment on Naïve HBeAg positive Chronic Hepatitis B

    Directory of Open Access Journals (Sweden)

    Xiao-Feng Zhu

    2011-12-01

    Full Text Available Background: Antiviral treatment with nucleoside analogs has been used for chronic hepatitis B (CHB. Each kind of nucleoside analog has its own characteristics and suitability for patients. Telbivudine (LdT, brand name: Sebivo, Beijing Novartis Pharma Ltd is the newest nucleoside analog, with strong and rapid viral suppression. However, its resistance rate is relatively high during long-term application, due to low genetic barriers to resistance. So, it is necessary to increase the effect and reduce resistance with effective management, according to baseline factors and early on-treatment responses.Objectives: To reveal possible predictive factors of the effect of telbivudine (LdT treatment on naïve HBeAg-positive chronic hepatitis B (CHB patients to optimize treatment.Patients and Methods: A total 71 naïve chronic hepatitis B (CHB patients who met the inclusion criteria were enrolled. All patients were treated with LdT 600 mg Qd for at least 52 weeks. Multiple logistic regression analyses were done to investigate the predictive values of baseline factors and responses at Week 24.Results: The reduction in hepatitis virus B (HBV DNA level was 6.44 ± 2.38 lg copies/mL at Week 52 compared with baseline. The complete virus response (CVR, biochemical response (BR, serological response (SR, and drug resistance (DR were 61.99%, 77.46%, 35.21%, and 8.45% respectively. By multiple regression analysis, baseline alanine aminotransferase (ALT levels significantly affected CVR (P = 0.024, OR = 1.008, and baseline ALT and baseline HBV DNA levels were independent compact factors of SR (P = 0.012, OR = 1.007; P = 0.001, OR = 0.423. The differences in CVR, SR, and DR in patients with ALT > 120 Iu/mL compared with patients with ALT ≤ 120 Iu/mL were statistically significant. The differences in SR in patients with HBV DNA > 107 copies/mL compared with patients with HBV DNA ≤ 107 copies/mL were statistically significant. Additionally, CVR, BR, and SR were

  10. The Numerical Analysis of the Phenomena of Superficial Hardening of the Hot-Work Tool Steel Elements / Analiza Numeryczna Zjawisk Przypowierzchniowego Hartowania Elementów Ze Stali Narzędziowej Do Pracy Na Gorąco

    Directory of Open Access Journals (Sweden)

    Bokota A.

    2015-12-01

    Full Text Available In the paper the complex model of hardening of the hot-work tool steel is presented. Model of estimation of phase fractions and their kinetics is based on the continuous heating diagram (CHT and cooling diagram (CCT. Phase fractions which occur during the continuous heating and cooling (austenite, pearlite or bainite are described by Johnson-Mehl (JM formula. To determine of the formed martensite the modified Koistinen-Marburger (KM equation is used. Model takes into account the thermal, structural, plastic strains and transformation plasticity. To calculate the plastic strains the Huber-Mises plasticity condition with isotopic hardening is used. Whereas to determine transformations induced plasticity the Leblond model is applied. The numerical analysis of phase compositions and residual stresses in the hot-work steel (W360 element is considered.

  11. 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.

  12. SNC meteorites and their implications for reservoirs of Martian volatiles

    Science.gov (United States)

    Jones, J. H.

    1993-01-01

    The SNC meteorites and the measurements of the Viking landers provide our only direct information about the abundance and isotopic composition of Martian volatiles. Indirect measurements include spectroscopic determinations of the D/H ratio of the Martian atmosphere. A personal view of volatile element reservoirs on Mars is presented, largely as inferred from the meteoritic evidence. This view is that the Martian mantle has had several opportunities for dehydration and is most likely dry, although not completely degassed. Consequently, the water contained in SNC meteorites was most likely incorporated during ascent through the crust. Thus, it is possible that water can be decoupled from other volatile/incompatible elements, making the SNC meteorites suspect as indicators of water inventories on Mars.

  13. Ferromagnetism in 4H-GaN polytype doped by non-magnetic light elements Li, Be, B, C, O, F, Ne, Na, and Mg: Ab-initio study

    Energy Technology Data Exchange (ETDEWEB)

    Torrichi, M. [LPMF, Département de Physique Energétique, Faculté des Sciences, Université des Sciences et de la Technologie d’Oran Mohamed Boudiaf, Oran (Algeria); Ferhat, M. [LPMF, Département de Génie Physique, Faculté des Sciences, Université des Sciences et de la Technologie d’Oran Mohamed Boudiaf, Oran (Algeria); Bouhafs, B., E-mail: bbouhafs@gmail.com [Laboratoire de Modélisation et Simulation en Sciences des Matériaux, Université Djillali Liabès de Sidi Bel-Abbés, Sidi Bel-Abbés 22000 (Algeria)

    2016-09-15

    Using density-functional theory within the generalized-gradient approximation, we explore the magnetic behavior induced by nonmagnetic impurity X atoms, such as Li, Be, B, C, O, F, Ne, Na, and Mg on cation site in 4H-GaN polytype. The results reveal that Ne doped 4H-GaN has the highest magnetic moment of 3µ{sub B}, whereas Mg doped 4H-GaN has the lowest magnetic moment of 0.75µ{sub B}. Among the systems studied 4H-GaN doped Ne has been found to be half-metallic, whereas 4H-GaN doped F and Na are found to be nearly half-metallic. The partial density of states evidence that magnetism is achieved through a p-p like coupling between the impurity and the host 2p states. Furthermore, we inspect whether there exists a relationship between the spin-polarization and the local structure around the doping X atoms. It is found that for all the compounds studied, the total magnetic moment increases with increasing the X–N bond lengths. Interestingly, 4H-GaN:Be becomes ferromagnetic with increasing the Be–N bond length, whereas 4H-GaN:Na and 4H-GaN:F become half-metallic with increasing Na–N and F–N bond lengths. - Highlights: • The partial densities of states of 4H-GaN polytype doped light nonmagnetic elements have been investigated. • We found that 4H-GaN:Ne is half metallic. • We found that N atoms induced strong local magnetic. • We found that doping with half-filled X-s impurity states promotes ferromagnetism. • We found that doping with full-filled X-s impurity annihilates ferromagnetism.

  14. Option Pricing using Realized Volatility

    DEFF Research Database (Denmark)

    Stentoft, Lars Peter

    In the present paper we suggest to model Realized Volatility, an estimate of daily volatility based on high frequency data, as an Inverse Gaussian distributed variable with time varying mean, and we examine the joint properties of Realized Volatility and asset returns. We derive the appropriate...... benchmark model estimated on return data alone. Hence the paper provides evidence on the value of using high frequency data for option pricing purposes....

  15. Option Pricing using Realized Volatility

    DEFF Research Database (Denmark)

    Stentoft, Lars Peter

    In the present paper we suggest to model Realized Volatility, an estimate of daily volatility based on high frequency data, as an Inverse Gaussian distributed variable with time varying mean, and we examine the joint properties of Realized Volatility and asset returns. We derive the appropriate d...... benchmark model estimated on return data alone. Hence the paper provides evidence on the value of using high frequency data for option pricing purposes....

  16. An Analysis of the Condensation Temperature of Elements of Extrasolar Planetary Systems

    Institute of Scientific and Technical Information of China (English)

    Cong Huang; Gang Zhao; Hua-Wei Zhang; Yu-Qin Chen

    2005-01-01

    Using high signal-to-noise ratio spectra of extrasolar planet-hosting stars, we obtained the atmospheric parameters, accurate metallicities and the differential abundance for 15 elements (C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn,Ni and Ba). In a search for possible signatures of metal-rich material accreting onto the parent stars, we found that, for a given element, there is no significant trend of increasing [X/H] with increasing condensation temperature Tc. In our sample of planet-harboring stars, the volatile and refractory elements behave similarly, and we can not confirm if there exists any significant dependence on the condensation temperature Tc.

  17. Self-assembled three-dimensional non-volatile memories

    NARCIS (Netherlands)

    Abelmann, Leon; Tas, Niels; Berenschot, Erwin; Elwenspoek, Miko

    2010-01-01

    The continuous increase in capacity of non-volatile data storage systems will lead to bit densities of one bit per atom in 2020. Beyond this point, capacity can be increased by moving into the third dimension. We propose to use self-assembly of nanosized elements, either as a loosely organised assoc

  18. Volatile signals during pregnancy.

    Science.gov (United States)

    Vaglio, Stefano

    2010-01-01

    Scents play a key role in mediating reproductive interactions in many vertebrates including mammals. Nowadays, several studies indicate that humans seem to use remarkably olfactory communication and are even able to produce and perceive pheromones. Furthermore, over the past several years, it became increasingly clear that pheromone-like chemical signals probably play a role in offspring identification and mother recognition. Recently developed technical procedures (solid-phase microextraction and dynamic headspace extraction) now allow investigators to characterize volatile compounds with high reliability. We analyzed the volatile compounds in sweat patch samples collected from the para-axillary and nipple-areola regions of women during pregnancy and after childbirth. We hypothesized that, at the time of birth and during the first weeks of life, the distinctive olfactory pattern of the para-axillary area is probably useful to newborn babies for recognizing and distinguishing their own mother, whereas the characteristic pattern of the nipple-areola region is probably useful as a guide to nourishment.

  19. 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.

  20. Avaliação de compostos não-voláteis em diferentes cultivares de cafeeiro produzidas na região sul de Minas Gerais = Evaluation of non-volatile compounds in different cultivars of coffee cultivated in southern Minas Gerais

    Directory of Open Access Journals (Sweden)

    Marcelo Ribeiro Malta

    2009-01-01

    Full Text Available O presente trabalho teve como objetivo avaliar os teores de trigonelina, ácidos clorogênicos (5-ACQ e cafeína em grãos de diferentes cultivares de cafeeiro (Coffea arabica L.. As cultivares avaliadas foram coletadas na Fazenda Experimental da Epamig em Lavras,Estado de Minas Gerais, no ano agrícola de 2005/2006. O delineamento experimental utilizado foi um inteiramente casualizado constando de oito cultivares de café com três repetições. Foram avaliadas as cultivares: Oeiras MG 6851, Acaiá Cerrado MG 1474, CatuaíVermelho IAC 99, Rubi MG 1192, Topázio MG 1190, Mundo Novo IAC 379/19, Catucaí Amarelo 2 SL e Catuaí Amarelo IAC 62. Após a colheita dos cafés por derriça manual no pano, estes foram lavados e submetidos ao processo de descascamento e despolpamento. Depois dos grãos serem despolpados, foram secados em terreiro de cimento até atingirem 11%-12% de umidade. Os grãos de café beneficiados foram então moídos para a realização das análises de cafeína, trigonelina e 5-ACQ por cromatografia líquida de alta eficiência. Os resultados obtidos permitiram concluir que existem diferenças nos constituintes nãovoláteis entre as cultivares estudadas nas condições ambientais de cultivo similares para todas cultivares. Catuaí Amarelo IAC 62 e Rubi MG 1192 apresentaram os maiores teores de trigonelina; Catuaí Amarelo IAC 62, Catuaí Vermelho IAC 99, Rubi MG 1192 e Oeiras MG 6851 apresentaram os maiores teores de 5-ACQ; o menor teor de cafeína foi observado na cultivar Oeiras MG 6851, seguida pela cultivar Mundo Novo IAC 379-19.This research was conducted to evaluate trigonelline, chlorogenic acids (5-CQA and caffeine contents in grains of different cultivars of coffee (Coffea arabica L. The cultivars were colleted at the Experimental Farm of the EPAMIG-Lavras, Minas Gerais state, during 2005/2006. The experimental design was completely randomized with eight cultivars of coffee: Oeiras MG 6851, Acaiá Cerrado MG 1474

  1. Efeito do tipo de elemento de rosca na degradação de polipropileno durante múltiplas extrusões Effect of screw element on the polypropylene degradation during multiple extrusions

    Directory of Open Access Journals (Sweden)

    Ana Clélia Babetto

    2000-06-01

    Full Text Available A configuração da rosca de uma extrusora de dupla rosca modular pode ser projetada com vários tipos de elementos de condução e mistura, produzindo diferentes níveis de degradação no polímero fundido. Neste trabalho determinou-se o nível de degradação do polipropileno durante múltiplas extrusões em várias configurações de rosca, através de cromatografia por exclusão de tamanho e espectroscopia de infravermelho. Houve decréscimo do peso molecular e estreitamento da sua distribuição em função do número de extrusões e do aumento da agressividade da rosca, assim como, aumento da concentração de carbonilas e insaturações na cadeia polimérica. O elemento de mistura EM90 causou o maior nível de degradação e a adição de elementos de condução esquerdos ECE reduziram o nível de degradação.The screw configuration of a double screw extruder can be designed to contain kneading and conveying elements inducing different levels of degradation in the polymer melt. In this work the level of degradation in polypropylene have been measured after multiple extrusions for various screw configurations using Size Exclusion Chromatography and Infra-Red Spectroscopy. The average molecular weight and the polydispersity are reduced and the carbonyl and unsaturation indices increase as the number of extrusions and the agressiveness of the screw increase. The kneading element with 90 degrees caused the greater level of degradation and the addition of left hand elements have reduced the level of degradation.

  2. 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...

  3. Political institutions and economic volatility

    NARCIS (Netherlands)

    Klomp, Jeroen; de Haan, Jakob

    2009-01-01

    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

  4. 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.

  5. 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.

  6. Volatility Exposure for Strategic Asset Allocation

    OpenAIRE

    Briere, Marie; Burgues, Alexandre; Signori, Ombretta

    2010-01-01

    The authors examine the advantages of incorporating strategic exposure to equity volatility into the investment opportunity set of a long-term equity investor. They consider two standard volatility investments: implied volatility and volatility risk premium strategies. An analytical framework, which offers pragmatic solutions for long-term investors who seek exposure to volatility, is used to calibrate and assess the risk-return profiles of portfolios. The benefit of volatility exposure for a...

  7. Reduced Heart Rate Volatility

    Science.gov (United States)

    Grogan, Eric L.; Morris, John A.; Norris, Patrick R.; France, Daniel J.; Ozdas, Asli; Stiles, Renée A.; Harris, Paul A.; Dawant, Benoit M.; Speroff, Theodore

    2004-01-01

    Objective: To determine if using dense data capture to measure heart rate volatility (standard deviation) measured in 5-minute intervals predicts death. Background: Fundamental approaches to assessing vital signs in the critically ill have changed little since the early 1900s. Our prior work in this area has demonstrated the utility of densely sampled data and, in particular, heart rate volatility over the entire patient stay, for predicting death and prolonged ventilation. Methods: Approximately 120 million heart rate data points were prospectively collected and archived from 1316 trauma ICU patients over 30 months. Data were sampled every 1 to 4 seconds, stored in a relational database, linked to outcome data, and de-identified. HR standard deviation was continuously computed over 5-minute intervals (CVRD, cardiac volatility–related dysfunction). Logistic regression models incorporating age and injury severity score were developed on a test set of patients (N = 923), and prospectively analyzed in a distinct validation set (N = 393) for the first 24 hours of ICU data. Results: Distribution of CVRD varied by survival in the test set. Prospective evaluation of the model in the validation set gave an area in the receiver operating curve of 0.81 with a sensitivity and specificity of 70.1 and 80.0, respectively. CVRD predict death as early as 24 hours in the validation set. Conclusions: CVRD identifies a subgroup of patients with a high probability of dying. Death is predicted within first 24 hours of stay. We hypothesize CVRD is a surrogate for autonomic nervous system dysfunction. PMID:15319726

  8. Trichloroethylene Volatilization Enhancement by the Addition of a Brine Solution

    Science.gov (United States)

    Irizarry, M. L.; Padilla, I. Y.

    2008-12-01

    Trichloroethylene (TCE) is one of the most widely detected organic contaminants at National Priority List (NPL) sites. In many sites, TCE is trapped as a dense non-aqueous phase liquid (DNAPL) in formations of low permeability, and serves as long-term source of contamination. Cost effective remediation technologies that can be applied to tight formations need to be developed. This study investigates the enhancement of TCE volatilization from unsaturated clayey soils by adding a NaCl brine solution. It is postulated that the overall effect of the brine solution causing structured water around soil particles, increased relative permeability, and increased fugacity into the vapor phase, is to enhance TCE volatilization. TCE removal through the soil vapor extraction (SVE) technique can then be enhanced. Preliminary experimental work involves the use of static and dynamic flux reactors, containing TCE, water and clay. NaCl brine solution is added at different concentrations to evaluate the effect on TCE concentrations and volatilization rates. In the static flux mode, vapor concentrations in the headspace of sealed reactors are measured after a two-day period. In the dynamic flux mode, air is swept through the headspace of the reactors and TCE vapor concentrations are measured over time. Plots relating static TCE vapor concentration to brine concentration are used to show the effect of brine concentrations on TCE fugacity. Temporal concentration distributions of TCE show the effect of brine on the rate of volatilization. Keywords: Trichloroethylene (TCE), Soil vapor extraction (SVE), clay

  9. Sensitivity analysis for heat diffusion in a fin on a nuclear fuel element; Analise de sensitividade na difusao de calor em uma aleta de um elemento combustivel nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Tito, Max Werner de Carvalho

    2001-11-15

    The modern thermal systems generally present a growing complexity, as is in the case of nuclear power plants. It seems that is necessary the use of complex computation and mathematical tools in order to increase the efficiency of the operations, reduce costs and maximize profits while maintaining the integrity of its components. The use of sensitivity calculations plays an important role in this process providing relevant information regarding the resultant influence of variation or perturbation of its parameters as the system works. This technique is better known as sensitivity analysis and through its use makes possible the understanding of the effects of the parameters, which are fundamental for the project preparation, and for the development of preventive and corrective handling measurements of many pieces of equipment of modern engineering. The sensitivity calculation methodology is based generally on the response surface technique (graphic description of the functions of interest based in the results obtained from the system parameter variation). This method presents a lot of disadvantages and sometimes is even impracticable since many parameters can cause alterations or perturbations to the system and the model to analyse it can be very complex as well. The utilization of perturbative methods result appropriate as a practical solution to this problem especially in the presence of complex equations. Also it reduces the resultant computational calculus time considerably. The use of these methods becomes an essential tool to simplify the sensitivity analysis. In this dissertation, the differential perturbative method is applied in a heat conduction problem within a thermal system, made up of a one-dimensional circumferential fin on a nuclear fuel element. The fins are used to extend the thermal surfaces where convection occurs; thus increasing the heat transfer to many thermal pieces of equipment in order to obtain better results. The finned claddings are

  10. Effect of Hypericum perforatum extract on in vitro labelling of blood elements with technetium-{sup 99m} and on bioavailability of sodium pertechnetate in Wistar rats; Efeito de um extrato de Hiperico (Hypericum perforatum) na marcacao in vitro de elementos sanguineos com tecnecio-99m e na biodisponibilidade do radiofarmaco pertecnetato de sodio em ratos Wistar

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Filho, Sebastiao David [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Pos-Graduacao em Ciencias da Saude; Bernardo-Filho, Mario [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Dept. de Biofisica e Biometria

    2005-07-01

    Purpose: To evaluate the effect of a hypericum extract (Hypericum perforatum) on the labeling of blood elements with technetium-{sup 99m} ({sup 99m}Tc) and in the bioavailability of the radiopharmaceutical sodium pertechnetate in Wistar rats. Methods: Blood (heparinized) withdrawn from Wistar rats is incubated with a hypericum extract, with a stannous chloride and with {sup 99m}Tc, as sodium pertechnetate ({sup 99m}TcO Na). Plasma (P) and cells (C) are isolated by centrifugation. Samples of P and C are also precipitated with trichloroacetic acid (TCA 5%) and soluble (FS-P; FS-C) and insoluble (FI-P; FI-C) fractions are separated. In the bioavailability analysis, the extract or NaCl 0.9% solution is administrated into Wistar rats (gavage) during 15 days. Sodium pertechnetate was administered and after 10 min, the animals are sacrificed, the organs were isolated, the radioactivity determined in a well counter, and the percentages of radioactivity per gram (%ATI/g) in the organs are calculated. Results: The hypericum extract decreased significantly (P<0.05) the %ATI in the cells, cellular insoluble fraction and plasma insoluble fraction. The biodistribution was significantly (P<0.01) decreased in bone, muscle and thyroid and significantly (P<0.05) increased in pancreas. Conclusion: The analysis of the results indicates that in studied extract should have substances that should oxidize the stannous ion, reducing the fixation of the {sup 99m}Tc on the erythrocytes and plasma and cellular proteins. Moreover, it could produce metabolic alterations with influence in the uptake of the radiopharmaceutical {sup 99m}TcO{sub 4}Na in bone, muscle, pancreas and thyroid. (author)

  11. The role of volatiles in the genesis of cenozoic magmatism in Northern Victoria Land (NVL), Antarctica

    Science.gov (United States)

    Giacomoni, Pier Paolo; Coltorti, Massimo; Bonadiman, Costanza; Ferlito, Carmelo; Zanetti, Alberto; Ottolini, Luisa

    2017-04-01

    This study offers an innovative view of the petrogenetic processes responsible for the magmas erupted in the Western Antarctic Rift System (WARS) by studying the chemical composition and the volatiles content of basic lavas and olivine-hosted melt inclusions (MI). Lavas come from three localities: Shield Nunatak (Mt. Melbourne), Eldridge Bluff and Handler Ridge. They are olivine-phyric basanites (42.41-44.80 SiO2 wt%; 3.11-6.19 Na2O+K2O wt%) and basalts (44.91-48.73 SiO2 wt%; 2.81-4.55 Na2O+K2O wt%) with minor clinopyroxene and plagioclase. Samples from Handler Ridge clearly differ by having the highest TiO2 (3.55-3.65 wt%), Rb, Ba, Nb, La, Zr despite their more primitive features (60.83-44.87 Mg#, MgO/(MgO+FeO) %mol). Olivine-hosted melt inclusions (MI) were analyzed for major element and volatiles (H2O. CO2, S, F, and Cl) after HT (1300°C) and HP (6 kbar) homogenization. Despite a larger variability, MI are compositionally comparable with the host lavas and are characterized by two distinct trends (high-Fe-Ti-K and low-Fe-Ti-K). The H2O content in MI ranges from 0.70 wt% to 2.64 wt% and CO2 from 25 ppm to 341 ppm (H2O/CO2 1). At comparable H2O contents, few samples show a higher CO2 values (1322 ppm to 3905 ppm) with a H2O/CO2 molar ratio down to 0.8. F and Cl content varies from 1386 ppm to 10 ppm and from 1336 ppm to 38 ppm respectively. Concentration of volatiles show a good correlation with alkalies, especially with K2O; Handler Ridge presents the highest total value of F and Cl (2675 ppm). Chondrite-normalized trace elements concentration in MI show an intraplate pattern with negative anomalies in Rb, K, Ti. Accordingly, to the lava contents, MI from Handler Ridge have a significantly higher concentration in Rb (12-45 ppm), Sr (700-834 ppm), Ba (433-554) and Nb (48.8-83.4 ppm) with respect to the other localities at comparable Mg#. Mantle melting mass balance calculations simulate the observed H2O, CO2 and Cl concentration by melting a spinel lhezolite from

  12. Chemical composition and non-volatile components of three wild edible mushrooms collected from northwest Tunisia

    Directory of Open Access Journals (Sweden)

    ibtissem Kacem Jedidi

    2016-04-01

    Full Text Available In Tunisia, many people collect wild edible mushrooms as pickers for their own consumption. The present work aims at contributing to the determination of the chemical composition, non volatile components content (soluble sugars, free amino acids and minerals and trace elements of three popular Tunisian wild edible mushrooms species collected from the northwest of Tunisia (Agaricus campestris, Boletus edulis and Cantharellus cibarius.All investigated mushrooms revealed that these species are rich sources of proteins (123.70 – 374.10 g kg-1 dry weight (DW and carbohydrates (403.3 – 722.40 g kg-1 DW, and low content of fat (28.2 – 39.9 g kg-1 DW; the highest energetic contribution was guaranteed by C. cibarius (1542.71 kJ / 100 g. A. compestris (33.14 mg/g DW showed the highest concentration of essential amino acids. The composition in individual sugars was also determined, mannitol and trehalose being the most abundant sugars. C. cibarius revealed the highest concentrations of carbohydrates (722.4 g kg-1 DW and A. compestris the lowest concentration (403.3 g kg-1 DW. Potassium (K and sodium (Na are the most abundant minerals in analyzed samples (A. compestris showed the highest concentrations of K and Na, 49141.44 and 9263.886 µg/g DW respectively.

  13. 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...

  14. 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

  15. On forecasting Exchange Rate Volatility.

    OpenAIRE

    Hafner, Christian

    2003-01-01

    In an efficient market, foreign exchange rates have to guarantee absence of triangular arbitrage. This note shows that the no-arbitrage condition can be exploited for forecasting the volatility of a single rate by using the information contained in the other rates. Linearly transforming the volatility forecasts of a bivariate model is shown to be more efficient than using a univariate model for the cross-rate.

  16. Shock-induced volatile loss from a carbonaceous chondrite Implications for planetary accretion

    Science.gov (United States)

    Tyburczy, James A.; Frisch, Benjamin; Ahrens, Thomas J.

    1986-01-01

    Solid recovery impact-induced volatile loss experiments on the Murchison C2M meteorite indicate that for an impact of a given velocity, H2O and total volatiles are driven from the sample in the same proportion as present initially. The primitive surface volatile budget of a planet growing by accretion would have the same bulk elemental composition as the volatiles in the incident planetesimals. Incipient devolatilization of Murchison occurs at an initial shock pressure of about 11 GPa and complete devolatilization occurs at a pressure of about 30 GPa. For the earth, incipient and complete devolatilization of accreting planetesimals would occur when the planet reached approximately 12 percent and 27 percent, respectively, of its present-day radius. Impact-induced devolatilization would profoundly affect the volatile distribution within the accreting planet. Prior to metallic core formation and internal differentiation the growing planet would have a very small core with the same volatile content as the incident material, a volatile depleted mantle, and an extremely volatile rich surface. In the case of the earth, 99.4 wt pct of the total incident volatile material would end up on or near the planetary surface.

  17. Shock-induced volatile loss from a carbonaceous chondrite: Implications for planetary accretion

    Science.gov (United States)

    Tyburczy, J. A.; Frisch, B.; Ahrens, T. J.

    1986-01-01

    Solid recovery impact-induced volatile loss experiments on the Murchison C2M meteorite indicate that for an impact of a given velocity, H2O and total volatiles are driven from the sample in the same proportion as present initially. The primitive surface volatile budget of a planet growing by accretion would have the same bulk elemental composition as the volatiles in the incident planetesimals. Incipient devolatilization of Murchison occurs at an initial shock pressure of about 11 GPa and complete devolatilization occurs at a pressure of about 30 GPa. For the Earth, incipient and complete devolatilization of accreting planetesimals would occur when the planet reached approximately 12% and 27%, respectively, of its present-day radius. Impact-induced devolatilization would profoundly affect the volatile distribution within the accreting planet. Prior to metallic core formation and internal differentiation the growing planet would have a very small core with the same volatile content as the incident material, a volatile depleted mantle, and an extremely volatile rich surface. In the case of the Earth, 99.4 wt% of the total incident volatile material would end up on or near the planetary surface.

  18. Recent Advances in Volatiles of Teas

    Directory of Open Access Journals (Sweden)

    Xin-Qiang Zheng

    2016-03-01

    Full Text Available Volatile compounds are important components of tea aroma, a key attribute of sensory quality. The present review examines the formation of aromatic volatiles of various kinds of teas and factors influencing the formation of tea volatiles, including tea cultivar, growing environment and agronomic practices, processing method and storage of tea. The determination of tea volatiles and the relationship of active-aroma volatiles with the sensory qualities of tea are also discussed in the present paper.

  19. Volatile organo-selenium speciation in biological matter by solid phase microextraction-moderate temperature multicapillary gas chromatography with microwave induced plasma atomic emission spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Dietz, C.; Sanz Landaluze, J.; Ximenez-Embun, P.; Madrid-Albarran, Y.; Camara, C

    2004-01-16

    Microwave induced plasma atomic emission spectrometry (MIP-AES) in combination with multicapillary (MC) gas chromatography could be proven to be useful for element specific detection of volatile species. Solid phase microextraction (SPME) was used for preconcentration and sample-matrix separation. The fiber desorption unit as well as the heating control for the MC column were in-house developed and multicapillary column was operated at moderate temperatures (30-100 deg. C). The method was optimized for organo-selenium species (dimethylselenide (DMSe), diethylselenide (DEtSe) and dimethyldiselenide (DMDSe)), using a chemometric approach. Stationary phases for the separation column were optimized using a conventional GC and contrasted with the results obtained with the MC. Application was focussed on selenium accumulating biological matter, such as lupine, yeast, Indian mustard and garlic. These samples were grown in hydroponic solution containing inorganic selenium (Na{sub 2}SeO{sub 3} and Na{sub 2}SeO{sub 4}). SPME sampling was carried out in fixed volume flow boxes in headspace above the living plants and in vials using treated samples. Results demonstrate inorganic selenium transformation into volatile organic species during metabolism. Separation is fast, a chromatogram can be obtained in less than 3 min and detection limits were at sub-ppb level for all investigated species. The system is independent from the use of a conventional gas chromatographic oven and can be used as a versatile alternative to highly cost intensive methods such as GC-ICP-MS.

  20. Development of an ion source for volatile elements at DREAMS

    Energy Technology Data Exchange (ETDEWEB)

    Pavetich, Stefan; Akhmadaliev, Shavkat; Merchel, Silke; Rugel, Georg [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Ion Beam Physics and Materials Research, Dresden (Germany)

    2012-07-01

    After successful measurements of {sup 10}Be, {sup 26}Al and {sup 41}Ca at DREAMS (DResden Accelerator Mass Spectrometry), extensive test measurements of {sup 36}Cl started. Besides the challenge of separating the stable isobar {sup 36}S, which at DREAMS is accomplished by post-stripping and a split-anode-ionization-chamber, the problem of ion source memory must be solved. To characterize this effect we use {sup 35}Cl/{sup 37}Cl samples of natural composition and {sup 35}Cl-enriched samples with a {sup 35}Cl/{sup 37}Cl-ratio >100. Similar measurements at the French AMS facility ASTER showed differences of 2-4% in the {sup 35}Cl/{sup 37}Cl ratios of the highly enriched samples after 24 h of sputtering samples with natural isotopic ratios. To minimize the long-term-memory effect, two modified designs of the original source (HVEE) were constructed at DREAMS. A more open geometry was used to improve the vacuum level, and parts of the target loading system were modified to allow the exchange of the individual cathode aperture with each target.

  1. 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.

  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. Occurrence of volatile and non-volatile N-nitrosamines in processed meat products and the role of heat treatment

    DEFF Research Database (Denmark)

    Herrmann, Susan Strange; Duedahl-Olesen, Lene; Granby, Kit

    2015-01-01

    Most of the available data on the occurrence of N-nitrosamines (NA) in processed meat products have been generated in the 1980s and 1990s and especially data on the occurrence of non-volatile NA (NVNA) are scarce. Therefore we have studied the levels of volatile nitrosamines (VNA) and NVNA...... in processed meat products on the Danish market (N = 70) and for comparison also products on the Belgian market (N = 20). The effect of heat treatment on the NA levels, in selected samples, was also studied, in order to enable an evaluation of how preparation before consumption affects the levels of NA...... μg kg−1 for one Danish sample and two Belgian samples. Levels of up to 2000 and 4000 μg kg−1 of N-nitroso-thiazolidine-4-carboxylic acid (NTCA) an NVNA occurred in the Danish and the Belgian samples, respectively. The majority of the Danish processed meat products contain NVNA but also VNA occur...

  4. Spiral mining for lunar volatiles

    Science.gov (United States)

    Schmitt, H. H.; Kulcinski, G. L.; Sviatoslavsky, I. N.; Carrier, W. D., III

    Lunar spiral mining, extending outward from a periodically mobile central power and processing station represents an alternative for comparison with more traditional mining schemes. In this concept, a mining machine would separate regolith fines and extract the contained volatiles. Volatiles then would be pumped along the miner's support arm to the central station for refining and for export or storage. The basic architecture of the central processing station would be cylindrical. A central core area could house the power subsystem of hydrogen-oxygen engines or fuel cells. Habitat sections and other crew occupied areas could be arranged around the power generation core. The outer cylinder could include all volatile refining subsystems. Solar thermal power collectors and reflectors would be positioned on top of the central station. Long term exploitation of a volatile resource region would begin with establishment of a support base at the center of a long boundary of the region. The mining tract for each spiral mining system would extend orthogonal to this boundary. New spiral mining systems would be activated along parallel tracts as demand for lunar He-3 and other solar wind volatiles increased.

  5. RICE PRICE VOLATILITY IN EAST JAVA

    Directory of Open Access Journals (Sweden)

    Wati R.Y.E.

    2017-09-01

    Full Text Available The purpose of the research is analyzing the volatility and volatility spillover of monthly price of paddy at the level of farmers and consumers in 2010-2016. ARCH/GARCH used to analyze volatility and GARCH BEKK-model is used to analyze the volatility spillover. The results of the analysis show that price volatility at the farmer level is very high (extremely high volatility, price volatility at the consumer level is low (low volatility, and volatility spillover does not occur between the farmers and the consumers market. The need to guarantee an effective floor price as well as information disclosure related to the market commodity prices so that the pattern of prices transmission among interrelated markets can be symmetrical.

  6. Geochemical Constraints for Mechanisms of Planetary Differentiation and Volatile Depletion

    OpenAIRE

    Dhaliwal, Jasmeet Kaur

    2016-01-01

    The evolution of the terrestrial planets involved a range of complex processes, including accretion, core formation, post-core formation accretion, mantle differentiation and volatile depletion. The earliest processes of accretion and core formation have largely been overprinted on Earth and Mars, but can be investigated using geochemical measurements of extraterrestrial materials. Highly siderophile elements (HSE; Os, Ir, Ru, Rh, Pt, Pd, Re, Au) preferentially partition into metal phases an...

  7. Elemental concentrations of four types of human gallstones by PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Suhara, M. (Department oh Hygiene and Public Health, School of Medicine, Iwate Medical Univ., Iwate (Japan)); Matsuda, K.; Sera, K.

    1998-01-01

    Elemental concentrations of human gallstones were determined by PIXE method. Gallstone samples analyzed in this report are classified into cholestrol gallstone (pure cholestrol stone and mixed stone) and pigment gallstone (black stone and calcium bilirubinate stone). The targets were prepared by paste spreading method previously reported, which enable us to determine also volatile elements, such as halogen atoms, Hg and so on, under acidic condition. Concentrations of 17 kinds of elements were determined and characteristic distributions are presented for each type of gallstone. Ca values are the highest among them in all types of gallstones. Pigment gallstones contain significantly higher concentrations of 9 kinds of elements (Na, Mg, S, Cl, Ca, Mn, Fe, Cu, Zn) than cholesterol gallstones. Concentrations of S, Fe, and Zn in black stones are significantly higher than those in calcium bilirubinate stones. Almost all elements contained in the samples can be determined by PIXE method, and it is supposed that the elements or some of them affect formation of gallstones and their pigment. Some samples of the pigment gallstones included I, Hg, and Pb. (author)

  8. The loss of Na and Cl during the pyrolysis of a NaCl-loaded brown coal sample

    Energy Technology Data Exchange (ETDEWEB)

    Mody, D.; Li, C.Z.

    1999-07-01

    A Victorian brown coal was physically loaded with NaCl and pyrolyzed in a quartz fluidized-bed reactor. The fluidized-bed reactor was equipped with a quartz frit in the freeboard zone to enable the total devolatilization of the coal particles. The introduction of NaCl into the coal has caused only minor reductions in the weight loss. A significant amount of chlorine was volatilized during pyrolysis at temperatures as low as 200 C. At temperatures around 400--500 C where the loss of sodium was not very significant, about 70% of chlorine was volatilized from the coal particles. With the volatilization of chlorine at this temperature level, sodium must have been bonded to the char matrix. With increasing temperature, the volatilization of chlorine decreased and then increased again, whereas the volatilization of sodium increased monotonically with increasing temperature. Almost all the Na in coal could be volatilized at temperatures higher than about 800 C. These experimental results clearly indicate that chlorine and Na interacted strongly with coal/char at high temperatures. Na and Cl in the coal did not volatilize as NaCl molecules. Significant amounts of species containing a COO-group such as acetate, formate and oxalate were observed in the pyrolysis products although the exact forms of these species (i.e., as acids, salts or esters) in the pyrolysis product remain unknown. The yields of the species containing a COO-group decreased with increasing temperature, possibly due to the intensified thermal cracking reactions at high temperatures.

  9. 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.

  10. Consistent ranking of volatility models

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger

    2006-01-01

    result in an inferior model being chosen as "best" with a probability that converges to one as the sample size increases. We document the practical relevance of this problem in an empirical application and by simulation experiments. Our results provide an additional argument for using the realized...... 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.......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...

  11. 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...

  12. Rhenium volatilization in waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kai; Pierce, David A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Hrma, Pavel, E-mail: pavel.hrma@pnnl.gov [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Schweiger, Michael J. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland, WA 99352 (United States)

    2015-09-15

    Highlights: • Re did not volatilize from a HLW feed until 1000 °C. • Re began to volatilize from LAW feeds at ∼600 °C. • The vigorous foaming and generation of gases from salts enhanced Re evaporation in LAW feeds. • The HLW glass with less foaming and salts is a promising medium for Tc immobilization. - Abstract: We investigated volatilization of rhenium (Re), sulfur, cesium, and iodine during the course of conversion of high-level waste melter feed to glass and compared the results for Re volatilization with those in low-activity waste borosilicate glasses. Whereas Re did not volatilize from high-level waste feed heated at 5 K min{sup −1} until 1000 °C, it began to volatilize from low-activity waste borosilicate glass feeds at ∼600 °C, a temperature ∼200 °C below the onset temperature of evaporation from pure KReO{sub 4}. Below 800 °C, perrhenate evaporation in low-activity waste melter feeds was enhanced by vigorous foaming and generation of gases from molten salts as they reacted with the glass-forming constituents. At high temperatures, when the glass-forming phase was consolidated, perrhenates were transported to the top surface of glass melt in bubbles, typically together with sulfates and halides. Based on the results of this study (to be considered preliminary at this stage), the high-level waste glass with less foaming and salts appears a promising medium for technetium immobilization.

  13. ALH85085: a unique volatile-poor carbonaceous chondrite with possible implications for nebular fractionation processes

    Science.gov (United States)

    Grossman, J.N.; Rubin, A.E.; MacPherson, G.J.

    1988-01-01

    Allan Hills 85085 is a unique chondrite with affinities to the Al Rais-Renazzo clan of carbonaceous chondrites. Its constituents are less than 50 ??m in mean size. Chondrules and microchondrules of all textures are present; nonporphyritic chondrules are unusually abundant. The mean compositions of porphyritic, nonporphyritic and barred olivine chondrules resemble those in ordinary chondrites except that they are depleted in volatile elements. Ca-, Al-rich inclusions are abundant and largely free of nebular alteration; they comprise types similar to those in CM and CO chondrites, as well as unique types. Calcium dialuminate occurs in several inclusions. Metal, silicate and sulfide compositions are close to those in CM-CO chondrites and Al Rais and Renazzo. C1-chondrite clasts and metal-rich "reduced" clasts are present, but opaque matrix is absent. Siderophile abundances in ALH85085 are extremely high (e.g., Fe Si = 1.7 ?? solar), and volatiles are depleted (e.g., Na Si = 0.25 ?? solar, S Si = 0.03 ?? solar). Nonvolatile lithophile abundances are similar to those in Al Rais, Renazzo, and CM and CO chondrites. ALH85085 agglomerated when temperatures in the nebula were near 1000 K, in the same region where Renazzo, Al Rais and the CI chondrites formed. Agglomeration of high-temperature material may thus be a mechanism by which the fractionation of refractory lithophiles occurred in the nebula. Chondrule formation must have occurred at high temperatures when clumps of precursors were small. After agglomeration, ALH85085 was annealed and lightly shocked. C1 and other clasts were subsequently incorporated during late-stage brecciation. ?? 1988.

  14. 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.

  15. Factors affecting the volatilization of volatile organic compounds from wastewater

    Directory of Open Access Journals (Sweden)

    Junya Intamanee

    2006-09-01

    Full Text Available This study aimed to understand the influence of the wind speed (U10cm, water depth (h and suspended solids (SS on mass transfer coefficient (KOLa of volatile organic compounds (VOCs volatilized from wastewater. The novelty of this work is not the method used to determine KOLa but rather the use of actual wastewater instead of pure water as previously reported. The influence of U10cm, h, and SS on KOLa was performed using a volatilization tank with the volume of 100-350 L. Methyl Ethyl Ketone (MEK was selected as a representative of VOCs investigated here in. The results revealed that the relationship between KOLa and the wind speeds falls into two regimes with a break at the wind speed of 2.4 m/s. At U10cm 2.4 m/s, KOLa increased more rapidly. The relationship between KOLa and U10cm was also linear but has a distinctly higher slope. For the KOLa dependency on water depth, the KOLa decreased significantly with increasing water depth up to a certain water depth after that the increase in water depth had small effect on KOLa. The suspended solids in wastewater also played an important role on KOLa. Increased SS resulted in a significant reduction of KOLa over the investigated range of SS. Finally, the comparison between KOLa obtained from wastewater and that of pure water revealed that KOLa from wastewater were much lower than that of pure water which was pronounced at high wind speed and at small water depth. This was due the presence of organic mass in wastewater which provided a barrier to mass transfer and reduced the degree of turbulence in the water body resulting in low volatilization rate and thus KOLa. From these results, the mass transfer model for predicting VOCs emission from wastewater should be developed based on the volatilization of VOCs from wastewater rather than that from pure water.

  16. Variações no teor e na composição volátil de Hyptis marrubioides EPL: cultivada no campo e em casa de vegetação Variation in the content and volatile composition of Hyptis marrubioides EPL: cultivated in field and greenhouse

    Directory of Open Access Journals (Sweden)

    Priscila Pereira Botrel

    2010-01-01

    Full Text Available This work describes the chemical composition of the volatile oil of Hyptis marrubioides cultivated in field and greenhouse. The experimental design was completely randomized, with ten replications for each type of cultivation. The volatile oil was extracted by hydrodistillation and analyzed by GC-MS. The highest content of volatile oil was found for plants grown in field. The highest percentage of the compounds present in oils was observed in samples grown in the field, such as germacra-4(15,5,10(14-trien-1-α-ol (16.34%, β-caryophyllene (10.42%, γ-muurolene (12.83% and trans-thujone (9.98%. However, some compounds were found only in plants grown in a greenhouse, such as cis-muurol-5-en-4α-ol (10.84%, α-cadinol (3.06% and eudesma-4(15,7-dien-1β-ol (6.82%.

  17. Modeling the Volatility in Global Fertilizer Prices

    NARCIS (Netherlands)

    P-Y. Chen (Ping-Yu); C-L. Chang (Chia-Lin); C-C. Chen (Chi-Chung); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe main purpose of this paper is to estimate the volatility in global fertilizer prices. The endogenous structural breakpoint unit root test and alternative volatility models, including the generalized autoregressive conditional heteroskedasticity (GARCH) model, Exponential GARCH (EGARC

  18. 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.

  19. 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

  20. 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...

  1. The partitioning of sulfur and chlorine between andesite melts and magmatic volatiles and the exchange coefficients of major cations

    Science.gov (United States)

    Zajacz, Zoltán; Candela, Philip A.; Piccoli, Philip M.; Sanchez-Valle, Carmen

    2012-07-01

    Andesite melts were equilibrated with an H-O-S-bearing volatile phase to determine the partition coefficients for S and Cl as a function of melt composition and oxygen fugacity. The experiments were conducted in rapid-quench MHC vessel assemblies at 200 MPa and 1000 °C, and over a range of imposed fO2 between NNO-1.2 and NNO+1.8. High fluid/melt mass ratios (∼15) were employed, allowing precise and accurate partition coefficients to be obtained by mass balance calculations. Chlorine exhibits Henrian behavior at ClO-0.5 activities typical for arc magmas, with D Cl volatile/melt = 1.36 ± 0.06 (1σ) below 0.2 wt.% Cl in the melt; at higher ClO-0.5 activities, D Cl volatile/melt increases linearly to 2.11 ± 0.02 at 1 wt.% Cl in the melt. In the volatile phase: FeCl2 ∼ NaCl > KCl ∼ HCl. The determination of cation exchange coefficients for major cations yielded: K K,Na volatile/melt = 1.23 ± 0.10 (1σ) and ∗K Fe,Na volatile/melt = D Fe volatile/melt / D Na volatile/melt = 1.08 ± 0.16 (1σ). Under these conditions, the concentration of HCl in the vapor is negatively correlated with the (Na + K)/(Al + Fe3+) ratio in the melt. Reduced sulfur (S2-) appears to obey Henry's law in andesite melt-volatile system at fH2S below pyrrhotite saturation. The partition coefficient for S at fO2 = NNO-0.5 correlates negatively with the FeO concentration in the melt, changing from 254 ± 25 at 4.0 wt.% FeO to 88 ± 6 at 7.5 wt.% FeO. Pyrrhotite saturation is reached when approximately 3.2 mol% S is present in the volatile phase at fO2 = NNO-0.5. At the sulfide/sulfate transition, the partition coefficient of S drops from 171 ± 23 to 21 ± 1 at a constant FeO content of ∼6 wt.% in the melt. At fO2 = NNO+1.8, anhydrite saturation is reached at ∼3.3 mol% S present in the volatile phase. Aqueous volatiles exsolving from intermediate to mafic magmas can efficiently extract S, and effect its transfer to sites of magmatic-hydrothermal ore deposit formation.

  2. Business Cycles, Financial Crises, and Stock Volatility

    OpenAIRE

    G. William Schwert

    1989-01-01

    This paper shows that stock volatility increases during recessions and financial crises from 1834-1987. The evidence reinforces the notion that stock prices are an important business cycle indicator. Using two different statistical models for stock volatility, I show that volatility increases after major financial crises. Moreover. stock volatility decreases and stock prices rise before the Fed increases margin requirements. Thus, there is little reason to believe that public policies can con...

  3. 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...... (stock) volatilities are mainly influenced by bond (stock) effects. Global, regional, and local volatility effects are all important. The introduction of the euro is associated with a structural break....

  4. The january effect across volatility regimes

    OpenAIRE

    Agnani, Betty; Aray, Henry

    2007-01-01

    Using a Markov regime switching model, this article presents evidence on the well-known January effect on stock returns. The specification allows a distinction to be drawn between two regimes, one with high volatility and other with low volatility. We obtain a time-varying January effect that is, in general, positive and significant in both volatility regimes. However, this effect is larger in the high volatility regime. In sharp contrast with most previous literature we find two major result...

  5. Exponential Smoothing, Long Memory and Volatility Prediction

    DEFF Research Database (Denmark)

    Proietti, Tommaso

    Extracting and forecasting the volatility of financial markets is an important empirical problem. The paper provides a time series characterization of the volatility components arising when the volatility process is fractionally integrated, and proposes a new predictor that can be seen as extensi...... methods for forecasting realized volatility, and that the estimated model confidence sets include the newly proposed fractional lag predictor in all occurrences....

  6. Volatilization of heavy metals during incineration of municipal solid wastes

    Institute of Scientific and Technical Information of China (English)

    SUN Lu-shi; S. Abanades; J.D.Lu; G.Flamant; D.Gauthier

    2004-01-01

    Incineration experiments with MSW, which had been impregnated with heavy metals, were presented toobtain information on the volatilization behavior of the elements cadmium (Cd), lead (Pb), and zinc (Zn) underdifferent conditions. Experiments were carried out in a bubbling fluid bed system connected to a customizedinductively coupled plasma optical emission spectroscopy(ICP-OES) for analyzing metals in the flue gas. The resultsindicated that the combustion temperature, the gas atmosphere, and the chlorine content in the flue gas could affectthe volatilization behavior of heavy metals. In the fluidized bed combustion, a large surface area was provided by thebed sand particles, and they may act as absorbents for the gaseous ash-forming compound. Comparer with themetals Cd and Pb, the vaporization of Zn was Iow. The formation of stable compounds such as ZnO·Al2O3 couldgreatly decrease the metals volatilization. The presence of chlorine would enhance the volatilization of heavy metalsby increasing the formation of metal chlorides. However, when the oxygen content was high, the chlorinatingreaction was kinetically hindered, which heavy metals release would be delayed.

  7. 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 r...

  8. Volatiles in inter-specific bacterial interactions

    NARCIS (Netherlands)

    Tyc, O.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures o

  9. Volatiles in inter-specific bacterial interactions

    NARCIS (Netherlands)

    Tyc, O.; Zweers, H.; De Boer, W.; Garbeva, P.V.

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures

  10. Ammonia volatilization from intensively managed dairy pastures.

    NARCIS (Netherlands)

    Bussink, D.W.

    1996-01-01

    The objectives of this thesis are (i) to quantify NH 3 volatilization from grassland, (ii) to gain understanding of the NH3 volatilization processes on grassland and (iii) to study measures how to reduce NH 3 volatilization from gra

  11. 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 r...

  12. Cost Linkages Transmit Volatility Across Markets

    DEFF Research Database (Denmark)

    Nguyen, Daniel Xuyen; Schaur, Georg

    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...

  13. MINERALIZAÇÃO E VOLATILIZAÇÃO DO NITROGÊNIO DA VINHAÇA-15N NA PRESENÇA OU NÃO DE URÉIA E DE PALHA DE CANA- DE-AÇÚCAR MINERALIZATION AND VOLATILIZATION OF NITROGEN FROM VINASSE-15N IN THE PRESENCE OR ABSENCE OF UREA AND SUGARCANE TRASH

    Directory of Open Access Journals (Sweden)

    Vilma Maria Silva

    1999-01-01

    Full Text Available O N mineral e o N volatilizado derivado da vinhaça marcada com 15N foram determinados em amostras de dois solos (Podzólico Vermelho-Amarelo, arenoso - PV, e Latossolo Roxo, argiloso - LR do município de Piracicaba, SP, em experimento de laboratório. Os solos foram tratados com vinhaça marcada com 15N (V* na dose de 100 mg.kg-1 de N-vinhaça. Os tratamentos constaram da aplicação de vinhaça isoladamente (V*, de vinhaça e uréia (V*+U, de vinhaça e palha de cana-de-açúcar (V*+P, e de vinhaça mais uréia e palha (V*+U+P, e foram incubados por 7, 14, 21, 28 e 35 dias. As parcelas foram constituídas por 50 g de solo. As doses de incorporação de N-uréia e palha de cana-de-açúcar foram de 220 mg.kg-1 e 22 g.kg-1, respectivamente. As concentrações de N-NH4+ e N-NO3- no solo proveniente da vinhaça foram influenciadas pelo tipo de solo. A adição aos solos da uréia e da vinhaça promoveu uma maior disponibilidade de N-NH4+ e de N-NO3- proveniente da vinhaça. A adição de palha e de vinhaça não alterou as concentrações de N-NH4+ e de N-NO3- provenientes da vinhaça nos solos. A adição da palha, da uréia e da vinhaça não alterou as concentrações de N-NH4+ e as concentrações de N-NO3- aumentaram apenas no solo LR ao longo do tempo. As perdas por volatilização de N da vinhaça foram, em geral, crescentes, para todos os tratamentos no solo PV e mais elevadas (14 % que no solo LR (5%; neste, foram bem similares.The mineralized and volatilized nitrogen derived from vinasse labelled with 15N were determined in a laboratory experiment, using samples of two soils [a sandy Red-Yellow Podzolic - PV and a clayey Latosol - LR (Oxisol], collected in Piracicaba, SP, Brazil. The experiment consisted of four treatments: application of vinasse (V*; vinasse with urea (V*+U; vinasse with sugarcane straw (V*+P; and vinasse with urea and sugarcane straw (V*+U+P. Vinasse, labelled with 15N (V* was applied at a rate of 100 mg.kg-1 of N

  14. A power-efficient and non-volatile programmable logic array based on phase change memory

    Science.gov (United States)

    Du, Yuan; Ye, Yong; Kang, Yong; Xia, Yangyang; Song, Zhitang; Chen, Bomy

    2016-10-01

    Recently, numerous efforts have been made on NVM-based Field Programmable Gate Arrays (FPGAs) because the emerging non-volatile memory (NVM) technologies have the advantages of lower leakage power and higher density than Static Random Access Memory (SRAM) technology. However, the cost and the scale of FPGAs are so high and large that they can't be applied in the consumer electronics field and Internet of Things (IoT). Due to the small scale and low cost, Programmable Logic Array (PLA) is an ideal option for these fields. However, up to now there are few researches on non-volatile PLA based on emerging NVMs. In this paper, a power-efficient non-volatile PLA based on Phase Change Memory (PCM) is proposed. The proposed non-volatile PLA architecture has been evaluated using the 40 nm Complementary Metal Oxide Semiconductor (CMOS) technology, and the simulation results show the correct functionality of the PLA. After the PLA reads the configuration bits from the non-volatile programmable elements (PEs), the power of the programmable elements can be OFF. Therefore, the standby power of the programmable elements is much smaller than that of the commonly SRAM-based PLAs. The simulation results also show that the total power of nvPLA is reduced by about 53.6% when the supply power of Programmable Element is OFF.

  15. 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 human exposure. The occurrence of each element in food classes from different regions is presented. Some of the current toxicological risk assessments on toxic elements, the human health effect of each toxic element, and their contents in the food legislations are presented. An overview of analytical...... techniques and challenges for determination of toxic elements in food is also given....

  16. Level Shifts in Volatility and the Implied-Realized Volatility Relation

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; de Magistris, Paolo Santucci

    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....

  17. Sucata como elemento de comunicação na enfermagem "Desperdicios" como elemento de comunicación en la enfermería "Scrap" as an element of communication in nursing

    Directory of Open Access Journals (Sweden)

    Elizabeth Esperidião

    1996-04-01

    Full Text Available À partir do entendimento de que alunos e profissionais de Enfermagem demonstram dificuldades em se posicionarem como “pessoas” na profissão, realizamos um estudo descritivo exploratório, com abordagem qualitativa. Oferecemos na II Jornada Goiana de Enfermagem uma oficina de trabalho intitulada “Conhecendo o SER Enfermeiro”. Dentre as várias técnicas de grupo, a sucata como elemento de comunicação foi um recurso utilizado em determinada dinâmica, sendo o objeto deste estudo que se propôs: identificar como é a representação do auto-retrato do SER Enfermeiro, verificar qual é o processo de interação indivíduo-sucata, durante a realização do trabalho e averiguar se o objeto de escolha assume uma representação diferente do que ele é. Encontramos que existem especificidades na representação de cada auto-retrato do SER Enfermeiro. Quanto à interação indivíduo-sucata houve uma certa seqüência obedecida: estranheza com o material e/ou trabalho proposto, manipulação e identificação dos objetos, seleção de sucatas e concretização da tarefa realizada. Em relação aos objetos escolhidos percebemos nítida preferência aos correlacionados com a profissão, embora outros também o foram. Finalizando, sugerimos que outros estudos sejam realizados, utilizando sucata enquanto elemento de comunicação.A partir del entendimiento que los alumnos y profesionales de enfermería demuestran dificultades en posicionarse como personas en la profesión, realizamos un estudio descriptivo exploratorio, con abordaje cualitativa, ofreciendo en la II Jornada de Enfermería en Goiania un taller de trabajo titulado "Conociendo el SER Enfermero". Entre varias técnicas de grupo, el "desperdicio" como elemento de comunicación fue un recurso utilizado en determinada dinámica, siendo el objeto de este estudio que se propuso: identificar cómo es la representación del auto retrato del SER Enfermero, verificar cual es el proceso de

  18. 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...... develop a new class of affine discrete-time option valuation models that use daily returns as well as realized volatility. We derive convenient closed-form option valuation formulas, and we assess the option valuation properties using Standard & Poor’s (S&P) 500 return and option data. We find...... that realized volatility reduces the pricing errors of the benchmark model significantly across moneyness, maturity, and volatility levels....

  19. Volatiles and refratories in solar analogs: no terrestial planet connection

    CERN Document Server

    Hernandez, J I Gonzalez; Santos, N C; Sousa, S; Delgado-Mena, E; Neves, V; Udry, S

    2010-01-01

    We have analysed very high-quality HARPS and UVES spectra of 95 solar analogs, 24 hosting planets and 71 without detected planets, to search for any possible signature of terrestial planets in the chemical abundances of volatile and refractory elements with respect to the solar abundances. We demonstrate that stars with and without planets in this sample show similar mean abundance ratios, in particular, a sub-sample of 14 planet-host and 14 "single" solar analogs in the metallicity range 0.14<[Fe/H]<0.36. In addition, two of the planetary systems in this sub-sample, containing each of them a super-Earth-like planet with masses in the range ~ 7-11 Earth masses, have different volatile-to-refratory abundance ratios to what would be expected from the presence of a terrestial planets. Finally, we check that after removing the Galactic chemical evolution effects any possible difference in mean abundances, with respect to solar values, of refratory and volatile elements practically dissappears.

  20. An element

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K.; Iidzima, K.

    1983-03-30

    An anode of a light metal is used in the element, along with an electrolyte which consists of an ether solvent and an ionogenic additive in the form of a salt of dithiocarbamic acid. The element has good discharge characteristics.

  1. Arbitrage and Volatility in Chinese Stock's Markets

    Science.gov (United States)

    Lu, Shu Quan; Ito, Takao; Zhang, Jianbo

    From the point of view of no-arbitrage pricing, what matters is how much volatility the stock has, for volatility measures the amount of profit that can be made from shorting stocks and purchasing options. With the short-sales constraints or in the absence of options, however, high volatility is likely to mean arbitrage from stock market. As emerging stock markets for China, investors are increasingly concerned about volatilities of Chinese two stock markets. We estimate volatility's models for Chinese stock markets' indexes using Markov chain Monte Carlo (MCMC) method and GARCH. We find that estimated values of volatility parameters are very high for all data frequencies. It suggests that stock returns are extremely volatile even at long term intervals in Chinese markets. Furthermore, this result could be considered that there seems to be arbitrage opportunities in Chinese stock markets.

  2. 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)

  3. 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.

  4. Chirospecific analysis of plant volatiles

    Science.gov (United States)

    Tkachev, A. V.

    2007-10-01

    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.

  5. Volatiles in Inter-Specific Bacterial Interactions.

    Science.gov (United States)

    Tyc, Olaf; Zweers, Hans; de Boer, Wietse; Garbeva, Paolina

    2015-01-01

    The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well-described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium, and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal, and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide) were tested for their effect on three target bacteria. Here, we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities.

  6. Volatiles in inter-specific bacterial interactions

    Directory of Open Access Journals (Sweden)

    Olaf eTyc

    2015-12-01

    Full Text Available The importance of volatile organic compounds for functioning of microbes is receiving increased research attention. However, to date very little is known on how inter-specific bacterial interactions effect volatiles production as most studies have been focused on volatiles produced by monocultures of well described bacterial genera. In this study we aimed to understand how inter-specific bacterial interactions affect the composition, production and activity of volatiles. Four phylogenetically different bacterial species namely: Chryseobacterium, Dyella, Janthinobacterium and Tsukamurella were selected. Earlier results had shown that pairwise combinations of these bacteria induced antimicrobial activity in agar media whereas this was not the case for monocultures. In the current study, we examined if these observations were also reflected by the production of antimicrobial volatiles. Thus, the identity and antimicrobial activity of volatiles produced by the bacteria were determined in monoculture as well in pairwise combinations. Antimicrobial activity of the volatiles was assessed against fungal, oomycetal and bacterial model organisms. Our results revealed that inter-specific bacterial interactions affected volatiles blend composition. Fungi and oomycetes showed high sensitivity to bacterial volatiles whereas the effect of volatiles on bacteria varied between no effects, growth inhibition to growth promotion depending on the volatile blend composition. In total 35 volatile compounds were detected most of which were sulfur-containing compounds. Two commonly produced sulfur-containing volatile compounds (dimethyl disulfide and dimethyl trisulfide were tested for their effect on three target bacteria. Here we display the importance of inter-specific interactions on bacterial volatiles production and their antimicrobial activities.

  7. 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.

  8. Volatility at Karachi Stock Exchange

    OpenAIRE

    Aslam Farid; Javed Ashraf

    1995-01-01

    Frequent “crashes” of the stock market reported during the year 1994 suggest that the Karachi bourse is rapidly converting into a volatile market. This cannot be viewed as a positive sign for this developing market of South Asia. Though heavy fluctuations in stock prices are not an unusual phenomena and it has been observed at almost all big and small exchanges of the world. Focusing on the reasons for such fluctuations is instructive and likely to have important policy implications. Proponen...

  9. Asthenospheric kimberlites: Volatile contents and bulk compositions at 7 GPa

    Science.gov (United States)

    Stamm, Natalia; Schmidt, Max W.

    2017-09-01

    During ascent, kimberlites react with the lithospheric mantle, entrain and assimilate xenolithic material, loose volatiles and suffer from syn- and post-magmatic alteration. Consequently, kimberlite rocks deviate heavily from their primary melt. Experiments at 7 GPa, 1300-1480 °C, 10-30 wt% CO2 and 0.46 wt% H2O on a proposed primitive composition from the Jericho kimberlite show that saturation with a lherzolitic mineral assemblage occurs only at 1300-1350 °C for a carbonatitic melt with 35 wt% CO2. At asthenospheric temperatures of >1400 °C, where the Jericho melt stays kimberlitic, this composition saturates only in low-Ca pyroxene, garnet and partly olivine. We hence forced the primitive Jericho kimberlite into multiple saturation with a lherzolitic assemblage by adding a compound peridotite. Saturation in olivine, low- and high-Ca pyroxene and garnet was obtained at 1400-1650 °C (7 GPa), melts are kimberlitic with 18-29 wt% SiO2 + Al2O3, 22.1-24.6 wt% MgO, 15-27 wt% CO2 and 0.4-7.1 wt% H2O; with a trade-off of H2O vs. CO2 and temperature. Melts in equilibrium with high-Ca pyroxene with typical mantle compositions have ≥2.5 wt% Na2O, much higher than the commonly proposed 0.1-0.2 wt%. The experiments allow for a model of kimberlite origin in the convective upper mantle, which only requires mantle upwelling that causes melting at the depth where elemental carbon (in metal, diamond or carbide) converts to CO2 (at ∼250 km). If primary melts leading to kimberlites contain a few wt% H2O, then adiabatic temperatures of 1400-1500 °C would yield asthenospheric mantle melts that are kimberlitic (>18 wt% SiO2 + Al2O3) but not carbonatitic (<10 wt% SiO2 + Al2O3) in composition, carbonatites only forming 100-200 °C below the adiabat. These kimberlites represent small melt fractions concentrating CO2 and H2O and then acquire part of their chemical signature by assimilation/fractionation during ascent in the subcratonic lithosphere.

  10. Diamonds from the Juina-5 kimberlite provide evidence for crustal volatile recycling into the deep Earth

    Science.gov (United States)

    Thomson, Andrew; Walter, Michael; Kohn, Simon; Burnham, Antony; Bulanova, Galina; Smith, Chris; Araujo, Debora

    2014-05-01

    'Superdeep' diamonds originate from a depth range spanning the asthenospheric upper mantle, transition zone and shallowest parts of the lower mantle [1]. Sporadically they entrap small inclusions of pre-existing or co-precipitating minerals during their crystallisation from volatile-rich melts or fluids. Such samples therefore preserve important petrologic, tectonic and geodynamic information about their growth environment together with evidence of the deep volatile cycling. The Juina-5 kimberlite has previously been recognised as a source of 'superdeep' diamonds [2]. Here we present and discuss data from an extended collection of Juina-5 diamonds. This work has revealed that these diamonds are dominantly composed of isotopically light carbon and contain a mineral inclusion cargo mostly of eclogitic affinity consisting of many former Mg- and Ca-perovskite, NAL-phase, CF-phase, stishovite, majoritic garnet, sodic pyroxene, ferropericlase, Fe or Fe-carbide and sulphide minerals. Together these observations suggest that the diamonds form from material of a subducted crustal origin. The high enrichment of the inclusions' trace element compositions implies that they cannot represent trapped fragments of formerly subsolidus mantle material. Geochemical modelling instead allows the compositions of Ca-perovskite and majorite inclusions to be directly linked to formation from a slab-derived carbonate bearing melt. It is suggested that the formation of 'superdeep' diamonds, and their inclusions, is the result of 'redox-freezing' during the interaction of oxidised slab melts and reducing mantle rocks [3]. It is expected that such melts will be produced during slab foundering and thermal equilibration in the upper/lower mantle boundary region, where tomographic evidence suggests slab subduction often stalls [4]. This hypothesis has been tested with experiments performed at transition zone pressures using the multi-anvil apparatus. At 20 GPa the composition of a low degree melt

  11. 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.

  12. 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.

  13. 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.

  14. REE and Other Trace Element Chemistry of Oldhamite(CaS) in the Qingzhen Chondrite(EH3) and Their Genetic Implications

    Institute of Scientific and Technical Information of China (English)

    陈永享; ERNSTPERNICKA; 等

    1993-01-01

    Instrumental neutron activation analysis(INAA) of 14 single oldhamite grains separated from the Qingzhen chondrite (EH3) for refractory(La,Ce,Sm ,Eu,Yb,Lu,Ca,Sc,Hf, and Th),volatile (Na,Cr,Zn,Se,Br,etc.)and siderophile elements (Fe,Ni,Co,Ir,Au ,and As) revealed that oldhamite is highly rich in refractory elements.The mineral serves as the principal carrier of REE and contains about 80% of the REEs in the Qingzhen enstatite chondrite .Furthermore, the large enrichment of LREE relative to HREE is noticed in oldhamite from the Qingzhen .In general, the oldhamite from metal-sulfide assemblages is richer in REE than that from the matrix,i.e.,the earlier the oldhamite grains condensed, the richer they are in REE. Meanwhile.oldhamite is also rich in vol-atile elements such as Se,Br, etc.In terms of the distribution of trace elements in oldhamitc from the Qingzhen ,the chondrite is srggested to have resulted from high-temperature condensation of solar nebula.

  15. Spider mites adaptively learn recognizing mycorrhiza-induced changes in host plant volatiles.

    Science.gov (United States)

    Patiño-Ruiz, J David; Schausberger, Peter

    2014-12-01

    Symbiotic root micro-organisms such as arbuscular mycorrhizal fungi commonly change morphological, physiological and biochemical traits of their host plants and may thus influence the interaction of aboveground plant parts with herbivores and their natural enemies. While quite a few studies tested the effects of mycorrhiza on life history traits, such as growth, development and reproduction, of aboveground herbivores, information on possible effects of mycorrhiza on host plant choice of herbivores via constitutive and/or induced plant volatiles is lacking. Here we assessed whether symbiosis of the mycorrhizal fungus Glomus mosseae with common bean plants Phaseolus vulgaris influences the response of the two-spotted spider mite Tetranychus urticae to volatiles of plants that were clean or infested with spider mites. Mycorrhiza-naïve and -experienced spider mites, reared on mycorrhizal or non-mycorrhizal bean plants for several days before the experiments, were subjected to Y-tube olfactometer choice tests. Experienced but not naïve spider mites distinguished between constitutive volatiles of clean non-mycorrhizal and mycorrhizal plants, preferring the latter. Neither naïve nor experienced spider mites distinguished between spider mite-induced volatiles of mycorrhizal and non-mycorrhizal plants. Learning the odor of clean mycorrhizal plants, resulting in a subsequent preference for these odors, is adaptive because mycorrhizal plants are more favorable host plants for fitness of the spider mites than are non-mycorrhizal plants.

  16. Volatile heavy metal mobility in silicate liquids: Implications for volcanic degassing and eruption prediction

    Science.gov (United States)

    MacKenzie, Jason M.; Canil, Dante

    2008-05-01

    The volatilization of Cd, Re, Tl, Pb, Sb and Te from melts in the system CaO-MgO-Al 2O 3-SiO 2 (CMAS) and Na 2O-MgO-Al 2O 3-SiO 2 (NMAS) has been investigated at 0.1 MPa and 1200-1350 °C. Experiments were conducted in air using metal-doped melts in Pt crucibles. Analysis of quenched glasses by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) normal to the melt/gas interface produced concentration profiles for Cd, Re, Tl, Pb, Sb and Te to which a semi-infinite one-dimensional diffusion model could be applied to extract diffusion coefficients ( D). The melt was also doped with Cu, Zn, In, Mo, Sn and W but concentration profiles for these metals did not develop. In the CMAS composition at 1300 °C, the fastest diffusing element was Cd having a log DCd = - 6.5 ± 0.2. The slowest element was Re with log DRe = - 7.5 ± 0.3. Diffusivities of Sb, Te, Pb and Tl have intermediate values where log DSb = - 7.1 ± 0.1, log DTe = - 7.2 ± 0.3, log DPb = - 7.1 ± 0.2, log DTl = - 7.0 ± 0.2 cm 2/s. In the NMAS composition, log DRe = - 6.5 ± 0.2, log DSb = - 6.0 ± 0.2, log DPb = - 6.1 ± 0.1, log DTl = - 5.8 ± 0.2 cm 2/s (values for Cd and Te were not determined). Differences in diffusivity of volatile heavy metal ions to a melt-gas interface lead to significant fractionation between these metals in magmas during degassing. Given the observed differences in Cd and Re diffusivities in the CMAS composition, we predict an increase in the normalized Cd/Re ratio in the gas phase with increasing bubble growth rate. Monitoring of the Cd/Re ratios in aerosols from degassing volcanoes may provide a tool for predicting volcanic eruption.

  17. Review: Circulation of Inorganic Elements in Combustion of Alternative Fuels in Cement Plants

    DEFF Research Database (Denmark)

    Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Jappe Frandsen, Flemming;

    2015-01-01

    Cement production is an energy-intensive process, which traditionally has been dependent on fossil fuels. However, the use of alternative fuels, i.e., selected waste, biomass, and byproducts with recoverable calorific value, is constantly increasing. Combustion of these fuels is more challenging......, compared to fossil fuels, because of a lack of experience and different chemical and physical properties. When complete oxidation Of fuels in the calciner and main burner is not achieved, they burn in direct contact with the bed material of the rotary kiln, causing local reducing conditions and increasing...... the internal circulation of S, Cl, Na, and K. Compounds containing these elements, such as alkali salts, evaporate when exposed to high temperatures and subsequently condense in colder parts of the plant. The transformation of the volatile inorganic species at different locations in the cement plant...

  18. Using Jupiter's Volatile Inventory to Trace the History Of Ices During Planet Formation

    Science.gov (United States)

    Ciesla, F.

    2014-12-01

    The Galileo probe's measurement of a uniform enrichment of Jupiter's atmosphere in volatiles, including noble gases, relative to a gas of solar composition has proven to be a challenge to models of planet formation. This uniform enrichment requires that Jupiter accreted planetesimals with solar ratios in all elements, except for hydrogen and helium. Given the very low temperatures needed to achieve such compositions if all elements behaved chemically as pure substances, efforts have focused on understanding how extremely volatile elements could be physically incorporated into ices and organics at low temperatures. Two primary methods for incorporation of these volatiles have emerged: formation of clathrate hydrates and trapping of gases during the formation of amorphous ice. These modes for incorporating volatiles make different predictions about the amount of water that would be contained within Jupiter, an issue that will be addressed by the Juno Mission. Either mode for incorporating volatiles will reveal details about the dynamical behavior of ices during planet formation and the environments in which planetary materials were formed. For example, Ciesla (2014) showed that amorphous ice formation, and thus trapping of volatiles in this manner, can occur as water molecules are photodesorbed and freeze-out again on grain surfaces, thus requiring high UV flux environments at the birth of the solar system or significant vertical lofting of grains in the disk by turbulence. I will review the conditions that are required for amorphous trapping and clathrate hydrate formation to have occurred in the solar nebula and discuss the implications for the compositions of the other giant planets and cometary bodies, as well as the relation of these materials to the sources of volatiles on terrestrial planets.

  19. Molecular Diffusion of Volatiles in Lunar Regolith during the Resource Prospector Mission Sample Acquisition

    Science.gov (United States)

    Teodoro, L. A.; Colaprete, A.; Roush, T. L.; Elphic, R. C.; Cook, A.; Kleinhenz, J.; Fritzler, E.; Smith, J. T.; Zacny, K.

    2016-12-01

    In the context of NASA's Resource Prospector (RP) mission to the high latitudes and permanently shadowed regions of the Moon, we study 3D models of volatile transport in the lunar regolith. This mission's goal is to extract and identify volatile species in the top meter of the lunar regolith layer. Roughly, RP consists of 5 elements: i) the Neutron Spectrometer System will search for high hydrogen concentrations and in turn select optimum drilling locations; ii) The Near Infrared Volatile Spectrometer System (NIRVSS) will characterize the nature of the surficial water ice; iii) The Drill Sub-system will extract samples from the top meter of the lunar surface and deliver them to the Oxygen and Volatile Extraction Node (OVEN); iv) OVEN will heat up the sample and extract the volatiles therein, that will be v) transferred to the Lunar Advanced Volatiles Analysis system for chemical composition analysis. A series of vacuum cryogenic experiments have been carried out at Glenn Research Center with the aim of quantifying the volatile losses during the drilling/sample acquisition phase and sample delivery to crucibles steps. These experiments' outputs include: i) Pressure measurements of several chemical species (e.g. H2O, Ar); ii) Temperature measurements within and at the surface of the lunar simulant using thermocouples; and iii) Surficial temperature NIRVSS measurements. Here, we report on the numerical modeling we are carrying out to understand the physics underpinning these experiments. The models include 2 main parts: i) reliable computation of temperature variation throughout the lunar soil container during the experiment as constrained by temperature measurements; and ii) molecular diffusion of volatiles. The latter includes both Fick's (flight of the molecules in the porous) and Knudsen's (sublimation of volatile molecules at the grain surface) laws. We also mimic the soil porosity by randomly allocating 75 microns particles in the simulation volume. Our

  20. 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.

  1. Alkali element depletion by core formation and vaporization on the early Earth

    Science.gov (United States)

    Lodders, K.; Fegley, B., Jr.

    1994-01-01

    The depletion of Na, K, Rb, and Cs in the Earth's upper mantle and crust relative to their abundances in chondrites is a long standing problem in geochemistry. Here we consider two commonly invoked mechanisms, namely core formation, and vaporization, for producing the observed depletions. Our models predict that a significant percentage of the Earth's bulk alkali element inventory is in the core (30 percent for Na, 52 percent for K, 74 percent for Rb, and 92 percent for Cs). These predictions agree with independent estimates from nebular volatility trends and (for K) from terrestrial heat flow data. Our models also predict that vaporization and thermal escape during planetary accretion are unlikely to produce the observed alkali element depletion pattern. However, loss during the putative giant impact which formed the Moon cannot be ruled out. Experimental, observational, and theoretical tests of our predictions are also described. Alkali element partitioning into the Earth's core was modeled by assuming that alkali element partitioning during core formation on the aubrite parent body (APB) is analogous to that on the early Earth. The analogy is reasonable for three reasons. First, the enstatite meteorites are the only known meteorites with the same oxygen isotope systematics as the Earth-Moon system. Second, the large core size of the Earth and the V depletion in the mantle requires accretion from planetesimals as reduced as the enstatite chondrites. Third, experimental studies of K partitioning between silicate and metal plus sulfide show that more K goes into the metal plus sulfide at higher pressures than at one atmosphere pressure. Thus partitioning in the relatively low pressure natural laboratory of the APB is a good guide to alkali elemental partitioning during the growth of the Earth.

  2. [Unusual elements in renal calculi].

    Science.gov (United States)

    Rodríguez-Miñón Cifuentes, J L; Salvador, E; Traba Villameytide, M L

    2006-01-01

    A group of 54 renal calculi were spontaneously passed renal stone after a nephritic colic. Two groups of calculi were found: papillary and non-papillary calculi. All calculi were analyzed by infrared spectroscopy and electronic microscopy scan (EMS) and EDAX. When the stones were analyzed with EDAX, elements such as C, N, O, Na, S, Mg, Al, Si, Cl, K, Ca, Mn, Fe, Ni, Zn were detected. The possible origin of these elements is discussed in this work.

  3. Milk Price Volatility and its Determinants

    OpenAIRE

    Dong, Fengxia; Du, Xiaodong; Gould, Brian W.

    2011-01-01

    The classified pricing of fluid milk under the Federal Milk Marketing Orders (FMMO) system combined with the cash settlement feature of Class IIII milk futures contracts generate a unique volatility pattern of these futures markets in the sense that the volatility gradually decreases as the USDA price announcement dates approaching in the month. Focusing on the evolution of volatility in Class III milk futures market, this study quantifies the relative importance of a set of factors driving m...

  4. DOES VOLATILITY RESPOND ASYMMETRIC TO PAST SHOCKS?

    OpenAIRE

    Claudiu Botoc

    2014-01-01

    The main aim of the paper is to examine if the stock market volatility exhibits asymmetric or an asymmetric response to past shocks, for certain CEE countries (Romania,Hungary, Bulgaria, Poland) over the period May 2004 - September 2014. For the stock marketsfrom East Europe the results are in line with the symmetric volatility, i.e. volatility is similaraffected by both positive and negative returns with the same magnitude. For the stock marketsfrom Central Europe the results are consistent ...

  5. The Determinants of Public Deficit Volatility

    OpenAIRE

    2009-01-01

    This paper empirically analyzes the political, institutional and economic sources of public deficit volatility. Using the system-GMM estimator for linear dynamic panel data models and a sample of 125 countries analyzed from 1980 to 2006, we show that higher public deficit volatility is typically associated with higher levels of political instability and less democracy. In addition, public deficit volatility tends to be magnified for small countries, in the outcome of hyper-inflation episodes ...

  6. Exchange Rate Volatility in BRICS Countries

    OpenAIRE

    2012-01-01

    This paper measures the impact of bilateral exchange rates, the world agricultural GDP and third-country exchange rate volatilities (Yen/USD and Euro/USD) on the BRICS agricultural exports using a vector autoregressive (VAR) model. Two measures of volatility are used: the standard deviation and the coefficient of variation of the rates of change of the real exchange rates. We found that most variables are integrated of order two except the third-country exchange rate volatilities which are st...

  7. Volatile halogenated hydrocarbons in foods

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, Makoto; Toyoda, Masatake; Saito, Yukio [National Institute of Health Services, Tokyo (Japan)] [and others

    1995-02-01

    Volatile halogenated organic compounds were determined in foods. Statistical treatment of the data for 13 sampled from 20 families living in suburban Tokyo (Saitama prefecture) indicated that the foods were contaminated by water pollution and/or substances introduced by the process of food production. Butter and margarine were contaminated by chlorinated ethylene, ethane, and related compounds released by dry cleaning and other operations. Soybean sprouts and tofu (soybean curd) contained chloroform and related trihalomethanes absorbed during the production process. 27 refs., 6 figs., 5 tabs.

  8. Volatile Constituents of Zhumaria Majdae

    Directory of Open Access Journals (Sweden)

    Yazdanparst

    1993-07-01

    Full Text Available Capillary gas chromatography mass spectrometry (GC- MS analyses of a sample of essential oil of zhumaria Linalool ned by simple water distillation of the pulverized air - dired leaves and flowers of the plant indicated that Linalool and comphor are the two major constituents of the volatile oil. Sylvestrene , y -terpinene, a- Pinene, b - carene, camphene, and Epiborneol constitute the other main components of the essential oil. The GC - MS chromatogram indicated the presence of more than fifty - components in the oil, most of them were present in trace amounts. In this study, the chemical structures of twenty of these consti tuents were elucidated using GC - MS analysis.

  9. Dietary exposure to volatile and non-volatile N-nitrosamines from processed meat products in Denmark.

    Science.gov (United States)

    Herrmann, S S; Duedahl-Olesen, L; Christensen, T; Olesen, P T; Granby, K

    2015-06-01

    Recent epidemiological studies show a positive association between cancer incidence and high intake of processed meat. N-nitrosamines (NAs) in these products have been suggested as one potential causative factor. Most volatile NAs (VNAs) are classified as probable human carcinogens, whereas the carcinogenicity for the majority of the non-volatile NA (NVNA) remains to be elucidated. Danish adults (15-75 years) and children (4-6 years) consume 20 g and 16 g of processed meat per day (95th percentile), respectively. The consumption is primarily accounted for by sausages, salami, pork flank (spiced and boiled) and ham. This consumption results in an exposure to NVNA of 33 and 90 ng kg bw(-1) day(-1) for adults and children, respectively. The exposure to VNA is significantly lower amounting to 0.34 and 1.1 ng kg bw(-1) day(-1) for adults and children, respectively. Based on a BMDL10 of 29 µg kg bw(-1) day(-1) a MOE value ≥17,000 was derived for the exposure to NA known to be carcinogenic (VNA including NSAR), indicating an exposure of low concern. The exposure to the NVNA is substantially higher and if found to be of toxicological significance the exposure may be of concern.

  10. [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.

  11. 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.

  12. Assessing Relative Volatility/Intermittency/Energy Dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko; Schmiegel, Jürgen

    We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency even when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... process in particular. While this estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, we apply it also to energy price data. Moreover, we develop a probabilistic asymptotic theory for relative power variations of Brownian semistationary...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  13. Volatiles and refratories in solar analogs: no terrestial planet connection

    OpenAIRE

    Hernandez, J. I. Gonzalez; Israelian, G.; Santos,N.C.; Sousa, S.; Delgado-Mena, E.; Neves, V.; Udry, S.

    2010-01-01

    We have analysed very high-quality HARPS and UVES spectra of 95 solar analogs, 24 hosting planets and 71 without detected planets, to search for any possible signature of terrestial planets in the chemical abundances of volatile and refractory elements with respect to the solar abundances. We demonstrate that stars with and without planets in this sample show similar mean abundance ratios, in particular, a sub-sample of 14 planet-host and 14 "single" solar analogs in the metallicity range 0.14

  14. CMAT non-volatile spintronic computing: complementary MTJ logic

    Science.gov (United States)

    Friedman, Joseph S.

    2016-10-01

    Magnetic tunnel junctions (MTJs) have thoroughly demonstrated their utility as a non-volatile memory storage element, inspiring their application to a memory-in-logic computer that would overcome the von Neumann bottleneck. However, MTJ logic gates must be able to cause other MTJs to switch, thus ensuring the cascading capability fundamental to efficient computing. Complementary MTJ logic (CMAT) provides a simple circuit structure through which MTJs can be cascaded directly to perform logic operations. In this novel logic family, charge pulses resulting from MTJ switching create magnetic fields that switch other MTJs, providing impetus for further development of MTJs for computing applications.

  15. Efeito de um extrato de Hipérico (Hypericum perforatum na marcação in vitro de elementos sangüíneos com tecnécio-99m e na biodisponibilidade do radiofármaco pertecnetato de sódio em ratos Wistar Effect of Hypericum perforatum extract on in vitro labelling of blood elements with technetium-99m and on biodisponibility of sodium pertecnetate in Wistar rats

    Directory of Open Access Journals (Sweden)

    Sebastião David Santos-Filho

    2005-01-01

    Full Text Available OBJETIVO: Avaliar o efeito de um extrato de hipérico (Hypericum perforatum na marcação de elementos sanguíneos com tecnécio-99m (99mTc e na biodisponibilidade do radiofármaco pertecnetato de sódio em ratos Wistar. MÉTODOS: Sangue (heparinizado de ratos Wistar é incubado com um extrato de hipérico, com cloreto estanoso e a seguir com Tc-99m, como pertecnetato de sódio (99mTcO4Na. Plasma (P e células (CS são isolados por centrifugação. Amostras de P e CS também são precipitadas com ácido tricloroacético 5%, e separadas as frações solúveis (FS-P e FS-CS e insolúveis (FI-P e FI-CS. Para a análise da biodistribuição, 0,3 mL do radiofármaco 99mTcO4Na foi administrada em ratos Wistar que receberam por gavagem extrato ou salina (NaCl 0,9% por 15 dias. Após 10 minutos os animais foram sacrificados e os órgãos isolados para contagem da atividade radioativa. RESULTADOS: O extrato de hipérico reduziu de forma significativa (PPURPOSE: To evaluate the effect of a hiperico extract (Hypericum perforatum on the labeling of blood elements with technetium-99m (99mTc and in the bioavailability of the radiopharmaceutical sodium pertechnetate in Wistar rats. METHODS: Blood (heparinized withdrawn from Wistar rats is incubated with a hiperico extract, with a stannous cloride and with 99mTc, as sodium pertechnetate (99mTcO4Na. Plasma (P and cells (C are isolated by centrifugation. Samples of P and C are also precipitated with trichloroacetic acid (TCA 5% and soluble (FS-P; FS-C and isoluble (FI-P; FI-C fractions are separated. In the bioavailability analysis, the extract or NaCl 0.9% solution is administrated into Wistar rats (gavage during 15 days. Sodium pertechnetate was administered and after 10 min, the animals are sacrificed, the organs were isolated, the radioactivity determined in a well counter, and the percentages of radioactivity per gram (%ATI/g in the organs are calculated. RESULTS: The hiperico extract decreased significantly

  16. 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 hosts

  17. 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 hosts

  18. Tracing recycled volatiles in a heterogeneous mantle with boron isotopes

    Science.gov (United States)

    Walowski, Kristina; Kirstein, Linda; de Hoog, Cees-Jan; Elliot, Tim; Savov, Ivan; Devey, Colin

    2016-04-01

    Recycling of oceanic lithosphere drives the chemical evolution of the Earth's mantle supplying both solids and volatiles to the Earth's interior. Yet, how subducted material influences mantle composition remains unclear. A perfect tracer for slab recycling should be only fractionated at the Earth's surface, have a strong influence on mantle compositions but be resistant to perturbations en route back to the surface. Current understanding suggests that boron concentrations linked to B isotope determinations fulfil all these requirements and should be an excellent tracer of heterogeneity in the deep mantle. Here, we present the trace element, volatile and the B isotope composition of basaltic glasses and melt inclusions in olivine from distinct end-member ocean island basalts (OIB) to track the fate of recycled lithosphere and ultimately document how recycling contributes to mantle heterogeneity. The chosen samples represent the different end member OIB compositions and include: EMI (Pitcairn), EMII (MacDonald), HIMU (St. Helena), and FOZO (Cape Verde & Reunion). The data is derived from both submarine and subaerial deposits, with B isotope determination of both basaltic glass and melt inclusions from each locality. Preliminary results suggest OIB have B isotopic compositions that overlap the MORB array (-7.5‰±0.7; Marschall et al., 2015) but extend to both lighter and heavier values. These results suggest that B isotopes will be useful for resolving mantle source heterogeneity at different ocean islands and contribute to our understanding of the volatile budget of the deep mantle.

  19. Rubidium isotopic composition of the Earth, meteorites, and the Moon: Evidence for the origin of volatile loss during planetary accretion

    Science.gov (United States)

    Pringle, Emily A.; Moynier, Frédéric

    2017-09-01

    Understanding the origin of volatile element variations in the inner Solar System has long been a goal of cosmochemistry, but many early studies searching for the fingerprint of volatile loss using stable isotope systems failed to find any resolvable variations. An improved method for the chemical purification of Rb for high-precision isotope ratio measurements by multi-collector inductively-coupled-plasma mass-spectrometry. This method has been used to measure the Rb isotopic composition for a suite of planetary materials, including carbonaceous, ordinary, and enstatite chondrites, as well as achondrites (eucrite, angrite), terrestrial igneous rocks (basalt, andesite, granite), and Apollo lunar samples (mare basalts, alkali suite). Volatile depleted bodies (e.g. HED parent body, thermally metamorphosed meteorites) are enriched in the heavy isotope of Rb by up to several per mil compared to chondrites, suggesting volatile loss by evaporation at the surface of planetesimals. In addition, the Moon is isotopically distinct from the Moon in Rb. The variations in Rb isotope compositions in the volatile-poor samples are attributed to volatile loss from planetesimals during accretion. This suggests that either the Rb (and other volatile elements) were lost during or following the giant impact or by evaporation earlier during the accretion history of Theia.

  20. 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.

  1. Belief biases and volatility of assets

    Science.gov (United States)

    Lei-Sun, Wen-Zou, Hui

    2014-10-01

    Based on an overlapping generation model, this paper introduces the noise traders with belief biases and rational traders. With an equilibrium analysis, this paper examines the volatility of risky asset. The results show that the belief biases, the probability of economy state, and the domain capability are all the factors that have effects on the volatility of the market.

  2. Explaining output volatility: The case of taxation

    DEFF Research Database (Denmark)

    Posch, Olaf

    empirical link between e ective tax rates and output volatility, with some evidence of a cointegrating relationship. In accordance with theory, taxes on labor income and corporate income empirically are found to be negatively related to volatility of macro aggregates whereas the capital tax ratio has...

  3. 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.

  4. 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...

  5. 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....

  6. Analyzing volatile compounds in dairy products

    Science.gov (United States)

    Volatile compounds give the first indication of the flavor in a dairy product. Volatiles are isolated from the sample matrix and then analyzed by chromatography, sensory methods, or an electronic nose. Isolation may be performed by solvent extraction or headspace analysis, and gas chromatography i...

  7. 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

  8. 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

  9. 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.

  10. 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 metab

  11. Price volatility in wind dominant electricity markets

    DEFF Research Database (Denmark)

    Farashbashi-Astaneh, Seyed-Mostafa; Chen, Zhe

    2013-01-01

    High penetration of intermittent renewable energy sources causes price volatility in future electricity markets. This is specially the case in European countries that plan high penetration levels. This highlights the necessity for revising market regulations and mechanisms in accordance to genera......High penetration of intermittent renewable energy sources causes price volatility in future electricity markets. This is specially the case in European countries that plan high penetration levels. This highlights the necessity for revising market regulations and mechanisms in accordance...... electricity markets. High price volatility is unappreciated because it imposes high financial risk levels to both electricity consumers and producers. Additionally high price variations impede tracking price signals by consumers in future smart grid and jeopardize implementation of demand response concepts....... The main contribution of this paper is to quantify volatility patterns of electricity price, as penetration level of wind power increases. Results explain a direct relationship between wind penetration and electricity price volatility in a quantitative manner....

  12. 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.

  13. Clustered volatility in multiagent dynamics

    CERN Document Server

    Youssefmir, M; Youssefmir, Michael; Huberman, Bernardo

    1995-01-01

    Large distributed multiagent systems are characterized by vast numbers of agents trying to gain access to limited resources in an unpredictable environment. Agents in these system continuously switch strategies in order to opportunistically find improvements in their utilities. We have analyzed the fluctuations around equilibrium that arise from strategy switching and discovered the existence of a new phenomenon. It consists of the appearance of sudden bursts of activity that punctuate the fixed point, and is due to an effective random walk consistent with overall stability. This clustered volatility is followed by relaxation to the fixed point but with different strategy mixes from the previous one. This phenomenon is quite general for systems in which agents explore strategies in search of local improvements.

  14. Investigating Planetary Volatile Accretion Mechanisms Using the Halogens

    Science.gov (United States)

    Ballentine, C. J.; Clay, P. L.; Burgess, R.; Busemann, H.; Ruzié, L.; Joachim, B.; Day, J. M.

    2014-12-01

    Depletion of the volatile elements in the Earth relative to the CI chondrites is roughly correlated with volatility, or decreasing condensation temperature. For the heavy halogen group elements (Cl, Br and I), volatility alone does not account for their apparent depletion, which early data has suggested is far greater than predicted [1-2]. Such depletion has been used to argue for the preferential loss of halogens by, amongst other processes, impact-driven erosive loss from Earth's surface [2]. Little consensus exists as to why the halogens should exhibit such preferential behavior during accretionary processes. Early efforts to constrain halogen abundance and understand their behavior in both Earth and planetary materials [3-6] have been hampered by their typically low abundance (ppb level) in most geologic materials. We present the results of halogen analysis of 23 chondrite samples, selected to represent diverse groups and petrologic type. Halogen abundances were measured by neutron irradiation noble gas mass spectrometry (NI-NGMS). Significant concentration heterogeneity is observed within some samples. However, a single Br/Cl and I/Cl ratio of 1.9 ± 0.2 (x 10-3) and 335 ± 10 (x 10-6) can be defined for carbonaceous chondrites with a good correlation between Br and Cl (R2 = 0.97) and between I and Cl (R2 = 0.84). Ratios of I/Cl overlap with terrestrial estimates of Bulk Silicate Earth and Mid Ocean Ridge Basalts. Similarly, good correlations are derived for enstatite (E) chondrites and a sulfide- and halogen- rich subset of E-chondrites. Chlorine abundances of CI (Orgueil) in this study are lower by factor of ~ 3 than the value of ~ 700 ppm Cl (compilation in [1]). Our results are similar to early discarded low values for Ivuna and Orgueil from [5,6] and agree more closely with values for CM chondrites. Halogens may not be as depleted in Earth as previously suggested, or a high degree of heterogeneity in the abundance of these volatile elements in

  15. Forecasting Exchange Rate Volatility in the Presence of Jumps

    DEFF Research Database (Denmark)

    Busch, Thomas; Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    of exchange rate futures options, allowingcalculation of option implied volatility. We find that implied volatility is an informationallyefficient but biased forecast of future realized exchange rate volatility. Furthermore,we show that log-normality is an even better distributional approximation...... for impliedvolatility than for realized volatility in this market. Finally, we show that the jump componentof future realized exchange rate volatility is to some extent predictable, and thatoption implied volatility is the dominant forecast of the future jump component....

  16. Trace element emissions when firing pulverized coal in a pilot-scale combustion facility

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.F.; Wincek, R.T.; Miller, B.G.; Scaroni, A.W. [Pennsylvania State Univ., University Park, PA (United States)

    1998-04-01

    Title Ed of the Clean Air Act Amendments of 1990 designates 189 hazardous air pollutants (HAPs). Fourteen of the 189 substances identified are: antimony (Sb), beryllium (Be), chlorine (0), cobalt (Co), manganese (Mn), nickel (Ni), selenium (Se), fluorine (F), arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg), and phosphorous (P). Eleven of these elements have been detected in the flue gas of pulverized coal-fired utility boilers. Currently there are no regulations that limit the emissions of these elements during coal combustion in utility- or industrial-scale boilers. Given the growing body of risk assessment data on these elements and their impact on the environment and human health, it is possible that regulations on emission levels for certain elements will be imposed. A knowledge of the occurrence of trace elements in coal and their behavior during combustion is essential to predict emissions and to develop control technologies for remediation. The partitioning of trace elements during combustion can be traced to their volatility within the system. For purposes of this paper, the classification of trace elements summarized by Clarke and Sloss will be used: Group I elements, i.e., elements that are not easily volatilized and form larger bottom ash and fly ash particles; Group H elements, i.e., elements that are partially or completely volatilization followed by condensation as small particles or on the surface of small particles; and Group III elements, i.e., elements that are readily volatilized and usually remain in the gas phase system.

  17. 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.

  18. Radioactive Elements on Mercury's Surface from MESSENGER: Implications for the Planet's Formation and Evolution

    National Research Council Canada - National Science Library

    Patrick N. Peplowski; Larry G. Evans; Steven A. Hauck; Timothy J. McCoy; William V. Boynton; Jeffery J. Gillis-Davis; Denton S. Ebel; John O. Goldsten; David K. Hamara; David J. Lawrence; Ralph L. McNutt; Larry R. Nittler; Sean C. Solomon; Edgar A. Rhodes; Ann L. Sprague; Richard D. Starr; Karen R. Stockstill-Cahill

    2011-01-01

    ...) in Mercury's northern hemisphere. The abundance of the moderately volatile element K, relative to Th and U, is inconsistent with physical models for the formation of Mercury requiring extreme heating of the planet or its precursor...

  19. Trace Element Composition of Metal and Sulphides in Iron Meteorites Determined Using ICP-MS

    Science.gov (United States)

    Giscard, M. D.; Hammond, S. J.; Bland, P. A.; Benedix, G. K.; Rogers, N. W.; Russell, S. S.; Genge, M. J.; Rehkamper, M.

    2012-09-01

    We measured trace element concentrations in Nantan, Toluca, Cape York, Carthage, Gibeon and Dronino. Poikiloblastic daubreelite in Gibeon indicates shock metamorphism. There is a volatile depletion in metal and sulphides.

  20. Aspects of the history of 66095 based on trace elements in clasts and whole rock

    Science.gov (United States)

    Jovanovic, S.; Reed, G. W., Jr.

    1982-01-01

    Halogens, P, U and Na are reported in anorthositic and basaltic clasts and matrix from rusty rock 66095. Large fractions of Cl and Br associated with the separated phases from 66095 are soluble in H2O. Up to two orders of magnitude variation in concentrations of these elements in the breccia components and varying H2O-soluble Cl/Br ratios indicate different sources of volatiles. An approximately constant ratio of the H2O- to 0.1 M HNO3-soluble Br in the various components suggests no appreciable alteration in the original distributions of this element in the breccia forming processes. Up to 50% or more of the phosphorus and of the non-H2O-soluble Cl was dissolved from most of the breccia components by 0.1 M HNO3. Clast and matrix residues from the leaching steps contain, in most cases, the Cl/P2O5 ratio found in 66095 whole rock and in a number of other Apollo 16 samples. Evidence that phosphates are the major P-phases in the breccia is based on the 0.1 M acid solubility of Cl and P in the matrix sample and on elemental concentrations which are consistent with those of KREEP.

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

    Directory of Open Access Journals (Sweden)

    W. M. Landing

    2009-12-01

    Full Text Available To understand and quantify the impact of local, regional, and 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 mercury, volatile elements As, Se, and Sn, and a suite of trace elements including Al, Bi, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ho, Ga, Gd, La, Li, Lu, Mg, Mn, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, Sb, Sc, Si, Sm, Sr, Tb, Th, Ti, Tm, U, V, Y, Yb, and Zn. Nutrients and major ions were also measured on each sample.

    Multivariate statistical methods are used to sort these tracers into factors that represent potential source components that contribute to the rainfall chemistry. Hg, As, Se, Sn, Sb, and non sea-salt sulfate were all significantly correlated with one anthropogenic factor. Using various Hg/element ratios, we can estimate that 22–33% of the rainfall mercury in the region results from coal combustion.

  2. Determination of 11 major and minor elements in chondritic meteorites by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Wolf, Stephen F; Compton, Joseph R; Gagnon, Christopher J L

    2012-10-15

    We have developed a new method for the quantification of 11 major and minor elements (Na, Mg, Al, P, S, K, Ca, Cr, Mn, Fe, and Ni) in chondritic meteorites by ICPMS using external calibration with a matrix-matched standard prepared from the Allende Standard Reference Meteorite. We have demonstrated the method's accuracy and assessed three different measures of precision by performing replicate dissolutions and analyses of 0.10-g samples of a homogenized samples of the CM2 meteorite Murchison and compared our results to literature values. We subsequently applied this method to the analysis of a set of four chondritic meteorites possessing a relatively wide range of chondritic compositions with results in accord with previously published values. Because our method is designed to use the same instrumentation and can use samples and standards prepared according to methods previously validated for the determination of a comprehensive suite of minor, trace, moderately and highly volatile trace elements (i.e., Li, Sc, Ti, V, Mn, Co, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ru, Pd, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, all 14 naturally occurring lanthanoids, Hf, W, Re, Ir, Pt, Tl, Bi, Th, and U) it complements these methods and allows a single laboratory to determine the concentrations of 60 elements in semimicroscopic amounts of chondritic material. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Mineralization and volatilization of nitrogen from vinasse-{sup 15} N in the presence or absence of urea and sugar cane straw; Mineralizacao e volatilizacao do nitrogenio da vinhaca-{sup 15} N na presenca ou nao de ureia e de palha de cana-de-acucar

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Vilma Maria; Colaco, Waldeciro [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear; Trivelin, Paulo Cesar Ocheuse [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil); Encarnacao, Fernando Antonio Franco da [Alagoas Univ., Maceio, AL (Brazil). Dept. de Geologia e Topografia; Cabezas, Waldo Alejandro Ruben Lara [Uberlandia Univ., MG (Brazil). Dept. de Agronomia

    1999-03-01

    The mineralized and volatilized nitrogen derived from vinasse labelled with {sup 15} N were determined in a laboratory experiment, using samples of two soils [a sandy Red-Yellow-Podzolic-PV and a clayey Latosol - LR (Oxisol)], collected in Piracicaba, SP, Brazil. The experiment consisted of four treatments: application of vinasse (V{sup *}); vinasse with urea (V{sup *}+U); vinasse with sugar cane straw (V{sup *}+P); and vinasse with urea and sugar cane straw (V{sup *}+U+P). Vinasse, labelled with {sup 15} N (V{sup *}) was applied at a rate of 100 mg.kg{sup -1} of N-vinasse. All treatments, were incubated for 7, 14, 21, 28 and 35 days. N-urea and sugar cane straw were incorporated in the soil at rates of 220 mg.kg{sup -1} and 22 g.kg{sup -1}, respectively. N H{sub 4}{sup +} -N and NO{sub 3}{sup -} -N concentrations, as a result of the vinasse addition, were affected by soil type. A larger availability of N H{sub 4}{sup +} -N and NO{sub 3}{sup -} -N derived from vinasse were observed, when urea was added. Sugar cane straw plus vinasse did not alter the concentrations of N H{sub 4}{sup +} - N and NO{sub 3}{sup -} - N derived from vinasse. Urea plus sugar cane straw did not affect N H{sub 4}{sup +} -N concentrations, and affected the NO{sub 3}{sup -} -N concentration in LR soil over time. Losses of vinasse-N, due to volatilization, increased with time for all treatments, and were larger for PV (14%) than for LR(5%); but such losses were similar in LR soil. (author)

  4. 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.

  5. 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.

  6. 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.

  7. Securing non-volatile memory regions

    Science.gov (United States)

    Faraboschi, Paolo; Ranganathan, Parthasarathy; Muralimanohar, Naveen

    2013-08-20

    Methods, apparatus and articles of manufacture to secure non-volatile memory regions are disclosed. An example method disclosed herein comprises associating a first key pair and a second key pair different than the first key pair with a process, using the first key pair to secure a first region of a non-volatile memory for the process, and using the second key pair to secure a second region of the non-volatile memory for the same process, the second region being different than the first region.

  8. Simultaneous determination of Si, Al and Na concentrations by particle induced gamma-ray emission and applications to reference materials and ceramic archaeological artifacts

    Science.gov (United States)

    Dasari, K. B.; Chhillar, S.; Acharya, R.; Ray, D. K.; Behera, A.; Lakshmana Das, N.; Pujari, P. K.

    2014-11-01

    A particle induced gamma ray emission (PIGE) method using 4 MeV proton beam was standardized for simultaneous determination of Si, Al and Na concentrations and has been applied for non-destructive analysis of several reference materials and archaeological clay pottery samples. Current normalized count rates of gamma-rays for the three elements listed above were obtained by an in situ method using Li as internal standard. The paper presents application of the in situ current normalized PIGE method for grouping study of 39 clay potteries, obtained from Rajasthan and Andhra Pradesh states of India. Grouping of artifacts was carried out using the ratios of SiO2 to Al2O3 concentrations, due to their non volatile nature. Powder samples and elemental standards in pellet forms (cellulose matrix) were irradiated using the 4 MeV proton beam (∼10 nA) from the 3 MV tandem accelerator at IOP Bhubaneswar, and assay of prompt gamma rays was carried out using a 60% relative efficiency HPGe detector coupled to MCA. The concentration ratio values of SiO2/Al2O3 indicated that pottery samples fell into two major groups, which are in good agreement with their collection areas. Reference materials from IAEA and NIST were analyzed for quantification of Si, Al and Na concentrations as a part of validation as well as application of PIGE method.

  9. Simultaneous determination of Si, Al and Na concentrations by particle induced gamma-ray emission and applications to reference materials and ceramic archaeological artifacts

    Energy Technology Data Exchange (ETDEWEB)

    Dasari, K.B. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); GITAM Institute of Science, GITAM University, Visakhapatnam 530045 (India); Chhillar, S. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Acharya, R., E-mail: racharya@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Ray, D.K.; Behera, A. [Ion Beam Laboratory, Institute of Physics, Bhubaneswar 751005 (India); Lakshmana Das, N. [GITAM Institute of Science, GITAM University, Visakhapatnam 530045 (India); Pujari, P.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2014-11-15

    A particle induced gamma ray emission (PIGE) method using 4 MeV proton beam was standardized for simultaneous determination of Si, Al and Na concentrations and has been applied for non-destructive analysis of several reference materials and archaeological clay pottery samples. Current normalized count rates of gamma-rays for the three elements listed above were obtained by an in situ method using Li as internal standard. The paper presents application of the in situ current normalized PIGE method for grouping study of 39 clay potteries, obtained from Rajasthan and Andhra Pradesh states of India. Grouping of artifacts was carried out using the ratios of SiO{sub 2} to Al{sub 2}O{sub 3} concentrations, due to their non volatile nature. Powder samples and elemental standards in pellet forms (cellulose matrix) were irradiated using the 4 MeV proton beam (∼10 nA) from the 3 MV tandem accelerator at IOP Bhubaneswar, and assay of prompt gamma rays was carried out using a 60% relative efficiency HPGe detector coupled to MCA. The concentration ratio values of SiO{sub 2}/Al{sub 2}O{sub 3} indicated that pottery samples fell into two major groups, which are in good agreement with their collection areas. Reference materials from IAEA and NIST were analyzed for quantification of Si, Al and Na concentrations as a part of validation as well as application of PIGE method.

  10. Element Research.

    Science.gov (United States)

    Herald, Christine

    2001-01-01

    Describes a research assignment for 8th grade students on the elements of the periodic table. Students use web-based resources and a chemistry handbook to gather information, construct concept maps, and present the findings to the full class using the mode of their choice: a humorous story, a slideshow or gameboard, a brochure, a song, or skit.…

  11. Myositis in mixed connective tissue disease: a unique syndrome characterized by immunohistopathologic elements of both polymyositis and dermatomyositis Miosite na doença mista do tecido conectivo: achados imunopatológicos de polimiosite e dermatomiosite

    Directory of Open Access Journals (Sweden)

    Maria Angela A.G. Vianna

    2004-12-01

    Full Text Available OBJECTIVE: To characterize the inflammatory cells, the expression pattern of adhesion molecules (ICAM-1 and VCAM-1, membrane attack complex (C5b-9, and major histocompatibility complex (MHC antigens in muscle biopsy of mixed connective tissue disease (MCTD. METHOD: We studied 14 patients with MCTD, and compared to 8 polimyositis (PM patients, 5 dermatomyositis (DM and 4 dystrophies. Inflammatory cells were examined for CD4+, CD8+, memory and naïve T cells, natural killer cells, and macrophages. Expression of MHC-I and -II, ICAM-1, VCAM-1 and C5b -9 were characterized on muscle fibers and vessels. RESULTS: Morphological analysis displayed a pattern of PM. Immunohistochemical study revealed a decreased number of capillaries, predominance of CD4+ and B cells in perivascular regions and predominance of CD8+ and CD45RO+ in endomysial regions. The expression of MHC-I on vessels and on degenerated muscle fibers, MHC-II expression on vessels and perifascicular muscle fibers, and the expression of ICAM-1 / VCAM-1 on endothelial cells indicated both vascular and cellular-immune mediated processes causing the muscular lesion. CONCLUSION:Our findings revealed a mixed mechanism in MCTD, both vascular involvement as DM, and cell-mediated like PM.OBJETIVO: Caracterizar as células do infiltrado inflamatório, o padrão de expressão das moléculas de adesão (ICAM-1 e VCAM-1, complexo de ataque à membrana (C5b-9 e antígenos de histocompatibilidade maior (MHC em biópsias musculares de patientes com doença mista do tecido conectivo (DMTC. MÉTODO: Foram estudados14 pacientes com DMTC e comparadas com 8 pacientes com polimiosite (PM, 5 com dermatomiosite (DM e 4 com distrofias. As células inflamatórias foram caracterizadas como CD4+, CD8+, células T de memória (CD45RO+ e virgens, células "natural killer" e macrófagos. As expressões de MHC-I e -II, ICAM-1, VCAM-1 e C5b-9 foram caracterizadas em fibras musculares e vasos. RESULTADOS:A análise morfol

  12. 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.

  13. Comportamento de Cistus Ladanifer L. e Cistus Monspeliensis L. face aos elementos vestigiais em solos na área mineira do Chança Cistus Ladanifer L. and Cistus Monspeliensis L. behaviour in Chança mine soils contaminated with trace elements

    Directory of Open Access Journals (Sweden)

    Eliana Fernandes

    2011-07-01

    Full Text Available Comparou-se a acumulação e translocação de elementos vestigiais em duas espécies de plantas espontâneas na área mineira do Chança, Cistus ladanifer L. e Cistus monspeliensis L., e caracterizaram-se os solos da área da rizosfera. Os solos apresentaram diferenças no conteúdo em arsénio, cobre, crómio, manganês, vanádio e zinco e alguns elementos atingiram valores totais (mg kg-1 de: 151 (As; 320 (Cr; 926 (Cu; 1010 (Mn; 235 (V. As concentrações em crómio, manganês e vanádio são diferentes na raiz das duas espécies. Na parte aérea, apenas a concentração de manganês e de níquel é semelhante. As espécies mostraram comportamento acumulador relativamente ao manganês, com excepção do C. monspeliensis numa das zonas de amostragem. Para a maioria dos elementos vestigiais, o C. monspeliensis possui maior capacidade de translocação (raiz-parte aérea do que o C. ladanifer. Os coeficientes de translocação do crómio, manganês, níquel e zinco são superiores a 1,5 nas duas espécies.Trace elements accumulation and translocation in two spontaneous plants of genus Cistus, Cistus ladanifer L. and Cistus monspeliensis L., growing in the Chança mine area, were compared. Samples of plants and soils from rizosphere were collected and characterized. Soil samples showed different total content of arsenic, chromium, copper, manganese, vanadium and zinc, and some of the trace elements had the following total values (mg kg-1: 151 (As; 320 (Cr; 926 (Cu; 1010 (Mn; 235 (V. The concentrations of chromium, manganese and vanadium in roots were different between species. In the shoots, only manganese and nickel concentrations were similar. The two species were manganese accumulators, with C. mon-speliensis exception in one of the sampled areas. Cistus monspeliensis showed the largest translocation capacity of trace elements from roots to shoots. Both species presented the translocation coefficient of chromium, manganese, nickel and zinc

  14. Does Energy Consumption Volatility Affect Real GDP Volatility? An Empirical Analysis for the UK

    OpenAIRE

    Abdul Rashid; Ozge Kandemir Kocaaslan

    2013-01-01

    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...

  15. Sampling and major element chemistry of the recent (A.D. 1631-1944) Vesuvius activity

    Science.gov (United States)

    Belkin, H.E.; Kilburn, C.R.J.; de Vivo, B.

    1993-01-01

    Detailed sampling of the Vesuvius lavas erupted in the period A.D. 1631-1944 provides a suite of samples for comprehensive chemical analyses and related studies. Major elements (Si, Ti, Al, Fetotal, Mn, Mg, Ca, Na, K and P), volatile species (Cl, F, S, H2O+, H2O- and CO2), and ferrous iron (Fe2+) were determined for one hundred and forty-nine lavas and five tephra from the A.D. 1631-1944 Vesuvius activity. The lavas represent a relatively homogeneous suite with respect to SiO2, TiO2, FeOtotal, MnO and P2O5, but show systematic variations among MgO, K2O, Na2O, Al2O3 and CaO. The average SiO2 content is 48.0 wt.% and the rocks are classified as tephriphonolites according to their content of alkalis. All of the lavas are silica-undersaturated and are nepheline, leucite, and olivine normative. There is no systematic variation in major-element composition with time, over the period A.D. 1631-1944. The inter-eruption and intra-eruption compositional differences are the same magnitude. The lavas are highly porphyritic with clinopyroxene and leucite as the major phases. Fractionation effects are not reflected in the silica content of the lavas. The variability of MgO, K2O, Na2O, and CaO can be modelled as a relative depletion or accumulation of clinopyroxene. ?? 1993.

  16. Lunar In-Situ Volatile Extraction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A method of extracting volatile resources from the Lunar regolith is proposed to reduce the launch mass and cost of bringing such resources from the Earth to enable...

  17. Food commodity price volatility and food insecurity

    National Research Council Canada - National Science Library

    Alexander Sarris

    2013-01-01

      The paper first reviews several issues relevant to global food commodity market volatility as it pertains to food security, and food importing developing countries, and then discusses international...

  18. Volatility and the natural resource curse

    NARCIS (Netherlands)

    van der Ploeg, F.; Poelhekke, S.

    2009-01-01

    We provide cross-country evidence that rejects the traditional interpretation of the natural resource curse. First, growth depends negatively on volatility of unanticipated output growth independent of initial income, investment, human capital, trade openness, natural resource dependence, and popula

  19. 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.

  20. Volatile profile of wine Teran PTP

    Directory of Open Access Journals (Sweden)

    Helena BAŠA ČESNIK

    2015-11-01

    Full Text Available Teran PTP is a protected wine with a recognized traditional denomination produced from a grapevine variety ‘Refošk’ in winegrowing district Kras in Slovenia (European Union, 2009; Pravilnik, 2008. The aromatic profile of 82 Teran PTP wines produced in years 2011, 2012 and 2013 was monitored. Intotal the content of 16 volatile compounds was determined. The volatile compounds from wine were extracted following the liquid-liquid extraction and determined with a GC-MS method. The odour activity values and relative odour contributions were calculated for each volatile compound identified. Among sensorial important volatiles the highest odour activity values were determined for ethyl octanoate, ethyl hexanoate, isoamyl acetate and ethyl butyrate. Other research papers also showed, that all red wines investigated except one contained ethyl octanoate, ethyl hexanoate, isoamyl acetate and ethyl butyrate above sensory thresholds.

  1. STOCK MARKET VOLATILITY: DEVELOPED AND EMERGING MARKETS

    National Research Council Canada - National Science Library

    Mohammad Athar Noor; Mohd Asif Khan

    2012-01-01

      This paper examines the general patterns of recent global stock market returns and the volatility of such returns using 17 global stock indexes of countries classified into developed and emerging...

  2. 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

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

    African Journals Online (AJOL)

    kshale

    2013-05-15

    May 15, 2013 ... spectrometry. K. Shale1*, J. Mukamugema2, R. J. Lues1, P. Venter3 and K. K. Mokoena1 ..... Cajka T, Riddellova K, Tomaniova M, Hajslova J (2010). Recognition of ... volatile organic compounds of coniferous needle litter.

  4. Assessing relative volatility/intermittency/energy dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko S.; Schmiegel, Jürgen

    2014-01-01

    We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... process in particular. This estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, but it is also applicable in other areas. We develop a probabilistic asymptotic theory for realised relative power variations of Brownian semistationary processes......, and introduce inference methods based on the theory. We also discuss how to extend the asymptotic theory to other classes of processes exhibiting stochastic volatility/intermittency. As an empirical application, we study relative energy dissipation in data of atmospheric turbulence....

  5. Impact of Thermal Decomposition on Thermal Desorption Instruments: Advantage of Thermogram Analysis for Quantifying Volatility Distributions of Organic Species.

    Science.gov (United States)

    Stark, Harald; Yatavelli, Reddy L N; Thompson, Samantha L; Kang, Hyungu; Krechmer, Jordan E; Kimmel, Joel R; Palm, Brett B; Hu, Weiwei; Hayes, Patrick L; Day, Douglas A; Campuzano-Jost, Pedro; Canagaratna, Manjula R; Jayne, John T; Worsnop, Douglas R; Jimenez, Jose L

    2017-08-01

    We present results from a high-resolution chemical ionization time-of-flight mass spectrometer (HRToF-CIMS), operated with two different thermal desorption inlets, designed to characterize the gas and aerosol composition. Data from two field campaigns at forested sites are shown. Particle volatility distributions are estimated using three different methods: thermograms, elemental formulas, and measured partitioning. Thermogram-based results are consistent with those from an aerosol mass spectrometer (AMS) with a thermal denuder, implying that thermal desorption is reproducible across very different experimental setups. Estimated volatilities from the detected elemental formulas are much higher than from thermograms since many of the detected species are thermal decomposition products rather than actual SOA molecules. We show that up to 65% of citric acid decomposes substantially in the FIGAERO-CIMS, with ∼20% of its mass detected as gas-phase CO2, CO, and H2O. Once thermal decomposition effects on the detected formulas are taken into account, formula-derived volatilities can be reconciled with the thermogram method. The volatility distribution estimated from partitioning measurements is very narrow, likely due to signal-to-noise limits in the measurements. Our findings indicate that many commonly used thermal desorption methods might lead to inaccurate results when estimating volatilities from observed ion formulas found in SOA. The volatility distributions from the thermogram method are likely the closest to the real distributions.

  6. Dietary exposure to volatile and non-volatile N-nitrosamines from processed meat products in Denmark

    DEFF Research Database (Denmark)

    Herrmann, Susan Strange; Duedahl-Olesen, Lene; Christensen, Tue

    2015-01-01

    the carcinogenicity for the majority of the non-volatile NA (NVNA) remains to be elucidated. Danish adults (15–75 years) and children (4–6 years) consume 20 g and 16 g of processed meat per day (95th percentile), respectively. The consumption is primarily accounted for by sausages, salami, pork flank (spiced...... and boiled) and ham. This consumption results in an exposure to NVNA of 33 and 90 ng kg bw−1 day−1 for adults and children, respectively. The exposure to VNA is significantly lower amounting to 0.34 and 1.1 ng kg bw−1 day−1 for adults and children, respectively. Based on a BMDL10 of 29 µg kg bw−1 day−1 a MOE...

  7. 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...

  8. 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.

  9. 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...

  10. 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...

  11. Anticipating Long-Term Stock Market Volatility

    OpenAIRE

    Conrad, Christian; Loch, Karin

    2012-01-01

    We investigate the relationship between long-term U.S. stock market risks and the macroeconomic environment using a two component GARCH-MIDAS model. Our results provide strong evidence in favor of counter-cyclical behavior of long-term stock market volatility. Among the various macro variables in our dataset the term spread, housing starts, corporate profits and the unemployment rate have the highest predictive ability for stock market volatility . While the term spread and housing starts are...

  12. 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.

  13. Comparison of volatile and polyphenolic compounds in Brazilian green propolis and its botanical origin Baccharis dracunculifolia Comparação de volatilidade e compostos polifenólicos na própolis verde brasileira e sua origem botânica Baccharis dracunculifolia

    Directory of Open Access Journals (Sweden)

    Mário Roberto Maróstica Junior

    2008-03-01

    Full Text Available Ethanolic extracts and essential oils from Green Propolis from southeastern Brazil and leaf buds from its botanical origin Baccharis dracunculifolia were analyzed by Reversed Phase High Performance Liquid Chromatography (RP-HPLC, Reversed Phase High Performance Thin Layer Chromatography (RP-HPTLC and Gas Chromatography - Mass Spectrometry (GC-MS. The essential oils were obtained by hydro-distillation. Both ethanolic extracts and essential oils showed similar chromatographic profiles. Thirteen flavonoids were identified by RP-HPLC and RP-HPTLC analyses in both samples. Twenty-three volatile compounds were identified by GC-MS analyses. Seventeen were present in both essential oils. The major flavonoid compound in both extracts was artepillin C. The major volatile compound in both essential oils was nerolidol. The major compounds identified in this work could be used as chemical markers in order to classify and identify botanical origins of propolis.Extratos etanólicos e óleos essenciais de própolis verde do sudeste brasileiro e gemas de sua origem botânica (Baccharis dracunculifolia foram analisados por CLAE-FR (Cromatografia Líquida de Alta Eficiência em Fase Reversa, CCDAE (Cromatografia em Camada Delgada de Alta Eficiência e CG-EM (Cromatografia Gasosa acoplada a Espectrometria de Massas. Os óleos essenciais foram obtidos por hidro destilação. Extratos etanólicos e óleos essenciais de Baccharis dracunculifolia e de própolis mostraram perfis cromatográficos similares entre si. Treze flavonóides foram identificados por CLAE-FR e CCDAE em ambas as amostras. Vinte e três compostos voláteis foram identificados por CG EM, sendo dezessete deles presentes em ambos os óleos essenciais. Artepillin C foi o flavonóide encontrado em maiores concentrações em ambas as amostras, enquanto nerolidol foi o volátil majoritário em ambos os óleos essenciais. Os compostos majoritários identificados neste trabalho podem ser utilizados como

  14. 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.

  15. Market volatility modeling for short time window

    Science.gov (United States)

    de Mattos Neto, Paulo S. G.; Silva, David A.; Ferreira, Tiago A. E.; Cavalcanti, George D. C.

    2011-10-01

    The gain or loss of an investment can be defined by the movement of the market. This movement can be estimated by the difference between the magnitudes of two stock prices in distinct periods and this difference can be used to calculate the volatility of the markets. The volatility characterizes the sensitivity of a market change in the world economy. Traditionally, the probability density function (pdf) of the movement of the markets is analyzed by using power laws. The contributions of this work is two-fold: (i) an analysis of the volatility dynamic of the world market indexes is performed by using a two-year window time data. In this case, the experiments show that the pdf of the volatility is better fitted by exponential function than power laws, in all range of pdf; (ii) after that, we investigate a relationship between the volatility of the markets and the coefficient of the exponential function based on the Maxwell-Boltzmann ideal gas theory. The results show an inverse relationship between the volatility and the coefficient of the exponential function. This information can be used, for example, to predict the future behavior of the markets or to cluster the markets in order to analyze economic patterns.

  16. Effect of the partial replacement of sodium chloride by other salts on the formation of volatile compounds during ripening of dry-cured ham.

    Science.gov (United States)

    Armenteros, Mónica; Toldrá, Fidel; Aristoy, M-Concepción; Ventanas, Jesús; Estévez, Mario

    2012-08-01

    The effect of the partial NaCl replacement by other salts (potassium, calcium, and magnesium chloride) on the formation of volatile compounds through the processing of dry-cured ham was studied using solid-phase microextraction (SPME). Three salt formulations were considered, namely, I (100% NaCl), II (50% NaCl and 50% KCl), and III (55% NaCl, 25% KCl, 15% CaCl(2), and 5% MgCl(2)). There was an intense formation of volatile compounds throughout the processing of dry-cured hams, particularly during the "hot-cellar" stage. The differences between treatments were found to be more remarkable at the end of the curing process. Hams from formulations I and II had significantly higher amounts of lipid-derived volatiles such as hexanal than hams from formulation III, whereas the latter had significantly higher amounts of Strecker aldehydes and alcohols. Plausible mechanisms by which salt replacement may affect the generation of volatile compounds include the influence of such replacement on lipid oxidation and proteolysis phenomena. The potential influence of the volatiles profile on the aroma of the products is also addressed in the present paper.

  17. Composição química de alguns solos do estado de São Paulo: I - Elementos K, Na, Ca e Mg Chemical composition of some São Paulo soils: 1 - Elements K, Na, Ca and Mg

    Directory of Open Access Journals (Sweden)

    F. Da Costa Verdade

    1960-01-01

    Full Text Available O estudo dos elementos K, Na, Ca e Mg nos formas totais e trocáveis foi conduzido em solos derivados das rochas mais comumente encontrados no Estado de São Paulo. Os solos do Estado em geral são desprovidos de bases, como conseqüência de forte meteorismo atuando durante muito tempo. O potássio apresenta teor mais elevado quando a rocha se encontra a pequena profundidade, as suas porcentagens mais comuns variando entre 0 e 1 % de K2O. O sódio é muito removido e, com uma única exceção, não ultrapassa 0,1 % em Na2O. Para os elementos cálcio e magnésio não existe dependência de rocha superficial, como no caso do potássio, e seus teores variam em geral entre 0,2 a 0,8% para o CaO e 0,22 o 1,80% para o MgO. A comparação dos teores totais com os de grandes grupos citados no bibliografia indica semelhança com os latossolos e o vermelho-amorelo podzólico, que são encontrados neste Estado. O teor potencial (teor total menos o teor trocável segue, em linhas gerais, o total, havendo solos com pequeno ou nenhum teor potencial. O estudo do potencial entre as diversas camadas do perfil não mostra nenhuma diferença entre elas. A relação entre o potencial e o trocável nos elementos K, Na e Ca aumenta em profundidade, em virtude da presença de maior quantidade de trocável na superfície, mas existem muitas exceções. No caso do Mg encontrou-se um aumento do relação. A relação potencial/trocável permite prever quais as rochas que darão solos com teor potencial apreciável. Verifica-se que os solos derivados de tilitos, arenito Glacial, arenito de Bauru Inferior (Caiuá e diabase parecem não conter potencial em K; para o cálcio estariam nessas condições o anfibolito, algumas vêzes a diabase e o arenito de Bauru. No caso do Mg, todos os solos parecem contê-lo numa forma não trocável. O elemento sódio parece não existir em quantidades apreciáveis, na forma potencial. A relação do teor potencial ou teor trocável entre

  18. NA44 experiment

    CERN Document Server

    1990-01-01

    General view of NA44 experiment. NA44 is one of the seven experiments (NA44, NA45, NA49, NA50, NA52, WA97/NA57 and WA98) involved in CERN'S Heavy Ion programme which provided evidence for the existence of a new state of matter in which quarks, instead of being bound up into more complex particles such as protons and neutrons, are liberated and roam freely. Theory predicts that this state must have existed at about 10 microseconds after the Big Bang, before the formation of matter as we know it today.

  19. Toxicity of Volatile Methylated Species of Bismuth, Arsenic, Tin, and Mercury in Mammalian Cells In Vitro

    Directory of Open Access Journals (Sweden)

    E. Dopp

    2011-01-01

    Full Text Available The biochemical transformation of mercury, tin, arsenic and bismuth through formation of volatile alkylated species performs a fundamental role in determining the environmental processing of these elements. While the toxicity of inorganic forms of most of these compounds are well documented (e.g., arsenic, mercury and some of them are of relatively low toxicity (e.g., tin, bismuth, the more lipid-soluble organometals can be highly toxic. In the present study we investigated the cyto- and genotoxicity of five volatile metal(loid compounds: trimethylbismuth, dimethylarsenic iodide, trimethylarsine, tetramethyltin, and dimethylmercury. As far as we know, this is the first study investigating the toxicity of volatile metal(loid compounds in vitro. Our results showed that dimethylmercury was most toxic to all three used cell lines (CHO-9 cells, CaCo, Hep-G2 followed by dimethylarsenic iodide. Tetramethyltin was the least toxic compound; however, the toxicity was also dependend upon the cell type. Human colon cells (CaCo were most susceptible to the toxicity of the volatile compounds compared to the other cell lines. We conclude from our study that volatile metal(loid compounds can be toxic to mammalian cells already at very low concentrations but the toxicity depends upon the metal(loid species and the exposed cell type.

  20. Multifractal diffusion entropy analysis on stock volatility in financial markets

    Science.gov (United States)

    Huang, Jingjing; Shang, Pengjian; Zhao, Xiaojun

    2012-11-01

    This paper introduces a generalized diffusion entropy analysis method to analyze long-range correlation then applies this method to stock volatility series. The method uses the techniques of the diffusion process and Rényi entropy to focus on the scaling behaviors of regular volatility and extreme volatility respectively in developed and emerging markets. It successfully distinguishes their differences where regular volatility exhibits long-range persistence while extreme volatility reveals anti-persistence.

  1. Volcanic sanidinites: an example for the mobilization of high field strength elements (HFSE) in magmatic systems

    Science.gov (United States)

    Aßbichler, Donjá; Heuss-Aßbichler, Soraya; Müller, Dirk; Kunzmann, Thomas

    2016-04-01

    In earth science the mobility of high field strength elements (HFSE) is generally discussed in context of hydrothermal processes. Recent investigations mainly address processes in (late) magmatic-, metamorphic- and submarine hydrothermal systems. They have all in common that H2O is main solvent. The transport of HFSE is suggested to be favored by volatiles, like boron, fluorine, phosphate and sulfate (Jiang et al., 2005). In this study processes in magmatic system are investigated. Sanidinites are rare rocks of igneous origin and are found as volcanic ejecta of explosive volcanoes. They consist mainly of sanidine and minerals of the sodalite group. The very porous fabric of these rocks is an indication of their aggregation from a gaseous magmatic phase. The large sanidine crystals (up to several centimeters) are mostly interlocking, creating large cavities between some crystals. In these pores Zr crystallizes as oxide (baddeleyite, ZrO2) or silicate (zircon, ZrSiO4). The euhedral shape of these minerals is a further indication of their formation out of the gas phase. Furthermore, bubbles in glass observed in some samples are evidence for gas-rich reaction conditions during the formation of the sanidinites. The formation of sanidinites is suggested to be an example for solvothermal processes in natural systems. Solvothermal processes imply the solvation, transport and recrystallization of elements in a gas phase. Results obtained from whole rock analysis from sanidinites from Laacher See (Germany) show a positive correlation between LOI, sulfate, Cl, and Na with the HFSE like Zr. Na-rich conditions seem to ameliorate the solvothermal transport of Zr. All these features point to the formation of sanidinites in the upper part of a magma chamber, where fluid consisting of SO3 and Cl compounds in addition to H2O, CO2 and HFSE (high field strength elements) like Zr accumulate.

  2. 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.

  3. Effects of soy sauce and packaging method on volatile compounds and lipid oxidation of cooked irradiated beef patties

    Science.gov (United States)

    Kim, Hyun-Wook; Lee, Soo-Yeon; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Ham, Yun-Kyung; Lee, Choong-Hee; Choi, Yun-Sang; Lee, Ju-Woon; Kim, Cheon-Jei

    2014-10-01

    The objective of this study is to determine the effect of soy sauce on volatile compounds and lipid oxidation of cooked irradiated beef patties. Sulfur-containing volatile components, which are produced by irradiation, were not found in all treatments. Volatile components derived from soy sauce, such as 3-hydroxy-2-butanone, acetic acid, 3-methyl-1-butanol and 2-methyl-1-butanol, were detected in beef patties containing soy sauce regardless of irradiation and packaging method. Volatile aldehydes, including hexanal, significantly decreased the irradiated beef patty prepared with soy sauce compared to those of irradiated beef patty made with NaCl at 1 day and 5 days after irradiation. In addition, combined use of vacuum packaging and soy sauce treatments could inhibit the formation of volatile compounds and 2-thiobarbituric acid reactive substances during chilled storage. Therefore, the use of soy sauce in cooked and irradiated beef could reduce the production of volatile components associated with the irradiation-induced off-flavor and lipid oxidation.

  4. Volatile behavior and trace metal transport in the magmatic-geothermal system at Pūtauaki (Mt. Edgecumbe), New Zealand

    Science.gov (United States)

    Norling, B.; Rowe, M. C.; Chambefort, I.; Tepley, F. J.; Morrow, S.

    2016-05-01

    The present-day hydrothermal system beneath the Kawerau Geothermal Field, in the Taupo Volcanic Zone, New Zealand, is likely heated from the Pūtauaki (Mt. Edgecumbe) magma system. The aim of this work, as an analog for present day processes, is to identify whether or not earlier erupted Pūtauaki magmas show evidence for volatile exsolution. This may have led to the transfer of volatile components from the magmatic to hydrothermal systems. To accomplish this, minerals and melt inclusions from volcanic products were analyzed for abundances of volatile and ore-forming elements (S, Cl, Li, Cu, Sn, Mo, W, Sb, As, and Tl). The variations in abundance of these elements were used to assess magma evolution and volatile exsolution or fluxing in the magma system. Melt inclusions suggest the evolution of Pūtauaki andesite-dacite magmas is predominantly driven by crystallization processes resulting in rhyodacite-rhyolite glass compositions (although textural and geochemical evidence still indicate a role for magma mixing). Measured mineral-melt partition coefficients for trace metals of interest indicates that, with the exception of Tl in biotite, analyzed metals are all incompatible in Pūtauaki crystallization products. Excluding Li and Cu, other volatile and ore metals recorded in melt inclusions behave incompatibly, with concentrations increasing during evolution from rhyodacitic to rhyolitic melt compositions. Li and Cu appear to have increased mobility likely resulting from diffusive exchange post-crystallization, and may be related to late volatile fluxing. Although S and Cl concentrations decrease with melt evolution, no mineralogical evidence exists to indicate the exsolution and mobility of ore-forming metals from the magma at the time of crystallization. This observation cannot rule out the potential for post-crystallization volatile exsolution and ore-forming metal mobilization, which may only be recorded as diffusive re-equilibration of more rapidly diffusing

  5. The effect of phosphorus level in the sheep diet on the element uptake by the erythrocytes; Influencia dos niveis de fosforo na dieta de ovinos sobre a incorporacao do elemento pelos eritrocitos

    Energy Technology Data Exchange (ETDEWEB)

    Silva Filho, J.C. da; Vitti, D.M.S.S. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1995-12-31

    A trial with sheep was carried out to investigate the effect of the level of phosphorus in the diet on the {sup 32} P uptake by the red blood cells. Twenty four male sheep were kept in individual cages, during two periods of 45 days each. In the first one the animals received a basal diet without phosphorus supplementation. In the second period the animals were divided in four groups and different amounts of bone meal were offered to supply 1,2 and 3 gP/head/day. The control group received only the basal diet. An in vitro technique was used to incubate total blood and {sup 32} P solution as Na HP O{sub 4}. After 3 hours incubation, the red blood cells were washed thrice with an isotonic saline solution. The solid material was transferred to crucibles, dried at 100{sup 0} C and reduced to ash 500{sup 0} C. Diggestion with 6N H{sub 2} SO{sub 4} solution was followed and radioactivity was detected by Cherenkov effect. The average {sup 32}P uptake were: 6.04{+-} 0.40 and 6.56 {+-}- 1.94, 6.18{+-} 0.36 and 5.53 {+-} 1.06, 5.84 {+-} 0.48 and 6.31 {+-} 1.32, 6.0 {+-} 0.80 and 6.03 {+-} 1.50 at the first and second periods in treatments 0, 1, 2 and 3gP/head/day, respectively. There was no differences between treatments. (author). 22 refs, 1 tab.

  6. Characterization of volatile and non-volatile compounds of fresh pepper (Capsicum annuum)

    NARCIS (Netherlands)

    Eggink, P.M.; Haanstra, J.P.W.; Tikunov, Y.M.; Bovy, A.G.; Visser, R.G.F.

    2010-01-01

    In this study volatile and non-volatile compounds and several agronomical important parameters were measured in mature fruits of elite sweet pepper breeding lines and hybrids and several genebank accessions from different Capsicum species. The sweet pepper breeding lines and hybrids were chosen to

  7. Modelling the Volatility-Return Trade-off when Volatility may be Nonstationary

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; Iglesias, Emma M.

    In this paper a new GARCH-M type model, denoted the GARCH-AR, is proposed. In particular, it is shown that it is possible to generate a volatility-return trade-off in a regression model simply by introducing dynamics in the standardized disturbance process. Importantly, the volatility in the GARCH...

  8. Volatility Spillover and Multivariate Volatility Impulse Response Analysis of GFC News Events

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert); A.K. Singh (Abhay)

    2016-01-01

    textabstractThis paper applies two measures to assess spillovers across markets: the Diebold Yilmaz (2012) Spillover Index and the Hafner and Herwartz (2006) analysis of multivariate GARCH models using volatility impulse response analysis. We use two sets of data, daily realized volatility estimates

  9. Volatile dimethyl polonium produced by aerobic marine microorganisms.

    Science.gov (United States)

    Bahrou, Andrew S; Ollivier, Patrick R L; Hanson, Thomas E; Tessier, Emmanuel; Amouroux, David; Church, Thomas M

    2012-10-16

    The production of volatile polonium (Po(v)), a naturally occurring radioactive element, by pure cultures of aerobic marine tellurite-resistant microorganisms was investigated. Rhodotorula mucilaginosa, a carotogenic yeast, and a Bacillus sp. strain, a Gram-positive bacterium, generated approximately one and 2 orders of magnitude, respectively, greater amounts of Po(v) compared to the other organisms tested. Gas chromatography-inductively coupled plasma-mass spectrometry (GC-ICP-MS) analysis identified dimethyl polonide (DMPo) as the predominant volatile Po compound in culture headspace of the yeast. This species assignment is based on the exact relation between GC retention times and boiling points of this and other Group VI B analogues (S, Se, and Te). The extent of the biotic Po(v) production correlates exponentially with elevated particulate Po (Po(p)): dissolved Po (Po(aq)) ratios in the cultures, consistent with efficient Po bioaccumulation. Further experimentation demonstrated that some abiotic Po(v) generation is possible. However, high-level Po(v) generation in these cultures is predominantly biotic.

  10. Integrated photonics with programmable non-volatile memory

    Science.gov (United States)

    Song, Jun-Feng; Luo, Xian-Shu; Lim, Andy Eu-Jin; Li, Chao; Fang, Qing; Liow, Tsung-Yang; Jia, Lian-Xi; Tu, Xiao-Guang; Huang, Ying; Zhou, Hai-Feng; Lo, Guo-Qiang

    2016-03-01

    Silicon photonics integrated circuits (Si-PIC) with well-established active and passive building elements are progressing towards large-scale commercialization in optical communications and high speed optical interconnects applications. However, current Si-PICs do not have memory capabilities, in particular, the non-volatile memory functionality for energy efficient data storage. Here, we propose an electrically programmable, multi-level non-volatile photonics memory cell (PMC) fabricated by standard complementary-metal-oxide-semiconductor (CMOS) compatible processes. A micro-ring resonator (MRR) was built using the PMC to optically read the memory states. Switching energy smaller than 20 pJ was achieved. Additionally, a MRR memory array was employed to demonstrate a four-bit memory read capacity. Theoretically, this can be increased up to ~400 times using a 100 nm free spectral range broadband light source. The fundamental concept of this design provides a route to eliminate the von Neumann bottleneck. The energy-efficient optical storage can complement on-chip optical interconnects for neutral networking, memory input/output interfaces and other computational intensive applications.

  11. Hidden temporal order unveiled in stock market volatility variance

    Directory of Open Access Journals (Sweden)

    Y. Shapira

    2011-06-01

    Full Text Available When analyzed by standard statistical methods, the time series of the daily return of financial indices appear to behave as Markov random series with no apparent temporal order or memory. This empirical result seems to be counter intuitive since investor are influenced by both short and long term past market behaviors. Consequently much effort has been devoted to unveil hidden temporal order in the market dynamics. Here we show that temporal order is hidden in the series of the variance of the stocks volatility. First we show that the correlation between the variances of the daily returns and means of segments of these time series is very large and thus cannot be the output of random series, unless it has some temporal order in it. Next we show that while the temporal order does not show in the series of the daily return, rather in the variation of the corresponding volatility series. More specifically, we found that the behavior of the shuffled time series is equivalent to that of a random time series, while that of the original time series have large deviations from the expected random behavior, which is the result of temporal structure. We found the same generic behavior in 10 different stock markets from 7 different countries. We also present analysis of specially constructed sequences in order to better understand the origin of the observed temporal order in the market sequences. Each sequence was constructed from segments with equal number of elements taken from algebraic distributions of three different slopes.

  12. Tendências recentes nos elementos do clima e suas implicações na evapotranspiração da cultura do milho em Viçosa - MG Recent trends in the weather elements and its implications in the maize crop evapotranspiration in Viçosa-MG, Brazil

    Directory of Open Access Journals (Sweden)

    Leonidas P. de Alencar

    2011-01-01

    Full Text Available A mudança nas condições climáticas tem gerado grandes preocupações em nível mundial, sendo que uma das grandes questões, neste contexto, é o aquecimento global. As alterações ocorridas nas condições climáticas podem afetar a demanda de água das plantas, porque a evapotranspiração é afetada por mudanças nos elementos climáticos. O objetivo deste trabalho foi analisar os efeitos das possíveis mudanças dos elementos do clima na evapotranspiração de referência e na evapotranspiração da cultura do milho para a região de Viçosa - MG. Mediante análise de tendência pelo teste de Mann-Kendall e da estatística do teste t da regressão linear, verificou-se o comportamento dos seguintes elementos climáticos: temperaturas máxima e mínima, insolação, velocidade do vento e umidade relativa. Observou-se uma redução na evapotranspiração de referência e da cultura do milho ao longo dos últimos 41 anos, principalmente em razão da redução da insolação e da velocidade do vento. A evapotranspiração de referência apresentou redução da ordem de 4,2 mm por ano.The change in weather conditions has caused great concern in the world and the major issue, in this context, is the global warming. The changes in climate may affect the water demand of plants, because the evapotranspiration is affected by changes in climatic elements. The objective of this study was to examine the possible effects of climatological changes in evapotranspiration and reference evapotranspiration of corn in Viçosa - MG, Brazil. Trend analysis by the Mann-Kendall statistic and student t test of the linear regression were used to study the behavior of the following weather elements: maximum and minimum temperatures, sunshine duration, wind speed and relative humidity. It was observed a reduction in the reference evapotranspiration and maize crop evapotranspiration over the recent past 41 years, mainly because of reduced solar radiation and wind

  13. In situ extraction and analysis of volatiles and simple molecules in interplanetary dust particles, contaminants, and silica aerogel

    Science.gov (United States)

    Hartmetz, C. P.; Gibson, E. K., Jr.; Blanford, G. E.

    1990-01-01

    Results are presented for the analyses of eight interplanetary dust particles (IDPs) for the volatile elements H, C, N, O, and S and their molecular species, as well as of the volatiles associated with contaminants (i.e., the compounds used during the collection and curation of IDPs), which were carried out using a laser microprobe interfaced with a quadrupole mass spectrometer. It was found that the volatile species from contaminants were always present in the spectra of IDPs. Despite the contamination problems, several indigenous molecular species could be identified, including OH, CO2 or C2H4, C and CS2, CO2 along with CO (possibly indicating the presence of carbonate), H2S, SO, COS, SO2, and CS2. In some cases, the sulfur components can be attributed to aerosols; however, in one of the IDPs, the presence of H2S, SO, COS, and SO2 indicates the possible presence of elemental sulfur.

  14. Trace element geochemistry of CR chondrite metal

    CERN Document Server

    Jacquet, Emmanuel; Alard, Olivier; Kearsley, Anton T; Gounelle, Matthieu

    2015-01-01

    We report trace element analyses by laser ablation inductively coupled plasma mass spectrometry of metal grains from 9 different CR chondrites, distinguishing grains from chondrule interior ("interior grains"), chondrule surficial shells ("margin grains") and the matrix ("isolated grains"). Save for a few anomalous grains, Ni-normalized trace element patterns are similar for all three petrographical settings, with largely unfractionated refractory siderophile elements and depleted volatile Au, Cu, Ag, S. All types of grains are interpreted to derive from a common precursor approximated by the least melted, fine-grained objects in CR chondrites. This also excludes recondensation of metal vapor as the origin of the bulk of margin grains. The metal precursors presumably formed by incomplete condensation, with evidence for high-temperature isolation of refractory platinum-group-element (PGE)-rich condensates before mixing with lower temperature PGE-depleted condensates. The rounded shape of the Ni-rich, interior ...

  15. Volatile profile and physical, chemical, and biochemical changes in fresh cut watermelon during storage Perfil volátil e alterações físicas, químicas e bioquímicas na melancia minimamente processada durante o armazenamento

    Directory of Open Access Journals (Sweden)

    Andréa Luiza Ramos Pereira Xisto

    2012-03-01

    Full Text Available Existing data about the aroma of fresh-cut watermelon and the metabolic changes that occur with minimal processing are scarce. Given the close relationship that exists between aroma, texture, and quality characteristics, it is necessary to investigate the changes in the volatile profile and texture of watermelon, a fruit extensively sold in supermarket chains throughout Brazil. The objective of this work was to analyze the volatile profile using solid phase microextraction (SPME as well as texture changes in fresh-cut watermelon stored at 5 °C for ten days. Chromatography associated with sensory analysis (sniffing led us to conclude that 9-carbon (C9 alcohols and aldehydes are the major responsible for the flavor and aroma of minimally processed watermelon stored at 5 ± 1 °C/90 ± 5% RH for ten days, and also that the aroma diminishes in intensity with storage, but it does not affect the final quality of the product. It was noted that the amount of drained liquid, soluble pectin, and weight loss increased during storage concurrently with a reduction in firmness and a structural breakdown of the cells. Pectin methyl esterase activity remained constant and polygalacturonase activity was not detected.Existe pouca informação a respeito do aroma de melancia minimamente processada e das alterações metabólicas que ocorrem com o processamento mínimo. Sabendo-se que há estreita relação entre aroma característico, textura e qualidade torna-se necessário o conhecimento a respeito das alterações do perfil volátil e textura deste produto, que é intensamente comercializado nas redes de supermercados do Brasil. Diante disso, o objetivo deste trabalho foi analisar o perfil volátil utilizando a técnica de microextração em fase sólida (SPME e as modificações relacionadas à textura de melancia minimamente processada armazenada a 5 °C, por dez dias. A cromatografia associada com análise sensorial ('sniffing' permitiu concluir que os

  16. Combination of volatile and non-volatile functions in a single memory cell and its scalability

    Science.gov (United States)

    Kim, Hyungjin; Hwang, Sungmin; Lee, Jong-Ho; Park, Byung-Gook

    2017-04-01

    A single memory cell which combines volatile memory and non-volatile memory functions has been demonstrated with an independent asymmetric dual-gate structure. Owing to the second gate whose dielectric is composed of oxide/nitride/oxide layers, floating body effect was observed even on a fully depleted silicon-on-insulator device and the non-volatile memory function was measured. In addition, read retention characteristics of the volatile memory function depending on the non-volatile memory state were evaluated and analyzed. Further scalability in body thickness was also verified through simulation studies. These results indicate that the proposed device is a promising candidate for high-density embedded memory applications.

  17. Implicit Volatility versus Statistical Volatility: an Exercise Using Options and Telemar S.A. Stock

    Directory of Open Access Journals (Sweden)

    Marcelo Savino Portugal

    2004-06-01

    Full Text Available The main goal this article was to find the best way of making forecast about future volatility using implicit or statistic forecast. The work is based on Telemar S.A. shares data from 21/09/1998 to 21/10/2002 and Telemar S.A. shares data from 2/10/2000 to 21/10/2002. The implicit volatility was obtained using back-out procedure from the Black-Scholes model. The statistics forecasts were obtained using weighted moving average models, GARCH, EGARCH and FIGARCH models. The Wald statistic shows that EGARCH and FIGARCH models are efficient and are not biased forecasts for Telemar S.A. absolute variation between t and t + 1. The volatility evaluation during the maturity time of an option, rejects the hypothesis that implicit volatility is the best forecast to future volatility and the Wald statistic show that FIGARCH model is an efficient and not biased forecast.

  18. Diffusive fractionation of volatiles and their isotopes during bubble growth in magmas

    Science.gov (United States)

    Watson, E. Bruce

    2017-08-01

    Bubbles grow in decompressing magmas by simple expansion and by diffusive supply of volatiles to the bubble/melt interface. The latter phenomenon is of significant geochemical interest because diffusion can fractionate elements and isotopes (or isotopologues) of dissolved components. This raises the possibility that the character of volatile components in bubbles may not reflect that of volatiles dissolved in the host melt over the lifetime of a bubble—even in the absence of equilibrium vapor/melt isotopic fractionation. Recent experiments have confirmed the existence of an isotope mass effect on diffusion of the volatile element Cl in silicate melt [Fortin et al. (Isotopic fractionation of chlorine during chemical diffusion in a dacitic melt and its implications for isotope behavior during bubble growth (abstract), 2016 Fall AGU Meeting, 2016)], so there is a clear need to understand the efficacy of diffusive fractionation during bubble growth. In this study, numerical models of diffusion and mass redistribution during bubble growth were implemented for both "passive" volatiles—those whose concentrations are generally well below saturation levels—and "active" volatiles such as CO2 and H2O, whose elevated concentrations and limited solubilities are the cause of bubble nucleation and growth. Both diffusive and convective bubble-growth scenarios were explored. The magnitude of the isotope mass effect on passive volatiles partitioned into bubbles growing at a constant rate R in a static system depends upon R/ D L, K d and D H/ D L ( K d = bubble/melt partition coefficient; D H/ D L = diffusivity ratio of the heavy and light isotopes). During convective bubble growth, the presence of a discrete (physical) melt boundary layer against the growing bubble (of width x BL) simplifies outcomes because it leads to the quick onset of steady-state fractionation during growth, the magnitude of which depends mainly upon R•x BL/ D L and D H/ D L (bubble/melt fractionation

  19. Optimal directional volatile transport in retronasal olfaction

    Science.gov (United States)

    Ni, Rui; Michalski, Mark H.; Brown, Elliott; Doan, Ngoc; Zinter, Joseph; Ouellette, Nicholas T.; Shepherd, Gordon M.

    2015-01-01

    The ability of humans to distinguish the delicate differences in food flavors depends mostly on retronasal smell, in which food volatiles entrained into the airway at the back of the oral cavity are transported by exhaled air through the nasal cavity to stimulate the olfactory receptor neurons. Little is known whether food volatiles are preferentially carried by retronasal flow toward the nasal cavity rather than by orthonasal flow into the lung. To study the differences between retronasal and orthonasal flow, we obtained computed tomography (CT) images of the orthonasal airway from a healthy human subject, printed an experimental model using a 3D printer, and analyzed the flow field inside the airway. The results show that, during inhalation, the anatomical structure of the oropharynx creates an air curtain outside a virtual cavity connecting the oropharynx and the back of the mouth, which prevents food volatiles from being transported into the main stream toward the lung. In contrast, during exhalation, the flow preferentially sweeps through this virtual cavity and effectively enhances the entrainment of food volatiles into the main retronasal flow. This asymmetrical transport efficiency is also found to have a nonmonotonic Reynolds number dependence: The asymmetry peaks at a range of an intermediate Reynolds number close to 800, because the air curtain effect during inhalation becomes strongest in this range. This study provides the first experimental evidence, to our knowledge, for adaptations of the geometry of the human oropharynx for efficient transport of food volatiles toward the olfactory receptors in the nasal cavity. PMID:26553982

  20. A bacterial volatile signal for biofilm formation

    Directory of Open Access Journals (Sweden)

    Yun Chen

    2015-09-01

    Full Text Available Bacteria constantly monitor the environment they reside in and respond to potential changes in the environment through a variety of signal sensing and transduction mechanisms in a timely fashion. Those signaling mechanisms often involve application of small, diffusible chemical molecules. Volatiles are a group of small air-transmittable chemicals that are produced universally by all kingdoms of organisms. Past studies have shown that volatiles can function as cell-cell communication signals not only within species, but also cross-species. However, little is known about how the volatile-mediated signaling mechanism works. In our recent study (Chen, et al. mBio (2015, 6: e00392-15, we demonstrated that the soil bacterium Bacillus subtilis uses acetic acid as a volatile signal to coordinate the timing of biofilm formation within physically separated cells in the community. We also showed that the bacterium possesses an intertwined gene network to produce, secrete, sense, and respond to acetic acid, in stimulating biofilm formation. Interestingly, many of those genes are highly conserved in other bacterial species, raising the possibility that acetic acid may act as a volatile signal for cross-species communication.

  1. A bacterial volatile signal for biofilm formation

    Science.gov (United States)

    Chen, Yun; Gozzi, Kevin; Chai, Yunrong

    2015-01-01

    Bacteria constantly monitor the environment they reside in and respond to potential changes in the environment through a variety of signal sensing and transduction mechanisms in a timely fashion. Those signaling mechanisms often involve application of small, diffusible chemical molecules. Volatiles are a group of small air-transmittable chemicals that are produced universally by all kingdoms of organisms. Past studies have shown that volatiles can function as cell-cell communication signals not only within species, but also cross-species. However, little is known about how the volatile-mediated signaling mechanism works. In our recent study (Chen, et al. mBio (2015), 6: e00392-15), we demonstrated that the soil bacterium Bacillus subtilis uses acetic acid as a volatile signal to coordinate the timing of biofilm formation within physically separated cells in the community. We also showed that the bacterium possesses an intertwined gene network to produce, secrete, sense, and respond to acetic acid, in stimulating biofilm formation. Interestingly, many of those genes are highly conserved in other bacterial species, raising the possibility that acetic acid may act as a volatile signal for cross-species communication.

  2. Modeling and forecasting petroleum futures volatility

    Energy Technology Data Exchange (ETDEWEB)

    Sadorsky, Perry [York Univ., Schulich School of Business, Toronto, ON (Canada)

    2006-07-15

    Forecasts of oil price volatility are important inputs into macroeconometric models, financial market risk assessment calculations like value at risk, and option pricing formulas for futures contracts. This paper uses several different univariate and multivariate statistical models to estimate forecasts of daily volatility in petroleum futures price returns. The out-of-sample forecasts are evaluated using forecast accuracy tests and market timing tests. The TGARCH model fits well for heating oil and natural gas volatility and the GARCH model fits well for crude oil and unleaded gasoline volatility. Simple moving average models seem to fit well in some cases provided the correct order is chosen. Despite the increased complexity, models like state space, vector autoregression and bivariate GARCH do not perform as well as the single equation GARCH model. Most models out perform a random walk and there is evidence of market timing. Parametric and non-parametric value at risk measures are calculated and compared. Non-parametric models outperform the parametric models in terms of number of exceedences in backtests. These results are useful for anyone needing forecasts of petroleum futures volatility. (author)

  3. A conservative discontinuous target volatility strategy

    Directory of Open Access Journals (Sweden)

    Simone Cirelli

    2017-07-01

    Full Text Available The asset management sector is constantly looking for a reliable investment strategy, which is able to keep its promises. One of the most used approaches is the target volatility strategy that combines a risky asset with a risk-free trying to maintain the portfolio volatility constant over time. Several analyses highlight that such target is fulfilled on average, but in periods of crisis, the portfolio still suffers market’s turmoils. In this paper, the authors introduce an innovative target volatility strategy: the discontinuous target volatility. Such approach turns out to be more conservative in high volatility periods. Moreover, the authors compare the adoption of the VIX Index as a risk measure instead of the classical standard deviation and show whether the former is better than the latter. In the last section, the authors also extend the analysis to remove the risk-free assumption and to include the correlation structure between two risky assets. Empirical results on a wide time span show the capability of the new proposed strategy to enhance the portfolio performance in terms of standard measures and according to stochastic dominance theory.

  4. Optimal directional volatile transport in retronasal olfaction.

    Science.gov (United States)

    Ni, Rui; Michalski, Mark H; Brown, Elliott; Doan, Ngoc; Zinter, Joseph; Ouellette, Nicholas T; Shepherd, Gordon M

    2015-11-24

    The ability of humans to distinguish the delicate differences in food flavors depends mostly on retronasal smell, in which food volatiles entrained into the airway at the back of the oral cavity are transported by exhaled air through the nasal cavity to stimulate the olfactory receptor neurons. Little is known whether food volatiles are preferentially carried by retronasal flow toward the nasal cavity rather than by orthonasal flow into the lung. To study the differences between retronasal and orthonasal flow, we obtained computed tomography (CT) images of the orthonasal airway from a healthy human subject, printed an experimental model using a 3D printer, and analyzed the flow field inside the airway. The results show that, during inhalation, the anatomical structure of the oropharynx creates an air curtain outside a virtual cavity connecting the oropharynx and the back of the mouth, which prevents food volatiles from being transported into the main stream toward the lung. In contrast, during exhalation, the flow preferentially sweeps through this virtual cavity and effectively enhances the entrainment of food volatiles into the main retronasal flow. This asymmetrical transport efficiency is also found to have a nonmonotonic Reynolds number dependence: The asymmetry peaks at a range of an intermediate Reynolds number close to 800, because the air curtain effect during inhalation becomes strongest in this range. This study provides the first experimental evidence, to our knowledge, for adaptations of the geometry of the human oropharynx for efficient transport of food volatiles toward the olfactory receptors in the nasal cavity.

  5. Volatile profile of yellow passion fruit juice by static headspace and solid phase microextraction techniques

    Directory of Open Access Journals (Sweden)

    Gilberto Costa Braga

    2015-02-01

    Full Text Available The profile of volatile compounds of yellow passion fruit juice was analyzed by solid phase microextraction headspace (HS-SPME and optimized static headspace (S-HS extraction techniques. Time, temperature, NaCl concentration and sample volume headspace equilibrium parameters was adjusted to the S-HS technique. The gaseous phase in the headspace of samples was collected and injected into a gas chromatograph coupled to a mass spectrometer. In the HS-SPME technique was identified 44 volatile compounds from the yellow passion fruit juice, but with S-HS only 30 compounds were identified. Volatile esters were majority in both techniques, being identified ethyl butanoate, ethyl hexanoate, (3z-3-hexenyl acetate, hexyl acetate, hexyl butanoate and hexyl hexanoate. Aldehydes and ketones were not identified in S-HS, but were in HS-SPME. β-Pinene, p-cymene, limonene, (Z-β-ocimene, (E-β-ocimene, γ-terpinene, α-terpinolene and (E -4,8-dimethyl-1, 3,7 - nonatriene terpenes were identified in both techniques. This study showed that the S-HS optimized extraction technique was effective to recovery high concentrations of the major volatile characteristics compounds in the passion fruit, such as ethyl butanoate and ethyl hexanoate, which can be advantageous due to the simplicity of the method.

  6. DripFume: A Visual Basic Program For Simulating Distribution And Atmospheric Volatilization Of Soil Fumigants Applied Through Drip Irrigation

    Science.gov (United States)

    A Windows-based graphical user interface program (DripFume) was developed in MS Visual Basic (VB) to utilize a two-dimensional multi-phase finite element pesticide transport model to simulate distribution and emission of volatile fumigant chemicals when applied through drip irrigation or shank injec...

  7. 49 CFR 563.7 - Data elements.

    Science.gov (United States)

    2010-10-01

    ... other data N/A 1Pre-crash data and crash data are asynchronous. The sample time accuracy requirement for... passenger If recorded -1.0 sec N/A 1 Pre-crash data and crash data are asynchronous The sample time accuracy... 49 Transportation 6 2010-10-01 2010-10-01 false Data elements. 563.7 Section 563.7...

  8. Volatility jumps and their economic determinants

    DEFF Research Database (Denmark)

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

    that there is a positive probability of jumps in volatility. A common factor in the volatility jumps is shown to be related to a set of financial covariates (such as variance risk premium, S&P500 volume, credit-default swap, and federal fund rates). The credit-default swap on US banks and variance risk premium have...... predictive power on expected jump moves, thus confirming the common interpretation that sudden and large increases in equity volatility can be anticipated by credit deterioration of the US bank sector as well as changes in the market expectations of future risks. Finally, the model is extended to incorporate...... the credit-default swap and the variance risk premium in the dynamics of the jump size and intensity....

  9. 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...... features for representing the surface and its dynamics: a general dynamic factor model, restricted factor models designed to capture the key features of the surface along the moneyness and maturity dimensions, and in-between spline-based methods. Key findings are that: (i) the restricted and spline......-based models are both rejected against the general dynamic factor model, (ii) the factors driving the surface are highly persistent, (iii) for the restricted models option Delta is preferred over the more often used strike relative to spot price as measure for moneyness....

  10. The volatility of stock market prices.

    Science.gov (United States)

    Shiller, R J

    1987-01-02

    If the volatility of stock market prices is to be understood in terms of the efficient markets hypothesis, then there should be evidence that true investment value changes through time sufficiently to justify the price changes. Three indicators of change in true investment value of the aggregate stock market in the United States from 1871 to 1986 are considered: changes in dividends, in real interest rates, and in a direct measure of intertemporal marginal rates of substitution. Although there are some ambiguities in interpreting the evidence, dividend changes appear to contribute very little toward justifying the observed historical volatility of stock prices. The other indicators contribute some, but still most of the volatility of stock market prices appears unexplained.

  11. Volatile components and continental material of planets

    Science.gov (United States)

    Florenskiy, K. P.; Nikolayeva, O. V.

    1986-01-01

    It is shown that the continental material of the terrestrial planets varies in composition from planet to planet according to the abundances and composition of true volatiles (H20, CO2, etc.) in the outer shells of the planets. The formation of these shells occurs very early in a planet's evolution when the role of endogenous processes is indistinct and continental materials are subject to melting and vaporizing in the absence of an atmosphere. As a result, the chemical properties of continental materials are related not only to fractionation processes but also to meltability and volatility. For planets retaining a certain quantity of true volatile components, the chemical transformation of continental material is characterized by a close interaction between impact melting vaporization and endogeneous geological processes.

  12. Volatile species retention during metallic fuel casting

    Science.gov (United States)

    Fielding, Randall S.; Porter, Douglas L.

    2013-10-01

    Metallic nuclear fuels are candidate transmutation fuel forms for advanced fuel cycles. Through the operation of the Experimental Breeder Reactor II metallic nuclear fuels have been shown to be robust and easily manufactured. However, concerns have been raised concerning loss of americium during the casting process because of its high vapor pressure. In order to address these concerns a gaseous diffusion model was developed and a series of experiments using both manganese and samarium as surrogates for americium were conducted. The modeling results showed that volatility losses can be controlled to essentially no losses with a modest overpressure. Experimental results also showed volatile species retention down to no detectable losses through overpressure, and although the loss values varied from the model results the same trend was seen. Based on these results it is very probable that americium losses through volatility can be controlled to no detectable losses through application of a modest overpressure during casting.

  13. 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.

  14. Optimizing cyanobacteria growth conditions in a sealed environment to enable chemical inhibition tests with volatile chemicals.

    Science.gov (United States)

    Johnson, Tylor J; Zahler, Jacob D; Baldwin, Emily L; Zhou, Ruanbao; Gibbons, William R

    2016-07-01

    Cyanobacteria are currently being engineered to photosynthetically produce next-generation biofuels and high-value chemicals. Many of these chemicals are highly toxic to cyanobacteria, thus strains with increased tolerance need to be developed. The volatility of these chemicals may necessitate that experiments be conducted in a sealed environment to maintain chemical concentrations. Therefore, carbon sources such as NaHCO3 must be used for supporting cyanobacterial growth instead of CO2 sparging. The primary goal of this study was to determine the optimal initial concentration of NaHCO3 for use in growth trials, as well as if daily supplementation of NaHCO3 would allow for increased growth. The secondary goal was to determine the most accurate method to assess growth of Anabaena sp. PCC 7120 in a sealed environment with low biomass titers and small sample volumes. An initial concentration of 0.5g/L NaHCO3 was found to be optimal for cyanobacteria growth, and fed-batch additions of NaHCO3 marginally improved growth. A separate study determined that a sealed test tube environment is necessary to maintain stable titers of volatile chemicals in solution. This study also showed that a SYTO® 9 fluorescence-based assay for cell viability was superior for monitoring filamentous cyanobacterial growth compared to absorbance, chlorophyll α (chl a) content, and biomass content due to its accuracy, small sampling size (100μL), and high throughput capabilities. Therefore, in future chemical inhibition trials, it is recommended that 0.5g/L NaHCO3 is used as the carbon source, and that culture viability is monitored via the SYTO® 9 fluorescence-based assay that requires minimum sample size. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Changes in dark chocolate volatiles during storage.

    Science.gov (United States)

    Nightingale, Lia M; Cadwallader, Keith R; Engeseth, Nicki J

    2012-05-09

    Chocolate storage is critical to the quality of the final product. Inadequate storage, especially with temperature fluctuations, may lead to a change in crystal structure, which may eventually cause fat bloom. Bloom is the main cause of quality loss in the chocolate industry. The impact of various storage conditions on the flavor quality of dark chocolate was determined. Dark chocolate was stored in different conditions leading to either fat or sugar bloom and analyzed at 0, 4, and 8 weeks of storage. Changes in chocolate flavor were determined by volatile analysis and descriptive sensory evaluation. Results were analyzed by analysis of variance (ANOVA), cluster analysis, principal component analysis (PCA), and linear partial least-squares regression analysis (PLS). Volatile concentration and loss were significantly affected by storage conditions. Chocolates stored at high temperature were the most visually and texturally compromised, but volatile concentrations were affected the least, whereas samples stored at ambient, frozen, and high relative humidity conditions had significant volatile loss during storage. It was determined that high-temperature storage caused a change in crystal state due to the polymorphic shift to form VI, leading to an increase in sample hardness. Decreased solid fat content (SFC) during high-temperature storage increased instrumentally determined volatile retention, although no difference was detected in chocolate flavor during sensory analysis, possibly due to instrumental and sensory sampling techniques. When all instrumental and sensory data had been taken into account, the storage condition that had the least impact on texture, surface roughness, grain size, lipid polymorphism, fat bloom formation, volatile concentrations, and sensory attributes was storage at constant temperature and 75% relative humidity.

  16. Different methods for volatile sampling in mammals.

    Science.gov (United States)

    Kücklich, Marlen; Möller, Manfred; Marcillo, Andrea; Einspanier, Almuth; Weiß, Brigitte M; Birkemeyer, Claudia; Widdig, Anja

    2017-01-01

    Previous studies showed that olfactory cues are important for mammalian communication. However, many specific compounds that convey information between conspecifics are still unknown. To understand mechanisms and functions of olfactory cues, olfactory signals such as volatile compounds emitted from individuals need to be assessed. Sampling of animals with and without scent glands was typically conducted using cotton swabs rubbed over the skin or fur and analysed by gas chromatography-mass spectrometry (GC-MS). However, this method has various drawbacks, including a high level of contaminations. Thus, we adapted two methods of volatile sampling from other research fields and compared them to sampling with cotton swabs. To do so we assessed the body odor of common marmosets (Callithrix jacchus) using cotton swabs, thermal desorption (TD) tubes and, alternatively, a mobile GC-MS device containing a thermal desorption trap. Overall, TD tubes comprised most compounds (N = 113), with half of those compounds being volatile (N = 52). The mobile GC-MS captured the fewest compounds (N = 35), of which all were volatile. Cotton swabs contained an intermediate number of compounds (N = 55), but very few volatiles (N = 10). Almost all compounds found with the mobile GC-MS were also captured with TD tubes (94%). Hence, we recommend TD tubes for state of the art sampling of body odor of mammals or other vertebrates, particularly for field studies, as they can be easily transported, stored and analysed with high performance instruments in the lab. Nevertheless, cotton swabs capture compounds which still may contribute to the body odor, e.g. after bacterial fermentation, while profiles from mobile GC-MS include only the most abundant volatiles of the body odor.

  17. Different methods for volatile sampling in mammals

    Science.gov (United States)

    Möller, Manfred; Marcillo, Andrea; Einspanier, Almuth; Weiß, Brigitte M.

    2017-01-01

    Previous studies showed that olfactory cues are important for mammalian communication. However, many specific compounds that convey information between conspecifics are still unknown. To understand mechanisms and functions of olfactory cues, olfactory signals such as volatile compounds emitted from individuals need to be assessed. Sampling of animals with and without scent glands was typically conducted using cotton swabs rubbed over the skin or fur and analysed by gas chromatography-mass spectrometry (GC-MS). However, this method has various drawbacks, including a high level of contaminations. Thus, we adapted two methods of volatile sampling from other research fields and compared them to sampling with cotton swabs. To do so we assessed the body odor of common marmosets (Callithrix jacchus) using cotton swabs, thermal desorption (TD) tubes and, alternatively, a mobile GC-MS device containing a thermal desorption trap. Overall, TD tubes comprised most compounds (N = 113), with half of those compounds being volatile (N = 52). The mobile GC-MS captured the fewest compounds (N = 35), of which all were volatile. Cotton swabs contained an intermediate number of compounds (N = 55), but very few volatiles (N = 10). Almost all compounds found with the mobile GC-MS were also captured with TD tubes (94%). Hence, we recommend TD tubes for state of the art sampling of body odor of mammals or other vertebrates, particularly for field studies, as they can be easily transported, stored and analysed with high performance instruments in the lab. Nevertheless, cotton swabs capture compounds which still may contribute to the body odor, e.g. after bacterial fermentation, while profiles from mobile GC-MS include only the most abundant volatiles of the body odor. PMID:28841690

  18. Volatile compound formation during argan kernel roasting.

    Science.gov (United States)

    El Monfalouti, Hanae; Charrouf, Zoubida; Giordano, Manuela; Guillaume, Dominique; Kartah, Badreddine; Harhar, Hicham; Gharby, Saïd; Denhez, Clément; Zeppa, Giuseppe

    2013-01-01

    Virgin edible argan oil is prepared by cold-pressing argan kernels previously roasted at 110 degrees C for up to 25 minutes. The concentration of 40 volatile compounds in virgin edible argan oil was determined as a function of argan kernel roasting time. Most of the volatile compounds begin to be formed after 15 to 25 minutes of roasting. This suggests that a strictly controlled roasting time should allow the modulation of argan oil taste and thus satisfy different types of consumers. This could be of major importance considering the present booming use of edible argan oil.

  19. Local Volatility Calibration Using An Adjoint Proxy

    Directory of Open Access Journals (Sweden)

    Gabriel TURINICI

    2008-11-01

    Full Text Available We document the calibration of the local volatility in a framework similar to Coleman, Li and Verma. The quality of a surface is assessed through a functional to be optimized; the specificity of the approach is to separate the optimization (performed with any suitable optimization algorithm from the computation of the functional where we use an adjoint (as in L. Jiang et. al. to obtain an approximation; moreover our main calibration variable is the implied volatility (the procedure can also accommodate the Greeks. The procedure performs well on benchmarks from the literature and on FOREX data.

  20. Temperature-induced volatility of molecular markers in ambient airborne particulate matter

    Directory of Open Access Journals (Sweden)

    C. R. Ruehl

    2010-08-01

    Full Text Available Molecular markers are organic compounds used to represent known sources of particulate matter (PM in statistical source apportionment studies. The utility of molecular markers depends on, among other things, their ability to represent PM volatility under realistic atmospheric conditions. We measured the particle-phase concentrations and temperature-induced volatility of commonly-used molecular markers in California's heavily polluted San Joaqin Valley. Concentrations of elemental carbon, organic carbon, levoglucosan, and polycyclic aromatic hydrocarbons were not reduced by mild (~10 K heating. In contrast, both hopane/sterane and n-alkane concentrations were reduced, especially during the summer sampling events at the urban site. These results suggest that hopanes and steranes have effective saturation concentrations ~1 μg m−3, and therefore can be considered semi-volatile in realistic ambient conditions. The volatility behavior of n-alkanes during the urban summer is consistent with that predicted for absorption by suberic acid (a C8 diacid using a group contribution modelling method. Observations can also be matched by an absorbent whose composition is based on recently-obtained high-resolution aerosol mass spectrometer factors (approximately 33% "hydrocarbon-like" and 67% oxygenated organic aerosol. The diminished volatility of the n-alkanes, hopanes, and steranes during rural and/or winter experiments could be explained by a more oxygenated absorbing phase along with a non-absorptive partitioning mechanism, such as adsorption to soot. This suggests that the temperature-induced volatility of large hydrocarbons in PM is most important if a relatively non-polar absorbing organic phase exists. While the activity coefficients of most organic aerosol compounds may be close to unity, the assumption of ideality for large hydrocarbons (e.g., hopanes may result in large errors in partitioning calculations.

  1. Phase partitioning and volatility of secondary organic aerosol components formed from α-pinene ozonolysis and OH oxidation: the importance of accretion products and other low volatility compounds

    Directory of Open Access Journals (Sweden)

    F. D. Lopez-Hilfiker

    2015-02-01

    Full Text Available We measured a large suite of gas and particle phase multi-functional organic compounds with a Filter Inlet for Gases and AEROsols (FIGAERO coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS developed at the University of Washington. The instrument was deployed on environmental simulation chambers to study monoterpene oxidation as a secondary organic aerosol (SOA source. We focus here on results from experiments utilizing an ionization method most selective towards acids (acetate negative ion proton transfer, but our conclusions are based on more general physical and chemical properties of the SOA. Hundreds of compounds were observed in both gas and particle phases, the latter being detected upon temperature programmed thermal desorption of collected particles. Particulate organic compounds detected by the FIGAERO HR-ToF-CIMS are highly correlated with, and explain at least 25–50% of, the organic aerosol mass measured by an Aerodyne Aerosol Mass Spectrometer (AMS. Reproducible multi-modal structures in the thermograms for individual compounds of a given elemental composition reveal a significant SOA mass contribution from large molecular weight organics and/or oligomers (i.e. multi-phase accretion reaction products. Approximately 50% of the HR-ToF-CIMS particle phase mass is associated with compounds having effective vapor pressures 4 or more orders of magnitude lower than commonly measured monoterpene oxidation products. The relative importance of these accretion-type and other extremely low volatility products appears to vary with photochemical conditions. We present a desorption temperature based framework for apportionment of thermogram signals into volatility bins. The volatility-based apportionment greatly improves agreement between measured and modeled gas–particle partitioning for select major and minor components of the SOA, consistent with thermal decomposition during desorption causing

  2. Inelastic processes in Na+-Ne, Na+-Ar, Ne+-Na, and Ar+-Na collisions in the energy range 0.5-14 keV

    Science.gov (United States)

    Lomsadze, R. A.; Gochitashvili, M. R.; Kezerashvili, R. Ya.

    2015-12-01

    Absolute cross sections for charge-exchange, ionization, and excitation in Na+-Ne and Na+-Ar collisions were measured in the ion energy range 0.5 -10 keV using a refined version of a capacitor method and collision and optical spectroscopy methods simultaneously in the same experimental setup. Ionization cross sections for Ne+-Na and Ar+-Na collisions are measured at energies of 2 -14 keV using a crossed-beam spectroscopy method. The experimental data and the schematic correlation diagrams are used to analyze and determine the mechanisms for these processes. For the charge-exchange process in Na+-Ar collisions two nonadiabatic regions are revealed and mechanisms responsible for these regions are explained. Structural peculiarity on the excitation function for the resonance lines of argon atoms in Na+-Ar collisions are observed and the possible mechanisms of this phenomenon are explored. The measured ionization cross sections for Na+-Ne and Ne+-Na collisions in conjunction with the Landau-Zener formula are used to determine the coupling matrix element and transition probability in a region of pseudocrossing of the potential curves.

  3. Algal growth inhibition test in filled, closed bottles for volatile and sorptive materials

    DEFF Research Database (Denmark)

    Mayer, Philipp; Nyholm, Niels; Verbruggen, Eric M. J.;

    2000-01-01

    Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well as to the......Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well...... as to the test container. A simple filled closed bottle test with low algal densities and bicarbonate enrichment is described here as an approach to minimize the loss of test material from solution. The algal medium was enriched with 300 mg NaHCO3/L, the pH was adjusted to 7.0 by addition of HCl...

  4. Angelite: Paziteli na vhoda

    Directory of Open Access Journals (Sweden)

    Gerov Georgi

    2009-01-01

    Full Text Available (bugarski Statijata prosledjava ikonografskata evoljucija na izobraženijata na arhangelite Mihail i Gavriil, pomesteni pri vhoda na pravoslavnija hram. Povraten moment v neja e 13 vek. Togava arhangel Mihail započva da se izobrazjava kato voin. S tova apotropejnite mu funkcii namirat adekvaten vizualen izraz. K'm kraja na stoletieto arhangel Gavriil započva da se izobrazjava kato pisar - ikonografija, kojato šče b'de dorazvita i utv'rdena prez 14 vek. Prez postvizantijskata epoha v obraza na Mihail se pojavjavat elementi, koito akcentirat v'rhu roljata mu na psihopomp.

  5. Compositional Design of Dielectric, Ferroelectric and Piezoelectric Properties of (K, NaNbO3 and (Ba, Na(Ti, NbO3 Based Ceramics Prepared by Different Sintering Routes

    Directory of Open Access Journals (Sweden)

    José A. Eiras

    2016-03-01

    Full Text Available Lead free piezoelectric materials are being intensively investigated in order to substitute lead based ones, commonly used in many different applications. Among the most promising lead-free materials are those with modified NaNbO3, such as (K, NaNbO3 (KNN and (Ba, Na(Ti, NbO3 (BTNN families. From a ceramic processing point of view, high density single phase KNN and BTNN ceramics are very difficult to sinter due to the volatility of the alkaline elements, the narrow sintering temperature range and the anomalous grain growth. In this work, Spark Plasma Sintering (SPS and high-energy ball milling (HEBM, following heat treatments (calcining and sintering, in oxidative (O2 atmosphere have been used to prepare single phase highly densified KNN (“pure” and Cu2+ or Li1+ doped, with theoretical densities ρth > 97% and BTNN ceramics (ρth - 90%, respectively. Using BTTN ceramics with a P4mm perovskite-like structure, we showed that by increasing the NaNbO3 content, the ferroelectric properties change from having a relaxor effect to an almost “normal” ferroelectric character, while the tetragonality and grain size increase and the shear piezoelectric coefficients (k15, g15 and d15 improve. For KNN ceramics, the results reveal that the values for remanent polarization as well as for most of the coercive field are quite similar among all compositions. These facts evidenced that Cu2+ may be incorporated into the A and/or B sites of the perovskite structure, having both hardening and softening effects.

  6. Development and validation of automatic HS-SPME with a gas chromatography-ion trap/mass spectrometry method for analysis of volatiles in wines.

    Science.gov (United States)

    Paula Barros, Elisabete; Moreira, Nathalie; Elias Pereira, Giuliano; Leite, Selma Gomes Ferreira; Moraes Rezende, Claudia; Guedes de Pinho, Paula

    2012-11-15

    An automated headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-ion trap/mass spectrometry (GC-IT/MS) was developed in order to quantify a large number of volatile compounds in wines such as alcohols, ester, norisoprenoids and terpenes. The procedures were optimized for SPME fiber selection, pre-incubation temperature and time, extraction temperature and time, and salt addition. A central composite experimental design was used in the optimization of the extraction conditions. The volatile compounds showed optimal extraction using a DVB/CAR/PDMS fiber, incubation of 5 ml of wine with 2g NaCl at 45 °C during 5 min, and subsequent extraction of 30 min at the same temperature. The method allowed the identification of 64 volatile compounds. Afterwards, the method was validated successfully for the most significant compounds and was applied to study the volatile composition of different white wines.

  7. Forecasting Exchange Rate Volatility in the Presence of Jumps

    DEFF Research Database (Denmark)

    Busch, Thomas; Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    of exchange rate futures options, allowingcalculation of option implied volatility. We find that implied volatility is an informationallyefficient but biased forecast of future realized exchange rate volatility. Furthermore,we show that log-normality is an even better distributional approximation...... for impliedvolatility than for realized volatility in this market. Finally, we show that the jump componentof future realized exchange rate volatility is to some extent predictable, and thatoption implied volatility is the dominant forecast of the future jump component.......We study measures of foreign exchange rate volatility based on high-frequency (5-minute) $/DM exchange rate returns using recent nonparametric statistical techniquesto compute realized return volatility and its separate continuous sample path and jumpcomponents, and measures based on prices...

  8. Volatility of an Indian stock market A random matrix approach

    CERN Document Server

    Kulkarni, V

    2005-01-01

    We examine volatility of an Indian stock market in terms of aspects like participation, synchronization of stocks and quantification of volatility using the random matrix approach. Volatility pattern of the market is found using the BSE index for the three-year period 2000-2002. Random matrix analysis is carried out using daily returns of 70 stocks for several time windows of 85 days in 2001 to (i) do a brief comparative analysis with statistics of eigenvalues and eigenvectors of the matrix C of correlations between price fluctuations, in time regimes of different volatilities. While a bulk of eigenvalues falls within RMT bounds in all the time periods, we see that the largest (deviating) eigenvalue correlates well with the volatility of the index, the corresponding eigenvector clearly shows a shift in the distribution of its components from volatile to less volatile periods and verifies the qualitative association between participation and volatility (ii) observe that the Inverse participation ratio for the ...

  9. Volatile components from Anthriscus sylvestris (L.) Hoffm

    NARCIS (Netherlands)

    Bos, R.; Koulman, A; Woerdenbag, H.J.; Quax, Wim; Pras, N.

    2002-01-01

    The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC-MS. This was compared to dichloromethane extracts of both fresh and dried leaf and root material. The monoterpene fraction (69-70%) dominated, whil

  10. Volatile organic compound emissions from silage systems

    Science.gov (United States)

    As a precursor to smog, emission of volatile organic compounds (VOCs) to the atmosphere is an environmental concern in some regions. The major source from farms is silage, with emissions coming from the silo face, mixing wagon, and feed bunk. The major compounds emitted are alcohols with other impor...

  11. Volatile-mediated interactions in the rhizosphere

    NARCIS (Netherlands)

    Cordovez da Cunha, Viviane

    2016-01-01

    Plants and microorganisms are constantly engaged in highly dynamic interactions both above- and belowground. Several of these interactions are mediated by volatile organic compounds (VOCs), small carbon-based compounds with high vapor pressure at ambient temperature. In the rhizosphere, VOCs have an

  12. Linux Incident Response Volatile Data Analysis Framework

    Science.gov (United States)

    McFadden, Matthew

    2013-01-01

    Cyber incident response is an emphasized subject area in cybersecurity in information technology with increased need for the protection of data. Due to ongoing threats, cybersecurity imposes many challenges and requires new investigative response techniques. In this study a Linux Incident Response Framework is designed for collecting volatile data…

  13. The economic value of realized volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jacobs, Kris

    2014-01-01

    develop a new class of affine discrete-time option valuation models that use daily returns as well as realized volatility. We derive convenient closed-form option valuation formulas, and we assess the option valuation properties using Standard & Poor’s (S&P) 500 return and option data. We find...

  14. Permeation of volatile compounds through starch films

    NARCIS (Netherlands)

    Yilmaz, G.; Jongboom, R.O.J.; Feil, H.; Dijk, van C.; Hennink, W.E.

    2004-01-01

    The aim of this study was to gain insight into the factors that affect the permeation of volatiles through starch films. These films were obtained by casting gelatinized starch/water/glycerol mixtures. The films were dried and conditioned under different conditions (temperature and relative humidity

  15. Do Macroeconomic Announcements Cause Asymetric Volatility?

    NARCIS (Netherlands)

    P. de Goeij (Peter); W.A. Marquering (Wessel)

    2002-01-01

    textabstractIn this paper we study the impact of macroeconomic news announcements on the conditional volatility of stock and bond returns. Using daily returns on the S&P 500 index, the NASDAQ index, and the 1 and 10 year U.S. Treasury bonds, for January 1982 - August 2001, some interesting results e

  16. Volatility and conditional distribution in financial markets

    OpenAIRE

    Abberger, Klaus

    1995-01-01

    There are various parametric models to analyse the volatility in time series of financial market data. For maximum likelihood estimation these parametric methods require the assumption of a known conditional distribution. In this paper we examine the conditional distribution of daily DAX returns with the help of nonparametric methods. We use kernel estimators for conditional quantiles resulting from a kernel estimation of conditional distributions.

  17. There's more to volatility than volume

    CERN Document Server

    Gillemot, L; Lillo, F; Gillemot, Laszlo; Lillo, Fabrizio

    2005-01-01

    It is widely believed that fluctuations in transaction volume, as reflected in the number of transactions and to a lesser extent their size, are the main cause of clustered volatility. Under this view bursts of rapid or slow price diffusion reflect bursts of frequent or less frequent trading, which cause both clustered volatility and heavy tails in price returns. We investigate this hypothesis using tick by tick data from the New York and London Stock Exchanges and show that only a small fraction of volatility fluctuations are explained in this manner. Clustered volatility is still very strong even if price changes are recorded on intervals in which the total transaction volume or number of transactions is held constant. In addition the distribution of price returns conditioned on volume or transaction frequency being held constant is similar to that in real time, making it clear that neither of these are the principal cause of heavy tails in price returns. We analyze recent results of Ane and Geman (2000) an...

  18. Measuring volatility with the realized range

    NARCIS (Netherlands)

    M.P.E. Martens (Martin); D.J.C. van Dijk (Dick)

    2006-01-01

    textabstractRealized variance, being the summation of squared intra-day returns, has quickly gained popularity as a measure of daily volatility. Following Parkinson (1980) we replace each squared intra-day return by the high-low range for that period to create a novel and more efficient estimator

  19. Bayesian Vector Autoregressions with Stochastic Volatility

    NARCIS (Netherlands)

    Uhlig, H.F.H.V.S.

    1996-01-01

    This paper proposes a Bayesian approach to a vector autoregression with stochastic volatility, where the multiplicative evolution of the precision matrix is driven by a multivariate beta variate.Exact updating formulas are given to the nonlinear filtering of the precision matrix.Estimation of the au

  20. Volatile components from Anthriscus sylvestris (L.) Hoffm

    NARCIS (Netherlands)

    Bos, R.; Koulman, A; Woerdenbag, H.J.; Quax, Wim; Pras, N.

    2002-01-01

    The volatile components of fresh leaves and roots from Anthriscus sylvestris (L.) Hoffm., obtained through hydrodistillation, were analysed by GC and GC-MS. This was compared to dichloromethane extracts of both fresh and dried leaf and root material. The monoterpene fraction (69-70%) dominated, whil

  1. Recovery of volatile bioproducts by pervaporation

    Energy Technology Data Exchange (ETDEWEB)

    Boeddeker, K.W.

    1994-01-01

    Organophilic prevaporation is linkened to steam distillation in the recovery of volatile bioproducts of fermentation or plant origin. Potential applications are to biosynthetic chemicals (e.g., EtOH; BuOH), aroma compounds (e.g., gamma-decalactone; 6-pentyl-2-pyrone), and essential oils. Unlike steam distillation, pervaporation may be combined with an active fermenter. (orig.)

  2. Volatility Spillover Effects in European Equity Markets

    NARCIS (Netherlands)

    Baele, L.

    2003-01-01

    This paper quantifies the magnitude and time-varying nature of volatility spillovers from the aggregate European (EU) and US market to 13 local European equity markets.I develop a shock spillover model that decomposes local unexpected returns into a country speciffic shock, a regional European shock

  3. Volume, Volatility and Public News Announcements

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Jia; Xue, Yuan

    We provide new empirical evidence for the way in which financial markets process information. Our results are based on high-frequency intraday data along with new econometric techniques for making inference on the relationship between trading intensity and spot volatility around public news...

  4. Explaining output volatility: The case of taxation

    DEFF Research Database (Denmark)

    Posch, Olaf

    the second moment of output growth rates without (long-run) effects on the first moment. Taking the model to the data, we exploit observed heterogeneity patterns to estimate effects of tax rates on macro volatility using panel estimation, explicitly modeling the unobserved variance process. We find a strong...

  5. Acid volatile sulfide (AVS)- a comment

    NARCIS (Netherlands)

    Meysman, F.J.R.; Middelburg, J.J.

    2005-01-01

    The review by Rickard and Morse (this volume) adequately summarizes our current understanding with respect to acid-volatile sulfides (AVS). At the same time, this review addresses some of the misunderstandings with regard to measurements and dynamics of this important sedimentary sulfur pool. In

  6. Bayesian Vector Autoregressions with Stochastic Volatility

    NARCIS (Netherlands)

    Uhlig, H.F.H.V.S.

    1996-01-01

    This paper proposes a Bayesian approach to a vector autoregression with stochastic volatility, where the multiplicative evolution of the precision matrix is driven by a multivariate beta variate.Exact updating formulas are given to the nonlinear filtering of the precision matrix.Estimation of the

  7. Volatile terpenoids from aeciospores of Cronartium fusiforme.

    Science.gov (United States)

    Laseter, J. L.; Weete, J. D.; Walkinshaw, C. H.

    1973-01-01

    Identification of the terpenoids present in the volatile fraction from aeciospores of the gall rust fungus Cronartium fusiforme. The major monoterpenoid hydrocarbons found to be present with only traces of camphene include alpha-pinene, beta-pinene, delta(3)-carene, myrcene, linonene, beta-phellandrene, and delta-terpinene. A number of monoterpenoid alcohols, acyclic sesquiterpenes, and aromatic compounds were also present.

  8. Linux Incident Response Volatile Data Analysis Framework

    Science.gov (United States)

    McFadden, Matthew

    2013-01-01

    Cyber incident response is an emphasized subject area in cybersecurity in information technology with increased need for the protection of data. Due to ongoing threats, cybersecurity imposes many challenges and requires new investigative response techniques. In this study a Linux Incident Response Framework is designed for collecting volatile data…

  9. On multi-scaling in volatility processes

    NARCIS (Netherlands)

    Capobianco, E.

    2002-01-01

    Among the statistical features of financial volatility processes, the most challenging for statistical inference purposes are non-gaussianity and non-stationarity. In this study I present results from experiments aimed to empirically modeling return generating processes in which the underlying volat

  10. Elementos traço na água e em vísceras de peixes da Bacia Hidrográfica Butuí-Icamaquã, Rio Grande do Sul, Brasil Trace elements in water and viscera of fish from Butuí-Icamaquã Basin, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Santos Porto

    2009-12-01

    Full Text Available Metais pesados, também denominados elementos traço, podem ser essenciais ao metabolismo de organismos vivos, e, ao mesmo tempo, dependendo de suas concentrações, altamente tóxicos. Com o objetivo de investigar a toxicidade da água da Bacia dos Rios Butuí-Icamaquã, na fronteira oeste do Rio Grande do Sul, foram analisados, através de espectrofotômetro de absorção atômica, os teores de alumínio, cádmio, chumbo, cobre, cromo, manganês, níquel e zinco em vísceras abdominais de peixes, coletados, entre junho de 2007 e fevereiro de 2008, em pontos determinados nos rios Butuí, Icamaquã e Uruguai. Mostraram-se acima do nível considerado seguro para consumo humano: alumínio, cádmio, manganês e níquel e teores próximos aos limites legais foram encontrados para cobre e cromo. A análise simultânea de amostras da água coletadas nos mesmos locais acusou em espectrofotômetro de luz visível, níveis superiores aos limites legais de bromo, chumbo, cianeto, cobre, cromato, fenóis, fosfato, manganês e sulfeto. Estes elementos, em tais concentrações na água e nos peixes, podem comprometer o ecossistema ou representar riscos à saúde humana.Heavy metals, also called trace elements, may be essential to the metabolism of living organisms, and at the same time, depending on their concentrations, highly toxic. With the objective to investigate the toxicity of water of the Butuí-Icamaquã Rivers Basin on the border west of Rio Grande do Sul, were analyzed by atomic absorption spectrophotometer, the contents of aluminum, cadmium, chromium, copper, lead, manganese, nickel and zinc in abdominal viscera of fish, collected between June 2007 and February 2008, at selected points in Butuí, Icamaquã and Uruguai rivers. Aluminum, cadmium, manganese and nickel were above the levels considered safe for human consumption and levels near the legal limit were found for chrome and copper. The simultaneous analysis of water samples collected in

  11. Experience with CsI(Na) crystals for calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Aulchenko, V.M. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Baibusinov, B.O. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Baldin, E.M. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Bondar, A.E. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Gaidarev, P.B. [Cornell Univ., Ithaca, NY (United States); Kuzmin, A.S. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Leontiev, L.A. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Oreshkin, S.B. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Ovechkin, R.P. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Shwartz, B.A. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki

    1996-09-21

    The performance of cesium iodide doped with sodium is studied. The design and parameters of a CsI(Na) endcap calorimeter for the KEDR detector are presented. Also reported are the results of the study of a calorimeter element consisting of a CsI(Na) crystal coupled to a vacuum phototriode. (orig.).

  12. Geochemical diversity in first rocks examined by the Curiosity Rover in Gale Crater: Evidence for and significance of an alkali and volatile-rich igneous source

    Science.gov (United States)

    Schmidt, M. E.; Campbell, J. L.; Gellert, R.; Perrett, G. M.; Treiman, A. H.; Blaney, D. L.; Olilla, A.; Calef, F. J.; Edgar, L.; Elliott, B. E.; Grotzinger, J.; Hurowitz, J.; King, P. L.; Minitti, M. E.; Sautter, V.; Stack, K.; Berger, J. A.; Bridges, J. C.; Ehlmann, B. L.; Forni, O.; Leshin, L. A.; Lewis, K. W.; McLennan, S. M.; Ming, D. W.; Newsom, H.; Pradler, I.; Squyres, S. W.; Stolper, E. M.; Thompson, L.; VanBommel, S.; Wiens, R. C.

    2014-01-01

    first four rocks examined by the Mars Science Laboratory Alpha Particle X-ray Spectrometer indicate that Curiosity landed in a lithologically diverse region of Mars. These rocks, collectively dubbed the Bradbury assemblage, were studied along an eastward traverse (sols 46-102). Compositions range from Na- and Al-rich mugearite Jake_Matijevic to Fe-, Mg-, and Zn-rich alkali-rich basalt/hawaiite Bathurst_Inlet and span nearly the entire range in FeO* and MnO of the data sets from previous Martian missions and Martian meteorites. The Bradbury assemblage is also enriched in K and moderately volatile metals (Zn and Ge). These elements do not correlate with Cl or S, suggesting that they are associated with the rocks themselves and not with salt-rich coatings. Three out of the four Bradbury rocks plot along a line in elemental variation diagrams, suggesting mixing between Al-rich and Fe-rich components. ChemCam analyses give insight to their degree of chemical heterogeneity and grain size. Variations in trace elements detected by ChemCam suggest chemical weathering (Li) and concentration in mineral phases (e.g., Rb and Sr in feldspars). We interpret the Bradbury assemblage to be broadly volcanic and/or volcaniclastic, derived either from near the Gale crater rim and transported by the Peace Vallis fan network, or from a local volcanic source within Gale Crater. High Fe and Fe/Mn in Et_Then likely reflect secondary precipitation of Fe3+ oxides as a cement or rind. The K-rich signature of the Bradbury assemblage, if igneous in origin, may have formed by small degrees of partial melting of metasomatized mantle.

  13. The influence of operating loads on the state of stress and strain in selected load-bearing elements of a tower-type headgear structure / Wpływ obciążeń eksploatacyjnych na stan naprężenia oraz przemieszczenia wybranych elementów nośnych konstrukcji basztowej wieży szybowych

    Science.gov (United States)

    Wolny, Stanisław

    2012-12-01

    The headgear structure allows the conveyance to be moved over the shaft top to the loading (unloading) point, at the same time it keeps in place the rope pulleys while tower-type headgear structures also accommodate the entire winder installations. The headgear is where the final stage of the hoisting installation is located and where the surface transport systems begin. These aspects strongly impact the actual shape of the tower, its height and in some cases determine the design of the entire winding gear. In order that all the headgear functions should be provided, it is required that the ultimate state conditions should be maintained throughout its entire service life. In order to assess the critical service conditions, the computation procedure should be applied based on design loads and fatigue endurance parameters. The computations of characteristic loads acting on the headgear structure use the developed model of the system based on the dynamic analysis carried out for a specific case: a hoisting installation operated in one of the underground collieries in Poland. The maximal and minimal loads acting on a Koepe pulley and those required for the system operation are determined accordingly. The laws of dynamics provide a background for finding the forces and moments of forces acting in the components of the driving system (including the electric motors and pulley blocks) for the specified loading of the Koepe pulley. Underlying the numerical FEM model of the tower-type headgear structure are the technical specifications of the analysed object and FEM calculations followed by endurance analysis to find the state of stress in structural elements of the headgear under the typical service conditions. The results help in assessing how the design of the hoisting installation should impact on safety features of load-bearing elements in the headgear structure.

  14. Does implied volatility of currency futures option imply volatility of exchange rates?

    Science.gov (United States)

    Wang, Alan T.

    2007-02-01

    By investigating currency futures options, this paper provides an alternative economic implication for the result reported by Stein [Overreactions in the options market, Journal of Finance 44 (1989) 1011-1023] that long-maturity options tend to overreact to changes in the implied volatility of short-maturity options. When a GARCH process is assumed for exchange rates, a continuous-time relationship is developed. We provide evidence that implied volatilities may not be the simple average of future expected volatilities. By comparing the term-structure relationship of implied volatilities with the process of the underlying exchange rates, we find that long-maturity options are more consistent with the exchange rates process. In sum, short-maturity options overreact to the dynamics of underlying assets rather than long-maturity options overreacting to short-maturity options.

  15. THREE-POINT VOLATILITY SMILE CLASSIFICATION: EVIDENCE FROM THE WARSOW STOCK EXCHANGE DURING VOLATILE SUMMER 2011

    Directory of Open Access Journals (Sweden)

    García-Machado, Juan J.

    2015-01-01

    Full Text Available This paper studies the behavior of the smile in the Warsaw Stock Exchange (WSE during the volatile summer of 2011.We investigate the volatility smile derived from liquid call and put options on the Polish WIG20 index which option series expired on September 2011. In this period, the polish index has dropped about 20% in two weeks time. By linear interpolation, implied volatilities for moneyness points needed were calculated, then we construct 355 smile curves for calls and puts options to study and make some kind of smile-types classification. We propose seventeen types-smiles which represent all possible cases of three points (three moneynesses graphical patterns. This classification is made basing upon relationship higher/equal/lower values of implied volatility for each of three points. Furthermore, we distinguish the convexity of pattern. We can note that smiles, smirks and ups are convex in shape, while reversed ones and downs are concave functions.

  16. Implied volatility transmissions between Thai and selected advanced stock markets

    OpenAIRE

    Thakolsri, Supachok; Sethapramote, Yuthana; Jiranyakul, Komain

    2015-01-01

    This paper investigates the impacts of changes in the U. S. implied volatility on the changes in implied volatilities of the Euro and Thai stock markets. For that purpose, volatilities implicit in stock index option prices from the U. S., Euro and Thai stock markets are analyzed using the standard Granger causality test, impulse response analysis, and variance decompositions. The results found in this study suggest that the U. S. stock market is the leading source of volatility transmissions ...

  17. Forecasting Exchange Rate Volatility in the Presence of Jumps

    OpenAIRE

    Busch, Thomas; Christensen, Bent Jesper; Nielsen, Morten Ørregaard

    2005-01-01

    We study measures of foreign exchange rate volatility based on high-frequency (5-minute) $/DM exchange rate returns using recent nonparametric statistical techniques to compute realized return volatility and its separate continuous sample path and jump components, and measures based on prices of exchange rate futures options, allowing calculation of option implied volatility. We find that implied volatility is an informationally efficient but biased forecast of future realized exchange rate v...

  18. Volatile hydrocarbons inhibit methanogenic crude oil degradation

    Directory of Open Access Journals (Sweden)

    Angela eSherry

    2014-04-01

    Full Text Available Methanogenic degradation of crude oil in subsurface sediments occurs slowly, but without the need for exogenous electron acceptors, is sustained for long periods and has enormous economic and environmental consequences. Here we show that volatile hydrocarbons are inhibitory to methanogenic oil biodegradation by comparing degradation of an artificially weathered crude oil with volatile hydrocarbons removed, with the same oil that was not weathered. Volatile hydrocarbons (nC5-nC10, methylcyclohexane, benzene, toluene and xylenes were quantified in the headspace of microcosms. Aliphatic (n-alkanes nC12-nC34 and aromatic hydrocarbons (4-methylbiphenyl, 3-methylbiphenyl, 2-methylnaphthalene, 1-methylnaphthalene were quantified in the total hydrocarbon fraction extracted from the microcosms. 16S rRNA genes from key microorganisms known to play an important role in methanogenic alkane degradation (Smithella and Methanomicrobiales were quantified by quantitative PCR. Methane production from degradation of weathered oil in microcosms was rapid (1.1 ± 0.1 µmol CH4/g sediment/day with stoichiometric yields consistent with degradation of heavier n-alkanes (nC12-nC34. For non-weathered oil, degradation rates in microcosms were significantly lower (0.4 ± 0.3 µmol CH4/g sediment/day. This indicated that volatile hydrocarbons present in the non-weathered oil inhibit, but do not completely halt, methanogenic alkane biodegradation. These findings are significant with respect to rates of biodegradation of crude oils with abundant volatile hydrocarbons in anoxic, sulphate-depleted subsurface environments, such as contaminated marine sediments which have been entrained below the sulfate-reduction zone, as well as crude oil biodegradation in petroleum reservoirs and contaminated aquifers.

  19. Design and Analysis of SAW Based MEMS Gas Sensor for the Detection of Volatile Organic Gases

    Directory of Open Access Journals (Sweden)

    Staline Johnson

    2014-03-01

    Full Text Available This paper portrays the design and analysis of SAW based MEMS gas sensor for the detection of volatile organic gases. The gas sensor consists of interdigitated transducers modeled on a piezoelectric substrate and covered by a thin film of polyisobutylene (PIB which acts as the sensing layer. The piezoelectric substrate material used is YZ cut Lithium Niobate (LiNbO3 and electrodes used are made of Aluminium (Al. Mass loading effect on the sensing layer is used for the detection of volatile organic gases. The design and simultions were carried out by using comsol multiphysics software based on Finite Element Method (FEM for analytical simulations. The resonant frequency of the SAW device was determined and simulations are carried out by exposing the sensor to 100 ppm of various volatile organic gases and corresponding shift in resonant frequency for various gases are determined. The reduction in the resonant frequency is used for the detection of volatile organic gases such as chloromethane, dichloromethane, trichloromethane, tetrachloroethene, carbon tetrachloride and trichloroethylene.

  20. Age-related changes of elements in the anterior commissures and the relationships among their elements.

    Science.gov (United States)

    Ongkana, Nutcharin; Tohno, Setsuko; Tohno, Yoshiyuki; Suwannahoy, Patipath; Mahakkanukrauh, Pasuk; Azuma, Cho; Minami, Takeshi

    2010-06-01

    To elucidate compositional changes of the anterior commissure with aging, the authors investigated age-related changes of elements in the anterior commissures and the relationships among their elements. After ordinary dissection at Nara Medical University was finished, the anterior commissures were resected from 45 subjects, ranging in age from 70 to 101 years. The subjects consisted of 22 men and 23 women. After ashing with nitric acid and perchloric acid, the element content of the anterior commissures was determined by inductively coupled plasma-atomic emission spectrometry. The seven element contents of Ca, P, S, Mg, Zn, Fe, and Na did not change significantly in the anterior commissures with aging. Regarding the relationships among their element contents, significant correlations were found among the contents of Ca, Mg, Zn, and Na in the anterior commissures. The gender difference that the Zn content was significantly higher in men than in women was found in the anterior commissure.

  1. The Volatility Effect: Lower Risk without Lower Return

    NARCIS (Netherlands)

    D.C. Blitz (David); P. van Vliet (Pim)

    2007-01-01

    textabstractWe present empirical evidence that stocks with low volatility earn high risk-adjusted returns. The annual alpha spread of global low versus high volatility decile portfolios amounts to 12% over the 1986-2006 period. We also observe this volatility effect within the US, European and Japan

  2. 21 CFR 573.914 - Salts of volatile fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Salts of volatile fatty acids. 573.914 Section 573... Food Additive Listing § 573.914 Salts of volatile fatty acids. (a) Identity. The food additive is a... contains ammonium or calcium salts of volatile fatty acids and shall conform to the...

  3. Emerald ash borer responses to induced plant volatiles

    Science.gov (United States)

    Cesar Rodriguez-Saona; Therese M. Poland; James Miller; Lukasz Stelinski; Linda Buchan; Gary Grant; Peter de Groot; Linda MacDonald

    2007-01-01

    Herbivore feeding and methyl jasmonate, a volatile derivative of the stress-eliciting plant hormone, jasmonic acid, induce responses in plants which include the synthesis and emission of volatiles. These induced volatiles can serve to attract or repel herbivores; therefore, they may have potential use in pest management programs. The exotic emerald ash borer (EAB),...

  4. System of extraction of volatiles from soil using microwave processes

    Science.gov (United States)

    Ethridge, Edwin C. (Inventor); Kaukler, William F. (Inventor)

    2013-01-01

    A device for the extraction and collection of volatiles from soil or planetary regolith. The device utilizes core drilled holes to gain access to underlying volatiles below the surface. Microwave energy beamed into the holes penetrates through the soil or regolith to heat it, and thereby produces vapor by sublimation. The device confines and transports volatiles to a cold trap for collection.

  5. Another Look at the Volatility of Stock Prices

    Science.gov (United States)

    Maruszewski, Richard F., Jr.

    2007-01-01

    Investors are interested in the volatility of a stock for various reasons. One investor may desire to purchase a low volatility stock for peace of mind. Another may be interested in a high volatility stock in order to have the opportunity to buy low and sell high as the price of the stock oscillates. This author had the fortunate timing of reading…

  6. Factor Structure in Commodity Futures Return and Volatility

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Lunde, Asger; Olesen, Kasper Vinther

    Using data on more than 750 million futures trades during 2004-2013, we analyze eight stylized facts of commodity price and volatility dynamics in the post financialization period. We pay particular attention to the factor structure in returns and volatility and to commodity market integration...... volatility indicates a nontrivial degree of market integration....

  7. On the non-causal link between volatility and growth

    DEFF Research Database (Denmark)

    Posch, Olaf; Wälde, Klaus

    di er both in their volatility and growth. Using a continuous-time DSGE model with plausible parametric restrictions, we obtain closedform measures of macro volatility based on cyclical components and output growth rates. Given our results, empirical volatility-growth analysis should include controls...

  8. 40 CFR 53.66 - Test procedure: Volatility test.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test procedure: Volatility test. 53.66... Characteristics of Class II Equivalent Methods for PM2.5 § 53.66 Test procedure: Volatility test. (a) Overview. This test is designed to ensure that the candidate method's losses due to volatility when sampling...

  9. Volatility transmission and volatility impulse response functions in European electricity forward markets

    Energy Technology Data Exchange (ETDEWEB)

    Le Pen, Yannick [Institut d' Economie et de Management de Nantes - IAE, Universite de Nantes, Chemin de la Censive du Tertre, BP 52231, 44322 Nantes cedex 3 (France); Sevi, Benoit [Universite d' Angers (GRANEM), Faculte de Droit, Economie et Gestion, Universite d' Angers, 13 allee Francois Mitterrand, BP 13633, 49036 Angers cedex 01 (France)

    2010-07-15

    Using daily data from March 2001 to June 2005, we estimate a VAR-BEKK model and find evidence of return and volatility spillovers between the German, the Dutch and the British forward electricity markets. We apply Hafner and Herwartz [2006, Journal of International Money and Finance 25, 719-740] Volatility Impulse Response Function (VIRF) to quantify the impact of shock on expected conditional volatility. We observe that a shock has a high positive impact only if its size is large compared to the current level of volatility. The impact of shocks are usually not persistent, which may be a consequence of the non-storability of power. Finally, we estimate the density of the VIRF at different forecast horizons. These fitted distributions are asymmetric and show that large increases in expected conditional volatilities are possible even if their probability is low. These results have interesting implications for market participants whose risk management policy depends on option prices which themselves depend on the characteristics of volatility. (author)

  10. 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

  11. Highly Stretchable Non-volatile Nylon Thread Memory

    Science.gov (United States)

    Kang, Ting-Kuo

    2016-04-01

    Integration of electronic elements into textiles, to afford e-textiles, can provide an ideal platform for the development of lightweight, thin, flexible, and stretchable e-textiles. This approach will enable us to meet the demands of the rapidly growing market of wearable-electronics on arbitrary non-conventional substrates. However the actual integration of the e-textiles that undergo mechanical deformations during both assembly and daily wear or satisfy the requirements of the low-end applications, remains a challenge. Resistive memory elements can also be fabricated onto a nylon thread (NT) for e-textile applications. In this study, a simple dip-and-dry process using graphene-PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) ink is proposed for the fabrication of a highly stretchable non-volatile NT memory. The NT memory appears to have typical write-once-read-many-times characteristics. The results show that an ON/OFF ratio of approximately 103 is maintained for a retention time of 106 s. Furthermore, a highly stretchable strain and a long-term digital-storage capability of the ON-OFF-ON states are demonstrated in the NT memory. The actual integration of the knitted NT memories into textiles will enable new design possibilities for low-cost and large-area e-textile memory applications.

  12. Long Memory in Stock Market Volatility and the Volatility-in-Mean Effect: The FIEGARCH-M Model

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Nielsen, Morten Ørregaard; Zhu, Jie

    We extend the fractionally integrated exponential GARCH (FIEGARCH) model for daily stock return data with long memory in return volatility of Bollerslev and Mikkelsen (1996) by introducing a possible volatility-in-mean effect. To avoid that the long memory property of volatility carries over to r...

  13. Long Memory in Stock Market Volatility and the Volatility-in-Mean Effect: The FIEGARCH-M Model

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Nielsen, Morten Ørregaard; Zhu, Jie

    We extend the fractionally integrated exponential GARCH (FIEGARCH) model for daily stock return data with long memory in return volatility of Bollerslev and Mikkelsen (1996) by introducing a possible volatility-in-mean effect. To avoid that the long memory property of volatility carries over to r...

  14. Proteomic and metabolomic analyses provide insight into production of volatile and non-volatile flavor components in mandarin hybrid fruit

    Science.gov (United States)

    Although many of the volatile constituents of flavor and aroma in citrus have been identified, the molecular mechanism and regulation of volatile production is not well understood. Our aim was to understand mechanisms of flavor volatile production and regulation in mandarin fruit. To this end fruits...

  15. Study of volatile compounds induced in fat-containing media by various treatments: application to detection of radiation treatment; Etude de la fraction volatile d'une matrice alimentaire riche en lipides en fonction de divers traitements. Application a la detection du traitement ionisant

    Energy Technology Data Exchange (ETDEWEB)

    Lassoued Ben Miled, G.

    1998-07-01

    A methodology has been developed to study the volatile fractions of fat-containing media by a dynamic headspace system followed by a gas chromatography. This methodology has been applied to the volatile fractions of many food media to study the radiolysis mechanism of fat-containing products function of their physical state. A study on the volatile fraction induced by thermolysis of edible oils, has been realized. A comparative study of the thermal-induced and radio-induced hydrocarbons allowed to distinguish these two elements. A detection protocol of ionized food, quick, simple and economic has also been validated on yolk powder and dried fruits. (A.L.B.)

  16. An Experimental Investigation of Effects of Fluxes (Na3AlF6 and K2TiF6), Element Alloys (Mg), and Composite Powders ((Al + TiC)CP and (Al + B4C)CP) on Distribution of Particles and Phases in Al-B4C and Al-TiC Composites

    Science.gov (United States)

    Mazaheri, Younes; Emadi, Rahmatollah; Meratian, Mahmood; Zarchi, Mehdi Karimi

    2017-01-01

    The wettability, incorporation, and gravity segregation of TiC and B4C particles into molten aluminum are important problems in the production of Al-TiC and Al-B4C composites by the casting techniques. In order to solve these problems, different methods consisting of adding the Na3AlF6 and K2TiF6 fluxes and Mg (as the alloying element) into the molten aluminum and injection of the (Al + TiC)CP and (Al + B4C)CP composite powders instead of B4C and TiC particles are evaluated. In this work, the conditions of sample preparation, such as particle addition temperature, stirring speed, and stirring time, are determined after many studies and tests. Microstructural characterizations of samples are investigated by scanning electron microscopy equipped with energy dispersive spectroscopy (EDS) and X-ray diffractometry. The results show better distribution and incorporation of TiCp and B4Cp in aluminum matrix when the fluxes are used, as well as EDS analysis of the interface between the matrix and reinforcement-strengthened formation of the different phases such as Al4C3 in the Al-TiC composites and Al3BC, TiB2 in the Al-B4C composites.

  17. An Experimental Investigation of Effects of Fluxes (Na3AlF6 and K2TiF6), Element Alloys (Mg), and Composite Powders ((Al + TiC)CP and (Al + B4C)CP) on Distribution of Particles and Phases in Al-B4C and Al-TiC Composites

    Science.gov (United States)

    Mazaheri, Younes; Emadi, Rahmatollah; Meratian, Mahmood; Zarchi, Mehdi Karimi

    2017-04-01

    The wettability, incorporation, and gravity segregation of TiC and B4C particles into molten aluminum are important problems in the production of Al-TiC and Al-B4C composites by the casting techniques. In order to solve these problems, different methods consisting of adding the Na3AlF6 and K2TiF6 fluxes and Mg (as the alloying element) into the molten aluminum and injection of the (Al + TiC)CP and (Al + B4C)CP composite powders instead of B4C and TiC particles are evaluated. In this work, the conditions of sample preparation, such as particle addition temperature, stirring speed, and stirring time, are determined after many studies and tests. Microstructural characterizations of samples are investigated by scanning electron microscopy equipped with energy dispersive spectroscopy (EDS) and X-ray diffractometry. The results show better distribution and incorporation of TiCp and B4Cp in aluminum matrix when the fluxes are used, as well as EDS analysis of the interface between the matrix and reinforcement-strengthened formation of the different phases such as Al4C3 in the Al-TiC composites and Al3BC, TiB2 in the Al-B4C composites.

  18. [Influence of exogenous sulfur-containing compounds on the exchange fluxes of volatile organic sulfur compounds].

    Science.gov (United States)

    Yi, Zhi-Gang; Wang, Xin-Ming

    2011-08-01

    The influences of cysteine, sodium sulfide (Na2S) and sodium sulfate (Na2SO4) on the soil-air exchange fluxes of volatile organic sulfur compounds (VOSCs), including carbonyl sulfide (COS), dimethyl sulfide (DMS), carbon disulfide (CS2) and dimethyl disulfide (DMDS), were studied employing static chamber enclosure followed by laboratory determination using an Entech 7100 preconcentrator coupled with an Agilent 5973 GC-MSD. The results showed that after the addition of cysteine, the soil for the exchange fluxes of COS and CS2 shifted to be the source from sink and the emissions of DMS and DMDS increased significant. The emission amount of DMS and CS2 accounted for 89.2% to the total VOSCs after the addition of cysteine, implying that cysteine is an important precursor for DMS and CS2 in the soil. The amount of DMDS accounted for 93.2% to the total sulfur from the soil after addition of Na2S, indicating that Na2S is a key precursor for DMDS. No significant difference of VOSCs fluxes was found between the controlled soil and the soil with addition of Na2SO4, suggesting Na2SO4 was not the direct precursor for VOSCs in soil. VOSCs exchange rates reached the maximum at 6 to 8 days after addition of cysteine. As for addition of Na2S, the maximal emission rates of different VOSCs appeared at different dates, and the dates differed significantly from those after addition of cysteine, implying that the formation process of VOSCs from the soil with addition of Na2S was more complex and different from the soil with addition of cysteine.

  19. Visualization of electrolyte volatile phenomenon in DIR-MCFC

    Science.gov (United States)

    Sugiura, Kimihiko; Yodo, Tadakatsu; Yamauchi, Makoto; Tanimoto, Kazumi

    Volatilization of molten salt is one of the factors that control the performance of molten carbonate fuel cells (MCFC). Volatilization of molten salt promotes cross-leakage and the corrosion of metallic components. Moreover, piping blockage is caused by the solidification of volatile matter. Because reforming catalysts filling the anode channel are polluted by molten salt volatile matter in direct internal reforming molten carbonate fuel cells (DIR-MCFC), the volatilization of molten salt is an especially serious subject. However, neither the behaviour nor the volatilization volume of molten salt volatile matter has heretofore been elucidated on. Because molten salt volatile matter that has strong alkalinity cannot be supplied directly to an analyzer, its volatilization volume is small, and analytical accuracy is poor. Therefore, an attempt has been made to elucidate about the electrolyte volatile phenomenon in an MCFC by using a non-contact image measurement technique. A 16 cm 2 MCFC single cell frame has an observation window and an irradiation window. The image of the volatile phenomenon is shown by irradiating a YAG laser light sheet 2 mm thick from an irradiation window into the anode channel, and taking measurements from an observation window with a high spatial resolution video camera (12 bit). As a result, though the volatile matter is not observed in an anode channel at OCV, the volatile matter flows in a belt-like manner from the inlet side near the electrode toward the outlet at a current density of 150 mA cm -2. In addition, volatile matter is difficult to observe with the conventional thickness of an anode electrode. Because the composition of these volatile matters is 15Li 2CO 3/85K 2CO 3 (the result of conversion into molten salt) by ion chromatography analysis, it is not an electrolyte (62Li 2CO 3/38K 2CO 3) but rather the volatile matter of potassium, such as KOH. Therefore, it is understood that the volatile matter K 2CO 3 is generated as KOH

  20. Estudo sobre os elementos de uma interpretação invasiva na abordagem psicanalítica winnicottiana Estudio sobre los elementos de una interpretación invasiva en el abordaje psicoanalítico winnicottiano Study on the elements of an invasive interpretation in the Winnicott psychoanalytical approach

    Directory of Open Access Journals (Sweden)

    Conceição Aparecida Serralha

    2012-04-01

    Full Text Available Partindo dos textos freudianos, este estudo reapresenta brevemente a técnica da interpretação em psicanálise e, baseando-se na obra de Winnicott, discute os elementos de uma interpretação sentida de forma invasiva pelo analisando. São identificados, nomeados e discutidos os elementos apontados por este autor: tempo, modo, graus de confiabilidade, objetividade e conhecimento, sendo ilustrados por alguns fragmentos de sessão de casos de Winnicott e de um caso da autora. O estudo evidencia a importância da capacidade de o analista se identificar com o analisando para interpretar, recebendo e entendendo a comunicação deste sobre a adequação de todos esses elementos ao seu caso.Partiendo de los textos freudianos, este estudio reapresenta brevemente la técnica de la interpretación en psicoanálisis y, basándose en la obra de Winnicott, discute los elementos de una interpretación sentida de forma invasiva por el analizando. Son identificados, nombrados y discutidos los elementos apuntados por este autor: tiempo, modo, grados de confiabilidad, objetividad y conocimiento, siendo ilustrados por algunos fragmentos de sesión de casos de Winnicott y de un caso de lo autor. El estudio evidencia la importancia de la capacidad de el analista identificarse con el analizando para interpretar, recibiendo y entendiendo la comunicación de este sobre la adecuación de todos esos elementos a su caso.From the Freudian texts, this study reintroduces briefly the technique of interpretation in psychoanalysis and, based on the Winnicott's works, discusses the elements of an interpretation felt invasive by the patient. The elements pointed out by this author and identified, named and discussed include: time, manner, degrees of trustworthiness, objectiveness and knowledge. They are illustrated with fragments of session of Winnicott's cases and one case of the author. The study highlights the importance of the analyst's capacity of identifying him

  1. Size distributions and sources of elements in particulate matter at curbside,urban and rural sites in Beijing

    Institute of Scientific and Technical Information of China (English)

    Jingchun Duan; Jihua Tan; Shulan Wang; Jimin Hao; Fahe Chai

    2012-01-01

    Size distributions of 29 elements in aerosols collected at urban,rural and curbside sites in Beijing were studied.High levels of Mn,Ni,As,Cd and Pb indicate the pollution of toxic heavy metals cannot be neglected in Beijing.Principal component analysis (PCA)indicates 4 sources of combustion emission,crust related sources,traffic related sources and volatile species from coal combustion.The elements can be roughly divided into 3 groups by size distribution and enrichment factors method (EFs).Group 1 elements are crust related and mainly found within coarse mode including Al,Mg,Ca,Sc,Ti,Fe,Sr,Zr and Ba; Group 2 elements are fossil fuel related and mostly concentrated in accumulation mode including S,As,Se,Ag,Cd,T1 and Pb; Group 3 elements are multi-source related and show multi-mode distribution including Be,Na,K,Cr,Mn,Co,Ni,Cu,Zn,Ga,Mo,Sn and Sb.The EFs of Be,S,Cr,Co,Ni,Cu,Ga,Se,Mo,Ag,Cd,Sb,T1 and Pb show higher values in winter than in summer indicating sources of coal combustion for heating in winter.The abundance of Cu and Sb in coarse mode is about 2-6 times higher at curbside site than at urban site indicating their traffic sources.Coal burning may be the major source of Pb in Beijing since the phase out of leaded gasoline,as the EFs of Pb are comparable at both urban and curbside sites,and about two times higher in winter than that in summer.

  2. Elemental mercury poisoning in a family of seven.

    Science.gov (United States)

    Cherry, Debra; Lowry, Larry; Velez, Larissa; Cotrell, Cindy; Keyes, D Christopher

    2002-01-01

    Mercury poisoning in children is rare but may have devastating health consequences when exposure is unrecognized. Mercury occurs in three forms: elemental, inorganic, and organic. Elemental mercury (Hg(0)) vapor may become volatile following an accidental spill and may be readily absorbed from the lungs. The following case study describes how the poison center, health department, physicians, and others worked together to treat a family with long-term exposure to elemental mercury vapor in the home. Identification and prevention of this type of exposure in the community are discussed.

  3. The fate of volatiles in mid-ocean ridge magmatism

    CERN Document Server

    Keller, Tobias; Hirschmann, Marc M

    2016-01-01

    Deep-Earth volatile cycles couple the mantle with near-surface reservoirs. Volatiles are emitted by volcanism and, in particular, from mid-ocean ridges, which are the most prolific source of basaltic volcanism. Estimates of volatile extraction from the asthenosphere beneath ridges typically rely on measurements of undegassed lavas combined with simple petrogenetic models of the mean degree of melting. Estimated volatile fluxes have large uncertainties; this is partly due to a poor understanding of how volatiles are transported by magma in the asthenosphere. Here, we assess the fate of mantle volatiles through numerical simulations of melting and melt transport at mid-ocean ridges. Our simulations are based on two-phase, magma/mantle dynamics theory coupled to an idealised thermodynamic model of mantle melting in the presence of water and carbon dioxide. We combine simulation results with catalogued observations of all ridge segments to estimate a range of likely volatile output from the global mid-ocean ridge...

  4. Aspects of volatility targeting for South African equity investors

    Directory of Open Access Journals (Sweden)

    Bhekinkosi Khuzwayo

    2014-11-01

    Full Text Available We consider so-called volatility targeting strategies in the South African equity market. These strategies are aimed at keeping the volatility of a portfolio consisting of a risky asset, typically an equity index, and cash fixed. This is done by changing the allocation of the assets based on an indicator of the future volatility of the risky asset. We use the three month rolling implied volatility as an indicator of future volatility to influence our asset allocation. We compare investments based on different volatility targets to the performance of bonds, equities, property as well as the Absolute Return peer mean. We examine risk and return characteristics of the volatility targeting strategy as compared to different asset classes.

  5. A Utilização do Rejeito Industrial Cerâmico - Chamote - como Fator de Qualidade na Fabricação de Elementos Cerâmicos: um Estudo Experimental The Use of Industrial Ceramic Waste - Brick Powder - to Improve Product Quality in Ceramic Elements Manufacture: an Experimental Study

    Directory of Open Access Journals (Sweden)

    Francisco Ripoli Filho

    1997-08-01

    Full Text Available Este trabalho descreve pesquisa desenvolvida sobre a fabricação de elementos cerâmicos, através da utilização de chamote adicionado à argila. Chamote pode ser definido como um subproduto proveniente de rejeitos de material cerâmico. O experimento envolveu a utilização de sete tipos de amostras obtidas em olaria próxima à UFSM, as quais serviram para estudar as seguintes variáveis: teor de umidade de moldagem, proporção das misturas, argila-base e temperatura de queima. As principais características físicas e mecânicas observadas foram: retração linear de queima, absorção de água, porosidade, massa específica aparente e sucção inicial. A partir dessas observações chegou-se às seguintes conclusões: a possibilidade de utilizar o chamote homogeneizado na fabricação de elementos cerâmicos, desde que em proporção ideal e queimado a temperatura adequada; b as tensões de ruptura e absorção de água obtidas estão de acordo com aquelas previstas pelas normas brasileiras; c a adição de chamote à argila contribui potencialmente para o controle da retração. Por fim, verifica-se que a adição de chamote à argila permite o aproveitamento desse tipo de resíduo na fabricação de produtos de boa qualidade e contribui para reduzir a poluição ambiental.This work describes a reseach carried out on the manufacture of ceramic elements through the addition of brick powder to clay. Brick powder can the defined as a waste resulted from processing of ceramic materials. That experiment was developed using seven different clay samples from pottery located in the surroundings of UFSM. This material was used to study the following variables: basic clay, proportion of each component of the mixture, moisture drift to the moulding and burning temperature. The main physical and mechanical characteristics observed were: drying linear retraction, rupture tension, fire damage, burning linear contraction, water absorption, porosity

  6. Volatile compounds of commercial Milano salami.

    Science.gov (United States)

    Meynier, A; Novelli, E; Chizzolini, R; Zanardi, E; Gandemer, G

    1999-02-01

    The relationship between extracted volatiles of Milano salami, one of the main dry-cured sausages produced in Italy, and their olfactory properties was studied. Volatile compounds were extracted by a purge-and-trap method, quantified using a flame ionisation detector and identified by mass spectrometry. Olfactory analysis was performed by sniffing the gas chromatographic effluent. Nearly 80 compounds were identified and quantified: most came from spices (60.5%), 18.9% from lipid oxidation, 11.8% from amino acid catabolism and 4.9% from fermentation processes. Panellists detected 19 odours by sniffing. These odours were associated with spices, lipid oxidation or fermentation and were in agreement with the contributions of each reaction to the overall aroma of the product.

  7. Recent developments in volatility modeling and applications

    Directory of Open Access Journals (Sweden)

    A. Thavaneswaran

    2006-01-01

    Full Text Available In financial modeling, it has been constantly pointed out that volatility clustering and conditional nonnormality induced leptokurtosis observed in high frequency data. Financial time series data are not adequately modeled by normal distribution, and empirical evidence on the non-normality assumption is well documented in the financial literature (details are illustrated by Engle (1982 and Bollerslev (1986. An ARMA representation has been used by Thavaneswaran et al., in 2005, to derive the kurtosis of the various class of GARCH models such as power GARCH, non-Gaussian GARCH, nonstationary and random coefficient GARCH. Several empirical studies have shown that mixture distributions are more likely to capture heteroskedasticity observed in high frequency data than normal distribution. In this paper, some results on moment properties are generalized to stationary ARMA process with GARCH errors. Application to volatility forecasts and option pricing are also discussed in some detail.

  8. Water on The Moon, III. Volatiles & Activity

    CERN Document Server

    Crotts, Arlin

    2012-01-01

    For centuries some scientists have argued that there is activity on the Moon (or water, as recounted in Parts I & II), while others have thought the Moon is simply a dead, inactive world. The question comes in several forms: is there a detectable atmosphere? Does the surface of the Moon change? What causes interior seismic activity? From a more modern viewpoint, we now know that as much carbon monoxide as water was excavated during the LCROSS impact, as detailed in Part I, and a comparable amount of other volatiles were found. At one time the Moon outgassed prodigious amounts of water and hydrogen in volcanic fire fountains, but released similar amounts of volatile sulfur (or SO2), and presumably large amounts of carbon dioxide or monoxide, if theory is to be believed. So water on the Moon is associated with other gases. We review what is known (and touch on what is unknown) about outgassing of various gases from the Moon.

  9. Selenium Uptake and Volatilization by Marine Algae

    Science.gov (United States)

    Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

    2015-04-01

    Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se

  10. Multifractal Models, Intertrade Durations and Return Volatility

    OpenAIRE

    Segnon, Mawuli Kouami

    2015-01-01

    This thesis covers the application of multifractal processes in modeling financial time series. It aims to demonstrate the capacity and the robustness of the multifractal processes to better model return volatility and ultra high frequency financial data than both the generalized autoregressive conditional heteroscedasticity (GARCH)-type and autoregressive conditional duration (ACD) models currently used in research and practice. The thesis is comprised of four main parts that ...

  11. Parametric Portfolio Policies with Common Volatility Dynamics

    OpenAIRE

    Ergemen, Yunus Emre; Taamouti, Abderrahim

    2015-01-01

    A parametric portfolio policy function is considered that incorporates common stock volatility dynamics to optimally determine portfolio weights. Reducing dimension of the traditional portfolio selection problem significantly, only a number of policy parameters corresponding to first- and second-order characteristics are estimated based on a standard method-of-moments technique. The method, allowing for the calculation of portfolio weight and return statistics, is illustrated with an empirica...

  12. MIEC (mixed-ionic-electronic-conduction)-based access devices for non-volatile crossbar memory arrays

    Science.gov (United States)

    Shenoy, Rohit S.; Burr, Geoffrey W.; Virwani, Kumar; Jackson, Bryan; Padilla, Alvaro; Narayanan, Pritish; Rettner, Charles T.; Shelby, Robert M.; Bethune, Donald S.; Raman, Karthik V.; BrightSky, Matthew; Joseph, Eric; Rice, Philip M.; Topuria, Teya; Kellock, Andrew J.; Kurdi, Bülent; Gopalakrishnan, Kailash

    2014-10-01

    Several attractive applications call for the organization of memristive devices (or other resistive non-volatile memory (NVM)) into large, densely-packed crossbar arrays. While resistive-NVM devices frequently possess some degree of inherent nonlinearity (typically 3-30× contrast), the operation of large (\\gt 1000×1000 device) arrays at low power tends to require quite large (\\gt 1e7) ON-to-OFF ratios (between the currents passed at high and at low voltages). One path to such large nonlinearities is the inclusion of a distinct access device (AD) together with each of the state-bearing resistive-NVM elements. While such an AD need not store data, its list of requirements is almost as challenging as the specifications demanded of the memory device. Several candidate ADs have been proposed, but obtaining high performance without requiring single-crystal silicon and/or the high processing temperatures of the front-end-of-the-line—which would eliminate any opportunity for 3D stacking—has been difficult. We review our work at IBM Research—Almaden on high-performance ADs based on Cu-containing mixed-ionic-electronic conduction (MIEC) materials [1-7]. These devices require only the low processing temperatures of the back-end-of-the-line, making them highly suitable for implementing multi-layer cross-bar arrays. MIEC-based ADs offer large ON/OFF ratios (\\gt 1e7), a significant voltage margin {{V}m} (over which current \\lt 10 nA), and ultra-low leakage (\\lt 10 pA), while also offering the high current densities needed for phase-change memory and the fully bipolar operation needed for high-performance RRAM. Scalability to critical lateral dimensions \\lt 30 nm and thicknesses \\lt 15 nm, tight distributions and 100% yield in large (512 kBit) arrays, long-term stability of the ultra-low leakage states, and sub-50 ns turn-ON times have all been demonstrated. Numerical modeling of these MIEC-based ADs shows that their operation depends on C{{u}+} mediated hole

  13. Delineating Effects of Ionic Strength and Suspended Solids on Ammonia Volatilization from Dairy Manure Slurry

    Science.gov (United States)

    Koirala, K.

    2014-12-01

    Ammonia emission is a major concern due to its adverse effects on animal and human health. Ionic strength and suspended solids play key roles in the ammonia volatilization process. These two parameters, however, are usually lumped together in form of total solids. The objective of this study was to separate the contribution of suspended solids (SS) from that of ionic strength (IS) on ammonia volatilization in liquid dairy manure. A two-way factorial experiment was conducted to simultaneously test the effects of IS and SS on ammonium dissociation: a key element of the ammonia volatilization process. The fraction of ammonia (β) in total ammoniacal nitrogen (TAN) was experimentally determined in a convective emission chamber, for each level of SS and IS, at a constant wind speed of 1.5 m s-1, and air and liquid temperature of 25°C. The two way analysis of variance showed a significant effect of SS concentration (p = 0.04) on fraction of ammonia in the liquid dairy manure, while the effect of ionic strength was marginal (p = 0.05). The highest dissociation of ammonium was observed in manure with the lowest SS concentration (0%) and the lowest ionic strength (0.10 mol L-1). Significant increases in suspended solids concentration and ionic strength were necessary to influence the ammonium dissociation in dairy manure. Results revealed that substantially high content of suspended solids (> 3.0%) or relatively high dilution of manure with water (30%) were necessary for these two parameters to play significant roles in the ammonia volatilization mechanism in liquid dairy manure. Results also showed that the β was more sensitive to the changes in suspended solids concentration than in the changes in ionic strength within the ranges of SS and IS examined in this study. Overall, the SS and IS effects on ammonium dissociation (and by extension on ammonia volatilization process) were thus found negligible within the normal ranges of liquid dairy manure characteristics.

  14. Water-rich and volatile-undersaturated magmas at Hekla volcano, Iceland

    Science.gov (United States)

    Lucic, Gregor; Berg, Anne-Sophie; Stix, John

    2016-08-01

    Olivine-hosted melt inclusions from four eruptions at Hekla volcano in Iceland were analyzed for their dissolved H2O, CO2, S, and Cl contents. A positive correlation among the repose interval, magmatic evolution, and volatile contents of magmas is revealed. H2O is the dominant volatile species; it behaves as an incompatible component, increasing in concentration over time as a result of fractional crystallization in the magma. The full suite of H2O contents ranges from a low of 0.80 wt % in basaltic andesites to a maximum of 5.67 wt % in rhyolites. Decreasing H2O/K2O at fixed major element compositions suggests that syneruptive degassing reduces H2O contents significantly. Hekla magmas are CO2 poor, with very low concentrations present only in the most evolved compositions (˜20-30 ppm or less). The decrease in S content from basaltic andesite to rhyolite demonstrates that sulfide saturation is attained when the melt composition reaches basaltic andesite, resulting in the precipitation of pyrrhotite. Low CO2/Nb ratios suggest that vapor saturation is most likely reached during an early period of cooling and solidification in the crust. Fresh injections of mafic magma interact with previously solidified intrusives, producing new melts that are volatile undersaturated. Vapor saturation pressures obtained using the most volatile-rich melt inclusions suggest the presence of a magma chamber at a minimum depth of ˜7 km. This is in agreement with geophysical observations from recent small-volume eruptions, but given the possibility of volatile-undersaturated melts, some of the magmas may reside at greater depths.

  15. Thermal injuries caused by ignition of volatile substances by gas water heaters.

    Science.gov (United States)

    Rutan, R L; Desai, M H; Herndon, D N

    1993-01-01

    Based on the cumulative data of this tertiary care facility over the past 25 years, one out of every 70 pediatric patients admitted to our institution sustained their injuries during an explosive event instigated by the ignition of volatile substances from gas water heaters. The majority of injuries related to gas water heaters can be prevented by decreasing the temperature setpoint of the heater, by protecting the heater element itself, and by elevating the water heater to 18 inches above the floor. The first two issues have been adequately addressed; however, gas-fueled water heaters continue to be installed at floor level. Current national guidelines are too rigid and do not adequately address water-heater installation in private residences. Although general prevention campaigns target appropriate storage of volatile substances, they rarely address the explosive potential of gas water heaters in combination with combustible fumes.

  16. Unexpected uncertainty, volatility and decision-making

    Directory of Open Access Journals (Sweden)

    Amy Rachel Bland

    2012-06-01

    Full Text Available The study of uncertainty in decision making is receiving greater attention in the fields of cognitive and computational neuroscience. Several lines of evidence are beginning to elucidate different variants of uncertainty. Particularly, risk, ambiguity and expected and unexpected forms of uncertainty are well articulated in the literature. In this article we review both empirical and theoretical evidence arguing for the potential distinction between three forms of uncertainty; expected uncertainty, unexpected uncertainty and volatility. Particular attention will be devoted to exploring the distinction between unexpected uncertainty and volatility which has been less appreciated in the literature. This includes evidence from computational modelling, neuromodulation, neuroimaging and electrophysiological studies. We further address the possible differentiation of cognitive control mechanisms used to deal with these forms of uncertainty. Particularly we explore a role for conflict monitoring and the temporal integration of information into working memory. Finally, we explore whether the Dual Modes of Control theory provides a theoretical framework for understanding the distinction between unexpected uncertainty and volatility.

  17. Subduction and volatile recycling in Earth's mantle

    Science.gov (United States)

    King, S. D.; Ita, J. J.; Staudigel, H.

    1994-01-01

    The subduction of water and other volatiles into the mantle from oceanic sediments and altered oceanic crust is the major source of volatile recycling in the mantle. Until now, the geotherms that have been used to estimate the amount of volatiles that are recycled at subduction zones have been produced using the hypothesis that the slab is rigid and undergoes no internal deformation. On the other hand, most fluid dynamical mantle flow calculations assume that the slab has no greater strength than the surrounding mantle. Both of these views are inconsistent with laboratory work on the deformation of mantle minerals at high pressures. We consider the effects of the strength of the slab using two-dimensional calculations of a slab-like thermal downwelling with an endothermic phase change. Because the rheology and composition of subducting slabs are uncertain, we consider a range of Clapeyron slopes which bound current laboratory estimates of the spinel to perovskite plus magnesiowustite phase transition and simple temperature-dependent rheologies based on an Arrhenius law diffusion mechanism. In uniform viscosity convection models, subducted material piles up above the phase change until the pile becomes gravitationally unstable and sinks into the lower mantle (the avalanche). Strong slabs moderate the 'catastrophic' effects of the instabilities seen in many constant-viscosity convection calculations; however, even in the strongest slabs we consider, there is some retardation of the slab descent due to the presence of the phase change.

  18. Financial market volatility and contagion effect: A copula-multifractal volatility approach

    Science.gov (United States)

    Chen, Wang; Wei, Yu; Lang, Qiaoqi; Lin, Yu; Liu, Maojuan

    2014-03-01

    In this paper, we propose a new approach based on the multifractal volatility method (MFV) to study the contagion effect between the U.S. and Chinese stock markets. From recent studies, which reveal that multifractal characteristics exist in both developed and emerging financial markets, according to the econophysics literature we could draw conclusions as follows: Firstly, we estimate volatility using the multifractal volatility method, and find out that the MFV method performs best among other volatility models, such as GARCH-type and realized volatility models. Secondly, we analyze the tail dependence structure between the U.S. and Chinese stock market. The estimated static copula results for the entire period show that the SJC copula performs best, indicating asymmetric characteristics of the tail dependence structure. The estimated dynamic copula results show that the time-varying t copula achieves the best performance, which means the symmetry dynamic t copula is also a good choice, for it is easy to estimate and is able to depict both the upper and lower tail dependence structure. Finally, with the results of the previous two steps, we analyze the contagion effect between the U.S. and Chinese stock markets during the subprime mortgage crisis. The empirical results show that the subprime mortgage crisis started in the U.S. and that its stock market has had an obvious contagion effect on the Chinese stock market. Our empirical results should/might be useful for investors allocating their portfolios.

  19. Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

    Directory of Open Access Journals (Sweden)

    M. S. T. Barroso

    2011-06-01

    Full Text Available Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa, whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa. The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves.

  20. PERUBAHAN KOMPONEN VOLATIL SELAMA FERMENTASI KECAP [Change Volatile Components During Soy Sauce Fermentation

    Directory of Open Access Journals (Sweden)

    Anton Apriyantono1

    2004-08-01

    Full Text Available A study has been conducted to investigate changes of volatile components during soy sauce fermentation. During the fermentation, many volatile components produced may contribute to soy sauce flavor. THe volatile identified by GC-MS werw classified into hydrocarbon (15, alcohol (15, aldehyde (14, ester (14, ketone (9, benzene derivative (11, fatty acid (9, furan (5, terpenoid (18, pyrazine (3, thiazole (1, pyridine (1 and sulfur containing compound (2.Concentration of compounds found in almost all fermentation steps, such as hexanal and benzaldehyde did. These compounds may be derived from raw soybean, since they were all present in raw soybean and their concentration did not change during fermentation. Concentration of palmitic acid and benzeneacetaldehyde, in general, increased during all fermentation steps. They are probably derived from lipid degradation or microorganism activities. Concentrations of some fatty acids, esters and hydrocarbons, such as linoleic acid, methyl palmitate and heptadecane increased during salt fermentation only. Concentration of some other compounds, such as 2,4 decadienal decreased or undetected during fermentation.The absence of some volatile compounds, e.g. (E-nerolidol and (E,E-famesol in boiled soybean which were previously present in raw soybean may be due to evaporation of these compounds during boiling. Some volatile compounds such as, methyl heptadecanoate and few aromatic alcohols are likely derived from Aspergillus sojae, since these compounds were identified only in 0 day koji

  1. Crystal Growth of CsB3O5 from NaF Flux

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nonlinear optical CsB3O5 single crystals have been grown successfully using NaF as a flux. The primary CsB3O5-NaF quasi-binary system has been investigated by X-ray diffraction and differential thermal analysis. There is a single eutectic point, and the eutectic composition corresponds to 40mol% NaF with the temperature of 690.5 ℃ in CsB3O5-NaF system. Volatility of the CsB3O5-NaF system along the liquidus has been measured, and the volatiles of the solution were collected and detected by XRD method. Growth of CsB3Os crystals was carried out by different composition of NaF in CsB3O5-NaF system, and the growth parameters were discussed. Simultaneously, the properties of grown crystals from NaF flux were characterized by transmission spectrum and scanning electron microscopy.

  2. Characterisation of calamansi (Citrus microcarpa). Part II: volatiles, physicochemical properties and non-volatiles in the juice.

    Science.gov (United States)

    Cheong, Mun Wai; Zhu, Danping; Sng, Jingting; Liu, Shao Quan; Zhou, Weibiao; Curran, Philip; Yu, Bin

    2012-09-15

    Calamansi juices from three countries (Malaysia, the Philippines and Vietnam) were characterised through measuring volatiles, physicochemical properties and non-volatiles (sugars, organic acids and phenolic acids). The volatile components of manually squeezed calamansi juices were extracted using dichloromethane and headspace solid-phase microextraction, and then analysed using gas chromatography-mass spectrometry/flame ionisation detector, respectively. A total of 60 volatile compounds were identified. The results indicated that the Vietnam calamansi juice contained the highest amount of volatiles. Two principal components obtained from principal component analysis (PCA) represented 89.65% of the cumulative total variations of the volatiles. Among the non-volatile components, these three calamansi juices could be, to some extent, differentiated according to fructose and glucose concentrations. Hence, this study of calamansi juices could lead to a better understanding of calamansi fruits.

  3. Monitoring of jökulhlaups and element fluxes in proglacial Icelandic rivers using osmotic samplers

    Science.gov (United States)

    Jones, Morgan T.; Gałeczka, Iwona M.; Gkritzalis-Papadopoulos, Athanasios; Palmer, Martin R.; Mowlem, Matthew C.; Vogfjörð, Kristín; Jónsson, Þorsteinn; Gislason, Sigurður R.

    2015-01-01

    The quantification of volatile emissions from volcanoes is an integral part of understanding magmatic systems, with the exsolution and extent of volcanic degassing having a large impact on the nature of an eruption. Measurements of volatiles have traditionally focused on gas emissions into the atmosphere, but volatiles can also become dissolved in proximal water bodies en route to the surface. Thus the monitoring of rivers draining active volcanic areas can provide insights to identifying changes in activity. This process is particularly important for sub-glacial volcanoes in Iceland, where much of the volatile release is transported within glacial outbreak floods, termed jökulhlaups. Monitoring and characterising these phenomena is hampered by the dependence on spot sampling of stochastic events under challenging field conditions, which often leads to bias in the collected data. A recent technological advance is the osmotic sampler, an electricity-free pump that continuously collects water that can subsequently be divided into time-averaged samples. This technique allows for continued and unsupervised deployment of a sampler for weeks to months, representing a cost-efficient form of chemical monitoring. In this study we deployed osmotic samplers in two rivers in southern Iceland. Skálm is a proglacial river from Mýrdalsjökull glacier and Katla volcano, while Skaftá is a larger drainage system from the western part of Vatnajökull glacier. Both rivers are prone to jökulhlaups from geothermal and volcanic sources, and a small jökulhlaup of geothermal origin occurred during the second deployment in Skaftá in January 2014. The two deployments show that osmotic samplers are capable of delivering accurate chemical data in turbulent conditions for several key elements. Total dissolved fluxes for the deployment at Skaftá are calculated to be Na = 9.9 tonnes/day, Mg = 10.5 t/d, Si = 34.7 t/d, Cl = 11.0 t/d, Ca = 31.6 t/d, DIC = 50.8 t/d, and SO4 = 28.3 t/d, with

  4. O Processo de Internacionalização como Elemento Gerador de Capacidades Dinâmicas: o caso da WEG na Argentina e na ChinaThe Internationalization Process as Generator Element of Dynamic Capacities: the case of WEG in Argentina and ChinaEl Proceso de Internacionalización como Elemento Generador de Capacidades Dinámicas: el caso de WEG en Argentina y China

    Directory of Open Access Journals (Sweden)

    FLEURY, Maria Tereza Leme

    2009-12-01

    Full Text Available RESUMOO artigo tem o objetivo de investigar as capacidades dinâmicas desenvolvidas e utilizadas pela WEG no processo de internacionalização e explicar como essas capacidades contribuem para que a empresa defenda e sustente a vantagem competitiva. De forma mais específica, o artigo apresenta um estudo exploratório por meio do caso do processo de internacionalização da empresa WEG na Argentina e na China. Tal artigo, tendo como enfoque de análise as capacidades dinâmicas, contribui à literatura de gestão internacional em dois aspectos. Primeiro, acrescenta o olhar analítico da internacionalização baseado em capacidades dinâmicas que ainda é bem restrito. Segundo, ao trabalhar as capacidades dinâmicas como elemento central da análise do processo de internacionalização propõe um framework de análise integrativo das teorias econômica e comportamental que são muito usadas para explicar o processo de internacionalização de empresas, porém são tratadas de maneira independente e por vezes antagônica. O resultado mostra como as capacidades dinâmicas são articuladas no caso da WEG no processo de internacionalização para a Argentina e o subsequente movimento para a China. As capacidades dinâmicas desenvolvidas na Argentina foram adquiridas pela matriz brasileira e puderam ser aplicadas com as devidas proporções no processo de internacionalização para a China. Entretanto, não pode ser identificado uma estrutura organizacional mais complexa em que os relacionamentos diretos inter-subsidiárias pudessem compartilhar capacidades dinâmicas como proposto no framework.ABSTRACTThe objective of the article is to research the dynamic capacities developed and used by WEG in its internationalization process and to explain how these capacities help the company defends and supports competitive advantage. The article presents an exploratory study of the internationalization process of WEG in Argentina and China. This article has as

  5. Measurements of hygroscopicity and volatility of atmospheric ultrafine particles in the rural Pearl River Delta area of China

    Science.gov (United States)

    Kim, Jae-Seok; Kim, Young J.; Park, Kihong

    2011-09-01

    A hygroscopicity and volatility tandem differential mobility analyzer (HVTDMA) technique was used to determine the time- and size-resolved properties of ultrafine particles and to infer relative volume fractions of non-volatile and non-hygroscopic (NV_NH), volatile and non-hygroscopic (V_NH), volatile and hygroscopic (V_H), and non-volatile and hygroscopic (NV_H) groups. Cluster analysis of wind direction and air mass backward trajectory have revealed that enhanced ultrafine particle concentrations were often observed when air mass was transported with high wind speed (>3 m s -1) from the polluted northeast region containing a significant amount of SO 2 and experienced a strong photochemical activity. We found the photochemically-produced ultrafine particles to consist primarily of NV_H with a little V_NH and V_H. In morning traffic events, we estimated ultrafine particles to consist of 61% NV_NH, 36% V (volatile group = the sum of V_NH and V_H), and 2% NV_H, while during biomass burning events, ultrafine particles consisted of 69% NV_NH, 21% V and 10% NV_H. Further, as determined by TEM/EDS analysis, the increase in NV_H during the biomass burning event was consistent with the frequent existence of K element in ultrafine particles. Comparison of data among different geometric locations in China and Korea revealed ultrafine particle hygroscopicity and volatility during the photochemical event as being highly variable in locations affected by diverse sources and variable precursor gases (e.g., SO 2 and VOC), while during the combustion events, less hygroscopicity variation across different locations was observed.

  6. Passive degassing at Nyiragongo (D.R. Congo) and Etna (Italy) volcanoes: the chemical characterization of the emissions and assessment of their uptake of trace elements emissions on the local environment

    Science.gov (United States)

    Calabrese, Sergio; Scaglione, Sarah; Milazzo, Silvia; D'Alessandro, Walter; Bobrowski, Nicole; Giuffrida, Giovanni; Tedesco, Dario; Parello, Francesco

    2014-05-01

    the plume in Si, Al, Fe, Ti, Mg, Ca, Na, K and other trace elements like Ni, Cr, Co, Th and U; another one components, is dominated by volatile trace elements (As, Bi, Cd, Cu, Hg, Se, Te, Tl) related to the gas volatile phase (H2O, CO2, SO2, HCl, HF) and transported to the atmosphere mainly as hydro-soluble salts and/or in gaseous form in some cases. The large amount of emitted trace elements have a strong impact on the close surrounding of both volcanoes. This is clearly reflected by in the chemical composition of rain water collected at the summit areas both for Etna and Nyiragongo. In fact, rain water samples have low pH values (leaves of Senecio species collected in on both volcanoes, showing a clear influence of volcanic deposition.

  7. Controlled release properties of Chitosan encapsulated volatile Citronella Oil microcapsules by thermal treatments.

    Science.gov (United States)

    Hsieh, Wen-Chuan; Chang, Chih-Pong; Gao, Ying-Lin

    2006-12-01

    This research uses modified orifice method to prepare the O/W type Chitosan encapsulated volatile Citronella Oil microcapsules. In this article, we investigated the forming condition of microcapsules and the influence to sustained release effect of volatile Citronella Oil by applying thermal pretreatment to microcapsules. The results suggest that the forming of microcapsules should be processed under the fundamental conditions of: (1) the concentration of Chitosan is at least 0.2wt%, (2) NaOH is greater than 0.1wt%, and (3) with the additive of coconut oil as natural surfactant, so that we could obtain final product of microcapsules with better formation and dispersion. The changes in concentration of Chitosan will affect the encapsulation efficiency of the volatile Citronella Oil. When the concentrations of Chitosan are 0.5%, 1.0% and 1.5%, the encapsulation efficiencies are 98.2%, 95.8% and 94.7%, respectively. The particle size of Chitosan microcapsules would decrease as the emulsification stirring speed increases. When the stirring speeds are 400 rpm, 800 rpm, and 1500 rpm, the average particle sizes of microcapsules produced are 225+/-24 microm, 131+/-20 microm, and 11+/-3 microm, respectively. If the microcapsules were thermal pretreated at 80 degrees C, the structure of Chitosan wall membrane would shrink and thus achieve the effect of sustained release. The sustaining effect would increase along with treatment time increases.

  8. Simultaneous distillation-extraction of high-value volatile compounds from Cistus ladanifer L.

    Science.gov (United States)

    Teixeira, Salomé; Mendes, Adélio; Alves, Arminda; Santos, Lúcia

    2007-02-19

    The present paper describes a procedure to isolate volatiles from rock-rose (Cistus ladanifer L.) using simultaneous distillation-extraction (SDE). High-value volatile compounds (HVVC) were selected and the influence of the extraction conditions investigated. The effect of the solvent nature and extraction time on SDE efficiency was studied. The best performance was achieved with pentane in 1 h operation. The extraction efficiencies ranged from 65% to 85% and the repeatability varied between 4% and 6% (as a CV%). The C. ladanifer SDE extracts were analysed by headspace solid phase microextraction (HS-SPME) followed by gas chromatography with flame ionization detection (GC-FID). The HS-SPME sampling conditions such as fiber coating, temperature, ionic strength and exposure time were optimized. The best results were achieved with an 85 microm polyacrylate fiber for a 60 min headspace extraction at 40 degrees C with 20% (w/v) of NaCl. For optimized conditions the recovery was in average higher than 90% for all compounds and the intermediate precision ranged from 4 to 9% (as CV %). The volatiles alpha-pinene (22.2 mg g(-1) of extract), 2,2,6-trimethylcyclohexanone (6.1 mg g(-1) of extract), borneol (3.0 mg g(-1) of extract) and bornyl acetate (3.9 mg g(-1) of extract) were identified in the SDE extracts obtained from the fresh plant material.

  9. Efektite na prostaciklin vo tretmanot na dijabeticnata nefropatija kaj staorci

    Directory of Open Access Journals (Sweden)

    Jasmina Trojacanec

    2006-06-01

    Full Text Available Mikrovaskularnite komplikacii, a pred se dijabeticnata nefropatija, se edni od najteskite komplikacii na dijabetot, od koi vo golema mera zavisi i prognozata na dijabetot kaj ovie pacienti. Etiopatogenezata na ovaa komplikacija e multifaktorijalna i za sega se uste ne kompletno rasvetlena, a vklucuva morfoloski, patolosko-anatomski i biohemiski metabolni narusuvanja. Se smeta deka narusuvanjeto na modularnata funkcija na endoteliumot moze da bide kriticen i inicijalen faktor vo razvojot na dijabeticnite vaskularni komplikacii. Vrz osnova na farmakodinamskite efekti koi sto gi poseduva prostaciklinot (PGI2 i negovite analozi, se smeta deka istite moze da bidat korisni vo tretmanot na dijabeti~nata nefropatija. Osnovna cel na ovaa studija be{e da se procenat efektite na prostaciklin (PGI2 vo tretmanot na dijabeticnata nefropatija, eksperimentalno predizvikana so streptozocin. Kaj normotenzivni staorci od sojot Wistar, eksperimentalno bese induciran najprvin dijabet so ednokratna i.p. administracija na streptozocin (STZ, a kako komplikacija na dijabetot i jasni znaci i simptomi na dijabeticna nefropatija (proteinurija, zgolemeno serumsko nivo na urea i kreatinin, poliurija, zgolemena aktivnost na NAG vo mockata. Tretman so prostaciklin (p.o. vo doza od 0.1 mg/kg /t.t./den, vo tekot na 4 nedeli, dovede do signifikantno namaluvanje na simptomite i znacite na bubreznite ostetuvanja, vo odnos na grupata zivotni koi ne primaa prostaciklin. Vrz osnova na dobienite rezultati moze da se zakluci deka prostaciklinot moze da ima znacajna uloga vo tretmanot na dijabeticnata nefropatija, eksperimentalno inducirana so streptozocin.

  10. IVO, a device for In situ Volatilization and On-line detection of products from heavy ion reactions

    CERN Document Server

    Duellmann, C E; Eichler, R; Gäggeler, H W; Jost, D T; Piguet, D; Türler, A

    2002-01-01

    A new gaschromatographic separation system to rapidly isolate heavy ion reaction products in the form of highly volatile species is described. Reaction products recoiling from the target are stopped in a gas volume and converted in situ to volatile species, which are swept by the carrier gas to a chromatography column. Species that are volatile under the given conditions pass through the column. In a cluster chamber, which is directly attached to the exit of the column, the isolated volatile species are chemically adsorbed to the surface of aerosol particles and transported to an on-line detection system. The whole set-up was tested using short-lived osmium (Os) and mercury (Hg) nuclides produced in heavy ion reactions to model future chemical studies with hassium (Hs, Z=108) and element 112. By varying the temperature of the isothermal section of the chromatography column between room temperature and -80 deg. C, yield measurements of given species can be conducted, yielding information about the volatility o...

  11. An empirical analysis of freight rate and vessel price volatility transmission in global dry bulk shipping market

    Directory of Open Access Journals (Sweden)

    Lei Dai

    2015-10-01

    Full Text Available Global dry bulk shipping market is an important element of global economy and trade. Since newbuilding and secondhand vessels are often traded as assets and the freight rate is the key determinant of vessel price, it is important for shipping market participants to understand the market dynamics and price transmission mechanism over time to make suitable strategic decisions. To address this issue, a multi-variate GARCH model was applied in this paper to explore the volatility spillover effects across the vessel markets (including newbuilding and secondhand vessel markets and freight market. Specifically, the BEKK parameterization of the multi-variate GARCH model (BEKK GARCH was proposed to capture the volatility transmission effect from the freight market, newbuilding and secondhand vessel markets in the global dry bulk shipping industry. Empirical results reveal that significant volatility transmission effects exist in each market sector, i.e. capesize, panamax, handymax and handysize. Besides, the market volatility transmission mechanism varies among different vessel types. Moreover, some bilateral effects are found in the dry bulk shipping market, showing that lagged variances could affect the current variance in a counterpart market, regardless of the volatility transmission. A simple ratio is proposed to guide investors optimizing their portfolio allocations. The findings in this paper could provide unique insights for investors to understand the market and hedge their portfolios well.

  12. Investigate Volatility Jumps in Chinese Stock Index Future and Spot Markets Based on Realized Volatility

    Institute of Scientific and Technical Information of China (English)

    Zhang qiang

    2014-01-01

    This paper aims to investigate Chinese stock index future and spot market's volatility jumps characteristics by using recentlydeveloped jumpstest(Barndorff-Nielsenand Shephard,2004).Thedataisoneyearhigh frequencydatafromthe period19/04/2012 to 19/04/2013. The empirical results show two important points. Firstly, the logarithm of adjusted realized volatility shows a high degree of autocorrelation and folows a normal distribution nearly perfect. These characteristics show a potential high forecast ability. Secondly,thedailyrealizedvolatilityjumpsshowalowdegreeofautocorrealtionbutwithsignificantvolatilityclusters.Ingeneral,thejumps component has a low percentage in realized volatility estimation for both future and spot market. On average, there is one significant jumpswithinevery ten continue trading days.Spotmarkets showshigherdegree of jumps,anda rapidly jumpscharacterises.It implies that jumps may transmission from spot to future market, and spot market dominate future market at some degree.

  13. PRODUCTION OF VOLATILE FATTY ACIDS EVALUATED BY SEMIAUTOMATIC TECHNIQUE IN VITRO IN THE RUMINANT FEEDS WITH DIFFERENT CARBOHYDRATE SOURCES IN THE ROUGHAGES RATE Producción de Ácidos Grasos Volátiles Evaluados por la Técnica Semiautomática in vitro en Los Alimentos para Rumiantes en Adicción de Fuentes de Carboidratos em la porcion volumosa PRODUÇÃO DE ÁCIDOS GRAXOS VOLÁTEIS, AVALIADA PELA TÉCNICA SEMIAUTOMÁTICA IN VITRO, NA DIETA DE RUMINANTES COM DIFERENTES FONTES DE CARBOIDRATOS NA FRAÇÃO VOLUMOSA

    OpenAIRE

    Roberto de Camargo Wascheck; Alberto Correa Mendonça; Pedro Leonardo de Paula Rezende; Ronaldo Braga Reis; Paulo Cesar Moreira; Apóstolo Ferreira Martins

    2009-01-01

    The effect of carbohydrates sources (dent corn or flint corn or citrus pulp) addition to forages (corn silage, sorghum silage + silage of corn residue, elephant grass, sugarcane, silage of corn residue) was measured, through volatile fatty acids (VFA’s) production at the time of incubation of 2, 6, 12 e 24 hours. A completely randomized design in split plot with the time factor in the subplots Was used. The averages gas productions were treated by the France parameters. The acetate was VFA of...

  14. Herbivore-induced blueberry volatiles and intra-plant signaling.

    Science.gov (United States)

    Rodriguez-Saona, Cesar R

    2011-12-18

    Herbivore-induced plant volatiles (HIPVs) are commonly emitted from plants after herbivore attack. These HIPVs are mainly regulated by the defensive plant hormone jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA). Over the past 3 decades researchers have documented that HIPVs can repel or attract herbivores, attract the natural enemies of herbivores, and in some cases they can induce or prime plant defenses prior to herbivore attack. In a recent paper, I reported that feeding by gypsy moth caterpillars, exogenous MeJA application, and mechanical damage induce the emissions of volatiles from blueberry plants, albeit differently. In addition, blueberry branches respond to HIPVs emitted from neighboring branches of the same plant by increasing the levels of JA and resistance to herbivores (i.e., direct plant defenses), and by priming volatile emissions (i.e., indirect plant defenses). Similar findings have been reported recently for sagebrush, poplar, and lima beans. Here, I describe a push-pull method for collecting blueberry volatiles induced by herbivore (gypsy moth) feeding, exogenous MeJA application, and mechanical damage. The volatile collection unit consists of a 4 L volatile collection chamber, a 2-piece guillotine, an air delivery system that purifies incoming air, and a vacuum system connected to a trap filled with Super-Q adsorbent to collect volatiles. Volatiles collected in Super-Q traps are eluted with dichloromethane and then separated and quantified using Gas Chromatography (GC). This volatile collection method was used in my study to investigate the volatile response of undamaged branches to exposure to volatiles from herbivore-damaged branches within blueberry plants. These methods are described here. Briefly, undamaged blueberry branches are exposed to HIPVs from neighboring branches within the same plant. Using the same techniques described above, volatiles emitted from branches after exposure to HIPVs are collected and

  15. A serendipidade na medicina e na anestesiologia

    OpenAIRE

    Vale,Nilton Bezerra do; Delfino,José; Vale,Lúcio Flávio Bezerra do

    2005-01-01

    JUSTIFICATIVA E OBJETIVOS: Neste trabalho foram examinados mais de uma centena dos mais felizes acoplamentos de uma mente brilhante com a sorte benfazeja (serendipidade), através da releitura das mais relevantes histórias sobre invenções e descobertas relacionadas à ciência (n = 46), à Medicina (n = 46) e à Anestesiologia (n = 16). CONTEÚDO: Conceito de serendipidade; exemplos célebres de serendipidade em Ciência e Tecnologia; serendipidade na pesquisa e prática médicas; serendipidade na Anes...

  16. New approach on volatile contents determination in silicate melt inclusions: A coupling X-ray microtomography and geochemical approach in Los Humeros caldera complex (Eastern Mexican Volcanic Belt)

    Science.gov (United States)

    Creon, L.; Levresse, G.; Carrasco Nuñez, G.

    2016-12-01

    Volatile contents and magma degassing behavior are known to affect the style, frequency, and intensity of near-surface magmatic processes. For this reason, much effort have been devoted to characterize the volatile evolution of shallow magmatic systems to better constrain volcanic history. Silicate melt inclusions (SMI) represent samples of melt that were isolated from the bulk magma at depth, thus preserving the PTX conditions of the pre-eruptive material. SMI are often affected by the formation of a bubble after trapping; this is a natural consequence of the PVTX properties of crystal-melt-volatile systems. Previous workers have recognized that bubble formation is an obstacle, which affects the interpretation of SMI trapping conditions based only on analysis of the glass phase. Indeed, they explained that bubbles can contain a significant percentage of the volatiles, particularly for those with low solubility in the melt (e.g. CO2). In this study, we propose to define the pre-eruptive PTX conditions of Los Humeros magma chamber using SMI from the various eruption events within 460 and 30 Ka. An innovative analytical coupling has been used in order to determine: (1) the volume of the SMI glass and bubble, using high resolution 3D X-ray microtomography; (2) the density and composition of the bubbles, using Raman spectroscopy; (3) the volatile element contents in glass, using NanoSIMS; and, (4) the major elements composition of the glass, using EPMA. The recalculated volatile concentrations of the total SMI (glass + bubble), illustrate clearly that the volatile content determinations using only the glass phase, underestimate drastically the total volatile content and therefore induce significant error on the determination of the pre-eruptive volcanic budget and on the constrain on the volcanic and thermal history. This study had moreover highlighted the complex evolution of Los Humeros composite magma chamber and, gave constrains for geothermal exploration purpose.

  17. Inorganic analyses of volatilized and condensed species within prototypic Defense Waste Processing Facility (DWPF) canistered waste

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.M.

    1992-06-30

    The high-level radioactive waste currently stored in carbon steel tanks at the Savannah River Site (SRS) will be immobilized in a borosilicate glass in the Defense Waste Processing Facility (DWPF). The canistered waste will be sent to a geologic repository for final disposal. The Waste Acceptance Preliminary Specifications (WAPS) require the identification of any inorganic phases that may be present in the canister that may lead to internal corrosion of the canister or that could potentially adversely affect normal canister handling. During vitrification, volatilization of mixed (Na, K, Cs)Cl, (Na, K, Cs){sub 2}SO{sub 4}, (Na, K, Cs)BF{sub 4}, (Na, K){sub 2}B{sub 4}O{sub 7} and (Na,K)CrO{sub 4} species from glass melt condensed in the melter off-gas and in the cyclone separator in the canister pour spout vacuum line. A full-scale DWPF prototypic canister filled during Campaign 10 of the SRS Scale Glass Melter was sectioned and examined. Mixed (NaK)CI, (NaK){sub 2}SO{sub 4}, (NaK) borates, and a (Na,K) fluoride phase (either NaF or Na{sub 2}BF{sub 4}) were identified on the interior canister walls, neck, and shoulder above the melt pour surface. Similar deposits were found on the glass melt surface and on glass fracture surfaces. Chromates were not found. Spinel crystals were found associated with the glass pour surface. Reference amounts of the halides and sulfates were found retained in the glass and the glass chemistry, including the distribution of the halides and sulfates, was homogeneous. In all cases where rust was observed, heavy metals (Zn, Ti, Sn) from the cutting blade/fluid were present indicating that the rust was a reaction product of the cutting fluid with glass and heat sensitized canister or with carbon-steel contamination on canister interior. Only minimal water vapor is present so that internal corrosion of the canister, will not occur.

  18. PARAMETER ESTIMATION FOR A DISCRETELY OBSERVED STOCHASTIC VOLATILITY MODEL WITH JUMPS IN THE VOLATILITY

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper a stochastic volatility model is considered. That is, a log price process Y whichis given in terms of a volatility process V is studied. The latter is defined such that the logprice possesses some of the properties empirically observed by Barndorff-Nielsen & Jiang[6]. Inthe model there are two sets of unknown parameters, one set corresponding to the marginaldistribution of V and one to autocorrelation of V. Based on discrete time observations ofthe log price the authors discuss how to estimate the parameters appearing in the marginaldistribution and find the asymptotic properties.

  19. Plume composition and volatile flux from Nyamulagira volcano

    Science.gov (United States)

    Calabrese, Sergio; Bobrowski, Nicole; Giuffrida, Giovanni Bruno; Scaglione, Sarah; Liotta, Marcello; Brusca, Lorenzo; D'Alessandro, Walter; Arellano, Santiago; Yalire, Matiew; Galle, Bo; Tedesco, Dario

    2015-04-01

    Nyamulagira, in the Virunga volcanic province (VVP), Democratic Republic of Congo, is one of the most active volcanoes in Africa. The volcano is located about 25 km north-northwest of Lake Kivu in the Western Branch of the East African Rift System (EARS). The activity is characterized by frequent eruptions (on average, one eruption every 2-4 years) which occur both from the summit crater and from the flanks (31 flank eruptions over the last 110 years). Due to the peculiar low viscosity of its lava and its location in the floor of the rift, Nyamulagira morphology is characterized by a wide lava field that covers over 1100 km2 and contains more than 100 flank cones. Indeed, Nyamulagira is a SiO2- undersaturated and alkali-rich basaltic shield volcano with a 3058 m high summit caldera with an extension of about 2 km in diameter. In November 2014 a field expedition was carried out at Nyamulagira volcano and we report here the first assessment of the plume composition and volatile flux from Nyamulagira volcano. Helicopter flights and field observations allowed us to recognize the presence of lava fountains inside an about 350-meter wide pit crater. The lava fountains originated from an extended area of about 20 to 40 m2, in the northeast sector of the central caldera. A second smaller source, close to the previous described one, was clearly visible with vigorous spattering activity. There was no evidence of a lave lake but the persistence of intense activity and the geometry of the bottom of the caldera might evolve in a new lava lake. Using a variety of in situ and remote sensing techniques, we determined the bulk plume concentrations of major volatiles, halogens and trace elements. We deployed a portable MultiGAS station at the rim of Nyamulagira crater, measuring (at 0.5 Hz for about 3 hours) the concentrations of major volcanogenic gas species in the plume (H2O, CO2, SO2, H2S). Simultaneously, scanning differential optical absorption spectroscopy instruments were

  20. Mass Spectrometry in Jupiter's Atmosphere: Vertical Variation of Volatile Vapors

    Science.gov (United States)

    Wong, Michael H.; Atreya, Sushil K.; Mahaffy, Paul R.

    2014-05-01

    The Galileo Probe made the first and only in situ measurements of composition in Jupiter's atmosphere, led by the Galileo Probe Mass Spectrometer, or GPMS [1]. The major contribution from this instrument was the measurement of abundances and isotope ratios of the noble gases, as well as the volatile gases CH4, NH3, H2O, and H2S [2,3]. These initial results were further refined by detailed laboratory calibrations for the noble gases [4] and the volatiles [5]. The probe measurements resulted in the first determination of the heavy element abundances (except carbon that was known previously) and He/H ratio, which provide critical constraints to models of the formation of Jupiter and the origin of its atmosphere [6,7]. The condensable volatiles, or CVs (ammonia, H2S, and water), increased with depth in the probe entry site. This vertical variation was observed at levels much deeper than the modeled cloud bases, as predicted by one-dimensional chemical equilibrium models. The discrepancy is due to the probe's entry into a dry region known as a 5-μm hot spot. The 5-μm hot spots are part of an atmospheric wave system that encircles Jupiter just north of the equator. Despite the anomalous meteorology, the bulk abundances of NH3 and H2S were measured by the probe, and found to be enriched with respect to solar composition (similarly to the non-condensable volatile CH4). The deepest water mixing ratio, however, was observed to be depleted relative to solar composition. We review an updated context for the CV vertical profiles measured by the GPMS, based on the latest results from remote sensing, simulation, and reinterpretation of Galileo Probe measurements. In particular, we find that (1) the bulk abundance of water in Jupiter's atmosphere must be greater than the subsolar abundance derived from the deepest GPMS measurements [8], and that (2) CV mixing ratios are controlled by a range of processes in addition to condensation of the ices NH3, NH4SH, and H2O [5-9]. Both

  1. Concepções do profissional farmacêutico sobre a assistência farmacêutica na unidade básica de saúde: dificuldades e elementos para a mudança Conceptions of the pharmaceutical professional about the pharmaceutical assistance in basic health care units: difficulties and elements for change

    Directory of Open Access Journals (Sweden)

    Aílson da Luz André de Araújo

    2006-03-01

    Full Text Available No presente estudo foi feita avaliação da Assistência Farmacêutica em farmácias de Unidades de Saúde do município de Ribeirão Preto, no Estado de São Paulo, Brasil. Partindo-se do referencial de avaliação tecnológica em saúde e suas interfaces, foram realizadas entrevistas com os profissionais farmacêuticos, procurando-se conhecer as concepções desses atores sobre a assistência farmacêutica. Os resultados obtidos mostram um trabalho baseado na gestão burocrática dos medicamentos com objeto no controle de estoque do medicamento. Alguns elementos emergentes que poderão contribuir para a alteração deste quadro foram detectados: voluntarismo, busca pela valorização profissional, iniciativa de integração com a equipe de saúde, percepção do paciente como objeto de trabalho e formação profissional complementar.In the present study we evaluated the Pharmaceutical Assistance in pharmacies of Basic Health Care Units in Ribeirão Preto, State of São Paulo, Brazil. Considering the technological evaluation reference in health and its interfaces, pharmaceutical professionals were interviewed in a way to find out their conceptions about pharmaceutical assistance. The results showed a work based on the bureaucratic management of medicines specially the control of medicine supplies. Some emergent elements were thought to contribute to change this system: voluntarism, professional valorization, integration of the health team, perception of the patient as object of the work and complementary professional formation.

  2. Characteristics of Coal Ashes in Yanzhou Mining District and Distribution of Trace Elements in Them

    Institute of Scientific and Technical Information of China (English)

    刘桂建; 彭子成; 杨萍玥; 桂和荣; 王桂梁

    2001-01-01

    In the process of combustion of coal organic and inorganic materials in it will undergo a complex variation. Part of them will become volatiles and, together with coal smoke, enter into atmosphere, some will remain in micro-particulates such as ash and dust and find their way into atmosphere in the form of solid particles, and the rest will be retained in ash and slag. Coal ashes are the residues of organic and inorganic substances in coal left after coal combustion and the composition of coal ashes is dependent on that of minerals and organic matter in coal This paper deals with the chemical composition of coal ashes, the distribution of trace elements in them and their petrological characteristics, and also studies the relationship between the yield of coal ashes and the distribution of trace elements. In addition, a preliminary study is also under taken on the factors that affect the chemical composition of coal ashes. As viewed from the analyses of coal ash samples collected from the Yanzhou mining district, it can be seen clearly that coal ashes from the region studied are composed chiefly of crystalline materials, glassy ma terials and uncombusted organic matter and the major chemical compositions are SiO2, A12O3,Fe2O3, and CaO, as well as minor amounts of SO3, P2O5, Na2O, K2O and TiO2. During the combustion of coal, its trace elements will be redistributed and most of them are enriched in coal ashes. At the same time, the concentrations of the trace elements in flying ash are much higher than those of bottom ash, i.e. , with decreasing particle-size of coal ashes their concen trations will become higher and higher. So the contents of trace elements are negatively propor tional to the particle-size of coal ashes. There has been found a positive correlation between the trace elements Th, V, Zn, Cu and Pb and the yield of coal ashes while a negative correlation between C1 and the yield of coal ashes.

  3. Volatile emissions during storing of green food waste under different aeration conditions.

    Science.gov (United States)

    Agapiou, A; Vamvakari, J P; Andrianopoulos, A; Pappa, A

    2016-05-01

    Controlled field experiments were carried out for monitoring the emissions of three plastic commercial household waste bins, which were adapted for studying the effect of aeration process in the evolved volatiles, during house storing of green food waste for 2 weeks, prior to collection. Three experimental scenarios were examined based on no aeration ("NA," closed commercial waste bin), diffusion-based aeration ("DA," closed commercial waste bin with tiny holes), and enforced aeration ("EA," closed commercial waste bin with tiny holes and enforced aeration). The monitoring of volatile organic compounds (VOCs) emitted from organic household kitchen waste was performed using solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis. Portable sensors were also used for monitoring selected gases and parameters of environmental, bioprocess, and health interest (e.g., CO2, O2, H2S, CH4, NH3, % RH, waste temperatures). VOC emissions are strongly dependent on the waste material. The most frequent VOCs identified over the storing waste, showing over 50 % appearance in all examined samples, were terpenes (e.g., di-limonene, beta-myrcene, delta-3-carene, alpha-pinene, alpha-terpinolene, linalool, etc.), sulfides (dimethyl disulfide), aromatics (benzene, 1-methyl-2-(2-propenyl)), alkanes (e.g., decane, dodecane), ketones (2-propanone), esters (e.g., acetic acid ethyl ester, acetic acid methyl ester), and alcohols (e.g., 3-cyclohexen-1-ol, 4-methyl-1-(1-methylethyl)). The prominent role of terpenes in the "pre-compost" odor and especially that of di-limonene was highlighted. In all examined scenarios, the emitted volatiles were increased at raised temperatures and later decreased in time. Aeration of waste bins slightly affected the volatilization process resulting in higher profiles of VOCs; uniformity in the composition of VOCs was also noted. Slight modifications of commercial waste bins may favor the initiation of home composting.

  4. Bolonja na hrvatski način

    OpenAIRE

    Krstović, Jasna

    2009-01-01

    Iako je osnovna značajka obrazovnog sustava Republike Hrvatske horizontalna i okomita protočnost, ova se značajka još uvijek ne odnosi na obrazovanje odgajatelja. No u posljednje vrijeme događaju se pomaci i kvalitativne promjene koje su zahvatile i sustav obrazovanja hrvatskih odgajatelja.

  5. Assessing Requirements Volatility and Risk Using Bayesian Networks

    Science.gov (United States)

    Russell, Michael S.

    2010-01-01

    There are many factors that affect the level of requirements volatility a system experiences over its lifecycle and the risk that volatility imparts. Improper requirements generation, undocumented user expectations, conflicting design decisions, and anticipated / unanticipated world states are representative of these volatility factors. Combined, these volatility factors can increase programmatic risk and adversely affect successful system development. This paper proposes that a Bayesian Network can be used to support reasonable judgments concerning the most likely sources and types of requirements volatility a developing system will experience prior to starting development and by doing so it is possible to predict the level of requirements volatility the system will experience over its lifecycle. This assessment offers valuable insight to the system's developers, particularly by providing a starting point for risk mitigation planning and execution.

  6. Detecting instability in the volatility of carbon prices

    Energy Technology Data Exchange (ETDEWEB)

    Chevallier, Julien [Univ. Paris Dauphine (France)

    2011-01-15

    This article investigates the presence of outliers in the volatility of carbon prices. We compute three different measures of volatility for European Union Allowances, based on daily data (EGARCH model), option prices (implied volatility), and intraday data (realized volatility). Based on the methodology developed by Zeileis et al. (2003) and Zeileis (2006), we detect instability in the volatility of carbon prices based on two kinds of tests: retrospective tests (OLS-/Recursive-based CUSUM processes, F-statistics, and residual sum of squares), and forward-looking tests (by monitoring structural changes recursively or with moving estimates). We show evidence of strong shifts mainly for the EGARCH and IV models during the time period. Overall, we suggest that yearly compliance events, and growing uncertainties in post-Kyoto international agreements, may explain the instability in the volatility of carbon prices. (author)

  7. Estimation of Stochastic Volatility Models by Nonparametric Filtering

    DEFF Research Database (Denmark)

    Kanaya, Shin; Kristensen, Dennis

    2016-01-01

    /estimated volatility process replacing the latent process. Our estimation strategy is applicable to both parametric and nonparametric stochastic volatility models, and can handle both jumps and market microstructure noise. The resulting estimators of the stochastic volatility model will carry additional biases......A two-step estimation method of stochastic volatility models is proposed: In the first step, we nonparametrically estimate the (unobserved) instantaneous volatility process. In the second step, standard estimation methods for fully observed diffusion processes are employed, but with the filtered...... and variances due to the first-step estimation, but under regularity conditions we show that these vanish asymptotically and our estimators inherit the asymptotic properties of the infeasible estimators based on observations of the volatility process. A simulation study examines the finite-sample properties...

  8. Asymmetry Effects of shocks in Chinese Stock Markets Volatility

    DEFF Research Database (Denmark)

    Hou, Ai Jun

    2013-01-01

    The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modelling return volatility with the parametric GARCH family models. This paper therefore applies a ge...... nonparametric model demonstrates a better performance for return volatility forecasts, particularly for the out-of-sample forecast. The results from this paper have important implications in risk management, portfolio selection, and hedging strategy.......The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modelling return volatility with the parametric GARCH family models. This paper therefore applies...... a generalized additive nonparametric smoothing technique to examine the volatility of the Chinese stock markets. The empirical results indicate that an asymmetric effect of negative news exists in the Chinese stock markets. Furthermore, compared with other parametric models, the generalized additive...

  9. Variation of volatile compounds among wheat varieties and landraces.

    Science.gov (United States)

    Starr, G; Petersen, M A; Jespersen, B M; Hansen, Å S

    2015-05-01

    Analysis of volatile compounds was performed on 81 wheat varieties and landraces, grown under controlled greenhouse conditions, in order to investigate the possibility of differentiating wheat varieties according to their volatile compound profiles. Volatile compounds from wheat samples were extracted by dynamic headspace extraction and analysed by gas chromatography-mass spectrometry. Seventy-two volatile compounds were identified in the wheat samples. Multivariate analysis of the data showed a large diversity in volatile profiles between samples. Differences occurred between samples from Austria compared to British, French and Danish varieties. Landraces were distinguishable from modern varieties and they were characterised by higher averaged peak areas for esters, alcohols, and some furans. Modern varieties were characterised by higher averaged peak areas for terpenes, pyrazines and straight-chained aldehydes. Differences in volatile profiles are demonstrated between wheat samples for the first time, based on variety. These results are significant to plant breeders and commercial users of wheat.

  10. A Jump-Diffusion Model with Stochastic Volatility and Durations

    DEFF Research Database (Denmark)

    Wei, Wei; Pelletier, Denis

    Market microstructure theories suggest that the durations between transactions carry information about volatility. This paper puts forward a model featuring stochastic volatility, stochastic conditional duration, and jumps to analyze high frequency returns and durations. Durations affect price...... jumps in two ways: as exogenous sampling intervals, and through the interaction with volatility. We adopt a bivariate Ornstein-Ulenbeck process to model intraday volatility and conditional duration. We develop a MCMC algorithm for the inference on irregularly spaced multivariate processes with jumps....... The algorithm provides smoothed estimates of the latent variables such as spot volatility, conditional duration, jump times, and jump sizes. We apply this model to IBM data and find that volatility and conditional duration are interdependent. We also find that jumps play an important role in return variation...

  11. Volatile loss from accreting icy protoplanets

    Science.gov (United States)

    Stevenson, D. J.

    1993-03-01

    A large self-gravitating body does not easily lose significant mass because the escape velocity is much larger than the sound speed of atmosphere-forming species under ambient thermal conditions. The most significant exceptions to this are giant impacts or impact jetting by fast-moving projectiles. A very small object (e.g. a comet) also does not easily lose significant volatile mass upon formation because the energy release associated with its accretion is so small. (It can however lose a great deal of mass if it is subsequently moved closer to the Sun.) I argue that there is an intermediate mass range (corresponding to bodies with radii of approximately 300-800 km) for which the ambient steady-state mass loss is a maximum. By ambient, I mean those conditions pertaining to the formation region of the body. By steady state, I mean to exclude infrequent traumas (giant impacts). The existence of a preferred intermediate mass arises through the competition of growing gravitational containment and growing energy release by accretion; it corresponds typically to GM/(Rcs2) approximately equals 2 to 4, where M is the protoplanet mass of radius R, and cs is the sound speed. Several factors determine the amount of volatile loss is this vulnerable zone during accretion but in general the loss is a substantial fraction of the volatiles, sometimes approaching 100 percent. The principal implication is that bodies larger than a few hundred kilometers in radius will not have a 'primitive' (i.e. cometary) composition. This is relevant for understanding Triton, Pluto, Charon, and perhaps Chiron.

  12. Volatility Measurements Of Reaction Chamber-Generated Particles

    Energy Technology Data Exchange (ETDEWEB)

    Paulsen, D. [PSI and ETH Zuerich (Switzerland); Duplissy, J.; Weingartner, E.; Alfarra, R. [University of Manchester (United Kingdom); Baltensperger, U.

    2005-03-01

    A volatility-tandem differential mobility analyzer (VTDMA) was designed to monitor the non-volatile fraction of reaction chamber-generated organic particles. Using a coiled-tube heater for particle volatilization, particle volume fraction remaining measurements were made for wall temperatures of 100, 150, and 200 C. Oligomerization of organic particles generated from irradiations of {alpha}-pinene/NO{sub x} in the reaction chamber shows a strong linear relationship with time. (author)

  13. Asymmetry Effects of shocks in Chinese Stock Markets Volatility

    DEFF Research Database (Denmark)

    Hou, Ai Jun

    2013-01-01

    The unique characteristics of the Chinese stock markets make it difficult to assume a particular distribution for innovations in returns and the specification form of the volatility process when modelling return volatility with the parametric GARCH family models. This paper therefore applies...... a generalized additive nonparametric smoothing technique to examine the volatility of the Chinese stock markets. The empirical results indicate that an asymmetric effect of negative news exists in the Chinese stock markets. Furthermore, compared with other parametric models, the generalized additive...

  14. Financial market volatility and inflation uncertainty: An empirical investigation

    OpenAIRE

    Döpke, Jörg; Pierdzioch, Christian

    1999-01-01

    Using monthly data for Germany from 1968 through 1998, the relationship betweenfluctuations of prices in financial markets and inflation is analyzed. The results of Granger-causality tests reveal that stock market has no predictive power volatility for inflation uncertainty, et vice versa. Regarding the subsequent volatility of short-term and of long-term interest rate. In contrast, inflation uncertainty provides some information. The hypothesis of a causality running from the volatility of t...

  15. Financial Crisis, Monetary Policy, and Stock Market Volatility in China

    OpenAIRE

    Cheng-si Zhang; Da-yin Zhang; Jeffery Breece

    2011-01-01

    This paper employs the Markov regime switching GARCH model to capture the nature of China's stock market volatility in 2003-2009. We find a significant regime shift in the volatility of the stock market when the People's Bank of China adopted an accommodative monetary policy in response to the global financial crisis of 2007-2008. After the structural change, China's stock market moved into a regime with increased volatility, which appears to be persisting into the near future. This finding s...

  16. Volatility spillover in Indonesia, USA, and Japan capital market

    OpenAIRE

    Mulyadi, Martin Surya

    2009-01-01

    Globalization and advanced information technology easing us for obtaining information from global stock markets. With that condition, volatility in domestic capital market could be affected by volatility from global stock markets. That concern will be answered in this research, about volatility spillover in Indonesia, USA, and Japan capital market. This research using daily return data from each country indices from January 2004 until December 2008 employing econometric model GARCH (1,1). ...

  17. Do Time-Varying Covariances, Volatility Comovement and Spillover Matter?

    OpenAIRE

    Lakshmi Balasubramanyan

    2005-01-01

    Financial markets and their respective assets are so intertwined; analyzing any single market in isolation ignores important information. We investigate whether time varying volatility comovement and spillover impact the true variance-covariance matrix under a time-varying correlation set up. Statistically significant volatility spillover and comovement between US, UK and Japan is found. To demonstrate the importance of modelling volatility comovement and spillover, we look at a simple portfo...

  18. Robust estimation of nonstationary, fractionally integrated, autoregressive, stochastic volatility

    OpenAIRE

    Mark J. Jensen

    2015-01-01

    Empirical volatility studies have discovered nonstationary, long-memory dynamics in the volatility of the stock market and foreign exchange rates. This highly persistent, infinite variance - but still mean reverting - behavior is commonly found with nonparametric estimates of the fractional differencing parameter d, for financial volatility. In this paper, a fully parametric Bayesian estimator, robust to nonstationarity, is designed for the fractionally integrated, autoregressive, stochastic ...

  19. Dynamic headspace analyses of residual volatiles in pharmaceuticals.

    Science.gov (United States)

    Wampler, T P; Bowe, W A; Levy, E J

    1985-02-01

    Pharmaceutical preparations may be assayed for volatile organic compounds by purging them with a stream of inert carrier gas and collecting the organics onto a suitable sorbent material, from which they may be backflushed to a gas chromatograph. Compared to solvent extraction, the process offers advantages of increased sensitivity, ease of automation, and elimination of the solvent peak. Examples are given of three major sources of volatiles in pharmaceuticals, with the development of a method for quantitating the volatiles using an internal standard.

  20. Natural Gas Price Volatility in the UK and North America

    OpenAIRE

    2012-01-01

    Lacking a commonly held definition, volatility is an often over-generalised term with different meanings to different constituencies. This does not detract from the importance of the subject. To traders volatility is a source of revenue, to energy intensive industrial end-users it is often perceived as a threat. Midstream utilities actively work to risk-manage volatility in order to deliver a ‘dampened’ price offer to end-user customers. In this working paper Sofya Alterman summarises ...