WorldWideScience

Sample records for element abundance determinations

  1. Gaia FGK benchmark stars: opening the black box of stellar element abundance determination

    Science.gov (United States)

    Jofré, P.; Heiter, U.; Worley, C. C.; Blanco-Cuaresma, S.; Soubiran, C.; Masseron, T.; Hawkins, K.; Adibekyan, V.; Buder, S.; Casamiquela, L.; Gilmore, G.; Hourihane, A.; Tabernero, H.

    2017-05-01

    Gaia and its complementary spectroscopic surveys combined will yield the most comprehensive database of kinematic and chemical information of stars in the Milky Way. The Gaia FGK benchmark stars play a central role in this matter as they are calibration pillars for the atmospheric parameters and chemical abundances for various surveys. The spectroscopic analyses of the benchmark stars are done by combining different methods, and the results will be affected by the systematic uncertainties inherent in each method. In this paper, we explore some of these systematic uncertainties. We determined line abundances of Ca, Cr, Mn and Co for four benchmark stars using six different methods. We changed the default input parameters of the different codes in a systematic way and found, in some cases, significant differences between the results. Since there is no consensus on the correct values for many of these default parameters, we urge the community to raise discussions towards standard input parameters that could alleviate the difference in abundances obtained by different methods. In this work, we provide quantitative estimates of uncertainties in elemental abundances due to the effect of differing technical assumptions in spectrum modelling.

  2. $\\textit{Gaia}$ FGK benchmark stars: opening the black box of stellar element abundance determination

    OpenAIRE

    Jofre, P.; Heiter, U; Worley, CC; Blanco-Cuaresma, S.; Soubiran, C.; Masseron, T.; Hawkins, K.; Adibekyan, V.; Buder, S.; Casamiquela, L; Gilmore, Gerard Francis; Hourihane, A.; Tabernero, H.

    2017-01-01

    $\\textit{Gaia}$ and its complementary spectroscopic surveys combined will yield the most comprehensive database of kinematic and chemical information of stars in the Milky Way. The $\\textit{Gaia}$ FGK benchmark stars play a central role in this matter as they are calibration pillars for the atmospheric parameters and chemical abundances for various surveys. The spectroscopic analyses of the benchmark stars are done by combining different methods, and the results will be affected by the system...

  3. New functionalities in abundant element oxides: ubiquitous element strategy.

    Science.gov (United States)

    Hosono, Hideo; Hayashi, Katsuro; Kamiya, Toshio; Atou, Toshiyuki; Susaki, Tomofumi

    2011-06-01

    While most ceramics are composed of ubiquitous elements (the ten most abundant elements within the Earth's crust), many advanced materials are based on rare elements. A 'rare-element crisis' is approaching owing to the imbalance between the limited supply of rare elements and the increasing demand. Therefore, we propose a 'ubiquitous element strategy' for materials research, which aims to apply abundant elements in a variety of innovative applications. Creation of innovative oxide materials and devices based on conventional ceramics is one specific challenge. This review describes the concept of ubiquitous element strategy and gives some highlights of our recent research on the synthesis of electronic, thermionic and structural materials using ubiquitous elements.

  4. Transition Element Abundances in MORB Basalts

    Science.gov (United States)

    Yang, S.; Humayun, M.; Salters, V. J.; Fields, D.; Jefferson, G.; Perfit, M. R.

    2012-12-01

    The mineralogy of the mantle sources of basalts is an important, but hard to constrain parameter, especially with the basalts as chemical probes of major element mantle composition. Geophysical models imply that the deep mantle may have significant variations in Fe and Si relative to the ambient mantle sampled by MORB. Some petrological models of sub-ridge melting involve both pyroxenite and peridotite, implying that basalts preferentially sample a pyroxenite endmember. The First-Row Transition Elements (FRTE), Ga and Ge are compatible to moderately incompatible during partial melting, and are sensitive to mineralogical variability in the mantle and thus can provide constraints on mantle source mineralogy for MORB. We have analyzed major elements, FRTE, Ga and Ge on 231 basaltic glasses from the Middle Atlantic Ridge (MAR between -23°S to 36.44°N), 30 Mid-Cayman Rise basaltic glasses, 12 glasses from the Siqueiros Fracture Zone (EPR), 9 glasses from the Blanco Trough, Juan de Fuca ridge, and Galapagos Spreading Centers (EPR), and 4 Indian Ocean MORB. Large spots (150 μm) were precisely (±1%) analyzed by a New Wave UP193FX excimer (193 nm) laser ablation system coupled to a high-resolution ICP-MS at the National High Magnetic Field Laboratory using a high ablation rate (50 Hz) to yield blank contributions <1% for all elements, particularly Ge. The data demonstrate that the Ge/Si (6.96 x 10E-6 ± 3%, 1σ) and Fe/Mn (55 ± 2%) ratios for MORB are insensitive to fractional crystallization within the MgO range 6%-10%. MORB have Zn/Fe (9.9 x 10E-4 ± 7%), Ga/Sc (0.37-0.50), Ga/Al (2.2 x 10E-4 ± 11%) ratios, with the variations mostly due to the effects of fractional crystallization. Recent experimental determination of FRTE, Ga and Ge partition coefficients provide a framework within which to interpret these data [1]. Using these new partition coefficients, we have modeled the sensitivity of each element to mineralogical variations in the mantle source. Olivine

  5. Determinations of rare earth element abundance and U-Pb age of zircons using multispot laser ablation-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Yokoyama, Takaomi D; Suzuki, Toshihiro; Kon, Yoshiaki; Hirata, Takafumi

    2011-12-01

    We have developed a new calibration technique for multielement determination and U-Pb dating of zircon samples using laser ablation-inductively coupled plasma mass spectrometry (ICPMS) coupled with galvanometric optics. With the galvanometric optics, laser ablation of two or more sample materials could be achieved in very short time intervals (~10 ms). The resulting sample aerosols released from different ablation pits or different solid samples were mixed and homogenized within the sample cell and then transported into the ICP ion source. Multiple spot laser ablation enables spiking of analytes or internal standard elements directly into the solid samples, and therefore the standard addition calibration method can be applied for the determination of trace elements in solid samples. In this study, we have measured the rare earth element (REE) abundances of two zircon samples (Nancy 91500 and Prešovice) based on the standard addition technique, using a direct spiking of analytes through a multispot laser ablation of the glass standard material (NIST SRM612). The resulting REE abundance data show good agreement with previously reported values within analytical uncertainties achieved in this study (10% for most elements). Our experiments demonstrated that nonspectroscopic interferences on 14 REEs could be significantly reduced by the standard addition technique employed here. Another advantage of galvanometric devices is the accumulation of sample aerosol released from multiple spots. In this study we have measured the U-Pb age of a zircon sample (LMR) using an accumulation of sample aerosols released from 10 separate ablation pits of low diameters (~8 μm). The resulting (238)U-(206)Pb age data for the LMR zircons was 369 ± 64 Ma, which is in good agreement with previously reported age data (367.6 ± 1.5 Ma). (1) The data obtained here clearly demonstrate that the multiple spot laser ablation-ICPMS technique can become a powerful approach for elemental and isotopic

  6. New functionalities in abundant element oxides: ubiquitous element strategy

    Directory of Open Access Journals (Sweden)

    Hideo Hosono, Katsuro Hayashi, Toshio Kamiya, Toshiyuki Atou and Tomofumi Susaki

    2011-01-01

    Full Text Available While most ceramics are composed of ubiquitous elements (the ten most abundant elements within the Earth's crust, many advanced materials are based on rare elements. A 'rare-element crisis' is approaching owing to the imbalance between the limited supply of rare elements and the increasing demand. Therefore, we propose a 'ubiquitous element strategy' for materials research, which aims to apply abundant elements in a variety of innovative applications. Creation of innovative oxide materials and devices based on conventional ceramics is one specific challenge. This review describes the concept of ubiquitous element strategy and gives some highlights of our recent research on the synthesis of electronic, thermionic and structural materials using ubiquitous elements.

  7. Coronae of Stars with Supersolar Elemental Abundances

    Science.gov (United States)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-01-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, iota Hor, HR 7291, tau Boo, and alpha Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and tau Boo no FIP effect is present, while iota Hor, HR 7291, and alpha Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  8. Rare earth element abundances in presolar SiC

    Science.gov (United States)

    Ireland, T. R.; Ávila, J. N.; Lugaro, M.; Cristallo, S.; Holden, P.; Lanc, P.; Nittler, L.; Alexander, C. M. O'D.; Gyngard, F.; Amari, S.

    2018-01-01

    Individual isotope abundances of Ba, lanthanides of the rare earth element (REE) group, and Hf have been determined in bulk samples of fine-grained silicon carbide (SiC) from the Murchison CM2 chondrite. The analytical protocol involved secondary ion mass spectrometry with combined high mass resolution and energy filtering to exclude REE oxide isobars and Si-C-O clusters from the peaks of interest. Relative sensitivity factors were determined through analysis of NIST SRM reference glasses (610 and 612) as well as a trace-element enriched SiC ceramic. When normalised to chondrite abundances, the presolar SiC REE pattern shows significant deficits at Eu and Yb, which are the most volatile of the REE. The pattern is very similar to that observed for Group III refractory inclusions. The SiC abundances were also normalised to s-process model predictions for the envelope compositions of low-mass (1.5-3 M⊙) AGB stars with close-to-solar metallicities (Z = 0.014 and 0.02). The overall trace element abundances (excluding Eu and Yb) appear consistent with the predicted s-process patterns. The depletions of Eu and Yb suggest that these elements remained in the gas phase during the condensation of SiC. The lack of depletion in some other moderately refractory elements (like Ba), and the presence of volatile elements (e.g. Xe) indicates that these elements were incorporated into SiC by other mechanisms, most likely ion implantation.

  9. A back-arc setting for mafic rocks of the Honeysuckle Beds, southeastern N.S.W.: the use of trace and rare earth element abundances determined by INAA

    Energy Technology Data Exchange (ETDEWEB)

    Dadd, K.A. [University of Technology, Sydney, NSW (Australia)

    1993-12-31

    Major, trace and rare earth elements abundance in mafic rocks of the Honeysuckle Beds was determined by x-ray fluorescence and neutron activation analysis . A comparison with typical mid-ocean ridge basalt compositions reveals an enrichment in light rare earths elements (Ba, Rb, and Th) and depletion in Nb, Ta and Ti, consistent with modifications of the source by subduction-related fluids. 9 refs., 6 figs.

  10. Neutron-capture Element Abundances in Magellanic Cloud Planetary Nebulae

    Science.gov (United States)

    Mashburn, A. L.; Sterling, N. C.; Madonna, S.; Dinerstein, Harriet L.; Roederer, I. U.; Geballe, T. R.

    2016-11-01

    We present near-infrared spectra of 10 planetary nebulae (PNe) in the Large and Small Magellanic Clouds (LMC and SMC), acquired with the FIRE and GNIRS spectrometers on the 6.5 m Baade and 8.1 m Gemini South Telescopes, respectively. We detect Se and/or Kr emission lines in eight of these objects, the first detections of n-capture elements in Magellanic Cloud PNe. Our abundance analysis shows large s-process enrichments of Kr (0.6-1.3 dex) in the six PNe in which it was detected, and Se is enriched by 0.5-0.9 dex in five objects. We also estimate upper limits to Rb and Cd abundances in these objects. Our abundance results for the LMC are consistent with the hypothesis that PNe with 2-3 M ⊙ progenitors dominate the bright end of the PN luminosity function in young gas-rich galaxies. We find no significant correlations between s-process enrichments and other elemental abundances, central star temperature, or progenitor mass, though this is likely due to our small sample size. We determine S abundances from our spectra and find that [S/H] agrees with [Ar/H] to within 0.2 dex for most objects, but is lower than [O/H] by 0.2-0.4 dex in some PNe, possibly due to O enrichment via third dredge-up. Our results demonstrate that n-capture elements can be detected in PNe belonging to nearby galaxies with ground-based telescopes, allowing s-process enrichments to be studied in PN populations with well-determined distances. This paper includes data obtained with the 6.5-m Magellan Telescopes located at Las Campanas Observatory, Chile, and with the Gemini-South Telescope at Cerro Pachon, Chile.

  11. Abundances of the heavy elements in the Magellanic Clouds. I. Metal abundances of F-type supergiants

    Energy Technology Data Exchange (ETDEWEB)

    Russell, S.C.; Bessell, M.S. (Mount Stromlo and Siding Spring Observatories, Canberra (Australia))

    1989-08-01

    Metal abundances of eight F-type supergiants in each of the Magellanic Clouds were determined using the results of high-resolution spectroscopy analysis of these stars, together with new Stromgren uvby and Cousins (1980) BVRI photometry. It was found that the mean Fe abundance (Fe/H) for the SMC is -0.65 + or - 0.2 dex, and the mean Fe abundance for the LMC is -0.30 + or - 0.2 dex. The abundances of stars in both the SMC and LMC appear relatively uniform, and the abundances of the elements relative to Fe are very similar in both Magellanic Clouds and in Canopus (the carbon-to-iron abundances are the same for all three). It was also found that Nd and Sm are overabundant in both clouds, supporting the trends found by Spite et al. (1988) for the three SMC stars they studied. 140 refs.

  12. The RAVE Catalog of Stellar Elemental Abundances : First Data Release

    NARCIS (Netherlands)

    Boeche, C.; Siebert, A.; Williams, M.; de Jong, R. S.; Steinmetz, M.; Fulbright, J. P.; Ruchti, G. R.; Bienayme, O.; Bland-Hawthorn, J.; Campbell, R.; Freeman, K. C.; Gibson, B. K.; Gilmore, G.; Grebel, E. K.; Helmi, A.; Munari, U.; Navarro, J. F.; Parker, Q. A.; Reid, W.; Seabroke, G. M.; Siviero, A.; Watson, F. G.; Wyse, R. F. G.; Zwitter, T.

    2011-01-01

    We present chemical elemental abundances for 36,561 stars observed by the RAdial Velocity Experiment (RAVE), an ambitious spectroscopic survey of our Galaxy at Galactic latitudes vertical bar b vertical bar > 25 degrees and with magnitudes in the range 9

  13. Abundances of chemical elements in the atmospheres of K gaints

    Energy Technology Data Exchange (ETDEWEB)

    Komarov, N.S.; Shcherbak, A.N.

    1980-05-01

    The physical parameters of seven stars are investigated in the report by a modified method of differential curves of growth. The abundances of chemical elements in their atmospheres are found. All the investigated stars, of spectral class KO III, belong to various open clusters.

  14. Trace Element Abundances in Extraterrestrial Apatite and Merrillite

    Science.gov (United States)

    Ward, D.; Bischoff, A.; Roszjar, J.; Berndt, J.; Whitehouse, M. J.

    2016-08-01

    The trace element abundances (Sc, Ti, V, Cr, Mn, Co, As, Rb, Sr, Y, Zr, Nb, Ba, Hf, Ta, Pb, Th, U, as well as the REE) of 133 apatite and 163 merrillite grains from 24 meteorites, covering 9 different classes were analyzed by LA-ICP-MS and SIMS.

  15. Trace Element Abundances in Refractory Inclusions from Antarctic Micrometeorites

    Science.gov (United States)

    Greshake, A.; Hoppe, P.; Bischoff, A.

    1995-09-01

    Refractory inclusions are charcteristic components in carbonaceous chondrites. Therefore, refractory inclusions found in micrometeorites can give important hints about the relationship between micrometeorites and carbonaceous chondrites. So far, only a few inclusions were found in micrometeorites [1-4]. In this study we report the first trace element analysis of perovskite and fassaite found in micrometeorites. We studied two Antarctic micrometeorites by ASEM, EMP, and SIMS. The first particle is 120 micrometers in size mainly consisting of a fine-grained matrix of dehydrated former phyllosilikates that enclose a 5 micrometers sized perovskite [5]. The perovskite is surrounded by a 1 micrometers thick rim of ilmenite and contains up to 1.3 wt% FeO as determined by EMP. The trace element abundances were determined by SIMS following the procedure described by [6]. The REE pattern of the perovskite is shown in Fig. 1. The pattern is closely related to the Group II pattern with its typical depletion of the more refractory REEs [7]. It is also very similar to the REE abundances of perovskite from Murchison (CM) [8] and CH-chondrites [9]. This may indicate a relationship between this micrometeorite and components in carbonaceous chondrites. The second micrometeorite is 100 micrometers in size consisting of a fine-grained (20 micrometers across) and a coarse-grained (80 micrometers across) area. Both areas contain fassaite with different chemical compositions. The particle was previously analyzed by Lindstrom and Kloeck [1] without knowing the mineralogy. We carried out SIMS analysis of each area of the micrometeorite separately. The TEE patterns of these two areas are similar and show in general a Group III pattern (20-30x CI) in which the more refractory REEs are not fractionated. The negative Eu anomaly is much more apparent in the coarse-grained area and no Yb anomaly is apparent in one of the areas. This is the first CAI of a micrometeorite showing a Group III REE

  16. Isotope-abundance variations of selected elements (IUPAC technical report)

    Science.gov (United States)

    Coplen, T.B.; Böhlke, J.K.; De Bievre, P.; Ding, T.; Holden, N.E.; Hopple, J.A.; Krouse, H.R.; Lamberty, A.; Peiser, H.S.; Revesz, K.; Rieder, S.E.; Rosman, K.J.R.; Roth, E.; Taylor, P.D.P.; Vocke, R.D.; Xiao, Y.K.

    2002-01-01

    Documented variations in the isotopic compositions of some chemical elements are responsible for expanded uncertainties in the standard atomic weights published by the Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry. This report summarizes reported variations in the isotopic compositions of 20 elements that are due to physical and chemical fractionation processes (not due to radioactive decay) and their effects on the standard atomic-weight uncertainties. For 11 of those elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulfur, chlorine, copper, and selenium), standard atomic-weight uncertainties have been assigned values that are substantially larger than analytical uncertainties because of common isotope-abundance variations in materials of natural terrestrial origin. For 2 elements (chromium and thallium), recently reported isotope-abundance variations potentially are large enough to result in future expansion of their atomic-weight uncertainties. For 7 elements (magnesium, calcium, iron, zinc, molybdenum, palladium, and tellurium), documented isotope variations in materials of natural terrestrial origin are too small to have a significant effect on their standard atomic-weight uncertainties. This compilation indicates the extent to which the atomic weight of an element in a given material may differ from the standard atomic weight of the element. For most elements given above, data are graphically illustrated by a diagram in which the materials are specified in the ordinate and the compositional ranges are plotted along the abscissa in scales of (1) atomic weight, (2) mole fraction of a selected isotope, and (3) delta value of a selected isotope ratio.

  17. BOND: Bayesian Oxygen and Nitrogen abundance Determinations

    Science.gov (United States)

    Vale Asari, N.; Stasinska, G.; Morisset, C.; Cid Fernandes, R.

    2018-01-01

    BOND determines oxygen and nitrogen abundances in giant H II regions by comparison with a large grid of photoionization models. The grid spans a wide range in O/H, N/O and ionization parameter U, and covers different starburst ages and nebular geometries. Unlike other statistical methods, BOND relies on the [Ar III]/[Ne III] emission line ratio to break the oxygen abundance bimodality. By doing so, it can measure oxygen and nitrogen abundances without assuming any a priori relation between N/O and O/H. BOND takes into account changes in the hardness of the ionizing radiation field, which can come about due to the ageing of H II regions or the stochastically sampling of the IMF. The emission line ratio He I/Hβ, in addition to commonly used strong lines, constrains the hardness of the ionizing radiation field. BOND relies on the emission line ratios [O III]/Hβ, [O II]/Hβ and [N II]/Hβ, [Ar III]/Hβ, [Ne III]/Hβ, He I/Hβ as its input parameters, while its output values are the measurements and uncertainties for O/H and N/O.

  18. The elemental abundances (with uncertainties) of the most Earth-like planet

    Science.gov (United States)

    Wang, Haiyang S.; Lineweaver, Charles H.; Ireland, Trevor R.

    2018-01-01

    To first order, the Earth as well as other rocky planets in the Solar System and rocky exoplanets orbiting other stars, are refractory pieces of the stellar nebula out of which they formed. To estimate the chemical composition of rocky exoplanets based on their stellar hosts' elemental abundances, we need a better understanding of the devolatilization that produced the Earth. To quantify the chemical relationships between the Earth, the Sun and other bodies in the Solar System, the elemental abundances of the bulk Earth are required. The key to comparing Earth's composition with those of other objects is to have a determination of the bulk composition with an appropriate estimate of uncertainties. Here we present concordance estimates (with uncertainties) of the elemental abundances of the bulk Earth, which can be used in such studies. First we compile, combine and renormalize a large set of heterogeneous literature values of the primitive mantle (PM) and of the core. We then integrate standard radial density profiles of the Earth and renormalize them to the current best estimate for the mass of the Earth. Using estimates of the uncertainties in i) the density profiles, ii) the core-mantle boundary and iii) the inner core boundary, we employ standard error propagation to obtain a core mass fraction of 32.5 ± 0.3 wt%. Our bulk Earth abundances are the weighted sum of our concordance core abundances and concordance PM abundances. Unlike previous efforts, the uncertainty on the core mass fraction is propagated to the uncertainties on the bulk Earth elemental abundances. Our concordance estimates for the abundances of Mg, Sn, Br, B, Cd and Be are significantly lower than previous estimates of the bulk Earth. Our concordance estimates for the abundances of Na, K, Cl, Zn, Sr, F, Ga, Rb, Nb, Gd, Ta, He, Ar, and Kr are significantly higher. The uncertainties on our elemental abundances usefully calibrate the unresolved discrepancies between standard Earth models under

  19. Chemical Cartography in the Milky Way with SDSS/APOGEE: Multi-element abundances and abundance ratio variations

    Science.gov (United States)

    Holtzman, Jon A.; Hasselquist, Sten; Johnson, Jennifer; Bird, Jonathan C.; Majewski, Steven R.; SDSS/APOGEE Team

    2017-01-01

    The SDSS/APOGEE project is measuring abundances of multiple elements for several hundred thousand stars across the Milky Way. These allow the mapping of abundances and abundance ratio variations. Results will be presented for multiple abundance ratios across of the Galactic disk. The interpretation of mean abundance maps is complicated by variations in star formation history across the disk and by changing abundance ratios that result from an overall metallicity gradient. Variations in chemical abundance sequences, however, show the potential for using abundance ratios to track the movement of stars through the disk, and provide key information for constraining Galaxy formation and chemical evolution models.

  20. Elemental abundances of flaring solar plasma - Enhanced neon and sulfur

    Science.gov (United States)

    Schmelz, J. T.

    1993-01-01

    Elemental abundances of two flares observed with the SMM Flat Crystal Spectrometer are compared and contrasted. The first had a gradual rise and a slow decay, while the second was much more impulsive. Simultaneous spectra of seven bright soft X-ray resonance lines provide information over a broad temperature range and are available throughout both flares, making these events unique in the SMM data base. For the first flare, the plasma seemed to be characterized by coronal abundances but, for the second, the plasma composition could not be coronal, photospheric, or a linear combination of both. A good differential emission measure fit required enhanced neon such that Ne/O = 0.32 +/- 0.02, a value which is inconsistent with the current models of coronal abundances based on the elemental first-ionization potential. Similar values of enhanced neon are found for flaring plasma observed by the SMM gamma-ray spectrometer, in (He-3)-rich solar energetic particle events, and in the decay phase of several long duration soft X-ray events. Sulfur is also enhanced in the impulsive flare, but not as dramatically as neon. These events are compared with two models which attempt to explain the enhanced values of neon and sulfur.

  1. Measuring 14 Elemental Abundances with R = 1800 LAMOST Spectra

    Science.gov (United States)

    Ting, Yuan-Sen; Rix, Hans-Walter; Conroy, Charlie; Ho, Anna Y. Q.; Lin, Jane

    2017-11-01

    The LAMOST survey has acquired low-resolution spectra (R = 1800) for 5 million stars across the Milky Way, far more than any current stellar survey at a corresponding or higher spectral resolution. It is often assumed that only very few elemental abundances can be measured from such low-resolution spectra, limiting their utility for Galactic archaeology studies. However, Ting et al. used ab initio models to argue that low-resolution spectra should enable precision measurements of many elemental abundances, at least in theory. Here, we verify this claim in practice by measuring the relative abundances of 14 elements from LAMOST spectra with a precision of ≲ 0.1 dex for objects with {{S}}/{{{N}}}{LAMOST}≳ 30 (per pixel). We employ a spectral modeling method in which a data-driven model is combined with priors that the model gradient spectra should resemble ab initio spectral models. This approach assures that the data-driven abundance determinations draw on physically sensible features in the spectrum in their predictions and do not just exploit astrophysical correlations among abundances. Our analysis is constrained to the number of elemental abundances measured in the APOGEE survey, which is the source of the training labels. Obtaining high quality/resolution spectra for a subset of LAMOST stars to measure more elemental abundances as training labels and then applying this method to the full LAMOST catalog will provide a sample with more than 20 elemental abundances, which is an order of magnitude larger than current high-resolution surveys, substantially increasing the sample size for Galactic archaeology.

  2. Atomic Diffusion, Mixing, and Element Abundances in Main Sequence Stars

    Science.gov (United States)

    Vauclair, S.

    2013-12-01

    Atomic diffusion is now recognized as a standard process working in stars, and gravitational settling is introduced in most stellar evolution codes. Helioseismology proved the importance of the downward diffusion of helium and heavy elements below the solar convective zone. However, in more massive stars, the effect of selective radiative accelerations cannot be neglected. It has been known for a long time that the resulting atomic levitation may, in some cases, lead to abundance variations in stellar atmospheres, as observed in the so-called chemically peculiar stars. But this was only part of the story. We have now discovered that, when acting on important elements like iron or nickel, radiative levitation may also lead to global macroscopic effects inside stars, like extra convective zones, wave excitation by the κ-mechanism, and double-diffusive mixing processes like fingering (thermohaline) convection. This paper presents some links between these processes and their consequences.

  3. Isotope-abundance variations and atomic weights of selected elements: 2016 (IUPAC Technical Report)

    Science.gov (United States)

    Coplen, Tyler B.; Shrestha, Yesha

    2016-01-01

    There are 63 chemical elements that have two or more isotopes that are used to determine their standard atomic weights. The isotopic abundances and atomic weights of these elements can vary in normal materials due to physical and chemical fractionation processes (not due to radioactive decay). These variations are well known for 12 elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnesium, silicon, sulfur, chlorine, bromine, and thallium), and the standard atomic weight of each of these elements is given by IUPAC as an interval with lower and upper bounds. Graphical plots of selected materials and compounds of each of these elements have been published previously. Herein and at the URL http://dx.doi.org/10.5066/F7GF0RN2, we provide isotopic abundances, isotope-delta values, and atomic weights for each of the upper and lower bounds of these materials and compounds.

  4. Determination of rare earth and refractory trace element ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    elemental abundances in solids with spatial reso- lution of a few microns is ideally suited for this purpose and has been used extensively in recent years for determining REE abundances in micro- scopic extraterrestrial samples (Fahey et al 1987;. Hinton et al 1988; Ireland et al 1988; Ireland 1990,. Sahijpal et al 2000).

  5. THE ATOMIC WEIGHTS COMMISSION AND ISOTOPIC ABUNDANCE RATIO DETERMINATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN, N.E.

    2005-08-07

    Following Thomson's discovery of stable isotopes in non-radioactive chemical elements, the derivation of atomic weight values from mass spectrometric measurements of isotopic abundance ratios moved very slowly. Forty years later, only 3 1/2 % of the recommended values were based on mass spectrometric measurements and only 38% in the first half century. It might be noted that two chemical elements (tellurium and mercury) are still based on chemical measurements, where the atomic weight value calculated from the relative isotopic abundance measurement either agrees with the value from the chemical measurement or the atomic weight value calculated from the relative isotopic abundance measurement falls within the uncertainty of the chemical measurement of the atomic weight. Of the 19 chemical elements, whose atomic weight is based on non-corrected relative isotopic abundance measurements, five of these are two isotope systems (indium, iridium, lanthanum, lutetium and tantalum) and one is a three-isotope system (oxygen).

  6. Abundances of neutron-capture elements in G 24-25

    DEFF Research Database (Denmark)

    Liu, S.; Nissen, Poul Erik; Schuster, W. J.

    2012-01-01

    Aims. The differences between the neutron-capture element abundances of halo stars are important to our understanding of the nucleosynthesis of elements heavier than the iron group. We present a detailed abundance analysis of carbon and twelve neutron-capture elements from Sr up to Pb...... overabundances of carbon and heavy s-process elements and mild overabundances of Eu and light s-process elements. This abundance distribution is consistent with that of a typical CH giant. The abundance pattern can be explained by mass transfer from a former asymptotic giant branch component, which is now...

  7. VizieR Online Data Catalog: Line list for abundance determination in Sun siblings (Liu+, 2015)

    Science.gov (United States)

    Liu, C.; Ruchti, G.; Feltzing, S.; Martinez-Barbosa, A. C.; Bensby, T.; Brown, G. A. A.; Portegies Zwart, F. S.

    2015-01-01

    On table 2 we list all spectral lines that have been used to determine elemental abundances. Columns 1 gives the element with a degree of ionization. The wavelength, excitation potential and adopted loggf values are listed in the Columns 2, 3, and 4, respectively. References to the adopted log gf values are given in Column 5. (2 data files).

  8. Nanomaterials made of earth-abundant elements for photovoltaics

    Science.gov (United States)

    Molk, Doreen

    Of the many types of solar cells currently under exploration, multijunction photovoltaics (MJPVs) are of the most interest due to their record-breaking solar energy conversion efficiencies (over 40%). However, MJPV device fabrication is expensive because they require a costly synthesis technique that utilizes rare elements such as gallium, arsenic, and indium. To resolve this issue, our efforts have been focused on the replacement of the thin-film materials currently employed in MJPVs with a more earth-abundant alternative, Zn-alloyed iron pyrite (ZnxFe(1-x)S2). The synthesis of ZnxFe(1-x)S2 nanoparticles is of particular interest because a nanoparticle 'ink' can be inserted into a roll-to-roll processor, which is an inexpensive technique of creating defect-free thin-films for electronics. The first part of this work explores the synthesis of Zn-alloyed iron pyrite nanoparticles via the modification of a solvothermal method from the literature. The nanoparticles generated using this method at first indicated zinc-alloying was successful; yet, further studies into the electronic structure of the particles necessitated the addition of a spin-purification step to ensure only highly soluble particles remained for spin-coating deposition. Compositional and structural analysis of the particles that remained after the additional spin-purification step showed evidence of both the ZnS and FeS2 phases. The second part of this work focuses on the development of an alternative method of generating iron pyrite nanoparticles, which would also eventually be used for zinc-alloying. The two approaches focused on are a hydrothermal method in an acid-digestion bomb and a non-injection solvothermal method in an inert environment. The synthesized particles using these methods were phase-pure and did not contain any detectable quantity of other iron sulfides.

  9. X-shooter spectroscopy of young stellar objects in Lupus. Lithium, iron, and barium elemental abundances

    Science.gov (United States)

    Biazzo, K.; Frasca, A.; Alcalá, J. M.; Zusi, M.; Covino, E.; Randich, S.; Esposito, M.; Manara, C. F.; Antoniucci, S.; Nisini, B.; Rigliaco, E.; Getman, F.

    2017-09-01

    Aims: With the purpose of performing a homogeneous determination of elemental abundances for members of the Lupus T association, we analyzed three chemical elements: lithium, iron, and barium. The aims were: 1) to derive the lithium abundance for the almost complete sample ( 90%) of known class II stars in the Lupus I, II, III, and IV clouds; 2) to perform chemical tagging of a region where few iron abundance measurements have been obtained in the past, and no determination of the barium content has been done up to now. We also investigated possible barium enhancement at the very young age of the region, as this element has become increasingly interesting in the last few years following the evidence of barium over-abundance in young clusters, the origin of which is still unknown. Methods: Using the X-shooter spectrograph mounted on the Unit 2 (UT2) at the Very Large Telescope (VLT), we analyzed the spectra of 89 cluster members, both class II (82) and class III (7) stars. We measured the strength of the lithium line at λ6707.8 Å and derived the abundance of this element through equivalent width measurements and curves of growth. For six class II stars we also derived the iron and barium abundances using the spectral synthesis method and the code MOOG. The veiling contribution was taken into account in the abundance analysis for all three elements. Results: We find a dispersion in the strength of the lithium line at low effective temperatures and identify three targets with severe Li depletion. The nuclear age inferred for these highly lithium-depleted stars is around 15 Myr, which exceeds by an order of magnitude the isochronal one. We derive a nearly solar metallicity for the members whose spectra could be analyzed. We find that Ba is over-abundant by 0.7 dex with respect to the Sun. Since current theoretical models cannot reproduce this abundance pattern, we investigated whether this unusually large Ba content might be related to effects due to stellar

  10. High-precision abundances of elements in Kepler LEGACY stars. Verification of trends with stellar age

    Science.gov (United States)

    Nissen, P. E.; Silva Aguirre, V.; Christensen-Dalsgaard, J.; Collet, R.; Grundahl, F.; Slumstrup, D.

    2017-12-01

    Context. A previous study of solar twin stars has revealed the existence of correlations between some abundance ratios and stellar age providing new knowledge about nucleosynthesis and Galactic chemical evolution. Aims: High-precision abundances of elements are determined for stars with asteroseismic ages in order to test the solar twin relations. Methods: HARPS-N spectra with signal-to-noise ratios S/N ≳ 250 and MARCS model atmospheres were used to derive abundances of C, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, and Y in ten stars from the Kepler LEGACY sample (including the binary pair 16 Cyg A and B) selected to have metallicities in the range - 0.15 LTE iron abundances derived from Fe I and Fe II lines. Available non-LTE corrections were also applied when deriving abundances of the other elements. Results: The abundances of the Kepler stars support the [X/Fe]-age relations previously found for solar twins. [Mg/Fe], [Al/Fe], and [Zn/Fe] decrease by 0.1 dex over the lifetime of the Galactic thin disk due to delayed contribution of iron from Type Ia supernovae relative to prompt production of Mg, Al, and Zn in Type II supernovae. [Y/Mg] and [Y/Al], on the other hand, increase by 0.3 dex, which can be explained by an increasing contribution of s-process elements from low-mass AGB stars as time goes on. The trends of [C/Fe] and [O/Fe] are more complicated due to variations of the ratio between refractory and volatile elements among stars of similar age. Two stars with about the same age as the Sun show very different trends of [X/H] as a function of elemental condensation temperature Tc and for 16 Cyg, the two components have an abundance difference, which increases with Tc. These anomalies may be connected to planet-star interactions. Based on spectra obtained with HARPS-N@TNG under programme A33TAC_1.Tables 1 and 2 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc

  11. Prospects for Measuring Abundances of >20 Elements with Low-resolution Stellar Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Ting Yuan-Sen; Conroy, Charlie; Cargile, Phillip [Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rix, Hans-Walter [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)

    2017-07-01

    Understanding the evolution of the Milky Way calls for the precise abundance determination of many elements in many stars. A common perception is that deriving more than a few elemental abundances ([Fe/H], [ α /Fe], perhaps [C/H], [N/H]) requires medium-to-high spectral resolution, R ≳ 10,000, mostly to overcome the effects of line blending. In a recent work, we presented an efficient and practical way to model the full stellar spectrum, even when fitting a large number of stellar labels simultaneously. In this paper, we quantify to what precision the abundances of many different elements can be recovered, as a function of spectroscopic resolution and wavelength range. In the limit of perfect spectral models and spectral normalization, we show that the precision of elemental abundances is nearly independent of resolution, for a fixed exposure time and number of detector pixels; low-resolution spectra simply afford much higher S/N per pixel and generally larger wavelength range in a single setting. We also show that estimates of most stellar labels are not strongly correlated with one another once R ≳ 1000. Modest errors in the line-spread function, as well as small radial velocity errors, do not affect these conclusions, and data-driven models indicate that spectral (continuum) normalization can be achieved well enough in practice. These results, to be confirmed with an analysis of observed low-resolution data, open up new possibilities for the design of large spectroscopic stellar surveys and for the reanalysis of archival low-resolution data sets.

  12. The abundance of some elements in hair from Tanzanian children ...

    African Journals Online (AJOL)

    Samples of hair from children living in three regions in Tanzania were analysed for their elemental content using instrumental neutron activation analysis (INAA) of Nuclear Physics Institute (NPI) at Rez, Czech Republic. The elements were tested for the type of probability distribution; hence frequency histograms for the ...

  13. The light element abundance distribution in NGC 5128 from planetary nebulae

    NARCIS (Netherlands)

    Walsh, J. R.; Jacoby, G. H.; Peletier, R. F.; Walton, N. A.

    Context. Planetary nebulae in the nearest large elliptical galaxy provide light element abundances difficult or impossible to measure by other means in a stellar system very different from the galaxies in the Local Group. Aims. The light element abundance pattern from many planetary nebulae (PNe) at

  14. Spatial Distribution of Element Abundances and Ionization States in Solar Energetic-Particle Events

    Science.gov (United States)

    Reames, Donald V.

    2017-08-01

    We have studied the spatial and temporal distribution of abundances of chemical elements in large "gradual" solar energetic-particle (SEP) events, and especially the source plasma temperatures, derived from those abundances, using measurements from the Wind and Solar TErrestrial RElations Observatory (STEREO) spacecraft, widely separated in solar longitude. A power-law relationship between abundance enhancements and mass-to-charge ratios [A/Q] of the ions can be used to determine Q-values and source plasma temperatures at remote spacecraft with instruments that were not designed for charge-state measurements. We search for possible source variations along the accelerating shock wave, finding one clear case where the accelerating shock wave appears to dispatch ions from 3.2± 0.8 MK plasma toward one spacecraft and those from 1.6± 0.2 MK plasma toward another, 116∘ away. The difference persists for three days and then fades away. Three other SEP events show less-extreme variation in source temperatures at different spacecraft, in one case observed over 222∘ in longitude. This initial study shows how the power-law relation between abundance enhancements and ion A/Q-values provides a new technique to determine Q and plasma temperatures in the seed population of SEP ions over a broad region of space using remote spacecraft with instruments that were not originally designed for measurements of ionization states.

  15. Abundances of the light elements from UV (HST) and red (ESO) spectra in the very old star HD 84937

    Science.gov (United States)

    Spite, M.; Peterson, R. C.; Gallagher, A. J.; Barbuy, B.; Spite, F.

    2017-04-01

    Aims: In order to provide a better basis for the study of mechanisms of nucleosynthesis of the light elements beyond hydrogen and helium in the oldest stars, the abundances of C, O, Mg, Si, P, S, K, and Ca have been derived from UV-HST and visible-ESO high resolution spectra in the old, very metal-poor star HD 84937, at a metallicity that is 1/200 that of the Sun's. For this halo main-sequence turnoff star, the abundance determination of P and S are the first published determinations. Methods: The LTE profiles of the lines were computed and fitted to the observed spectra. Wherever possible, we compared the abundances derived from the UV spectrum to abundances derived from the visible or near-infrared spectra, and also corrected the derived abundances for non-LTE effects. Three-dimensional (3D) CO5BOLD model atmospheres have been used to determine the abundances of C and O from molecular CH and OH bands. Results: The abundances of these light elements relative to iron in HD 84937 are found to agree well with the abundances of these elements in classical metal-poor stars. Our HD 84937 carbon abundance determination points toward a solar (or mildly enhanced above solar) value of [C/Fe]. The modest overabundance of the α elements of even atomic number Z, typical of halo turnoff stars, is confirmed in this example. The odd-Z element P is found to be somewhat deficient in HD 84937, at [P/Fe] = -0.32, which is again consistent with the handful of existing determinations for turnoff stars of such low metallicity. We show that the abundance of oxygen, deduced from the OH band from 3D computations, is not compatible with the abundance deduced from the red oxygen triplet. This incompatibility is explained by the existence of a chromosphere heating the shallow layers of the atmosphere where the OH band, in 3D computations, is mainly formed. Conclusions: The abundance ratios are compared to the predictions of models of galactic nucleosynthesis and evolution. Based on

  16. Determinants of protein abundance and translation efficiency in S. cerevisiae.

    Directory of Open Access Journals (Sweden)

    Tamir Tuller

    2007-12-01

    Full Text Available The translation efficiency of most Saccharomyces cerevisiae genes remains fairly constant across poor and rich growth media. This observation has led us to revisit the available data and to examine the potential utility of a protein abundance predictor in reinterpreting existing mRNA expression data. Our predictor is based on large-scale data of mRNA levels, the tRNA adaptation index, and the evolutionary rate. It attains a correlation of 0.76 with experimentally determined protein abundance levels on unseen data and successfully cross-predicts protein abundance levels in another yeast species (Schizosaccharomyces pombe. The predicted abundance levels of proteins in known S. cerevisiae complexes, and of interacting proteins, are significantly more coherent than their corresponding mRNA expression levels. Analysis of gene expression measurement experiments using the predicted protein abundance levels yields new insights that are not readily discernable when clustering the corresponding mRNA expression levels. Comparing protein abundance levels across poor and rich media, we find a general trend for homeostatic regulation where transcription and translation change in a reciprocal manner. This phenomenon is more prominent near origins of replications. Our analysis shows that in parallel to the adaptation occurring at the tRNA level via the codon bias, proteins do undergo a complementary adaptation at the amino acid level to further increase their abundance.

  17. Land use determinants of small mammals abundance and ...

    African Journals Online (AJOL)

    Small mammals are considered to be involved in the transmission cycle of bubonic plague, still occurring in different parts of the world, including the Lushoto district in Tanzania. The objective of this study was to determine the relationship between land use types and practices and small mammal abundance and distribution.

  18. Using Cepheids to determine the galactic abundance gradient. I. The solar neighbourhood

    Science.gov (United States)

    Andrievsky, S. M.; Kovtyukh, V. V.; Luck, R. E.; Lépine, J. R. D.; Bersier, D.; Maciel, W. J.; Barbuy, B.; Klochkova, V. G.; Panchuk, V. E.; Karpischek, R. U.

    2002-01-01

    A number of studies of abundance gradients in the galactic disk have been performed in recent years. The results obtained are rather disparate: from no detectable gradient to a rather significant slope of about -0.1 dex kpc-1. The present study concerns the abundance gradient based on the spectroscopic analysis of a sample of classical Cepheids. These stars enable one to obtain reliable abundances of a variety of chemical elements. Additionally, they have well determined distances which allow an accurate determination of abundance distributions in the galactic disc. Using 236 high resolution spectra of 77 galactic Cepheids, the radial elemental distribution in the galactic disc between galactocentric distances in the range 6-11 kpc has been investigated. Gradients for 25 chemical elements (from carbon to gadolinium) are derived. The following results were obtained in this study. Almost all investigated elements show rather flat abundance distributions in the middle part of galactic disc. Typical values for iron-group elements lie within an interval from ~-0.02 to ~-0.04 dex kpc-1 (in particular, for iron we obtained d[Fe/H]/dRG =-0.029 dex kpc-1). Similar gradients were also obtained for O, Mg, Al, Si, and Ca. For sulphur we have found a steeper gradient (-0.05 dex kpc-1). For elements from Zr to Gd we obtained (within the error bars) a near to zero gradient value. This result is reported for the first time. Those elements whose abundance is not expected to be altered during the early stellar evolution (e.g. the iron-group elements) show at the solar galactocentric distance [El/H] values which are essentially solar. Therefore, there is no apparent reason to consider our Sun as a metal-rich star. The gradient values obtained in the present study indicate that the radial abundance distribution within 6-11 kpc is quite homogeneous, and this result favors a galactic model including a bar structure which may induce radial flows in the disc, and thus may be responsible

  19. Element distribution and noble gas isotopic abundances in lunar meteorite Allan Hills A81005

    Science.gov (United States)

    Kraehenbuehl, U.; Eugster, O.; Niedermann, S.

    1986-01-01

    Antarctic meteorite ALLAN HILLS A81005, an anorthositic breccia, is recognized to be of lunar origin. The noble gases in this meteorite were analyzed and found to be solar-wind implanted gases, whose absolute and relative concentrations are quite similar to those in lunar regolith samples. A sample of this meteorite was obtained for the analysis of the noble gas isotopes, including Kr(81), and for the determination of the elemental abundances. In order to better determine the volume derived from the surface correlated gases, grain size fractions were prepared. The results of the instrumental measurements of the gamma radiation are listed. From the amounts of cosmic ray produced noble gases and respective production rates, the lunar surface residence times were calculated. It was concluded that the lunar surface time is about half a billion years.

  20. Anatomy of a cluster IDP. Part 2: Noble gas abundances, trace element geochemistry, isotopic abundances, and trace organic chemistry of several fragments from L2008#5

    Science.gov (United States)

    Thomas, K. L.; Clemett, S. J.; Flynn, G. J.; Keller, L. P.; Mckay, David S.; Messenger, S.; Nier, A. O.; Schlutter, D. J.; Sutton, S. R.; Walker, R. M.

    1994-01-01

    The topics discussed include the following: noble gas content and release temperatures; trace element abundances; heating summary of cluster fragments; isotopic measurements; and trace organic chemistry.

  1. Is Markhamia lutea's abundance determined by animal foraging?

    Science.gov (United States)

    Chapman, Colin A; Bonnell, Tyler R; Sengupta, Raja; Goldberg, Tony L; Rothman, Jessica M

    2013-11-15

    Understanding the determinants of tropical forest tree richness and spatial distribution is a central goal of forest ecology; however, the role of herbivorous mammals has received little attention. Here we explore the potential for red colobus monkeys (Procolobus rufomitratus) to influence the abundance of Markhamia lutea trees in a tropical forest by feeding extensively on the tree's flowers, such that this tree population is not able to regularly set fruit. Using 14 years of data from Kibale National Park, Uganda, we quantify M. lutea flower and fruit production. Similarly, using 21 years of data, we quantify temporal changes in the abundance of stems in size classes from 1 m tall and above. Our analyses demonstrate that M. lutea is rarely able to produce fruit and that this corresponds to a general decline in its abundance across all size classes. Moreover, using 7 years of feeding records, we demonstrate that red colobus feed on M. lutea, consuming large amounts of leaf and flower buds whenever they were available, suggesting that this behavior limits fruit production. Therefore, we suggest that red colobus are presently important for structuring the distribution and abundance of M. lutea in Kibale. This dynamic raises the intriguing question of how a large M. lutea population was able to originally establish. There is no evidence of a change in red colobus population size; however, if this old-growth forest is in a non-equilibrium state, M. lutea may have become established when red colobus ate a different diet.

  2. AlterBBN: A program for calculating the BBN abundances of the elements in alternative cosmologies

    CERN Document Server

    Arbey, Alexandre

    2012-01-01

    We describe AlterBBN, a public C program for evaluating the abundances of the elements generated by Big-Bang nucleosynthesis (BBN). This program enables the user to compute the abundances of the elements in the standard model of cosmology, and additionally provides possibilities to alter the assumptions of the cosmological model in order to study their consequences on the abundances of the elements. In particular the baryon-to-photon ratio and the effective number of neutrinos, as well as the expansion rate and the entropy content of the Universe during BBN can be modified in AlterBBN. Such features allow the user to test the cosmological models by confronting them to BBN constraints. A presentation of the physics of BBN and the features of AlterBBN is provided here under the form of a manual.

  3. The Abundance of Iron-Peak Elements and the Dust Composition in eta Carinae: Manganese

    Science.gov (United States)

    Bautista, M. A.; Melendez, M.; Hartman, H.; Gull, T. R.; Lodders, K.

    2010-01-01

    We study the chemical abundances of the Strontium Filament found in the ejecta of (eta) Carinae. In particular, we derive the abundances of iron-peak elements front spectra of their singly ionized ions present in the optical/IR spectra. In this paper we analyze the spectrum of Mn II using a new non-LTE model for this system. In constructing this models we carried out theoretical calculations of radiative transition rates and electron impact excitation rate coefficients. We find that relative to Ni the gas phase abundance ratio of Mn is roughly solar, similar to the Cr abundance but in contrast to the large enhancements in the abundances of Sc and Ti. NVe interpret this result as an indication of non-equilibrium condensation in the ejecta of (eta) Carinae.

  4. Detailed chemical abundances in NGC 5824: another metal-poor globular cluster with internal heavy element abundance variations

    Science.gov (United States)

    Roederer, Ian U.; Mateo, Mario; Bailey, John I.; Spencer, Meghin; Crane, Jeffrey D.; Shectman, Stephen A.

    2016-01-01

    We present radial velocities, stellar parameters, and detailed abundances of 39 elements derived from high-resolution spectroscopic observations of red giant stars in the luminous, metal-poor globular cluster NGC 5824. We observe 26 stars in NGC 5824 using the Michigan/Magellan Fiber System (M2FS) and two stars using the Magellan Inamori Kyocera Echelle spectrograph. We derive a mean metallicity of [Fe/H] = -1.94 ± 0.02 (statistical) ±0.10 (systematic). The metallicity dispersion of this sample of stars, 0.08 dex, is in agreement with previous work and does not exceed the expected observational errors. Previous work suggested an internal metallicity spread only when fainter samples of stars were considered, so we cannot exclude the possibility of an intrinsic metallicity dispersion in NGC 5824. The M2FS spectra reveal a large internal dispersion in [Mg/Fe], 0.28 dex, which is found in a few other luminous, metal-poor clusters. [Mg/Fe] is correlated with [O/Fe] and anticorrelated with [Na/Fe] and [Al/Fe]. There is no evidence for internal dispersion among the other α- or Fe-group abundance ratios. 25 of the 26 stars exhibit a n-capture enrichment pattern dominated by r-process nucleosynthesis ( = +0.11 ± 0.12; = -0.66 ± 0.05). Only one star shows evidence of substantial s-process enhancement ([Ba/Fe] = +0.56 ± 0.12; [Ba/Eu] = +0.38 ± 0.14), but this star does not exhibit other characteristics associated with s-process enhancement via mass transfer from a binary companion. The Pb and other heavy elements produced by the s-process suggest a time-scale of no more than a few hundred Myr for star formation and chemical enrichment, like the complex globular clusters M2, M22, and NGC 5286.

  5. An MCMC determination of the primordial helium abundance

    Energy Technology Data Exchange (ETDEWEB)

    Aver, Erik; Olive, Keith A.; Skillman, Evan D., E-mail: aver@physics.umn.edu, E-mail: olive@umn.edu, E-mail: skillman@astro.umn.edu [School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States)

    2012-04-01

    Spectroscopic observations of the chemical abundances in metal-poor H II regions provide an independent method for estimating the primordial helium abundance. H II regions are described by several physical parameters such as electron density, electron temperature, and reddening, in addition to y, the ratio of helium to hydrogen. It had been customary to estimate or determine self-consistently these parameters to calculate y. Frequentist analyses of the parameter space have been shown to be successful in these parameter determinations, and Markov Chain Monte Carlo (MCMC) techniques have proven to be very efficient in sampling this parameter space. Nevertheless, accurate determination of the primordial helium abundance from observations of H II regions is constrained by both systematic and statistical uncertainties. In an attempt to better reduce the latter, and continue to better characterize the former, we apply MCMC methods to the large dataset recently compiled by Izotov, Thuan, and Stasińska (2007). To improve the reliability of the determination, a high quality dataset is needed. In pursuit of this, a variety of cuts are explored. The efficacy of the He I λ4026 emission line as a constraint on the solutions is first examined, revealing the introduction of systematic bias through its absence. As a clear measure of the quality of the physical solution, a χ{sup 2} analysis proves instrumental in the selection of data compatible with the theoretical model. Nearly two-thirds of the observations fall outside a standard 95% confidence level cut, which highlights the care necessary in selecting systems and warrants further investigation into potential deficiencies of the model or data. In addition, the method also allows us to exclude systems for which parameter estimations are statistical outliers. As a result, the final selected dataset gains in reliability and exhibits improved consistency. Regression to zero metallicity yields Y{sub p} = 0.2534 ± 0.0083, in

  6. The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Optical Extension for Neutron Capture Elements

    Science.gov (United States)

    Melendez, Matthew; O'Connell, Julia; Frinchaboy, Peter M.; Donor, John; Cunha, Katia M. L.; Shetrone, Matthew D.; Majewski, Steven R.; Zasowski, Gail; Pinsonneault, Marc H.; Roman-Lopes, Alexandre; Stassun, Keivan G.; APOGEE Team

    2017-01-01

    The Open Cluster Chemical Abundance & Mapping (OCCAM) survey is a systematic survey of Galactic open clusters using data primarily from the SDSS-III/APOGEE-1 survey. However, neutron capture elements are very limited in the IR region covered by APOGEE. In an effort to fully study detailed Galactic chemical evolution, we are conducting a high resolution (R~60,000) spectroscopic abundance analysis of neutron capture elements for OCCAM clusters in the optical regime to complement the APOGEE results. As part of this effort, we present Ba II, La II, Ce II and Eu II results for a few open clusters without previous abundance measurements using data obtained at McDonald Observatory with the 2.1m Otto Struve telescope and Sandiford Echelle Spectrograph.This work is supported by an NSF AAG grant AST-1311835.

  7. VizieR Online Data Catalog: α-element abundances of Cepheid stars (Genovali+, 2015)

    Science.gov (United States)

    Genovali, K.; Lemasle, B.; da Silva, R.; Bono, G.; Fabrizio, M.; Bergemann, M.; Buonanno, R.; Ferraro, I.; Francois, P.; Iannicola, G.; Inno, L.; Laney, C. D.; Kudritzki, R.-P.; Matsunaga, N.; Nonino, M.; Primas, F.; Romaniello, M.; Urbaneja, M. A.; Thevenin, F.

    2015-04-01

    The abundances of Fe, Na, Al, and three alpha elements (Mg, Si, Ca) for our sample of 75 Cepheids plus data available in the literature for other 364 Cepheids are shown. We first show the abundances derived based on individual spectra for the 75 stars, then the averaged values, and finally the data from the literature. The original abundances available in the literature were rescaled according to the zero-point differences listed in Table 3. The priority was given in the following order: we first adopt the abundances provided by our group, this study (TS) and Lemasle et al. (2013A&A...558A..31L, LEM), and then those provided by the other studies, Luck & Lambert (2011AJ....142..136L, LIII), Luck et al. (2011AJ....142...51L, LII), and Yong et al. (2006AJ....131.2256Y, YON). (3 data files).

  8. Probabilisitc Geobiological Classification Using Elemental Abundance Distributions and Lossless Image Compression in Recent and Modern Organisms

    Science.gov (United States)

    Storrie-Lombardi, Michael C.; Hoover, Richard B.

    2005-01-01

    Last year we presented techniques for the detection of fossils during robotic missions to Mars using both structural and chemical signatures[Storrie-Lombardi and Hoover, 2004]. Analyses included lossless compression of photographic images to estimate the relative complexity of a putative fossil compared to the rock matrix [Corsetti and Storrie-Lombardi, 2003] and elemental abundance distributions to provide mineralogical classification of the rock matrix [Storrie-Lombardi and Fisk, 2004]. We presented a classification strategy employing two exploratory classification algorithms (Principal Component Analysis and Hierarchical Cluster Analysis) and non-linear stochastic neural network to produce a Bayesian estimate of classification accuracy. We now present an extension of our previous experiments exploring putative fossil forms morphologically resembling cyanobacteria discovered in the Orgueil meteorite. Elemental abundances (C6, N7, O8, Na11, Mg12, Ai13, Si14, P15, S16, Cl17, K19, Ca20, Fe26) obtained for both extant cyanobacteria and fossil trilobites produce signatures readily distinguishing them from meteorite targets. When compared to elemental abundance signatures for extant cyanobacteria Orgueil structures exhibit decreased abundances for C6, N7, Na11, All3, P15, Cl17, K19, Ca20 and increases in Mg12, S16, Fe26. Diatoms and silicified portions of cyanobacterial sheaths exhibiting high levels of silicon and correspondingly low levels of carbon cluster more closely with terrestrial fossils than with extant cyanobacteria. Compression indices verify that variations in random and redundant textural patterns between perceived forms and the background matrix contribute significantly to morphological visual identification. The results provide a quantitative probabilistic methodology for discriminating putatitive fossils from the surrounding rock matrix and &om extant organisms using both structural and chemical information. The techniques described appear applicable

  9. Determination of osmium isotope abundances by high resolution laser spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schieder, R.; Sorgalla, K.H.; Herr, W.

    1981-01-01

    A new optical method for isotopic abundance determinations based on Laser saturation spectroscopy is described. The technique has been applied on gaseous OsO/sub 4/ at low pressure, using a single mode CO/sub 2/-Laser at lambda = 10,4 ..mu..m. Compared with the linear absorption spectroscopy, the saturation method has the advantage that higher sensitivity is easiliy achieved by phase sensitive detection. As an example radiogenic /sup 187/Os in a molybdenite from S.W. Africa is measured and the age of the ore, determined by the Re/Os-method is (5.3 +- 0.4) x 10/sup 8/ years. Further, the /sup 186/Os(n,..gamma..)/sup 187/Os cross section was evaluated by breeding Os-isotopes from Rhenium in a high flux nuclear reactor. In this case, a cross section ratio R = sigmasub(eff)(/sup 186/Os)/ sigmasub(eff)(/sup 187/Os) = O.245 was obtained. The /sup 186/Os-resonance integral was estimated to be Isub(infinite) = 375 +- 90 b. Certain implications of R, with respect to the age of the universe (duration of the nucleosynthesis) are pointed out.

  10. The Origin of Solar Filament Plasma Inferred from In Situ Observations of Elemental Abundances

    Energy Technology Data Exchange (ETDEWEB)

    Song, H. Q.; Chen, Y.; Li, B. [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, and Institute of Space Sciences, Shandong University, Weihai, Shandong 264209 (China); Li, L. P. [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Zhao, L. [Department of Climate and Space sciences and Engineering, University of Michigan, Ann Arbor, MI 48105 (United States); He, J. S.; Duan, D. [School of Earth and Space Sciences, Peking University, Beijing 100871 (China); Cheng, X. [School of Astronomy and Space Science, Nanjing University, Nanjing, Jiangsu 210093 (China); Zhang, J., E-mail: hqsong@sdu.edu.cn [Department of Physics and Astronomy, George Mason University, Fairfax, VA 22030 (United States)

    2017-02-10

    Solar filaments/prominences are one of the most common features in the corona, which may lead to energetic coronal mass ejections (CMEs) and flares when they erupt. Filaments are about 100 times cooler and denser than the coronal material, and physical understanding of their material origin remains controversial. Two types of scenarios have been proposed: one argues that the filament plasma is brought into the corona from photosphere or chromosphere through a siphon or evaporation/injection process, while the other suggests that the material condenses from the surrounding coronal plasma due to thermal instability. The elemental abundance analysis is a reasonable clue to constrain the models, as the siphon or evaporation/injection model would predict that the filament material abundances are close to the photospheric or chromospheric ones, while the condensation model should have coronal abundances. In this Letter, we analyze the elemental abundances of a magnetic cloud that contains the ejected filament material. The corresponding filament eruption occurred on 1998 April 29, accompanying an M6.8 class soft X-ray flare located at the heliographic coordinates S18E20 (NOAA 08210) and a fast halo CME with the linear velocity of 1374 km s{sup −1} near the Sun. We find that the abundance ratios of elements with low and high first ionization potential such as Fe/O, Mg/O, and Si/O are 0.150, 0.050, and 0.070, respectively, approaching their corresponding photospheric values 0.065, 0.081, and 0.066, which does not support the coronal origin of the filament plasma.

  11. Revisiting the plant hyperaccumulation criteria to rare plants and earth abundant elements

    Energy Technology Data Exchange (ETDEWEB)

    Branquinho, Cristina [Universidade de Lisboa, Faculdade de Ciencias, Centro de Ecologia e Biologia Vegetal, Campo Grande C2, Piso 4, 1749-016 Lisbon (Portugal) and Universidade Atlantica, Antiga Fabrica da Polvora de Barcarena, 2745-615 Barcarena (Portugal)]. E-mail: cmbranquinho@fc.ul.pt; Serrano, Helena Cristina [Universidade de Lisboa, Museu Nacional de Historia Natural, Jardim Botanico (Portugal); Pinto, Manuel Joao [Universidade de Lisboa, Museu Nacional de Historia Natural, Jardim Botanico (Portugal); Martins-Loucao, Maria Amelia [Universidade de Lisboa, Faculdade de Ciencias, Centro de Ecologia e Biologia Vegetal, Campo Grande C2, Piso 4, 1749-016 Lisbon (Portugal); Universidade de Lisboa, Museu Nacional de Historia Natural, Jardim Botanico (Portugal)

    2007-03-15

    The several established criteria to define a hyperaccumulator plant were applied to a rare and endangered species, Plantago almogravensis, and to the 3rd most abundant element in the earth crust, Al. Using the most common criteria, P. almogravensis undoubtedly is an Al hyperaccumulator plant. If the recent proposed requirements were considered, most of them matching those for a plant to be used in phytoextraction, it can only be considered an unusual accumulator of Al. A discussion is made concerning the several criteria of a hyperaccumulator plant in order to include rare and endemic ones and abundant elements. In ecological terms, the enrichment in Al and Fe observed may account for the differences in the vegetation pattern. Due to the rarity and endangered nature of this plant, the contribution of this work is also relevant for the ecological understanding and the development of conservation options of this endemic species. - Revisiting plant hyperaccumulation criteria.

  12. A new determination of the primordial helium abundance

    Science.gov (United States)

    Peimbert, M.; Peimbert, A.; Luridiana, V.

    2017-07-01

    We present new Y values for five H II regions, from these values we determine the primordial helium abundance, YP, and obtain that YP = 0.2446 ± 0.0029, (Peimbert, A. et al. 2016, RMxAA, 52, 419). The main difference of our new value with the YP value by Peimbert, M. et al. (2007, ApJ , 666, 633) is due to the use of updated atomic physics parameters. Our YP value is consistent with that by Aver, E. et al. (2015, JCAP, 7, 11), that amounts to YP = 0.2449 ± 0.0040, but in disagreement by more than 3σ with that by Izotov, Y. I. et al. (2014, MNRAS, 443, 778), that amounts to YP = 0.2551 ± 0.0022. YP together with Big Bang Nucleosynthesis, BBN, can be used to put constraints on the number of neutrino families, Nν, and the neutron mean life, τn. The adoption of a neutron mean life of τn = 880.3 ± 1.1 (s) (Olive, K. A et al. 2014, Chinese Physics C, 38, 090001) and our YP value imply that Neff = 2.90 ± 0.22, consistent with 3 neutrino families but not with 4 neutrino families. The adoption of Neff = 3.046 (Mangano, G. and Serpico, P. D. 2011, PhLB, 701, 296) and our YP value imply that τn = 872 ± 14 (s), consistent with both high and low values of τn in the literature. An increase on the quality of the YP determination from H II regions will provide stronger constraints on the Nν and τn values.

  13. Using Elemental Abundances and Petrophysical Properties to Trace Sediment Transport in the Hudson River

    Science.gov (United States)

    Chang, C.; Kenna, T. C.; Nitsche, F. O.

    2016-12-01

    The IPCC predicts that the frequency and severity of storms worldwide will increase due to climate change, a growing concern for the highly populated coastal areas near the Hudson River estuary. Storms have the potential to change the river's sediment budget, and it is necessary to update the current understanding of the effect of storms on sediment dynamics. In 2011, Tropical Storm Lee and Hurricane Irene delivered over 2.7 million tons of sediment to the Hudson River including over 1.5 million tons from the Mohawk River, a freshwater tributary, in addition to record amounts contributed from other major tributaries. The goals of this project are to use sediment elemental compositions to trace the major tributaries contributing to this storm-deposited sediment and to determine where sediment is accumulating as a result of storm activity. Chemical analysis of over 800 archived sediment samples are compiled to provide a pre-storm background level. These samples are compared to newly deposited sediment and material from specific tributaries. Elemental abundances (K, Ca, Ti, Cr, Mn, Fe, Co, Cu, Zn, Rb, Sr, Zr, Pb, and U) are measured using a field portable X-Ray Fluorescence (XRF) unit and core scanning XRF unit. Bulk matrix density is measured using a pycnometer. The measurements are used to identify elemental signatures from tributary sediment and to trace the influence of specific tributaries on deposition through the river. Our results suggests measureable signatures in sediment from individual tributaries. The Mohawk River contributes high concentrations of Ca due to the calcite deposits in its watershed. XRF measurements also show the effect of human activity on sediment deposition; variations in Rb and Zr indicate changes in deposition due to dredging in Haverstraw Bay. The salt wedge front, where ocean and fresh water meets is evident in areas of below average matrix density. This project shows significant geochemical variability between sediment from different

  14. Rare earth element abundances in rocks and minerals from the Fiskenaesset Complex, West Greenland. [comparison with lunar anorthosites

    Science.gov (United States)

    Henderson, P.; Fishlock, S. J.; Laul, J. C.; Cooper, T. D.; Conard, R. L.; Boynton, W. V.; Schmitt, R. A.

    1976-01-01

    The paper reports activation-analysis determinations of rare-earth-element (REE) and other trace-element concentrations in selected rocks, plagioclase, and mafic separates from the Fiskenaesset Complex. The REE abundances are found to be very low and atypical in comparison with other terrestrial anorthosites. The plagioclases are shown to be characterized by a deficiency in heavy RE elements relative to light ones and a positive Eu anomaly, while the mafic separates are enriched in heavy rare earths and have no Eu anomaly, except in one sample. It is found that the bulk and trace-element abundances of the plagioclases are similar to those observed in some lunar anorthosites, but the degree of Eu anomaly is less in the plagioclases. The data are taken as confirmation of the idea that fractionation processes were involved in the origin of the Complex, and it is concluded that the Complex may have been produced from a magma generated by partial melting of a garnet-bearing source.

  15. Disk Evolution, Element Abundances and Cloud Properties of Young Gas Giant Planets

    Directory of Open Access Journals (Sweden)

    Christiane Helling

    2014-04-01

    Full Text Available We discuss the chemical pre-conditions for planet formation, in terms of gas and ice abundances in a protoplanetary disk, as function of time and position, and the resulting chemical composition and cloud properties in the atmosphere when young gas giant planets form, in particular discussing the effects of unusual, non-solar carbon and oxygen abundances. Large deviations between the abundances of the host star and its gas giants seem likely to occur if the planet formation follows the core-accretion scenario. These deviations stem from the separate evolution of gas and dust in the disk, where the dust forms the planet cores, followed by the final run-away accretion of the left-over gas. This gas will contain only traces of elements like C, N and O, because those elements have frozen out as ices. PRODIMO protoplanetary disk models are used to predict the chemical evolution of gas and ice in the midplane. We find that cosmic rays play a crucial role in slowly un-blocking the CO, where the liberated oxygen forms water, which then freezes out quickly. Therefore, the C/O ratio in the gas phase is found to gradually increase with time, in a region bracketed by the water and CO ice-lines. In this regions, C/O is found to approach unity after about 5 Myrs, scaling with the cosmic ray ionization rate assumed. We then explore how the atmospheric chemistry and cloud properties in young gas giants are affected when the non-solar C/O ratios predicted by the disk models are assumed. The DRIFT cloud formation model is applied to study the formation of atmospheric clouds under the influence of varying premordial element abundances and its feedback onto the local gas. We demonstrate that element depletion by cloud formation plays a crucial role in converting an oxygen-rich atmosphere gas into carbon-rich gas when non-solar, premordial element abundances are considered as suggested by disk models.

  16. Elemental abundance studies of CP stars. II. The silicon stars HD 133029 and HD 192913

    CERN Document Server

    López-García, Z

    1999-01-01

    For pt.1 see ibid., vol.107, no.2, p.353-63 (1994). Fine analyses of the silicon stars HD 133029 and HD 192913 are presented using ATLAS9 model atmospheres whose predictions fit the optical region spectrophotometry and H gamma profiles and have the same bulk metallicity as the deduced abundances. Both are very He poor stars. The light elements are mostly solar except for silicon, and all the heavier elements, except nickel in HD 133029 which is solar, are greatly overabundant. The iron peak elements are typically 10 times overabundant. SrYZr are of order of 100 times solar. The rare earths are 1000 or more times overabundant. Table 4 is is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html. (50 refs).

  17. Dispersal ability determines the scaling properties of species abundance distributions

    DEFF Research Database (Denmark)

    Borda-De-Água, Luís; Whittaker, Robert James; Cardoso, Pedro

    2017-01-01

    Species abundance distributions (SAD) are central to the description of diversity and have played a major role in the development of theories of biodiversity and biogeography. However, most work on species abundance distributions has focused on one single spatial scale. Here we used data on arthr......Species abundance distributions (SAD) are central to the description of diversity and have played a major role in the development of theories of biodiversity and biogeography. However, most work on species abundance distributions has focused on one single spatial scale. Here we used data...... on arthropods to test predictions obtained with computer simulations on whether dispersal ability influences the rate of change of SADs as a function of sample size. To characterize the change of the shape of the SADs we use the moments of the distributions: the skewness and the raw moments. In agreement...... with computer simulations, low dispersal ability species generate a hump for intermediate abundance classes earlier than the distributions of high dispersal ability species. Importantly, when plotted as function of sample size, the raw moments of the SADs of arthropods have a power law pattern similar...

  18. First determination of the tropospheric CO abundance in Saturn

    Science.gov (United States)

    Fouchet, Thierry; Lellouch, Emmanuel; Cavalié, Thibault; Bézard, Bruno

    2017-10-01

    In Giant Planets, CO has two potential origins: i) an external source in form of cometary impacts, infalling ring/satellite dust or/and interplanetary particles; ii) an internal origin that involves convective transport from the deep, dense, hot atmosphere where the thermodynamic equilibrium CO abundance is relatively large.In Saturn, submilimeter stratospheric CO emissions have been detected (Cavalié et al. A&A, 510, A88, 2010; Cavalié et al. Icarus, 203, 531, 2009), suggesting a cometary impact 200 years ago. In contrast, no observation was in position to confirm or rule out the presence of CO in Saturn's troposphere (Noll et al. Icarus, 89, 168, 1990).Here, we present CRIRES/ELT 5-μm observations of Saturn that definitely confirm the presence of CO in Saturn's troposphere. We will present the derived CO abundance and its implication for Saturn's tropospheric transport rate and water deep abundance.

  19. Asymptotic size determines species abundance in the marine size spectrum

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Beyer, Jan

    2006-01-01

    The majority of higher organisms in the marine environment display indeterminate growth; that is, they continue to grow throughout their life, limited by an asymptotic size. We derive the abundance of species as a function of their asymptotic size. The derivation is based on size-spectrum theory...

  20. 1 Land use determinants of small mammal abundance and ...

    African Journals Online (AJOL)

    as potato and maize appeared to positively influence the distribution and abundance of small mammals .... Two major categories namely, land management practices and crop types were classified. The land management practices were identified by characteristic land cover ..... in aquatic insect community composition.

  1. Physical determinants of the distribution and abundance of the ...

    African Journals Online (AJOL)

    Two estuaries in KwaZulu-Natal, namely St. Lucia and the Mhlathuze, were chosen to investigate the influence of temperature, salinity, distance from the mouth and nature of the substratum (median phi value, sorting coefficient and organic content) on the distribution and abundance of the crab. Multiple and stepwise ...

  2. SP_Ace: a new code to derive stellar parameters and elemental abundances

    Science.gov (United States)

    Boeche, C.; Grebel, E. K.

    2016-03-01

    Context. Ongoing and future massive spectroscopic surveys will collect large numbers (106-107) of stellar spectra that need to be analyzed. Highly automated software is needed to derive stellar parameters and chemical abundances from these spectra. Aims: We developed a new method of estimating the stellar parameters Teff, log g, [M/H], and elemental abundances. This method was implemented in a new code, SP_Ace (Stellar Parameters And Chemical abundances Estimator). This is a highly automated code suitable for analyzing the spectra of large spectroscopic surveys with low or medium spectral resolution (R = 2000-20 000). Methods: After the astrophysical calibration of the oscillator strengths of 4643 absorption lines covering the wavelength ranges 5212-6860 Å and 8400-8924 Å, we constructed a library that contains the equivalent widths (EW) of these lines for a grid of stellar parameters. The EWs of each line are fit by a polynomial function that describes the EW of the line as a function of the stellar parameters. The coefficients of these polynomial functions are stored in a library called the "GCOG library". SP_Ace, a code written in FORTRAN95, uses the GCOG library to compute the EWs of the lines, constructs models of spectra as a function of the stellar parameters and abundances, and searches for the model that minimizes the χ2 deviation when compared to the observed spectrum. The code has been tested on synthetic and real spectra for a wide range of signal-to-noise and spectral resolutions. Results: SP_Ace derives stellar parameters such as Teff, log g, [M/H], and chemical abundances of up to ten elements for low to medium resolution spectra of FGK-type stars with precision comparable to the one usually obtained with spectra of higher resolution. Systematic errors in stellar parameters and chemical abundances are presented and identified with tests on synthetic and real spectra. Stochastic errors are automatically estimated by the code for all the parameters

  3. Trace Element Abundances in an Unusual Hibonite-Perovskite Refractory Inclusion from Allende

    Science.gov (United States)

    Mane, Prajkta; Wadhwa, M.; Keller, L. P.

    2013-01-01

    Calcium-aluminum-rich refractory inclusions (CAIs) are thought to be the first-formed solids in the Solar protoplanetary disk and can provide information about the earliest Solar System processes (e.g., [1]). A hibonite-perovskitebearing CAI from the Allende CV3 chondrite (SHAL, [2]) contains a single of 500 micrometers hibonite grain and coarse-grained perovskite. The mineralogy and oxygen isotopic composition of this CAI shows similarities with FUN inclusions, especially HAL [2]. Here we present trace element abundances in SHAL.

  4. Neutral Theory Predicts the Relative Abundance and Diversity of Genetic Elements in a Broad Array of Eukaryotic Genomes

    Science.gov (United States)

    Serra, François; Becher, Verónica; Dopazo, Hernán

    2013-01-01

    It is universally true in ecological communities, terrestrial or aquatic, temperate or tropical, that some species are very abundant, others are moderately common, and the majority are rare. Likewise, eukaryotic genomes also contain classes or “species” of genetic elements that vary greatly in abundance: DNA transposons, retrotransposons, satellite sequences, simple repeats and their less abundant functional sequences such as RNA or genes. Are the patterns of relative species abundance and diversity similar among ecological communities and genomes? Previous dynamical models of genomic diversity have focused on the selective forces shaping the abundance and diversity of transposable elements (TEs). However, ideally, models of genome dynamics should consider not only TEs, but also the diversity of all genetic classes or “species” populating eukaryotic genomes. Here, in an analysis of the diversity and abundance of genetic elements in >500 eukaryotic chromosomes, we show that the patterns are consistent with a neutral hypothesis of genome assembly in virtually all chromosomes tested. The distributions of relative abundance of genetic elements are quite precisely predicted by the dynamics of an ecological model for which the principle of functional equivalence is the main assumption. We hypothesize that at large temporal scales an overarching neutral or nearly neutral process governs the evolution of abundance and diversity of genetic elements in eukaryotic genomes. PMID:23798991

  5. Neutral theory predicts the relative abundance and diversity of genetic elements in a broad array of eukaryotic genomes.

    Directory of Open Access Journals (Sweden)

    François Serra

    Full Text Available It is universally true in ecological communities, terrestrial or aquatic, temperate or tropical, that some species are very abundant, others are moderately common, and the majority are rare. Likewise, eukaryotic genomes also contain classes or "species" of genetic elements that vary greatly in abundance: DNA transposons, retrotransposons, satellite sequences, simple repeats and their less abundant functional sequences such as RNA or genes. Are the patterns of relative species abundance and diversity similar among ecological communities and genomes? Previous dynamical models of genomic diversity have focused on the selective forces shaping the abundance and diversity of transposable elements (TEs. However, ideally, models of genome dynamics should consider not only TEs, but also the diversity of all genetic classes or "species" populating eukaryotic genomes. Here, in an analysis of the diversity and abundance of genetic elements in >500 eukaryotic chromosomes, we show that the patterns are consistent with a neutral hypothesis of genome assembly in virtually all chromosomes tested. The distributions of relative abundance of genetic elements are quite precisely predicted by the dynamics of an ecological model for which the principle of functional equivalence is the main assumption. We hypothesize that at large temporal scales an overarching neutral or nearly neutral process governs the evolution of abundance and diversity of genetic elements in eukaryotic genomes.

  6. Neutral theory predicts the relative abundance and diversity of genetic elements in a broad array of eukaryotic genomes.

    Science.gov (United States)

    Serra, François; Becher, Verónica; Dopazo, Hernán

    2013-01-01

    It is universally true in ecological communities, terrestrial or aquatic, temperate or tropical, that some species are very abundant, others are moderately common, and the majority are rare. Likewise, eukaryotic genomes also contain classes or "species" of genetic elements that vary greatly in abundance: DNA transposons, retrotransposons, satellite sequences, simple repeats and their less abundant functional sequences such as RNA or genes. Are the patterns of relative species abundance and diversity similar among ecological communities and genomes? Previous dynamical models of genomic diversity have focused on the selective forces shaping the abundance and diversity of transposable elements (TEs). However, ideally, models of genome dynamics should consider not only TEs, but also the diversity of all genetic classes or "species" populating eukaryotic genomes. Here, in an analysis of the diversity and abundance of genetic elements in >500 eukaryotic chromosomes, we show that the patterns are consistent with a neutral hypothesis of genome assembly in virtually all chromosomes tested. The distributions of relative abundance of genetic elements are quite precisely predicted by the dynamics of an ecological model for which the principle of functional equivalence is the main assumption. We hypothesize that at large temporal scales an overarching neutral or nearly neutral process governs the evolution of abundance and diversity of genetic elements in eukaryotic genomes.

  7. Histogrammatic Method for Determining Relative Abundance of Input Gas Pulse

    Science.gov (United States)

    Mandrake, Lukas; Bornstein, Benjamin J.; Madzunkov, Stojan; MacAskill, John A.

    2012-01-01

    To satisfy the Major Constituents Analysis (MCA) requirements for the Vehicle Cabin Atmosphere Monitor (VCAM), this software analyzes the relative abundance ratios for N2, O2, Ar, and CO2 as a function of time and constructs their best-estimate mean. A histogram is first built of all abundance ratios for each of the species vs time. The abundance peaks corresponding to the intended measurement and any obfuscating background are then separated via standard peak-finding techniques in histogram space. A voting scheme is then used to include/exclude this particular time sample in the final average based on its membership to the intended measurement or the background population. This results in a robust and reasonable estimate of the abundance of trace components such as CO2 and Ar even in the presence of obfuscating backgrounds internal to the VCAM device. VCAM can provide a means for monitoring the air within the enclosed environments, such as the ISS (International Space Station), Crew Exploration Vehicle (CEV), a Lunar Habitat, or another vehicle traveling to Mars. Its miniature pre-concentrator, gas chromatograph (GC), and mass spectrometer can provide unbiased detection of a large number of organic species as well as MCA analysis. VCAM s software can identify the concentration of trace chemicals and whether the chemicals are on a targeted list of hazardous compounds. This innovation s performance and reliability on orbit, along with the ground team s assessment of its raw data and analysis results, will validate its technology for future use and development.

  8. Light, alpha, and Fe-peak element abundances in the galactic bulge

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Christian I. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-15, Cambridge, MA 02138 (United States); Rich, R. Michael [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Kobayashi, Chiaki [Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Kunder, Andrea [Leibniz-Institute für Astrophysik Potsdam (AIP), Ander Sternwarte 16, D-14482, Potsdam (Germany); Koch, Andreas, E-mail: cjohnson@cfa.harvard.edu, E-mail: rmr@astro.ucla.edu, E-mail: c.kobayashi@herts.ac.uk, E-mail: akunder@aip.de, E-mail: akoch@lsw.uni-heidelberg.de [Zentrum für Astronomie der Universität Heidelberg, Landessternwarte, Königstuhl 12, Heidelberg (Germany)

    2014-10-01

    We present radial velocities and chemical abundances of O, Na, Mg, Al, Si, Ca, Cr, Fe, Co, Ni, and Cu for a sample of 156 red giant branch stars in two Galactic bulge fields centered near (l, b) = (+5.25,–3.02) and (0,–12). The (+5.25,–3.02) field also includes observations of the bulge globular cluster NGC 6553. The results are based on high-resolution (R ∼ 20,000), high signal-to-noise ration (S/N ≳ 70) FLAMES-GIRAFFE spectra obtained through the European Southern Observatory archive. However, we only selected a subset of the original observations that included spectra with both high S/N and that did not show strong TiO absorption bands. This work extends previous analyses of this data set beyond Fe and the α-elements Mg, Si, Ca, and Ti. While we find reasonable agreement with past work, the data presented here indicate that the bulge may exhibit a different chemical composition than the local thick disk, especially at [Fe/H] ≳ –0.5. In particular, the bulge [α/Fe] ratios may remain enhanced to a slightly higher [Fe/H] than the thick disk, and the Fe-peak elements Co, Ni, and Cu appear enhanced compared to the disk. There is also some evidence that the [Na/Fe] (but not [Al/Fe]) trends between the bulge and local disk may be different at low and high metallicity. We also find that the velocity dispersion decreases as a function of increasing [Fe/H] for both fields, and do not detect any significant cold, high-velocity populations. A comparison with chemical enrichment models indicates that a significant fraction of hypernovae may be required to explain the bulge abundance trends, and that initial mass functions that are steep, top-heavy (and do not include strong outflow), or truncated to avoid including contributions from stars >40 M {sub ☉} are ruled out, in particular because of disagreement with the Fe-peak abundance data. For most elements, the NGC 6553 stars exhibit abundance trends nearly identical to comparable metallicity bulge field

  9. Rare Earth Element Abundances and Pb-Pb Ages of Merrillite in Jinju H5 Chondrite: Implications to Shock Metamorphism

    Science.gov (United States)

    Goh, S.; Choi, B.-G.

    2016-08-01

    Jinju merrillite shows homogeneous REE abundances and relatively young Pb-Pb ages. Jinju H5 chondrite was probably neither equilibrated nor compacted prior to the impact and the shock made trace elements including REEs and U-Pb equilibrated.

  10. SXT/R391 integrative and conjugative elements in Proteus species reveal abundant genetic diversity and multidrug resistance

    Science.gov (United States)

    Li, Xinyue; Du, Yu; Du, Pengcheng; Dai, Hang; Fang, Yujie; Li, Zhenpeng; Lv, Na; Zhu, Baoli; Kan, Biao; Wang, Duochun

    2016-01-01

    SXT/R391 integrative and conjugative elements (ICEs) are self-transmissible mobile genetic elements that are found in most members of Enterobacteriaceae. Here, we determined fifteen SXT/R391 ICEs carried by Proteus isolates from food (4.2%) and diarrhoea patients (17.3%). BLASTn searches against GenBank showed that the fifteen SXT/R391 ICEs were closely related to that from different Enterobacteriaceae species, including Proteus mirabilis. Using core gene phylogenetic analysis, the fifteen SXT/R391 ICEs were grouped into six distinct clusters, including a dominant cluster and three clusters that have not been previously reported in Proteus isolates. The SXT/R391 ICEs shared a common structure with a set of conserved genes, five hotspots and two variable regions, which contained more foreign genes, including drug-resistance genes. Notably, a class A β-lactamase gene was identified in nine SXT/R391 ICEs. Collectively, the ICE-carrying isolates carried resistance genes for 20 tested drugs. Six isolates were resistant to chloramphenicol, kanamycin, streptomycin, trimethoprim-sulfamethoxazole, sulfisoxazole and tetracycline, which are drug resistances commonly encoded by ICEs. Our results demonstrate abundant genetic diversity and multidrug resistance of the SXT/R391 ICEs carried by Proteus isolates, which may have significance for public health. It is therefore necessary to continuously monitor the antimicrobial resistance and related mobile elements among Proteus isolates. PMID:27892525

  11. Element abundances, patterns, and mobility in Nakhlite Miller Range 03346 and implications for aqueous alteration

    Science.gov (United States)

    Stopar, Julie D.; Taylor, G. Jeffrey; Velbel, Michael A.; Norman, Marc D.; Vicenzi, Edward P.; Hallis, Lydia J.

    2013-07-01

    Nakhlite Miller Range (MIL) 03346 contains many secondary phases resulting from aqueous processes, including formation of poorly crystalline iddingsite-like veins in olivine, the precipitation of Ca-sulfates and Fe,K-sulfates from evaporating fluids, alteration of titanomagnetite to secondary Fe-oxides, and the dissolution of magmatic Ca-phosphates and residual glass in the mesostasis. A surprising variety of alteration products occur in association with olivine in MIL 03346, including: patches of incipiently-altered olivine, large Si-enriched olivine-hosted veins (up to 10 μm across) some of which are complex in morphology and are composed of several phases, small Fe,S(±K)-rich veinlets that crosscut the Si-enriched veins, Ca-sulfates filling cracks in olivine, and secondary Ca-phosphates. Elemental abundances and distributions in these alteration products are consistent with the mobilization of elements from readily dissolved phases in the mesostasis such as phosphates and residual glass. Under favorable weathering conditions, these phases dissolve more readily than pyroxenes, plagioclase, and even olivine at low pH. The occurrence (crosscut and devolatilized by the fusion crust) and composition of Si-enriched alteration veins in olivine are consistent with their formation on Mars. Si-enriched, poorly crystalline alteration products and secondary Ca-sulfates commonly occur in nakhlites, but the habit and composition of these alteration products differ between meteorites. Elemental distributions in these secondary phases suggest at least two episodes of alteration have affected MIL 03346, and subtle differences in secondary minerals and chemistry indicate that each nakhlite experienced its own unique alteration history either on Mars, Earth, or both. The variable Al content and range of morphologies of the olivine-hosted Si-enriched veins suggest variable alteration conditions consistent with a water-limited regime. If the secondary phases in MIL 03346 can be

  12. Determination of rare earth and refractory trace element ...

    Indian Academy of Sciences (India)

    Experimental and analytical procedures devised for measurement of rare earth element (REE) abundances using a secondary ion mass spectrometer (ion microprobe) are described. This approach is more versatile than the conventional techniques such as neutron activation analysis and isotope dilution mass spectrometry ...

  13. INAA Application for Trace Element Determination in Biological Reference Material

    Science.gov (United States)

    Atmodjo, D. P. D.; Kurniawati, S.; Lestiani, D. D.; Adventini, N.

    2017-06-01

    Trace element determination in biological samples is often used in the study of health and toxicology. Determination change to its essentiality and toxicity of trace element require an accurate determination method, which implies that a good Quality Control (QC) procedure should be performed. In this study, QC for trace element determination in biological samples was applied by analyzing the Standard Reference Material (SRM) Bovine muscle 8414 NIST using Instrumental Neutron Activation Analysis (INAA). Three selected trace element such as Fe, Zn, and Se were determined. Accuracy of the elements showed as %recovery and precision as %coefficient of variance (%CV). The result showed that %recovery of Fe, Zn, and Se were in the range between 99.4-107%, 92.7-103%, and 91.9-112%, respectively, whereas %CV were 2.92, 3.70, and 5.37%, respectively. These results showed that INAA method is precise and accurate for trace element determination in biological matrices.

  14. Evaluation of strontium isotope abundance ratios in combination with multi-elemental analysis as a possible tool to study the geographical origin of ciders

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Ruiz, Silvia [Department of Physical and Analytical Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain); Moldovan, Mariella [Department of Physical and Analytical Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain); Fortunato, Giuseppino [Swiss Federal Laboratories for Materials Testing and Research EMPA, 9014 St. Gallen (Switzerland); Wunderli, Samuel [Swiss Federal Laboratories for Materials Testing and Research EMPA, 9014 St. Gallen (Switzerland); Garcia Alonso, J. Ignacio [Department of Physical and Analytical Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain)]. E-mail: jiga@uniovi.es

    2007-05-02

    In order to evaluate alternative analytical methodologies to study the geographical origin of ciders, both multi-elemental analysis and Sr isotope abundance ratios in combination with multivariate statistical analysis were estimated in 67 samples from England, Switzerland, France and two Spanish regions (Asturias and the Basque Country). A methodology for the precise and accurate determination of the {sup 87}Sr/{sup 86}Sr isotope abundance ratio in ciders by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) was developed. Major elements (Na, K, Ca and Mg) were measured by ICP-AES and minor and trace elements (Li, Be, B, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, W, Tl, Pb, Bi, Th and U) were measured by ICP-MS using a collision cell instrument operated in multitune mode. An analysis of variance (ANOVA test) indicated that group means for B, Cr, Fe, Ni, Cu, Se, Cd, Cs, Ce, W, Pb, Bi and U did not show any significant differences at the 95% confidence level, so these elements were rejected for further statistical analysis. Another group of elements (Li, Be, Sc, Co, Ga, Y, Sn, Sb, La, Tl, Th) was removed from the data set because concentrations were close to the limits of detection for many samples. Therefore, the remaining elements (Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba) together with {sup 87}Sr/{sup 86}Sr isotope abundance ratio were considered for principal component analysis (PCA) and linear discriminant analysis (LDA). Finally, LDA was able to classify correctly 100% of cider samples coming from different Spanish regions, France, England and Switzerland when considering Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba and {sup 87}Sr/{sup 86}Sr isotope abundance ratio as original variables.

  15. Optical determination of material abundances by using neural networks for the derivation of spectral filters

    Science.gov (United States)

    Krippner, Wolfgang; Wagner, Felix; Bauer, Sebastian; Puente León, Fernando

    2017-06-01

    Using appropriately designed spectral filters allows to optically determine material abundances. While an infinite number of possibilities exist for determining spectral filters, we take advantage of using neural networks to derive spectral filters leading to precise estimations. To overcome some drawbacks that regularly influence the determination of material abundances using hyperspectral data, we incorporate the spectral variability of the raw materials into the training of the considered neural networks. As a main result, we successfully classify quantized material abundances optically. Thus, the main part of the high computational load, which belongs to the use of neural networks, is avoided. In addition, the derived material abundances become invariant against spatially varying illumination intensity as a remarkable benefit in comparison with spectral filters based on the Moore-Penrose pseudoinverse, for instance.

  16. Galactic abundance gradients from Cepheids : α and heavy elements in the outer disk

    NARCIS (Netherlands)

    Lemasle, B.; Francois, P.; Genovali, K.; Kovtyukh, V. V.; Bono, G.; Inno, L.; Laney, C. D.; Kaper, L.; Bergemann, M.; Fabrizio, M.; Matsunaga, N.; Pedicelli, S.; Primas, F.; Romaniello, M.

    2013-01-01

    Context. Galactic abundance gradients set strong constraints to chemo-dynamical evolutionary models of the Milky Way. Given the period-luminosity relations that provide accurate distances and the large number of spectral lines, Cepheids are excellent tracers of the present-day abundance gradients.

  17. Solar abundances of rock-forming elements, extreme oxygen and hydrogen in a young polluted white dwarf

    Science.gov (United States)

    Farihi, J.; Koester, D.; Zuckerman, B.; Vican, L.; Gänsicke, B. T.; Smith, N.; Walth, G.; Breedt, E.

    2016-12-01

    The Teff = 20 800 K white dwarf WD 1536+520 is shown to have broadly solar abundances of the major rock-forming elements O, Mg, Al, Si, Ca, and Fe, together with a strong relative depletion in the volatile elements C and S. In addition to the highest metal abundances observed to date, including log (O/He) = -3.4, the helium-dominated atmosphere has an exceptional hydrogen abundance at log (H/He) = -1.7. Within the uncertainties, the metal-to-metal ratios are consistent with the accretion of an H2O-rich and rocky parent body, an interpretation supported by the anomalously high trace hydrogen. The mixed atmosphere yields unusually short diffusion time-scales for a helium atmosphere white dwarf, of no more than a few hundred years, and equivalent to those in a much cooler, hydrogen-rich star. The overall heavy element abundances of the disrupted parent body deviate modestly from a bulk Earth pattern, and suggest the deposition of some core-like material. The total inferred accretion rate is 4.2 × 109 g s-1, and at least four times higher than for any white dwarf with a comparable diffusion time-scale. Notably, when accretion is exhausted in this system, both metals and hydrogen will become undetectable within roughly 300 Myr, thus supporting a scenario where the trace hydrogen is related to the ongoing accretion of planetary debris.

  18. Study of galaxies in the Lynx-Cancer void. II. Element abundances

    Science.gov (United States)

    Pustilnik, S. A.; Tepliakova, A. L.; Kniazev, A. Yu.

    2011-07-01

    In the framework of study of the evolutionary status of galaxies in the nearby Lynx-Cancer void, we present the results of the SAO RAS 6-m telescope spectroscopy for 20 objects in this region. The principal faint line [O iii]λ4363 Å, used to determine the electron temperature and oxygen abundance (O/H) by the classicalmethod, is clearly detected in only about 2/3 of the studied objects. For the remaining galaxies this line is either faint or undetected. To obtain the oxygen abundances in these galaxies we as well apply the semi-empirical method by Izotov and Thuan, and/or the empirical methods of Pilyugin et al., which are only employing the intensities of sufficiently strong lines. We also present our O/H measurements for 22 Lynx-Cancer void galaxies, for which the suitable Sloan Digital Sky Survey (SDSS) spectra are available. In total, we present the combined O/H data for 48 Lynx-Cancer void galaxies, including the data adopted from the literature and our own earlier results. We make a comparison of their locations on the (O/H)-MB diagram with those of the dwarf galaxies of the Local Volume in the regions with denser environment. We infer that the majority of galaxies from this void on the average reveal an about 30% lower metallicity. In addition, a substantial fraction (not less than 10%) of the void dwarf galaxies have a much larger O/H deficiency (up to a factor of 5). Most of them belong to the tiny group of objects with the gas metallicity Z

  19. METALLICITY DISTRIBUTION FUNCTIONS, RADIAL VELOCITIES, AND ALPHA ELEMENT ABUNDANCES IN THREE OFF-AXIS BULGE FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Christian I.; Rich, R. Michael [Department of Physics and Astronomy, UCLA, 430 Portola Plaza, Box 951547, Los Angeles, CA 90095-1547 (United States); Kobayashi, Chiaki [Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB (United Kingdom); Kunder, Andrea; De Propris, Roberto [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Pilachowski, Catherine A. [Department of Astronomy, Indiana University, Swain West 319, 727 East Third Street, Bloomington, IN 47405-7105 (United States); Koch, Andreas, E-mail: cijohnson@astro.ucla.edu, E-mail: rmr@astro.ucla.edu, E-mail: c.kobayashi@herts.ac.uk, E-mail: akunder@ctio.noao.edu, E-mail: catyp@astro.indiana.edu, E-mail: akoch@lsw.uni-heidelberg.de [Zentrum fuer Astronomie der Universitaet Heidelberg, Landessternwarte, Koenigstuhl 12, Heidelberg (Germany)

    2013-03-10

    We present radial velocities and chemical abundance ratios of [Fe/H], [O/Fe], [Si/Fe], and [Ca/Fe] for 264 red giant branch stars in three Galactic bulge off-axis fields located near (l, b) = (-5.5, -7), (-4, -9), and (+8.5, +9). The results are based on equivalent width and spectrum synthesis analyses of moderate resolution (R Almost-Equal-To 18,000), high signal-to-noise ratio (S/N {approx} 75-300 pixel{sup -1}) spectra obtained with the Hydra spectrographs on the Blanco 4 m and WIYN 3.5 m telescopes. The targets were selected from the blue side of the giant branch to avoid cool stars that would be strongly affected by CN and TiO; however, a comparison of the color-metallicity distribution in literature samples suggests that our selection of bluer targets should not present a significant bias against metal-rich stars. We find a full range in metallicity that spans [Fe/H] Almost-Equal-To -1.5 to +0.5, and that, in accordance with the previously observed minor-axis vertical metallicity gradient, the median [Fe/H] also declines with increasing Galactic latitude in off-axis fields. The off-axis vertical [Fe/H] gradient in the southern bulge is estimated to be {approx}0.4 dex kpc{sup -1}; however, comparison with the minor-axis data suggests that a strong radial gradient does not exist. The (+8.5, +9) field exhibits a higher than expected metallicity, with a median [Fe/H] = -0.23, that might be related to a stronger presence of the X-shaped bulge structure along that line-of-sight. This could also be the cause of an anomalous increase in the median radial velocity for intermediate metallicity stars in the (+8.5, +9) field. However, the overall radial velocity and dispersion for each field are in good agreement with recent surveys and bulge models. All fields exhibit an identical, strong decrease in velocity dispersion with increasing metallicity that is consistent with observations in similar minor-axis outer bulge fields. Additionally, the [O/Fe], [Si/Fe], and [Ca

  20. VizieR Online Data Catalog: Neutron-capture elements abundances in Cepheids (da Silva+ 2016)

    Science.gov (United States)

    da Silva, R.; Lemasle, B.; Bono, G.; Genovali, K.; McWilliam, A.; Cristallo, S.; Bergemann, M.; Buonanno, R.; Fabrizio, M.; Ferraro, I.; Francois, P.; Iannicola, G.; Inno, L.; Laney, C. D.; Kudritzki, R.-P.; Matsunaga, N.; Nonino, M.; Primas, F.; Przybilla, N.; Romaniello, M.; Thevenin, F.; Urbaneja, M. A.

    2015-11-01

    The abundances of Fe, Y, La, Ce, Nd, and Eu for our sample of 73 Cepheids plus data available in the literature for other 362 Cepheids are shown. We first show the abundances derived based on individual spectra for the 73 stars, then the averaged values, and finally the data from the literature. The original abundances available in the literature were rescaled according to the zero-point differences listed in Table 5. The priority was given in the following order: we first adopt the abundances provided by our group, this study (TS) and Lemasle et al. (2013A&A...558A..31L, LEM), and then those provided by the other studies, Luck & Lambert (2011AJ....142..136L, LIII), and Luck et al. (2011AJ....142...51L, LII). (4 data files).

  1. Determining the elements of procedural quality.

    Science.gov (United States)

    Berkowitz, Oren; Jones, Kristen; Lunsford, L Dade; Kondziolka, Douglas

    2013-08-01

    The definition and determination of quality health care is an important topic. The purpose of this study was to develop a longitudinal method to define a quality procedure by creating a formal approach to pre- and postoperative outcomes documentation. The authors worked to define quality outcomes by first documenting the patient's condition. Goals were determined together by the surgeon and the patient and then were evaluated to see if those goals were met. The population consisted of cancer patients with newly diagnosed metastatic brain disease who were scheduled to undergo stereotactic radiosurgery. Surgeons recorded perioperatively objective information related to preoperative goals, clinical findings, surgical performance and/or error, and whether goals were met. In addition, patients completed pre- and postprocedure questionnaires (Rand 36-Item Short-Form Health Survey 1.0 [SF-36]). Procedural goals, defined as completing radiosurgery without error or complication and same-day discharge, were met in all patients. The clinically predetermined goal of tumor palliation was met in all but 1 patient at follow-up. The SF-36 scores remained stable except for the general health domain, which was lower (p = 0.006). Procedural goals can be defined and objectively measured serially. The authors think that quality care can be defined as a process that achieves predefined goals without significant error and maintains or improves health.

  2. ECONOMIC EFFICIENCY - DETERMINED ELEMENT IN INVESTMENT DECISION

    Directory of Open Access Journals (Sweden)

    Claudia MUNGIU-PUPAZAN

    2010-03-01

    Full Text Available Economic activity of a country are conducted by industry, under branches and production sectors, each with special characteristics and conditions of work, which, of course, put their imprint on the organization manner of the production process By an analysis of the concept of economic efficiency of investment is found that this is an amount of qualitative factors, which gives the latter a complex character, aimed to improving activity in the area where are taking place to the putting into service of such investment, which can be modernization, bringing new equipments, reconstruction and development. Study the economic efficiency of investment involves, as a base, an analysis of causal factors that determine the decision in the afferent medium of risk. Corresponding to peculiarities of the production process, it requires a proper methodology of assessment the economic efficiency of investment, with specification to maintain the general principles for calculating the economic efficiency indicators and specific indicators come only to complete the picture of indicators of general, basic and supplementary already calculated in order to provide additional clues, afferent to branch, under-branch or sector of activity.

  3. HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance.

    Science.gov (United States)

    Wakeford, Hannah R; Sing, David K; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric D; Tremblin, Pascal; Amundsen, David S; Lewis, Nikole K; Mandell, Avi M; Fortney, Jonathan J; Knutson, Heather; Benneke, Björn; Evans, Thomas M

    2017-05-12

    A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent H2O absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b's atmospheric heavy element content ([Formula: see text] times solar). This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals. Copyright © 2017, American Association for the Advancement of Science.

  4. HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance

    Science.gov (United States)

    Wakeford, Hannah R.; Sing, David K.; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric D.; Tremblin, Pascal; Amundsen, David S.; Lewis, Nikole K.; Mandell, Avi M.; Fortney, Jonathan J.; Knutson, Heather; Benneke, Björn; Evans, Thomas M.

    2017-05-01

    A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent H2O absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b’s atmospheric heavy element content (4.8-4.0+21.5 times solar). This likely indicates that HAT-P-26b’s atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals.

  5. Sabang Submarine Volcano Aceh, Indonesia: Review of Some Trace and Rare Earth Elements Abundances Produced by Seafloor Fumarole Activities

    Directory of Open Access Journals (Sweden)

    Hananto kurnio

    2016-11-01

    Full Text Available DOI:10.17014/ijog.3.3.173-182Geochemical analyses of selected coastal and seafloor samples from Sabang Area revealed abundances of trace and rare earth elements. The selected samples of element abundances were mostly taken from seafloor in the vicinities of active fumaroles either by grab sampler operated from survey boat above fumarole point or by diver directly took the samples on the seafloor especially at Serui - Sabang Bay. Results show that samples closed to seafloor fumaroles demonstrate plenty of trace and rare earth elements. The trace and rare earth elements mean values (n=10 are: Nb (4.33 ppm, La (16.52 ppm, Ce (38.82 ppm, Nd (19.15 ppm, Ce (38.82 ppm, Pr (4.907 ppm, Nd (19.15 ppm, Sm (4.04 ppm, Gd (3.95 ppm, Dy (3.38 ppm, Th (6.432 ppm, and U (4.335 ppm. Negatively, statistical correlations between Fe, Zn, and Ni as the main sulphide elements with sulphur is interpreted that sulphide minerals do not form in the Sabang Sea. Sea water influence in the mineralization process was shown by the good correlations between Fe, Zn, Pb, Ni, and Ba.

  6. Elemental gas-phase abundances of intermediate redshift type Ia supernova star-forming host galaxies

    Science.gov (United States)

    Moreno-Raya, ME; Galbany, L.; López-Sánchez, ÁR; Mollá, M.; González-Gaitán, S.; Vílchez, JM; Carnero, A.

    2018-01-01

    The maximum luminosity of type Ia supernovae (SNe Ia) depends on the oxygen abundance of the regions of the host galaxies where they explode. This metallicity dependence reduces the dispersion in the Hubble diagram (HD) when included with the traditional two-parameter calibration of SN Ia light-curve (LC) parameters and absolute magnitude. In this work, we use empirical calibrations to carefully estimate the oxygen abundance of galaxies hosting SNe Ia from the SDSS-II/SNe Survey at intermediate redshift, by measuring their emission line intensities. We also derive electronic temperature with the direct method for a small fraction of objects for consistency. We find a trend of decreasing oxygen abundance with increasing redshift for the most massive galaxies. Moreover, we study the dependence of the HD residuals (HR) with galaxy oxygen abundance obtaining a correlation in line with those found in other works. In particular, the HR vs oxygen abundance shows a slope of -0.186±0.123 mag dex-1 (1.52σ), in good agreement with theoretical expectations. This implies smaller distance modulii after corrections for SNe Ia in metal-rich galaxies. Based on our previous results on local SNe Ia, we propose this dependence to be due to the lower luminosity of the SNe Ia produced in more metal-rich environments.

  7. THE CURIOUS CASE OF ELEMENTAL ABUNDANCE DIFFERENCES IN THE DUAL HOT JUPITER HOSTS WASP-94A AND B

    Energy Technology Data Exchange (ETDEWEB)

    Teske, Johanna K. [Carnegie Department of Terrestrial Magnetism, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States); Khanal, Sandhya; Ramírez, Ivan, E-mail: jteske@carnegiescience.edu [McDonald Observatory and Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1402, Austin, TX 78712-1205 (United States)

    2016-03-01

    Binary stars provide an ideal laboratory for investigating the potential effects of planet formation on stellar composition. Assuming that the stars formed in the same environment/from the same material, any compositional anomalies between binary components might indicate differences in how material was sequestered in planets, or accreted by the star in the process of planet formation. We present here a study of the elemental abundance differences between WASP-94A and B, a pair of stars that each host a hot Jupiter exoplanet. The two stars are very similar in spectral type (F8 and F9), and their ∼2700 au separation suggests that their protoplanetary disks were likely not influenced by stellar interactions, but WASP-94Ab’s orbit—misaligned with the host star spin axis and likely retrograde—points toward a dynamically active formation mechanism, perhaps different from that of WASP-94Bb, which is not misaligned and has a nearly circular orbit. Based on our high-quality spectra and strictly relative abundance analysis, we detect a depletion of volatiles (∼−0.02 dex, on average) and enhancement of refractories (∼0.01 dex) in WASP-94A relative to B (standard errors are ∼0.005 dex). This is different from every other published case of binary host star abundances, in which either no significant abundance differences are reported or there is some degree of enhancement in all elements, including volatiles. Several scenarios that may explain the abundance trend are discussed, but none can be definitively accepted or rejected. Additional high-contrast imaging observations to search for companions that may be dynamically affecting the system, as well as a larger sample of binary host star studies, are needed to better understand the curious abundance trends we observe in WASP-94A and B.

  8. Major and trace element abundances, and Sr and Nd isotopic composition of Carbonatites from Amba Dongar, Gujarat, India

    Science.gov (United States)

    Chandra, Jyoti; Paul, Debajyoti; Viladkar, Shrinivas G.; Sensarma, Sarajit

    2015-04-01

    Despite significant progress during the last decade, the petrogenesis of carbonatites is still highly debated regarding the exact mechanism of carbonatite magma generation (fractional crystallization of carbonated-silicate magmas, liquid immiscibility of carbonated-silicate magmas, partial melting of carbonated mantle peridotite or carbonated lherzolitic mantle) and its evolution. The Amba Dongar carbonatite complex in Chhota Udaipur district, Gujarat is the youngest Indian carbonatite complex, which intruded into the ~ 90 Ma Bagh sandstones and limestone and 68-65 Ma Deccan flood basalts. The emplacement age (40Ar/39Ar age of 65±0.3 Ma; Ray and Pande, 1999) coincides with the age of main pulse of Deccan flood basalts at ca. 65 Ma. We report new geochemical data (major oxide and trace element abundances, and Sr and Nd isotopic ratios) on 23 carbonatite samples from Amba Dongar. The Amba Dongar carbonatite complex consists of carbonatite (sövite, and ankerite), and associated nephelinite, phonolite, and both pre- and post-carbonatite basalts. Detailed minerology of carbonatite include dominant calcite along with pyrochlore, apatite, magnetite, aegirine-augite and accessory phases. Apatite crystals are observed in carbonatite as well as in nephelinite. In sövites, apatite occur in various forms including cumulus, clusters and scattered within and along the boundary of calcite crystals. Two generation of apatite crystals are commonly observed in sövite and nephelinite; textural changes suggest presence of different five pulses of sövitic magma during the emplacement of the sövite ring dike. Bulk major oxides and trace element (including REEs) compositions of carbonatites and associated silicate rocks are determined by WD-XRF and ICP-MS, respectively. Major oxides abundances are consistent with the already available data on the Amba Dongar carbonatite complex. Trace element concentrations for the sövite reveals high concentrations of Sr (929-7476 ppm), Ba (344

  9. Determination of chilling temperature effects on nutrient elements ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... Baydas E (2006). Trace element changes during hibernation of. Drosophila melanogaster by WDXRF analyses at chilling temperature. J. Quant. Spec. Rad. Tran. 102: 492-498. Dumlupinar R, Demir F, Bostan H (2007). Determination of Chilling. Temprature Effects on Inorganic Element Composition and.

  10. Determination of chilling temperature effects on nutrient elements ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... Full Length Research Paper. Determination of chilling temperature effects on ... Results indicated that the distribution of some inorganic elements among organs (roots, stem and leaves) of cole ... Key words: Common cole (Brassica oleracea cv. Acephala), inorganic element, chilling temperature, X-ray,.

  11. What environmental factors are important determinants of structure, species richness, and abundance of mosquito assemblages?

    Science.gov (United States)

    Beketov, Mikhail A; Yurchenko, Yury A; Belevich, Olga E; Liess, Matthias

    2010-03-01

    Despite numerous ecological studies with mosquitoes, it remains unclear what environmental factors are the most important determinants of structure, species richness, and abundance of mosquito assemblages. In the current study, we investigated relations between these characteristics of mosquito larvae assemblages and environmental factors in a large set of different habitats. Particular objectives were (1) to rank the factors regarding their explanatory power, and (2) to quantify the contribution of major sets of factors such as habitat spatial/hydrological (H), water physico-chemical (W), and aquatic vegetation characteristics (V). Variance partitioning and forward selection based on ordinations and multiple regressions were applied to the data set on 79 water-bodies in southwestern Siberia covering a wide gradient of environmental characteristics and diverse mosquito assemblages. The results showed that richness and abundance inter-correlated poorly (r2 = 0.21), and assemblage structure, richness, and abundance depended on different sets of predictors. Explanatory importance of the three sets of environmental factors differed among the three assemblage variables: H, W, and V had equal importance for assemblage structure, while richness and abundance depended on H and V more than on W. The study showed that contradiction between the aims of conservation (support biodiversity) and mosquito control (reduce mosquito abundance) can be avoided, as relevant environmental factors can be used to define habitats with high richness and low abundance (i.e., high conservation value and low nuisance and disease transmission risk) for conservation activities, and conversely for control measures.

  12. Iron abundance determination for the solar-like stars HR 4345 and HR 6573

    Directory of Open Access Journals (Sweden)

    Vince Oliver I.

    2004-01-01

    Full Text Available Using the BLACKWELL software package written by R.O. Gray, the iron abundance of the solar-like stars HR 4345 and HR 6573 has been determined. The method is based on determination of the minimum dispersion (or the region of least confusion of the iron abundance versus microturbulent velocity functions for some selected spectral lines of neutral iron. The input data used by BLACKWELL are the observed equivalent widths of several spectral lines of neutral iron. They are obtained from spectra observed at the Observatoire de Haute-Provence, France, with the 1.52-m telescope and Aurelie spectrograph. Reduction of the raw spectra and the measurement of the equivalent widths of spectral lines are carried out using IRAF and SPE software packages. The measured values of iron abundances of HR 4345 and HR 6573 are 7.72±0.03 and 7.63±0.05 respectively.

  13. Elemental abundances in Milky Way-like galaxies from a hierarchical galaxy formation model

    NARCIS (Netherlands)

    De Lucia, Gabriella; Tornatore, Luca; Frenk, Carlos S.; Helmi, Amina; Navarro, Julio F.; White, Simon D. M.

    2014-01-01

    We develop a new method to account for the finite lifetimes of stars and trace individual abundances within a semi-analytic model of galaxy formation. At variance with previous methods, based on the storage of the (binned) past star formation history of model galaxies, our method projects the

  14. Disk Evolution, Element Abundances and Cloud Properties of Young Gas Giant Planets

    NARCIS (Netherlands)

    Helling, Christiane; Woitke, Peter; Rimmer, Paul B.; Kamp, Inga; Thi, Wing-Fai; Meijerink, Rowin

    We discuss the chemical pre-conditions for planet formation, in terms of gas and ice abundances in a protoplanetary disk, as function of time and position, and the resulting chemical composition and cloud properties in the atmosphere when young gas giant planets form, in particular discussing the

  15. The Solar Photospheric Nitrogen Abundance : Determination with 3D and 1D Model Atmospheres

    NARCIS (Netherlands)

    Maiorca, E.; Caffau, E.; Bonifacio, P.; Busso, M.; Faraggiana, R.; Steffen, M.; Ludwig, H. -G.; Kamp, I.

    2009-01-01

    We present a new determination of the solar nitrogen abundance making use of 3D hydrodynamical modelling of the solar photosphere, which is more physically motivated than traditional static 1D models. We selected suitable atomic spectral lines, relying on equivalent width measurements already

  16. Determination of a synchronous generator characteristics via Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Kolondzovski Zlatko

    2005-01-01

    Full Text Available In the paper a determination of characteristics of a small salient pole synchronous generator (SG is presented. Machine characteristics are determined via Finite Element Analysis (FEA and for that purpose is used the software package FEMM Version 3.3. After performing their calculation and analysis, one can conclude that most of the characteristics presented in this paper can be obtained only by using the Finite Element Method (FEM.

  17. The simulation about elemental abundances in cosmic rays to investigate the origin

    Science.gov (United States)

    Yamagiwa, I.; Kato, C.; Munakata, K.

    The problem of cosmic ray origin and propagation has been discussed for a long time. When we discuss about the origin, it is important to measure the abundances of ultraheavy nuclei. The ultraheavy nuclei are mainly created in s p r o c e s s or r-- proces s. We are interested in which process is predominant, s-process or r-process at the source. If r-process is predominant, it supports the opinion that the origin of cosmic ray is in supernova explosion. We believe that r process is occurred in- supernova exp losion. We intend to simulate about the ultraheavy nuclei abundances at earth orbit. In this paper, we report our simulation result about the ratio of Fe secondaries to Fe in the cosmic rays at the earth orbit as a first step.

  18. The Helium r-Process and Neutron-Capture Element Abundances in Low Metallicity Stars

    Science.gov (United States)

    Truran, J. W.; Cowan, J. J.

    2000-05-01

    There is increasingly strong observational evidence that the r-process isotopes identified in solar system matter are in fact the products of two distinct classes of r-process nucleosynthesis events. Spectroscopic observations of extremely metal deficient halo field stars and globular cluster stars provide confirmation of the occurrence of a robust r-process mechanism for the production of the main r-process component, at mass numbers A ≳ 130-140. This main component is variously argued to have its origin in regions outside the neutronized core, in magnetic jets from the collapsing core, or in neutron star-neutron star mergers. The stellar abundance data available to date suggests, however, that the bulk of the r-process nuclei in the mass region A post shock conditions insures that this process is not as robust as that responsible for the main r-process component A ≳ 130-140. We discuss the implications of our numerical results for the interpretation both of the abundances in metal poor stars and of the anomalous r-process-like isotopic abundances observed in meteoritic silicon carbide grains (Pellin et al. 2000). This research was funded in part by NSF grant AST-9618332 to JJC and by the ASCI/Alliances Center for Astrophysical Thermonuclear Flashes at the University of Chicago under DOE contract B341495 (JWT).

  19. Elemental Abundance Ratios in Stars of the Outer Galactic Disk. IV. A New Sample of Open Clusters

    Science.gov (United States)

    Yong, David; Carney, Bruce W.; Friel, Eileen D.

    2012-10-01

    We present radial velocities and chemical abundances for nine stars in the old, distant open clusters Be18, Be21, Be22, Be32, and PWM4. For Be18 and PWM4, these are the first chemical abundance measurements. Combining our data with literature results produces a compilation of some 68 chemical abundance measurements in 49 unique clusters. For this combined sample, we study the chemical abundances of open clusters as a function of distance, age, and metallicity. We confirm that the metallicity gradient in the outer disk is flatter than the gradient in the vicinity of the solar neighborhood. We also confirm that the open clusters in the outer disk are metal-poor with enhancements in the ratios [α/Fe] and perhaps [Eu/Fe]. All elements show negligible or small trends between [X/Fe] and distance ( 13 kpc) samples may have different trends with distance. There is no evidence for significant abundance trends versus age (history different from that of the solar neighborhood, we echo the sentiments expressed by Friel et al. that definitive conclusions await homogeneous analyses of larger samples of stars in larger numbers of clusters. Arguably, our understanding of the evolution of the outer disk from open clusters is currently limited by systematic abundance differences between various studies. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  20. Abundances of chemical elements in granitoids of different geological ages and their characteristics in China

    Directory of Open Access Journals (Sweden)

    Changyi Shi

    2011-04-01

    Full Text Available Actual granitoid analytical data of 767 composited samples are presented here. The data source is 6080 samples collected mainly from 750 large- to middle-sized granitoid bodies across China. Data from the composited samples, which includes that of 70 elements, is analyzed according to geological age — Archeozoic (Ar, Proterozoic (Pt, Eopaleozoic (Pz1, Neopaleozoic (Pz2, Mesozoic (Mz, and Cenozoic (Cz — and three major compositional varieties, e.g. alkali-feldspar granite, syenogranite and adamellite. Petrochemical parameters, trace-element content and rare-earth element (REE distributions of the different rock types and geological ages are characterized, and change tendencies through Archean to Cenozoic time are recorded. The comprehensive analytical data presented here has not been previously published. This significant data set can be used as fundamental information in studies of basic China geology, magma petrogenesis, ore exploration and geochemistry.

  1. Effects of superabsorbent polymers on the abundances of antibiotic resistance genes, mobile genetic elements, and the bacterial community during swine manure composting.

    Science.gov (United States)

    Guo, Aiyun; Gu, Jie; Wang, Xiaojuan; Zhang, Ranran; Yin, Yanan; Sun, Wei; Tuo, Xiaxia; Zhang, Li

    2017-11-01

    Superabsorbent polymers (SAPs) are considered suitable amendments for reducing the selection pressure due to heavy metals and the abundances of antibiotic resistance genes (ARGs) during composting. In this study, three SAP (sodium polyacrylate) levels (0, 5, and 15mgkg-1 of compost) were applied and their effects on the abundances of ARGs, mobile genetic elements (MGEs), and the bacterial community were investigated. After composting, the abundances of ARGs and MGEs decreased to different extent, where the removal efficiencies for tetW, dfrA7, ermX, aac(6')-ib-cr and MGEs exceeded 90%. The high SAP concentration significantly reduced the abundances of ARGs and MGEs, and changed the microbial community. Redundancy analysis indicated that the moisture content mainly explained the changes in ARGs and MGEs. Network analysis determined the potential hosts of ARGs and MGEs, and their co-occurrence. The results suggested that applying 15mgkg-1 SAP is appropriate for reducing ARGs in compost. Copyright © 2017. Published by Elsevier Ltd.

  2. The effects of He I λ10830 on helium abundance determinations

    Energy Technology Data Exchange (ETDEWEB)

    Aver, Erik [Department of Physics, Gonzaga University, 502 E Boone Ave, Spokane, WA 99258 (United States); Olive, Keith A.; Skillman, Evan D., E-mail: aver@gonzaga.edu, E-mail: olive@umn.edu, E-mail: skillman@astro.umn.edu [School of Physics and Astronomy, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States)

    2015-07-01

    Observations of helium and hydrogen emission lines from metal-poor extragalactic H II regions, combined with estimates of metallicity, provide an independent method for determining the primordial helium abundance, Y{sub p}. Traditionally, the emission lines employed are in the visible wavelength range, and the number of suitable lines is limited. Furthermore, when using these lines, large systematic uncertainties in helium abundance determinations arise due to the degeneracy of physical parameters, such as temperature and density. Recently, Izotov, Thuan, and Guseva (2014) have pioneered adding the He I λ10830 infrared emission line in helium abundance determinations. The strong electron density dependence of He I λ10830 makes it ideal for better constraining density, potentially breaking the degeneracy with temperature. We revisit our analysis of the dataset published by Izotov, Thuan, and Stasi and apos;nska (2007) and incorporate the newly available observations of He I λ10830 by scaling them using the observed-to-theoretical Paschen-gamma ratio. The solutions are better constrained, in particular for electron density, temperature, and the neutral hydrogen fraction, improving the model fit to data, with the result that more spectra now pass screening for quality and reliability, in addition to a standard 95% confidence level cut. Furthermore, the addition of He I λ10830 decreases the uncertainty on the helium abundance for all galaxies, with reductions in the uncertainty ranging from 10–80%. Overall, we find a reduction in the uncertainty on Y{sub p} by over 50%. From a regression to zero metallicity, we determine Y{sub p} = 0.2449 ± 0.0040, consistent with the BBN result, Y{sub p} = 0.2470 ± 0.0002, based on the Planck determination of the baryon density. The dramatic improvement in the uncertainty from incorporating He I λ10830 strongly supports the case for simultaneous (thus not requiring scaling) observations of visible and infrared helium

  3. Determination of lithium isotopes at natural abundance levels by atomic absorption spectrometry

    Science.gov (United States)

    Meier, A.L.

    1982-01-01

    The relationships of the absorption of 6Li and 7Li hollow cathode lamp emissions are used to determine lithium isotopic composition in the natural abundance range of geologic materials. Absorption was found to have a nonlinear dependence upon total lithium concentration and isotopic composition. A method using nonlinear equations to describe the relationship of the absorption of 6Li and 7Li lamp radiation is proposed as a means of calculating isotopic composition that is independent of total lithium concentration.

  4. METAL-RICH ACCRETION AND THERMOHALINE INSTABILITIES IN EXOPLANET-HOST STARS: CONSEQUENCES ON THE LIGHT ELEMENTS ABUNDANCES

    Energy Technology Data Exchange (ETDEWEB)

    Theado, Sylvie; Vauclair, Sylvie, E-mail: stheado@ast.obs-mip.fr [Institut de Recherches en Astrophysique et Planetologie, Universite de Toulouse, CNRS, 14 avenue Edouard Belin, 31400 Toulouse (France)

    2012-01-10

    The early evolution of planetary systems is expected to depend on various periods of disk matter accretion onto the central star, which may include the accretion of metal-rich matter after the star settles on the main sequence. When this happens, the accreted material is rapidly mixed within the surface convective zone and induces an inverse mean-molecular-weight gradient, unstable for thermohaline convection. The induced mixing, which dilutes the metal excess, may also have important consequences on the light elements abundances. We model and analyze this process, and present the results according to various possible accretion scenarios. We give a detailed discussion of the different ways of treating thermohaline mixing, as proposed by previous authors, and converge on a consistent view, including the most recent numerical simulations. We show how the observations of light elements in stars can be used as tracers of such events.

  5. Mineralogical analyses of surface sediments in the Antarctic Dry Valleys: coordinated analyses of Raman spectra, reflectance spectra and elemental abundances.

    Science.gov (United States)

    Bishop, Janice L; Englert, Peter A J; Patel, Shital; Tirsch, Daniela; Roy, Alex J; Koeberl, Christian; Böttger, Ute; Hanke, Franziska; Jaumann, Ralf

    2014-12-13

    Surface sediments at Lakes Fryxell, Vanda and Brownworth in the Antarctic Dry Valleys (ADV) were investigated as analogues for the cold, dry environment on Mars. Sediments were sampled from regions surrounding the lakes and from the ice cover on top of the lakes. The ADV sediments were studied using Raman spectra of individual grains and reflectance spectra of bulk particulate samples and compared with previous analyses of subsurface and lakebottom sediments. Elemental abundances were coordinated with the spectral data in order to assess trends in sediment alteration. The surface sediments in this study were compared with lakebottom sediments (Bishop JL et al. 2003 Int. J. Astrobiol. 2, 273-287 (doi:10.1017/S1473550403001654)) and samples from soil pits (Englert P et al. 2013 In European Planetary Science Congress, abstract no. 96; Englert P et al. 2014 In 45th Lunar and Planetary Science Conf., abstract no. 1707). Feldspar, quartz and pyroxene are common minerals found in all the sediments. Minor abundances of carbonate, chlorite, actinolite and allophane are also found in the surface sediments, and are similar to minerals found in greater abundance in the lakebottom sediments. Surface sediment formation is dominated by physical processes; a few centimetres below the surface chemical alteration sets in, whereas lakebottom sediments experience biomineralization. Characterizing the mineralogical variations in these samples provides insights into the alteration processes occurring in the ADV and supports understanding alteration in the cold and dry environment on Mars. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  6. Helioseismic models of the sun with a low heavy element abundance

    Science.gov (United States)

    Ayukov, S. V.; Baturin, V. A.

    2017-10-01

    Helioseismology and neutrino experiments probing the internal structure of the Sun have yieldedmuch information, such as the adiabatic elasticity index, density, and sound speed in the convective and radiative zones, the depth of the convective zone, and the flux of neutrinos from the core. The standard model of the Sun does not adequately reproduce these characteristics, with models with low heavy element contents (mass fraction of metals Z = 0.013 in the convective zone) deviating from the helioseismic data appreciably more strongly than models with high heavy element contents ( Z = 0.018). However, a spectroscopic low Z value is supported by studies reconstructing the Γ 1 profile in the adiabatic part of the convective zone based on the oscillation frequencies. Models of the convective zone show a good agreement precisely for low Z values. This study attempts to construct a model for the Sun with low Z that satisfies the helioseismic constraints. This model requires changes in the p + p reaction cross section and the opacities in the radiative zone. In our view, the helioseismic result for the mass concentrated in the convective zone testifies that the p + p reaction cross section or the electron-screening coefficient in the solar core must be increased by several percent over the current values. This requires a comparatively small correction to the opacities (by less than 5%), in order to obtain a solar model with low Z that is in agreement with the results of helioseismology and the observed solar neutrino fluxes.

  7. Determination of heavy elements in Nigerian river sediments using ...

    African Journals Online (AJOL)

    Energy Dispersive X-Ray Fluoresecence (EDXRF) Technique was used to determine eleven heavy elements (K, Ca, Ti, V, Fe, Co, Zn, Rb, Sr, Zr, Nb) from sediments of the Kubanni river in Nigeria. Six of them (K, Ca, Ti, Fe, Co, Sr) were found to be depleted, while lthe others were enriched with respect to their Clarke values.

  8. New trace element determinations in the fingernails of ALS patients

    Energy Technology Data Exchange (ETDEWEB)

    Van Dalsem, D.J.; Robinson, L. [Oak Ridge National Lab., TN (United States); Ehmann, W.D. [Kentucky Univ., Lexington, KY (United States). Dept. of Chemistry

    1996-02-01

    ORNL`s High Flux Isotope Reactor was used in a neutron activation analysis experiment to determine selected elemental composition of fingernails from patients afflicted with amyotrophic lateral sclerosis (AL). While no statistical difference were found in aluminium a suggestive difference was observed for copper concentrations.

  9. determination of elemental constituents for three herbal plants

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    The dried leaves are grinded to fine powder using pestle and mortar. The powdered samples are put into three transparent plastic bags (30 mm × 15 mm) and labeled A, B and. C.A hand held XRF machine is used to determine the elemental constituents of the respective leaves which appear on the screen of the machine.

  10. Abundance, distribution and bioavailability of major and trace elements in surface sediments from the Cai River estuary and Nha Trang Bay (South China Sea, Vietnam)

    Science.gov (United States)

    Koukina, S. E.; Lobus, N. V.; Peresypkin, V. I.; Dara, O. M.; Smurov, A. V.

    2017-11-01

    Major (Si, Al, Fe, Ti, Mg, Ca, Na, K, S, P), minor (Mn) and trace (Li, V, Cr, Co, Ni, Cu, Zn, As, Sr, Zr, Mo, Cd, Ag, Sn, Sb, Cs, Ba, Hg, Pb, Bi and U) elements, their chemical forms and the mineral composition, organic matter (TOC) and carbonates (TIC) in surface sediments from the Cai River estuary and Nha Trang Bay were first determined along the salinity gradient. The abundance and ratio of major and trace elements in surface sediments are discussed in relation to the mineralogy, grain size, depositional conditions, reference background and SQG values. Most trace-element contents are at natural levels and are derived from the composition of rocks and soils in the watershed. A severe enrichment of Ag is most likely derived from metal-rich detrital heavy minerals such as Ag-sulfosalts. Along the salinity gradient, several zones of metal enrichment occur in surface sediments because of the geochemical fractionation of the riverine material. The parts of actually and potentially bioavailable forms (isolated by four single chemical reagent extractions) are most elevated for Mn and Pb (up to 36% and 32% of total content, respectively). The possible anthropogenic input of Pb in the region requires further study. Overall, the most bioavailable parts of trace elements are associated with easily soluble amorphous Fe and Mn oxyhydroxides. The sediments are primarily enriched with bioavailable metal forms in the riverine part of the estuary. Natural (such as turbidities) and human-generated (such as urban and industrial activities) pressures are shown to influence the abundance and speciation of potential contaminants and therefore change their bioavailability in this estuarine system.

  11. The metallicity and elemental abundance gradients of simulated galaxies and their environmental dependence

    Science.gov (United States)

    Taylor, Philip; Kobayashi, Chiaki

    2017-11-01

    The internal distribution of heavy elements, in particular the radial metallicity gradient, offers insight into the merging history of galaxies. Using our cosmological, chemodynamical simulations that include both detailed chemical enrichment and feedback from active galactic nuclei (AGN), we find that stellar metallicity gradients in the most massive galaxies (≳3 × 1010M⊙) are made flatter by mergers and are unable to regenerate due to the quenching of star formation by AGN feedback. The fitting range is chosen on a galaxy-by-galaxy basis in order to mask satellite galaxies. The evolutionary paths of the gradients can be summarized as follows: (I) creation of initial steep gradients by gas-rich assembly, (II) passive evolution by star formation and/or stellar accretion at outskirts, and (III) sudden flattening by mergers. There is a significant scatter in gradients at a given mass, which originates from the last path, and therefore from galaxy type. Some variation remains at given galaxy mass and type because of the complexity of merging events, and hence we find only a weak environmental dependence. Our early-type galaxies (ETGs), defined from the star formation main sequence rather than their morphology, are in excellent agreement with the observed stellar metallicity gradients of ETGs in the SAURON and ATLAS3D surveys. We find small positive [O/Fe] gradients of stars in our simulated galaxies, although they are smaller with AGN feedback. Gas-phase metallicity and [O/Fe] gradients also show variation, the origin of which is not as clear as for stellar populations.

  12. Food abundance does not determine bird use of early-successional habitat.

    Energy Technology Data Exchange (ETDEWEB)

    Champlin, Tracey B.; Kilgo, John C.; Moorman, Christopher E.

    2009-06-01

    Abstract. Few attempts have been made to experimentally address the extent to which temporal or spatial variation in food availability influences avian habitat use. We used an experimental approach to investigate whether bird use differed between treated (arthropods reduced through insecticide application) and control (untreated) forest canopy gaps within a bottomland hardwood forest in the Upper Coastal Plain of South Carolina, USA. Gaps were two- to three-year-old group selection timber harvest openings of three sizes (0.13, 0.26, and 0.50 ha). Our study was conducted during four bird use periods (spring migration, breeding, post-breeding, and fall migration) in 2002 and 2003. Arthropods were reduced in treated gaps by 68% in 2002 and 73% in 2003. We used mist-netting captures and foraging attack rates to assess the influence of arthropod abundance on avian habitat use. Evidence that birds responded to arthropod abundance was limited and inconsistent. In 2002, we generally captured more birds in treated gaps of the smallest size (0.13 ha) and fewer birds in treated gaps of the larger sizes. In 2003, we recorded few differences in the number of captures in treated and control gaps. Foraging attack rates generally were lower in treated than in control gaps, indicating that birds were able to adapt to the reduced food availability and remain in treated gaps. We conclude that arthropod abundance was not a proximate factor controlling whether forest birds used our gaps. The abundance of food resources may not be as important in determining avian habitat selection as previous research has indicated, at least for passerines in temperate subtropical regions.

  13. Problems and methods for determining reserves of renewable elements

    Energy Technology Data Exchange (ETDEWEB)

    Dalkowski, T.; Dabrowska, I.

    1983-01-01

    The effects of spare parts on reliability of mining equipment used in coal surface mining are discussed. The optimum number of spare parts and elements used in equipment repair depends on reliability and service life of each element and on failure rates, which are influenced by local conditions. A method for determining the optimum number of spare parts for mining equipment which treats a machine failure as an event of random character is analyzed. Problems associated with replacing elements removed due to wear or failures as well as problems of repair are investigated. A model of spare part management and repair shop management in a coal surface mine is evaluated. Spare part management in the Belchatow brown coal surface mine is discussed with the example of maintenance and repair of belt conveyors. 10 references.

  14. Methods for determining the abundance, diversity and activity of soil microbial communities

    Science.gov (United States)

    Pereg, Lily

    2014-05-01

    The diversity and abundance of soil microbial communities play important roles in determining soil structure, quality and productivity. The past decade has seen an increase in the number and efficiency of methods for determining microbial diversity, abundance and function. Recognising that only a very small proportion of the soil microbial community can be cultured, most current studies use molecular techniques based on the 16S and 18S rRNA encoding sequences (DGGE, TRFLP, OFRG, ARISA, SSCP) as well as techniques based on the cellular composition of the microbes (PLFA composition). Recent developments include high-throughput sequencing and microarrays, representing major advances in microbial community analysis. While the diversity of microbes can be determined using DNA-based techniques, microbial activity changes under various conditions. Therefore, the analysis of soil function at any given time requires the analysis of gene expression using RNA-based techniques. Molecular techniques have tremendously advanced our knowledge in the field of soil microbiology, however, the limitations should not be underestimated. This presentation will critically review both the advantages and the limitations of techniques used in soil microbial analysis.

  15. ELEMENTAL ABUNDANCES AND THEIR IMPLICATIONS FOR THE CHEMICAL ENRICHMENT OF THE BOOeTES I ULTRAFAINT GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, Gerard [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Norris, John E.; Yong, David [Research School of Astronomy and Astrophysics, The Australian National University, Weston, ACT 2611 (Australia); Monaco, Lorenzo [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Santiago 19 (Chile); Wyse, Rosemary F. G. [Department of Physics and Astronomy, The Johns Hopkins University, 3900 North Charles Street, Baltimore, MD 21218 (United States); Geisler, D., E-mail: gil@ast.cam.ac.uk, E-mail: jen@mso.anu.edu.au, E-mail: yong@mso.anu.edu.au, E-mail: lmonaco@eso.org, E-mail: wyse@pha.jhu.edu, E-mail: dgeisler@astro-udec.cl [Departamento de Astronomia, Universidad de Concepcion (Chile)

    2013-01-20

    We present a double-blind analysis of high-dispersion spectra of seven red giant members of the Booetes I ultrafaint dwarf spheroidal galaxy, complemented with re-analysis of a similar spectrum of an eighth-member star. The stars cover [Fe/H] from -3.7 to -1.9 and include a CEMP-no star with [Fe/H] = -3.33. We conclude from our chemical abundance data that Booetes I has evolved as a self-enriching star-forming system, from essentially primordial initial abundances. This allows us uniquely to investigate the place of CEMP-no stars in a chemically evolving system, in addition to limiting the timescale of star formation. The elemental abundances are formally consistent with a halo-like distribution, with enhanced mean [{alpha}/Fe] and small scatter about the mean. This is in accord with the high-mass stellar initial mass function in this low-stellar-density, low-metallicity system being indistinguishable from the present-day solar neighborhood value. There is a non-significant hint of a decline in [{alpha}/Fe] with [Fe/H]; together with the low scatter, this requires low star formation rates, allowing time for supernova ejecta to be mixed over the large spatial scales of interest. One star has very high [Ti/Fe], but we do not confirm a previously published high value of [Mg/Fe] for another star. We discuss the existence of CEMP-no stars, and the absence of any stars with lower CEMP-no enhancements at higher [Fe/H], a situation that is consistent with knowledge of CEMP-no stars in the Galactic field. We show that this observation requires there be two enrichment paths at very low metallicities: CEMP-no and 'carbon-normal'.

  16. Process to determine light elements content of steel and alloys

    Energy Technology Data Exchange (ETDEWEB)

    Quintella, Cristina M.A.L.T.M.H.; Castro, Martha T.P.O. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica. LabLaser; Mac-Culloch, Joao N.L.M. [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The present work reports a process to determine qualitatively and quantitatively elements of molar mass inferior to 23 within materials, by X rays spectra associated with multivariate data analysis, or chemometric analysis. The spectra is acquired between 5 keV and 22 keV when the materials are exposed to X radiation. Here is reported the direct determination of carbon content in steel and metallic alloys. The process is more effective when using spectral regions which are not usually used. From the analysis of these spectral regions which were not considered before, it was possible to detect light elements with molar mass lower than 23, which have low capacity of absorbing and emitting radiation, but have high capacity of scattering radiation. The process here reported has the advantage that X-Ray spectra obtained are calibrated multivariately, showing high potential for development in order to be used in a portable field equipment. (author)

  17. Determination of the CKM Element V(Ub)

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, Dominique; /Victoria U.

    2007-04-06

    The precise determination of the CKM matrix element |V{sub ub}| is crucial in testing the Standard Model mechanism for CP violation. From a sample of 88 million B{bar B} pairs collected with the BABAR detector, charmless semileptonic B decays are selected using simultaneous requirements on the electron energy, E{sub e}, and the invariant mass squared of the electron-neutrino pair, q{sup 2}. The partial branching fraction, unfolded for detector effects, is determined in a region of the q{sup 2}-E{sub e} plane where the dominating semileptonic decays to charm mesons are highly suppressed. Theoretical calculations based on the Heavy Quark Expanion allows for a determination of |V{sub ub}| = (3.95 {+-} 0.27{sub -0.42}{sup +0.58} {+-} 0.25) x 10{sup -3}, where the errors represent experimental, heavy quark parameters and theoretical uncertainties, respectively.

  18. Formation of the Abundance Boundaries of the Heavier Neutron-capture Elements in Metal-poor Stars

    Science.gov (United States)

    Yang, Guochao; Li, Hongjie; Liu, Nian; Zhang, Lu; Cui, Wenyuan; Liang, Yanchun; Niu, Ping; Zhang, Bo

    2017-06-01

    The abundance scatter of heavier r-process elements (Z≥slant 56) relative to Fe ([r/Fe]) in metal-poor stars preserves excellent information of the star formation history and provides important insights into the various situations of the Galactic chemical enrichment. In this respect, the upper and lower boundaries of [r/Fe] could present useful clues for investigating the extreme situations of the star formation history and the early Galactic chemical evolution. In this paper, we investigate the formation of the upper and lower boundaries of [r/Fe] for the gas clouds. We find that, for a cloud from which metal-poor stars formed, the formation of the upper limits of [r/Fe] is mainly due to the pollution from a single main r-process event. For a cloud from which metal-poor stars formed, the formation of the lower limits of [r/Fe] is mainly due to the pollution from a single SN II event that ejects primary Fe.

  19. Content of nutritional elements in sudangrass and ryegrass determined by ICP-AES.

    Science.gov (United States)

    Li, Wen-Xi; Lu, Jian-Wei; Seneweera, Saman P; Wu, Ji; Chen, Fang; Lu, Jun-Ming; Li, Xiao-Kun

    2011-09-01

    The sudangrass (Sorghum sudanense) and ryegrass (Lolium multi florum L.) rotation is a new type of cropping system, which has developed rapidly in recent years in the south of China. The contents of nutritional elements for forage grass in the sudangrass and ryegrass rotation system were determined by ICP-AES. The results showed that there were abundant and essential nutritional elements for animals in sudangrass and ryegrass. The contents of P, K, Ca, Mg, S, Fe, B, Cu, Zn and Mn for sudangrass were 0.20% -0.29%, 1.94%-2.57%, 0.62%-0.97%, 0.39%-0.69%, 0.12%-0.18%, 108.35-180.12, 3.04-5.96, 6.17-10.02, 20.37-31.36 and 46.80-101.29 mg x kg(-1), respectively. The contents of P, K, Ca, Mg, S, Fe, B, Cu, Zn, Mn for ryegrass were 0.39%-0.70%, 3.77%-5.07%, 0.61%-0.84%, 0.28% -0.47%, 0.32%-0.41%, 291.65- 632.20, 2.13-3.23, 13.29-15.19, 30.73-42.98 and 92.08-156.04 mg x kg(-1), respectively, and there were differences between various periods in nutritional elements in the two forage grasses. The application of ICP-AES could reflect fast and efficiently the content of nutritional elements for forage grass as animals feed.

  20. New trace element determinations in the fingernails of ALS patients

    Energy Technology Data Exchange (ETDEWEB)

    Van Dalsem, D.J.; Ehmann, W.D. [Univ. of Kentucky, Lexington, KY (United States); Robinson, L. [Oak Ridge National Laboratory, TN (United States)

    1996-12-31

    Amyotrophic lateral sclerosis (ALS) afflicts 2 of every 100,000 people in the United States each year. A well-known example of ALS today is Stephen Hawking. He is a theoretical physicist, the author of A Brief History of Time, and is virtually immobilized by ALS. Diseases that cause progressive paralysis because of motor neuron degeneration in the central nervous system are termed motor neuron disorders (MND). Amyotrophic lateral sclerosis is a common form of MND. Pain-free, progressive muscular weakness is the most common clinical symptom. There is chronic weakness with atrophy of the affected muscles by the time the disease is diagnosed. Atrophy eventually results in wheelchair confinement and then only bed without the ability to speak or swallow. Death often occurs as a result of respiratory problems. Unlike other neurodegenerative diseases, in ALS the patient`s bladder and bowel control, eye movement, and mental faculties are preserved. The question today is whether or not certain trace elements are involved in the etiology or pathogenesis of ALS. A collaborative study was undertaken by the University of Kentucky and Oak Ridge National Laboratory (ORNL) using neutron activation analysis (NAA) to study trace element concentrations in ALS patients fingernails to determine if there existed statistically significant imbalances.

  1. Determination of rare-earth elements in rocks by isotope-excited X-ray fluorescence spectrometry

    DEFF Research Database (Denmark)

    Kunzendorf, Helmar; Wollenberg, H.A.

    1970-01-01

    Isotope-excited X-ray fluorescence spectrometry furnishes a rapid determination of rare-earth elements in unprepared rock samples. The samples are excited by 241Am γ-rays, generating X-ray spectra on a multichannel pulse-height analyser. Gaussian peaks of the Kα and Kβ X-ray energies are treated......-ray spectrometric scan of a longitudinally sliced drill core showed a close correlation between rare-earth abundances and appropriate minerals....

  2. Solution structure determination of oligoureas using methylene spin state selective NMR at 13C natural abundance.

    Science.gov (United States)

    Guichard, Gilles; Violette, Aude; Chassaing, Gérard; Miclet, Emeric

    2008-10-01

    Ability of N,N'-linked oligoureas containing proteinogenic side chains to adopt a stable helix conformation in solution has been described recently. NMR as well as circular dichroism (CD) spectroscopies were employed to gain insight into their specific fold. It is herein proposed to extend the structural information available on these peptidomimetics by an advantageous use of a methylene spin state selective NMR experiment. Homodecoupling provided by the pulse scheme made it possible to readily measure conformation-dependent (3)J(HH) constants that are difficult if not impossible to obtain with standard NMR experiments. Adding those couplings to the NMR restraints improved the quality of the structure calculations significantly, as judged by a ca 30% decrease of the root mean square deviation (RMSD) obtained over an ensemble of 20 structures. Moreover, accurate determination of individual (1)J(CH) couplings within each methylene group revealed uniform values throughout the oligourea sequence, with (1)J(CH) systematically slightly larger for the pro-S hydrogen than for the pro-R. As shown in this study, the methylene spin state selective NMR experiment displays a good intrinsic sensitivity and could therefore provide valuable structural information at (13)C natural abundance for peptidomimetic molecules and foldamers bearing diastereotopic methylene protons. Copyright (c) 2008 John Wiley & Sons, Ltd.

  3. A broad assessment of factors determining Culicoides imicola abundance: modelling the present and forecasting its future in climate change scenarios.

    Science.gov (United States)

    Acevedo, Pelayo; Ruiz-Fons, Francisco; Estrada, Rosa; Márquez, Ana Luz; Miranda, Miguel Angel; Gortázar, Christian; Lucientes, Javier

    2010-12-06

    Bluetongue (BT) is still present in Europe and the introduction of new serotypes from endemic areas in the African continent is a possible threat. Culicoides imicola remains one of the most relevant BT vectors in Spain and research on the environmental determinants driving its life cycle is key to preventing and controlling BT. Our aim was to improve our understanding of the biotic and abiotic determinants of C. imicola by modelling its present abundance, studying the spatial pattern of predicted abundance in relation to BT outbreaks, and investigating how the predicted current distribution and abundance patterns might change under future (2011-2040) scenarios of climate change according to the Intergovernmental Panel on Climate Change. C. imicola abundance data from the bluetongue national surveillance programme were modelled with spatial, topoclimatic, host and soil factors. The influence of these factors was further assessed by variation partitioning procedures. The predicted abundance of C. imicola was also projected to a future period. Variation partitioning demonstrated that the pure effect of host and topoclimate factors explained a high percentage (>80%) of the variation. The pure effect of soil followed in importance in explaining the abundance of C. imicola. A close link was confirmed between C. imicola abundance and BT outbreaks. To the best of our knowledge, this study is the first to consider wild and domestic hosts in predictive modelling for an arthropod vector. The main findings regarding the near future show that there is no evidence to suggest that there will be an important increase in the distribution range of C. imicola; this contrasts with an expected increase in abundance in the areas where it is already present in mainland Spain. What may be expected regarding the future scenario for orbiviruses in mainland Spain, is that higher predicted C. imicola abundance may significantly change the rate of transmission of orbiviruses.

  4. The Ages, Metallicities, and Element Abundance Ratios of Massive Quenched Galaxies at z ≥ 1.6

    Science.gov (United States)

    Onodera, M.; Carollo, C. M.; Renzini, A.; Cappellari, M.; Mancini, C.; Arimoto, N.; Daddi, E.; Gobat, R.; Strazzullo, V.; Tacchella, S.; Yamada, Y.

    2015-08-01

    We investigate the stellar population properties of a sample of 24 massive quenched galaxies at 1.25population properties as close to their major formation epoch as possible, we try to put constraints on the star formation history, post-quenching evolution, and possible progenitor star-forming populations for such massive quenched galaxies. By using a set of Lick absorption line indices on a rest-frame optical composite spectrum, the average age, metallicity [Z/H], and α-to-iron element abundance ratio [α/Fe] are derived as log(age/Gyr)=0.04-0.08+0.10, [Z/H]=0.24-0.14+0.20, and [α /Fe]=0.31-0.12+0.12, respectively. If our sample of quenched galaxies at population properties will align in excellent agreement with local counterparts at similar stellar velocity dispersions, which qualifies them as progenitors of local massive early-type galaxies. Redshift evolution of stellar population ages in quenched galaxies combined with low redshift measurements from the literature suggests a formation redshift of zf∼ 2.3, around which the bulk of stars in these galaxies have been formed. The measured [α/Fe] value indicates a star formation timescale of ≲ 1 Gyr, which can be translated into a specific star formation rate of ≃ 1 Gyr-1 prior to quenching. Based on these findings, we discuss identifying possible progenitor star-forming galaxies at z≃ 2.3. We identify normal star-forming galaxies, i.e., those on the star-forming main sequence, followed by a rapid quenching event, as likely precursors of the quenched galaxies at Japan. (Proposal IDs: S09A-043, S10A-058, and S11A-075.)

  5. Vole abundance and reindeer carcasses determine breeding activity of Arctic foxes in low Arctic Yamal, Russia.

    Science.gov (United States)

    Ehrich, Dorothee; Cerezo, Maite; Rodnikova, Anna Y; Sokolova, Natalya A; Fuglei, Eva; Shtro, Victor G; Sokolov, Aleksandr A

    2017-09-16

    High latitude ecosystems are at present changing rapidly under the influence of climate warming, and specialized Arctic species at the southern margin of the Arctic may be particularly affected. The Arctic fox (Vulpes lagopus), a small mammalian predator endemic to northern tundra areas, is able to exploit different resources in the context of varying tundra ecosystems. Although generally widespread, it is critically endangered in subarctic Fennoscandia, where a fading out of the characteristic lemming cycles and competition with abundant red foxes have been identified as main threats. We studied an Arctic fox population at the Erkuta Tundra Monitoring site in low Arctic Yamal (Russia) during 10 years in order to determine which resources support the breeding activity in this population. In the study area, lemmings have been rare during the last 15 years and red foxes are nearly absent, creating an interesting contrast to the situation in Fennoscandia. Arctic fox was breeding in nine of the 10 years of the study. The number of active dens was on average 2.6 (range 0-6) per 100 km2 and increased with small rodent abundance. It was also higher after winters with many reindeer carcasses, which occurred when mortality was unusually high due to icy pastures following rain-on-snow events. Average litter size was 5.2 (SD = 2.1). Scat dissection suggested that small rodents (mostly Microtus spp.) were the most important prey category. Prey remains observed at dens show that birds, notably waterfowl, were also an important resource in summer. The Arctic fox in southern Yamal, which is part of a species-rich low Arctic food web, seems at present able to cope with a state shift of the small rodent community from high amplitude cyclicity with lemming dominated peaks, to a vole community with low amplitude fluctuations. The estimated breeding parameters characterized the population as intermediate between the lemming fox and the coastal fox ecotype. Only continued

  6. Twenty-First Century Spectroscopic Data for Determinations of Interstellar Ice Abundances

    Science.gov (United States)

    Hudson, Reggie

    The molecular chemistry of interstellar and circumstellar environments consists of a complex interplay between gas- and solid-phase processes. An important step in unraveling this chemistry has been the observation and identification of gas-phase molecules, mainly by radio and microwave observations. Nearly 200 interstellar and circumstellar gas-phase molecules are known, but only about 10 identifications, mostly from infrared (IR) studies, have been made of solid-phase species, usually termed “ices”. Determining the abundances of icy molecules has been a continual challenge due to the lack of appropriate laboratory measurements of spectral band strengths, optical constants, refractive indices, and ice densities. Our research group is now engaged in two new laboratory programs for just such measurements. In one program we measure IR optical constants (n and k) for molecules found in molecular ices. Our second new laboratory program focuses on densities and refractive indices, which are required for generating optical constants and spectral band strengths from laboratory IR data. This combination of research efforts within a single facility provides an unusual, if not unique, opportunity for producing the lab data required for more-accurate analysis and interpretation of Spitzer, and other, observations of interstellar ices. In spite of a general belief that such lab results may already be available, a careful literature search quickly reveals significant, surprising, and stunning gaps and deficiencies. The current situation is paradoxical in that twenty-first century spectra of astronomical ices near 10 K are being analyzed for molecular abundances using room-temperature physical properties and results from vacuum-tube dispersive spectrometers and mechanical planimeters. Here we propose a systematic effort to bring the lab data into the twenty-first century through the measurement of IR spectra and optical constants, refractive indices, and densities of several

  7. 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.

  8. Determination of rare earth elements and other trace elements (Y, Mn, Co, Cr) in seawater using Tm addition and Mg(OH)₂ co-precipitation.

    Science.gov (United States)

    Freslon, Nicolas; Bayon, Germain; Birot, Dominique; Bollinger, Claire; Barrat, Jean Alix

    2011-07-15

    This paper reports on a novel procedure for determining trace element abundances (REE and Y, Cr, Mn, Co) in seawater by inductively coupled plasma sector field mass spectrometry (ICP-SFMS). The procedure uses a combination of pre-concentration using co-precipitation onto magnesium hydroxides and addition of thulium spike. The validity of the method was assessed onto 25 ml volumes of certified reference materials (NASS- and CASS-4) and in house seawater standard. Procedural blanks were determined by applying the same procedure to aliquots of seawater previously depleted in trace elements by successive Mg(OH)(2) co-precipitations, yielding estimated contributions to the studied samples better than 1.1% for all elements, with the exception of Cr (<3.3%) and Co (up to 8%). The reproducibility of the method over the six month duration of the study was smaller than 11% RSD for all the studied elements. Results obtained for NASS-5 and CASS-4 agree well with published working values for trace elements. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Parasite abundance and its determinants in fishes from Brazil: an eco-epidemiological approach

    Directory of Open Access Journals (Sweden)

    Cristina Fernandes do Amarante

    2016-01-01

    Full Text Available Abstract The variability in parasite abundance has an ecological basis; however, from an epidemiological point of view, the contribution of factors inherent to the host to the variability in parasite abundance remains an open question. A database consisting of 3,746 specimens of 73 fish species was used to verify the relation between the distribution of parasite abundance in fishes and a set of biotic factors inherent to the hosts. Classical and mixed Poisson regression models were constructed. Prevalence ratios (PR and their respective 95% confidence intervals were estimated. The parasite abundance was significantly higher in female hosts, nonschooling species, species from benthopelagic and pelagic habitats, and fishes with greater body length. Overall, these results suggest that the variability in the abundance of infection is an attribute of the parasite species. Although the results are biologically plausible, important gaps may still exist and should be explored to better understand the variations in parasite abundance, which has great relevance in epidemiological studies. We reinforce the importance of choosing the statistical model most appropriate for the nature of the data to avoid spurious results, especially when the autocorrelation in the data is not taken into account.

  10. Full-scale mesophilic biogas plants using manure as C-source: bacterial community shifts along the process cause changes in the abundance of resistance genes and mobile genetic elements.

    Science.gov (United States)

    Wolters, Birgit; Ding, Guo-Chun; Kreuzig, Robert; Smalla, Kornelia

    2016-02-01

    The application of manure, typically harboring bacteria carrying resistance genes (RGs) and mobile genetic elements (MGEs), as co-substrate in biogas plants (BGPs) might be critical when digestates are used as fertilizers. In the present study, the relative abundance of RGs and MGEs in total community (TC-) DNA from manure, fermenters and digestate samples taken at eight full-scale BGPs co-fermenting manure were determined by real-time PCR. In addition, the bacterial community composition of all digestates as well as manure and fermenter material from one BGP (BGP3) was characterized by 454-pyrosequencing of 16S rRNA amplicons from TC-DNA. Compared to respective input manures, relative abundances determined for sul1, sul2, tet(M), tet(Q), intI1, qacEΔ1, korB and traN were significantly lower in fermenters, whereas relative abundances of tet(W) were often higher in fermenters. The bacterial communities in all digestates were dominated by Firmicutes and Bacteroidetes while Proteobacteria were low in abundance and no Enterobacteriaceae were detected. High-throughput sequencing revealed shifts in bacterial communities during treatment for BGP3. Although in comparison to manure, digestate bacteria had lower relative abundances of RGs and MGEs except for tet(W), mesophilic BGPs seem not to be effective for prevention of the spread of RGs and MGEs via digestates into arable soils. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Novel concept for the mass spectrometric determination of absolute isotopic abundances with improved measurement uncertainty: Part 1 - theoretical derivation and feasibility study

    Science.gov (United States)

    Rienitz, Olaf; Pramann, Axel; Schiel, Detlef

    2010-01-01

    The development of a new method for the experimental determination of absolute isotopic abundances using a modified isotope dilution mass spectrometry (IDMS) technique is described. The intention and thus main application will be the quantification of molar masses M of highly enriched materials with improved measurement uncertainty (Urel(M) [approximate] 10-8 with k = 2). In part 1 of the current work, the theoretical foundation of the new method and its mathematical derivation is shown in detail, while part 2 will cover the experiments based on the new method described. Its core idea is the introduction of a virtual element (VE) consisting of all isotopes but the one having the largest or smallest abundance. IDMS is used to determine the mass fraction of this VE in its matrix, namely the element itself. A new set of equations serve to calculate all isotopic abundances (even the large one omitted with the introduction of the VE) merely from the mass fraction of the VE. A comprehensive uncertainty budget according to the Guide to the Expression of Uncertainty in Measurement (GUM) was set up in order to discuss and validate the novel concept. The hypothetical input data of the uncertainty budget were estimated to resemble a silicon material highly enriched with respect to 28Si used in the context of the international Avogadro Project. Considering the calculated results, the experimental determination of the molar mass of the above mentioned silicon seems very promising. As far as the authors know, this will be the first time IDMS was applied to determine a molar mass.

  12. Neutron-capture element abundances in the planetary nebula NGC 5315 from deep optical and near-infrared spectrophotometry★†

    Science.gov (United States)

    Madonna, S.; García-Rojas, J.; Sterling, N. C.; Delgado-Inglada, G.; Mesa-Delgado, A.; Luridiana, V.; Roederer, I. U.; Mashburn, A. L.

    2017-10-01

    We analyse the chemical composition of the planetary nebula (PN) NGC 5315, through high-resolution (R ˜ 40000) optical spectroscopy with Ultraviolet-Visual Echelle Spectrograph at the Very Large Telescope, and medium-resolution (R ˜ 4800) near-infrared spectroscopy with Folded-port InfraRed Echellette at Magellan Baade Telescope, covering a wide spectral range from 0.31 to 2.50 μm. The main aim of this work is to investigate neutron (n)-capture element abundances to study the operation of the slow n-capture ('s-process') in the asymptotic giant branch (AGB) progenitor of NGC 5315. We detect more than 700 emission lines, including ions of the n-capture elements Se, Kr, Xe and possibly Br. We compute physical conditions from a large number of diagnostic line ratios, and derive ionic abundances for species with available atomic data. The total abundances are computed using recent ionization correction factors (ICFs) or by summing ionic abundances. Total abundances of common elements are in good agreement with previous work on this object. Based on our abundance analysis of NGC 5315, including the lack of s-process enrichment, we speculate that the most probable evolutionary scenario is that the progenitor star is in a binary system as hinted at by radial velocity studies, and interactions with its companion truncated the AGB before s-process enrichment could occur. However there are other two possible scenarios for its evolution, that cannot be ruled out: (I) the progenitor is a low-mass single star that did not undergo third dredge-up; (II) the progenitor star of NGC 5315 had an initial mass of 3-5 M⊙, and any s-process enhancements were heavily diluted by the massive envelope during the AGB phase.

  13. Does white clover (Trifolium repens abundance in temperate pastures determine Sitona obsoletus (Coleoptera: Curculionidae larval populations?

    Directory of Open Access Journals (Sweden)

    Mark Richard McNeill

    2016-09-01

    Full Text Available To determine if host plant abundance determined the size of clover root weevil (CRW Sitona obsoletus larval populations, a study was conducted over four years in plots sown in ryegrass (Lolium perenne (cv. Nui sown at either 6 or 30 kg/ha and white clover (Trifolium repens sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand with % clover measured in autumn (April and spring (September of each year. Overall, mean larval densities measured in spring 2012, 2013, 2014 and 2015 were 310, 38, 59 and 31 larvae m-2, respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3 and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October larval populations to % white clover measured in each plot in autumn (April found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted

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

    Science.gov (United States)

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

    2018-01-01

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

  15. Development of low-cost technology for the next generation of high efficiency solar cells composed of earth abundant elements

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Rakesh [Purdue Univ., West Lafayette, IN (United States)

    2014-09-28

    The development of renewable, affordable, and environmentally conscious means of generating energy on a global scale represents a grand challenge of our time. Due to the “permanence” of radiation from the sun, solar energy promises to remain a viable and sustainable power source far into the future. Established single-junction photovoltaic technologies achieve high power conversion efficiencies (pce) near 20% but require complicated manufacturing processes that prohibit the marriage of large-scale throughput (e.g. on the GW scale), profitability, and quality control. Our approach to this problem begins with the synthesis of nanocrystals of semiconductor materials comprising earth abundant elements and characterized by material and optoelectronic properties ideal for photovoltaic applications, namely Cu2ZnSn(S,Se)4 (CZTSSe). Once synthesized, such nanocrystals are formulated into an ink, coated onto substrates, and processed into completed solar cells in such a way that enables scale-up to high throughput, roll-to-roll manufacturing processes. This project aimed to address the major limitation to CZTSSe solar cell pce’s – the low open-circuit voltage (Voc) reported throughout literature for devices comprised of this material. Throughout the project significant advancements have been made in fundamental understanding of the CZTSSe material and device limitations associated with this material system. Additionally, notable improvements have been made to our nanocrystal based processing technique to alleviate performance limitations due to the identified device limitations. Notably, (1) significant improvements have been made in reducing intra- and inter-nanoparticle heterogeneity, (2) improvements in device performance have been realized with novel cation substitution in Ge-alloyed CZTGeSSe absorbers, (3) systematic analysis of absorber sintering has been conducted to optimize the selenization process for large grain CZTSSe absorbers, (4) novel electrical

  16. THE DETERMINATION OF TRACE ELEMENTS IN TUNGSTEN AND MOLYBDENUM BY ATOMIC ABSORPTION SPECTROPHOTOMETRY.

    Science.gov (United States)

    The determination of trace elements in tungsten and molybdenum by optical emission spectroscopy is complicated by the complex spectra and continuum...of value for this analysis. As many as 10 trace elements have been determined. Only one element can be determined at a time but the total time for the

  17. Alternative First Principle Approach for Determination of Elements of ...

    African Journals Online (AJOL)

    Stiffness coefficients which in essence are elements of stiffness matrix of a uniform beam element are derived in this work from first principles using elastic curve equation and initial value method. The obtained initial value solution enables exact values of stiffness coefficients, fixed end moments and shears as well as ...

  18. Bird Surveys at DARHT Before and During Operations: Comparison of Species Abundance and Composition and Trace Element Uptake

    Energy Technology Data Exchange (ETDEWEB)

    P. R. Fresquez, D. C. Keller, C. D. Hathcock

    2007-11-30

    The Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility Mitigation Action Plan specifies the comparison of baseline conditions in biotic and abiotic media with those collected after operations have started. Operations at DARHT at Los Alamos National Laboratory started in 2000. In this study, the abundance and composition of birds collected near the DARHT facility from 2003 through 2006 were determined and compared to a preoperational period (1999). In addition, the levels of radionuclides and other inorganic chemicals in birds were compared to regional statistical reference levels (RSRLs). The number and diversity of bird species generally increased over preoperational levels with the greatest number of birds (412) and species (46) occurring in 2005. The most common bird species collected regardless of time periods were the chipping sparrow (Spizella passerina), the Virginia's warbler (Vermivora virginiae), the western bluebird (Sialia mexicana), the broad-tailed hummingbird (Selasphorus platycercus), the sage sparrow (Amphispiza belli), and the western tanager (Piranga ludoviciana). Most radionuclides, with the exception of uranium-234 and uranium-238, in (whole body) birds collected after operations began were either not detected or below RSRLs. Uranium-234 and uranium-238 concentrations in a few samples were far below screening levels and do not pose a potential unacceptable dose to the birds. In contrast, many inorganic chemicals, particularly arsenic and silver, in birds collected before and after operations began were in higher concentrations than RSRLs. Because birds (skin plus feathers) collected in the years before operations began contained higher levels of arsenic and silver than RSRLs and because there was no evidence of these metals in soil and sediment directly around the DARHT facility, the elevated levels of these metals in birds during early operations are probably not related to DARHT operations. Arsenic and silver in birds, however

  19. Determination of minor and trace elements concentration in kidney stones using elemental analysis techniques

    Science.gov (United States)

    Srivastava, Anjali

    The determination of accurate material composition of a kidney stone is crucial for understanding the formation of the kidney stone as well as for preventive therapeutic strategies. Radiations probing instrumental activation analysis techniques are excellent tools for identification of involved materials present in the kidney stone. The X-ray fluorescence (XRF) and neutron activation analysis (NAA) experiments were performed and different kidney stones were analyzed. The interactions of X-ray photons and neutrons with matter are complementary in nature, resulting in distinctly different materials detection. This is the first approach to utilize combined X-ray fluorescence and neutron activation analysis for a comprehensive analysis of the kideny stones. Presently, experimental studies in conjunction with analytical techniques were used to determine the exact composition of the kidney stone. The use of open source program Python Multi-Channel Analyzer was utilized to unfold the XRF spectrum. A new type of experimental set-up was developed and utilized for XRF and NAA analysis of the kidney stone. To verify the experimental results with analytical calculation, several sets of kidney stones were analyzed using XRF and NAA technique. The elements which were identified from XRF technique are Br, Cu, Ga, Ge, Mo, Nb, Ni, Rb, Se, Sr, Y, Zr. And, by using Neutron Activation Analysis (NAA) are Au, Br, Ca, Er, Hg, I, K, Na, Pm, Sb, Sc, Sm, Tb, Yb, Zn. This thesis presents a new approach for exact detection of accurate material composition of kidney stone materials using XRF and NAA instrumental activation analysis techniques.

  20. IMPROVED Cr II log(gf ) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937.

    Science.gov (United States)

    Lawler, J E; Sneden, C; Nave, G; Den Hartog, E A; Emrahođlu, N; Cowan, J J

    2017-01-01

    New emission branching fraction (BF) measurements for 183 lines of the second spectrum of chromium (Cr II) and new radiative lifetime measurements from laser-induced fluorescence for 8 levels of Cr+ are reported. The goals of this study are to improve transition probability measurements in Cr II and reconcile solar and stellar Cr abundance values based on Cr I and Cr II lines. Eighteen spectra from three Fourier Transform Spectrometers supplemented with ultraviolet spectra from a high-resolution echelle spectrometer are used in the BF measurements. Radiative lifetimes from this study and earlier publications are used to convert the BFs into absolute transition probabilities. These new laboratory data are applied to determine the Cr abundance log ε in the Sun and metal-poor star HD 84937. The mean result in the Sun is 〈logε (Cr II)〉 = 5.624±0.009 compared to 〈logε(Cr I)〉 = 5.644 ± 0.006 on a scale with the hydrogen abundance log ε(H) = 12 and with the uncertainty representing only line-to-line scatter. A Saha (ionization balance) test on the photosphere of HD 84937 is also performed, yielding 〈logε(Cr II)〉 = 3.417 ± 0.006 and 〈log ε(Cr I, lower level excitation potential E. P. >30 eV)〉 = 3.3743±30.011 for this dwarf star. We find a correlation of Cr with the iron-peak element Ti, suggesting an associated nucleosynthetic production. Four iron-peak elements (Cr along with Ti, V, and Sc) appear to have a similar (or correlated) production history-other iron-peak elements appear not to be associated with Cr.

  1. Determining minimal display element requirements for surface map displays

    Science.gov (United States)

    2003-04-14

    There is a great deal of interest in developing electronic surface map displays to enhance safety and reduce incidents and incursions on or near the airport surface. There is a lack of research, however, detailing the minimal display elements require...

  2. Trace element determination in vitamin E using ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Ponce de Leon, Claudia A.; Montes Bayon, Maria; Caruso, Joseph A. [Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221 (United States)

    2002-09-01

    Vitamin E supplements are either isolated from plants sources or prepared synthetically. Isolation from plants includes eight different tocopherol structures. Vitamin E synthesis includes seven different stereoisomers, which involves the use of several catalysts that may lead to trace element contamination in the vitamin. The use of ICP-MS is an ideal technique for detecting these trace elements. However, the oily nature of the samples requires the development of a sample preparation methodology. This study was done upon the request of synthetic vitamin E manufacturers to test the trace metal purity of their samples. In this work, the comparison of an acid microwave digestion and emulsion preparation is discussed. Cromium, nickel, tin and lead were found in the synthetic vitamin E analyzed and 200, 60, 9 and 45 ppb were the concentrations found respectively for these elements. Digesting the samples gives slightly lower detection limits compared to the emulsion preparation. (orig.)

  3. Determination of Mineral Elements of Some Coarse Grains by Microwave Digestion with Inductively Coupled Plasma Atomic Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    Li Yang

    2012-01-01

    Full Text Available To determinate the mineral elements contents in millet,maise,oat,buckwheat,sorghum and purple rice, microwave digestion procedure optimized was applied for digesting six coarse grains. Nineteen mineral element concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES. Results displayed the limits of detection (LODs and the limits of quantification (LOQs range from 0.0047 to 0.1250 μg/mL and 0.0155 to 0.4125 μg/mL. The relative standard deviations (RSDs range from 0.83% to 5.03%, which showed that this proposed method was accurate and precise to detect mineral elements in coarse grains simultaneously. Correlation coefficients (r were calculated in the range of 0.999096-0.999989. The sufficient dada obtained described that the coarse grains selected were abundant in mineral element contents in the human body on daily diet. The success of combining the microwave digestion technology with the ICP-AES was a simple and precise method to determine many mineral elements in coarse grains simultaneously.

  4. The significance of oxygen as oxides and hydroxides in controlling the abundance and residence times of elements in seawater

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.

    A model is presented which signifies the role of oxygen (as oxides and hydroxides) in controlling the composition of seawater. respective concentration and residence times for the unknown elements can be estimated. Geometric and statistical indices...

  5. trace element determination in municipal water supply of Damaturu

    African Journals Online (AJOL)

    DR. AMINU

    Groundwater is the only source of drinking water for residents of Damaturu Metropolis. This is because surface water is ... examination of water and wastewater from the US Environmental Protection Agency (USEPA). The result of the ... Key words: Contamination, Trace elements, Toxic, underground water. INTRODUCTION.

  6. DETERMINATION OF MULTI ELEMENT LEVELS IN LEAVES AND ...

    African Journals Online (AJOL)

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    plants and the humans and animals who feed on these plants. ... Al, Cu, Fe, Mn, Sr and Zn are multi-elements which have major significance for human ... until analysis. The different digests of tea samples were analysed for heavy metal content using. ICP-OES. All the standard solutions (1000 mg/L) for Al, Ba, Cr, Cu, Fe, Mn ...

  7. accurate determination of calcium and other elements in cerea.

    African Journals Online (AJOL)

    eeeS00 00 33_31_ 00 c0S. Reproducibility studies. One gramme of sample 3 was weighed out in six replicates, ashed and analysed for all elements of interestas described in the recommended procedure. Application of procedure and comparison of results *. One gramme of each sample in Table 3 was weighed out in ...

  8. Trace elements in higher fungi (mushrooms) determined by activation analysis

    Czech Academy of Sciences Publication Activity Database

    Řanda, Zdeněk; Kučera, Jan

    2004-01-01

    Roč. 259, č. 1 (2004), s. 99-107 ISSN 0236-5731 R&D Projects: GA ČR GV202/97/K038 Institutional research plan: CEZ:AV0Z1048901 Keywords : trace elements * activation analysis * mushrooms Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.457, year: 2004

  9. determination of elemental composition of air particulates and soils ...

    African Journals Online (AJOL)

    Mgina

    aerodynamic diameter of 2.5µm. The virtual impactor, through its fine channel, was capable of collecting airborne particles with an aerodynamic diameter of 2.5 μm. Energy Dispersive X-Ray. Fluorescence (EDXRF) analysis was used to study the elemental concentrations of the air and soil samples. The analysis of the ...

  10. Determination of elemental composition of air particulates and soils ...

    African Journals Online (AJOL)

    Investigations were also performed for the elemental composition of soils at the same locations. A cyclone and a dichotomous virtual impactor were used to measure the air particulates. The cyclone was adjusted to collect particles having an aerodynamic diameter of 2.5!m. The virtual impactor, through its fine channel, was ...

  11. Trace elements determination in municpal water supply in Damaturu ...

    African Journals Online (AJOL)

    Groundwater is the only source of drinking water for residents of Damaturu Metropolis. This is because surface water is very scarce as a result of the very low and erratic rainfall in the region. This study examines the presence of trace elements in the municipal water supplies of Damaturu Metropolis, Yobe state. The trace ...

  12. Enchytraeid abundance in Araucaria Mixed Forest determined by cold and hot wet extraction

    Directory of Open Access Journals (Sweden)

    C. C. Niva

    Full Text Available Abstract Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region. The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold and 5.000-12.000 ind./ m2 (hot, respectively, with a maximum of 44.000 ind./ m2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.

  13. Enchytraeid abundance in Araucaria Mixed Forest determined by cold and hot wet extraction.

    Science.gov (United States)

    Niva, C C; Cezar, R M; Fonseca, P M; Zagatto, M R G; Oliveira, E M; Bush, E F; Clasen, L A; Brown, G G

    2015-11-01

    Enchytraeids are small oligochaetes found worldwide in soils with sufficient moisture and organic matter, but scarcely studied in the Southern hemisphere. This is the third study on enchytraeid abundance in Brazil using wet extraction and the first carried out in Araucaria Mixed Forest (subtropical region). The sampling and extraction were based on the standard method ISO 23611-3/2007 using an adapted split soil corer and wet extraction with and without heat to assess the abundance of enchytraeids in a forest fragment at Embrapa Forestry in Colombo, Paraná State. The samplings were performed in 3 occasions between September 2011 and April 2012. The average numbers estimated by each method varied from appr. 2.000-12.000 (cold) and 5.000-12.000 ind./ m2 (hot), respectively, with a maximum of 44.000 ind./ m2 in one of the samples, the highest value reported so far in Brazil. The hot extraction was more advantageous, given the speed and preservation of the specimens in vivo, allowing taxonomic identification. Advantages and disadvantages of wet extractions compared to handsorting and formol methods are also discussed. Guaranidrilus, Hemienchytraeus, Enchytraeus, Fridericia and Achaeta were the genera identified in the samples.

  14. Determination a static limiting load curves for slewing bearing with application of the finite element methods

    Directory of Open Access Journals (Sweden)

    Marek Krynke

    2013-02-01

    Full Text Available In slewing bearings, a great number of contact pairs are present on the contact surfaces between the rolling elements and raceways of the bearing. Computations to determine the load of the individual rolling elements, taking into account the flexibility of the bearing ring, are most often carried out using the finite element method. Construction of a FEM full model of the bearing, taking into account the shape of the rolling elements and the determination of the contact problem for every rolling element, leads to a singularity of stiffness matrix, which in turn makes the problem impossible to solve. In FEM models the rolling elements are replaced by one-dimensional finite elements (linear elements to simplify the computation procedure and to obtain an optimal time for computations. replaced by truss elements with a material non-linear characteristic located between the raceway centres of the curvatures in their axial section, are presented in the paper

  15. Edxrf determination of major and minor elements in compound fertilizers

    DEFF Research Database (Denmark)

    Christensen, Leif Højslet; Rasmussen, Leif W.

    1985-01-01

    The combination of the energy-dispersive x-ray fluorescence technique and a backscatter/fundamental parameter-based matrix correction approach provides a new and unique solution to elemental analyses of fertilizers. This is demonstrated by means of results obtained for three reference materials...... and a range of in-house fertilizers. The results further demonstrate problems of sample preparation as well as the precision and accuracy of the method....

  16. ICP OES determination of contaminant elements leached from food packaging films

    National Research Council Canada - National Science Library

    Santos, Éder José Dos; Oliveira, Fernanda Mara Pimentel; Herrmann, Amanda Beatriz; Sturgeon, Ralph Edward

    2017-01-01

    Determination of potential contaminants elements in food packing films arising from contact with acidic aqueous foods was undertaken by inductively coupled plasma optical emission spectrometry (ICP OES...

  17. ICP OES Determination of Contaminant Elements Leached from Food Packaging Films

    National Research Council Canada - National Science Library

    Éder José dos Santos; Fernanda Mara Pimentel Oliveira; Amanda Beatriz Herrmann; Ralph Edward Sturgeon

    2017-01-01

    ABSTRACT Determination of potential contaminants elements in food packing films arising from contact with acidic aqueous foods was undertaken by inductively coupled plasma optical emission spectrometry (ICP OES...

  18. Isotopic and Elemental Determination in Some Romanian Apple Fruit Juices

    Directory of Open Access Journals (Sweden)

    Dana Alina Magdas

    2012-01-01

    Full Text Available H, C, O stable isotope ratios and the content of some heavy elements of 31 Romanian single-strength organic apple juices collected from four Transylvanian areas are discussed in this study. The aim of this study was to measure the 2H/1H, 18O/16O, 13C/12C ratios of these juices and their elemental profile and to establish a database of authentic values to be used for adulteration and authenticity testing. Our results have shown mean values of δ18O=-4.2‰ and δDδ-46.5‰, respectively, for apples from Transylvania and at the same time the mean value of δ13C=-28.2‰. The content of Cd, Pb, U, Zn, As was below the acceptable limits stipulated in US-EPA standard for drinking water. Cu and Cr limits exceeded for one single juice; Ni content for some apple juices from Maramures, Alba, and Cluj was higher than the acceptable value.

  19. Determination of elements in ayurvedic medicinal plants by AAS

    Energy Technology Data Exchange (ETDEWEB)

    Teerthe, Santoshkumar S.; Kerur, B. R., E-mail: kerurbrk@yahoo.com [Department of Physics, Gulbarga University, Gulbarga, and Karnataka, India – 585106 (India)

    2015-08-28

    India has a rich country for the uses of Ayurvedic medicinal plants for treatment and also the north- Karnataka boasts an unparallel diversity of medicinal plants. The present study attempts to estimate and compare the level of trace and heavy metals in some selected leaves and root samples of Ayurvedic medicinal plants such as Mg, Al, K, Cr, Mn, Fe, Cu, Zn, and Cd. The samples are collected from different places of North-Karnataka regions and sample solutions prepared as the ratio of 1:25:25+950ml=1000ppm.the trace and heavy elemental concentration was estimated using Atomic Absorption Spectrometric (AAS) Method. The average concentrations of Mg, Mn, Fe and Zn, are ranging from 2ppm to 5250.2ppm and potassium (K) has more concentration as compare to all other. The other elements likes Al, Cr, Cu, and Cd were also estimed and presented in the table. Therefore, these medicinal plants are rich in some essential minerals, especially K, Mg, Mn, Fe and Zn which are essential for human health.

  20. Abundances of the elements in sharp-lined early-type stars from IUE high-dispersion spectrograms; 2, the nitrogen deficiency in mercury- manganese stars

    CERN Document Server

    Roby, S W; Adelman, S J

    1999-01-01

    For pt.I see ibid., vol.419, no.1, p.276-85 (1993). The authors determine nitrogen abundances from co-added IUE high-dispersion SWP spectrograms of four HgMn stars and five normal or superficially normal main-sequence B and A stars. They find N deficiencies in the HgMn stars greater than previously reported (depletion factors of 135-400 relative to the Sun). N abundance discrepancies from UV and IR studies of normal stars are discussed in light of possible non-LTE effects. Their data set for their sample of HgMn stars (observed with a consistent strategy to maximize the benefits of co-additions) is an improvement over the single or few images previously used to derive N abundances for most of these stars. (37 refs).

  1. Where to nest? Ecological determinants of chimpanzee nest abundance and distribution at the habitat and tree species scale.

    Science.gov (United States)

    Carvalho, Joana S; Meyer, Christoph F J; Vicente, Luis; Marques, Tiago A

    2015-02-01

    Conversion of forests to anthropogenic land-uses increasingly subjects chimpanzee populations to habitat changes and concomitant alterations in the plant resources available to them for nesting and feeding. Based on nest count surveys conducted during the dry season, we investigated nest tree species selection and the effect of vegetation attributes on nest abundance of the western chimpanzee, Pan troglodytes verus, at Lagoas de Cufada Natural Park (LCNP), Guinea-Bissau, a forest-savannah mosaic widely disturbed by humans. Further, we assessed patterns of nest height distribution to determine support for the anti-predator hypothesis. A zero-altered generalized linear mixed model showed that nest abundance was negatively related to floristic diversity (exponential form of the Shannon index) and positively with the availability of smaller-sized trees, reflecting characteristics of dense-canopy forest. A positive correlation between nest abundance and floristic richness (number of plant species) and composition indicated that species-rich open habitats are also important in nest site selection. Restricting this analysis to feeding trees, nest abundance was again positively associated with the availability of smaller-sized trees, further supporting the preference for nesting in food tree species from dense forest. Nest tree species selection was non-random, and oil palms were used at a much lower proportion (10%) than previously reported from other study sites in forest-savannah mosaics. While this study suggests that human disturbance may underlie the exclusive arboreal nesting at LCNP, better quantitative data are needed to determine to what extent the construction of elevated nests is in fact a response to predators able to climb trees. Given the importance of LCNP as refuge for Pan t. verus our findings can improve conservation decisions for the management of this important umbrella species as well as its remaining suitable habitats. © 2014 Wiley Periodicals, Inc.

  2. Occurrence and abundance of a mariner-like element in freshwater and terrestrial planarians (Platyhelminthes, Tricladida from southern Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda Sperb

    2009-01-01

    Full Text Available Transposable elements are DNA sequences present in all the large phylogenetic groups, both capable of changing position within the genome and constituting a significant part of eukaryotic genomes. The mariner family of transposons is one of the few which occurs in a wide variety of taxonomic groups, including freshwater planarians. Nevertheless, so far only five planarian species have been reported to carry mariner-like elements (MLEs, although several different species have been investigated. Regarding the number of copies of MLEs, Girardia tigrina is the only planarian species in which this has been evaluated, with an estimation of 8,000 copies of the element per haploid genome. Preliminary results obtained in our laboratory demonstrated that MLE is found in a large number of different species of planarians, including terrestrial. With this in mind, the aim was to evaluate the occurrence and estimate the number of MLE copies in different planarian species collected in south Brazil. Twenty-eight individuals from 15 planarian species were analyzed. By using PCR and the hybridization of nucleic acids, it was found that MLE was present in all the analyzed species, the number of copies being high, probably over 10³ per haploid genome.

  3. Ultra-metal-poor Stars: Spectroscopic Determination of Stellar Atmospheric Parameters Using Iron Non-LTE Line Abundances

    Science.gov (United States)

    Ezzeddine, Rana; Frebel, Anna; Plez, Bertrand

    2017-10-01

    We present new ultra-metal-poor stars parameters with [Fe/H] LTE in their atmospheric parameters and show that they can grow up to ˜1.00 dex in [Fe/H], ˜150 K in {T}{eff} and ˜0.5 dex in log g toward the lowest metallicities. Accurate NLTE atmospheric stellar parameters, in particular [Fe/H] being significantly higher, are the first step to eventually providing full NLTE abundance patterns that can be compared with Population III supernova nucleosynthesis yields to derive properties of the first stars. Overall, this maximizes the potential of these likely second-generation stars to investigate the early universe and how the chemical elements were formed.

  4. Determination of the abundance of cosmic matter via the cell count moments of the galaxy distribution

    Science.gov (United States)

    Bel, J.; Marinoni, C.

    2014-03-01

    We demonstrate that accurate and precise information about the matter content of the universe can be retrieved via a simple cell count analysis of the 3D spatial distribution of galaxies. A new clustering statistic, the galaxy clustering ratioη, is the key to this process. This is defined as the ratio between one- and two-point second-order moments of the smoothed galaxy density distribution. The distinguishing feature of this statistic is its universality: on large cosmic scales both galaxies (in redshift space) and mass (in real space) display the same η amplitude. This quantity, in addition, does not evolve as a function of redshift. As a consequence, the η statistic provides insight into characteristic parameters of the real-space power spectrum of mass density fluctuations without the need to specify the galaxy biasing function, neither a model for galaxy redshift distortions, nor the growing mode of density ripples. We demonstrate the method with the luminous red galaxy (LRG) sample extracted from the spectroscopic Sloan Digital Sky Survey (SDSS) data release 7 (DR7) catalogue. Taking weak (flat) priors of the curvature of the universe (Ωk) and of the constant value of the dark energy equation of state (w), and strong (Gaussian) priors of the physical baryon density Ωbh2, of the Hubble constant H0, and of the spectral index of primordial density perturbations ns, we estimate the abundance of matter with a relative error of 8% (Ωm=0.283±0.023). We expect that this approach will be instrumental in searching for evidence of new physics beyond the standard model of cosmology and in planning future redshift surveys, such as BigBOSS or EUCLID.

  5. Anomalous abundance and redistribution patterns of rare earth elements in soils of a mining area in Inner Mongolia, China.

    Science.gov (United States)

    Wang, Lingqing; Liang, Tao

    2016-06-01

    The Bayan Obo Mine, the largest rare earth element (REE) deposit ever found in the world, has been mined for nearly 60 years for iron and rare earth elements. To assess the influences of mining activities on geochemical behavior of REEs in soils, 27 surface soil samples and three soil profile samples were collected from different directions in the vicinity of the mine area. The total concentrations of REEs in surface soils varied from 149.75 to 18,891.81 mg kg(-1) with an average value of 1906.12 mg kg(-1), which was apparently higher than the average values in China (181 mg kg(-1)). The order of the average concentrations of individual REEs in surface soils was similar to that in Bayan Obo ores, which confirmed that the concentration and distribution of REEs in the soils was influenced by the mining activities. The concentrations of single REE in the soil profiles showed a similar trend with depth with an increase at 0-25 cm section, then decreased and remained relatively stable in the deep part. The normalized curves inclined to the right side, showing the conspicuous fractionation between the light and heavy REEs, which supported by the North American Shale Composite (NASC) and Post-Archean Australian Shale (PAAS) normalized concentration ratios calculated for selected elements (La N /Yb N , La N /Sm N , Gd N /Yb N ). Slight positive Ce anomaly and negative Eu anomaly were also observed.

  6. Determining the Permeable Efficiency of Elements in Transport Networks

    Directory of Open Access Journals (Sweden)

    V. Svoboda

    2001-01-01

    Full Text Available The transport network is simulated by a directed graph. Its edges are evaluated by length (in linear units or time units, by permeability and by the cost of driving through in a transport unit. Its peaks (nodes are evaluated in terms of permeability, the time of driving through the node in time units and the cost of driving a transport unit (set through this node.For such a conception of the transport network a role of optimisation and disintegration of transport flow was formulated, defined by a number of transport units (transport sets. These units enter the network at the initial node and exit the network (or vanish at the defined node. The aim of optimization was to disintegrate the transport flow so that the permeability was not exceeded in any element of the network (edge, nod, so that the relocation of the defined transport flow was completed in a prearranged time and so that the cost of driving through the transport net between the entry and exit knots was minimal.

  7. Isotopic and elemental analysis of fish tissues for provenance determination

    Science.gov (United States)

    Zannella, Carmela; Adamo, Paola; Opper, Christine; Schwendinger, Susanne; Knezevic, Sara; Van den Oever, Sabrina; Tchaikovsky, Anastassiya; Zitek, Andreas; Prohaska, Thomas

    2017-04-01

    The reliable tracing of the productions flows of food products through the entire supply chain is an essential requirement for all types of food commodities qualified by origin, composition and quality. This is a minimum requirement to implement safety for the consumer, enhance consumer confidence and countervail fraudulent practices. One important food commodity is fish and fish products. Reliable methods to trace the origin of fish have become of high importance. The investigation focused on the identification of adequate geochemical marker in fish meat and the corresponding linkage to the ambient water. The Sr/Ca ratio along with the 87Sr/86Sr isotope ratio analyzed by (multi collector) inductively coupled plasma mass spectrometry (MC ICP-MS) proved to be the most potential tools in this respect. For the first time, a direct link of fish meat to water could be accomplished.In addition, fish hard parts (otoliths, fin rays, fish bones) were under investigation to reconstruct the habitat changes during the lifespan of a fishes life. Fish hard parts have the potential to serve as "life time recorder". Thus the spatial investigation of the elemental and isotopic composition can be used to monitor habitat changes with time. The spatially resolved data of hard tissues was collected by means of Laser Ablation Split Stream ICP-MS/MC ICP-MS. This work is accomplished within the scope of the project "CSI: TRACE YOUR FOOD".

  8. Combinatorial Platform for Discovery of Nanocrystal-Ink Based Earth Abundant Element PV with Efficiency Greater than 20%

    Energy Technology Data Exchange (ETDEWEB)

    Hillhouse, Hugh W. [Univ. of Washington, Seattle, WA (United States)

    2017-12-31

    (1) We successfully developed an ultrasonic spray coating system that can be used to deposit thin chalcogenide films with composition gradients. 4 publications under the contract have been published with the instrument. The instrument was used to reveal the effects of intrinsic composition and examine the effects of 25 different dopant elements. Surprisingly, doping with most elements had little to no effect on the quasi-Fermi level splitting of bare films. Ge and Li were explored in depth, and our best devices utilize lithium doping. (2) We developed a new model of absorption coefficients, that when combined with absolute intensity photoluminescence, yield the steady-state quasi-Fermi level splitting and a way to quantify the sub-bandgap absorption. This has resulted in 2 publications on the method, with another in preparation. This is a significant development that should impact other PV technologies. (3) We found that lithium doping has several beneficial effects on CZTSSe. It improves the open-circuit voltage, short circuit current, fill factor, and shunt resistance. By using scanning Kelvin probe microscopy (SKPM) and conductive AFM (along with device measurements, DLPC, and XPS), we discovered that lithium acts to increase the p-type doping in both the grain and grain boundaries (GBs). The effect is stronger in the GBs and changes the direction of the electric field at the GB. In lithium doped devices, an electric field repels minority carrier electrons away from the GB. This resulted in a publication and the fabrication of 11.8% efficient devices from a DMSO-thiourea molecular ink. The mechanism of action is most likely due to the formation of LiCu, which inhibits the formation of the donor defect ZnCu. This reduces compensation and increases the net p-type doping. (4) By alloying with germanium, we have fabricated CZTGSSe devices with the best open-circuit voltage (relative the maximum theoretical open-circuit voltage for the bandgap) for any kesterite

  9. Determining bruise etiology in muscle tissue using finite element analysis.

    Science.gov (United States)

    Tang, Kevin; Sharpe, Wyatt; Schulz, Alexandra; Tam, Edric; Grosse, Ian; Tis, John; Cullinane, Dennis

    2014-03-01

    Bruising, the result of capillary failure, is a common physical exam finding due to blunt trauma and, depending on location and severity, a potential indicator of abuse. Despite its clinical relevance, few studies have investigated the etiology of capillary failure. The goal of this study was to determine whether capillaries primarily fail under shear stress or hydraulic-induced tensile stress. An arteriole bifurcating into four capillaries was modeled using ANSYS 14.0 (®) . The capillaries were embedded in muscle tissue and a pressure of 20.4 kPa was applied. Any tensile stress exceeding 8.4 × 10(4)  Pa was considered failure. Results showed that failure occurred directly under the impact zone and where capillaries bifurcated, rather than along the line of greatest shear stress, indicating that internal tensile stress is likely the primary mode of capillary failure in bruising. These results are supported by the concept that bruising can occur via blunt trauma in which no shearing lacerations occur. © 2013 American Academy of Forensic Sciences.

  10. Determination of Trace Elements in Nickel Base Alloys by Atomic Absorption Spectrophotometry.

    Science.gov (United States)

    An investigation is described to ascertain whether or not atomic absorption spectrophotometry could be used to determine the concentration of trace ... elements such as silver (Ag), bismuth (Bi), cadmium (Cd), lead (Pb), phosphorus (P), and arsenic (As) in nickel alloys such as Udimet 500 without interference of other constituent elements. (Author)

  11. Determining e-Portfolio Elements in Learning Process Using Fuzzy Delphi Analysis

    Science.gov (United States)

    Mohamad, Syamsul Nor Azlan; Embi, Mohamad Amin; Nordin, Norazah

    2015-01-01

    The present article introduces the Fuzzy Delphi method results obtained in the study on determining e-Portfolio elements in learning process for art and design context. This method bases on qualified experts that assure the validity of the collected information. In particular, the confirmation of elements is based on experts' opinion and…

  12. Relative importance of Microcystis abundance and diversity in determining microcystin dynamics in Lake Erie coastal wetland and downstream beach water.

    Science.gov (United States)

    Hu, C; Rea, C; Yu, Z; Lee, J

    2016-01-01

    Microcystis population and microcystin (MC) dynamics were investigated in western Lake Erie coastal wetlands and downstream beach water. A three-dimensional (3-D) model was developed to quantify how Microcystis population size and structure affect MCs. Real-time PCR, denaturing gradient gel electrophoresis (DGGE) and enzyme-linked immunoabsorbent assay (ELISA) were used. A moderate-low level of Microcystis abundance and MCs were detected with a significant increase along the wetland flow and the spatiotemporal homogeneity of Microcystis populations. The proportion of toxigenic and nontoxgenic genotypes appeared to be more affected by the variation in two major Microcystis PC-IGS genotypes. MC dynamics was associated with the changing Microcystis population size and structure. The 3-D model showed that Microcystis population with greater Microcystis PC-IGS abundance (and simultaneously higher diversity) had more MCs. Microcystin variation was significantly affected by Microcystis population size and structure. The 3-D model also revealed the relative importance of Microcystis population size and structure in determining MCs in the Lake Erie costal wetland and downstream beach water. This study enriches our understanding of Microcystis population and microcystin ecology in a western Lake Erie coastal wetland and downstream beach water. Our illustrative model brings a new perspective for understanding the ecological relationship between Microcystis population size and structure and MCs. © 2015 The Society for Applied Microbiology.

  13. Splicing Regulatory Elements and mRNA-abundance of dlg1 and capt, Genetically Interacting with dFMRP in Drosophila Brain

    Directory of Open Access Journals (Sweden)

    Maria Petrova

    2014-09-01

    Full Text Available To further understand the molecular and cellular mechanisms underlying the disease, we used the Drososphila FraX model and investigated a not well studied role of Drosophila Fragile X Mental Retardation Protein (dFMRP in alternative splicing of neuronal mRNAs to which it binds via a G-quartet sequence. By means of qRT-PCR we established the relative abundance of some isoforms of the gene dlg1, resulting from alternative exon skipping nearby a G-quartet and an exonic ESE-sequence, both acting as exonic splicing enhancers. We also investigated the relative mRNA-abundance of all capt-isoforms and the pre-mRNAs of both genes. We proposed a possible involvement of dFMRP in alternative splicing of genes, interacting with dfmr1. In the absence of dFMRP in larval and pupal brains, we found a change in the mRNA-level of one of the studied isoforms of dlg1 and of its pre-mRNA.We also established previously reported splicing regulatory elements and predicted computationally novel hexamere sequences in the exonic/intronic ends of both genes with p upative regulatory roles in alternative splicing.

  14. Determination of rare-earth elements in Luna 16 regolith sample by chemical spectral method

    Science.gov (United States)

    Stroganova, N. S.; Ryabukhin, V. A.; Laktinova, N. V.; Ageyeva, L. V.; Galkina, I. P.; Gatinskaya, N. G.; Yermakov, A. N.; Karyakin, A. V.

    1974-01-01

    An analysis was made of regolith from layer A of the Luna 16 sample for rare earth elements, by a chemical spectral method. Chemical and ion exchange concentrations were used to determine the content of 12 elements and Y at the level 0.001 to 0.0001 percent with 10 to 15 percent reproducibility of the emission determination. Results within the limits of reproducibility agree with data obtained by mass spectra, activation, and X-ray fluorescent methods.

  15. Mass-spectrometric determination of trace elements in aqueous media without preconcentration

    Energy Technology Data Exchange (ETDEWEB)

    Foss, Gordon Oluf [Iowa State Univ., Ames, IA (United States)

    1981-10-01

    Feasibility of using a low pressure glow discharge as an ion source for the mass spectrometric determination of trace elements in aqueous media was investigated. A cryogenically cooled hollow cathode ion source was developed to analyze aqueous samples without external preconcentration. Aqueous solutions containing seventy elements were analyzed and the detection limits, sensitivity factors, and linear regression correlation coefficients were determined. A standard test solution of trace elements in water was analyzed and the concentrations of trace elements were calculated using the sensitivity factors determined previously. The results compared favorably within the error limits predicted by the semiquantitative survey methods used. Tap water and natural lake water samples were examined and minimal interference effects due to organic compounds and biological compounds were noted. A research ion optical system (RIOS) was developed as a flexible mass analyzer for the development of new ion sources. The RIOS is a double focussing mass analyzer designed utilizing the Mattauch-Herzog geometry with externally adjustable slit assemblies.

  16. [Study on the determination of 14 inorganic elements in coffee by inductively coupled plasma mass spectrometry].

    Science.gov (United States)

    Nie, Xi-Du; Fu, Liang

    2013-07-01

    Samples of coffee were digested by microwave digestion, and inorganic elements amounts of Na, Mg, P, Ca, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Mo and Pb in sample solutions were determined by inductively coupled plasma mass spectrometry (ICP-MS). HNO3 + H2O2 was used to achieve the complete decomposition of the organic matrix in a closed-vessel microwave oven. The working parameters of the instrument were optimized. The results showed that the relative standard deviation (RSD) was less than 3.84% for all the elements, and the recovery was found to be 92.00% -106.52% by adding standard recovery experiment. This method was simple, sensitive and precise and can perform simultaneous multi-elements determination of coffee, which could satisfy the sample examination request and provide scientific rationale for determining inorganic elements of coffee.

  17. Raccoon abundance inventory report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the results of a raccoon abundance inventory on Clarence Cannon National Wildlife Refuge in 2012. Determining raccoon abundance allows for...

  18. Determining Adult Pacific Lamprey Abundance and Spawning Habitat in the Lower Deschutes River Sub-Basin, Oregon, 2008 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Matt; Graham, Jennifer C. [Confederated Tribes of the Warm Springs Reservation, Oregon

    2009-04-30

    An adult Pacific lamprey (Lampetra tridentata) escapement estimate was generated in the lower Deschutes River during run year 2008. This included a mark-recapture study to determine adult abundance and a tribal subsistence creel. Fish measuring less than 10.5 cm received two marks for the mark-recapture estimate while those measuring greater than 10.5 cm were surgically implanted with radio transmitters to monitor migration upstream of Sherars Falls (rkm 70.4). Radio telemetry was used to determine habitat, focal spawning areas and spawn timing. All fish were collected at the Sherars Falls fish ladder from July-October 2008 using a long handled dip-net. Escapement was generated using a two event mark-recapture experiment. Adult lamprey populations were estimated at 3,471 (95% CI = 2,384-5,041; M = 101; C = 885 R = 25) using Chapman's modification of the Peterson estimate. The relative precision around the estimate was 31.42. Tribal harvest was approximately 806 adult lamprey (95% CI = +/- 74) with a total escapement of 2,669. Fourteen lamprey received radio tags and were released at Lower Blue Hole recreation site (rkm 77.3). Movement was recorded by mobile, fixed site and aerial telemetry methods. Upstream movements of lamprey were documented from July through December 2008 with most lamprey over-wintering in the mainstem Deschutes River.

  19. Seasonal change in the abundance of Synechococcus and multiple distinct phylotypes in Monterey Bay determined by rbcL and narB quantitative PCR.

    Science.gov (United States)

    Paerl, Ryan W; Turk, Kendra A; Beinart, Roxanne A; Chavez, Francisco P; Zehr, Jonathan P

    2012-03-01

    Synechococcus is a cosmopolitan marine cyanobacterial genus, and is often the most abundant picocyanobacterial genus in coastal waters. Little is known about Synechococcus seasonal dynamics in coastal zones highly impacted by upwelling. This was investigated by collecting seasonal samples from an upwelling-impacted Monterey Bay (MB) monitoring station M0, in parallel with measurements of oceanographic conditions during 2006-2008. Synechococcus abundances were determined using quantitative PCR (qPCR) assays and flow cytometry (FCM). A new qPCR assay was designed to target dominant Synechococcus in MB using the rbcL gene, while previously designed assays targeted distinct phylotypes (called narB subgroups) with the narB gene. The rbcL qPCR assay successfully tracked abundant Synechococcus in MB, accounting for on average 89% (± 57%) of FCM-based counts. Annual spring upwelling caused decreases in Synechococcus and narB subgroup abundances. Differences in narB subgroup abundance maxima and abundance patterns support the view that subgroups differ in their ecologies, including subgroup D_C1, which seems to specifically thrive in coastal waters. Correlations between narB subgroup abundances and measured environmental variables were similar among the subgroups. Therefore, non-measured environmental factors (e.g. metals, mortality) likely had different influences on subgroups, which led to their distinct abundance patterns at M0. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  20. Determination of element levels in human serum: Total reflection X-ray fluorescence applications

    Science.gov (United States)

    Majewska, U.; Łyżwa, P.; Łyżwa, K.; Banaś, D.; Kubala-Kukuś, A.; Wudarczyk-Moćko, J.; Stabrawa, I.; Braziewicz, J.; Pajek, M.; Antczak, G.; Borkowska, B.; Góźdź, S.

    2016-08-01

    Deficiency or excess of elements could disrupt proper functioning of the human body and could lead to several disorders. Determination of their concentrations in different biological human fluids and tissues should become a routine practice in medical treatment. Therefore the knowledge about appropriate element concentrations in human organism is required. The purpose of this study was to determine the concentration of several elements (P, S, Cl, K, Ca, Cr, Fe, Cu, Zn, Se, Br, Rb, Pb) in human serum and to define the reference values of element concentration. Samples of serum were obtained from 105 normal presumably healthy volunteers (66 women aged between 15 and 78 years old; 39 men aged between 15 and 77 years old). Analysis has been done for the whole studied population and for subgroups by sex and age. It is probably first so a wide study of elemental composition of serum performed in the case of Świętokrzyskie region. Total reflection X-ray fluorescence (TXRF) method was used to perform the elemental analysis. Spectrometer S2 Picofox (Bruker AXS Microanalysis GmbH) was used to identify and measure elemental composition of serum samples. Finally, 1st and 3rd quartiles were accepted as minimum and maximum values of concentration reference range.

  1. Trace element determinations in brain tissues from normal and clinically demented individuals

    Energy Technology Data Exchange (ETDEWEB)

    Saiki, Mitiko; Genezini, Frederico A., E-mail: mitiko@ipen.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro do Reator de Pesquisas; Leite, Renata E.P.; Grinberg, Lea T.; Ferretti, Renata E.L.; Suemoto, Claudia; Pasqualucci, Carlos A.; Jacob-Filho, Wilson, E-mail: renataleite@usp.br, E-mail: lea@grinberg.com.br, E-mail: reloah@usp.br, E-mail: farfel@usp.br, E-mail: csuemoto@gmail.com, E-mail: cpasqua@usp.br, E-mail: wijac@usp.br [Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Fac. de Medicina

    2013-07-01

    Studies on trace element levels in human brains under normal and pathological conditions have indicated a possible correlation between some trace element concentrations and neurodegenerative diseases. In this study, analysis of brain tissues was carried out to investigate if there are any differences in elemental concentrations between brain tissues from a normal population above 50 years of age presenting Clinical Dementia Rating (CDR) equal to zero (CDR=0) and that cognitively affected population ( CDR=3). The tissues were dissected, ground, freeze-dried and then analyzed by instrumental neutron activation analysis. Samples and elemental standards were irradiated in a neutron flux at the IEA-R1 nuclear research reactor for Br, Fe, K, Na, Rb, Se and Zn determinations. The induced gamma ray activities were measured using a hyperpure Ge detector coupled to a gamma ray spectrometer. The one-way ANOVA test (p< 0.05) was used to compare the results. All the elements determined in the hippocampus brain region presented differences between the groups presenting CDR=0 and CDR=3. In the case of frontal region only the elements Na, Rb and Zn showed differences between these two groups. These findings proved the correlation between elemental levels present in brain tissues neurodegenerative diseases. Biological standard reference materials SRM 1566b Oyster Tissue and SRM 1577b Bovine Liver analyzed for quality control indicated good accuracy and precision of the results. (author)

  2. Determination of low-Z elements in individual environmental particles using windowless EPMA.

    Science.gov (United States)

    Ro, C U; Osán, J; Van Grieken, R

    1999-04-15

    The determination of low-Z elements such as carbon, nitrogen, and oxygen in atmospheric aerosol particles is of interest in studying environmental pollution. Conventional electron probe microanalysis technique has a limitation for the determination of the low-Z elements, mainly because the Be window in an energy-dispersive X-ray (EDX) detector hinders the detection of characteristic X-rays from light elements. The feasibility of low-Z element determination in individual particles using a windowless EDX detector is investigated. To develop a method capable of identifying chemical species of individual particles, both the matrix and the geometric effects of particles have to be evaluated. X-rays of low-Z elements generated by an electron beam are so soft that important matrix effects, mostly due to X-ray absorption, exist even within particles in the micrometer size range. Also, the observed radiation, especially that of light elements, experiences different extents of absorption, depending on the shape and size of the particles. Monte Carlo calculation is applied to explain the variation of observed X-ray intensities according to the geometric and chemical compositional variation of individual particles, at different primary electron beam energies. A comparison is carried out between simulated and experimental data, collected for standard individual particles with chemical compositions as generally observed in marine and continental aerosols. Despite the many fundamental problematic analytical factors involved in the observation of X-rays from low-Z elements, the Monte Carlo calculation proves to be quite reliable to evaluate those matrix and geometric effects. Practical aspects of the Monte Carlo calculation for the determination of light elements in individual particles are also considered.

  3. Determining the absolute abundance of dinoflagellate cysts in recent marine sediments: The Lycopodium marker-grain method put to the test

    DEFF Research Database (Denmark)

    Mertens, K; Verhoeven; Verleye

    2009-01-01

    Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An inter-laboratory calibration exercise was set up in order to test the comparability of results...... extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute...... the proposed standard method which circumvents critical steps, adding Lycopodium tablets at the end of the preparation and using an alternative method....

  4. [Study on determination and principal component analysis of inorganic elements in Polygonum multiflorum from different areas].

    Science.gov (United States)

    Yan, Han-Jing; Fang, Zhi-Jian

    2008-02-01

    To explore the character of inorganic elements in Polygonum multiflorum. The contents of elements such as Al, B, Ba, Ca, Cu, Mn, Mg, Fe, Na, Ni, P, Se, Sr, Ti and Zn in nine P. multiflorum samples were determined by means of ICP-AEC. The results were used for the development of element distrubution diagram. The principal component analysis and one-way ANOVA of SPSS were applied for the study of characteristic elements in P. multiflorum. The contents of Al, Ca, K, Mg, Sr,Ti in wild P. multiflorum were remarkable higher than those in cultured P. multiflorum, and there was no significant difference between cultured and wild in the other elements. Five principal components which accounted for over 90% of the total variance were extracted from the original data. The analysis results show that Al, B, Ba, Fe, Na, Ni, Ti, Ca and Sr may be the characteristic elements in P. multiflorum. The element distrubution diagram of the sample from Tianyang was remarkable different comparing with the others. The principal component analysis could be used in data processing in inorganic elements.

  5. Trace Elements in Human Myocardial Infarction Determined by Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wester, P.O.

    1965-05-15

    By means of neutron activation analysis, injured and adjacent uninjured human heart tissue from 12 autopsy cases with myocardial infarction are investigated with respect to the concentration of 23 trace elements. The bulk elements K, Na and P are also determined. A recently developed ion-exchange technique, combined with subsequent y-spectrometry, is used. The following trace elements are determined: Ag, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Rb, Sb, Sc, Se, Sm, Zn and W. In the injured tissue compared to the uninjured, calculation on a wet weight basis showed a decrease in Co, Cs, K, Mo, P, Rb and Zn, and an increase in Br, Ca, Ce, La, Na, Sb and Sm. The differences in Ca, La, Mo, P and Zn are dependent on the age of the myocardial infarction, and the regression lines for these elements are given. The concentration of the trace elements in uninjured tissue from infarcted hearts is compared to the concentration of these elements in normal heart tissue, determined in a previous study. In the uninjured tissue from infarcted hearts a decrease is found in Cu and Mo, and an increase in As and Ce.

  6. The determination of minor isotope abundances in naturally occurring uranium materials. The tracing power of isotopic signatures for uranium

    Energy Technology Data Exchange (ETDEWEB)

    Ovaskainen, R

    1999-11-01

    The mass spectrometric determination of minor abundant isotopes, {sup 234}U and {sup 236}U in naturally occurring uranium materials requires instruments of high abundance sensitivity and the use of highly sensitive detection systems. In this study the thermal ionisation mass spectrometer Finnigan MAT 262RPQ was used. It was equipped with 6 Faraday cups and a Secondary Electron Multiplier (SEM), which was operated in pulse counting mode for the detection of extremely low ion currents. The dynamic measurement range was increased considerably combining these two different detectors. The instrument calibration was performed carefully. The linearity of each detector, the deadtime of the ion counting detector, the detector normalisation factor, the baseline of each detector and the mass discrimination in the ion source were checked and optimised. A measurement technique based on the combination of a Gas Source Mass Spectrometry (GSMS) and a Thermal Ionisation Mass Spectrometry (TIMS) was developed for the accurate determination of isotopic composition in naturally occurring uranium materials. Because the expected ratio of n({sup 234}U)/n({sup 238}U) exceeded the dynamic measurement range of the Faraday detectors of the TIMS instrument, an experimental design using a combination of two detectors was developed. The n({sup 234}U)/n({sup 235}U) and n({sup 236}U)/n({sup 235}U) ratios were determined using ion counting in combination with the decelerating device. The n({sup 235}U)/n({sup 238}U) ratio was determined by the Faraday detector. This experimental design allowed the detector cross calibration to be circumvented. Precisions of less than 1 percent for the n({sup 234}U)/n({sup 235}U) ratios and 5-25 percent for the n({sup 236}U)/n({sup 235}U) ratios were achieved. The purpose of the study was to establish a register of isotopic signatures for natural uranium materials. The amount ratio, and isotopic composition of 18 ore concentrates, collected by the International

  7. Short interspersed nuclear elements (SINEs) are abundant in Solanaceae and have a family-specific impact on gene structure and genome organization.

    Science.gov (United States)

    Seibt, Kathrin M; Wenke, Torsten; Muders, Katja; Truberg, Bernd; Schmidt, Thomas

    2016-05-01

    Short interspersed nuclear elements (SINEs) are highly abundant non-autonomous retrotransposons that are widespread in plants. They are short in size, non-coding, show high sequence diversity, and are therefore mostly not or not correctly annotated in plant genome sequences. Hence, comparative studies on genomic SINE populations are rare. To explore the structural organization and impact of SINEs, we comparatively investigated the genome sequences of the Solanaceae species potato (Solanum tuberosum), tomato (Solanum lycopersicum), wild tomato (Solanum pennellii), and two pepper cultivars (Capsicum annuum). Based on 8.5 Gbp sequence data, we annotated 82 983 SINE copies belonging to 10 families and subfamilies on a base pair level. Solanaceae SINEs are dispersed over all chromosomes with enrichments in distal regions. Depending on the genome assemblies and gene predictions, 30% of all SINE copies are associated with genes, particularly frequent in introns and untranslated regions (UTRs). The close association with genes is family specific. More than 10% of all genes annotated in the Solanaceae species investigated contain at least one SINE insertion, and we found genes harbouring up to 16 SINE copies. We demonstrate the involvement of SINEs in gene and genome evolution including the donation of splice sites, start and stop codons and exons to genes, enlargement of introns and UTRs, generation of tandem-like duplications and transduction of adjacent sequence regions. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  8. Facile Spray-Pyrolysis Synthesis of Yolk-Shell Earth-Abundant Elemental Nickel-Iron-Based Nanohybrid Electrocatalysts for Full Water Splitting.

    Science.gov (United States)

    Li, Hao; Ci, Suqin; Zhang, Mengtian; Chen, Junxiang; Lai, Keyuan; Wen, Zhenhai

    2017-12-08

    The development of high-activity electrocatalysts for water splitting that comprise only inexpensive, earth-abundant elements is critical but remains a daunting challenge. In this work, yolk-shell Ni 3 Fe/Ni 3 FeN was prepared by a spray-pyrolysis technique, which could be scaleable. The yolk-shell Ni 3 Fe/Ni 3 FeN presents excellent catalytic activity for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) with overpotentials of 268 and 166 mV at 10 mA cm -2 , respectively, and bears a prominent electrochemical durability. Overall water splitting with an electrolyzer containing the yolk-shell Ni 3 Fe/Ni 3 FeN as the cathode and anode only requires a cell voltage of 1.62 V to reach a current density of 10 mA cm -2 . The present research not only introduces a new route for the synthesis of advanced functional electrocatalysts for overall water splitting but also sheds light on their potential commercial applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Determination of the transition to the high entropy regime for alloys of refractory elements

    Energy Technology Data Exchange (ETDEWEB)

    Grosso, Mariela F. del [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499 (B1650KNA), San Martin (Argentina); CONICET, Buenos Aires (Argentina); Grupo de Caracterizacion y Modelizacion de Materiales, UTN, FRGP, H. Yrigoyen 288, (B1617FRG) Gral. Pacheco (Argentina); Bozzolo, Guillermo, E-mail: guille_bozzolo@yahoo.com [Loyola University Maryland, 4501 N. Charles St., Baltimore, MD 21210 (United States); Mosca, Hugo O. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499 (B1650KNA), San Martin (Argentina); Grupo de Caracterizacion y Modelizacion de Materiales, UTN, FRGP, H. Yrigoyen 288, (B1617FRG) Gral. Pacheco (Argentina)

    2012-09-05

    Highlights: Black-Right-Pointing-Pointer Atomistic modeling using a quantum approximate method for the energetics. Black-Right-Pointing-Pointer Modeling of the phase structure of high entropy alloys of refractory elements. Black-Right-Pointing-Pointer Comparison of modeled structure with experimental results for five-element alloys. Black-Right-Pointing-Pointer Determination of bulk properties of transitional chains from 4 to 5 element alloys. Black-Right-Pointing-Pointer Introduction of an algorithm to aid in the design of high entropy alloys. - Abstract: The development of high entropy alloys is currently limited to experimental work aimed at the determination of specific compositions that exhibit particular properties. The main feature of these alloys is their particular phase structure, which tends to be a continuous solid solution in spite of the large number of constituents which would otherwise form a large number of intermetallic phases. While it is known that equimolar concentrations and large number of elements are two necessary conditions for achieving high entropy behavior, not much is known regarding the transition to this regime in the presence of specific elements. Such knowledge would be useful when determining alloy compositions, as it would set boundaries for the necessary concentrations of each element in experimental situations. In this work, results of a computational modeling effort are presented, where a recently developed 5-element high entropy alloy of refractory elements is used as the foundation needed to examine such transition and determine the necessary lower bounds for the concentration of each element. Details of the phase structure of the quaternary combinations of W, Nb, Mo, Ta and V as they evolve upon the addition of a fifth element are discussed. The results are compared to the experimental case for the case of V added to W-Nb-Mo-Ta. Using these examples as a reference, the concept of critical concentrations for each element

  10. Chitosan membranes as sorbents for trace elements determination in surface waters: chitosan membranes as sorbents for trace elements.

    Science.gov (United States)

    Mladenova, Elisaveta K; Dakova, Ivanka Grigorova; Karadjova, Irina B

    2011-11-01

    Chitosan membranes (non-crosslinked, crosslinked, and modified with L-cysteine) were evaluated as sorbents prior to electrothermal atomic absorption spectrometry (ETAAS) determination of total dissolved metal content in surface water samples. Different types of chitosan membranes were prepared in the presence or absence of L-cysteine. Chemical parameters for quantitative sorption/desorption of trace analytes have been optimized. The optimal pH for Cd(II), Cu(II), Ni(II), and Pb(II) sorption using L-cysteine-modified membrane is between 7 and 8.5 and coincides with typical surface water pH, allowing in situ preconcentration of analytes without any additional water sample pretreatments. Non-crosslinked chitosan membrane could be used for simultaneous sampling, transportation, and laboratory determination of Hg(II). Determination limits (calculated as 10σ) achieved for total dissolved metal contents are: Cd 0.001 μg/L, Cu 0.02 μg/L, Ni and Pb 0.05 μg/L, and relative standard deviations were 10-15% for all elements at concentration level of 0.05-2 μg/L. The determination limit achieved for Hg(II) was 0.012 μg/L and relative standard deviations at concentration levels 0.015-2 μg/L were within 9% and 15%. Non-crosslinked chitosan membrane was proposed as an efficient sorbent for Hg(II) preconcentration and determination in river and lake waters; L: -cysteine modified chitosan membrane was recommended for solid phase extraction of Cd(II), Cu(II), Ni(II), and Pb(II) from surface (lake, river, and sea) waters. The application of chitosan membranes as adsorbents for in situ field preconcentration of the analytes and their subsequent determination by CVAAS and ETAAS in water samples has been demonstrated.

  11. Testing iSpec for the determination of atmospheric parameters and abundances of δ Cephei and RR Lyrae

    Science.gov (United States)

    Blanco-Cuaresma, S.; Anderson, R. I.; Eyer, L.; Mowlavi, N.

    2017-03-01

    Classical Cepheids and RR Lyrae stars are radially pulsating stars where the spectral type varies according to pulsation phase. Several studies used synthesis and the equivalent width method to determine the variations of effective temperature, surface gravity and metallicity for classical Cepheids and RR Lyrae stars (Luck and Andrievsky 2004; Kovtyukh et al. 2005; Andrievsky et al 2005; Luck et al 2008; Takeda et al. 2013; Fossati et al. 2014). We evaluated the applicability of iSpec (Blanco-Cuaresma et al. 2014 - http://www.blancocuaresma.com/s/), which has been extensively used with non-pulsating FGK stars, and derived atmospheric parameters as a function of phase for δ Cephei and RR Lyrae (the two prototypes stars for each class). The results showed that when we apply a non-adapted traditional spectroscopic method to pulsating stars, derived gravities do not seem to follow a physically logical evolution. Nevertheless, metallicity is globally stable and effective temperature variations globally agree with expectations from the radius variations indicated by the radial velocity variability. Max/min values and average results agree with the literature. In terms of broadening parameters, macroturbulent and projected rotation velocities are very difficult to disentangle even if their profiles are not exactly the same. Individual chemical abundances as function of phase are stable as it was expected (the chemical composition of the star should not vary). We plan to use this information to identify absorption lines that are reliable and stable (less affected by blending) during the whole pulsating cycle. This new line selection may help to improve the determination of atmospheric parameters and it could allow us to be more confident in the study of other less known Cepheids and RR Lyrae stars.

  12. [Determination of elements in the leaves of Prunus mongolica by ICP-AES].

    Science.gov (United States)

    Niu, Shu-Fang; Shi, Song-Li; Wang, Deng-Kui; Cheng, Xiang-Hui; Liu, Zong-Qiang

    2013-01-01

    For determination of elements in the leaves of Prunus mongolica, the samples were digested by nitric acid-perchloric. The contents of Ca, Mg, Fe, Mn, Cu, Zn, Al, Sr, Sn and Pb in the leaves of Prunus mongolica were determined by ICP-AES, at the same time a blank experiment was carried out. The results showed that the recovery rate of the ten elements was between 93% and 110%, and the relative standard deviation was between 0.33% and 2.94%. This method is fast, simple and accurate.

  13. Determining Lamprey Species Composition, Larval Distribution and Adult Abundance in the Deschutes River Subbasin, Oregon ; 2007 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Matt; Graham, Jennifer C. [Department of Natural Resources, Confederated Tribes of the Warm Springs Reservation, Oregon

    2009-06-26

    We will report results of an ongoing project in the Deschutes River Subbasin to describe Pacific lamprey (Lampetra tridentata) life history. Project objectives were to determine adult lamprey escapement from Sherars Falls located at Rkm 70.4 and determine lamprey focal spawning areas, spawn timing and habitat through radio telemetry. A mark-recapture study and tribal creel was conducted to determine adult escapement. Lamprey were radio tagged and are currently being mobile, aerial and fixed site tracked to describe spawning. Adult lamprey were collected at Sherars Falls using a long-handled dip net from June-September 2007. The fate of lamprey collected at Sherars Falls was determined based on girth measurements. Fish measuring less than 10.5 cm received two markings for the mark-recapture estimation while those measuring 10.5 cm or greater were implanted with radio transmitters. Two-hundred and nine lamprey were marked during first event sampling, 2,501 lamprey inspected for marks and 64 recaptured during second event sampling. We estimate lamprey abundance to be 8,083 (6,352-10,279) with a relative precision of 19.8. Tribal harvest was 2,303 +/- 88. Escapement was estimated at 5,780 adult lamprey. Thirty-six lamprey received radio transmitters. Lamprey were transported upstream 6.3 Rkm for surgery, held to recover from anesthesia and released. Mobile tracking efforts started mid-July 2007 and are on-going. To date 35 of the 36 lamprey have been detected. Upon release, extensive ground-based tracking was conducted until fish became dormant in mid-October. Since, fixed site downloading and tracking have occurred weekly on the mainstem Deschutes River. Majority of lamprey (88%) are holding in the mainstem Deschutes River. Three lamprey moved upstream more than 70 Rkms into westside tributaries from August-December. Three moved approximately 18 Rkms downstream of the release site. Tracking will continue through the spawning season when redd characteristics will be

  14. [Determination of 27 elements in Maca nationality's medicine by microwave digestion ICP-MS].

    Science.gov (United States)

    Yu, Gui-fang; Zhong, Hai-jie; Hu, Jun-hua; Wang, Jing; Huang, Wen-zhe; Wang, Zhen-zhong; Xiao, Wei

    2015-12-01

    An analysis method has been established to test 27 elements (Li, Be, B, Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Sr, Mo, Cd, Sn, Sb, Ba, La, Hg, Pb, Bi) in Maca nationality's medicine with microwave digestion-ICP-MS. Sample solutions were analyzed by ICP-MS after microwave digestion, and the contents of elements were calculated according to their calibration curves, and internal standard method was adopted to reduce matrix effect and other interference effects. The experimental results showed that the linear relations of all the elements were very good; the correlation coefficient (r) was 0.9994-1.0000 (Hg was 0.9982) ; the limits of detection were 0.003-2.662 microg x L(-1); the relative standard deviations for all elements of reproducibility were lower than 5% (except the individual elements); the recovery rate were 78.5%-123.7% with RSD lower than 5% ( except the individual elements). The analytical results of standard material showed acceptable agreement with the certified values. This method was applicable to determinate the contents of multi-elements in Maca which had a high sensitivity, good specificity and good repeatability, and provide basis for the quality control of Maca.

  15. Determination of an Initial Mesh Density for Finite Element Computations via Data Mining

    Energy Technology Data Exchange (ETDEWEB)

    Kanapady, R; Bathina, S K; Tamma, K K; Kamath, C; Kumar, V

    2001-07-23

    Numerical analysis software packages which employ a coarse first mesh or an inadequate initial mesh need to undergo a cumbersome and time consuming mesh refinement studies to obtain solutions with acceptable accuracy. Hence, it is critical for numerical methods such as finite element analysis to be able to determine a good initial mesh density for the subsequent finite element computations or as an input to a subsequent adaptive mesh generator. This paper explores the use of data mining techniques for obtaining an initial approximate finite element density that avoids significant trial and error to start finite element computations. As an illustration of proof of concept, a square plate which is simply supported at its edges and is subjected to a concentrated load is employed for the test case. Although simplistic, the present study provides insight into addressing the above considerations.

  16. Determination of Trace Elements in Edible Nuts in the Beijing Market by ICP-M.

    Science.gov (United States)

    Yin, Liang Liang; Tian, Qing; Shao, Xian Zhang; Kong, Xiang Yin; Ji, Yan Qin

    2015-06-01

    Nuts have received increased attention from the public in recent years as important sources of some essential elements, and information on the levels of elements in edible nuts is useful to consumers. Determination of the elemental distributions in nuts is not only necessary in evaluating the total dietary intake of the essential elements, but also useful in detecting heavy metal contamination in food. The aim of this study was to determine the mineral contents in edible nuts, and to assess the food safety of nuts in the Beijing market. Levels of Li, Cr, Mn, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, Cs, Ba, Pb, Th, and U in 11 types of edible nuts and seeds (macadamia nuts, lotus nuts, pistachios, sunflower seeds, pine nuts, almonds, walnuts, chestnuts, hazelnuts, cashews, and ginkgo nuts) as well as raisins were determined by inductively coupled plasma mass spectrometry (ICP-MS). The accuracy of the method was validated using standard reference materials GBW10014 (cabbage) and GBW10016 (tea). Our results provide useful information for evaluating the levels of trace elements in edible nuts in the Beijing market, will be helpful for improving food safety, and will aid in better protecting consumer interests. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  17. The Human Release Hypothesis for biological invasions: human activity as a determinant of the abundance of invasive plant species

    Science.gov (United States)

    Zimmermann, Heike; Brandt, Patric; Fischer, Joern; Welk, Erik; von Wehrden, Henrik

    2014-01-01

    Research on biological invasions has increased rapidly over the past 30 years, generating numerous explanations of how species become invasive. While the mechanisms of invasive species establishment are well studied, the mechanisms driving abundance patterns (i.e. patterns of population density and population size) remain poorly understood. It is assumed that invasive species typically have higher abundances in their new environments than in their native ranges, and patterns of invasive species abundance differ between invaded regions. To explain differences in invasive species abundance, we propose the Human Release Hypothesis. In parallel to the established Enemy Release Hypothesis, this hypothesis states that the differences in abundance of invasive species are found between regions because population expansion is reduced in some regions through continuous land management and associated cutting of the invasive species. The Human Release Hypothesis does not negate other important drivers of species invasions, but rather should be considered as a potentially important complementary mechanism. We illustrate the hypothesis via a case study on an invasive rose species, and hypothesize which locations globally may be most likely to support high abundances of invasive species. We propose that more extensive empirical work on the Human Release Hypothesis could be useful to test its general applicability. PMID:25352979

  18. The Human Release Hypothesis for biological invasions: human activity as a determinant of the abundance of invasive plant species.

    Science.gov (United States)

    Zimmermann, Heike; Brandt, Patric; Fischer, Joern; Welk, Erik; von Wehrden, Henrik

    2014-01-01

    Research on biological invasions has increased rapidly over the past 30 years, generating numerous explanations of how species become invasive. While the mechanisms of invasive species establishment are well studied, the mechanisms driving abundance patterns (i.e. patterns of population density and population size) remain poorly understood. It is assumed that invasive species typically have higher abundances in their new environments than in their native ranges, and patterns of invasive species abundance differ between invaded regions. To explain differences in invasive species abundance, we propose the Human Release Hypothesis. In parallel to the established Enemy Release Hypothesis, this hypothesis states that the differences in abundance of invasive species are found between regions because population expansion is reduced in some regions through continuous land management and associated cutting of the invasive species. The Human Release Hypothesis does not negate other important drivers of species invasions, but rather should be considered as a potentially important complementary mechanism. We illustrate the hypothesis via a case study on an invasive rose species, and hypothesize which locations globally may be most likely to support high abundances of invasive species. We propose that more extensive empirical work on the Human Release Hypothesis could be useful to test its general applicability.

  19. Geographic origins of Korean and Chinese kimchi determined by multiple elements.

    Science.gov (United States)

    Bong, Yeon-Sik; Gautam, Mukesh Kumar; LA, Mi-Ran; Lee, Kwang-Sik

    2012-01-01

    An elemental analysis was performed on 30 Korean and Chinese kimchi samples in combination with strontium (Sr) isotope ratio measurements to develop a method for tracing the geographic origins of Korean and Chinese kimchi. We found a distinct difference between Korean and Chinese kimchi in such specific elements as K, Na, Ca, Ba, Sr, Zn, Li, and Sc, but no significant difference in the Sr isotope ratio. A comparative analysis was performed with washed kimchi (containing no submaterial) and unwashed kimchi to evaluate the effect of submaterials on the determination of geographic origin. A linear discriminant analysis provided a clear distinction between Korean and Chinese kimchi. The results indicate that combining multi-elemental and statistical analyses has the potential to determine the geographic origins of such processed food as kimchi.

  20. Determination of Trace Elements in Nickel Base Gas Turbine Parts by Atomic Absorption Spectrophotometry.

    Science.gov (United States)

    An investigation is described to ascertain whether or not atomic absorption spectrophotometry could be used to determine the concentration of trace ... elements such as silver (Ag), bismuth (Bi), cadmium (Cd), and lead (Pb) in nickel base alloys such as IN100, B1900 and 713C, without interference from

  1. Identification and determination of elements in Taraxacum officinale plant from different Bratislava localities

    Energy Technology Data Exchange (ETDEWEB)

    Havranek, E.; Bumbalova, A.; Jombik, J.; Harangozo, M. (Komenskeho Univ., Bratislava (Czechoslovakia). Farmaceuticka Fakulta)

    1983-01-01

    Elements Ti, Mn, Fe, Ni, Cu, Zn, Pb, Br, Rb and Sr were determined by the method of radionuclide X-ray fluorescence analysis with semiconductor detection in samples of Taraxacum officinale from various localities of Bratislava. The dependence of their content on the source and the degree of the air pollution was found out.

  2. Determining elemental composition of phytochemicals in camelina seed meal by high mass accuracy and spectral accuracy

    Science.gov (United States)

    An optimized single run evaluation that would accurately determine the elemental composition of as many compounds present in an extract would greatly aid in the evaluation of plant tissues. For phytochemicals, we have used accurate mass analysis to quickly characterize the potential chemical formula...

  3. Determination of trace elements (Fe, Cu and Zn) in serum and tail ...

    African Journals Online (AJOL)

    Strong and poor relationships between the levels of trace elements in blood, tissue and hair have been determined in various studies. The horses in this study have been fed with dry straw and artificial feed in winter months, with fresh grass in autumn and spring. The purpose was to investigate possible changes in the ...

  4. Determination of some wear elements in used car engine oil and oil ...

    African Journals Online (AJOL)

    In the present investigation, wear elements in used car engine oil and in oil filter paper were determined using instrumental neutron activation analysis (INAA). The objective was to identify an effective and scientific method of monitoring car engine health. Results obtained from analysing blank and used samples of engine ...

  5. Determination of trace elements and their concentrations in clay balls: problem of geophagia practice in Ghana.

    Science.gov (United States)

    Arhin, Emmanuel; Zango, Musah S

    2017-02-01

    Ten samples of 100 g weight were subsampled from 1400 g of the clay balls from which the contained trace element levels were determined by X-ray fluorescence technique. The results of trace elements in the clay balls were calibrated using certified reference materials "MAJMON" and "BH-1." The results showed elevated concentrations but with different concentration levels in the regions, particularly with arsenic, chromium, cobalt, Cs, Zr and La. These trace elements contained in the clay balls are known to be hazardous to human health. Thence the relatively high concentrations of these listed trace elements in clay balls in the three regions, namely Ashanti, Upper East and Volta, which are widely sold in markets in Ghana, could present negative health impact on consumers if consumed at 70 g per day or more and on regular basis. On the basis of these, the study concludes an investigation to establish breakeven range for trace element concentrations in the clay balls as it has been able to demonstrate the uneven and elevated values in them. The standardized safe ranges of trace elements will make the practice safer for the people that ingest clay balls in Ghana.

  6. [Determination of multi-element contents in gypsum by ICP-AES].

    Science.gov (United States)

    Guo, Zhong-bao; Bai, Yong-zhi; Cui, Jin-hua; Mei, Yi-fei; Ma, Zhen-zhu

    2014-08-01

    The content of multi-element in gypsum was determined by ICP-AES. The sample was pretreated by acid-soluble method or alkali-fusion method. Acid-soluble method is suitable for the determination of CaO, SOs, Al2O3, Fe2O3, MgO, K2O, Na2O, TiO2, P2O5, MnO, SrO and BaO. Alkali-fusion method is suitable for the determination of CaO, SO3, SiO2, Al2O3, Fe2O3, MgO, TiO2, P2O5, MnO, SrO, BaO and B2O3. Different series standard solutions were prepared considering the properties and content of elements and solution matrix. The limit of detection and quantification were confirmed for each element under their best analysis spectral lines. The recoveries of the two pretreatment methods were from 93% to 110%, besides that for TiO2 was 81%-87% as pretreated by acid-soluble method. All RSDs (n=6) of tests were from 0.70%-3.42%. The accuracies of CaO and SO3 with ICP-AES method were less than the chemical analysis method. The determination of CaO and SO3 with ICP-AES method is only suitable for the case of low accuracy requirement. The results showed that the method can be used for the determination of multi-element contents in gypsum, with simple operation, fast analysis and reliable results. Total elements can be analysed with both acid-soluble method and alkali-fusion method.

  7. Determining annual suspended sediment and sediment-associated trace element and nutrient fluxes

    Science.gov (United States)

    Horowitz, A.J.

    2008-01-01

    Suspended sediment is a major factor in the biological and geochemical cycling of trace elements and nutrients in aquatic systems. The design of effective studies involving the collection, processing, and subsequent chemical analysis of suspended sediment requires a clear understanding of the problems associated with using this sample medium. This review summarizes the current state of knowledge relative to the various issues/problems associated with the collection of representative suspended sediment samples in fluvial systems. It also addresses issues associated with accurately determining the concentrations and fluxes of sediment-associated trace elements and nutrients.

  8. Finite Element Model of the Strain Gauge For Determining Uniaxial Tension

    Directory of Open Access Journals (Sweden)

    Vladimír GOGA

    2013-12-01

    Full Text Available Strain gauge is device used to measure the mechanical strains of solid bodies. Deformation of the strain gauge element causes changes its electrical resistance. This resistance change, usually measured using a Wheatstone bridge, is related to the strain by the quantity known as the gauge factor. When the stains are known, it is possible to determined state of stress at a point of measured body using generalized Hooke`s law and Mohr`s circle. Finite element analysis of strain gauge measurement using ANSYS software is subject of this article.

  9. Qualitative and Quantitative Content Determination of Macro-Minor Elements in Bryonia Alba L. Roots using Flame Atomic Absorption Spectroscopy Technique.

    Science.gov (United States)

    Karpiuk, Uliana Vladimirovna; Al Azzam, Khaldun Mohammad; Abudayeh, Zead Helmi Mahmoud; Kislichenko, Viktoria; Naddaf, Ahmad; Cholak, Irina; Yemelianova, Oksana

    2016-06-01

    To determine the elements in Bryonia alba L. roots, collected from the Crimean Peninsula region in Ukraine. Dry ashing was used as a flexible method and all elements were determined using atomic absorption spectrometry (AAS) equipped with flame and graphite furnace. The average concentrations of the determined elements, expressed as mg/100 g dry weight of the sample, were as follow: 13.000 for Fe, 78.000 for Si, 88.000 for P, 7.800 for Al, 0.130 for Mn, 105.000 for Mg, 0.030 for Pb, 0.052 for Ni, 0.030 for Mo, 210.000 for Ca, 0.130 for Cu, 5.200 for Zn, 13.000 for Na, 1170.000 for K, 0.780 for Sr, 0.030 for Co, 0.010 for Cd, 0.010 for As, and 0.010 for Hg. Toxic elements such as Cd and Pb were also found but at very low concentration. Among the analyzed elements, K was the most abundant followed by Ca, Mg, P, Si, Fe, Na, and Zn, whereas Hg, As, Cd, Co, Mo, and Pb were found in low concentration. The results suggest that the roots of Bryonia alba L. plant has potential medicinal property through their high element contents present. Moreover, it showed that the AAS method is a simple, fast, and reliable for the determination of elements in plant materials. The obtained results of the current study provide justification for the usage of such fruit in daily diet for nutrition and for medicinal usage in the treatment of various diseases.

  10. Element Abundances in the Galactic Cosmic Rays with Atomic Number (Z) in the Interval 30 is less than or equal to Z is less than or equal to 40

    Science.gov (United States)

    Barbier, Louis; Binns, W. R.; Christian, E.; deNolfo, G.; Geier, S.; Israel, M. H.; Link, J. T.; Mewaldt, R. A.; Mitchell, J.; Rauch, B. F.

    2004-01-01

    We present new results on the elemental abundances of galactic cosmic rays with atomic number, Z, greater than 30, and comparison of these observations with abundances expected from galactic propagation of various suggested models of the cosmic-ray source. We combine preliminary results from the 2003-04 flight of the Trans-Iron Galactic Element Recorder (TIGER) cosmic-ray detector with previously reported results from the 2001-02 flight. This instrument flew over Antarctica for nearly 32 days at a mean atmospheric depth of 5.2 mb in December 2001 - January 2002. At the time of submission of this abstract, January 8, 2004, TIGER was again in the air over Antarctica having completed 22 days of an expected 30day flight at a mean atmospheric depth of about 4 nb, Data from the first flight demonstrated excellent resolution of individual elements, and we expect similar resolution from the second flight.

  11. [Study on determination of eight metal elements in Hainan arecanut leaf by flame atomic absorption spectrophotometry].

    Science.gov (United States)

    Liu, Li-yun; Wang, Ping; Feng, Mei-li; Dong, Zhi-guo; Li, Jie

    2008-12-01

    Arecanut is a sort of palm that is important economic crop for the farmers in Hainan province of China, wherein there are many kinds of metal elements such as K, Ca, Na, Mg, Fe, Mn, Cu, Zn etc. These elements are important nutrition for the growth of arecanut. It is very valuable to study on the content of these metal elements in arecanut leaf in terms of plant nutriology of arecanut. The arecanut leaf in Wangling county, Hainan province of China was sampled by diagonal-field-sampling method. Refering to other plant sample determination by FAAS, the detailed studies are done with different digestion and determination methods. In the present paper the effects of mixed acid of HNO3-HClO4 digestion method on determining the amount of metal elements in the arecanut leaf by FAAS is reported, and another one is incineration digestion method. FAAS method was established for the determination of K, Ca, Mg, Na, Fe, Mn, Cu and Zn The samples were incinerated or heated with HNO3-HClO4 (4:1). In the meantime, the optimum parameters of FAAS and effects of different digestion methods on the results were discussed. The recovery rate of standard addition is 98.36%-102.38% in the first method; RSD is 0.42%-2.328% (n=6); The recovery rate of standard addition is 99.22%-103.72% in the second method; RSD is 0.58%-1.283 (n=6). The metal amount determined by the first method is lower than the second method, the ratio is 0.9703-0.9934. The two methods are satisfied, but the latter is better. It is precise enough to common experiment to use flame atomic absorption spectrophotometry with digestion by incineration If the especially precise experiment is required, the digestion methods with mixed acid of HNO3-HClO4 may be introduced. The paper introduced methods dependable for determination of some metal elements in order to study on some nutrient effects of these metal elements in arecanut.

  12. EDXRF for determination of chemical elements in the beetle Alphitobius diaperinus

    Energy Technology Data Exchange (ETDEWEB)

    Cantinha, Rebeca S.; Farias, Emerson E.G. de; Magalhaes, Marcelo L.R. de; Franca, Elvis J. de, E-mail: rebecanuclear@gmail.com, E-mail: emersonemiliano@yahoo.com.br, E-mail: marcelo_rlm@hotmail.com, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Cunha, Franklin M. da; Zacarias, Vyvyane L., E-mail: ukento@yahoo.com.br, E-mail: vyvyanebiologicas@gmail.com [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil)

    2015-07-01

    Energy Dispersion X-Ray Fluorescence (EDXRF) spectrometry has been widely employed for chemical element determination of biological matrices, including insects. The beetle Alphitobius diaperinus is a major problem in poultry production, thereby infesting poultry litter and stored grains. Up to now, little is known about the behavior, physiology and environmental interactions of this insect. In this paper, EDXRF was applied to quantify the main chemical elements in A. diaperinus. For the quality of the analytical protocol, certified reference materials produced by National Institute of Standards and Technology - NIST were analyzed together with the samples. The technique was able to quantify Cl, P, S and Zn in this insect, presenting no significant variation at the 95% confidence level among the repetitions (n = 4). A different pattern of chemical element accumulation in this beetle was noticed compared to other Coleoptera species, in which the concentration of the chemical elements were markedly lower in A. diaperinus, probably associated to the restricted availability of chemical elements in food. Since no result has been found in the literature before, A. diaperinus was firstly chemically characterized in this paper. (author)

  13. Determination of essential and toxic elements in clay soil commonly consumed by pregnant women in Tanzania

    Science.gov (United States)

    Mwalongo, D.; Mohammed, N. K.

    2013-10-01

    A habit of eating clay soil especially among pregnant women is a common practice in Tanzania. This practice known as geophagy might introduce toxic elements in the consumer's body to endanger the health of the mother and her child. Therefore it is very important to have information on the elemental composition of the eaten soil so as to assess the safety nature of the habit. In this study 100 samples of clay soil, which were reported to be originating from five regions in Tanzania and are consumed by pregnant women were analyzed to determine their levels of essential and toxic elements. The analysis was carried out using energy dispersive X-ray fluorescent technique (EDXRF) of Tanzania Atomic Energy Commission, Arusha. Essential elements Fe, Zn, Cu, Se and Mn and toxic elements As, Pb, Co, Ni, U and Th were detected in concentrations above WHO permissible limits in some of the samples. The results from this study show that the habit of eating soil is exposing the pregnant mothers and their children to metal toxicity which is detrimental to their health. Hence, further actions should be taken to discourage the habit of eating soil at all levels.

  14. Testing the Bergerhoff method to determine the bulk deposition loads of 49 elements

    Science.gov (United States)

    Thöni, Lotti; Krieg, Fritz; Siewers, Ulrich

    The suitability of the simple and rather cheap Bergerhoff method for the determination of bulk deposition loads of 49 elements was tested. The method is suitable for the following elements: Ag, Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Ge, In, K, La, Li, Mg, Mn, Mo, Na, Nb, Ni, Pb, Rb, S, Sb, Sc, Se, Sn, Sr, Th, Ti, Tl, V, W, Y and Zn provided that for some of these elements one does not get total recovery with HNO 3-digestion. This, nevertheless, supplies sufficient information for most concerns. Analytical problems were encountered for the following elements: U and Te concentrations in our samples were close to the blanks; P and Ta were highly variable within the sampling areas; B, Hf and Zr leached out of the glass of the digestion vessels; Hg is highly volatile. Field studies at three background sites in Switzerland, two on the northern side of the Alps and one in the southern Alps, showed higher burdens of element emissions in the latter, partly because of higher precipitation, and partly because of higher concentrations in the dust. An anthropogenic influence can be inferred for Ag, Bi, Cd, Cu, Hg, Mo, Pb, Sb, Te, W and Zn and probably also for As, P, S (with associated Se) and Sn.

  15. [Determination of 22 inorganic elements in different parts of Lantana camara by ICP-OES].

    Science.gov (United States)

    Zhou, Wei-ming; Wang, Ru-yi; Chen, Liu-sheng; Huang, Chuan-bin

    2014-09-01

    To determine the contents of 22 inorganic elements in different parts of Lantana camara by inductively coupled plasma optical emission spectroscopy (ICP-OES). HNO3-H2 02 digested system was used to completely decomposed the organic compounds effectually by microwave digestion. 22 inorganic elements such as K, Ca, Mg, Fe, Al, Na, Zn, Mn and Cr were determined by ICP-OES under set up working conditions. The contents of K, Ca and Mg were the most in different parts of Lantana camrnara; The contents of K, Ca, Mg, Mn, Sr and Cu in the leaves of Lantana camara were more than that in the root and the branch. The contents of Fe and Na in the root of Lantana camara were more than that in the leaves and the branch. The contents of Pb and Cd were higher than the national standard and Cr had high content in different parts of Lantana camara. The determination method is quick, easy and accurate with high sensitivity,which can determine the contents of 22 inorganic elements accurately in different parts of Lantana camara.

  16. EDXRF applied to the chemical element determination of small invertebrate samples

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Marcelo L.R.; Santos, Mariana L.O.; Cantinha, Rebeca S.; Souza, Thomas Marques de; Franca, Elvis J. de, E-mail: marcelo_rlm@hotmail.com, E-mail: marianasantos_ufpe@hotmail.com, E-mail: rebecanuclear@gmail.com, E-mail: thomasmarques@live.com.pt, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2015-07-01

    Energy Dispersion X-Ray Fluorescence - EDXRF is a fast analytical technique of easy operation, however demanding reliable analytical curves due to the intrinsic matrix dependence and interference during the analysis. By using biological materials of diverse matrices, multielemental analytical protocols can be implemented and a group of chemical elements could be determined in diverse biological matrices depending on the chemical element concentration. Particularly for invertebrates, EDXRF presents some advantages associated to the possibility of the analysis of small size samples, in which a collimator can be used that directing the incidence of X-rays to a small surface of the analyzed samples. In this work, EDXRF was applied to determine Cl, Fe, P, S and Zn in invertebrate samples using the collimator of 3 mm and 10 mm. For the assessment of the analytical protocol, the SRM 2976 Trace Elements in Mollusk produced and SRM 8415 Whole Egg Powder by the National Institute of Standards and Technology - NIST were also analyzed. After sampling by using pitfall traps, invertebrate were lyophilized, milled and transferred to polyethylene vials covered by XRF polyethylene. Analyses were performed at atmosphere lower than 30 Pa, varying voltage and electric current according to the chemical element to be analyzed. For comparison, Zn in the invertebrate material was also quantified by graphite furnace atomic absorption spectrometry after acid treatment (mixture of nitric acid and hydrogen peroxide) of samples have. Compared to the collimator of 10 mm, the SRM 2976 and SRM 8415 results obtained by the 3 mm collimator agreed well at the 95% confidence level since the E{sub n} Number were in the range of -1 and 1. Results from GFAAS were in accordance to the EDXRF values for composite samples. Therefore, determination of some chemical elements by EDXRF can be recommended for very small invertebrate samples (lower than 100 mg) with advantage of preserving the samples. (author)

  17. Trace Elements in the Conductive Tissue of Beef Heart Determined by Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wester, P.O.

    1965-08-15

    By means of neutron activation analysis, samples of four beef hearts taken from the bundle of His and adjacent ventricular muscle, the AV node and adjacent atrial muscle are investigated with respect to the concentration of 23 trace elements. The bulk elements K, Na and P are also determined. A recently developed ion-exchange technique, combined with subsequent {gamma}-spectrometry, is used. The following trace elements are determined: Ag, As, Au, Ba, Br, .Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Rb, Sb, Sc, Se, Sm, W and Zn. In the conductive tissue compared to adjacent muscle tissue, calculations on a wet weight basis show a lower concentration of Cs, Cu, Fe, K, P, Rb and Zn in the former, and a higher concentration of Ag, Au, Br, Ca and Na. The mean differences ({mu}g/g wet tissue), as well as their degree of significance, between the bundle of His and adjacent tissue from the ventricular septum, between the AV node and adjacent atrial muscle, between the ventricular septum and the right atrium, and between the bundle of His and the AV node are given for the elements Cu, Fe, K, Na, P and Zn.

  18. Isotopes and trace elements as geo-location markers for biosecurity: determining the origin of exotic pests.

    Science.gov (United States)

    Holder, Peter W.; Armstrong, Karen; Clough, Tim; Frew, Russell; van Hale, Robert; Baker, Joel A.; Millet, Marc-Alban

    2010-05-01

    Background. The benefits of accurate point of origin discrimination in biosecurity include achieving appropriate operational responses in exotic pest eradication and post-border incursion campaigns, and identifying risk pathways. Reading natural abundance biogeochemical markers via mass spectrometry methods is a powerful tool for tracing ecological pathways and provenance determination of agricultural products and items of forensic interest. However, the application of these methods to trace insects - man's most damaging competitors - has been underutilised to date and our understanding in this field is still in a phase of basic development. Stable isotope ratio analyses using δ2H, δ13C have given spatial resolution in the monarch butterfly, single host system in eastern North America. Subsequently, the same method was employed in an attempt to determine the origin of important biosecurity pests in New Zealand. However, the results were contentious as the accuracy and limitations of the method in a biosecurity application were unknown. Further investigation has shown the value of existing invertebrate stable isotope geo-location methodology (i.e., using only two light elements) is tenuous in the biosecurity context, where the sample sizes are usually only one or two insects, and the specimens are generally polyphagous and accidentally introduced, and so from an unknown and unpredictable place, point in time and host: The spatial distribution of 2H in New Zealand may not be reliable over insect life-span time-scales; and fractional variables are un-quantified and potentially overwhelm any New Zealand signal. Further, the geo-location value of 13C is uncertain, especially for polyphagous insects. Research aims. The internationally distributed Helicoverpa armigera [Noctuidae] is being used to examine the processes fundamental to the location-to-plant-to-insect biogeochemical profile imprinting in phytophagous insects, including the turn over of elements in adult

  19. Determination of Thermoelastic Properties of Carbon Nanotube/Epoxy Composites Using Finite Element Method

    Science.gov (United States)

    Kirtania, Sushen; Chakraborty, Debabrata

    2017-10-01

    In the present study, three-dimensional finite element (FE) analysis has been performed for determination of thermoelastic properties of carbon nanotube (CNT)/epoxy composites considering both linear and nonlinear stress-strain relations of CNT. A square representative volume element has been considered for the FE analysis (FEA), and the effect of considering nonlinear stress-strain relation of CNT on the prediction of thermoelastic properties has been determined by comparing the results with the theoretical results. Results show that in order to obtain realistic values of thermoelastic properties, the nonlinear stress-strain relation of CNT needs to be used in the FEA. Not considering nonlinear stress-strain relation of CNTs in the FEA may lead to estimating erroneous values of thermoelastic properties of CNT composites which may have adverse effect in the design of structural components made of such composites subjected to thermomechanical loading.

  20. A study on chemical element determinations in human nails by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, Thalita Pinheiro; Saiki, Mitiko, E-mail: thalitapsanches@usp.br, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Nail analyses have been the object of study in order to assess the levels of elements accumulated in the human organism and to use this tissue to monitor environmental and occupational exposure, to evaluate the nutritional status, to verify intoxication by toxic metals and to diagnose or to prevent diseases. Nail analyses present advantages due to easy sample collection, storage, transportation and this tissue provides element level accumulation over time. However, there is controversy regarding the application of nail analysis data due to difficulties to establish reliable reference values or element concentration ranges as control values. The objective of this study was to evaluate the factors that can affect nail element concentrations for further sample analyses of a group of individuals by applying neutron activation analysis (NAA). Fingernails and toenails collected from adult individuals of both genders, aged 18 to 71 years, living in the Sao Paulo Metropolitan Region were cut in small fragments, cleaned and dried for analyses. Samples and element standards were irradiated for 16 h under a thermal neutron flux of about 4.5 x 10{sup 12} n cm{sup -2} s{sup -1} at the IEA-R1 nuclear research reactor followed by gamma ray spectrometry. Element concentrations for As, Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se and Zn were determined. For quality control of the analytical results, certified reference materials were analysed and the results showed good accuracy and precision with relative errors and relative standard deviations lower than 5.1 % and 11.6 %, respectively. Preliminary assays indicated that the contribution due to impurities from plastic involucres used in the irradiation as well as those from nail polishes is very low and could be considered negligible. Results from the nail sample cleaning process using distinct procedures indicated that HNO{sub 3} solution may cause sample dissolution. Sample homogeneity was verified by analysis of a sample in

  1. Determination of toxic and essential elements in children's blood with inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Bazzi, Ali; Nriagu, Jerome O; Linder, Aaron M

    2008-10-01

    Recent studies have suggested that low blood lead level, less than 50 microg L(-1), can influence the neurobehavioral performance of children. In addition, nutritional deficiencies in some essential elements may increase the toxicity of lead, and some essential elements may influence the blood concentrations of lead and other toxic metals. These findings, coupled with the scarcity of available data on some elements in children's blood and the introduction of methylcyclopentadienyl manganese tricarbonyl (MMT) to gasoline, accentuate the need to monitor the concentrations of lead, manganese, and other heavy metals and essential elements in children's blood. This study reports on the multi-element analysis of blood of South African school children using inductively coupled plasma-mass spectrometry (ICP-MS). The sample preparation consisted of a nitric acid/hydrogen peroxide open digestion and subsequent dilution with MilliQ water. The accuracy and precision were evaluated from quintuplet analyses of Seronorm trace elements whole blood reference material and human blood samples. Concentrations of lead, arsenic, manganese, copper, zinc, selenium, cobalt, and chromium in the blood of South African school children were determined. The average values were: lead 56.4 microg L(-1), arsenic 1.53 microg L(-1), manganese 8.48 microg L(-1), copper 1195 microg L(-1), zinc 3431 microg L(-1), selenium 176 microg L(-1), cobalt 0.80 microg L(-1), and chromium 1.25 microg L(-1). The level of lead was in line with some reported lower concentrations. The concentrations of arsenic and manganese were generally lower than those found in the literature. The concentrations of cobalt, copper, selenium, and chromium were higher than those found in other studies, whereas that of zinc was lower.

  2. INAA for determination of trace elements in bottom sediments of the Selenga river basin in Mongolia

    Science.gov (United States)

    Baljinnyam, N.; Frontasyeva, M. V.; Aleksiayenak, Yu. V.

    2014-03-01

    Instrumental neutron activation analysis (INAA) was used for the determination of major, minor and trace elements in samples of bottom sediments of the inflows of the Selenga river basin to assess the impact of the contamination from the industrial complex Erdenet and other industrial enterprises in Mongolia. A total of 42 elements (Na, Mg, Cl, K, Ca, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Sr, Rb, Sr, Zr, Nb, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Tm, Hf, Ta, W, Au, Hg, Th, and U) was determined by combination of conventional and epithermal neutron activation analysis at the IBR-2 reactor, FLNP JINR, Dubna. For the first time such a large set of elements was used for characterization of the bottom sediments as accumulating media which may reflect industrial contamination of the water basin. The concentrations of heavy metals and other trace elements in the samples from three inflows of the Selenga river basin were compared with data from the previous studies. It was shown that the industrial zone of the Erdenet Mining Corporation (EMC) and gold mining zone Zaamar are the sources of strong environmental contamination. The concentrations of Cu and Sb determined in sediment samples of the River Khangal and Govil near the EMC exceed average crustal rock and soil values by factors of 50 and 15, respectively. In the area of the gold mining zone Zaamar concentrations of Au, As, and Sb exceed crustal rock and soil values by factors of 4, 25, and 6, respectively. The relatively high levels of As, V, Zn, V, and Sr in the sediments of the studied rivers are obviously due to the discharges of untreated wastewater of desalination plant, electrical power station, textile industry and mining activities as well as domestic wastewater.

  3. Experimentally determined subsolidus metal-olivine element partitioning with applications to pallasites

    Science.gov (United States)

    Donohue, Patrick H.; Hill, Eddy; Huss, Gary R.

    2018-02-01

    Pallasite meteorites, which consist primarily of olivine and metal, may be remnants of disrupted core-mantle boundaries of differentiated asteroids or planetesimals. The early thermal histories of pallasites are potentially recorded by minor- and trace-element zonation in olivine. However, constraining this history requires knowledge of element behavior under the conditions of pallasite formation, which is lacking for many of the main elements of interest (e.g., Co, Cr, Mn). In this study, we experimentally determined metal/olivine partition coefficients for Fe, Ni, Co, Cr, and Mn in a pallasite analogue at subsolidus temperatures. Metal/olivine partition coefficients (KM) increase in the order KMn < KCr < 1 < KFe < KCo < KNi, with five orders of magnitude separating KMn from KNi. Transition metals also become more siderophile with increasing experimental temperature (900-1550 °C). The experiments incidentally produced diffusion profiles in olivine for these elements; our results suggest they diffuse through olivine at similar rates. Core compositions of pallasite olivines are consistent with high-temperature equilibration with FeNi-metal. Olivine zonation toward crystal rims varies significantly for the investigated transition metals. We suggest rim zonation results from partial re-equilibration during late stage crystallization of minor phases (e.g., chromite, phosphates). This re-equilibration occurred over short timescales relative to overall pallasite cooling, likely tied to initial cooling rates on the order of 100-300 °C/Myr.

  4. Informative importance of determination of trace elements in biologocal mediums in patients with endocrine pathology

    Directory of Open Access Journals (Sweden)

    Ирина Николаевна Андрусишина

    2015-07-01

    Full Text Available Aim. The changes of mineral metabolism in human organism caused by the deficiency or excess of trace elements in environment (air, food stuffs, water can lead to disorder of functional status of organism.An excess or deficiency of the certain metals disturb the balance of metabolic processes in organism that causes the different changes in endocrine system too. That is why the aim of research was to detect the peculiarities of distribution of macro and trace elements in patients with different endocrine pathology and to show the reasonability of the complex approach in assessment of microelementoses at hyperthyroidism and diabetes mellitus.Methods. The balance of 15 macro and trace elements in different biological mediums (hairs, whole blood, blood serum, urine was studied using EAAS and AES-ICP methods.Result. There was demonstrated the high informative importance of determination of K, Mg, Mn, Cr, Zn at pancreas pathology and Cr, Mn, Se, Zn- at thyroid pathology in human. There was detected that endocrine pathology is characterized with the surplus accumulation of Al, As and Pb in organism of examined patients.Conclusions. To increase the reliability and efficiency of the clinical diagnostics of endocrine human pathology there was demonstrated the high informative importance of the complex approach in choice of biological mediums at assessment of the trace elements imbalance. 

  5. [Determination of mineral elements in soybean from different producing areas by ICP-AES].

    Science.gov (United States)

    Wan, Jie; Liu, Cheng-Mei; Liu, Wei; Tu, Zong-Cai; Li, Chu; Zhang, Wen-Qin

    2010-02-01

    Soybeans from Jiangxi, Heilongjiang, Jilin and Anhui were digested by nitric acid. The contents of mineral elements K, P, Mg, Ca, Fe, Al, Zn, Mn and Na in four samples were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). The differences between samples were determined by Duncan's multiple-range test, and evaluations were based on a significance level of P human body needs. The contents of K, P, Mg, Ca and Fe are higher than the others, and the order from high to low does not change with the producing area. The order of Mn, Zn, Al, Na varied with the producing area. Producting area does not affect the contents of elements K, P and Mg significantly (P > 0.05). It can be concluded that the demands for major mineral elements K, P and Mg are stable in the growth of soybeans with the same variety. However, producing area has a great influence on the contents of elements Al, Ca, Fe, Na, Mn and Zn in soybean (P soil and so on.

  6. [Determination of 24 metal elements and their compounds in air of workplace by ICP-AES].

    Science.gov (United States)

    Wang, Xiang; Qiu, Jianguo; Zhao, Zhonglin; Guo, Ying

    2014-06-01

    To establish a method for determination of the levels of 24 metal elements and their compounds in the air of workplace by inductively coupled plasma-atomic emission spectroscopy (ICP- AES). Sampling filters were digested by microwave, and diluted to 25 ml. Twenty-four elements (Mg, Ni, K, Mo, Zn, Ca, Ba, Pb, Mn, Cd, Cr, Co, Cu, Sr, Bi, Tl, Sn, Li, Sb, Zr, In, V, Y, and Be) were simultaneously measured by ICP-AES. The detection limits for 24 elements were 0.001∼0.029 mg/L; liner correlation coefficient r values were all equal to or above 0.9994; the relative standard derivations were less than 5%; the recovery rates were 91.2%∼103.9%; the degradation rates in 7 days were less than 9.7%. ICP-AES technique is a simple, rapid, accurate, and reliable method, which can be used to measure 24 metal elements and their compounds in the air of workplace.

  7. Experimental determination of chosen document elements parameters from raster graphics sources

    Directory of Open Access Journals (Sweden)

    Jiří Rybička

    2010-01-01

    Full Text Available Visual appearance of documents and their formal quality is considered to be as important as the content quality. Formal and typographical quality of documents can be evaluated by an automated system that processes raster images of documents. A document is described by a formal model that treats a page as an object and also as a set of elements, whereas page elements include text and graphic object. All elements are described by their parameters depending on elements’ type. For future evaluation, mainly text objects are important. This paper describes the experimental determination of chosen document elements parameters from raster images. Techniques for image processing are used, where an image is represented as a matrix of dots and parameter values are extracted. Algorithms for parameter extraction from raster images were designed and were aimed mainly at typographical parameters like indentation, alignment, font size or spacing. Algorithms were tested on a set of 100 images of paragraphs or pages and provide very good results. Extracted parameters can be directly used for typographical quality evaluation.

  8. Danube catchment water chemistry monitoring - elemental pattern determination from source to mouth using ICP-MS

    Science.gov (United States)

    Tchaikovsky, Anastassiya; Zitek, Andreas; Irrgeher, Johanna; Prohaska, Thomas

    2014-05-01

    Monitoring the elemental composition of river water is an important tool to determine the chemical status of a river. However, currently many studies are limited to the analysis of heavy metals included in the EU Water Framework Directive Priority Substances List (Cd, Hg, Ni, Pb). Yet, the assessment of further elements (e.g. Ca, Mg, Si) can give additional relevant information for understanding catchment processes such as soil erosion, weathering, hydrological changes or glacial melting. In addition, site specific "elemental pattern" can be used as tracer for ecological studies, like habitat and migration studies of fish or birds. Elemental information is of particular interest complementary to isotopic data where only little variability in the isotopic signatures can be observed. In this work, we investigated water samples collected from 68 sampling sites along the longitudinal course of the river Danube including the major tributaries during the Joint Danube Survey 3 (JDS3) in 2013. Water samples were obtained as triplicates in the middle of the river and analyzed using Inductively Coupled - Plasma Mass Spectrometry (ICP-MS). Method validation was performed using riverine water (NRC SLRS-5) certified reference material as well as in-house prepared quality control standards. Due to the diverse geology and changing natural and anthropogenic factors along the longitudinal course of the Danube, pronounced elemental variations among the water samples were documented. For instance, especially some major elements (Ca, K, Mg, Na) together with some minor elements (Si, Sr) are known to reflect in particular regional geological morphologies. In addition, the variation in Si/Ca ratios can be used as an indicator for weathering conditions, especially in the mountainous areas along the Danube. Elevated concentrations of Cd, Cu, Fe, Ni, and Pb downstream of some large cities and industrial areas are signs of significant anthropogenic impact. In combination, the chemical

  9. Determination of essential elements in commercial infant foods by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vallinoto, Priscila; Maihara, Vera A., E-mail: pvallinoto@ipen.br, E-mail: vmaihara@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Eating habits are important determinants of health conditions during childhood. Commercial infant food is an important part of the diet for many babies. As such it is necessary that such food contain sufficient amounts of essential elements. Inadequate complementary feeding is a major cause of high rates of malnutrition throughout the world. Commercial infant food is classified into four different stages: Stages 1 and 2 are adequate for babies older than 6 months, but new flavors and food are introduced in stage 2; Stage 3 is offered to 8 month old babies; Junior Stage is recommended to children over 1 year old. In this study, essential elements: Ca, Cl, Co, Cr, Fe K, Mg, Mn, Na, Se and Zn were determined in commercial infant food samples by Instrumental Neutron Activation Analysis (INAA). Twenty-seven infant food samples were bought in stores around Sao Paulo city during 2011. These samples were freeze-dried and homogenized before analysis. The powdered samples were irradiated in the IEA-R1 nuclear research reactor of IPEN-CNEN/SP. For validation of the methodology, INCT MPH-2 Mixed Polish Herbs and NIST-SRM 1577b Bovine Liver reference materials were analyzed. Most of the concentration results were below the World Health Organization's recommended daily intake for infants from 6 to 12 months old. These low essential element concentration results in commercial infant foods obtained in our study indicate that infants should not only be fed with commercial baby foods. (author)

  10. Preliminary study on element mass fraction determination on catfish samples from Paraguay

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Edson G.; Catharino, Marilia G.M.; Vasconcellos, Marina B.A., E-mail: emoreira@ipen.br, E-mail: mbvascon@ipen.br, E-mail: mariliasemmler@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Frutos, Sixto A.; Insaurralde, Mario S., E-mail: tony8013@hotmail.com, E-mail: insaurraldemar9@hotmail.com [Universidad Nacional de Asuncion (FCV/UNA), San Lorenzo (Paraguay). Facultad de Ciencias Veterinarias. Departamento de Pesca y Acuicultura

    2013-07-01

    South American catfish (Pseudoplatystoma), commonly known in Spanish as atigrado or surubi and in Portuguese as surubim or pintado is a large fish that typically reaches 1 m long and weighs 60 kg to 80 kg and may be found at the basins of the Amazon, the Sao Francisco and de la Plata rivers, usually in riverbeds and deep wells. Being a much appreciated fish for human consumption, it is quite sought after by fishermen who have been contributing to the reduction of the stocks. This fact attracted the attention of the Paraguayan authorities to the point of imposing restrictions to free fishing and commercialization. This study aims to assist the conservation efforts towards this fish by investigating its exposure to possible pollutants. Preliminary results on element determination on six samples of catfish from Paraguayan rivers are presented. Cs, Co, Fe, Se and Zn were determined by applying an Instrumental Neutron Activation Analysis method. While these element levels were lower than the legislation for human consumption, the elements As, Cr e La were not detected in the samples as they are below the detection limit of the method employed. Atomic Absorption Spectrometry was used to investigate the presence of Cd, Hg and Pb in the samples. Hg was detected in the samples while Cd and Pb were below the detection limit of the method. (author)

  11. Fracture toughness determination of dental materials by laboratory testing and finite element models.

    Science.gov (United States)

    Pidaparti, R M; Beatty, M W

    1995-03-01

    This study assessed the effectiveness of finite element analysis in predicting the stress intensity factor (KIC) for three types of dental materials: a glass ionomer, a dental amalgam, and a composite resin. Laboratory tests were conducted on small single-edge notch specimens loaded in three-point bending to determine values for fracture toughness (KQ). Using the dimensions measured for each laboratory specimen, a J integral approach was employed to calculate KIC using finite element analysis. Both two-dimensional plane strain and three-dimensional models were used in determining KIC for each specimen, and these values were compared to the KQ values obtained from laboratory tests. The results indicated that no significant differences existed between laboratory results and those obtained from both two- and three-dimensional finite element models (P > .85). For the three-dimensional model, values for KIC were found to vary across the specimen thickness, with the values at the center of the specimen closely paralleling those obtained from the two-dimensional plane strain model. It was concluded that the two-dimensional plane strain J integral technique was as effective as the three-dimensional technique in calculating values for KIC.

  12. Assessing Biological and Stratigraphic Determinants of Fossil Abundance: A Case Example from the Late Quaternary of Po Plain, Italy

    Science.gov (United States)

    Kowalewski, Michal; Azzarone, Michele; Kusnerik, Kristopher; Dexter, Troy; Wittmer, Jacalyn; Scarponi, Daniele

    2017-04-01

    Absolute fossil abundance [AFA] can be defined as a relative concentration of identifiable fossils per unit of sediment. AFA, or "sediment shelliness", is controlled by the interplay between the rate of input of skeletal remains (biological productivity), pace of shell destruction (taphonomy), rate of sedimentation, and sediment compaction. Understanding the relative importance of those drivers can augment both stratigraphic and biological interpretations of the fossil record. Using 336 samples from a network of late Quaternary cores drilled in Po Plain (Italy), we examined the importance of those factors in controlling the stratigraphic distribution of fossils. All samples were vertically and volumetrically equivalent, each representing a 10 cm long interval of a core with a diameter of 7 cm ( 0.375 dm3 sediment per sample). Sample-level estimates of AFA (1) varied over 4 orders of magnitudes (from 4000 specimens per dm3) were characterized by exceedingly low evenness reflecting dominance by one super-abundant species (Berger-Parker index > 0.8 in all cases). These super-abundant species were limited to small r-selective mollusks capable of an explosive population growth: the marine corbulid bivalve Lentidium mediterraneum and the brackish hyrdobiid gastropod Ecrobia ventrosa. Moreover, despite high mollusk diversity (534 species total), >80% of samples are dominated by one of the five mollusk species, which all represent small, r-selective, deposit and suspension feeders. Trends in absolute fossil abundance within late Quaternary deposits of the Po Plain appear to have been driven primarily by biological productivity of opportunistic shelly species from lowest trophic levels. In the studied system, biodiversity and shelliness of samples is unlikely to reflect stratigraphic or taphonomic overprints, but rather records the ecological importance of r-selective species that dominated the investigated area throughout the late Quaternary. The joint consideration of

  13. Determination of mineral, trace element, and pesticide levels in honey samples originating from different regions of Malaysia compared to manuka honey.

    Science.gov (United States)

    Moniruzzaman, Mohammed; Chowdhury, Muhammed Alamgir Zaman; Rahman, Mohammad Abdur; Sulaiman, Siti Amrah; Gan, Siew Hua

    2014-01-01

    The present study was undertaken to determine the content of six minerals, five trace elements, and ten pesticide residues in honeys originating from different regions of Malaysia. Calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) were analyzed by flame atomic absorption spectrometry (FAAS), while sodium (Na) and potassium (K) were analyzed by flame emission spectrometry (FAES). Trace elements such as arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co) were analyzed by graphite furnace atomic absorption spectrometry (GFAAS) following the microwave digestion of honey. High mineral contents were observed in the investigated honeys with K, Na, Ca, and Fe being the most abundant elements (mean concentrations of 1349.34, 236.80, 183.67, and 162.31 mg/kg, resp.). The concentrations of the trace elements were within the recommended limits, indicating that the honeys were of good quality. Principal component analysis reveals good discrimination between the different honey samples. The pesticide analysis for the presence of organophosphorus and carbamates was performed by high performance liquid chromatography (HPLC). No pesticide residues were detected in any of the investigated honey samples, indicating that the honeys were pure. Our study reveals that Malaysian honeys are rich sources of minerals with trace elements present within permissible limits and that they are free from pesticide contamination.

  14. Determination of Mineral, Trace Element, and Pesticide Levels in Honey Samples Originating from Different Regions of Malaysia Compared to Manuka Honey

    Directory of Open Access Journals (Sweden)

    Mohammed Moniruzzaman

    2014-01-01

    Full Text Available The present study was undertaken to determine the content of six minerals, five trace elements, and ten pesticide residues in honeys originating from different regions of Malaysia. Calcium (Ca, magnesium (Mg, iron (Fe, and zinc (Zn were analyzed by flame atomic absorption spectrometry (FAAS, while sodium (Na and potassium (K were analyzed by flame emission spectrometry (FAES. Trace elements such as arsenic (As, lead (Pb, cadmium (Cd, copper (Cu, and cobalt (Co were analyzed by graphite furnace atomic absorption spectrometry (GFAAS following the microwave digestion of honey. High mineral contents were observed in the investigated honeys with K, Na, Ca, and Fe being the most abundant elements (mean concentrations of 1349.34, 236.80, 183.67, and 162.31 mg/kg, resp.. The concentrations of the trace elements were within the recommended limits, indicating that the honeys were of good quality. Principal component analysis reveals good discrimination between the different honey samples. The pesticide analysis for the presence of organophosphorus and carbamates was performed by high performance liquid chromatography (HPLC. No pesticide residues were detected in any of the investigated honey samples, indicating that the honeys were pure. Our study reveals that Malaysian honeys are rich sources of minerals with trace elements present within permissible limits and that they are free from pesticide contamination.

  15. Determination of Mineral, Trace Element, and Pesticide Levels in Honey Samples Originating from Different Regions of Malaysia Compared to Manuka Honey

    Science.gov (United States)

    Moniruzzaman, Mohammed; Chowdhury, Muhammed Alamgir Zaman; Rahman, Mohammad Abdur; Sulaiman, Siti Amrah; Gan, Siew Hua

    2014-01-01

    The present study was undertaken to determine the content of six minerals, five trace elements, and ten pesticide residues in honeys originating from different regions of Malaysia. Calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) were analyzed by flame atomic absorption spectrometry (FAAS), while sodium (Na) and potassium (K) were analyzed by flame emission spectrometry (FAES). Trace elements such as arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co) were analyzed by graphite furnace atomic absorption spectrometry (GFAAS) following the microwave digestion of honey. High mineral contents were observed in the investigated honeys with K, Na, Ca, and Fe being the most abundant elements (mean concentrations of 1349.34, 236.80, 183.67, and 162.31 mg/kg, resp.). The concentrations of the trace elements were within the recommended limits, indicating that the honeys were of good quality. Principal component analysis reveals good discrimination between the different honey samples. The pesticide analysis for the presence of organophosphorus and carbamates was performed by high performance liquid chromatography (HPLC). No pesticide residues were detected in any of the investigated honey samples, indicating that the honeys were pure. Our study reveals that Malaysian honeys are rich sources of minerals with trace elements present within permissible limits and that they are free from pesticide contamination. PMID:24982869

  16. [Determination of Mineral Elements in Choerospondias Axillaris and Its Extractives by ICP-AES].

    Science.gov (United States)

    Zhai, Yu-xin; Chen, Jun; Li, Ti; Liu, Ji-yan; Wang, Xie-yi; Cheng, Chao; Liu, Cheng-mei

    2015-04-01

    Nine elements in Choerospondias axillaris flesh, peels, aqueous extractives and gastric digesta were determined by the inductively coupled plasma atomic emission spectrometry (ICP-AES) in the present study. The results showed that the contents of Fe, Ca, Zn, Mn, Al, Mg, Cu, K and P in the flesh were 27.37, 269.88, 1.51, 2.45, 1.95, 195.30, 2.45, 2,970.11, and 133.94 µg · g(-1), respectively. They are lower than that in the peels, about 40.31%, 11.70%, 21.68%, 4.27%, 10.58%, 15.76%, 68.72%, 42.04%, and 22.59%, respectively. For microwave assistant extraction, the release rate of Mn was highest (81.68%), while Fe was lowest (4.42%) in the flesh. The release rate of Zn was the highest (79.00%), while that of A1 was the lowest (4.94%) in the peels. Except Fe, Cu and Zn, the release rates of the other elements in flesh were higher than those in the peels. After gastric digestion, the release rates of nine elements were 3.25%-87.51% in the flesh and 7.11%-50.69% in the peels. The release rates of minerals in the flesh were found to be higher than those in the peels except Fe and Cu. Microwave assistant extraction can more efficiently release Fe, Ca, Mn, Mg and K from the flesh than the gastric digestion do. While gastric digestion had a significant effect on the peels, the release rates of elements, except Zn, were higher than those in microwave assistant extraction. Therefore, the difference of distribution and release of mineral elements between peels and flesh of Choerospondias axillaris was understood, which will provide a positive guide for further study of bioavailability of minerals for human body.

  17. Trace element determination in amniotic fluid by total reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Greaves, E.D.; Sajo-Bohus, L.; Castelli, C.; Borgerg, C. [Universidad Simon Bolivar, Caracas (Venezuela); Meitin, J.; Liendo, J.

    1995-03-01

    A new method is reported for the determination of Fe, Cu, Zn, and Br in amniotic fluid (AF) by Total Reflection X-Ray Fluorescence. The irradiation of AF samples with monochromatic X-Rays reduces the scattering background from the organic matrix and avoids the need for sample digestion. Sample manipulation is reduced to centrifuging and adding cobalt as internal standard. Lower detection limits obtained are 109, 53, 44 and 37 ppb for Fe, Cu, Zn and Br respectively. Measurement precision depends on element concentrations and can be as low as 1.5% SD. Results of the analysis of 34 AF samples from Venezuelan pregnant patients agree with previously reported ranges of Fe, Cu and Zn. Other elements observed but not quantified are Cl, K, Ca in all spectra and Pb and Sr in some of them. (author).

  18. Rare earth elements determination in medicinal plants by Neutron Activation Analisys

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Rodolfo D.M.R.; Francisconi, Lucilaine S.; Silva, Paulo S.C. da, E-mail: rdmrg89@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Rare Earth Elements (REEs) have been considered nontoxic for human health and for the environment; however, the use of REEs in the development of recent technologies has increased the interest un their biological effects. Some studies related to their concentration in foodstuffs were published but REEs levels in medicinal plants are still unknown. The objective of this study was to determine the Rees concentration in the set of 59 medicinal herbs commonly used by Brazilian folk. Results showed that plants can concentrate REEs in their aerial parts, but the amount transferred to the extract of these plants is relatively low, resulting in little ingestion of these elements by the population during the extract consumption. (author)

  19. Determination of minor and trace elements in geological materials used as raw ceramic materials

    Energy Technology Data Exchange (ETDEWEB)

    Gazulla Barreda, M.F.; Rodrigo Edo, M.; Orduña Cordero, M.; Ventura Vaquer, M.J.

    2016-07-01

    A study has been undertaken to develop a methodology to determine minor and trace elements in geological ceramic raw materials by wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometry. The set up of the methodology has been done either by optimising not only the sample preparation process but also optimising the measurement with the aid of the software Pro-Trace, and also by making an exhaustive compilation of reference materials for calibration and validation. The developed method is precise and accurate and allows the analysis of Ba, Ce, Co, Cr, Cu, Fe, La, Mn, Ni, Pb, Rb, S, Sr, Ta, Th, U, V, Y, Zn and Zr present in the sample as minor or trace elements in geological materials used as raw ceramic material in a relatively short period of time. Besides, the method is more environmentally friendly than other methodologies as it does not require the use of solvents or reagents. (Author)

  20. Isotopic Compositions of the Elements 1989

    Science.gov (United States)

    De Laeter, J. R.; Heumann, K. G.; Rosman, K. J. R.

    1991-11-01

    The Subcommittee for Isotopic Abundance Measurements (SIAM) of the IUPAC Commission on Atomic Weights and Isotopic Abundances has carried out its biennial review of isotopic compositions, as determined by mass spectrometry and other relevant methods. The Subcommittee's critical evaluation of the published literature element by element forms the basis of the Table of Isotopic Compositions of the Elements as Determined by Mass Spectrometry 1989, which is presented in this Report. Atomic Weights calculated from the tabulated isotopic abundances are consistent with Ar(E) values listed in the Table of Standard Atomic Weights 1989.

  1. Determination of mechanical properties from depth-sensing indentation data and results of finite element modeling

    Science.gov (United States)

    Isaenkova, M. G.; Perlovich, Yu A.; Krymskaya, O. A.; Zhuk, D. I.

    2016-04-01

    3D finite element model of indentation process with Berkovich tip was created. Using this model with different type of test materials, several series of calculations were made. These calculations lead to determination of material behavior features during indentation. Relations between material properties and its behavior during instrumented indentation were used for construction of dimensionless functions required for development the calculation algorithm, suitable to determine mechanical properties of materials by results of the depth-sensing indentation. Results of mechanical properties determination using elaborated algorithm for AISI 1020 steel grade were compared to properties obtained with standard compression tests. These two results differ by less than 10% for yield stress that evidence of a good accuracy of the proposed technique.

  2. Collaborative study to improve the quality control of rare earth element determinations in environmental matrices.

    Science.gov (United States)

    Kramer, K J; Dorten, W S; van het Groenewoud, H; de Haan, E; Kramer, G N; Monteiro, L; Muntau, H; Quevauviller, P

    1999-02-01

    In order to control the quality of rare earth determinations in environmental matrices, the Standards, Measurements and Testing Programme (formerly Community Bureau of Reference, BCR) of the European Commission has started a project, the final aim of which is to certify four types of matrices (tuna muscle, mussel tissue, aquatic plant and estuarine sediment) for their contents of a range of rare earth elements (Sc, Y and the lanthanides: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The elements U and Th were added to the study. The first part of this project consisted of an interlaboratory study which aimed to test the feasibility of preparation of environmental reference materials and to detect and remove most of the pitfalls observed in rare earth determinations. This paper presents the preparation of the four matrices for the intercomparison study and for the candidate reference material. The main results are presented of the interlaboratory study that was carried out prior to the certification campaign. This collaborative trial is the first attempt ever carried out at this scale to evaluate the state-of-the-art of rare earth determinations in the environment. Its impact on the improvement of chemical measurements will have positive effects on the comparability of data necessary for environmental monitoring.

  3. Determination of minor and trace elements in kidney stones by x-ray fluorescence analysis

    Science.gov (United States)

    Srivastava, Anjali; Heisinger, Brianne J.; Sinha, Vaibhav; Lee, Hyong-Koo; Liu, Xin; Qu, Mingliang; Duan, Xinhui; Leng, Shuai; McCollough, Cynthia H.

    2014-03-01

    The determination of accurate material composition of a kidney stone is crucial for understanding the formation of the kidney stone as well as for preventive therapeutic strategies. Radiations probing instrumental activation analysis techniques are excellent tools for identification of involved materials present in the kidney stone. In particular, x-ray fluorescence (XRF) can be very useful for the determination of minor and trace materials in the kidney stone. The X-ray fluorescence measurements were performed at the Radiation Measurements and Spectroscopy Laboratory (RMSL) of department of nuclear engineering of Missouri University of Science and Technology and different kidney stones were acquired from the Mayo Clinic, Rochester, Minnesota. Presently, experimental studies in conjunction with analytical techniques were used to determine the exact composition of the kidney stone. A new type of experimental set-up was developed and utilized for XRF analysis of the kidney stone. The correlation of applied radiation source intensity, emission of X-ray spectrum from involving elements and absorption coefficient characteristics were analyzed. To verify the experimental results with analytical calculation, several sets of kidney stones were analyzed using XRF technique. The elements which were identified from this techniques are Silver (Ag), Arsenic (As), Bromine (Br), Chromium (Cr), Copper (Cu), Gallium (Ga), Germanium (Ge), Molybdenum (Mo), Niobium (Nb), Rubidium (Rb), Selenium (Se), Strontium (Sr), Yttrium (Y), Zirconium (Zr). This paper presents a new approach for exact detection of accurate material composition of kidney stone materials using XRF instrumental activation analysis technique.

  4. Designing synthetic RNAs to determine the relevance of structural motifs in picornavirus IRES elements

    Science.gov (United States)

    Fernandez-Chamorro, Javier; Lozano, Gloria; Garcia-Martin, Juan Antonio; Ramajo, Jorge; Dotu, Ivan; Clote, Peter; Martinez-Salas, Encarnacion

    2016-04-01

    The function of Internal Ribosome Entry Site (IRES) elements is intimately linked to their RNA structure. Viral IRES elements are organized in modular domains consisting of one or more stem-loops that harbor conserved RNA motifs critical for internal initiation of translation. A conserved motif is the pyrimidine-tract located upstream of the functional initiation codon in type I and II picornavirus IRES. By computationally designing synthetic RNAs to fold into a structure that sequesters the polypyrimidine tract in a hairpin, we establish a correlation between predicted inaccessibility of the pyrimidine tract and IRES activity, as determined in both in vitro and in vivo systems. Our data supports the hypothesis that structural sequestration of the pyrimidine-tract within a stable hairpin inactivates IRES activity, since the stronger the stability of the hairpin the higher the inhibition of protein synthesis. Destabilization of the stem-loop immediately upstream of the pyrimidine-tract also decreases IRES activity. Our work introduces a hybrid computational/experimental method to determine the importance of structural motifs for biological function. Specifically, we show the feasibility of using the software RNAiFold to design synthetic RNAs with particular sequence and structural motifs that permit subsequent experimental determination of the importance of such motifs for biological function.

  5. ICP-AES determination of minor- and major elements in apples after microwave assisted digestion.

    Science.gov (United States)

    Juranović Cindrić, Iva; Krizman, Ivona; Zeiner, Michaela; Kampić, Štefica; Medunić, Gordana; Stingeder, Gerhard

    2012-12-15

    The aim of this paper was to determine the content of minor and major elements in apples by inductively coupled plasma atomic emission spectrometry (ICP-AES). Prior to ICP-AES measurement, dried apples were digested in a microwave assisted digestion system. The differences in the measured element concentrations after application of open and closed microwave system as sample preparation procedures are discussed. In whole apples, flesh and peel Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were analysed after optimisation and validating the analytical method using ICP-AES. The accuracy of the method determined by spiking experiments was very good (recoveries 88-115%) and the limits of detection of elements of interest were from 0.01 up to 14.7 μg g(-1). The reference ranges determined in all apple samples are 39-47 mg g(-1) for K, 9-14 mg g(-1) for Na, 3-7 mg g(-1) for Mg, 3-7 μg g(-1) for Zn, 0.7-2.8 μg g(-1) for Sr. The range of Mn in peel 4-6 μg g(-1) is higher compared to whole apple from 0.7 to 1.7 μg g(-1). Cd is found only in peel, in the concentration range of 0.4-1.1 μg g(-1). Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. The solar system abundance of tin

    Energy Technology Data Exchange (ETDEWEB)

    Loss, R.D.; Rosman, K.K.R.; De Laeter, J.R. (Curtin Univ. of Technology, Perth (Australia))

    1989-04-01

    The elemental abundance of tin has been determined by the mass spectrometric isotope dilution technique for four carbonaceous chondrites, including the Cl chondrites Orgueil and Ivuna. A solar system abundance of 3.98 (normalized to Si = 10{sup 6} atoms) can be derived from these data, which is in excellent agreement with the presently accepted value. Recently, a theoretical value of 2.82 {plus minus} 0.21 (Si = 10{sup 6} atoms) has been proposed for the abundance of tin based on an s-process nucleosynthesis model. This value is 26% lower than the presently accepted solar system abundance. The present data confirm the higher value for tin and indicate that a reexamination of the assumptions on which the nucleosynthetic value is based is required.

  7. LOOKING FOR A CONNECTION BETWEEN THE Am PHENOMENON AND HYBRID {delta} Sct -{gamma} Dor PULSATION: DETERMINATION OF THE FUNDAMENTAL PARAMETERS AND ABUNDANCES OF HD 114839 AND BD +18 4914

    Energy Technology Data Exchange (ETDEWEB)

    Hareter, M.; Weiss, W. [Department of Astronomy, University of Vienna, Tuerkenschanzstrasse 17, A-1180 Wien (Austria); Fossati, L. [Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes MK6 7AA (United Kingdom); Suarez, J. C. [Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia S/N, 18008, Granada (Spain); Uytterhoeven, K. [Kiepenheuer-Institut fuer Sonnenphysik, Schoeneckstr. 6, D-79104 Freiburg (Germany); Rainer, M.; Poretti, E., E-mail: hareter@astro.univie.ac.at [INAF-Osservatorio Astronomico di Brera, Via E. Bianchi 46, 23807, Merate (Saint Lucia) (Italy)

    2011-12-20

    {delta} Sct-{gamma} Dor hybrids pulsate simultaneously in p- and g-modes, which carry information on the structure of the envelope as well as to the core. Hence, they are key objects for investigating A and F type stars with asteroseismic techniques. An important requirement for seismic modeling is small errors in temperature, gravity, and chemical composition. Furthermore, we want to investigate the existence of an abundance indicator typical for hybrids, something that is well established for the roAp stars. Previous to the present investigation, the abundance pattern of only one hybrid and another hybrid candidate has been published. We obtained high-resolution spectra of HD 114839 and BD +18 4914 using the SOPHIE spectrograph of the Observatoire de Haute-Provence and the HARPS spectrograph at ESO La Silla. For each star we determined fundamental parameters and photospheric abundances of 16 chemical elements by comparing synthetic spectra with the observations. We compare our results to that of seven {delta} Sct and nine {gamma} Dor stars. For the evolved BD +18 4914 we found an abundance pattern typical for an Am star, but could not confirm this peculiarity for the less evolved star HD 114839, which is classified in the literature as uncertain Am star. Our result supports the concept of evolved Am stars being unstable. With our investigation we nearly doubled the number of spectroscopically analyzed {delta} Sct-{gamma} Dor hybrid stars, but did not yet succeed in identifying a spectroscopic signature for this group of pulsating stars. A statistically significant spectroscopic investigation of {delta} Sct- {gamma} Dor hybrid stars is still missing, but would be rewarding considering the asteroseismological potential of this group.

  8. Instrument for determining the transuranic element content of chopped leached fuel hulls and other materials

    Energy Technology Data Exchange (ETDEWEB)

    Brodzinski, R. L.; Wogman, N. A.; Nielson, H. L.; Brown, D. P.

    1979-07-01

    An instrument has been designed, constructed, and evaluated for the identification and quantitative determination of transuranic elements by detection of neutrons emitted from their (..cap alpha.., n) and spontaneous fission reactions. Although optimized for batch evaluation of chopped leached nuclear fuel cladding hulls, the principle can be adapted to continuous feed operations. Unique electronic circuitry permits the sorting of neutron emissions depending on their origin which can be directly related to the isotopic composition of very small amounts of transuranic activities present in extreme gamma radiation fields. Efficiencies, sensitivities, and detection limits are discussed.

  9. Direct determination of asymptotic structural postbuckling behaviour by the finite element method

    DEFF Research Database (Denmark)

    Poulsen, Peter Noe; Damkilde, Lars

    1997-01-01

    Application of the Finite Element Method to Koiter's asymptotic postbuckling theory often leads to numerical problems. Generally it is believed that these problems are due to locking of nonlinear terms of different orders. A general method is given here that explains the reason for the numerical...... problems and eliminates these problems. The reason for the numerical problems is that the postbuckling stresses are inaccurately determined. By including a local stress contribution the postbuckling stresses are calculated correctly. The present method gives smooth postbuckling stresses and shows a quick...

  10. Application of solid phase extraction procedures for rare earth elements determination in environmental samples.

    Science.gov (United States)

    Pyrzynska, Krystyna; Kubiak, Anna; Wysocka, Irena

    2016-07-01

    Determination of rare earth elements in environmental samples requires often pre-concentration and separation step due to a low metal content and high concentration of the interfering matrix components. A solid phase extraction technique with different kind of solid sorbents offers a high enrichment factor, rapid phase separation and the possibility of its combination with various detection techniques used either in on-line or off-line mode. The recent developments in this area published over the last five years are presented and discussed in this paper. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Rapid method of element determination in rye crispbread by ICP OES

    Directory of Open Access Journals (Sweden)

    Anna Szymczycha-Madeja

    2017-05-01

    Full Text Available In this work, various sample preparation procedures, i.e., microwave-assisted acid digestion in a mixture of HNO3 and H2O2 solutions, solubilisation in aqua regia or tetramethyl ammonium hydroxide and extraction in diluted HNO3 or in HCl, for the determination of the total content of Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb, Sr and Zn in rye crispbread using inductively coupled plasma optical emission spectrometry were compared. Analytical characteristic was evaluated by comparing the accuracy and precision of the results and limits of detection of elements. Among these five procedures solubilisation in aqua regia provides the best results, i.e., limits of detection of elements within 0.12–31.4 ng mL−1, precision of 0.4–5% and accuracy better than 5%. Additionally, a good agreement between the measured and certified values of the NIST 1567a was found for all elements. The proposed procedure is simple, reduces sample handling and minimises time and reagent consumption. Thus, it can be alternatively used instead of microwave-assisted acid digestion for routine analysis. Six different rye crispbreads were analysed with this procedure.

  12. Use of Hg-Electroplated-Pt Ultramicroelectrode for Determining Elemental Sulphur in Naphtha Samples

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Andrade

    2012-01-01

    Full Text Available This paper describes the applicability of a Hg-electroplated-Pt ultramicroelectrode in the quantification of elemental sulphur in naphtha samples by square-wave voltammetry. A reproducible deposition methodology was studied and is reported in this paper. This methodology is innovative and relies on the quality of the mercury stock solution to obtain reproducible surfaces required for the analytical methodology. All analyses were performed using a Hg-electroplated-Pt ultramicroelectrode (Hg-Pt UME due to the low sensibility of such devices to ohmic drops in resistive solutions. The responses of the peak areas in voltammetric experiments were linear in all of the range studied. The method developed here is accurate and reproducible, with a detection limit of 0.010 mg L−1 and a good recovery range for both standard solutions of elemental sulphur (85 to 99% and real naphtha sample (79%. These results attest to the potential for the application of this electroanalytical methodology in determining elemental sulphur in naphtha samples containing mercaptans and disulphides.

  13. Use of hg-electroplated-pt ultramicroelectrode for determining elemental sulphur in naphtha samples.

    Science.gov (United States)

    de Andrade, Carlos Eduardo; de Souza, Flávia C; Fernandes, Daniella R; Machado, Sérgio A S; D'Elia, Eliane

    2012-01-01

    This paper describes the applicability of a Hg-electroplated-Pt ultramicroelectrode in the quantification of elemental sulphur in naphtha samples by square-wave voltammetry. A reproducible deposition methodology was studied and is reported in this paper. This methodology is innovative and relies on the quality of the mercury stock solution to obtain reproducible surfaces required for the analytical methodology. All analyses were performed using a Hg-electroplated-Pt ultramicroelectrode (Hg-Pt UME) due to the low sensibility of such devices to ohmic drops in resistive solutions. The responses of the peak areas in voltammetric experiments were linear in all of the range studied. The method developed here is accurate and reproducible, with a detection limit of 0.010 mg L(-1) and a good recovery range for both standard solutions of elemental sulphur (85 to 99%) and real naphtha sample (79%). These results attest to the potential for the application of this electroanalytical methodology in determining elemental sulphur in naphtha samples containing mercaptans and disulphides.

  14. Determination of elemental composition of metals using ambient organic mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shiea, Christopher [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, Kaohsiung 807, Taiwan (China); Huang, Yeou-Lih [Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, Kaohsiung 807, Taiwan (China); Department of Chemistry, National Sun Yat-Sen University, 70 Lien-Hai Rd, Kaohsiung 804, Taiwan (China); Cheng, Sy-Chyi; Chen, Yi-Lun [Department of Chemistry, National Sun Yat-Sen University, 70 Lien-Hai Rd, Kaohsiung 804, Taiwan (China); Shiea, Jentaie, E-mail: jetea@mail.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, 70 Lien-Hai Rd, Kaohsiung 804, Taiwan (China); Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd, Kaohsiung 807, Taiwan (China)

    2017-05-22

    Conventional inorganic mass spectrometric (MS) analysis of metals can require time-consuming and tedious sample preparation. We thus report the novel and direct characterization of metals in solid samples using an organic MS technique known as electrospray laser desorption ionization mass spectrometry (ELDI/MS). No sample pretreatment was needed, and results were rapidly obtained due to the ambient and laser-based nature of ELDI/MS. Metals from samples were desorbed and ionized by laser irradiation, after which they reacted with EDTA and then post-ionized and detected as metal-EDTA complexes. Aluminum, copper, iron, lead, nickel, and zinc from plates, foils, and coins were characterized in seconds. This study demonstrates that an ESI/MS system can be easily modified to analyze metal elements in solids by involving a chelating agent, indicating a potentially promising development in MS towards the analysis of metals using organic MS. - Highlights: • “Organic MS” was utilized as “inorganic MS” to detect metal ions in solid samples. • Element ions desorbed by laser irradiation rapidly reacted with a chelating reagent before they were detected by MS. • Elemental composition of metals was determined by this “Organic MS” method.

  15. Determination of trace elements in volcanic rock samples collected from cenozoic lava eruption sites using LIBS.

    Science.gov (United States)

    Gondal, Mohammed A; Nasr, Mohamed M; Ahmed, Zulfiqar; Yamani, Zain H

    2009-04-01

    Trace elements of environmental significance present in the volcanic rock samples collected from sites of the Cenozoic era flood basalt flows and eruptions were detected using locally developed laser-induced breakdown spectrometer. For spectro-chemical analysis of these samples, the plasma was generated by focusing a pulsed Nd: YAG laser radiation at 1064 nm wavelength on the target rock samples. These samples were collected from four widely separated locations surrounding the volcanic eruption sites belonging to the Harrat Hutaymah volcanic field in the vicinity of Taba town, situated to the east of Hail city of northern Saudi Arabia. These samples represent the scoria basalt lava flows as well as a large tuff-ring crater and it contains xenoliths. These flows occur widespread over the Earth's surface in this region, and their contained xenoliths are brought up from depths of a few tens of kilometers. This volcanic field has received much less attention in the previous geological studies; and consequently, its effects on the environment are not well defined. The concentration of different elements of environmental significance like Cr, Pb, Mn, Cd, Sr and other trace metals like Cu, Al, Ca, Mg, Zn, Ti and Fe in these rock samples were determined by spectral analysis. Parametric dependence for improvement of LIBS sensitivity for detection of these elements was also carried out. The highest concentration detected of environmentally significant elements like Cr, Mn, Pb, Sr and Ni are 1910, 1399, 90.5, 12412 and 461.5 ppm, respectively in four different lava samples which are considered to be much higher than the safe permissible limits. The LIBS results were compared with the results obtained using other analytical techniques such as the inductively coupled plasma atomic emission spectroscopy (ICP-AES).

  16. Heterogeneity of elemental composition and natural abundance of stables isotopes of C and N in soils and leaves of mangroves at their southernmost West Atlantic range.

    Science.gov (United States)

    Tognella, M M P; Soares, M L G; Cuevas, E; Medina, E

    2016-01-01

    Mangrove communities were selected in the state of Santa Catarina, Brazil, near their southernmost limit of distribution, to study mineral nutrient relation in soils and plants. Communities included three true mangrove species, Rhizophora mangle, Laguncularia racemosa and Avicennia germinans, and two associated species, the fern Acrostichum danaeifolium, and the grass Spartina densiflora. The sites included communities in the lower Río Tavares near Florianopolis city, Sonho beach near Palhoça city, and the Santo Antonio lagoon. These sites included a full range of mangroves under humid climate where winter temperatures, instead of salinity, may be the main factor regulating their productive capacity and species composition. Soil salinity was determined by the concentration of soluble Na, and soil C and N were linearly correlated indicating their association in organic matter. Tavares site showed higher specific conductivity, and concentrations of Na and Mg in the soil layer below 40 cm depth, indicating larger influence of marine water. Isotopic signature of C increased with soil depth suggesting that microorganisms decomposing organic matter are releasing 13C depleted CO2. Nitrogen isotopic signature decreased with soil depth, indicating enrichment in 15N possibly as a result of denitrification in the upper soil layers. Mineral elements in leaf tissues showed A. schaueriana with higher concentrations of N, P, Na, K, Cu, Zn, and Na/Ca ratio. Spartina densiflora was characterized by the lowest N and K concentrations, and the highest concentrations of Al and Fe. Rhizophora mangle and L. racemosa had the highest Ca concentrations. Carbon isotopic signatures identified S. densiflora as a C4 plant, and A. schaueriana as the mangrove species occupying comparatively more water stressed microsites than the rest. Leaf nitrogen isotopic signatures were positive, in correspondence with the soil values. The results support the hypothesis that sites sampled were comparatively

  17. Effect of heterogeneity on the quantitative determination of trace elements in concrete.

    Science.gov (United States)

    Weritz, Friederike; Schaurich, Dieter; Taffe, Alexander; Wilsch, Gerd

    2006-05-01

    Laser-induced breakdown spectroscopy has been used for quantitative measurement of trace elements, e.g. sulfur and chlorine, in concrete. Chloride and sulfate ions have a large effect on the durability of concrete structures, and quantitative measurement is important for condition assessment and quality assurance. Concrete is a highly heterogeneous material in composition and grain-size distribution, i.e. the spatial distribution of elements. Calibration plots were determined by use of laboratory-made reference samples consisting of pressings of cement powder, hydrated cement, cement mortar, and concrete, in which the heterogeneity of the material is increasing because of the aggregates. Coarse aggregate and cement paste are distinguishable by the intensity of the Ca spectral lines. More advanced evaluation is necessary to account for the effect of the fine aggregate. The three series of reference samples enable systematic study of the effects of heterogeneity on spectral intensity, signal fluctuation, uncertainty, and limits of detection. Spatially resolved measurements and many spectra enable statistical evaluation of the data. The heterogeneity has an effect on measurement of the sulfur and chlorine content, because both occur mainly in the cement matrix. Critical chloride concentrations are approximately 0.04% (m/m). The chlorine spectral line at 837.6 nm is evaluated. The natural sulfur content of concrete is approximately 0.1% (m/m). The spectral line at 921.3 nm is evaluated. One future application may be simultaneous determination of the amount of damaging trace elements and the cement content of the concrete.

  18. Determination of p-y Curves for Bucket Foundations in Sand Using Finite Element Modeling

    DEFF Research Database (Denmark)

    Knudsen, Bjørn S.; Østergaard, Martin Underlin; Ibsen, Lars Bo

    , the suction bucket has a much smaller ratio between length and diameter, and the suction buckets will thus act more as a rigid object during rotation in the soil. To improve the design of suction buckets through analytical methods, the soil pressure needs to be calculated more precisely since currently...... available p􀀀y curves, linking displacement and soil pressure, are based on more slender cylindrical structures. Using finite element methods, the p􀀀y curves for suction buckets will be determined as a function of the internal angle of friction of the soil, the diameter and the skirt length...... of the suction buckets, which can in turn be applied in determination of soil pressures for analytical design methods of suction bucket foundations....

  19. Employment of Both Mn I and II Transitions to Determine the Abundance Trend and Ionization Balance in Three Stellar Evolutionary Classes

    Science.gov (United States)

    Sobeck, Jennifer; Den Hartog, B.; Lawler, J.; Sneden, C.

    2010-01-01

    Several prior investigations have repeatedly found that Manganese is under-abundant with respect to solar in metal-deficient stars. However a recent study, which employed a non-LTE approach/methodology, found that the [Mn/Fe] abundance ratio remains solar in the range -2.5 < [Fe/H] < 0 (results which stand in direct contrast to previous data). We will re-determine the [Mn/Fe] ratio over a large range of metallicity in a statistically significant sample consisting of stars from three evolutionary classes (dwarf, turnoff, and giant). We will employ new laboratory work (reported also at this meeting) to analyze the transitions of *both* the neutral (Mn I) and the first-ionized species (Mn II) in stellar spectra. We intend to determine the ionization equilibrium within each star and identify departures from LTE in each stellar group. We will explore the Mn abundance trend with metallicity and provide insight into its astrophysical origin (with special emphasis on the explosive nucleosynthetic contribution).

  20. Determination of the Mineral Composition and Toxic Element Contents of Propolis by Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    M. Inmaculada González-Martín

    2015-11-01

    Full Text Available The potential of near infrared spectroscopy (NIR with remote reflectance fiber-optic probes for determining the mineral composition of propolis was evaluated. This technology allows direct measurements without prior sample treatment. Ninety one samples of propolis were collected in Chile (Bio-Bio region and Spain (Castilla-León and Galicia regions. The minerals measured were aluminum, calcium, iron, potassium, magnesium, phosphorus, and some potentially toxic trace elements such as zinc, chromium, nickel, copper and lead. The modified partial least squares (MPLS regression method was used to develop the NIR calibration model. The determination coefficient (R2 and root mean square error of prediction (RMSEP obtained for aluminum (0.79, 53, calcium (0.83, 94, iron (0.69, 134 potassium (0.95, 117, magnesium (0.70, 99, phosphorus (0.94, 24 zinc (0.87, 10 chromium (0.48, 0.6 nickel (0.52, 0.7 copper (0.64, 0.9 and lead (0.70, 2 in ppm. The results demonstrated that the capacity for prediction can be considered good for wide ranges of potassium, phosphorus and zinc concentrations, and acceptable for aluminum, calcium, magnesium, iron and lead. This indicated that the NIR method is comparable to chemical methods. The method is of interest in the rapid prediction of potentially toxic elements in propolis before consumption.

  1. Trace element determination in a mussel reference material using short irradiation instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Edson G.; Seo, Daniele; Vasconcellos, Marina B.A.; Saiki, Mitiko, E-mail: emoreira@ipen.b, E-mail: mbvascon@ipen.b, E-mail: mitiko@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The production of certified reference materials in Brazil, and the consequent availability to national end users, is an important task for the enhancement of Metrology in Chemistry status in the country, as these materials are used for method validation, equipment calibration and for establishing metrological traceability links. In this study, Instrumental Neutron Activation Analysis (INAA) was applied to the determination of magnesium, manganese and vanadium in a mussel reference material produced at IPEN-CNEN/SP. For the determination of these elements via the comparative INAA method, the respective analytical radionuclides, {sup 27}Mg, {sup 56}Mn, and {sup 52}V, are short lived and then, short irradiations are used. The main advantage over longer irradiation methods is the faster output of analytical results. Six subsamples from two bottles of the Perna perna mussel reference material were analyzed. Each subsample was simultaneously irradiated with elemental standards for 10 s at the IEA - R1 research nuclear reactor through a pneumatic transfer system. After suitable decay periods, gamma radioactivity measurements were carried out, using a hyperpure germanium detector. The accuracy of the method was checked by using the NIST SRM 1566b - 'Oyster Tissue' certified reference material. The comparison of the obtained results to the robust mean of the interlaboratorial collaborative trial used for the characterization of the mussel reference material showed that the short irradiation INAA method is suitable for the characterization of new reference materials. (author)

  2. Determination of the Mineral Composition and Toxic Element Contents of Propolis by Near Infrared Spectroscopy

    Science.gov (United States)

    González-Martín, M. Inmaculada; Escuredo, Olga; Revilla, Isabel; Vivar-Quintana, Ana M.; Coello, M. Carmen; Palacios Riocerezo, Carlos; Wells Moncada, Guillermo

    2015-01-01

    The potential of near infrared spectroscopy (NIR) with remote reflectance fiber-optic probes for determining the mineral composition of propolis was evaluated. This technology allows direct measurements without prior sample treatment. Ninety one samples of propolis were collected in Chile (Bio-Bio region) and Spain (Castilla-León and Galicia regions). The minerals measured were aluminum, calcium, iron, potassium, magnesium, phosphorus, and some potentially toxic trace elements such as zinc, chromium, nickel, copper and lead. The modified partial least squares (MPLS) regression method was used to develop the NIR calibration model. The determination coefficient (R2) and root mean square error of prediction (RMSEP) obtained for aluminum (0.79, 53), calcium (0.83, 94), iron (0.69, 134) potassium (0.95, 117), magnesium (0.70, 99), phosphorus (0.94, 24) zinc (0.87, 10) chromium (0.48, 0.6) nickel (0.52, 0.7) copper (0.64, 0.9) and lead (0.70, 2) in ppm. The results demonstrated that the capacity for prediction can be considered good for wide ranges of potassium, phosphorus and zinc concentrations, and acceptable for aluminum, calcium, magnesium, iron and lead. This indicated that the NIR method is comparable to chemical methods. The method is of interest in the rapid prediction of potentially toxic elements in propolis before consumption. PMID:26540058

  3. Determination of essential elements in commercial baby foods by INAA (Instrumental Neutron Activation Analysis)

    Energy Technology Data Exchange (ETDEWEB)

    Vallinoto, Priscila; Maihara, Vera A., E-mail: pvallinoto@ipen.br, E-mail: vmaihara@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The World Health Organization recommends that infants be breast feed exclusively at least six months after birth. After this period, it is recommended to introduce complementary foods, in order to meet nutritional amounts, minerals and energy needs of children. Commercial food products intended for infants form an important part of the diet for many babies, so it is very important that such food contains sufficient amounts of minerals. Inadequate complementary feeding is a major cause of high rates of malnutrition in developing countries. In this study, essential elements: Ca, Co, Cr, Cs, Fe, K, Na and Zn levels were determined in seven different commercial food products samples by Instrumental Neutron Activation Analysis. The seven baby food samples were acquired in the markets of Sao Paulo city. After 8-hour irradiations in the IEA-R1 nuclear research reactor under a thermal neutron flux of 10{sup 12} n cm{sup -2} s{sup -1}, the essential elements were determined and the concentrations obtained were lower than the WHO requirements. For validation of the methodology, INCT MPH-2 Mixed Polish Herbs and NIST SRM 1577{sup b} Bovine Liver were analysed. (author)

  4. Ultra-High Sensitivity Techniques for the Determination of 3 He /4 He Abundances in Helium by Accelerator Mass Spectrometry

    Science.gov (United States)

    Mumm, H. P.; Huber, M.; Bauder, W.; Abrams, N.; Deibel, C.; Huffer, C.; Huffman, P.; Schelhammer, K.; Janssens, R.; Jiang, C.; Scott, R.; Pardo, R.; Rehm, K.; Vondrasek, R.; Swank, C.; O'Shaughnessy, C.; Paul, M.; Yang, L.

    2017-01-01

    We report the development of an Accelerator Mass Spectrometry technique to measure the 3He/4He isotopic ratio using a radio frequency (RF) discharge source and the ATLAS facility at Argonne National Laboratory. Control over 3He/4He ratio in helium several orders of magnitude lower than natural abundance is critical for neutron lifetime and source experiments using liquid helium. Due to low ultimate beam currents, the ATLAS accelerator and beam line were tuned using a succession of species of the same M/q. A unique RF source was developed for the experiment due to large natural 3He backgrounds. Analog H_3 + and DH + molecular ions are eliminated by dissociation via a gold stripper foil near the detector. The stripped ions were dispersed in a magnetic spectrograph and 3He2 + ions counted in the focal plane detector. This technique is sensitive to 3 He /4 He ratios in the regime of 10-12 with backgrounds that appear to be below 10-14. The techniques used to reduce the backgrounds and remaining outstanding problems will be presented along with results from measurements on high purity 4He samples.

  5. Food Abundance Is the Main Determinant of High-Altitude Range Use in Snub-Nosed Monkeys

    Directory of Open Access Journals (Sweden)

    Cyril C. Grueter

    2012-01-01

    Full Text Available High-altitude dwelling primates have to optimize navigating a space that contains both a vertical and horizontal component. Black-and-white or Yunnan snub-nosed monkeys (Rhinopithecus bieti are extreme by primate standards in inhabiting relatively cold subalpine temperate forests at very high altitudes where large seasonal variation in climate and food availability is expected to profoundly modulate their ranging strategies so as to ensure a positive energy balance. A “semi-nomadic” group of R. bieti was followed for 20 months in the montane Samage Forest, Baimaxueshan Nature Reserve, Yunnan, PRC, which consisted of evergreen conifers, oaks, and deciduous broadleaf trees. The aim of this study was to disentangle the effects of climate and phenology on patterns of altitudinal range use. Altitude used by the group ranged from a maximum of 3550 m in July 2007 to a minimum of 3060 m in April 2006. The proportional use of lichen, the monkeys’ staple fallback food, in the diet explained more variation in monthly use of altitudes than climatic factors and availability of flush and fruit. The abundance of lichens at high altitudes, the lack of alternative foods in winter, and the need to satisfy the monkey's basal energetic requirements explain the effect of lichenivory on use of altitudes.

  6. Determination of the correlation between elemental and organic carbons to trace elemental substances and anions in DPM samples

    CSIR Research Space (South Africa)

    Mahlangu, Vusi J

    2016-09-01

    Full Text Available (DPM) is a result of the incomplete combustion of diesel fuel in motor vehicles and other diesel machinery. This DPM is released as part of the exhaust gas which is formed by a mixture of poly-aromatic hydrocarbons (PAHs) and soot aerosol [6]. DPM is..., phosphates, carbonates, borates and some oxides and silicates. However, this is an exception in certain cases for some pure elements that are below the reactivity potential of hydrogen (H). The hydrogen ions (H+) would not be displaced from their chloride...

  7. Heterogeneity of elemental composition and natural abundance of stables isotopes of C and N in soils and leaves of mangroves at their southernmost West Atlantic range

    Directory of Open Access Journals (Sweden)

    M. M. P. Tognella

    Full Text Available Abstract Mangrove communities were selected in the state of Santa Catarina, Brazil, near their southernmost limit of distribution, to study mineral nutrient relation in soils and plants. Communities included three true mangrove species, Rhizophora mangle, Laguncularia racemosa and Avicennia germinans, and two associated species, the fern Acrostichum danaeifolium, and the grass Spartina densiflora. The sites included communities in the lower Río Tavares near Florianopolis city, Sonho beach near Palhoça city, and the Santo Antonio lagoon. These sites included a full range of mangroves under humid climate where winter temperatures, instead of salinity, may be the main factor regulating their productive capacity and species composition. Soil salinity was determined by the concentration of soluble Na, and soil C and N were linearly correlated indicating their association in organic matter. Tavares site showed higher specific conductivity, and concentrations of Na and Mg in the soil layer below 40 cm depth, indicating larger influence of marine water. Isotopic signature of C increased with soil depth suggesting that microorganisms decomposing organic matter are releasing 13C depleted CO2. Nitrogen isotopic signature decreased with soil depth, indicating enrichment in 15N possibly as a result of denitrification in the upper soil layers. Mineral elements in leaf tissues showed A. schaueriana with higher concentrations of N, P, Na, K, Cu, Zn, and Na/Ca ratio. Spartina densiflora was characterized by the lowest N and K concentrations, and the highest concentrations of Al and Fe. Rhizophora mangle and L. racemosa had the highest Ca concentrations. Carbon isotopic signatures identified S. densiflora as a C4 plant, and A. schaueriana as the mangrove species occupying comparatively more water stressed microsites than the rest. Leaf nitrogen isotopic signatures were positive, in correspondence with the soil values. The results support the hypothesis that

  8. Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bentlin, Fabrina R.S. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil); Pozebon, Dirce [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil)], E-mail: dircepoz@iq.ufrgs.br; Mello, Paola A.; Flores, Erico M.M. [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900 Santa Maria, RS (Brazil)

    2007-10-17

    A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO{sub 3}){sub 2} was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 {mu}g g{sup -1} of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

  9. Transcriptional rewiring of the sex determining dmrt1 gene duplicate by transposable elements.

    Directory of Open Access Journals (Sweden)

    Amaury Herpin

    2010-02-01

    Full Text Available Control and coordination of eukaryotic gene expression rely on transcriptional and posttranscriptional regulatory networks. Evolutionary innovations and adaptations often require rapid changes of such networks. It has long been hypothesized that transposable elements (TE might contribute to the rewiring of regulatory interactions. More recently it emerged that TEs might bring in ready-to-use transcription factor binding sites to create alterations to the promoters by which they were captured. A process where the gene regulatory architecture is of remarkable plasticity is sex determination. While the more downstream components of the sex determination cascades are evolutionary conserved, the master regulators can switch between groups of organisms even on the interspecies level or between populations. In the medaka fish (Oryzias latipes a duplicated copy of dmrt1, designated dmrt1bY or DMY, on the Y chromosome was shown to be the master regulator of male development, similar to Sry in mammals. We found that the dmrt1bY gene has acquired a new feedback downregulation of its expression. Additionally, the autosomal dmrt1a gene is also able to regulate transcription of its duplicated paralog by binding to a unique target Dmrt1 site nested within the dmrt1bY proximal promoter region. We could trace back this novel regulatory element to a highly conserved sequence within a new type of TE that inserted into the upstream region of dmrt1bY shortly after the duplication event. Our data provide functional evidence for a role of TEs in transcriptional network rewiring for sub- and/or neo-functionalization of duplicated genes. In the particular case of dmrt1bY, this contributed to create new hierarchies of sex-determining genes.

  10. System to determine present elements in oily samples; Sistema para determinar elementos presentes en muestras oleosas

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza G, Y

    2004-11-01

    In the Chemistry Department of the National Institute of Nuclear Investigations of Mexico, dedicated to analyze samples of oleaginous material and of another origin, to determine the elements of the periodic table present in the samples, through the Neutron activation analysis technique (NAA). This technique has been developed to determine majority elements in any solid, aqueous, industrial and environmental sample, which consists basically on to irradiate a sample with neutrons coming from the TRIGA Mark III reactor and to carry out the analysis to obtain those gamma spectra that it emits, for finally to process the information, the quantification of the analysis it is carried out in a manual way, which requires to carry out a great quantity of calculations. The main objective of this project is the development of a software that allows to carry out the quantitative analysis of the NAA for the multielemental determination of samples in an automatic way. To fulfill the objective of this project it has been divided in four chapters: In the first chapter it is shortly presented the history on radioactivity and basic concepts that will allow us penetrate better to this work. In the second chapter the NAA is explained which is used in the sample analysis, the description of the process to be carried out, its are mentioned the characteristics of the used devices and an example of the process is illustrated. In the third chapter it is described the development of the algorithm and the selection of the programming language. The fourth chapter it is shown the structure of the system, the general form of operation, the execution of processes and the obtention of results. Later on the launched results are presented in the development of the present project. (Author)

  11. Element determination of fine particles in environmental aerosols using PIXE; Determinacion elemental de paticulas finas en aerosoles ambientales usando PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Garcia O, B. [ITT, 50000 Toluca (Mexico); Aldape U, F. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: gaolivab@gmail.com

    2007-07-01

    The Mexico city is classified as one of the more populated cities of the world which presents a decrease in the air quality and that gives place to a severe problematic in atmospheric pollution. To cooperate in the solution of this problem it is necessary to carry out studies that allow a better knowledge of the atmosphere of the city. This study presents the results of a monitoring campaign of fine particle carried out from September 21 to December 12, 2001 in three sites of the Mexico City center area. The samples were collected every third day with a collector type unit of heaped filters (Gent). The analysis of these samples was carried out in the 2 MV accelerator of the National Institute of Nuclear Research (ININ) applying the PIXE technique and with this analysis its were identified in the samples approximately 15 elements in each one of the 3 sites and was calculated the concentration in that its were present. With these results a database was created and by means of it mathematical treatment the Enrichment factor (FE), the time series of each element and the multiple correlation matrix were evaluated. The obtained results showed that the Civil Registration site (Salto del Agua) it was the more polluted coinciding that to a bigger concentration of activities a bigger increase in the pollution is generated. (Author)

  12. IMPROVED V I log(gf) VALUES AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, J. E.; Wood, M. P.; Den Hartog, E. A.; Feigenson, T. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Sneden, C. [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Cowan, J. J., E-mail: jelawler@wisc.edu, E-mail: mpwood@wisc.edu, E-mail: eadenhar@wisc.edu, E-mail: tfeigenson@wisc.edu, E-mail: chris@verdi.as.utexas.edu, E-mail: cowan@nhn.ou.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2015-01-01

    New emission branching fraction measurements for 836 lines of the first spectrum of vanadium (V I) are determined from hollow cathode lamp spectra recorded with the National Solar Observatory 1 m Fourier transform spectrometer (FTS) and a high-resolution echelle spectrometer. The branching fractions are combined with recently published radiative lifetimes from laser-induced fluorescence measurements to determine accurate absolute atomic transition probabilities for the 836 lines. The FTS data are also used to extract new hyperfine structure A coefficients for 26 levels of neutral vanadium. These new laboratory data are applied to determine the V abundance in the Sun and metal-poor star HD 84937, yielding log ε(V) = 3.956 ± 0.004 (σ = 0.037) based on 93 V I lines and log ε(V) = 1.89 ± 0.03 (σ = 0.07) based on nine V I lines, respectively, using the Holweger-Müller 1D model. These new V I abundance values for the Sun and HD 84937 agree well with our earlier determinations based upon V II.

  13. The effect of acidified sample storage time on the determination of trace element concentration in ice cores by ICP-SFMS

    Science.gov (United States)

    Uglietti, C.; Gabrielli, P.; Lutton, A.; Olesik, J.; Thompson, L. G.

    2012-12-01

    Trace elements in micro-particles entrapped in ice cores are a valuable proxy of past climate and environmental variations. Inductively coupled plasma sector field mass spectrometry (ICP-SFMS) is generally recognized as a sensitive and accurate technique for the quantification of ultra-trace element concentrations in ice cores. Usually, ICP-SFMS analyses of ice core samples are performed by melting and acidifying aliquots. Acidification is important to transfer trace elements from particles into solution by partial and/or complete dissolution. Only elements in solution and in sufficiently small particles will be vaporized and converted to elemental ions in the plasma for detection by ICP-SFMS. However, experimental results indicate that differences in acidified sample storage time at room temperature may lead to the recovery of different trace element fractions. Moreover, different lithologies of the relatively abundant crustal material entrapped in the ice matrix could also influence the fraction of trace elements that are converted into elemental ions in the plasma. These factors might affect the determination of trace elements concentrations in ice core samples and hamper the comparison of results obtained from ice cores from different locations and/or epochs. In order to monitor the transfer of elements from particles into solution in acidified melted ice core samples during storage, a test was performed on sections from nine ice cores retrieved from low latitude drilling sites around the world. When compared to ice cores from polar regions, these samples are characterized by a relative high content of micro-particles that may leach trace elements into solution differently. Of the nine ice cores, five are from the Tibetan Plateau (Dasuopu, Guliya, Naimonanyi, Puruogangri and Dunde), two from the Andes (Quelccaya and Huascaran), one from Africa (Kilimanjaro) and one from the Eastern Alps (Ortles). These samples were decontaminated by triple rinsing, melted and

  14. [Determination of mineral elements in cistanche and its extractives by ICP-AES].

    Science.gov (United States)

    Zhu, Yan-Xia; Guo, Yu-Hai

    2013-03-01

    Determination of Fe, Zn, Cu, K, P, Ca, Mg, Na, B and Al in cistanche and its extractives was carried out by the inductively coupled plasma atomic emission spectrometry (ICP-AES). The results showed that (1) the contents of Mn, K, Ca, Mg and Na in cistanche deserticola Y. C. Ma were 17.70, 16,278. 03, 1,947.25, 1,662.76, and 106.79 respectively (microg.g-1), much higher than in Cistanche tubulosa (Schrenk) Wight; (2) the contents of Fe, Cu and P in 50% methanol extract of Cistanche deserticola were 1.5, 2.4, and 1.1 times that of aqueous extract respectively, the contents of Mn, Zn, K, P, Mg and Na were 3.8, 1.2, 1.6, 2.3, 2.2, and 1.1 times that of methanol extract respectively; (3) the contents of Cu and P in 50% methanol extract of Cistanche tubulosa were 1.6 and 1.2 times that of aqueous extract, the contents of Mn, Zn, K, P, Mg, Na and Al were 2.0, 1.6, 1.6, 1.4, 1.8, 1.2, and 1.2 times that of methanol extract respectively; (4) the leaching rate of 11 mineral elements in Cistanche deserticola and Cistanche tubulosa were 60.79%-83. 10% and 44. 58%-83.84% in 50% methanol respectively, and the leaching rate of Mn, Zn, K, P, Ca, Na and Al were much higher than in water and 100% methanol extracted. The research provided the basic data of mineral element in comparative study on Cistanche deserticola and Cistanche tubulosa, and provide scientific basis for efficient utilization of mineral element in cistanche.

  15. Determination of rare earth elements concentration at different depth profile of Precambrian pegmatites using instrumental neutron activation analysis.

    Science.gov (United States)

    Sadiq Aliyu, Abubakar; Musa, Yahaya; Liman, M S; Abba, Habu T; Chaanda, Mohammed S; Ngene, Nnamani C; Garba, N N

    2018-01-01

    The Keffi area hosts abundant pegmatite bodies as a result of the surrounding granitic intrusions. Keffi is part of areas that are geologically classified as North Central Basement Complex. Data on the mineralogy and mineralogical zonation of the Keffi pegmatite are scanty. Hence the need to understand the geology and mineralogical zonation of Keffi pegmatites especially at different depth profiles is relevant as a study of the elemental composition of the pegmatite is essential for the estimation of its economic viability. Here, the relative standardization method of instrumental neutron activation analysis (INAA) has been used to investigate the vertical deviations of the elemental concentrations of rare earth elements (REEs) at different depth profile of Keffi pegmatite. This study adopted the following metrics in investigating the vertical variations of REEs concentrations. Namely, the total contents of rare earth elements (∑REE); ratio of light to heavy rare earth elements (LREE/HREE), which defines the enrichment or depletion of REEs; europium anomaly (Eu/Sm); La/Lu ratio relative to chondritic meteorites. The study showed no significant variations in the total content of rare elements between the vertical depth profiles (100-250m). However, higher total concentrations of REEs (~ 92.65ppm) were recorded at the upper depth of the pegmatite and the europium anomaly was consistently negative at all the depth profiles suggesting that the Keffi pegmatite is enriched with light REEs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Effects of long-lived 10 MeV-scale sterile neutrinos on primordial elemental abundances and the effective neutrino number

    Science.gov (United States)

    Ishida, Hiroyuki; Kusakabe, Motohiko; Okada, Hiroshi

    2014-10-01

    The primordial lithium abundance inferred from spectroscopic observations of metal-poor stars is ˜3 times smaller than the theoretical prediction in the standard big bang nucleosynthesis (BBN) model. We assume a simple model composed of standard model particles and a sterile neutrino νH with mass of O(10) MeV which decays long after BBN. We then investigate cosmological effects of a sterile neutrino decay, and check if a sterile neutrino can reduce the primordial lithium abundance. We formulate the injection spectrum of nonthermal photon induced by the νH decay. We take into account the generation of electrons and positrons, e±'s, and active neutrinos at the νH decay, the primary photon production via the inverse Compton scattering of cosmic background radiation (CBR) by energetic e±, and electromagnetic cascade showers induced by the primary photons. The steady state injection spectrum is then derived as a function of the νH mass and the photon temperature. The νH decay produces energetic active neutrinos which are not thermalized, and e±'s which are thermalized. We then derive formulas relevant to the νH decay rates and formulas for the baryon-to-photon ratio η and effective neutrino number Neff. The initial abundance, mass, and lifetime of νH are taken as free parameters. We then consistently solve (1) the cosmic thermal history, (2) nonthermal nucleosynthesis induced by the nonthermal photons, (3) the η value, and (4) the Neff value. We find that an effective Be7 destruction can occur only if the sterile neutrino decays at photon temperature T =O(1) keV. Amounts of energy injection at the νH decay are constrained from limits on primordial D and Li7 abundances, the Neff value, and the CBR energy spectrum. We find that Be7 is photodisintegrated and the Li problem is partially solved for the lifetime 104-105 s and the mass ≳14 MeV. Be7 destruction by more than a factor of 3 is not possible because of an associated D overdestruction. In the

  17. Determination of elemental composition in dietary supplements by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vitor I.; Saiki, Mitiko, E-mail: vitor.ito@outlook.com, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Dietary supplements intake has grown in the last years because of their potential health benefits. This supplementation is very common among athletes, elderly population and consumers that want to increase the total daily nutrient intake. Consequently, elemental composition evaluation in these supplements is of great interest due to its increasingly high consumption and the brand variety offered in the market. This study aimed to evaluate the elemental composition in three types of dietary supplements acquired in a pharmacy and drugstore in Sao Paulo city. Concentrations of As, Br, Ca, Co, Cr, Cu, Fe, K, La, Na, Sb, Sc, Se and Zn were determined in these supplements by applying neutron activation analysis (NAA) followed by a gamma ray spectrometry. from the concentrations obtained in the dietary supplement analyses, the data obtained were compared to the values presented on the product label. These comparisons indicated in general, a good agreement of the data obtained and the values of the product label depending on the supplement. From the results obtained it can be concluded that NAA is an important tool for the analysis of this type of products due to its reliability of results and its multielemental character. (author)

  18. Minor and trace elemental determination in the Indian herbal and other medicinal preparations.

    Science.gov (United States)

    Samudralwar, D L; Garg, A N

    1996-08-01

    Medicinal plants described in the Indian "Ayurvedic" literature viz. Tulsi (Ocimum sanctum), Gulvel (Tinospora cardifolia), bitter Neem (Azadirachta indica), Kanher (Nerium Andicum), Vekhand (Acorus calamus), and Peacock's feather (ash) were analyzed for minor and trace elements by instrumental neutron activation analysis. The samples and the standards from the National Institute of Standards and Technology, USA and IAEA, Vienna were irradiated for 5 min, 1 h, 5 h, and 10 h with thermal neutrons at a flux of 10(12)-10(13) n cm-2 s-1 in APSARA and CIRUS reactor at BARC, Bombay. High resolution gamma ray spectrometry was performed using a 45 cm3 HPGe detector and a 4096 MCA system. Concentrations of 13 elements were determined. Zinc, manganese, and sodium were significantly higher in Tulsi leaves while zinc is higher in Neem leaves. Peacock's feathers were found to be rich in manganese, iron, copper, and zinc. A high concentration of mercury was also found in the peacock's feather ash. The therapeutic significance in restoring ionic balance is discussed.

  19. Pop III i-process nucleosynthesis and the elemental abundances of SMSS J0313-6708 and the most iron-poor stars

    Science.gov (United States)

    Clarkson, O.; Herwig, F.; Pignatari, M.

    2018-02-01

    We have investigated a highly energetic H-ingestion event during shell He burning leading to H-burning luminosities of log (LH/L⊙) ˜ 13 in a 45 M⊙ Pop III massive stellar model. In order to track the nucleosynthesis which may occur in such an event, we run a series of single-zone nucleosynthesis models for typical conditions found in the stellar evolution model. Such nucleosynthesis conditions may lead to i-process neutron densities of up to ˜1013 cm-3. The resulting simulation abundance pattern, where Mg comes from He burning and Ca from the i process, agrees with the general observed pattern of the most iron-poor star currently known, SMSS J031300.36-670839.3. However, Na is also efficiently produced in these i-process conditions, and the prediction exceeds observations by ˜2.5 dex. While this probably rules out this model for SMSS J031300.36-670839.3, the typical i-process signature of combined He burning and i process of higher than solar [Na/Mg], [Mg/Al], and low [Ca/Mg] is reproducing abundance features of the two next most iron-poor stars HE 1017-5240 and HE 1327-2326 very well. The i process does not reach Fe which would have to come from a low level of additional enrichment. i process in hyper-metal-poor or Pop III massive stars may be able to explain certain abundance patterns observed in some of the most metal-poor CEMP-no stars.

  20. Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests

    NARCIS (Netherlands)

    Hofmeester, Tim R.; Sprong, Hein; Jansen, Patrick A.; Prins, Herbert H.T.; Wieren, Van Sipke E.

    2017-01-01

    Background: Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density

  1. Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population.

    Science.gov (United States)

    Penning, Bryan W; Sykes, Robert W; Babcock, Nicholas C; Dugard, Christopher K; Held, Michael A; Klimek, John F; Shreve, Jacob T; Fowler, Matthew; Ziebell, Angela; Davis, Mark F; Decker, Stephen R; Turner, Geoffrey B; Mosier, Nathan S; Springer, Nathan M; Thimmapuram, Jyothi; Weil, Clifford F; McCann, Maureen C; Carpita, Nicholas C

    2014-08-01

    Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 × Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282-member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. These results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass. © 2014 American Society of Plant Biologists. All Rights Reserved.

  2. Genetic Determinants for Enzymatic Digestion of Lignocellulosic Biomass Are Independent of Those for Lignin Abundance in a Maize Recombinant Inbred Population1[W][OPEN

    Science.gov (United States)

    Penning, Bryan W.; Sykes, Robert W.; Babcock, Nicholas C.; Dugard, Christopher K.; Held, Michael A.; Klimek, John F.; Shreve, Jacob T.; Fowler, Matthew; Ziebell, Angela; Davis, Mark F.; Decker, Stephen R.; Turner, Geoffrey B.; Mosier, Nathan S.; Springer, Nathan M.; Thimmapuram, Jyothi; Weil, Clifford F.; McCann, Maureen C.; Carpita, Nicholas C.

    2014-01-01

    Biotechnological approaches to reduce or modify lignin in biomass crops are predicated on the assumption that it is the principal determinant of the recalcitrance of biomass to enzymatic digestion for biofuels production. We defined quantitative trait loci (QTL) in the Intermated B73 × Mo17 recombinant inbred maize (Zea mays) population using pyrolysis molecular-beam mass spectrometry to establish stem lignin content and an enzymatic hydrolysis assay to measure glucose and xylose yield. Among five multiyear QTL for lignin abundance, two for 4-vinylphenol abundance, and four for glucose and/or xylose yield, not a single QTL for aromatic abundance and sugar yield was shared. A genome-wide association study for lignin abundance and sugar yield of the 282-member maize association panel provided candidate genes in the 11 QTL of the B73 and Mo17 parents but showed that many other alleles impacting these traits exist among this broader pool of maize genetic diversity. B73 and Mo17 genotypes exhibited large differences in gene expression in developing stem tissues independent of allelic variation. Combining these complementary genetic approaches provides a narrowed list of candidate genes. A cluster of SCARECROW-LIKE9 and SCARECROW-LIKE14 transcription factor genes provides exceptionally strong candidate genes emerging from the genome-wide association study. In addition to these and genes associated with cell wall metabolism, candidates include several other transcription factors associated with vascularization and fiber formation and components of cellular signaling pathways. These results provide new insights and strategies beyond the modification of lignin to enhance yields of biofuels from genetically modified biomass. PMID:24972714

  3. Method 200.12 - Determination of Trace Elements in Marine Waters by StabilizedTemperature Graphite Furnace Atomic Absorption

    Science.gov (United States)

    This method provides procedures for the determination of total recoverable elements by graphite furnace atomic absorption (GFAA) in marine waters, including estuarine, ocean and brines with salinities of up to 35 ppt.

  4. Socio-Psycho-Linguistic Determined Expert-Search System (SPLDESS) Development with Multimedia Illustration Elements

    Science.gov (United States)

    Ponomarev, Vasily

    SPLDESS development with the elements of a multimedia illustration of traditional hypertext search results by Internet search engine provides research of information propagation innovative effect during the public access information-recruiting networks of information kiosks formation at the experimental stage with the mirrors at the constantly updating portal for Internet users. Author of this publication put the emphasis on a condition of pertinent search engine results of the total answer by the user inquiries, that provide the politically correct and not usurping socially-network data mining effect at urgent monitoring. Development of the access by devices of the new communication types with the newest technologies of data transmission, multimedia and an information exchange from the first innovation line usage support portal is presented also (including the device of social-psycho-linguistic determination according the author's conception).

  5. Simultaneous determination of major, minor and trace elements in biocarbonates by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Sun, Yali; Sun, Min

    2002-12-01

    A method was developed for simultaneous determination of major (Ca), minor (Mg and Sr) and trace (Ba and U) elements in biocarbonates by inductively coupled plasma mass spectrometry (ICP-MS). The method precision (RSD%) is 0.73% for Ca, 0.77% for Mg, 0.59% for Sr, 2.02% for Ba, 1.13% for U, 0.67% for Mg/Ca, 0.27% for Sr/Ca, 2.06% for Ba/Ca and 1.23% for U/Ca. The ratio precision suggests that ICP-MS is satisfactory for obtaining multi-ratio data from biocarbonates. This technique was applied to 67 continuous coral samples.

  6. Simultaneous determination of major, minor and trace elements in biocarbonates by inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yali; Sun, Min [Department of Earth Sciences, the University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2002-12-01

    A method was developed for simultaneous determination of major (Ca), minor (Mg and Sr) and trace (Ba and U) elements in biocarbonates by inductively coupled plasma mass spectrometry (ICP-MS). The method precision (RSD%) is 0.73% for Ca, 0.77% for Mg, 0.59% for Sr, 2.02% for Ba, 1.13% for U, 0.67% for Mg/Ca, 0.27% for Sr/Ca, 2.06% for Ba/Ca and 1.23% for U/Ca. The ratio precision suggests that ICP-MS is satisfactory for obtaining multi-ratio data from biocarbonates. This technique was applied to 67 continuous coral samples. (orig.)

  7. Using of the natural radioactive elements for determining Ge-detector efficiencies

    CERN Document Server

    Tertyshnik, E G

    2012-01-01

    A method is proposed to use of the mixture of Uran oxide and non-active matrix (e.g., NaCl) and also potassium and lanthanum for determining Ge-detector efficiencies. The preparations containing of known amouts of the U or K, or La were measured by means of the Ge-detector, which a efficiency curve has been obtained through the reference solutions of 241Am, 109Cd, 57Co, 139Ce, 137Cs, 60Co. Results the measurements were compared the activities of the preparations calculated from mass of 235U, 238U, 138La, 40K in the samples, its natural abundance, half lives and intensities of gamma lines. Discrepancy of the activities in the energy range between 163 and 1461 keV does not exeed 7 %. For correct comparison of the activities the coefficients {\\omega} were calculated, which took into consideration a varied sorption of gamma-rays in water and in mixture of the Uran oxide and matrix.

  8. Fast sequential multi-element determination of major and minor elements in environmental samples and drinking waters by high-resolution continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Gómez-Nieto, Beatriz; Gismera, Ma Jesús; Sevilla, Ma Teresa; Procopio, Jesús R

    2015-01-07

    The fast sequential multi-element determination of 11 elements present at different concentration levels in environmental samples and drinking waters has been investigated using high-resolution continuum source flame atomic absorption spectrometry. The main lines for Cu (324.754 nm), Zn (213.857 nm), Cd (228.802 nm), Ni (232.003 nm) and Pb (217.001 nm), main and secondary absorption lines for Mn (279.482 and 279.827 nm), Fe (248.327, 248.514 and 302.064 nm) and Ca (422.673 and 239.856 nm), secondary lines with different sensitivities for Na (589.592 and 330.237 nm) and K (769.897 and 404.414 nm) and a secondary line for Mg (202.582 nm) have been chosen to perform the analysis. A flow injection system has been used for sample introduction so sample consumption has been reduced up to less than 1 mL per element, measured in triplicate. Furthermore, the use of multiplets for Fe and the side pixel registration approach for Mg have been studied in order to reduce sensitivity and extend the linear working range. The figures of merit have been calculated and the proposed method was applied to determine these elements in a pine needles reference material (SRM 1575a), drinking and natural waters and soil extracts. Recoveries of analytes added at different concentration levels to water samples and extracts of soils were within 88-115% interval. In this way, the fast sequential multi-element determination of major and minor elements can be carried out, in triplicate, with successful results without requiring additional dilutions of samples or several different strategies for sample preparation using about 8-9 mL of sample. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Nested insertions and accumulation of indels are negatively correlated with abundance of mutator-like transposable elements in maize and rice.

    Directory of Open Access Journals (Sweden)

    Dongyan Zhao

    Full Text Available Mutator-like transposable elements (MULEs are widespread in plants and were first discovered in maize where there are a total of 12,900 MULEs. In comparison, rice, with a much smaller genome, harbors over 30,000 MULEs. Since maize and rice are close relatives, the differential amplification of MULEs raised an inquiry into the underlying mechanism. We hypothesize this is partly attributed to the differential copy number of autonomous MULEs with the potential to generate the transposase that is required for transposition. To this end, we mined the two genomes and detected 530 and 476 MULEs containing transposase sequences (candidate coding-MULEs in maize and rice, respectively. Over 1/3 of the candidate coding-MULEs harbor nested insertions and the ratios are similar in the two genomes. Among the maize elements with nested insertions, 24% have insertions in coding regions and over half of them harbor two or more insertions. In contrast, only 12% of the rice elements have insertions in coding regions and 19% have multiple insertions, suggesting that nested insertions in maize are more disruptive. This is because most nested insertions in maize are from LTR retrotransposons, which are large in size and are prevalent in the maize genome. Our results suggest that the amplification of retrotransposons may limit the amplification of DNA transposons but not vice versa. In addition, more indels are detected among maize elements than rice elements whereas defects caused by point mutations are comparable between the two species. Taken together, more disruptive nested insertions combined with higher frequency of indels resulted in few (6% coding-MULEs that may encode functional transposases in maize. In contrast, 35% of the coding-MULEs in rice retain putative intact transposase. This is in addition to the higher expression frequency of rice coding-MULEs, which may explain the higher occurrence of MULEs in rice than that in maize.

  10. An Ultra-Depleted Mantle Component in the Ontong Java Plateau Revealed by Major, Trace and Volatile Element Abundances in Olivine-Hosted Melt Inclusions

    Science.gov (United States)

    Jackson, M. G.; Cabral, R. A.; Rose-Koga, E. F.; Koga, K. T.; Price, A. A.; Hauri, E. H.; Michael, P. J.

    2014-12-01

    The Ontong Java Plateau (OJP) represents the most voluminous large igneous province (LIP) preserved in the geologic record. The most voluminous volcanic stages of the OJP—the Kroenke and Kwaimbaita stages, which dominate the accessible portions of the plateau—have relatively flat primitive mantle normalized rare earth element (REE) patterns, or spidergrams. With the exception of relatively small volumes of late-stage melts—referred to as the Singgalo stage—that are characterized by slightly enriched REE spidergrams, the volcanic stages that dominated the eruptive history of the OJP exhibit remarkably homogeneous, flat REE patterns. Here we isolate, for the first time, olivine-hosted melt inclusions from OJP. We show that the melt inclusions have two clear populations defined by having distinct trace element characteristics. The first population has relatively flat trace element patterns that are similar to that observed in whole rock lavas from the most voluminous volcanic stages (Kroenke and Kwaimbaita stages) recorded in the OJP. In contrast, a second group of melt inclusions, referred to as UDM (ultra-depleted melt) inclusions, exhibit strikingly depleted REE spidergrams; these trace element patterns are far more depleted than any previously reported lava from OJP. The UDM have unique trace element signatures that preclude an origin by assimilation of hydrothermally-altered oceanic crust or re-melting the depleted mantle source left over after melt extraction during construction of the OJP. We interpret the new UDM compositions to be the result of melting of a previously unrecognized ultra-depleted component hosted in the OJP mantle source.

  11. [Study of the elements determination method in animal fur by microwave digestion ICP-AES].

    Science.gov (United States)

    Hou, Tian-ping; Wang, Song-jun; Cao, Lin; Chang, Ping; Hou, Yue

    2008-08-01

    Considering the complex matrix of the sample, the animal fur is carried on to the sample pretreatment method studies specially. The microwave closed system has its unique merit: The microwave radiation has the very strong penetrability and the rapid in-depth heating function. After absorbing microwave the sample and the molecules of reactant may carry on the reaction in short time. But the microwave power is very weak, reaction consumes much time, the resolution is also incomplete. Besides the output excessively is high dispels in the pot the reagent differential pressure to increase the test solution to produce the storm rapidly to boil. As a result of those flaws, the minute step microwave heating digestion method is used to digest test specimen after treated by the acid pickling over night. In the experiment, the specialized microwave reactor is replaced by civil microwave; the microwave heating technology is adopted. According to the different characteristics of reagents, different allocated proportion and the test solution volume of nitric acid, hydrogen peroxide, hydrochloric acid and the water are tested separately. Meanwhile, in order to optimize the experimental condition, the different response power and respond time is also studied. At last, the experimental condition is determined: HNO3-H2O2-HCl-H2O acid system is chose(four reagent allocated proportions are 8:1:1:5); test specimen is heated up 10 minutes when the output is 150 W and 5 minutes when the output is 360 W continuously; carries on the test specimen airtight resolution processing animal fur by the sample. To guarantee the standard solution system is consistent with the biological sample substrate, the artificial simulation biology sample substrate is used to match law configuration standard solution; the ration the substrate element calcium is added. To eliminate disturbance of the sample complex substrate, the substrate match law, which reduces the substrate element disturbance is used

  12. A system and a method comprising an array of bending elements for determining a condition

    DEFF Research Database (Denmark)

    2014-01-01

    A system comprising a sensor element and a sensing system, a method of operating it, a sensor element and a method of providing it, where the sensor element has a substrate from which a plurality of elongate, bendable elements extend. The elongated elements are configured to bend, in the same...... direction, when exposed to a condition, which may be a temperature, a pressure, a pH, a humidity or a presence of a predetermined molecule. The elongated elements may have a first surface and a second surface having different degrees of contraction/extension when exposed to the condition, where the first...... surfaces all point in the same direction. The sensing system may relate on a large number of elongate elements positioned within a given area on the sensor element....

  13. Determination of actinide elements in environmental samples by ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Truscott, J.B

    2000-11-01

    Methods for the determination of the actinide elements in water, biological, soil and sediment samples have been developed using on-line solid phase extraction and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS). Initial applications utilised a commercially available resin, namely TRU-Spec resin, for efficient removal of the matrix prior to elution of uranium and thorium analytes. Comparative analyses of reference materials and natural water samples from Plymouth and Dartmoor demonstrated significant improvement in precision and speed of analysis by using TRU-Spec coupled to ICP-MS compared with alpha spectrometry. Further applications of the TRU-Spec resin for the determination of the transuranic actinide elements neptunium, plutonium and americium, resulted in the successful determination of {sup 239}Pu and {sup 217}Np in biological reference materials. Detection limits were 700, 850, and 600 attograms (ag) for {sup 237}Np, {sup 233}Pu, and {sup 241}Am, respectively, for a 0.5 mI sample injection, and better than 200 ag g{sup -1} with 50 ml pre-concentration when sector field (SF) ICP-MS was used. A method for the selective sequential elution of uranium and plutonium was also developed to facilitate the determination of {sup 239}Pu without interference due to the {sup 238}U{sup 1}H{sup +} polyatomic ion, caused by high concentrations of {sup 238}U in sediment samples. Investigations were performed into the use of a polymeric substrate, which was dynamically coated with chelating dyes such as xylenol orange and 4-(2-pyridylazo) resorcinol, and a silica substrate coated with permanently bonded iminodiacetic acid. The latter was used for the successful determination of uranium and thorium in certified reference material waters. However, the column was found to have a high affinity for iron, making it unsuitable for the determination of the actinides in soil and sediment samples. Subsequently, a

  14. Determination of Trace Elements in Uranium by HPLC-ID-ICP-MS: NTNFC Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Manard, Benjamin Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wylie, Ernest Miller II [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Xu, Ning [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-19

    This report covers the FY 16 effort for the HPLC-ID-ICP-MS methodology 1) sub-method validation for the group I&II elements, 2) sub-method stood-up and validation for REE, 3) sub-method development for the transition element, and 4) completion of a comprehensive SOP for three families of elements.

  15. Food Resources of Stream Macronivertebrates Determined by Natural-Abundance stable C and N Isotopes and a 15N Tracer Addition

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, P. J.

    2000-01-01

    Trophic relationships were examined using natural-abundance {sup 13}C and {sup 15}N analyses and a {sup 15}N-tracer addition experiment in Walker Branch, a 1st-order forested stream in eastern Tennessee. In the {sup 15}N-tracer addition experiment, we added {sup 15}NH{sub 4} to stream water over a 6-wk period in early spring, and measured {sup 15}N:{sup 14}N ratios in different taxa and biomass compartments over distance and time. Samples collected from a station upstream from the {sup 15}N addition provided data on natural-abundance {sup 13}C:{sup 12}C and {sup 15}N:{sup 14}N ratios. The natural-abundance {sup 15}N analysis proved to be of limited value in identifying food resources of macroinvertebrates because {sup 15}N values were not greatly different among food resources. In general, the natural-abundance stable isotope approach was most useful for determining whether epilithon or detritus were important food resources for organisms that may use both (e.g., the snail Elimia clavaeformis), and to provide corroborative evidence of food resources of taxa for which the {sup 15}N tracer results were not definitive. The {sup 15}N tracer results showed that the mayflies Stenonema spp. and Baetis spp. assimilated primarily epilithon, although Baetis appeared to assimilate a portion of the epilithon (e.g., algal cells) with more rapid N turnover than the bulk pool sampled. Although Elimia did not reach isotopic equilibrium during the tracer experiment, application of a N-turnover model to the field data suggested that it assimilated a combination of epilithon and detritus. The amphipod Gammarus minus appeared to depend mostly on fine benthic organic matter (FBOM), and the coleopteran Anchytarsus bicolor on epixylon. The caddisfly Diplectrona modesta appeared to assimilate primarily a fast N-turnover portion of the FBOM pool, and Simuliidae a fast N-turnover component of the suspended particulate organic matter pool rather than the bulk pool sampled. Together, the

  16. Determination of trace elements in refined gold samples by inductively coupled plasma atomic emission spectrometry

    Directory of Open Access Journals (Sweden)

    Steharnik Mirjana

    2013-01-01

    Full Text Available This paper presents a method for determination the trace contents of silver, copper, iron, palladium, zinc and platinum in refined gold samples. Simultaneous inductively coupled plasma atomic emission spectrometer with radial torch position and cross flow nebulizer was used for determination. In order to compare the different calibration strategies, two sets of calibration standards were prepared. The first set was based on matrix matched calibration standards and the second was prepared without the addition of matrix material. Detection limits for matrix matching calibrations were higher for some elements than those without matrix matching. In addition, the internal standardization method was applied and experiments indicated that indium was the best option as internal standard. The obtained results for gold sample by matrix matching and matrix free calibrations were compared with the obtained results by standard addition method. The accuracy of the methods was tested performing recovery test. Recoveries for spiked sample were in the range of 90-115 %. The accuracy of the methods was also tested by analysis of certified reference material of high pure goldAuGHP1. The best results were achieved by matrix free calibration and standard addition method using indium as internal standard at wavelength of 230 nm. [Projekat Ministarstva nauke Republike Srbije, br. 34024: Development of Technologies for Recycling of Precious, Rare and Associated Metals from Solid Waste in Serbia to High Purity Products

  17. Inorganic elemental determinations of marine traditional Chinese Medicine Meretricis concha from Jiaozhou Bay: The construction of inorganic elemental fingerprint based on chemometric analysis

    Science.gov (United States)

    Shao, Mingying; Li, Xuejie; Zheng, Kang; Jiang, Man; Yan, Cuiwei; Li, Yantuan

    2016-04-01

    The goal of this paper is to explore the relationship between the inorganic elemental fingerprint and the geographical origin identification of Meretricis concha, which is a commonly used marine traditional Chinese medicine (TCM) for the treatment of asthma and scald burns. For that, the inorganic elemental contents of Meretricis concha from five sampling points in Jiaozhou Bay have been determined by means of inductively coupled plasma optical emission spectrometry, and the comparative investigations based on the contents of 14 inorganic elements (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se and Zn) of the samples from Jiaozhou Bay and the previous reported Rushan Bay were performed. It has been found that the samples from the two bays are approximately classified into two kinds using hierarchical cluster analysis, and a four-factor model based on principle component analysis could explain approximately 75% of the detection data, also linear discriminant analysis can be used to develop a prediction model to distinguish the samples from Jiaozhou Bay and Rushan Bay with accuracy of about 93%. The results of the present investigation suggested that the inorganic elemental fingerprint based on the combination of the measured elemental content and chemometric analysis is a promising approach for verifying the geographical origin of Meretricis concha, and this strategy should be valuable for the authenticity discrimination of some marine TCM.

  18. IMPROVED V II log(gf) VALUES, HYPERFINE STRUCTURE CONSTANTS, AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937

    Energy Technology Data Exchange (ETDEWEB)

    Wood, M. P.; Lawler, J. E.; Den Hartog, E. A. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Sneden, C. [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Cowan, J. J., E-mail: mpwood@wisc.edu, E-mail: jelawler@wisc.edu, E-mail: eadenhar@wisc.edu, E-mail: chris@verdi.as.utexas.edu, E-mail: cowan@nhn.ou.edu [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2014-10-01

    New experimental absolute atomic transition probabilities are reported for 203 lines of V II. Branching fractions are measured from spectra recorded using a Fourier transform spectrometer and an echelle spectrometer. The branching fractions are normalized with radiative lifetime measurements to determine the new transition probabilities. Generally good agreement is found between this work and previously reported V II transition probabilities. Two spectrometers, independent radiometric calibration methods, and independent data analysis routines enable a reduction in systematic uncertainties, in particular those due to optical depth errors. In addition, new hyperfine structure constants are measured for selected levels by least squares fitting line profiles in the FTS spectra. The new V II data are applied to high resolution visible and UV spectra of the Sun and metal-poor star HD 84937 to determine new, more accurate V abundances. Lines covering a range of wavelength and excitation potential are used to search for non-LTE effects. Very good agreement is found between our new solar photospheric V abundance, log ε(V) = 3.95 from 15 V II lines, and the solar-system meteoritic value. In HD 84937, we derive [V/H] = –2.08 from 68 lines, leading to a value of [V/Fe] = 0.24.

  19. [Determination of trace elements in Lophatherum gracile brongn from different habitat by microwave digestion-atomic absorption spectroscopy].

    Science.gov (United States)

    Yuan, Ke; Xue, Yue-Qin; Gui, Ren-Yi; Sun, Su-Qin; Yin, Ming-Wen

    2010-03-01

    A method of microwave digestion technique was proposed to determine the content of Zn, Fe, Cu, Mn, K, Ca, Mg, Ni, Cd, Pb, Cr, Co, Al, Se and As in Lophatherum gracile brongn of different habitat by atomic absorption spectroscopy. The RSD of the method was between 1.23% and 3.32%, and the recovery rates obtained by standard addition method were between 95.8% and 104.20%. The results of the study indicate that the proposed method has the advantages of simplicity, speediness and sensitivity. It is suitable for the determination of the contents of metal elements in Lophatherum gracile brongn. The experimental results also indicated that different areas' Lophantherum gracile brongn had different trace elements content. The content of trace elements K, Mg, Ca, Fe and Mn beneficial to the human body was rich. The content of the heavy metal trace element Pb in Lophantherum gracile brongn of Hunan province was slightly high. The content of the heavy metal trace element Cu in Lophantherum gracile brongn of Guangdong province and Anhui province is also slightly higher. Beside, the contents of harmful trace heavy metal elements Cd, Cu, Cr, Pb and As in Lophatherum gracile brongn of different habitat are all lower than the limits of Chinese Pharmacopoeia and Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation and National Food Sanitation Standard. These determination results provided the scientific data for further discussing the relationship between the content of trace elements in Lophantherum gracile brongn and the medicine efficacy.

  20. ICP OES Determination of Contaminant Elements Leached from Food Packaging Films

    Directory of Open Access Journals (Sweden)

    Éder José dos Santos

    2017-08-01

    Full Text Available ABSTRACT Determination of potential contaminants elements in food packing films arising from contact with acidic aqueous foods was undertaken by inductively coupled plasma optical emission spectrometry (ICP OES in accordance with DIN EN 1186-1. Test sections from plastic films were totally immersed in 3% w/v CH3COOH used as the food simulant. Testing was conducted under three conditions: (1 10 days at 40 ºC; (2 30 min at 70 ºC and 10 days at 40 ºC; and (3 30 min at 100 ºC and 10 days at 40 ºC. These time and temperature conditions were considered to be the most severe situations likely to be encountered in practice. Several different containers were investigated, including a borosilicate glass beaker, a glass bottle used for food canning, as well as one of polystyrene. The glass bottle was selected for testing treatments according to procedure (3 and a polystyrene one was chosen for use with procedures (1 and (2. Limits of quantitation were adequate for the determination of Ag, B, Ba, Cd, Cr, Cu, Pb, Sb, Sn and Zn by solution nebulization ICP OES and As by chemical vapor generation (CVG-ICP OES. Results for the analysis of AccuStandard certified reference materials as well as spike recoveries show good agreement with expected concentrations, demonstrating the accuracy and precision of the determinations. Eleven samples of food packing material were analyzed. The lead was present in the range 4.8 - 85.3 µg L-1 in 10 of 11 evaluated packing material, showing the importance of quality control measures.

  1. Dye-Sensitized Solar Cells: The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells (Adv. Mater. 20/2016).

    Science.gov (United States)

    Briscoe, Joe; Dunn, Steve

    2016-05-01

    Sustainability is an important concept generating traction in the research community. To be really sustainable the full life cycle of a product needs to be carefully considered. A key aspect of this is using elements that are either readily recycled or accessible in the Earth's biosphere. Jigsawing these materials together in compounds to address our future energy needs represents a great opportunity for the current generation of researchers. On page 3802, S. Dunn and J. Briscoe summarize the performance of a selection of alternative materials to replace platinum in the counter electrodes of dye-sensitized solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Direct determination of trace elements in powdered samples by in-cell isotope dilution femtosecond laser ablation ICPMS.

    Science.gov (United States)

    Fernández, Beatriz; Claverie, Fanny; Pécheyran, Christophe; Alexis, Joel; Donard, Olivier F X

    2008-09-15

    A method has been developed for the direct and simultaneous multielement determination of Cu, Zn, Sn, and Pb in soil and sediment samples using femtosecond laser ablation inductively coupled plasma mass spectrometry (fs-LA-ICPMS) in combination with isotope dilution mass spectrometry (IDMS). The in-cell isotope dilution fs-LA-ICPMS method proposed in this work was based on the quasi-simultaneous ablation of the natural abundance sample and the isotopically enriched solid spike, which was performed using a high repetition rate laser and a fast scanning beam device in a combined manner. Both the sample preparation procedure and the total analysis time have been drastically reduced, in comparison with previous approaches, since a unique multielement isotopically enriched solid spike was employed to analyze different powdered samples. Numerous experimental parameters were carefully selected (e.g., carrier gas flow rate, inlet diameter of the ablation cell, sample translation speed, scanner speed, etc.) in order to ensure the complete mixing between the sample and the solid spike aerosols. The proposed in-cell fs-LA-ICP-IDMS method was tested for the analysis of two soil (CRM 142R, GBW-07405) and two sediment (PACS-2, IAEA-405) reference materials, and the analysis of Cu, Zn, Sn, and Pb yielded good agreement of usually not more than 10% deviation from the certified values and precisions of less than 15% relative standard deviation. Furthermore, the concentrations were in agreement not only with the certified values but also with those obtained by ICP-IDMS after the microwave-assisted digestion of the solid samples, demonstrating therefore that in-cell fs-LA-ICP-IDMS opens the possibility for accurate and precise determinations of trace elements in powdered samples reducing the total sample preparation time to less than 5 min. Additionally, scanning electron microscope measurements showed that the aerosol generated by in-cell fs-LA-ICP-IDMS predominantly consisted of

  3. Simultaneous multi-element determination in different seed samples of Dodonaea viscosa hopseed using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    El-Sweify, Fatma H.; El-Amir, Mahmoud A.; Mostafa, Mohamed; Ramadan, Hala E.; Rashad, Ghada M. [Atomic Energy Authority, Cairo (Egypt). Hot Lab. Center

    2016-07-01

    Instrumental neutron activation analysis technique (INAA) was applied for nondestructive multi-element analysis of seed samples of the plant Dodonaea viscosa hopseed. This plant is distributed all over Egypt, because of its suitable properties. The samples were collected from some bushes grown at different sites in some governorates, in July of each year during the period from 2004 to 2011. The determined elements are: Co, Cs, Eu, Fe, Hg, Ni, Rb, Sc, Se, Sr and Zn, under the chosen irradiation and cooling times. The content of some elements has been compared with data obtained from previous work on analysis of various kinds of seeds. The influence of some parameters on the determined elemental content is discussed. Standard reference materials IAEA-155 and IAEA-V-10 were used to assure quality control, accuracy and precision of the technique.

  4. Trace elements determination in ginseng and ginkgo biloba medicinal plants; Determinacao de elementos traco nos fitofarmacos ginseng e ginkgo biloba

    Energy Technology Data Exchange (ETDEWEB)

    Avino, Simone; Saiki, Mitiko; Fulfaro, Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2002-07-01

    Determinations of trace elements in medicinal plants or in their extracts are of great interest since some elements are components of active constituents or they can affect the plant metabolism and consequently the formation of active constituents. In this work, inorganic components in medicinal drugs, Ginseng e Ginkgo Biloba provided from different laboratories, were analyzed by neutron activation analysis. Elements As, Br, Ca, Cl, Co Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, and Zn, were determined in these samples. Comparisons carried out between the results obtained for samples from different laboratories indicated distinct concentrations for several elements. These results may be attributed to the effect of soil composition and environmental conditions where these plants were cultivated. The precision and accuracy of the results were evaluated by analyzing reference materials Bowen's Kale from IUAPC and Cabbage from IAEA. (author)

  5. Determination of Depth in Transmission Raman Spectroscopy in Turbid Media Using a Beam Enhancing Element.

    Science.gov (United States)

    Vardaki, Martha Z; Sheridan, Hannah; Stone, Nicholas; Matousek, Pavel

    2017-08-01

    This study demonstrates experimentally a method to enable prediction of depth of a chemical species buried in a turbid medium by using transmission Raman spectroscopy alone. The method allows the prediction of the depth of a single, chemically distinct layer within a turbid matrix by performing two measurements, with and without a beam enhancing element, or "photon diode." The samples employed consisted of two different polymers, of total thickness 3.6 mm, whose optical properties are loosely relevant to pharmaceutical applications. A polymer layer of low-density polyethylene (LDPE) was placed at different positions within multiple layers of the polytetrafluoroethylene (PTFE) matrix and Raman spectra were recorded in each case. Both univariate and multivariate analyses were utilized to determine whether the depth of the LDPE layer could be predicted using the obtained data. The best-achieved RMSE of prediction was 4.2% of the total sample size (i.e., +/- 0.15 mm) with the multivariate approach.

  6. Determination of the centre of resistance during en masse retraction combined with corticotomy: finite element analysis.

    Science.gov (United States)

    Ouejiaraphant, Tanes; Samruajbenjakun, Bancha; Chaichanasiri, Ekachai

    2017-11-22

    To determine the effect of corticotomy on the change in the centre of resistance of the six maxillary anterior teeth Materials and methods: Three-dimensional finite element models of the maxillary anterior teeth with and without corticotomy were constructed. Brackets (size 0.022 inch × 0.028 inch) were placed passively on all anterior teeth that were set at the centre of the labial surface in the mesio-distal dimension and 3 mm from the incisal edge to the bracket slot in the vertical direction. The power arm was set mesial of the canine bracket. For the model with corticotomy, the bone density was decreased from initial value at 5% to 25%. The point of force application was varied in order to locate the centre of resistance. The centre of resistance was located by measurement of the difference of the displacement between the apical and incisal edges. The position of force was varied by moving apically parallel to the occlusal plane to simulate tooth movement. As the alveolar bone density decreased from initial value to 25%, the location of the centre of resistance moved apically from the bracket slot from 10.8 mm to 11.2 mm, respectively. The change of alveolar bone density due to corticotomy was associated with the location of the centre of resistance. The location of the centre of resistance moved apically as the alveolar bone density decreased but it was not clinically noticeable.

  7. Determination of Preliminary Orbital Elements of the Great Comet C/1665 in Korean History

    Directory of Open Access Journals (Sweden)

    Sang-Hyeon Ahn

    2006-03-01

    Full Text Available There are many astronomical records of comets in Korean history books. We collected those of the comet that appeared in the winter of the year 1664. These records were written in Daily Reports of the Royal Observatory on Astronomical Events, Final Reports of the Royal Observatory on An Astronomical Events , the Daily Records of the Royal Secretariat of the Joseon Dynasty, and the Chronicle of the Joseon Dynasty. We used the Olbers' method for determination of preliminary orbit of the comet, and compared the result with the previous researches. In the Oblers' method the orbit is assumed to be parabolic (e=1. We obtained the following orbital elements: perifocal distance q=1.07 +- 0.008 AU, perifocal passage time T=2329 165.50 +- 0.72 days, argument of the perifocus omega =318°2 +- 2°29, longitude of ascending node Omega =85°23 +- 2°53 (J1665, inclination i=160°28 +- 1°56.

  8. Determination of trace elements in three mushroom samples of basidiomycetes from Shandong, China.

    Science.gov (United States)

    Wang, Chao; Hou, Yunhua

    2011-09-01

    We have determined the trace element composition of three mushrooms of Basidiomycetes, used in traditional Chinese medicine using atomic absorption spectrophotometer (AAS). Metal concentrations in mushrooms were 203-401 mg/kg for iron, 22-51 mg/kg for manganese, 84-116 mg/kg for zinc, 24.1-41.3 mg/kg for copper, 1.6-5.6 mg/kg for lead, 3.3-4.4 mg/kg for chromium, 9.3-11.5 mg/kg for nickel, 0 mg/kg for vanadium, and 55.3-71 mg/kg for magnesium. The trace metal concentrations in mushrooms are hardly affected by the ecosystem and soil where they grew, as well as by the mushroom species and trace metal species. The results can be used to set new standards to control the quality of the three mushrooms of Basidiomycetes-Ganoderma lucidum, Coprinus comatus, and Grifola frondosa.

  9. CubeSAT X-ray Telescope (CubeX) for Elemental Abundance Mapping of Airless Bodies and X-ray Pulsar Navigation (XNAV)

    Science.gov (United States)

    Romaine, S.; Hong, J.; Elvis, M.

    2017-09-01

    The CubeSAT X-ray Telescope (CubeX) is a concept for a 12U planetary X-ray telescope, which utilizes Miniature Wolter-I X-ray optics (MiXO) and a combination of X-ray CMOS and SDD sensors for the focal plane. CubeX will map the surface elemental composition of diverse airless bodies using X-ray Fluorescence (XRF), which can help us to understand the formation and evolutionary history of the individual bodies and the workings of the Solar system as a whole. CubeX will also conduct a feasibility and performance test of X-ray pulsar timing based deep space navigation (XNAV), which can lower operation costs of space navigation and enable autonomous deep space navigation.

  10. r-process abundances near the mass 130 peak

    Energy Technology Data Exchange (ETDEWEB)

    De Laeter, J.R.; Rosman, K.J.R.

    1983-07-15

    A recent article by Kaeppeler et al. has reevaluated r-process abundances in the light of new neutron-capture cross section and elemental abundance data. The height of the r-process peak near mass 130 is largely determined by the r-only process nuclides /sup 128/Te and /sup 130/Te. Recent work by Smith, De Laeter and Rosman has not been given due consideration is assessing the solar system abundance of tellurium. These data indicate a 25% reduction in the height of the mass 130 peak, in agreement with predictions from s-process systematics.

  11. Thermal effects on rare earth element and strontium isotope chemistry in single conodont elements.

    NARCIS (Netherlands)

    Armstrong, H.A.; Pearson, D.G.; Griselin, M.

    2001-01-01

    A low-blank, high sensitivity isotope dilution, ICP-MS analytical technique has been used to obtain REE abundance data from single conodont elements weighing as little as 5 μg. Sr isotopes can also be measured from the column eluants enabling Sr isotope ratios and REE abundance to be determined from

  12. Precise determination of the absolute isotopic abundance ratio and the atomic weight of chlorine in three international reference materials by the positive thermal ionization mass spectrometer-Cs2Cl+-graphite method.

    Science.gov (United States)

    Wei, Hai-Zhen; Jiang, Shao-Yong; Xiao, Ying-Kai; Wang, Jun; Lu, Hai; Wu, Bin; Wu, He-Pin; Li, Qing; Luo, Chong-Guang

    2012-12-04

    Because the variation in chlorine isotopic abundances of naturally occurring chlorine bearing substances is significant, the IUPAC Inorganic Chemistry Division, Commission on Isotopic Abundances and Atomic Weights (CIAAW-IUPAC) decided that the uncertainty of atomic weight of chlorine (A(r)(Cl)) should be increased so that the implied range was related to terrestrial variability in 1999 (Coplen, T. B. Atomic weights of the elements 1999 (IUPAC Technical Report), Pure Appl. Chem.2001, 73(4), 667-683; and then, it emphasized that the standard atomic weights of ten elements including chlorine were not constants of nature but depend upon the physical, chemical, and nuclear history of the materials in 2009 (Wieser, M. E.; Coplen, T. B. Pure Appl. Chem.2011, 83(2), 359-396). According to the agreement by CIAAW that an atomic weight could be defined for one specified sample of terrestrial origin (Wieser, M. E.; Coplen, T. B. Pure Appl. Chem.2011, 83(2), 359-396), the absolute isotope ratios and atomic weight of chlorine in standard reference materials (NIST 975, NIST 975a, ISL 354) were accurately determined using the high-precision positive thermal ionization mass spectrometer (PTIMS)-Cs(2)Cl(+)-graphite method. After eliminating the weighing error caused from evaporation by designing a special weighing container and accurately determining the chlorine contents in two highly enriched Na(37)Cl and Na(35)Cl salts by the current constant coulometric titration, one series of gravimetric synthetic mixtures prepared from two highly enriched Na(37)Cl and Na(35)Cl salts was used to calibrate two thermal ionization mass spectrometers in two individual laboratories. The correction factors (i.e., K(37/35) = R(37/35meas)/R(37/35calc)) were obtained from five cycles of iterative calculations on the basis of calculated and determined R((37)Cl/(35)Cl) values in gravimetric synthetic mixtures. The absolute R((37)Cl/(35)Cl) ratios for NIST SRM 975, NIST 975a, and ISL 354 by the precise

  13. Abundances and distribution of minerals and elements in high-alumina coal fly ash from the Jungar Power Plant, Inner Mongolia, China

    Science.gov (United States)

    Dai, S.; Zhao, L.; Peng, S.; Chou, C.-L.; Wang, X.; Zhang, Y.; Li, D.; Sun, Y.

    2010-01-01

    The fly ash from the Jungar Power Plant, Inner Mongolia, China, is unique because it is highly enriched in alumina (Al2O3>50%). The fly ash mainly consists of amorphous glass and mullite and trace amounts of corundum, quartz, char, calcite, K-feldspar, clay minerals, and Fe-bearing minerals. The mullite content in fly ash is as high as 37.4% because of high boehmite and kaolinite contents in feed coal. Corundum is a characteristic mineral formed during the combustion of boehmite-rich coal.Samples from the economizer were sieved into six size fractions (500 mesh) and separated into magnetic, mullite+corundum+quartz (MCQ) and glass phases for mineralogical and chemical analysis. The corundum content increases but amorphous glass decreases with decreasing particle size. Fractions of small particle sizes are relatively high in mullite, probably because mullite was formed from fine clay mineral particles under high-temperature combustion condition. Similarly, fine corundum crystals formed in the boiler from boehmite in feed coal. The magnetic phase consists of hematite, magnetite, magnesioferrite, and MgFeAlO4 crystals. The MCQ phase is composed of 89% mullite, 6.1% corundum, 4.5% quartz, and 0.5% K-feldspar.Overall, the fly ash from the power plant is significantly enriched in Al2O3 with an average of 51.9%, but poor in SiO2, Fe2O3, CaO, MgO, Na2O, P2O5, and As. Arsenic, TiO2, Th, Al2O3, Bi, La, Ga, Ni, and V are high in mullite, and the magnetic matter is enriched in Fe2O3, CaO, MnO, TiO2, Cs, Co, As, Cd, Ba, Ni, Sb, MgO, Zn, and V. The remaining elements are high in the glass fraction. The concentration of K2O, Na2O, P2O5, Nb, Cr, Ta, U, W, Rb, and Ni do not clearly vary with particle size, while SiO2 and Hg decrease and the remaining elements clearly increase with decreasing particle size. ?? 2009 Elsevier B.V.

  14. [Use of radionuclide x-ray fluorescence analysis in pharmacy practice--determination of levels of elements in pharmaceutic aids].

    Science.gov (United States)

    Sýkorová, M; Havránek, E

    2003-07-01

    X-ray fluorescence analysis (XRF) has been employed for the identification and determination of elements with Z > 18. In pharmacy, it can be used to determine the content of elements in drugs and pharmaceutical auxiliary substances. The method makes it possible to distinguish heavy metals in the tests of purity of drugs. It can also be used to verify the origin of the raw material or drug on the basis of its elemental composition. The present paper is concerned with the preparation of samples of pharmaceutical auxiliary substances for the determination of the content of the elements Fe, Cu, Zn, and Pb by the XRF method with the use of a radionuclide source of 238Pu. For the determination of the content of elements, three kinds of standards were prepared aiming to remove the effect of absorption properties of the sample. The results with statistical evaluations of precision of measurement are tabulated. The study carried out an analysis of 7 samples of fillers, 3 samples of gelatine, 2 samples of SILOXID, and 1 sample of AEROSIL.

  15. Genetic Drift, Not Life History or RNAi, Determine Long-Term Evolution of Transposable Elements.

    Science.gov (United States)

    Szitenberg, Amir; Cha, Soyeon; Opperman, Charles H; Bird, David M; Blaxter, Mark L; Lunt, David H

    2016-10-05

    Transposable elements (TEs) are a major source of genome variation across the branches of life. Although TEs may play an adaptive role in their host's genome, they are more often deleterious, and purifying selection is an important factor controlling their genomic loads. In contrast, life history, mating system, GC content, and RNAi pathways have been suggested to account for the disparity of TE loads in different species. Previous studies of fungal, plant, and animal genomes have reported conflicting results regarding the direction in which these genomic features drive TE evolution. Many of these studies have had limited power, however, because they studied taxonomically narrow systems, comparing only a limited number of phylogenetically independent contrasts, and did not address long-term effects on TE evolution. Here, we test the long-term determinants of TE evolution by comparing 42 nematode genomes spanning over 500 million years of diversification. This analysis includes numerous transitions between life history states, and RNAi pathways, and evaluates if these forces are sufficiently persistent to affect the long-term evolution of TE loads in eukaryotic genomes. Although we demonstrate statistical power to detect selection, we find no evidence that variation in these factors influence genomic TE loads across extended periods of time. In contrast, the effects of genetic drift appear to persist and control TE variation among species. We suggest that variation in the tested factors are largely inconsequential to the large differences in TE content observed between genomes, and only by these large-scale comparisons can we distinguish long-term and persistent effects from transient or random changes. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  16. Interannual variation of rare earth element abundances in corals from northern coast of the South China Sea and its relation with sea-level change and human activities

    Science.gov (United States)

    Liu, Yajing; Peng, Z.; Wei, G.; Chen, T.; Sun, W.; He, J.; Liu, Gaisheng; Chou, C.-L.; Shen, C.-C.

    2011-01-01

    Here we present interannual rare earth element (REE) records spanning the last two decades of the 20th century in two living Porites corals, collected from Longwan Bay, close to the estuarine zones off Wanquan River of Hainan Island and Hong Kong off the Pearl River Delta of Guangdong Province in the northern South China Sea. The results show that both coral REE contents (0.5-40 ng g-1 in Longwan Bay and 2-250 ng g-1 in Hong Kong for La-Lu) are characterized with a declining trend, which are significantly negative correlated with regional sea-level rise (9.4 mm a-1 from 1981 to 1996 in Longwan Bay, 13.7 mm a-1 from 1991 to 2001 in Hong Kong). The REE features are proposed to be resulted from seawater intrusion into the estuaries in response to contemporary sea-level rise. However, the tendency for the coral Er/Nd time series at Hong Kong site is absent and there is no significant relation between Er/Nd and total REEs as found for the coral at Longwan Bay site. The observations are likely attributed to changes of the water discharge and sediment load of Pearl River, which have been significantly affected by intense human activities, such as the construction of dams/reservoirs and riverbed sediment mining, in past decades. The riverine sediment load/discharge ratio of the Pearl River decreased sharply with a rate of 0.02 kg m-3 a-1, which could make significant contribution to the declining trend of coral REE. We propose that coastal corals in Longwan Bay and similar unexplored sites with little influences of river discharge and anthropogenic disruption are ideal candidates to investigate the influence of sea-level change on seawater/coral REE. ?? 2010 Elsevier Ltd.

  17. A new XRF probe for in-situ determining concentration of multi-elements in ocean sediments

    CERN Document Server

    Ge Liang Quan; Zhou Si Chun; Lin Ling; Lin Yan Chang; Ren Jia Fu

    2001-01-01

    The author introduces a new X-ray fluorescence probe for in-situ determining the concentration of multi-elements in ocean sediments. The probe consists of Si-Pin X-ray detector with an electro-thermal colder, two isotope sources, essential electrical signal processing units and a notebook computer. More than 10 elements can be simultaneously determined at a detection limit of (10-200) x 10 sup - sup 6 and precision of 5%-30% without liquid Nitrogen supply. tests show that the probe can perform the analytical tasks under the water at the depth of less than 1000 meters

  18. Inductively coupled plasma-atomic emission spectroscopy: a computer controlled, scanning monochromator system for the rapid determination of the elements

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, M.A.

    1980-03-01

    A computer controlled, scanning monochromator system specifically designed for the rapid, sequential determination of the elements is described. The monochromator is combined with an inductively coupled plasma excitation source so that elements at major, minor, trace, and ultratrace levels may be determined, in sequence, without changing experimental parameters other than the spectral line observed. A number of distinctive features not found in previously described versions are incorporated into the system here described. Performance characteristics of the entire system and several analytical applications are discussed.

  19. OXYGEN ABUNDANCES IN CEPHEIDS

    Energy Technology Data Exchange (ETDEWEB)

    Luck, R. E.; Andrievsky, S. M. [Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States); Korotin, S. N.; Kovtyukh, V. V., E-mail: luck@fafnir.astr.cwru.edu, E-mail: serkor@skyline.od.ua, E-mail: val@deneb1.odessa.ua, E-mail: scan@deneb1.odessa.ua [Department of Astronomy and Astronomical Observatory, Odessa National University, Isaac Newton Institute of Chile, Odessa Branch, Shevchenko Park, 65014 Odessa (Ukraine)

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  20. Determination of 61 elements in urine samples collected from a non-occupationally exposed UK adult population.

    Science.gov (United States)

    Morton, Jackie; Tan, Emma; Leese, Elizabeth; Cocker, John

    2014-12-01

    levels for 61 elements were established in urine samples collected from 132 occupationally unexposed UK adults. In this study all elements were determined by inductively coupled plasma-mass spectrometry, but methods were 'tailored' to the elements; in total six analytical methods were undertaken. For the first time in a UK population 95th percentile values are reported for 19 elements for which there is no available comparison. Repeat urine samples were collected from some individuals and mixed effects modelling was carried out on the data to give an estimation of variation both between individuals and within the same individual. The mixed effects modelling was undertaken on 31 of the 61 elements for which there were more than two thirds of data above the LOQ and variations of between and within individuals are reported. The analysis found that creatinine adjustment of analyte concentrations was found to be beneficial for 22 of the 31 elements and that smokers were found to exhibit significantly higher cadmium but lower boron than non-smokers. For most elements, the data compare well with other published data but higher concentrations were observed in this study for urinary lead, chromium, vanadium and tungsten. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  1. Method for determining a spring constant for a deformable scanning probe microscope element, and scanning probe microscope and calibration device arranged for determining a spring constant for a probe element

    NARCIS (Netherlands)

    Sadeghian, H.; Yang, C.K.; Bossche, A.; French, P.J.; Goosen, J.F.L.; Van Keulen, A.

    2012-01-01

    A method for determining a spring constant k for a deformable probe element (102) of a scanning probe microscope SPM (100). The probe (102) has an outer surface area consisting of a tip area (112) on a first probe side (108) and a tip-less area (113). The probe (102) also has a probe electrode (114)

  2. Determination of the elemental constituents of a natural dolerite using NIRR-1.

    Science.gov (United States)

    Mokobia, C E; Ogundare, F O; Inyang, E P; Balogun, F A; Jonah, S A

    2008-12-01

    Elemental characterization of natural dolerite obtained from South Western Nigeria has been carried out using Nigeria Research Reactor-1 (NIRR-1) located at the Centre for Energy Research and Training (CERT), Ahmadu Bello University, Zaria. The measurements showed the presence of aluminum, calcium, magnesium, titanium and iron with concentrations 69,990+/-3499, 61,140+/-8.0, 38,330+/-3929, 13,880+/-1804 and 8319+/-150 ppm, respectively, as the major elements. In addition, 16 other elements, in minor and trace quantities, including Th, a radioactive rare earth element and five other rare earth elements La, Ce, Sm, Dy and Lu were identified. The presence of the rare earth elements may be a confirmation of the previous argument that the observed single but broad glow peak in the glow curve of this rock is rather an overlap of more than one glow peak. The presence of Th suggests the possibility of internal radioactivity in the rock, a necessary criterion for using a material for luminescence dating. Thus, this work indicates that dolerite can be used for luminescence dating if properly developed for the purpose.

  3. Stoichiometry, Absolute Abundance, and Localization of Proteins in the Bacillus cereus Spore Coat Insoluble Fraction Determined Using a QconCAT Approach.

    Science.gov (United States)

    Stelder, Sacha K; Benito de Moya, Celia; Hoefsloot, Huub C J; de Koning, Leo J; Brul, Stanley; de Koster, Chris G

    2018-01-04

    Spores of Bacillus cereus pose a threat to food safety due to their high resistance to the heat or acid treatments commonly used to make food microbiologically safe. Spores may survive these treatments and later resume growth either on foodstuffs or, after ingestion, upon entering the gut they are capable of producing toxins, which cause either vomiting or diarrhea. The outer layers of the spore, the spore coat and exosporium, consist primarily of proteins that may serve as potential biomarkers for detection. The major morphogenetic protein CotE is important for correct assembly and attachment of the outermost layer, the exosporium, and by extension retention of many proteins. However, characterization of the proteins affected by deletion of CotE has been limited to electrophoretic patterns. Here we report the effect of CotE deletion on the insoluble fraction of the spore proteome through liquid chromatography-Fourier transform tandem mass spectrometry (LC-FTMS/MS) analysis. A total of 560 proteins have been identified in both mutant and wild-type spore coat isolates. A further 163 proteins were identified exclusively in wild-type spore isolates indicating that they are dependent on CotE for their association with the spore. Several of these are newly confirmed as associated with the exosporium, namely BC_2569 (BclF), BC_3345, BC_2427, BC_2878, BC_0666, BC_2984, BC_3481, and BC_2570. A total of 153 proteins were only identified in ΔCotE spore isolates. This was observed for proteins that are known or likely to be interacting with or are encased by CotE. Crucial spore proteins were quantified using a QconCAT reference standard, the first time this was used in a biochemically heterogeneous system. This allowed us to determine the absolute abundance of 21 proteins, which spanned across three orders of magnitude and together covered 5.66% ± 0.51 of the total spore weight. Applying the QconCAT methodology to the ΔCotE mutant allowed us to quantify 4.13% ± 0.14 of

  4. Risk Factors for the Presence of Chikungunya and Dengue Vectors (Aedes aegypti and Aedes albopictus), Their Altitudinal Distribution and Climatic Determinants of Their Abundance in Central Nepal

    Science.gov (United States)

    Dhimal, Meghnath; Gautam, Ishan; Joshi, Hari Datt; O’Hara, Robert B.; Ahrens, Bodo; Kuch, Ulrich

    2015-01-01

    Background The presence of the recently introduced primary dengue virus vector mosquito Aedes aegypti in Nepal, in association with the likely indigenous secondary vector Aedes albopictus, raises public health concerns. Chikungunya fever cases have also been reported in Nepal, and the virus causing this disease is also transmitted by these mosquito species. Here we report the results of a study on the risk factors for the presence of chikungunya and dengue virus vectors, their elevational ceiling of distribution, and climatic determinants of their abundance in central Nepal. Methodology/Principal Findings We collected immature stages of mosquitoes during six monthly cross-sectional surveys covering six administrative districts along an altitudinal transect in central Nepal that extended from Birgunj (80 m above sea level [asl]) to Dhunche (highest altitude sampled: 2,100 m asl). The dengue vectors Ae. aegypti and Ae. albopictus were commonly found up to 1,350 m asl in Kathmandu valley and were present but rarely found from 1,750 to 2,100 m asl in Dhunche. The lymphatic filariasis vector Culex quinquefasciatus was commonly found throughout the study transect. Physiographic region, month of collection, collection station and container type were significant predictors of the occurrence and co-occurrence of Ae. aegypti and Ae. albopictus. The climatic variables rainfall, temperature, and relative humidity were significant predictors of chikungunya and dengue virus vectors abundance. Conclusions/Significance We conclude that chikungunya and dengue virus vectors have already established their populations up to the High Mountain region of Nepal and that this may be attributed to the environmental and climate change that has been observed over the decades in Nepal. The rapid expansion of the distribution of these important disease vectors in the High Mountain region, previously considered to be non-endemic for dengue and chikungunya fever, calls for urgent actions to

  5. 64-element scintillator hodoscope for the determination of the pion momentum of the. pi. M1 beam at SIN

    Energy Technology Data Exchange (ETDEWEB)

    Baran, R.; Fiedler, K.; Hofmann, A.; Olszewski, R.; Ortner, H.W.; Patzelt, C.

    1987-12-15

    A 64-element scintillator hodoscope with an active area of 280x38 mm/sup 3/ is described. It has been developed to determine the momentum of the pions in the ..pi..M1 channel at the Swiss Institute for Nuclear Research (SIN) with high resolution and high efficiency.

  6. A 64-element scintillator hodoscope for the determination of the pion momentum of the π M1 beam at sin

    Science.gov (United States)

    Baran, R.; Fiedler, K.; Hofmann, A.; Olszewski, R.; Ortner, H. W.; Patzelt, C.

    1987-12-01

    A 64-element scintillator hodoscope with an active area of 280 × 38 mm 2 is described. It has been developed to determine the momentum of the pions in the π M1 channel at the Swiss Institut for Nuclear Research (SIN) with high resolution with resolution and high efficiency.

  7. The microwave induced plasma with optical emission spectrometry (MIP-OES) in 23 elements determination in geological samples.

    Science.gov (United States)

    Niedzielski, P; Kozak, L; Wachelka, M; Jakubowski, K; Wybieralska, J

    2015-01-01

    The article presents the optimisation, validation and application of the microwave induced plasma optical emission spectrometry (MIP-OES) dedicated for a routine determination of Ag, Al, B, Ba, Bi, Ca, Cd, Cr, Cu, Fe, Ga, In, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sr, Tl, Zn, in the geological samples. The three procedures of sample preparation has been proposed: sample digestion with the use of hydrofluoric acid for determination of total concentration of elements, extraction by aqua regia for determination of the quasi-total element concentration and extraction by hydrochloric acid solution to determine contents of the elements in acid leachable fraction. The detection limits were on the level 0.001-0.121 mg L(-1) (from 0.010-0.10 to 1.2-12 mg kg(-1) depend on the samples preparation procedure); the precision: 0.20-1.37%; accuracy 85-115% (for recovery for certified standards materials analysis and parallel analysis by independent analytical techniques: X-ray fluorescence (XRF) and flame absorption spectrometry (FAAS)). The conformity of the results obtained by MIP-OES analytical procedures with the results obtained by XRF and FAAS analysis allows to propose the procedures for studies of elemental composition of the fraction of the geological samples. Additionally, the MIP-OES technique is much less expensive than ICP techniques and much less time-consuming than AAS techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Determination of radionuclides and elemental composition of clay soils by gamma- and X-ray spectrometry.

    Science.gov (United States)

    Omoniyi, Isinkaye M; Oludare, Shitta M B; Oluwaseyi, Oderinde M

    2013-12-01

    Radiochemical and elemental analysis of clay soils collected from different locations within Ekiti State have been performed in this study using gamma and XRF spectrometric measurements. The results of this study show that the mean concentrations of uranium ranged from 2.2 ± 1.0 mg/kg to 3.2 ± 1.1 mg/kg, that of thorium ranged from 4.0 ± 0.5 mg/kg to 5.7 ± 1.7 mg/kg, while potasium presented in % by weight ranged from 0.4 ± 0.2 to 1.3 ± 0.3 in all the locations. The overall mean concentrations of these radionuclides are comparable to values from other locations around the world. The XRF analysis revealed 4 major elements and 11 minor or trace elements present in the clay samples. The distribution of the various major and trace elements in all the sampling sites do not follow any systematic trend but vary from point to point. To assess the level of contamination and the possible anthropogenic impact in the clay soils, the enrichment factor (EF) and the geoaccumulation index (Igeo) were estimated for some potential hazardous elements. The results indicate that Cu, Zn, Ni and Mn have EF < 2 indicating minimal or no enrichment while Pb is moderately enriched in all the locations.

  9. Determination of elements by atomic absorption spectrometry in medicinal plants employed to alleviate common cold symptoms.

    Science.gov (United States)

    Küçükbay, F Zehra; Kuyumcu, Ebru

    2014-09-01

    Eleven important medicinal plants generally used by the people of Turkey for the treatment of common cold have been studied for their mineral contents. Eleven minor and major elements (essential, non-essential and toxic) were identified in the Asplenium adiantum-nigrum L. , Althaea officinalis L. , Verbascum phlomoides L., Euphorbia chamaesyce L., Zizyphus jujube Miller, Peganum harmala L., Arum dioscoridis Sm., Sambucus nigra L., Piperlongum L., Tussilago farfara L. and Elettaria cardamomum Maton by employing flame atomic absorption and emission spectrometry and electro-thermal atomic absorption spectrometry. Microwave digestion procedure for total concentration was applied under optimized conditions for dissolution of medicinal plants. Plant based biological certified reference materials (CRMs) served as standards for quantification. These elements are found to be present in varying concentrations in the studied plants. The baseline data presented in this work can be used in understanding the role of essential, non-essential and toxic elements in nutritive, preventive and therapeutic properties of medicinal plants.

  10. Simplified Qualitative Discrete Numerical Model to Determine Cracking Pattern in Brittle Materials by Means of Finite Element Method

    Directory of Open Access Journals (Sweden)

    J. Ochoa-Avendaño

    2017-01-01

    Full Text Available This paper presents the formulation, implementation, and validation of a simplified qualitative model to determine the crack path of solids considering static loads, infinitesimal strain, and plane stress condition. This model is based on finite element method with a special meshing technique, where nonlinear link elements are included between the faces of the linear triangular elements. The stiffness loss of some link elements represents the crack opening. Three experimental tests of bending beams are simulated, where the cracking pattern calculated with the proposed numerical model is similar to experimental result. The advantages of the proposed model compared to discrete crack approaches with interface elements can be the implementation simplicity, the numerical stability, and the very low computational cost. The simulation with greater values of the initial stiffness of the link elements does not affect the discontinuity path and the stability of the numerical solution. The exploded mesh procedure presented in this model avoids a complex nonlinear analysis and regenerative or adaptive meshes.

  11. Total reflection X-ray fluorescence as a convenient tool for determination of trace elements in microscale gasoline and diesel

    Science.gov (United States)

    Zhang, Airui; Jin, Axiang; Wang, Hai; Wang, Xiaokang; Zha, Pengfei; Wang, Meiling; Song, Xiaoping; Gao, Sitian

    2018-03-01

    Quantitative determination of trace elements like S, Fe, Cu, Mn and Pb in gasoline and S in diesel is of great importance due to the growing concerns over air pollution, human health and engine failure caused by utilization of gasoline and diesel with these harmful elements. A method of total reflection X-ray fluorescence (TXRF) was developed to measure these harmful trace elements in gasoline and diesel. A variety of factors to affect measurement results, including TXRF parameters, microwave-assisted digestion conditions and internal standard element and its addition, were examined to optimize these experimental procedures. The hydrophobic treatment of the surface of quartz reflectors to support the analyte with neutral silicone solutions could prepare thin films of gasoline and diesel digestion solutions for subsequent TXRF analysis. The proposed method shows good potential and reliability to determine the content of harmful trace elements in gasoline and diesel with high sensitivity and accuracy without drawing different standard calibration curves, and can be easily employed to screen gasoline and diesel in routine quality control and assurance.

  12. Back-extraction of trace elements from organometallic-halide extracts for determination by flameless atomic absorption spectrometry

    Science.gov (United States)

    Clark, J.R.; Viets, J.G.

    1981-01-01

    The Methyl isobutyl ketone-Amine synerGistic Iodkte Complex (MAGIC) extraction system offers the advantage that a large number of trace elements can be rapidly determined with a single sample preparation procedure. However, many of the elements extracted by the MAGIC system form volatile organometallic halide salts when the organic extract is heated in the graphite furnace. High concentrations of some elements such as Cu and Zn extracted by the system from anomalous geological samples produce serious interferences when certain other elements are determined by flameless atomic absorption. Stripping systems have been developed using solutions of HNO3, H2SO4, and CH3COOH individually or combined with H2O2 in order to circumvent these problems. With these systems most of the elements in the organic extract can be sequentially stripped into an aqueous phase. Organometallic volatilization and the most serious interelement interferences, therefore, can be eliminated by stripping with various combinations of reagents in a series of steps.

  13. Assessment and modifications of digestion procedures to determine trace elements in urine of hypertensive and diabetes mellitus patients

    Directory of Open Access Journals (Sweden)

    Awad Abdalla Momen

    2013-01-01

    Full Text Available Context: There is accumulating evidence that the metabolism of several trace elements like Cr, Cu, Pb, Cd, Co, Mn and Zn might have specific roles in the pathogenesis and progress of many diseases like hypertension (HTN and diabetes mellitus (DM. Objectives: To provide a fast, efficient, sensitive, and reliable analytical procedure for trace element determination in urine samples of HTN and DM patients using inductively coupled plasma optical emission spectrometry (ICP-OES. Setting and Design: The ICP-OES operating conditions were optimised and carefully selected in order to maximise the sensitivity, precision and accuracy. Factors affecting analytical and biological variability of the concentrations under study were discussed and carefully optimised. Materials and Methods: Different digestion procedures with acids and oxidising reagents were tested. The suitable procedure ICP-OES was selected, carefully modified and applied. The validity and accuracy of the different elements were determined by spiking of samples with known amounts of multi-element standard solution. Statistical Analysis: Student t-test and analysis of variance (ANOVA test were used for analysis. Microsoft Excel was used to assess the significance of the difference between variables. The concentrations obtained were expressed as mean value ± standard deviation (P = 0.05. Results: The results of this study showed that the mean concentrations of Cd, Zn, Pb, Cu, Cr and Mn in urine from both HTN (study group A and DM (study group B patients were higher than the corresponding values observed in the control group. However, while the mean value of Co was low as compared to the control group, the differences found were not significant (P = 0.05. Conclusion: The method used had excellent sensitivity, multi-element data could be obtained with very short acquisition time. The elements Cr, Cd, Pb and Zn might have specific roles in the pathogenesis and progress of HTN and DM. Further

  14. Determination of trace elements in airborne particulates by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yong Sam; Jung, Yung Joo; Jung, Eui Sik [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Cho, Seung Yun [Yonsei Univ., Seoul (Korea, Republic of)

    1995-04-01

    Trace elements in airborne particulates were analyzed by instrumental neutron activation analysis(INAA) under the optimum analytical condition. Neutron irradiation for sample was done at the irradiation hole(neutron flux, 1 x 10{sup 13} n/cm{sup 2} s) of TRIGA MARK-III research reactor in the Korea Atomic Energy Research Institute. For the verification of the analytical method, NIST SRM-1648 and NIES CRM No.8 were chosen and analyzed. The accuracy and precision of the analysis of 40 and 24 trace elements in the samples were compared with the certified and reported values, respectively. The analytical method was found to be reliable enough when the analytical data of NIES sample were compared with those of different countries. In the analytical result of two or both of standard reference materials, relative standard deviation was within the 15% except a few elements and the relative error was within the 10%. We used this method to analyze 30 trace elements in airborne particulates collected with the high volume air sampler(PM-10) at two different locations and also confirmed the possibility to use this method as a routine monitoring tool to find out environmental pollution sources. 3 figs., 8 tabs., 19 refs. (Author).

  15. Determination of selected toxic elements in leaves of White Hawthorn grown in a remote area

    Directory of Open Access Journals (Sweden)

    Zeiner M.

    2013-04-01

    Full Text Available One important plant of the Rosaceae family which is commonly used as phytopharmaceutical in Europe and North America is Hawthorn (Crataegus monogyna. The fruits, the leaves together with their extracts are applied in patients suffering mild cardiac disorders or nervosity. Since the leaves as well as the berries act as diuretics a sufficient micronutrient supply has to be guaranteed. On the other the quantities of toxic elements present in the plant parts should be at levels without harmful effects on human health. For this purpose Hawthorn leaves and flowers were collected in a remote area in 2011 and 2012 and analysed for their elemental composition. The metals uptaken from the soil were supposed to be in a similar range, thus the impact of airborne contamination by heavy metal translocation could be studied. The elements investigated were Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, and Zn. After harvesting the samples were dried, homogenized, digested and then analysed by ICP-AES. The contents of all elements are in the μg/g range. In the samples of 2012 higher concentrations were found for Co, Cu, Mn, Ni, and Zn, lower concentrations were registered for Ba, Pb, and Sr. The amounts of Cd and Cr were statistically insignificantly lower in 2012 than 2011.

  16. Stoichiometry of Zn(II)-heparin-glycine complex, determined using data from elemental and thermal analysis

    Science.gov (United States)

    Feofanova, M. A.; Skobin, M. I.; Kryukov, T. V.; Alekseev, V. G.; Ryasenskii, S. S.

    2017-10-01

    Ternary polymer Zn(II)-heparin-glycine complex with the composition {Na3[ZnHepGly]·H2O} n , where Hep4- is the monomer chain of a heparin polyanion and Gly- is the chain of a glycine anion, is isolated in a solid state from a water solution, and is characterized via elemental and thermal analysis.

  17. Direct Determination of Asymptotic Structural Postbuckling Behaviour by the finite element method

    DEFF Research Database (Denmark)

    Poulsen, Peter Noe; Damkilde, Lars

    1998-01-01

    Application of the finite element method to Koiter's asymptotic postbuckling theory often leads to numerical problems. Generally it is believed that these problems are due to locking of non-linear terms of different orders. A general method is given here that explains the reason for the numerical...... convergence of the postbuckling coefficients. (C) 1998 John Wiley & Sons, Ltd....

  18. Determination of the stability limit of a thermoacoustic engine by means of finite elements

    NARCIS (Netherlands)

    de Jong, Anne; Wijnant, Ysbrand H.; de Boer, Andries

    2013-01-01

    A finite element model is presented to obtain the stability limit of, as an example, 2D standing wave thermoacoustic engine. The stability limit is the required heating to obtain self-sustained (thermo)acoustic oscillations. The method used to obtain the stability limit is not restricted to the

  19. Accelerator SIMS, a technique for the determination of stable trace elements in ultrapure materials

    Energy Technology Data Exchange (ETDEWEB)

    Ender, R.M.; Suter, M. [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Doebeli, M.; Synal, H.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    A new sputtering chamber with special precautions against sample contamination from the surroundings of the sample has been added to the AMS beamline of the tandem accelerator. This allows the detection of trace element concentrations in ultrapure materials below the ppb range in many cases. (author) 1 fig., 2 refs.

  20. Determination of essential and toxic elements in products of milling wheat

    Directory of Open Access Journals (Sweden)

    Ludajić Gordana I.

    2016-01-01

    Full Text Available In the production bread wheat bran is used as a raw material rich in dietary fiber. Therefore, it is necessary to monitor the content of essential and toxic elements in the flour and bran. This paper investigates essential (Zn, Cu, Fe and Mn and toxic (Pb, Cd, Hg and As elements in products of milling wheat grown in the whole territory of Banat, the region in Serbia. Inductively Coupled Plasma Mass Spectrometry was used for analysis. The mean contents of the following elements Pb, Cd, Hg, As, Fe, Mn and Zn in wheat kernels were 0.143 mg/kg, 0.007 mg/kg, 0.017 mg/kg, 35.7643 mg/kg, 50.865 mg/kg, and 21.174 mg/kg, respectively. Cluster Analysis (CA and Principal component analysis (PCA was applied to discriminate and to group the different samples, according to element content. Quality results show that the first two principal components, accounting for 80.17% of the total variance, can be considered sufficient for data representation and the first two principal components of toxic elements and essential microelements. Cd (15.28%, Zn (17.91%, Cu (17.08, Fe (16.91% and Mn (17.54%, have been found the most influential for the first factor coordinate calculation, while the contribution of Pb (27.93% and Hg (61.86% has been the most important variable for the second factor coordinate calculation. [Projekat Ministarstva nauke Republike Srbije, TRI 46005

  1. A multibody modelling approach to determine load sharing between passive elements of the lumbar spine.

    Science.gov (United States)

    Abouhossein, Alireza; Weisse, Bernhard; Ferguson, Stephen J

    2011-06-01

    The human spinal segment is an inherently complex structure, a combination of flexible and semi-rigid articulating elements stabilised by seven principal ligaments. An understanding of how mechanical loading is shared among these passive elements of the segment is required to estimate tissue failure stresses. A 3D rigid body model of the complete lumbar spine has been developed to facilitate the prediction of load sharing across the passive elements. In contrast to previous multibody models, this model includes a non-linear, six degrees of freedom intervertebral disc, facet bony articulations and all spinal ligaments. Predictions of segmental kinematics and facet joint forces, in response to pure moment loading (flexion-extension), were compared to published in vitro data. On inclusion of detailed representation of the disc and facets, the multibody model fully captures the non-linear flexibility response of the spinal segment, i.e. coupled motions and a mobile instantaneous centre of rotation. Predicted facet joint forces corresponded well with reported values. For the loading case considered, the model predicted that the ligaments are the main stabilising elements within the physiological motion range; however, the disc resists a greater proportion of the applied load as the spine is fully flexed. In extension, the facets and capsular ligaments provide the principal resistance. Overall patterns of load distribution to the spinal ligaments are in agreement with previous predictions; however, the current model highlights the important role of the intraspinous ligament in flexion and the potentially high risk of failure. Several important refinements to the multibody modelling of the passive elements of the spine have been described, and such an enhanced passive model can be easily integrated into a full musculoskeletal model for the prediction of spinal loading for a variety of daily activities.

  2. Determination of trace elements in Ethiopian, Vietnamese, and Japanese women using high-resolution IC-PMS.

    Science.gov (United States)

    Tekeste, Zinaye; Amare, Bemnet; Asfaw, Fanaye; Fantahun, Bereket; van Nguyen, Nhien; Nishikawa, Takeshi; Yabutani, Tomoki; Okayasu, Takako; Ota, Fusao; Kassu, Afework

    2015-10-01

    Humans and other living organisms require small quantities of trace elements throughout life. Both insufficient and excessive intakes of trace elements can have negative consequences. However, there is little information on serum level of trace elements in different populations. This study examines serum levels of trace elements in Ethiopian, Japanese, and Vietnamese women. Random samples of healthy women who were referred for routine hospital laboratory examinations in the cities of Hanoi, Sapporo, and Gondar were invited to participate in the study. Serum levels of magnesium, zinc, copper, iron, selenium, and calcium were determined using an inductively coupled plasma mass spectrometer. Furthermore, body mass index of each study participant was determined. The mean ± SD serum concentrations of zinc (μg/dL), copper (μg/dL), iron (μg/dL), selenium (μg/dL) and calcium (mg/dL), respectively, were 76.51 ± 39.16, 152.20 ± 55.37, 385.68 ± 217.95, 9.15 ± 4.21, and 14.18 ± 3.91 in Ethiopian women; 111.49 ± 52.92, 105.86 ± 26.02, 155.09 ± 94.83, 14.11 ± 3.41, and 11.66 ± 2.51 in Vietnamese women; and 60.69 ± 9.76, 107 ± 156, 268 ± 128, 8.33 ± 3.65, and 11.18 ± 0.68 in Japanese participants. Ethiopian women had significantly higher level of serum calcium than Vietnamese and Japanese women (both P difference was not statistically significant (P > 0.05). Furthermore, compared with Japanese women, Ethiopian women had significantly high iron and copper concentrations (P difference in serum concentrations of trace elements in women from different countries, implying differences in trace elements in the food or soil. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Multielemental determination of trace elements in radiopharmaceuticals produced at the radiopharmacy center using ICP-OES technique

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Angelica T.; Martins, Patricia de A.; Fukumori, Neuza T.O.; Mengatti, Jair; Matsuda, Margareth M.N., E-mail: angelicatamiao@gmail.com, E-mail: patyosborne@yahoo.com, E-mail: ntfukuma@ipen.br, E-mail: mengatti@ipen.br, E-mail: mmatsuda@ipen.br [Institito de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The control of chemical impurities in radiopharmaceuticals is critical to their safety and efficacy. According to the U.S. Pharmacopeia (USP), the elemental impurities with potential toxicity must be quantified. A proposed revision of USP 35 introduces the technique of atomic emission spectrometry for the analysis of elements. The aim of this work was to study the concentration of chemicals elements in FDG-Fluor-18, IPEN-TEC Generator and MIBI-TEC using an ICP-OES technique. One analytical curve composed by 27 elements (Ag, A1, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Pd, Se, Sr, Te, T1, Zn) was constructed in two analytical ranges. The analyses were carried out simultaneously in an ICP-OES Vista MPX (Agilent). Some parameters for analysis and method validation were evaluated. The cleaning and maintenance of equipment influenced the emission intensity of the elements. 1.2 power and 10s sample uptake resulted in a consumption of 1.6 mL of sample and Mg II/Mg I ratio relation equal to 9.40. Linearity, LOD and LOQ were determined. The analysis were performed using 1:40 dilution with purified water. The main elements studied in this work were A1, Cu and Zn. The % recovery was determined with final concentrations of 0.3, 0.5 and 0.8 μg mL{sup -1}. The analyses were performed in triplicate with three different batches. The % recovery was between 96.65 and 117.61% and the values for precision (CV) were less than 5% indicating good accuracy of the method. (author)

  4. Determination of trace elements in freshwater rotifers and ciliates by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Woelfl, S.; Óvári, M.; Nimptsch, J.; Neu, T. R.; Mages, M.

    2016-02-01

    Element determination in plankton is important for the assessment of metal contamination of aquatic environments. Until recently, it has been difficult to determine elemental content in rotifers or ciliates derived from natural plankton samples because of the difficulty in handling and separation of these fragile organisms. The aim of this study was to evaluate methods for separation of rotifers and large ciliates from natural plankton samples (μg range dry weight) and subsequent analysis of their elemental content using total-reflection X-ray fluorescence spectrometry (TXRF). Plankton samples were collected from different aquatic environments (three lakes, one river) in Chile, Argentina and Hungary. From one to eighty specimens of five rotifer species (Brachionus calyciflorus, Brachionus falcatus, Asplanchna sieboldii, Asplanchna sp., Philodina sp.) and four to twelve specimens of one large ciliate (Stentor amethystinus) were prepared according to the dry method originally developed for microcrustaceans, and analysed by TRXF following in situ microdigestion. Our results demonstrated that it possible to process these small and fragile organisms (individual dry mass: 0.17-9.39 μg ind- 1) via careful washing and preparation procedures. We found species-dependent differences of the element mass fractions for some of the elements studied (Cr, Mn, Fe, Ni, Cu, Zn, As, Pb), especially for Cu, Fe and Mn. One large rotifer species (A. sieboldii) also showed a negative correlation between individual dry weight and the element content for Pb, Ni and Cr. We conclude that our application of the in situ microdigestion-TRXF method is suitable even for rotifers and ciliates, greatly expanding the possibilities for use of plankton in biomonitoring of metal contamination in aquatic environments.

  5. Quasar Elemental Abundances at High Redshifts

    DEFF Research Database (Denmark)

    Dietrich, M.; Hamann, F.; Shields, J. C.

    2003-01-01

    We examine rest-frame ultraviolet spectra of 70 high redshift quasars (z>3.5) to study the chemical enrichment history of the gas closely related to the quasars, and thereby estimate the epoch of first star formation. The fluxes of several ultraviolet emission lines were investigated within...... scale of t_evol = 0.5 - 0.8 Gyrs for the chemical enrichment of the gas, the first major star formation for quasars with z>=4 should have started at a redshift of z_f = 6 - 8, corresponding to an age of the universe of several 10^8 yrs (H_o = 65 km/s/Mpc, Omega_M = 0.3, Omega_Lambda = 0.7). We note...

  6. Official Methods for the Determination of Minerals and Trace Elements in Infant Formula and Milk Products: A Review.

    Science.gov (United States)

    Poitevin, Eric

    2016-01-01

    The minerals and trace elements that account for about 4% of total human body mass serve as materials and regulators in numerous biological activities in body structure building. Infant formula and milk products are important sources of endogenic and added minerals and trace elements and hence, must comply with regulatory as well as nutritional and safety requirements. In addition, reliable analytical data are necessary to support product content and innovation, health claims, or declaration and specific safety issues. Adequate analytical platforms and methods must be implemented to demonstrate both the compliance and safety assessment of all declared and regulated minerals and trace elements, especially trace-element contaminant surveillance. The first part of this paper presents general information on the mineral composition of infant formula and milk products and their regulatory status. In the second part, a survey describes the main techniques and related current official methods determining minerals and trace elements in infant formula and milk products applied for by various international organizations (AOAC INTERNATIONAL, the International Organization for Standardization, the International Dairy Federation, and the European Committe for Standardization). The third part summarizes method officialization activities by Stakeholder Panels on Infant Formula and Adult Nutritionals and Stakeholder Panel on Strategic Food Analytical Methods. The final part covers a general discussion focusing on analytical gaps and future trends in inorganic analysis that have been applied for in infant formula and milk-based products.

  7. DETERMINATION of the TRACE ELEMENT LEVELS in HAIR of SMOKERS and NON-SMOKERS by ICP-MS

    Directory of Open Access Journals (Sweden)

    Elif Varhan Oral

    2016-09-01

    Full Text Available For at least 50 years, determination of the trace element levels in human hair has been used to assess environmental and vocational exposure to toxic elements . As compared to other biological matrices (e.g. blood, urine, human hair is stable and therefore useful as a matrice. In this study, analyses of toxic and essential trace elements, such as Cd, Pb, Cu and Fe, were done in hair samples which we collected from male smokers (10 people and non-smokers (10 people who live in Diyarbakır, Turkey and concentrations in hair samples were compared. Hair samples were washed by a standard procedure proposed by the International Atomic Energy Agency. Then the samples were dried for 16 h at 110°C in an oven. Solubilization procedure was carried out by nitric acid hydrogen peroxide mixture (3:1 in closed vessels in a microwave oven. Trace element analyses were carried out by using inductively coupled plasma-mass spectrometry (ICP-MS  technique. In our study, while concentrations of Cd, Pb, and Fe elements were found to be considerably higher in smokers than non-smokers, similar results were observed in Cu concentrations. The precision and accuracy of the method was evaluated by applying spike method to samples. Analytical recovery results were found between 91.2% and 104.6%.

  8. Inductively coupled plasma atomic emission spectrometric determination of 27 trace elements in table salts after coprecipitation with indium phosphate.

    Science.gov (United States)

    Kagaya, Shigehiro; Mizuno, Toshiyuki; Tohda, Koji

    2009-07-15

    The coprecipitation method using indium phosphate as a new coprecipitant has been developed for the separation of trace elements in table salts prior to their determination using inductively coupled plasma atomic emission spectrometry (ICP-AES). Indium phosphate could quantitatively coprecipitate 27 trace elements, namely, Be, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, in a table salt solution at pH 10. The rapid coprecipitation technique, in which complete recovery of the precipitate was not required in the precipitate-separation process, was completely applicable, and, therefore, the operation for the coprecipitation was quite simple. The coprecipitated elements could be determined accurately and precisely by ICP-AES using indium as an internal standard element after dissolution of the precipitate with 5 mL of 1 mol L(-1) nitric acid. The detection limits (three times the standard deviation of the blank values, n=10) ranged from 0.001 microg (Lu) to 0.11 microg (Zn) in 300 mL of a 10% (w/v) table salt solution. The method proposed here could be applied to the analyses of commercially available table salts.

  9. Exploring the uncertainty in attributing sediment contributions in fingerprinting studies due to uncertainty in determining element concentrations in source areas.

    Science.gov (United States)

    Gomez, Jose Alfonso; Owens, Phillip N.; Koiter, Alex J.; Lobb, David

    2016-04-01

    One of the major sources of uncertainty in attributing sediment sources in fingerprinting studies is the uncertainty in determining the concentrations of the elements used in the mixing model due to the variability of the concentrations of these elements in the source materials (e.g., Kraushaar et al., 2015). The uncertainty in determining the "true" concentration of a given element in each one of the source areas depends on several factors, among them the spatial variability of that element, the sampling procedure and sampling density. Researchers have limited control over these factors, and usually sampling density tends to be sparse, limited by time and the resources available. Monte Carlo analysis has been used regularly in fingerprinting studies to explore the probable solutions within the measured variability of the elements in the source areas, providing an appraisal of the probability of the different solutions (e.g., Collins et al., 2012). This problem can be considered analogous to the propagation of uncertainty in hydrologic models due to uncertainty in the determination of the values of the model parameters, and there are many examples of Monte Carlo analysis of this uncertainty (e.g., Freeze, 1980; Gómez et al., 2001). Some of these model analyses rely on the simulation of "virtual" situations that were calibrated from parameter values found in the literature, with the purpose of providing insight about the response of the model to different configurations of input parameters. This approach - evaluating the answer for a "virtual" problem whose solution could be known in advance - might be useful in evaluating the propagation of uncertainty in mixing models in sediment fingerprinting studies. In this communication, we present the preliminary results of an on-going study evaluating the effect of variability of element concentrations in source materials, sampling density, and the number of elements included in the mixing models. For this study a virtual

  10. [Determination of six heavy metal elements in Zanthoxylum nitidum in twelve habitats of guangxi by ICP-AES].

    Science.gov (United States)

    Wang, Dong-Mei; Feng, Jie; Qin, Fu-Jing; Mo, Yi-Sheng

    2012-03-01

    To determine the contents of six heavy metal elements in traditional Chinese medicine of Zanthoxylum nitidum in twelve habitats by ICP-AES. Nitric acid- perchloric acid mixed acid digested system was used to completely decomposed the organic compounds effectually. The As, Cr, Hg, Ni, Cd and Pb were determined by the absorption spectroscopy under set up working conditions. An efficient, simple and accurate method was established. The recoveries were 90.82%-101.21% and RSDs were within 3.0%. The contents of six heavy metal elements are different in Zanthoxylum nitidum from different habitats. As, Cr and Hg were not detected. The content of Pb which from eleven habitats is consistent with the standards of medicine and export except from Nanning habitats, meanwhile the content of Cd all exceeds those standards.

  11. [Comparative study on five pretreatment methods for ICP-OES determination of mineral elements in Rosa rugosa].

    Science.gov (United States)

    Zhao, Ning; Yang, Bin; Duan, Yu-Cen; Lei, Ran

    2011-08-01

    Abstract Five different pretreatment methods, including dry ashing and microwave digestion with four acid systems (HNO3 + H2O2, HNO3 + H2O2 + HF, HNO3 + HClO4 and HNO3 + HClO4 + HF), were employed for digestion of the samples of Rosa rugosa. Nine major and trace elements were determined using ICP-OES method. The addition standard recovery rates indicate that, with the system of HNO3 + HClO4, better results can be obtained for most of the determined elements. With this method, except for Fe, the recovery rates are in the range of 95.4%-104.6%. For Fe, higher recovery rate (99%) was obtained with HNO3 + H2O2 + HF system.

  12. Determination of several trace elements in silicate rocks by an XRF method with background and matrix corrections

    Energy Technology Data Exchange (ETDEWEB)

    Pascual, J.

    1987-12-01

    An X-ray fluorescence method for determining trace elements in silicate rock samples was studied. The procedure focused on the application of the pertinent matrix corrections. Either the Compton peak or the reciprocal of the mass absorption coefficient of the sample was used as internal standard for this purpose. X-ray tubes with W or Cr anodes were employed, and the W L..beta.. and Cr K..cap alpha.. Compton intensities scattered by the sample were measured. The mass absorption coefficients at both sides of the absorption edge for Fe (1.658 and 1.936 A) were calculated. The elements Zr, Y, Rb, Zn, Ni, Cr and V were determined in 15 international reference rocks covering wide ranges of concentration. Relative mean errors were in many cases less than 10%.

  13. Using Major Elements to Determine Sources of Nitrate in Groundwater, Suffolk County, Long Island, NY

    Science.gov (United States)

    Munster, J.; Hanson, G.; Bokuniewicz, H.

    2004-05-01

    Suffolk County is the eastern most county on Long Island with an area of 2,500 square kilometers and a population of 1.4 million. Groundwater is the only source of potable water for Suffolk County. Nitrate levels have become a concern as a result of the continued eastward urbanization of Long Island since the mid 1900's. In 2003, 2% of 1000 public supply wells had greater than 10 ppm nitrogen as nitrate, 8% had 6 to 10 ppm nitrogen as nitrate and 62% of the wells were rated as susceptible to increased nitrate contamination based on land use, travel time and prevalence. Nitrogen as nitrate above 10 ppm is harmful to infants and is currently the drinking water standard of the Environmental Protection Agency. The major sources of the nitrate in the urbanized areas are most likely turf grass fertilizer and sewage from septic tank/cesspool systems and sewage treatment plants that provide only secondary treatment. Turf grass occupies about 28% of the land. Two-thirds of the houses have septic tank/cesspool systems and a majority of the sewage treatment plants discharge effluent to the groundwater. Previous investigators of the sources of nitrate in groundwater on Long Island have used 15N values of nitrate-nitrogen to identify nitrate contamination (Bleifuss et al., 2000; Flipse and Bonner, 1985; Flipse et al., 1984; Kreitler et al., 1978). However, due to overlapping source signatures, nitrogen isotopes alone were not sufficient to characterize the sources of nitrate. More recent studies have shown that major elements that accompany nitrate in the groundwater (Bleifuss et al., 2000; Elhatip et al., 2003; Trauth and Xanthopoulos, 1997) may distinguish sources of nitrate with less ambiguity. In this study samples of waste water from septic tank/cesspool systems and sewage treatment plants and samples of soil water collected below turf grass that is not fertilized, fertilized with organic fertilizer and fertilized with chemical fertilizer were analyzed for major elements

  14. Stellar abundances in the solar neighborhood: The Hypatia Catalog

    Energy Technology Data Exchange (ETDEWEB)

    Hinkel, Natalie R.; Timmes, F.X.; Young, Patrick A.; Pagano, Michael D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Turnbull, Margaret C. [Global Science Institute, P.O. Box 252, Antigo, WI 54409 (United States)

    2014-09-01

    We compile spectroscopic abundance data from 84 literature sources for 50 elements across 3058 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. We evaluate the variability of the spread in abundance measurements reported for the same star by different surveys. We also explore the likely association of the star within the Galactic disk, the corresponding observation and abundance determination methods for all catalogs in Hypatia, the influence of specific catalogs on the overall abundance trends, and the effect of normalizing all abundances to the same solar scale. The resulting stellar abundance determinations in the Hypatia Catalog are analyzed only for thin-disk stars with observations that are consistent between literature sources. As a result of our large data set, we find that the stars in the solar neighborhood may reveal an asymmetric abundance distribution, such that a [Fe/H]-rich group near the midplane is deficient in Mg, Si, S, Ca, Sc II, Cr II, and Ni as compared to stars farther from the plane. The Hypatia Catalog has a wide number of applications, including exoplanet hosts, thick- and thin-disk stars, and stars with different kinematic properties.

  15. Ecological and biological determinants of trace elements accumulation in liver and kidney of Pontoporia blainvillei

    Energy Technology Data Exchange (ETDEWEB)

    Seixas, Tercia G. [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil); Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21941-902 Rio de Janeiro, RJ (Brazil)], E-mail: tercia@rdc.puc-rio.br; Kehrig, Helena do A. [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21941-902 Rio de Janeiro, RJ (Brazil); Fillmann, Gilberto [Departamento de Oceanografia, FURG, 96201-900 Rio Grande, RS (Brazil); Di Beneditto, Ana Paula M.; Souza, Cristina M.M. [Laboratorio de Ciencias Ambientais, CBB-UENF, 28013-602 Campos dos Goytacazes, RJ (Brazil); Secchi, Eduardo R. [Departamento de Oceanografia, FURG, 96201-900 Rio Grande, RS (Brazil); Laboratorio de Tartarugas e Mamiferos Marinhos, Departamento de Oceonagrafia e Museu Oceanografico ' Prof. E.C. Rios' , FURG, 96201-900, Rio Grande, RS (Brazil); Moreira, Isabel [Departamento de Quimica, PUC-Rio, 22453-900 Rio de Janeiro, RJ (Brazil); Malm, Olaf [Laboratorio de Radioisotopos Eduardo Penna Franca, IBCCF-UFRJ, 21941-902 Rio de Janeiro, RJ (Brazil)

    2007-10-15

    The present work tested whether ecological and biological variables have an influence on the assimilation of trace elements by the tissues of a cetacean from the Western South Atlantic Ocean. No significant differences were observed in the concentrations for both sexes. As individuals from the two sampling areas belong to distinct genetic and morphological populations, animals of similar body length were older on the southeastern than on the southern coast. The liver showed the highest concentrations of mercury, whereas the highest levels of cadmium were found in the kidney. Hepatic mercury, cadmium and selenium in individuals from the south coast were about four times as high as those from the southeast coast. However, arsenic in the liver and kidney were similar in both coastal areas. Hepatic mercury, cadmium and selenium concentrations increased with body length in individuals from the southeastern coast, although no significant correlations (P > 0.05) were observed between body length from either area and the renal and hepatic As concentrations. A significant positive linear relationship was observed between molar concentrations of Hg and Se in the liver of all individuals from both areas (r{sup 2} = 0.93; P < 0.001), presenting Se:Hg ratios close to 4. Differences found among the concentrations of Hg, Cd and Se in dolphins from both areas were probably due to the preferred prey, bioavailability of elements in each marine environment, and environment variables (water temperature, net primary production). As a consequence, concentrations of trace elements in the tissues of this species can be considered to be a result of the surrounding environment.

  16. Determination and correlation of spatial distribution of trace elements in normal and neoplastic breast tissues evaluated by {mu}-XRF

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.P.; Oliveira, M.A.; Poletti, M.E. [Universidade de Sao Paulo (USP),Ribeirao Preto, SP (Brazil)

    2012-07-01

    Full text: Some trace elements, naturally present in breast tissues, participate in a large number of biological processes, which include among others, activation or inhibition of enzymatic reactions and changes on cell membranes permeability, suggesting that these elements may influence carcinogenic processes. Thus, knowledge of the amounts of these elements and their spatial distribution in normal and neoplastic tissues may help in understanding the role of these elements in the carcinogenic process and tumor progression of breast cancers. Concentrations of trace elements like Ca, Fe, Cu and Zn, previously studied at LNLS using TXRF and conventional XRF, were elevated in neoplastic breast tissues compared to normal tissues. In this study we determined the spatial distribution of these elements in normal and neoplastic breast tissues using {mu}-XRF technique. We analyzed 22 samples of normal and neoplastic breast tissues (malignant and benign) obtained from paraffin blocks available for study at the Department of Pathology HC-FMRP/USP. From the blocks, a small fraction of material was removed and subjected to histological sections of 60 {mu}m thick made with a microtome. The slices where placed in holder samples and covered with ultralen film. Tissue samples were irradiated with a white beam of synchrotron radiation. The samples were positioned at 45 degrees with respect to the incident beam on a table with 3 freedom degrees (x, y and z), allowing independent positioning of the sample in these directions. The white beam was collimated by a 20 {mu}m microcapillary and samples were fully scanned. At each step, a spectrum was detected for 10 s. The fluorescence emitted by elements present in the sample was detected by a Si (Li) detector with 165 eV at 5.9 keV energy resolution, placed at 90 deg with respect to the incident beam. Results reveal that trace elements Ca-Zn and Fe-Cu could to be correlated in malignant breast tissues. Quantitative results, achieved by

  17. A Fast Radiochemical Method for the Determination of Some Essential Trace Elements in Biology and Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Samsahl, K.

    1966-02-15

    An anion-exchange method based on fast selective sorption steps from mixtures of sulfuric, hydrobromic, and hydrochloric acid solutions has been developed for the separation of five different groups of radioactive trace elements in neutron-irradiated biological material. The separations are performed automatically with a simple proportioning pump apparatus. The apparatus allows the exact adjustment of influent solutions to the series of ion-exchange columns. The practical application of the method is described in detail. The successful use of the method is practically independent on the level of Na activity present in the sample.

  18. Determination of Rare Earth Elements in Geological Samples Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Bhatt, Chet R; Jain, Jinesh C; Goueguel, Christian L; McIntyre, Dustin L; Singh, Jagdish P

    2018-01-01

    Laser-induced breakdown spectroscopy (LIBS) was used to detect rare earth elements (REEs) in natural geological samples. Low and high intensity emission lines of Ce, La, Nd, Y, Pr, Sm, Eu, Gd, and Dy were identified in the spectra recorded from the samples to claim the presence of these REEs. Multivariate analysis was executed by developing partial least squares regression (PLS-R) models for the quantification of Ce, La, and Nd. Analysis of unknown samples indicated that the prediction results of these samples were found comparable to those obtained by inductively coupled plasma mass spectrometry analysis. Data support that LIBS has potential to quantify REEs in geological minerals/ores.

  19. What Level Design Elements Determine Flow? : How Light and Objects Guide the Player in Overwatch and Doom

    OpenAIRE

    Eliasson, David

    2017-01-01

    This thesis presents a comparative study between Overwatch (2016) and Doom (2016) to determine how these fast-paced games facilitate flow in their gameplay. The second chapter looks at formal definitions of flow and level design to establish a vocabulary for following chapters. Through formal analysis the level designs of both games are then examined to establish what elements in them guide players and keep the flow in gameplay. The thesis also examines how the initial gameplay design princip...

  20. Reduction of acid effects on trace element determination in food samples by CH4 mixed plasma-DRC-MS.

    Science.gov (United States)

    Guo, Wei; Hu, Shenghong; Zhang, Jiangyi; Hu, Zhaochu; Zhang, Hongfei; Wang, Yanxin

    2012-03-15

    A robust method for trace element determination in food samples by addition of methane to the plasma of a dynamic reaction cell mass spectrometer (CH(4) mixed plasma-DRC-MS) was developed. Addition of 3 mL min(-1) methane to Ar-plasma eliminates the signal suppressions of various elements (As, Se, Hg, etc.) due to the high concentration of nitric acid (10%, v/v). The CH(4)-Ar mixed plasma may compensate for the plasma cooling effects due to the highly concentrated nitric acid. The interfering polyatomic ions (40)Ar(12)C(+), (40)Ar(35)Cl(+) and (40)Ar(40)Ar(+) on (52)Cr(+), (75)As(+) and (80)Se(+) determination were removed effectively using the DRC with CH(4) as the reaction gas. The limits of quantification (LOQ, 10σ) were 0.35 ng g(-1), 0.07 ng g(-1), 0.35 ng g(-1), 0.07 ng g(-1), 0.15 ng g(-1), and 0.07 ng g(-1) for As, Cd, Cr, Hg, Pb and Se, respectively. The proposed method was applied to the determination of these trace elements in four food standard reference materials (NIST1577b, GBW10018, NIST1570a and GBW10016), and the results were in good agreement with the certified values. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Magellanic Cloud Cepheids - Abundances

    Science.gov (United States)

    Luck, R. Earle; Moffett, Thomas J.; Barnes, Thomas G., III; Gieren, Wolfgang P.

    1998-02-01

    We have determined parameters and abundances for three SMC and nine LMC Cepheids that have not been previously studied spectroscopically for metallicity, as well as three SMC and one LMC Cepheids observed previously by Luck and Lambert. This work nearly doubles the number of Cepheids with spectroscopic metallicities in the SMC and triples the number in the LMC. For Galactic reference stars we have determined the abundances of 11 supergiants of spectral type F0 to K1. These abundances are used herein to examine the dispersion in cosmic (Fe/H) values found in LMC Cepheids by Luck and Lambert. The Magellanic Cloud Cepheids tend to be longer-period Cepheids, and thus have physical gravities that are 1.0 dex and lower. Spectroscopic gravities are even lower. Fortunately, the (Fe/H) content as determined from Fe I is not strongly dependent on gravity and is thus well determined. We combine our abundances with other published high-resolution spectroscopic results, deriving a mean (Fe/H) for the SMC of -0.68. The total range seen in the (Fe/H) ratios derived herein is -0.84 to -0.65. This result is in agreement with previous studies showing a small intrinsic range in the metallicities in the SMC. For the LMC, from the Cepheids studied here we obtain -0.30, with a range of -0.55 to -0.19. Combining all available data, we obtain a mean (Fe/H) of -0.34. From this analysis, there is little evidence for a significant metallicity dispersion in the LMC.

  2. Using Elemental Budgets to Determine Effects of Simulated Climate Change on Phosphorus Cycling in a Grassland Ecosystem

    Science.gov (United States)

    Yoo, S.; Paytan, A.; Mellett, T.

    2013-12-01

    The purpose of the Jasper Ridge Global Change Experiment is to find out the effects of climate change on a terrestrial grassland ecosystem. The different treatments include increased carbon dioxide, nitrogen deposition, temperature, and precipitation. A portion of the above ground biomass of each plot was harvested, and an abundant species chosen to analyze. The goal of this project was to investigate the effects of climate change on phosphorus cycling in the grassland vegetation. Total phosphorus content of each sample was determined by combustion and acid digestion along with optical emission spectrometry. Total nitrogen and carbon was determined via flash combustion in an isotope ratio mass spectrometer. This information was combined to evaluate the limitation of phosphorus in each treatment and better understand how climate change may affect phosphorus cycling in terrestrial grasslands.

  3. In Situ Determination of Siderophile Trace Elements in Metals and Sulfides in Enstatite Achondrites

    Science.gov (United States)

    vanAcken, D.; Humayun, M.; Brandon, A. D.; Peslier, A.

    2010-01-01

    Enstatite meteorites are identified by their extremely reduced mineralogy (1) and similar oxygen isotope composition (2). The enstatite meteorite clan incorporates both EH and EL chondrites, as well as a wide variety of enstatite achondrites, such as aubrites or anomalous enstatite meteorites (e.g. Mt. Egerton, Shallowater, Zaklodzie, NWA 2526). The role of nebular versus planetary processes in the formation of enstatite meteorites is still under debate (e.g. 3-5). Past studies showed a significant influence of metal segregation in the formation of enstatite achondrites. Casanova et al. (6) suggested incomplete metal-silicate segregation during core formation and attributed the unfractionated siderophile element patterns in aubrites metals to a lack of fractional crystallization in a planetary core. Recent studies suggest a significant role of impact melting in the formation of primitive enstatite chondrites (7) and identified NWA 2526 as a partial melt residue of an enstatite chondrite (8). To understand the nature of siderophile element-bearing phases in enstatite achondrites, establish links between enstatite achondrites and enstatite chondrites (9), and constrain planetary differentiation on their respective parent bodies and their petrogenetic histories, we present laser ablation ICP-MS measurements of metal and sulfide phases in Shallowater, Mt. Egerton, and the aubrites Aubres, Cumberland Falls, and Mayo Belwa.

  4. Isotopic Compositions of the Elements 1997

    Science.gov (United States)

    Rosman, K. J. R.; Taylor, P. D. P.

    1998-11-01

    The Commission's Subcommittee for the Isotopic Composition of the Elements has carried out its biennial review of isotopic compositions, as determined by mass spectrometry and other relevant methods. This involves a critical evaluation of the published literature, element by element, and forms the basis of the Table of Isotopic Compositions of the Elements as Determined by Mass Spectrometry presented here. New guidelines have been used to arrive at the uncertainties on the isotopic abundances and there are numerous changes to the table since it was last published in 1991. Atomic Weights calculated from this table are consistent with Ar(E) values listed in the Table of Standard Atomic Weights 1997.

  5. Experimental Determination of Major Element Diffusivity in Natural High-K Calc-alkaline Melts

    Science.gov (United States)

    González-García, D.; Behrens, H.; Vetere, F. P.; Petrelli, M.; Zezza, A.; Morgavi, D.; Perugini, D.

    2016-12-01

    Chemical diffusion is of major importance in several magmatic processes and, as a time dependent process, can be used as a timescale indicator. In particular, the study of diffusive exchange in magma mixing events leading to explosive volcanic eruptions has the potential shed light on timescales involved in such processes. To achieve this, a basic knowledge of diffusion rates in different natural silicate melts with a variety of conditions is mandatory. We use a set of diffusion couple experiments to quantify the influence of dissolved water content in the interdiffusion of major elements between two natural high-K calc-alkaline end-members: a shoshonite and a rhyolite from Vulcano island (Aeolian archipelago, Italy). Experiments are run using AuPd alloy capsules at 1200 °C and pressures of 0.5, 1 and 3 kbar, with variable added water content (`nominally dry', 1wt. % and 2 wt.% H2O), and finished by a rapid quench in order to avoid crystal formation. Run products are analyzed by FTIR spectroscopy and electron microprobe, and final diffusion coefficients are obtained from the evaluation of composition-distance profiles by a modified Boltzmann-Matano analysis. Among measured major elements (Si, Ti, Al, Fe, Mg, Ca, K), dissolved H2O content in the melt has the highest influence in diffusivity in our experimental setup: a difference of up to 1.4 orders of magnitude is observed between 0.3 and 2 wt. % H2O bearing glasses. In the investigated range, enhancement of diffusion is higher in the lower water contents and slightly diminishes to 2 wt. %. Compositional gradients result in a 0.4 to 0.8 log units increase of diffusivity in the mafic terms relative to the silicic ones. Si and Ti are the slowest diffusing components. Al is also a slow diffusing component and displays uphill diffusion. The diffusivities of the other elements follow similar behavior, suggesting a strong influence of crossed diffusion and coupling.

  6. Advanced functional materials in solid phase extraction for ICP-MS determination of trace elements and their species - A review.

    Science.gov (United States)

    He, Man; Huang, Lijin; Zhao, Bingshan; Chen, Beibei; Hu, Bin

    2017-06-22

    For the determination of trace elements and their species in various real samples by inductively coupled plasma mass spectrometry (ICP-MS), solid phase extraction (SPE) is a commonly used sample pretreatment technique to remove complex matrix, pre-concentrate target analytes and make the samples suitable for subsequent sample introduction and measurements. The sensitivity, selectivity/anti-interference ability, sample throughput and application potential of the methodology of SPE-ICP-MS are greatly dependent on SPE adsorbents. This article presents a general overview of the use of advanced functional materials (AFMs) in SPE for ICP-MS determination of trace elements and their species in the past decade. Herein the AFMs refer to the materials featuring with high adsorption capacity, good selectivity, fast adsorption/desorption dynamics and satisfying special requirements in real sample analysis, including nanometer-sized materials, porous materials, ion imprinting polymers, restricted access materials and magnetic materials. Carbon/silica/metal/metal oxide nanometer-sized adsorbents with high surface area and plenty of adsorption sites exhibit high adsorption capacity, and porous adsorbents would provide more adsorption sites and faster adsorption dynamics. The selectivity of the materials for target elements/species can be improved by using physical/chemical modification, ion imprinting and restricted accessed technique. Magnetic adsorbents in conventional batch operation offer unique magnetic response and high surface area-volume ratio which provide a very easy phase separation, greater extraction capacity and efficiency over conventional adsorbents, and chip-based magnetic SPE provides a versatile platform for special requirement (e.g. cell analysis). The performance of these adsorbents for the determination of trace elements and their species in different matrices by ICP-MS is discussed in detail, along with perspectives and possible challenges in the future

  7. Trace elements determination by energy dispersive X-ray fluorescence (EDXRF) in human placenta and membrane: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Custodio, P.J.; Carvalho, M.L. [Centro Fisica Atomica, Universidade de Lisboa, Av. Prof. Gama Pinto, 2, 1649-003, Lisboa (Portugal); Nunes, F. [Hospital Garcia de Orta, Almada (Portugal)

    2003-04-01

    This work is an application of energy dispersive X-ray fluorescence (EDXRF) as an analytical technique for trace elemental determination in human membrane and placenta and elemental concentrations correlations in both tissues. Whole samples were collected during the delivery from healthy mothers and full-term pregnancies. The age of the mother was between 25 and 40 years old, and the weight of the infants ranged from 2.56 to 4.05 kg. Samples were lyophilised and analysed without any chemical treatment. No significant differences in elemental content of placenta and membrane samples were observed except for Ca. Very low levels of Se, As and Pb were observed in all the analysed samples. Zn, considered as one of the key elements in newborn health, was not significantly different in the analysed samples, all of which originated from healthy mothers and healthy babies. The obtained values agree with the literature except for Ca, which is much higher in the studied samples. (orig.)

  8. Simultaneous determination of hydride and non-hydride forming elements by inductively coupled plasma optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Benzo, Z. [Instituto Venezolano de Investigaciones Cientificas, IVIC, Altos de Pipe, Caracas (Venezuela, Bolivarian Republic of); Matos-Reyes, M.N.; Cervera, M.L.; Guardia, M. de la, E-mail: m.luisa.cervera@uv.es [Department of Analytical Chemistry, University of Valencia, Valencia (Spain)

    2011-09-15

    The operating characteristics of a dual nebulization system were studied including instrumental and chemical conditions for the hydride generation and analytical figures of merit for both, hydride and non hydride forming elements. Analytical performance of the nebulization system was characterized by detection limits from 0.002 to 0.0026 {mu}g mL{sup -1} for the hydride forming elements and between 0.0034 and 0.0121 {mu}g mL{sup -1} for the non-hydride forming elements, relative standard deviation for 10 replicate measurements at 0.25 mg L{sup -1} level and recovery percentages between 97 and 103%. The feasibility of the system was demonstrated in the simultaneous determination of Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Zn, As, Bi, Sb, Se, and Te in the NIST 1549 (non-fat milk powder), NIST 1570a (spinach leaves), DORM-2 (dogfish muscle) and TORT-2 (lobster hepatopancreas) certified samples for trace elements. Results found were in good agreement with the certified ones. (author)

  9. Calibration of handheld X-ray fluorescence (XRF) equipment for optimum determination of elemental concentrations in sediment samples.

    Science.gov (United States)

    Mejía-Piña, K Gabriela; Huerta-Diaz, Miguel Angel; González-Yajimovich, O

    2016-12-01

    Handheld X-ray fluorescence spectrometers (XRFs) represent a more practical, efficient and economic tool to determine the elemental composition of solid inorganic and organic samples than conventional analytical techniques. The objective of this work was to demonstrate that handheld XRFs could be a precise, accurate and reliable tool to analyze up to 27 different elements. This objective was accomplished through the optimization of an empirical calibration curve that, in addition to include certified reference materials (CRM), it also introduced new approaches, such as the use of solid CRM mixtures and combinations of organic and inorganic matrices. These approaches significantly increased the number of calibration points and eliminated hiatuses in the calibration curve. Several factors were evaluated before construction of the calibration curve: incidence time of the X-ray beam, type of film through which the X-ray beams reach the samples, container type, minimum sample volume and sample moisture content. Results show that single elements can be analyzed with variable exposure times or, alternatively, multielemental analyses can be carried out with a constant exposure time (180s). Costs can be reduced by using Ziploc ® bags as sample containers, but the number of measurable elements drops from 27 to 21, while the possibility of contamination increases. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Gene-specific factors determine mitotic expression and bookmarking via alternate regulatory elements.

    Science.gov (United States)

    Arampatzi, Panagiota; Gialitakis, Manolis; Makatounakis, Takis; Papamatheakis, Joseph

    2013-02-01

    Transcriptional silencing during mitosis is caused by inactivation of critical transcriptional regulators and/or chromatin condensation. Inheritance of gene expression patterns through cell division involves various bookmarking mechanisms. In this report, we have examined the mitotic and post-mitotic expression of the DRA major histocompatibility class II (MHCII) gene in different cell types. During mitosis the constitutively MHCII-expressing B lymphoblastoid cells showed sustained occupancy of the proximal promoter by the cognate enhanceosome and general transcription factors. In contrast, although mitotic epithelial cells were depleted of these proteins irrespectively of their MHCII transcriptional activity, a distal enhancer selectively recruited the PP2A phosphatase via NFY and maintained chromatin accessibility. Based on our data, we propose a novel chromatin anti-condensation role for this element in mitotic bookmarking and timing of post-mitotic transcriptional reactivation.

  11. The elemental status of ancient human bones from Edesheim/Rheinland-Pfalz determined by PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Jankuhn, S.; Vogt, J.; Butz, T. [Fakultaet fuer Physik und Geowissenschaften, Universitaet Leipzig, Leipzig (Germany)

    1999-07-01

    We report on ion beam investigations of 40 bone samples from the archaeological site Edesheim/Rheinland-Pfalz, Germany, a burial site of a Merowingian population (6-8th century AD). The samples were prepared as pellets from the so-called WARD's triangle. This region is an inner part of the femoral neck and one of the areas of high fracture risk in the case of osteoporosis. The experiments were carried out with an 1.5 MeV H{sup +} beam at the 2 MV VAN DE GRAAFF accelerator of the University of Leipzig. Simultaneously to the PIXE measurements, PBS and PICE spectra were recorded. We will present a correlation matrix for 11 selected elements detected by PIXE, which exhibits trends and dependences from which preliminary information on various diagenetic processes can be derived. (author)

  12. Determination of trace elements in goat and ovine milk from Calabria (Italy) by ICP-AES.

    Science.gov (United States)

    Licata, P; Di Bella, G; Potortì, A G; Lo Turco, V; Salvo, A; Dugo, G Mo

    2012-01-01

    There are many sources of contamination to which milk could be exposed: grazing animals can ingest contaminants present in nature, such as lead in soil, or that have been deposited on grass, resulting from industrial emissions. Another possible route of contamination is represented by feed for animals, which may contain heavy and essential metals. The potential of high-resolution inductively coupled plasma spectrometry was evaluated to quantify reliably various toxic and essential elements (Fe, Zn, Pb, Cr, Ni, Cu, As, Se, Cd) in 47 samples of goat and ovine milk from various farms in Calabria (southern Italy). The results showed that concentrations of cadmium were below the limit of detection. Lead levels were below the maximum limits as set by the EC in almost all samples tested. The highest values were those of Zn followed by Fe, Cu and Se.

  13. Determination of naturally radioactive elements in chalk sticks by means of gamma spectroscopy

    Science.gov (United States)

    Abd El-Wahab, Magda; Morsy, Zeinab; El-Faramawy, Nabil

    2010-04-01

    The radiation hazards due to ingestion of chalkboard dust were investigated. Sixteen samples from three different origin fabricates were used. The estimation of radiation hazard indices were based on the evaluation of the concentration activities of the natural radionuclides 238U, 232Th and 40K. The radium equivalent activity, external hazard index, internal hazard index and the annual dose equivalent associated with the radionuclides were calculated and compared with international recommended values to assess the radiation hazard. The values of internal and external radiation hazard indices were found to be less than unity. The annual effective dose rate obtained, E eff, and the annual gonadal dose equivalent (AGDE) are found to be less than the limit of the doses recommended by the International Commission on Radiological Protection for the general public. The analytical results show that besides the main calcium content, some toxic elements, S, Mo and Pb and Ni and Pb, in the Egyptian and imported chalk stocks, respectively, existed.

  14. mHealth Intervention Elements and User Characteristics Determine Utility: A Mixed-Methods Analysis.

    Science.gov (United States)

    Nelson, Lyndsay A; Mulvaney, Shelagh A; Johnson, Kevin B; Osborn, Chandra Y

    2017-01-01

    Mobile health (mHealth) interventions are improving the medication adherence of adults with type 2 diabetes mellitus (T2DM), but few studies examine how users experience these interventions. Therefore, we used a mixed-methods approach to understand how T2DM users experience a text messaging and interactive voice response (IVR)-delivered medication adherence intervention called MEssaging for Diabetes (MED). Adults with T2DM used MED as part of a 3-month pilot study. MED sends daily tailored text messages addressing adherence barriers, daily assessment text messages asking about adherence, and weekly tailored IVR calls providing adherence feedback, encouragement, and questions to facilitate problem solving. Sixty participants completed feedback interviews. We used a mixed-methods approach to understand their experience, examining associations between participants' characteristics and their feedback. Participants who completed feedback interviews were on average 50.0 ± 10.1 years old; 65% female, 62% non-white; 15% had less than a high school education, 70% had annual incomes less than $20K; and average hemoglobin A1c was 8.0% ± 1.9%. Participants rated each intervention element favorably; common reasons for MED's helpfulness included receiving novel information about diabetes medications, emotional support, and reminders to take medication. People who were younger and more recently diagnosed with T2DM had more favorable experiences using MED. In general, users valued text messages more than IVR calls. Consideration of the user experience is critical for developing engaging mHealth interventions. User feedback reveals what mHealth elements have the most value and why, which users to target, and how to optimize an intervention's utility and appeal.

  15. [Direct determination of impurity elements in antimony products with ICP-AES].

    Science.gov (United States)

    Yuan, Q

    2001-08-01

    The direct determination of As, Cu, Fe, Pb and Se in antimony products with ICP-AES is presented. We selected compromise condition to determine of As, Cu, Fe, Pb and Se and the influence of matrix concentration is discussed. The detection limits are 0.028-0.327 microgram.mL-1 and the rates of recovery are 94.0%-107.1% and RSD are less than 5%.

  16. Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide.

    Science.gov (United States)

    Saracoglu, Sibel; Soylak, Mustafa; Cabuk, Dilek; Topalak, Zeynep; Karagozlu, Yasemin

    2012-01-01

    The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry.

  17. [Indirect determination of rare earth elements in Chinese herbal medicines by hydride generation-atomic fluorescence spectrometry].

    Science.gov (United States)

    Zeng, Chao; Lu, Jian-Ping; Xue, Min-Hua; Tan, Fang-Wei; Wu, Xiao-Yan

    2014-07-01

    Based on their similarity in chemical properties, rare earth elements were able to form stable coordinated compounds with arsenazo III which were extractable into butanol in the presence of diphenylguanidine. The butanol was removed under reduced pressure distillation; the residue was dissolved with diluted hydrochloric acid. As was released with the assistance of KMnO4 and determined by hydrogen generation-atomic fluorescence spectrometry in terms of rare earth elements. When cesium sulfate worked as standard solution, extraction conditions, KMnO4 amount, distillation temperature, arsenazo III amount, interfering ions, etc were optimized. The accuracy and precision of the method were validated using national standard certified materials, showing a good agreement. Under optimum condition, the linear relationship located in 0.2-25 microg x mL(-1) and detection limit was 0.44 microg x mL(-1). After the herbal samples were digested with nitric acid and hydrogen peroxide, the rare earth elements were determined by this method, showing satisfactory results with relative standard deviation of 1.3%-2.5%, and recoveries of 94.4%-106.0%. The method showed the merits of convenience and rapidness, simple instrumentation and high accuracy. With the rare earths enriched into organic phase, the separation of analytes from matrix was accomplished, which eliminated the interference. With the residue dissolved by diluted hydrochloric acid after the solvent was removed, aqueous sample introduction eliminated the impact of organic phase on the tubing connected to pneumatic pump.

  18. Chemical abundances and kinematics of TYC 5619-109-1

    Science.gov (United States)

    Pereira, C. B.; Smith, V. V.; Drake, N. A.; Roig, F.; Hasselquist, S.; Cunha, K.; Jilinski, E.

    2017-07-01

    Previous determinations of chemical abundances of the metal-poor red giant TYC 5619-109-1, derived via high-resolution near-infrared spectra from the Apache Point Observatory Galactic Evolution Experiment survey, indicate that this star is strongly enriched in the elements N and Al. Here, we obtain and analyse high-resolution optical spectra of TYC 5619-109-1 to verify these large N and Al overabundances and to measure abundances of a wider range of chemical elements. Our analysis confirms the N- and Al-rich nature of this star, and shows that the abundances of the s-process elements are also strongly enhanced, particularly in the heavy second s-process peak elements (Ba, La, Ce, Nd). Lighter s-process elements (Y, Zr) show smaller overabundances, and the ratio of the light-to-heavy s-process elements is consistent with the 13C(α, n)16O neutron source operating in a low-metallicity environment. The lack of Tc i lines and the abundance of Nb compared to Zr indicate that this red giant is probably not a thermally pulsing asymptotic giant branch (TP-AGB) star. Mass transfer from a former s-process-rich TP-AGB companion may produce the observed overabundances, but our radial velocity analysis provides no evidence that TYC 5619-109-1 is a binary with a white dwarf companion. We suggest that TYC 5619-109-1 formed from gas already strongly enriched in s-process elements, as found in many dwarf galaxies and globular clusters. A dynamical analysis reveals that there is only a small probability that TYC 5619-109-1 is an escaped member of a globular cluster, and in this case the most likely candidate would be ω Cen.

  19. β-Globin cis-elements determine differential nuclear targeting through epigenetic modifications

    Science.gov (United States)

    Bian, Qian; Khanna, Nimish; Alvikas, Jurgis

    2013-01-01

    Increasing evidence points to nuclear compartmentalization as a contributing mechanism for gene regulation, yet mechanisms for compartmentalization remain unclear. In this paper, we use autonomous targeting of bacterial artificial chromosome (BAC) transgenes to reveal cis requirements for peripheral targeting. Three peripheral targeting regions (PTRs) within an HBB BAC bias a competition between pericentric versus peripheral heterochromatin targeting toward the nuclear periphery, which correlates with increased H3K9me3 across the β-globin gene cluster and locus control region. Targeting to both heterochromatin compartments is dependent on Suv39H-mediated H3K9me3 methylation. In different chromosomal contexts, PTRs confer no targeting, targeting to pericentric heterochromatin, or targeting to the periphery. A combination of fluorescent in situ hybridization, BAC transgenesis, and knockdown experiments reveals that peripheral tethering of the endogenous HBB locus depends both on Suv39H-mediated H3K9me3 methylation over hundreds of kilobases surrounding HBB and on G9a-mediated H3K9me2 methylation over flanking sequences in an adjacent lamin-associated domain. Our results demonstrate that multiple cis-elements regulate the overall balance of specific epigenetic marks and peripheral gene targeting. PMID:24297746

  20. Collaborative study to improve the quality control of rare earth element determinations in environmental matrices

    NARCIS (Netherlands)

    Kramer, K.J.M.; Dorten, W.S.; Groenewoud, H. van het; Haan, E. de; Kramer, G.N.; Monteiro, L.; Muntau, H.; Quevauviller, P.

    1999-01-01

    In order to control the quality of rare earth determinations in environmental matrices, the Standards, Measurements and Testing Programme (formerly Community Bureau of Reference, BCR) of the European Commission has started a project, the final aim of which is to certify four types of matrices (tuna

  1. Direct Electrothermal Atomic Absorption Determination of Trace Elements in Body Fluids (Review)

    Science.gov (United States)

    Zacharia, A. N.; Arabadji, M. V.; Chebotarev, A. N.

    2017-03-01

    This review is focused on the state and development of tendencies of electrothermal atomic absorption spectroscopy over the last 25 years (from 1990 to 2016) in the direct determination of Cu, Zn, Pb, Cd, Mn, Se, As, Cr, Co, Ni, Al, and Hg in body fluids such as blood, urine, saliva, and breast milk.

  2. Using Rare Earth Elements (REE) to determine wind-driven soil dispersal from a point source

    Science.gov (United States)

    Although erosion of soil by water is a predictably directional process, the erosion of soil by wind is determined by wind direction on an event-wise basis. The wind-driven dispersal patterns of chemical constituents including natural soil components and anthropogenic contaminants are not well under...

  3. Atmospheric deposition levels of chosen elements in the Czech Republic determined in the framework of the International Bryomonitoring Program 1995.

    Science.gov (United States)

    Sucharová, J; Suchara, I

    1998-11-03

    In order to determine the atmospheric loads of 13 elements (Al, As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb, S, V, Zn), samples of Pleurozium schreberi (81.1%), Hypnum cupressiforme (11.2%) and Pseudoscleropodium purum (7.7%) bryophytes (mosses) were taken and analysed from an approx. 20 x 20-km grid extending over the entire territory (78,864 km2) of the Czech Republic (abbreviated 'the CZ' in this study). The level of the elements found in the bryophytes reflects the relative atmospheric deposition loads of the elements at the investigated sites. Five hot spots indicating relatively high deposition levels were identified in the CZ. The marginal hot spots are the following: the CZ part of the so-called Black Triangle I territory in northwestern CZ; the CZ part of the Black Triangle II territory in northeastern CZ; and the CZ part of the Sudeten mountains (Jizerské Mts and Giant Mts) and their foothills in northern CZ. Inland hot spots were found in the southwestern industrial part of central Bohemia and in the southern Moravian industrial district. The average element contents in CZ bryophytes were comparable with the respective average values obtained in Germany and Poland. However, the CZ average bryophyte values were higher and lower in comparison to the average Austrian and Slovak values, respectively. The CZ average relative atmospheric deposition loads of the elements were found to be 2-3 times higher than the respective loads in the cleanest parts of Europe (e.g. clean parts of Nordic countries). A comparison of the analytical results obtained repeatedly at 20 identical localities in the CZ showed a significant decrease in the relative deposition loads of all of the investigated elements in 1995 as compared to 1991. This decrease has been caused by the dramatic restriction of the industrial production, mainly that of the metallurgical and chemical industries, in the CZ. Desulphurisation programs and the effective trapping of flying dust particles in CZ power plants

  4. [Extraction-catalytic kinetic spectrophotometric determination of trace element in tumor tissue].

    Science.gov (United States)

    Zhao, X; Zhang, H

    2000-06-01

    In this paper an isochromatic dye ion-pairs extraction-catalytic spectrophotometric method for the determination of trace copper is studied. The method is based on the copper catalyzed oxidation of isochromatic dye ion-pairs formed by buthylrhodamine B and bromophenol blue by hydrogen peroxide in ammoniac medium. The reaction time, concentration of isochromatic dye ion-pairs in aqueous phase and degree of reaction are controlled by extraction equilibrium. The detection limit of this method is 0.02 microgram.L-1. The linear range is 0.1-10 micrograms.L-1. The method has been applied to the determination of trace copper in tumor tissue with satisfactory results.

  5. The Cell Cycle Independence of HIV Infections Is Not Determined by Known Karyophilic Viral Elements.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available Human immunodeficiency virus and other lentiviruses infect cells independent of cell cycle progression, but gammaretroviruses, such as the murine leukemia virus (MLV require passage of cells through mitosis. This property is thought to be important for the ability of HIV to infect resting CD4+ T cells and terminally differentiated macrophages. Multiple and independent redundant nuclear localization signals encoded by HIV have been hypothesized to facilitate migration of viral genomes into the nucleus. The integrase (IN protein of HIV is one of the HIV elements that targets to the nucleus; however, its role in nuclear entry of virus genomes has been difficult to describe because mutations in IN are pleiotropic. To investigate the importance of the HIV IN protein for infection of non-dividing cells, and to investigate whether or not IN was redundant with other viral signals for cell cycle-independent nuclear entry, we constructed an HIV-based chimeric virus in which the entire IN protein of HIV was replaced by that of MLV. This chimeric virus with a heterologous IN was infectious at a low level, and was able to integrate in an IN-dependent manner. Furthermore, this virus infected non-dividing cells as well as it infected dividing cells. Moreover, we used the chimeric HIV with MLV IN to further eliminate all of the other described nuclear localization signals from an HIV genome-matrix, IN, Viral Protein R, and the central polypurine tract-and show that no combination of the virally encoded NLS is essential for the ability of HIV to infect non-dividing cells.

  6. The cell cycle independence of HIV infections is not determined by known karyophilic viral elements.

    Directory of Open Access Journals (Sweden)

    Masahiro Yamashita

    2005-11-01

    Full Text Available Human immunodeficiency virus and other lentiviruses infect cells independent of cell cycle progression, but gammaretroviruses, such as the murine leukemia virus (MLV require passage of cells through mitosis. This property is thought to be important for the ability of HIV to infect resting CD4+ T cells and terminally differentiated macrophages. Multiple and independent redundant nuclear localization signals encoded by HIV have been hypothesized to facilitate migration of viral genomes into the nucleus. The integrase (IN protein of HIV is one of the HIV elements that targets to the nucleus; however, its role in nuclear entry of virus genomes has been difficult to describe because mutations in IN are pleiotropic. To investigate the importance of the HIV IN protein for infection of non-dividing cells, and to investigate whether or not IN was redundant with other viral signals for cell cycle-independent nuclear entry, we constructed an HIV-based chimeric virus in which the entire IN protein of HIV was replaced by that of MLV. This chimeric virus with a heterologous IN was infectious at a low level, and was able to integrate in an IN-dependent manner. Furthermore, this virus infected non-dividing cells as well as it infected dividing cells. Moreover, we used the chimeric HIV with MLV IN to further eliminate all of the other described nuclear localization signals from an HIV genome--matrix, IN, Viral Protein R, and the central polypurine tract--and show that no combination of the virally encoded NLS is essential for the ability of HIV to infect non-dividing cells.

  7. Determination of trace element levels in leaves of Nerium oleander using X-Ray Fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Ramon S.; Sanches, Francis A.C.R.A.; Neves, Arthur O.P.; Oliveira, Luis F.; Oliveira, Davi F.; Anjos, Marcelino J. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica Armando Dias Tavares. Dept. de Fisica Aplicada e Termodinamica

    2013-07-01

    The environmental pollution by human activity has been one of the most concerns in the last years, principally due to rapid urban growth in the cities and the industrialization process. The air pollution can be increased due to several different kinds of emissions: urban traffic, industrial activities, burning fuel, civil industry of construction/demolition, fires and natural phenomena. Many of these emissions move from long distances due to convections currents and finally tend to deposit mainly in the plants leaves and in the soil. Thus, the plants leaves works as a natural sampler by the emissions deposit in these ones. In this study Nerium oleander leaves were used to measure the environmental pollutions levels in different sampling urban regions in the city of Rio de Janeiro/RJ: Andarai, Benfica, Bonsucesso, Caju, Engenho de Dentro, Engenho Novo, Estacio, Grajau, Inhauma, Lins, Maracana, Maria da Graca, Meier, Praca da Bandeira, Riachuelo, Rio Comprido, Sao Cristovao, Tijuca, Vila Isabel and city Center. The control samples were collected in Campo Grande near of Parque Nacional da Pedra Branca/RJ (National Park of Pedra Branca/RJ). The leaves were collected from adult plants and after the collection the samples were cleaned and placed in the greenhouse for drying, then were mashed and pressed into tablets forms. The analyses were performed using the energy dispersion X-ray fluorescence (EDXRF), developed on the own laboratory and based in a SiPIN detector and a mini X ray tube. It was possible to detect 16 elements in the analyzed samples: K, Ca, Cr, Mn, Fe, Cu, Zn, Br, Rb, Sr, Ba and Pb. The results shows that, in the studied areas, the analysis of the Nerium oleander plant shows a low-cost option and with a substantial efficiency as an environmental pollution biomonitor. (author)

  8. Spheronization process particle kinematics determined by discrete element simulations and particle image velocimentry measurements.

    Science.gov (United States)

    Koester, Martin; García, R Edwin; Thommes, Markus

    2014-12-30

    Spheronization is an important pharmaceutical manufacturing technique to produce spherical agglomerates of 0.5-2mm diameter. These pellets have a narrow size distribution and a spherical shape. During the spheronization process, the extruded cylindrical strands break in short cylinders and evolve from a cylindrical to a spherical state by deformation and attrition/agglomeration mechanisms. Using the discrete element method, an integrated modeling-experimental framework is presented, that captures the particle motion during the spheronization process. Simulations were directly compared and validated against particle image velocimetry (PIV) experiments with monodisperse spherical and dry γ-Al2O3 particles. demonstrate a characteristic torus like flow pattern, with particle velocities about three times slower than the rotation speed of the friction plate. Five characteristic zones controlling the spheronization process are identified: Zone I, where particles undergo shear forces that favors attrition and contributes material to the agglomeration process; Zone II, where the static wall contributes to the mass exchange between particles; Zone III, where gravitational forces combined with particle motion induce particles to collide with the moving plate and re-enter Zone I; Zone IV, where a subpopulation of particles are ejected into the air when in contact with the friction plate structure; and Zone V where the low poloidal velocity favors a stagnant particle population and is entirely controlled by the batch size. These new insights in to the particle motion are leading to deeper process understanding, e.g., the effect of load and rotation speed to the pellet formation kinetics. This could be beneficial for the optimization of a manufacturing process as well as for the development of new formulations. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. L X-ray fluorescence cross sections experimentally determined for elements with 45

    Energy Technology Data Exchange (ETDEWEB)

    Bonzi, Edgardo V., E-mail: bonzie@famaf.unc.edu.ar [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria-5010, Cordoba (Argentina); Badiger, Nagappa M. [Departments of Physics, Karnatak University, Dharwad 580 003, Karnataka (India); Grad, Gabriela B. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria-5010, Cordoba (Argentina); Barrea, Raul A. [The Biophysics Collaborative Access Team (BioCAT), Dept of Biological Chemical, and Physical Sciences, Illinois Institute of Technology, Chicago, IL 60616 (United States); Figueroa, Rodolo G. [Departamento de Cs. Fisicas, Universidad de La Frontera, Temuco (Chile)

    2012-04-15

    Experimental determination of L fluorescence cross-sections for elements with 45determined at 9 keV using Synchrotron radiation. This work is part of an investigation we did at low energies in the same group of elements. The individual L X-ray photons, Ll, L{alpha}, L{beta}{sub I}, L{beta}{sub II}, L{gamma}{sub {Iota}} and L{gamma}{sub {Iota}{Iota}} produced in the target were measured using a Si(Li) detector. The experimental set-up provided a low background by using linearly polarized monoenergetic photon beam, improving the signal-to-noise ratio. The experimental cross sections obtained in this work were compared with data calculated using coefficients from , , and Scofield and Puri et al. (1993, 1995) - Highlights: Black-Right-Pointing-Pointer Experimental data of L fluorescence cross-sections with 45determined at 9 keV by Synchrotron radiation. Black-Right-Pointing-Pointer The cross sections Ll, L{alpha}, L{beta}{sub I}, L{beta}{sub II}, L{gamma}{sub {Iota}} and L{gamma}{sub {Iota}{Iota}} obtained, were compared with calculated data. Black-Right-Pointing-Pointer The Hypermet function was used to fit the data, because it considers a tail on the left side of the peak. Black-Right-Pointing-Pointer The tail is relevant when a small peak has another one on the right side with a big area.

  10. Determination of rare earth elements in natural water samples – A review of sample separation, preconcentration and direct methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Andrew, E-mail: afisher@plymouth.ac.uk [School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, Devon, PL4 8AA (United Kingdom); Kara, Derya [Department of Chemistry, Art and Science Faculty, Balikesir University, 10100, Balikesir (Turkey)

    2016-09-07

    This review discusses and compares the methods given for the determination of rare earth elements (REE) in natural water samples, including sea, river, lake, tap, ground and waste waters as well as Antarctic ice. Since REE are at very low concentrations in natural waters, numerous different preconcentration methods have been proposed to enable their measurement. These include liquid liquid extraction, dispersive liquid-liquid micro-extraction and solidified floating drop micro-extraction. In addition to liquid-liquid extraction methods, solid phase extraction using commercial resins, resins made in-house, silica-based exchange materials and other solid media is also discussed. These and other techniques such as precipitation/co-precipitation and flotation are compared in terms of speed, preconcentration factors achieved, precision, accuracy and limits of detection (LOD). Some papers have discussed the direct determination of REE in these sample types. Some have used specialised sample introduction systems such as ultrasonic nebulization whereas others have used a standard sample introduction system coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection. These direct methods have also been discussed and compared. - Highlights: • The determination of rare earth elements in waters is reviewed. • Assorted preconcentration techniques are discussed and evaluated. • Detection techniques include atomic spectrometry, potentiometry and spectrophotometry. • Special nebulisers and electrothermal vaporization approaches are reviewed.

  11. Standard test method for determining elements in waste Streams by inductively coupled plasma-atomic emission spectroscopy

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the determination of trace, minor, and major elements in waste streams by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) following an acid digestion of the sample. Waste streams from manufacturing processes of nuclear and non-nuclear materials can be analyzed. This test method is applicable to the determination of total metals. Results from this test method can be used to characterize waste received by treatment facilities and to formulate appropriate treatment recipes. The results are also usable in process control within waste treatment facilities. 1.2 This test method is applicable only to waste streams that contain radioactivity levels that do not require special personnel or environmental protection. 1.3 A list of the elements determined in waste streams and the corresponding lower reporting limit is found in Table 1. 1.4 This test method has been used successfully for treatment of a large variety of waste solutions and industrial process liquids. The com...

  12. Possibilities of High Resolution Inductively Coupled Plasma Optical Emission Spectrometry in the Determination of Trace Elements in Environmental Materials

    Directory of Open Access Journals (Sweden)

    Nikolaya Velitchkova

    2013-01-01

    Full Text Available This paper presents new quantitative data for the spectral interferences obtained by high resolution 40.68 MHz radial viewing inductively coupled plasma optical emission spectrometry (HR-ICP-OES in the determination of Zn, Cd, Sb, Cu, Mn, Pb, Sn, Cr, U, and Ba in environmental materials in the presence of a complex matrix, containing Al, Ca, Fe, Mg, and Ti. The -concept for quantification of spectral interferences was used. The optimum line selection for trace analysis of a variety of multicomponent matrices requires the choice of prominent lines, which are free or negligibly influenced by line interference problems. The versatility of -concept as basic methodology was experimentally demonstrated in the determination of trace of elements in soil and drinking water. The detection limits are lower in comparison with corresponding threshold concentration levels for soil and drinking water in accordance with environmental regulations. This paper shows the possibilities of present day ICP-OES equipment in the direct determination of trace elements (without preconcentration of impurities in environmental samples.

  13. Do contemporary (1980–2015 emissions determine the elemental carbon deposition trend at Holtedahlfonna glacier, Svalbard?

    Directory of Open Access Journals (Sweden)

    M. M. Ruppel

    2017-10-01

    Full Text Available The climate impact of black carbon (BC is notably amplified in the Arctic by its deposition, which causes albedo decrease and subsequent earlier snow and ice spring melt. To comprehensively assess the climate impact of BC in the Arctic, information on both atmospheric BC concentrations and deposition is essential. Currently, Arctic BC deposition data are very scarce, while atmospheric BC concentrations have been shown to generally decrease since the 1990s. However, a 300-year Svalbard ice core showed a distinct increase in EC (elemental carbon, proxy for BC deposition from 1970 to 2004 contradicting atmospheric measurements and modelling studies. Here, our objective was to decipher whether this increase has continued in the 21st century and to investigate the drivers of the observed EC deposition trends. For this, a shallow firn core was collected from the same Svalbard glacier, and a regional-to-meso-scale chemical transport model (SILAM was run from 1980 to 2015. The ice and firn core data indicate peaking EC deposition values at the end of the 1990s and lower values thereafter. The modelled BC deposition results generally support the observed glacier EC variations. However, the ice and firn core results clearly deviate from both measured and modelled atmospheric BC concentration trends, and the modelled BC deposition trend shows variations seemingly independent from BC emission or atmospheric BC concentration trends. Furthermore, according to the model ca. 99 % BC mass is wet-deposited at this Svalbard glacier, indicating that meteorological processes such as precipitation and scavenging efficiency have most likely a stronger influence on the BC deposition trend than BC emission or atmospheric concentration trends. BC emission source sectors contribute differently to the modelled atmospheric BC concentrations and BC deposition, which further supports our conclusion that different processes affect atmospheric BC concentration and

  14. Do contemporary (1980-2015) emissions determine the elemental carbon deposition trend at Holtedahlfonna glacier, Svalbard?

    Science.gov (United States)

    Ruppel, Meri M.; Soares, Joana; Gallet, Jean-Charles; Isaksson, Elisabeth; Martma, Tõnu; Svensson, Jonas; Kohler, Jack; Pedersen, Christina A.; Manninen, Sirkku; Korhola, Atte; Ström, Johan

    2017-10-01

    The climate impact of black carbon (BC) is notably amplified in the Arctic by its deposition, which causes albedo decrease and subsequent earlier snow and ice spring melt. To comprehensively assess the climate impact of BC in the Arctic, information on both atmospheric BC concentrations and deposition is essential. Currently, Arctic BC deposition data are very scarce, while atmospheric BC concentrations have been shown to generally decrease since the 1990s. However, a 300-year Svalbard ice core showed a distinct increase in EC (elemental carbon, proxy for BC) deposition from 1970 to 2004 contradicting atmospheric measurements and modelling studies. Here, our objective was to decipher whether this increase has continued in the 21st century and to investigate the drivers of the observed EC deposition trends. For this, a shallow firn core was collected from the same Svalbard glacier, and a regional-to-meso-scale chemical transport model (SILAM) was run from 1980 to 2015. The ice and firn core data indicate peaking EC deposition values at the end of the 1990s and lower values thereafter. The modelled BC deposition results generally support the observed glacier EC variations. However, the ice and firn core results clearly deviate from both measured and modelled atmospheric BC concentration trends, and the modelled BC deposition trend shows variations seemingly independent from BC emission or atmospheric BC concentration trends. Furthermore, according to the model ca. 99 % BC mass is wet-deposited at this Svalbard glacier, indicating that meteorological processes such as precipitation and scavenging efficiency have most likely a stronger influence on the BC deposition trend than BC emission or atmospheric concentration trends. BC emission source sectors contribute differently to the modelled atmospheric BC concentrations and BC deposition, which further supports our conclusion that different processes affect atmospheric BC concentration and deposition trends

  15. Determining the geographical origin of Asian longhorn beetle (Anoplophora glabripennis) specimens using stable isotope and trace element analyses.

    Science.gov (United States)

    Heinrich, Katharina; Collins, Larissa

    2017-05-01

    An outbreak of EU-quarantine-listed pest Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambicidae), the Asian longhorn beetle, in Kent (UK) resulted in environmentally and financially costly eradication action being taken. In this study the potential of using multi-element stable isotope or trace element analyses to determine the geographical origin of individual specimens has been investigated. The isotope ratios of A. glabripennis individuals for hydrogen varied within and across five locations. Carbon isotope ratios fell within the expected values for C3 plants (trees using the photosynthetic pathway common for moderate climates). Nitrogen isotope ratios indicated separation of UK laboratory from US (New York, Ohio, Massachusetts) beetles, while sulphur isotope ratios distinguished beetles from New York against the other four locations. Three trace elements (TEs) separated UK laboratory-reared beetles from US beetles (Ohio and New York) with ∼ 68% confidence. Stable isotope and TE analyses show potential to differentiate between newly arrived A. glabripennis individuals and those from previously undetected in-country populations, which would be of immediate practical benefit in making appropriate strategic decisions on surveillance and eradication. Analyses of additional samples from (i) the same populations, (ii) different locations and (iii) a variety of host trees will enhance the overall picture. © 2016 Crown copyright. Pest Management Science © 2016 Society of Chemical Industry. © 2016 Crown copyright. Pest Management Science © 2016 Society of Chemical Industry.

  16. Do ICP-MS based methods fulfill the EU monitoring requirements for the determination of elements in our environment?

    Science.gov (United States)

    Tirez, Kristof; Vanhoof, Chris; Bronders, Jan; Seuntjens, Piet; Bleux, Nico; Berghmans, Patrick; De Brucker, Nicole; Vanhaecke, Frank

    2015-12-01

    Undoubtedly, the most important advance in the environmental regulatory monitoring of elements of the last decade is the widespread introduction of ICP-mass spectrometry (ICP-MS) due to standards developed by the European Committee for Standardization. The versatility of ICP-MS units as a tool for the determination of major, minor and trace elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, Ti, V and Zn) in surface water, groundwater, river sediment, topsoil, subsoil, fine particulates and atmospheric deposition is illustrated in this paper. Ranges of background concentrations for major, minor and trace elements obtained from a regional case study (Flanders, Belgium) are summarized for all of these environmental compartments and discussed in the context of a harmonized implementation of European regulatory monitoring requirements. The results were derived from monitoring programs in support of EU environmental quality directives and were based on a selection of (non-polluted) background locations. Because of the availability of ICP-MS instruments nowadays, it can be argued that the main hindrance for meeting the European environmental monitoring requirements is no longer the technical feasibility of analysis at these concentration levels, but rather (i) potential contamination during sampling and analysis, (ii) too limited implementation of quality control programs, validating the routinely applied methods (including sampling and low level verification) and (iii) lack of harmonization in reporting of the chemical environmental status between the individual member states.

  17. FLOW INJECTION ANALYSIS SYSTEM COUPLED WITH ICP-EOS FOR DETERMINATION OF SOME METALLIC ELEMENTS IN DRINKING WATER

    Directory of Open Access Journals (Sweden)

    Cristina Dinu

    2009-06-01

    Full Text Available The European Drinking Water Directive (98/83/EC, transposed in Romanian Legislation as Low 458/2002, amended by Low 311/2004, imposes the limit of concentration for metallic elements in water intended for human consumption. The toxic metals arsenic and selenium are among these elements and the limit value is 10 μg/L. In the paper there are presented the working conditions for determination of As and Se from drinking water using modern techniques based on the fl ow injection-hydride generation with the inductively coupled plasma atomic emission spectrometry (FIAS-ICP-EOS. The analyses were performed on Optima 5300 DV Perkin Elmer equipment with FIAS 400 Flow Injection System, Perkin Elmer type. For the hydride generation two types of solution were used: 10% (v/v HCl as a carrier solution and 0.2 % NaBH4 in 0.05%NaOH solution as a reducing agent [1]. The treatment step of the samples and standard solutions consisted in reducing with mixed solutions of KI and ascorbic acid in acidic condition (HCl for As and only with HCl and high temperature for Se [2,3]. The paper contains the characteristic parameters of the methods, such as: low detection limit, quantifi cation limit, repeatability, precision, recovery, which were evaluated using Certifi ed Reference Materials for each element.

  18. X-Ray fluorescence determination of potentially toxic elements in quarry dust from Umuoghara industrial crushing site

    Directory of Open Access Journals (Sweden)

    Nduka OMAKA

    2014-11-01

    Full Text Available Rapid population growth coupled with increasing demand for construction materials like granite and gravel have necessitated the continued growth of quarry activities in different parts of Nigeria. This study was carried out in Umuoghara town, a major quarry industrial zone in Ezza North Local Government Area of Ebonyi State. X-Ray fluoroscopy was used to determine the metal content and concentration of 5 elements (Ni, Cu, Pb, Cd and Zn in dust samples randomly collected (8 hourly interval from different locations within the study site on selected days in January to June, 2012. Elemental concentrations in dust samples are as follows: Cd (75.00 mg/kg, Zn (11.62mg/kg, Pb (4.91mg/kg, Cu (1.71mg/kg and Ni (2.43mg/kg. The data was compared to the elemental composition of urban dust from selected cities in Nigeria and other cities around the world. Overall, the dust samples contained trace metals in comparable quantities that do not pose excessive health threats to both the workers and local inhabitants.

  19. Differences in determination of chemical elements in soil and attic dust samples due to various acid treatments, Slovenia

    Directory of Open Access Journals (Sweden)

    Robert Šajn

    2003-12-01

    Full Text Available The paper gives an assessment of relationship existing between analytical values of samples, which were treated with two different acid procedures: four acid digestion and extraction in aqua regia. The sample population consisted of 256 soil samples and 139 atticdust samples collected within the frame of various geochemical studies in Slovenia. After acid treatments, elementary composition of the samples was determined by means of ICP method. As we were interested in functional relationships between both treatment procedures, we performed bivariate analysis of elementary compositions. A regression line based on the logarithms of data was used as a basic correlation indicator. We correlated the following 31 elements: Al, Ag, As, Au, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, La, Mg, Mn,Mo, Na, Ni, P, Pb, S, Sb, Sc, Sr, Th, Ti, U, V, W and Zn.The majority of analytical values for elements in our samples, treated with both procedures,showed a high degree of correlation and a good functional relationship. A weak relationship existed only between those elements that were on detection limits of theanalytical method or had a weak variability (Ag, Ba, Bi, K, Na, Ti, and W. On the basis of the results of double treatment and analysis of samples we calculated the boundary, warning and critical values, which are related to four acid digestion.

  20. JV Task-123 Determination of Trace Element Concentrations at an Eastern Bituminous Coal Plant Employing an SCR and Wet FGD

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Laudal

    2008-05-01

    The Energy & Environmental Research Center (EERC), in partnership with Babcock & Wilcox (B&W) and with funding from U.S. Department of Energy (DOE), conducting tests to prove that a high level of mercury control (>90%) can be achieved at a power plant burning a high-sulfur eastern bituminous coal. With funding from the Electric Power Research Institute (EPRI), DOE, and Center for Air Toxic Metals{reg_sign} (CATM{reg_sign}) Affiliates Program, the EERC completed an additional sampling project to provide data as to the behavior of a number of trace elements across the various pollution control devices, with a special emphasis on the wet flue gas desulfurization (FGD) system. Results showed that the concentrations of almost all the elements of interest leaving the stack were very low, and a high percentage of the trace elements were captured in the electrostatic precipitator (ESP) (for most, >80%). Although, with a few exceptions, the overall mass balances were generally quite good, the mass balances across the wet FGD were more variable. This is most likely a result of some of the concentrations being very low and also the uncertainties in determining flows within a wet FGD.

  1. Simultaneous determination of macronutrients, micronutrients and trace elements in mineral fertilizers by inductively coupled plasma optical emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Souza, Sidnei de [Laboratório de Química Analítica Ambiental (LQA), Departamento de Química, Centro de Ciências Exatas e Tecnologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristovão, SE (Brazil); Silvério Lopes da Costa, Silvânio [Laboratório de Química Analítica Ambiental (LQA), Departamento de Química, Centro de Ciências Exatas e Tecnologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristovão, SE (Brazil); Coordenação de Química, Universidade Federal de Alagoas (UFAL), Campus Arapiraca, 57309-005, Arapiraca, AL (Brazil); Santos, Dayane Melo; Santos Pinto, Jéssica dos; Garcia, Carlos Alexandre Borges [Laboratório de Química Analítica Ambiental (LQA), Departamento de Química, Centro de Ciências Exatas e Tecnologia, Universidade Federal de Sergipe (UFS), 49100-000, São Cristovão, SE (Brazil); and others

    2014-06-01

    An analytical method for simultaneous determination of macronutrients (Ca, Mg, Na and P), micronutrients (Cu, Fe, Mn and Zn) and trace elements (Al, As, Cd, Pb and V) in mineral fertilizers was optimized. Two-level full factorial design was applied to evaluate the optimal proportions of reagents used in the sample digestion on hot plate. A Doehlert design for two variables was used to evaluate the operating conditions of the inductively coupled plasma optical emission spectrometer in order to accomplish the simultaneous determination of the analyte concentrations. The limits of quantification (LOQs) ranged from 2.0 mg kg{sup −1} for Mn to 77.3 mg kg{sup −1} for P. The accuracy and precision of the proposed method were evaluated by analysis of standard reference materials (SRMs) of Western phosphate rock (NIST 694), Florida phosphate rock (NIST 120C) and Trace elements in multi-nutrient fertilizer (NIST 695), considered to be adequate for simultaneous determination. Twenty-one samples of mineral fertilizers collected in Sergipe State, Brazil, were analyzed. For all samples, the As, Ca, Cd and Pb concentrations were below the LOQ values of the analytical method. For As, Cd and Pb the obtained LOQ values were below the maximum limit allowed by the Brazilian Ministry of Agriculture, Livestock and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento — MAPA). The optimized method presented good accuracy and was effectively applied to quantitative simultaneous determination of the analytes in mineral fertilizers by inductively coupled plasma optical emission spectrometry (ICP OES). - Highlights: • Determination of inorganic constituents in mineral fertilizers was proposed. • Experimental design methodology was used to optimize analytical method. • The sample preparation procedure using diluted reagents (HNO{sub 3} and H{sub 2}O{sub 2}) was employed. • The analytical method was satisfactorily to the determination of thirteen elements. • The

  2. 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....

  3. Multi-elements determination in medical and edible Alpinia oxyphylla and Morinda officinalis and their decoctions by ICP-MS.

    Science.gov (United States)

    Zhao, Xiangsheng; Wei, Jianhe; Shu, Xiaoyan; Kong, Weijun; Yang, Meihua

    2016-12-01

    Contents of twenty elements (Mg, K, Ca, Na, Fe, Al, Zn, Ba, Mn, Cu, Mo, Cr, Ni, As, Se, Cd, Hg, Tl, Pb and V) in two medical and edible plant species, Alpinia oxyphylla and Morinda officinalis were simultaneously determined by inductively coupled plasma-mass spectrometry (ICP-MS) method after microwave digestion with HNO3-H2O2 (6:1, v/v) as the digestion solvent. Certified standard reference material Poplar leaf was used to assess the accuracy of the method. The greatest contents of Mg, K, Ca, Al, Fe and Na were found in dried Alpinia oxyphylla and Morinda officinalis samples. The contents of five heavy metals including Pb, Cd, As, Hg and Cu in Alpinia oxyphylla did not exceed the limits. The contents of Pb in 76.67% samples and Cd in two batches of Morinda officinalis samples exceeded the limits set by Chinese Pharmacopeia. The contents of the selected elements in different parts (leaves, stems, roots and fruits) of Alpinia oxyphylla varied considerably. The highest concentrations of Mg, Ca, Mn and Se were found in the leaves of Alpinia oxyphylla, at the same time, while, the contents of 9 elements including Cd, Cr, Cu, As, Pb in the roots were the highest. The transfer ratios of selected elements from both species of herbs into their decoctions were reduced. Especially for the heavy metals, the transfer ratios were below 30% except As (79.73%) in Morinda officinalis. The results showed that decoction of the samples may reduce the intake of heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. DETERMINATION OF ATTENUATION INDEX CURVE "Ri(f" FOR HOMOGENEOUS DOUBLE LOCKING ELEMENTS

    Directory of Open Access Journals (Sweden)

    BUZATU G. C.

    2016-12-01

    Full Text Available The paper is structured in three parts. In the first part of the paper, are presented some theoretical notions regarding the sound, noise, the sound insulations materials. Also in the first part of the paper are presented some characteristic regarding the insulation materials and there effects. In the second part it is described an calculation example for a homogeneous wall with double structure in order to determine the attenuation index curve "Ri(f". The example calculation contains 10 steps that must be followed and the final results are presented in table 7 and figure 3. The last part of the paper is represented by conclusions, where the authors tried to explain the importance of the curve "Ri(f" for reducing the noise in the buildings.

  5. Determination of Elements and Carbon Content of Stainless Steel Welded Pipeline

    Directory of Open Access Journals (Sweden)

    Pavel Hudeček

    2016-01-01

    Full Text Available Find out defects or problems of welds are not so simple from time to time. Specially, if weld has been made in rough environmental conditions like high temperature, dusty wind and humidity. It is important to assure have good conditions to realize basic step of welding. For welding, have been used welding procedures specification and procedure qualification record. However, difficult conditions, documentations rightness or human errors are always here. Common weld defects like cracks, porosity, lack of penetration and distortion can compromise the strength of the base metal, as well as the integrity of the weld. According of site inspection, there were suspicion of inclusions, leaker or segregation in root of weld. Surface treatment after welding and keep the intervals between single welds to not overheat the pipes. To recognize those suspicions, mechanical testing around weld joint, determination of carbon content and inductively coupled plasma atomic emission spectroscopy will be done.

  6. [Ultra-Fine Pressed Powder Pellet Sample Preparation XRF Determination of Multi-Elements and Carbon Dioxide in Carbonate].

    Science.gov (United States)

    Li, Xiao-li; An, Shu-qing; Xu, Tie-min; Liu, Yi-bo; Zhang, Li-juan; Zeng, Jiang-ping; Wang, Na

    2015-06-01

    The main analysis error of pressed powder pellet of carbonate comes from particle-size effect and mineral effect. So in the article in order to eliminate the particle-size effect, the ultrafine pressed powder pellet sample preparation is used to the determination of multi-elements and carbon-dioxide in carbonate. To prepare the ultrafine powder the FRITSCH planetary Micro Mill machine and tungsten carbide media is utilized. To conquer the conglomeration during the process of grinding, the wet grinding is preferred. The surface morphology of the pellet is more smooth and neat, the Compton scatter effect is reduced with the decrease in particle size. The intensity of the spectral line is varied with the change of the particle size, generally the intensity of the spectral line is increased with the decrease in the particle size. But when the particle size of more than one component of the material is decreased, the intensity of the spectral line may increase for S, Si, Mg, or decrease for Ca, Al, Ti, K, which depend on the respective mass absorption coefficient . The change of the composition of the phase with milling is also researched. The incident depth of respective element is given from theoretical calculation. When the sample is grounded to the particle size of less than the penetration depth of all the analyte, the effect of the particle size on the intensity of the spectral line is much reduced. In the experiment, when grounded the sample to less than 8 μm(d95), the particle-size effect is much eliminated, with the correction method of theoretical α coefficient and the empirical coefficient, 14 major, minor and trace element in the carbonate can be determined accurately. And the precision of the method is much improved with RSD < 2%, except Na2O. Carbon is ultra-light element, the fluorescence yield is low and the interference is serious. With the manual multi-layer crystal PX4, coarse collimator, empirical correction, X-ray spectrometer can be used to

  7. Evaluation of some procedures relevant to the determination of trace elemental components in biological materials by destructive neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Berry, D.L.

    1979-01-01

    The development of a simplified procedure for the analysis of biological materials by destructive neutron activation analysis (DNAA) is described. The sample manipulations preceding gamma ray assay were investigated as five specific stages of processing: (1) pre-irradiation treatment; (2) sample irradiation; (3) removal of the organic matrix; (4) removal of interfering radioactivities; and (5) concentration and separation of analyte activities. Each stage was evaluated with respect to susceptibility to sample contamination, loss of trace elemental components, and compatibility with other operations in the overall DNAA procedures. A complete DNAA procedure was proposed and evaluated for the analysis of standard bovine liver and blood samples. The DNAA system was effective for the determination of As, Cu, Fe, Hg, Mo, Rb, Sb, Se, and Zn without yield determinations and with a minimum turn-around time of approximately 3 days.

  8. Sequence and structure-specific elements of HERG mRNA determine channel synthesis and trafficking efficiency

    Science.gov (United States)

    Sroubek, Jakub; Krishnan, Yamini; McDonald, Thomas V.

    2013-01-01

    Human ether-á-gogo-related gene (HERG) encodes a potassium channel that is highly susceptible to deleterious mutations resulting in susceptibility to fatal cardiac arrhythmias. Most mutations adversely affect HERG channel assembly and trafficking. Why the channel is so vulnerable to missense mutations is not well understood. Since nothing is known of how mRNA structural elements factor in channel processing, we synthesized a codon-modified HERG cDNA (HERG-CM) where the codons were synonymously changed to reduce GC content, secondary structure, and rare codon usage. HERG-CM produced typical IKr-like currents; however, channel synthesis and processing were markedly different. Translation efficiency was reduced for HERG-CM, as determined by heterologous expression, in vitro translation, and polysomal profiling. Trafficking efficiency to the cell surface was greatly enhanced, as assayed by immunofluorescence, subcellular fractionation, and surface labeling. Chimeras of HERG-NT/CM indicated that trafficking efficiency was largely dependent on 5′ sequences, while translation efficiency involved multiple areas. These results suggest that HERG translation and trafficking rates are independently governed by noncoding information in various regions of the mRNA molecule. Noncoding information embedded within the mRNA may play a role in the pathogenesis of hereditary arrhythmia syndromes and could provide an avenue for targeted therapeutics.—Sroubek, J., Krishnan, Y., McDonald, T V. Sequence- and structure-specific elements of HERG mRNA determine channel synthesis and trafficking efficiency. PMID:23608144

  9. Determination of water-soluble and insoluble elements in PM2.5 by ICP-MS.

    Science.gov (United States)

    Manousakas, M; Papaefthymiou, H; Eleftheriadis, K; Katsanou, K

    2014-09-15

    The elemental composition of water-soluble and acid-soluble fractions of PM2.5 samples from two different Greek cities (Patras and Megalopolis) was investigated. Patras and Megalopolis represent different environments. Specifically, Patras is an urban environment with proximity to a large port, while Megalopolis is a small city located close to lignite power plants. Both cities can serve as a representative example of European cities with similar characteristics. The concentration of 14 elements (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Fe, Sr, Ti, V and Zn) was determined in each fraction by ICP-MS. Microwave assisted digestion was used to digest the samples using a mixture of HNO3 and HF. For the determination of the water soluble fraction, water was chosen as the simplest and most universal extraction solvent. For the validation of the extraction procedure, the recoveries were tested on two certified reference materials (NIST SRM 1648 Urban Particulate Matter and NIST 1649a Urban Dust). Results showed that Zn has the highest total concentration (273 and 186 ng/m(3)) and Co the lowest (0.48 and 0.23 ng/m(3)) for Patras and Megalopolis samples, respectively. Nickel with 65% for Patras and As with 49% for Megalopolis displayed the highest solubility, whereas Fe (10%) and Ti (2%) the lowest ones, respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Simultaneous determination of macronutrients, micronutrients and trace elements in mineral fertilizers by inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    de Oliveira Souza, Sidnei; da Costa, Silvânio Silvério Lopes; Santos, Dayane Melo; dos Santos Pinto, Jéssica; Garcia, Carlos Alexandre Borges; Alves, José do Patrocínio Hora; Araujo, Rennan Geovanny Oliveira

    2014-06-01

    An analytical method for simultaneous determination of macronutrients (Ca, Mg, Na and P), micronutrients (Cu, Fe, Mn and Zn) and trace elements (Al, As, Cd, Pb and V) in mineral fertilizers was optimized. Two-level full factorial design was applied to evaluate the optimal proportions of reagents used in the sample digestion on hot plate. A Doehlert design for two variables was used to evaluate the operating conditions of the inductively coupled plasma optical emission spectrometer in order to accomplish the simultaneous determination of the analyte concentrations. The limits of quantification (LOQs) ranged from 2.0 mg kg- 1 for Mn to 77.3 mg kg- 1 for P. The accuracy and precision of the proposed method were evaluated by analysis of standard reference materials (SRMs) of Western phosphate rock (NIST 694), Florida phosphate rock (NIST 120C) and Trace elements in multi-nutrient fertilizer (NIST 695), considered to be adequate for simultaneous determination. Twenty-one samples of mineral fertilizers collected in Sergipe State, Brazil, were analyzed. For all samples, the As, Ca, Cd and Pb concentrations were below the LOQ values of the analytical method. For As, Cd and Pb the obtained LOQ values were below the maximum limit allowed by the Brazilian Ministry of Agriculture, Livestock and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento - MAPA). The optimized method presented good accuracy and was effectively applied to quantitative simultaneous determination of the analytes in mineral fertilizers by inductively coupled plasma optical emission spectrometry (ICP OES).

  11. Accurate LTE abundances of seven well established lambda Bootis stars

    Science.gov (United States)

    Paunzen, E.; Andrievsky, S. M.; Chernyshova, I. V.; Klochkova, V. G.; Panchuk, V. E.; Handler, G.

    1999-11-01

    High resolution and high signal-to-noise CCD spectra were analyzed to determine accurate LTE abundances for seven well established {lambda Bootis} stars (a group of A to F-type stars with strong underabundances of Fe-peak elements whereas the C, N, O and S appear to be solar abundant): HD 31295, HD 125162, HD 142994, HD 149303, HD 192640, HD 204041 and HD 221756. In general, 13 elements were investigated. The effective temperatures of our program stars range from 7200 to 9000 K. The main results are the following: C, O, Na and S seem to be nearly solar abundant for all investigated stars. A wide range of underabundances within the individual stars exists for all other elements. No correlation of the individual abundances with astrophysical parameters such as T_eff, log g and v sin i was found. These results are consistent with the accretion/diffusion model which is currently adopted for the explanation of the {lambda Bootis} phenomenon. Based on observations from the Special Astrophysical Observatory of the Russian Academy of Sciences, Russia, Northern Caucasus and the McDonald Observatory

  12. Chemical Abundance Analysis of Moving Group W11450 (Latham 1)

    Science.gov (United States)

    O'Connell, Julia E.; Martens, Kylee; Frinchaboy, Peter M.

    2016-12-01

    We present elemental abundances for all seven stars in Moving Group W11450 (Latham 1) to determine if they may be chemically related. These stars appear to be both spatially and kinematically related, but no spectroscopic abundance analysis exists in literature. Abundances for eight elements were derived via equivalent width analyses of high-resolution (R ˜ 60,000), high-signal-to-noise ratio ( ˜ 100) spectra obtained with the Otto Struve 2.1 m telescope and the Sandiford Echelle Spectrograph at McDonald Observatory. The large star-to-star scatter in metallicity, -0.55 ≤ [Fe/H] ≤slant 0.06 dex (σ = 0.25), implies these stars were not produced from the same chemically homogeneous molecular cloud, and are therefore not part of a remnant or open cluster as previously proposed. Prior to this analysis, it was suggested that two stars in the group, W11449 and W11450, are possible wide binaries. The candidate wide binary pair show similar chemical abundance patterns with not only iron but with other elements analyzed in this study, suggesting the proposed connection between these two stars may be real.

  13. Determination of the content of selected elements in medieval waterlogged oak wood from the Lednica Lake-a case study.

    Science.gov (United States)

    Broda, Magdalena; Frankowski, Marcin

    2017-10-01

    The content of selected elements: Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Si, Ti, V and Zn was determined in archaeological waterlogged oak wood from the Lednica Lake by using the inductively coupled plasma optical emission spectrometry (ICP-OES) method. The concentration of metals (especially heavy metals) in wood is typically specified to characterise this material and evaluate the possibility to use it for industrial purposes. In case of waterlogged archaeological wood intended for further research on new methods of conservation, such an analysis is important for other reasons. As it has been confirmed by numerous conservators and researchers, the presence of metal compounds is a serious problem not only due to their destructive influence on wood tissue but also from a conservation/re-conservation perspective. Metal-containing chemicals may influence conservation treatments by reacting with substances used for wood conservation and causing irreversible damage to wooden objects. Therefore, while developing new solutions for wood conservation, a broad knowledge not only on the state of wood preservation and deterioration but also on interacting chemical factors is required. The results of the research clearly show that content of minerals in waterlogged wood excavated from the bottom of the Lednica Lake considerably exceeded the average percentage of these elements in contemporary wood, which is associated with the mineralisation process. Moreover, variability in metal content was observed between waterlogged and contemporary wood. In waterlogged wood, the highest concentrations of Ca, Fe, Mg and P were observed, while in contemporary oak wood the predominant concentrations of K, Ca, Mn and Si were determined. Statistical analysis showed the variability in content of elements between different archaeological wood zones and contemporary wood. On the basis of the results obtained, it could be concluded that the studied waterlogged

  14. Application of activation analysis for determination of some elements in cassiterite samples; Aplicacao da analise por ativacao para a determinacao de alguns elementos em amostras de cassiterita

    Energy Technology Data Exchange (ETDEWEB)

    Armelin, Maria Jose Aguirre

    1978-07-01

    This work consists in the development of an analytical method using activation by thermal neutrons for the determination of some minor elements and traces present in cassiterite (tin ore). This method was then applied to determine these elements in samples of cassiterite from different regions of Brazil. An analysis was made of the mineralogy characteristic of cassiterite as well as of the minerals most commonly associated with it. Four main types of interference were found to occur in the analysis by activation of trace elements in samples of cassiterite. The method involves the analysis without chemical separation for the determination of some elements and the analysis with chemical separation for the determination of other elements. The steps involved in both types of analysis are described. In the analysis with chemical separation the matrix element (tin) is separated by distillation in an H{sub 2}SO{sub 4}-HBr medium, after fusion of the ore with Na{sub 2}O{sub 2}. Arsine and antimony are determined in the distilled, whereas some lanthanide elements and uranium are determined in the distillation residue by separating them as a group by precipitation with lanthanum fluoride. A discussion on the precision, accuracy and sensibility of the method is also included. (author)

  15. Determination of essential elements in formulas commercialized at the Sao Paulo state, Brazil; Determinacao de elementos essenciais em formulas infantis comercializadas em Sao Paulo-Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Vinicius Dias; Vallinoto, Priscila; Maihara, Vera Akiko, E-mail: pvallinoto@ipen.br, E-mail: vmaihara@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    This paper intends to determine the concentration of elements, presents in the infant formulas, by using the Neutron Activation Analysis for verification if the quantity is not exceeding the toxicity limit, and if the concentration of each element is correct as presented on the label of each packaging

  16. Finite Element Modeling of CNS White Matter Kinematics: Use of a 3D-RVE to Determine Material Properties

    Directory of Open Access Journals (Sweden)

    Yi ePan

    2013-12-01

    Full Text Available Axonal injury represents a critical target area for the prevention and treatment of traumatic brain and spinal cord injuries. Finite element (FE models of the head and/or brain are often used to predict brain injury caused by external mechanical loadings, such as explosive waves and direct impact. The accuracy of these numerical models depends on correctly determining the material properties and on the precise depiction of the tissues’ microstructure (microscopic level. Moreover, since the axonal microstructure for specific regions of the brain white matter is locally oriented, the stress and strain fields are highly anisotropic and axon orientation dependent. Additionally, mechanical strain has been identified as the proximal cause of axonal injury, which further demonstrates the importance of this multi-scale relationship. In this study, our previously developed FE and kinematic axonal models are coupled and applied to a pseudo 3-dimensional representative volume element (RVE of central nervous system white matter to investigate the multi-scale mechanical behavior. An inverse FE procedure was developed to identify material parameters of spinal cord white matter by combining the results of uniaxial testing with FE modeling. A satisfactory balance between simulation and experiment was achieved via optimization by minimizing the squared error between the simulated and experimental force-stretch curve. The combination of experimental testing and FE analysis provides a useful analysis tool for soft biological tissues in general, and specifically enables evaluations of the axonal response to tissue-level loading and subsequent predictions of axonal damage.

  17. Flexible Automation System for Determination of Elemental Composition of Incrustations in Clogged Biliary Endoprostheses Using ICP-MS.

    Science.gov (United States)

    Fleischer, Heidi; Ramani, Kinjal; Blitti, Koffi; Roddelkopf, Thomas; Warkentin, Mareike; Behrend, Detlef; Thurow, Kerstin

    2018-02-01

    Automation systems are well established in industries and life science laboratories, especially in bioscreening and high-throughput applications. An increasing demand of automation solutions can be seen in the field of analytical measurement in chemical synthesis, quality control, and medical and pharmaceutical fields, as well as research and development. In this study, an automation solution was developed and optimized for the investigation of new biliary endoprostheses (stents), which should reduce clogging after implantation in the human body. The material inside the stents (incrustations) has to be controlled regularly and under identical conditions. The elemental composition is one criterion to be monitored in stent development. The manual procedure was transferred to an automated process including sample preparation, elemental analysis using inductively coupled plasma mass spectrometry (ICP-MS), and data evaluation. Due to safety issues, microwave-assisted acid digestion was executed outside of the automation system. The performance of the automated process was determined and validated. The measurement results and the processing times were compared for both the manual and the automated procedure. Finally, real samples of stent incrustations and pig bile were analyzed using the automation system.

  18. Trace elements determination in seawater by ICP-MS with on-line pre-concentration on a Chelex-100 column using a ‘standard’ instrument setup.

    Directory of Open Access Journals (Sweden)

    Jens Søndergaard

    2015-01-01

    • Accurate determination of the elements V, Mn, Co, Ni, Cu, Zn, Cd and Pb in a range of different seawater matrices verified by participation in 6 successive rounds of the international laboratory intercalibration program QUASIMEME.

  19. Digital image correlation and finite element modelling as a method to determine mechanical properties of human soft tissue in vivo

    CERN Document Server

    Moerman, Kevin M; Evans, Sam L; Simms, Ciaran K

    2016-01-01

    The mechanical properties of human soft tissue are crucial for impact biomechanics, rehabilitation engineering and surgical simulation. Validation of these constitutive models using human data remains challenging and often requires the use of non-invasive imaging and inverse finite element (FE) analysis. Post processing data from imaging methods such as tagged magnetic resonance imaging (MRI) can be challenging. Digital Image Correlation (DIC) however is a relatively straightforward imaging method and thus the goal of this study was to assess the use of DIC in combination with FE modelling to determine the bulk material properties of human soft tissue. Indentation experiments were performed on a silicone gel soft tissue phantom. A two camera DIC setup was then used to record the 3D surface deformation. The experiment was then simulated using a FE model.

  20. An inverse finite element method for determining the tissue compressibility of human left ventricular wall during the cardiac cycle.

    Science.gov (United States)

    Hassaballah, Abdallah I; Hassan, Mohsen A; Mardi, Azizi N; Hamdi, Mohd

    2013-01-01

    The determination of the myocardium's tissue properties is important in constructing functional finite element (FE) models of the human heart. To obtain accurate properties especially for functional modeling of a heart, tissue properties have to be determined in vivo. At present, there are only few in vivo methods that can be applied to characterize the internal myocardium tissue mechanics. This work introduced and evaluated an FE inverse method to determine the myocardial tissue compressibility. Specifically, it combined an inverse FE method with the experimentally-measured left ventricular (LV) internal cavity pressure and volume versus time curves. Results indicated that the FE inverse method showed good correlation between LV repolarization and the variations in the myocardium tissue bulk modulus K (K = 1/compressibility), as well as provided an ability to describe in vivo human myocardium material behavior. The myocardium bulk modulus can be effectively used as a diagnostic tool of the heart ejection fraction. The model developed is proved to be robust and efficient. It offers a new perspective and means to the study of living-myocardium tissue properties, as it shows the variation of the bulk modulus throughout the cardiac cycle.

  1. An inverse finite element method for determining the tissue compressibility of human left ventricular wall during the cardiac cycle.

    Directory of Open Access Journals (Sweden)

    Abdallah I Hassaballah

    Full Text Available The determination of the myocardium's tissue properties is important in constructing functional finite element (FE models of the human heart. To obtain accurate properties especially for functional modeling of a heart, tissue properties have to be determined in vivo. At present, there are only few in vivo methods that can be applied to characterize the internal myocardium tissue mechanics. This work introduced and evaluated an FE inverse method to determine the myocardial tissue compressibility. Specifically, it combined an inverse FE method with the experimentally-measured left ventricular (LV internal cavity pressure and volume versus time curves. Results indicated that the FE inverse method showed good correlation between LV repolarization and the variations in the myocardium tissue bulk modulus K (K = 1/compressibility, as well as provided an ability to describe in vivo human myocardium material behavior. The myocardium bulk modulus can be effectively used as a diagnostic tool of the heart ejection fraction. The model developed is proved to be robust and efficient. It offers a new perspective and means to the study of living-myocardium tissue properties, as it shows the variation of the bulk modulus throughout the cardiac cycle.

  2. Protein energetic conformational analysis from NMR chemical shifts (PECAN) and its use in determining secondary structural elements

    Energy Technology Data Exchange (ETDEWEB)

    Eghbalnia, Hamid R.; Wang Liya; Bahrami, Arash [National Magnetic Resonance Facility at Madison, Biochemistry Department (United States); Assadi, Amir [University of Wisconsin-Madison, Mathematics Department (United States); Markley, John L. [National Magnetic Resonance Facility at Madison, Biochemistry Department (United States)], E-mail: eghbalni@nmrfam.wisc.edu

    2005-05-15

    We present an energy model that combines information from the amino acid sequence of a protein and available NMR chemical shifts for the purposes of identifying low energy conformations and determining elements of secondary structure. The model ('PECAN', Protein Energetic Conformational Analysis from NMR chemical shifts) optimizes a combination of sequence information and residue-specific statistical energy function to yield energetic descriptions most favorable to predicting secondary structure. Compared to prior methods for secondary structure determination, PECAN provides increased accuracy and range, particularly in regions of extended structure. Moreover, PECAN uses the energetics to identify residues located at the boundaries between regions of predicted secondary structure that may not fit the stringent secondary structure class definitions. The energy model offers insights into the local energetic patterns that underlie conformational preferences. For example, it shows that the information content for defining secondary structure is localized about a residue and reaches a maximum when two residues on either side are considered. The current release of the PECAN software determines the well-defined regions of secondary structure in novel proteins with assigned chemical shifts with an overall accuracy of 90%, which is close to the practical limit of achievable accuracy in classifying the states.

  3. An Inverse Finite Element Method for Determining the Tissue Compressibility of Human Left Ventricular Wall during the Cardiac Cycle

    Science.gov (United States)

    Hassaballah, Abdallah I.; Hassan, Mohsen A.; Mardi, Azizi N.; Hamdi, Mohd

    2013-01-01

    The determination of the myocardium’s tissue properties is important in constructing functional finite element (FE) models of the human heart. To obtain accurate properties especially for functional modeling of a heart, tissue properties have to be determined in vivo. At present, there are only few in vivo methods that can be applied to characterize the internal myocardium tissue mechanics. This work introduced and evaluated an FE inverse method to determine the myocardial tissue compressibility. Specifically, it combined an inverse FE method with the experimentally-measured left ventricular (LV) internal cavity pressure and volume versus time curves. Results indicated that the FE inverse method showed good correlation between LV repolarization and the variations in the myocardium tissue bulk modulus K (K = 1/compressibility), as well as provided an ability to describe in vivo human myocardium material behavior. The myocardium bulk modulus can be effectively used as a diagnostic tool of the heart ejection fraction. The model developed is proved to be robust and efficient. It offers a new perspective and means to the study of living-myocardium tissue properties, as it shows the variation of the bulk modulus throughout the cardiac cycle. PMID:24367544

  4. Microwave digestion methods for the determination of trace elements in brain and liver samples by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Krachler, M; Radner, H; Irgolic, K J

    1996-05-01

    Two microwave digestion systems (open-focused and closed-pressurized) were tested for the mineralization of human brain and bovine liver (NIST SRM 1577a) as dissolution steps prior to the determination of 16 trace elements (Bi, Cd, Co, Cs, Cu, Fe, Hg, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, and Zn) by inductively coupled plasma mass spectrometry (ICP-MS). Digestion parameters (mass of sample, digestion mixture, and power/time steps) were optimized using temperature and pressure sensors. Digestions with the open-focused microwave system require larger volumes of conc. HNO(3) and 30% H(2)O(2) than digestions with the closed-pressurized system. Both systems produce correct results for the bovine liver samples. The concentrations obtained for the digests of the open-focused system tend to be less precise than the concentrations from the "closed-pressurized" digests. Because the "open-focused" digests must be diluted to 50 mL to bring the acid concentration to 0.7-2.0 mol/L required by the ICP-MS (closed-pressurized digests need to be diluted to only 20 mL), the detection limits for the system with the open-focused digestion are higher than for the system with the closed-pressurized digestor. The open-focused digestor cannot handle more than 150 mg brain tissue, whereas the closed-pressurized system can mineralize 470 mg. The latter method gave better results with brain tissue than the open-focused system. The preparation of brain tissue as reference material for the determination of trace elements in brain samples is described.

  5. Determination of trace rare earth elements in gadolinium aluminate by inductively coupled plasma time of flight mass spectrometry

    Science.gov (United States)

    Saha, Abhijit; Deb, S. B.; Nagar, B. K.; Saxena, M. K.

    An analytical methodology was developed for the precise quantification of ten trace rare earth elements (REEs), namely, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, and Tm, in gadolinium aluminate (GdAlO3) employing an ultrasonic nebulizer (USN)-desolvating device based inductively coupled plasma mass spectrometry (ICP-MS). A microwave digestion procedure was optimized for digesting 100 mg of the refractory oxide using a mixture of sulphuric acid (H2SO4), phosphoric acid (H3PO4) and water (H2O) with 1400 W power, 10 min ramp and 60 min hold time. An USN-desolvating sample introduction system was employed to enhance analyte sensitivities by minimizing their oxide ion formation in the plasma. Studies on the effect of various matrix concentrations on the analyte intensities revealed that precise quantification of the analytes was possible with matrix level of 250 mg L- 1. The possibility of using indium as an internal standard was explored and applied to correct for matrix effect and variation in analyte sensitivity under plasma operating conditions. Individual oxide ion formation yields were determined in matrix matched solution and employed for correcting polyatomic interferences of light REE (LREE) oxide ions on the intensities of middle and heavy rare earth elements (MREEs and HREEs). Recoveries of ≥ 90% were achieved for the analytes employing standard addition technique. Three real samples were analyzed for traces of REEs by the proposed method and cross validated for Eu and Nd by isotope dilution mass spectrometry (IDMS). The results show no significant difference in the values at 95% confidence level. The expanded uncertainty (coverage factor 1σ) in the determination of trace REEs in the samples were found to be between 3 and 8%. The instrument detection limits (IDLs) and the method detection limits (MDLs) for the ten REEs lie in the ranges 1-5 ng L- 1 and 7-64 μg kg- 1 respectively.

  6. Determination of 15N abundance in nanogram pools of NO3 - and NO2 - by denitrification bioassay and mass spectrometry

    DEFF Research Database (Denmark)

    Højberg, Ole; Johansen, H. S.; Sorensen, J.

    1994-01-01

    Suspensions of two strains of Pseudomonas aeruginosa (ON12 and ON12-1) were used to reduce NO3 - and NO2 -, respectively, to N2O. The evolved N2O was quantified by gas chromatography with electron capture detection, and the 15N abundance was determined by mass spectrometry with a special inlet sy...... studies of inorganic N transformations by, e.g., nitrifying or denitrifying bacteria in the environment....

  7. Sulfur and zinc abundances of red giant stars†

    Science.gov (United States)

    Takeda, Yoichi; Omiya, Masashi; Harakawa, Hiroki; Sato, Bun'ei

    2016-10-01

    Sulfur and zinc are chemically volatile elements, which play significant roles as depletion-free tracers in studying galactic chemical evolution. However, regarding red giants having evolved off the main sequence, reliable abundance determinations of S and Zn seem to be difficult, despite the several studies that have been reported so far. Given this situation, we tried to establish the abundances of these elements for an extensive sample of 239 field GK giants ( - 0.8 ≲ [Fe/H] ≲ +0.2), by applying the spectrum-fitting technique to S I 8694-5, S I 6757, and Zn I 6362 lines and by taking into account the non-LTE effect. Besides, similar abundance analysis was done for 160 FGK dwarfs to be used for comparison. The non-LTE corrections for the S and Zn abundances derived from these lines turned out to be ≲ 0.1(-0.2) dex for most cases and not very significant. It revealed that the S I 6757 feature is more reliable as an abundance indicator than S I 8694-5 for the case of red giants, because the latter suffers blending of unidentified lines. The finally resulting [S/Fe]-[Fe/H] and [Zn/Fe]-[Fe/H] relations for GK giants were confirmed to be in good agreement with those for FGK dwarfs, indicating that S and Zn abundances of red giants are reliably determinable from the S I 6757 and Zn I 6362 lines. Accordingly, not only main-sequence stars but also evolved red giant stars are usable for tracing the chemical evolution history of S and Zn in the regime of disk metallicity by using these lines.

  8. Calibration of the WFC3 Emission-Line Filters and Application of the Results to the Greatest Source of Uncertainties in Determining Abundances in Gase

    Science.gov (United States)

    O'Dell, C.

    2010-09-01

    The WFC3 is arguably the most powerful camera that has been used on the HST. This capability arises in part from the uniquely complete set of narrow-band filters that were incorporated for making images of nebulae in emission-lines. Turning these oft-times beautiful images into scientifically useful information requires accurate flux calibration of the filters, which is the first subject of this proposal. The present plan is that WFC3 calibration will be done from pre-launch properties of the filters and observations of stars. The WFC3 filters transmission profiles were measured pre-launch in a different optical configuration and temperature than applies within the WFC3, thus rendering uncertain any flux calibrations tied to those pre-launch measurements. We propose to perform a ?ground-truth? calibration of the WFC3 narrow-band filters using NGC 6720 as a reference source, in much the same manner that the PI did when calibrating similar filters in the WFPC2 and the ACS.These new calibrations will then be used to address the t^2 problem in Gaseous Nebulae. This is the source of uncertainties in the relative abundances of factors 1.1 to 10 and undermines efforts to trace the abundance variations within our Galaxy and other galaxies. The t^2 problem remains unresolved after four decades and the NGC 6720 images used for the filter calibration may resolve the problem if they show that regions of small-scale temperature fluctuations arise from low-temperature shadow-zones behind knots that are known to exist within the nebula or from high-temperature shocks that have been posited. Unlike the case of the Orion Nebula, where we have addressed this problem with fewer diagnostic filters, the geometry of NGC 6720 is ideally favorable for seeing these temperature variations and identifying their cause.

  9. Determination of penetration depth at high velocity impact using finite element method and artificial neural network tools

    Directory of Open Access Journals (Sweden)

    Namık KılıÇ

    2015-06-01

    Full Text Available Determination of ballistic performance of an armor solution is a complicated task and evolved significantly with the application of finite element methods (FEM in this research field. The traditional armor design studies performed with FEM requires sophisticated procedures and intensive computational effort, therefore simpler and accurate numerical approaches are always worthwhile to decrease armor development time. This study aims to apply a hybrid method using FEM simulation and artificial neural network (ANN analysis to approximate ballistic limit thickness for armor steels. To achieve this objective, a predictive model based on the artificial neural networks is developed to determine ballistic resistance of high hardness armor steels against 7.62 mm armor piercing ammunition. In this methodology, the FEM simulations are used to create training cases for Multilayer Perceptron (MLP three layer networks. In order to validate FE simulation methodology, ballistic shot tests on 20 mm thickness target were performed according to standard Stanag 4569. Afterwards, the successfully trained ANN(s is used to predict the ballistic limit thickness of 500 HB high hardness steel armor. Results show that even with limited number of data, FEM-ANN approach can be used to predict ballistic penetration depth with adequate accuracy.

  10. A novel total reflection X-ray fluorescence procedure for the direct determination of trace elements in petrochemical products

    Energy Technology Data Exchange (ETDEWEB)

    Cinosi, Amedeo [Sasol Italy SpA, Paderno Dugnano (Italy); GNR srl, Agrate Conturbia, Novara (Italy); Andriollo, Nunzio [Sasol Italy SpA, Paderno Dugnano (Italy); Pepponi, Giancarlo [Fondazione Bruno Kessler, Povo, Trento (Italy); Monticelli, Damiano [Universita degli Studi dell' Insubria - sede di Como, Dipartimento di Scienze Chimiche e Ambientali, Como, CO (Italy)

    2011-01-15

    A total reflection X-ray fluorescence (TXRF) procedure was developed for the determination of metal traces in petrochemical end products or intermediates for surfactant synthesis. The method combines a fast and straightforward sample preparation, i.e. deposition on the sample holder and evaporation of the sample matrix, with an efficient quantification method based on internal standardization (organic gallium standard). The method developed showed detection limits below 0.05 {mu}g g{sup -1} and in most cases below 0.005 {mu}g g{sup -1}. Fifteen elements (Ca, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Rh, Sn, Sr, V and Zn) were determined in matrices such as paraffins, n-olefins, linear alkylbenzenes, long-chain alkyl alcohols and esters: typical metal contents were below 1 {mu}g g{sup -1}. The results were compared with the reference method ASTM D5708 (test method B) based on inductively coupled plasma optical emission spectroscopy: advantages and drawbacks of the two procedures were critically evaluated. The TXRF method developed showed comparable precision and absence of bias with respect to the reference method. A comparison of the performances of the two methods is presented. (orig.)

  11. Determination of reference values of elements in whole blood of the wistar rats using neutron activation analysis (NAA)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Laura C.; Zamboni, Cibele B., E-mail: laura@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Some investigations, especially biochemistry analysis, can be performed using whole blood if the normality limits are established. The present study deals with the determination of reference values for elements of clinical interest, in whole blood of Wistar rats using the Neutron Activation Analysis technique. Usually these small-sized animals are used as guinea-pig on experiments that involves testing new medicines and medical diagnostic studies. In this investigation, the reference values for blood were determined for: Br (0.0011 - 0.0095 gL{sup -1}), Ca (0.0 - 0.66 gL{sup -1}), Cl (2.35 - 4.91 gL{sup -1}), K (1.00 - 3.12 gL{sup -1}), Mg (0.044 - 0.108 gL{sup -1}), Na (1.13 - 3.09 gL{sup -1}) and S (0.53 - 1.81 gL{sup -1}). These data will allow researchers to optimize their studies, both in terms of cost and time by selecting species that fits to the experimental model as a clinical reference as well as performing biochemical analyses in whole blood using small quantities (few {mu}L) compared to the conventional analyses performed in serum (few mL). (author)

  12. Abundances and Kinematics of OB Stars in the Leading Arm of the Magellanic System

    Science.gov (United States)

    Zhang, L.; Moni Bidin, C.; Casetti-Dinescu, D. I.; Mendez, R. A.; Girard, T. M.; Korchagin, V. I.; Vieira, K.; van Altena, W. F.; Zhao, G.

    2018-01-01

    We determined seven element abundances (He, C, N, O, Mg, Si, and S) and kinematics for eight O-/B- type stars which is selected from 42 candidates (Casetti-Dinescu et al. 2014) of membership in the Leading Arm (LA) of the Magellanic System. The high resolution spectra were taken with the MIKE instrument on the Magellan 6.5m Clay telescope.

  13. Development of a certified reference material (NMIJ CRM 7512-a) for the determination of trace elements in milk powder.

    Science.gov (United States)

    Zhu, Yanbei; Narukawa, Tomohiro; Miyashita, Shin-ichi; Kuroiwa, Takayoshi; Inagaki, Kazumi; Chiba, Koichi; Hioki, Akiharu

    2013-01-01

    A certified reference material (CRM), NMIJ CRM 7512-a, was developed for the determination of trace elements in milk powder. At least three independent analytical methods were applied to characterize the certified value of each element; all of these analytical methods were based on microwave acid digestions and carried out using different analytical instruments. The certified value was given on a dry-mass basis, where the dry-mass correction factor was obtained by drying the sample at 65°C for 15 to 25 h. The certified values in the units of mass fractions for 13 elements were as follows: Ca, 8.65 (0.38) g kg(-1); Fe, 0.104 (0.007) g kg(-1); K, 8.41 (0.33) g kg(-1); Mg, 0.819 (0.024) g kg(-1); Na, 1.87 (0.09) g kg(-1); P, 5.62 (0.23) g kg(-1); Ba, 0.449 (0.013) mg kg(-1); Cu, 4.66 (0.23) mg kg(-1); Mn, 0.931 (0.032) mg kg(-1); Mo, 0.223 (0.012) mg kg(-1); Rb, 8.93 (0.31) mg kg(-1); Sr, 5.88 (0.20) mg kg(-1); and Zn, 41.3 (1.4) mg kg(-1), where the numbers in the parentheses are the expanded uncertainties with a coverage factor of 2. The expanded uncertainties were estimated considering the contribution of the analytical methods, the method-to-method variance, the sample homogeneity, the dry-mass correction factor, and the concentrations of the standard solutions for calibration. The concentrations of As (2.1 μg kg(-1)), Cd (0.2 μg kg(-1)), Cr (1.3 μg kg(-1)), Pb (0.3 μg kg(-1)), and Y (64 μg kg(-1)) were given as information values for the present CRM.

  14. Distributions and determinants of mercury concentrations in toenails among American young adults: the CARDIA Trace Element Study.

    Science.gov (United States)

    Xun, Pengcheng; Liu, Kiang; Morris, J Steve; Jordan, Joanne M; He, Ka

    2013-03-01

    Since data on mercury (Hg) levels in Caucasians and African Americans (AAs) of both genders are lacking, this study aims to present toenail Hg distributions and explore the potential determinants using data from the Coronary Artery Risk Development in Young Adults Trace Element Study. Data from 4,344 Americans, aged 20-32 in 1987, recruited from Oakland, Chicago, Minneapolis, and Birmingham were used to measure toenail Hg levels by instrumental neutron-activation method. The Hg distribution was described with selected percentiles and geometric means. Multivariable linear regression (MLR) was used to examine potential determinants of Hg levels within ethnicity-gender subgroups. The geometric mean of toenail Hg was 0.212 (95 % CI = 0.207-0.218) μg/g. Hg levels varied geographically with Oakland the highest [0.381 (0.367-0.395) μg/g] and Minneapolis the lowest [0.140 (0.134-0.147) μg/g]. MLR analyses showed that male gender and AA ethnicity were negatively associated with toenail Hg levels, and that age, living in Oakland city, education level, alcohol consumption, and total fish intake were positively associated with toenail Hg concentrations within each ethnicity-gender subgroup. Current smokers were found to have higher Hg only in AA men. This study suggested age, gender, ethnicity, study center, alcohol, education level, and fish consumption consistently predict toenail Hg levels. As fish consumption was the key determinant, avoiding certain types of fish that have relatively high Hg levels may be crucial in reducing Hg intake.

  15. Finite element analysis of equine incisor teeth. Part 1: determination of the material parameters of the periodontal ligament.

    Science.gov (United States)

    Schrock, P; Lüpke, M; Seifert, H; Borchers, L; Staszyk, C

    2013-12-01

    In equine dentistry, periodontal diseases are frequently found in aged horses. Excessive strains and stresses within the periodontal ligament (PDL) occurring during the masticatory cycle may be predisposing factors especially in old horses with short, worn teeth. The finite element (FE) analysis is a valuable tool to investigate such strains and stresses in biological materials but a precondition for a realistic and reliable FE analysis is accurate knowledge of material parameters. As no data exist concerning the PDL of equine incisor teeth, this study was undertaken to determine the equine specific, age related and load dependent Young's modulus of equine incisors. To determine the biomechanical behaviour of the PDL, the incisor jaw-regions of horses of different ages were sectioned into 5mm thick slice samples and the incisors experimentally intruded (i.e. axially displaced into the alveolus) while recording the load-displacement relationship. Based on high resolution micro-computer tomography (μCT)-datasets, reliable and detailed 3-dimensional models of the slice samples were constructed focusing on precisely modelling the anatomy of the PDL. FE calculations were then performed and set-actual comparisons of the FE results with the experimentally measured displacements enabled the Young's modulus of the PDL to be determined. The results of this study reflect the typical non-linear behaviour of the collagen fibres of the PDL and present a high load dependency of the PDL's Young's modulus. Further investigations calculating the strains and stresses within the periodontal ligament, teeth and surrounding bone of the entire rostral aspect of the jaw are warranted. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Determination of trace rare earth elements in gadolinium aluminate by inductively coupled plasma time of flight mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Abhijit; Deb, S.B.; Nagar, B.K.; Saxena, M.K., E-mail: saxenamk@barc.gov.in

    2014-04-01

    An analytical methodology was developed for the precise quantification of ten trace rare earth elements (REEs), namely, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, and Tm, in gadolinium aluminate (GdAlO{sub 3}) employing an ultrasonic nebulizer (USN)-desolvating device based inductively coupled plasma mass spectrometry (ICP-MS). A microwave digestion procedure was optimized for digesting 100 mg of the refractory oxide using a mixture of sulphuric acid (H{sub 2}SO{sub 4}), phosphoric acid (H{sub 3}PO{sub 4}) and water (H{sub 2}O) with 1400 W power, 10 min ramp and 60 min hold time. An USN-desolvating sample introduction system was employed to enhance analyte sensitivities by minimizing their oxide ion formation in the plasma. Studies on the effect of various matrix concentrations on the analyte intensities revealed that precise quantification of the analytes was possible with matrix level of 250 mg L{sup −1}. The possibility of using indium as an internal standard was explored and applied to correct for matrix effect and variation in analyte sensitivity under plasma operating conditions. Individual oxide ion formation yields were determined in matrix matched solution and employed for correcting polyatomic interferences of light REE (LREE) oxide ions on the intensities of middle and heavy rare earth elements (MREEs and HREEs). Recoveries of ≥ 90% were achieved for the analytes employing standard addition technique. Three real samples were analyzed for traces of REEs by the proposed method and cross validated for Eu and Nd by isotope dilution mass spectrometry (IDMS). The results show no significant difference in the values at 95% confidence level. The expanded uncertainty (coverage factor 1σ) in the determination of trace REEs in the samples were found to be between 3 and 8%. The instrument detection limits (IDLs) and the method detection limits (MDLs) for the ten REEs lie in the ranges 1–5 ng L{sup −1} and 7–64 μg kg{sup −1} respectively. - Highlights: • A

  17. Determination of Fatty Acid, C, H, N and Trace Element Composition in Grape Seed by GC/MS, FTIR, Elemental Analyzer and ICP/OES

    OpenAIRE

    Seçilmiş Canbay, Hale; Bardakçı, Belgin

    2011-01-01

    Abstract: Four different methods were used for the investigation of fatty acid, C, H, N and trace element composition of grape seed oil and pulp. The fatty acid profile of the grape seed oil was measured by GC/MS. Moreover, structural analysis of the oil was carried out by FT/IR spectrometry with a Zn Se ATR accessory. The quantification of selected metals Na, K, Mg, Ca, Mn, Fe, Zn and Cu in grape seed oil and pulp was carried out using microwave assisted digestion followed by ICP/OES. Grape ...

  18. La citometría de flujo en el estudio de tumores mediastinales ricos en elementos linfoides Flow cytometry for the study of mediastinal tumors with abundant lymphoid elements

    Directory of Open Access Journals (Sweden)

    Gerardo Vides Almonacid

    2008-02-01

    Full Text Available El mediastino anterior es un sitio frecuente de localización de tumores ricos en elementos linfoides. La identificación correcta de cada entidad es de importancia en el tratamiento de los pacientes. En ocasiones puede plantearse el diagnóstico diferencial entre timoma y linfoma linfoblástico con fenotipo de precursor T (LLB-T. La Citometría de Flujo (CF es una técnica complementaria útil para estos tumores de la cual se obtiene información cualitativa y cuantitativa. Revisamos 38 tumores mediastinales que tenían estudio de CF. Además comparamos los resultados de CF de timomas y tejido tímico normal con 42 casos de LLB-T de otras localizaciones anatómicas. De los 38 tumores mediastinales 6 eran lesiones benignas, 9 linfomas difusos de células grandes con fenotipo B (LDCG-B, 10 linfomas de Hodgkin (LH, 11 timomas y 2 LLB-T. En 24 casos la CF aportó información positiva, definiendo el inmunofenotipo de las células linfoides neoplásicas, o los linfocitos característicos que acompañan a los timomas. La CF en los 10 casos de LH y en 4 lesiones benignas permitió descartar otros tipos de linfoma (LDCG-B, LLB-T, etc.. Las marcaciones para CD3, CD4 y CD8 fueron las más útiles para el diagnóstico diferencial entre timomas y LLB-T. En conclusión, la CF es una técnica complementaria de utilidad que aporta información en lesiones mediastinales de manera rápida, requiriendo cantidades pequeñas de material, tanto para el diagnóstico inicial como para el monitoreo de estas enfermedades.The anterior mediastinum is a common site of tumors with abundant lymphoid elements. Flow cytometry is a useful complementary technique to analyze this type of tumors, which provides qualitative and quantitative information. A differential diagnosis can be sometimes made between thymoma and precursor T-lymphoblastic lymphoma (T-LBL. Correct identification is of utmost importance for patient treatment. A total of 38 mediastinal tumors were analyzed, and

  19. Abundances in Galactic bulge planetary nebulae from optical, ultraviolet and infrared observations

    Science.gov (United States)

    Smith, Christina L.; Zijlstra, Albert A.; Gesicki, Krzysztof M.; Dinerstein, Harriet L.

    2017-11-01

    Iron suffers from high levels of depletion in the highly ionized environments of planetary nebulae, making the direct determination of undepleted elemental iron abundances difficult. Zinc, which does not suffer from the same depletion effects as iron, may be used as a surrogate element to measure iron abundances as there is an approximately constant zinc-to-iron ratio across a wide range of metallicities. In this paper, we report zinc abundances of six Galactic bulge planetary nebulae determined from new observations taken with Infrared Spectrometer And Array Camera (ISAAC) on the Very Large Telescope, Chile, prior to the instrument's decommissioning as well as a further three based upon literature observations. Ultraviolet and Visual Echelle Spectrograph (UVES) data of the sample planetary nebulae are presented and have been used to derive abundances, temperatures and densities of a variety of elements and ions. The abundances derived from the UVES data agree well with results from the literature. [Zn/H], determined from the ISAAC observations, is found to be generally subsolar and [O/Zn] is found to be either consistent or enriched with respect to solar.

  20. Applying of Factor Analyses for Determination of Trace Elements Distribution in Water from River Vardar and Its Tributaries, Macedonia/Greece

    Directory of Open Access Journals (Sweden)

    Stanko Ilić Popov

    2014-01-01

    Full Text Available A systematic study was carried out to investigate the distribution of fifty-six elements in the water samples from river Vardar (Republic of Macedonia and Greece and its major tributaries. The samples were collected from 27 sampling sites. Analyses were performed by mass spectrometry with inductively coupled plasma (ICP-MS and atomic emission spectrometry with inductively coupled plasma (ICP-AES. Cluster and R mode factor analysis (FA was used to identify and characterise element associations and four associations of elements were determined by the method of multivariate statistics. Three factors represent the associations of elements that occur in the river water naturally while Factor 3 represents an anthropogenic association of the elements (Cd, Ga, In, Pb, Re, Tl, Cu, and Zn introduced in the river waters from the waste waters from the mining and metallurgical activities in the country.

  1. Determination of elements in blood of golden hamster by NAA; Determinacao de elementos em sangue de hamster dourado usando AAN

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Rodrigo Oliveira de

    2009-07-01

    In the present study Neutron Activation Analysis technique has been used to determine, simultaneously, some element concentrations of clinical relevance in whole blood samples of golden hamster. The normal range for Br, Ca, Cl K, Mg, Na and S considering 2 {sigma} (Two Standard deviations) was 0.011 0.047 gL{sup -1} (Br); 0.11 0.35 gL{sup -1} (Ca); 2.11 3.75 gL{sup -1} (Cl); 1.35 2.79 gL{sup -1} (K), 0.026 0.090 gL{sup -1} (Mg), 1.03 2.51 gL{sup -1} (Na) e 0.97 2.01 gL{sup -1} (S). The knowledge of these limits became possible to perform clinical investigation in this animal model using whole blood. The comparison with the results from human being whole blood estimation (Hamster and human) became possible to check the similarities or physiologic differences, an important data for animal experimentation. (author)

  2. The biomechanical determinants of concussion: finite element simulations to investigate brain tissue deformations during sporting impacts to the unprotected head.

    Science.gov (United States)

    Patton, Declan A; McIntosh, Andrew S; Kleiven, Svein

    2013-12-01

    Concussion is an injury of specific interest in collision and contact sports, resulting in a need to develop effective preventive strategies. A detailed finite element model of the human head was used to approximate the regional distribution of tissue deformations in the brain by simulating reconstructions of unhelmeted concussion and no-injury head impacts. The results were evaluated using logistic regression analysis and it was found that angular kinematics, in the coronal plane, and maximum principal strains, in all regions of the brain, were significantly associated with concussion. The results suggested that impacts to the temporal region of the head cause coronal rotations, which render injurious strain levels in the brain. Tentative strain tolerance levels of 0.13, 0.15, and 0.26 in the thalamus, corpus callosum, and white matter, respectively, for a 50% likelihood of concussion were determined by logistic regression. The tentative strain tolerance levels compared well with previously reported results from reconstruction studies of American football and single axon, optic nerve, and brain slice culture model studies. The methods used in the current study provide an opportunity to collect unique kinematic data of sporting impacts to the unprotected head, which can be employed in various ways to broaden the understanding of concussion.

  3. Determining the Optimum Exposure and Recovery Periods for Efficient Operation of a QCM Based Elemental Mercury Vapor Sensor

    Directory of Open Access Journals (Sweden)

    K. M. Mohibul Kabir

    2015-01-01

    Full Text Available In recent years, mass based transducers such as quartz crystal microbalance (QCM have gained huge interest as potential sensors for online detection of elemental mercury (Hg0 vapor from anthropogenic sources due to their high portability and robust nature enabling them to withstand harsh industrial environments. In this study, we determined the optimal Hg0 exposure and recovery times of a QCM based sensor for ensuring its efficient operation while monitoring low concentrations of Hg0 vapor (<400 ppbv. The developed sensor was based on an AT-cut quartz substrate and utilized two gold (Au films on either side of the substrate which functions as the electrodes and selective layer simultaneously. Given the temporal response mechanisms associated with mass based mercury sensors, the experiments involved the variation of Hg0 vapor exposure periods while keeping the recovery time constant following each exposure and vice versa. The results indicated that an optimum exposure and recovery periods of 30 and 90 minutes, respectively, can be utilized to acquire the highest response magnitudes and recovery rate towards a certain concentration of Hg0 vapor whilst keeping the time it takes to report an accurate reading by the sensor to a minimum level as required in real-world applications.

  4. Determinations Of The Matrix Element V(ub) From Inclusive Semileptonic B Decays With Reduced Model Dependency

    CERN Document Server

    Hill, E J

    2005-01-01

    This thesis presents several measurements of the CKM quark mixing matrix element |Vub| with reduced theoretical model dependency. The data sample for these results consists of about 90 million ϒ(4 S) → BB¯ decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric- energy e+e- collider, located at the Stanford Linear Accelerator Center. The determinations of | Vub| are performed by measuring the invariant hadronic mass spectrum from inclusive semileptonic B meson decays recoiling from a fully reconstructed B meson decaying hadronically. In one method, the partial rate extracted from the charmless semileptonic hadronic mass spectrum below 1.67 GeV/c2 is combined with a weighted integral over the endpoint of the photon energy spectrum from b → sγ decays and the result |Vub| = (4.43 ± 0.38stat ± 0.25syst ± 0.28theo ) × 10- 3 is obtained. In a second method, the charmless hadronic mass spectrum ...

  5. Magnetic Sector ICPMS with Desolvating Micronebulization:  Interference-Free Subpicogram Determination of Rare Earth Elements in Natural Samples.

    Science.gov (United States)

    Field, M P; Sherrell, R M

    1998-11-01

    A new method has been developed combining desolvating micronebulization with magnetic sector inductively coupled plasma mass spectrometry (ICPMS) for the analysis of all 14 stable rare earth elements (REEs) in small samples of marine particulate matter. Application is demonstrated for REEs in suspended particles from a deep ocean hydrothermal vent plume and a geological reference material. A 100-fold reduction in oxide formation, relative to standard nebulizer-spray chamber sample introduction, makes oxide interference correction negligible, even for samples that are very enriched in Ba and light REEs. Enriched isotopes for one light and one heavy REE ((145)Nd and (171)Yb) are used as both isotope dilution and internal standards, providing determination of all the REEs in one analysis. This standardization scheme eliminates the need for multimass drift correction used previously to achieve acceptable accuracy with external standardization techniques. Instead, the method exploits capabilities for accurate and precise determination of isotope ratios, a principal strength of ICPMS, and the mass-independent sensitivity of electric field scans on our double-focusing instrument. We demonstrate overall precision of ≤2% (1σ) and accuracy better than 6% for all the REEs (except Er = 8.7%), based on comparison to recommended values for USGS certified reference material BHVO-1 (basalt). This performance is similar to that obtained by full isotope dilution mass spectrometric techniques, but the new method is far simpler, requires 5 min sample(-)(1), and avoids interferences introduced by complex mixtures of enriched isotopes. Sensitivity of (1.2-1.4) × 10(6) counts s(-)(1) ppb(-)(1) and background intensities of 2-60 counts s(-)(1) provide excellent detection limits of 1-40 ppq, a 100-fold improvement on established ICPMS methods. The low sample introduction rate (100 μL min(-)(1)) allows unprecedented absolute detection limits of 1-20 fg.

  6. Determination the allowable error to adjustment of a diffractive optical element and the accuracy demanded to set the parameters of the focused beam

    Science.gov (United States)

    Murzin, Serguei P.; Kazanskiy, Nikolay L.

    2017-04-01

    Diffractive optical elements capable of transforming the wavefront in a predetermined manner, with high efficiency may be apply in recording systems and reading information, and also its transmission in the optical range. To improve the efficiency use of diffractive optical elements is expedient to determine the requirements for their adjustment and the accuracy of beam setting parameters forming. As an example, considered the use of a diffractive optical element for transmitting high-power laser beam for the purpose to conducting the appropriate heat treatment of the process object. It was determined that the permissible error of alignment of the optical element is no more ΔU1 = ΔV = 0.18·10-3 m, the accuracy of the focused beam parameters should not be lower ΔrΦ/rΦ = 3.1 %; ΔRΦ/RΦ = 2%, and the permissible value of rotation angle Φ error of the diffractive optical element is ΔΦ = 2.30. To solve this problem a diffractive optical element is characterized by adequate values of allowable errors. Keywords: diffractive optical element, laser beam, adjustment, accuracy

  7. Rapid and simultaneous determination of essential minerals and trace elements in human milk by improved flame atomic absorption spectroscopy (FAAS) with microwave digestion.

    Science.gov (United States)

    Luo, Yang; Zhang, Bo; Chen, Ming; Wang, Jue; Zhang, Xue; Gao, Wei-Yin; Huang, Jun-Fu; Fu, Wei-Ling

    2010-09-08

    A method for the simultaneous and economical determination of many trace elements in human milk is developed. Two multi-element hollow cathode lamps (HCLs) were used instead of single-element HCLs to improve the sample throughput of flame atomic absorption spectroscopy (FAAS). The microwave digestion of milk is optimized prior to detection, and the performance characteristics of the improved analysis method are identified. Clinical samples are detected by both FAAS and inductively coupled plasma-optical emission spectroscopy (ICP-OES) for methodology evaluation. Results reveal that the proposed FAAS with multi-element HCLs could determine six essential minerals and trace elements within 15 min. This method provides a linear analytical range of 0.01-10 mg L(-1). For Ca, Cu, Fe, Mg, Mn, and Zn, the limits of determination are 1.5, 3, 1.8, 2.2, 2.1, and 1.3 microg L(-1), respectively. The mean relative standard deviations (RSDs) of intra- and interassays are lower than 7%. Excellent operational characteristics of rapidity, simplicity, and economy make the proposed method a promising one for the quantification of trace elements in human milk in clinics of underdeveloped areas.

  8. Estimating species abundance from occurrence

    OpenAIRE

    He, F.; Gaston, K.J.

    2000-01-01

    The number of individuals, or the abundance, of a species\\ud in an area is a fundamental ecological parameter and a\\ud critical consideration when making management and conservation decisions (Andrewartha and Birch 1954; Krebs\\ud 1978; Gaston 1994; Caughley and Gunn 1996). However,\\ud unless the scale is very fine or localized (e.g., in a measurable habitat or a forest stand), abundance is not readily determined. At coarse or regional scales for many species, information on commonness and rar...

  9. Evolutionary Significance of Wolbachia-to-Animal Horizontal Gene Transfer: Female Sex Determination and the f Element in the Isopod Armadillidium vulgare.

    Science.gov (United States)

    Cordaux, Richard; Gilbert, Clément

    2017-07-21

    An increasing number of horizontal gene transfer (HGT) events from bacteria to animals have been reported in the past years, many of which involve Wolbachia bacterial endosymbionts and their invertebrate hosts. Most transferred Wolbachia genes are neutrally-evolving fossils embedded in host genomes. A remarkable case of Wolbachia HGT for which a clear evolutionary significance has been demonstrated is the " f element", a nuclear Wolbachia insert involved in female sex determination in the terrestrial isopod Armadillidium vulgare . The f element represents an instance of bacteria-to-animal HGT that has occurred so recently that it was possible to infer the donor (feminizing Wolbachia closely related to the w VulC Wolbachia strain of A. vulgare ) and the mechanism of integration (a nearly complete genome inserted by micro-homology-mediated recombination). In this review, we summarize our current knowledge of the f element and discuss arising perspectives regarding female sex determination, unstable inheritance, population dynamics and the molecular evolution of the f element. Overall, the f element unifies three major areas in evolutionary biology: symbiosis, HGT and sex determination. Its characterization highlights the tremendous impact sex ratio distorters can have on the evolution of sex determination mechanisms and sex chromosomes in animals and plants.

  10. Correlating laser-induced breakdown spectroscopy with neutron activation analysis to determine the elemental concentration in the ionome of the Populus trichocarpa leaf

    Science.gov (United States)

    Martin, Madhavi Z.; Glasgow, David C.; Tschaplinski, Timothy J.; Tuskan, Gerald A.; Gunter, Lee E.; Engle, Nancy L.; Wymore, Ann M.; Weston, David J.

    2017-12-01

    The black cottonwood poplar (Populus trichocarpa) leaf ionome (inorganic trace elements and mineral nutrients) is an important aspect for determining the physiological and developmental processes contributing to biomass production. A number of techniques are used to measure the ionome, yet characterizing the leaf spatial heterogeneity remains a challenge, especially in solid samples. Laser-induced breakdown spectroscopy (LIBS) has been used to determine the elemental composition of leaves and is able to raster across solid matrixes at 10 μm resolution. Here, we evaluate the use of LIBS for solid sample leaf elemental characterization in relation to neutron activation. In fact, neutron activation analysis is a laboratory-based technique which is used by the National Institute of Standards and Technology (NIST) to certify trace elements in candidate reference materials including plant leaf matrices. Introduction to the techniques used in this research has been presented in this manuscript. Neutron activation analysis (NAA) data has been correlated to the LIBS spectra to achieve quantification of the elements or ions present within poplar leaves. The regression coefficients of calibration and validation using multivariate analysis (MVA) methodology for six out of seven elements have been determined and vary between 0.810 and 0.998. LIBS and NAA data has been presented for the elements such as, calcium, magnesium, manganese, aluminum, copper, and potassium. Chlorine was also detected but it did not show good correlation between the LIBS and NAA techniques. This research shows that LIBS can be used as a fast, high-spatial resolution technique to quantify elements as part of large-scale field phenotyping projects.

  11. Solar and stellar photospheric abundances

    Directory of Open Access Journals (Sweden)

    Carlos Allende Prieto

    2016-07-01

    Full Text Available Abstract The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  12. Multi-elements (aluminium, copper, magnesium, manganese, selenium and zinc) determination in serum by dynamic reaction cell-inductively coupled plasma-mass spectrometry.

    Science.gov (United States)

    Wah Fong, Bonnie Mei; Siu, Tak Shing; Kit Lee, Joseph Sai; Tam, Sidney

    2009-01-01

    Trace element determination in laboratory medicine is widely carried out by atomic absorption or emission spectroscopy. In the last decade, there has been a rapid growth in the use of inductively coupled plasma-mass spectrometry because of its strong detection power, and the possibility of multi-elements analysis in a single run. Having the advantages of smaller sample volume and better detection limit, we developed a method for the simultaneous determinations of six trace elements by using 100 microL serum, and the assay can be accomplished within 3 min. The method developed gave recovery of the six elements ranging from 97% to 117%. The method covered a wide dynamic range with manganese in the range of nmol/L, while magnesium was in the range of mmol/L. The detection limits were 0.001 mmol/L, 0.05 micromol/L, 2.0 nmol/L, 0.2 micromol/L, 0.05 micromol/L, and 0.01 micromol/L for magnesium, aluminium, manganese, copper, zinc, and selenium, respectively. All the six elements had intra-assay imprecision of less than 5%, and inter-assay imprecision of less than 8%. This fast and robust method is suitable for use in the clinical laboratory where short turnaround time is needed for managing patients with trace element deficiency or toxicity.

  13. Interstellar Abundances Toward X Per, Revisited

    Science.gov (United States)

    Valencic, Lynne A.; Smith, Randall K.

    2014-01-01

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of 0, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ ACIS-S and XMM-Newton's RGS instruments. In general, we find that the abundances and their ratios are similar to those of young F and G stars and the most recent solar values. We compare our results with abundances required by dust grain models.

  14. [Determination of elements in branches and leaves and the fruits of Sorbus tianschanica Ruper. from different habitats in Xinjiang by microwave digestion-ICP-AES].

    Science.gov (United States)

    He, Jia-Wei; Chang, Jun-Min; Yao, Jun; Zhang, Qian; Xue, Hai-Yan; Liu, Yu-Hua

    2013-02-01

    The contents of ten elements Ca, K, Mg, Na, Fe, Mn, Zn, Cu, Pb and As in branches and leaves and the fruits of Sorbus tianschanica Ruper. from different habitats in Xinjiang were determined by ICP-AES using microwave digestion. The study indicated that the contents of elements in branches and leaves and the fruits of Sorbus tianschanica Ruper. from different habitats in Xinjiang are different, and the contents of elements in branches are richer than that in the fruits of Sorbus tianschanica Ruper. The contents of Ca, K, Mg, Na, Fe, Mn, Zn, and Cu are all high, and the harmful elements such as Pb and As are low. The results provide scientific basis for the development and utilization of the medicinal resource of Sorbus tianschanica Ruper. in Xinjiang.

  15. Implementation of fully coupled heat and mass transport model to determine the behaviour of timber elements in fire

    DEFF Research Database (Denmark)

    Pečenko, Robert; Huč, Sabina; Turk, Goran

    2014-01-01

    In this paper we present results of numerical analysis of timber beam exposed to fire. The numerical procedure is divided into two physically separated but closely related phases. In the first phase coupled problem of moisture and heat transfer over the timber beam is numerically solved using...... the enhanced finite element method. The results of the first computational stage were used as the input data for the numerical analysis of mechanical response of timber element....

  16. Determination of macro and trace elements in multivitamin dietary supplements by high-resolution continuum source graphite furnace atomic absorption spectrometry with slurry sampling.

    Science.gov (United States)

    Krawczyk, Magdalena

    2014-01-01

    In this research, three different commercially available multivitamin dietary supplements were analyzed by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) with slurry sampling. The concentrations of Cr, Cu, Fe, Mn, and Se were determined and compared to the amounts stated by producers. The safety of multivitamin dietary supplements depends on various factors including the manufacturing process and the purity and origins of the raw ingredients. For this reason, this research determined concentrations of several toxic elements (As, Cd, and Pb). Microwave-assisted high pressure Teflon bomb digestion was used to determine total amounts of elements in samples. Samples were prepared as slurries at a concentration of 0.1% (m/v) for macro elements (Cr, Cu, Fe, Mn, and Se) and at a concentration of % (m/v) for trace elements (As, Cd, and Pb) in acidic media (3M HNO3). The influence of acid concentration, Triton X-100 addition, sonication time, and sonication power on absorbance was investigated. The accuracy of this method was validated by analyses of NRCC LUTS-1 (Lobster hepatopancreas), NRCC DORM-1 (Dogfish Muscle), NRCC DOLT-2 (Dogfish Liver), NBS SRM 1570 (Spinach Leaves) and NBS SRM 1573 (Tomato Leaves) certified reference materials. The measured elements contents in these reference materials (except NRCC DOLT-2) were in satisfactory agreement with the certified values according to the t-test for a 95% confidence level. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. The width of the lateral element of the synaptonemal complex is determined by a multilayered organization of its components

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Rosario, E-mail: r_oh@ciencias.unam.mx [Laboratorio de Microscopía Electrónica, Facultad de Ciencias, Universidad Nacional Autónoma de México, México DF 04510, México (Mexico); Kouznetsova, Anna, E-mail: Anna.Kouznetsova@ki.se [Department of Cell and Molecular Biology, Karolinska Institutet, Berzelius väg 35, 171 77 Stockholm (Sweden); Echeverría-Martínez, Olga M., E-mail: omem@ciencias.unam.mx [Laboratorio de Microscopía Electrónica, Facultad de Ciencias, Universidad Nacional Autónoma de México, México DF 04510, México (Mexico); Vázquez-Nin, Gerardo H., E-mail: vazqueznin@ciencias.unam.mx [Laboratorio de Microscopía Electrónica, Facultad de Ciencias, Universidad Nacional Autónoma de México, México DF 04510, México (Mexico); Hernández-Hernández, Abrahan, E-mail: abrahan.hernandez@ki.se [Department of Cell and Molecular Biology, Karolinska Institutet, Berzelius väg 35, 171 77 Stockholm (Sweden)

    2016-05-15

    The synaptonemal complex (SC) is a proteinaceous structure that holds the homologous chromosomes in close proximity while they exchange genetic material in a process known as meiotic recombination. This meiotic recombination leads to genetic variability in sexually reproducing organisms. The ultrastructure of the SC is studied by electron microscopy and it is observed as a tripartite structure. Two lateral elements (LE) separated by a central region (CR) confer its classical tripartite organization. The LEs are the anchoring platform for the replicated homologous chromosomes to properly exchange genetic material with one another. An accurate assembly of the LE is indispensable for the proper completion of meiosis. Ultrastructural studies suggested that the LE is organized as a multilayered unit. However, no validation of this model has been previously provided. In this ultrastructural study, by using mice with different genetic backgrounds that affect the LE width, we provide further evidence that support a multilayered organization of the LE. Additionally, we provide data suggesting additional roles of the different cohesin complex components in the structure of the LEs of the SC. - Highlights: • The lateral element of the synaptonemal complex is a multilayered structure. • The width of the lateral element in synaptonemal complex-null mice is different. • Two cohesin complex cores plus one axial element form a wild-type lateral element. • The layers of the lateral element can be analyzed in different null mice models.

  18. Characterisation of a novel integrative and conjugative element ICESsD9 carrying erm(B) and tet(O) resistance determinants in Streptococcus suis, and the distribution of ICESsD9-like elements in clinical isolates.

    Science.gov (United States)

    Huang, Kaisong; Song, Yajing; Zhang, Qiang; Zhang, Anding; Jin, Meilin

    2016-12-01

    This study identified a novel integrative and conjugative element (ICESsD9) carrying erm(B) and tet(O) resistance determinants in Streptococcus suis D9 and determined its prevalence in clinical isolates. Comparative genome analysis was performed using Mauve and Artemis Comparison Tool visualisation programs. Inverse PCR was utilised to detect its circular intermediate. The transfer capacity of ICESsD9 was evaluated by mating assays using S. suis A7 and Enterococcus faecalis JH2-2 as recipients. A genome walking approach was employed to analyse the characteristics of integration sites in transconjugants. A total of 118 clinical S. suis isolates were tested by PCR mapping assays to detect ICESsD9-like elements. MLST was performed on isolates containing ICESsD9 variants to determine their clonal relatedness. This 55 683-bp element can actively excise from the chromosome. Additionally, it was capable of transferring both into S. suis and E. faecalis with frequencies of 1.2×10(-4) and 5.8×10(-6) per donor, respectively. When investigating integration site features, it was found that ICESsD9 can enter S. suis and E. faecalis chromosomes by different sites, generating 15-bp and 3-bp direct repeat sequences, respectively. Twelve isolates mainly belonging to sequence types ST1, ST7 and ST28 were confirmed to harbour ICESsD9-like elements. In conclusion, this study provides the first description of an ICE in S. suis that is capable of transferring both into S. suis and E. faecalis. The presence of different ICESsD9 variants in clinical isolates suggests already wide dissemination of this family element in S. suis in China. Copyright © 2016 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  19. Determination of the minor and trace elements in Biriniwa's tin pyrite and ornamental lead/zinc ore using neutron activation analysis

    Directory of Open Access Journals (Sweden)

    A.O. Adebayo

    2002-12-01

    Full Text Available Preliminary results of analysis of two common decorative/ornamental minerals analysed for minor and trace elements with the neutron activation analysis technique are discussed. The samples of interest were the Biriniwa tin pyrite, which the local indigenous used to paint their huts and the ornamental lead which women use to adorn their eyelashes nation-wide. These samples were irradiated along the certified reference sample, CANMET-BLI, with thermal neutron at the Julich Reactor Centre, Julich, Germany. The prominent elements determined in the ornamental lead included zinc (35.8%, iron (6.15%, Na, Sb, Cd, Hg, Ag and Co at trace level (μg g-1. Tin pyrite sample was found to contain traces of Na, K, As, Br, Sb, Fe, La, Nd, Sm and Ce as the prominent impurities. Lead and tin, the major elements, respectively, of the lead/zinc ore and tin pyrite samples were determined by classical methods.

  20. Trace Elements in River Waters

    Science.gov (United States)

    Gaillardet, J.; Viers, J.; Dupré, B.

    2003-12-01

    Trace elements are characterized by concentrations lower than 1 mg L-1 in natural waters. This means that trace elements are not considered when "total dissolved solids" are calculated in rivers, lakes, or groundwaters, because their combined mass is not significant compared to the sum of Na+, K+, Ca2+, Mg2+, H4SiO4, HCO3-, CO32-, SO42-, Cl-, and NO3-. Therefore, most of the elements, except about ten of them, occur at trace levels in natural waters. Being trace elements in natural waters does not necessarily qualify them as trace elements in rocks. For example, aluminum, iron, and titanium are major elements in rocks, but they occur as trace elements in waters, due to their low mobility at the Earth's surface. Conversely, trace elements in rocks such as chlorine and carbon are major elements in waters.The geochemistry of trace elements in river waters, like that of groundwater and seawater, is receiving increasing attention. This growing interest is clearly triggered by the technical advances made in the determination of concentrations at lower levels in water. In particular, the development of inductively coupled plasma mass spectrometry (ICP-MS) has considerably improved our knowledge of trace-element levels in waters since the early 1990s. ICP-MS provides the capability of determining trace elements having isotopes of interest for geochemical dating or tracing, even where their dissolved concentrations are extremely low.The determination of trace elements in natural waters is motivated by a number of issues. Although rare, trace elements in natural systems can play a major role in hydrosystems. This is particularly evident for toxic elements such as aluminum, whose concentrations are related to the abundance of fish in rivers. Many trace elements have been exploited from natural accumulation sites and used over thousands of years by human activities. Trace elements are therefore highly sensitive indexes of human impact from local to global scale. Pollution

  1. Origin of Stream Bed Sediments in Northwest New Jersey: Factors of Land Use and Source Determined by Trace Element Analysis

    Science.gov (United States)

    Pope, G. A.; Starks, L. M.; Torres, A. J.; Galster, J. C.; Feng, H.; Wu, M. S.

    2012-12-01

    Streams in northern New Jersey span a broad range of environments and land covers, including urban, agriculture, wetlands, and forest. Stream sediments receive input from these environments, and indicate pulses or stages of land use change, or stability. In this project, we use trace elements, including rare earth elements, to fingerprint sediment sources and differentiate between land use as well as immediate sources of sediment, such as stream banks, floodplains, uplands, or urban inputs. Samples of stream bed, stream bank, floodplain sediments, and urban and upland soils were obtained from eight locations in the Flat Brook, Rockaway River, and Wallkill River watersheds in Sussex and Morris counties in New Jersey. Samples were prepared for trace element analysis with inductively coupled plasma mass spectrometry (ICPMS). Element content was compared to land use, sediment source, and a stream stability index (the Rapid Geomorphic Assessment, RGA). Several elements (V, Cr, Ni, Sr, Pb) were statistically significant at distinguishing between land use. Zr and W were able to distinguish sediment source (i.e. floodplain, bank, upland, etc.) with statistical confidence. Related to stream and bank stability, the RGA showed significant positive correlation with Cr and Co content (increasing Cr and Co with increasing instability), indicating these elements as good proxy indicators for bank erosion. Ongoing studies of element ratios, combined with Cs-136 and Pb-210 activity levels by gamma detector, will further refine the sediment characterization, with an eventual goal of approximating a sediment budget across different land uses and identifying hot spots that deliver disproportionately high amounts of sediment.; Increase in Co content corresponds to an increase in channel and bank instability, indicated by increasing RGA value.

  2. Experimental and statistical models of impact determination of the electron beam parameters on surface layers properties of optical elements in precision instruments building

    Directory of Open Access Journals (Sweden)

    I.V. Yatsenko

    2016-05-01

    Full Text Available Modern devices with optical elements for measurement and thermal control of different physical nature objects subjected to intense external thermal actions. To prevent destruction of optical elements the electron beam methods of work surfaces finishing at the stage of manufacture has practical significance. These methods can improve the properties of the element surface layers and thus make them more resistant to external thermal and mechanical action. Aim: The aim is to determine the optimal ranges of parameters of the electron beam and the development of experimental and statistical models that will automatically generate database with improved properties of the surface layers of optical elements in real time mode after previous electron beam treatment. Materials and Methods: To study the influence of parameters of the electron beam on the properties of the surface layers of the optical elements used plates of optical glass (K8, K108, etc. and ceramics (KO1, KO2, etc.. The strip electron beam has the following characteristics: density of heat flow Fn = 5∙10^6…9∙10^8 W/m2 and rate of displacement V = 0…0.1 m/s. Determination of the surface layers properties of the optical elements before and after electron beam treatment was carried out by known methods of physical and chemical analysis. Results: It was established that under the influence of the electron beam on the surface of the optical element there is visible clearing of various impurities take place, various micro-defects that remain on it after standard processing methods (mechanical, chemical, etc. remove and also its smoothness significantly increases, i.e. height of residual asperities on the surface is reduced. It was also found that the processing of optical glass elements by electron beam their surface layers change their structure, which is close to the quartz. It is shown that the surface of the preprocessed electron beam elements able to withstand the critical value of

  3. Determination of Abundance of Tellurite-Resistant Bacteria and the Ability of Remove of them from Qom Province Industrial Wastewater, Qom, Iran

    Directory of Open Access Journals (Sweden)

    Mahboubeh Soleimani Sasani

    2013-02-01

    Full Text Available Background and Objectives: Accumulation of toxic oxyanion of potassium tellurite, which has increased in the environment due to industrial activities, can cause complications in human, such as skin irritation, dermatitis, anorexia, tremor, nausea, vomiting, nervous system stimulation, convulsion, and respiratory arrest. The purpose of this research was to isolate tellurite-resistant bacteria, determine the minimum inhibitory concentration (MIC, and evaluate bioreduction of tellurite in strains.Methods: MIC was measured by agar dilution method in 84 resistant strains isolated from wastewater. QWTm6 strain with tolerance of tellurite concentration of 6684μg/ml was selected as superior strain. Toleration of this level of tellurite has not been reported yet. Results: According to biochemical, phenotypic, and physiological characteristics, QWTm6 was initially classified into Staphylococcus genus. Using the spectrophotometric technique and DDTC reagent (A340nm & sodium diethyldithiocarbamate trihydrate, maximum elimination was seen in 0.4mM concentration of potassium tellurite in 24 hours. The strain showed high ability in the elimination of toxic oxyanion of potassium tellurite under a wide range of factors such as pH=(5-11, temperature (15-50◦C, blender speed (50, 100, 150, and 200rpm, various oxyanion concentrations (0.04-1mM, and different percentages of NaCl (0-20%. This strain was also resistant to penicillin, cefixime, tetracycline, chloramphenicol, streptomycin, neomycin, erythromycin, gentamicin, kanamycin, norfloxacin, and ciprofloxacin.Conclusion: The results of this study showed that QWTm6 could be introduced in the international societies as an acceptable candidate for bioremediation, because of its high ability in removal and reduction of potassium tellurite.

  4. Genomic characterization of Defluviitoga tunisiensis L3, a key hydrolytic bacterium in a thermophilic biogas plant and its abundance as determined by metagenome fragment recruitment.

    Science.gov (United States)

    Maus, Irena; Cibis, Katharina Gabriela; Bremges, Andreas; Stolze, Yvonne; Wibberg, Daniel; Tomazetto, Geizecler; Blom, Jochen; Sczyrba, Alexander; König, Helmut; Pühler, Alfred; Schlüter, Andreas

    2016-08-20

    The genome sequence of Defluviitoga tunisiensis L3 originating from a thermophilic biogas-production plant was established and recently published as Genome Announcement by our group. The circular chromosome of D. tunisiensis L3 has a size of 2,053,097bp and a mean GC content of 31.38%. To analyze the D. tunisiensis L3 genome sequence in more detail, a phylogenetic analysis of completely sequenced Thermotogae strains based on shared core genes was performed. It appeared that Petrotoga mobilis DSM 10674(T), originally isolated from a North Sea oil-production well, is the closest relative of D. tunisiensis L3. Comparative genome analyses of P. mobilis DSM 10674(T) and D. tunisiensis L3 showed moderate similarities regarding occurrence of orthologous genes. Both genomes share a common set of 1351 core genes. Reconstruction of metabolic pathways important for the biogas production process revealed that the D. tunisiensis L3 genome encodes a large set of genes predicted to facilitate utilization of a variety of complex polysaccharides including cellulose, chitin and xylan. Ethanol, acetate, hydrogen (H2) and carbon dioxide (CO2) were found as possible end-products of the fermentation process. The latter three metabolites are considered to represent substrates for methanogenic Archaea, the key organisms in the final step of the anaerobic digestion process. To determine the degree of relatedness between D. tunisiensis L3 and dominant biogas community members within the thermophilic biogas-production plant, metagenome sequences obtained from the corresponding microbial community were mapped onto the L3 genome sequence. This fragment recruitment revealed that the D. tunisiensis L3 genome is almost completely covered with metagenome sequences featuring high matching accuracy. This result indicates that strains highly related or even identical to the reference strain D. tunisiensis L3 play a dominant role within the community of the thermophilic biogas-production plant

  5. Temporal changes in elemental composition in decomposing filamentous algae (Cladophora glomerata and Pilayella littoralis) determined with PIXE and PIGE

    Energy Technology Data Exchange (ETDEWEB)

    Lill, J.-O., E-mail: jlill@abo.fi [Accelerator Laboratory, Turku PET Centre, Abo Akademi University, Porthansg. 3, FI-20500 Turku (Finland); Department of Natural Sciences, Abo Akademi University, Porthansg. 3, FI-20500 Turku (Finland); Salovius-Lauren, S. [Department of Biosciences, Abo Akademi University, Artillerig. 6, FI-20520 Turku (Finland); Harju, L. [Department of Chemical Engineering, Abo Akademi University, Biskopsg. 8, FI-20500 Turku (Finland); Rajander, J. [Accelerator Laboratory, Turku PET Centre, Abo Akademi University, Porthansg. 3, FI-20500 Turku (Finland); Department of Chemical Engineering, Abo Akademi University, Biskopsg. 8, FI-20500 Turku (Finland); Saarela, K.-E. [Department of Chemical Engineering, Abo Akademi University, Biskopsg. 8, FI-20500 Turku (Finland); Lindroos, A. [Department of Natural Sciences, Abo Akademi University, Porthansg. 3, FI-20500 Turku (Finland); Heselius, S.-J. [Accelerator Laboratory, Turku PET Centre, Abo Akademi University, Porthansg. 3, FI-20500 Turku (Finland)

    2012-01-01

    Particle-induced X-ray emission and particle-induced gamma-ray emission spectrometry were successfully applied in a study of the elemental composition of decomposing filamentous algae. Fresh brown (Pilayella littoralis) and green (Cladophora glomerata) algal materials were placed in cages at 4 m depth in a water column of 8 m in the Archipelago Sea, northern Baltic Sea. Every second week decaying algae were sampled from the cages to allow measurements of changes in the elemental compositions. In the study of the elemental losses the concentrations were compensated for the mass reduction. The results show that sulphur, chlorine and partly potassium were lost during decomposition of P. littoralis and C. glomerata. Most of the other elements studied were recovered in the remaining algal mass. Special attention was paid to sorption and desorption of elements, including metal binding capacity, in the decaying algal materials. The affinity order of different cations to the two algal species was established by calculation of conditional distribution coefficients, D Prime {sub M}. For instance for P. littoralis the following series of binding strength (affinity) of cations were obtained: Al > Ti > Fe Much-Greater-Than Mn > Ni, Cu > Ba, Cr, Zn Much-Greater-Than Rb > K, Sr > Pb Much-Greater-Than Ca Much-Greater-Than Na > Mg. Notably is that the binding strength of strontium was more than 10 times higher for P. littoralis than for C. glomerata. Due to their high binding capacity and good affinity and selectivity for heavy metal ions these algae have great potential as biological sorbents. Large variations in elemental content during decomposition complicate the use of algae for environmental monitoring. - Highlights: Black-Right-Pointing-Pointer Elemental concentrations in P. littoralis and C. glomerata from the Archipelago Sea in Finland were measured during decomposition. Black-Right-Pointing-Pointer PIXE and PIGE were successfully used for chemical analysis of 24 elements

  6. Recent developments in automated determinations of trace level concentrations of elements and on-line fractionations schemes exploiting the micro-sequential injection - lab-on-valve approach

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Miró, Manuel; Long, Xiangbao

    2006-01-01

    The determination of trace level concentrations of elements, such as metal species, in complex matrices by atomic absorption or emission spectrometric methods often require appropriate pretreatments comprising separation of the analyte from interfering constituents and analyte preconcentration......-up, and the combination of SPE with fractionation schemes of environmentally interesting solid samples (such as soils or sediments) in order to conduct ecotoxicological studies....

  7. Determination os essential elements in diet and light foods using neutron activation analysis; Determinacao de elementos essenciais em alimentos diet e light por analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Gerson Hideo [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica]. E-mail: gehideo@gmail.com; Maihara, Vera Akiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica]. E-mail: vmaihara@ipen.br

    2007-07-01

    The object of this study was to determine essential elements on the diet and light foods and their normal similar through the neutron activation analysis (NAA) and to compare their results. Samples of sweetning, cappuccino, gelatine and chocolate collected at the Sao Paulo commerce were irradiated by a period of 8 hours, under a 10{sup 12} n cm{sub -2} s{sub -1} thermal neutron flux at the IEA-R1 research reactor - IPEN/CNEN-SP, Brazil, together with reference materials and elementary standards, for the determination the concentrations of Br, Ca, Cr, Co, K, Na, Fe, Se and Zn. The obtained results shown that the diet gelatine samples presented concentrations higher for determined elements related to the light and normal gelatines samples. Compared with cappucino samples there was not differences among the concentrations of the determined elements, excepted the element Cr for the cappuccino light. For the chocolate light they presents higher values related to the normal type. The sweetening did not present differences among the samples. (author)

  8. Methodology to determine skull bone and brain responses from ballistic helmet-to-head contact loading using experiments and finite element analysis

    NARCIS (Netherlands)

    Pintar, F.A.; Philippens, M.M.G.M.; Zhang, J.; Yoganandan, N.

    2013-01-01

    The objective of the study was to obtain helmet-to-head contact forces from experiments, use a human head finite element model to determine regional responses, and compare outputs to skull fracture and brain injury thresholds. Tests were conducted using two types of helmets (A and B) fitted to a

  9. Evolutionary Significance of Wolbachia-to-Animal Horizontal Gene Transfer: Female Sex Determination and the f Element in the Isopod Armadillidium vulgare

    Directory of Open Access Journals (Sweden)

    Richard Cordaux

    2017-07-01

    Full Text Available An increasing number of horizontal gene transfer (HGT events from bacteria to animals have been reported in the past years, many of which involve Wolbachia bacterial endosymbionts and their invertebrate hosts. Most transferred Wolbachia genes are neutrally-evolving fossils embedded in host genomes. A remarkable case of Wolbachia HGT for which a clear evolutionary significance has been demonstrated is the “f element”, a nuclear Wolbachia insert involved in female sex determination in the terrestrial isopod Armadillidium vulgare. The f element represents an instance of bacteria-to-animal HGT that has occurred so recently that it was possible to infer the donor (feminizing Wolbachia closely related to the wVulC Wolbachia strain of A. vulgare and the mechanism of integration (a nearly complete genome inserted by micro-homology-mediated recombination. In this review, we summarize our current knowledge of the f element and discuss arising perspectives regarding female sex determination, unstable inheritance, population dynamics and the molecular evolution of the f element. Overall, the f element unifies three major areas in evolutionary biology: symbiosis, HGT and sex determination. Its characterization highlights the tremendous impact sex ratio distorters can have on the evolution of sex determination mechanisms and sex chromosomes in animals and plants.

  10. Use of an oxidative destruction and quadrupole mass spectrometric (QMS) detection for the determination of the organic elemental composition of suspended matter in surface water

    NARCIS (Netherlands)

    Reijnders, H.F.R.; Onderdelinden, D.; Visser, M.G.; Griepink, B.

    1980-01-01

    A study was made of the applicability of a system consisting of a combustion followed by QMS-detection for the determination of the elemental composition of organic matter suspended in surface water. The solid material obtained from several types of water was collected by centrifugation. The results

  11. Determination of the elemental composition of ferromanganese formations certified reference materials by mass-spectrometry with inductively coupled plasma

    Directory of Open Access Journals (Sweden)

    N. V. Zarubina

    2014-01-01

    Full Text Available Contents of 41 elements in the Russian standard samples of ferromanganese nodules OOPE 601, OOPE 602, OOPE 603 and ore crust OOPE 604 were identified by mass-spectrometry with inductively-coupled plasma. Content of W was firstly presented in the sample OOPE-603. Relative standard deviation for most elements was in the range of 3-10%. A description of ICP-MS technique including sample preparation procedure and other instrumental parameters were given as well as analysis of ferromanganese nodules standard samples NOD-A-1 and NOD-P-1 of U.S. Geological Survey was demonstrated for validation. Normalized to chondrite distribution curves of REE in the studied samples were shown as an indicator of the internal consistency offound concentrations. The available literature data on the content of a wide range of elements and its comparison with the matter obtained by us was produced. Measured contents of elements in the established CRM may be useful in the analytical practice to evaluate precision of results. There is a lack of relevant information on a variety of geochemically important elements in the Russian standard samples of OOPE series and the new data can be taken into account in their certification.

  12. Subtelomeric repetitive elements determine TERRA regulation by Rap1/Rif and Rap1/Sir complexes in yeast

    Science.gov (United States)

    Iglesias, Nahid; Redon, Sophie; Pfeiffer, Verena; Dees, Martina; Lingner, Joachim; Luke, Brian

    2011-01-01

    Telomeric repeat-containing RNA (TERRA) has been implicated in the control of heterochromatin and telomerase. We demonstrate that yeast TERRA is regulated by telomere-binding proteins in a chromosome-end-specific manner that is dependent on subtelomeric repetitive DNA elements. At telomeres that contain only X-elements, the Rap1 carboxy-terminal domain recruits the Sir2/3/4 and Rif1/2 complexes to repress transcription in addition to promoting Rat1-nuclease-dependent TERRA degradation. At telomeres that contain Y′ elements, however, Rap1 represses TERRA through recruitment of Rif1 and Rif2. Our work emphasizes the importance of subtelomeric DNA in the control of telomeric protein composition and telomere transcription. PMID:21525956

  13. Chronological development of element concentrations in grapes during growth and ripeness and during fermentation of must determined by instrumental neutron-activation analyses

    Energy Technology Data Exchange (ETDEWEB)

    Feige, Markus; Hampel, Gabriele; Kratz, Jens Volker; Wiehl, Norbert [Mainz Univ. (Germany). Inst. fuer Kernchemie; Koenig, Helmut [Mainz Univ. (Germany). Inst. fuer Mikrobiologie und Weinforschung; Wagner, Andreas [Weingut Wagner, Essenheim (Germany)

    2014-07-01

    The chronological development of element concentrations during growth and ripeness of grapes described in the literature has only been concerned with the macro elements Mg, K, and Ca. Concentrations of trace elements in must are only described as a snapshot at the end of the ripeness. Therefore, the motivation for the present work was to accompany the growth and the ripening process of grapes successively by systematically determining element concentrations in grapes of Riesling and Cabernet Sauvignon by neutron-activation analyses. While for a number of elements, the concentrations in the grapes increased as a function of grape development (e.g., Na, K, Rb, Al), other concentrations decreased (e.g., Mg, Ca, Mn). These decreases are not only to be attributed to a dilution by an increasing uptake of water during growth, but also by an active transport of the cations out of the berries. Furthermore, the interest focused on the influence of mineral substances on the process of fermentation and on the uptake of trace elements by the yeasts. (orig.)

  14. Imaging the elusive H-poor gas in planetary nebulae with large abundance discrepancy factors

    Science.gov (United States)

    García-Rojas, Jorge; Corradi, Romano L. M.; Boffin, Henri M. J.; Monteiro, Hektor; Jones, David; Wesson, Roger; Cabrera-Lavers, Antonio; Rodríguez-Gil, Pablo

    2017-10-01

    The discrepancy between abundances computed using optical recombination lines (ORLs) and collisionally excited lines (CELs) is a major, unresolved problem with significant implications for the determination of chemical abundances throughout the Universe. In planetary nebulae (PNe), the most common explanation for the discrepancy is that two different gas phases coexist: a hot component with standard metallicity, and a much colder plasma enhanced in heavy elements. This dual nature is not predicted by mass loss theories, and direct observational support for it is still weak. In this work, we present our recent findings that demonstrate that the largest abundance discrepancies are associated with close binary central stars. OSIRIS-GTC tunable filter imaging of the faint O ii ORLs and MUSE-VLT deep 2D spectrophotometry confirm that O ii ORL emission is more centrally concentrated than that of [Oiii] CELs and, therefore, that the abundance discrepancy may be closely linked to binary evolution.

  15. Estimating abundance: Chapter 27

    Science.gov (United States)

    Royle, J. Andrew

    2016-01-01

    This chapter provides a non-technical overview of ‘closed population capture–recapture’ models, a class of well-established models that are widely applied in ecology, such as removal sampling, covariate models, and distance sampling. These methods are regularly adopted for studies of reptiles, in order to estimate abundance from counts of marked individuals while accounting for imperfect detection. Thus, the chapter describes some classic closed population models for estimating abundance, with considerations for some recent extensions that provide a spatial context for the estimation of abundance, and therefore density. Finally, the chapter suggests some software for use in data analysis, such as the Windows-based program MARK, and provides an example of estimating abundance and density of reptiles using an artificial cover object survey of Slow Worms (Anguis fragilis).

  16. Determining the Local Abundance of Martian Methane and its 13-C/l2-C and D/H Isotopic Ratios for Comparison with Related Gas and Soil Analysis on the 2011 Mars Science Laboratory (MSL) Mission

    Science.gov (United States)

    Webster, Christopher R.; Mahaffy, Paul R.

    2011-01-01

    Understanding the origin of Martian methane will require numerous complementary measurements from both in situ and remote sensing investigations and laboratory work to correlate planetary surface geophysics with atmospheric dynamics and chemistry. Three instruments (Quadrupole Mass Spectrometer (QMS), Gas Chromatograph (GC) and Tunable Laser Spectrometer (TLS)) with sophisticated sample handling and processing capability make up the Sample Analysis at Mars (SAM) analytical chemistry suite on NASA s 2011 Mars Science Laboratory (MSL) Mission. Leveraging off the SAM sample and gas processing capability that includes methane enrichment, TLS has unprecedented sensitivity for measuring absolute methane (parts-per-trillion), water, and carbon dioxide abundances in both the Martian atmosphere and evolved from heated soil samples. In concert with a wide variety of associated trace gases (e.g. SO2, H2S, NH3, higher hydrocarbons, organics, etc.) and other isotope ratios measured by SAM, TLS will focus on determining the absolute abundances of methane, water and carbon dioxide, and their isotope ratios: 13C/12C and D/H in methane; 13C/12C and 18O/17O/16O in carbon dioxide; and 18O/17O/16O and D/H in water. Measurements near the MSL landing site will be correlated with satellite (Mars Express, Mars 2016) and ground-based observations.

  17. The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF)

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, Warren R.L.; Cozzi, Giulio [Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); De Boni, Antonella; Gabrieli, Jacopo [University of Venice, Department of Environmental Science, Venice (Italy); Asti, Massimo; Merlone Borla, Edoardo; Parussa, Flavio [Centro Ricerche Fiat, Orbassano (Italy); Moretto, Ezio [FIAT Powertrain Technologies S.p.A, Turin (Italy); Cescon, Paolo; Barbante, Carlo [University of Venice, Department of Environmental Science, Venice (Italy); Institute for the Dynamics of Environmental Processes-CNR, Venice (Italy); Boutron, Claude [Laboratoire de Glaciologie et Geophysique de l' Environnement, UMR CNRS 5183, B.P. 96, Saint Martin d' Heres Cedex (France)

    2011-03-15

    Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g{sup -1} for Pd, 0.4 ng g{sup -1} for Rh and 4.3 ng g{sup -1} for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and ''soluble'' phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km{sup -1} for Rh to 70.5 ng km{sup -1} for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter. (orig.)

  18. The use of cation exchange matrix separation coupled with ICP-MS to directly determine platinum group element (PGE) and other trace element emissions from passenger cars equipped with diesel particulate filters (DPF).

    Science.gov (United States)

    Cairns, Warren R L; De Boni, Antonella; Cozzi, Giulio; Asti, Massimo; Borla, Edoardo Merlone; Parussa, Flavio; Moretto, Ezio; Cescon, Paolo; Boutron, Claude; Gabrieli, Jacopo; Barbante, Carlo

    2011-03-01

    Inductively coupled plasma-mass spectrometry coupled with cation exchange matrix separation has been optimised for the direct determination of platinum group element (PGE) and trace element emissions from a diesel engine car. After matrix separation method detection limits of 1.6 ng g(-1) for Pd, 0.4 ng g(-1) for Rh and 4.3 ng g(-1) for Pt were achieved, the method was validated against the certified reference material BCR 723, urban road dust. The test vehicle was fitted with new and aged catalytic converters with and without diesel particulate filters (DPF). Samples were collected after three consecutive New European Driving Cycle (NEDC) of the particulate and "soluble" phases using a home-made sampler optimised for trace element analysis. Emission factors for the PGEs ranged from 0.021 ng km(-1) for Rh to 70.5 ng km(-1) for Pt; when a DPF was fitted, the emission factors for the PGEs actually used in the catalysts dropped by up to 97% (for Pt). Trace element emission factors were found to drop by a maximum of 92% for Ni to a minimum of 18% for Y when a DPF was fitted; a new DPF was also found to cause a reduction of up to 86% in the emission of particulate matter.

  19. The Cosmic Abundance of 3He: Green Bank Telescope Observations

    Science.gov (United States)

    Balser, Dana; Bania, Thomas

    2018-01-01

    The Big Bang theory for the origin of the Universe predicts that during the first ~1,000 seconds significant amounts of the light elements (2H, 3He, 4He, and 7Li) were produced. Many generations of stellar evolution in the Galaxy modifies these primordial abundances. Observations of the 3He+ hyperfine transition in Galactic HII regions reveals a 3He/H abundance ratio that is constant with Galactocentric radius to within the uncertainties, and is consistent with the primordial value as determined from cosmic microwave background experiments (e.g., WMAP). This "3He Plateau" indicates that the net production and destruction of 3He in stars is approximately zero. Recent stellar evolution models that include thermohaline mixing, however, predict that 3He/H abundance ratios should slightly decrease with Galactocentric radius, or in places in the Galaxy with lower star formation rates. Here we discuss sensitive Green Bank Telescope (GBT) observations of 3He+ at 3.46 cm in a subset of our HII region sample. We develop HII region models and derive accurate 3He/H abundance ratios to better constrain these new stellar evolution models.

  20. Hierarchical clustering of Alzheimer and "normal" brains using elemental concentrations and glucose metabolism determined by PIXE, INAA and PET

    NARCIS (Netherlands)

    Cutts, DA; Spyrou, NM; Maguire, RP; Leenders, KL

    Brain tissue samples, obtained from the Alzheimer Disease Brain Bank, Institute of Psychiatry, London, were taken from both left and right hemispheres of three regions of the cerebrum, namely the frontal, parietal and occipital lobes for both Alzheimer and 'normal' subjects. Trace element