WorldWideScience

Sample records for group element concentrations

  1. Factors Governing concentration of platinum group elements in layered complexes

    DEFF Research Database (Denmark)

    Makovicky, E.; Rose-Hansen, J.; Karup-Møller, Sven

    1996-01-01

    This report covers the synthetic research results obtained by the Danish group on: (1) The phase system Fe-Ir-S at 1100o, 1000o and 800oC, (2) Metal-rich portions of the phase system Pt-Ir-Fe-S: Pt-Fe-Ir alloys and associated sulfides at 1000oC and 1100oC, (3) The Fe (Cu)-Pt-Rh-S system: alloys a...

  2. Anthropogenic platinum group element (Pt, Pd, Rh) concentrations in PM10 and PM2.5 from Kolkata, India.

    Science.gov (United States)

    Diong, Huey Ting; Das, Reshmi; Khezri, Bahareh; Srivastava, Bijayen; Wang, Xianfeng; Sikdar, Pradip K; Webster, Richard D

    2016-01-01

    This study investigates platinum group elements (PGEs) in the breathable (PM10) and respirable (PM2.5) fractions of air particulates from a heavily polluted Indian metro city. The samples were collected from traffic junctions at the heart of the city and industrial sites in the suburbs during winter and monsoon seasons of 2013-2014. PGE concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). The PGE concentrations in the samples from traffic junctions are within the range of 2.7-111 ng/m(3) for Pd, 0.86-12.3 ng/m(3) for Pt and 0.09-3.13 ng/m(3) for Rh, and from industrial sites are within the range of 3.12-32.3 ng/m(3) for Pd, 0.73-7.39 ng/m(3) for Pt and 0.1-0.69 ng/m(3) for Rh. Pt concentrations were lower in the monsoon compared to winter while Pd concentrations increased during monsoon and Rh stayed relatively unaffected across seasons. For all seasons and locations, concentrations of Pd > Pt > Rh, indicating dominance of Pd-containing exhaust converters. Most of the PGEs were concentrated in the PM2.5 fraction. A strong correlation (R ≥ 0.62) between the PGEs from traffic junction indicates a common emission source viz. catalytic converters, whereas a moderate to weak correlation (R ≤ 0.5) from the industrial sites indicate mixing of different sources like coal, raw materials used in the factories and automobile. A wider range of Pt/Pd, Pt/Rh and Pd/Rh ratios measured in the traffic junction possibly hint towards varying proportions of PGEs used for catalyst productions in numerous rising and established car brands.

  3. Platinum-group element concentrations in pyrite from the Main Sulfide Zone of the Great Dyke of Zimbabwe

    Science.gov (United States)

    Piña, R.; Gervilla, F.; Barnes, S.-J.; Oberthür, T.; Lunar, R.

    2016-10-01

    The Main Sulfide Zone (MSZ) of the Great Dyke of Zimbabwe hosts the world's second largest resource of platinum-group elements (PGE) after the Bushveld Complex in South Africa. The sulfide assemblage of the MSZ comprises pyrrhotite, pentlandite, chalcopyrite, and minor pyrite. Recently, several studies have observed in a number of Ni-Cu-PGE ore deposits that pyrite may host significant amounts of PGE, particularly Pt and Rh. In this study, we have determined PGE and other trace element contents in pyrite from the Hartley, Ngezi, Unki, and Mimosa mines of the Great Dyke by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Based on the textures and PGE contents, two types of pyrite can be differentiated. Py1 occurs as individual euhedral or subhedral grains or clusters of crystals mostly within chalcopyrite and pentlandite, in some cases in the form of symplectitic intergrowths, and is PGE rich (up to 99 ppm Pt and 61 ppm Rh; 1.7 to 47.1 ppm Ru, 0.1 to 7.8 ppm Os, and 1.2 to 20.2 ppm Ir). Py2 occurs as small individual euhedral or subhedral crystals within pyrrhotite, pentlandite, and less frequently within chalcopyrite and silicates and has low PGE contents (<0.11 ppm Pt, <0.34 ppm Rh, <2.5 ppm Ru, <0.37 ppm Ir, and <0.40 ppm Os). Py1 contains higher Os, Ir, Ru, Rh, and Pt contents than the associated pyrrhotite, pentlandite, and chalcopyrite, whereas Py2 has similar PGE contents as coexisting pyrrhotite and pentlandite. Based on the textural relationships, two different origins are attributed for each pyrite type. Py1 intergrowth with pentlandite and chalcopyrite is inferred to have formed by late, low temperature (<300 °C) decomposition of residual Ni-rich monosulfide solid solution, whereas Py2 is suggested to have formed by replacement of pyrrhotite and pentlandite caused by late magmatic/hydrothermal fluids.

  4. Effects of mother lode-type gold mineralization on 187Os/188Os and platinum group element concentrations in peridotite: Alleghany District, California

    Science.gov (United States)

    Walker, R.J.; Böhlke, J.K.; McDonough, W.F.; Li, J.

    2007-01-01

    Osmium isotope compositions and concentrations of Re, platinum group elements (PGE), and Au were determined for host peridotites (serpentinites and barzburgites) and hydrothermally altered ultramafic wall rocks associated with Mother Lode-type hydrothermal gold-quartz vein mineralization in the Alleghany district, California. The host peridotites have Os isotope compositions and Re, PGE, and Au abundances typical of the upper mantle at their presumed formation age during the late Proterozoic or early Paleozoic. The hydrothermally altered rocks have highly variable initial Os isotope compositions with ??os, values (% deviation of 187OS/188OS from the chondritic average calculated for the approx. 120 Ma time of mineralization) ranging from -1.4 to -8.3. The lowest Os isotope compositions are consistent with Re depletion of a chondritic source (e.g., the upper mantle) at ca. 1.6 Ga. Most of the altered samples are enriched in Au and have depleted and fractionated abundances of Re and PGE relative to their precursor peridotites. Geoehemical characteristics of the altered samples suggest that Re and some PGE were variably removed from the ultramafic rocks during the mineralization event. In addition to Re, the Pt and Pd abundances of the most intensely altered rocks appear to have been most affected by mineralization. The 187Os-depleted isotopic compositions of some altered rocks are interpreted to be a result of preferential 187Os loss via destruction of Re-rich phases during the event. For these rocks, Os evidently is not a useful tracer of the mineralizing fluids. The results do, however, provide evidence for differential mobility of these elements, and mobility of 187Os relative to the initial bulk Os isotope composition during hydrothermal metasomatic alteration of ultramafic rocks. ?? 2007 Society of Economic Geologists, Inc.

  5. Splitting fields of elements in arithmetic groups

    CERN Document Server

    Gorodnik, Alex

    2011-01-01

    We prove that the number of unimodular integral matrices in a norm ball whose characteristic polynomial has Galois group different than the full symmetric group is of strictly lower order of magnitude than the number of all such matrices in the ball, as the radius increases. More generally, we prove a similar result for the Galois groups associated with elements in any connected semisimple linear algebraic group defined and simple over a number field $F$. Our method is based on the abstract large sieve method developed by Kowalski, and the study of Galois groups via reductions modulo primes developed by Jouve, Kowalski and Zywina. The two key ingredients are a uniform quantitative lattice point counting result, and a non-concentration phenomenon for lattice points in algebraic subvarieties of the group variety, both established previously by the authors. The results answer a question posed by Rivin and by Jouve, Kowalski and Zywina, who have considered Galois groups of random products of elements in algebraic...

  6. Elements with Square Roots in Finite Groups

    Institute of Scientific and Technical Information of China (English)

    M.S. Lucido; M.R. Pournaki

    2005-01-01

    In this paper, we study the probability that a randomly chosen element in a finite group has a square root, in particular the simple groups of Lie type of rank 1, the sporadic finite simple groups and the alternating groups.

  7. MASS CONCENTRATIONS AND ELEMENTAL COMPOSITION OF ...

    African Journals Online (AJOL)

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    concentration surpassed the WHO safe guideline value of 150 µg/m3 and 79 % of .... Kotebe Waste Water Treatment Plant site (KWWT) is located in the eastern part ... Each filter paper was oven dried, weighed and stored in desiccator before and ... and blank filter samples were analyzed for elements using standard method.

  8. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    NA

    2004-11-22

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  9. Molecular clusters of the main group elements

    CERN Document Server

    Driess, Matthias

    2008-01-01

    ""To summarize, Molecular Clusters of the Main Group Elements is certainly not a popular science book, nor is it a textbook; it is a very good, up-to-date collection of articles for the specialist. Als Fazit bleibt: Molecular Clusters of the Main Group Elements ist sicher kein populissenschaftliches Werk, auch kein Lehrbuch, aber eine gelungene, hoch aktuelle Zusammenstellung fen interessierten Fachmann."" -Michael Ruck, TU Dresden, Angewandte Chemie, 2004 - 116/36 + International Edition 2004 - 43/36

  10. Elemental concentration in mealworm beetle (Tenebrio molitor L.) during metamorphosis.

    Science.gov (United States)

    Simon, Edina; Baranyai, Edina; Braun, Mihály; Fábián, István; Tóthmérész, Béla

    2013-07-01

    Mealworm beetles have been used in numerous experiments as bioindicators. The aim of our experiment was to study the elemental composition in three larvae, pupae and first and second generation adult stages during their life cycle. We selected 180 larvae from a genetically similar population and put them in three groups, in two boxes (60 larvae in each box). Larvae were fed with mashed potato made of the same quality and quantity of potato powder. Then, we selected 10 individuals from each stage to the elemental analysis, using the ICP-OES method. The following elements were analysed in the studied stages: Ca, Cu, Fe, K, Mg, Mn, Na, P, S, Sr and Zn. The results of principal component analysis demonstrated that based on elemental composition, different stages were separated with each other, but in the cases of the three larvae stages, high overlap was found. The results of the GLM ANOVA showed significant differences between the different stages of metamorphosis-based elemental composition. Our results show that the calcium and magnesium were found in a relatively high concentration, while the iron and zinc may be essential elements during the metamorphosis. Our results also show that in insect, the concentration of sodium was higher than in the pupa which may cause by hemolymph. We also demonstrated that the metamorphosis has an effect on the concentration of elements. Our study shows that in the different stages of insects, there are significant changes in the elemental composition of different stages of insects during their metamorphosis.

  11. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    P. Bernot

    2005-07-13

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for the actinides discussed in this report. These models cover broad ranges of environmental conditions so they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or

  12. Transmissive Diffractive Optical Element Solar Concentrators

    Science.gov (United States)

    Baron, Richard; Moynihan, Philip; Price, Douglas

    2008-01-01

    Solar-thermal-radiation concentrators in the form of transmissive diffractive optical elements (DOEs) have been proposed as alternatives to mirror-type solar concentrators now in use. In comparison with functionally equivalent mirror-type solar concentrators, the transmissive, diffractive solar concentrators would weigh and cost less, and would be subject to relaxed mechanical tolerances. A DOE concentrator would be made from a thin, flat disk or membrane of a transmissive material having a suitable index of refraction. By virtue of its thinness, the DOE concentrator would have an areal mass density significantly less than that of a functionally equivalent conventional mirror. The DOE concentrator would have a relatively wide aperture--characterized by a focal-length/aperture-diameter ratio ('f number') on the order of 1. A kinoform (a surface-relief phase hologram) of high diffractive order would be microfabricated onto one face of the disk. The kinoform (see figure) would be designed to both diffract and refract incident solar radiation onto a desired focal region, without concern for forming an image of the Sun. The high diffractive order of this kinoform (in contradistinction to the low diffractive orders of some other kinoforms) would be necessary to obtain the desired f number of 1, which, in turn, would be necessary for obtaining a desired concentration ratio of 2,500 or greater. The design process of optimizing the concentration ratio of a proposed DOE solar concentrator includes computing convolutions of the optical bandwidth of the Sun with the optical transmission of the diffractive medium. Because, as in the cases of other non-imaging, light-concentrating optics, image quality is not a design requirement, the process also includes trading image quality against concentration ratio. A baseline design for one example calls for an aperture diameter of 1 m. This baseline design would be scalable to a diameter as large as 10 m, or to a smaller diameter for a

  13. Concentrations of Platinum Group Elements (Pt, Pd, Rh in Airborne Particulate Matter (PM2.5 and PM10-2.5 Collected at Selected Canadian Urban Sites: a Case Study

    Directory of Open Access Journals (Sweden)

    Celo V.

    2013-04-01

    Full Text Available Increasing environmental concentrations of platinum group elements (PGEs, in particular platinum (Pt, palladium (Pd and rhodium (Rh, from catalytic converters has been reported worldwide. Initially it was believed that the emitted PGEs remain in the roadside environment, but recent studies have shown that fine PGE-containing particles can be transported and distributed at regional and long-range levels. Therefore, the monitoring of PGEs in airborne particulate matter (PM is important for the estimation of potential risks to human health and to the ecosystem. The aim of this study is to present the first results from an analysis on the concentration and distribution of Pt, Pd and Rh in PM collected on Teflon filters at two selected urban sites (Toronto, Ontario; Edmonton, Alberta collected within the Canadian National Air Pollution Surveillance (NAPS network. In this work, a quadruple inductively coupled plasma mass spectrometry (ICP-MS, combined with microwave assisted acid digestion using aqua regia was used. A cation exchange separation was used to alleviate the matrix-induced spectral and nonspectral interferences prior to ICP-MS analysis. To obtain sufficient material needed for PGEs analysis, fine PM (particles with aerodynamic diameter less than 2.5 mm; PM2.5 and coarse PM (with aerodynamic diameter between 2.5 and 10 mm; PM10-2.5 samples were combined into composite samples on a seasonal basis. The obtained results will be discussed and compared with literature data.

  14. Stable kagome lattices from group IV elements

    Science.gov (United States)

    Leenaerts, O.; Schoeters, B.; Partoens, B.

    2015-03-01

    A thorough investigation of three-dimensional kagome lattices of group IV elements is performed with first-principles calculations. The investigated kagome lattices of silicon and germanium are found to be of similar stability as the recently proposed carbon kagome lattice. Carbon and silicon kagome lattices are both direct-gap semiconductors but they have qualitatively different electronic band structures. While direct optical transitions between the valence and conduction bands are allowed in the carbon case, no such transitions can be observed for silicon. The kagome lattice of germanium exhibits semimetallic behavior but can be transformed into a semiconductor after compression.

  15. The role of lysosomes in the selective concentration of mineral elements. A microanalytical study.

    Science.gov (United States)

    Berry, J P

    1996-05-01

    The role of the lysosome during the intracellular concentration of diverse mineral elements has been evidenced by the electron probe X-ray microanalysis (EPMA). This highly sensitive technique allows an in situ chemical analysis of any chemical element with an atomic number greater than 11, present in ultra-thin tissue sections. Therefore, it has been demonstrated by using this EPMA that 21 out of the 92 elements of the periodic table, once injected in a soluble form, were selectively concentrated within lysosomes of several types of mammalian cells. Amongst these 21 elements, 15 are concentrated and precipitated in an insoluble from in association with phosphorus whereas the other 6 are precipitated in association with sulphur. Amongst the 15 elements which precipitate with phosphorus in lysosomes, there are: 3 group IIIB elements of the periodic system, (aluminium, gallium and indium); the rare-earth elements (cerium, gadolinium, lanthanum, thulium and samarium); 2 group IVA elements (hafnium and zirconium), two actinides (uranium and thorium) and elements such as chromium and niobium. The 6 elements which precipitate with sulphur comprise the 3 group VIII elements of the classification (nickel, palladium, platinum) and the 3 group IB elements (copper, silver and gold). The mechanisms responsible for this selective concentration involve enzymatic processes and predominantly acid phosphatases for elements precipitating as phosphates and arylsulfatases for elements precipitating with sulphur.

  16. Properties of Group Five and Group Seven transactinium elements

    Energy Technology Data Exchange (ETDEWEB)

    Wilk, Philip A. [Univ. of California, Berkeley, CA (United States)

    2001-05-01

    The detection and positive identification of the short-lived, low cross section isotopes used in the chemical studies of the heaviest elements are usually accomplished by measuring their alpha-decay, thus the nuclear properties of the heaviest elements must be examined simultaneously with their chemical properties. The isotopes 224 Pa and 266,267 Bh have been studied extensively as an integral part of the investigation of the heaviest members of the groups five and seven of the periodic table. The half-life of 224 Pa was determined to be 855 ±19 ms by measuring its alpha-decay using our rotating wheel, solid state detector system at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Protactinium was produced by bombardment of a bismuth target. New neutron rich isotopes, 267 Bh and 266 Bh, were produced in bombardments of a 249 Bk target and their decay was observed using the rotating wheel system. The 266 Bh that was produced decays with a half-life of approximately 1 s by emission of alpha particles with an average energy of 9.25 plus/minus 0.03 MeV. 267 Bh was observed to decay with a 17 s half-life by emission of alpha-particles with an average energy of 8.83 plus/minus 0.03 MeV. The chemical behavior of hafnium, Ha (element 105) was investigated using the fast on-line continuous liquid extraction and detection system SISAK-LISSY. Hafnium was not observed in this experiment following transport and extraction. Protactinium was used as on-line test of the apparatus to determine the experimental efficiency of the entire system. Unfortunately, the amount of protactinium observed after the extraction, compared to the amount produced, was extremely small, only 2.5%. The extraction of the protactinium isotope indicated the efficiency of the apparatus was too low to observe the extraction of hafnium. The chemical behavior of oxychloride compounds of bohrium was

  17. Properties of Group Five and Group Seven transactinium elements

    Energy Technology Data Exchange (ETDEWEB)

    Wilk, Philip A.

    2001-05-01

    The detection and positive identification of the short-lived, low cross section isotopes used in the chemical studies of the heaviest elements are usually accomplished by measuring their alpha-decay, thus the nuclear properties of the heaviest elements must be examined simultaneously with their chemical properties. The isotopes 224 Pa and 266,267 Bh have been studied extensively as an integral part of the investigation of the heaviest members of the groups five and seven of the periodic table. The half-life of 224 Pa was determined to be 855 plus/minus19 ms by measuring its alpha-decay using our rotating wheel, solid state detector system at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron. Protactinium was produced by bombardment of a bismuth target. New neutron rich isotopes, 267 Bh and 266 Bh, were produced in bombardments of a 249 Bk target and their decay was observed using the rotating wheel system. The 266 Bh that was produced decays with a half-life of approximately 1 s by emission of alpha particles with an average energy of 9.25 plus/minus 0.03 MeV. 267 Bh was observed to decay with a 17 s half-life by emission of alpha-particles with an average energy of 8.83 plus/minus 0.03 MeV. The chemical behavior of hafnium, Ha (element 105) was investigated using the fast on-line continuous liquid extraction and detection system SISAK-LISSY. Hafnium was not observed in this experiment following transport and extraction. Protactinium was used as on-line test of the apparatus to determine the experimental efficiency of the entire system. Unfortunately, the amount of protactinium observed after the extraction, compared to the amount produced, was extremely small, only 2.5%. The extraction of the protactinium isotope indicated the efficiency of the apparatus was too low to observe the extraction of hafnium. The chemical behavior of oxychloride compounds of bohrium was investigated by isothermal gas adsorption chromatography in a quartz column at 180, 150

  18. Finite element method for thermal analysis of concentrating solar receivers

    OpenAIRE

    Shtrakov, Stanko; Stoilov, Anton

    2006-01-01

    Application of finite element method and heat conductivity transfer model for calculation of temperature distribution in receiver for dish-Stirling concentrating solar system is described. The method yields discretized equations that are entirely local to the elements and provides complete geometric flexibility. A computer program solving the finite element method problem is created and great number of numerical experiments is carried out. Illustrative numerical results are given for an array...

  19. Nutrient stoichiometry in winter wheat: Element concentration pattern reflects developmental stage and weather.

    Science.gov (United States)

    Weih, M; Pourazari, F; Vico, G

    2016-10-24

    At least 16 nutrient elements are required by plants for growth and survival, but the factors affecting element concentration and their temporal evolution are poorly understood. The objective was to investigate i) element concentration pattern in winter wheat as affected by crop developmental stage and weather, and ii) whether, in the short term, element stoichiometry reflects the type of preceding crop. We assessed the temporal trajectories of element concentration pattern (N, P, K, Ca, Mg, S, Mn, Fe, Cu, Na, Zn) across the life cycle (from seed to seed) of winter wheat field-grown in cool-temperate Sweden during two years with contrasting weather and when cultivated in monoculture or after different non-wheat preceding crops. We found strong influence of developmental stage on concentration pattern, with the greatest deviation from grain concentrations found in plants at the start of stem elongation in spring. Inter-annual differences in weather affected stoichiometry, but no evidence was found for a short-term preceding-crop effect on element stoichiometry. Winter wheat element stoichiometry is similar in actively growing plant tissues and seeds. Nitrogen exerts a strong influence on the concentration pattern for all elements. Three groups of elements with concentrations changing in concert were identified.

  20. Nutrient stoichiometry in winter wheat: Element concentration pattern reflects developmental stage and weather

    Science.gov (United States)

    Weih, M.; Pourazari, F.; Vico, G.

    2016-10-01

    At least 16 nutrient elements are required by plants for growth and survival, but the factors affecting element concentration and their temporal evolution are poorly understood. The objective was to investigate i) element concentration pattern in winter wheat as affected by crop developmental stage and weather, and ii) whether, in the short term, element stoichiometry reflects the type of preceding crop. We assessed the temporal trajectories of element concentration pattern (N, P, K, Ca, Mg, S, Mn, Fe, Cu, Na, Zn) across the life cycle (from seed to seed) of winter wheat field-grown in cool-temperate Sweden during two years with contrasting weather and when cultivated in monoculture or after different non-wheat preceding crops. We found strong influence of developmental stage on concentration pattern, with the greatest deviation from grain concentrations found in plants at the start of stem elongation in spring. Inter-annual differences in weather affected stoichiometry, but no evidence was found for a short-term preceding–crop effect on element stoichiometry. Winter wheat element stoichiometry is similar in actively growing plant tissues and seeds. Nitrogen exerts a strong influence on the concentration pattern for all elements. Three groups of elements with concentrations changing in concert were identified.

  1. Discrimination of lichen genera and species using element concentrations

    Science.gov (United States)

    Bennett, James P.

    2008-01-01

    The importance of organic chemistry in the classification of lichens is well established, but inorganic chemistry has been largely overlooked. Six lichen species were studied over a period of 23 years that were growing in 11 protected areas of the northern Great Lakes ecoregion, which were not greatly influenced by anthropogenic particulates or gaseous air pollutants. The elemental data from these studies were aggregated in order to test the hypothesis that differences among species in tissue element concentrations were large enough to discriminate between taxa faithfully. Concentrations of 16 chemical elements that were found in tissue samples from Cladonia rangiferina, Evernia mesomorpha, Flavopunctelia flaventior, Hypogymnia physodes, Parmelia sulcata, and Punctelia rudecta were analyzed statistically using multivariate discriminant functions and CART analyses, as well as t-tests. Genera and species were clearly separated in element space, and elemental discriminant functions were able to classify 91-100 of the samples correctly into species. At the broadest level, a Zn concentration of 51 ppm in tissues of four of the lichen species effectively discriminated foliose from fruticose species. Similarly, a S concentration of 680 ppm discriminated C. rangiferina and E. mesomorpha, and a Ca concentration of 10 436 ppm discriminated H. physodes from P. sulcata. For the three parmelioid species, a Ca concentration >32 837 ppm discriminated Punctelia rudecta from the other two species, while a Zn concentration of 56 ppm discriminated Parmelia sulcata from F. flaventior. Foliose species also had higher concentrations than did fruticose species of all elements except Na. Elemental signatures for each of the six species were developed using standardized means. Twenty-four mechanisms explaining the differences among species are summarized. Finally, the relationships of four species based on element concentrations, using additive-trees clustering of a Euclidean

  2. Concentrations and bioaccessibilities of trace elements in barbecue charcoals.

    Science.gov (United States)

    Sharp, Annabel; Turner, Andrew

    2013-11-15

    Total and bioaccessible concentrations of trace elements (Al, As, Cd, Cu, Fe, Hg, Mn, Ni, Pb and Zn) have been measured in charcoals from 15 barbecue products available from UK retailers. Total concentrations (available to boiling aqua regia) were greater in briquetted products (with mean concentrations ranging from 0.16 μg g(-1) for Cd to 3240 μg g(-1) for Al) than in lumpwoods (0.007 μg g(-1) for Cd to 28 μg g(-1) for Fe), presumably because of the use of additives and secondary constituents (e.g. coal) in the former. On ashing, and with the exception of Hg, elemental concentrations increased by factors ranging from about 1.5 to 50, an effect attributed to the combustion of organic components and offset to varying extents by the different volatilities of the elements. Concentrations in the ashed products that were bioaccessible, or available to a physiologically based extraction test (PBET) that simulates, successively, the chemical conditions in the human stomach and intestine, exhibited considerable variation among the elements studied. Overall, however, bioaccessible concentrations relative to corresponding total concentrations were greatest for As, Cu and Ni (attaining 100% in either or both simulated PBET phases in some cases) and lowest for Pb (generally <1% in both phases). A comparison of bioaccessible concentrations in ashed charcoals with estimates of daily dietary intake suggest that Al and As are the trace elements of greatest concern to human health from barbecuing. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Concentration of trace elements on branded cigarette in Malaysia

    Science.gov (United States)

    Azman, Muhammad Azfar; Yasir, Muhamad Samudi; Rahman, Irman Abdul; Hamzah, Suhaimi; Rahman, Shamsiah Abdul; Elias, Md Suhaimi; Abdullah, Nazaratul Ashifa; Hashim, Azian; Shukor, Shakirah Abd

    2016-01-01

    Tobacco is a plant that is used as a recreational drug since the beginning of its use by the Native Americans. Now with the development of the tobacco industry, smoking has become a norm for the public in Malaysia. Trace elements in plants are mostly due to the uptake processes from the soils into the roots of the plants. The concentration of the elements may also be influenced by the elements contained in the water and also fertilizers. This paper aim to analyze the concentration of the trace elements contained in the branded cigarettes sold in Malaysia by utilizing the neutron activation analysis. The tobaccos were taken out from the cigarettes. The collected samples were air dried and passed through 2 mm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia Triga Mark II reactor with a neutron flux of 2.0 x 1012 n cm-2 s-1. The samples then were analyzed using ORTEC Gamma Spectrometer a co-axial n-type HPGe detector with resolution of 2.0 keV at 1332 keV and relative efficiency of 20%. The data obtained could help in assessing the concentration of the trace elements that complying with the standard limitation dose proposed by World Health Organization (WHO).

  4. Concentration of trace elements on branded cigarette in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Azman, Muhammad Azfar, E-mail: m-azfar@nuclearmalaysia.gov.my; Hamzah, Suhaimi; Rahman, Shamsiah Abdul; Elias, Md Suhaimi; Abdullah, Nazaratul Ashifa; Hashim, Azian; Shukor, Shakirah Abd [Blok 18, Makmal Kimia Analisis (ACA/BAS), Agensi Nuklear Malaysia, 43000 Kajang, Selangor (Malaysia); Yasir, Muhamad Samudi; Rahman, Irman Abdul [Bangunan Sains Nuklear, Fakulti Sains & Teknologi, UKM Bangi, 43600 Bangi, Selangor (Malaysia)

    2016-01-22

    Tobacco is a plant that is used as a recreational drug since the beginning of its use by the Native Americans. Now with the development of the tobacco industry, smoking has become a norm for the public in Malaysia. Trace elements in plants are mostly due to the uptake processes from the soils into the roots of the plants. The concentration of the elements may also be influenced by the elements contained in the water and also fertilizers. This paper aim to analyze the concentration of the trace elements contained in the branded cigarettes sold in Malaysia by utilizing the neutron activation analysis. The tobaccos were taken out from the cigarettes. The collected samples were air dried and passed through 2 mm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia Triga Mark II reactor with a neutron flux of 2.0 x 10{sup 12} n cm{sup -2} s{sup -1}. The samples then were analyzed using ORTEC Gamma Spectrometer a co-axial n-type HPGe detector with resolution of 2.0 keV at 1332 keV and relative efficiency of 20%. The data obtained could help in assessing the concentration of the trace elements that complying with the standard limitation dose proposed by World Health Organization (WHO)

  5. Covariance biplot analysis of trace element concentrations in urinary stones.

    Science.gov (United States)

    Wandt, M A; Underhill, L G

    1988-06-01

    The covariance biplot, a relatively new technique for displaying multivariate data, was applied to trace element contents and compound concentrations of urinary stones. The biplot is demonstrated to give a compact graphical representation of the multivariate data with interpretations in terms of familiar statistical concepts such as correlations and standard deviations. It displays strong correlations between various trace elements like Zn and Sr, and Sr and Na. The biplot also suggests concentration relationships which could play a hitherto unknown role in the genesis of calculi. It is shown to help in the interpretation of analytical results as well as in exposing erroneous or incomplete analyses.

  6. STUDIES OF CHOSEN TOXIC ELEMENTS CONCENTRATION IN MULTIFLOWER BEE HONEY

    Directory of Open Access Journals (Sweden)

    Ewa Popiela

    2011-04-01

    Full Text Available 72 544x376 Normal 0 21 false false false  The aim of the study was to determine the bioaccumulation level of chosen toxic elements (Zn, Cu, Pb, As and Cd in multiflower honey collected from Brzeg area. Biological material (honey was mineralized using the microwave technique at an elevated pressure in the microprocessor station of pressure in the type Mars 5. Quantitative analysis of elements (As, Cd, Cu, Pb and Zn was performed by plasma spectrometry method using a Varian ICP-AES apparatus. The presence of toxic elements was determined in examined biological materials. The elements fallowed the fallowing decreasing order with respect to their content of honey: Zn>Cu>Pb>As>Cd. The average concentrations of studied elements observed in multi-flower honey were as follows: 6.24 mg.kg-1 of zinc, 2.75 mg.kg-1 of copper, 0.53, 0.071, 0.042 mg.kg-1of lead, arsenic and cadmium, respectively. Lead was the most problematic in bee honey because its average content exceeded the maximum acceptable concentration. Additionally, this metal concentration was 60% higher in studied samples than allowable standard of lead content.doi:10.5219/134 

  7. Elemental concentrations in Triticale straw, a potential bioenergy feedstock

    Science.gov (United States)

    Triticale (X Triticosecale Wittmack) is produced on more than three million ha world wide including 344,000 ha in the USA. Straw resulting from triticale production could provide feedstock for bioenergy production in many regions of the world, but high concentrations of certain elements, including s...

  8. Maximum Permissible Concentrations and Negligible Concentrations for Rare Earth Elements (REEs)

    NARCIS (Netherlands)

    Sneller FEC; Kalf DF; Weltje L; Wezel AP van; CSR

    2000-01-01

    In this report maximum permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for Rare Earth Elements (REEs), which are also known as lanthanides. The REEs selected for derivation of environmental risk limits in this report are Yttrium (Y), Lanthanum (La), Cerium (Ce), Pra

  9. Parallel and Serial Grouping of Image Elements in Visual Perception

    Science.gov (United States)

    Houtkamp, Roos; Roelfsema, Pieter R.

    2010-01-01

    The visual system groups image elements that belong to an object and segregates them from other objects and the background. Important cues for this grouping process are the Gestalt criteria, and most theories propose that these are applied in parallel across the visual scene. Here, we find that Gestalt grouping can indeed occur in parallel in some…

  10. Conjugacy classes of periodic elements in Garside groups

    CERN Document Server

    Lee, Eon-Kyung

    2010-01-01

    Let $G$ be a Garside group with Garside element $\\Delta$. An element $g\\in G$ is said to be 'periodic' if some power of it is a power of $\\Delta$. In this paper, we study the conjugacy classes of periodic elements in Garside groups. By a classical theorem of Brouwer, Kerekjarto and Eilenberg, an $n$-braid is periodic if and only if it is conjugate to a power of one of two specific roots of $\\Delta^2$. We generalize this to Garside groups by showing that every periodic element is conjugate to a power of a root of $\\Delta^m$ where $\\Delta^m$ is the minimal positive power of $\\Delta$ which is central. For periodic elements in Garside groups, we introduce the notions of slimness and precentrality, and show that the super summit set of a slim, precentral periodic element is closed under any partial cycling. For the conjugacy problem, we may assume the slimness without loss of generality. For the Artin groups of type $A_n$, $B_n$, $D_n$, $I_2(e)$ and the braid group of the complex reflection group of type $(e,e,n)$...

  11. Effect of membrane filtration artifacts on dissolved trace element concentrations

    Science.gov (United States)

    Horowitz, Arthur J.; Elrick, Kent A.; Colberg, Mark R.

    1992-01-01

    Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one; only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter 'dissolved' trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual 'dissolved' chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

  12. Finite Groups with Three Conjugacy Class Sizes of some Elements

    Indian Academy of Sciences (India)

    Qingjun Kong

    2012-08-01

    Let be a finite group. We prove as follows: Let be a -solvable group for a fixed prime . If the conjugacy class sizes of all elements of primary and biprimary orders of are $\\{1,p^a,n\\}$ with and two positive integers and (,)=1, then is -nilpotent or has abelian Sylow -subgroups.

  13. Cognitive impairment related changes in the elemental concentration in the brain of old rat

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, R.F.B. [Federal University of Rio de Janeiro/COPPE, Nuclear Instrumentation Laboratory, P.O. Box: 68509, Zip Code: 21941-972, Rio de Janeiro (Brazil)]. E-mail: renata@lin.ufrj.br; Jesus, E.F.O. de [University of Rio de Janeiro State, Physics Institute, RJ (Brazil); Anjos, M.J. [Federal University of Rio de Janeiro/COPPE, Nuclear Instrumentation Laboratory, P.O. Box: 68509, Zip Code: 21941-972, Rio de Janeiro (Brazil); University of Rio de Janeiro State, Physics Institute, RJ (Brazil); Lopes, R.T. [Federal University of Rio de Janeiro/COPPE, Nuclear Instrumentation Laboratory, P.O. Box: 68509, Zip Code: 21941-972, Rio de Janeiro (Brazil); Carmo, M.G.T. do [Federal University of Rio de Janeiro, Nutrition Institute, RJ (Brazil); Rocha, M.S. [Federal University of Rio de Janeiro, Department of Basics and Clinic Pharmacy, RJ (Brazil); Rodrigues, L.C. [Federal University of Rio de Janeiro, Department of Basics and Clinic Pharmacy, RJ (Brazil); Moreira, S. [University of Campinas State, Civil Engineering Department, SP (Brazil); Martinez, A.M.B. [Federal University of Rio de Janeiro, Department of Histology and Embryology, RJ (Brazil)

    2006-11-15

    In order to evaluate the elemental concentration as a function of learning and memory deficiency, six different structures of the brain were analyzed by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). To evaluate the cognitive processes, the animals were tested in an adaptation of the Morris water maze. After the test, the animals were divided into two groups: cognitively healthy (control group) and cognitively impaired. The measurements were carried out at XRF beam line at Light Synchrotron Brazilian laboratory, Campinas, Brazil. The following elements were identified: Al, P, S, Cl, K, Ca, Ti, Cr, Fe, Cu, Zn, Br and Rb. K concentration was higher in all regions of the brain studied for control group than the cognitively impaired group. Moreover, the control group presented higher levels for P and Fe in the entorhinal cortex, in the temporal cortex (only P), in the hypothalamus and in the thalamus, than the cognitively impaired group. Br concentration in the animals which presented cognitive impairment was three times larger in the hypothalamus and thalamus, twice larger in temporal cortex and higher in visual cortex than the cognitively healthy group. Cu was more remarkable in the hippocampus and hypothalamus from the animals with cognitive impairment than the control group. We observed that the cognitively impaired group presented highest concentrations of Br and Cu in certain areas than the control group, on the other hand, this group presented highest levels of K for all brain areas studied.

  14. The probability that a pair of group elements is autoconjugate

    Indian Academy of Sciences (India)

    Mohammad Reza R Moghaddam; Esmat Motaghi; Mohammad Amin Rostamyari

    2016-02-01

    Let and ℎ be arbitrary elements of a given finite group . Then and ℎ are said to be autoconjugate if there exists some automorphism of such that ℎ = . In this article, we construct some sharp bounds for the probability that two random elements of are autoconjugate, denoted by $\\mathcal{P}_{a}(G)$. It is also shown that $\\mathcal{P}_{a}(G)|G|$ depends only on the autoisoclinism class of .

  15. Platinum-group elements: so many excellent properties

    Science.gov (United States)

    Zientek, Michael L.; Loferski, Patricia J.

    2014-01-01

    The platinum-group elements (PGE) include platinum, palladium, rhodium, ruthenium, iridium, and osmium. These metals have similar physical and chemical properties and occur together in nature. The properties of PGE, such as high melting points, corrosion resistance, and catalytic qualities, make them indispensable to many industrial applications. PGE are strategic and critical materials for many nations because they are essential for important industrial applications but are mined in a limited number of places and have no adequate substitutes. Exploration and mining companies have found approximately 104,000 metric tons of PGE (with minor gold) in mineral deposits around the world that could be developed. For PGE, almost all known production and resources are associated with three geologic features: the Bushveld Complex, a layered mafic-to-ultramafic intrusion in South Africa; the Great Dyke, a layered mafic-to-ultramafic intrusion in Zimbabwe; and sill-like intrusions associated with flood basalts in the Noril’sk-Talnakh area, Russia. To help predict where PGE supplies might be located, USGS scientists study how and where PGE resources are concentrated in the Earth's crust and use that knowledge to assess the likelihood that undiscovered PGE deposits may exist. Techniques used for assessing mineral resources were developed by the USGS to support the stewardship of Federal lands and evaluate mineral resource availability in a global context. The USGS also compiles statistics and information on the worldwide supply, demand, and flow of PGE. These data are all used to inform U.S. national policymakers.

  16. Systems of elements preserving measure on varieties of groups

    Energy Technology Data Exchange (ETDEWEB)

    Timoshenko, E I [Novosibirsk State Technical University, Novosibirsk (Russian Federation)

    2013-12-31

    It is proved that for any l, 1≤l≤r, a system of elements (v{sub 1},…,v{sub l}) of a free metabelian group S of rank r≥2 is primitive if and only if it preserves measure on the variety of metabelian groups A{sup 2}. From this we obtain the result that a system of elements (v{sub 1},…,v{sub l}) is primitive in the group S if and only if it is primitive in its profinite completion S-hat . Furthermore, it is proved that there exist a variety M and a nonprimitive element v∈F{sub r}(M) such that v preserves measure on M. Bibliography: 13 titles.

  17. Elliptic elements in a Weyl group: a homogeneity property

    CERN Document Server

    Lusztig, G

    2010-01-01

    Let G be a reductive group over an algebraically closed field whose characteristic is not a bad prime for G. Let w be an elliptic element of the Weyl group which has minimal length in its conjugacy class. We show that there exists a unique unipotent class X in G such that the following holds: if V is the variety of pairs consisting of an element g in X and a Borel subgroup B such that B,gBg^{-1} are in relative position w, then V is a homogeneous G-space.

  18. Aerosol chemical elemental mass concentration at lower free troposphere

    Energy Technology Data Exchange (ETDEWEB)

    Carmo Freitas, Maria do [Reactor-ITN, Technological and Nuclear Institute, E.N. 10, 2686-953 Sacavem (Portugal)], E-mail: cfreitas@itn.pt; Dionisio, Isabel [Reactor-ITN, Technological and Nuclear Institute, E.N. 10, 2686-953 Sacavem (Portugal); Fialho, Paulo; Barata, Filipe [Chemistry and Physics of Atmosphere, Azores University, 9701-851 Terra Cha (Portugal)

    2007-08-21

    This paper shows the use of Instrumental neutron activation analysis (INAA) technique to determine elemental masses collected by a seven-wavelength Aethalometer instrument at the summit of Pico mountain in the Azorean archipelago, situated in the Central North Atlantic Ocean. Each sample corresponds to air particulate matter measured continuously for periods of approximately 24 h taken from 14th July 2001 through 14th July 2002. The statistical analysis of the coefficients of correlation between all the elements identified, permitted to establish six groups that could potentially be associated with the type of source responsible for the aerosol sampled in the lower free troposphere at the Azorean archipelago. Calculation of the synoptic back trajectories helped to corroborate the use of the iron/cesium relation as a tracer for the Saharan dust aerosol. It was demonstrated that INAA constituted an important tool to identify these events.

  19. Major element concentrations in Mangrove Pore Water, Sepetiba Bay, Brazil

    Directory of Open Access Journals (Sweden)

    Christian J. Sanders

    2012-03-01

    Full Text Available Concentrations of cations and anions of major elements (Na+, Ca2+, Mg2+, K+, Cl-, SO4 2- were analyzed in the pore water of a mangrove habitat. Site specific major element concentrations were identified along a four piezometric well transect, which were placed in distinct geobotanic facies. Evapotranspiration was evident in the apicum station, given the high salinity and major element concentrations. The station landward of an apicum was where major element/Cl- ratios standard deviations are greatest, suggesting intense in situ diagenesis. Molar ratios in the most continental station (4 are significantly lower than the nearby freshwater source, indicating a strong influence of sea water flux into the outer reaches of the mangrove ecosystem and encroaching on the Atlantic rain forest. Indeed, the SO4 2-/Cl- and Ca2+/Cl- ratios suggest limited SO4 2- reduction and relatively high Ca2+/Cl- ratios indicate a region of recent saltwater contact.As concentrações dos elementos maiores (Na+, Ca2+, Mg2+, K+, Cl-, SO4(2- foram analisadas na água intersticial de poços piezométricos localizados em diferentes fácies geobotânicas ao longo de um transecto num ecossistema de manguezal na Baía de Sepetiba - Rio de Janeiro. Maiores salinidades e concentrações dos íons maiores são evidencias de evapotranspiração no fácies apicum. Ainda no apicum foram observados os maiores desvios padrão da razão elemento/Cl− durante o período do estudo, indicando intensa diagênese in situ. Razões molares no piezômetro, localizado na borda do manguezal foram consideravelmente menores do que a fonte de água doce, indicando forte influência do fluxo de água marinha. Os resultados das razões molares, SO4(2-/Cl− e Ca2+/Cl− na borda do manguezal adjacente ao continente sugerem limitada redução de SO4(2- enquanto os valores relativamente altos na razão Ca2+/Cl− indicam contacto recente com água marinha.

  20. On spectral synthesis on element-wise compact Abelian groups

    Science.gov (United States)

    Platonov, S. S.

    2015-08-01

    Let G be an arbitrary locally compact Abelian group and let C(G) be the space of all continuous complex-valued functions on G. A closed linear subspace \\mathscr H\\subseteq C(G) is referred to as an invariant subspace if it is invariant with respect to the shifts τ_y\\colon f(x)\\mapsto f(xy), y\\in G. By definition, an invariant subspace \\mathscr H\\subseteq C(G) admits strict spectral synthesis if \\mathscr H coincides with the closure in C(G) of the linear span of all characters of G belonging to \\mathscr H. We say that strict spectral synthesis holds in the space C(G) on G if every invariant subspace \\mathscr H\\subseteq C(G) admits strict spectral synthesis. An element x of a topological group G is said to be compact if x is contained in some compact subgroup of G. A group G is said to be element-wise compact if all elements of G are compact. The main result of the paper is the proof of the fact that strict spectral synthesis holds in C(G) for a locally compact Abelian group G if and only if G is element-wise compact. Bibliography: 14 titles.

  1. Using water, bryophytes, and macroinvertebrates to assess trace element concentrations in the Upper Colorado River Basin

    Science.gov (United States)

    Deacon, J.R.; Spahr, N.E.; Mize, S.V.; Boulger, R.W.

    2001-01-01

    This study examined trace elements concentrations and macroinvertebrate community structure at 32 sites in 22 streams in Colorado. Sites affected by mining activities (mining sites) and sites that were minimally disturbed (nonmining sites) were selected for the assessment. Water and transplanted aquatic bryophyte samples were analyzed for trace elements. Macroinvertebrate samples were collected to assess the effects of trace elements on the aquatic community of the stream. All samples of aquatic bryophytes had detectable concentrations of Cd, Cu, Pb and Zn. Principal components analysis of chemical and physical properties classified sites into three groups. The first group represented sites that were unaffected to minimally affected by mining activities; the second group was characterized by sites with Cd, Pb and Zn predominant in the mineralogy; and the third group was characterized by sites with Cu predominant in the mineralogy. Six macroinvertebrate families were common in the study area. Median values of total abundance, taxa richness and mayfly and stonefly abundance were reduced at mining sites. Abundances of Heptageniidae, Chloroperlidae and Rhyacophila and Baetis sp. also were reduced at sites with elevated trace element concentrations. Tanytarsini chironomids were most abundant at reference and minimally-disturbed sites.

  2. Element concentrations and cataract: an experimental animal model.

    Science.gov (United States)

    Ciaralli, L; Giordano, R; Costantini, S; Sepe, A; Cruciani, F; Moramarco, A; Antonelli, B; Balacco-Gabrieli, C

    2001-04-01

    The determination of inorganic ions in cataractous human lenses has been the subject of several investigations; nevertheless, few studies have been concerned with trace element contents in lenses, and data are sometimes contradictory. An animal experimental model of induced cataract is here proposed with the aim of evaluating the changes of Ca, Na, K, Cu and Zn concentrations. The cataract was produced by an Nd:YAG Laser treatment of the right eye of sexteen male rabbits. The determination of the elements was performed by atomic absorption spectrometry (both flame and flameless methods) after an acid digestion of samples. Compared with the results obtained in left lenses used as a control (Ca 14.4+/-5.7 mg/kg d.w.; Na 1.3+/-0.5 g/kg d.w.; K 9.9+/-1.1 g/kg d.w.; Cu 0.24+/-0.09 mg/kg d.w.; Zn 24.8+/-2.3 mg/kg d.w.), the mean concentration values of opaque lenses showed some significant changes for Ca, Na, and Cu (Ca 123.7+/-106.6 mg/kg d.w.; Na 4.5+/-4.3 g/kg d.w; Cu 0.43+/-0.21 mg/kg d.w.). Potassium showed a tendency to decrease, and zinc to increase. Positive correlations were found between calcium and sodium both in controls (r=0.73, p<0.001) and in treated lenses (r= 0.87, p<0.0001). An inverse correlation between Ca and K confirmed the tendency of potassium to decrease.

  3. Elemental concentration analysis in PCa, BPH and normal prostate tissues using SR-TXRF

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Roberta G.; Anjos, Marcelino J.; Canellas, Catarine G.L.; Lopes, Ricardo T., E-mail: roberta@lin.ufrj.b [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Correia, Rodrigo C., E-mail: marcelin@lin.ufrj.b [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica; Palumbo Junior, Antonio; Souza, Pedro A.V.R.; Nasciutti, Luiz E., E-mail: nasciutt@ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Ciencias da Saude. Lab. de Interacoes Celulares; Ferreira, Luiz C., E-mail: luiz.ferreira@ipec.fiocruz.b [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    Prostate cancer (PCa) is one of the main causes of illness and death all over the world. In Brazil, prostate cancer currently represents the second most prevalent malignant neoplasia in men, representing 21% of all cancer cases. Benign Prostate Hyperplasia (BPH) is an illness prevailing in men above the age of 50, close to 90% after the age of 80. The prostate presents a high zinc concentration, about 10-fold higher than any other body tissue. In this work, samples of human prostate tissues with cancer (PCa), BPH and normal tissue were analyzed utilizing the total reflection X-ray fluorescence spectroscopy using synchrotron radiation technique (SRTXRF) to investigate the differences in the elemental concentrations in these tissues. SR-TXRF analyses were performed at the X-Ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo. It was possible to determine the concentrations of the following elements: P, S, K, Ca, Fe, Cu, Zn, Br and Rb. By using Mann-Whitney U test it was observed that almost all elements presented concentrations with significant differences alpha = 0.05) between the groups studied. The elements and groups were: S, K, Ca, Fe, Zn, Br and Rb (PCa X Normal); S, Fe, Zn and Br (PCa X BPH); K, Ca, Fe, Zn, Br and Rb (BPH X Normal). (author)

  4. Metallomics approach to changes in element concentration during differentiation from fibroblasts into adipocytes by element array analysis.

    Science.gov (United States)

    Ogra, Yasumitsu; Nagasaki, Shu; Yawata, Ayako; Anan, Yasumi; Hamada, Koichi; Mizutani, Akihiro

    2016-04-01

    We aimed to establish an element array analysis that involves the simultaneous detection of all elements in cells and the display of changes in element concentration before and after a cellular event. In this study, we demonstrated changes in element concentration during the differentiation of 3T3-L1 mouse fibroblasts into adipocytes. This metallomics approach yielded unique information of cellular response to physiological and toxicological events.

  5. How many tuples of group elements have a given property?

    CERN Document Server

    Klyachko, Anton A

    2012-01-01

    Generalising Solomon's theorem, Gordon and Rodriguez-Villegas have proven recently that, in any group, the number of solutions to a system of coefficient-free equations is divisible by the order of this group whenever the rank of the matrix composed of the exponent sums of i-th unknown in j-th equation is less than the number of unknowns. We generalise this result in two directions: first, we consider equations with coefficients, and secondly, we consider not only systems of equations but also any first-order formulae in the group language (with constants). Our theorem implies some amusing facts; for example, the number of group elements whose squares lie in a given subgroup is divisible by the order this subgroup.

  6. Phosphogypsum analysis: total content and extractable element concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Gennari, Roseli F.; Medina, Nilberto H., E-mail: rgennari@dfn.if.usp.br, E-mail: medina@if.usp.br [Departamento de Fisica Nuclear, Instituto de Fisica (USP), Sao Paulo, SP (Brazil); Garcia, Isabella; Silveira, Marcilei A.G., E-mail: shila@if.usp.br [Centro Universitario da FEI. Sao Bernardo do Campo, SP (Brazil)

    2011-07-01

    Phosphogypsum stand for the chemical origin gypsum generated in fertilizers production, in which phosphate rock is attacked by sulfuric acid resulting in phosphoric acid (H{sub 3}PO{sub 4}) and phosphate fertilizers. Phosphogypsum is not a commercial product and it is stocked in large open areas or accumulated in lakes inducing to a major environmental problem due to the presence of toxic and radioactive elements. The increasing world agricultural demand is the real responsible for the severity of this environmental problem. Nevertheless, there are some possibilities for the application of this reject material, such as civil construction, waste water treatment, and in cultivated lands, etc. In the agriculture the phosphogypsum is commonly used as a nutrient source due to its large amounts of phosphorus, calcium and sulfur. However, there are still some environmental questions related to the use of this by-product since phosphogypsum is classified as TENORM (Technologically Enhanced Naturally Occurring Radioactive Material), which is a solid waste containing heavy metals and naturally occurring radioactive elements from the rock matrix. In this work, Plasma Mass Spectrometry (ICP-MS) was used to study phosphogypsum samples. Several acid solutions for samples digestion were evaluated in order to be feasible the chemical analysis. BCR sequential extractions were also performed. The results showed analyte concentrations are highly dependent on the acid solution used. The BCR guidelines could not be applied as used for soil, since the phosphogypsum solubility is different. So, it would be necessary to use different mass aliquots in the extractions, to be feasible an environmental evaluation. (author)

  7. Quantitative analysis of trace element concentrations in some gem-quality diamonds

    Science.gov (United States)

    McNeill, J.; Pearson, D. G.; Klein-Ben David, O.; Nowell, G. M.; Ottley, C. J.; Chinn, I.

    2009-09-01

    The geochemical signature of diamond-forming fluids can be used to unravel diamond-forming processes and is of potential use in the detection of so-called 'conflict' diamonds. While fluid-rich fibrous diamonds can be analyzed by a variety of techniques, very few data have been published for fluid-poor, gem-quality diamonds because of their very low impurity levels. Here we present a new ICPMS-based (ICPMS: inductively coupled plasma mass spectrometry) method for the analysis of trace element concentrations within fluid-poor, gem-quality diamonds. The method employs a closed-system laser ablation cell. Diamonds are ablated and the products trapped for later pre-concentration into solutions that are analyzed by sector-field ICPMS. We show that our limits of quantification for a wide range of elements are at the sub-pg to low pg level. The method is applied to a suite of 10 diamonds from the Cullinan Mine (previously known as Premier), South Africa, along with other diamonds from Siberia (Mir and Udachnaya) and Venezuela. The concentrations of a wide range of elements for all the samples (expressed by weight in the solid) are very low, with rare earth elements along with Y, Nb, Cs ranging from 0.01 to 2 ppb. Large ion lithophile elements (LILE) such as Rb and Ba vary from 1 to 30 ppb. Ti ranges from ppb levels up to 2 ppm. From the combined, currently small data set we observe two kinds of diamond-forming fluids within gem diamonds. One group has enrichments in LILE over Nb, whereas a second group has normalized LILE abundances more similar to those of Nb. These two groups bear some similarity to different groups of fluid-rich diamonds, providing some supporting evidence of a link between the parental fluids for both fluid-inclusion-rich and gem diamonds.

  8. Elemental Mercury Diffusion Processes and Concentration at the Lunar Poles

    Science.gov (United States)

    Moxley, Frederick; Killen, Rosemary M.; Hurley, Dana M.

    2011-01-01

    In 2009, the Lyman Alpha Mapping Project (LAMP) spectrograph onboard the Lunar Reconnaissance Orbiter (LRO) spacecraft made the first detection of element mercury (Hg) vapor in the lunar exosphere after the Lunar Crater Observing and Sensing Satellite (LCROSS) Centaur rocket impacted into the Cabeus crater in the southern polar region of the Moon. The lunar regolith core samples from the Apollo missions determined that Hg had a devolatilized pattern with a concentration gradient increasing with depth, in addition to a layered pattern suggesting multiple episodes of burial and volatile loss. Hg migration on the lunar surface resulted in cold trapping at the poles. We have modeled the rate at which indigenous Hg is lost from the regolith through diffusion out of lunar grains. We secondly modeled the migration of Hg vapor in the exosphere and estimated the rate of cold-trapping at the poles using a Monte Carlo technique. The Hg vapor may be lost from the exosphere via ionization, Jeans escape, or re-impact into the surface causing reabsorption.

  9. Stable single-layer structure of group-V elements

    Science.gov (United States)

    Ersan, F.; Aktürk, E.; Ciraci, S.

    2016-12-01

    In addition to stable single-layer buckled honeycomb and washboard structures of group-V elements (or pnictogens P, As, Sb, and Bi) we show that these elements can also form two-dimensional, single-layer structures consisting of buckled square and octagon rings. An extensive analysis comprising the calculation of mechanical properties, vibration frequencies, and finite-temperature ab initio molecular dynamics confirms that these structures are dynamically and thermally stable and suitable for applications at room temperature and above. All these structures are semiconductors with a fundamental band gap, which is wide for P but decreases with increasing row number. The effect of the spin-orbit coupling decreases the band gap and is found to be crucial for Sb and Bi. These results are obtained from first-principles calculations based on density functional theory.

  10. Studies on Concentrations of Trace Elements in Organs and Tissues

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Trace elements are important parts of human body compositions, and some of them are essential for life activities. To provide bases for parameters of the Chinese Reference Man and current data in China for research on relationship between trace elements and health, 30 trace elements in 10 kinds of organs and tissues are determined by neutron activation analysis.Neutron activation analysis is one of the most effective methods for trace elements. I and Br are determined by epithermal neutron activation analysis , and other 28 elements such as Al, Ca, Fe, Zn are determined by instrumentation neutron activation analysis. The analytical conditions are

  11. Study on the concentration and seasonal variation of inorganic elements in 35 species of marine algae

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Yan, X.J.

    1998-01-01

    The concentrations of five major and 28 trace elements in 35 marine algae collected along the coast of China were determined by instrumental neutron activation analysis. The concentrations of halogens, rare earth elements and many transition metal elements in marine algae are remarkably higher than...... those in terrestrial plants. The concentration factors for 31 elements in all collected algae were calculated, those for tri- and tetra-valent elements were higher than those of the mono- and di-valent elements in marine algae. The biogeochemical characteristics of inorganic elements in marine algae...

  12. Tunnelling characteristics of Stone-Wales defects in monolayers of Sn and group-V elements

    Science.gov (United States)

    Jamdagni, Pooja; Kumar, Ashok; Thakur, Anil; Pandey, Ravindra; Ahluwalia, P. K.

    2017-10-01

    Topological defects in ultrathin layers are often formed during synthesis and processing, thereby strongly influencing the electronic properties of layered systems. For the monolayers of Sn and group-V elements, we report the results based on density functional theory determining the role of Stone-Wales (SW) defects in modifying their electronic properties. The calculated results find the electronic properties of the Sn monolayer to be strongly dependent on the concentration of SW defects, e.g. defective stanene has nearly zero band gap (≈0.03 eV) for the defect concentration of 2.2  ×  1013 cm-2 which opens up to 0.2 eV for the defect concentration of 3.7  ×  1013 cm-2. In contrast, SW defects appear to induce conduction states in the semiconducting monolayers of group-V elements. These conduction states act as channels for electron tunnelling, and the calculated tunnelling characteristics show the highest differential conductance for the negative bias with the asymmetric current-voltage characteristics. On the other hand, the highest differential conductance was found for the positive bias in stanene. Simulated STM topographical images of stanene and group-V monolayers show distinctly different features in terms of their cross-sectional views and distance-height profiles. These distinctive features can serve as fingerprints to identify the topological defects in experiments for the monolayers of group-IV and group-V elements.

  13. effect of soil moisture on trace elements concentrations using ...

    African Journals Online (AJOL)

    H. Sahraoui and M. Hachicha

    2017-01-01

    Jan 1, 2017 ... produced by the water influence moisture content and corrected ... Previous studies indicated that PXRF analysis was capable of detecting soil trace elements ..... determination of some heavy metals in soil using an x-ray ...

  14. Grouping of contextual elements that affect vernier thresholds.

    Science.gov (United States)

    Malania, Maka; Herzog, Michael H; Westheimer, Gerald

    2007-01-29

    To reveal the mechanisms of spatial interference in the fovea, we examined the capacity of a variety of lateral flanking configurations to interfere with alignment thresholds of a vertical vernier. A single line on each side of the vernier, at the optimal separation of 2-3 arcmin, raises thresholds threefold or more and masks most effectively when its length equals that of the vernier. For an array of equal lines whose length differs from that of the vernier, masking is reduced but not when vernier and flanks have the same length. The reduction for shorter and longer flanks can be reversed by inserting a gap in the row of flanks. By comparing the masking effect of arrays of mixed line lengths, we show that when a pair of flanks, which by itself masks strongly, becomes a component of a coherent contextual configuration, it loses much of its effectiveness to interact. Observers' ranking of the conspicuity of the vernier test pattern among the flanking elements is negatively correlated with the threshold elevation. We conclude that clustering of contextual patterns influences their capacity to mask. Discrimination of a target deteriorates when the target is grouped within an array of surrounding elements.

  15. Selected Trace Element Concentrations in Peat Used for Cosmetic Production - A Case Study from Southern Poland

    Science.gov (United States)

    Glina, Bartłomiej

    2016-12-01

    The aim of the study was to assess the concentration of selected trace elements in organic soils used as a source to obtain a unique peat extract for cosmetics production. Peat material for laboratory analysis were collected from fen peatland located in the Prosna River Valley (Borek village). Studied peatland is managed by "Torf Corporation" company as a source of material to obtain peat extract for cosmetics production. In the collected soil samples (four soil profiles) Zn, Cu and Pb concentrations were determined by using atomic absorption spectrometer SpectraAA 220 (Varian), after acid digestion. Obtained results showed that the highest concentrations of selected trace elements were recorded in the surface horizons of organic soils. This fact might be the results of Prosna river flooding or air deposition. Howevere, according to the new Polish regulations (Ordinance of the Minister for Environment 01.09.2016 - the way of conducting contamination assessment of the earth surface), the content of trace elements in the examined soils was greatly belowe the permissible limit for areas from group IV (mine lands). Thus, described soils are proper to obtain peat extract used as a component in cosmetic production.

  16. Comprehensive Analyses of the Spectra of Iron-group Elements

    Science.gov (United States)

    Nave, Gillian; Sansonetti, Craig J; Pickering, Juliet C; Liggins, Florence

    2014-06-01

    For many decades, the Atomic Spectroscopy Group at NIST has measured atomic data of vital use to astronomy and other fields using high resolution spectrometers that are found in few other places in the world. These now include the 2-m Fourier transform (FT) spectrometer covering the region 285 nm to 5500 nm, the FT700 vacuum ultraviolet (VUV) FT spectrometer covering the region 143 nm to 900 nm, and a 10.7-m normal incidence spectrograph (NIVS) covering 30 nm to 500 nm. Recent work focused on the measurement and analysis of wavelengths and energy levels of iron-group elements to provide extensive data for the analysis of astrophysical spectra. Our comprehensive linelist for Fe II from 90 nm to 5500 nm contains over 13 600 lines with order of magnitude improvements in the wavelengths compared to previous work [Nave & Johansson, ApJSS 204, 1(2013)]. The spectra were observed in high-current continuous and pulsed hollow cathode (HCL) discharges using FT spectrometers and our NIVS spectrograph. A similar analysis of Cr II contains over 5300 lines and extends the knowledge of this spectrum to the previously unobserved region between 731 nm at 5500 nm [Sansonetti, Nave, Reader & Kerber, ApJSS 202, 15 (2012); Sansonetti & Nave, ApJSS (in prep.)]. Our analysis of the Co III spectrum contains 750 lines observed in Penning discharge lamps and an additional 900 lines compiled from previous work, including Ritz wavelengths, optimized energy levels, and calculated log(gf) values [Smillie, Pickering, Nave & Smith, ApJSS (in prep.)]. NIST and ICL are currently collaborating to complete the measurement and analysis of wavelengths, energy levels, and hyperfine structure parameters for all singly-ionized iron-group elements of astrophysical interest, covering the wavelength range 80 nm to 5500 nm. This project uses archival data from FT spectrometers at NIST, ICL and Kitt Peak National Observatory, with additional spectra of HCL and Penning discharge sources taken using our FT and

  17. Interannual heavy element and nutrient concentration trends in the top sediments of Venice Lagoon (Italy).

    Science.gov (United States)

    Masiol, Mauro; Facca, Chiara; Visin, Flavia; Sfriso, Adriano; Pavoni, Bruno

    2014-12-15

    The elemental composition of surficial sediments of Venice Lagoon (Italy) in 1987, 1993, 1998 and 2003 were investigated. Zn and Cr concentrations resulted in higher than background levels, but only Cd and Hg were higher than legal quality standards (Italian Decree 2010/260 and Water Framework Directive 2000/60/EC). Contaminants with similar spatial distribution are sorted into three groups by means of correlation analysis: (i) As, Co, Cd, Cu, Fe, Pb, Zn; (ii) Ni, Cr; (iii) Hg. Interannual concentrations are compared by applying a factor analysis to the matrix of differences between subsequent samplings. A general decrease of heavy metal levels is observed from 1987 to 1993, whereas particularly high concentrations of Ni and Cr are recorded in 1998 as a consequence of intense clam fishing, subsequently mitigated by better prevention of illegal harvesting. Due to the major role played by anthropogenic sediment resuspension, bathymetric variations are also considered.

  18. Concentration of Key Elements in North American Meat & Bone Meal

    Science.gov (United States)

    Meat & bone meal (MBM) and related rendered protein commodities have potential for use in applications other than animal feed, including use as a fuel or a phosphorus fertilizer. In order to develop these applications, data on the elemental composition are required; the currently available elementa...

  19. Trace element analysis of teeth from pre-Columbian population groups in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Solis, C.; Oliver, A.; Andrade, E.; Macias, R. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico (Mexico); Mansilla, J. [Departamento de Antropologia Fisica, Instituto Nacional de Antropologia e Historia, Mexico (Mexico); Chavez-Lomeli, M.E.

    1999-07-01

    Human teeth from pre-Columbian and recent population groups have been analyzed by PIXE. Ancient teeth corresponding to children and adults were obtained from archaeological burials located in five geographic areas of Mexico. Inter-specific and inter-site differences in the trace element contents of enamel were compared in order to get some insight into differences in diet, environmental conditions, teeth health, disease state and post mortem alteration among the co-occurring populations. For permanent teeth from adults, small variations in trace element levels were found depending on the collection site or tooth health, but for deciduous teeth from children, the concentration of elements such as Mn, Fe and Sr varied considerably. In this work, the possible sources of variation are discussed. (author)

  20. Group Waterpipe Tobacco Smoking Increases Smoke Toxicant Concentration.

    Science.gov (United States)

    Ramôa, Carolina P; Shihadeh, Alan; Salman, Rola; Eissenberg, Thomas

    2016-05-01

    Waterpipe tobacco smoking is a global health concern. Laboratory research has focused on individual waterpipe users while group use is common. This study examined user toxicant exposure and smoke toxicant yield associated with individual and group waterpipe smoking. Twenty-two pairs of waterpipe smokers used a waterpipe individually and as a dyad. Before and after smoking, blood was sampled and expired carbon monoxide (CO) measured; puff topography was recorded throughout. One participant from each pair was selected randomly and their plasma nicotine and expired air CO concentrations were compared when smoking alone to when smoking as part of a dyad. Recorded puff topography was used to machine-produce smoke that was analyzed for toxicant content. There was no difference in mean plasma nicotine concentration when an individual smoked as part of a dyad (mean = 14.9 ng/ml; standard error of the mean [SEM] = 3.0) compared to when smoking alone (mean = 10.0 ng/ml; SEM = 1.5). An individual smoking as part of as a dyad had, on average, lower CO (mean = 15.8 ppm; SEM = 2.0) compared to when smoking alone (mean= 21.3 ppm; SEM = 2.7). When two participants smoked as a dyad they took, on average, more puffs (mean = 109.8; SEM = 7.6) than a singleton smoker (mean = 77.7; SEM = 8.1) and a shorter interpuff interval (IPI; dyad mean = 23.8 seconds; SEM = 1.9; singleton mean = 40.8 seconds; SEM = 4.8). Higher concentrations of several toxicants were observed in dyad-produced smoke. Dyad smoking may increase smoke toxicant content, likely due to the dyad's shorter IPIs and greater puff number. More work is needed to understand if group waterpipe smoking alters the health risks of waterpipe tobacco smoking. This study is the first to measure toxicants in smoke generated from a waterpipe when used by a dyad. Relative to smoke generated by a singleton, dyad smoke had higher concentration of some toxicants. These differences may be attributed to differences in puffing behavior

  1. Food group contribution of essential elements of the Sao Paulo State market basket

    Energy Technology Data Exchange (ETDEWEB)

    Avegliano, Roseane P.; Maihara, Vera A., E-mail: pagliaro@usp.b, E-mail: vmaihara@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Silva, Fabio F. da, E-mail: ffsusp@uol.com.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Matematica e Estatistica. Empresa Junior de Informatica, Matematica e Estatistica

    2009-07-01

    To establish a Market Basket of Sao Paulo state seventy-one foods, with a mean consumption of more than 2 g day{sup -1} per person, were grouped into 30 food categories. The food groups were: cereals, leguminous, leafy vegetables, fruity vegetables, tuberous vegetables, tropical fruits, other fruits, flours, pastas, breads, biscuits, prime grade beef, standard grade beef, pork meats, other meats, poultry, milk/cream, other dairy products, sugars, sweets, salts, sauces, oils, fats, alcoholic beverages, non-alcoholic beverages, coffee, ready-made dishes, saltwater and freshwater fishes. Information about individual food consumption was obtained from a recent national household food budget survey 'POF 2002-2003' conducted by the Brazilian Institute for Geography and Statistics from July 2002 to June 2003. Sampling and kitchen preparation of foods were carried out in restaurants of the University of Sao Paulo. Each food item was individually prepared table-ready. Foods of the same group were mixed, homogenized, pulverized and analyzed for the determination of Ca, Cr, Fe, K, Na and Zn concentrations by Instrumental Neutron Activation Analysis. Average daily intake of each element was calculated by multiplying the element concentration in the food by the corresponding weight of the ready-to-consume food group. The contribution of each food group to the total daily intake of elements by the ready-to-consume food groups of the Market Basket was evaluated. The food groups representing the highest contributions were salts: 79% Na; breads: 37% Fe and 46% Cr; cereals: 19% Zn and milk/cream: 58% Ca and 24% K. (author)

  2. Serum Concentrations of Trace Elements in Patients with Tuberculosis and Its Association with Treatment Outcome

    Directory of Open Access Journals (Sweden)

    Rihwa Choi

    2015-07-01

    Full Text Available Deficiencies in essential trace elements are associated with impaired immunity in tuberculosis infection. However, the trace element concentrations in the serum of Korean patients with tuberculosis have not yet been investigated. This study aimed to compare the serum trace element concentrations of Korean adult patients with tuberculosis with noninfected controls and to assess the impact of serum trace element concentration on clinical outcome after antituberculosis treatment. The serum concentrations of four trace elements in 141 consecutively recruited patients with tuberculosis and 79 controls were analyzed by inductively coupled plasma-mass spectrometry. Demographic characteristics were also analyzed. Serum cobalt and copper concentrations were significantly higher in patients with tuberculosis compared with controls, while zinc and selenium concentrations were significantly lower (p < 0.01. Moreover, serum selenium and zinc concentrations were positively correlated (ρ = 0.41, p < 0.05. A high serum copper concentration was associated with a worse clinical outcome, as assessed after one month of antituberculosis therapy. Specifically, culture-positive patients had higher serum copper concentrations than culture-negative patients (p < 0.05. Patients with tuberculosis had altered serum trace element concentrations. Further research is needed to elucidate the roles of individual trace elements and to determine their clinical impact on patients with tuberculosis.

  3. Carbon Nanotube Based Microfluidic Elements for Filtration and Concentration

    Energy Technology Data Exchange (ETDEWEB)

    Bakajin, O; Ben-Barak, N; Peng, J; Noy, A

    2003-06-25

    We have developed a method for integration of patterned arrays of carbon nanotubes or the ''nanotube mesh'' into microfabricated channels. The method includes standard lithographic methods for patterning and etching the substrate, followed by catalyst patterning, CVD deposition of nanotubes, and anodic bonding of coverslip top. We will describe a carbon nanotube filtering device fabricated using this method and discuss the use of carbon nanotube arrays as molecular concentration and separation media.

  4. Analyses of platinum group elements in mosses as indicators of road traffic emissions in Austria

    Science.gov (United States)

    Zechmeister, Harald G.; Hagendorfer, Harald; Hohenwallner, Daniela; Hanus-Illnar, Andrea; Riss, Alarich

    The concentrations of platinum group elements (PGE; platinum, palladium, rhodium) and 17 other elements in mosses growing at 32 sampling sites along 12 roads in Austria were analysed. The study included passive monitoring of naturally growing mosses with an experimental design using mosses samples exposed in a tunnel experiment. PGEs (Pt, Pd, Rh) were analysed by ICP-MS (ELAN DRC II, Perkin Elmer SCIEX) according to EN ISO 17294-2 Tl.29. Mean concentrations of PGEs in five moss species were: Pt 7.07±9.97, Pd 2.8±5.2 und Rh 0.6±0.8 ng g -1 dry weight. This is comparable to data derived from measurements of gasoline autocatalyst emissions or airborne particles (<10 μm). Compared to soils and road dust along highways, concentrations in mosses were lower by a factor of ten, compared to grasses they were comparable or somewhat higher. The ratios between the various PGEs were calculated as follows (mean values): Pt/Pd 7.9±10.2, Pt/Rh 12.6±8.3 and Pd/Rh 3.7±2.2. The number of light duty vehicles (<3.5 t) and the distance from the road were the main influential factors for PGE concentrations. Especially strong correlations could be found between Pt and Sb, Cu, Zn, and Cd (in decreasing order), which are all elements derived mainly from road traffic emissions. Cluster analysis (Partioning Around Medoids Method) separated elements derived mainly from soil dust (Ca, Al). An analysis of spatial deposition patterns of PGEs showed a reciprocal decrease of concentrations with increasing distance from the road, reaching background values at distances between 10 and 200 m, sometimes even more, but outside the spatial range of our investigation.

  5. Element composition of biota, water and sediment in the Forsmark area, Baltic Sea. Concentrations, bioconcentration factors and partitioning coefficients (K{sub d}) of 48 elements

    Energy Technology Data Exchange (ETDEWEB)

    Kumblad, Linda; Bradshaw, Clare (Dept. of Systems Ecology, Stockholm Univ. (Sweden))

    2008-08-15

    In this study the elemental composition of biota, water and sediment from a shallow bay in the Forsmark region have been determined. The report presents data for 48 different elements (Al, As, Ba, Br, C, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Gd, Hg, Ho, I, K, Li, Lu, Mg, Mn, N, Na, Nd, Ni, P, Pb, Pr, Ra, Rb, S, Se, Si, Sm, Tb, Th, Ti, Tm, V, Yb, Zn, Zr) in all major functional groups of the coastal ecosystem (phytoplankton, zooplankton, benthic microalgae, macroalgae, macrophytes, benthic herbivores, benthic filter feeders, benthic detrivores, planktivorous fish, benthic omnivorous fish, carnivorous fish, dissolved and particulate matter in the water and the sediment) during spring 2005. The overall aim of the study is to contribute to a better understanding of ecological properties and processes that govern uptake and transfer of trace elements, heavy-metals, radionuclides and other non-essential elements/contaminants in coastal environments of the Baltic Sea. In addition, the data was collected to provide site-specific Bioconcentration Factors (BCF), Biomagnification Factors (BMF), partitioning coefficients (K{sub d}) and element ratios (relative to carbon) for use in ongoing SKB safety assessments. All these values, as well as the element concentration data from which they are derived, are presented here. As such, this is mainly a data report, although initial interpretations of the data also are presented and discussed. Reported data include element concentrations, CNP-stoichiometry, and multivariate data analysis. Elemental concentrations varied greatly between organisms and environmental components, depending on the function of the elements, and the habitat, ecosystem function, trophic level and morphology (taxonomy) of the organisms. The results show for instance that food intake and metabolism strongly influence the elemental composition of organisms. The three macrophytes had quite similar elemental composition (despite their taxonomic

  6. X-ray fluorescence study of the concentration of selected trace and minor elements in human brain tumours

    Science.gov (United States)

    Wandzilak, Aleksandra; Czyzycki, Mateusz; Radwanska, Edyta; Adamek, Dariusz; Geraki, Kalotina; Lankosz, Marek

    2015-12-01

    Neoplastic and healthy brain tissues were analysed to discern the changes in the spatial distribution and overall concentration of elements using micro X-ray fluorescence spectroscopy. High-resolution distribution maps of minor and trace elements such as P, S, Cl, K, Ca, Fe, Cu and Zn made it possible to distinguish between homogeneous cancerous tissue and areas where some structures could be identified, such as blood vessels and calcifications. Concentrations of the elements in the selected homogeneous areas of brain tissue were compared between tumours with various malignancy grades and with the controls. The study showed a decrease in the average concentration of Fe, P, S and Ca in tissues with high grades of malignancy as compared to the control group, whereas the concentration of Zn in these tissues was increased. The changes in the concentration were found to be correlated with the tumour malignancy grade. The efficacy of micro X-ray fluorescence spectroscopy to distinguish between various types of cancer based on the concentrations of studied elements was confirmed by multivariate discriminant analysis. Our analysis showed that the most important elements for tissue classification are Cu, K, Fe, Ca, and Zn. This method made it possible to correctly classify histopathological types in 99.93% of the cases used to build the model and in as much as 99.16% of new cases.

  7. Effect of long-term geomagnetic field deprivation on the concentration of some elements in the hair of laboratory rats.

    Science.gov (United States)

    Tombarkiewicz, Barbara

    2008-07-01

    The aim of the study was to determine the effect of long-term geomagnetic field (GMF) deprivation on the concentration of selected elements in the hair of laboratory rats. A total of 32 Wistar laboratory rats were divided into four equal groups (males and females) kept under hypomagnetic conditions (GMF vertical component below 20nT) and two control groups (males and females) kept free of field disturbances (GMF vertical component approx. 38000nT). At the beginning and at 7 months of the experiment, hair was taken from the dorsal part of all rats and analysed using atomic emission spectrometry for the concentration of selected magnetic elements (Fe, Ni, Co, Cr, Mn and Cu). Long-term GMF deprivation was found to affect the concentration of Fe, Mn, Cu and Cr, but had no significant effect on the concentration of Co or Ni in the hair of the analysed rats.

  8. [Concentration of trace elements in children from northern Chile].

    Science.gov (United States)

    Peña Clunes, L; Jamett, A; Santander, M; Gras, N; Muñoz, L

    1992-01-01

    Industrial processes may lead to severe alterations of environment affecting the health and quality of life of neighbouring communities. The present study reports the concentrations of Cu, As, Br, Na, K, Se, Hg, Cr, Co, Zn, Fe and Sb in samples of hair from children 6 years of age living in Antofagasta, Chuquicamata, María Elena, Calama and San Pedro de Atacama. Results were compared to those obtained in children of the same age living in Santiago. Samples were obtained according to recommendations from the International Nuclear Energy Organization and were analyzed by the neutron activation method at facilities of the Chilean Nuclear Energy Commission. Values for Cu (38.8 ppm), Cr (4.29 ppm) and As (19.2 ppm) in children from Chuquicamata are considered dangerous according to international standards.

  9. Statistical Study of Trace Elemental Concentrations in Major Types of Organisms from Typical Chinese Coastal Waters

    Institute of Scientific and Technical Information of China (English)

    郭卫东; 胡明辉; 石谦; 杨逸萍

    2004-01-01

    Frequency distribution characteristics of trace elements Fe, Mn, Zn, Cu. Sr and Ba are studied for the marine organisms collected from typical Chinese coastal waters and compared with those of major elements Ca and Mg. Nearly all the distributions for trace elements in macroalgae, benthic molluscs, crustaceans, cephalopods and different tissues of fish ( muscle, liver and bone ) are found to show some degree of positive skewness, indicating a relatively large number of marine organisms with low concentrations for a particular element and only a few organisms with disproportionately high concentrations. Their distribution types are generally logarithmic normal distribution or nearly logarithmic normal distribution. Distribution of Ca is similar to that of trace elements, while Mg shows normal distribution. Average elemental concentrations of major types of organisms are calculated based on their frequency distributions.

  10. Biomonitoring urban air pollution using transplanted lichens: element concentrations across seasons.

    Science.gov (United States)

    Malaspina, Paola; Tixi, Sara; Brunialti, Giorgio; Frati, Luisa; Paoli, Luca; Giordani, Paolo; Modenesi, Paolo; Loppi, Stefano

    2014-11-01

    We investigated the bioaccumulation of selected trace elements in samples of the lichen Evernia prunastri (L.) Ach. transplanted across two seasons in the urban area of Genoa (NW Italy), which is heavily affected by traffic and industrial pollution. Total concentration of most elements did not exhibit differences between seasons, exceptions being Al and Na, higher in summer, and As, Cd, and Ti, higher in winter. Differences emerged in the initial concentrations of some elements in control samples, and this was accounted for by the use of exposed-to-control (EC) ratios, which allowed interpretation of changes in element concentrations. The study area resulted highly polluted, likely by particulate matter, as suggested also by the higher concentrations of airborne PM10 during winter months. Bioaccumulation of particulate matter seems to be affected by differences in rainfall regimes across seasons, since element solubilization and leaching due to precipitation may vary considerably.

  11. Accumulation of platinum group elements by the marine gastropod Littorina littorea

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, Rachel [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Turner, Andrew, E-mail: aturner@plymouth.ac.uk [School of Geography, Earth and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2011-04-15

    The accumulation and trophic transfer of the platinum group elements (PGE): Rh, Pd and Pt; have been studied in short-term (5 day) exposures conducted in aquaria containing the marine macroalga, Ulva lactuca, and/or the grazing mollusc, Littorina littorea. Metals added to sea water (to concentrations of 20 {mu}g L{sup -1}) were taken up by U. lactuca in the order Rh, Pt > Pd and by L. littorea in the order Pd {>=} Pt {>=} Rh, with greatest metal accumulation in the latter generally occurring in the visceral complex and kidney. When fed contaminated alga, accumulation of Rh and Pd by L. littorea, relative to total available metal, increased by an order of magnitude, while accumulation of Pt was not readily detected. We conclude that the diet is the most important vector for accumulation of Rh and Pd, while accumulation of Pt appears to proceed mainly from the aqueous phase. - Research highlights: > Platinum group elements are accumulated by, Littorina littorea. > The aqueous phase and diet are important vehicles for Rh and Pd accumulation by the snail. > Grazing molluscs may serve as biomonitors of coastal PGE contamination. - Platinum group elements are accumulated by the marine snail, Littorina littorea, from both the aqueous phase and the diet.

  12. Boundary element analysis for elastic and elastoplastic problems of 2D orthotropic media with stress concentration

    Institute of Scientific and Technical Information of China (English)

    Xiushan Sun; Lixin Huang; Yinghua Liu; Zhangzhi Cen; Keren Wang

    2005-01-01

    Both the orthotropy and the stress concentration are common issues in modern structural engineering. This paper introduces the boundary element method (BEM) into the elastic and elastoplastic analyses for 2D orthotropic media with stress concentration. The discretized boundary element formulations are established, and the stress formulae as well as the fundamental solutions are derived in matrix notations. The numerical procedures are proposed to analyze both elastic and elastoplastic problems of2D orthotropic media with stress concentration. To obtain more precise stress values with fewer elements, the quadratic isoparametric element formulation is adopted in the boundary discretization and numerical procedures. Numerical examples show that there are significant stress concentrations and different elastoplastic behaviors in some orthotropic media, and some of the computational results are compared with other solutions.Good agreements are also observed, which demonstrates the efficiency and reliability of the present BEM in the stress concentration analysis for orthotropic media.

  13. Distribution of Platinum group elements in road dust in Beijing metropolitan area, China

    Institute of Scientific and Technical Information of China (English)

    WANG Juan; ZHU Ruo-hua; SHI Yan-zhi

    2007-01-01

    Dust samples collected from the Beijing metropolitan area (China) were evaluated to determine the distribution and the concentration of platinum group elements (PGEs). The dust particles that were smaller than 100 mesh size fraction (150 μm) were analyzed after aqua regia digestion. Concentrations[RL2] of Pt, Rh, and Pd were found to be between 3.96 and 356.3 ng/g, 2.76 and 97.11 ng/g, and 0.1 and 124.9 ng/g, respectively, in the urban areas of Beijing, whereas for the background samples collected from the suburbs of Beijing, the concentration of Pt, Pd, and Rh were very low and ranged from 0.1 to 0.9 ng/g, 0.5 to 1.4 ng/g, and 0.8 to 2.2 ng/g, respectively. The[RL3] distributions of PGEs in road dust were an accurate reflection of the levels of pollution and were found to match with the local traffic conditions. A strong positive correlation was established among all the elements found in road dust. This suggests that emissions of abraded fragments from vehicle exhausts may be the source of the high concentration of Pt, Rh, and Pd in road dust along the main roads of Beijing.

  14. Leaves of Phragmites australis as potential atmospheric biomonitors of Platinum Group Elements.

    Science.gov (United States)

    Bonanno, Giuseppe; Pavone, Pietro

    2015-04-01

    The increasing emissions of Platinum Group Elements (PGEs), namely Pt, Pd and Rh, may pose a significant risk to ecosystem processes and human health. A periodic assessment of PGEs distribution in the environment is thus of the utmost importance for the implementation of timely measures of mitigation. Although several studies have quantified PGEs in different life forms such as mammals, birds, fish, crustaceans, algae, mosses and even human beings, data about vascular plants need further surveys. This study aimed to test the suitability of the grass Phragmites australis (common reed) as a biomonitor of PGEs atmospheric pollution. The results showed that Pd and Pt concentrations in leaves are significantly higher in urban areas. In particular, Pd showed the highest range of values in line with current studies that consider palladium as the main element of traffic-related pollution. Overall, the leaves of Phragmites australis reflected the different gradient of PGEs emissions, and may thus be considered as potential biomonitors of atmospheric pollution.

  15. Relationships among developmental stage, metamorphic timing, and concentrations of elements in bullfrogs (Rana catesbeiana)

    Energy Technology Data Exchange (ETDEWEB)

    Snodgrass, J.W.; Hopkins, W.A.; Roe, J.H. [Towson University, Towson, MD (United States). Dept. for Biological Science

    2003-07-01

    We collected bullfrog (Rana catesbeiana) larvae from a coal combustion waste settling basin to investigate the effects of developmental stage and timing of metamorphosis on concentrations of a series of trace elements in bullfrog tissues. Bullfrogs at four stages of development (from no hind limbs to recently metamorphosed juveniles) and bullfrogs that metamorphosed in the fall or overwintered in the contaminated basin and metamorphosed in the spring were analyzed for whole-body concentrations of Al, V, Cr, Ni, Cu, As, Pb, Cd, Zn, Ag, Sr, and Se. After the effects of dry mass were removed, tissue concentrations of six elements (Al, V, Cr, Ni, Cu, As, and Pb) decreased from the late larval stage through metamorphosis. Decreases in concentrations through metamorphosis ranged from 40% for Cu to 97% for Al. Tissue concentrations of these elements were also similar or higher in spring; Al and Cr concentrations were 34 and 90% higher in the spring, respectively, whereas As, Ni, Cu, and Pb concentrations were {lt} 10% higher. Concentrations of Cd, Se, and Ag varied among seasons but not among stages; Cd and Ag concentrations were 40 and 62% lower, respectively, and Se concentrations were 21% higher in spring. Concentrations of Zn varied only among stages; concentrations decreased gradually through late larval stage and then increased through metamorphosis. Concentrations of Sr varied among stages, but this variation was dependent on the season. Concentrations of Sr were higher in larval stages during the spring, but because concentrations of Sr increased 122% through metamorphosis in the fall and only 22% in the spring, concentrations were higher in fall metamorphs when compared with spring metamorphs. Our results indicate that metamorphosis and season of metamorphosis affects trace element concentrations in bullfrogs and may have important implications for the health of juveniles and the transfer of pollutants from the aquatic to the terrestrial environment.

  16. Elements of the representation theory of the Jacobi group

    CERN Document Server

    Berndt, Rolf

    1998-01-01

    The Jacobi group is a semidirect product of a symplectic group with a Heisenberg group. It is an important example for a non-reductive group and sets the frame within which to treat theta functions as well as elliptic functions - in particular, the universal elliptic curve. This text gathers for the first time material from the representation theory of this group in both local (archimedean and non-archimedean) cases and in the global number field case. Via a bridge to Waldspurger's theory for the metaplectic group, complete classification theorems for irreducible representations are obtained. Further topics include differential operators, Whittaker models, Hecke operators, spherical representations and theta functions. The global theory is aimed at the correspondence between automorphic representations and Jacobi forms. This volume is thus a complement to the seminal book on Jacobi forms by M. Eichler and D. Zagier. Incorporating results of the authors' original research, this exposition is meant for research...

  17. Sampling and analysis of chemical element concentration distribution in rock units and orebodies

    National Research Council Canada - National Science Library

    F P Agterberg

    2012-01-01

      Existing sampling techniques applied within known orebodies, such as sampling along mining drifts, yield element concentration values for larger blocks of ore if they are extended into their surroundings...

  18. Concentrations of selected elements in the Kiamichi River above Hugo Reservoir

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Bulk element concentrations in soil collected from undisturbed forested sites throughout the Kiamichi River watershed above Hugo Reservoir were significantly higher...

  19. On the distribution of trace element concentrations in multiple bone elements in 10 Danish medieval and post-medieval individuals.

    Science.gov (United States)

    Lund Rasmussen, Kaare; Skytte, Lilian; D'imporzano, Paolo; Orla Thomsen, Per; Søvsø, Morten; Lier Boldsen, Jesper

    2017-01-01

    The differences in trace element concentrations among 19 different bone elements procured from 10 archaeologically derived human skeletons have been investigated. The 10 individuals are dated archaeologically and some by radiocarbon dating to the medieval and post-medieval period, an interval from ca. AD 1150 to ca. AD 1810. This study is relevant for two reasons. First, most archaeometric studies analyze only one bone sample from each individual; so to what degree are the bones in the human body equal in trace element chemistry? Second, differences in turnover time of the bone elements makes the cortical tissues record the trace element concentrations in equilibrium with the blood stream over a longer time earlier in life than the trabecular. Therefore, any differences in trace element concentrations between the bone elements can yield what can be termed a chemical life history of the individual, revealing changes in diet, provenance, or medication throughout life. Thorough decontamination and strict exclusion of non-viable data has secured a dataset of high quality. The measurements were carried out using Inductively Coupled Plasma Mass Spectrometry (for Fe, Mn, Al, Ca, Mg, Na, Ba, Sr, Zn, Pb and As) and Cold Vapor Atomic Absorption Spectroscopy (for Hg) on ca. 20 mg samples. Twelve major and trace elements have been measured on 19 bone elements from 10 different individuals interred at five cemeteries widely distributed in medieval and renaissance Denmark. The ranges of the concentrations of elements were: Na (2240-5660 µg g(-1) ), Mg (440-2490 µg g(-1) ), Al (9-2030 µg g(-1) ), Ca (22-36 wt. %), Mn (5-11450 µg g(-1) ), Fe (32-41850 µg g(-1) ), Zn (69-2610 µg g(-1) ), As (0.4-120 µg g(-1) ), Sr (101-815 µg g(-1) ), Ba (8-880 µg g(-1) ), Hg (7-78730 ng g(-1) ), and Pb (0.8-426 µg g(-1) ). It is found that excess As is mainly of diagenetic origin. The results support that Ba and Sr concentrations are effective provenance or dietary indicators

  20. Hepatic element concentrations of lesser scaup (aythya affinis) during spring migration in the upper midwest

    Science.gov (United States)

    Pillatzki, A.E.; Neiger, R.D.; Chipps, S.R.; Higgins, K.F.; Thiex, N.; Afton, A.D.

    2011-01-01

    High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 ??g/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 ??g/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction. ?? 2010 Springer Science+Business Media, LLC.

  1. Hepatic element concentrations of lesser scaup (Aythya affinis) during spring migration in the upper Midwest.

    Science.gov (United States)

    Pillatzki, Angela E; Neiger, Regg D; Chipps, Steven R; Higgins, Kenneth F; Thiex, Nancy; Afton, Alan D

    2011-07-01

    High concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (Aythya affinis) population. We evaluated hepatic element concentrations of male and female lesser scaup collected from the upper Midwest (Iowa, Minnesota, North Dakota, and South Dakota) during the 2003 and 2004 spring migrations. We measured concentrations of 24 elements in livers of 117 lesser scaup. We found that only selenium concentrations were at levels (>3.0 μg/g wet weight [ww)]) proposed to adversely affect reproduction. Approximately 49% of females (n = 61) had individual hepatic concentrations >3.0 μg/g ww selenium (Se). Our observed hepatic concentration of Se was similar to that reported in lesser scaup collected from the mid-continental United States but less than Se concentrations reported from the Great Lakes region. We found that the liver cadmium (Cd) concentration for males was significantly higher than that for females. Gender differences in hepatic Cd concentrations have not been previously reported for lesser scaup, but Cd is known to have negative impacts on male reproduction. Our results indicate that lesser scaup migrating through the upper Midwest in spring have elevated Se levels and that males carry a significantly greater Cd burden than females. Moreover, elemental concentrations might be high enough to affect reproduction in both male and female lesser scaup, but controlled laboratory studies are needed to adequately assess the effects of Se and Cd on lesser scaup reproduction.

  2. Magnetic field distribution and element concentration on the CP2 star CU Virginis

    CERN Document Server

    Glagolevskij, Y V; Hildebrandt, G; Scholz, G; Glagolevskij, Yu.V.

    1998-01-01

    We search for a relation between the published distributions of different elements and the calculated magnetic field structure, following from a dipole-quadrupole configuration, of the CP2 star CU Vir. The highest concentration of individual chemical elements on the stellar surface coincides obviously with the regions of the highest values of the magnetic field strength.

  3. Change in field turbidity and trace element concentrations during well purging

    Science.gov (United States)

    Gibs, J.; Szabo, Z.; Ivahnenko, T.; Wilde, F.D.

    2000-01-01

    Various physical and chemical properties were monitored sequentially in the field during well purging as indicators of stabilization of the composition of the water in the well. Turbidity was monitored on site during purging of oxic water from three wells with screened intervals open to an unconfined aquifer system in the Coastal Plain of southern New Jersey to determine if stabilization of turbidity is a reliable indicator of the optimum purge time required to collect unbiased trace element samples. Concurrent split (one filtered, one unfiltered) samples collected during purging of the wells were analyzed for concentrations of trace elements so that the relationships between trace element concentrations and turbidity could be compared. Turbidity correlated with the whole water recoverable (WWR) concentration of trace element species, such as iron (Fe), aluminum (Al), and manganese (Mn) in the oxic ground water. Turbidity appeared to be independent of other field-measured characteristics of water such as conductivity, pH, temperature, and dissolved oxygen. The WWR concentrations of lead and copper, considered to be hydrophobic, correlated significantly with the sum of the WWR concentration of Fe, Al, and Mn. High values of field-measured turbidity were a key indicator of an overestimate of ambient hydrophobic trace element WWR concentrations. Stabilization of turbidity was a better indicator of stable, unfiltered trace element concentrations than were the other commonly measured field characteristics. At one well, turbidity was a better indicator of stable, filtered trace element concentrations than the other commonly measured field characteristics. As analytical methods for trace elements improve resulting in smaller MRLs (method reporting levels) and better precision, turbidity of ground water at values of less than 10 NTU (nepheiometric turbidity units) will become important in interpreting the significance of both unfiltered and filtered sample results.

  4. Hair trace elements concentration to describe polymetallic mining waste exposure in Bolivian Altiplano.

    Science.gov (United States)

    Barbieri, Flavia Laura; Cournil, Amandine; Souza Sarkis, Jorge Eduardo; Bénéfice, Eric; Gardon, Jacques

    2011-01-01

    Severe polymetallic contamination is frequently observed in the mining communities of Bolivian Altiplano. We evaluated hair trace elements concentrations at the population level to characterise exposure profile in different contexts of contact with mining and metallurgical pollution. We sampled 242 children aged 7 to 12 years in schools from five Oruro districts located in different contexts of potential contamination. Hair trace elements concentrations were measured using ICP-MS (Pb, As, Hg, Cd, Sb, Sn, Bi, Ag, Ni, Se, Cu, Cr, Mn, Co and Zn). We compared concentration according to school areas and gender. Concentrations were markedly different depending on school areas. Children from schools near industrial areas were far more exposed to non essential elements than children from downtown and suburban schools, as well as the rural school. The most concentrated non-essential element was Pb (geometric means (SD): 1.6 (1.3) µg/g in rural school; 2.0 (2.3) µg/g in suburban school; 2.3 (3.0) µg/g in downtown school; 14.1 (2.7) µg/g in the mine school and 21.2 (3.3) µg/g in the smelter school). Boys showed higher levels for all non-essential elements while girls had higher levels of Zn. Hair trace elements concentrations highlighted the heterogeneity of exposure profiles, identifying the most contaminated districts.

  5. Effects of seasons on the concentration of selected trace elements in horse hair

    Directory of Open Access Journals (Sweden)

    Jadwiga TOPCZEWSKA

    2012-12-01

    Full Text Available The studies were conducted on a group of 20 mares of the Hucul breed kept in free range system. The horses made use of pastures in summer periods while being fed with hay or silage during the winter. Mares that bore offspring regularly, in good conditions and healthy were involved in the analysis. Hair samples of about 500 mg were taken from areas around the neck under the mane of each horse four times a year. The concentration of 6 elements, i.e., B, Ni, Si, Mo, I and Cr were measured in each sample. Much higher concentrations of molybdenum and nickel were found in hair samples collected in spring, but more of boron in autumn while those from winter contained more of chromium, silicon and iodine. The concentration of all the analyzed minerals differed significantly in relation to the season. A significant positive relationship between levels of nickel and molybdenum on the one hand as well as between silicon and chromium on the other was demonstrated. A negative correlation was, however, observed between the levels of iodine and molybdenum as well as between iodine and nickel.

  6. Trace Element Concentrations in Human Tissues of Death Cases Associated With Secondary Infection and MOF After Severe Trauma.

    Science.gov (United States)

    Xu, Guangtao; Su, Ruibing; Li, Bo; Lv, Junyao; Sun, Weiqi; Hu, Bo; Li, Xianxian; Gu, Jiang; Yu, Xiaojun

    2015-12-01

    Proper trace element level is crucial for the organs in maintaining normal physiological functions. Multiple organ failure (MOF) might be added to critically ill patients due to a lack of trace elements. Alterations of trace element levels in brain, heart, liver, and kidney after severe trauma, however, have been little studied so far. In this study, tissue samples of the frontal cortex of the brain, interventricular septum of the heart, right lobe of the liver, and upper pole of the kidney were obtained from forensic autopsies, of which 120 cases died during the 5th to 15th day of hospitalization, whereas the trauma death group and 43 cases immediately died due to severe craniocerebral trauma as the control group. Copper (Cu), iron (Fe), zinc (Zn), and selenium (Se) were quantified by inductively coupled plasma atomic emission spectrophotometry (ICP-AES). Cu, Fe, Zn, and Se concentrations in the brain, heart, liver, and kidney in the trauma group decreased dramatically (pMOF) in the trauma death group were 78.33 and 29.17%, respectively. The concentrations of all elements exhibited a significant correlation with secondary infection and MOF (pMOF after severe trauma, which to some extent results in death.

  7. Evaluation of Essential and Toxic Element Concentrations in Buckwheat by Experimental and Chemometric Approaches

    Institute of Scientific and Technical Information of China (English)

    PENG Lian-xin; HUANG Yan-fei; LIU Yuan; ZHANG Zhi-feng; LU Lu-yang; ZHAO Gang

    2014-01-01

    The essential and toxic element concentrations in buckwheat were analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). The concentration data were subjected to common chemometrics analyses, including correlation analysis (CA), principal component analysis (PCA) and hierarchical cluster analysis (HCA), to gain better understanding of the differences among the tested samples. Our results indicated that the essential and toxic element concentrations were not different between Fagopyrum tataricum (L.) Gaertn and F. esculentum Moench. The element concentrations varied among buckwheat samples from different sources. Commercial tartary buckwheat tea contained several essential elements, thus, could be used as the source of essential elements. The detection of toxic heavy metals in commercial tartary buckwheat tea suggested that safety issue of such buckwheat products should be seriously concerned. Our results also revealed that the place of origin and the processing protocol of tartary buckwheat affected the element concentrations of the commercial form. The implications to the quality control and safety evaluation of buckwheat were extensively discussed.

  8. Urinary Concentrations of Toxic and Essential Trace Elements among Rural Residents in Hainan Island, China

    Directory of Open Access Journals (Sweden)

    Yosuke Inoue

    2014-12-01

    Full Text Available Background: Toxic element exposure and essential trace element consumption may have changed after the Chinese economy transformed to a market-oriented system. The objectives of this study were to measure urinary concentrations of toxic (arsenic, cadmium, lead and essential trace (selenium, zinc, copper elements among rural residents in Hainan, China and to examine if variations in economic development are linked to differences in toxic and trace element exposure. Methods: We conducted a questionnaire-based survey and undertook anthropometric measurements of residents aged ≥20 years (n = 599. Urinary samples were collected and analyzed using inductively coupled plasma mass spectrometry. Results: The median (μg/g creatinine element concentrations were: arsenic, 73.2; cadmium, 1.8; lead, 3.1; selenium, 36.5; zinc, 371; and copper, 11.0. Intra-community variation in element concentrations was explained by age (arsenic, cadmium, zinc and copper, sex (arsenic, cadmium and selenium: higher in females; zinc: higher in males, body mass index (cadmium and individual involvement in the market economy as indexed by agrochemical use (lead and selenium. The degree of community-level economic development, which was determined by the proportion of people living in better housing among the study communities, was positively associated with cadmium concentration. Conclusions: The degree of community-level economic development was positively associated with urinary cadmium concentration while individual involvement in the market economy was positively associated with lead and selenium.

  9. Trace element concentrations and gastrointestinal parasites of Arctic terns breeding in the Canadian High Arctic.

    Science.gov (United States)

    Provencher, J F; Braune, B M; Gilchrist, H G; Forbes, M R; Mallory, M L

    2014-04-01

    Baseline data on trace element concentrations are lacking for many species of Arctic marine birds. We measured essential and non-essential element concentrations in Arctic tern (Sterna paradisaea) liver tissue and brain tissue (mercury only) from Canada's High Arctic, and recorded the presence/absence of gastrointestinal parasites during four different phases of the breeding season. Arctic terns from northern Canada had similar trace element concentrations to other seabird species feeding at the same trophic level in the same region. Concentrations of bismuth, selenium, lead and mercury in Arctic terns were high compared to published threshold values for birds. Selenium and mercury concentrations were also higher in Arctic terns from northern Canada than bird species sampled in other Arctic areas. Selenium, mercury and arsenic concentrations varied across the time periods examined, suggesting potential regional differences in the exposure of biota to these elements. For unknown reasons, selenium concentrations were significantly higher in birds with gastrointestinal parasites as compared to those without parasites, while bismuth concentrations were higher in Arctic terns not infected with gastrointestinal parasites.

  10. Two-Element Generation of Unitary Groups Over Finite Fields

    Science.gov (United States)

    2013-01-31

    like to praise my Lord and Savior, Jesus Christ , for allowing me this opportunity to work on a Ph.D in mathematics, and for His sustaining grace...Ishibashi’s original result. The paper’s main theorem will show that all unitary groups over finite fields of odd characteristic are generated by only two

  11. X-ray fluorescence and energy dispersive x-ray diffraction for the quantification of elemental concentrations in breast tissue.

    Science.gov (United States)

    Geraki, K; Farquharson, M J; Bradley, D A

    2004-01-07

    This paper presents improvements on a previously reported method for the measurement of elements in breast tissue specimens (Geraki et al 2002 Phys. Med. Biol. 47 2327-39). A synchrotron-based system was used for the detection of the x-ray fluorescence (XRF) emitted from iron, copper, zinc and potassium in breast tissue specimens, healthy and cancerous. Calibration models resulting from the irradiation of standard aqueous solutions were used for the quantification of the elements. The present developments concentrate on increasing the convergence between the tissue samples and the calibration models, therefore improving accuracy. For this purpose the composition of the samples in terms of adipose and fibrous tissue was evaluated, using an energy dispersive x-ray diffraction (EDXRD) system. The relationships between the attenuation and scatter properties of the two tissue components and water were determined through Monte Carlo simulations. The results from the simulations and the EDXRD measurements allowed the XRF data from each specimen to be corrected according to its composition. The statistical analysis of the elemental concentrations of the different groups of specimens reveals that all four elements are found in elevated levels in the tumour specimens. The increase is less pronounced for iron and copper and most for potassium and zinc. Other observed features include the substantial degree of inhomogeneity of elemental distributions within the volume of the specimens, varying between 4% and 36% of the mean, depending on the element and the type of the sample. The accuracy of the technique, based on the measurement of a standard reference material, proved to be between 3% and 22% depending on the element, which presents only a marginal improvement (1%-3%) compared to the accuracy of the previously reported results. The measurement precision was between 1% and 9% while the calculated uncertainties on the final elemental concentrations ranged between 10% and 16%.

  12. Neutron activation analysis for assessing the concentrations of trace elements in laboratory detergents

    Energy Technology Data Exchange (ETDEWEB)

    Iskander, F.Y.

    1986-01-01

    Nondestructive instrumental neutron activation analysis was used to assess the concentration of 20 elements in the following laboratory detergents: Micro, Cavi-Clean liquid, RBS-35, Liqui-Nox, Treg-A-Zyme, Alcojet, Alconox, Alcotabs and Radiacwash: and a detergent additive: CaviClean additive. The upper detected limits or the concentration ranges for the detergents are (element concentration in ..mu..g/g): Ba, <20; Ce, <0.8; Cl, 27-10000; Co, <0.1; Cr, <1; Cs, <0.6; Eu, <0.009; Fe, <3-45; Hf, <0.07; Mn, <10; Ni, <5; Rb, <0.08-0.89; Sb, <0.006-1.8; Sc, <0.0003-0.008; Se, <0.05; Sr <30; Th, <0.6; U, <0.1; V, <10; Zn, <0.2-2.0. The concentrations of trace elements in the examined laboratory detergents are below those reported in the literature for household detergents.

  13. Temporal variations in elemental concentrations of atmospheric aerosols in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Aldape U, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1992-05-15

    Measurements are reported of elemental concentrations of airborne particulates in Mexico City and their time variation over a one-week period in the spring of 1988. Proton-induced X-ray emission analysis, PIXE, was used to analyse the atmospheric aerosols which were bombarded with 2.5 MeV protons from the 12 MV Tandem Van de Graaff accelerator at the National Institute of Nuclear Research, ININ. Variations in the elemental concentrations were observed over the time period studied. An intercomparison was made in the case of the element lead with PIXE results obtained at the Crocker Nuclear Laboratory, CNL, University of California for the same set of samples. Excellent agreement was obtained both for the time variation of the relative concentration and the absolute lead concentrations. These results give added confidence to the protocol adopted at ININ. (Author)

  14. Recent Development in Simultaneous Multi-Element Determination of the Platinum Group Elements and Gold in Geological and Environmental Samples

    Institute of Scientific and Technical Information of China (English)

    任曼; 邓海琳

    2004-01-01

    In recent years, the modern methods of multi-element analysis of precious metals have attracted wide attention in scientific research and industry. The application and development in the decomposition of samples, separation and enrichment, and modern instrumental analysis of the platinum-group elements (PGEs) and gold in geological and environmental samples have been reviewed. Finally, the tendency of analysis of precious metals is also prospected.

  15. Investigation on concentration of elements in wetland sediments and aquatic plants

    Directory of Open Access Journals (Sweden)

    H. Janadeleh

    2016-01-01

    Full Text Available The major aim of the present study was to investigate element (Fe, Ni, Pb, V, Zn concentrations in sediment and different tissues of Phragmities australis and Typha latifolia in Hor al-Azim Wetland Southwest Iran. Sampling of sediments and aquatic plants was carried out during spring and summer 2014. Results showed that the mean  concentrations of elements in Phragmities australis  in root and stem-leaf were as follows: Iron:4448 mg/kg, Nickel: 28 mg/kg, Lead:8 mg/kg, Vanadium:10 mg/kg  and Zinc 15.5 mg/kg in root and: Fe:645 mg/kg, Ni:15 mg/kg, Pb:4 mg/kg, V:4 mg/kg and Zinc 16 mg/kg respectively. Also, the mean concentrations of Fe, Ni, Pb, V and Zn in roots of Typha latifolia were 8696 mg/kg, 34 mg/kg, 5 mg/kg, 19 mg/kg and 27 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb, Zn in stem-leaves of Typha latifolia were as follows: 321 mg/kg, 3 mg/kg, 7 mg/kg, 2 mg/kg and 14 mg/kg respectively. The mean concentrations of Fe, Ni, V, Pb and zinc were as: 40991 mg/kg, 65 mg/kg, 60 mg/kg, 31 mg/kg, 60 mg/kg respectively in surface sediment of study area. Concentration pattern of elements in sediment were as: Fe>Ni>Zn>V>Pb. The highest concentration of elements in the plant was seen in the roots. Also, Typha latifolia can uptake more concentration of elements than Phragmities australis. Based on the enrichment factor, Ni in summer had the highest EF values among the elements studied and it has a moderate enrichment.

  16. Analysis of elemental concentration censored distributions in breast malignant and breast benign neoplasm tissues

    Energy Technology Data Exchange (ETDEWEB)

    Kubala-Kukus, A. [Institute of Physics, Swietokrzyska Academy, Swietokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Centre, Artwinskiego 3, 25-734 Kielce (Poland)], E-mail: Aldona.Kubala-Kukus@pu.kielce.pl; Banas, D.; Braziewicz, J. [Institute of Physics, Swietokrzyska Academy, Swietokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Centre, Artwinskiego 3, 25-734 Kielce (Poland); Gozdz, S. [Holycross Cancer Centre, Artwinskiego 3, 25-734 Kielce (Poland); Majewska, U. [Institute of Physics, Swietokrzyska Academy, Swietokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Centre, Artwinskiego 3, 25-734 Kielce (Poland); Pajek, M. [Institute of Physics, Swietokrzyska Academy, Swietokrzyska 15, 25-406 Kielce (Poland)

    2007-07-15

    The total reflection X-ray fluorescence method was applied to study the trace element concentrations in human breast malignant and breast benign neoplasm tissues taken from the women who were patients of Holycross Cancer Centre in Kielce (Poland). These investigations were mainly focused on the development of new possibilities of cancer diagnosis and therapy monitoring. This systematic comparative study was based on relatively large ({approx} 100) population studied, namely 26 samples of breast malignant and 68 samples of breast benign neoplasm tissues. The concentrations, being in the range from a few ppb to 0.1%, were determined for thirteen elements (from P to Pb). The results were carefully analysed to investigate the concentration distribution of trace elements in the studied samples. The measurements of concentration of trace elements by total reflection X-ray fluorescence were limited, however, by the detection limit of the method. It was observed that for more than 50% of elements determined, the concentrations were not measured in all samples. These incomplete measurements were treated within the statistical concept called left-random censoring and for the estimation of the mean value and median of censored concentration distributions, the Kaplan-Meier estimator was used. For comparison of concentrations in two populations, the log-rank test was applied, which allows to compare the censored total reflection X-ray fluorescence data. Found statistically significant differences are discussed in more details. It is noted that described data analysis procedures should be the standard tool to analyze the censored concentrations of trace elements analysed by X-ray fluorescence methods.

  17. Analysis of elemental concentration censored distributions in breast malignant and breast benign neoplasm tissues

    Science.gov (United States)

    Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J.; Góźdź, S.; Majewska, U.; Pajek, M.

    2007-07-01

    The total reflection X-ray fluorescence method was applied to study the trace element concentrations in human breast malignant and breast benign neoplasm tissues taken from the women who were patients of Holycross Cancer Centre in Kielce (Poland). These investigations were mainly focused on the development of new possibilities of cancer diagnosis and therapy monitoring. This systematic comparative study was based on relatively large (˜ 100) population studied, namely 26 samples of breast malignant and 68 samples of breast benign neoplasm tissues. The concentrations, being in the range from a few ppb to 0.1%, were determined for thirteen elements (from P to Pb). The results were carefully analysed to investigate the concentration distribution of trace elements in the studied samples. The measurements of concentration of trace elements by total reflection X-ray fluorescence were limited, however, by the detection limit of the method. It was observed that for more than 50% of elements determined, the concentrations were not measured in all samples. These incomplete measurements were treated within the statistical concept called left-random censoring and for the estimation of the mean value and median of censored concentration distributions, the Kaplan-Meier estimator was used. For comparison of concentrations in two populations, the log-rank test was applied, which allows to compare the censored total reflection X-ray fluorescence data. Found statistically significant differences are discussed in more details. It is noted that described data analysis procedures should be the standard tool to analyze the censored concentrations of trace elements analysed by X-ray fluorescence methods.

  18. Intercomparison of elemental concentrations in total and size-fractionated aerosol samples collected during the mace head experiment, April 1991

    Science.gov (United States)

    François, Filip; Maenhaut, Willy; Colin, Jean-Louis; Losno, Remi; Schulz, Michael; Stahlschmidt, Thomas; Spokes, Lucinda; Jickells, Timothy

    During an intercomparison field experiment, organized at the Atlantic coast station of Mace Head, Ireland, in April 1991, aerosol samples were collected by four research groups. A variety of samplers was used, combining both high- and low-volume devices, with different types of collection substrates: Hi-Vol Whatman 41 filter holders, single Nuclepore filters and stacked filter units, as well as PIXE cascade impactors. The samples were analyzed by each participating group, using in-house analytical techniques and procedures. The intercomparison of the daily concentrations for 15 elements, measured by two or more participants, revealed a good agreement for the low-volume samplers for the majority of the elements, but also indicated some specific analytical problems, owing to the very low concentrations of the non-sea-salt elements at the sampling site. With the Hi-Vol Whatman 41 filter sampler, on the other hand, much higher results were obtained in particular for the sea-salt and crustal elements. The discrepancy was dependent upon the wind speed and was attributed to a higher collection efficiency of the Hi-Vol sampler for the very coarse particles, as compared to the low-volume devices under high wind speed conditions. The elemental mass size distribution, as derived from parallel cascade impactor samplings by two groups, showed discrepancies in the submicrometer aerosol fraction, which were tentatively attributed to differences in stage cut-off diameters and/or to bounce-off or splintering effects on the quartz impactor slides used by one of the groups. However, the atmospheric concentrations (sums over all stages) were rather similar in the parallel impactor samples and were only slightly lower than those derived from stacked filter unit samples taken in parallel.

  19. Mutation increasing β-carotene concentrations does not adversely affect concentrations of essential mineral elements in pepper fruit

    Science.gov (United States)

    Thompson, Jacqueline A.; Penchev, Emil A.; Nielen, Stephan

    2017-01-01

    Vitamin and mineral deficiencies are prevalent in human populations throughout the world. Vitamin A deficiency affects hundreds of millions of pre-school age children in low income countries. Fruits of pepper (Capsicum annuum L.) can be a major dietary source of precursors to Vitamin A biosynthesis, such as β-carotene. Recently, pepper breeding programs have introduced the orange-fruited (of) trait of the mutant variety Oranzheva kapiya, which is associated with high fruit β-carotene concentrations, to the mutant variety Albena. In this manuscript, concentrations of β-carotene and mineral elements (magnesium, phosphorus, sulphur, potassium, zinc, calcium, manganese, iron and copper) were compared in fruit from P31, a red-fruited genotype derived from the variety Albena, and M38, a genotype developed by transferring the orange-fruited mutation (of) into Albena. It was observed that fruit from M38 plants had greater β-carotene concentration at both commercial and botanical maturity (4.9 and 52.7 mg / kg fresh weight, respectively) than fruit from P31 plants (2.3 and 30.1 mg / kg fresh weight, respectively). The mutation producing high β-carotene concentrations in pepper fruits had no detrimental effect on the concentrations of mineral elements required for human nutrition. PMID:28207797

  20. Atmospheric trace elements at Enewetak Atoll. I Concentrations, sources, and temporal variability

    Science.gov (United States)

    Duce, R. A.; Arimoto, R.; Ray, B. J.; Unni, C. K.; Harder, P. J.

    1983-06-01

    The concentrations of 29 elements in aerosol particles collected in 1979 during Searex (Sea/Air Exchange) experiments at Enewetak Atoll (11 deg N, 162 deg E), in the tropical North Pacific, are measured. The concentrations of Na, Mg, Cl, K, Ca, and Br are dominated by marine sources; the elements have similar mass-size distributions, and their atmospheric concentration ratios (normalized to Na) are similar to the corresponding ratios in bulk seawater. Atmospheric inputs of aluminosilicate particles from crustal weathering are found to control the aerosol particle concentration of Al, Sc, Mn, Fe, Co, Cs, Ba, Ce, Eu, Hf, Ta, and Th. The mean concentrations of these crustally derived elements decrease by an average of 91 percent (+ or - 4.1 percent) from the local dry season (April to May) to the wet season (July to August); this general decrease is attributed to the abatement of dust storms in Asia. At times, the influx of dust from Asia dominates the concentrations of V, Cr, Rb, and Cu in aerosol particles, but when dust concentrations decrease, noncrustal sources for these elements manifest themselves.

  1. Effect of Roasting Conditions on Concentration in Elements of Vietnam Robusta Coffee

    Directory of Open Access Journals (Sweden)

    Van Cuong Tran

    2014-12-01

    Full Text Available Vietnam Robusta Coffee was roasted at different roasting degree and roasting temperature and 9 element concentrations (K, Mg, Ca, Na, Fe, Cu, Mn, Zn and Pb of roasted coffee were analyzed by Flame atomic absorption method (FAAS in this study. The results showed that the concentrations were ranged in 1447.97 ~ 1342.10 (mg/100g, 768.22 ~ 1259.44 (μg/g,10.35 ~ 13.15 (μg/g, and 17.38 ~ 20.97 (μg/g for element of K, Ca, Cu and Mn in green and roasted coffee beans, respectively. All determined elements were the smallest value in green coffee, then increased with increasing roasting level and reached the highest value in Spain roast (roasting temperature of 250°C. Mg concentration ranged in 682.70 ~ 3647.73 (μg/g; Fe concentration ranged in 37.20 ~ 53.44 (μg/g; Zn concentration ranged in 5.97 ~ 6.89 (μg/g and Pb concentration ranged in 2.18 ~ 15.04 (μg/100g. Concentrations of all determined elements didn’t change with the increased roasting process.

  2. Concentration of selected trace elements in Xerocomus badius mushroom bodies - a health risk for humans?

    Directory of Open Access Journals (Sweden)

    Mirosław Mleczek

    2013-09-01

    Full Text Available Introduction. As regards a signifi cant intake of wild growing edible mushrooms, especially in East and Central Europe, concentrations of toxic elements should be periodically analysed. The aim of the study was to assess changes in concentrations of selected trace elements (Ba, Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb, Sr and Zn in a mushroom species, Xerocomus badius. Material and methods. Xerocomus badius fruiting bodies were collected from fi ve regions of Poland within the last 20 years (selected years when these mushrooms were growing. Flame atomic absorption spectrometry (FAAS was used for determination of 10 elements while for Hg cold vapour atomic absorption spectrometry (CVAAS was used. Results. Generally the results show no signifi cant differences in the accumulation effi ciency of individual elements by mushrooms collected from different regions of Poland, but signifi cant differences were observed in the accumulation effi ciency of these elements by mushrooms collected in particular years of their harvest. The highest accumulation indicated by bioconcentration factors (BCFs was observed for Cu (10.03, Hg (148.15 and Zn (4.88. Conclusion. Concentrations of Cu, Fe, Mn, Zn in the tested mushrooms were found to be lower than the values of the recommended dietary allowances (RDA, therefore the levels of these elements are not toxic for people. In our opinion, occasional consumption of these mushroom fruiting bodies within the last 20 years in Poland did not provide signifi cant amounts of analysed trace elements (no more than other foods.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

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

  4. Concentration of key elements in North American meat and bone meal

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Rafael A. [USDA-ARS, Eastern Regional Research Center, Fats, Oils and Animal Coproducts Research Unit, 600 E. Mermaid Lane Wyndmoor, PA 19038 (United States); Rosentrater, Kurt A. [USDA-ARS, North Central Agricultural Research Laboratory, Integrated Cropping Systems Research Unit, 2923 Medary Avenue, Brookings, SD 57006 (United States)

    2008-09-15

    Meat and bone meal (MBM) and related rendered protein commodities have potential for use in applications other than animal feed, including use as a fuel or a phosphorus fertilizer. In order to develop these applications, data on the elemental composition are required; the currently available elemental composition data have important limitations. To generate more appropriate and reliable data, MBM samples were collected from 17 North American rendering plants, carefully prepared and analyzed for 20 elements. Preliminary studies showed that the sample preparation process artificially increased levels of sulfur and nickel in a manner that was correctable. Concentrations of many elements were found to agree with previously published values, but concentrations of potassium, magnesium and copper were significantly different from the most authoritative reference. Concentrations of heavy metals tested for were low, and arsenic and cadmium were not detected in any sample. Among the elements tested, there were a number of pairs of elements whose concentration was correlated with high significance, which in some cases was due to the varying proportions of soft tissue and bone in the MBM. The data presented should allow the development of non-feed applications for MBM to proceed with increased confidence. (author)

  5. On Spaces of Commuting Elements in Lie Groups

    Science.gov (United States)

    2014-02-25

    these spaces inform on representation varieties associated to fundamental groups of Riemann surfaces, but it seems likely that these methods will...on J(X) and J( ∨ n≥1 X̂ n), respectively. Note that, by hypothesis , the action satisfies g ·∗ = ∗ for all g ∈ G. The map H : J(X)→ J( ∨ n≥1 X̂ n...Σ ( (Y ×G X̂q+1)/(Y ×G ∗) ) , g1 g2 g3 where g1 is a homotopy equivalence by hypothesis . Using the Serre spectral sequence for homol- ogy, it follows

  6. Trace-element concentrations in streambed sediment across the conterminous United States

    Science.gov (United States)

    Rice, Karen C.

    1999-01-01

    Trace-element concentrations in 541 streambed-sediment samples collected from 20 study areas across the conterminous United States were examined as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Sediment samples were sieved and the iron, titanium, and organic carbon were weakly or not at all correlated with the nine trace elements examined:  arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc. Four different methods of accounting for background/baseline concentrations were examined; however, normalization was not required because field sieving removed most of the background differences between samples. The sum of concentrations of trace elements characteristic of urban settings - copper, mercury, lead, and zinc - was well correlated with population density, nationwide. Median concentrations of seven trace elements (all nine examined except arsenic and selenium) were enriched in samples collected from urban settings relative to agricultural or forested settings. Forty-nine percent of the sites sampled in urban settings had concentrations of one or more trace elements that exceeded levels at which adverse biological effects could occur in aquatic biota.

  7. Democratic elements in group and project organized PBL

    DEFF Research Database (Denmark)

    Qvist, Palle

    2006-01-01

    Students in a democratic learning system as the Aalborg Model knows of and uses democratics skills as e.g. the ability to discuss and accept other points of view, negotiate, compromise, reach consensus or accept the result of a vote in striving to reach specific common or personal learning goals,...... that students make decisions related to learning and learning goals, learning processes and behaviour after discussions and so called rounds which indicates hat they develop democratic skill useful in social relations....... learning system. It contrasts it to an authoritarian or elitist systems. Then it brings the results from an investigation of 9 process analyses’ written at the end of the second semester 2005 by project groups from The Technical Natural Scientific Basic Year at Aalborg University and concludes...

  8. Assessment of Trace Element Concentrations in Birds of Prey in Korea.

    Science.gov (United States)

    Kim, Jungsoo; Oh, Jong-Min

    2016-07-01

    This study presents liver concentrations of trace elements of cinereous vultures (Aegypius monachus), common buzzards (Buteo buteo), common kestrels (Falco tinnunculus), and Eurasian eagle owls (Bubo bubo) collected in Korea from 2007 to 2008. Iron (Fe), manganese (Mn), copper (Cu), lead (Pb), and cadmium (Cd) concentrations in common kestrel juveniles were greater than in other juveniles of birds of prey. Adult cinereous vultures had greater Fe, Pb, and Cd concentrations than in those of other species, but common kestrels had greater Mn and Cu concentrations than in those of other birds of prey. Zinc concentrations in Eurasian eagle owl juveniles and adults were greater than in juveniles and adults of other species, respectively. In common kestrels, Fe, Cu, Pb, and Cd concentrations were significantly greater in adults than in juveniles. In Eurasian eagle owls, only Pb concentrations were greater in adults than in juveniles. Essential elements, such as Fe, Zn, Mn, and Cu concentrations, were within the range of other birds of prey studies. Seventeen individual birds of prey (30 %) were at a level considered Pb exposed (6-30 µg/g dw). This is a greater proportion than reported earlier in herons, egrets, and other birds from Korea. Elevated Pb concentration might be attributed to ingestion of Pb shot and bullet fragments for cinereous vultures and common buzzards, and urbanization for common kestrels. Cadmium concentrations in birds of prey were within the background concentrations (birds.

  9. On silicon group elements ejected by supernovae type IA

    Energy Technology Data Exchange (ETDEWEB)

    De, Soma; Timmes, F. X. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ (United States); Brown, Edward F. [Joint Institute for Nuclear Astrophysics, University of Notre Dame, IN 46556 (United States); Calder, Alan C. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY (United States); Townsley, Dean M. [Department of Physics and Astronomy, The University of Alabama, Tuscaloosa, AL (United States); Athanassiadou, Themis [Swiss National Supercomputing Centre, Via Trevano 131, 6900 Lugano (Switzerland); Chamulak, David A. [Physics Division, Argonne National Laboratory, Argonne, IL (United States); Hawley, Wendy [Laboratoire d' Astrophysique de Marseille, Marseille cedex 13 F-13388 (France); Jack, Dennis, E-mail: somad@asu.edu [Departamento de Astronomía, Universidad de Guanajuato, Apartado Postal 144, 36000 Guanajuato (Mexico)

    2014-06-01

    There is evidence that the peak brightness of a Type Ia supernova is affected by the electron fraction Y {sub e} at the time of the explosion. The electron fraction is set by the aboriginal composition of the white dwarf and the reactions that occur during the pre-explosive convective burning. To date, determining the makeup of the white dwarf progenitor has relied on indirect proxies, such as the average metallicity of the host stellar population. In this paper, we present analytical calculations supporting the idea that the electron fraction of the progenitor systematically influences the nucleosynthesis of silicon group ejecta in Type Ia supernovae. In particular, we suggest the abundances generated in quasi-nuclear statistical equilibrium are preserved during the subsequent freeze-out. This allows potential recovery of Y {sub e} at explosion from the abundances recovered from an observed spectra. We show that measurement of {sup 28}Si, {sup 32}S, {sup 40}Ca, and {sup 54}Fe abundances can be used to construct Y {sub e} in the silicon-rich regions of the supernovae. If these four abundances are determined exactly, they are sufficient to recover Y {sub e} to 6%. This is because these isotopes dominate the composition of silicon-rich material and iron-rich material in quasi-nuclear statistical equilibrium. Analytical analysis shows the {sup 28}Si abundance is insensitive to Y {sub e}, the {sup 32}S abundance has a nearly linear trend with Y {sub e}, and the {sup 40}Ca abundance has a nearly quadratic trend with Y {sub e}. We verify these trends with post-processing of one-dimensional models and show that these trends are reflected in the model's synthetic spectra.

  10. Divergent variations in concentrations of chemical elements among shrub organs in a temperate desert.

    Science.gov (United States)

    He, Mingzhu; Song, Xin; Tian, Fuping; Zhang, Ke; Zhang, Zhishan; Chen, Ning; Li, Xinrong

    2016-01-28

    Desert shrubs, a dominant component of desert ecosystems, need to maintain sufficient levels of nutrients in their different organs to ensure operation of various physiological functions for the purpose of survival and reproduction. In the present study, we analyzed 10 elements in leaves, stems, and roots of 24 dominant shrub species from 52 sites across a temperate desert ecosystem in northwestern China. We found that concentrations of all 10 elements were higher in leaves than in stems and roots, that non-legumes had higher levels of leaf Na and Mg than did legumes, and that Na was more concentrated in C4 leaves than in C3 leaves. Scaling relationships of elements between the photosynthetic organ (leaf) and non-photosynthetic organs (stem and root) were allometric. Results of principal components analysis (PCA) highlighted the important role of the elements responsible for osmoregulation (K and Na) in water utilization of desert shrubs. Soil properties and taxonomy explained most variation of element concentrations in desert shrubs. Desert shrubs may not be particularly susceptible to future change in climate factors, because most elements (including N, P, K, Ca, Mn, Zn, and Cu) associated with photosynthesis, osmoregulation, enzyme activity, and water use efficiency primarily depend on soil conditions.

  11. Concentration of 17 Elements in Subcellular Fractions of Beef Heart Tissue Determined by Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wester, P.O.

    1964-12-15

    Subcellular fractions of beef heart tissue are investigated, by means of neutron activation analysis, with respect to their concentration of 17 different elements. A recently developed ion-exchange technique combined with gamma spectrometry is used. The homogeneity of the subcellular fractions is examined electron microscopically. The following elements are determined: As, Ba, Br, Cas Co, Cs, Cu, Fe, Hg, La, Mo, P, Rb, Se, Sm, W and Zn. The determination of Ag, Au, Cd, Ce, Cr, Sb and Sc is omitted, in view of contamination. Reproducible and characteristic patterns of distribution are obtained for all elements studied.

  12. Element concentrations in urine of patients suffering from chronic arsenic poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y.X.; Miyamato, H.; Kondo, M.; Koga, H.; Zhang, A.; Ohmichi, M.; Inaba, Y.; Chiba, M. [Juntendo University, Tokyo (Japan). School of Medicine, Dept. of Epidemiology and Environmental Health

    2001-03-01

    In order to know the element levels in the urine of patients with chronic arsenic poisoning caused by arsenic assimilated from burning coal via air and food, the authors investigated various elements in the urine of 16 patients with this disease and 16 controls living in the same county in Guizhou Province of China. Concentrations of 25 elements (Al, As, Ba, Be, Bi, Ca, Cd, Cr, Cu, Fe, Ga, Mg, Mn, Mo, Ni, P, Pb, Rb, Sb, Se, Sn, Sr, Ti, V and Zn) were determined by an inductively coupled plasma mass spectrometer or an inductively coupled plasma atomic emission spectrometer. The average concentrations of Cu, Ga and Sn as well as As in the patients were significantly higher, and those of Cr, Rb, Sr and Ti in the patients were significantly lower than the control values. Al, Ba, Mn, Ni and Se mere under detection limit in the patients, though they could be detected in the controls. There were no positive correlations between the concentration of As and the concentrations of other elements, including Cu, Ca and Sn in the patients. The results of this study suggest that As from burning coal might influence the urinary excretion of some elements.

  13. Accumulation of platinum group elements by the marine gastropod Littorina littorea.

    Science.gov (United States)

    Mulholland, Rachel; Turner, Andrew

    2011-04-01

    The accumulation and trophic transfer of the platinum group elements (PGE): Rh, Pd and Pt; have been studied in short-term (5 day) exposures conducted in aquaria containing the marine macroalga, Ulva lactuca, and/or the grazing mollusc, Littorina littorea. Metals added to sea water (to concentrations of 20 μg L⁻¹) were taken up by U. lactuca in the order Rh, Pt > Pd and by L. littorea in the order Pd ≥ Pt ≥ Rh, with greatest metal accumulation in the latter generally occurring in the visceral complex and kidney. When fed contaminated alga, accumulation of Rh and Pd by L. littorea, relative to total available metal, increased by an order of magnitude, while accumulation of Pt was not readily detected. We conclude that the diet is the most important vector for accumulation of Rh and Pd, while accumulation of Pt appears to proceed mainly from the aqueous phase.

  14. Characterization of the Sukinda and Nausahi ultramafic complexes, Orissa, India by platinum-group element geochemistry

    Science.gov (United States)

    Page, N.J.; Banerji, P.K.; Haffty, J.

    1985-01-01

    Samples of 20 chromitite, 14 ultramafic and mafic rock, and 9 laterite and soil samples from the Precambrian Sukinda and Nausahi ultramafic complexes, Orissa, India were analyzed for platinum-group elements (PGE). The maximum concentrations are: palladium, 13 parts per billion (ppb); platinum, 120 ppb; rhodium, 21 ppb; iridium, 210 ppb; and ruthenium, 630 ppb. Comparison of chondrite-normalized ratios of PGE for the chromitite samples of lower Proterozoic to Archean age with similar data from Paleozoic and Mesozoic ophiolite complexes strongly implies that these complexes represent Precambrian analogs of ophiolite complexes. This finding is consistent with the geology and petrology of the Indian complexes and suggests that plate-tectonic and ocean basin developement models probably apply to some parts of Precambrian shield areas. ?? 1985.

  15. Optimal Design of a Secondary Optical Element for a Noncoplanar Two-Reflector Solar Concentrator

    Directory of Open Access Journals (Sweden)

    Yi-Cheng Chen

    2015-01-01

    Full Text Available This paper presents the results of a parametric design process used to achieve an optimal secondary optical element (SOE in a noncoplanar solar concentrator composed of two reflectors. The noncoplanar solar concentrator comprises a primary parabolic mirror (M1 and a secondary hyperbolic mirror (M2. The optical performance (i.e., acceptance angle, optical efficiency, and irradiance distribution of concentrators with various SOEs was compared using ray-tracing simulation. The parametric design process for the SOE was divided into two phases, and an optimal SOE was obtained. The sensitivity to assembly errors of the solar concentrator when using the optimal SOE was studied and the findings are discussed.

  16. Platinum-group elements and minerals in the lower and middle group chromitites of the western Bushveld Complex, South Africa

    Science.gov (United States)

    Junge, Malte; Oberthür, Thomas; Osbahr, Inga; Gutter, Paul

    2016-10-01

    The chromitites of the Bushveld Complex in South Africa contain vast resources of platinum-group elements (PGE). However, knowledge of the distribution and the mineralogical siting of the PGE in the lower group (LG) and middle group (MG) chromitite seams of the Bushveld Complex is limited. We studied concentrates from the LG-6 and MG-2 chromitites of the western Bushveld Complex by a variety of microanalytical techniques. The dominant PGM are sulfides, namely laurite, cooperite-braggite, and malanite-cuprorhodsite, followed by PGE-sulfarsenides, sperrylite, and Pt-Fe alloys. Laurite is the most abundant PGM (vol%). The matching sets of PGM present in the LG and MG chromitites of both the western and the eastern Bushveld Complex, and in the UG-2 chromitite, show strong similarities which support the assumption of a characteristic and general chromitite-related PGM assemblage. Palladium and Rh contents in pentlandite are low and erratic although maximum contents of 7730 ppm Pd and 6020 ppm Rh were detected. Rare thiospinels of the polydymite-linnaeite-greigite series have PGE contents of 1430 ppm Pt, 5370 ppm Rh, and 1460 ppm Pd. The various PGE occur in different deportment: Platinum is generally present in the form of discrete PGM (sulfides, arsenides, alloys). Palladium is present as a large variety of discrete PGM and also incorporated in pentlandite. Rhodium forms discrete PGM and is occasionally present in pentlandite. The IPGE (Os, Ir, and Ru) are dominantly incorporated in laurite (often as inclusions in chromite) and also occur as sulfarsenides.

  17. Investigation on concentration of elements in wetland sediments and aquatic plants

    OpenAIRE

    H. Janadeleh; A. Hosseini Alhashemi; S.M.B. Nabavi

    2016-01-01

    The major aim of the present study was to investigate element (Fe, Ni, Pb, V, Zn) concentrations in sediment and different tissues of Phragmities australis and Typha latifolia in Hor al-Azim Wetland Southwest Iran. Sampling of sediments and aquatic plants was carried out during spring and summer 2014. Results showed that the mean  concentrations of elements in Phragmities australis  in root and stem-leaf were as follows: Iron:4448 mg/kg, Nickel: 28 mg/kg, Lead:8 mg/kg, Vanadium:10 mg/kg  and ...

  18. Elevated concentrations of trace elements in soil do not necessarily reflect metals available to plants.

    Science.gov (United States)

    Antonious, George F; Silitonga, Maifan R; Tsegaye, Teferi D; Unrine, Jason M; Coolong, Timothy; Snyder, John C

    2013-01-01

    Bioaccumulation and entry of trace elements from soil into the food chain have made trace-elements major environmental pollutants. The main objective of this investigation was to study the impact of mixing native agricultural soil with municipal sewage sludge (SS) or SS mixed with yard waste (SS+YW) compost on total concentration of trace elements in soil, metals available to plants, and mobility of metals from soil into peppers and melon fruits. Regardless of soil treatment, the average concentrations of Ni, Cd, Pb, Cr, Cu, Zn, and Mo in melon fruits were 5.2, 0.7, 3.9, 0.9, 34.3, 96.1, and 3.5μg g(-1), respectively. Overall concentrations of Ni, Cd, Pb, and Zn in melon fruits were significantly greater (P metal concentrations and metal ions in soil available to melon and pepper plants were also determined. Total concentration of each metal in the soil was significantly greater than concentration of metal ions available to plants. Elevated Ni and Mo bioaccumulation factor (BAF > 1) of melon fruits of plants grown in SS+YW mixed soil is a characteristic that would be less favorable when plants grown on sites having high concentrations of these metals.

  19. Concentrations of Chemical Elements in Willow Biomass Depend on Clone, Site and Management in the Field

    DEFF Research Database (Denmark)

    Liu, Na; Jørgensen, Uffe; Lærke, Poul Erik

    2016-01-01

    Eight willow (Salix) clones (Inger, Klara, Linnea, Resolution, Stina, Terra Nova, Tora, Tordis) were planted on two soil types in Denmark. The biomass quality was evaluated after 3 years of growth by measuring differences in concentrations of 14 elements associated with ash behavior during...... to 22, 27, 35, and 23 % higher concentrations of K, S, Ca, and total ash than the other clones. In addition to clone and site, appropriate management could further improve the fuel quality of willow biomass. When shoots of Inger were harvested annually (1-year shoots) high concentrations of K and Cl...... plant densities (8000 and 12,000 trees ha−1) of the clones Inger and Tora after the first 3-year rotation when grown at the site with a coarse sandy soil. The study indicates considerable diversity in concentration of elements within commercially available willow cultivars and suggests breeders...

  20. Relationships between hepatic trace element concentrations, reproductive status, and body condition of female greater scaup

    Science.gov (United States)

    Badzinski, S.S.; Flint, P.L.; Gorman, K.B.; Petrie, S.A.

    2009-01-01

    We collected female greater scaup (Aythya marila) on the Yukon-Kuskokwim Delta, Alaska during two breeding seasons to determine if concentrations of 18 trace elements in livers and eggs were elevated and if hepatic concentrations correlated with body condition or affected reproductive status. Fifty-six percent, 5%, and 42% of females, respectively, had elevated hepatic cadmium (Cd: >3 ??g g-1 dry weight [dw]), mercury (Hg: >3 ??g g-1 dw), and selenium (Se: >10 ??g g-1 dw). Somatic protein and lipid reserves were not correlated with hepatic Cd or Hg, but there was a weak negative correlation between protein and Se. Hepatic Cd, Hg, and Se were similar in females that had and had not initiated egg production. In a sample of six eggs, 33% and 100%, respectively, contained Se and Hg, but concentrations were below embryotoxicity thresholds. We conclude that trace element concentrations documented likely were not adversely impacting this study population. ?? 2009 Elsevier Ltd.

  1. Platinum group elements in stream sediments of mining zones: The Hex River (Bushveld Igneous Complex, South Africa)

    Science.gov (United States)

    Almécija, Clara; Cobelo-García, Antonio; Wepener, Victor; Prego, Ricardo

    2017-05-01

    Assessment of the environmental impact of platinum group elements (PGE) and other trace elements from mining activities is essential to prevent potential environmental risks. This study evaluates the concentrations of PGE in stream sediments of the Hex River, which drains the mining area of the Bushveld Igneous Complex (South Africa), at four sampling points. Major, minor and trace elements (Fe, Ca, Al, Mg, Mn, V, Cr, Zn, Cu, As, Co, Ni, Cd, and Pb) were analyzed by FAAS and ETAAS in suspended particulate matter and different sediment fractions (rocks. The highest concentrations were observed closer to the mining area, decreasing with distance and in the cycle, increasing the presence of PGE in the fine fraction of river sediments. We propose that indicators such as airborne particulate matter, and soil and river sediment quality, should be added to the protocols for evaluating the sustainability of mining activities.

  2. [Pollution characteristics of platinum group elements in road rust in Xiamen].

    Science.gov (United States)

    Hong, Zhen-yu; Hong, You-wei; Yin, Li-qian; Chen, Jin-sheng; Chen, Yan-ting; Xu, Ling-ling

    2015-01-01

    With the potential risks for the environment and human health, the concentration and distribution characteristics of platinum group element(PGEs) in road dust in Xiamen city were investigated. Road dust samples were collected from the traffic trunk road, tunnel, tourism area, and industrial area of Xiamen on October 2012. The samples were digested with aqua regia in a microwave assisted digestion system under high pressure condition, separated and purified with cation exchange resin( Dowex AG50W-X8), and the resulting solutions were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the average concentrations(range) of Pd, Pt and Rh in road dust were 246.82 (58.68-765.52) ng x g(-1), 95.45 (42.14-371.36) ng x g(-1) and 51.76 (21.04-119.72) ng x g(-1), respectively, which were two orders of magnitude higher than the background values. Compared with other cities worldwide, the concentrations of Pd, Pt and Rh in road dust in Xiamen were at higher levels. Theconcentrations of PGEs for different functional areas were listed in the following order: tunnel > urban district > industrial area > tourism area, which indicated that their spatial distributions were mainly affected by the traffic intensity. Correlation analysis results showed that concentration of Pd in the urban traffic artery was significantly correlated with Rh, while Pt was not so correlated with Pd and Rh, suggesting that other sources contributed to PGEs in road dust in addition to the vehicle emission. Although motor vehicle traveling was banned in tourist area, the concentration of PGEs was still at a high level. Some of them might originate from the road dust in surrounding area by atmosphere diffusion.

  3. The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies

    Science.gov (United States)

    Migaszewski, Z.M.; Lamothe, P.J.; Crock, J.G.; Galuszka, A.; Dolegowska, S.

    2011-01-01

    Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the purpose of a study. Our hypothesis is that the method of sample preparation is important for interpretation of the results. Here we compare the results of 36 element determinations performed by ICP-MS on ashed and on acid-digested (HNO3, H2O2) samples of two moss species (Hylocomium splendens and Pleurozium schreberi) collected in Alaska and in south-central Poland. We found that dry ashing of the moss samples prior to analysis resulted in considerably lower detection limits of all the elements examined. We also show that this sample preparation technique facilitated the determination of interregional and interspecies differences in the chemistry of trace elements. Compared to the Polish mosses, the Alaskan mosses displayed more positive correlations of the major rock-forming elements with ash content, reflecting those elements' geogenic origin. Of the two moss species, P. schreberi from both Alaska and Poland was also highlighted by a larger number of positive element pair correlations. The cluster analysis suggests that the more uniform element distribution pattern of the Polish mosses primarily reflects regional air pollution sources. Our study has shown that the method of sample preparation is an important factor in statistical interpretation of the results of trace element determinations. ?? 2010 Springer-Verlag.

  4. 40 CFR Table 1 to Subpart D of... - Concentration for Group Determination

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Concentration for Group Determination... Table 1 to Subpart D of Part 65—Concentration for Group Determination Referencing subpart Concentration... of TOC. Subpart G of Part 63 50 ppmv of HAP 2. 1 The 50 ppm HAP concentration cutoff only applies to...

  5. Essential and non-essential element concentrations in two sleeper shark species collected in arctic waters

    Energy Technology Data Exchange (ETDEWEB)

    McMeans, Bailey C. [Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4 (Canada); Borga, Katrine [Norwegian Institute for Water Research, P.O. Box 173, Kjelsas, N-0411 Oslo (Norway); Bechtol, William R. [Alaska Department of Fish and Game, Division of Commercial Fisheries, Anchorage, AK 99518-1599 (United States); Higginbotham, David [Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602-2152 (United States); Fisk, Aaron T. [Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4 (Canada)]. E-mail: afisk@uwindsor.ca

    2007-07-15

    A number of elements/metals have increased in arctic biota and are of concern due to their potential toxicity. Most studies on elements in the Arctic have focused on marine mammals and seabirds, but concentrations in the Greenland shark (Somniosus microcephalus) and Pacific sleeper shark (Somniosus pacificus), the only two shark species known to regularly inhabit arctic waters, have never been reported. To address this data gap, concentrations and patterns of 25 elements were analyzed in liver of Greenland sharks collected about Cumberland Sound (n = 24) and Pacific sleeper sharks collected about Prince William Sound (n = 14). Several non-essential elements differed between species/locations, which could suggest geographical exposure differences or ecological (e.g., diet) differences between the species. Certain essential elements also differed between the two sleeper sharks, which may indicate different physiological requirements between these closely related shark species, although information on such relationships are lacking for sharks and fish. - Patterns of essential and non-essential elements provide insight into sleeper shark biology and physiology.

  6. Toxic element concentrations in the Razorbill Alca torda (Charadriiformes, Alcidae) in Portugal.

    Science.gov (United States)

    Ribeiro, A R; Eira, C; Torres, J; Mendes, P; Miquel, J; Soares, A M V M; Vingada, J

    2009-04-01

    The present study provides the first data on inorganic element levels (As, Cd, Co, Cr, Cu, Hg, Mn, Pb, Se, and Zn) in juvenile, immature, and adult razorbills (Alca torda) collected along the central coast of Portugal. Element concentrations were assessed by ICP-MS in kidney, liver, muscle, and feathers of 28 razorbills, including 4 juveniles, 17 subadults, and 7 adults. The effect of age and tissue on element accumulation was also assessed. The detected levels in razorbills may indicate a possible contamination risk by Hg and Cr. With respect to bird tissues, higher accumulation of Se and Cd was detected in kidney, Zn and Pb in feathers, and As and Mn in liver. Age was found to affect the accumulation of Cd, Cr, Cu, Hg, and Mn, juveniles presenting higher levels of Cu and Mn than older individuals. In razorbill kidney, Zn-Hg constituted the most significant relationship among metal concentrations. Liver presented the highest number of significant relationships (mostly involving Zn and Co). With regard to feathers, the most significant relationships involved Se, Zn, Cr and Cu concentrations. Positive linear relationships were detected among kidney, liver, and muscle, with emphasis on relationships involving Se and Hg, which may be indicative of similar accumulation/regulation mechanisms in those organs. Element concentrations are discussed in view of possible detoxification mechanisms in seabirds.

  7. Bridging Creativity and Group by Elements of Problem-Based Learning (PBL)

    DEFF Research Database (Denmark)

    Zhou, Chunfang

    2015-01-01

    As the recent studies have discussed Problem-Based Learning (PBL) as popular model of fostering creativity, this paper aims to provide a theoretical framework bridging creativity and student group context by elements of PBL. According to the literature review, the elements at least include group...... learning, problem solving, interdisciplinary learning, project management and facilitation. The main five elements construct PBL as a suitable learning environment to develop individual creativity and to stimulate interplay of individual creativity and group creativity. Thus, a theoretical model...

  8. Investigation of Trace Element Concentrations in Tumor Tissues of Patients with Laryngeal Carcinoma

    Science.gov (United States)

    Aysun, Kaçakçi; Selmin, Toplan; Birsen, Aydemir; Osman, Aslan

    2007-04-01

    Larynx cancer is one of the most frequently seen cancer type between head and neck cancers. Even thought the effective mechanisms in cancer development are not well describe, it is accepted that the effect of some elements carry out important etiology in carcinogenesis. In present study we investigated some trace element concentrations in tumor tissue (n=30) and free-adjacent tissue samples (n=30) of larynx cancer patients. All of the patients were smokers about 20 years. Trace elements were determined by atomic absorption spectrophotometer (Shimadzu AA-680). When Cu, Cd and Zn concentrations of cancer tissue and free-adjacent tissue compared, Cu and Cd levels were found to be higher (pcancer tissue (p0,05). Malign tumors may be increase by smoking about long years. Accumulation of high metals in the organism may be change the structure of cells.

  9. Spatial Distribution of Lead Isotope Ratios and Inorganic Element Concentrations in Epiphytic Lichens from the Athabasca Oil Sands Region

    Science.gov (United States)

    Graney, J. R.; Landis, M. S.; Puckett, K.; Edgerton, E.; Krupa, S.; Percy, K.

    2013-12-01

    Coupled studies of inorganic element concentrations and lead (Pb) isotope ratios have been conducted on Hypogymnia physodes samples collected in the Athabasca Oil Sands Region (AOSR) in Alberta, Canada in 2002, 2008, and 2011. To investigate the spatial extent of air emissions, the lichens were collected from sites as far as 160 km from the mining and processing operations. 30 milligram sub-samples of the lichens were microwave digested, and the extracts were analyzed using DRC-ICPMS to determine elemental concentrations, and sector field ICPMS to measure Pb isotope ratios. Concentrations of elements in the lichens were found to reflect proximity to mining and oil processing sites as well as topography, ecosystem differences, and the metabolic biogeochemistry of the lichens. An exponential decrease in concentration of metals associated with fugitive dust (aluminum and others) versus distance from the mining sites, suggests elevated coarse particle emissions associated with mining operations. Near source concentrations of metals with an oil signature (vanadium and others) are less enhanced and more homogeneous than the metals in the fugitive dust, reflecting emission and deposition of smaller diameter particles at greater distances from oil processing sources. The mining and oil processing signatures are superimposed over elemental concentrations that reflect the nutrient needs of the lichens. These findings are being confirmed through ongoing studies using dichot samplers to collect coarse and fine particulate aerosol samples. The lichen samples collected beyond 50 km from the mining and processing sites cluster into a Pb isotope grouping with a 207Pb / 206Pb ratio of 0.8650 and a 208Pb / 206Pb ratio near 2.095. This grouping likely reflects the regional background Pb isotope ratio signature. 207Pb / 206Pb and 208Pb / 206Pb ratios decrease as one nears the mining and processing operations. This indicates that other Pb source(s), (e.g. Pb in the bitumen from the oil

  10. Concentrations of trace elements in American alligators (Alligator mississippiensis) from Florida, USA.

    Science.gov (United States)

    Horai, Sawako; Itai, Takaaki; Noguchi, Takako; Yasuda, Yusuke; Adachi, Haruki; Hyobu, Yuika; Riyadi, Adi S; Boggs, Ashley S P; Lowers, Russell; Guillette, Louis J; Tanabe, Shinsuke

    2014-08-01

    Concentrations of 28 trace elements (Li, Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Tl, Hg, Pb, and Bi) in the livers of juvenile and adult American alligators inhabiting two central Florida lakes, Lake Apopka (LA), and Lake Woodruff National Wildlife Refuge (LW) and one lagoon population located in Merritt Island National Wildlife Refuge (MINWR; NASA), were determined. In juveniles from MINWR, concentrations of nine elements (Li, Fe, Ni, Sr, In, Sb, Hg, Pb and Bi) were significantly higher, whereas six elements (V, Fe, As, Sr, Hg and Bi) were elevated in adults (p<0.05) obtained from MINWR. Significant enrichment of some trace elements in adults, relative to juveniles, was observed at all three sampling areas. Specifically, Fe, Pb and Hg were significantly elevated in adults when compared to juveniles, suggesting age-dependent accumulation of these elements. Further, As, Se and Sn showed the same trend but only in animals collected from MINWR. Mean Fe concentrations in the livers of adults from LA, LW and MINWR were 1770 μg g(-1) DW, 3690 μg g(-1) DW and 5250 μg g(-1) DW, respectively. More than half of the adult specimens from LW and MINWR exhibited elevated hepatic Fe concentrations that exceed the threshold value for toxic effects in donkey, red deer and human. These results prompted us to express our concern on possible exposure and health effects in American alligators by some trace elements derived from NASA activities.

  11. Evaluation of trace element concentration in cancerous and non-cancerous tissues of human stomach.

    Science.gov (United States)

    Kohzadi, Shadi; Sheikhesmaili, Farshad; Rahehagh, Ramesh; Parhizkar, Baran; Ghaderi, Ebrahim; Loqmani, Hozan; Shahmoradi, Behzad; Mohammadi, Ebrahim; Maleki, Afshin

    2017-10-01

    Gastric cancer has a high mortality rate in west of Iran. Various environmental elements are proposed as cancer risk factors including trace elements. Trace elements can induce initiation or progression of carcinogenesis via oxidative stress and DNA injury. The aim of this study was to measure and compare some trace element concentration (Ca, Cu, Fe, As, Mg, Ni, Cd and Cr) in gastric cancer tissues and normal tissues. For this purpose, 35 patients with gastric cancer and 30 without any cancer were biopsied. Biopsies were taken from cancerous tissue and non-cancerous tissue of gastric cancer patients and gastric tissue of normal patients. The analysis of trace elements was performed using Inductively coupled plasma mass spectrometry (ICP-MS). Data analysis was carried out using SPSS and STATA 12 software. The research found that the concentrations of Fe, Mg, and As were higher in cancerous tissues compared with non-cancerous tissues whereas Cr, Cu, Ca, and Ni concentrations were higher in non-cancerous tissues of cancerous patients. When comparisons were made for cancer and normal samples, copper was the only metal, which was significantly higher in cancerous samples (p tissues was significantly higher compared with cancerous tissues (P = 0.02). Chi-Square test showed that there was no significant relationship in the demographic information between cancerous and normal patients except for location with K(2) = 7.604. Increased Cu and As concentration in gastric patients (both tissues) propose that these elements may have carcinogenic effects, although further study is suggested. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Boundary element analysis of the directional sensitivity of the concentric EMG electrode

    DEFF Research Database (Denmark)

    Henneberg, Kaj-åge; R., Plonsey

    1993-01-01

    Assessment of the motor unit architecture based on concentric electrode motor unit potentials requires a thorough understanding of the recording characteristics of the concentric EMG electrode. Previous simulation studies have attempted to include the effect of EMG electrodes on the recorded...... waveforms by uniformly averaging the tissue potential at the coordinates of one- or two-dimensional electrode models. By employing the boundary element method, this paper improves earlier models of the concentric EMG electrode by including an accurate geometric representation of the electrode, as well...

  13. Element concentrations on Hypogymnia physodes after three years of transplanting along Lake Michigan

    Science.gov (United States)

    Bennett, J.P.; Dibben, M.J.; Lyman, K.J.

    1996-01-01

    Improvements in air quality in air polluted areas are often followed by recolonization of habitats by sensitive lichens that had died out when air quality was worse. To test the hypothesis that air quality at Indiana Dunes National Lakeshore has improved such that lichens could recolonize the area, samples of a species that once grew in the park, Hypogymnia physodes, were transplanted from Door County, Wisconsin to the park and three other sites along the western shore of Lake Michigan, including one at the site of origin as a control. The lichens were sampled for 3 years and tissue concentrations of 20 chemical elements were measured. There were no significant differences between concentrations over the 3 year study duration at the control site in Door County, suggesting that transplanting itself had no impacts on tissue concentrations. All but two elements increased in concentration from north to south with the greatest increases occurring in the third year of the study. Lichens at Indiana Dunes at the end of the study had suffered severe mortality. Chromium increased the most from north to south but concentrations were not higher than maxima observed in other studies. Arsenic and sulfur, however, exceeded known toxic thresholds or maxima observed in other studies on this species. Four hypotheses are presented to explain the toxicity of elements to this species.

  14. Relationships between hepatic trace element concentrations, reproductive status, and body condition of female greater scaup

    Energy Technology Data Exchange (ETDEWEB)

    Badzinski, Shannon S., E-mail: sbadzinski@bsc-eoc.or [Long Point Waterfowl, Bird Studies Canada, PO Box 160, Port Rowan, Ontario N0E 1M0 (Canada); Flint, Paul L., E-mail: pflint@usgs.go [U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508 (United States); Gorman, Kristen B., E-mail: kgorman@alumni.sfu.c [Centre for Wildlife Ecology, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6 (Canada); Petrie, Scott A., E-mail: spetrie@bsc-eoc.or [Long Point Waterfowl, Bird Studies Canada, PO Box 160, Port Rowan, Ontario N0E 1M0 (Canada)

    2009-06-15

    We collected female greater scaup (Aythya marila) on the Yukon-Kuskokwim Delta, Alaska during two breeding seasons to determine if concentrations of 18 trace elements in livers and eggs were elevated and if hepatic concentrations correlated with body condition or affected reproductive status. Fifty-six percent, 5%, and 42% of females, respectively, had elevated hepatic cadmium (Cd: >3 mug g{sup -1} dry weight [dw]), mercury (Hg: >3 mug g{sup -1} dw), and selenium (Se: >10 mug g{sup -1} dw). Somatic protein and lipid reserves were not correlated with hepatic Cd or Hg, but there was a weak negative correlation between protein and Se. Hepatic Cd, Hg, and Se were similar in females that had and had not initiated egg production. In a sample of six eggs, 33% and 100%, respectively, contained Se and Hg, but concentrations were below embryotoxicity thresholds. We conclude that trace element concentrations documented likely were not adversely impacting this study population. - Some female greater scaup initiate nesting with elevated hepatic concentrations of some trace elements, but adverse effects on condition and productivity are unlikely.

  15. Trace element concentrations in freshwater mussels and macrophytes as related to those in their environment

    Directory of Open Access Journals (Sweden)

    Gian Maria BEONE

    2003-02-01

    Full Text Available This study was primarily designed to contribute to the debate "Do accumulator species reflect the element contamination level of their environment?" This research was carried out: 1 to know the distribution of 15 trace elements and calcium in shell and soft tissues of three species of freshwater mussels and macrophytes; 2 to compare the accumulation capacity of each trace element by mussels and by eight species of macrophytes and 3 to test the relationships between the metal concentrations in the mussels and macrophytes and those in water and sediments. The variability of element residues in the mussels is the major limit to accumulator monitoring. The most important causes are: seasonal cycle, physical environment and biological factors such as the size, age and growth rate. This research was designed to eliminate the consequence of variability deriving from the season and the environment. To this end the mussels and macrophytes were collected at the same time from the same habitat: Ranco Bay, Lago Maggiore, Northern Italy. In addition, the element concentrations in more size-classes of the most abundant mussel species (Unio pictorum and Dreissena polymorpha were measured. Trace elements were analyzed by Inductive Coupled Plasma-Mass Spectrometry (ICP-MS. By arranging the data in sequences of decreasing element concentrations in the organisms as well as in water and sediments, we were able to compare the accumulating ability of the tested species and evaluate their capacity to reflect environmental availability. Neither the sequences in the shell nor those in the tissues were similar to the sequence in the water. The differences between the sequences of the mussel tissues and those of the sediments were less striking than those between shells and sediments. Similar results were obtained by macrophytes. In conclusion, the results of this study (which mimics the monitoring practice prove that bioaccumulators cannot be used to evaluate the

  16. Trace element concentrations in the moss Hypnum cupressiforme growing in a presumably unpolluted area.

    Science.gov (United States)

    Boquete, M T; Fernández, J A; Aboal, J R; Carballeira, A; Martínez-Abaigar, J; Tomás-Las-Heras, R; Núñez-Olivera, E

    2016-09-01

    In this study we determined the concentrations of As, Cd, Hg, Ni and Pb in samples of the moss Hypnum cupressiforme collected during 5 different sampling surveys (2006-2014) in a presumably unpolluted area in northern Spain (25 sampling sites). We then applied factor analysis (FA) to the data to explore the factors underlying the spatial and temporal variability in the concentrations. The percentage of variance explained by the FA ranged between 34 and 98%, and was usually higher than 70%. The FA yielded 5 factors that explained the variance in the concentrations of Cd, As, Hg and Pb in all sampling surveys and also a single factor that explained the variance in Hg and Pb concentrations in 2006. Although the lack of obvious sources of pollution in the study region (at least for the elements considered) suggests that most elements (except perhaps Ni) probably originated from long-range atmospheric transport, this would not explain the results of the FA. We suggest that rather than being due to the origin of the pollutants (as frequently assumed), the spatio-temporal variability in the concentrations of these elements is probably determined by a series of other factors: the physicochemical characteristics of the pollutants and of the moss binding surfaces, physiological processes (e.g. moss growth), and the characteristics of the sampling sites (e.g. vegetation cover, elevation, slope, aspect). We therefore conclude that the assumption that variations in element concentrations in moss tissues are due to the origin of the pollutants is an oversimplification that leads to erroneous interpretation of the results of biomonitoring studies with terrestrial mosses.

  17. Matrix Elements of One- and Two-Body Operators in the Unitary Group Approach (II) - Application

    Institute of Scientific and Technical Information of China (English)

    DAI Lian-Rong; PAN Feng

    2001-01-01

    Simple analytical expressions for one- and two-body matrix elements in the unitary group approach to the configuration interaction problems of many-electron systems are obtained based on the previous results for general Un irreps.

  18. Ion-selective electrodes in organic elemental and functional group analysis: a review

    Energy Technology Data Exchange (ETDEWEB)

    Selig, W.

    1977-11-08

    The literature on the use of ion-selective electrodes in organic elemental and functional group analysis is surveyed in some detail. The survey is complete through Chemical Abstracts, Vol. 83 (1975). 40 figures, 52 tables, 236 references.

  19. Effect of sildenafil citrate (Viagra®) on trace element concentration in serum and brain of rats.

    Science.gov (United States)

    Fayed, Abdel-Hasseb A; Gad, Shereen B

    2011-12-01

    As a vasodilator with good hemodynamic effects, sildenafil has been successfully used in the treatment of patients with pulmonary hypertension and cardiovascular diseases. By selectively inhibiting phosphodiestrase type 5 (PDE-5) and thus effectively reducing the breakdown of c GMP, sildenafil administration can markedly improve the erectile dysfunction. Sildenafil also elevates localized cerebral blood flow in rat brain. The objective of the present study was to investigate the effect of sildenafil on the level of trace elements (Zinc (Zn), copper (Cu), iron (Fe), selenium (Se), cobalt (Co), and chromium (Cr)) in blood and brain of rats. Sixteen male albino rats weighing 180-200 g were divided into two groups (8 rats/group). Sildenafil (Viagra, Pfizer Inc.) was dissolved in saline and administered at a dose of 10mg/kg i.p. (0.5 ml volume) to rats in the treated group every 72 h for 12 injections. Rats in the control group were administered the same volume of saline as in treated group. All rats were sacrificed 24h after the last injection. Blood samples were collected and serum was separated and stored at -20°C. Brains were dissected and stored frozen until analysis. Trace elements concentrations were determined by flame emission atomic absorption spectrophotometer. Results showed that sildenafil injection significantly (P<0.05) increased serum and brain Se and Cu concentrations. Moreover, sildenafil increased the Cr concentration in the brain tissue. It was concluded that sildenafil citrate administration increased serum Se and Cu as well as, increased brain Se, Cu, and Cr concentrations in rats.

  20. Element concentrations in surface soils of the Coconino Plateau, Grand Canyon region, Coconino County, Arizona

    Science.gov (United States)

    Van Gosen, Bradley S.

    2016-09-15

    This report provides the geochemical analyses of a large set of background soils collected from the surface of the Coconino Plateau in northern Arizona. More than 700 soil samples were collected at 46 widespread areas, sampled from sites that appear unaffected by mineralization and (or) anthropogenic contamination. The soils were analyzed for 47 elements, thereby providing data on metal concentrations in soils representative of the plateau. These background concentrations can be used, for instance, for comparison to metal concentrations found in soils potentially affected by natural and anthropogenic influences on the Coconino Plateau in the Grand Canyon region of Arizona.The soil sampling survey revealed low concentrations for the metals most commonly of environmental concern, such as arsenic, cobalt, chromium, copper, mercury, manganese, molybdenum, lead, uranium, vanadium, and zinc. For example, the median concentrations of the metals in soils of the Coconino Plateau were found to be comparable to the mean values previously reported for soils of the western United States.

  1. Gas concentration pre-warning system based on fuzzy structured element

    Institute of Scientific and Technical Information of China (English)

    REN Zhi-ling; YU Qun

    2008-01-01

    In order to accurately test gas concentration and effectively pre-waming when the gas concentration over-limited on work face,used the high-performance and low prices SCM and the low-cost and high transfer efficiency bluetooth technology to forecast the gas concentration in real time.The data tested by SCM,then got the corresponding mathematical model of the data.Put forward the idea of using fuzzy structured element theory to dynamic forecast the gas concentration,analyzed the features in abnormal-effusing on work face and judge whether there was the possibility of abnormal gas-effusion.Simulation results show that mathematical model of this system about gas concentration is correct.This system changes coal mine monitoring system's traditional way of after-alarming into early-warning,and thus enhances its feasibility.

  2. Gas concentration pre-warning system based on fuzzy structured element

    Institute of Scientific and Technical Information of China (English)

    REN Zhi-ling; YU Qun

    2008-01-01

    In order to accurately test gas concentration and effectively pre-warning when the gas concentration over-limited on work face, used the high-performance and low prices SCM and the low-cost and high transfer efficiency bluetooth technology to forecast the gas concentration in real time. The data tested by SCM, then got the corresponding mathematical model of the data. Put forward the idea of using fuzzy structured element theory to dynamic forecast the gas concentration, analyzed the features in abnor-mal-effusing on work face and judge whether there was the possibility of abnormal gas-effusion. Simulation results show that mathematical model of this system about gas concentration is correct. This system changes coal mine monitoring system's traditional way of after-alarming into early-warning, and thus enhances its feasibility.

  3. Effect of Phosphatization on Element Concentration of Cobalt-Rich Ferromanganese Crusts

    Institute of Scientific and Technical Information of China (English)

    PAN Jiahua; E. H. De CARLO; YANG Yi; LIU Shuqin; YOU Guoqin

    2005-01-01

    A detailed study on a small scale of the effect of phosphatization on the chemistry of marine cobalt-rich ferromanganese crusts supplies useful information for the evaluation and comprehensive utilization of crust mineral resources. Sub-samples from top to bottom of a 10-cm thick sample from the NW Pacific Magellan seamount were taken at 5 mm intervals. The concentration profiles of ore-forming and rare earth elements show that obvious differences exist between young unphosphatized crusts and old phosphatized crusts. In the old crusts Fe, Mn, Si, Al, Zn, Mg, Co, Ni and Cu elements are depleted and Ca, P, Sr, Ba and Pb elements are enriched. The order of depletion is Co > Ni > Mg > Al > Mn >Si> Cu > Zn > Fe, while the order of enrichment is P > Ca > Ba > Pb > Sr. The phosphate mineral controls the concentration variation of the ore-forming elements in crusts and causes loss of the main ore-forming elements such as Co and Ni. The phosphatization also affects the abundance of REEs in the crusts. REEs are more abundant and the content of Ce in old crusts is higher than that in young crusts, however, the pattern of REEs and their fractionation characteristics in new and old crusts are not fundamentally changed. A Y-positive anomaly in old crusts has no relationship to the phosphatization.

  4. Concentration of trace elements in human semen and relation to spermatozoa quality.

    Science.gov (United States)

    Slivkova, Jana; Popelkova, Miroslava; Massanyi, Peter; Toporcerova, Silvia; Stawarz, Robert; Formicki, Grzegorz; Lukac, Norbert; Putała, Aldona; Guzik, Marek

    2009-03-01

    In this study the concentrations of trace elements such as lead, cadmium, iron, nickel, copper and zinc in the human semen (n = 47), occurrence of pathological spermatozoa, and correlations of these elements to pathological forms were investigated. For each sample of human spermatozoa at least 500 spermatozoa were evaluated. Metal contents were determined by the voltametric method and flame absorption spectrophotometry method. The concentrations of trace elements in human semen were: lead 1.49 +/- 0.40 mg x kg(- 1), cadmium 0.13 +/- 0.15 mg x kg(- 1), iron 2.59 +/- 0.21 mg x kg(- 1), nickel 0.40 +/- 0.07 mg x kg(- 1), copper 0.28 +/- 0.06 mg x kg(- 1), and zinc 153.93 +/- 67.08 mg x kg(- 1), respectively. The total percentage of pathological spermatozoa was 41.61 +/- 9.80% with predominancy of broken flagellum, flagellum torso and separated flagellum. In relation to trace elements the analysis showed correlation between copper and lead (r = -0.47), nickel and iron (r = 0.36), lead and flagellum ball (r = -0.39), cadmium and large heads (r = 0.37) and between iron and other forms of pathological spermatozoa (r = -0.32). Results of this study describe possible effects of trace elements on the spermatozoa quality in normal human sperm.

  5. Element concentrations in candidate biological and environmental reference materials by k[sub 0]-standardized INAA

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, M.C. (LNETI, Inst. de Ciencias e Engenharia Nucleares, Dept. de Energia e Engenharia Nucleares, Sacavem (Portugal))

    1993-01-01

    k[sub 0]-Based Neutron Activation Analysis (k[sub 0]INAA) was used to analyze the candidate reference materials Apple Leaves and Peach Leaves, and Oriental Tobacco Leaves and Virginia Tobacco Leaves. Concentration values for 27 elements were measured. The accuracy was ascertained by analysis of two certified reference materials. NIST 1572 Citrus Leaves and 1573 Tomato Leaves. The homogeneity test of the IAEA Evernia prunastri candidate reference material in aliquots [>=] 100 mg is extended to the elements Sc, Cr, Fe, Co, Zn, Rb, Sb, Cs, Ba, Ce and Th. (orig.).

  6. Structural variations in aromatic 2-electron three-membered rings of the main group elements

    Indian Academy of Sciences (India)

    Dibyendu Mallick; Eluvathingal D Jemmis

    2015-02-01

    Structural variations of different 2-aromatic three-membered ring systems of main group elements, especially group 14 and 13 elements as compared to the classical description of cyclopropenyl cation has been reviewed in this article. The structures of heavier analogues as well as group 13 analogues of cyclopropenyl cation showed an emergence of dramatic structural patterns which do not conform to the generalnorms of carbon chemistry. Isolobal analogies between the main group fragments have been efficiently used to explain the peculiarities observed in these three-membered ring systems.

  7. Selected Trace Element Concentrations in Peat Used for Cosmetic Production – A Case Study from Southern Poland

    Directory of Open Access Journals (Sweden)

    Glina Bartłomiej

    2016-12-01

    Full Text Available The aim of the study was to assess the concentration of selected trace elements in organic soils used as a source to obtain a unique peat extract for cosmetics production. Peat material for laboratory analysis were collected from fen peatland located in the Prosna River Valley (Borek village. Studied peatland is managed by “Torf Corporation” company as a source of material to obtain peat extract for cosmetics production. In the collected soil samples (four soil profiles Zn, Cu and Pb concentrations were determined by using atomic absorption spectrometer SpectraAA 220 (Varian, after acid digestion. Obtained results showed that the highest concentrations of selected trace elements were recorded in the surface horizons of organic soils. This fact might be the results of Prosna river flooding or air deposition. Howevere, according to the new Polish regulations (Ordinance of the Minister for Environment 01.09.2016 - the way of conducting contamination assessment of the earth surface, the content of trace elements in the examined soils was greatly belowe the permissible limit for areas from group IV (mine lands. Thus, described soils are proper to obtain peat extract used as a component in cosmetic production.

  8. Structural elements of construction of individual and group exercises’ competition compositions in calisthenics

    Directory of Open Access Journals (Sweden)

    Kovalenko Y.O.

    2016-02-01

    Full Text Available Purpose: to analyze content of individual and group exercises’ competition compositions in calisthenics. Material: in the research HEEs’ girl students (n=20, junior sportswomen (n=10, experts (n=30, coaches with 10-40 years’ working experience participated. Results: it was found that temporary indicators permit to assess level of female gymnasts’ readiness for fulfillment of competition compositions’ elements; facilitated rational correlation of body and object’s elements of complexity. Quickness of preparation to elements and directly time of exercise’s fulfillment acquire great importance. In individual and group exercises the most important are distribution of sportswoman’s moving on all site with frequent change of directions. It was established that realization of structural elements facilitates full opening of female gymnast’s artistic image. Conclusions: for building of competition compositions coaches shall fully use indicators of space and time structural elements.

  9. Distribution and insertion numbers of transposable elements in species of the Drosophila saltans group

    Directory of Open Access Journals (Sweden)

    Juliana P. de Castro

    2006-01-01

    Full Text Available Information about the distribution and insertion numbers of many transposable elements is restricted to few species of Drosophila, although these elements are widely distributed throughout the genus. The aim of this work was to describe the distribution and insertion numbers of four retrotransposons (copia, gypsy, micropia, I and four transposons (hobo, mariner, Minos and Bari-1 in the saltans group of Drosophila. Our data shows that, except for mariner, all the other elements are widespread within the saltans group and show variable insertion numbers of up to 24 copies.

  10. Straightened cervical lordosis causes stress concentration: a finite element model study.

    Science.gov (United States)

    Wei, Wei; Liao, Shenhui; Shi, Shiyuan; Fei, Jun; Wang, Yifan; Chen, Chunyue

    2013-03-01

    In this study, we propose a finite element analysis of the complete cervical spine with straightened and normal physiological curvature by using a specially designed modelling system. An accurate finite element model is established to recommend plausible approaches to treatment of cervical spondylosis through the finite element analysis results. There are few reports of biomechanics influence of the straightened cervical curve. It is difficult to measure internal responses of cervical spine directly. However, the finite element method has been reported to have the capability to quantify both external and internal responses to mechanical loading, such as the strain and stress distribution of spinal components. We choose a subject with a straightened cervical spine from whom to collect the CT scan data, which formed the basis of the finite element analysis. By using a specially designed modelling system, a high quality finite element model of the complete cervical spine with straightened curvature was generated, which was then mapped to reconstruct a normal physiological curvature model by a volumetric mesh deformation method based on discrete differential properties. Then, the same boundary conditions were applied to do a comparison. The result demonstrated that the active movement range of straightened cervical spine decreased by 24-33 %, but the stress increased by 5-95 %. The stress was concentrated at the facet joint cartilage, uncovertebral joint and the disk. The results suggest that cervical lordosis may have a direct impact on cervical spondylosis treatment. These results may be useful for clinical treatment of cervical spondylosis with straightened curvature.

  11. Trace element concentrations in the top predator jumbo squid (Dosidicus gigas) from the Gulf of California.

    Science.gov (United States)

    Raimundo, Joana; Vale, Carlos; Rosa, Rui

    2014-04-01

    Jumbo (or Humboldt) squid, Dosidicus gigas, is a large jet-propelled top oceanic predator off the Eastern Pacific. The present study reports, for the first time, concentrations of V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd and Pb in gills, mantle and digestive gland of this powerful pelagic squid in the Gulf of California. Zinc and Cu were the most abundant elements. All elements, with the exception of As, were largely stored in digestive gland; particularly Cd that reached concentrations between 57 and 509 µg g(-1). Significant relationships between tissues were found for Co (digestive gland-gills), As (gills-mantle) and Cd (digestive gland-mantle). Proportionality of Cd concentrations between mantle and digestive gland suggested that detoxification capacity by digestive gland was insufficient to avoid the transfer of this element to mantle and other tissues. Nonetheless, Cd concentrations in the mantle were always below the regulatory limit and, therefore lack of constraints for human consumption. On the basis of the fishery landings, one may estimate that up to 1t of Cd can be annually removed by jumbo squid fisheries.

  12. Inorganic speciation of dissolved elements in seawater: the influence of pH on concentration ratios

    Directory of Open Access Journals (Sweden)

    Byrne Robert H

    2002-01-01

    Full Text Available Assessments of inorganic elemental speciation in seawater span the past four decades. Experimentation, compilation and critical review of equilibrium data over the past forty years have, in particular, considerably improved our understanding of cation hydrolysis and the complexation of cations by carbonate ions in solution. Through experimental investigations and critical evaluation it is now known that more than forty elements have seawater speciation schemes that are strongly influenced by pH. In the present work, the speciation of the elements in seawater is summarized in a manner that highlights the significance of pH variations. For elements that have pH-dependent species concentration ratios, this work summarizes equilibrium data (S = 35, t = 25°C that can be used to assess regions of dominance and relative species concentrations. Concentration ratios of complex species are expressed in the form log[A]/[B] = pH - C where brackets denote species concentrations in solution, A and B are species important at higher (A and lower (B solution pH, and C is a constant dependent on salinity, temperature and pressure. In the case of equilibria involving complex oxy-anions (MOx(OHy or hydroxy complexes (M(OHn, C is written as pKn = -log Kn or pKn* = -log Kn* respectively, where Kn and Kn* are equilibrium constants. For equilibria involving carbonate complexation, the constant C is written as pQ = -log(K2lKn [HCO3-] where K2l is the HCO3 - dissociation constant, Kn is a cation complexation constant and [HCO3-] is approximated as 1.9 × 10-3 molar. Equilibrium data expressed in this manner clearly show dominant species transitions, ranges of dominance, and relative concentrations at any pH.

  13. The structural basis for promoter -35 element recognition by the group IV sigma factors.

    Directory of Open Access Journals (Sweden)

    William J Lane

    2006-09-01

    Full Text Available The control of bacterial transcription initiation depends on a primary sigma factor for housekeeping functions, as well as alternative sigma factors that control regulons in response to environmental stresses. The largest and most diverse subgroup of alternative sigma factors, the group IV extracytoplasmic function sigma factors, directs the transcription of genes that regulate a wide variety of responses, including envelope stress and pathogenesis. We determined the 2.3-A resolution crystal structure of the -35 element recognition domain of a group IV sigma factor, Escherichia coli sigma(E4, bound to its consensus -35 element, GGAACTT. Despite similar function and secondary structure, the primary and group IV sigma factors recognize their -35 elements using distinct mechanisms. Conserved sequence elements of the sigma(E -35 element induce a DNA geometry characteristic of AA/TT-tract DNA, including a rigid, straight double-helical axis and a narrow minor groove. For this reason, the highly conserved AA in the middle of the GGAACTT motif is essential for -35 element recognition by sigma(E4, despite the absence of direct protein-DNA interactions with these DNA bases. These principles of sigma(E4/-35 element recognition can be applied to a wide range of other group IV sigma factors.

  14. Concentrations of 17 elements, including mercury, in the tissues, food and abiotic environment of Arctic shorebirds

    Energy Technology Data Exchange (ETDEWEB)

    Hargreaves, Anna L., E-mail: alhargreaves@gmail.com [Calgary Zoo, Centre for Conservation Research, 1300 Zoo Rd NE, Calgary, AB, T2E 7V6 (Canada); Whiteside, Douglas P. [Calgary Zoo, Animal Health Centre, 1300 Zoo Rd NE, Calgary, AB, T2E 7V6 (Canada); University of Calgary, Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, 2500 University Dr. NW, Calgary, AB, T2N 1N4 (Canada); Gilchrist, Grant [Carleton University, National Wildlife Research Centre, Ottawa, ON, KIA OH3 (Canada)

    2011-09-01

    Exposure to contaminants is one hypothesis proposed to explain the global decline in shorebirds, and is also an increasing concern in the Arctic. We assessed potential contaminants (As, Be, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) at a shorebird breeding site in Nunavut, Canada. We compared element levels in soil, invertebrates and shorebird blood to assess evidence for bioconcentration and biomagnification within the Arctic-based food chain. We tested whether elements in blood, feathers and eggs of six shorebird species (Pluvialis squatarola, Calidris alpina, C. fuscicollis, Phalaropus fulicarius, Charadrius semipalmatus, and Arenaria interpres) were related to fitness endpoints: adult body condition, blood-parasite load, egg size, eggshell thickness, nest duration, and hatching success. To facilitate comparison to other sites, we summarise the published data on toxic metals in shorebird blood and egg contents. Element concentrations and invertebrate composition differed strongly among habitats, and habitat use and element concentrations differed among shorebird species. Hg, Se, Cd, Cu, and Zn bioconcentrated from soil to invertebrates, and Hg, Se and Fe biomagnified from invertebrates to shorebird blood. As, Ni, Pb, Co and Mn showed significant biodilution from soil to invertebrates to shorebirds. Soil element levels were within Canadian guidelines, and invertebrate Hg levels were below dietary levels suggested for the protection of wildlife. However, maximum Hg in blood and eggs approached levels associated with toxicological effects and Hg-pollution in other bird species. Parental blood-Hg was negatively related to egg volume, although the relationship varied among species. No other elements approached established toxicological thresholds. In conclusion, whereas we found little evidence that exposure to elements at this site is leading to the declines of the species studied, Hg, as found elsewhere in the Canadian Arctic, is of potential

  15. Osmium-Isotope and Platinum-Group-Element Systematics of Impact-Melt Rocks, Chesapeake Bay Impact Structure, Virginia, USA

    Science.gov (United States)

    Lee, Seung Ryeol; Wright Horton, J., Jr.; Walker, Richard J.

    2005-01-01

    Osmium (Os) isotopes and platinum-group elements (PGEs) are useful for geochemically identifying a meteoritic component within impact structures, because meteorites are typically characterized by low (187)Os/(188)Os ratios and high PGE concentrations. In contrast, most types of crustal target rocks have high radiogenic Os and very low PGE concentrations. We have examined Os isotope and PGE systematics of impact-melt rocks and pre-impact target rocks from a 2004 test hole in the late Eocene Chesapeake Bay impact structure and from nearby coreholes. Our goal is to determine the proportion of the projectile component in the melt rock Additional information is included in the original extended abstract.

  16. [Mechanism of renal elimination of 2 elements of group IIIA of the periodic table : aluminum and indium].

    Science.gov (United States)

    Galle, P

    1981-01-05

    Aluminium and indium, two elements of group IIIA of the periodic table, are concentrated by the kidney inside lysosomes of proximal tubule cell. In these lysosomes, aluminium and indium are precipitated as non-soluble phosphate salts and these precipitates are then expelled in the tubular lumen and eliminated with the urinary flow. These data have been visualized by analytical microscopy (ion microscopy and X ray microanalysis). Local acid phosphatases are assumed to permit the concentration of aluminium and indium salts inside the lysosomes.

  17. Trace elements in particulate matter from metropolitan regions of Northern China: Sources, concentrations and size distributions.

    Science.gov (United States)

    Pan, Yuepeng; Tian, Shili; Li, Xingru; Sun, Ying; Li, Yi; Wentworth, Gregory R; Wang, Yuesi

    2015-12-15

    Public concerns over airborne trace elements (TEs) in metropolitan areas are increasing, but long-term and multi-site observations of size-resolved aerosol TEs in China are still lacking. Here, we identify highly elevated levels of atmospheric TEs in megacities and industrial sites in a Beijing-Tianjin-Hebei urban agglomeration relative to background areas, with the annual mean values of As, Pb, Ni, Cd and Mn exceeding the acceptable limits of the World Health Organization. Despite the spatial variability in concentrations, the size distribution pattern of each trace element was quite similar across the region. Crustal elements of Al and Fe were mainly found in coarse particles (2.1-9 μm), whereas the main fraction of toxic metals, such as Cu, Zn, As, Se, Cd and Pb, was found in submicron particles (environmental standards in China are required to reduce the amounts of these hazardous pollutants released into the atmosphere.

  18. Mineral Element Concentrations in Vegetables Cultivated in Acidic Compared to Alkaline Areas of South Sweden

    Directory of Open Access Journals (Sweden)

    Ingegerd Rosborg

    2009-01-01

    Full Text Available A study in 1997, on mineral levels in acidic compared to alkaline well waters, and in women’s hair, revealed higher concentrations of a number of mineral elements like Ca, Mo and Se in alkaline waters and hair. Thus, median Ca levels were six times higher in well water and five times higher in hair from the alkaline area compared to the acidic area. This finding raised the probability of similar differences in vegetables from these areas. Thus, in the year 2006, 60 women who had participated in the study in 1997 were asked to cultivate parsley, lettuce, carrot and chive. During the spring of 2006, the women from the water and hair study of 1997, 30 of them from the acidic area and 30 women from the alkaline district cultivated vegetables: carrot (Daucus carota L, parsley (Petroselinum crispum, chive (Allium schoenoprasum and lettuce (Eruca sativa. The vegetables were harvested, and rinsed in tap water from the kitchens of the participating women in August. The concentrations of about 35 elements and ions were determined by ICP OES and ICP-MS predominantly. In addition, soil samples from the different cultivators were also analyzed for a number of elements. Lettuce and parsley showed the highest concentrations of mineral elements per gram dry weight. Only Mo concentrations were significantly higher in all the different vegetables from the alkaline district compared to vegetables from the acidic areas. On the other hand, the concentrations of Ba, Br, Mn, Rb and Zn were higher in all the different vegetables from the acidic area. In the soil, only pH and exchangeable Ca from the alkaline area were higher than from the acidic area, while exchangeable Fe, Mn and Na concentrations were higher in soils from the acidic area. Soil elements like Al, Fe, Li, Ni, Pb, Si, Ti, V, Zn and Zr were found in higher concentrations in lettuce and parsley, which were attributed to soil particles being splashed on the plants by the rain and absorbed by the leaves

  19. Complex anthropogenic sources of platinum group elements in aerosols on Cape Cod, USA.

    Science.gov (United States)

    Sen, Indra S; Peucker-Ehrenbrink, Bernhard; Geboy, Nicholas

    2013-09-17

    Platinum group elements (PGE) of anthropogenic origin have been reported in rainwater, snow, roadside soil and vegetation, industrial waste, and urban airborne particles around the world. As recent studies have shown that PGE are bioavailable in the environment and pose health risks at chronic levels, the extent of PGE pollution is of global concern. In this study, we report PGE concentrations and osmium isotope ((187)Os/(188)Os) ratios of airborne particles (particulate matter, PM10) collected in Woods Hole, a small coastal village on Cape Cod, Massachusetts, U.S.A. The sampling site is more than 100 km away from the nearest urban centers (Boston, Providence) and has no large industrial emission center within a 30 km radius. The study reveals that, although PGE concentrations in rural airborne particulate matter are orders of magnitude lower than in urban aerosols, 69% of the total osmium is of anthropogenic origin. Anthropogenic PGE signatures in airborne particles are thus not restricted to large cities with high traffic flows and substantial industries; they can also be found in rural environments. We further conclude that the combination of Pt/Rh concentration ratios and (187)Os/(188)Os composition can be used to trace PGE sources. The Pt/Rh and (187)Os/(188)Os composition of Woods Hole aerosols indicate that the anthropogenic PGE fraction is primarily sourced from ore smelting processes, with possible minor contributions from fossil fuel burning and automobile catalyst-derived materials. Our results further substantiate the use of (187)Os/(188)Os in source apportionment studies on continental scales.

  20. Concentrations of trace element in human dentin by sex and age.

    Science.gov (United States)

    Kumagai, Akiko; Fujita, Yuji; Endo, Shigeatsu; Itai, Kazuyoshi

    2012-06-10

    Teeth are recently drawing attention for their potential as biological modeling investigation samples due to their ability to be collected and their slow substance metabolism. There is no active metabolism of elements after the completion of dentin. Dentin is surrounded by enamel and cementum, and is not affected by the oral environment. Therefore, the amount of trace elements in dentin may change with age, and this is considered to be a reliable biological load index. The objectives in this study are to demonstrate concentrations of elements in the dentin of healthy Japanese subjects by sex and age, and to reveal the relationship between element levels and age. 121 healthy teeth samples were extracted due to periodontal disease or orthodontic treatment. Each tooth was sliced from the crown to the root apex into 0.5-1mm thickness, then enamel, cementum, and the pulp were removed; the dentins were used as samples. The concentration of 10 trace elements (B, Mn, Co, Cu, Zn, Rb, Sr, Mo, Cd, and Pb) in the dentin was measured using inductively coupled plasma mass spectrometer (ICP-MS). The differences Co and Pb in the dentin between men and women were significant (p<0.01). Significant positive correlation was observed between B, Co, Cu, Zn, Sr and Pb concentrations in the dentin and age (p<0.001). The results of the present study suggest that human dentin is an appropriate substance for relativity with sex and age at further future research. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Effect of embedded shot on trace element concentrations in livers of Anseriformes species.

    Science.gov (United States)

    Kim, Jungsoo; Kim, In-Kyu; Oh, Jong-Min

    2016-12-01

    Trace elements were analyzed in the liver of white-fronted geese (Anser albifrons, n=15), mallards (Anas platyrhynchos, n=4) and spot-billed ducks (Anas poecilorhyncha, n=13) found dead in Gimpo, Korea. All mallards and eight spot-billed ducks had embedded lead shot. Embedded shot could be affected elevated trace element concentrations on geese and ducks. Element concentrations of cadmium (Cd), lead (Pb), chromium (Cr), aluminum (Al), copper (Cr), manganese (Mn) and zinc (Zn) differed among species and white-fronted geese without embedded shot had the lowest concentrations for all elements (geomean 0.36, 0.43, 0.07, 1.46, 7.60, 2.61 and 13.5µg/g dw, respectively). Cadmium in four (3.27-7.77µg/g dw) of 32 individuals and Pb in eight (5.07-9.72µg/g dw) of 32 individuals exceeded a tentative threshold effect level of Cd (>3.0µg/g dw) and Pb (>5.0µg/g dw) for birds; all geese and ducks for Cr (0.07-0.43µg/g dw) were within the background level (embedded shot than without shot. Essential trace elements such as Cr, Al (geomean 1.46-37.3µg/g dw), Cu (7.60-57.1µg/g dw), Mn (2.61-27.6µg/g dw) and Zn (13.5-176µg/g dw) were within the normal range and were probably maintained by normal homeostatic mechanisms.

  2. Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System.

    Science.gov (United States)

    Yao, Yuhan; Liu, He; Wu, Wei

    2015-07-18

    High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.

  3. The effect of membrane filtration artifacts on dissolved trace element concentrations

    Science.gov (United States)

    Horowitz, A.J.; Elrick, K.A.; Colberg, M.R.

    1992-01-01

    Among environment scientists, the current and almost universally accepted definition of dissolved constituents is an operational one only those materials which pass through a 0.45-??m membrane filter are considered to be dissolved. Detailed laboratory and field studies on Fe and Al indicate that a number of factors associated with filtration, other than just pore size, can substantially alter 'dissolved' trace element concentrations; these include: filter type, filter diameter, filtration method, volume of sample processed, suspended sediment concentration, suspended sediment grain-size distribution, concentration of colloids and colloidally-associated trace elements and concentration of organic matter. As such, reported filtered-water concentrations employing the same pore size filter may not be equal. Filtration artifacts may lead to the production of chemical data that indicate seasonal or annual 'dissolved' chemical trends which do not reflect actual environmental conditions. Further, the development of worldwide averages for various dissolved chemical constituents, the quantification of geochemical cycles, and the determination of short- or long-term environmental chemical trends may be subject to substantial errors, due to filtration artifacts, when data from the same or multiple sources are combined. Finally, filtration effects could have a substantial impact on various regulatory requirements.

  4. AMS method for depth profiling of trace elements concentration in materials – Construction and applications

    Energy Technology Data Exchange (ETDEWEB)

    Stan-Sion, C.; Enachescu, M.

    2015-10-15

    The need to investigate the behavior of solid state materials on the impact/retention/repulsion/contamination/impregnation with special trace elements or radioactive elements has driven us to develop a modified Accelerator Mass Spectrometry (AMS) analyzing method that is able to perform the measurement of the concentration depth profile of an element in a host material. This upgraded method that we call AMS-depth profiling method (AMS-DP) measures continuously the concentration of a trace element in a given sample material as a function of the depth from the surface (e.g., tritium in carbon, deuterium in tungsten, etc.). However, in order to perform depth profiling, common AMS facilities have to undergo several changes: a new replaceable sample target-holder has to be constructed to accept small plates of solid material as samples; their position has to be adjusted in the focus point of the sputter beam; crater rim effects of the produced hole in the sample have to be avoided or removed from the registered events in the detector; suitable reference samples have to be prepared and used for calibration. All procedures are presented in the paper together with several applications.

  5. AMS method for depth profiling of trace elements concentration in materials - Construction and applications

    Science.gov (United States)

    Stan-Sion, C.; Enachescu, M.

    2015-10-01

    The need to investigate the behavior of solid state materials on the impact/retention/repulsion/contamination/impregnation with special trace elements or radioactive elements has driven us to develop a modified Accelerator Mass Spectrometry (AMS) analyzing method that is able to perform the measurement of the concentration depth profile of an element in a host material. This upgraded method that we call AMS-depth profiling method (AMS-DP) measures continuously the concentration of a trace element in a given sample material as a function of the depth from the surface (e.g., tritium in carbon, deuterium in tungsten, etc.). However, in order to perform depth profiling, common AMS facilities have to undergo several changes: a new replaceable sample target-holder has to be constructed to accept small plates of solid material as samples; their position has to be adjusted in the focus point of the sputter beam; crater rim effects of the produced hole in the sample have to be avoided or removed from the registered events in the detector; suitable reference samples have to be prepared and used for calibration. All procedures are presented in the paper together with several applications.

  6. Trace element concentration in soils and plants in the vicinity of Miduk copper mine

    Directory of Open Access Journals (Sweden)

    Farid Moore

    2014-10-01

    Full Text Available Introduction High concentrations of metals are usually encountered in surface soil and vegetation in areas affected by mining activity (Liu et al., 2006. Different distribution of elements in chemical fractions result in different bioavailability; therefore knowledge of the total content of an element in soil is not a sufficient criterion to estimate the environmental implications of trace metal presence (Maiz et al., 2000. Sequential extraction analysis gives information on the element distribution among different phases of soil. Several schemes of sequential extraction are used for the determination of commonly distinguished metal species, which are in general: (1 easily exchangeable or water soluble; (2 specifically sorbed; e.g., by carbonates or phosphates; (3 organically bound; (4 occluded by Fe-Mn oxides and hydroxides; and (5 structurally bound in minerals or residual (Kabata-Pendias and Mukherjee, 2007. The main objectives of this study are: (1 to describe the distribution pattern of elements in rocks and soils of the Miduk area; (2 to assess the fractionation of elements in soil and the mining impact on the mobility of trace elements; (3 to investigate the uptake of analyzed elements by selected indigenous plant species. Materials and Methods In this study, 32 soil samples at two depths (0-5 cm and 15-20 cm, were analyzed for total concentration of 45 elements. In order to assess the possible bioaccumulation of the elements, the roots and the overground parts of 3 plant species (Astragalus-Fabaceae, Acanthophyllum -Caryophyllaceae, Artemisia -Asteraceae were also collected and analyzed. Enrichment factors (EFs were calculated to assess whether the concentrations observed represent background or contaminated levels. The Tessier et al. method (Tessier et al., 1979 was chosen for sequential extraction of 6 subsoil samples. Correlation analysis was used to examine the relationship between the analyzed elements in soil. The plant’s ability

  7. Finite element analysis of the stress-concentrating effect of fraenal notches in complete dentures.

    Science.gov (United States)

    Rees, J S; Huggett, R; Harrison, A

    1990-01-01

    Based on clinical experience and empiricism, it was postulated that fraenal notches and midline diastemas lead to fracture of complete dentures. This study used finite element stress analysis to investigate the stress-concentrating effect of a fraenal notch with and without a midline diastema. It was found that a large fraenal notch resulted in high stress levels and that these stresses were augmented more by a narrow median diastema than its wider counterpart.

  8. A RECOGNITION OF SIMPLE GROUPS PSL(3, q) BY THEIR ELEMENT ORDERS

    Institute of Scientific and Technical Information of China (English)

    M. R. Darafsheh; A. R. Moghaddamfar; A.R. Zokayi

    2004-01-01

    For any group G, denote by 7πe(G) the set of orders of elements in G. Given a finite group G, let h(πe(G)) be the number of isomorphism classes of finite groups with the same set πe(G) of element orders. A group G is called k-recognizable if h(πe(G)) =k <∞, otherwise G is called non-recognizable. Also a 1-recognizable group is called a recognizable (or characterizable) group. In this paper the authors show that the simple groups PSL(3, q), where 3 < q ≡±2 (mod 5) and (6, (q - 1)/2) = 1, are recognizable.

  9. Effects of cadmium hyperaccumulation on the concentrations of four trace elements in Lonicera japonica Thunb.

    Science.gov (United States)

    Liu, Zhouli; He, Xingyuan; Chen, Wei

    2011-06-01

    Hyperaccumulators are important in the phytoremediation of cadmium (Cd)-contaminated soil. In this study, Cd accumulation and the interactions between Cd and four other trace elements (Fe, Mn, Cu, and Zn) in Lonicera japonica Thunb. were investigated. As a result of exposure to soil containing 50 mg kg(-1) Cd, stem and shoot Cd concentrations reached 344.49 ± 0.71 and 286.12 ± 9.38 μg g(-1) DW respectively, without showing symptoms of visible damage to the plants. This suggests that L. japonica has a strong tolerance to Cd. It is proposed that trace metal elements are involved in the Cd-detoxification mechanisms shown by hyperaccumulators. There is a synergistic interaction in accumulation and translocation between Cd and Fe and a significantly negative correlation between Cd and Cu or Zn concentrations in L. japonica plant tissues. The imbalanced trace element concentrations influences detoxification processes to Cd, therefore, L. japonica could be considered as a new Cd-hyperaccumulator model to investigate the metal tolerance strategies of plants.

  10. Non-destructive determination of trace-element concentrations. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, G.E.; Zoller, W.H.; Walters, W.B.

    1978-08-01

    A beam port has been installed at the National Bureau of Standards (NBS) reactor by the University of Maryland group in cooperation with the NBS staff in order to initiate studies of a new analytical technique: neutron-capture prompt ..gamma..-ray activation analysis (PGAA). A detection system based on a large, high resolution Ge(Li) detector surrounded by NaI crystal has been developed for measurement of prompt ..gamma.. rays from 80 keV to 11 MeV. With a temporary external beam tube in place, neutron and ..gamma..-ray backgrounds were investigated prior to design and construction of a well-shielded beam tube and massive shielding for the detection system. With the backgrounds suitably low, it has been possible to investigate ..gamma..-ray spectra of a wide range of samples. These spectra are being carefully analyzed to identify species contributing the observed lines. Whenever an element's presence is suspected. Standards of the pure element or simple compounds are irradiated to determine its complete spectrum. This is necessary in order to determine which lines are useful for analytical purposes and which have interferences from other elements. From the results to date, it appears that PGAA will be able to measure the following elements in many types of samples: H, B, C, N, Na, Al, Si, S, Cl, K, Ca, Ti, V, Mn, Fe, Cd, Sm, and Gd. Many other elements will be measurable in certain classes of samples. Furthermore, the list of elements is incomplete, as not all lines have yet been identified in the spectra. The quantitative application of the method is being tested using a wide range of NBS Standard Reference Materials whose elemental compositions are well characterized. Measurements are reported for about fourteen elements in several standards. In general, the agreement with previous measurements is quite good.

  11. Intraurban Variation of Fine Particle Elemental Concentrations in New York City.

    Science.gov (United States)

    Ito, Kazuhiko; Johnson, Sarah; Kheirbek, Iyad; Clougherty, Jane; Pezeshki, Grant; Ross, Zev; Eisl, Holger; Matte, Thomas D

    2016-07-19

    Few past studies have collected and analyzed within-city variation of fine particulate matter (PM2.5) elements. We developed land-use regression (LUR) models to characterize spatial variation of 15 PM2.5 elements collected at 150 street-level locations in New York City during December 2008-November 2009: aluminum, bromine, calcium, copper, iron, potassium, manganese, sodium, nickel, lead, sulfur, silicon, titanium, vanadium, and zinc. Summer- and winter-only data available at 99 locations in the subsequent 3 years, up to November 2012, were analyzed to examine variation of LUR results across years. Spatial variation of each element was modeled in LUR including six major emission indicators: boilers burning residual oil; traffic density; industrial structures; construction/demolition (these four indicators in buffers of 50 to 1000 m), commercial cooking based on a dispersion model; and ship traffic based on inverse distance to navigation path weighted by associated port berth volume. All the elements except sodium were associated with at least one source, with R(2) ranging from 0.2 to 0.8. Strong source-element associations, persistent across years, were found for residual oil burning (nickel, zinc), near-road traffic (copper, iron, and titanium), and ship traffic (vanadium). These emission source indicators were also significant and consistent predictors of PM2.5 concentrations across years.

  12. Gold and tin of fluid-magmatic systems: causes of combination-separation of concentration elements

    Institute of Scientific and Technical Information of China (English)

    I.I. Fatyanov; V.G. Khomich

    2009-01-01

    The aim of the investigation is to reveal possible causes of isolation and co-occurrence of the economically significant concentrations of gold and tin. Comparative analysis of the different-rank factors that influenced migration and concentration of these elements show that different geochemical properties of Au and Sn are responsible for isolation of their big concentrations giving rise to independent metallogenic provinces, zones, and ore nodes. These differences resulted in individualization of the element migration ways to the level of ore concentration within the fluid-magmatic columns. Three main factors influenced the Au and Sn migration activity: different patterns of metal connection with the melt structure, different relation with oxygen, and different relation with other strong oxidizers. By the moment when ore-bearing fluid became isolated from magmas, the metallogenic signature of the melts, contrasting in redox-potential, had already been defined that was confirmed by the fact that tin ores associate predominantly with the granitoids of ilmenite series and gold ores - with those of magnetite series. The fluid-magmatic systems with an intermediate degree of the melt reduction-oxidation may be considered the potential producers of the combined metal concentrations. In these cases, the combined concentrating of tin and gold is plagued by an opposite direction of the oxidation-reduction reactions when their most common minerals are formed: the main migration form of Sn +2 must be oxidized (with cassiterite portioning), and the forms of Au + or Au +3 must be reduced (with native gold portioning). Probably, because of this the combined tin and gold concentrations are dominated by one of the metals with a tendency of accumulation in different-stage mineral complexes.

  13. Atmospheric trace element concentrations in total suspended particles near Paris, France

    Science.gov (United States)

    Ayrault, Sophie; Senhou, Abderrahmane; Moskura, Mélanie; Gaudry, André

    2010-09-01

    To evaluate today's trace element atmospheric concentrations in large urban areas, an atmospheric survey was carried out for 18 months, from March 2002 to September 2003, in Saclay, nearby Paris. The total suspended particulate matter (TSP) was collected continuously on quartz fibre filters. The TSP contents were determined for 36 elements (including Ag, Bi, Mo and Sb) using two analytical methods: Instrumental Neutron Activation Analysis (INAA) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The measured concentrations were in agreement within the uncertainties with the certified values for the polycarbonate reference material filter SRM-2783 (National Institute for Standard Technology NIST, USA). The measured concentrations were significantly lower than the recommended atmospheric concentrations. In 2003, the Pb atmospheric level at Saclay was 15 ng/m 3, compared to the 500 ng/m 3 guideline level and to the 200 ng/m 3 observed value in 1994. The typical urban background TSP values of 1-2, 0.2-1, 4-6, 10-30 and 3-5 ng/m 3 for As, Co, Cr, Cu and Sb, respectively, were inferred from this study and were compared with the literature data. The typical urban background TSP concentrations could not be realised for Cd, Pb and Zn, since these air concentrations are highly influenced by local features. The Zn concentrations and Zn/Pb ratio observed in Saclay represented a characteristic fingerprint of the exceptionally large extent of zinc-made roofs in Paris and its suburbs. The traffic-related origin of Ba, Cr, Cu, Pb and Sb was demonstrated, while the atmospheric source(s) of Ag was not identified.

  14. Symmetry elements in space groups and point groups. Addenda to two IUCr reports on the nomenclature of symmetry.

    Science.gov (United States)

    Flack, H D; Wondratschek, H; Hahn, T; Abrahams, S C

    2000-01-01

    The definition of 'symmetry element' given in the Report of the IUCr Ad-Hoc Committee on the Nomenclature of Symmetry by de Wolff et al. [Acta Cryst. (1989). A45, 494-499] is shown to contain an ambiguity in the case of space groups P6/m, P6/mmm, P6/mcc and point groups 6/m and 6/mmm. The ambiguity is removed by redefining the 'geometric element' as a labelled geometric item in which the label is related to the rotation angle of the rotation or rotoinversion symmetry operation. The complete set of different types of glide plane is shown to contain three more than the 15 that are illustrated in the 1992 Report by de Wolff et al. [Acta Cryst. (1992). A48, 727-732].

  15. Laser ablation-laser induced breakdown spectroscopy for the measurement of total elemental concentration in soils.

    Science.gov (United States)

    Pareja, Jhon; López, Sebastian; Jaramillo, Daniel; Hahn, David W; Molina, Alejandro

    2013-04-10

    The performances of traditional laser-induced breakdown spectroscopy (LIBS) and laser ablation-LIBS (LA-LIBS) were compared by quantifying the total elemental concentration of potassium in highly heterogeneous solid samples, namely soils. Calibration curves for a set of fifteen samples with a wide range of potassium concentrations were generated. The LA-LIBS approach produced a superior linear response different than the traditional LIBS scheme. The analytical response of LA-LIBS was tested with a large set of different soil samples for the quantification of the total concentration of Fe, Mn, Mg, Ca, Na, and K. Results showed an acceptable linear response for Ca, Fe, Mg, and K while poor signal responses were found for Na and Mn. Signs of remaining matrix effects for the LA-LIBS approach in the case of soil analysis were found and discussed. Finally, some improvements and possibilities for future studies toward quantitative soil analysis with the LA-LIBS technique are suggested.

  16. Trace element concentrations in harvested auks from Newfoundland: Toxicological risk of a traditional hunt.

    Science.gov (United States)

    Bond, Alexander L; Robertson, Gregory J; Lavers, Jennifer L; Hobson, Keith A; Ryan, Pierre C

    2015-05-01

    Common (Uria aalge) and Thick-billed Murres (Uria lomvia) are apex predators in the North Atlantic Ocean, and are also subject to a traditional hunt in Newfoundland and Labrador during the winter months, along with small numbers of illegally harvested Razorbills (Alca torda). Because of their high trophic position, auks are at risk from high contaminant burdens that bioaccumulate and biomagnify, and could therefore pose a toxicological risk to human consumers. We analysed trace element concentrations from breast muscle of 51 auks collected off Newfoundland in the 2011-2012 hunting season. There were few differences in contaminant concentrations among species. In total, 14 (27%) exceeded Health Canada or international guidelines for arsenic, lead, or cadmium; none exceeded guidelines for mercury. Cadmium concentrations >0.05μg/g have persisted in Newfoundland murres for the last 25 years. We urge the integration of this consumptive harvest for high-trophic marine predators into periodic human health risk assessments.

  17. Transposon display supports transpositional activity of elements in species of the saltans group of Drosophila

    Indian Academy of Sciences (India)

    Nathalia De Setta; Ana Paula Pimentel Costa; Fabrício Ramon Lopes; Marie-Anne Van Sluys; Cláudia Márcia Aparecida Carareto

    2007-01-01

    Mobilization of two element subfamilies (canonical and O-type) from Drosophila sturtevanti and D. saltans was evaluated for copy number and transposition activity using the transposon display (TD) technique. Pairwise distances between strains regarding the insertion polymorphism profile were estimated. Amplification of the element based on copy number estimates was highly variable among the strains (D. sturtevanti, canonical 20.11, O-type 9.00; D. saltans, canonical 16.4, O-type 12.60 insertions, on average). The larger values obtained by TD compared to our previous data by Southern blotting support the higher sensitivity of TD over Southern analysis for estimating transposable element copy numbers. The higher numbers of the canonical element and the greater divergence in its distribution within the genome of D. sturtevanti (24.8%) compared to the O-type (16.7%), as well as the greater divergence in the distribution of the canonical P element, between the D. sturtevanti (24.8%) and the D. saltans (18.3%) strains, suggest that the canonical element occupies more sites within the D. sturtevanti genome, most probably due to recent transposition activity. These data corroborate the hypothesis that the O-type is the oldest subfamily of elements in the saltans group and suggest that the canonical element is or has been transpositionally active until more recently in D. sturtevanti.

  18. sp3-hybridized framework structure of group-14 elements discovered by genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Manh Cuong [Ames Laboratory; Zhao, Xin [Ames Laboratory; Wang, Cai-Zhuang [Ames Laboratory; Ho, Kai-Ming [Ames Laboratory

    2014-05-01

    Group-14 elements, including C, Si, Ge, and Sn, can form various stable and metastable structures. Finding new metastable structures of group-14 elements with desirable physical properties for new technological applications has attracted a lot of interest. Using a genetic algorithm, we discovered a new low-energy metastable distorted sp3-hybridized framework structure of the group-14 elements. It has P42/mnm symmetry with 12 atoms per unit cell. The void volume of this structure is as large as 139.7Å3 for Si P42/mnm, and it can be used for gas or metal-atom encapsulation. Band-structure calculations show that P42/mnm structures of Si and Ge are semiconducting with energy band gaps close to the optimal values for optoelectronic or photovoltaic applications. With metal-atom encapsulation, the P42/mnm structure would also be a candidate for rattling-mediated superconducting or used as thermoelectric materials.

  19. Visualizing lone pairs in compounds containing heavier congeners of the carbon and nitrogen group elements

    Indian Academy of Sciences (India)

    Ram Seshadri

    2001-10-01

    In this mini-review, I discuss some recent work on the stereochemistry and bonding of lone pairs of electrons in divalent compounds of the heavier carbon group elements (SnII, PbII) and in trivalent compounds of the heavier nitrogen group elements (BiIII). Recently developed methods that permit the real-space visualization of bonding patterns on the basis of density functional calculations of electronic structure, reveal details of the nature of selectron lone pairs in compounds of the heavier main group elements - their stereochemistry and their inertness (or lack thereof). An examination of tetragonal 4/ SnO, -PbO and BiOF, and cubic $\\bar{3}$ PbS provides a segue into perovskite phases of technological significance, including ferroelectric PbTiO3 and antiferroelectric/piezoelectric PbZrO3, in both of which the lone pairs on Pb atoms play a pivotal rôle.

  20. Acceleration of high resolution temperature based optimization for hyperthermia treatment planning using element grouping.

    Science.gov (United States)

    Kok, H P; de Greef, M; Bel, A; Crezee, J

    2009-08-01

    In regional hyperthermia, optimization is useful to obtain adequate applicator settings. A speed-up of the previously published method for high resolution temperature based optimization is proposed. Element grouping as described in literature uses selected voxel sets instead of single voxels to reduce computation time. Elements which achieve their maximum heating potential for approximately the same phase/amplitude setting are grouped. To form groups, eigenvalues and eigenvectors of precomputed temperature matrices are used. At high resolution temperature matrices are unknown and temperatures are estimated using low resolution (1 cm) computations and the high resolution (2 mm) temperature distribution computed for low resolution optimized settings using zooming. This technique can be applied to estimate an upper bound for high resolution eigenvalues. The heating potential of elements was estimated using these upper bounds. Correlations between elements were estimated with low resolution eigenvalues and eigenvectors, since high resolution eigenvectors remain unknown. Four different grouping criteria were applied. Constraints were set to the average group temperatures. Element grouping was applied for five patients and optimal settings for the AMC-8 system were determined. Without element grouping the average computation times for five and ten runs were 7.1 and 14.4 h, respectively. Strict grouping criteria were necessary to prevent an unacceptable exceeding of the normal tissue constraints (up to approximately 2 degrees C), caused by constraining average instead of maximum temperatures. When strict criteria were applied, speed-up factors of 1.8-2.1 and 2.6-3.5 were achieved for five and ten runs, respectively, depending on the grouping criteria. When many runs are performed, the speed-up factor will converge to 4.3-8.5, which is the average reduction factor of the constraints and depends on the grouping criteria. Tumor temperatures were comparable. Maximum exceeding

  1. Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

    Energy Technology Data Exchange (ETDEWEB)

    Jerez, Silvia [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Motas, Miguel, E-mail: motas@um.es [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Palacios, Maria Jose; Valera, Francisco [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Cuervo, Jose Javier; Barbosa, Andres [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, C/Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2011-10-15

    Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 {mu}g g{sup -1} dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 {mu}g g{sup -1} dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: > We study levels of trace elements in feathers of Antarctic penguins. > Eight different rookeries throughout the Antarctic Peninsula were sampled. > Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. > Relatively high metal levels were found in areas with major human presence. > Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.

  2. Torsional Vibrations of a Conic Shaft with Opposite Tapers Carrying Arbitrary Concentrated Elements

    Directory of Open Access Journals (Sweden)

    Jia-Jang Wu

    2013-01-01

    Full Text Available The purpose of this paper is to present the exact solution for free torsional vibrations of a linearly tapered circular shaft carrying a number of concentrated elements. First of all, the equation of motion for free torsional vibration of a conic shaft is transformed into a Bessel equation, and, based on which, the exact displacement function in terms of Bessel functions is obtained. Next, the equations for compatibility of deformations and equilibrium of torsional moments at each attaching point (including the shaft ends between the concentrated elements and the conic shaft with positive and negative tapers are derived. From the last equations, a characteristic equation of the form is obtained. Then, the natural frequencies of the torsional shaft are determined from the determinant equation , and, corresponding to each natural frequency, the column vector for the integration constants, , is obtained from the equation . Substitution of the last integration constants into the associated displacement functions gives the corresponding mode shape of the entire conic shaft. To confirm the reliability of the presented theory, all numerical results obtained from the exact method are compared with those obtained from the conventional finite element method (FEM and good agreement is achieved.

  3. Air pollution assessment based on elemental concentration of leaves tissue and foliage dust along an urbanization gradient in Vienna.

    Science.gov (United States)

    Simon, Edina; Braun, Mihály; Vidic, Andreas; Bogyó, Dávid; Fábián, István; Tóthmérész, Béla

    2011-05-01

    Foliage dust contains heavy metal that may have harmful effects on human health. The elemental contents of tree leaves and foliage dust are especially useful to assess air environmental pollution. We studied the elemental concentrations in foliage dust and leaves of Acer pseudoplatanus along an urbanization gradient in Vienna, Austria. Samples were collected from urban, suburban and rural areas. We analysed 19 elements in both kind of samples: aluminium, barium, calcium, copper, iron, potassium, magnesium, sodium, phosphor, sulphur, strontium and zinc. We found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for aluminium, barium, iron, lead, phosphor and selenium. Elemental concentrations of leaves were significantly higher in urban than in rural area for manganese and strontium. Urbanization changed significantly the elemental concentrations of foliage dust and leaves and the applied method can be useful for monitoring the environmental load.

  4. 25 years of N-heterocyclic carbenes: activation of both main-group element-element bonds and NHCs themselves.

    Science.gov (United States)

    Würtemberger-Pietsch, Sabrina; Radius, Udo; Marder, Todd B

    2016-04-14

    N-Heterocyclic carbenes (NHCs) are widely used ligands and reagents in modern inorganic synthesis as well as in homogeneous catalysis and organocatalysis. However, NHCs are not always innocent bystanders. In the last few years, more and more examples were reported of reactions of NHCs with main-group elements which resulted in modification of the NHC. Many of these reactions lead to ring expansion and the formation of six-membered heterocyclic rings involving insertion of the heteroatom into the C-N bond and migration of hydrides, phenyl groups or boron-containing fragments. Furthermore, a few related NHC rearrangements were observed some decades ago. In this Perspective, we summarise the history of NHC ring expansion reactions from the 1960s till the present.

  5. Trace element concentrations in the Mediterranean monk seal (Monachus monachus) in the eastern Mediterranean Sea.

    Science.gov (United States)

    Formigaro, Costanza; Karamanlidis, Alexandros A; Dendrinos, Panagiotis; Marsili, Letizia; Silvi, Marina; Zaccaroni, Annalisa

    2017-01-15

    The Mediterranean monk seal (Monachus monachus) is one of the most endangered marine mammals in the world. The biggest sub-population of the species survives in Greece, where understanding the effects of pollution on the survival of the species has been identified as a national research and conservation priority. From 1990 to 2013 we collected tissue samples from 59 deceased monk seals in order to: (i) Define the concentration of trace elements (As, Pb, Cd, Hg, Se, Cr, Ni) in three different matrices (i.e., blubber, liver and kidney), (ii) Determine whether differences in trace element concentrations are age- or gender-related, (iii) Evaluate the potential effects of these pollutants. The study recorded differences in trace element concentrations among matrices, but in general, trace element exposure in Mediterranean monk seals in Greece was low and within the non-acutely toxic levels for Pinnipeds. Only arsenic concentrations were at the upper limit of the normal range observed in other marine mammals (0.69±0.55mg/kg w.w. in blubber, 0.79±0.62mg/kg w.w. in liver and 0.79±0.59mg/kg w.w. in kidney). We recorded also exceptionally high Hg concentrations in a single adult female (24.88mg/kg w.w.). Age- and gender-related differences were also recorded and were due to various biological, ecological and chemical factors. Based on the results of the study, potentially adverse effects on the immune and endocrine system of the Mediterranean monk seal from some pollutants (e.g., As, Cd, Se, Ni, Cr) cannot be ruled out, which may expose the Mediterranean seal population in Greece to epizootics and stochastic phenomena of mass mortality. It is therefore of utmost importance that pollutant monitoring becomes an integral component of the standard monitoring protocol of the endangered Mediterranean monk seal in the eastern Mediterranean. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Molecules and Models The molecular structures of main group element compounds

    CERN Document Server

    Haaland, Arne

    2008-01-01

    This book provides a systematic description of the molecular structures and bonding in simple compounds of the main group elements with particular emphasis on bond distances, bond energies and coordination geometries. The description includes the structures of hydrogen, halogen and methyl derivatives of the elements in each group, some of these molecules are ionic, some polar covalent. The survey of molecules whose structures conform to well-established trends is followed byrepresentative examples of molecules that do not conform. We also describe electron donor-acceptor and hydrogen bonded co

  7. Air pollution assessment based on elemental concentration of leaves tissue and foliage dust along an urbanization gradient in Vienna

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Edina, E-mail: edina.simon@gmail.com [Department of Ecology, University of Debrecen, H-4010 Debrecen, P.O. Box 71 (Hungary); Braun, Mihaly [Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen, P.O. Box 21 (Hungary); Vidic, Andreas [Department fuer Naturschutzbiologie, Vegetations- und Landschaftsoekologie, Universitat Wien, Althanstrasse 14, 1090 Wien (Austria); Bogyo, David [Department of Ecology, University of Debrecen, H-4010 Debrecen, P.O. Box 71 (Hungary); Fabian, Istvan [Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen, P.O. Box 21 (Hungary); Tothmeresz, Bela [Department of Ecology, University of Debrecen, H-4010 Debrecen, P.O. Box 71 (Hungary)

    2011-05-15

    Foliage dust contains heavy metal that may have harmful effects on human health. The elemental contents of tree leaves and foliage dust are especially useful to assess air environmental pollution. We studied the elemental concentrations in foliage dust and leaves of Acer pseudoplatanus along an urbanization gradient in Vienna, Austria. Samples were collected from urban, suburban and rural areas. We analysed 19 elements in both kind of samples: aluminium, barium, calcium, copper, iron, potassium, magnesium, sodium, phosphor, sulphur, strontium and zinc. We found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for aluminium, barium, iron, lead, phosphor and selenium. Elemental concentrations of leaves were significantly higher in urban than in rural area for manganese and strontium. Urbanization changed significantly the elemental concentrations of foliage dust and leaves and the applied method can be useful for monitoring the environmental load. - Highlights: > We studied the elements in dust and leaves along an urbanization gradient, Austria. > We analysed 19 elements: Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Na, P, Pb, S, Sr and Zn. > Elemental concentrations were higher in urban area than in the rural area. > Studied areas were separated by CDA based on the elemental concentrations. > Dust and leaves can be useful for monitoring the environmental load. - Studying the elements (Al, Ba, Ca, Cu, Fe, K, Mg, Na, P, S, Sr, Zn) in dust and leaves along an urbanization gradient in Wien, Austria we found that the elemental concentrations of foliage dust were significantly higher in the urban area than in the rural area for Al, Ba, Fe, Pb, P and Se, and concentrations of leaves were significantly higher in urban than in rural area for Mn and Sr.

  8. Uranium, thorium and rare earth elements in macrofungi: what are the genuine concentrations?

    Science.gov (United States)

    Borovička, Jan; Kubrová, Jaroslava; Rohovec, Jan; Randa, Zdeněk; Dunn, Colin E

    2011-10-01

    Concentrations of uranium, thorium and rare earth elements (REE) in 36 species of ectomycorrhizal (26 samples) and saprobic (25 samples) macrofungi from unpolluted sites with differing bedrock geochemistry were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Analytical results are supported by use of certified reference materials (BCR-670, BCR-667, NIST-1575a) and the reliability of the determination of uranium was verified by epithermal neutron activation analysis (ENAA). It appears that data recently published on these elements are erroneous, in part because of use of an inappropriate analytical method; and in part because of apparent contamination by soil particles resulting in elevated levels of thorium and REE. Macrofungi from unpolluted areas, in general, did not accumulate high levels of the investigated metals. Concentrations of uranium and thorium were generally below 30 and 125 μg kg(-1) (dry weight), respectively. Concentrations of REE in macrofungi did not exceed 360 μg kg(-1) (dry weight) and their distribution more or less followed the trend observed in post-Archean shales and loess.

  9. Bioconversion of high concentrations of hydrogen sulfide to elemental sulfur in airlift bioreactor.

    Science.gov (United States)

    Zytoon, Mohamed Abdel-Monaem; AlZahrani, Abdulraheem Ahmad; Noweir, Madbuli Hamed; El-Marakby, Fadia Ahmed

    2014-01-01

    Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift bioreactor fed with high concentrations of H2S with special emphasis on the effect of pH in combination with other factors such as H2S loading rate, oxygen availability, and sulfide accumulation. H2S inlet concentrations between 1,008 ppm and 31,215 ppm were applied and elimination capacities up to 113 g H2S m(-3) h(-1) were achieved in the airlift bioreactor under investigation at a pH range 6.5-8.5. Acidic pH values reduced the elimination capacity. Elemental sulfur recovery up to 95% was achieved under oxygen limited conditions (DO bioreactor tolerated accumulated dissolved sulfide concentrations >500 mg/L at pH values 8.0-8.5, and near 100% removal efficiency was achieved. Overall, the resident microorganisms in the studied airlift bioreactor favored pH values in the alkaline range. The bioreactor performance in terms of elimination capacity and sulfur recovery was better at pH range 8-8.5.

  10. Seminal concentration of trace elements in fox and relationships to spermatozoa quality.

    Science.gov (United States)

    Massányi, Peter; Trandzik, Jozef; Nad, Pavol; Skalická, Magdalena; Koréneková, Beata; Lukac, Norbert; Fabis, Marian; Toman, Robert

    2005-01-01

    Concentrations of copper, zinc, iron, cadmium, lead, and nickel in the semen of foxes (Vulpes vulpes, n = 10), microscopic analysis of occurrence of pathological spermatozoa, and correlations of these elements with pathological forms were studied. Samples were analyzed by using an atomic absorption spectrophotometer. For analysis of pathological spermatozoa semen samples fixed with Hancock's solution and stained with Giemsa were prepared. For each fox at least 1000 spermatozoa were evaluated. The concentrations of copper, zinc, and iron in semen of foxes were found to be 2.16+/-0.53 mg/kg, 13.09+/-5.22 mg/kg, and 33.16+/-24.36 mg/kg, respectively, on wet weight basis. Concentration of cadmium was low (0.07+/-0.05 mg/kg). The levels of lead and nickel in the semen of foxes were 0.08+/-0.06 mg/kg and 0.35+/-0.24 mg/kg, respectively. The total percentage of pathological spermatozoa was 7.76+/-1.33% with predominancy of knob twisted flagellum, separated flagellum, and broken flagellum. In relation to trace elements the analysis showed significant (p spermatozoa (r = -0.72), zinc and broken flagellum (r = -0.69), iron and retention of cytoplasmic drop (r = 0.87), cadmium and separated flagellum (r = -0.68), and between cadmium retention of cytoplasmic drop (r = 0.87).

  11. Trace element concentrations in wild mussels from the coastal area of the southeastern Adriatic, Montenegro

    Directory of Open Access Journals (Sweden)

    Markovic Jelena

    2012-01-01

    Full Text Available The aim of the present investigation was to quantify the levels of trace elements (Zn, Cu, As, Pb, Cd and total Hg in the Mediterranean mussel, Mytilus galloprovincialis (L.. Based on their levels, the quality of Montenegro seawater for future mussel farming was estimated. The mussel M. galloprovincialis (L. was collected from four sites in the Montenegrin costal area in the period of two years to determine trace element concentrations and to classify the quality of the coastal water and possible health risks from its consumption. The mean metal concentrations in the mussels ranged from 133.5-205.9 for Zn, 7.50-14.5 for Cu, 4.42-13.3 for As, 4.70-12.9 for Pb, 1.73-2.41 for Cd and 0.07-0.59 for total Hg in mg/kg dry weight. The levels of toxic metals (except for Pb in the mussels were within the maximum residual levels prescribed by the laws of Montenegro, the EU and the USFDA. In addition, the trace metal concentrations found in the mussels in this study were similar to regional data using this mussel as a biomonitoring agent of seawater quality.

  12. Concentrations of trace elements in muscle of sturgeons in the Caspian Sea.

    Science.gov (United States)

    Agusa, Tetsuro; Kunito, Takashi; Tanabe, Shinsuke; Pourkazemi, Mohammad; Aubrey, David G

    2004-11-01

    Concentrations of 21 trace elements were determined in muscle of beluga (Huso huso), Persian sturgeon (Acipenser persicus), Russian sturgeon (Acipenser gueldenstaedtii), ship sturgeon (Acipenser nudiventris) and stellate sturgeon (Acipenser stellatus) collected from coastal regions of Azerbaijan, Iran, Kazakhstan and Turkmenistan, surrounding the Caspian Sea during 2000-2001. Concentrations of Mn, Co, Cu, Mo, Sn, Hg, Pb and Bi in the muscle were apparently different among the five species of sturgeons. Especially, beluga showed the highest concentrations of Hg, Pb and Mn in all the five species. In addition, more than half of the individuals of beluga exceeded the guideline level (0.3 microg/g wet wt.) of Hg for food in UK. However, V, Cr, Zn, Ga, Rb, Sr and Ba concentrations were similar among five sturgeons. Growth-dependent increase in Hg in beluga, Cu in Persian sturgeon, and Zn in Russian sturgeon were observed, whereas V, Mn, Co, Cu, Ga, Sr, Mo, Sn, Hg and Bi concentrations in Persian sturgeon, Pb in ship sturgeon, and Cr, Mn, and Rb in stellate sturgeon were negatively correlated with body length. All species of sturgeon in Azerbaijan showed the highest concentration of Sr and the lowest concentration of Rb, while the five sturgeons from Iran showed opposite trends. Concentration of V, which is present in oil, in sturgeons in the Caspian Sea was considerably lower than that of fish from Kuwait, but was comparable to that of Cambodia and the Gulf and Gulf of Oman. To our knowledge, this study provides the first extensive data on multielemental accumulation in sturgeons of the Caspian Sea.

  13. [Study on the relationship between PMI and the concentration of 21 elements in vitreous humor of rabbit after death].

    Science.gov (United States)

    Gong, Zhi-qiang; Zeng, Xian-bin; Sun, Yue-gang

    2002-05-01

    To seek a precise method for estimating postmortem interval (PMI) in forensic medicine practice. This study detected the concentration of 21 elements in the vitreous humor of rabbit within 96 hours after death and explored the relationship between their concentration and PMI using the method of ICP-MS. It was shown that the concentration of 9 elements in vitreous humor of rabbit within different intervals after death were correlated to PMI available as a reference indicator to estimate PMI. The changes in the concentration of certain elements in vitreous humor of vitreous humor are correlated with PMI and determination of such changes can be used to estimate the time of death.

  14. Gaseous elemental mercury concentration in atmosphere at urban and remote sites in China

    Institute of Scientific and Technical Information of China (English)

    WANG Zhang-wei; CHEN Zuo-shuai; DUAN Ning; ZHANG Xiao-shan

    2007-01-01

    An investigation of gaseous elemental mercury concentration in atmosphere was conducted at Beijing and Guangzhou urban, Yangtze Delta regional sites and China Global Atmosphere Watch Baseline Observatory (CGAWBO) in Mt. Waliguan of remote continental area of China. High temporal resolved data were obtained using automated mercury analyzer RA-915+. Results showed that the overall hourly mean Hg0 concentrations in Mt. Waliguan were 1.7± 1.1 ng/m3 in summer and 0.6±0.08 ng/m3 in winter. The concentration in Yangtze Delta regional site was 5.4±4.1 ng/m3, which was much higher than those in Waliguan continental background area and also higher than that found in North America and Europe rural areas. In Beijing urban area the overall hourly mean Hg0 concentrations were 8.3±3.6 ng/m3 in winter, 6.5±5.2 ng/m3 in spring, 4.9±3.3 ng/m3 in summer, and 6.7±3.5 ng/m3 in autumn, respectively, and the concentration was 13.5±7.1 ng/m3 in Guangzhou site. The mean concentration reached the lowest value at 14:00 and the highest at 02:00 or 20:00 in all monitoring campaigns in Beijing and Guangzhou urban areas, which contrasted with the results measured in Yangtze Delta regional site and Mt. Waliguan. The features of concentration and diurnal variation of Hg0 in Beijing and Guangzhou implied the importance of local anthropogenic sources in contributing to the high Hg0 concentration in urban areas of China. Contrary seasonal variation patterns of Hg0 concentration were found between urban and remote sites. In Beijing the highest Hg0concentration was in winter and the lowest in summer, while in Mt. Waliguan the Hg0 concentration in summer was higher than that in winter. These indicated that different processes and factors controlled Hg0 concentration in urban, regional and remote areas.

  15. Effects of Alloying Elements on the Concentration Profile of Equilibrium Phases in Transformation Induced Plasticity Steel

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    With the two sublattices model, equilibrium compositions of ferrite (α) and austenite (γ) phases, as well as thevolume percent of austenite (γ) in different TRIP steels are calculated. Concentration profiles of carbon, manganese,aluminum and silicon in these steels are also estimated under the lattice fixed frame of reference so as to identifyif the equilibrium state is obtained. Through the comparison between the profiles after different time diffusion, thedistribution of elements in phases is exhibited and the complex effect due to the mutual interaction of the elementson diffusion is discussed.

  16. Finite element vibration analysis of a partially covered cantilever beam with concentrated tip mass

    Energy Technology Data Exchange (ETDEWEB)

    Yaman, Mustafa [Department of Mechanical Engineering, Ataturk University, 25240 Erzurum (Turkey)]. E-mail: myaman@atauni.edu.tr

    2006-07-01

    The work presented in this paper is the theoretical investigation of the dynamical behavior of a cantilever beam, partially covered by damping and constraining layers, with concentrated mass at the free end. A finite element method is used in order to obtain the resonant frequencies and loss factors. The resonant frequencies and loss factors for different physical and geometrical parameters are determined. The variations of these two parameters are found to be strongly dependent on the geometrical and physical properties of the constraining layers and the mass ratio.

  17. Uranium hydrogeochemical and stream sediment reconnaissance of the Arminto NTMS quadrangle, Wyoming, including concentrations of forty-three additional elements

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, T.L.

    1979-11-01

    During the summers of 1976 and 1977, 570 water and 1249 sediment samples were collected from 1517 locations within the 18,000-km/sup 2/ area of the Arminto NTMS quadrangle of central Wyoming. Water samples were collected from wells, springs, streams, and artifical ponds; sediment samples were collected from wet and dry streams, springs, and wet and dry ponds. All water samples were analyzed for 13 elements, including uranium, and each sediment sample was analyzed for 43 elements, including uranium and thorium. Uranium concentrations in water samples range from below the detection limit to 84.60 parts per billion (ppb) with a mean of 4.32 ppb. All water sample types except pond water samples were considered as a single population in interpreting the data. Pond water samples were excluded due to possible concentration of uranium by evaporation. Most of the water samples containing greater than 20 ppb uranium grouped into six clusters that indicate possible areas of interest for further investigation. One cluster is associated with the Pumpkin Buttes District, and two others are near the Kaycee and Mayoworth areas of uranium mineralization. The largest cluster is located on the west side of the Powder River Basin. One cluster is located in the central Big Horn Basin and another is in the Wind River Basin; both are in areas underlain by favorable host units. Uranium concentrations in sediment samples range from 0.08 parts per million (ppm) to 115.50 ppm with a mean of 3.50 ppm. Two clusters of sediment samples over 7 ppm were delineated. The first, containing the two highest-concentration samples, corresponds with the Copper Mountain District. Many of the high uranium concentrations in samples in this cluster may be due to contamination from mining or prospecting activity upstream from the sample sites. The second cluster encompasses a wide area in the Wind River Basin along the southern boundary of the quadrangle.

  18. Geochemical distribution of trace element concentrations in the vicinity of Boroo gold mine, Selenge Province, Mongolia.

    Science.gov (United States)

    Inam, Edu; Khantotong, Supawan; Kim, Kyoung-Woong; Tumendemberel, Bulgan; Erdenetsetseg, Sugar; Puntsag, Tamir

    2011-01-01

    The environmental impacts of Boroo gold mine project in Mongolia was evaluated by chemical characterization of trace element concentrations in water, soils and tailing dam sediment samples. The results showed that concentrations of B, Cd, Ni and Se in the water samples were within the accepted levels of the Mongolia water quality standard (MNS4586: 1998). However, the concentrations of Al, As, Cu, Mn, Fe, Pb, U and Zn were higher than the maximum allowable concentration especially in the monitoring and heap leach wells. The average concentrations of As, Cd, Cu, Ni, Pb and Zn in the tailing dam sediment were 4419, 58.5, 56.0, 4.8, 20.6 and 25.7 mg/kg, respectively. Generally, arsenic and heavy metals in the soil samples were within the acceptable concentrations of the soil standard of Mongolia (MNS 5850: 2008). The chemical characterization of As solid phase in tailing dam sediment showed that the majority of As were found in the residual fraction comprising about 74% of total As. Assessing the potential risk to humans, simple bioavailability extraction test was used to estimate bioavailability of arsenic and heavy metals, and the concentrations extracted from tailing dam sediment were; 288.2 mg/kg As, 7.2 mg/kg Cd, 41.1 mg/kg Cu, 13.5 mg/kg Pb, 4.7 mg/kg Ni and 23.5 mg/kg Zn, respectively. From these results, the Boroo gold mine project has presently not significantly impacted the environment, but there is a high probability that it may act as a source of future contamination.

  19. Trace element concentrations in ashes from various types of lichen biomass species

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, A. [Selcuk University, Konya (Turkey)

    2004-04-15

    Lichens are useful as pollution biomonitors because their biomass can strongly concentrate heavy metals, pollutant gases, and radionuclides from aerosol fallout, precipitation, or runoff. Lichens tend to concentrate pollutants such as sulfur dioxide and heavy metals. The results obtained from the analysis of the lichen biomass gave information about the predominant direction of pollutant transportation, while those related to the concentrations found in the air particulate allowed the evaluation of the degree of the local trace metals atmospheric pollution. Sixteen elements (Fe, Mn, Zn, Cu, Pb, Ni, Cr, Cd, P, K, Ca, Mg, Al, Na, B and S) were determined in 17 different lichen biomass genera Cladina rangiferina, Cladonia foliacea, Cladonia furcata, Cladonia pyxidata, Cladonia rangiformis, Cladonia stellaris, Dermatocarpon miniatum, Diploschistes scruposus, Evernia mesomorpha, Hypogymnia physodes, Parmelia caperata, Parmelia sulcata, Peltiqera canina, Physcita adcenders, Pseadevernia furfurace, Xanthoria calcicola, and Xanthoria parietina by atomic absorption (AAS) and spectrophotometric methods. The highest K, Ca, Mn, and Hg concentrations were 5125, 4627, 126.4, and 0.72 mg/kg in Xanthoria parietina, respectively. The highest P, B, S, Zn and Pb concentrations were 1561, 6.18, 1226, 82.72, and 16.82 mg/kg in Parmelia sulcata, respectively. The highest Cu, Ni, Cr, and Cd concentrations were 17.53, 1.75, 15.36 and 3.86 mg/kg in Xanthoria calcicola, respectively. The highest Mg, Al, Fe and Na concentrations were 601.8, 951.8, 925.2 and 76.33 mg/kg in Cladonia pyxidata, respectively. (author)

  20. Concentration of trace element in milk of West African dwarf goats affected by state of lactation

    Energy Technology Data Exchange (ETDEWEB)

    Akinsoyinu, A.O.; Tewe, O.O.; Mba, A.U.

    1979-06-01

    Ten adult West African dwarf (Fouta djallon) does about 2 yr old and weighing from 22 to 28 kg were kept for two lactations with 18 wk per lactation. During these periods the does were handmilked twice daily, and the daily samples were bulked for each animal for subsequent chemical analysis. Each goat was fed Cynodon nlemfuensis ad libitum and 1 kg of dairy concentrate mixture daily. Colostrum contained (mg/liter) much higher iron, 2.46 +- .27; copper, 3.14 +- .12; manganese, .20 +- .03; zinc, 14.11 +- .45; and iodine, 319.69 +- 14.13 mg/liter than the corresponding values in mature milk which were .43 +- .12; .28 +- .20; .5 +- .04; 4.01 +- .51, and 108.52 +- 28.25. These elements in the colostrum approached normal values between the 5th and 6th day after parturition. The concentration decreased with advance in lactation except for zinc.

  1. IMPORTANCE OF ACTIVATED CARBON'S OXYGEN SURFACE FUNCTIONAL GROUPS ON ELEMENTAL MERCURY ADSORPTION

    Science.gov (United States)

    The effect of varying physical and chemical properties of activated carbons on adsorption of elemental mercury [Hg(0)] was studied by treating two activated carbons to modify their surface functional groups and pore structures. Heat treatment (1200 K) in nitrogen (N2), air oxidat...

  2. Cohomology of Deligne-Lusztig varieties for short-length regular elements in exceptional groups

    CERN Document Server

    Dudas, Olivier

    2011-01-01

    We determine the cohomology of Deligne-Lusztig varieties associated to some short-length regular elements for split groups of type F4 and En. As a byproduct, we obtain conjectural Brauer trees for the principal Phi_{14}-block of E7 and the principal Phi_{24}-block of E8.

  3. Sampling and analysis of chemical element concentration distribution in rock units and orebodies

    Directory of Open Access Journals (Sweden)

    F. P. Agterberg

    2012-01-01

    Full Text Available Existing sampling techniques applied within known orebodies, such as sampling along mining drifts, yield element concentration values for larger blocks of ore if they are extended into their surroundings. The resulting average concentration values have relatively small "extension variance". These techniques can be used for multifractal modeling as well as ore reserve estimation approaches. Geometric probability theory can aid in local spatial covariance modeling. It provides information about increase of variability of element concentration over short distances exceeding microscopic scale. In general, the local clustering of ore crystals results in small-scale variability known as the "nugget effect". Parameters to characterize spatial covariance estimated from ore samples subjected to chemical analysis for ore reserve estimation may not be valid at local scale because of the nugget effect. The novel method of local singularity mapping applied within orebodies provides new insights into the nature of the nugget effect. Within the Pulacayo orebody, Bolivia, local singularity for zinc is linearly related with logarithmically transformed concentration value. If there is a nugget effect, moving averages resulting from covariance models or estimated by other methods that have a smoothing effect, such as kriging, can be improved by incorporating local singularities indicating local element enrichment or depletion. Although there have been many successful applications of the multifractal binomial/p model, its application within the Pulacayo orebody results in inconsistencies, indicating some shortcomings of this relatively simple approach. Local singularity analysis and universal multifractal modeling are two promising new approaches to improve upon results obtained by commonly used geostatistical techniques and use of the binomial/p model. All methods in this paper are illustrated using a single example (118 Pulacayo zinc values, and

  4. Variability in concentrations of potentially toxic elements in urban parks from six European cities.

    Science.gov (United States)

    Madrid, L; Diaz-Barrientos, E; Ruiz-Cortés, E; Reinoso, R; Biasioli, M; Davidson, C M; Duarte, A C; Grcman, H; Hossack, I; Hursthouse, A S; Kralj, T; Ljung, K; Otabbong, E; Rodrigues, S; Urquhart, G J; Ajmone-Marsan, F

    2006-11-01

    Use of a harmonised sampling regime has allowed comparison of concentrations of copper, chromium, nickel, lead and zinc in six urban parks located in different European cities differing markedly in their climate and industrial history. Wide concentrations ranges were found for copper, lead and zinc at most sites, but for chromium and nickel a wide range was only seen in the Italian park, where levels were also considerably greater than in other soils. As might be expected, the soils from older cities with a legacy of heavy manufacturing industry (Glasgow, Torino) were richest in potentially toxic elements (PTEs); soils from Ljubljana, Sevilla and Uppsala had intermediate metal contents, and soils from the most recently established park, in the least industrialised city (Aveiro), displayed lowest concentrations. When principal component analysis was applied to the data, associations were revealed between pH and organic carbon content; and between all five PTEs. When pH and organic carbon content were excluded from the PCA, a distinction became clear between copper, lead and zinc (the "urban" metals) on the one hand, and chromium and nickel on the other. Similar results were obtained for the surface (0-10 cm depth) and sub-surface (10-20 cm depth) samples. Comparisons with target or limit concentrations were limited by the existence of different legislation in different countries and the fact that few guidelines deal specifically with public-access urban soils intended for recreational use.

  5. Relating urban airborne particle concentrations to shipping using carbon based elemental emission ratios

    Science.gov (United States)

    Johnson, Graham R.; Juwono, Alamsyah M.; Friend, Adrian J.; Cheung, Hing-Cho; Stelcer, Eduard; Cohen, David; Ayoko, Godwin A.; Morawska, Lidia

    2014-10-01

    This study demonstrates a novel method for testing the hypothesis that variations in primary and secondary particle number concentration (PNC) in urban air are related to residual fuel oil combustion at a coastal port lying 30 km upwind, by examining the correlation between PNC and airborne particle composition signatures chosen for their sensitivity to the elemental contaminants present in residual fuel oil. Residual fuel oil combustion indicators were chosen by comparing the sensitivity of a range of concentration ratios to airborne emissions originating from the port. The most responsive were combinations of vanadium and sulphur concentration ([S], [V]) expressed as ratios with respect to black carbon concentration ([BC]). These correlated significantly with ship activity at the port and with the fraction of time during which the wind blew from the port. The average [V] when the wind was predominantly from the port was 0.52 ng m-3 (87%) higher than the average for all wind directions and 0.83 ng m-3 (280%) higher than that for the lowest vanadium yielding wind direction considered to approximate the natural background. Shipping was found to be the main source of V impacting urban air quality in Brisbane. However, contrary to the stated hypothesis, increases in PNC related measures did not correlate with ship emission indicators or ship traffic. Hence at this site ship emissions were not found to be a major contributor to PNC compared to other fossil fuel combustion sources such as road traffic, airport and refinery emissions.

  6. The Influence of Distance and Atmospheric Elements on the Concentration of Odour from Refuse Derived Fuel (RDF Operations

    Directory of Open Access Journals (Sweden)

    Zaini Sakawi

    2013-08-01

    Full Text Available Odour is an environmental element that occurs as varieties of aroma, either pleasant or otherwise to its immediate community. The various sources of odour pollution may come from either natural or of human activities. Odour concentration may change due to environmental factors such as atmosphere, topography, distance and mitigation efforts. This study describes a study on the influence of distance and athmospheric elements on concentration of odour generated by the Refuse Derived Fuel (RDF operations. The distribution of odour concentration was measured using Odour concentration meter XP-329 III series per its distance from the RDF operations. The results indicated that distance factors did influence the odour concentration. Results at test stations of distances farther from the RDF showed incrementally higher distribution of odour concentration compared to those nearer to the RDF. In addition, athmosperic elements like temperatures, humidity, wind speed and directions also evidenlty linked to the distribution of odour concentration.

  7. Seasonal variations in the concentration and solubility of elements in atmospheric particulate matter: a case study in Northern Italy

    Directory of Open Access Journals (Sweden)

    Canepari S.

    2013-04-01

    Full Text Available Atmospheric particulate matter is characterized by a variety of chemical components, generally produced by different sources. Chemical fractionation of elements, namely the determination of their extractable and residual fractions, may reliably increase the selectivity of some elements as tracers of specific PM sources. Seasonal variations of atmospheric particulate matter concentration in PM10 and PM2.5, of elemental concentration in PM10 and PM2.5, of the extractable and residual fraction of elements in different size fractions in the range 0.18 – 18 μm are reported in this paper. The effect of the ageing of the air masses is discussed.

  8. Long-term aerosol measurements in Gran Canaria, Canary Islands: Particle concentration, sources and elemental composition

    Science.gov (United States)

    Gelado-Caballero, MaríA. D.; López-GarcíA, Patricia; Prieto, Sandra; Patey, Matthew D.; Collado, Cayetano; HéRnáNdez-Brito, José J.

    2012-02-01

    There are very few sets of long-term measurements of aerosol concentrations over the North Atlantic Ocean, yet such data is invaluable in quantifying atmospheric dust inputs to this ocean region. We present an 8-year record of total suspended particles (TSP) collected at three stations on Gran Canaria Island, Spain (Taliarte at sea level, Tafira 269 m above sea level (a.s.l.) and Pico de la Gorra 1930 m a.s.l.). Using wet and dry deposition measurements, the mean dust flux was calculated at 42.3 mg m-2 d-1. Air mass back trajectories (HYSPLIT, NOAA) suggested that the Sahara desert is the major source of African dust (dominant during 32-50% of days), while the Sahel desert was the major source only 2-10% of the time (maximum in summer). Elemental composition ratios of African samples indicate that, despite the homogeneity of the dust in collected samples, some signatures of the bedrocks can still be detected. Differences were found for the Sahel, Central Sahara and North of Sahara regions in Ti/Al, Mg/Al and Ca/Al ratios, respectively. Elements often associated with pollution (Pb, Cd, Ni, Zn) appeared to share a common origin, while Cu may have a predominantly local source, as suggested by a decrease in the enrichment factor (EF) of Cu during dust events. The inter-annual variability of dust concentrations is investigated in this work. During winter, African dust concentration measurements at the Pico de la Gorra station were found to correlate with the North Atlantic Oscillation (NAO) index.

  9. Determination of thorium, uranium and potassium elemental concentrations in surface soils in Cyprus.

    Science.gov (United States)

    Tzortzis, Michalis; Tsertos, Haralabos

    2004-01-01

    A comprehensive study was conducted to determine thorium, uranium and potassium elemental concentrations in surface soils throughout the accessible area of Cyprus using high-resolution gamma-ray spectrometry. A total of 115 soil samples was collected from all over the bedrock surface of the island based on the different lithological units of the study area. The soil samples were air-dried, sieved through a fine mesh, sealed in 1000-ml plastic Marinelli beakers, and measured in the laboratory in terms of their gamma radioactivity for a counting time of 18 h each. From the measured gamma-ray spectra, elemental concentrations were determined for thorium (range from 2.5 x 10(-3) to 9.8 microg g(-1)), uranium (from 8.1 x 10(-4) to 3.2 microg g(-1)) and potassium (from 1.3 x 10(-4) to 1.9%). The arithmetic mean values (A.M. +/- S.D.) calculated from all samples are: (1.2+/-1.7 microg g(-1)), (0.6+/-0.7) microg g(-1), and (0.4+/-0.3%), for thorium, uranium and potassium, respectively, which are by a factor of three-six lower than the world average values of 7.4 microg g(-1) (Th), 2.8 microg g(-1) (U) and 1.3% (K) derived from all data available worldwide. The best-fitting relation between the concentrations of Th and K versus U and also of K versus Th, is essentially of linear type with a correlation coefficient of 0.93, 0.84 and 0.90, respectively. The Th/U, K/U and K/Th ratios (slopes) extracted are equal to 2.0, 2.8 x 10(3) and 1.4 x 10(3), respectively.

  10. Carbon concentration in species of the araucaria forest and effect of the ecological group

    Directory of Open Access Journals (Sweden)

    Luciano Farinha Watzlawick

    2014-12-01

    Full Text Available This study was conducted in Boa Ventura do São Roque, Paraná State, Brazil, aiming to evaluate the carbon concentration in components of 12 arboreal species from the Araucaria Forest, as well as the performance of the 0.5 conversion factor and the influence of trees ecological groups in their carbon concentration. Carbon concentration averages were obtained from the tree components, and compared among them, among the species and the conversion factor, to assess the interspecific differences and the reliability of the conversion factor. To analyze the influence of ecological groups over the carbon concentration of the species, cluster analyzes were performed. It was not found significant difference among the carbon concentration in the components of the trees. However, comparing the 12 species, Luehea divaricata, Albizia polycephala and Cestrum sp. differed significantly, presenting lower carbon concentration. Comparison between carbon concentration average of the species and the 0.5 conversion factor indicated that the latter overestimates the carbon concentration in the trees at an average rate of 14.27%. No correlation was found between the ecological groups of the species and their carbon concentration, since groups were formed by species with distinct ecological traits.

  11. Toward Universality in Similarity Renormalization Group Evolved Few-body Potential Matrix Elements

    CERN Document Server

    Dainton, Brian

    2015-01-01

    We first examine how T-matrix equivalence drives the flow of similarity renormalization group (SRG) evolved potential matrix elements to a universal form, with the ultimate goal of gaining insight into universality for three-nucleon forces. In agreement with observations made previously for Lee-Suzuki transformations, regions of universal potential matrix elements are restricted to where half-on-shell T-matrix equivalence holds, but the potentials must also reproduce binding energies. We find universality in local energy regions, reflecting a local decoupling by the SRG. To continue the study in the 3-body sector, we create a simple 1-D spinless boson "theoretical laboratory" for a dramatic improvement in computational efficiency. We introduce a basis-transformation, harmonic oscillator (HO) basis, which is used for current many-body calculations and discuss the imposed truncations. When SRG evolving in a HO-basis, we show that the evolved matrix elements, once transformed back into momentum-representation, d...

  12. Study on learning acrobatic elements with groups of girls using programmed instruction in gymnasium

    Directory of Open Access Journals (Sweden)

    Talaghir Laurentiu

    2016-01-01

    Full Text Available This paper presents a part of an extensive research which was conducted with students of class VI in secondary school. In this research were developed several learning strategies with acrobatic elements that are specified in the curriculum for this age level. The paper aims to outline the results achieved in the experiment groups of girls. Also, the paper presents the model proposed for the realization of teaching strategies based on programmed instruction method. Three of acrobatic elements whom were applied these teaching strategies were common elements (performed by girls and boys and one had a character specific to girls. Through the results obtained we can say that the effectiveness of applied strategies was proved by practice, thus achieving the learning unit objectives.

  13. Elemental concentrations in deposited dust on leaves along an urbanization gradient.

    Science.gov (United States)

    Simon, Edina; Baranyai, Edina; Braun, Mihály; Cserháti, Csaba; Fábián, István; Tóthmérész, Béla

    2014-08-15

    Environmental health is an essential component of the quality of life in modern societies. Monitoring of environmental quality and the assessment of environmental risks are often species based on the elemental concentration of deposited dust. Our result suggested that stomata size and distribution were the most important factors influencing the accumulation of air contaminants in leaves. We found that the leaves' surfaces of Acer negundo and Celtis occidentalis were covered by a large number of trichomes, and these species have proven to be suitable biomonitors for atmospheric pollution difficult; these can be overcome using bioindicator species. Leaves of Padus serotina, Acer campestre, A. negundo, Quercus robur and C. occidentalis were used to assess the amount of deposited dust and the concentration of contaminants in deposited dust in and around the city of Debrecen, Hungary. Samples were collected from an urban, suburban and rural area along an urbanization gradient. The concentrations of Ba, Cu, Fe, Mn, Ni, Pb, S, Sr and Zn were determined in deposited dust using ICP-OES. Scanning electron microscopy (SEM) was used to explore the morphological structure and dust absorbing capacity of leaves. We found significant differences in dust deposition among species, and dust deposition correlated with trichomes' density. Principal component analysis (PCA) also showed a total separation of tree.

  14. Investigation of whey protein concentration by ultrafiltration elements designed for water treatment

    Directory of Open Access Journals (Sweden)

    Kukučka Miroslav Đ.

    2013-01-01

    Full Text Available Suitability of polysulfone ultrafiltration membranes (UFM commercial designed for water treatment have been investigated for separation of protein (PR from sweet whey. Ultrafiltration (UF of whey originated from dairy has been realized by self-made pilot plant which has been in service about one year. Influence of two whey temperatures (9 oC and 30 oC on efficiency of protein concentration has been examined. Application of investigated UF elements has given whey protein concentrate (WPC with 5 to 6 times excess amount of protein content in regard to starting one. In the same time the prevalent content of lactose has been removed to permeate. Better results have been occurred during the cold whey filtration. Besides the fact that molecular weight cut-off (MWCO of investigated membranes were 50-100 kDa, results showed very successful concentrating of whey proteins of dominantly lower molar weights than 50-100 kDa. Investigated membranes are beneficial for design and construction of UF plants for exploitation in small dairies.

  15. Quality evaluation of value sets from cancer study common data elements using the UMLS semantic groups

    Science.gov (United States)

    Solbrig, Harold R; Chute, Christopher G

    2012-01-01

    Objective The objective of this study is to develop an approach to evaluate the quality of terminological annotations on the value set (ie, enumerated value domain) components of the common data elements (CDEs) in the context of clinical research using both unified medical language system (UMLS) semantic types and groups. Materials and methods The CDEs of the National Cancer Institute (NCI) Cancer Data Standards Repository, the NCI Thesaurus (NCIt) concepts and the UMLS semantic network were integrated using a semantic web-based framework for a SPARQL-enabled evaluation. First, the set of CDE-permissible values with corresponding meanings in external controlled terminologies were isolated. The corresponding value meanings were then evaluated against their NCI- or UMLS-generated semantic network mapping to determine whether all of the meanings fell within the same semantic group. Results Of the enumerated CDEs in the Cancer Data Standards Repository, 3093 (26.2%) had elements drawn from more than one UMLS semantic group. A random sample (n=100) of this set of elements indicated that 17% of them were likely to have been misclassified. Discussion The use of existing semantic web tools can support a high-throughput mechanism for evaluating the quality of large CDE collections. This study demonstrates that the involvement of multiple semantic groups in an enumerated value domain of a CDE is an effective anchor to trigger an auditing point for quality evaluation activities. Conclusion This approach produces a useful quality assurance mechanism for a clinical study CDE repository. PMID:22511016

  16. Accumulation of germanium and rare earth elements in functional groups of selected energy crops cultivated on two different soils

    Science.gov (United States)

    Wiche, Oliver; Székely, Balázs

    2016-04-01

    A field experiment was conducted to investigate the uptake of Ge and selected REEs in functional groups of selected crop species. Five species belonging to the functional group of grasses (Hordeum vulgare, Zea mays, Avena sativa, Panicum miliaceum and Phalaris arundinacea) and four species from the group of herbs (Lupinus albus, Lupinus angustifolius, Fagopyrum esculentum and Brassica napus) were cultivated in parallel on two soils with slightly alkaline (soil A: pH = 7.8) and slightly acidic (soil B: pH = 6.8) conditions. After harvest, concentrations of Ge, La, Nd, Gd, Er, P, Fe, Mn and Si in shoot tissues were determined with ICP-MS. Concentrations of Ge were significantly higher in grasses than in herbs. Conversely, concentrations of La and Nd were significantly higher in herbs, than in grasses. Highest concentrations were measured in Brassica napus (REEs) and Zea mays (Ge). Concentrations of Ge significantly correlated with that of Si in the shoots showing low concentrations in herbs and high concentrations in grasses, indicating a common mechanism during the uptake in grasses. Concentrations of REEs correlated significantly with that of Fe, indicating increasing concentrations of REEs with increasing concentrations of Fe. Cultivation of species on the slightly acidic soil significantly increased the uptake Ge in Lupinus albus and Phalaris arundinacea and the uptake of La and Nd in all species except of Phalaris arundinacea. This study demonstrated that commonly used field crops could be regarded as suitable candidates for a phytomining of Ge and REEs, since these species develop high yields of shoots, high concentrations of elements and are widely used in agricultural practice. Under soil conditions where bioavailability of Ge and REEs is expected to be low (soil A) accumulation can be estimated at 1.8 g/ha Ge in Z. mays and 3.7 g/ha REEs (1.5 g/ha La, 1.4 g/ha Nd, 0.6 g/ha Gd, 0.3 g/ha Er), respectively, in B. napus, assuming a constant high efficiency of

  17. Baseline element concentrations in soils and plants, Wattenmeer National Park, North and East Frisian Islands, Federal Republic of Germany

    Science.gov (United States)

    Severson, R.C.; Gough, L.P.; van den Boom, G.

    1992-01-01

    Baseline element concentrations are given for dune grass (Ammophilia arenaria), willow (Salix repens), moss (Hylocomium splendens) and associated surface soils. Baseline and variability data for pH, ash, Al, As, Ba, C, Ca, Cd, Ce, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Na, Nb, Nd, Ni, P, Pb, S, Sc, Se, Sr, Th, Ti, V, Y, Yb, and Zn are reported; however, not all variables are reported for all media because, in some media, certain elements were below the analytical detection limit. Spatial variation in element concentration between five Frisian Islands are given for each of the sample media. In general, only a few elements in each media showed statistically significant differences between the islands sampled. The measured concentrations in all sample media exhibited ranges that cannot be attributed to anthropogenic additions of trace elements, with the possible exception of Hg and Pb in surface soils.Baseline element concentrations are given for dune grass (Ammophilia arenaria), willow (Salix repens), moss (Hylocomium splendens) and associated surface soils. Baseline and variability data for pH, ash, Al, As, Ba, C, Ca, Cd, Ce, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Na, Nb, Nd, Ni, P, Pb, S, Sc, Se, Sr, Th, Ti, V, Y, Yb, and Zn are reported; however, not all variables are reported for all media because, in some media, certain elements were below the analytical detection limit. Spatial variation in element concentration between five Frisian Islands are given for each of the sample media. In general, only a few elements in each media showed statistically significant differences between the islands sampled. The measured concentrations in all sample media exhibited ranges that cannot be attributed to anthropogenic additions of trace elements, with the possible exception of Hg and Pb in surface soils.

  18. Concentrations of selected essential and non-essential elements in adult male polar bears (Ursus maritimus) from Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Concentrations of selected essential and non-essential elements, including mercury, cadmium, lead, arsenic, selenium, copper, zinc, and vanadium were measured in...

  19. Evaluation of local trace element status and 8-Iso-prostaglandin F2[alpha] concentrations in patients with Tinea pedis

    National Research Council Canada - National Science Library

    Kurutas, Ergul Belge; Miraloglu, Meral; Ozturk, Perihan; Arican, Ozer

    2016-01-01

    .... Up to the now, the local 8-iso-prostaglandin F.sub.2[alpha] (8-iso-PGF.sub.2[alpha]), concentration as oxidative stress biomarker and trace elements status have not been published in patients with TP...

  20. Batch leaching tests of motherboards to assess environmental contamination by bromine, platinum group elements and other selected heavy metals.

    Science.gov (United States)

    Almeida, César; Grosselli, Melina; González, Patricia; Martínez, Dante; Gil, Raúl

    2016-02-01

    In this study, a batch leaching test was executed to evaluate the toxicity associated with chemicals contained in motherboards. The leaching solutions used were distilled water, nitric acid, acetic acid and synthetic acid rain solution. A total of 21 elements including Ag, As, Au, Br, Cd, Co, Cr, Cu, Hf, Ir, Mn, Ni, Os, Pb, Pd, Pt, Rd, Rh, Se, U and Zn were analyzed. In this study, the pH values of all the leachates fell within the range of 2.33-4.88. The highest concentrations of metals were obtained from the acid rain solution, whilst the maximum value of bromine was achieved with solution of acetic acid. Appreciable concentrations of platinum group elements were detected with concentrations around 3.45, 1.43, 1.21 and 22.19 µg L(-1) for Ir, Pd, Pt and Rh, respectively. The different leaching of the motherboards revealed the predominant presence of the toxic substances in the leached from the e-waste.

  1. Multi-elemental concentrations in the tissues of the oceanic squid Todarodes filippovae from Tasmania and the southern Indian Ocean.

    Science.gov (United States)

    Kojadinovic, Jessica; Jackson, Christine H; Cherel, Yves; Jackson, George D; Bustamante, Paco

    2011-07-01

    This study investigates 14 elements (Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V and Zn) in the tissues of the oceanic ommastrephid squid Todarodes filippovae from waters surrounding Île Amsterdam (southern Indian Ocean) and Tasmania (Australia). As for other cephalopod species, the digestive gland and branchial hearts showed the highest concentrations of many elements (Ag, Cd, Se, V and Zn, and Cr and Ni, respectively) highlighting their role in bioaccumulation and detoxification processes. With the exception of As and Hg, the muscles showed relatively low trace element concentrations. Squid size was positively correlated to Ag, As, Cd, Hg and Zn concentrations in Tasmanian squid and negatively correlated to all but Hg and Zn concentrations in Île Amsterdam squid. Furthermore, no differences in elemental concentrations were noted between sexes. There were, however, some differences between mated and non-mated females from Tasmania. Comparing elemental concentrations in squid from both islands, higher concentrations of Cd, Co, Cr, Ni, Pb and V in squid sampled in Île Amsterdam reflect different exposure conditions. When considering T. filippovae as a dietary resource for humans it should be noted that, given their Hg content, squids from Île Amsterdam are not recommended for consumption on a regular basis. Moreover, regardless of the squid's origin, digestive glands should be avoided as Cd and Hg concentrations were above the European Union authorized limits in these organs.

  2. 20/30 GHz dual-band circularly polarized reflectarray antenna based on the concentric dual split-loop element

    DEFF Research Database (Denmark)

    Smith, Thomas Gunst; Vesterdal Larsen, Niels; Vesterager Gothelf, Ulrich

    2012-01-01

    A concentric dual split-loop element is designed and investigated for reflectarray antenna design in the emerging 20 GHz and 30 GHz Ka-band satellite communication spectrum. The element is capable of providing adjustment of the phase of reflection coefficients for circular plane waves in two...

  3. The concentrations of arsenic and other toxic elements in Bangladesh's drinking water.

    Science.gov (United States)

    Frisbie, Seth H; Ortega, Richard; Maynard, Donald M; Sarkar, Bibudhendra

    2002-01-01

    For drinking water, the people of Bangladesh used to rely on surface water, which was often contaminated with bacteria causing diarrhea, cholera, typhoid, and other life-threatening diseases. To reduce the incidences of these diseases, millions of tubewells were installed in Bangladesh since independence in 1971. This recent transition from surface water to groundwater has significantly reduced deaths from waterborne pathogens; however, new evidence suggests disease and death from arsenic (As) and other toxic elements in groundwater are affecting large areas of Bangladesh. In this evaluation, the areal and vertical distribution of As and 29 other inorganic chemicals in groundwater were determined throughout Bangladesh. This study of 30 analytes per sample and 112 samples suggests that the most significant health risk from drinking Bangladesh's tubewell water is chronic As poisoning. The As concentration ranged from prevent the toxic effects of As. PMID:12417487

  4. Design of the Secondary Optical Elements for Concentrated Photovoltaic Units with Fresnel Lenses

    Directory of Open Access Journals (Sweden)

    Yi-Cheng Chen

    2015-10-01

    Full Text Available The goal of this presented study was to determine the optimum parameters of secondary optical elements (SOEs for concentrated photovoltaic (CPV units with flat Fresnel lenses. Three types of SOEs are under consideration in the design process, including kaleidoscope with equal optical path design (KOD, kaleidoscope with flat top surface (KFTS, and open-truncated tetrahedral pyramid with specular walls (SP. The function of using a SOE with a Fresnel lens in a CPV unit is to achieve high optical efficiency, low sensitivity to the sun tracking error, and improved uniformity of irradiance distribution on the solar cell. Ray tracing technique was developed to simulate the optical characteristics of the CPV unit with various design parameters of each type of SOE. Finally, an optimum KOD-type SOE was determined by parametric design process. The resulting optical performance of the CPV unit with the optimum SOE was evaluated in both single-wavelength and broadband simulation of solar spectrum.

  5. Preliminary results of determination of chemical element concentrations in the aerosol of Venus clouds

    Science.gov (United States)

    Andreychikov, B. M.; Mukhin, L. M.; Korchuganov, B. N.; Akhmetshin, I. K.; Tokarev, Y. N.; Medvedev, A. V.; Goldfeld, M. N.; Faynboym, V. M.; Kalyuzhnyy, A. V.; Petryanov, I. V.

    1986-01-01

    An X-ray radiometeric experiment is described along with the results of measurements of the elemental composition of aerosols in Venusian clouds. A preliminary analysis of the data showed that sulfur is present in the range of heights 63 to 47 km with mean content of 5.8 mg/cu m and that chlorine is present in the height range 61 t0 52 km with a mean content of 4.1 mg/cu m. The results of measurements in the range 52 to 47 km may come to an agreement if phosphorus is present in the aerosol with a mean concentration of 7.7 mg/cu m.

  6. Neural substrates of global perception are modulated by local element grouping

    Institute of Scientific and Technical Information of China (English)

    MAO Lihua; ZHANG Xin; CHEN Jing; GU Hua; HAN Shihui

    2006-01-01

    Prior behavioral studies suggested that global perception of compound stimuli is modulated by the way the local elements are grouped into global structures. The current work examined whether distinct neural mechanisms are involved in global/local processing of compound stimuli when local elements are grouped into global shapes by proximity or by shape similarity. Functional magnetic resonance imaging (fMRI) was used to measure neural activities associated with global/local processing of compound shapes that were presented against either a black background (Experiment 1) or a background of crosses (Experiment 2) while subjects discriminated close or open shapes at the global or local level. Global processing induced activation in the medial occipital cortex in Experiment 1 but in the right inferior temporal, superior parietal, and inferior frontal cortex, and the left inferior parietal gyrus in Experiment 2. Local processing was associated with activations in the left precentral gyrus and right superior temporal gurys in Experiment 1 but in the left posterior inferior parietal gyrus in Experiment 2. The fMRI results suggest that global perception is mediated by distinct neural substrates depending upon how local elements are grouped into global structures.

  7. Cytogenetic mapping of the Muller F element genes in Drosophila willistoni group.

    Science.gov (United States)

    Pita, Sebastián; Panzera, Yanina; Lúcia da Silva Valente, Vera; de Melo, Zilpa das Graças Silva; Garcia, Carolina; Garcia, Ana Cristina Lauer; Montes, Martín Alejandro; Rohde, Claudia

    2014-10-01

    Comparative genomics in Drosophila began in 1940, when Muller stated that the ancestral haploid karyotype of this genus is constituted by five acrocentric chromosomes and one dot chromosome, named A to F elements. In some species of the willistoni group such as Drosophila willistoni and D. insularis, the F element, instead of a dot chromosome, has been incorporated into the E element, forming chromosome III (E + F fusion). The aim of this study was to investigate the scope of the E + F fusion in the willistoni group, evaluating six other species. Fluorescent in situ hybridization was used to locate two genes of the F element previously studied-cubitus interruptus (ci) and eyeless (ey)-in species of the willistoni and bocainensis subgroups. Moreover, polytene chromosome photomaps corresponding to the F element (basal portion of chromosome III) were constructed for each species studied. In D. willistoni, D. paulistorum and D. equinoxialis, the ci gene was located in subSectction 78B and the ey gene in 78C. In D. tropicalis, ci was located in subSection 76B and ey in 76C. In species of the bocainensis subgroup, ci and ey were localized, respectively, at subsections 76B and 76C in D. nebulosa and D. capricorni, and 76A and 76C in D. fumipennis. Despite the differences in the subsection numbers, all species showed the same position for ci and ey. The results confirm the synteny of E + F fusion in willistoni and bocainensis subgroups, and allow estimating the occurrence of this event at 15 Mya, at least.

  8. X-ray Microprobe Investigations of Elemental Distributions and Concentrations at Mineral-Microbe Interfaces

    Science.gov (United States)

    Kemner, K. M.; Kelly, S. D.; O'Loughlin, E. J.; Lai, B.; Maser, J.; Cai, Z.; Londer, Y.; Schiffer, M.; Nealson, K.

    2003-12-01

    Understanding the fate of heavy-metal contaminants in the environment is of fundamental importance in the development and evaluation of effective remediation and sequestration strategies. Bacteria and the extracellular material associated with them are thought to play a key role in determining a contaminant's speciation and thus its mobility in the environment. Additionally, the metabolism and surface properties of bacteria can be quite different depending upon whether the bacteria exhibit a planktonic (free-floating) or biofilm (surface adhered) habit. The microenvironment at and adjacent to actively metabolizing cells also can be significantly different from the bulk environment. Thus, to understand the microscopic physical, geological, chemical, and biological interfaces that determine a contaminant's macroscopic fate, the spatial distribution and chemical speciation of contaminants and elements that are key to biological processes must be characterized at micron and submicron lengthscales for bacteria in both planktonic and adhered states. Hard x-ray microimaging is a powerful technique for the element-specific investigation of complex environmental samples at the needed micron and submicron resolution. An important advantage of these techniques results from the large penetration depth of hard x-rays in water. This advantage minimizes the requirements for sample preparation and allows the detailed study of hydrated samples. The objectives of the studies to be presented are (1) to determine the spatial distribution, concentration, and chemical speciation of metals at, in, and near bacteria and bacteria-geosurface interfaces, (2) to use this information to identify the metabolic processes occurring within the microbes, and (3) to identify the interactions occurring near these interfaces among the metals, mineral surfaces, and bacteria under a variety of conditions. We have used x-ray fluorescence microscopy to investigate the spatial distribution of 3d elements

  9. Trace Element Concentrations in Bearded Seals (Erignathus barbatus Near Red Dog Mine Compared to Other Locations in Alaska

    Directory of Open Access Journals (Sweden)

    Lori Quakenbush

    2009-01-01

    Full Text Available To determine if bearded seals (Erignathus barbatus harvested near a zinc and lead mine (Red Dog, Alaska , USA by subsistence hunters from Kivalina, Alaska, were as safe to eat as bearded seals from other locations in Alaska, we compared 19 trace element concentrations in liver tissue. Liver concentrations from nine bearded seals harvested near the Red Dog Mine (RDM port site were compared with 15 bearded seals from two reference sites (Hooper Bay and Little Diomede, Alaska, USA. Concentrations did not differ by gender, but we found statistically significant trends in concentrations of cadmium, mercury, manganese, selenium, and vanadium with age. Arsenic and copper were the only elements found to be more concentrated in the liver of bearded seals harvested near RDM than in the other locations. The predominant form of arsenic in marine mammals is known to be a nontoxic organic form, not the toxic inorganic form, and copper is an essential element. Although elevated near RDM, neither element was found at concentrations that presented health risks. We found no evidence that bearded seals harvested near RDM were less safe to eat or that trace element concentrations were greater than those found in bearded seals harvested elsewhere in Alaska or Canada.

  10. Parmelia sulcata lichen transplants positioning towards wind direction (Part II): element concentrations and relationships with atmospheric element deposition

    NARCIS (Netherlands)

    Marques, A.P.; Freitas, M.C.; Wolterbeek, H.Th.; Verburg, T.

    2009-01-01

    Parmelia sulcata transplants were positioned in three different exposure systems allowing three different influxes: free influx (Fi), horizontal influx (Hi) and vertical influx (Vi). Results suggest the absence of any wind-directional effects on element accumulation within Fi and Hi systems, but und

  11. Ambient concentrations and insights on organic and elemental carbon dynamics in São Paulo, Brazil

    Science.gov (United States)

    Monteiro dos Santos, Djacinto A.; Brito, Joel F.; Godoy, José Marcus; Artaxo, Paulo

    2016-11-01

    The São Paulo Metropolitan Area (SPMA) is a megacity with about 20 million people and about 8 million vehicles, most of which are fueled with a significant fraction of ethanol - making it a unique case worldwide. This study presents organic and elemental carbon measurements using thermal-optical analysis from quartz filters collected in four sampling sites within the SPMA. Overall Organic Carbon (OC) concentration was comparable at all sites, where Street Canyon had the highest concentration (3.37 μg m-3) and Park site the lowest (2.65 μg m-3). Elemental Carbon (EC), emitted as result of incomplete combustion, has been significantly higher at the Street Canyon site (6.11 μg m-3) in contrast to all other three sites, ranging from 2.25 μg m-3 (Downtown) to 1.50 μg m-3 (Park). For all sampling sites, the average OC:EC ratio are found on the lower bound (urban site. An approach for apportionment between primary and secondary organic carbon based on primary OC:EC ratio was evaluated. The secondary OC was estimated to be 30-40% of total OC concentrations throughout the various sampling sites. The organic carbon dynamics has been further studied using each of the thermally-derived organic carbon fractions. Each of these has been studied regarding their correlation with EC and the correlation between different sites. The analyses have identified that the OC3 and OC4, i.e., the carbon fraction which evolves from the filter at temperatures above 450 °C, presents a regional behavior, with high correlation among all sites. Conversely, OC1, the first fraction to evolve, has depicted a more local characteristic. Furthermore, the fraction of OC which becomes char during the temperature increase under inert atmosphere (the Pyrolytic Carbon-PC) has been the only fraction not to present a significant correlation with EC. Since that EC is assumed to be a primary emission marker, it indicates that PC is not significant in traffic emissions. This study provided innovative

  12. Magnetic properties and element concentrations in lichens exposed to airborne pollutants released during cement production.

    Science.gov (United States)

    Paoli, Luca; Winkler, Aldo; Guttová, Anna; Sagnotti, Leonardo; Grassi, Alice; Lackovičová, Anna; Senko, Dušan; Loppi, Stefano

    2017-05-01

    The content of selected elements (Al, As, Ca, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S, Ti, V and Zn) was measured in samples of the lichen Evernia prunastri exposed for 30, 90 and 180 days around a cement mill, limestone and basalt quarries and urban and agricultural areas in SW Slovakia. Lichens transplanted around the investigated quarries and the cement mill rapidly (30 days) reflected the deposition of dust-associated elements, namely Ca (at the cement mill and the limestone quarry) and Fe, Ti and V (around the cement mill and the basalt quarry), and their content remained significantly higher throughout the whole period (30-180 days) with respect to the surrounding environment. Airborne pollutants (such as S) progressively increased in the study area from 30 to 180 days. The magnetic properties of lichen transplants exposed for 180 days have been characterized and compared with those of native lichens (Xanthoria parietina) and neighbouring bark, soil and rock samples, in order to test the suitability of native and transplanted samples as air pollution magnetic biomonitors. The magnetic mineralogy was homogeneous in all samples, with the exception of the samples from the basalt quarry. The transplants showed excellent correlations between the saturation remanent magnetization (Mrs) and the content of Fe. Native samples had a similar magnetic signature, but the values of the concentration-dependent magnetic parameters were up to two orders of magnitude higher, reflecting higher concentrations of magnetic particles. The concentrations of As, Ca and Cr in lichens correlated with Mrs values after neglecting the samples from the basalt quarry, which showed distinct magnetic properties, suggesting the cement mill as a likely source. Conversely, Ti and Mn were mostly (but not exclusively) associated with dust from the basalt quarry. It is suggested that the natural geological characteristics of the substrate may strongly affect the magnetic properties of lichen thalli

  13. Seminal concentrations of trace elements in various animals and their correlations

    Institute of Scientific and Technical Information of China (English)

    RMassanyi; J.Trandzik; M.Skalicka; R.Toman; B.Korenekova:

    2003-01-01

    =-0.854) was found. Conclusion: There are significant differences in the concentrations of seminal elements in different animals. There is a high concentration of seminal copper in ram and fox, a high zinc level in boar, a high iron level in bull, ram and fox and a high nickel level in ram and fox. (Asian J Androl 2003 Jun; 5:101-104 )

  14. Elemental concentrations in deposited dust on leaves along an urbanization gradient

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Edina, E-mail: edina.simon@gmail.com [Department of Ecology, University of Debrecen, H-4010 Debrecen, P.O. Box 71 (Hungary); Baranyai, Edina [Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen, P.O. Box 21 (Hungary); Agilent Atomic Spectroscopy Partner Laboratory, University of Debrecen, Egyetem tér 1, H-4032 Debrecen (Hungary); Braun, Mihály [Institute of Nuclear Research of the Hungarian Academy of Sciences, Herteleni Laboratory of Environmental Studies, 4026 Debrecen, Bem tér 18/C (Hungary); Cserháti, Csaba [Department of Solid State Physics, University of Debrecen, H-4010 Debrecen, P.O. Box 2 (Hungary); Fábián, István [Department of Inorganic and Analytical Chemistry, University of Debrecen, H-4010 Debrecen, P.O. Box 21 (Hungary); Tóthmérész, Béla [HAS-UD Biodiversity and Ecosystem Services Research Group, H-4010 Debrecen, P.O. Box 71 (Hungary)

    2014-08-15

    Environmental health is an essential component of the quality of life in modern societies. Monitoring of environmental quality and the assessment of environmental risks are often species based on the elemental concentration of deposited dust. Our result suggested that stomata size and distribution were the most important factors influencing the accumulation of air contaminants in leaves. We found that the leaves' surfaces of Acer negundo and Celtis occidentalis were covered by a large number of trichomes, and these species have proven to be suitable biomonitors for atmospheric pollution difficult; these can be overcome using bioindicator species. Leaves of Padus serotina, Acer campestre, A. negundo, Quercus robur and C. occidentalis were used to assess the amount of deposited dust and the concentration of contaminants in deposited dust in and around the city of Debrecen, Hungary. Samples were collected from an urban, suburban and rural area along an urbanization gradient. The concentrations of Ba, Cu, Fe, Mn, Ni, Pb, S, Sr and Zn were determined in deposited dust using ICP–OES. Scanning electron microscopy (SEM) was used to explore the morphological structure and dust absorbing capacity of leaves. We found significant differences in dust deposition among species, and dust deposition correlated with trichomes' density. Principal component analysis (PCA) also showed a total separation of tree. - Highlights: • Dust is used as indicators of the accumulation of inorganic pollutants. • Scanning EM was used to explore the morphological structure of leaves. • Amount of dust deposited of leaves correlated with trichomes' density. • A. negundo, C. occidentalis and Q. robur are suitable to indicate air contaminants. • A. negundo and C. occidentalis are suitable to decrease the amount of dust in air.

  15. 3D finite element analysis on pile-soil interaction of passive pile group

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ming-hua; LIU Dun-ping; ZHANG Ling; JIANG Chong

    2008-01-01

    The interaction between pile and soft soil of the passive pile group subjected to soil movement was analyzed with three-dimensional finite element model by using ANSYS software. The soil was assumed to be elastic-plastic complying with the Drucker-Prager yield criterion in the analysis. The large displacement of soil was considered and contact elements were used to evaluate the interaction between pile and soil. The influences of soil depth of layer and number of piles on the lateral pressure of the pile were investigated, and the lateral pressure distributions on the (2×1) pile group and on the (2×2) pile group were compared. The results show that the adjacent surcharge may result in significant lateral movement of the soft soil and cousiderable pressure on the pile. The pressure acting on the row near the surcharge is higher than that on the other row, due to the "barrier" and arching effects in pile groups. The passive load and its distribution should be taken into account in the design of the passive piles.

  16. PHYSIC AND CHEMICAL BASIS FOR THE INVOLVEMENT OF D-ELEMENTS OF THE FOURTH GROUP (TITANIUM, ZIRCONIUM, HAFNIUM IN THE SYNTHESIS OF BUILDING AND SILICATE MATERIALS

    Directory of Open Access Journals (Sweden)

    V. I. Bolshakov

    2007-11-01

    Full Text Available In the paper the studies of physico-chemical grounds of involving the fourth group elements (titanium, zirconium, hafnium for syntheses of construction silicate materials are presented. The physico-chemical approach proposed allows involving the great group of technogenic titanium-containing semi-products, concentrates, slags and slimes for production of construction silicate materials and manufacture the products and building structures.

  17. Depth Profile of Elemental Concentration of Soil Samples from a Farm Land Within Kaduna, Using X-ray Fluorescence

    Directory of Open Access Journals (Sweden)

    S.M. Oyeyemi

    2011-06-01

    Full Text Available The variation of soil elemental composition was studied to identify the minimum depth needed for optimum yield of crop. The percentage elemental concentration of soil obtained at depth ranging from 0.02-0.30 m at a farm land located in Kaduna state, Nigeria was carried out using X-ray fluorescence. Twenty five different elements were identified. Gallium, thorium, Uranium and Potassium were some of the Natural Occurring Radioactive Materials found at different concentration from depth of 0.02-0.06 m,but found missing beyond 0.06 m. Concentration of Potassium and other elements reduces and increases non-linearly with depth to a minimum concentration of 7.2% at depth of 0.11 m. It further increases and reduces in same trend with depth; Iron and Cobalt gave an anomalous high concentration of 75.6 and 8.5%, respectively at this depth. All other elements have minimum concentration at 0.11 m.

  18. Comparison of Plasma Copper Concentrations in Patients with Brucellosis and Control Group

    Directory of Open Access Journals (Sweden)

    A.R. Mobaien

    2008-07-01

    Full Text Available Introduction & Objective : There are some reports about influence of the rare nutrients such as copper and zinc on immune system. Serum concentrations of copper alter in patients with brucellosis. Brucellosis is a common and endemic disease and a health problem in Iran. We compared serum concentrations of copper in patients with brucellosis and healthy individuals.Materials & Methods: In a cross sectional study, serum concentrations of copper was measured in patients with brucellosis and control group. Eighty six subjects were enrolled in the study, including 43 patients with brucellosis (34 men and 9 women and 43 healthy individuals. Serum concentrations of copper was measured by automatic absorptive spectrophotometer in patients with brucellosis and compared with control group. We employed a non parametrical test, kolmogrov – smirnov, to determine if data distribution was normal or not. Results: Mean age of patients with brucellosis was 40.1415.10 years with the range of 14-60 years. The most frequent symptoms were arthralgia (86%. Serum concentrations of copper in patients with brucellosis were significantly higher than healthy subjects (160.8454.61, 101.7427.37 g/dl respectively, p<0.001.Conclusion: Serum concentrations of copper in patients with brucellosis showed significant alterations in comparison with healthy subjects. So, we recommend using serum copper concentrations in patients with brucellosis as a marker in brucellosis diagnosis. Also we recommend another study for detection of serum copper concentrations before and during treatment.

  19. Essential and toxic element concentrations in blood and urine and their associations with diet: results from a Norwegian population study including high-consumers of seafood and game.

    Science.gov (United States)

    Birgisdottir, B E; Knutsen, H K; Haugen, M; Gjelstad, I M; Jenssen, M T S; Ellingsen, D G; Thomassen, Y; Alexander, J; Meltzer, H M; Brantsæter, A L

    2013-10-01

    The first aim of the study was to evaluate calculated dietary intake and concentrations measured in blood or urine of essential and toxic elements in relation to nutritional and toxicological reference values. The second aim was to identify patterns of the element concentrations in blood and urine and to identify possible dietary determinants of the concentrations of these elements. Adults with a known high consumption of environmental contaminants (n=111), and a random sample of controls (n=76) answered a validated food frequency questionnaire (FFQ). Complete data on biological measures were available for 179 individuals. Blood and urine samples were analyzed for selenium, iodine, arsenic, mercury, cadmium and lead. Principal component analysis was used to identify underlying patterns of correlated blood and urine concentrations. The calculated intakes of selenium, iodine, inorganic arsenic and mercury were within guideline levels. For cadmium 24% of the high consumer group and 8% of the control group had intakes above the tolerable weekly intake. Concentrations of lead in blood exceeded the bench-mark dose lower confidence limits for some participants. However, overall, the examined exposures did not give rise to nutritional or toxicological concerns. Game consumption was associated with lead in blood (B(ln) 0.021; 95%CI:0.010, 0.031) and wine consumption. Seafood consumption was associated with urinary cadmium in non-smokers (B(ln) 0.009; 95%CI:0.003, 0.015). A novel finding was a distinct pattern of positively associated biological markers, comprising iodine, selenium, arsenic and mercury (eigenvalue 3.8), reflecting seafood intake (B 0.007; 95%CI:0.004, 0.010). The study clearly demonstrates the significance of seafood as a source of both essential nutrients and toxic elements simultaneously and shows that exposure to various essential and toxic elements can be intertwined.

  20. Model of Silicon Refining During Tapping: Removal of Ca, Al, and Other Selected Element Groups

    Science.gov (United States)

    Olsen, Jan Erik; Kero, Ida T.; Engh, Thorvald A.; Tranell, Gabriella

    2017-04-01

    A mathematical model for industrial refining of silicon alloys has been developed for the so-called oxidative ladle refining process. It is a lumped (zero-dimensional) model, based on the mass balances of metal, slag, and gas in the ladle, developed to operate with relatively short computational times for the sake of industrial relevance. The model accounts for a semi-continuous process which includes both the tapping and post-tapping refining stages. It predicts the concentrations of Ca, Al, and trace elements, most notably the alkaline metals, alkaline earth metal, and rare earth metals. The predictive power of the model depends on the quality of the model coefficients, the kinetic coefficient, τ, and the equilibrium partition coefficient, L for a given element. A sensitivity analysis indicates that the model results are most sensitive to L. The model has been compared to industrial measurement data and found to be able to qualitatively, and to some extent quantitatively, predict the data. The model is very well suited for alkaline and alkaline earth metals which respond relatively fast to the refining process. The model is less well suited for elements such as the lanthanides and Al, which are refined more slowly. A major challenge for the prediction of the behavior of the rare earth metals is that reliable thermodynamic data for true equilibrium conditions relevant to the industrial process is not typically available in literature.

  1. Model of Silicon Refining During Tapping: Removal of Ca, Al, and Other Selected Element Groups

    Science.gov (United States)

    Olsen, Jan Erik; Kero, Ida T.; Engh, Thorvald A.; Tranell, Gabriella

    2016-12-01

    A mathematical model for industrial refining of silicon alloys has been developed for the so-called oxidative ladle refining process. It is a lumped (zero-dimensional) model, based on the mass balances of metal, slag, and gas in the ladle, developed to operate with relatively short computational times for the sake of industrial relevance. The model accounts for a semi-continuous process which includes both the tapping and post-tapping refining stages. It predicts the concentrations of Ca, Al, and trace elements, most notably the alkaline metals, alkaline earth metal, and rare earth metals. The predictive power of the model depends on the quality of the model coefficients, the kinetic coefficient, τ, and the equilibrium partition coefficient, L for a given element. A sensitivity analysis indicates that the model results are most sensitive to L. The model has been compared to industrial measurement data and found to be able to qualitatively, and to some extent quantitatively, predict the data. The model is very well suited for alkaline and alkaline earth metals which respond relatively fast to the refining process. The model is less well suited for elements such as the lanthanides and Al, which are refined more slowly. A major challenge for the prediction of the behavior of the rare earth metals is that reliable thermodynamic data for true equilibrium conditions relevant to the industrial process is not typically available in literature.

  2. Hair concentration of essential trace elements in adult non-exposed Russian population.

    Science.gov (United States)

    Skalny, Anatoly V; Skalnaya, Margarita G; Tinkov, Alexey A; Serebryansky, Eugeny P; Demidov, Vasily A; Lobanova, Yulia N; Grabeklis, Andrei R; Berezkina, Elena S; Gryazeva, Irina V; Skalny, Andrey A; Skalnaya, Oksana A; Zhivaev, Nikolay G; Nikonorov, Alexandr A

    2015-11-01

    Appropriate reference values of hair trace element content are required for correct interpretation of biomonitoring data. The primary objective of the current study was to estimate the reference values of selected essential trace elements in hair of adult Russian population. Involved in current investigation were 7256 occupationally non-exposed adults aged from 20 to 60 years and living in the European part of Russia. Occipital hair essential metal and metalloid (Co, Cr, Cu, Fe, Mn, Se, V, Zn) content was estimated using inductively coupled plasma mass spectrometry. The reference ranges were calculated in accordance with the International Union of Pure and Applied Chemistry (IUPAC) recommendations. Women were characterized by 55, 18, 58, and 7% higher values of hair Co, Cu, Mn, and Zn content as compared to the values observed in men. At the same time, hair Cr, Fe, Se, and V concentration in men significantly exceeded the respective female values by 65, 13, 20, and 56%. Consequently, the reference ranges of essential hair trace elements content should be separately calculated for both men and women. The obtained reference ranges for hair Co, Cr, Cu, Fe, Mn, Se, V, and Zn in men were 0.11-0.67, 0.007-0.045, 10.4-22.6, 11.1-40.5, 0.24-1.05, 0.089-0.480, 0.014-0.083, and 125.7-262.8 μg/g, respectively. The respective values estimated for women were 0.06-0.40, 0.011-0.085, 12.1-44.5, 8.9-25.6, 0.32-2.05, 0.094-0.504, 0.010-0.056, and 140.0-315.1 μg/g. The reference ranges for hair Co (0.07-0.50), Cr (0.009-0.073), Cu (11.8-29.2), Fe (9.6-31.5), Mn (0.29-1.76), Se (0.093-0.482), V (0.011-0.069), and Zn (134.7-301.9) content (μg/g) in the general cohort were also calculated.

  3. Trace element concentration and speciation in selected urban soils in New York City.

    Science.gov (United States)

    Burt, R; Hernandez, L; Shaw, R; Tunstead, R; Ferguson, R; Peaslee, S

    2014-01-01

    A long history of urbanization and industrialization has affected trace elements in New York City (NYC) soils. Selected NYC pedons were analyzed by aqua regia microwave digestion and sequential chemical extraction as follows: water soluble (WS); exchangeable (EX); specifically sorbed/carbonate bound (SS/CAR); oxide-bound (OX); organic/sulfide bound (OM/S). Soils showed a range in properties (e.g., pH 3.9 to 7.4). Sum of total extractable (SUMTE) trace elements was higher in NYC parks compared to Bronx River watershed sites. NYC surface horizons showed higher total extractable (TE) levels compared to US non-anthropogenic soils. TE levels increased over 10 year in some of the relatively undisturbed and mostly wooded park sites. Surface horizons of park sites with long-term anthropogenic inputs showed elevated TE levels vs. subsurface horizons. Conversely, some Bronx River watershed soils showed increased concentrations with depth, reflective of their formation in a thick mantle of construction debris increasing with depth and intermingled with anthrotransported soil materials. Short-range variability was evident in primary pedons and satellite samples (e.g., Pb 253 ± 143 mg/kg). Long-range variability was indicated by PbTE (348 versus 156 mg/kg) and HgTE (1 versus 0.3 mg/kg) concentrations varying several-fold in the same soil but in different geographic locations. Relative predominance of fractions: RES (37 %) > SS/CAR (22 %) > OX (20 %) > OM/S (10 %) > EX (7 %) > WS (4 %). WS and EX fractions were greatest for Hg (7 %) and Cd (14 %), respectively. RES was predominant fraction for Co, Cr, Ni, and Zn (41 to 51 %); SS/CAR for Cd and Pb (40 and 63 %); OM/S for Cu and Hg (36 and 37 %); and OX for As (59 %).

  4. Evaluation of group electronegativities and hardness (softness) of group 14 elements and containing functional groups through density functional theory and correlation with NMR spectra data

    Energy Technology Data Exchange (ETDEWEB)

    Vivas-Reyes, R.; Aria, A. [Universidad de Cartagena, Cartagena (Colombia). Facultad de Ciencias Naturales y Exactas. Grupo de Quimica Cuantica y Computacional]. E-mail: rvivasr@unicartagena.edu.co

    2008-07-01

    Quantum Chemical calculations for group 14 elements of Periodic Table (C, Si, Ge, Sn, Pb) and their functional groups have been carried out using Density Functional Theory (DFT) based reactivity descriptors such as group electronegativities, hardness and softness. DFT calculations were performed for a large series of tetra coordinated Sn compounds of the CH{sub 3}SnRR'X type, where X is a halogen and R and R' are alkyl, halogenated alkyl, alkoxy, or alkyl thio groups. The results were interpreted in terms of calculated electronegativity and hardness of the SnRR'X groups, applying a methodology previously developed by Geerlings and coworkers (J. Phys. Chem. 1993, 97, 1826). These calculations allowed to see the regularities concerning the influence of the nature of organic groups RR' and inorganic group X on electronegativities and hardness of the SnRR'X groups; in this case, it was found a very good correlation between the electronegativity of the fragment and experimental {sup 119}Sn chemical shifts, a property that sensitively reflects the change in the valence electronic structure of molecules. This work was complemented with the study of some compounds of the EX and ER types, where E= C, Si, Ge, Sn and R= CH{sub 3}, H, which was performed to study the influence that the central atom has on the electronegativity and hardness of molecules, or whether these properties are mainly affected for the type of ligand bound to the central atom. All these calculations were performed using the B3PW91 functional together with the 6-3 1 1 + + G basis set level for H, C, Si, Ge, F, Cl and Br atoms and the 3-21G for Sn and I atoms. (author)

  5. [Analyzer Design of Atmospheric Particulate Matter's Concentration and Elemental Composition Based on β and X-Ray's Analysis Techniques].

    Science.gov (United States)

    Ge, Liang-quan; Liu, He-fan; Zeng, Guo-qiang; Zhang, Qing-xian; Ren, Mao-qiang; Li, Dan; Gu, Yi; Luo, Yao-yao; Zhao, Jian-kun

    2016-03-01

    Monitoring atmospheric particulate matter requires real-time analysis, such as particulate matter's concentrations, their element types and contents. An analyzer which is based on β and X rays analysis techniques is designed to meet those demands. Applying β-ray attenuation law and energy dispersive X-ray fluorescence analysis principle, the paper introduces the analyzer's overall design scheme, structure, FPGA circuit hardware and software for the analyzer. And the analyzer can measure atmospheric particulate matters' concentration, elements and their contents by on-line analysis. Pure elemental particle standard samples were prepared by deposition, and those standard samples were used to set the calibration for the analyzer in this paper. The analyzer can monitor atmospheric particulate matters concentration, 30 kinds of elements and content, such as TSP, PM10 and PM2.5. Comparing the measurement results from the analyzer to Chengdu Environmental Protection Agency's monitoring results for monitoring particulate matters, a high consistency is obtained by the application in eastern suburbs of Chengdu. Meanwhile, the analyzer are highly sensitive in monitoring particulate matters which contained heavy metal elements (such as As, Hg, Cd, Cr, Pb and so on). The analyzer has lots of characteristics through technical performance testing, such as continuous measurement, low detection limit, quick analysis, easy to use and so on. In conclusion, the analyzer can meet the demands for analyzing atmospheric particulate matter's concentration, elements and their contents in urban environmental monitoring.

  6. Platinum group and chalcophile element systematics of serpentinized peridotites from the St. Elena ophiolite in Costa Rica

    Science.gov (United States)

    Holm, J.; Bizimis, M.; Schwarzenbach, E. M.; Foustoukos, D.; Frisby, C. P.; Brandon, A. D.; Gazel, E.

    2015-12-01

    We present in situ LA-ICPMS data on platinum group element (PGE) and chalcophile element (namely Cu, Ag, Te, Au, Pb) systematics in sulfides from partially serpentinized peridotites of the St. Elena ophiolite, Costa Rica. PGE are strong indicators of primary mantle processes, though their behavior during low temperature alteration processes such as serpentinization is not well understood. St. Elena sulfides are dominantly pentlandites that coexist with Fe-Ni alloys and native Cu. This indicates extremely low fO2 and fS2 conditions likely established during the early stages of serpentinization. We observe extremely variable PGE-Re concentrations in the sulfides, (e.g. [Os] = 2 - 100,000 times primitive mantle, PM). Low [Os] sulfides have high Pd/Os, which in turn correlates positively with Cu concentrations, suggesting Pd enrichment through Cu-rich fluids (e.g. Schwarzenbach et al., 2014, CMP) as opposed to melt-rock reaction. Sulfide PM-normalized PGE-Re patterns are dominated by strong Pt depletions (e.g., Pt/Pd = 0.80-0.0009). Occasional Pt enrichments over Pd and Ru (or Rh) in a PM-normalized pattern (~5% of the sulfide population) often correlate with Te and/or Au enrichments. Pt enrichment was also observed in a composite pentlandite-awaruite, suggesting possible exsolution of Pt from sulfides under extremely low fS2 conditions. Pb concentrations do not correlate with other chalcophiles or PGE. Pb ranges from 0.01-31.64 ppm with the majority of sulfides <5 ppm, and an average concentration of 2.77 ppm (n=64). Assuming that this Pb concentration is representative of mantle sulfides, this implies that Pb is not dominantly held in sulfides in the upper mantle. Combination of in situ and bulk rock PGE analyses will be used to distinguish the effects of primary magmatic signatures (e.g., melt depletion, melt-rock interaction) and secondary processes such as serpentinization on the PGE-Re and chalcophile element systematics of these sulfides.

  7. Monolithic nanoscale photonics-electronics integration in silicon and other group IV elements

    CERN Document Server

    Radamson, Henry

    2014-01-01

    Silicon technology is evolving rapidly, particularly in board-to-board or chip-to chip applications. Increasingly, the electronic parts of silicon technology will carry out the data processing, while the photonic parts take care of the data communication. For the first time, this book describes the merging of photonics and electronics in silicon and other group IV elements. It presents the challenges, the limitations, and the upcoming possibilities of these developments. The book describes the evolution of CMOS integrated electronics, status and development, and the fundamentals of silicon p

  8. Controlled Synthesis of Polyions of Heavy Main-Group Elements in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Matthias F. Groh

    2016-09-01

    Full Text Available Ionic liquids (ILs have been proven to be valuable reaction media for the synthesis of inorganic materials among an abundance of other applications in different fields of chemistry. Up to now, the syntheses have remained mostly “black boxes”; and researchers have to resort to trial-and-error in order to establish a new synthetic route to a specific compound. This review comprises decisive reaction parameters and techniques for the directed synthesis of polyions of heavy main-group elements (fourth period and beyond in ILs. Several families of compounds are presented ranging from polyhalides over carbonyl complexes and selenidostannates to homo and heteropolycations.

  9. Lattice location of the group V elements As and Sb in ZnO

    CERN Document Server

    Wahl, Ulrich; Decoster, Stefan; Mendonça, Tânia

    2009-01-01

    The lattice locations of the potential p-type dopants arsenic and antimony in single-crystalline ZnO were studied by means of the electron emission channeling method following the implantation of radioactive $^{73}$As and $^{124}$Sb isotopes. The majority of the implanted As and Sb probe atoms was found to occupy substitutional Zn sites, with the possible fraction on substitutional O sites being at maximum a few percent. The obtained results illustrate the difficulty in introducing oversized group V impurities on O sites and thus put further into question whether these elements may act as simple chemical dopants in ZnO.

  10. Lattice location of the group V elements As and Sb in ZnO

    CERN Document Server

    Wahl, U; Decoster, S; Mendonca, T; 10.1016/j.physb.2009.08.174

    2009-01-01

    The lattice locations of the potential p-type dopants arsenic and antimony in single-crystalline ZnO were studied by means of the electron emission channeling method following the implantation of radioactive 73As and 124Sb isotopes. The majority of the implanted As and Sb probe atoms was found to occupy substitutional Zn sites, with the possible fraction on substitutional O sites being at maximum a few percent. The obtained results illustrate the difficulty in introducing oversized group V impurities on O sites and thus put further into question whether these elements may act as simple chemical dopants in ZnO.

  11. Investigation of group IVA elements combined with HAXPES and first-principles calculations

    Science.gov (United States)

    Cui, Y.-T.; Li, G.-L.; Oji, H.; Son, J.-Y.

    2014-04-01

    The core level and valence band spectra of group IVA elements were investigated with hard x-ray photoemission spectroscopy (HAXPES) photon energy of 7.939 keV by bulk sensitive manner. The survey and valance band spectra were presented, relative peaks intensity are discussed by thinking about inelastic mean free path (IMFP) and photoionization cross section of photoelectrons (PICS). In order to understand bulk band structures, valence bands are compared with the calculated ones by considering PICS, IMFP and total energy resolution. The calculated results by GGA, HSE06 and GW0 methods are simply discussed by comparing with experiment spectra.

  12. Variations in vanadium, nickel and lanthanoid element concentrations in urban air

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Teresa, E-mail: teresa.moreno@idaea.csic.es [Institute of Environmental Assessment and Water Research, IDAEA, CSIC, C/ Jordi Girona 18, 08034 Barcelona (Spain); Querol, Xavier; Alastuey, Andres [Institute of Environmental Assessment and Water Research, IDAEA, CSIC, C/ Jordi Girona 18, 08034 Barcelona (Spain); Rosa, Jesus de la [University of Huelva, University Campus El Carmen, 21071 Huelva (Spain); Sanchez de la Campa, Ana Maria [University of Huelva, University Campus El Carmen, 21071 Huelva (Spain); Estacion Experimental del Zaidin, CSIC, C/ Profesor Albareda 1, 18008 Granada (Spain); Minguillon, MariCruz; Pandolfi, Marco [Institute of Environmental Assessment and Water Research, IDAEA, CSIC, C/ Jordi Girona 18, 08034 Barcelona (Spain); Gonzalez-Castanedo, Yolanda [University of Huelva, University Campus El Carmen, 21071 Huelva (Spain); Monfort, Eliseo [Instituto de Tecnologia Ceramica, Campus Riu Sec, Universitat Jaume I, 12006 Castellon (Spain); Gibbons, Wes [AP 23075, Barcelona 08080 (Spain)

    2010-09-15

    The emission of trace metal pollutants by industry and transport takes place on a scale large enough to alter atmospheric chemistry and results in measurable differences between the urban background of inhalable particulate matter (PM) in different towns. This is particularly well demonstrated by the technogenic release into the atmosphere of V, Ni, and lanthanoid elements. We compare PM concentrations of these metals in large datasets from five industrial towns in Spain variously influenced by emissions from refinery, power station, shipping, stainless steel, ceramic tiles and brick-making. Increased La/Ce values in urban background inhalable PM, due to La-contamination from refineries and their residual products (fuel oils and petcoke), contrast with Ce-rich emissions from the ceramic related industry, and clearly demonstrate the value of this ratio as a sensitive and reliable tracer for many point source emissions. Similarly, anomalously high V/Ni values (> 4) can detect the influence of nearby high-V petcoke and fuel oil combustion, although the use of this ratio in urban background PM is limited by overlapping values in natural and anthropogenic materials. Geochemical characterisation of urban background PM is a valuable compliment to the physical monitoring of aerosols widely employed in urban areas, especially given the relevance of trace metal inhalation to urban health issues.

  13. Trace elements concentrations in aquatic biota from the Iron Gates wetlands in Romania

    Directory of Open Access Journals (Sweden)

    Matache M. L.

    2013-04-01

    Full Text Available Concentration of four heavy metals was studied in living organisms from the wetlands ecosystems within the Iron Gates Natural Park in Romania. Samples included aquatic plants (Ceratophyllum ssp., Potamogeton pectinatus, Potamogeton natans, molluscs (Sinanodonta woodiana, Unio tumidus, Unio pictorum and fish (Silurus glanis, Sander lucioperca, Aspius aspius, Cyprinus carpio, Carassius gibelio. Metals organotropism in fish samples (gills, liver, muscle, eggs has been studied (Kojadinovici et al., 2007; Foata et. Al, 2009; Dutton and Fisher, 2011; David et al., 2012. Metal contamination of the wetlandecosystems in the Iron Gates Natural Park has been documented in the past for sediments (Matache et. al, 2002 and soils (Matache et al., 2003. This is a consequence of the mining and quarrying activities performed in the Moldova Noua region between 1960’s and 2000’s. Zinc is the main metal contaminant in all categories of collected samples. For fish muscle tissue (part of the fish mainly consumed by the local inhabitants, comparison with EU standards has been performed. Issues related to human health appear especially for cadmium (EC, 2006. Potamogeton pectinatus is the least accumulating plant species, whilst Potamogeton natans and Ceratophyllum ssp. had shown similar accumulation capacities of the trace elements.

  14. How reliable are environmental data on 'orphan' elements? The case of bismuth concentrations in surface waters.

    Science.gov (United States)

    Filella, Montserrat

    2010-01-01

    Like all elements of the periodic table, bismuth is ubiquitously distributed throughout the environment as a result of natural processes and human activities. It is present as Bi(III) in environmental, biological and geochemical samples. Although bismuth and its compounds are considered to be non-toxic to humans, its increasing use as a replacement for lead has highlighted how little is known about its environmental and ecotoxicological behaviour. In this first critical review paper on the existing information on bismuth occurrence in natural waters, 125 papers on fresh and marine waters have been collated. Although the initial objective of this study was to establish the range of the typical concentrations of total dissolved bismuth in natural waters, this proved impossible to achieve due to the wide, and hitherto unexplained, dispersion of published data. Since analytical limitations might be one of the reasons underlying value dispersion, new analytical methods published since 2000--intended to be applied to natural waters--have also been reviewed. Disappointingly, the detection limits of the bulk of them are well above those required; they are thus of limited usefulness. Analysis of the existing information on bismuth in secondary references (i.e., books, review chapters) and on its chemical speciation in seawater revealed that the uncritical reproduction of old data is a widespread practice.

  15. A new structure of two-dimensional allotropes of group V elements

    Science.gov (United States)

    Li, Ping; Luo, Weidong

    2016-05-01

    The elemental two-dimensional (2D) materials such as graphene, silicene, germanene, and black phosphorus have attracted considerable attention due to their fascinating physical properties. Structurally they possess the honeycomb or distorted honeycomb lattices, which are composed of six-atom rings. Here we find a new structure of 2D allotropes of group V elements composed of eight-atom rings, which we name as the octagonal tiling (OT) structure. First-principles calculations indicate that these allotropes are dynamically stable and are also thermally stable at temperatures up to 600 K. These allotropes are semiconductors with band gaps ranging from 0.3 to 2.0 eV, thus they are potentially useful in near- and mid-infrared optoelectronic devices. OT-Bi is also a 2D topological insulator (TI) with a band gap of 0.33 eV, which is the largest among the reported elemental 2D TIs, and this gap can be increased further by applying compressive strains.

  16. Concentrations of trace elements in a rare and threatened coastal shark from the Arabian Gulf (smoothtooth blacktip Carcharhinus leiodon).

    Science.gov (United States)

    Moore, Alec B M; Bolam, Thi; Lyons, Brett P; Ellis, Jim R

    2015-11-30

    Kuwait's waters are one of only two locations where the smoothtooth blacktip shark Carcharhinus leiodon is known to occur. Concentrations of 11 trace elements were analysed in five juvenile and two adult specimens of this coastal predator. Concentrations of lead in muscle increased with length, whilst manganese concentration decreased. Arsenic concentrations in muscle were among the highest reported in elasmobranchs, and the concentration in the liver increased significantly in relation to length. In comparison to published literature, concentrations of manganese (liver), lead (muscle) and iron (muscle and liver) were high. Mercury concentrations in the muscle exceeded European Food Safety Authority limits and were among the highest reported in any elasmobranch. Concentrations of selenium, which may inhibit mercury toxicity, were also high. These results and previous studies indicate that potentially hazardous levels of mercury and other contaminants may occur in sharks in this region, adding further stressors to these vulnerable populations.

  17. Influence of Photosensitive Group Concentration on Birefringence Induced in Benzaldehyde Polymers

    Science.gov (United States)

    Mahilny, U. V.; Stankevich, A. I.; Trofimova, A. V.

    2014-01-01

    Induction of optical anisotropy in benzaldehyde polymer layers by linearly polarized UV radiation was investigated experimentally. Negative dichroism in absorption spectra and strong negative birefringence (-2 · 10-3) were related to the presence of an oriented ensemble of residual benzaldehyde groups. The thermal stability of photoinduced birefringence at high photosensitive group concentration was associated with a high density of photocross-links formed between macromolecules.

  18. Essential and toxic element concentrations in blood and urine and their associations with diet: Results from a Norwegian population study including high-consumers of seafood and game

    Energy Technology Data Exchange (ETDEWEB)

    Birgisdottir, B.E.; Knutsen, H.K.; Haugen, M.; Gjelstad, I.M. [Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo (Norway); Jenssen, M.T.S. [Norwegian Institute for Water Research, Oslo (Norway); Ellingsen, D.G.; Thomassen, Y. [National Institute of Occupational Health, Oslo (Norway); Alexander, J. [Office of the Director-General, Norwegian Institute of Public Health, Oslo (Norway); Meltzer, H.M. [Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo (Norway); Brantsæter, A.L., E-mail: Anne.Lise.Brantsaeter@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, Oslo (Norway)

    2013-10-01

    The first aim of the study was to evaluate calculated dietary intake and concentrations measured in blood or urine of essential and toxic elements in relation to nutritional and toxicological reference values. The second aim was to identify patterns of the element concentrations in blood and urine and to identify possible dietary determinants of the concentrations of these elements. Adults with a known high consumption of environmental contaminants (n = 111), and a random sample of controls (n = 76) answered a validated food frequency questionnaire (FFQ). Complete data on biological measures were available for 179 individuals. Blood and urine samples were analyzed for selenium, iodine, arsenic, mercury, cadmium and lead. Principal component analysis was used to identify underlying patterns of correlated blood and urine concentrations. The calculated intakes of selenium, iodine, inorganic arsenic and mercury were within guideline levels. For cadmium 24% of the high consumer group and 8% of the control group had intakes above the tolerable weekly intake. Concentrations of lead in blood exceeded the bench-mark dose lower confidence limits for some participants. However, overall, the examined exposures did not give rise to nutritional or toxicological concerns. Game consumption was associated with lead in blood (B{sub ln} 0.021; 95%CI:0.010, 0.031) and wine consumption. Seafood consumption was associated with urinary cadmium in non-smokers (B{sub ln} 0.009; 95%CI:0.003, 0.015). A novel finding was a distinct pattern of positively associated biological markers, comprising iodine, selenium, arsenic and mercury (eigenvalue 3.8), reflecting seafood intake (B 0.007; 95%CI:0.004, 0.010). The study clearly demonstrates the significance of seafood as a source of both essential nutrients and toxic elements simultaneously and shows that exposure to various essential and toxic elements can be intertwined. - Highlights: • A study on interplay and sources of six different

  19. Hepatic and renal concentrations of 10 trace elements in crocodiles (Crocodylus niloticus) in the Kafue and Luangwa rivers in Zambia.

    Science.gov (United States)

    Almli, Bjørn; Mwase, Maxwell; Sivertsen, Tore; Musonda, Mike M; Flåøyen, Arne

    2005-01-20

    Hepatic and renal concentrations of the elements arsenic, cadmium, cobalt, copper, lead, manganese, mercury, molybdenum, selenium and zinc were determined in samples collected from four crocodiles from the Kafue River, Kafue National Park and five crocodiles from the Luangwa River, Luangwa National Park, Zambia. The concentrations of the essential elements were similar to those reported in other vertebrates. Arsenic and cadmium concentrations were low (medians below 0.05 microg As/g and below 0.16 microg Cd/g, wet wt.). Mercury and lead concentrations were several orders of magnitude higher (medians up to 3.7 microg Hg/g, and up to 8.7 microg Pb/g, all wet wt.) than in hippopotami from the same rivers, probably as a result of food-chain biomagnification. Judging by the results obtained in this study, pollution from the mining activity around the Kafue River drainage area in the Copperbelt region has not significantly influenced the trace element concentrations in tissues of the crocodiles in the Kafue National Park. The trace element concentrations measured may serve as reference values in future studies on crocodilians.

  20. Hepatic and renal concentrations of 10 trace elements in crocodiles (Crocodylus niloticus) in the Kafue and Luangwa rivers in Zambia

    Energy Technology Data Exchange (ETDEWEB)

    Almli, Bjorn [National Veterinary Institute, POB 8156 Dep., N-0033 Oslo (Norway)]. E-mail: bjorn.almli@vetinst.no; Mwase, Maxwell [Samora Machel School of Veterinary Medicine, University of Zambia, POB 32379, Lusaka (Zambia); Sivertsen, Tore [Norwegian School of Veterinary Science, POB 8146 Dep., N-0033 Oslo (Norway); Musonda, Mike [Samora Machel School of Veterinary Medicine, University of Zambia, POB 32379, Lusaka (Zambia); Flaoyen, Arne [National Veterinary Institute, POB 8156 Dep., N-0033 Oslo (Norway); Norwegian School of Veterinary Science, POB 8146 Dep., N-0033 Oslo (Norway)

    2005-01-20

    Hepatic and renal concentrations of the elements arsenic, cadmium, cobalt, copper, lead, manganese, mercury, molybdenum, selenium and zinc were determined in samples collected from four crocodiles from the Kafue River, Kafue National Park and five crocodiles from the Luangwa River, Luangwa National Park, Zambia. The concentrations of the essential elements were similar to those reported in other vertebrates. Arsenic and cadmium concentrations were low (medians below 0.05 {mu}g As/g and below 0.16 {mu}g Cd/g, wet wt.). Mercury and lead concentrations were several orders of magnitude higher (medians up to 3.7 {mu}g Hg/g, and up to 8.7 {mu}g Pb/g, all wet wt.) than in hippopotami from the same rivers, probably as a result of food-chain biomagnification. Judging by the results obtained in this study, pollution from the mining activity around the Kafue River drainage area in the Copperbelt region has not significantly influenced the trace element concentrations in tissues of the crocodiles in the Kafue National Park. The trace element concentrations measured may serve as reference values in future studies on crocodilians.

  1. Element concentrations in mosses and surface waters of western Canadian mires relative to precipitation chemistry and hydrology

    Energy Technology Data Exchange (ETDEWEB)

    Malmer, N. (Dept. of Ecology, Plant Ecology, Lund Univ., Lund (SE)); Horton, D.G. (Dept. of Botany, the Univ. of Iowa, Iowa City (US)); Vitt, D.H. (Dept. of Botany, the Univ. of Alberta, Edmonton, Alberta (CA))

    1992-01-01

    Concentrations of N, P, S, Na, K, Mg, Ca, Mn, Fe, Cu, Cd, Zn, Pb, Al, and AIA (acid insoluble ash) in mosses (three Sphagnum species and Tomenthypnum nitens, all hummock species) from a variety of mires, both ombrotrophic and minerotrophic, in the coastal western and central parts of Canada are considered in relation to surface water pH and concentrations of Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Cl{sup -}, and SO{sub 4}{sup 2-}. Distinct west-east concentration gradients were present for most elements in both mosses and water, but there were correlations between surface water and moss concentrations only for Ca and Mg. On ombrotrophic sites and sites characterized by poor fen vegetation, wet deposition is the main source of elements in the surface water. On rich fen sites, additional Ca and Mg from surrounding soils change the elemental proportions. We conclude that hydrochemically the limit between poor and rich fen sites is more decisive than between bog and fen. The increase in Ca may give brown mosses a competitive advantage over Sphagnum. Moss concentrations of Na and Mg are the only ones decreasing inland. The constancy or inland increase of moss elemental concentrations may depend on either an increasing atmospheric supply (e.g. Pb), differences in moss growth rates (Especially N, P, and K) or site conditions related to the water regime (e.g. Fe and Al). (au).

  2. Matrix exponentials, SU(N) group elements, and real polynomial roots

    CERN Document Server

    Van Kortryk, T S

    2015-01-01

    The exponential of an NxN matrix can always be expressed as a matrix polynomial of order N-1. In particular, a general group element for the fundamental representation of SU(N) can be expressed as a matrix polynomial of order N-1 in a traceless NxN hermitian generating matrix, with polynomial coefficients consisting of elementary trigonometric functions dependent on N-2 invariants in addition to the group parameter. These invariants are just angles determined by the direction of a real N-vector whose components are the eigenvalues of the hermitian matrix. Equivalently, the eigenvalues are given by projecting the vertices of an (N-1)-simplex onto a particular axis passing through the center of the simplex. The orientation of the simplex relative to this axis determines the angular invariants and hence the real eigenvalues of the matrix.

  3. Non-essential and essential trace element concentrations in meat from cattle reared under organic, intensive or conventional production systems.

    Science.gov (United States)

    Blanco-Penedo, I; López-Alonso, M; Miranda, M; Hernández, J; Prieto, F; Shore, R F

    2010-01-01

    We evaluated if differences in non-essential and essential trace element accumulation in beef-cattle reared under different systems (including organic, conventional and intensive management) were reflected in the meat derived from these animals. Diaphragm muscle from 166 calves from nine farms were analysed. Muscle cadmium concentrations were low (organ concentrations that better reflect exposure), except for cobalt (positive association) and zinc (negative association). Non-essential and essential trace element concentrations in muscle in the studied animals did not generally reflect differences in exposure. This is particularly relevant for animals reared in systems (such as organic farms) where cattle are exposed to higher levels of non-essential elements (probably due to soil ingestion when grazing) but also can suffer from mineral deficiencies.

  4. Concentrations and health risk assessment of rare earth elements in vegetables from mining area in Shandong, China.

    Science.gov (United States)

    Zhuang, Maoqiang; Zhao, Jinshan; Li, Suyun; Liu, Danru; Wang, Kebo; Xiao, Peirui; Yu, Lianlong; Jiang, Ying; Song, Jian; Zhou, Jingyang; Wang, Liansen; Chu, Zunhua

    2017-02-01

    To investigate the concentrations of rare earth elements in vegetables and assess human health risk through vegetable consumption, a total of 301 vegetable samples were collected from mining area and control area in Shandong, China. The contents of 14 rare earth elements were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The total rare earth elements in vegetables from mining and control areas were 94.08 μg kg(-1) and 38.67 μg kg(-1), respectively, and the difference was statistically significant (p mining and control areas, respectively) and gourd vegetable had the lowest rare earth elements concentration (37.34 μg kg(-1) and 24.63 μg kg(-1) for mining and control areas, respectively). For both areas, the rare earth elements concentration in vegetables declined in the order of leaf vegetable > taproot vegetable > alliaceous vegetable > gourd vegetable. The rare earth elements distribution patterns for both areas were characterized by enrichment of light rare earth elements. The health risk assessment demonstrated that the estimated daily intakes (0.69 μg kg(-1) d(-1) and 0.28 μg kg(-1) d(-1) for mining and control areas, respectively) of rare earth elements through vegetable consumption were significantly lower than the acceptable daily intake (70 μg kg(-1) d(-1)). The damage to adults can be neglected, but more attention should be paid to the effects of continuous exposure to low levels of rare earth elements on children. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Lattice location of the group V elements Sb, As, and P in ZnO

    CERN Document Server

    Wahl, Ulrich; Mendonça, Tânia; Decoster, Stefan

    2010-01-01

    Modifying the properties of ZnO by means of incorporating antimony, arsenic or phosphorus impurities is of interest since these group V elements have been reported in the literature among the few successful p-type dopants in this technologically promising II-VI compound. The lattice location of ion-implanted Sb, As, and P in ZnO single crystals was investigated by means of the electron emission channeling technique using the radioactive isotopes $^{124}$Sb, $^{73}$As and $^{33}$P and it is found that they preferentially occupy substitutional Zn sites while the possible fractions on substitutional O sites are a few percent at maximum. The lattice site preference is understandable from the relatively large ionic size of the heavy mass group V elements. Unfortunately the presented results cannot finally settle the interesting issue whether substitutional Sb, As or P on oxygen sites or Sb$_{Zn}$−2V$_{Zn}$, As$_{Zn}$−2V$_{Zn}$ or P$_{Zn}$−2V$_{Zn}$ complexes (as suggested in the literature) are responsible f...

  6. Trace element concentrations in lichens collected in the Beskidy Mountains, the Outer Western Carpathians.

    Science.gov (United States)

    Klimek, Beata; Tarasek, Agata; Hajduk, Joanna

    2015-04-01

    The aim of the study was to assess trace metal air pollution in the Beskidy Mountains, the Outer Western Carpathians, Poland, with a widely used bioaccumulating organism, a lichen, Hypogymnia physodes. Lichens were collected at five stands (mountains) in parallel transect and analyzed for cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) content. Concentrations of Cd, Pb and Zn in lichens were elevated, indicating moderate air pollution. The studied sites grouped in two clusters, with the three more contaminated sites being at the west end of the transect, and the two less polluted sites being situated more eastward. Such a pattern can be explained by the location of industrial centers and prevailing wind direction in southern Poland. The strongest correlation was noticed between Zn and Pb, which are known to occur jointly in ore deposits and are being processed in nearby Polish and Czech industrial regions.

  7. Elemental concentrations in kidney and liver of mice fed with cafeteria or standard diet determined by particle induced X-ray emission

    Science.gov (United States)

    Leffa, Daniela Dimer; dos Santos, Carla Eliete Iochims; Debastiani, Rafaela; Amaral, Livio; Yoneama, Maria Lucia; Dias, Johnny Ferraz; Andrade, Vanessa Moraes

    2014-01-01

    The importance of trace elements in human health is well known and their main source is daily diet. Nowadays, one of the biggest issues is the presence of these micronutrients in levels much higher than required, leading to potential toxic effects. The aim of this work was to investigate the elemental content in organs of mice fed with cafeteria or standard diet using PIXE. Twelve male Swiss mice were divided into two groups: control group (standard chow) and cafeteria group (high-caloric diet). After 17 weeks, samples of different organs (kidney and liver) were collected and prepared for PIXE analysis. The Fe concentration in kidney and liver was statistically higher in animals that received the cafeteria diet (p cafeteria diet in relation to standard diet (p cafeteria diet in kidney, and for P, S and Zn (p < 0.005) in liver.

  8. Elevated trace element concentrations and standard metabolic rate in banded water snakes (Nerodia fasciata) exposed to coal combustion wastes

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, W.A.; Rowe, C.L.; Congdon, J.D. [Savannah River Ecology Laboratory, Aiken, SC (United States)

    1999-06-01

    Trace element concentrations in banded water snakes, Nerodia fasciata, and representative prey items from a site polluted by coal combustion wastes were compared with concentrations in conspecifics from a nearby reference site. Water snakes accumulated high concentrations of trace elements, especially arsenic (As) and selenium (Se), in the polluted habitat. In addition to being exposed to contaminants in water and sediments, snakes in the polluted site are exposed to contaminants by ingesting prey items that have elevated whole-body concentrations of trace elements, including As, cadmium (Cd), and Se. Snakes from the polluted site exhibited mean standard metabolic rates (SMR) 32% higher than snakes from the reference site. As a result, snakes from the polluted site appear to have elevated allocation of energy to maintenance and theoretically should have less energy available for growth, reproduction, and storage. It is hypothesized that long-term exposure to coal ash-derived trace elements and the resultant accumulation of some elements are responsible for observed increases in SMR.

  9. Oxo-group-14-element bond formation in binuclear uranium(V) Pacman complexes.

    Science.gov (United States)

    Jones, Guy M; Arnold, Polly L; Love, Jason B

    2013-07-29

    Simple and versatile routes to the functionalization of uranyl-derived U(V)-oxo groups are presented. The oxo-lithiated, binuclear uranium(V)-oxo complexes [{(py)3LiOUO}2(L)] and [{(py)3LiOUO}(OUOSiMe3)(L)] were prepared by the direct combination of the uranyl(VI) silylamide "ate" complex [Li(py)2][(OUO)(N")3] (N" = N(SiMe3)2) with the polypyrrolic macrocycle H4L or the mononuclear uranyl (VI) Pacman complex [UO2(py)(H2L)], respectively. These oxo-metalated complexes display distinct U-O single and multiple bonding patterns and an axial/equatorial arrangement of oxo ligands. Their ready availability allows the direct functionalization of the uranyl oxo group leading to the binuclear uranium(V) oxo-stannylated complexes [{(R3Sn)OUO}2(L)] (R = nBu, Ph), which represent rare examples of mixed uranium/tin complexes. Also, uranium-oxo-group exchange occurred in reactions with [TiCl(OiPr)3] to form U-O-C bonds [{(py)3LiOUO}(OUOiPr)(L)] and [(iPrOUO)2(L)]. Overall, these represent the first family of uranium(V) complexes that are oxo-functionalised by Group 14 elements.

  10. Elemental concentrations in the seed of mutants and natural variants of Arabidopsis thaliana grown under varying soil conditions.

    Directory of Open Access Journals (Sweden)

    Stephen C McDowell

    Full Text Available The concentrations of mineral nutrients in seeds are critical to both the life cycle of plants as well as human nutrition. These concentrations are strongly influenced by soil conditions, as shown here by quantifying the concentration of 14 elements in seeds from Arabidopsis thaliana plants grown under four different soil conditions: standard, or modified with NaCl, heavy metals, or alkali. Each of the modified soils resulted in a unique change to the seed ionome (the mineral nutrient content of the seeds. To help identify the genetic networks regulating the seed ionome, changes in elemental concentrations were evaluated using mutants corresponding to 760 genes as well as 10 naturally occurring accessions. The frequency of ionomic phenotypes supports an estimate that as much as 11% of the A. thaliana genome encodes proteins of functional relevance to ion homeostasis in seeds. A subset of mutants were analyzed with two independent alleles, providing five examples of genes important for regulation of the seed ionome: SOS2, ABH1, CCC, At3g14280 and CNGC2. In a comparison of nine different accessions to a Col-0 reference, eight accessions were observed to have reproducible differences in elemental concentrations, seven of which were dependent on specific soil conditions. These results indicate that the A. thaliana seed ionome is distinct from the vegetative ionome, and that elemental analysis is a sensitive approach to identify genes controlling ion homeostasis, including those that regulate gene expression, phospho-regulation, and ion transport.

  11. Trace element concentrations in skin of free-ranging bottlenose dolphins (Tursiops truncatus) from the southeast Atlantic coast.

    Science.gov (United States)

    Stavros, Hui-Chen W; Bossart, Gregory D; Hulsey, Thomas C; Fair, Patricia A

    2007-12-15

    Concentrations of trace elements (Al, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sb, Se, Sn, Tl, U, V, Zn) and total mercury (THg) were determined in skin samples collected from free-ranging bottlenose dolphin (Tursiops truncatus) populations. Dolphins were captured in the estuarine waters of Charleston (CHS), South Carolina (n=74) and the Indian River Lagoon (IRL), Florida (n=75) during 2003, 2004 and 2005. A subset of the skin tissue samples were used to determine methylmercury (MeHg) levels in CHS (n=17) and IRL (n=8) bottlenose dolphins. Distributions of trace element concentrations by age (adult vs. juvenile), gender (male vs. female) and study area (CHS vs. IRL) were examined. In general, higher elemental skin concentrations were found in CHS adult males than those of IRL adult males, except for THg and MeHg. For CHS dolphins, adult females showed significantly higher THg levels than juvenile females while higher Mn levels were found in juvenile females. For IRL dolphins, adult males showed significantly higher As concentrations than that in juvenile males and females while higher Co and V levels were found in juvenile males than adult males. Of all elements measured in this study, significantly higher levels of Fe, Se and Zn concentrations in skin tissue of both dolphin populations were similar to other studies reported previously. Percentage of MeHg/THg in skin tissue of CHS and IRL dolphin was about 72% and 73%, respectively. Dietary levels of trace elements may play an important role in contributing to concentration differences for As, Co, Mn, Sb, Se, THg and Tl between CHS and IRL dolphins. Total Hg concentrations were significantly correlated with the age of CHS dolphins, while an inverse relationship was detected for Cu, Mn, Pb, U and Zn. The only significant correlation found between trace element concentration and IRL dolphins' age was Mn. Geographic differences in several trace element concentrations (As, Co, Mn, Sb, Se, THg and Tl) in skin

  12. Controls on Highly Siderophile Element Concentrations in Martian Basalt: Sulfide Saturation and Under-Saturation

    Science.gov (United States)

    Righter, Kevin

    2009-01-01

    Highly siderophile elements (HSE; Re, Au and the platinum group elements) in shergottites exhibit a wide range from very high, similar to the terrestrial mantle, to very low, similar to sulfide saturated mid ocean ridge basalt (e.g., [1]). This large range has been difficult to explain without good constraints on sulfide saturation or under-saturation [2]. A new model for prediction of sulfide saturation places new constraints on this problem [3]. Shergottite data: For primitive shergottites, pressure and temperature estimates are between 1.2-1.5 GPa, and 1350-1470 C [4]. The range of oxygen fugacities is from FMQ-2 to IW, where the amount of Fe2O3 is low and thus does not have a significant effect on the S saturation values. Finally, the bulk compositions of shergottites have been reported in many recent studies (e.g., [5]). All of this information will be used to test whether shergottites are sulfide saturated [3]. Modeling values and results: The database for HSE partition coefficients has been growing with many new data for silicates and oxides [6-8] to complement a large sulfide database [9- 11]. Combining these data with simple batch melting models allows HSE contents of mantle melts to be estimated for sulfide-bearing vs. sulfide-free mantle. Combining such models with fractional crystallization modeling (e.g., [12]) allows HSE contents of more evolved liquids to be modeled. Most primitive shergottites have high HSE contents (and low S contents) that can be explained by sulfide under-saturated melting of the mantle. An exception is Dhofar 019 which has high S contents and very low HSE contents suggesting sulfide saturation. Most evolved basaltic shergottites have lower S contents than saturation, and intermediate HSE contents that can be explained by olivine, pyroxene, and chromite fractionation. An exception is EET A79001 lithology B, which has very low HSE contents and S contents higher than sulfide saturation values . evidence for sulfide saturation

  13. Concentration homeostasis and elements in hair and dried serum observed by X-ray fluorescence analysis using synchrotron radiation.

    Science.gov (United States)

    Chikawa, Jun-ichi; Mouri, Yoshitaka; Shima, Hiroki; Yamada, Kousaku; Yamamoto, Hitoshi; Yamamoto, Shingo

    2014-01-01

    Elemental concentrations in hair and dried serum have been evaluated by X-ray fluorescence analysis using relative concentration independent of specimen thickness. Dried serum samples from 5 male and 5 female subjects given two-week Ca supplementation showed the same concentration for Ca, and for each of the other elements Cl, K, S and P under renal control by parathyroid hormone (PTH). Hair concentrations of these elements have been evaluated for 50 randomly-selected females aged between 30 and 80. It was found that each element has two distinct levels in hair. The content of an element in growing hair must be equal to the inflow of that element into the hair-making cells from serum. Using this principle, the two levels can be attributed to the gating and closing of the ion channels in cell membranes and given as functions of the dried serum standard concentrations. Especially, the difference between [Ca] and [Sr] in hair shows whether Ca channels are gating or closing. The lower level of hair [Ca]_H is normal and is equal to 1/2 of the dried serum [Ca]; only the Ca on serum protein is to be incorporated into the hair in steady-state growth. Store-operated Ca channel gating occurs so as to maintain the normal [Ca]_H. The higher level is seen in cases of calcium deficiency, and implicated in other disease states. Prolonged Ca deficiency causes a higher hair [Ca]_H with Ca channel closing. PTH-operated Ca channel gating induces the Ca^{2+} inflow into the cells to form the hair [Ca]_H upper level and to deteriorate cell functions such as excretion of excess metals by hepatocytes. Hair analysis provides a new diagnostic tool based on cell ion channels.

  14. Poverty concentration and determinants in China's urban low-income neighbourhoods and social groups.

    Science.gov (United States)

    He, Shenjing; Wu, Fulong; Webster, Chris; Liu, Yuting

    2010-01-01

    Based on a large-scale household survey conducted in 2007, this article reports on poverty concentration and determinants in China's low-income neighbourhoods and social groups. Three types of neighbourhood are recognized: dilapidated inner-city neighbourhoods, declining workers' villages and urban villages. Respondents are grouped into four categories: working, laid-off/unemployed and retired urban residents, together with rural migrants. We first measure poverty concentration across different types of neighbourhood and different groups. The highest concentrations are found in dilapidated inner-city neighbourhoods and among the laid-off/unemployed. Mismatches are found between actual hardships, sense of deprivation and distribution of social welfare provision. Second, we examine poverty determinants. Variations in institutional protection and market remuneration are becoming equally important in predicting poverty generation, but are differently associated with it in the different neighbourhoods and groups. As China's urban economy is increasingly shaped by markets, the mechanism of market remuneration is becoming a more important determinant of poverty patterns, especially for people who are excluded from state institutions, notably laid-off workers and rural migrants.

  15. Variations in Concentration and Distribution of Health-Related Elements Affected by Environmental and Genotypic Differences in Rice Grains

    Institute of Scientific and Technical Information of China (English)

    REN Xue-liang; LIU Qing-long; WU Dian-xing; SHU Qing-yao

    2006-01-01

    A research work was conducted to investigate the variations in concentration and distribution of health-related elements affected by environmental and genotypic differences in rice grains. The grain of Xieqingzao B (indica rice variety) and Xiushui 110 (japonica rice variety) were divided into: hull, bran and milled rice, based on the conventional rice consumption and process. Xieqingzao B was grown at four different locations, and at one location, it was planted in the same field and season as Xiushui 110. In addition, another four indica and four japonica varieties were cultivated in the same field and time to analyze the elements in milled rice. The average concentrations of total P and phytic acid P were the highest in the bran, followed by milled rice and hull; Zn, K, Mg, and As concentrations were the highest in bran, followed by hull and milled rice, while Fe, Ca, and Cu concentrations were the highest in the hull, but similar in bran and milled rice. The result indicated that genotype and environment significantly affected the concentrations of all the tested elements, while the distribution of the above elements in grains was not in the same order as concentration. Moreover, all the elements except 97.7% of Cu and 93.2% of Fe was deposited in the hull on average, were mostly distributed either in the bran (37.3% and 57.7% for K and phytic acid P) or in milled rice (41.7%, 42.6%, 40.3%, 49.8% for Zn, Mg, As, total P, respectively).

  16. The impact of the hyperacid Ijen Crater Lake. Part I: Concentrations of elements in crops and soil.

    Science.gov (United States)

    Heikens, Alex; Widianarko, Budi; Dewi, Inge C; De Boer, Jan L M; Seinen, Willem; van Leeuwen, Kees

    2005-09-01

    In Asembagus (East Java, Indonesia) irrigation water is contaminated with effluent from the hyperacid Ijen Crater Lake resulting in a low pH and high levels of various elements. As a first step towards a risk assessment, locally produced food items (rice, maize, cassava leaf, cassava root, peanuts) were collected and concentrations of As, B, Ca, Cd, Co, Cu, Fe, Mg, Mn, Mo, Ni, Pb, V, Zn were compared to samples from a reference area and with literature values. Further, concentrations in rice were compared to total soil concentrations in paddy fields. Compared to the reference area, food items produced in the contaminated area had increased levels of Cd, Co, Ni and Mn in particular, while levels of Mo were lower. In contrast, total soil concentrations of Cd and Mn in particular have decreased whereas especially Mo was increased. In combination with the observed soil acidification, it is likely that the bioavailable concentration of most elements in the contaminated soil is higher (except for Mo) due to an increased weathering rate and/or input via the contaminated irrigation water. In terms of human health, concentrations in foods were generally within normal literature values. However, it was observed that essential elements (in particular Fe) known for their inhibitory effects on e.g. Cd and Mn toxicity did not accumulate in crops whereas Cd and Mn did.

  17. Concentrations of 17 elements in muscle, gills, liver and gonads of five economically important fish species from the Danube River

    Directory of Open Access Journals (Sweden)

    Lenhardt M.

    2013-01-01

    Full Text Available The Danube River in the vicinity of the city of Belgrade receives large amounts of untreated or poorly treated communal and industrial waste waters. The aim of this study was to assess elemental accumulation patterns in a number of economically important fish species in this area that belong to different trophic levels. Concentrations of 17 elements (Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Se, Sr and Zn were assessed in liver, muscle, gills and gonads of silver carp (Hypophthalmichthys molitrix, freshwater bream (Abramis brama, white bream (Blicca bjoerkna, common carp (Cyprinus carpio and wels catfish (Silurus glanis from the Danube River in Serbia by the use of ICP-OES. Silver carp specimens were differentiated from the other four species by high concentrations of Al and Fe in the liver. Common carp specimens were differentiated by high concentrations of Zn in gills, muscle and liver. Distribution of elements among different tissues had a consistent pattern among the species. Concentrations of Pb, Cd, As, Zn, Cu and Fe in muscle were at acceptable levels for human consumption, while concentrations of Fe and Zn were above maximum acceptable concentrations in liver and gonads.

  18. Trace element concentrations in eggshells and egg contents of black-tailed gull (Larus crassirostris) from Korea.

    Science.gov (United States)

    Kim, Jungsoo; Oh, Jong-Min

    2014-09-01

    Concentrations of trace elements (cadmium, lead, copper, manganese and zinc) were examined in eggs of black-tailed gulls (Larus crassirostris) from Hongdo Island, Korea to determine the difference and distribution of trace elements in eggshells and egg contents. Cadmium, lead and manganese concentrations were greater in eggshells than in egg contents. In contrast, zinc concentrations were higher in egg contents than in eggshells. Trace element concentrations followed the order: zinc > lead = manganese = copper > cadmium (eggshells) and zinc > copper > manganese > lead > cadmium (egg contents). Cadmium concentrations were relatively low (contents and eggshells. Concentrations of cadmium, lead and copper were significantly correlated between egg contents and eggshells. This indicates that cadmium, lead and copper levels in the eggshell can reflect their levels in the egg contents. There was also a high ratio (3.2) of eggshell/egg content for lead. These results indicate that the eggshell might be useful as a bio-indicator for monitoring cadmium, lead and copper in the egg content.

  19. Comparative analysis of element concentrations and translocation in three wetland congener plants: Typha domingensis, Typha latifolia and Typha angustifolia.

    Science.gov (United States)

    Bonanno, Giuseppe; Cirelli, Giuseppe Luigi

    2017-09-01

    This study analyzed the concentrations and distributions of Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn in three different cattail species growing spontaneously in a natural wetland subject to municipal wastewater and metal contamination. The cattail species included Typha domingensis, T. latifolia and T. angustifolia. Results showed that all Typha species have similar element concentrations in roots, rhizomes and leaves, and similar element mobility from sediments to roots and from roots to leaves. This study corroborated three patterns of Typha species growing in metal contaminated environments: high tolerance to toxic conditions, bulk element concentrations in roots, and restricted element translocation from roots to leaves. This study showed that three different Typha species respond similarly to metal inputs under the same polluting field conditions. Given their similar metal content and similar biomass size, our results suggest that T. domingensis, T. latifolia and T. angustifolia may have comparable capacity of phytoremediation. High element uptake and large biomass make Typha species some of the best species for phytoremediation of metal contaminated environments. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Study of Z > 18 elements concentration in tree rings from surroundings forests of the Mexico Valley using external beam PIXE

    Science.gov (United States)

    Calva-Vázquez, G.; Razo-Angel, G.; Rodríguez-Fernández, L.; Ruvalcaba-Sil, J. L.

    2006-08-01

    The concentration of elements with Z > 18 is measured in tree rings from forests at the surroundings of the Mexico Valley: El Chico National Park (ECP) and Desierto de los Leones National Park (DLP). The analysis was done by simultaneous PIXE-RBS using an external proton beam on tree rings of Pine and Sacred fir (species Pinus montezumae and Abies religiosa, respectively). This study provides information about the elemental concentration in trees of those parks during the years from 1965 to 2003. Typical elements such as K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr and Pb were detected using PIXE technique while the wood matrix composition (mainly C and O) was determined by RBS. In general, elemental contents present large variations but concentrations oscillate around the mean value during this period of time. Nevertheless, the measurements showed some trends for Fe and Zn in the tree-rings elemental composition that may be correlated to recent volcanic activities in the region. The low Mn contents indicate soil acidification in DLP from 1968 and the forest decline in ECP during the last 15 years.

  1. Study of Z > 18 elements concentration in tree rings from surroundings forests of the Mexico Valley using external beam PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Calva-Vazquez, G. [Laboratorio de Contaminacion Atmosferica, FES Zaragoza, UNAM, Calzada I. Zaragoza esq., Av. Guelatao s/n, 09230 Mexico, DF (Mexico); Razo-Angel, G. [Laboratorio de Contaminacion Atmosferica, FES Zaragoza, UNAM, Calzada I. Zaragoza esq., Av. Guelatao s/n, 09230 Mexico, DF (Mexico); Rodriguez-Fernandez, L. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, DF (Mexico); Ruvalcaba-Sil, J.L. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000 Mexico, DF (Mexico)]. E-mail: sil@fisica.unam.mx

    2006-08-15

    The concentration of elements with Z > 18 is measured in tree rings from forests at the surroundings of the Mexico Valley: El Chico National Park (ECP) and Desierto de los Leones National Park (DLP). The analysis was done by simultaneous PIXE-RBS using an external proton beam on tree rings of Pine and Sacred fir (species Pinus montezumae and Abies religiosa, respectively). This study provides information about the elemental concentration in trees of those parks during the years from 1965 to 2003. Typical elements such as K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr and Pb were detected using PIXE technique while the wood matrix composition (mainly C and O) was determined by RBS. In general, elemental contents present large variations but concentrations oscillate around the mean value during this period of time. Nevertheless, the measurements showed some trends for Fe and Zn in the tree-rings elemental composition that may be correlated to recent volcanic activities in the region. The low Mn contents indicate soil acidification in DLP from 1968 and the forest decline in ECP during the last 15 years.

  2. Nutrient and toxic element soil concentrations during repeated mineral and compost fertilization treatments in a Mediterranean agricultural soil.

    Science.gov (United States)

    Baldantoni, Daniela; Morra, Luigi; Saviello, Giovanni; Alfani, Anna

    2016-12-01

    Agricultural soils of semi-arid Mediterranean areas are often subjected to depletion of their chemical, physical, and biological properties. In this context, organic fertilization, in addition to providing nutrients for a longer time in respect to mineral fertilization, improves many other characteristics related to soil fertility. Moreover, the combined use of organic and mineral fertilizers may promote a more sustainable crop production. However, a concern on the long-term use of organic fertilizers arises in relation to the possible accumulation of toxic elements in soil and their transfer to human beings. For this reason, a long-term study on nutrient and toxic element total concentrations and availabilities during fertilization treatments was carried out. In particular, mineral NPK fertilized soils, soils amended with biowaste compost, soils amended with biowaste compost plus mineral nitrogen, and unfertilized soils were analyzed for 11 chemical elements. The results highlighted that temporal variations in total and bioavailable concentrations of both nutrients and toxic elements, occurring also in unfertilized soils, are wider than those related to fertilization treatments. Anyway, soil amendments with biowaste compost, alone or in combination with mineral fertilizers, reduce Cu bioavailability but improve K, Fe, Mn, and Zn availabilities, excluding at the same time a long-term accumulation in soil. Total and bioavailable toxic element concentrations (apart from available Cd) do not vary in relation to fertilization treatments.

  3. Association of Serum Concentration of Different Trace Elements with Biomarkers of Systemic Oxidant Status in Dairy Cattle.

    Science.gov (United States)

    Abuelo, Angel; Hernandez, Joaquín; Alves-Nores, Víctor; Benedito, José L; Castillo, Cristina

    2016-12-01

    There has been some recent criticism about the reliability of the assays commonly used to measure oxidant status in cattle, because some recent publications suggested that the concentration of different trace elements influences the results of these assays. The aim of this study was to test the correlation in 502 bovine serum samples between the concentration of several trace elements (Br, Co, Cr, Cu, Fe, I, Mn, Mo, Ni, Se, Sr, V and Zn) and markers of oxidant status (reactive oxygen species (ROS) and total serum antioxidant capacity (SAC)). The Oxidative Stress index (OSi) was also calculated as ROS/SAC. Some significant correlations were found, although weak (|ρ| < 0.50). Therefore, the relationships observed might be attributed to the different pro- and antioxidant effect of the different elements rather than to the assays detecting these elements instead of the oxidised molecules or total antioxidant potential, respectively. The OSi was poorly correlated (|ρ| ≤ 0.36) with the concentration of the studied trace elements, and therefore, its use is recommended to assess shifts in the systemic redox balance.

  4. Characteristics of platinum-group elements in basalts from spreading axis of Mariana Trough

    Institute of Scientific and Technical Information of China (English)

    CAO Zhimin; ZHENG Jianbin; ZHOU Meifu; AN Wei; QI Liang

    2007-01-01

    Total platinum-group elements (PGEs) abundances in basalts from the spreading axis of Mariana Trough ranged from 0.418 × 10-9 to 1.022 × 10-9, and primitive mantle-normalized PGE patterns are of positive slope showing the relative enrichment of PPGE (platinum, palladium, rhodium) and gold relative to IPGE. Compared with other mantle-originated rocks, these basalts have lower PGE contents and wider ranges of primitive mantle-normalized ratios of palladium content to iridium one, palladium content to platinum one and palladium content to gold one exhibiting relative platinum and iridium depletion. Characteristics of PGE patterns indicated that the studied Mariana Trough basalts originated from low partial melting, and the MORB mantle beneath the spreading center had been contaminated by the arc-island mantle. In the aspect of trace elements, Mariana Trough basalts showed the enrichment of LILE, lead and LREE, indicating that they had been influenced by subduction compositions. All these demonstrated that Mariana Trough basalts are products of partial melting from a mixed mantle ( the contamination of MORB mantle by arc-island mantle).

  5. Assessment of Bioavailable Concentrations of Germanium and Rare Earth Elements in the Rhizosphere of White Lupin (Lupinus albus L.)

    Science.gov (United States)

    Wiche, Oliver; Fischer, Ronny; Moschner, Christin; Székely, Balázs

    2015-04-01

    Concentrations of Germanium (Ge) and Rare Earth Elements in soils are estimated at 1.5 mg kg -1 (Ge), 25 mg kg -1 (La) and 20 mg kg -1 (Nd), which are only roughly smaller than concentrations of Pb and Zn. Germanium and rare earth elements are thus not rare but widely dispersed in soils and therefore up to date, only a few minable deposits are available. An environmental friendly and cost-effective way for Ge and rare earth element production could be phytomining. However, the most challenging part of a phytomining of these elements is to increase bioavailable concentrations of the elements in soils. Recent studies show, that mixed cultures with white lupine or other species with a high potential to mobilize trace metals in their rhizosphere due to an acidification of the soil and release of organic acids in the root zone could be a promising tool for phytomining. Complexation of Ge and rare earth elements by organic acids might play a key role in controlling bioavailability to plants as re-adsorption on soil particles and precipitation is prevented and thus, concentrations in the root zone of white lupine increase. This may also allow the complexes to diffuse along a concentration gradient to the roots of mixed culture growing species leading to enhanced plant uptake. However, to optimize mixed cultures it would be interesting to know to which extend mobilization of trace metals is dependent from chemical speciation of elements in soil due to the interspecific interaction of roots. A method for the identification of complexes of germanium and rare earth elements with organic acids, predominantly citric acid in the rhizosphere of white lupine was developed and successfully tested. The method is based on coupling of liquid chromatography with ICP-MS using a zic-philic column (SeQuant). As a preliminary result, we were able to show that complexes of germanium with citric acid exist in the rhizosphere of white lupin, what may contribute to the bioavailability of this

  6. Ab initio and DFT studies on vibrational spectra of some halides of group IIIB elements

    Science.gov (United States)

    Zhang, Yu; Zhao, Jianying; Tang, Guodong; Zhu, Longgen

    2005-11-01

    The vibrational spectra of some group IIIB elements halides MX 3 and their dimmers, M 2X 6 (M = Sc(III), Y(III), La(III); X = F, Cl, Br, I), have been systematically investigated by ab initio restricted Hartree-Fock (RHF) and density functional B3LYP methods with LanL2DZ and SDD basis sets. The optimized geometries and calculated vibrational frequencies are evaluated via comparison with experimental values. The vibrational frequencies, calculated by two methods with different basis sets, are compared to each other. The effect of the methods and the basis sets used on the calculated vibrational frequencies are discussed. Some vibrational frequencies of these complexes are also predicted.

  7. Dimers of heavy p-elements of groups IV-VI: Electronic, vibrational, and magnetic properties

    Science.gov (United States)

    Borisova, S. D.; Rusina, G. G.; Eremeev, S. V.; Chulkov, E. V.

    2016-04-01

    Equilibrium lengths and binding energies, vibrational frequencies, width of the HOMO-LUMO gap, and the magnetic anisotropy energies for one- and two-component dimers of heavy p elements of Groups IV (Sn, Pb), V (Sb, Bi), and VI (Se, Te) with a pronounced relativistic effect have been calculated with the use of the formalism of the density functional theory. It has been shown that it is necessary to take into account the spin-orbit coupling, which significantly affects the energy parameters of clusters. The analysis of the data obtained has revealed that the Pb-Te, Pb-Se, Sn-Te, and Sn-Se dimers have the widest gap at the Fermi level and the lowest reactivity. The magnetic anisotropy energy has been calculated for all single- and doublecomponent dimers and the direction of the easy magnetization axis has been determined.

  8. Elemental concentrations in scalp hair, nutritional status and health-related quality of life in hemodialysis patients.

    Science.gov (United States)

    Ochi, Akinobu; Ishimura, Eiji; Tsujimoto, Yoshihiro; Kakiya, Ryusuke; Tabata, Tsutomu; Mori, Katsuhito; Tahara, Hideki; Shoji, Tetsuo; Yasuda, Hiroshi; Nishizawa, Yoshiki; Inaba, Masaaki

    2012-04-01

    Elemental concentrations in hair from hemodialysis (HD) patients have not been well investigated. We examined the relationships between the elemental concentrations in scalp hair and health-related quality of life (HRQOL) and nutritional status in HD patients. Twenty six elemental concentrations were measured in scalp hair samples from 60 male HD patients using inductively-coupled plasma mass spectrometry. To evaluate HRQOL, the Short Form 36 item health survey (SF36) was used. As indices of nutritional status, body mass index, serum parameters, and geriatric nutritional risk index (GNRI) were used. Phosphorus correlated positively with serum creatinine, blood urea nitrogen (BUN), GNRI and the physical domains of the SF36. Zinc correlated positively with serum creatinine, BUN and the physical domains of the SF36. Mercury and arsenic correlated positively with BUN. Cadmium correlated negatively with serum albumin, BUN and GNRI. Copper correlated positively with the physical domains of the SF36. Iodine correlated negatively with the physical domains of the SF36. Selenium correlated negatively with the mental domains of the SF36. In conclusion, phosphorus and zinc concentrations in scalp hair can be additional biomarkers of HRQOL and/or nutritional status in HD patients. Cadmium accumulation correlated with malnutrition. Iodine and selenium accumulation may adversely affect HRQOL. Further investigation is necessary to determine precisely how these elements affect these measures.

  9. A potential dating technique using 228Th/228Ra ratio for tracing the chronosequence of elemental concentrations in plants.

    Science.gov (United States)

    Chao, J H; Niu, H; Chiu, C Y; Lin, C

    2007-06-01

    We propose a radiometric method based on measurement of the radioactivity of the naturally occurring radionuclides (228)Ra and 228)Th and the derived (228)Th/(228)Ra ratios in plant samples to estimate plant age and the corresponding nutritional conditions in a field-growing fern, Dicranopteris linearis. Plant age (tissue age) was associated with the (228)Th/(228)Ra ratio in fronds, which implies the accumulation time of immobile elements in the plant tissue or the life span of the fronds. Results indicated that the accumulation of alkaline earth elements in D. linearis is relatively constant with increased age, while the K concentration is reversed with age because of translocation among plant tissues. Estimation of dating uncertainty based on measurement conditions revealed that the radiometric technique can be applied to trace chronosequential changes of elemental concentrations and environmental pollutants in plants with ages of less than 10-15 years.

  10. Platinum group elements and gold in ferromanganese crusts from Afanasiy–Nikitin seamount, equatorial Indian Ocean: Sources and fractionation

    Indian Academy of Sciences (India)

    V K Banakar; J R Hein; R P Rajani; A R Chodankar

    2007-02-01

    The major element relationships in ferromanganese (Fe-Mn) crusts from Afanasiy-Nikitin seamount (ANS), eastern equatorial Indian Ocean, appear to be atypical. High positive correlations ( = 0.99) between Mn/Co and Fe/Co ratios, and lack of correlation of those ratios with Co, Ce, and Ce/Co, indicate that the ANS Fe-Mn crusts are distinct from Pacific seamount Fe-Mn crusts, and reflect region-specific chemical characteristics. The platinum group elements (PGE: Ir, Ru, Rh, Pt, and Pd) and Au in ANS Fe-Mn crusts are derived from seawater and are mainly of terrestrial origin, with a minor cosmogenic component. The Ru/Rh (0.5-2) and Pt/Ru ratios (7-28) are closely comparable to ratios in continental basalts, whereas Pd/Ir ratios exhibit values (> 2) similar to CI-chondrite (∼1). The chondrite-normalized PGE patterns are similar to those of igneous rocks, except that Pd is relatively depleted. The water depth of Fe-Mn crust formation appears to have a first-order control on both major element and PGE enrichments. These relationships are defined statistically by significant ( < 0.75) correlations between water depth and Mn/Co, Fe/Co, Ce/Co, Co, and the PGEs. Fractionation of the PGE-Au from seawater during colloidal precipitation of the major-oxide phases is indicated by well-defined linear positive correlations ( < 0.8) of Co and Ce with Ir, Ru, Rh, and Pt; Au/Co with Mn/Co; and by weak or no correlations of Pd with water depth, Co-normalized major-element ratios, and with the other PGE ( < 0.5). The strong enrichment of Pt (up to 1 ppm) relative to the other PGE and its positive correlations with Ce and Co demonstrate a common link for the high concentrations of all three elements, which likely involves an oxidation reaction on the Mn-oxide and Fe-oxyhydroxide surfaces. The documented fractionation of PGE-Au and their positive association with redox sensitive Co and Ce may have applications in reconstructing past-ocean redox conditions and water masses.

  11. Is the use of wildlife group-specific concentration ratios justified?

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Michael D. [School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Beresford, Nicholas A. [School of Environment and Life Sciences, University of Salford, Manchester, M4 4WT (United Kingdom); Centre for Ecology and Hydrology, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Copplestone, David [School of Natural Sciences, University of Stirling, Stirling, FK9 4LA (United Kingdom); Howard, Brenda J. [Centre for Ecology and Hydrology, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Yankovich, Tamara L. [International Atomic Energy Agency, Vienna International Centre, 1400 Vienna (Austria)

    2014-07-01

    The international Wildlife Transfer Database (WTD; www.wildlifetransferdatabase.org/?) provides the most comprehensive international compilation of radionuclide transfer parameters (concentration ratios) for wildlife. The concentration ratio (CR{sub wo-media}) is a constant that describes the ratio between the activity concentration of a radionuclide in the whole- organism and the activity concentration of that radionuclide in a reference environmental medium (e.g. soil or filtered water). Developed to support activities of the International Atomic Energy Agency (IAEA) and the International Commission on Radiological Protection (ICRP), the WTD now contains over 100,000 CR{sub wo-media} values. The WTD has been used to generate summary statistics for broad wildlife groups (e.g. amphibian, arthropod, mammal, reptile, shrub, tree etc). The group-specific summary statistics include mean and standard deviation (both arithmetic and geometric) and range. These summarised CR{sub wo-media} values (generally arithmetic or geometric mean) are used in most of the modelling approaches currently implemented for wildlife dose assessment. Beyond the broad organism group summary statistics presented within the WTD, it is possible to generate CR{sub wo-media} summary statistics for some organism sub-categories (e.g. carnivorous, herbivorous and omnivorous birds). However, using a statistical analysis we developed recently for the analysis of summarised datasets, we have shown that there is currently little statistical justification for the use of organism sub-category CR{sub wo-media} values. Large variability is a characteristic of many of the organism-radionuclide datasets within the WTD, even within individual input data sets. Therefore, the statistical validity of defining different CR{sub wo-media} values for these broad wildlife groups may also be questioned. However, no analysis has been undertaken to date to determine the statistical significance of any differences between

  12. Local anthropogenic impact on particulate elemental carbon concentrations at Summit, Greenland

    Directory of Open Access Journals (Sweden)

    G. S. W. Hagler

    2008-05-01

    Full Text Available Summit, Greenland is a remote Arctic research station allowing for field measurements at the highest point of the Greenland Ice Sheet. Due to the current reliance on diesel generators for electricity at Summit, unavoidable local emissions are a potential contamination threat to the measurement of combustion-related species in the air and snow. The effect of fossil-fuel combustion on particulate elemental carbon (EC is assessed by a combination of ambient measurements (~1 km from the main camp, a series of snow pits, and Gaussian plume modeling. Ambient measurements indicate that the air directly downwind of the research station generators experiences particulate absorption coefficient (closely related to EC values that are up to a factor of 200 higher than the summer 2006 non-camp-impacted ambient average. Local anthropogenic influence on snow EC content is also evident. The average EC concentration in 1-m snow pits in the "clean air" sector of Summit Camp are a factor of 1.8–2.4 higher than in snow pits located 10 km and 20 km to the north ("downwind" and south ("upwind" of the research site. Gaussian plume modeling performed using meteorological data from years 2003–2006 suggests a strong angular dependence of anthropogenic impact, with highest risk to the northwest of Summit Camp and lowest to the southeast. Along a transect to the southeast (5 degree angle bin, the modeled frequency of significant camp contribution to atmospheric EC (i.e. camp-produced EC>summer 2006 average EC at a distance of 0.5 km, 10 km, and 20 km is 1%, 0.2%, and 0.05%, respectively. According to both the snow pit and model results, a distance exceeding 10 km towards the southeast is expected to minimize risk of contamination. These results also suggest that other remote Arctic monitoring stations powered by local fuel combustion may need to account for local air and snow contamination in field sampling design and data interpretation.

  13. Effect of precursor concentration, temperature and capping group on the morphology of CdS nanoparticles

    CSIR Research Space (South Africa)

    Moloto, N

    2008-01-01

    Full Text Available -21 The overall aim of this study is to validate the influence of factors such as concentration, reaction temperature and capping group on both size and morphology of CdS nanoparticles. Experimental section General HDA (hexadecylamine), TOPO (tri... as size of the nanoparticles. Due to the different binding modes, the HDA capping agent favoured the formation of rods whilst TOPO formed spheres. References 1. J. G. Contreras, J. A. Gnecco, Anales de Quimica, 86, 740 (1990). 2. D. Adamczyk...

  14. Concentrations of selected trace elements in mineral and spring bottled waters on the Serbian market.

    Science.gov (United States)

    Ristić, M; Popović, I; Pocajt, V; Antanasijević, D; Perić-Grujić, A

    2011-01-01

    Eight selected trace elements, which are generally included in regulations, were analyzed in 23 types of bottled waters. Ten mineral and seven spring bottled waters were from the Serbian market and six mineral bottled waters were obtained in different EU countries. For the purpose of comparison, selected tap waters were also analyzed. Inductively coupled plasma mass spectrometry (ICP-MS) was used for the analysis of trace elements (arsenic, cadmium, copper, manganese, nickel, lead and antimony). Results were compared with the Serbian regulations for bottled water, EU regulations and guideline values set by the World Health Organization for drinking water. With few exceptions, the trace element levels of most bottled waters were below the guideline values. However, a higher content of antimony was observed in waters from polyethylene terephthalate (PET) containers, indicating a potential leaching of this element from the plastic packaging.

  15. Rare earth element concentrations and Nd isotopes in the Southeast Pacific Ocean

    National Research Council Canada - National Science Library

    Jeandel, C; Delattre, H; Grenier, M; Pradoux, C; Lacan, F

    2013-01-01

    .... At this station Nd isotopic compositions are clearly more radiogenic than in the open ocean, suggesting that boundary exchange process is releasing lithogenic rare earth element from the volcanic Andes...

  16. Multi-element concentrations in plant parts and fluids of Malaysian nickel hyperaccumulator plants and some economic and ecological considerations.

    Science.gov (United States)

    van der Ent, Antony; Mulligan, David

    2015-04-01

    Information about multi-elemental concentrations in different plant parts of tropical Ni hyperaccumulator species has the potential to provide insight into their unusual metabolism relative to a range of essential and non-essential elements, but this information is scant in the literature. As Ni hyperaccumulation, and possibly co-accumulation of other toxic elements, has been hypothesized to provide herbivore (insect) protection, there is a need to quantify a range of these elements in plant tissues and transport fluids to at least verify the possibility of this explanation. In this study, multiple elements were analyzed in a range of different plant parts and transport fluids from Ni hyperaccumulator species collected from Sabah (Malaysia). The results show preferential accumulation of Ni in leaves over woody parts, but the highest concentrations were found in the phloem tissue (up to 7.9 % in Rinorea bengalensis) and phloem sap (up to 16.9 % in Phyllanthus balgooyi), visible by a bright green coloration in the field fresh material. The amount of Ni contained in one mature R. bengalensis tree was calculated at 4.77 kg. The high Ni concentration in the flowers of Phyllanthus securinegoides could affect insect floral visitors and pollination. High concentrations of Ni in the seeds of this species also could supply the seedling with Ni and aid in herbivory protection during the first stages of development. Foliar Ca and Ni in P. cf. securinegoides and R. bengalensis are positively correlated. Low accumulation of Ca is desirable for phytomining but concentrations of Ca are high in most Ni hyperaccumulators examined, and this could have consequences for the economic viability of Ni extraction from bio ore if these species were to be used as 'metal crops'.

  17. Assessment of contamination based on trace element concentrations in Gomphus flavipes (Odonata: Insect) larvae of the Upper Tisza Region.

    Science.gov (United States)

    Simon, E; Kis, O; Jakab, T; Kolozsvári, I; Málnás, K; Harangi, S; Baranyai, E; Miskolczi, M; Tóthmérész, B; Dévai, Gy

    2017-02-01

    Odonata larvae are frequently used to assess the contamination of aquatic systems, because they tolerate a wide range of chemical and biological conditions in freshwater systems. In early 2000, the sediments of the Hungarian section of the River Tisza and the River Szamos were strongly enriched with heavy metals by an accidental mining spill. Earlier studies demonstrated higher contamination levels in the Szamos than in the Tisza, based on sediment analysis. The aim of our study was to assess the contamination in the Upper Tisza Region, along the upper reach of the Tisza, and the lower reach of the Szamos, based on the trace element concentrations of the Gomphus flavipes larvae. We collected 269 dragonfly specimens for the analyses. The Al, Ba, Cr, Cu, Fe, Mn, Pb, Sr and Zn element contents were analysed in the dragonfly larvae by microwave plasma atomic emission spectrometry (MP-AES). Significantly higher Ba and Cu concentrations were found in the dragonfly larvae of the Tisza than the Szamos. In spite of this, the Cr, Mn, Pb, Sr and Zn concentration was significantly lower in the dragonfly larvae of the Tisza than the Szamos. For all trace elements significant differences were found along the Tisza. Significant differences were also found in all trace element concentrations of dragonfly larvae among studied localities in the Szamos, except in the cases of Al and Ba. Our results demonstrated that the Szamos was more contaminated with Cr, Mn, Pb, Sr and Zn than the Tisza, but that the Tisza was more contaminated with Ba and Cu than the Szamos, based on the trace element concentrations in Gomphus flavipes larvae, which was likely to have been caused by the tributaries of the Tisza. In summary, our results indicated a continuous pollution of the Tisza and the Szamos and their tributaries.

  18. Effects of concentration, head group, and structure of surfactants on the degradation of phenanthrene

    Energy Technology Data Exchange (ETDEWEB)

    Jin Danyue; Jiang Xia [State Environmental Protect Key Laboratory of Lake Eutrophication Control, Research Center of Lake Environment, Chinese Research Academy of Environmental Science, No. 8 Dayangfang, An Wai Bei Yuan, Beijing 100012 (China)]. E-mail: jiangxia@craes.org.cn; Jing Xin [State Environmental Protect Agency of China (China); Ou Ziqing [Institute of Applied Ecology, Chinese Academy of Science, Shenyang 110016 (China)

    2007-06-01

    The effects of concentration, polar/ionic head group, and structure of surfactants on the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in the aqueous phase, as well as their effects on the bacterial activity were investigated. The toxicity ranking of studied surfactants is: non-ionic surfactants (Tween 80, Brij30, 10LE and Brij35) < anionic surfactants (LAS) < cationic surfactants (TDTMA). For the same head group and similar molecular structure, the toxicity to the bacteria is due to the chain length, in which the toxicity becomes lower as the chain length increases. The bacterial growth increased slightly when phenanthrene and LAS ({<=}10 mg L{sup -1}) served the sole carbon and energy resource. However, the degradation of {sup 14}C-phenanthrene showed either a decrease or no obvious change with the surfactants present at all tested concentrations (5-40 mg L{sup -1}). Thus, the surfactant addition is not beneficial to the removal of phenanthrene or other PAH contaminants due presumably to the preferential utilization of surfactants at low levels as the non-toxic nutrient resource and to the high toxicity of the surfactants at high levels to the microorganism activity. Biodegradation of phenanthrene was also influenced by the surfactant concentration, head group type, and structure. Much more research has yet to be completed on the use of surfactants for soil remediation due to the surfactant toxicity or biodegradation effect.

  19. Report of the IAU Working Group on cartographic coordinates and rotational elements: 2009

    Science.gov (United States)

    Archinal, B.A.; A'Hearn, M.F.; Bowell, E.; Conrad, A.; Consolmagno, G.J.; Courtin, R.; Fukushima, T.; Hestroffer, D.; Hilton, J.L.; Krasinsky, G.A.; Neumann, G.; Oberst, J.; Seidelmann, P.K.; Stooke, P.; Tholen, D.J.; Thomas, P.C.; Williams, I.P.

    2010-01-01

    Every three years the IAU Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report takes into account the IAU Working Group for Planetary System Nomenclature (WGPSN) and the IAU Committee on Small Body Nomenclature (CSBN) definition of dwarf planets, introduces improved values for the pole and rotation rate of Mercury, returns the rotation rate of Jupiter to a previous value, introduces improved values for the rotation of five satellites of Saturn, and adds the equatorial radius of the Sun for comparison. It also adds or updates size and shape information for the Earth, Mars’ satellites Deimos and Phobos, the four Galilean satellites of Jupiter, and 22 satellites of Saturn. Pole, rotation, and size information has been added for the asteroids (21) Lutetia, (511) Davida, and (2867) Šteins. Pole and rotation information has been added for (2) Pallas and (21) Lutetia. Pole and rotation and mean radius information has been added for (1) Ceres. Pole information has been updated for (4) Vesta. The high precision realization for the pole and rotation rate of the Moon is updated. Alternative orientation models for Mars, Jupiter, and Saturn are noted. The Working Group also reaffirms that once an observable feature at a defined longitude is chosen, a longitude definition origin should not change except under unusual circumstances. It is also noted that alternative coordinate systems may exist for various (e.g. dynamical) purposes, but specific cartographic coordinate system information continues to be recommended for each body. The Working Group elaborates on its purpose, and also announces its plans to occasionally provide limited updates to its recommendations via its website, in order to address community needs for some updates more often than every 3 years. Brief recommendations are also made to the general

  20. Probing Intracellular Element Concentration Changes during Neutrophil Extracellular Trap Formation Using Synchrotron Radiation Based X-Ray Fluorescence

    Science.gov (United States)

    Niemiec, Maria J.; Laforce, Brecht; Garrevoet, Jan; Vergucht, Eva; De Rycke, Riet; Cloetens, Peter; Urban, Constantin F.; Vincze, Laszlo

    2016-01-01

    High pressure frozen (HPF), cryo-substituted microtome sections of 2 μm thickness containing human neutrophils (white blood cells) were analyzed using synchrotron radiation based X-ray fluorescence (SR nano-XRF) at a spatial resolution of 50 nm. Besides neutrophils from a control culture, we also analyzed neutrophils stimulated for 1–2 h with phorbol myristate acetate (PMA), a substance inducing the formation of so-called Neutrophil Extracellular Traps (or NETs), a defense system again pathogens possibly involving proteins with metal chelating properties. In order to gain insight in metal transport during this process, precise local evaluation of elemental content was performed reaching limits of detection (LODs) of 1 ppb. Mean weight fractions within entire neutrophils, their nuclei and cytoplasms were determined for the three main elements P, S and Cl, but also for the 12 following trace elements: K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, Sr and Pb. Statistical analysis, including linear regression provided objective analysis and a measure for concentration changes. The nearly linear Ca and Cl concentration changes in neutrophils could be explained by already known phenomena such as the induction of Ca channels and the uptake of Cl under activation of NET forming neutrophils. Linear concentration changes were also found for P, S, K, Mn, Fe, Co and Se. The observed linear concentration increase for Mn could be related to scavenging of this metal from the pathogen by means of the neutrophil protein calprotectin, whereas the concentration increase of Se may be related to its antioxidant function protecting neutrophils from the reactive oxygen species they produce against pathogens. We emphasize synchrotron radiation based nanoscopic X-ray fluorescence as an enabling analytical technique to study changing (trace) element concentrations throughout cellular processes, provided accurate sample preparation and data-analysis. PMID:27812122

  1. Therapeutic elements in a self-management approach: experiences from group participation among people suffering from chronic pain.

    Science.gov (United States)

    Furnes, Bodil; Natvig, Gerd Karin; Dysvik, Elin

    2014-01-01

    Chronic pain is a complex, multifaceted subjective experience that involves the whole person. Self-management is the dynamic and continuous process of adapting one's situation to the cognitive, behavioral, and emotional responses necessary to maintain a satisfactory quality of life. Approaches based on cognitive behavioral therapy (CBT) are described as appropriate in assisting people suffering from chronic pain because they challenge maladaptive beliefs and behaviors in relation to pain. This study aimed to explore patients' experiences of therapeutic elements from group participation in a chronic pain management program. A qualitative research design with a phenomenological hermeneutic approach was used. Six months after participation in the 8-week course, 34 participants formulated and submitted written reports based on open-ended questions related to their group participation and self-help achievement. These reports were analyzed by elements of qualitative content analysis. THE ANALYSIS RESULTED IN TWO SUBTHEMES: "The significance of active involvement in gaining new insight" and "The significance of community and group support." These were abstracted in the main theme: "Successful self-management is related to several significant contributions in the group." An active role with writing, self-revelation, and exchanges of thoughts and feelings in the group seemed to be the key tools for success. In addition, group support and access to other group members' experiences were significant therapeutic elements. We suggest that successful self-management requires knowledge of essential therapeutic elements. In a CBT-based group approach, such elements may offer an important health care contribution.

  2. A randomized controlled trial on the effects of jujube fruit on the concentrations of some toxic trace elements in human milk

    Directory of Open Access Journals (Sweden)

    Roya Kelishadi

    2016-01-01

    Full Text Available Background: This study aims to investigate the concentrations of lead, cadmium, and arsenic in the human milk, and to assess the effect of jujube fruit consumption by lactating mothers in reducing the concentration of these heavy metals in their milk. Materials and Methods: This randomized controlled trial was conducted in 2014 among forty postpartum mothers in Isfahan, the second largest and polluted city in Iran. Mothers were randomized into two groups; the intervention group received 15 g/day of fresh jujube fruit, and the controls received routine care for 8 weeks. Results: In the beginning, the concentrations of lead, cadmium, and arsenic were high, without significant difference between groups. The mean (standard deviation concentrations of lead, cadmium, and arsenic were 29.49 (16.6, 4.65 (3.51, and 1.23 (0.63 μg/L, respectively. The smoothed empirical distribution of environmental pollutants showed that in both groups the mean values and variance of toxic metals decreased after 8 weeks, with a sharper decline in the intervention group. Quantile regression analysis showed that in the intervention group, lead concentration decreased by 2.54 μg/L at the 90th quintile, and cadmium decreased by 0.19 μg/Lat 75th quintile; without significant change in arsenic level. The corresponding figures were not significant in the control group. Conclusion: The concentrations of heavy metals were high in human milk, and the consumption of jujube fruit had some beneficial effects in reducing these harmful elements. Pregnant and lactating mothers should be advised to reduce their exposure to environmental pollutants, and consumption of some natural medicinal foods can be useful in reducing the concentration of pollutants in human milk. Because of numerous benefits of breast milk, in spite of the existence of some toxic trace elements, breastfeeding must be encouraged because such contaminants are also found in water and formula. The impact of the current

  3. Effects of prenatal and postnatal exposure of Wi-Fi on development of teeth and changes in teeth element concentration in rats. [corrected].

    Science.gov (United States)

    Çiftçi, Zülfikar Zahit; Kırzıoğlu, Zühal; Nazıroğlu, Mustafa; Özmen, Özlem

    2015-02-01

    The present study determined the effects of prenatal and postnatal exposure to Wi-Fi (2.45 GHz)-induced electromagnetic radiation (EMR) on tooth and surrounding tissue development as well as the element levels in growing rats. Twenty-four rats and their offspring were equally divided into two separate groups identified as experiment and control. The experiment group was exposed to 2.45 GHz EMR for 2 h/day during the periods of pregnancy (21 days) and lactation (21 days). The offspring of these dams were also exposed to EMR up to decapitation. The control group was exposed to cage stress for 2 h per day using the same protocol established for the experimental group. On the 7th, 14th, and 21st days after birth, 8 male offspring rats from each of the two groups were decapitated, and the jaws were taken for histological and immunohistochemical examination. Caspase-3 (1/50 dilution) was used in the immunohistochemical examination for apoptotic activity. On the last day of the experiment, the rats' incisors were also collected. In samples that were histologically and immunohistochemically examined, there was an increase in apoptosis and caspase-3 in both the control and the Wi-Fi groups during the development of the teeth. However, no significant difference was observed between the two groups in terms of development and apoptotic activity. Results from the elemental analysis showed that iron and strontium concentrations were increased in the Wi-Fi group, whereas boron, copper, and zinc concentrations were decreased. There were no statistically significant differences in calcium, cadmium, potassium, magnesium, sodium, or phosphorus values between the groups. Histological and immunohistochemical examinations between the experimental and control groups showed that exposure to 2.45 GHz EMR for 2 h per day does not interfere with the development of teeth and surrounding tissues. However, there were alterations in the elemental composition of the teeth, especially

  4. Concentrations and solubility of trace elements in fine particles at a mountain site, southern China: regional sources and cloud processing

    Science.gov (United States)

    Li, T.; Wang, Y.; Li, W. J.; Chen, J. M.; Wang, T.; Wang, W. X.

    2015-08-01

    The concentrations and solubility of twelve trace elements in PM2.5 at Mt. Lushan, southern China, were investigated during the summer of 2011 and the spring of 2012. The average PM2.5 mass was 55.2 ± 20.1 μg m-3 during the observation period. Temporal variations of all trace elements including total and water-soluble fractions with several dust storm spikes in total fractions of Al and Fe were observed. The enrichment factor (EF) values were 1 order of magnitude higher for the water-soluble fractions versus the total fractions of trace elements. Four major emission sources, namely nonferrous metal mining and smelting (for Cr, As, Ba and parts of Zn), coal combustion (for Pb, Zn, Se, Cu and Mn), crustal materials (for Al and Fe) and municipal solid waste incineration (for Cd and Mo), were classified by principal component analysis (PCA). Trajectory cluster analysis and the potential source contribution function (PSCF) consistently identified the Yangtze River delta (YRD), the Pearl River delta (PRD), and the neighbouring provinces of Mt. Lushan as the major source regions and transport pathways for anthropogenic elements. Northern China was identified as a major source region for crustal elements. It should be noted that apart from the YRD, the area around Mt. Lushan has become the most significant contributor to the solubility of most trace elements. Element solubility can be partially determined by emission sources. However, enhanced solubility of trace elements corresponding to increased concentrations of sulfate after the occurrence of cloud events indicated significant effects of cloud processing on aerosol element dissolution. Metal particles mixed with sulfate in cloud droplet residues were further investigated through transmission electron microscopy (TEM) analysis. Irreversible alteration of particle morphology by cloud processing was confirmed to be highly responsible for the enhancement of trace element solubility. The findings from this study imply an

  5. Role of Various Extractants in Removing Group-IIB Elements of Soils Incubated with EDTA

    Directory of Open Access Journals (Sweden)

    Tanmoy Karak

    2004-01-01

    Full Text Available This paper presents the results of an experimental investigation undertaken to evaluate different extractant solutions viz. HCl, Mg(NO32, and DTPA with the range of concentration from 0.001 to 0.1N after incubation with group-IIB metals (Zn, Cd, and Hg and EDTA to understand the capability to remove Zn, Cd, and Hg from soils. Two noncontaminated soils, one acidic (GHL and the other alkaline (KAP, in reaction were taken from an agricultural field of West Bengal, India for this investigation. Experiments were conducted on these two soils spiked with ZnII, CdII, and HgII in concentrations of 612, 321, and 215 mg/kg for soil GHL and 778, 298, and 157 mg/kg for soil KAP, respectively, which simulate typical electroplating waste contamination. The removal of Zn, Cd, and Hg in soil GHL within the range of HCl concentrations was 8.2–16.5, 12.2–19.1, and 4.3–6.9 whereas these were 6.5–7.6, 8.5–14.1, and 3.2–5.2 in soil KAP. The removal of Zn, Cd, and Hg in soil GHL within the range of Mg(NO32 concentrations were 12.2–28.5, 19.1–24.6, and 18.2–19.1 whereas these were 9.1–12.1, 8.3–12.1, and 10.6–48.1 in soil KAP. For DTPA extractant, the percent removal of metal was found to be significantly higher than the other two extractants, which corroborates that DTPA is a better extractant for soil cleaning.

  6. [A comparative analysis of occupational risk in industry employees based on concentrations of some elements in teeth and body fluids].

    Science.gov (United States)

    Poczatek, Michał; Machoy, Zygmunt; Gutowska, Izabela; Chlubek, Dariusz

    2004-01-01

    Work safety and hygiene is a set of basic measures to protect workers from the negative effects of manufacturing processes. So far, numerous procedures for assessment of occupational health risk have been described. We measured the concentrations of some elements in teeth and body fluids of employees working in three different industries with an established production profile: Zakłady Naprawcze Taboru Kolejowego (repairs of rail vehicles), Philips Lighting Poland (production of lighting systems) and Metalplast (build ing furbishing factory). Different technologies were in place at each of these plants. Basing on laboratory analyses, the risk of exposure to chemical substances was evaluated. The study material included 100 extracted teeth, as well as body fluid samples (saliva, urine and blood) collected during routine health checks. Whenever possible, concentrations of the following elements were measured: calcium, magnesium, fluorine, phosphorus in the form of phosphates, potassium, sodium, iron, zinc, copper, cadmium, and lead. Metal elements were measured spectrophotometrically (ASA), fluorine with an ion-selective electrode, and phosphates with a colorimetric method. We found that concentrations of the elements in teeth and body fluids differed depending on the industry. For teeth, statistically significant differences applied to magnesium, phosphates, zinc, sodium, and potassium. In body fluids, statistically significant differences were found for calcium (blood and urine), magnesium (blood, urine and saliva), zinc (blood, urine and saliva), iron, lead and copper (urine). In conclusion, our findings may be helpful for monitoring safety at work in industrial plants.

  7. The quality control of fruit juices by using the stable isotope ratios and trace metal elements concentrations

    Science.gov (United States)

    Magdas, D. A.; Dehelean, A.; Puscas, R.; Cristea, G.; Tusa, F.; Voica, C.

    2012-02-01

    In the last years, a growing number of research articles detailing the use of natural abundance light stable isotopes variations and trace metal elements concentration as geographic "tracers" to determine the provenance of food have been published. These investigations exploit the systematic global variations of stable hydrogen, oxygen and carbon isotope ratios in (combination) relation with trace metal element concentrations. The trace metal elements content of plants and also their light stable isotopic ratios are mainly related to the geological and pedoclimatic characteristics of the site of growth. The interpretation of such analysis requires an important number of data for authentic natural juices regarding the same seasonal and regional origin, because the isotopic analysis parameters of fruit juices show remarkable variability depending on climatologically factors. In this work was mesured H, C, O stable isotope ratios and the concentrations of 16 elements (P, K, Mg, Na, Ca, Cu, Cr, Ni, Zn, Pb, Co, As, Cd, Mn, Fe and Hg) from 12 single strength juices. The natural variations that appear due to different environmental and climatic conditions are presented and discussed.

  8. Carbon allocation and element composition in four Chlamydomonas mutants defective in genes related to the CO2 concentrating mechanism.

    Science.gov (United States)

    Memmola, Francesco; Mukherjee, Bratati; Moroney, James V; Giordano, Mario

    2014-09-01

    Four mutants of Chlamydomonas reinhardtii with defects in different components of the CO2 concentrating mechanism (CCM) or in Rubisco activase were grown autotrophically at high pCO2 and then transferred to low pCO2, in order to study the role of different components of the CCM on carbon allocation and elemental composition. To study carbon allocation, we measured the relative size of the main organic pools by Fourier Transform Infrared spectroscopy. Total reflection X-ray fluorescence was used to analyze the elemental composition of algal cells. Our data show that although the organic pools increased their size at high CO2 in all strains, their stoichiometry was highly homeostatic, i.e., the ratios between carbohydrates and proteins, lipid and proteins, and carbohydrates and lipids, did not change significantly. The only exception was the wild-type 137c, in which proteins decreased relative to carbohydrates and lipids, when the cells were transferred to low CO2. It is noticeable that the two wild types used in this study responded differently to the transition from high to low CO2. Malfunctions of the CCM influenced the concentration of several elements, somewhat altering cell elemental stoichiometry: especially the C/P and N/P ratios changed appreciably in almost all strains as a function of the growth CO2 concentration, except in 137c and the Rubisco activase mutant rca1. In strain cia3, defective in the lumenal carbonic anhydrase (CA), the cell quotas of P, S, Ca, Mn, Fe, and Zn were about 5-fold higher at low CO2 than at high CO2. A Principle Components Analysis showed that, mostly because of its elemental composition, cia3 behaved in a substantially different way from all other strains, at low CO2. The lumenal CA thus plays a crucial role, not only for the correct functioning of the CCM, but also for element utilization. Not surprisingly, growth at high CO2 attenuated differences among strains.

  9. Influence of Molecular Hydrogen Diffusion on Concentration and Distribution of Hydroxyl Groups in Silica Fibers

    Science.gov (United States)

    Plotnichenko, Victor G.; Ivanov, Gennadii A.; Kryukova, Elena B.; Aksenov, Vyacheslav A.; Sokolov, Vyacheslav O.; Isaev, Victor A.

    2005-01-01

    To study the hydroxyl (OH)-group contamination mechanisms in silica-based optical fibers, the transmission spectra of substrate tubes and fiber preforms made from various types of silica glasses ("Suprasil F-300," KS-4V, and KUVI) are measured by the method of infrared Fourier spectroscopy in a wavelength region of 2-5 μm. Due to the intensity of the fundamental OH stretching vibration band, the absorption coefficient, concentration, and a distribution profile of OH groups across the aforesaid samples are calculated. It is found that using an oxyhydrogen burner in the modified chemical vapor deposition (MCVD) process of manufacturing preforms and fiber drawing, the main source of impurity OH groups can be the molecular hydrogen H2 penetrating into glass much deeper than the OH groups diffusing from the substrate tube surface. A simple model explaining the formation and diffusion of OH groups into a fiber core and cladding is proposed. It is shown that heating tubes and preforms in a flame of oxyhydrogen burner during fiber fabrication causes a significant OH-group content growth (almost by two orders of magnitude) near to the outer preform surface. Using substrate tubes made from Suprasil F-300 glass, optical fibers are fabricated having a silica core and fluorosilicate reflecting cladding with optical losses of 0.3 dB/km at 1.55 μm and a refractive-index difference between core and cladding ~ 1 . 10^-2.

  10. Environmental exposure to trace elements and prostate cancer in three New Zealand ethnic groups.

    Science.gov (United States)

    Gray, Marion A; Centeno, Jose A; Slaney, David P; Ejnik, John W; Todorov, Todor; Nacey, John N

    2005-12-01

    A stratified random sample of 176 men was taken from a larger community prostate study group of 1405 eligible subjects from three ethnic groups in the Wellington region of New Zealand, in order to examine ethnic differences in exposure to cadmium (Cd), selenium (Se) and zinc (Zn) and possible associations of blood levels of Cd, Se and Zn with the prevalence of elevated serum Prostate Specific Antigen (PSA); a marker of prostate cancer. Maori and Pacific Islands men were found likely to have higher Cd exposure than New Zealand Europeans through diet, occupation and smoking. However, there was no significant difference between ethnic groups in mean blood Cd levels. Pacific Islands men had significantly higher levels of blood Se than both New Zealand European men and Maori men. Maori men had significantly higher levels of blood Zn than both New Zealand European men and Pacific Islands men. A positive association was found between blood Cd and total serum PSA. Se and Zn levels were not associated with elevated PSA. Maori and Pacific Islands men have higher prostate cancer mortality rates than New Zealand European men. Ethnic differences in mortality could be contributed to by differences in rates of disease progression, influenced by exposure and/or deficiency to trace elements. However, results did not reflect a consistent ethnic trend and highlight the complexity of the risk/protective mechanisms conferred by exposure factors. Further research is needed to ascertain whether the associations found between Cd and PSA levels are biologically important or are merely factors to be considered when interpreting PSA results clinically.

  11. Environmental Exposure to Trace Elements and Prostate Cancer in Three New Zealand Ethnic Groups

    Directory of Open Access Journals (Sweden)

    John N. Nacey

    2005-12-01

    Full Text Available A stratified random sample of 176 men was taken from a larger community prostate study group of 1405 eligible subjects from three ethnic groups in the Wellington region of New Zealand, in order to examine ethnic differences in exposure to cadmium (Cd, selenium (Se and zinc (Zn and possible associations of blood levels of Cd, Se and Zn with the prevalence of elevated serum Prostate Specific Antigen (PSA; a marker of prostate cancer. Maori and Pacific Islands men were found likely to have higher Cd exposure than New Zealand Europeans through diet, occupation and smoking. However, there was no significant difference between ethnic groups in mean blood Cd levels. Pacific Islands men had significantly higher levels of blood Se than both New Zealand European men and Maori men. Maori men had significantly higher levels of blood Zn than both New Zealand European men and Pacific Islands men. A positive association was found between blood Cd and total serum PSA. Se and Zn levels were not associated with elevated PSA. Maori and Pacific Islands men have higher prostate cancer mortality rates than New Zealand European men. Ethnic differences in mortality could be contributed to by differences in rates of disease progression, influenced by exposure and/or deficiency to trace elements. However, results did not reflect a consistent ethnic trend and highlight the complexity of the risk/protective mechanisms conferred by exposure factors. Further research is needed to ascertain whether the associations found between Cd and PSA levels are biologically important or are merely factors to be considered when interpreting PSA results clinically.

  12. Trace element concentrations on fine particles in the Ohio River Valley

    Energy Technology Data Exchange (ETDEWEB)

    Tuncel, S.G.; Gordon, G.E.; Olmez, I.; Parrington, J.R.; Shaw, R.W. Jr.; Paur, R.J.

    1986-04-01

    Trace element compositions of airborne particles are important for determining sources and behavior of regional aerosol, as emissions from major sources are characterized by their elemental composition patterns. The authors investigated airborne trace elements in a complex regional environment through application of receptor models. A subset (200) of fine fraction samples in the Ohio River Valley (ORV) and analyzed by X-ray fluorescence (XRF) were reanalyzed by instrumental neutron activation analysis (INAA). The combined data set, XRF plus INAA, was subjected to receptor-model interpretations, including chemical mass balances (CMBs) and factor analysis (FA). Back trajectories of air masses were calculated for each sampling period and used with XRF data to select samples to be analyzed by INAA.

  13. 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

  14. Determination of macro, micro nutrient and trace element concentrations in Indian medicinal and vegetable leaves using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Naidu, G.R.K.; Balaji, T. [Department of Chemistry, S.V. University, Tirupati (India); Denschlag, H.O.; Mauerhofer, E.; Porte, N. [Institut fuer Kernchemie, Johannes Gutenberg Universitaet, Mainz (Germany)

    1999-05-01

    Leafy samples often used as medicine in the Indian Ayurvedic system and vegetables were analyzed for 20 elements (As, Ba, Br, Ca, Ce, Cr, Cs, Co, Eu, Fe, K, La, Na, Rb, Sb, Sc, Sm, Sr, Th, Zn) by employing Instrumental Neutron Activation Analysis (INAA). The samples were irradiated at the 100 kW TRIGA-MAINZ nuclear reactor and the induced activities were counted by gamma ray spectrometry using an efficiency calibrated high resolution High Purity Germanium (HPGe) detector. The concentration of the elements in the medicinal and vegetable leaves and their biological effects on human beings are discussed.

  15. Platinum-group element abundance and distribution in chromite deposits of the Acoje Block, Zambales Ophiolite Complex, Philippines

    Science.gov (United States)

    Bacuta, G.C.; Kay, R.W.; Gibbs, A.K.; Lipin, B.R.

    1990-01-01

    Platinum-group elements (PGE) occur in ore-grade concentration in some of the chromite deposits related to the ultramafic section of the Acoje Block of the Zambales Ophiolite Complex. The deposits are of three types: Type 1 - associated with cumulate peridotites at the base of the crust; Type 2 - in dunite pods from the top 1 km of mantle harzburgite; and Type 3 - like Type 2, but in deeper levels of the harzburgite. Most of the deposites have chromite compositions that are high in Cr with Cr/(Cr + Al) (expressed as chromium index, Cr#) > 0.6; high-Al (Cr# Pd, thought to be characteristic of PGE-barren deposits) and positive slope (Ir Platinum and Pd occur as alloy inclusions (and possibly as solid solution) in interstitial Ni-Cu sulfides and as tellurobismuthides in serpentine and altered sulfides. Variability of PGE distribution may be explained by alteration, crystal fractionation or partial melting processes. Alteration and metamorphism were ruled out, because PGE contents do not correlate with degree of serpentinization or the abundance and type (hydroxyl versus non-hydroxyl) of silicate inclusions in chromite. Preliminary Os isotopic data do not support crustal contamination as a source of the PGEs in the Acoje deposits. The anomalous PGE concentrations in Type 1 high-Cr chromite deposits are attributed to two stages of enrichment: an early enrichment of their mantle source from previous melting events and a later stage of sulfide segregation accompanying chromite crystallization. High-Al chromite deposits which crystallized from basalts derived from relatively low degrees of melting owe their low PGE content to partitioning of PGEs in sulfides and alloys that remain in the mantle. High-Cr deposits crystallized from melts that were previously enriched with PGEs during early melting events of their mantle source; Pt and Pd ore concentrations (ppm levels) are attained by segregation of magmatic sulfides. The Acoje deposits indicate that ophiolites are a

  16. 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

  17. Finite Element Analysis for Prediction of Shear and Stress Concentration & Distribution in Femoral Bone

    Science.gov (United States)

    Suhendra, N.; Gustiono, D.; Nugroho, E. A.; Masmui; Yuliani, H.

    2017-02-01

    The effect of micromotion on the shear shielding and size of yielding region in the bone asperity in contact with metal of femoral stem was investigated. The main objective of this work was to gain an understanding of bone wear particleformation mechanism from the two-dimensional finite element model of cementless femoral stem type. To assess the influence of the parameters of interest, different friction coefficients and sliding distance (micromotion)were used in the numerical simulations. Results from the finite element analysis showed that the increase ofthe yielding region is strongly influenced by the rise in sliding distance (micromotion), which is related to the generation of bone wear particle formations. Finite element bone wearparticle formation model, based on strain discontinuities, was therefore proposed for further works. The results obtained in this study can lead to the development of an accurate finite element wearparticle formation mechanism model that would be of use in the assessment of an artificial implant performance and their development.

  18. Environmental concentration of selected elements and relation to physicochemical parameters in honey.

    Science.gov (United States)

    Kacaniova, Miroslava; Knazovicka, Vladimira; Melich, Martin; Fikselova, Martina; Massanyi, Peter; Stawarz, Robert; Hascik, Peter; Pechociak, Tomas; Kuczkowska, Anna; Putała, Aldona

    2009-03-01

    The purpose of this study was to evaluate the content of selected elements and physicochemical indicators of the honey of Apis mellifera. Samples of blossom, blend and honeydew honeys were randomly obtained from the Eastern, Western and Central of Slovakia. Contents of elements were measured with the use of flame atomic absorption spectrophotometry (FAAS) method and anodic stripping voltammetry (ASV) method with CGMDE as working electrode. The content of heavy metals (mg/kg dry weight) ranged as follows: Zn 0.25-3.82; Cu 0.12-1.37; Ni 0.06-0.60; Mg 0.10-50.43; Ca 10.32-87.21; Pb and Cd were under detectable limit (0.001 mg/kg). The physical and chemical indicators ranged as follows: moisture (%) 16.00-19.80; HMF (mg/kg) 10.00-40.00; pH 3.58-5.12; conductivity (mS/m) 13.45-99.12 and a(w) 0.456-0.659. Significant difference (P elements and physicochemical indicators was analyzed. Significant correlations between Cu - Zn, Cu - Ni, Cu - Mg, Ca - Zn and Ca - Mg were detected. With reference to Codex Alimentarius of Slovakia, maximal levels of heavy metals content and selected physicochemical properties were not exceeded. On average, the content of trace elements decreased in the order: Ca > Mg > Zn > Cu > Ni and physicochemical indicators decreased: conductivity > HMF > moisture > pH > a(w).

  19. Impact of inland shipping emissions on elemental carbon concentrations near waterways in The Netherlands

    NARCIS (Netherlands)

    Keuken, M.P.; Moerman, M.; Jonkers, J.; Hulskotte, J.; Denier van der Gon, H.A.C.; Hoek, G.; Sokhi, R.S.

    2014-01-01

    This study aims to quantify the impact of black carbon from inland shipping on air quality, expressed as elemental carbon (EC) near inland waterways in The Netherlands. Downwind measurements of particle numbers and EC were used to establish emission factors for EC from inland shipping using inverse

  20. Report of the IAU Working Group on cartographic coordinates and rotational elements: 2009

    Science.gov (United States)

    Archinal, Brent A.; A’Hearn, Michael F.; Bowell, Edward; Conrad, Al; Consolmagno, Guy J.; Courtin, Regis; Fukushima, Toshio; Hestroffer, Daniel; Hilton, James L.; Krasinsky, Georgij A.; Neumann, Gregory; Oberst, Jurgen; Seidelmann, P. Kenneth; Stooke, Philip; Tholen, David J.; Thomas, Peter C.; Williams, Iwan P.

    2010-01-01

    Every three years the IAU Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report takes into account the IAU Working Group for Planetary System Nomenclature (WGPSN) and the IAU Committee on Small Body Nomenclature (CSBN) definition of dwarf planets, introduces improved values for the pole and rotation rate of Mercury, returns the rotation rate of Jupiter to a previous value, introduces improved values for the rotation of five satellites of Saturn, and adds the equatorial radius of the Sun for comparison. It also adds or updates size and shape information for the Earth, Mars’ satellites Deimos and Phobos, the four Galilean satellites of Jupiter, and 22 satellites of Saturn. Pole, rotation, and size information has been added for the asteroids (21) Lutetia, (511) Davida, and (2867) Šteins. Pole and rotation information has been added for (2) Pallas and (21) Lutetia. Pole and rotation and mean radius information has been added for (1) Ceres. Pole information has been updated for (4) Vesta. The high precision realization for the pole and rotation rate of the Moon is updated. Alternative orientation models for Mars, Jupiter, and Saturn are noted. The Working Group also reaffirms that once an observable feature at a defined longitude is chosen, a longitude definition origin should not change except under unusual circumstances. It is also noted that alternative coordinate systems may exist for various (e.g. dynamical) purposes, but specific cartographic coordinate system information continues to be recommended for each body. The Working Group elaborates on its purpose, and also announces its plans to occasionally provide limited updates to its recommendations via its website, in order to address community needs for some updates more often than every 3 years. Brief recommendations are also made to the

  1. Platinum Group Elements (PGE) geochemistry of komatiites and boninites from Dharwar Craton, India: Implications for mantle melting processes

    Science.gov (United States)

    Saha, Abhishek; Manikyamba, C.; Santosh, M.; Ganguly, Sohini; Khelen, Arubam C.; Subramanyam, K. S. V.

    2015-06-01

    High MgO volcanic rocks having elevated concentrations of Ni and Cr are potential hosts for platinum group elements (PGE) owing to their primitive mantle origin and eruption at high temperatures. Though their higher PGE abundance is economically significant in mineral exploration studies, their lower concentrations are also valuable geochemical tools to evaluate petrogenetic processes. In this paper an attempt has been made to evaluate the PGE geochemistry of high MgO volcanic rocks from two greenstone belts of western and eastern Dharwar Craton and to discuss different mantle processes operative at diverse geodynamic settings during the Neoarchean time. The Bababudan greenstone belt of western and Gadwal greenstone belt of eastern Dharwar Cratons are dominantly composed of high MgO volcanic rocks which, based on distinct geochemical characteristics, have been identified as komatiites and boninites respectively. The Bababudan komatiites are essentially composed of olivine and clinopyroxene with rare plagioclase tending towards komatiitic basalts. The Gadwal boninites contain clinopyroxene, recrystallized hornblende with minor orthopyroxene, plagioclase and sulphide minerals. The Bababudan komatiites are Al-undepleted type (Al2O3/TiO2 = 23-59) with distinctly high MgO (27.4-35.8 wt.%), Ni (509-1066 ppm) and Cr (136-3036 ppm) contents. These rocks have low ΣPGE (9-42 ppb) contents with 0.2-2.4 ppb Iridium (Ir), 0.2-1.4 ppb Osmium (Os) and 0.4-4.4 ppb Ruthenium (Ru) among Iridium group PGE (IPGE); and 1.4-16.2 ppb Platinum (Pt), 2.8-19 ppb Palladium (Pd) and 0.2-9.8 ppb Rhodium (Rh) among Platinum group PGE (PPGE). The Gadwal boninites are high-Ca boninites with CaO/Al2O3 ratios varying between 0.8 and 1.0, with 12-24 wt.% MgO, 821-1168 ppm Ni and 2307-2765 ppm Cr. They show higher concentration of total PGE (82-207 ppb) with Pt concentration ranging from 13 to 19 ppb, Pd between 65 and 180 ppb and Rh in the range of 1.4-3 ppb compared to the Bababudan komatiites. Ir

  2. [Affinity of the elements in group VI of the periodic table to tumors and organs].

    Science.gov (United States)

    Ando, A; Hisada, K; Ando, I

    1976-10-01

    In order to investigate the tumor affinity radioisotopes, chromium (51Cr), molybdenum (99Mo), tungsten (181W), selenium (75Se) and tellurium (127mTe)--the elements of group VI in the periodic table--were examined, using the rats which were subcutaneously transplanted with Yoshida sarcoma. Seven preprarations, sodium chromate (Na251CrO4), chromium chloride (51CrCl3), normal ammonium molybdate ((NH4)299MoO7), sodium tungstate (Na2181WO4), sodium selenate (Na275SeO4), sodium selenite (Na275SeO3) and tellurous acid (H2127mTeO3) were injected intravenously to each group of tumor bearing rats. These rats were sacrificed at various periods after injection of each preparation: 3 hours, 24 hours and 48 hours in all preparations. The radioactivities of the tumor, blood, muscle, liver, kidney and spleen were measured by a well-type scintillation counter, and retention values (in every tissue including the tumor) were calculated in percent of administered dose per g-tissue weight. All of seven preparations did not have any affinity for malignant tumor. Na251CrO4 and H2127mTeO3 had some affinity for the kidneys, and Na275SeO3 had some affinity for the liver. Na2181WO4 and (NH4)299MoO4 disappeared very rapidly from the blood and soft tissue, and about seventy-five percent of radioactivity was excreted in urine within first 3 hours.

  3. Alkali Metal Cation Affinities of Anionic Main Group-Element Hydrides Across the Periodic Table.

    Science.gov (United States)

    Boughlala, Zakaria; Fonseca Guerra, Célia; Bickelhaupt, F Matthias

    2017-08-05

    We have carried out an extensive exploration of gas-phase alkali metal cation affinities (AMCA) of archetypal anionic bases across the periodic system using relativistic density functional theory at ZORA-BP86/QZ4P//ZORA-BP86/TZ2P. AMCA values of all bases were computed for the lithium, sodium, potassium, rubidium and cesium cations and compared with the corresponding proton affinities (PA). One purpose of this work is to provide an intrinsically consistent set of values of the 298 K AMCAs of all anionic (XHn-1(-) ) constituted by main group-element hydrides of groups 14-17 along the periods 2-6. In particular, we wish to establish the trend in affinity for a cation as the latter varies from proton to, and along, the alkali cations. Our main purpose is to understand these trends in terms of the underlying bonding mechanism using Kohn-Sham molecular orbital theory together with a quantitative bond energy decomposition analyses (EDA). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. KASCADE-Grande measurements of energy spectra for elemental groups of cosmic rays

    CERN Document Server

    :,; Arteaga-Velàzquez, J C; Bekk, K; Bertaina, M; Blümer, J; Bozdog, H; Brancus, I M; Cantoni, E; Chiavassa, A; Cossavella, F; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Engler, J; Finger, M; Fuchs, B; Fuhrmann, D; Gils, H J; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hörandel, J R; Huber, D; Huege, T; Kampert, K -H; Kang, D; Klages, H O; Link, K; Łuczak, P; Ludwig, M; Mathes, H J; Mayer, H J; Melissas, M; Milke, J; Mitrica, B; Morello, C; Oehlschläger, J; Ostapchenko, S; Palmieri, N; Petcu, M; Pierog, T; Rebel, H; Roth, M; Schieler, H; Schoo, S; Schröder, F G; Sima, O; Toma, G; Trinchero, G C; Ulrich, H; Weindl, A; Wochele, J; Wommer, M; Zabierowski, J

    2013-01-01

    The KASCADE-Grande air shower experiment [W. Apel, et al. (KASCADE-Grande collaboration), Nucl. Instrum. Methods A 620 (2010) 202] consists of, among others, a large scintillator array for measurements of charged particles, Nch, and of an array of shielded scintillation counters used for muon counting, Nmu. KASCADE-Grande is optimized for cosmic ray measurements in the energy range 10 PeV to about 2000 PeV, where exploring the composition is of fundamental importance for understanding the transition from galactic to extragalactic origin of cosmic rays. Following earlier studies of the all-particle and the elemental spectra reconstructed in the knee energy range from KASCADE data [T. Antoni, et al. (KASCADE collaboration), Astropart. Phys. 24 (2005) 1], we have now extended these measurements to beyond 200 PeV. By analysing the two-dimensional shower size spectrum Nch vs. Nmu for nearly vertical events, we reconstruct the energy spectra of different mass groups by means of unfolding methods over an energy rang...

  5. KASCADE-Grande measurements of energy spectra for elemental groups of cosmic rays

    CERN Document Server

    Fuhrmann, D; Arteaga-Velazquez, J C; Bekk, K; Bertaina, M; Bluemer, J; Bozdog, H; Brancus, I M; Cantoni, E; Chiavassa, A; Cossavella, F; Curcio, C; Daumiller, K; de Souza, V; Di Pierro, F; Doll, P; Engel, R; Engler, J; Fuchs, B; Gils, H J; Glasstetter, R; Grupen, C; Haungs, A; Heck, D; Hoerandel, J R; Huber, D; Huege, T; Kampert, K -H; Kang, D; Klages, H O; Link, K; Luczak, P; Ludwig, M; Mathes, H J; Mayer, H J; Melissas, M; Milke, J; Mitrica, B; Morello, C; Oehlschlaeger, J; Ostapchenko, S; Palmieri, N; Petcu, M; Pierog, T; Rebel, H; Roth, M; Schieler, H; Schoo, S; Schroeder, F G; Sima, O; Toma, G; Trinchero, G C; Ulrich, H; Weindl, A; Wochele, D; Wochele, J

    2013-01-01

    The KASCADE-Grande experiment, located at KIT-Karlsruhe, Germany, consists of a large scintillator array for measurements of charged particles, N_ch, and of an array of shielded scintillation counters used for muon counting, N_mu. KASCADE-Grande is optimized for cosmic ray measurements in the energy range 10 PeV to 1000 PeV, thereby enabling the verification of a knee in the iron spectrum expected at approximately 100 PeV. Exploring the composition in this energy range is of fundamental importance for understanding the transition from galactic to extragalactic cosmic rays. Following earlier studies of elemental spectra reconstructed in the knee energy range from KASCADE data, we have now extended these measurements to beyond 100 PeV. By analysing the two-dimensional shower size spectrum N_ch vs. N_mu, we reconstruct the energy spectra of different mass groups by means of unfolding methods. The procedure and its results, giving evidence for a knee-like structure in the spectrum of iron nuclei, will be presente...

  6. Structure and magnetism in novel group IV element-based magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, Frank [Univ. of North Carolina, Chapel Hill, NC (United States)

    2013-08-14

    The project is to investigate structure, magnetism and spin dependent states of novel group IV element-based magnetic thin films and heterostructures as a function of composition and epitaxial constraints. The materials systems of interest are Si-compatible epitaxial films and heterostructures of Si/Ge-based magnetic ternary alloys grown by non-equilibrium molecular beam epitaxy (MBE) techniques, specifically doped magnetic semiconductors (DMS) and half-metallic Heusler alloys. Systematic structural, chemical, magnetic, and electrical measurements are carried out, using x-ray microbeam techniques, magnetotunneling spectroscopy and microscopy, and magnetotransport. The work is aimed at elucidating the nature and interplay between structure, chemical order, magnetism, and spin-dependent states in these novel materials, at developing materials and techniques to realize and control fully spin polarized states, and at exploring fundamental processes that stabilize the epitaxial magnetic nanostructures and control the electronic and magnetic states in these complex materials. Combinatorial approach provides the means for the systematic studies, and the complex nature of the work necessitates this approach.

  7. The nature of the interaction of dimethylselenide with IIIA group element compounds.

    Science.gov (United States)

    Madzhidov, Timur I; Chmutova, Galina A

    2013-05-16

    The first systematic theoretical study of the nature of intermolecular bonding of dimethylselenide as donor and IIIA group element halides as acceptors was made with the help of the approach of Quantum Theory of Atoms in Molecules. Density Functional Theory with "old" Sapporo triple-ζ basis sets was used to calculate geometry, thermodynamics, and wave function of Me2Se···AX3 complexes. The analysis of the electron density distribution and the Laplacian of the electron density allowed us to reveal and explain the tendencies in the influence of the central atom (A = B, Al, Ga, In) and halogen (X = F, Cl, Br, I) on the nature of Se···A bonding. Significant changes in properties of the selenium lone pair upon complexation were described by means of the analysis of the Laplacian of the charge density. Charge transfer characteristics and the contributions to it from electron localization and delocalization were analyzed in terms of localization and delocalization indexes. Common features of the complexation and differences in the nature of bonding were revealed. Performed analysis evidenced that gallium and indium halide complexes can be attributed to charge transfer-driven complexes; aluminum halides complexes seem to be mainly of an electrostatic nature. The nature of bonding in different boron halides essentially varies; these complexes are stabilized mainly by covalent Se···B interaction. In all the complexes under study covalence of the Se···A interaction is rather high.

  8. Effects of depuration on the element concentration in bivalves: Comparison between sympatric Ruditapes decussatus and Ruditapes philippinarum

    Science.gov (United States)

    Freitas, R.; Ramos Pinto, L.; Sampaio, M.; Costa, A.; Silva, M.; Rodrigues, A. M.; Quintino, V.; Figueira, E.

    2012-09-01

    Organisms living in coastal ecosystems are frequently subjected to anthropogenic pressures such as metals. Metals, especially those not required for metabolic activity (e.g. mercury, lead and cadmium) can be toxic even at quite low concentrations not only to organisms that accumulate them, but also to their consumers. Throughout the world, Ruditapes decussatus and Ruditapes philippinarum have been successfully commercialised for human consumption and for monitoring environmental conditions such as contamination. These two clam species share similar habitats and requirements, successfully competing both in the natural environment and in aquaculture farms. Because differences in metal accumulation may exist between R. decussatus and R. philippinarum, different risks to public health may overcome as well as distinct ecological implications. The effect of depuration on the metal burden and biochemical status of both clams species may also diverge and since the information available is subjective and scarce, the aims of the present study were to: 1) assess the total metal accumulation and intracellular partitioning, at natural conditions, in the two clam species collected at the same site; 2) evaluate the effect of depuration as a mean of reducing the levels of distinct elements, assessing also the effect of depuration time (2 and 7 days); 3) investigate the efficiency of depuration by biochemical status of the two bivalve species, evaluating changes in lipid peroxidation and activity of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and of glutathione S-transferase (GST). Metal chelation by metallothioneins (MTs) was also determined. The results obtained showed that concentration of elements in clams was low, presenting very similar concentration levels for all elements. The present work further demonstrated that the total element concentration decreased in the shorter depuration period (2 days) and that R. decussatus and R. philippinarum partitioned

  9. Mapping differential elemental accumulation in fish tissues: assessment of metal and trace element concentrations in wels catfish (Silurus glanis) from the Danube River by ICP-MS.

    Science.gov (United States)

    Jovičić, Katarina; Nikolić, Dragica M; Višnjić-Jeftić, Željka; Đikanović, Vesna; Skorić, Stefan; Stefanović, Srđan M; Lenhardt, Mirjana; Hegediš, Aleksandar; Krpo-Ćetković, Jasmina; Jarić, Ivan

    2015-03-01

    Studies of metal accumulation in fish are mainly focused on the muscle tissue, while the metal accumulation patterns in other tissues have been largely neglected. Muscle is not always a good indicator of the whole fish body contamination. Elemental accumulation in many fish tissues and organs and their potential use in monitoring programs have not received proper attention. In the present study, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn concentrations were assessed by inductively coupled plasma mass spectrometry (ICP-MS) in the following 14 tissues of the wels catfish (Silurus glanis) from the Danube River: muscle, gills, spleen, liver, kidneys, intestine, gizzard, heart, brain, gallbladder, swim bladder, vertebra, operculum, and gonads. A high level of differential elemental accumulation among the studied tissues was observed. The maximum overall metal accumulation was observed in the vertebra, followed by the kidneys and liver, with the metal pollution index (MPI) values of 0.26, 0.25, and 0.24, respectively. The minimum values were observed in the gallbladder, muscle, brain, and swim bladder, with MPI values of 0.03, 0.06, 0.07, and 0.09, respectively. Average metal concentrations in the fish muscle were below the maximum allowed concentrations for human consumption. The mean As, Cd, Pb, Cu, Fe, and Zn concentrations in the muscle were 0.028, 0.001, 0.001, 0.192, 3.966, and 3.969 μg/g wet weight, respectively. We believe that the presented findings could be of interest for the scientific community and freshwater ecosystem managers. There is a need for further research that would assess less studied tissues in different fish species.

  10. Effect of temperature, precursor concentration and capping group on the shape of Cds nanoparticles

    CSIR Research Space (South Africa)

    Moloto, N

    2009-01-01

    Full Text Available semiconductor nanoparticles14-16. The overall aim of this study is to validate the influence of factors such as concentration, reaction temperature and capping group on both size and morphology of CdS nanoparticles. Experimental section General HDA... was observed. 13 References 1. J. G. Contreras, J. A. Gnecco, Anales de Quimica, 86, 740 (1990). 2. D. Adamczyk, Environmental Engineering Science, 23, 610 (2006). 3. L. I. Victoriano, Bol. Soc. Chil. Quím, 45, (2000). 4. I...

  11. Measuring the concentration of carboxylic acid groups in torrefied spruce wood.

    Science.gov (United States)

    Khazraie Shoulaifar, Tooran; Demartini, Nikolai; Ivaska, Ari; Fardim, Pedro; Hupa, Mikko

    2012-11-01

    Torrefaction is moderate thermal treatment (∼200-300°C) to improve the energy density, handling and storage properties of biomass fuels. In biomass, carboxylic sites are partially responsible for its hygroscopic. These sites are degraded to varying extents during torrefaction. In this paper, we apply methylene blue sorption and potentiometric titration to measure the concentration of carboxylic acid groups in spruce wood torrefied for 30min at temperatures between 180 and 300°C. The results from both methods were applicable and the values agreed well. A decrease in the equilibrium moisture content at different humidity was also measured for the torrefied wood samples, which is in good agreement with the decrease in carboxylic acid sites. Thus both methods offer a means of directly measuring the decomposition of carboxylic groups in biomass during torrefaction as a valuable parameter in evaluating the extent of torrefaction which provides new information to the chemical changes occurring during torrefaction.

  12. analysis of flow in a concentric annulus using finite element method

    African Journals Online (AJOL)

    user

    ABSTRACT. This work presents the computational modelling of the velocity distribution of an incompressible fluid flowing in a ... concentric annulus with center body rotation. [9] used .... pipe at a glance with a very high accuracy compared to.

  13. Trace element concentrations in needles and bark of Larix Sibirica within the Mo-W ore field (Buryat Republic, Russia)

    Science.gov (United States)

    Timofeev, Ivan; Kosheleva, Natalia

    2016-04-01

    The present study aims to assess the changes in the trace element (TE) composition of Larix Sibirica species growing in the impact area of Dzhida Mo-W plant in the Zakamensk city. The objectives of the study were: (1) to reveal the biogeochemical background features and changes in the TE composition of larch needles and bark in the mining region; (2) to determine patterns of spatial distribution of TE content in larch organs; (3) to assess the ecological state of larch plantation in different land-use zones of the city. A landscape-geochemical survey of the territory was carried out in summer of 2013. Total of 21 mixed (taken from 3-5 trees) samples of needles and bark were collected in undisturbed and different land-use areas. The bulk contents of TEs in dry plant samples were analyzed by mass spectrometry with induced coupled plasma. Sixteen priority pollutants were selected for thorough analysis, including elements of hazard classes I (Zn, As, Pb, Cd), II (Cr, Co, Ni, Cu, Mo, Sb), III (V, Sr, Ba, W), and some others (Sn, Bi). Concentrations of TEs (C_b) in background trees were compared with the global clarks (C_g) for annual increment of terrestrial vegetation (Dobrovol'skii 2003) via calculating the global enrichment EF_g=C_b/Cg and dispersion factors DF_g=C_g/C_b}. The concentrations of the elements in the urban samples Ci were grouped depending on the type of land use and compared with the background (C_b) via calculating the local enrichment EF_l=C_i/Cb and dispersion factors DF_l=C_b/C_i. The ecological state of the urban plants was diagnosed using three TE ratios. The Fe/Mn ratio represents photosynthetic activity with optimum value 1.5-2.5. The Pb/Mn ratio characterizes balance between technogenic and biophilic elements, its value for unpolluted terrestrial plants is 0.006. The Cu/Zn ratio determines the proportionality in the provision of enzyme synthesis with these metals, its optimum value is 0.27. TE composition of needles of background larch is

  14. Highly time-resolved trace element concentrations in aerosols during the Megapoli Paris campaigns

    Science.gov (United States)

    Furger, Markus; Visser, Suzanne; Slowik, Jay G.; Crippa, Monica; Poulain, Laurent; Appel, Karen; Flechsig, Uwe; Prevot, Andre S. H.; Baltensperger, Urs

    2014-05-01

    Trace elements contribute typically only a few percent to the total mass of air pollutants, however, they can affect the environment in significant ways, especially those that are toxic. Furthermore, they are advantageous with respect to a refinement of source apportionment when measured with high time resolution and appropriate size segregation. This approach is especially advantageous in an urban environment with numerous time-variant emission sources distributed across a relatively narrow space, as is typically the setting of a megacity. Two 1-month long field campaigns took place in the framework of the Megapoli project in Paris, France, in the summer of 2009 and in the winter of 2010. Rotating drum impactors (RDI) were operated at two sites in each campaign, one urban, the other one suburban. The RDI segregated the aerosols into three size ranges (PM10-2.5, PM2.5-1 and PM1-0.1) and sampled with 2-hour time resolution. The samples were analyzed with synchrotron radiation induced X-ray fluorescence spectrometry (SR-XRF) at the synchrotron facilities of Paul Scherrer Institute (SLS) and Deutsches Elektronen-Synchrotron (HASYLAB), where a broad range of elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Sr, Zr, Cd, Sn, Sb, Ba, Pb) was analyzed for each size range. Time series of the analyzed elements for the different sites and campaigns were prepared to characterize the aerosol trace element composition and temporal behavior for the different weather situations and urban environments. They allow for the distinction of regional vs. local sources and transport, and provide a basis for source apportionment calculations. Local and regional contributions of traffic, including re-suspension, break wear and exhaust, wood burning, marine and other sources will be discussed. Indications of long-range transport from Polish coal emissions in the city center of Paris were also found.

  15. Platinum-group elements. Quantification in collected exhaust fumes and studies of catalyst surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, M.A.; Gomez, M.M.; Moldovan, M. [Departamento de Quimica Analitica, Facultad de CC Quimicas, Universidad Complutense de Madrid, 28040- Madrid (Spain); Morrison, G.; Rauch, S. [Chalmers University of Technology, Gothenburg (Sweden); McLeod, C.; Ma, R. [University of Sheffield, Sheffield (United Kingdom); Laserna, J.; Lucena, P. [University of Malaga, Malaga (Spain); Caroli, S.; Alimonti, A.; Petrucci, F.; Bocca, B. [Istituto Superiore di Sanita, Rome (Italy); Schramel, P.; Lustig, S.; Zischka, M. [GSF-Forschung, Neuherberg (Germany); Wass, U.; Stenbom, B. [Volvo, Gothenberg (Sweden); Luna, M. [Ford, Madrid (Spain); Saenz, J.C. [Instituto Nacional de Tecnica Aeroespacial, INTA, Madrid (Spain); Santamaria, J.; Torrens, J.M. [Seat, Barcelona (Spain)

    2000-07-20

    Automotive catalytic converters, in which Pt, Pd and Rh (platinum-group elements; PGEs) are the active components for eliminating several noxious components from exhaust fumes, have become the main source of environmental urban pollution by PGEs. This work reports on the catalyst morphology through changes in catalyst surface by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and laser-induced breakdown spectrometry (LIBS) from fresh to aged catalytic converters. The distribution of these elements in the fresh catalysts analysed (Pt-Pd-Rh gasoline catalyst) is not uniform and occurs mainly in a longitudinal direction. This heterogeneity seems to be greater for Pt and Pd. PGEs released by the catalysts, fresh and aged 30000 km, were studied in parallel. Whole raw exhaust fumes from four catalysts of three different types were also examined. Two of these were gasoline catalysts (Pt-Pd-Rh and Pd-Rh) and the other two were diesel catalysts (Pt). Samples were collected following the 91441 EUDC driving cycle for light-duty vehicle testing. The results show that at 0 km the samples collected first have the highest content of particulate PGEs and although the general tendency is for the release to decrease with increasing number of samples taken, exceptions are frequent. At 30000 km the released PGEs in gasoline and diesel catalysts decreased significantly. For fresh gasoline catalysts the mean of the total amount released was approximately 100, 250 and 50 ng km{sup -1} for Pt, Pd and Rh, respectively. In diesel catalysts the Pt release varied in the range 400-800 ng km{sup -1}. After ageing the catalysts up to 30000 km, the gasoline catalysts released amounts of Pt between 6 and 8 ng km{sup -1}, Pd between 12 and 16 ng km{sup -1} and Rh between 3 and 12 ng km{sup -1}. In diesel catalysts the Pt release varied in the range 108-150 ng km{sup -1}. The soluble portion of PGEs in the HNO{sub 3} collector solution represented less than 5% of the

  16. Episodic memory, concentrated attention and processing speed in aging: A comparative study of Brazilian age groups

    Directory of Open Access Journals (Sweden)

    Rochele Paz Fonseca

    Full Text Available Abstract Neuropsychological studies on the processing of some specific cognitive functions throughout aging are essential for the understanding of human cognitive development from ages 19 to 89. Objectives: This study aimed to verify the occurrence of differences in the processing of episodic memory, concentrated attention and speed of attentional processing among four age groups of adults. Methods: A total of 136 neurologically healthy adults, aged 19-89, with 9 or more years of schooling, took part in the study. Participants were divided according to four age groups: young, middle-aged, elderly and oldest old adults. Subtests of the Brief Neuropsychological Evaluation Instrument (NEUPSILIN were applied for the cognitive assessment. Mean score of corrected answers and of response times were compared between groups by means of a one-way ANOVA test with post-hoc Scheffe procedures and ANCOVA including the co-variables of years of schooling and socio-economical scores. Results: In general, differences in performance were observed from 60 years old on. Only the episodic memory task of delayed recall reflected differences from the age of around 40 onwards and processing speed from around the age of 70 onwards. Thus, differences were found between the age groups regarding their cognitive performance, particularly between young adults and elderly adults, and young adults and oldest old adults. Conclusions: Our research indicates that the middle-aged group should be better analyzed and that comparative cross-sectional studies including only extreme groups such as young and elderly adults are not sufficient.

  17. Trace element concentrations along a gradient of urban pressure in forest and lawn soils of the Paris region (France).

    Science.gov (United States)

    Foti, Ludovic; Dubs, Florence; Gignoux, Jacques; Lata, Jean-Christophe; Lerch, Thomas Z; Mathieu, Jérôme; Nold, François; Nunan, Naoise; Raynaud, Xavier; Abbadie, Luc; Barot, Sébastien

    2017-11-15

    The concentration, degree of contamination and pollution of 7 trace elements (TEs) along an urban pressure gradient were measured in 180 lawn and wood soils of the Paris region (France). Iron (Fe), a major element, was used as reference element. Copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) were of anthropogenic origin, while arsenic (As), chromium (Cr) and nickel (Ni) were of natural origin. Road traffic was identified as the main source of anthropogenic TEs. In addition, the industrial activity of the Paris region, especially cement plants, was identified as secondary source of Cd. Soil characteristics (such as texture, organic carbon (OC) and total nitrogen (tot N) contents) tell the story of the soil origins and legacies along the urban pressure gradient and often can explain TE concentrations. The history of the land-use types was identified as a factor that allowed understanding the contamination and pollution by TEs. Urban wood soils were found to be more contaminated and polluted than urban lawns, probably because woods are much older than lawns and because of the legacy of the historical management of soils in the Paris region (Haussmann period). Lawn soils are similar to the fertile agricultural soils and relatively recently (mostly from the 1950s onwards) imported from the surrounding of Paris, so that they may be less influenced by urban conditions in terms of TE concentrations. Urban wood soils are heavily polluted by Cd, posing a high risk to the biological communities. The concentration of anthropogenic TEs increased from the rural to the urban areas, and the concentrations of most anthropogenic TEs in urban areas were equivalent to or above the regulatory reference values, raising the question of longer-term monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Assessment trace elements concentrations in tissues in Caspian Pond Turtle (Mauremys caspica) from Golestan province, Iran.

    Science.gov (United States)

    Yadollahvand, Reza; Kami, Haji Gholi; Mashroofeh, Abdulreza; Bakhtiari, Alireza Riyahi

    2014-03-01

    Concentrations of cadmium, lead, zinc, and copper were measured in different organs and tissues of 15 Caspian Pond Turtle (Mauremys caspica) collected from Gharehsu River, Golestan province, Iran in June and July 2012. Mean concentrations (dry weight) of zinc and copper were 66.9 and 6.7µgg(-1) in liver, 147 and 3.4µgg(-1) in heart, 93.2 and 4.9µgg(-1) in shell, and finally 150.7 and 4.5µgg(-1) in muscle, respectively. Mean concentrations of cadmium and lead were 5.8 and 32.4µgg(-1) in liver, 2.9 and 20.9µgg(-1) in heart, 3.5 and 21.5µgg(-1) in shell, and finally 2.5 and 27.5µgg(-1) in muscle, respectively. On average, lead, cadmium, copper and zinc concentrations in the analyzed tissues were much higher than those reported in other freshwater turtle species. In particular, the mean concentrations of lead in liver and muscle of Caspian Pond Turtle was extremely high. To our knowledge, this is the first report into metal accumulation in tissues and organs of Caspian Pond Turtle from of the Gharehsu River in Golestan province, Iran. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Optical Simulation and Experimental Verification of a Fresnel Solar Concentrator with a New Hybrid Second Optical Element

    Directory of Open Access Journals (Sweden)

    Guiqiang Li

    2016-01-01

    Full Text Available Fresnel solar concentrator is one of the most common solar concentrators in solar applications. For high Fresnel concentrating PV or PV/T systems, the second optical element (SOE is the key component for the high optical efficiency at a wider deflection angle, which is important for overcoming unavoidable errors from the tacking system, the Fresnel lens processing and installment technology, and so forth. In this paper, a new hybrid SOE was designed to match the Fresnel solar concentrator with the concentration ratio of 1090x. The ray-tracing technology was employed to indicate the optical properties. The simulation outcome showed that the Fresnel solar concentrator with the new hybrid SOE has a wider deflection angle scope with the high optical efficiency. Furthermore, the flux distribution with different deviation angles was also analyzed. In addition, the experiment of the Fresnel solar concentrator with the hybrid SOE under outdoor condition was carried out. The verifications from the electrical and thermal outputs were all made to analyze the optical efficiency comprehensively. The optical efficiency resulting from the experiment is found to be consistent with that from the simulation.

  20. Ensemble modeling coupled with six element concentrations in human blood for cancer diagnosis.

    Science.gov (United States)

    Chen, Hui; Tan, Chao; Wu, Tong

    2011-10-01

    Six important metal contents (i.e., zinc, barium, magnesium, calcium, copper, and selenium) in blood samples coupled with an ensemble classification algorithm have been used for the classification of normal people and cancer patients. A dataset containing 42 healthy samples and 32 cancer samples was used for experiment. The prediction results from this method outperformed those from the newly developed support vector machine, i.e., a sensitivity of 100%, a specificity of 95.2%, and an overall accuracy of 98.6%. It seems that ELDA coupled with blood element analysis can serve as a valuable tool for diagnosing cancer in clinical practice.

  1. Examination of Element Concentrations in Groundwater by ICP-MS for Monitoring of Pre-Earthquake Activities

    Institute of Scientific and Technical Information of China (English)

    Mehmet Yaman; Ahmet Sasmaz

    2013-01-01

    This study presents the results of hydrogeochemical studies carried out in Zeytun thermal springs in Kahramanmaras,located South Middle Anatolia-Turkey.More than 90 thermal water samples were collected on a regular basis from 2006 to 2008 to measure element concentrations as a monitor of earthquake precursors.Water samples were analyzed using ICP-MS.The observed B,Ba,Br and Ge concentrations for 16 months are in ranges of 79~422,103~167,28~93 and 0.3~1.2 μg · L-1,respectively.Chloride concentrations for these periods are in range of 7~21 mg · L-1.The data identify some element anomalies before earthquakes.These anomalies are characterized by decreases up to 158% in Ba and Cl concentrations.The occurrence of these anomalies can be attributed to stress/strain induced pressure changes in the subsurface water systems.It can be suggested that the thermal springs in the fault line area are ideal sites for precursors of earthquakes.

  2. Analysis on blood trace elements concentration levels of middle period pregnant women in Handan City%邯郸市孕中期妇女全血微量元素浓度水平分析

    Institute of Scientific and Technical Information of China (English)

    栾玉杰; 郭丽丽; 李守霞; 郭胜利; 赵素斌

    2013-01-01

    Objective To explore the whole blood concentration levels of copper, zinc, calcium, magnesium, iron trace elements of middle period pregnant women in Handan City and its clinical significance, in order to guide the intake and supplement trace elements during pregnancy. Methods Flame atomic absorption spectrometric was used to detect 5 trace elements concentration levels in whole blood among 368 cases of middle period pregnant women (pregnancy group) and 138 cases of healthy adult women (control group), then the data were analyzed and compared. Results The copper and calcium concentration levels in pregnancy group were higher than those of the control group, the differences were statistically significant (P 0.05). The deficient of copper, calcium, magnesium, iron had no significant differences between the two groups (P > 0.05). The zinc element lack rate in the pregnancy group was higher than the control group, the difference was statistically significant (P 0.05);铜、钙、镁、铁元素两组间缺乏率差异无统计学意义(P > 0.05);中孕组锌元素缺乏率明显高于对照组,差异有统计学意义(P < 0.05).结论 孕妇作为特殊人群,应加强微量元素监测以保证各种微量元素均衡摄入,做好孕期保健.

  3. PM mass and elemental species concentration data for I-96 monitoring sites

    Data.gov (United States)

    U.S. Environmental Protection Agency — PM2.5 (fine) and PM10-2.5 (coarse) mass concentrations for monitoring sites located 10 m, 100 m and 300 m north of Interstate I-96 in Detroit, the water-soluble and...

  4. Broadband behavior of transmission volume holographic optical elements for solar concentration.

    Science.gov (United States)

    Bañares-Palacios, Paula; Álvarez-Álvarez, Samuel; Marín-Sáez, Julia; Collados, María-Victoria; Chemisana, Daniel; Atencia, Jesús

    2015-06-01

    A ray tracing algorithm is developed to analyze the energy performance of transmission and phase volume holographic lenses that operate with broadband illumination. The agreement between the experimental data and the theoretical treatment has been tested. The model has been applied to analyze the optimum recording geometry for solar concentration applications.

  5. Validation of new superheavy elements and IUPAC-IUPAP joint working group

    Science.gov (United States)

    Jarlskog, Cecilia

    2016-12-01

    The great chemist Glenn Seaborg has written a delightful little book "Man-made Transuranium Elements", published in 1963, in which he points out that: "The former basic criterion for the discovery of a new element - namely, chemical identification and separation from all previously-known elements - had to be changed in the case of lawrencium (element 103). This also may be true for elements beyond lawrencium." Indeed this is what has happened. The elements with Z ≥ 103 are produced in nuclear reactions and are detected by counters. The detectors have undergone substantial refinement. For example one uses multiwire proportional chambers [for which George Charpak received the 1992 Nobel Prize in Physics] as well as solid state micro-strip detectors. In spite of this remarkable shift from chemistry to physics, the managerial staff of the International Union of Pure and Applied Chemistry (IUPAC) does not seem to be aware of what has been going on. The validation of superheavy elements should be done by physicists as the chemists lack the relevant competence as I will discuss here below. This article is about a collaboration between International Union of Pure and Applied Chemistry (IUPAC) and its sister organization International Union of Pure and Applied Physics (IUPAP), to deal with discovery of superheavy elements beyond Z = 112. I spent a great deal of time on this issue. In my opinion, the collaboration turned out to be a failure. For the sake of science, which should be our most important concern (and not politics), the rules for the future collaborations, if any, should be accurately defined and respected. The validation of new elements should be done by people who have the relevant competence - the physicists.

  6. Increase in platinum group elements in Mexico City as revealed from growth rings of Taxodium mucronatum ten.

    Science.gov (United States)

    Morton-Bermea, Ofelia; Beramendi-Orosco, Laura; Martínez-Reyes, Ángeles; Hernández-Álvarez, Elizabeth; González-Hernández, Galia

    2016-02-01

    Tree rings may be used as indicators of contamination events providing information on the chronology and the elemental composition of the contamination. In this framework, we report PGEs enrichment in growth rings of Taxodium mucronatum ten for trees growing in the central area of Mexico City as compared to trees growing in a non-urban environment. Concentrations of PGE were determined by ICP-MS analysis on microwave-digested tree rings. The element found in higher concentrations was Pd (1.13-87.98 μg kg(-1)), followed by Rh (0.28-36.81 μg kg(-1)) and Pt (0.106-7.21 μg kg(-1)). The concentration trends of PGEs in the tree-ring sequences from the urban area presented significant correlation values when comparing between trees (r between 0.618 and 0.98, P < 0.025) and between elements within individual trees (r between 0.76 and 0.994, P < 0.01). Furthermore, a clear increase was observed for rings after 1997, with enrichment of up to 60 times the mean concentration found for the sequence from the non-urban area and up to 40 times the mean concentration for the pre-1991 period in the urban trees. These results also demonstrate the feasibility of applying T. mucronatum ten to be used as a bioindicator of the increase in PGE in urban environments.

  7. The Effect of Nitrogen and Boron on Growth, Yield and Concentration of Some Nutrient Elements of Tomato

    Directory of Open Access Journals (Sweden)

    N. Farzaneh

    2010-08-01

    Full Text Available A completely randomized factorial experiment was set up with 16 treatments and three replicates to study the effect of nitrogen and boron on yield, shoot and root dry weights and leaf concentration of nutrient elements in hydroponically grown tomato in greenhouse of Agricultural College of Zanjan University in 2008. In this experiment, tomato seed of Rio Grande Ug was selected and simple and interaction effect of four levels of N (100, 200, 300 and 400 mgL-1 and four levels of B (0.5, 1.0, 1.5 and 2.0 mg L-1 on tomato yield, shoot and root dry weights and leaf concentration of nutrient elements was investigated. The results indicated that the simple and interaction effect of nitrogen and boron on yield and tomato shoot and root dry weights were significant. Te highest yield and root dry weights were obtained in N200B1.0 treatment and the highest shoot dry weight was obtained in N300B1.0 treatment. By increasing the nitrogen level in the nutrient solution, leaf N and Mn concentration increased while B, Fe and Zn concentration of leaves decreased significantly. In contrast, by increasing the boron levels, leaf N, B and Zn concentration increased and Fe and Mn concentration of leaves decreased significantly. With respect to the results of this study, applications of 200 mg L-1N and 1.0 mgL-1 B of nutrient solution are recommended to obtain higher yield and better quality for tomato in hydroponic culture.

  8. Oxidative stress indicators and trace element concentrations in tissues of mako shark (Isurus oxyrinchus).

    Science.gov (United States)

    Vélez-Alavez, Marcela; Labrada-Martagón, Vanessa; Méndez-Rodriguez, Lía C; Galván-Magaña, Felipe; Zenteno-Savín, Tania

    2013-08-01

    Liver, kidney and muscle from juvenile mako sharks (Isurus oxyrinchus) were collected in Baja California Sur. Lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) concentrations were determined by atomic absorption spectrophotometry. The production of superoxide radical (O2(•-)) was measured as an indicator of reactive oxygen species production; lipid peroxidation (TBARS) and protein carbonyl levels were quantified as indicators of oxidative damage, and the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) was assessed as indicator of antioxidant defenses. Two discriminant functions separated muscle from liver and kidney samples. Cd concentration was lower in muscle than in kidney (pshark.

  9. Trace element concentrations in surface estuarine and marine sediments along the Mississippi Gulf Coast following Hurricane Katrina.

    Science.gov (United States)

    Warren, Crystal; Duzgoren-Aydin, Nurdan S; Weston, James; Willett, Kristine L

    2012-01-01

    Hurricanes are relatively frequent ecological disturbances that may cause potentially long-term impacts to the coastal environment. Hurricane Katrina hit the Mississippi Gulf Coast in August 2005, and caused a storm surge with the potential to change the trace element content of coastal surface sediments. In this study, surface estuarine and marine sediments were collected monthly following the storm from ten sites along the Mississippi Gulf Coast (Mobile Bay, Grand Bay Bayous Heron and Cumbest, Pascagoula, Ocean Springs, Biloxi Gulf, Back Biloxi Bay, Gulfport Gulf, Gulfport Courthouse Rd, and Gulfport Marina). Concentrations of V, Cr, Mn, Fe, Co, Ni, Zn, As, Cd, and Pb were measured by inductively coupled plasma-mass spectrometry to evaluate their temporal and spatial variations in the year following Hurricane Katrina. Sediments were characterized by pH, particle size distribution and total carbon and nitrogen content. Trace element contents of the sediments were determined in both Hurricane Katrina would not cause an adverse impact on resident organisms. Instead, the concentrations of trace elements were site-dependent, with specific contaminants relating to the use of the area prior to Hurricane Katrina.

  10. Exposure to residual concentrations of elements from a remediated coal fly ash spill does not adversely influence stress and immune responses of nestling tree swallows.

    Science.gov (United States)

    Beck, Michelle L; Hopkins, William A; Hallagan, John J; Jackson, Brian P; Hawley, Dana M

    2014-01-01

    Anthropogenic activities often produce pollutants that can affect the physiology, growth and reproductive success of wildlife. Many metals and trace elements play important roles in physiological processes, and exposure to even moderately elevated concentrations of essential and non-essential elements could have subtle effects on physiology, particularly during development. We examined the effects of exposure to a number of elements from a coal fly ash spill that occurred in December 2008 and has since been remediated on the stress and immune responses of nestling tree swallows. We found that nestlings at the site of the spill had significantly greater blood concentrations of Cu, Hg, Se and Zn in 2011, but greater concentrations only of Se in 2012, in comparison to reference colonies. The concentrations of elements were below levels of significant toxicological concern in both years. In 2011, we found no relationship between exposure to elements associated with the spill and basal or stress-induced corticosterone concentrations in nestlings. In 2012, we found that Se exposure was not associated with cell-mediated immunity based on the response to phytohaemagglutinin injection. However, the bactericidal capacity of nestling plasma had a positive but weak association with blood Se concentrations, and this association was stronger at the spill site. Our results indicate that exposure to these low concentrations of elements had few effects on nestling endocrine and immune physiology. The long-term health consequences of low-level exposure to elements and of exposure to greater element concentrations in avian species require additional study.

  11. Thiolated pyrimidine nucleotides may interfere thiol groups concentrated at lipid rafts of HIV-1 infected cells.

    Science.gov (United States)

    Kanizsai, Szilvia; Ongrádi, Joseph; Aradi, János; Nagy, Károly

    2014-12-01

    Upon HIV infection, cells become activated and cell surface thiols are present in increased number. Earlier we demonstrated in vitro anti-HIV effect of thiolated pyrimidine nucleotide UD29, which interferes thiol function. To further analyse the redox processes required for HIV-1 entry and infection, toxicity assays were performed using HIV-1 infected monolayer HeLaCD4-LTR/ β-gal cells and suspension H9 T cells treated with several thiolated nucleotide derivatives of UD29. Selective cytotoxicity of thiolated pyrimidines on HIV-1 infected cells were observed. Results indicate that thiolated pyrimidine derivates may interfere with -SH (thiol) groups concentrated in lipid rafts of cell membrane and interacts HIV-1 infected (activated) cells resulting in a selective cytotoxicity of HIV-1 infected cells, and reducing HIV-1 entry.

  12. Concentration of radioactive elements (U, Th and K) derived from phosphatic fertilizers in cultivated soils

    Energy Technology Data Exchange (ETDEWEB)

    Becegato, Valter Antonio [Universidade do Estado de Santa Catarina, Florianopolis, SC (Brazil). Dept. de Engenharia Ambiental]. E-mail: becegato@cav.udesc.br; Ferreira, Francisco Jose Fonseca [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Lab. de Geofisica Aplicada]. E-mail: francisco.ferreira@ufpr.br; Machado, William Cesar Pollonio [Instituto Ambiental do Parana, Pato Branco, PR (Brazil)]. E-mail: wcpm@mail.crea-pr.org.br

    2008-11-15

    Gamma spectrometric measurements were obtained for the agricultural soils aiming at characterizing the spatial distribution of radionuclide concentrations (K, eU and eTh), as well for the samples of phosphatic fertilizers and agricultural gypsum. In the study areas, three types of soils occurred: Eutrophic Red Nitosol (Alfisoil), Eutroferric Red Latosol of clayey texture (Oxisoil) and Dystrophic Red Latosol of medium texture (Oxisoil). The results showed that the radionuclide concentrations in more clayey soils were higher than in more sandy soils, mainly as a function of a higher adsorption capacity of the former. For the area where human activity predominated, the average contents of K, eU and eTh were respectively 54.75; 10.22 and 7.27 Bq/Kg, significantly higher than those for the area where no fertilizers were used (34.15 Bq/Kg K; 1.69 Bq/Kg eU, and 5.36 Bq/Kg eTh). Variations in the radionuclide concentrations were also observed in various fertilizer formula used in soybean and wheat crops. (author)

  13. Source, concentration, and distribution of elemental mercury in the atmosphere in Toronto, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, Elaine; Tharumakulasingam, Kavitharan [Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3 (Canada); Athar, Makshoof [Institute of Chemistry, University of the Punjab, Lahore (Pakistan); Yousaf, Muhammad; Cheng, Irene; Huang, Y. [Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3 (Canada); Lu, Julia, E-mail: julialu@ryerson.ca [Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, ON M5B 2K3 (Canada); Yap, Dave [Ontario Ministry of the Environment, 125 Resources Road, Toronto, ON M9P 3V6 (Canada)

    2011-08-15

    Atmospheric gaseous elemental mercury [GEM] at 1.8, 4, and 59 m above ground, in parking lots, and in indoor and outdoor air was measured in Toronto City, Canada from May 2008-July 2009. The average GEM value at 1.8 m was 1.89 {+-} 0.62 ng m{sup -3}. The GEM values increased with elevation. The average GEM in underground parking lots ranged from 1.37 to 7.86 ng m{sup -3} and was higher than those observed from the surface parking lots. The GEM in the indoor air ranged from 1.21 to 28.50 ng m{sup -3}, was higher in the laboratories than in the offices, and was much higher than that in the outdoor air. All these indicate that buildings serve as sources of mercury to the urban atmosphere. More studies are needed to estimate the contribution of urban areas to the atmospheric mercury budget and the impact of indoor air on outdoor air quality and human health. - Highlights: > Buildings served as mercury sources to urban atmosphere. > Atmospheric mercury level increased with increasing height in the street canyon. > Emission from vehicles and ground surfaces was not the major sources of Hg to urban air. > Mercury levels were higher in indoor than outdoor air and in laboratories than in offices. > Mercury levels were higher in the outdoor air near building walls. - Buildings serve as sources of gaseous elemental mercury and research is needed to quantify the emission and to assess the impact of indoor air on outdoor air quality and human health.

  14. Extraction of some strategic elements from thorium–uranium concentrate using bioproducts of Aspergillus ficuum and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Osman A. Desouky

    2016-09-01

    Full Text Available The activity of the bioproducts from Aspergillus ficuum and Pseudomonas aeruginosa for extraction of thorium (Th4+, uranium (UO22+ and rare earth elements (REEs from thorium–uranium concentrate was studied. P. aeruginosa produce element-specific ligand (siderophore that is able to change pH and enhance chelation of Th4+ and UO22+. The produced siderophore at pH 5.3 has the ability to bioleach and is complexed with 68.00% of uranium and 65.00% of thorium. Also, A. ficuum produced different kinds of organic acids which leached 30.00% of uranium and 29.12% of thorium in addition to 20.00% of lanthanum, 33.00% of cerium and 2.51% of yttrium as rare earth elements at pH 3.0. Oxalic acid was efficient for Th4+, UO22+and REEs precipitation. The binocular stereo-microscope (BSM, environmental scanning electron microscope (ESEM and X-ray diffraction (XRD analyses confirmed the percentages of extracted metals. Exogenous polysaccharides (EPSs seem to play an important role in bioleaching and removal of these elements. It was found that EPSs produced by A. ficuum adsorbed Th4+, UO22+ and REEs while that produced by P. aeruginosa adsorbed REEs only.

  15. Elemental concentration analysis in the brain of young and old Wistar rats by total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, Renata F.B.; Jesus, Edgar F.O. de; Lopes, Ricardo T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Nuclear Instrumentation Lab.]. E-mail: renata@lin.ufrj.br; Anjos, Marcelino J. dos [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Physics Inst.]. E-mail: marcelin@lin.ufrj.br; Carmo, Maria G.T. do [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Nutrition Inst.; Rocha, Monica S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. of Basics and Clinic Pharmacy; Moreira, Silvana [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Civil Engineering Dept.; Martinez, Ana M.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. of Histology and Embryology

    2007-07-01

    It is well known that aging is associated with neurobehavioral deficits. The aging process of human brain is characterized by progressive neuronal loss. Furthermore, certain brain areas are more vulnerable to neuronal degeneration than others, reflecting an altered resistance to stress of the tissue itself and/or the lack of adequate immunological defense mechanisms in these regions. About the elemental levels in the brain, it is known that the excess ou deficiency of some elements are toxic for human healthy, being also related to several neurodegenerative diseases. In this way, the main goal of this work was to determine the elemental concentration in the hippocampus of young and old male (n = 10) and female (n = 10) Wistar rats by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). These measurements were carried out at XRF beam line at Light Synchrotron Brazilian Laboratory, Campinas, Brazil. About the results, we could observe that Al, Fe, Cu, Zn and Br levels were higher in the hippocampus of the old female rats than the young ones. On the other hand, only Cu levels were higher in the hippocampus of the old male rats than the young ones. Therefore, the aging of the hippocampus of the female rats can be characterized by an accumulate for Al, Fe, Cu, Zn and Br. The excess in these elements levels are also associated with several neurodegenerative disorders, such as Alzheimer' disease, Parkinson's disease and Huntington's disease. (author)

  16. Relationship between the types of binary alloy phase diagrams of VIII and IB group elements and the Mendeleev numbers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The relationship between the types of binary alloy phase diagrams of Vlll and IB group elements and the Men deleev numbers was discussed for the first time using the Vlll and IB group elements as solvent metals (A) and the other elements as solute metals (B), basesd on their alloy phase diagram types. The Mendeleev numbers of the solvent metals and the solute metals were expressed as Ma and MB, respectively. A two-dimension map of MdMB was drawn. It is indicated that there is an oblique line in the map, which divides the binary alloy phase diagram types of solvent metals into two symmetry parts, the phase diagram types of the other elements with solvent metals located at the above or down of the line respectively, while on the line, AM= 0. The phase diagrams between the solvent metals basically are simple systems, mainly belong to the types of continues solid solution and the peritectic (about 40% for each type). The solvent metals can be divided into three groups: Co, Ir, Rh, Ni, Pt, and Pd as the first group; Ag, Au, and Cu as the second group;and Fe, Os, and Ru as the third group. The characteristics of the phase diagrams formed between the elements in each group were discussed. About 80% phase diagrams belong to complex systems and less than 20% belong to the simple systems. The regular variation of the chemical scale, the metallic radii of the atoms, the number of valence electrons, and the first ionization energy with the Mendeleev numbers and the crystal structure were introduced as well.

  17. Effects of varying floor space on aggressive behavior and cortisol concentrations in group-housed sows.

    Science.gov (United States)

    Hemsworth, P H; Morrison, R S; Tilbrook, A J; Butler, K L; Rice, M; Moeller, S J

    2016-11-01

    Floor space is an important determinant of aggression and stress in group-housed sows, and the aim of the present experiment was to comprehensively examine the effects of floor space in the range of 1.45 to 2.90 m/sow from mixing until 27 d after insemination on aggression, stress, and reproduction of group-housed sows. A previous experiment on the effects of floor space indicated spatial variability across and along the research facility in both sow aggression and stress. To minimize this spatial variability within the research facility, similar-sized pens but with varying groups sizes (10-20) in 4 separate blocks of 3 contiguous pens within each of 9 time replicates (180 sows/replicate) were used to examine 6 space allowances (1.45-2.9 m/sow). Space treatments were appropriately randomized to pens. Although it may be argued that space allowance is confounded with group size in this design, there was no evidence in our previous experiment of group size effects, for pens of 10 to 80 sows, or appreciable interactions between space and group size on aggression, stress, and reproduction. In the present experiment, sows were introduced to treatments within 4 d of insemination and were floor fed 4 times per day (2.5 kg/sow per d). On both Days 2 and 26 after mixing, aggressive behavior (bites and knocks) at feeding and plasma cortisol concentrations were measured. Restricted maximum likelihood mixed model analyses were used to examine the treatment effect after accounting for replicate and random spatial location effects within replicate. There was a consistent linear effect of floor space allowance on aggression at feeding at Day 2 ( space. However, there were no effects of space allowance on aggression and stress at Day 26 ( = 0.14 and = 0.79, respectively). These results show that increased floor space in the immediate post-mixing period reduces aggression and stress and that sows may adapt to reduced floor space over time. A strategy of staged-gestation penning

  18. Hepatic and renal trace element concentrations in American alligators (Alligator mississippiensis) following chronic dietary exposure to coal fly ash contaminated prey.

    Science.gov (United States)

    Tuberville, Tracey D; Scott, David E; Metts, Brian S; Finger, John W; Hamilton, Matthew T

    2016-07-01

    Little is known about the propensity of crocodilians to bioaccumulate trace elements as a result of chronic dietary exposure. We exposed 36 juvenile alligators (Alligator mississippiensis) to one of four dietary treatments that varied in the relative frequency of meals containing prey from coal combustion waste (CCW)-contaminated habitats vs. prey from uncontaminated sites, and evaluated tissue residues and growth rates after 12 mo and 25 mo of exposure. Hepatic and renal concentrations of arsenic (As), cadmium (Cd) and selenium (Se) varied significantly among dietary treatment groups in a dose-dependent manner and were higher in kidneys than in livers. Exposure period did not affect Se or As levels but Cd levels were significantly higher after 25 mo than 12 mo of exposure. Kidney As and Se levels were negatively correlated with body size but neither growth rates nor body condition varied significantly among dietary treatment groups. Our study is among the first to experimentally examine bioaccumulation of trace element contaminants in crocodilians as a result of chronic dietary exposure. A combination of field surveys and laboratory experiments will be required to understand the effects of different exposure scenarios on tissue residues, and ultimately link these concentrations with effects on individual health.

  19. Microstructure and electrical properties of XInZnO (X = Ti, Zr, Hf) films and device performance of their thin film transistors—The effects of employing Group IV-B elements in place of Ga

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Mi Ran [Department of Physics, Institute of Basic Science, Brain Korea 21 Physics Research Division, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Jeon, Haseok; Na, Sekwon; Kim, Sunho [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Jung, Donggeun [Department of Physics, Institute of Basic Science, Brain Korea 21 Physics Research Division, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Hyoungsub [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Hoo-Jeong, E-mail: hlee@skku.edu [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2013-06-25

    Highlights: ► The effects of adding Group IV B elements have been evaluated in this study. ► Adding alloying elements affected the oxygen vacancy and carrier concentrations, and mobility. ► Adding alloying elements enhanced the bias stability in the order of Ti, Zr and Hf. -- Abstract: In this study, we systematically investigated the effects of employing Group IV-B metals (Ti, Zr, and Hf) in place of Ga in GaInZnO films by fabricating XInZnO films (X = Ti, Zr, or Hf) with a various ratio of the Group IV-B elements. Materials characterization using various analytical methods (including transmission electron microscopy and X-ray photoelectron spectroscopy) elucidates that upon the addition of a small amount of the alloying elements, while the microstructure turned into amorphous from nanocrystalline, the oxygen vacancy concentration decreased systematically along with the carrier concentration. The device characteristics (threshold voltage and field-effect mobility) of the transistors fabricated from the films sensitively reflect the changes in the film properties (carrier concentration and bulk mobility). The bias stability enhanced with the increase of the ratio of the alloying elements to an extent that apparently increases in the order of Ti, Zr and Hf, which is reverse to the order of the electronegativity.

  20. Concentrating partially entangled W-class states on nonlocal atoms using low- Q optical cavity and linear optical elements

    Science.gov (United States)

    Cao, Cong; Chen, Xi; Duan, YuWen; Fan, Ling; Zhang, Ru; Wang, TieJun; Wang, Chuan

    2016-10-01

    Entanglement plays an important role in quantum information science, especially in quantum communications. Here we present an efficient entanglement concentration protocol (ECP) for nonlocal atom systems in the partially entangled W-class states, using the single-photon input-output process regarding low- Q cavity and linear optical elements. Compared with previously published ECPs for the concentration of non-maximally entangled atomic states, our protocol is much simpler and more efficient as it employs the Faraday rotation in cavity quantum electrodynamics (QED) and the parameter-splitting method. The Faraday rotation requires the cavity with low- Q factor and weak coupling to the atom, which makes the requirement for entanglement concentration much less stringent than the previous methods, and achievable with current cavity QED techniques. The parameter-splitting method resorts to linear-optical elements only. This ECP has high efficiency and fidelity in realistic experiments, and some imperfections during the experiment can be avoided efficiently with currently available techniques.

  1. [Multivariate analysis of heavy metal element concentrations in atmospheric deposition in Harbin City, northeast China].

    Science.gov (United States)

    Tang, Jie; Han, Wei-Zheng; Li, Na; Li, Zhao-Yang; Bian, Jian-Min; Li, Hai-Yi

    2011-11-01

    In order to understand the characteristics of atmospheric heavy metal deposition in Harbin City, 46 deposition samples were collected which were taken using bulk deposition samplers during the period of 2008-2009 (about 365 days). The samples were analyzed for heavy metal concentration by atomic fluorescence spectrometry (AFS) and inductively coupled plasma-atomic spectrometry (ICP-AES). The deposition flux was calculated. Sources analysis was made by the method of principal component analysis (PCA), Pearsons and enrichment factor (EF). The following points can be gained through multivariate analysis. Mn and Co are mostly from natural sources while the others may be brought by coal dust, vehicle emissions and metal smelting.

  2. The Unusually High Halo Concentration of the Fossil Group NGC 6482: Evidence for Weak Adiabatic Contraction

    Science.gov (United States)

    Buote, David A.

    2017-01-01

    Although fossil galaxy systems are thought to be very old, and thus should possess above-average halo concentrations, typically fossils have unexceptional concentrations of their masses. We revisit the massive isolated elliptical galaxy/fossil group NGC 6482 for which previous X-ray studies of a modest Chandra observation obtained a very uncertain, but also possibly very high, halo concentration. We present new measurements of the hot gas surface brightness, temperature, and iron abundance using the modest Chandra observation and a previously unpublished Suzaku observation, the latter of which allows the measurements of the gas properties to be extended out to ∼ {r}2500. By constructing hydrostatic equilibrium models of the gas with separate components for the gas, the stellar mass of the large central galaxy (BCG), and the dark matter (DM), we measure {c}200=32.2+/- 7.1 and {M}200=(4.5+/- 0.6)× {10}12 {M}ȯ using a Navarro-Frenk-White (NFW) DM profile. For a halo of this mass, the measured concentration c200 exceeds the mean value (7.1) expected for relaxed ΛCDM halos by 3.5σ in terms of the observational error, and by 6σ considering the intrinsic scatter in the ΛCDM c–M relation, which situates NGC 6482 as the most extreme outlier known for a fossil system. We explored several variants of adiabatic contraction (AC) models and, while the AC models provide fits of the same quality as the uncontracted models, they do have the following advantages: (1) lower c200 that is less of an outlier in the ΛCDM c–M relation, and (2) baryon fractions ({f}{{b},200}) that agree better with the mean cosmic value. While the standard AC prescriptions yield a BCG stellar mass that is uncomfortably low compared to results from stellar population synthesis (SPS) models, a weaker AC variant that artificially shuts off cooling and star formation at z = 2 yields the same stellar mass as the uncontracted models. These are probably the reasons why our X-ray analysis prefers this

  3. Relationship between element concentrations and body size in the Lake Maggiore population of Unio pictorum mancus (Mollusca, Bivalvia

    Directory of Open Access Journals (Sweden)

    Ilenia CATTANI

    2011-08-01

    Full Text Available The study focused on using a fresh-water mussel (Unio pictorum mancus as a bioindicator of various pollutants, and particularly metals. The elements considered were: Al, As, Ca, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn. This research was carried out at a site where various other studies have been conducted on important characteristics of the same population of Unio. This site is a small bay called "Sabbie d’Oro" located on the south-east coast of Lake Maggiore. Our study involved quantifying the capacity of this mollusc to concentrate large amounts of metal in its body without evident consequences by using detoxification mechanisms. We analysed not only element concentrations, but also their variability (expressed as CV% in the soft tissues and in the shell, for two main reasons: i the sampling design should include a preliminary analysis to determine how many specimens is necessary collect to ensure a specified level of precision; ii the sample variability value may be combined with the value of analytical precision (BCR to obtain an estimate of the "experimental" precision. In soft tissue, Ca accumulation tended to increase with size, and Al accumulation decreased with size. In shell, Ca and Ni were stored more than in soft tissue, but not proportionally to size. V, Cr and Mo tended to accumulate in the shell progressively over the years, whereas Co and Al are "diluted" during growth, or are absorbed mainly during the juvenile stage. Partition between shell and soft tissue resulted roughly the same in the juvenile and adult stages for the following elements: Fe, Al, Co, As, Pb. The relationships among the various elements were schematized in a hierarchical tree plot.

  4. Concentrations and modes of occurrence of trace elements in the Late Permian coals from the Puan Coalfield, southwestern Guizhou, China

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.Y. [Xian University of Science & Technology, Xian (China)

    2006-12-15

    The concentration, mode of occurrence, and origin of trace elements in the Late Permian coals from the Puan Coalfield, southwestern Guizhou, China, were examined using inductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence (XRF), cold-vapor atomic absorption spectrometry (CV-AAS), ion-selective electrode method (ISE), sequential chemical extraction procedure (SCEP), scanning electron microscopy equipped with energy-dispersive X-ray (SEM-EDX), and optical microscope. Results show that minerals in the No. 2 Coal from the Puan Coalfield were mainly made up of epigenetic pyrite of low-temperature hydrothermal fluid origin and kaolinite of detrital terrigenous origin. Elements including As (36.9 {mu} g/g), Cd (10.2 {mu} g/g), Cr (167.3 {mu} g/g), Cu (365.4 {mu} g/g), Hg (2.82 {mu} g/g), Mo (92.6 {mu} g/g), Ni (82.6 {mu} g/g), Pb (184.6 {mu} g/g), Se (6.23 {mu} g/g), Zn (242.3 {mu} g/g), and U (132.7 {mu} g/g) are significantly enriched in the No. 2 Coal from the Puan Coalfield. However, concentrations of trace elements in the other four coals, the No. 1, No. 8, No. 11, and No. 18 Coals, were close to the usual ranges found for Guizhou of China, China, and USA. Results of SEM-EDX and SCEP showed that As, Cd, Hg, Mo, Ni, Pb, and Zn occur mainly in veined pyrite, while Cr, Cu, and U distribute mainly in kaolinite, indicating that the low-temperature hydrothermal fluid and detrital materials of terrigenous origin are the main contributors to the enrichment of these trace elements in the No. 2 Coal.

  5. Concentration of heavy metals and major elements in shallow well water and its relation with the evidence of oral and esophagus cancers in Namom District, Songkhla Province

    Directory of Open Access Journals (Sweden)

    Bhongsuwan, T.

    2004-09-01

    Full Text Available Altogether 39 water samples were collected from shallow wells in Namom district, Songkhla province. Two groups of sampling wells were recognized, i.e., a cancer related group and a no-cancer related group, which were related with the presence or absence of evidence of oral or esophagus cancers at the home of well owner. The pH, TDS, hardness and concentration of heavy metals and major elements (Ba, Cr, Mn, Fe, Ni, Cu, Cd, Zn, Pb, Mg and Ca of water samples were measured. The results showed that the pH of all water samples ranged from 4.5 to 7.4 among which 64.1% of water samples were not complied with the rural drinking water quality criteria B.E. 2531. Heavy metal and major element concentrations in all samples did not comply with the quality criteria except for cadmium in 1 sample (0.0055 mg/l and iron in 2 samples (0.77 and 0.59 mg/l. Results of multivariate factor analysis showed that three factors were extracted from 9 variables. Factor-1 included TDS, hardness, Mg and Ca, which were interpreted as a result of granite decomposition. Factor-2 included the concentrations of Ba and Zn, which originated from decomposed granite in the south of Krongrang and Tungkamin sub-districts before transporting towards the north into the Klong-Wa. Factor-3 included a single element, iron, which had no relation with any others. Results of the t-test revealed significant differences (p<0.1 for TDS, hardness, Mg and Ca between no-cancer related group samples and cancer related group samples. The TDS, hardness, Mg and Ca content in water samples were certainly not related to cancer in this area but another alkali earth metal ‘radium’, a natural radioactive substance, which is a well known carcinogen, probably plays an important role in this case. Measurement and analysis of radium and radon content in this water is urgently needed to confirm the radium content and its relation with oral and esophagus cancers in this area.

  6. Stress Concentration Study of Laminated Composite with Multiple Holes by Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Anand.A

    2016-10-01

    Full Text Available A “Composite” is considered as one material when two or more different materials combined together to create superior material. A composite laminate is a composite with combination of layers. They have great applications in many engineering domains like civil, marine, aerospace, biomedical etc. because of their excellent properties like low weight, better mechanical properties and ease of handling and low cost of production. The practical applications of composites enables that the composite structures usually consist cutouts in it in order to get the required design. Thus it is essential to study the behaviour of composites with multiple holes with respect to different applications in order to provide structural stability and to attain better design and mechanical Properties. This work presents Analytical and Finite Element Analysis of rectangular plate with and without multiple circular cut-outs of various sizes. The work is checked for deformation and stress obtained for various loads .The material considered was Glass/Epoxy laminate. The deformation and stress distribution for various loads is analysed by Ansys software. The specimens used are plate without hole, plate with 3 holes of 5mm each, plate with 6mm holes, plate with 8mm holes and plate with 10mm holes. The analytical and numerical results are compared in Stress - Strain curves and Load - Deformation curves and found that both are in good agreement

  7. Quantitative estimation of concentrations of dissolved rare earth elements using reflectance spectroscopy

    Science.gov (United States)

    Dai, Jingjing; Wang, Denghong; Wang, Runsheng; Chen, Zhenghui

    2013-01-01

    Characteristic spectral parameters such as the wavelength and depth of absorption bands are widely used to quantitatively estimate the composition of samples from hyperspectral reflectance data in soil science, mineralogy as well as vegetation study. However, little research has been conducted on the spectral characteristic of rare earth elements (REE) and their relationship with chemical composition of aqueous solutions. Reflectance spectra of ore leachate solutions and contaminated stream water from a few REE mines in the Jiangxi Province, China, are studied for the first time in this work. The results demonstrate that the six diagnostic absorption features of the rare earths are recognized in visible and near-infrared wavelengths at 574, 790, 736, 520, 861, and 443 nm. The intensity of each of these six absorption bands is linearly correlated with the abundance of total REE, with the r2 value >0.95 and the detection limit at ≥75,000 μg/L. It is suggested that reflectance spectroscopy provides an ideal routine analytical tool for characterizing leachate samples. The outcome of this study also has implications for monitoring the environmental effect of REE mining, in particular in stream water systems by hyperspectral remote sensing.

  8. Source, concentration, and distribution of elemental mercury in the atmosphere in Toronto, Canada.

    Science.gov (United States)

    Cairns, Elaine; Tharumakulasingam, Kavitharan; Athar, Makshoof; Yousaf, Muhammad; Cheng, Irene; Huang, Y; Lu, Julia; Yap, Dave

    2011-01-01

    Atmospheric gaseous elemental mercury [GEM] at 1.8, 4, and 59 m above ground, in parking lots, and in indoor and outdoor air was measured in Toronto City, Canada from May 2008-July 2009. The average GEM value at 1.8 m was 1.89 ± 0.62 ng m(-3). The GEM values increased with elevation. The average GEM in underground parking lots ranged from 1.37 to 7.86 ng m(-3) and was higher than those observed from the surface parking lots. The GEM in the indoor air ranged from 1.21 to 28.50 ng m(-3), was higher in the laboratories than in the offices, and was much higher than that in the outdoor air. All these indicate that buildings serve as sources of mercury to the urban atmosphere. More studies are needed to estimate the contribution of urban areas to the atmospheric mercury budget and the impact of indoor air on outdoor air quality and human health.

  9. Extension of Mediema's Macroscopic Atom Model to the Elements of Group 16 (O, S, Se, Te ,Po)

    CERN Document Server

    Neuhausen, J

    2003-01-01

    A consistent set of Miedema-parameters has been developed for the elements of the chalcogen group (Group 16 of the periodic table of the elements: 0, S, Se, Te, Po) from ab-initio quantum-mechanical calculations as weIl as empirical correlations. Using this parameter set thermochemical properties such as enthalpies of formation of solid metal chalcogenides, partial molar enthalpies of solution of chalcogens in liquid and solid metaIs, partial molar enthalpies of evaporation of the chalcogens from liquid metal solution into the monoatomic gaseous state, partial molar enthalpies of adsorption of chalcogenides on metal surfaces at zero coverage and partial molar enthalpies of segregation of the chalcogens in trace amounts within solid metal matrices have been calculated. These properties are compared with available experimental data and discussed with an emphasis on the periodic behaviour of the elements. The model calculations show that a description of the thermochemical properties of the chalcogens using the ...

  10. Thermal evolution of Earth's mantle and core: Influence of reference viscosity and concentration of radioactive elements in the mantle

    Science.gov (United States)

    Nakagawa, T.; Tackley, P. J.

    2010-12-01

    In a series of studies on the thermal evolution of Earth’s mantle and core [Nakagawa and Tackley, 2004; 2005; 2010], we have assumed a reference viscosity (at T=1600 K and P=0) of 1022 Pa.s and a concentration of radioactive elements based on the surface heat flux of the Earth’s mantle (6x10-12 W/kg). In addition, the initial mantle temperature in these studies was also based on the mantle adiabat estimated from present potential temperature (1600 K). Problems with these models are that (1) the average mantle temperature increases in the initial phase of the calculation and (2) the final (present-day) surface heat flux is a factor of two lower than expected from observational constraints (46 TW [Jaupart et al., 2007]), which means the Urey ratio is higher than the expected value (~0.3) [Jaupert et al., 2007; Korenaga, 2007]. Here we present results of a coupled model of thermo-chemical mantle convection in a 2-D spherical annulus and parameterized core heat balance, in which we vary (i) the reference viscosity down to 1020 Pa.s, giving a "surface" Rayleigh number of 109, (ii) the concentration of radioactive heat-producing elements in the mantle are tried (either a theoretical estimate [Schubert et al., 2001; 25 TW], geochemical estimate [McDonough and Sun, 1995; 20 TW] and modified geochemical estimate [Lyubetskaya and Korenaga, 2006; 16 TW]) and (iii) the initial mantle adiabat (up to 2500 K at the surface). Preliminary results indicate a preference for an initial mantle adiabat of more than 2500 K and the modified geochemical estimate of radioactive element concentration, in order to understand the current thermal state of Earth’s mantle when the reference viscosity is 1022 Pa s. Results with lower reference viscosity will be presented.

  11. A Comparative Analyses of Granulometry, Mineral Composition and Major and Trace Element Concentrations in Soils Commonly Ingested by Humans

    Directory of Open Access Journals (Sweden)

    Veronica M. Ngole-Jeme

    2015-07-01

    Full Text Available This study compared the granulometric properties, mineralogical composition and concentrations of major and trace element oxides of commonly ingested soils (geophagic soil collected from different countries with a view of understanding how varied they may be in these properties and to understand the possible health implications of ingesting them. Soil samples were collected from three different countries (South Africa, Swaziland and Democratic Republic of Congo (DRC and their granulometric properties, concentrations of major and trace element oxides as well as mineralogical composition determined. Differences were observed in the granulometric properties of geophagic soil from the three different countries with most of them having <20% clay content. The soils also showed varied degrees of weathering with values of Chemical Index of Alteration (CIA and Chemical Index of Weathering (CIW being between 60% and 99.9% respectively. The mineral assemblages of the soils from South Africa and Swaziland were dominated by the primary minerals quartz and feldspar whereas soils from DRC had more of kaolinite, a secondary mineral than primary minerals. Soils from DRC were associated with silt, clay, Al2O3, and CIA unlike most samples from South Africa which were associated with SiO2, sand, K2O, CaO, and MgO. The soils from Swaziland were closely associated with silt, H2O and Fe2O3(t. These associations reflect the mineralogy of the samples. These soils are not likely to serve as nutrient supplements because of the low concentrations of the nutrient elements contained. The coarse texture of the samples may also result in dental destruction during mastication. Sieving of the soils before ingestion to remove coarse particles is recommended to reduce the potential health threat associated with the ingestion of coarse-textured soils.

  12. Continuous Measurement of Number Concentrations and Elemental Composition of Aerosol Particles for a Dust Storm Event in Beijing

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A continuous measurement of number size distributions and chemical composition of aerosol particles was conducted in Beijing in a dust storm event during 21-26 March 2001. The number concentration of coarse particles (>2μm) increased more significantly than fine particles (<2μm) during the dust storm due to dust weather, while the anthropogenic aerosols collected during the non-dust-storm period tended to be associated with fine particles. Elemental compositions were analyzed by using proton-induced X-ray emission (PIXE). The results show that 20 elements in the dust storm were much higher than in the non-dust-storm period. The calculated soil dust concentration during the dust storm was, on average, 251.8μg m-3, while it was only 52.1 μg m-3 on non-dust-storm days. The enrichment factors for Mg, Al, P, K, Ca, Ti, Mn, Fe, Cl, Cu, Pb, and Zn show small variations between the dust storm and the non-dust-storm period, while those for Ca, Ni and Cr in the dust storm were much lower than those in the non-dust-storm period due to significant local emission sources. A high concentration and enrichment factor for S were observed during the dust storm, which implies that the dust particles were contaminated by aerosol particles from anthropogenic emissions during the long-range transport. A statistical analysis shows that the elemental composition of particles collected during the dust storm in Beijing were better correlated with those of desert soil colleted from desert regions in Inner Mongolia. Air mass back-trajectory analysis further confirmed that this dust storm event could be identified as streaks of dust plumes originating from Inner Mongolia.

  13. Concentration of radioactive elements (U, Th and K derived from phosphatic fertilizers in cultivated soils

    Directory of Open Access Journals (Sweden)

    Valter Antonio Becegato

    2008-12-01

    Full Text Available Gamma spectrometric measurements were obtained for the agricultural soils aiming at characterizing the spatial distribution of radionuclide concentrations (K, eU and eTh, as well for the samples of phosphatic fertilizers and agricultural gypsum. In the study areas, three types of soils occured: Eutrophic Red Nitosol (Alfisoil, Eutroferric Red Latosol of clayey texture (Oxisoil and Dystrophic Red Latosol of medium texture (Oxisoil. The results showed that the radionuclide concentrations in more clayey soils were higher than in more sandy soils, mainly as a function of a higher adsorption capacity of the former. For the area where human activity predominated, the average contents of K, eU and eTh were respectively 54.75; 10.22 and 7.27 Bq/Kg, significantly higher than those for the area where no fertilizers were used (34.15 Bq/Kg K; 1.69 Bq/Kg eU, and 5.36 Bq/Kg eTh. Variations in the radionuclide concentrations were also observed in various fertilizer formula used in soybean and wheat crops.Medições gamaespectrométricas foram obtidas em solos agrícolas objetivando caracterizar a distribuição espacial das concentrações de radionuclídeos (K, eU e eTh, bem como em amostras de fertilizantes fosfatados e gesso agrícola. Na área ocorrem três tipos de solos: Nitossolo Vermelho Eutrófico, Latossolo Vermelho Eutroférrico textura argilosa e Latossolo Vermelho Distrófico textura média. Constatou-se que as concentrações de radionuclídeos nos solos mais argilosos foram maiores do que nos solos mais arenosos, em função, principalmente, da maior adsorção pelos primeiros. Os teores médios em Bq/Kg de K, eU e eTh na área com atividade antrópica foram respectivamente de 54,75; 10,22 e 7,27, significativamente maiores do que em áreas virgens sem aplicação de fertilizantes (34,15 de K; 1,69 de eU e 5,36 de eTh. Foram também observadas variações nas concentrações de radionuclídeos em diferentes formulações de adubos utilizados nas

  14. Elemental concentration in normal skin and fibroepithelial polip lesions by synchrotron radiation total reflection X-ray fluorescence technique

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Julio C.A.C.R.; Canellas, Catarine G.L.; Lopes, Ricardo T., E-mail: ricardo@lin.ufrj.br, E-mail: jcorsini@lin.ufrj.br [Nuclear Laboratory Instrumentation/COPPE, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Anjos, Marcelino J., E-mail: marcelin@lin.ufrj.br [Physics Institute, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    In this work, the concentrations of trace elements were measured in acrochordon, a skin lesion also known as skin tag or fibroepithelial polyp, as well as in normal skin from the same patient. The samples were analysed by Synchrotron Radiation Total Reflection X- ray Fluorescence (SRTXRF) in the Synchrotron Light National Laboratory (LNLS) in Campinas/Sao Paulo-Brazil. The collection of lesion and healthy skin samples, including papillary dermis and epidermis, has involved 17 patients. It was evaluated the presence of P, S, Cl, K, Ca, Cr, Mn, Fe, Cu, Zn, Br and Rb in the paired samples, which were compared, and significant differences were found in some of them. (author)

  15. Elemental concentrations in skin of patients with fibroeptelial polip using synchrotron radiation total reflection x-ray fluorescence

    Science.gov (United States)

    Soares, Júlio C. A. C. R.; Anjos, Marcelino J.; Canellas, Catarine G. L.; Lopes, Ricardo T.

    2012-05-01

    In this work, the concentrations of trace elements were measured in acrochordon, a skin lesion also known as skin tag or fibroepithelial polyp, as well as in normal skin from the same patient. The samples were analyzed by Synchrotron Radiation Total Reflection X-ray Fluorescence (SRTXRF) in the Synchrotron Light National Laboratory (LNLS) in Campinas/São Paulo-Brazil. The collection of lesion and healthy skin samples, including papillary dermis and epidermis, has involved 17 patients. It was evaluated the presence of P, S, Cl, K, Ca, Fe, Cu and Zn in the paired samples, which were compared, and significant differences were found in some of them.

  16. A single diffractive optical element implementing spectrum-splitting and beam-concentration functions simultaneously with high diffraction efficiency

    Institute of Scientific and Technical Information of China (English)

    Ye Jia-Sheng; Wang Jin-Ze; Huang Qing-Li; Dong Bi-Zhen; Zhang Yan; Yang Guo-Zhen

    2013-01-01

    In this paper,a novel method is proposed and employed to design a single diffractive optical element (DOE) for implementing spectrum-splitting and beam-concentration (SSBC) functions simultaneously.We develop an optimization algorithm,through which the SSBC DOE can be optimized within an arbitrary thickness range according to the limitations of modem photolithography technology.Theoretical simulation results reveal that the designed SSBC DOE has a high optical focusing efficiency.It is expected that the designed SSBC DOE should have practical applications in high-efficiency solar cell systems.

  17. A single diffractive optical element for implementing spectrum-splitting and beam-concentration functions simultaneously with high diffraction efficiency

    CERN Document Server

    Ye, Jia-Sheng; Huang, Qing-Li; Dong, Bi-Zhen; Zhang, Yan; Yang, Guo-Zhen

    2013-01-01

    In this paper, a novel method is proposed, and employed to design a single diffractive optical element (DOE) for implementing spectrum-splitting and beam-concentration (SSBC) functions simultaneously. We develop an optimization algorithm, through which the SSBC DOE can be optimized within an arbitrary thickness range, according to the limitations of modern photolithography technology. Theoretical simulation results reveal that the designed SSBC DOE has a high optical focusing efficiency. It is expected that the designed SSBC DOE should have practical applications in high-efficiency solar cell systems.

  18. Sweat Rates, Sweat Sodium Concentrations, and Sodium Losses in 3 Groups of Professional Football Players

    Science.gov (United States)

    Godek, Sandra Fowkes; Peduzzi, Chris; Burkholder, Richard; Condon, Steve; Dorshimer, Gary; Bartolozzi, Arthur R.

    2010-01-01

    Abstract Context: Sweat sodium losses have never been reported in a large cohort of American football players. Objective: To compare sweat rates (SwtRs), sweat sodium concentrations (SwtNa+), and sodium losses in 3 groups of players (backs and receivers [BK], linebackers and quarterbacks [LB/QB], and linemen [LM]) to determine if positional differences and, therefore, size differences exist. Design: Observational study. Setting: Data were collected during practices in the second week of 2 consecutive training camps. The wet bulb globe temperature was 78.5°F ± 3.5°F (25.9°C ± 1.9°C). Patients or Other Participants: Eighteen BK, 12 LB/QB, and 14 LM volunteered. Intervention(s): Sterile sweat patches were applied to the right forearm after the skin was appropriately cleaned. The patches were removed during practice, placed in sterile tubes, centrifuged, frozen, and later analyzed by flame photometry. Main Outcome Measure(s): Sweat rate, SwtNa+, and sodium loss. We calculated SwtR by change in mass adjusted for urine produced and fluids consumed divided by practice time in hours. Results: Other than age, physical characteristics were different among groups (P < .001). The SwtR was different among groups (F2,41  =  7.3, P  =  .002). It was lower in BK (1.42 ± 0.45 L/h) than in LB/QB (1.98 ± 0.49 L/h) (P < .05) and LM (2.16 ± 0.75 L/h) (P < .01), but we found no differences between SwtRs for LB/QB and LM. The SwtNa+ was not different among groups (BK  =  50 ± 16 mEq/L, LB/QB  =  48.2 ± 23 mEq/L, and LM  =  52.8 ± 25 mEq/L) and ranged from 15 to 99 mEq/L. Sweat sodium losses ranged from 642 mg/h to 6.7 g/h, and findings for group comparisons approached significance (P  =  .06). On days when players practiced 4.5 hours, calculated sodium losses ranged from 2.3 to 30 g/d. Conclusions: The BK sweated at lower rates than did the midsized LB/QB and large LM, but LB/QB sweated similarly to LM. Sweat sodium concentration and daily

  19. Distribution of platinum group elements (Pt, Pd, Rh) in environmental and clinical matrices: Composition, analytical techniques and scientific outlook: Status report.

    Science.gov (United States)

    Hees, T; Wenclawiak, B; Lustig, S; Schramel, P; Schwarzer, M; Schuster, M; Verstraete, D; Dams, R; Helmers, E

    1998-01-01

    Trace concentrations of the platinum group elements (PGE; here: Pt, Pd and Rh) play an important role in environmental analysis and assessment. Their importance is based on 1. their increasing use as active compartments in automobile exhaust catalysts, 2. their use as cancer anti-tumor agents in medicine. Due to their allergenic and cytotoxic potential, it is necessary to improve selectivity and sensitivity during analytical investigation of matrices like soil, grass, urine or blood. This paper summarizes the present knowledge of PGE in the fields of analytical chemistry, automobile emission rates, bioavailability, toxicology and medicine.

  20. Elemental concentrations in kidney and liver of mice fed with cafeteria or standard diet determined by particle induced X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Dimer Leffa, Daniela [Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, 88806-000 Criciúma, SC (Brazil); Iochims dos Santos, Carla Eliete; Debastiani, Rafaela; Amaral, Livio; Yoneama, Maria Lucia; Ferraz Dias, Johnny [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Porto Alegre (Brazil); Moraes Andrade, Vanessa, E-mail: vmoraesdeandrade@yahoo.com.br [Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, 88806-000 Criciúma, SC (Brazil)

    2014-01-01

    The importance of trace elements in human health is well known and their main source is daily diet. Nowadays, one of the biggest issues is the presence of these micronutrients in levels much higher than required, leading to potential toxic effects. The aim of this work was to investigate the elemental content in organs of mice fed with cafeteria or standard diet using PIXE. Twelve male Swiss mice were divided into two groups: control group (standard chow) and cafeteria group (high-caloric diet). After 17 weeks, samples of different organs (kidney and liver) were collected and prepared for PIXE analysis. The Fe concentration in kidney and liver was statistically higher in animals that received the cafeteria diet (p < 0.001). The Al and Si kidney contents were significantly higher for cafeteria diet in relation to standard diet (p < 0.05). Moreover, the standard diet showed significant differences for Cl and K (p < 0.05) in comparison to cafeteria diet in kidney, and for P, S and Zn (p < 0.005) in liver.

  1. Trace element concentrations in reef associated sediments of Koswari Island, Gulf of Mannar biosphere reserve, southeast coast of India.

    Science.gov (United States)

    Krishnakumar, S; Ramasamy, S; Chandrasekar, N; Simon Peter, T; Gopal, V; Godson, Prince S; Magesh, N S

    2017-04-15

    Extensive field work was conducted in order to assess the sediment pollution level and potential ecological risk on coral reef ecosystem. Thirty three surface sample was collected using grid sampling technique. The calcium carbonate and organic matter were primarily controlled by the distribution of coral rubbles and seagrass meadows. The concentration of trace elements is higher than the crustal average in few locations and the same result was derived from index calculations. However, the significant concentration of lead was observed throughout the study area. The elevated level of lead is probably due to coal incinerating power plants, and confluence of urban runoff from the nearby coastal areas. Based on the sediment pollution index, the majority of the sediments belongs to highly polluted to dangerously polluted category. The ecological risk indicates that the sediments are under low risk to moderate risk category and this result was proved by correlation analysis.

  2. Comparative study on macro- and micro-elements concentration in Nicotiana tabacum and Faba siliquis plants by ICP-MS

    Science.gov (United States)

    Balazs, Zoltan; Voica, Cezara; Dehelean, Adriana; Magdas, Dana Alina; Ristoiu, Dumitru

    2015-12-01

    Plants are important components of ecosystems as they transfer elements from abiotic into biotic environments. The concentration of macro and micro-elements in tobacco leaves (Nicotiana tabacum) and bean (Faba siliquis) was analyzed using ICP-MS technique. The results obtained indicated that the mean concentration of Mg, P, K and Ca in tobacco leaves was 0.965, 0.812, 4.412 and 2.694 g.kg-1, respectively, while in bean samples were 0.899, 2.024, 6.725 and 1.387 g.kg-1, respectively. Mn concentration ranged from 156.835 mg.kg-1 to 234.593 mg.kg-1 in tobacco leaves and from 116.174 mg.kg-1 to 440.423 mg.kg-1 in bean samples. The results for Cu and Zn were between 7.262 mg.kg-1 and 105.738 mg.kg-1, 68.549 mg.kg-1 and 113.720 mg.kg-1 (tobacco leaves); and 6.830 mg.kg-1 and 46.034 mg.kg-1, 50.166 mg.kg-1 and 77.242 mg.kg-1 (bean samples), respectively. In analyzed samples, Pb, Cd and As concentrations ranged between <0.001-0.717 mg.kg-1, 0.046 mg.kg-1 -6.218 mg.kg-1, <0.001-0.381 mg.kg-1. The paper discusses the transfer of metal ions (Mn, As, Cd, Cu, Pb and Zn, respectively) from soil to these plants in terms of transfer factors (TF).

  3. Variation in the mineral element concentration of Moringa oleifera Lam. and M. stenopetala (Bak. f.) Cuf.: Role in human nutrition

    Science.gov (United States)

    Kumssa, Diriba B; Joy, Edward JM; Young, Scott D; Odee, David W; Ander, E Louise

    2017-01-01

    Background Moringa oleifera (MO) and M. stenopetala (MS) (family Moringaceae; order Brassicales) are multipurpose tree/shrub species. They thrive under marginal environmental conditions and produce nutritious edible parts. The aim of this study was to determine the mineral composition of different parts of MO and MS growing in their natural environments and their potential role in alleviating human mineral micronutrient deficiencies (MND) in sub-Saharan Africa. Methods Edible parts of MO (n = 146) and MS (n = 50), co-occurring cereals/vegetables and soils (n = 95) underneath their canopy were sampled from localities in southern Ethiopia and Kenya. The concentrations of seven mineral elements, namely, calcium (Ca), copper (Cu), iodine (I), iron (Fe), magnesium (Mg), selenium (Se), and zinc (Zn) in edible parts and soils were determined using inductively coupled plasma-mass spectrometry. Results In Ethiopian crops, MS leaves contained the highest median concentrations of all elements except Cu and Zn, which were greater in Enset (a.k.a., false banana). In Kenya, Mo flowers and MS leaves had the highest median Se concentration of 1.56 mg kg-1 and 3.96 mg kg-1, respectively. The median concentration of Se in MS leaves was 7-fold, 10-fold, 23-fold, 117-fold and 147-fold more than that in brassica leaves, amaranth leaves, baobab fruits, sorghum grain and maize grain, respectively. The median Se concentration was 78-fold and 98-fold greater in MO seeds than in sorghum and maize grain, respectively. There was a strong relationship between soil total Se and potassium dihydrogen phosphate (KH2PO4)-extractable Se, and Se concentration in the leaves of MO and MS. Conclusion This study confirms previous studies that Moringa is a good source of several of the measured mineral nutrients, and it includes the first wide assessment of Se and I concentrations in edible parts of MO and MS grown in various localities. Increasing the consumption of MO and MS, especially the leaves as a

  4. Variation in the mineral element concentration of Moringa oleifera Lam. and M. stenopetala (Bak. f.) Cuf.: Role in human nutrition.

    Science.gov (United States)

    Kumssa, Diriba B; Joy, Edward Jm; Young, Scott D; Odee, David W; Ander, E Louise; Broadley, Martin R

    2017-01-01

    Moringa oleifera (MO) and M. stenopetala (MS) (family Moringaceae; order Brassicales) are multipurpose tree/shrub species. They thrive under marginal environmental conditions and produce nutritious edible parts. The aim of this study was to determine the mineral composition of different parts of MO and MS growing in their natural environments and their potential role in alleviating human mineral micronutrient deficiencies (MND) in sub-Saharan Africa. Edible parts of MO (n = 146) and MS (n = 50), co-occurring cereals/vegetables and soils (n = 95) underneath their canopy were sampled from localities in southern Ethiopia and Kenya. The concentrations of seven mineral elements, namely, calcium (Ca), copper (Cu), iodine (I), iron (Fe), magnesium (Mg), selenium (Se), and zinc (Zn) in edible parts and soils were determined using inductively coupled plasma-mass spectrometry. In Ethiopian crops, MS leaves contained the highest median concentrations of all elements except Cu and Zn, which were greater in Enset (a.k.a., false banana). In Kenya, Mo flowers and MS leaves had the highest median Se concentration of 1.56 mg kg-1 and 3.96 mg kg-1, respectively. The median concentration of Se in MS leaves was 7-fold, 10-fold, 23-fold, 117-fold and 147-fold more than that in brassica leaves, amaranth leaves, baobab fruits, sorghum grain and maize grain, respectively. The median Se concentration was 78-fold and 98-fold greater in MO seeds than in sorghum and maize grain, respectively. There was a strong relationship between soil total Se and potassium dihydrogen phosphate (KH2PO4)-extractable Se, and Se concentration in the leaves of MO and MS. This study confirms previous studies that Moringa is a good source of several of the measured mineral nutrients, and it includes the first wide assessment of Se and I concentrations in edible parts of MO and MS grown in various localities. Increasing the consumption of MO and MS, especially the leaves as a fresh vegetable or in powdered form

  5. Effects of a Low-Element Challenge Course on Abstinence Self-Efficacy and Group Cohesion

    Science.gov (United States)

    Clem, Jamie M.; Smith, Thomas E.; Richards, Kristin V.

    2012-01-01

    Substance abuse researchers identify self-efficacy and group cohesion as important components in alcohol and other drug-dependency treatment. Objectives: The purpose of this single-group, pretest-posttest study is to explore the therapeutic value of a challenge course intervention on the self-efficacy and group cohesion of nine chemically…

  6. Trace Element Concentration and Speciation in Selected Mining-Contaminated Soils and Water in Willow Creek Floodplain, Colorado

    Directory of Open Access Journals (Sweden)

    R. Burt

    2011-01-01

    Full Text Available Long-term mining activities in the mountains around Creede, Colorado have resulted in significant contamination in soils and water in the Willow Creek floodplain. Total major and trace were determined for soils and water and sequential chemical extraction for soils. Objectives were to determine concentrations and potential reactivity of trace elements and investigate their relationship with other soil and water properties. Water trace elements showed significant variability among sites, ranging from 347 to 12108 μg/L. Relative trend showed (Zn > Sr > Ba > (Mn > W > Cd > (Sn > V ≈ Ni ≈ Cu > Co > (Ag. Soil trace elements showed significant short-range spatial variability, ranging from 2819 to 19274 mg/kg. Relative trend showed (Pb ≈ Zn > Mn > Ba > P > (As > Cu > Sr > V > Cd > Sb ≈ Ag > (Co ≈ Cr > Mo ≈ Sn ≈ Ni > (Be ≈ W > Se ≈ Hg. Predominant fractions were oxide, specifically-sorbed/carbonate bound, and residual. Water soluble and exchangeable fractions showed (Zn ≈ Cd > Pb and Cd > Zn > Pb, respectively. Mobility factors for highly contaminated soils showed Cd ≈ Zn > Pb > Cu > As.

  7. Chemo-dynamical evolution of the Local Group dwarf galaxies: The origin of r-process elements

    Science.gov (United States)

    Hirai, Y.; Ishimaru, Y.; Saitoh, T. R.; Fujii, M. S.; Hidaka, J.; Kajino, T.

    2016-06-01

    The r-process elements such as Au, Eu, and U are observed in the extremely metal-poor stars in the Milky Way halo and the Local Group dwarf galaxies. However, the origin of r-process elements has not yet been identified. The abundance of r-process elements of stars in the Local Group galaxies provides clues to clarify early evolutionary history of galaxies. It is important to understand the chemical evolution of the Local Group dwarf galaxies which would be building blocks of the Milky Way. In this study, we perform a series of N-body/smoothed particle hydrodynamic simulations of dwarf galaxies. We show that neutron star mergers can reproduce the observation of r-process elements. We find that the effects of gas mixing processes including metals in the star-forming region of a typical scale of giant molecular clouds ¥sim 10-100 pc play significant roles in the early chemical enrichment of dwarf galaxies. We also find that the star formation rate of ˜ 10^{-3} M_{⊙}yr^{-1} in early epoch (<1 Gyr) of galactic halo evolution is necessary for these results. Our results suggest that neutron star mergers are a major site of r-process.

  8. Control of oxygen vacancies and Ce{sup +3} concentrations in doped ceria nanoparticles via the selection of lanthanide element

    Energy Technology Data Exchange (ETDEWEB)

    Shehata, N., E-mail: nader83@vt.edu; Meehan, K.; Hudait, M.; Jain, N. [Virginia Tech, Bradley Department of Electrical and Computer Engineering (United States)

    2012-10-15

    The effect of lanthanides that have positive association energies with oxygen vacancies, such as samarium and neodymium, and the elements with negative association energies, such as holmium and erbium, on ionization state of cerium and, consequentially, the oxygen vacancy concentration in doped ceria nanoparticles are investigated in this article. Structural and optical characterizations of the doped and undoped ceria nanoparticles, synthesized using chemical precipitation, are carried out using transmission electron microscopy, X-ray diffractometry, optical absorption spectroscopy, and fluorescence spectroscopy. It is deduced that the negative association energy dopants decrease the conversion of Ce{sup +4} into Ce{sup +3} and, hence, scavenge the oxygen vacancies, evidenced by the observed increase in the allowed direct bandgap, decrease in the integrated fluorescence intensity, and increased the size of doped nanoparticles. The opposite trends are obtained when the positive association dopants are used. It is concluded that the determining factor as to whether a lanthanide dopant in ceria acts as a generator or scavenger of oxygen vacancies in ceria nanoparticles is the sign of the association energy between the element and the oxygen vacancies. The ability to tailor the ionization state of cerium and the oxygen vacancy concentration in ceria has applications in a broad range of fields, which include catalysis, biomedicine, electronics, and environmental sensing.

  9. The Unusually High Halo Concentration of the Fossil Group NGC 6482: Evidence for Weak Adiabatic Contraction

    CERN Document Server

    Buote, David A

    2016-01-01

    We revisit the massive isolated elliptical galaxy / fossil group NGC 6482 for which previous X-ray studies of a modest Chandra observation obtained a very uncertain, but also possibly very high, halo concentration. We present new measurements of the hot gas surface brightness, temperature, and iron abundance using the modest Chandra observation and a previously unpublished Suzaku observation, the latter of which allows measurements of the gas properties to be extended out to ~r_2500. By constructing hydrostatic equilibrium models of the gas with separate components for the gas, BCG stellar mass, and the dark matter (DM), we measure c_200 = 32.2 +/- 7.1 and M_200 = (4.5 +/- 0.6 x 10^12 M_sun using an NFW DM profile. For a halo of this mass, c_200 exceeds the mean value (7.1) expected for relaxed LCDM halos by $3.5 \\sigma$ in terms of the observational error, and by $6 \\sigma$ considering the intrinsic scatter in the LCDM c-M relation, which situates NGC 6482 as the most extreme outlier known for a fossil syste...

  10. The features of element concentration in natural waters of the Kola North in conditions of environmental contamination

    Science.gov (United States)

    Bazova, Mariya; Moiseenko, Tatyana

    2016-04-01

    The intensive use of fossil fuels and industrial development in last century led to the formation of acid rain and water acidification. The problem of water acidification greatly was denoted in the middle of last century in North America and in Europe as a result of air emissions of acid gases, primarily sulfur dioxide. The process of water acidification due to the interaction of two factors: 1) the high deposition of acidifying substances, taking into account the duration of exposure; 2) the sensitivity of the natural catchment area of geological, landscape, geographic and climatic characteristics (Moiseenko, 2005). The effects of acid rains on metal migration and cycling were discussed in a number of previous studies (Jeffries, 1997; Moiseenko, 1999; Manio, 2001; Moiseenko, Gashkina, 2007). The distribution of elements in water lakes has been mixed and due to the change of geochemical cycles of elements occurring in the catchment area and in water. On the Kola Peninsula as a result of long-term operation of the copper-nickel smelter was the anthropogenic acidification and water pollution metals. Increased contents of elements due to the combined effect of three factors: 1) landscape-geochemical characteristics of watersheds; 2) dispersion with flue emissions; 3) leaching elements and bonding of metals with organic matter, especially in forested watersheds and wetlands. This region is subject to long-term effects of mining and smelting industries, and therefore difficult to find of water bodies, which can serve as a background lakes. It is proved that manmade acid rain lead to leach into the water of a large group of elements entering the water as a result of man-made streams, as well as the elements that consist of the rocks forming the watersheds. In order to identify the relationships between the components of the elemental composition of the water in the lake was made a factor analysis using a computer program «STATISTICA 10". Factor analysis revealed the

  11. Influence of concentration and position of carboxyl groups on the electronic properties of single-walled carbon nanotubes.

    Science.gov (United States)

    Lara, Ivi Valentini; Zanella, Ivana; de Souza Filho, Antonio Gomes; Fagan, Solange Binotto

    2014-10-21

    The effects of attaching COOH groups at different sites and in various concentrations on electronic and structural properties of (8,0) single-walled carbon nanotubes (SWNT) were investigated using ab initio calculations. The binding energies and the charge transfers between the COOH functional groups and the tube were calculated for several configurations and a novel feature in the electronic structure of these groups was observed. The electronic character of these systems can be modulated by playing with the concentration and the position of the carboxyl groups bonded on the tube wall. The carboxyl groups bound to different carbon atom sub-lattices are more hybridized than those bound in the same one. These results suggested that SWNT-COOH systems are a playground for engineering electronic properties through a proper chemical functionalization which exploit both the attachment site and concentration of functional groups.

  12. Search for a meteoritic component in drill cores from the Bosumtwi impact structure, Ghana: Platinum group element contents and osmium isotopic characteristics

    Science.gov (United States)

    McDonald, Iain; Peucker-Ehrenbrink, Bernhard; Coney, Louise; Ferrière, Ludovic; Reimold, Wolf Uwe; Koeberl, Christian

    An attempt was made to detect a meteoritic component in both crater-fill (fallback) impact breccias and fallout suevites (outside the crater rim) at the Bosumtwi impact structure in Ghana. Thus far, the only clear indication for an extraterrestrial component related to this structure has been the discovery of a meteoritic signature in Ivory Coast tektites, which formed during the Bosumtwi impact event. Earlier work at Bosumtwi indicated unusually high levels of elements that are commonly used for the identification of meteoritic contamination (i.e., siderophile elements, including the platinum group elements [PGE]) in both target rocks and impact breccias from surface exposures around the crater structure, which does not allow unambiguous verification of an extraterrestrial signature. The present work, involving PGE abundance determinations and Os isotope measurements on drill core samples from inside and outside the crater rim, arrives at the same conclusion. Despite the potential of the Os isotope system to detect even small amounts of extraterrestrial contribution, the wide range in PGE concentrations and Os isotope composition observed in the target rocks makes the interpretation of unradiogenic, high-concentration samples as an impact signature ambiguous.

  13. Evaluation of wastewater treatment by-products as soil amendment: Growth of sorghum-sudan grass and trace elements concentrations.

    Science.gov (United States)

    Sivapatham, Paramasivam; Potts, Mariel C; Delise, Jeffrey A; Sajwan, Kenneth S; Alva, Ashok K; Jayaraman, Kuppuswamy; Chakraborty, Paromita

    2012-01-01

    Wastewater treatment by-products (WTBP), such as sewage sludge (SS) may be used to enhance soil chemical, physical, and biological properties. These enhanced soil properties, in turn, could from its source of production to its site of application. These concerns may be mitigated by incineration of the SS to produce ash (SSA) and dissolved in water and stored in ponds as contribute to an increase in plant growth, production, mineral nutrition. Some SS is difficult to handle due to bad odor in its raw state and has large mass, hence expensive for transportation weathered SSA (WSSA). A greenhouse study was conducted using Candler fine sand CFS; (CFS; pH = 6.8) and Ogeechee loamy sand OLS; (pH = 5.2) with application of either 0, 24.7, 49.4, 98.8, or 148.2 Mg ha(-1) as either SS, SSA, or WSSA to evaluate the biomass production and elemental composition responses of sorghum-sudan grass (Sorghum vulgaris var. Sudanese hitche). Shoot and root biomass were 2 to 3 fold greater in the soil amended with SS, than either SSA or WSSA. Concentrations of nutrient and trace elements in the shoots and roots increased with increasing rates of amendments. Application of these by-products up to 98.8 Mg ha(-1) rate did not adversely affect growth or accumulation of trace elements in sorghum-sudan grass. Long-term field studies are recommended to investigate the potential leaching of various elements from the amended soils in addition to evaluation of plant growth and production responses to determine the acceptable rates of these by-products as amendments to agricultural soils.

  14. Different variations of tissue B-group vitamin concentrations in short- and long-term starved rats.

    Science.gov (United States)

    Moriya, Aya; Fukuwatari, Tsutomu; Sano, Mitsue; Shibata, Katsumi

    2012-01-01

    Prolonged starvation changes energy metabolism; therefore, the metabolic response to starvation is divided into three phases according to changes in glucose, lipid and protein utilisation. B-group vitamins are involved in energy metabolism via metabolism of carbohydrates, fatty acids and amino acids. To determine how changes in energy metabolism alter B-group vitamin concentrations during starvation, we measured the concentration of eight kinds of B-group vitamins daily in rat blood, urine and in nine tissues including cerebrum, heart, lung, stomach, kidney, liver, spleen, testis and skeletal muscle during 8 d of starvation. Vitamin B1, vitamin B6, pantothenic acid, folate and biotin concentrations in the blood reduced after 6 or 8 d of starvation, and other vitamins did not change. Urinary excretion was decreased during starvation for all B-group vitamins except pantothenic acid and biotin. Less variation in B-group vitamin concentrations was found in the cerebrum and spleen. Concentrations of vitamin B1, vitamin B6, nicotinamide and pantothenic acid increased in the liver. The skeletal muscle and stomach showed reduced concentrations of five vitamins including vitamin B1, vitamin B2, vitamin B6, pantothenic acid and folate. Concentrations of two or three vitamins decreased in the kidney, testis and heart, and these changes showed different patterns in each tissue and for each vitamin. The concentration of pantothenic acid rapidly decreased in the heart, stomach, kidney and testis, whereas concentrations of nicotinamide were stable in all tissues except the liver. Different variations in B-group vitamin concentrations in the tissues of starved rats were found. The present findings will lead to a suitable supplementation of vitamins for the prevention of the re-feeding syndrome.

  15. Method of loading organic materials with group III plus lanthanide and actinide elements

    Science.gov (United States)

    Bell, Zane W.; Huei-Ho, Chuen; Brown, Gilbert M.; Hurlbut, Charles

    2003-04-08

    Disclosed is a composition of matter comprising a tributyl phosphate complex of a group 3, lanthanide, actinide, or group 13 salt in an organic carrier and a method of making the complex. These materials are suitable for use in solid or liquid organic scintillators, as in x-ray absorption standards, x-ray fluorescence standards, and neutron detector calibration standards.

  16. Final Report: Main Group Element Chemistry in Service of Hydrogen Storage and Activation

    Energy Technology Data Exchange (ETDEWEB)

    David A. Dixon; Anthony J. Arduengo, III

    2010-09-30

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an “endless” hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular

  17. Final Report: Main Group Element Chemistry in Service of Hydrogen Storage and Activation

    Energy Technology Data Exchange (ETDEWEB)

    David A. Dixon; Anthony J. Arduengo, III

    2010-09-30

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an “endless” hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular

  18. Isotope Anomalies in the Fe-group Elements in Meteorites and Connection to Nucleosynthesis in AGB Stars

    CERN Document Server

    Wasserburg, Gerald J; Busso, Maurizio

    2015-01-01

    We study the effects of neutron captures in AGB stars on \\oq Fe-group\\cqb elements, with an emphasis on Cr, Fe, and Ni. These elements show anomalies in $^{54}$Cr, $^{58}$Fe, and $^{64}$Ni in solar-system materials, which are commonly attributed to SNe. However, as large fractions of the interstellar medium (ISM) were reprocessed in AGB stars, these elements were reprocessed, too. We calculate the effects of such reprocessing on Cr, Fe, and Ni through 1.5\\msb and 3\\msb AGB models, adopting solar and 1/3 solar metallicities. All cases produce excesses of $^{54}$Cr, $^{58}$Fe, and $^{64}$Ni, while the other isotopes are little altered; hence, the observations may be explained by AGB processing. The results are robust and not dependent on the detailed initial isotopic composition. Consequences for other \\oq Fe group\\cqb elements are then explored. They include $^{50}$Ti excesses, and some production of $^{46,47,49}$Ti. In many circumstellar condensates, Ti quantitatively reflects these effects of AGB neutron cap...

  19. Platinum-group Elements Geochemistry of the Yangliuping Magmatic Ni-Cu-PGE Sulfide Deposit:Implications of Its Genetic Link with the Extrusive Basalts

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jianbin; CAO Zhimin; SONG Xieyan; AN Wei; LIU Ji

    2004-01-01

    Primitive mantle-normalized Platinum-group elements (PGE) concentration patterns for the Zhengziyanwo intrusion and Dashibao Formation basalts are of positive slope, similar to most of the world-class magmatic Ni-Cu-PGE sulfide deposits. Characters of this intrusion and its related ores and Dashibao Formation basalts are their negative Pt-anomaly and high concentration of Rh relative to Pt and Pd, facts being interpreted to be the results of crystallization and fractionation of Pt-alloys and spinel phase-free crystallization history for the magma, respectively. PGE parameters of the Dashibao Formation basalts are consistent with the general trend of those found for the Zhengziyanwo intrusion, and this might infer a genetic link between them.

  20. Hourly elemental concentrations in PM2.5 aerosols sampled simultaneously at urban background and road site

    Directory of Open Access Journals (Sweden)

    G. Calzolai

    2012-08-01

    Full Text Available Hourly-resolved aerosol chemical speciation data can be a highly powerful tool to determine the source origin of atmospheric pollutants in urban Environments. Aerosol mass concentrations of seventeen elements (Na, Mg, Al, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr and Pb were obtained by time (1 h and size (PM2.5 particulate matter 2.5 fraction simultaneously measured at the UB and RS sites: (1 the regional aerosol sources impact both monitoring sites at similar concentrations regardless their different ventilation conditions; (2 by contrast, local industrial aerosol plumes associated with shipping oil combustion and smelters activities have a higher impact on the more ventilated UB site; (3 a unique source of Pb-Cl (associated with industrial combustion emissions is found a to be the major (82% source of Cl in the urban agglomerate; (4 PM2.5 traffic brake dust (Fe-Cu is mainly primarily emitted and not resuspended, whereas PM2.5 urban crustal dust (Ca is found mainly resuspended by both traffic vortex and sea breeze; (5 urban dust (Ca is found the aerosol source most affected by land wetness, reduced by a factor of eight during rainy days and suggesting that wet roads may be a solution for reducing dust concentrations in road sites, far more effective than street sweeping activities.

  1. Characterization of a Test Site for the Measuring of the Focal Point of Reflective Optical Elements for Concentrator Photovoltaic

    CERN Document Server

    Frick, Manuel

    2014-01-01

    In order to achieve a large deployment of renewable energies, the electricity production costs have to be as low as possible. Many different technologies have been proposed to achieve the best efficiency to cost ratio. One of those is concentrating photovoltaics (CPV) which takes advantage of the high efficiency of multi-junction cells while limiting the costs by reducing the size of the cell and concentrating the direct irradiance with a cheaper optical element. Next to the widely used Fresnel lenses concave mirrors could be of interest as concentrator optic. As for the whole module those optics have to minimize losses and production costs at once. Measuring scattering and slope errors of the mirrors is of great importance to achieve an optimal design and production process. Therefore an optical test site doing so by observing the 2D irradiance distribution in the focal point has been built at the Fraunhofer ISE. The aim of this thesis is to characterize this test site. Therefore the behavior of the differen...

  2. Platinum-group elements for the mantle peridotites in the Dazhuka ophiolite, Tibet, China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The total PGE amounts of mantle peridotites in the Dazhuka ophiolite, Tibet, are 28.37-50.67 ng/g, slightly higher than those of mantle peridotites in the primitive mantle, and typical ophiolites in the world, and the Alps-type mantle peridotites. The PGE distribution patterns in the Dazhuka mantle peridotites are also different from those of the mantle peridotites of partial melting relict origin. The Dazhuka mantle peridotites have relatively high total PGE amounts and are enriched in Pt, Pd, and Ru. Their PGE distribution patterns belong to the positively inclined- or swallow-type patterns. The PGE distribution patterns in the mantle peridotites of partial melting relict origin belong to the negative-slope patterns or flat patterns. This reflects the unique features of the upper mantle in this region. Relative enrichment in Pt and Pd, as well as in the incompatible ele-ments Cu, Au, Cs, Rb, Ba, Th, U and LREE, indicates that the partial melting-derived relict mantle peridotites in the Dazhuka ophiolite had experienced intensive permeating and mixing processes of the melt and fluid both containing abundant incompatible elements.

  3. Group I twintrons: genetic elements in myxomycete and schizopyrenid amoeboflagellate ribosomal DNAs.

    Science.gov (United States)

    Einvik, C; Elde, M; Johansen, S

    1998-09-17

    Protists are unicellular eukaryotes which represent a significant fraction of the global biodiversity. The myxomycete Didymium and the schizopyrenid amoeboflagellate Naegleria are distantly related protists. However, we have noted several striking similarities in life cycle, cell morphology, and ribosomal DNA organization between these organisms. Both have multicopy nuclear extrachromosomal ribosomal DNAs. Here the small subunit ribosomal RNA genes are interrupted by an optional group I twintron, a novel category among the group I introns. Group I twintrons are mobile self-splicing introns of 1.3-1.4 kb in size, with a complex organization at the RNA level. A group I twintron consists of two distinct ribozymes (catalytic RNAs) with different functions in RNA processing, and an open reading frame encoding a functional homing endonuclease--all with prospects of application as molecular tools in biotechnology. Updated RNA secondary structure models of group I twintrons, as well as an example of in vitro ribozyme activity, are presented. We suggest that the group I twintrons have been independently established in myxomycetes and schizopyrenid amoeboflagellates by horizontal gene transfer due to a combination of the phagocytotic behavior in natural environments and the extrachromosomal multicopy nature of ribosomal DNA.

  4. 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...

  5. PERSONAL, INDOOR, AND OUTDOOR CONCENTRATIONS OF PM2.5, PARTICULATE NITRATE, AND ELEMENTAL CARBON FOR INDIVIDUALS WITH COPD IN LOS ANGELES, CA

    Science.gov (United States)

    This study characterizes the personal, indoor, and outdoor concentrations of PM2.5 and the major components of PM2.5, including nitrate (NO3-), elemental carbon (EC), and the elements for individuals with chronic obstructive pulmonary disease (COPD) living in Los Angeles, CA. ...

  6. The effect of nanoparticles and humic acid on technology critical element concentrations in aqueous solutions with soil and sand.

    Science.gov (United States)

    Stepka, Zane; Dror, Ishai; Berkowitz, Brian

    2017-08-23

    As a consequence of their growing use in electronic and industrial products, increasing amounts of technology critical elements (TCEs) are being released to the environment. Currently little is known about the fate of many of these elements. Initial research on their potential environmental impact identifies TCEs as emerging contaminants. TCE movement in the environment is often governed by water systems. Research on "natural" waters so far demonstrates that TCEs tend to be associated with suspended particulate matter (SPM), which influences TCE aqueous concentrations (here: concentration of TCEs in dissolved form and attached to SPM) and transport. However, the relative potential of different types of SPM to interact with TCEs is unknown. Here we examine the potential of various types of particulate matter, namely different nanoparticles (NPs; Al2O3, SiO2, CeO2, ZnO, montmorillonite, Ag, Au and carbon dots) and humic acid (HA), to impact TCE aqueous concentrations in aqueous solutions with soil and sand, and thus influence TCE transport in soil-water environments. We show that a combination of NPs and HA, and not NPs or HA individually, increases the aqueous concentrations of TCEs in soil solutions, for all tested NPs regardless of their type. TCEs retained on SPM, however, settle with time. In solutions with sand, HA alone is as influential as NPs+HA in keeping TCEs in the aqueous phase. Among NPs, Ag-NPs and Au-NPs demonstrate the highest potential for TCE transport. These results suggest that in natural soil-water environments, once TCEs are retained by soil, their partitioning to the aqueous phase by through-flowing water is unlikely. However, if TCEs are introduced to soil-water environments as part of solutions rich in NPs and HA, it is likely that NP and HA combinations can increase TCE stability in the aqueous phase and prevent their retention on soil and sand, thus facilitating TCE transport. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Free and Forced Vibrations of an Axially-Loaded Timoshenko Multi-Span Beam Carrying a Number of Various Concentrated Elements

    OpenAIRE

    Yusuf Yesilce

    2012-01-01

    In the existing reports regarding free and forced vibrations of the beams, most of them studied a uniform beam carrying various concentrated elements using Bernoulli-Euler Beam Theory (BET) but without axial force. The purpose of this paper is to utilize the numerical assembly technique to determine the exact frequency-response amplitudes of the axially-loaded Timoshenko multi-span beam carrying a number of various concentrated elements (including point masses, rotary inertias, linear springs...

  8. The effect of nutrient enrichment on the growth, nucleic acid concentrations, and elemental stoichiometry of coral reef macroalgae.

    Science.gov (United States)

    Reef, Ruth; Pandolfi, John M; Lovelock, Catherine E

    2012-08-01

    The growth rate hypothesis (GRH) links growth rates with organism elemental stoichiometry. Support for the GRH was found for many animal species, but less so for plants. This is the first study to test the GRH in macroalgae. Tropical coral reef macroalgae from three lineages, Caulerpa serrulata (Chlorophyta), Laurencia intricata (Rhodophyta), and Sargassum polyphyllum (Phaeophyceae) were grown enriched with nitrogen or phosphorous and under control conditions at Heron Island on the Great Barrier Reef, Australia. Growth rate, photosynthesis, nucleic acid composition, and elemental stoichiometry were measured. Nutrient enrichment had positive effects on photosynthetic rates and on investment in RNA. However, growth rate was not correlated with either photosynthetic rates or RNA content; thus, we did not find support for the GRH in tropical macroalgae. Macroalgae, especially L. intricata, accumulated P to very high levels (>0.6% of dry weight). The growth rate response to tissue P concentrations was unimodal. Above 0.21%, P accumulation had negative effects on growth. Nitrogen was not stored, but evidence of futile cycling was observed. The capacity to store large amounts of P is probably an adaptation to the low and patchy nutrient environment of the tropical oceans.

  9. Effect of fresh and mature organic amendments on the phytoremediation of technosols contaminated with high concentrations of trace elements.

    Science.gov (United States)

    Hattab, Nour; Motelica-Heino, Mikael; Faure, Olivier; Bouchardon, Jean-Luc

    2015-08-15

    Organic compounds resulting from the decomposition of organic amendments are used in the remediation of trace element (TE) contaminated soils. The mobility, phytoavailability and soil exposure intensity of molybdenum (Mo), chromium (Cr), zinc (Zn), copper (Cu), Cobalt (Co) and Arsenic (As) were evaluated in the phytoremediation of contaminated technosols after the addition of two organic matter types, fresh ramial chipped wood (RCW) and composted sewage sludge (CSS). The experiment consisted of nine main treatment blocks: (A) 3X unamended soil (NE), (B) 3X soil amended with RCW and (C) 3X soil amended with mature CSS. Total dissolved TE concentrations were determined in soil pore water (SPW) sampled by Rhizon samplers. The soil exposure intensity was assessed by standard Chelex 100 DGT (diffusive gradient in thin films) probes. TE phytoavailability was characterized by growing dwarf beans on potted soils and analyzing their foliar TE concentrations. The results of the present study indicate that the addition of fresh RCW and CSS has a positive effect on contaminated technosols. RCW decreased the mobility of all the studied TE in the SPW, whereas CSS reduced the mobility of Mo, Cr and Co, while it increased the mobility of Zn, Cu and As compared with the NE soil. The Zn soil exposure intensity assessed by DGT was not significantly changed by the addition of RCW and CSS, while the Cr soil exposure intensity was significantly decreased after RCW addition compared with the soil treated with CSS and the NE soil. In contrast Cu and Co were non labile in the three soils. Both RCW and CSS decreased the foliar concentration and the mineral mass of Mo, Zn, Cr, As and Co in the bean leaves but increased the foliar Cu concentration.

  10. Comparation of Organic and Elemental carbon concentrations in PM2.5 in five Mexican cities: Potencial Sources

    Science.gov (United States)

    Herrera Murillo, J.; Cardenas, B.; Campos-Ramos, A.; Blanco-Jimenez, S.; Angeles-Garcia, F.

    2011-12-01

    During 2006-2010 the National Center for Environmental Research and Training of the National Institute of Ecology of Mexico, carried out several short field studies in the cities of Salamanca, Gto, Tula, Hgo; Guadalajara, Jal; Toluca, Edo Mex; and Tijuana, BC to determine concentration and chemical compositions of PM2.5. These cities, although different in size population have all important industrial and area sources that contribute to high PM2.5 concentrations and therefore potential health impacts. Chemical analyses included organic and elemental carbon for which DRI Model 2001 Thermal/Optical Carbon Analyzer (Atmoslytic Inc, Calabasas, CA, USA) was used. Highest PM2.5 mass mean concentrations were obtained in Salamanca (46 μg/m3), followed by Toluca (43 μg/m3), Guadalajara (37 μg/m3), Tula (20 μg/m3) and Tijuana (18 μg/m3). For Salamanca and Tula, annual levels exceeded the Mexican PM2.5 annual standard of 15 μg/m3. Total carbonaceous aerosol accounted for 41.4%, 41.1%, 32.3%, 29.5% and 29.1% of PM2.5 mass in Tula, Toluca, Guadalajara, Salamanca and Tijuana, respectively. Higher OC2, OC3 and OC4 carbon fractions were observed in Guadalajara, Tijuana and Toluca, indicating an important contribution of gasoline and diesel vehicles emissions in these cities. As for Tula and Salamanca, cities in which refineries and power plants are present, OC3, OC4, EC1 and EC2 represent the higher fractions which could be attributed to stationary sources that use heavy fuels for their combustion process. UNMIX and PMF analyses were used in order to identify the most important sources that contributes to OC and EC concentrations.

  11. Hair from different ethnic groups vary in elemental composition and nitrogen and phosphorus mineralisation in soil.

    Science.gov (United States)

    Malepfane, N M; Muchaonyerwa, P

    2017-02-01

    Disposal of hair wastes at landfills causes nitrate leaching to ground water, and use of the waste as fertiliser could be a viable option. This study was to determine elemental composition of major hair types in South Africa and their nitrogen (N) and phosphorus (P) release in soil. Wastes of African, White and Indian hair were obtained from local salons and analysed for carbon (C), N and sulphur (S) with the Leco CNS analyzer, and P, bases, aluminium (Al) and micronutrients, with the ICP. We also conducted an incubation study to determine changes in mineral N and P in soil. Hair wastes were added to soil at increasing rates based on N, incubated at 25 °C with destructive sampling after 0, 28, 56 and 84 days and pH, ammonium-N, nitrate-N and extractable P measured. All data were subjected to analysis of variance. Indian and White hair had higher N than African. White hair had higher C and lower potassium (K) than those of other types. The Fe levels in hair were in the order White > African > Indian, whilst those of Al were African > Indian > White. African hair had higher calcium (Ca), manganese (Mn), zinc (Zn) and cobalt (Co) than the other types. Ammonium-N and nitrate-N releases were in the order: Indian > African > White, especially at higher rates. Ammonium-N increased in the first 28 days and declined thereafter, when nitrate-N increased and pH decreased. The findings implied that hair types differ in elemental composition and nitrogen release in soil, with implications on pollution and soil fertility.

  12. Siderophile element systematics of IAB complex iron meteorites: New insights into the formation of an enigmatic group

    Science.gov (United States)

    Worsham, Emily A.; Bermingham, Katherine R.; Walker, Richard J.

    2016-09-01

    Siderophile trace element abundances and the 187Re-187Os isotopic systematics of the metal phases of 58 IAB complex iron meteorites were determined in order to investigate formation processes and how meteorites within chemical subgroups may be related. Close adherence of 187Re-187Os isotopic data of most IAB iron meteorites to a primordial isochron indicates that the siderophile elements of most members of the complex remained closed to elemental disturbance soon after formation. Minor, presumably late-stage open-system behavior, however, is observed in some members of the sLM, sLH, sHL, and sHH subgroups. The new siderophile element abundance data are consistent with the findings of prior studies suggesting that the IAB subgroups cannot be related to one another by any known crystallization process. Equilibrium crystallization, coupled with crystal segregation, solid-liquid mixing, and subsequent fractional crystallization can account for the siderophile element variations among meteorites within the IAB main group (MG). The data for the sLM subgroup are consistent with equilibrium crystallization, combined with crystal segregation and mixing. By contrast, the limited fractionation of siderophile elements within the sLL subgroup is consistent with metal extraction from a chondritic source with little subsequent processing. The limited data for the other subgroups were insufficient to draw robust conclusions about crystallization processes involved in their formation. Collectively, multiple formational processes are represented in the IAB complex, and modeling results suggest that fractional crystallization within the MG may have been a more significant process than has been previously recognized.

  13. Natural variation in 210Po and 210Pb activity concentrations in the urine of Finnish population groups.

    Science.gov (United States)

    Muikku, Maarit; Heikkinen, Tarja; Solatie, Dina; Vesterbacka, Pia

    2011-11-01

    A study to determine activity concentrations of (210)Pb and (210)Po in the urine of certain Finnish population groups was conducted, to investigate the variation in natural background level of urinary excretion. The study participants were divided into three groups mainly based on their diet. The first group comprised recreational fishermen and the second group represented people consuming more reindeer meat than an average Finn, while people using drinking water with very high activity concentrations of (210)Po were selected for the third group. The fourth group was a control group. The mean urinary excretion of (210)Po in groups 1 and 2 was 73 and 100 mBq d(-1), respectively. These values were higher than the value of the control group (20 mBq d(-1)) and the mean values reported in the literature. The mean daily urinary excretion of (210)Pb in groups 1 and 2, 70 and 52 mBq d(-1), was also slightly higher than that in the control group (32 mBq d(-1)). In contrast, the excretion rates of both (210)Po and (210)Pb for the members of group 3 were one to two orders of magnitude higher than those reported in the literature. This was clearly due to the elevated levels of natural radionuclides in their drinking water. The present study demonstrates the importance of possessing good knowledge of the background levels, in order to allow the determination of the additional exposure due, for example, to the malevolent use of radiation.

  14. Effects of chemical functional groups on elemental mercury adsorption on carbonaceous surfaces.

    Science.gov (United States)

    Liu, Jing; Cheney, Marcos A; Wu, Fan; Li, Meng

    2011-02-15

    A systematic theoretical study using density functional theory is performed to provide molecular-level understanding of the effects of chemical functional groups on mercury adsorption on carbonaceous surfaces. The zigzag and armchair edges were used in modeling the carbonaceous surfaces to simulate different adsorption sites. The edge atoms on the upper side of the models are unsaturated to simulate active sites. All calculations (optimizations, energies, and frequencies) were made at B3PW91 density functional theory level, using RCEP60VDZ basis set for mercury and 6-31G(d) pople basis set for other atoms. The results indicate that the embedding of halogen atom can increase the activity of its neighboring site which in turn increases the adsorption capacity of the carbonaceous surface for Hg(0). The adsorption belongs to chemisorptions, which is in good agreement with the experimental results. For the effects of oxygen functional groups, lactone, carbonyl and semiquinone favor Hg(0) adsorption because they increase the neighboring site's activity for mercury adsorption. On the contrary, phenol and carboxyl functional groups show a physisorption of Hg(0), and reduce Hg capture. This result can explain the seemingly conflicting experimental results reported in the literature concerning the influence of oxygen functional groups on mercury adsorption on carbonaceous surface.

  15. The conserved lymphokine element-0 in the IL5 promoter binds to a high mobility group-1 protein.

    Science.gov (United States)

    Marrugo, J; Marsh, D G; Ghosh, B

    1996-10-01

    The conserved lymphokine elements-0 (CLE0) in the IL5 promoter is essential for the expression of IL-5. Here, we report the cloning and expression of a cDNA encoding a novel CLE0-binding protein, CLEBP-1 from a mouse Th2 clone, D10.G4.1. Interestingly, it was found that the CLEBP1 cDNA sequence was almost identical to the sequences of known high mobility group-1 (HMG1) cDNAs. When expressed as a recombinant fusion protein in Escherichia coli, CLEBP-1 was shown to bind to the IL5-CLE0 element in electrophoretic mobility-shift assays (EMSA) and southwestern blot analysis. The CLEBP-1 fusion protein cross-reacts with and-HMG-1/2 in Western blot analysis. It also binds to the CLE0 elements of IL4, GMCSF and GCSF genes. CLEBP-1 and closely related HMG-1 and HMG-2 proteins may play key roles in facilitating the expression of the lymphokine genes that contain CLE0 elements.

  16. Radioactivity and element concentrations in the coastal bottom sediments in the vicinity of Yonggwang nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Woong; Eun, Go-Yeo-Na; Cha, Jong Mun; Kim, In S.; Kim, Kyeong Hee; Kim, Ju Yong [Kwangju Institute if Science and Technology, Kwangju (Korea, Republic of); Hong, Kwang Phyo; Kim, Ki Nam [Korea Electric Power Corporation, Seoul (Korea, Republic of)

    1999-07-01

    In order to evaluate the influence of nuclear power plant operation on nearby coast, the radioactivity and element concentrations in coastal bottom sediments were investigated. The coastal bottom sediments were collected at 179 sampling stations around the Yonggwang nuclear power plant and analyzed for radioactivity by HP-Ge {upsilon}-spectrophotometer and Low Background {alpha}/{beta} Counter, and heavy metals by ICP-AES and AAS. In addition, particle size distribution in a number of sediments were measured and compared with other analytical results. According to the result of grain size distribution, most sediments are classified as silt loam with 23 percent sand, 65 percent silt and 12 percent clay contents. The radioactivities of most nuclides except {sup 137}Cs are below the limit of detection, and artificial nuclide of {sup 137} Cs may derived from past nuclear weapon tests. The heavy metal concentrations are within the normal range of marine sediments and the anomaly caused by the operation of nuclear power plant has not been monitored. (author). 7 refs., 2 tabs., 3 figs.

  17. Zinc concentrations in marine macroalgae and a lichen from western Ireland in relation to phylogenetic grouping, habitat and morphology

    Energy Technology Data Exchange (ETDEWEB)

    Stengel, Dagmar B.; Macken, Ailbhe; Morrison, Liam; Morley, Nicholas

    2004-05-01

    Zinc concentrations in 19 species of marine macroalgae and a lichen from western Ireland (Spiddal, Co. Galway) were analysed by atomic absorption spectrophotometry. Algae were collected from a single site but occupied different shore levels and belonged to distinct phylogenetic groupings and to different (previously recognised) morphological groups. Concentrations ranged from 15-115 {mu}g g{sup -1} dry weight. The greatest variation in concentration occurred amongst the red algal species, containing both maximum and minimum concentrations. Zn concentrations in brown and green algae were generally lower than those in red algae. When grouped according to thallus morphology, thin, branched sheets (which consisted mainly of red algae) contained the highest Zn concentrations. In filamentous algae, Zn levels were higher than in thick-leathery or coarsely branched algae. However, all green algal species examined had similar Zn concentrations, despite their different morphologies. In brown algae, the highest Zn levels were detected in mid-shore fucoids (Fucus vesiculosus and Fucus serratus), while thicker, subtidal and low-shore brown algae (Laminaria digitata, Halydris siliquosa) exhibited lower Zn concentrations. The lowest Zn concentrations were detected in high-intertidal species (Fucus spiralis, Pelvetia canaliculata), the only marine lichen examined (Ramalina siliquosa) and a red crustose alga (Corallina officinalis). In all morphological groups, red algal representatives contained relatively higher levels of Zn, the exception being Corallina officinalis. Zn levels in 4 species from a second, estuarine site in Galway Bay exhibited the same relative differences amongst species, but were all consistently higher than in algae from Spiddal. It is concluded that Zn accumulation in macroalgae is closely related to ecological growth strategies, following a functional-form model. However, the phylogenetic origin of species which determines carbohydrate and phenol composition

  18. The structural basis for promoter -35 element recognition by the group IV sigma factors.

    OpenAIRE

    William J Lane; Darst, Seth A.

    2006-01-01

    The control of bacterial transcription initiation depends on a primary sigma factor for housekeeping functions, as well as alternative sigma factors that control regulons in response to environmental stresses. The largest and most diverse subgroup of alternative sigma factors, the group IV extracytoplasmic function sigma factors, directs the transcription of genes that regulate a wide variety of responses, including envelope stress and pathogenesis. We determined the 2.3-A resolution crystal ...

  19. Extension of Mediema's Macroscopic Atom Model to the Elements of Group 16 (O, S, Se, Te ,Po)

    Energy Technology Data Exchange (ETDEWEB)

    Neuhausen, J.; Eichler, B

    2003-09-01

    A consistent set of Miedema-parameters has been developed for the elements of the chalcogen group (Group 16 of the periodic table of the elements: 0, S, Se, Te, Po) from ab-initio quantum-mechanical calculations as weIl as empirical correlations. Using this parameter set thermochemical properties such as enthalpies of formation of solid metal chalcogenides, partial molar enthalpies of solution of chalcogens in liquid and solid metaIs, partial molar enthalpies of evaporation of the chalcogens from liquid metal solution into the monoatomic gaseous state, partial molar enthalpies of adsorption of chalcogenides on metal surfaces at zero coverage and partial molar enthalpies of segregation of the chalcogens in trace amounts within solid metal matrices have been calculated. These properties are compared with available experimental data and discussed with an emphasis on the periodic behaviour of the elements. The model calculations show that a description of the thermochemical properties of the chalcogens using the semi-empirical Miedema approach is possible. The calculated properties can serve as a basis for the prediction of the chemical interactions for metal-chalcogen combinations that have not been studied experimentally so far. (author)

  20. Extension of Mediema's Macroscopic Atom Model to the Elements of Group 16 (O, S, Se, Te ,Po)

    Energy Technology Data Exchange (ETDEWEB)

    Neuhausen, J.; Eichler, B

    2003-09-01

    A consistent set of Miedema-parameters has been developed for the elements of the chalcogen group (Group 16 of the periodic table of the elements: 0, S, Se, Te, Po) from ab-initio quantum-mechanical calculations as weIl as empirical correlations. Using this parameter set thermochemical properties such as enthalpies of formation of solid metal chalcogenides, partial molar enthalpies of solution of chalcogens in liquid and solid metaIs, partial molar enthalpies of evaporation of the chalcogens from liquid metal solution into the monoatomic gaseous state, partial molar enthalpies of adsorption of chalcogenides on metal surfaces at zero coverage and partial molar enthalpies of segregation of the chalcogens in trace amounts within solid metal matrices have been calculated. These properties are compared with available experimental data and discussed with an emphasis on the periodic behaviour of the elements. The model calculations show that a description of the thermochemical properties of the chalcogens using the semi-empirical Miedema approach is possible. The calculated properties can serve as a basis for the prediction of the chemical interactions for metal-chalcogen combinations that have not been studied experimentally so far. (author)

  1. Technical Report on the Behavior of Trace Elements, Stable Isotopes, and Radiogenic Isotopes During the Processing of Uranium Ore to Uranium Ore Concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Marks, N. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Borg, L. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Eppich, G. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gaffney, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Genneti, V. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hutcheon, I. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kristo, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lindvall, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramon, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Robel, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberts, S. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schorzman, K. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sharp, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Singleton, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, R. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-09

    The goals of this SP-1 effort were to understand how isotopic and elemental signatures behave during mining, milling, and concentration and to identify analytes that might preserve geologic signatures of the protolith ores. The impurities that are preserved through the concentration process could provide useful forensic signatures and perhaps prove diagnostic of sample origin.

  2. Concentrations and source apportionment of PM10 and associated major and trace elements in the Rhodes Island, Greece.

    Science.gov (United States)

    Argyropoulos, Georgios; Manoli, Evangelia; Kouras, Athanasios; Samara, Constantini

    2012-08-15

    Ambient concentrations of PM(10) and associated major and trace elements were measured over the cold and the warm season of 2007 at two sites located in the Rhodes Island (Greece), in Eastern Mediterranean, aimed at source apportionment by Chemical Mass Balance (CMB) receptor modeling. Source chemical profiles, necessary in CMB modeling, were obtained for a variety of emission sources that could possibly affect the study area, including sea spray, geological material, soot emissions from the nearby oil-fuelled thermal power plant, and other anthropogenic activities, such as vehicular traffic, residential oil combustion, wood burning, and uncontrolled open-air burning of agricultural biomass and municipal waste. Source apportionment of PM(10) and elemental components was carried out by employing an advanced CMB version, the Robotic Chemical Mass Balance model (RCMB). Vehicular emissions were found to be major PM(10) contributor accounting, on average, for 36.8% and 31.7% during the cold period, and for 40.9% and 39.2% in the warm period at the two sites, respectively. The second largest source of ambient PM(10), with minor seasonal variation, was secondary sulfates (mainly ammonium and calcium sulfates), with total average contribution around 16.5% and 18% at the two sites. Soil dust was also a remarkable source contributing around 22% in the warm period, whereas only around 10% in the cold season. Soot emitted from the thermal power plant was found to be negligible contributor to ambient PM(10) (<1%), however it appeared to appreciably contribute to the ambient V and Ni (11.3% and 5.1%, respectively) at one of the sites during the warm period, when electricity production is intensified. Trajectory analysis did not indicate any transport of Sahara dust; on the contrary, long range transport of soil dust from arid continental regions of Minor Asia and of biomass burning aerosol from the countries surrounding the Black Sea was considered possible.

  3. Major- and trace-element concentrations in soils from two continental-scale transects of the United States and Canada

    Science.gov (United States)

    Smith, David B.; Cannon, William F.; Woodruff, Laurel G.; Garrett, Robert G.; Klassen, Rodney; Kilburn, James E.; Horton, John D.; King, Harley D.; Goldhaber, Martin B.; Morrison, Jean M.

    2005-01-01

    This report contains major- and trace-element concentration data for soil samples collected from 265 sites along two continental-scale transects in North America. One of the transects extends from northern Manitoba to the United States-Mexico border near El Paso, Tex. and consists of 105 sites. The other transect approximately follows the 38th parallel from the Pacific coast of the United States near San Francisco, Calif., to the Atlantic coast along the Maryland shore and consists of 160 sites. Sampling sites were defined by first dividing each transect into approximately 40-km segments. For each segment, a 1-km-wide latitudinal strip was randomly selected; within each strip, a potential sample site was selected from the most representative landscape within the most common soil type. At one in four sites, duplicate samples were collected 10 meters apart to estimate local spatial variability. At each site, up to four separate soil samples were collected as follows: (1) material from 0-5 cm depth; (2) O horizon, if present; (3) a composite of the A horizon; and (4) C horizon. Each sample collected was analyzed for total major- and trace-element composition by the following methods: (1) inductively coupled plasmamass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICPAES) for aluminum, antimony, arsenic, barium, beryllium, bismuth, cadmium, calcium, cerium, cesium, chromium, cobalt, copper, gallium, indium, iron, lanthanum, lead, lithium, magnesium, manganese, molybdenum, nickel, niobium, phosphorus, potassium, rubidium, scandium, silver, sodium, strontium, sulfur, tellurium, thallium, thorium, tin, titanium, tungsten, uranium, vanadium, yttrium, and zinc; (2) cold vapor- atomic absorption spectrometry for mercury; (3) hydride generation-atomic absorption spectrometry for antimony and selenium; (4) coulometric titration for carbonate carbon; and (5) combustion for total carbon and total sulfur.

  4. Application of the donor-acceptor concept to intercept low oxidation state group 14 element hydrides using a Wittig reagent as a Lewis base.

    Science.gov (United States)

    Swarnakar, Anindya K; McDonald, Sean M; Deutsch, Kelsey C; Choi, Paul; Ferguson, Michael J; McDonald, Robert; Rivard, Eric

    2014-08-18

    This article outlines our attempts to stabilize the Group 14 element dihydrides, GeH2 and SnH2, using commonly employed phosphine and pyridine donors; in each case, elemental Ge and Sn extrusion was noted. However, when these phosphorus and nitrogen donors were replaced with the ylidic Wittig ligand Ph3P═CMe2, stable inorganic methylene complexes (EH2) were obtained, demonstrating the utility of this under-explored ligand class in advancing main group element coordination chemistry.

  5. Comparison of trace element concentrations in livers of diseased, emaciated and non-diseased southern sea otters from the California coast

    Science.gov (United States)

    Kannan, K.; Agusa, T.; Perrotta, E.; Thomas, N.J.; Tanabe, S.

    2006-01-01

    Infectious diseases have been implicated as a cause of high rates of adult mortality in southern sea otters. Exposure to environmental contaminants can compromise the immuno-competence of animals, predisposing them to infectious diseases. In addition to organic pollutants, certain trace elements can modulate the immune system in marine mammals. Nevertheless, reports of occurrence of trace elements, including toxic heavy metals, in sea otters are not available. In this study, concentrations of 20 trace elements (V, Cr, Mn, Co, Cu, Zn, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi) were measured in livers of southern sea otters found dead along the central California coast (n = 80) from 1992 to 2002. Hepatic concentrations of trace elements were compared among sea otters that died from infectious diseases (n = 27), those that died from non-infectious causes (n = 26), and otters that died in emaciated condition with no evidence of another cause of death (n = 27). Concentrations of essential elements in sea otters varied within an order of magnitude, whereas concentrations of non-essential elements varied by two to five orders of magnitude. Hepatic concentrations of Cu and Cd were 10- to 100-fold higher in the sea otters in this study than concentrations reported for any other marine mammal species. Concentrations of Mn, Co, Zn, and Cd were elevated in the diseased and emaciated sea otters relative to the non-diseased sea otters. Elevated concentrations of essential elements such as Mn, Zn, and Co in the diseased/emaciated sea otters suggest that induction of synthesis of metallothionein and superoxide dismutase (SOD) enzyme is occurring in these animals, as a means of protecting the cells from oxidative stress-related injuries. Trace element profiles in diseased and emaciated sea otters suggest that oxidative stress mediates the perturbation of essential-element concentrations. Elevated concentrations of toxic metals such as Cd, in addition to several

  6. A comparison of methods used to calculate normal background concentrations of potentially toxic elements for urban soil

    Energy Technology Data Exchange (ETDEWEB)

    Rothwell, Katherine A., E-mail: k.rothwell@ncl.ac.uk; Cooke, Martin P., E-mail: martin.cooke@ncl.ac.uk

    2015-11-01

    To meet the requirements of regulation and to provide realistic remedial targets there is a need for the background concentration of potentially toxic elements (PTEs) in soils to be considered when assessing contaminated land. In England, normal background concentrations (NBCs) have been published for several priority contaminants for a number of spatial domains however updated regulatory guidance places the responsibility on Local Authorities to set NBCs for their jurisdiction. Due to the unique geochemical nature of urban areas, Local Authorities need to define NBC values specific to their area, which the national data is unable to provide. This study aims to calculate NBC levels for Gateshead, an urban Metropolitan Borough in the North East of England, using freely available data. The ‘median + 2MAD’, boxplot upper whisker and English NBC (according to the method adopted by the British Geological Survey) methods were compared for test PTEs lead, arsenic and cadmium. Due to the lack of systematically collected data for Gateshead in the national soil chemistry database, the use of site investigation (SI) data collected during the planning process was investigated. 12,087 SI soil chemistry data points were incorporated into a database and 27 comparison samples were taken from undisturbed locations across Gateshead. The SI data gave high resolution coverage of the area and Mann–Whitney tests confirmed statistical similarity for the undisturbed comparison samples and the SI data. SI data was successfully used to calculate NBCs for Gateshead and the median + 2MAD method was selected as most appropriate by the Local Authority according to the precautionary principle as it consistently provided the most conservative NBC values. The use of this data set provides a freely available, high resolution source of data that can be used for a range of environmental applications. - Highlights: • The use of site investigation data is proposed for land contamination studies

  7. Average bond energies between boron and elements of the fourth, fifth, sixth, and seventh groups of the periodic table

    Science.gov (United States)

    Altshuller, Aubrey P

    1955-01-01

    The average bond energies D(gm)(B-Z) for boron-containing molecules have been calculated by the Pauling geometric-mean equation. These calculated bond energies are compared with the average bond energies D(exp)(B-Z) obtained from experimental data. The higher values of D(exp)(B-Z) in comparison with D(gm)(B-Z) when Z is an element in the fifth, sixth, or seventh periodic group may be attributed to resonance stabilization or double-bond character.

  8. Electronic basis of the hcp, omega and bcc phases in group IVB elements under pressure or on alloying

    Science.gov (United States)

    Gyanchandani, Jyoti; Sikka, S. K.

    2013-03-01

    Using the first principles DFT calculations, we have elucidated the electronic basis of the α→ω and the ω→β transitions in group IVB elements. After considering several possible factors that could give rise to the structural stability of a particular crystal structure, the changes in the band structure energy due to Peierls-Jahn-Teller distortion and crystal-field effects on sub orbital of d bands coupled with Ewald energy differences have been identified as the causes for these transitions. The role of van Hove singularities and consequent electronic topological transitions has also been examined.

  9. Report of the IAU working group on cartographic coordinates and rotational elements of the planets and satellites - 1982

    Science.gov (United States)

    Davies, M. E.; Abalakin, V. K.; Lieske, J. H.; Seidelmann, P. K.; Sinclair, A. T.; Sinzi, A. M.; Smith, B. A.; Tjuflin, Y. S.

    1983-04-01

    This paper contains the report of the IAU Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites as presented at the XVIII General Assembly held at Patras, Greece, 1982. Tables give the recommended values for the direction of the north poles of rotation and the prime meridians of the planets and satellites referred to both the B1950 and J2000 standard coordinate systems. Reference surfaces for mapping these bodies are described. An appendix discusses the principal changes to the tables since 1979.

  10. Solution chemistry of element 105. Pt. 1. Hydrolysis of group 5 cations: Nb, Ta, Ha and Pa

    Energy Technology Data Exchange (ETDEWEB)

    Pershina, V.

    1998-01-01

    Relativistic molecular orbital calculations of the electronic structure of hydrated and hydrolyzed complexes have been performed for group 5 elements Nb, Ta, Ha and their pseudohomology, Pa. On their basis, relative values of the free energy changes and constants of hydrolysis reactions were defined. These results show that hydrolysis decreases in the order Nb>Ta>Ha>>Pa, which for Nb, Ta and Pa is in agreement with experiment. A decisive factor in the process turned out to be a predominant electrostatic metal-ligand interaction. (orig.)

  11. Does common spatial origin promote the auditory grouping of temporally separated signal elements in grey treefrogs?

    Science.gov (United States)

    Bee, Mark A; Riemersma, Kasen K

    2008-09-01

    'Sequential integration' represents a form of auditory grouping in which temporally separated sounds produced by the same source are perceptually bound together over time into a coherent 'auditory stream'. In humans, sequential integration plays important roles in music and speech perception. In this study of the grey treefrog (Hyla chrysoscelis), we took advantage of female selectivity for advertisement calls with conspecific pulse rates to investigate common spatial location as a cue for sequential integration. We presented females with two temporally interleaved pulse sequences with pulse rates of 25 pulses/s, which is half the conspecific pulse rate and more similar to that of H. versicolor, a syntopically breeding heterospecific. We tested the hypothesis that common spatial origin between the two pulse sequences would promote their integration into a coherent auditory stream with an attractive conspecific pulse rate. As the spatial separation between the speakers broadcasting the interleaved pulse sequences decreased from 180° to 0°, more females responded and females exhibited shorter response latencies and travelled shorter distances en route to a speaker. However, even in the 180° condition, most females (74%) still responded. Detailed video analyses revealed no evidence to suggest that patterns of female phonotaxis resulted from impaired abilities to localize sound sources in the spatially separated conditions. Together, our results suggest that females were fairly permissive of spatial incoherence between the interleaved pulses sequences and that common spatial origin may be only a relatively weak cue for sequential integration in grey treefrogs.

  12. Continuum in the X-Z---Y weak bonds: Z= main group elements.

    Science.gov (United States)

    Joy, Jyothish; Jose, Anex; Jemmis, Eluvathingal D

    2016-01-15

    The Continuum in the variation of the X-Z bond length change from blue-shifting to red-shifting through zero- shifting in the X-Z---Y complex is inevitable. This has been analyzed by ab-initio molecular orbital calculations using Z= Hydrogen, Halogens, Chalcogens, and Pnicogens as prototypical examples. Our analysis revealed that, the competition between negative hyperconjugation within the donor (X-Z) molecule and Charge Transfer (CT) from the acceptor (Y) molecule is the primary reason for the X-Z bond length change. Here, we report that, the proper tuning of X- and Y-group for a particular Z- can change the blue-shifting nature of X-Z bond to zero-shifting and further to red-shifting. This observation led to the proposal of a continuum in the variation of the X-Z bond length during the formation of X-Z---Y complex. The varying number of orbitals and electrons available around the Z-atom differentiates various classes of weak interactions and leads to interactions dramatically different from the H-Bond. Our explanations based on the model of anti-bonding orbitals can be transferred from one class of weak interactions to another. We further take the idea of continuum to the nature of chemical bonding in general.

  13. Seasonal variations in the chemical composition of particulate matter: a case study in the Po Valley. Part II: concentration and solubility of micro- and trace-elements.

    Science.gov (United States)

    Canepari, S; Astolfi, M L; Farao, C; Maretto, M; Frasca, D; Marcoccia, M; Perrino, C

    2014-03-01

    Size distribution (fine and coarse fraction) and solubility distribution (extracted and residual fraction) of 20 elements (As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Pb, Ni, Rb, S, Sb, Se, Sn, Sr, Ti, Tl, V) in atmospheric particulate matter (PM) were determined during a 5-year field study carried out in the Po Valley (peri-urban area of Ferrara, in Northern Italy). By studying the contribution of the two size fractions and the two solubility fractions to the atmospheric concentration of each element, it was possible to obtain interesting information about the variability of PM sources, to assess the role played by atmospheric stability in determining pollution episodes, and to obtain an estimate of the bio-accessible fraction. Atmospheric stability is confirmed to be one of the main causes of atmospheric pollution in this area and is to be responsible for the pronounced winter increase in both PM and elemental concentration. Long-range transport of natural and polluted air masses caused temporary increases in PM and elemental concentration, while local industrial emission seemed to play a secondary role. Regulated elements were well below their concentration limit, but many toxic elements were in the form of fine particles and soluble chemical species, more accessible to the environment, and the human body.

  14. Reliability assessment of MVP-BURN and JENDL-4.0 related to nuclear transmutation of light platinum group elements

    Science.gov (United States)

    Terashima, Atsunori; Nilsson, Mikael; Ozawa, Masaki; Chiba, Satoshi

    2017-09-01

    The Aprés ORIENT research program, as a concept of advanced nuclear fuel cycle, was initiated in FY2011 aiming at creating stable, highly-valuable elements by nuclear transmutation from ↓ssion products. In order to simulate creation of such elements by (n, γ) reaction succeeded by β- decay in reactors, a continuous-energy Monte Carlo burnup calculation code MVP-BURN was employed. Then, it is one of the most important tasks to con↓rm the reliability of MVP-BURN code and evaluated neutron cross section library. In this study, both an experiment of neutron activation analysis in TRIGA Mark I reactor at University of California, Irvine and the corresponding burnup calculation using MVP-BURN code were performed for validation of the simulation on transmutation of light platinum group elements. Especially, some neutron capture reactions such as 102Ru(n, γ)103Ru, 104Ru(n, γ)105Ru, and 108Pd(n, γ)109Pd were dealt with in this study. From a comparison between the calculation (C) and the experiment (E) about 102Ru(n, γ)103Ru, the deviation (C/E-1) was signi↓cantly large. Then, it is strongly suspected that not MVP-BURN code but the neutron capture cross section of 102Ru belonging to JENDL-4.0 used in this simulation have made the big di↑erence as (C/E-1) >20%.

  15. Reliability assessment of MVP-BURN and JENDL-4.0 related to nuclear transmutation of light platinum group elements

    Directory of Open Access Journals (Sweden)

    Terashima Atsunori

    2017-01-01

    Full Text Available The Aprés ORIENT research program, as a concept of advanced nuclear fuel cycle, was initiated in FY2011 aiming at creating stable, highly-valuable elements by nuclear transmutation from ↓ssion products. In order to simulate creation of such elements by (n, γ reaction succeeded by β− decay in reactors, a continuous-energy Monte Carlo burnup calculation code MVP-BURN was employed. Then, it is one of the most important tasks to con↓rm the reliability of MVP-BURN code and evaluated neutron cross section library. In this study, both an experiment of neutron activation analysis in TRIGA Mark I reactor at University of California, Irvine and the corresponding burnup calculation using MVP-BURN code were performed for validation of the simulation on transmutation of light platinum group elements. Especially, some neutron capture reactions such as 102Ru(n, γ103Ru, 104Ru(n, γ105Ru, and 108Pd(n, γ109Pd were dealt with in this study. From a comparison between the calculation (C and the experiment (E about 102Ru(n, γ103Ru, the deviation (C/E-1 was signi↓cantly large. Then, it is strongly suspected that not MVP-BURN code but the neutron capture cross section of 102Ru belonging to JENDL-4.0 used in this simulation have made the big di↑erence as (C/E-1 >20%.

  16. Spontaneous Double Hydrometallation Induced by N→M Coordination in Organometallic Hydrides of Group 14 Elements.

    Science.gov (United States)

    Novák, Miroslav; Dostál, Libor; Turek, Jan; Alonso, Mercedes; De Proft, Frank; Růžička, Aleš; Jambor, Roman

    2016-04-11

    Our attempts to synthesise N→M intramolecularly coordinated diorganometallic hydrides L2MH2 [M=Si (4), Ge (5), Sn (6)] containing the CH=N imine group (in which L is C,N-chelating ligand {2-[(2,6-iPr2C6H3)N=CH]C6 H4}(-)) yielded 1,1'-bis(2,6-diisopropylphenyl)-2,2'-spriobi[benzo[c][1,2]azasilole] (7), 1,1'-bis(2,6-diisopropylphenyl)-2,2'-spriobi[benzo[c][1,2]azagermole] (8) and C,N-chelated homoleptic stannylene L2Sn (10), respectively. Compounds 7 and 8 are an outcome of a spontaneous double hydrometallation of the two CH=N imine moieties induced by N→M intramolecular coordination (M=Si, Ge) in the absence of any catalyst. In contrast, the diorganotin hydride L2SnH2 (6) is redox-unstable and the reduction of the tin centre with the elimination of H2 provided the C,N-chelated homoleptic stannylene L2Sn (10). Compounds 7 and 8 were characterised by NMR spectroscopy and X-ray diffraction analysis. Because the proposed N→M intramolecularly coordinated diorganometallic hydrides L2MH2 [M=Si (4), Ge (5), Sn (6)] revealed two different types of reduction reactions, DFT calculations were performed to gain an insight into the structures and bonding of the non-isolable diorganometallic hydrides as well as the products of their subsequent reactions. Furthermore, the thermodynamic profiles of the different reaction pathways with respect to the central metal atom were also investigated.

  17. Effects of liquid immiscibility on trace element fractionation in magmatic iron meteorites: A case study of group IIIAB

    Science.gov (United States)

    Ulff-Moeller, Finn

    1998-03-01

    Magmatic iron meteorites are generally agreed to represent metal that crystallized in asteroidal cores from a large pool of liquid. Estimates suggest that the metallic liquid contained significant amounts of S and P, both of which are incompatible and exert a strong effect on trace-element partitioning. In tandem, S and P are also prone to cause immiscibility between sulfide liquid and P-rich metal liquid. The liquid immiscibility field occupies about 70% of the portion of the Fe-Ni-S-P system in which iron is the first phase to crystallize. In spite of this, previous fractional crystallization models have taken into account only one liquid phase and have encountered significant discrepancies between the meteorite data and model values for the key elements Ni, Ir, Ga, Ge and Au at even moderate degrees of fractionation. For the first time, a model for trace-element partitioning between immiscible liquids in the Fe-Ni-S-P system is presented in order to assess the effects on fractionation in magmatic iron meteorite groups. The onset of liquid immiscibility causes a significant change in the enrichment patterns of S and P in both liquids, so elements with contrasting partitioning behavior will show trends deviating clearly from one-liquid trends. A trend recorded in the solid metal will either be a smooth curve as long as equilibrium is maintained between the two liquids or the trend may diverge into a field limited by two extreme curves depending on the degree of disequilibrium. Bulk initial liquids for most magmatic groups have S/P (wt%) ratios well below 25. In these cases, and due to the constitution of the Fe-Ni-S-P system, most of the metal will crystallize from the rapidly decreasing volume of metal liquid and only a subordinate amount from the sulfide liquid. Because of the strong extraction of P into the metal liquid, P will have a much larger influence on trace-element partitioning than a low initial P content might suggest. My model calculations suggest

  18. High pressure stability of the monosilicides of cobalt and the platinum group elements

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, J.A., E-mail: jeanalexis.hernandez@ens-lyon.fr [Laboratoire de géologie de Lyon, CNRS UMR 5276, École Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, 46 Allée d’Italie, 69364 Lyon Cedex 07 (France); Vočadlo, L.; Wood, I.G. [Department of Earth Sciences, University College London, WC1E 6BT (United Kingdom)

    2015-03-25

    Highlights: • We model the high-pressure phases of cobalt- and platinum-group-monosilicides. • CoSi, RuSi, OsSi transform with pressure from the ε-FeSi to the CsCl structure. • RhSi and IrSi transform with pressure from the MnP structure to the ε-FeSi structure. • PdSi and PtSi transform with pressure from the MnP structure to the CuTi structure. - Abstract: The high pressure stability of CoSi, RuSi, RhSi, PdSi, OsSi, IrSi and PtSi was investigated by static first-principles calculations up to 300 GPa at 0 K. As found experimentally, at atmospheric pressure, CoSi, RuSi and OsSi were found to adopt the cubic ε-FeSi structure (P2{sub 1}3) whereas RhSi, PdSi, IrSi and PtSi were found to adopt the orthorhombic MnP (Pnma) structure. At high pressure, CoSi, RuSi and OsSi show a phase transition to the CsCl structure (Pm3{sup ¯}m) structure at 270 GPa, 7 GPa and 6 GPa respectively. RhSi and IrSi were found to transform to an ε-FeSi structure at 10 GPa and 25 GPa. For PdSi and PtSi, a transformation from the MnP structure to the tetragonal CuTi structure (P4/nmm) occurs at 13 GPa and 20 GPa. The pressure dependence of the electronic density of states reveals that RuSi and OsSi are semiconductors in the ε-FeSi structure and become metallic in the CsCl structure. RhSi and IrSi are metals in the MnP structure and become semimetals in their high pressure ε-FeSi form. CoSi in the ε-FeSi configuration is a semimetal. PdSi and PtSi remain metallic throughout up to 300 GPa.

  19. Platinum group elements and gold in ferromanganese crusts from Afanasiy-Nikitin seamount, equatorial Indian Ocean: Sources and fractionation

    Science.gov (United States)

    Banakar, V.K.; Hein, J.R.; Rajani, R.P.; Chodankar, A.R.

    2007-01-01

    The major element relationships in ferromanganese (Fe-Mn) crusts from Afanasiy-Nikitin seamount (ANS), eastern equatorial Indian Ocean, appear to be atypical. High positive correlations (r = 0.99) between Mn/Co and Fe/Co ratios, and lack of correlation of those ratios with Co, Ce, and Ce/Co, indicate that the ANS Fe-Mn crusts are distinct from Pacific seamount Fe-Mn crusts, and reflect region-specific chemical characteristics. The platinum group elements (PGE: Ir, Ru, Rh, Pt, and Pd) and Au in ANS Fe-Mn crusts are derived from seawater and are mainly of terrestrial origin, with a minor cosmogenic component. The Ru/Rh (0.5-2) and Pt/Ru ratios (7-28) are closely comparable to ratios in continental basalts, whereas Pd/Ir ratios exhibit values ( 0.75) correlations between water depth and Mn/Co, Fe/Co, Ce/Co, Co, and the PGEs. Fractionation of the PGE-Au from seawater during colloidal precipitation of the major-oxide phases is indicated by well-defined linear positive correlations (r > 0.8) of Co and Ce with Ir, Ru, Rh, and Pt; Au/Co with Mn/Co; and by weak or no correlations of Pd with water depth, Co-normalized major-element ratios, and with the other PGE (r elements, which likely involves an oxidation reaction on the Mn-oxide and Fe-oxyhydroxide surfaces. The documented fractionation of PGE-Au and their positive association with redox sensitive Co and Ce may have applications in reconstructing past-ocean redox conditions and water masses.

  20. Skin test concentrations for systemically administered drugs -- an ENDA/EAACI Drug Allergy Interest Group position paper

    DEFF Research Database (Denmark)

    Brockow, K; Garvey, L H; Aberer, W

    2013-01-01

    search on skin test drug concentration in MEDLINE and EMBASE, reviewed and evaluated the literature in five languages using the GRADE system for quality of evidence and strength of recommendation. Where the literature is poor, we have taken into consideration the collective experience of the group...

  1. Distribution Characteristics of Gold and Other Trace Elements in the Proterozoic Lengjiaxi Group,Northeastern Hunan Province

    Institute of Scientific and Technical Information of China (English)

    刘英俊; 季峰峰; 等

    1992-01-01

    Systematic geochemical studies of the Proterozoic Lengjiaxi Group in northeastern Hunan Province suggest that the Lengjiaxi Group is a Au-As-Sb-W association-type Au-bearing turbidite formation.The contents of Au,As,Sb,W,Cr,Mn,Pb and Zn in the turbidite formation are more than two times as high as the average contents of trace elements in the upper continental crust.The low abundance of Ag and the close correlation between Au and As are two important characteristic features.In the Au-bearing turbidite formation the enrichment of gold is due to the extensive occurrence of Au-bearing pyrites.Higher contents of Au,W,Sb and Ag in the greywacke indicate that they also exist in the form of heavy minerals.Au,Ag,As,Sb,W and REE in the Au-bearing turbidite formation have a close genetic relation with the chemistry of the gold deposits.

  2. Platinum group elements geochemistry of ultramafic and associated rocks from Pindar in Madawara Igneous Complex, Bundelkhand massif, central India

    Indian Academy of Sciences (India)

    V Balaram; S P Singh; M Satyanarayanan; K V Anjaiah

    2013-02-01

    Ultramafic rocks comprising dunite, harburgite, lehzolite, olivine webserite and websterite occur as intrusives in the form of small hillocks at around Pindar into the granite–gneisses of Bundelkhand Gneissic Complex (BnGC). The peridotites are dominated by olivine cumulates where chromite and precious metal-bearing sulphides crystallized along with pyroxenes, subsequent to crystallization of olivine into the interstitial spaces of cumulates during cooling. Ultramafic rocks of Pindar are characterized by high MgO (up to 46.0 wt%) and FeO (up to 5.8 wt%); low SiO2 (40.8 to 48.0 wt%), TiO2 (0.2 to 0.5 wt%), Al2O3 (∼3.2 wt% av.), CaO(∼ 2.7 wt% av.) and Cu (11 to 73 g/g). Cr and Ni values range from 2297 to 3150 g/g and 2434 to 2767 g/g, respectively. Distribution of Ir (up to 20 ng/g), Ru (27 to 90 ng/g), Rh (3 to 14 ng/g), Pt (18 to 72 ng/g), Pd (10 to 27 ng/g) and Au (22 to 57 ng/g) indicate platinum group element (PGE) and associated gold mineralization in these ultramafic rocks. A mineral phase representing sperrylite (PtAs2) was also identified within the sulphides in Scanning electron microscopy with energy dispersive spectrometer (SEM–EDS) studies. The primitive mantle-normalized siderophile elements pattern shows platinum group element PGE (PPGE) enrichment (Rh, Pt, Pd). Discrimination diagrams of Pd/Ir vs. Ni/Cu, Pd/Pt vs. Ni/Cu, Cu/Pd vs. Pd, and Cu vs. Pd for the peridotites of Pindar attribute to affinity towards komatiite magma, derived from high degree of partial melting of prolonged depleted mantle, and the sulphur saturation condition incurred during the crystallization of chromite which was favourable for PGE mineralization.

  3. Finite element analysis of second order wave radiation by a group of cylinders in the time domain

    Institute of Scientific and Technical Information of China (English)

    WANG Chi-zhong; MITRA Santanu; HUANG Hao-cai; KHOO Boo-cheong

    2013-01-01

    A finite element based numerical method is employed to analyze the wave radiation by multiple or a group of cylinders in the time domain.The nonlinear free surface and body surface boundary conditions are satisfied based on the perturbation method up to the second order.The first-and second-order velocity potential problems at each time step are solved through a Finite Element Method (FEM).The matrix equation of the FEM is solved through iteration and the initial solution is obtained from the result at the previous time step.The three-dimensional (3-D) mesh required is generated based on a two-dimensional (2-D) hybrid mesh on a horizontal plane and its extension in the vertical direction.The hybrid mesh is generated by combining an unstructured grid away from cylinders and two structured grids near the cylinder and the artificial boundary.The fluid velocity on the free surface and the cylinder surface are calculated by using a differential method.Results for various configurations including the cases of two cylinders and four cylinders and a group of eighteen cylinders are obtained to show the joint influences of cylinders on the first-and secondorder waves and forces,including the effects of spacing ratios and wave frequency on the second order waves and the mean force,in particular.

  4. Tracing of ca 800 yr old mining activity in peat bog using Pb elemental concentrations and isotope compositions.

    Science.gov (United States)

    Baron, S.; Carignan, J.; Ploquin, A.

    2003-04-01

    Sixty sites of slags have been documented on the Mont-Lozère in southern France. The petrographic analysis shows that slags are metallurgical wastes (800 to 850 yr BP) which certainly result from smelting activity for lead and silver extraction (Ploquin et al., 2001). The aims of this study are: 1) to trace the source of Pb ores which supplied the smelting sites, by using the Pb isotopic composition of several surrounding Pb deposits, 2) to evaluate the actual pollution caused by these slags, by using elemental and isotopic compositions of soils, water and vegetation, and 3) to document the pollution history of the region, by using elemental and isotopic compositions of peat bog cores collected in the neighbourhood of the historical smelting sites. The lead isotopic composition of galena collected in most surrounding ores is very similar to that of different slag samples. On the other hand, the high precision of the results allowed us to select the mineralised areas which were probably the ore sources. The Pb isotopic composition of slags is even more homogeneous: 208/206 Pb: 2.092±0.002; 206/207 Pb: 1.179±0.001; 208/204 Pb: 38.663±0.025; 207/204 Pb: 15.665±0.006; 206/204 Pb: 18.476±0.023, and will allow source tracing in the environment. The "Narses Mortes" peat bog, around which two smelting sites have been reported, is strongly minerotrophic and contains 8 to 60% ash. A 1.40 m core have been retrieved and divided into 58 individual samples. Minerotrophic peat bog records both atmospheric deposition, soils leaching and the grounwater influence. The measured metal concentrations are normalised to Al contents of peat bog samples and the metal/Al ratios are compared to that of the Mont-Lozère granite: relative excess in metal concentrations are found in peat bog samples. An increasing excess of most metals (Pb, Zn, Cd...) was measured for surface samples, from 55 cm depth to the top of the core (23 cm depth). This profil might be attributed to atmospheric

  5. 肺炎患儿血清中微量元素含量的临床探讨%Clinical study of serum trace elements concentrations in children with pneumonia

    Institute of Scientific and Technical Information of China (English)

    于晗澍

    2012-01-01

    Objective To study serum trace elements concentrations including copper, zinc, iron, magnesium and calcium in children with pneumonia. Methods 50 children suffering from pneumonia were selected as observation group, and 50 healthy children as control group. The serum trace elements concentrations in two groups were tested. Results Serum copper, zinc and calcium concentrations in the observation group were significantly lower than those in the control group, with statistical difference between the two groups( P < 0. 01 ); Serum calcium, magnesium, iron, zinc and copper concentrations of severe pneumonia were significantly lower than those of mild pneumonia in the observation group, with statistical difference( P <0. 01 ). Conclusions Serum trace elements concentrations existed metabolic disorder in children with pneumonia. Therefore, serum trace elements concentrations in children with pneumonia should be de-tected and reasonable supplement treatment should be done to facilitate the rapid recovery of the disease.%目的 研究肺炎患儿血清中铜、锌、铁、镁、钙等微量元素的含量的变化情况.方法 选择50例肺炎的患儿作为观察组,随机选择同期在我院门诊健康体检的50例健康儿童作为对照组,分别测定两组患儿血清中微量元素铜、锌、铁、镁、钙的含量.结果 观察组中患有肺炎的患儿血清中的铜、锌、钙的含量明显低于对照组,具有统计学意义(P<0.01);观察组中患有重症肺炎的患儿血清中钙.镁、铁、锌、铜的含量都比轻症肺炎患儿显著降低,具有显著差异性(P<0.01).结论 肺炎患儿血清中钙、铁、锌、铜、镁等微量元素的代谢紊乱,故应对肺炎患儿进行血微量元素的检测,并对缺乏者给予合理的补充治疗,以助疾病的迅速恢复.

  6. Modeling of the Critical Micelle Concentration (CMC) of Nonionic Surfactants with an Extended Group-Contribution Method

    DEFF Research Database (Denmark)

    Mattei, Michele; Kontogeorgis, Georgios; Gani, Rafiqul

    2013-01-01

    A group-contribution (GC) property prediction model for estimating the critical micelle concentration (CMC) of nonionic surfactants in water at 25 °C is presented. The model is based on the Marrero and Gani GC method. A systematic analysis of the model performance against experimental data......; and carbohydrate derivate ethers, esters, and thiols. The model developed consists of linear group contributions, and the critical micelle concentration is estimated using the molecular structure of the nonionic surfactant alone. Compared to other models used for the prediction of the critical micelle...... is carried out using data for a wide range of nonionic surfactants covering a wide range of molecular structures. As a result of this procedure, new third order groups based on the characteristic structures of nonionic surfactants are defined and are included in the Marrero and Gani GC model. In this way...

  7. Effect of concentration of dispersed organic matter on optical maturity parameters: Interlaboratory results of the organic matter concentration working group of the ICCP.

    Science.gov (United States)

    Mendonca, Filho J.G.; Araujo, C.V.; Borrego, A.G.; Cook, A.; Flores, D.; Hackley, P.; Hower, J.C.; Kern, M.L.; Kommeren, K.; Kus, J.; Mastalerz, Maria; Mendonca, J.O.; Menezes, T.R.; Newman, J.; Ranasinghe, P.; Souza, I.V.A.F.; Suarez-Ruiz, I.; Ujiie, Y.

    2010-01-01

    The main objective of this work was to study the effect of the kerogen isolation procedures on maturity parameters of organic matter using optical microscopes. This work represents the results of the Organic Matter Concentration Working Group (OMCWG) of the International Committee for Coal and Organic Petrology (ICCP) during the years 2008 and 2009. Four samples have been analysed covering a range of maturity (low and moderate) and terrestrial and marine geological settings. The analyses comprise random vitrinite reflectance measured on both kerogen concentrate and whole rock mounts and fluorescence spectra taken on alginite. Eighteen participants from twelve laboratories from all over the world performed the analyses. Samples of continental settings contained enough vitrinite for participants to record around 50 measurements whereas fewer readings were taken on samples from marine setting. The scatter of results was also larger in the samples of marine origin. Similar vitrinite reflectance values were in general recorded in the whole rock and in the kerogen concentrate. The small deviations of the trend cannot be attributed to the acid treatment involved in kerogen isolation but to reasons related to components identification or to the difficulty to achieve a good polish of samples with high mineral matter content. In samples difficult to polish, vitrinite reflectance was measured on whole rock tended to be lower. The presence or absence of rock fabric affected the selection of the vitrinite population for measurement and this also had an influence in the average value reported and in the scatter of the results. Slightly lower standard deviations were reported for the analyses run on kerogen concentrates. Considering the spectral fluorescence results, it was observed that the ??max presents a shift to higher wavelengths in the kerogen concentrate sample in comparison to the whole-rock sample, thus revealing an influence of preparation methods (acid treatment) on

  8. 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

  9. Streptococcal group B integrative and mobilizable element IMESag-rpsI encodes a functional relaxase involved in its transfer

    Science.gov (United States)

    Lorenzo-Diaz, Fabian; Fernández-Lopez, Cris; Douarre, Pierre-Emmanuel; Baez-Ortega, Adrian; Flores, Carlos; Glaser, Philippe

    2016-01-01

    Streptococcus agalactiae or Group B Streptococcus (GBS) are opportunistic bacteria that can cause lethal sepsis in children and immuno-compromised patients. Their genome is a reservoir of mobile genetic elements that can be horizontally transferred. Among them, integrative and conjugative elements (ICEs) and the smaller integrative and mobilizable elements (IMEs) primarily reside in the bacterial chromosome, yet have the ability to be transferred between cells by conjugation. ICEs and IMEs are therefore a source of genetic variability that participates in the spread of antibiotic resistance. Although IMEs seem to be the most prevalent class of elements transferable by conjugation, they are poorly known. Here, we have studied a GBS-IME, termed IMESag-rpsI, which is widely distributed in GBS despite not carrying any apparent virulence trait. Analyses of 240 whole genomes showed that IMESag-rpsI is present in approximately 47% of the genomes, has a roughly constant size (approx. 9 kb) and is always integrated at a single location, the 3′-end of the gene encoding the ribosomal protein S9 (rpsI). Based on their genetic variation, several IMESag-rpsI types were defined (A–J) and classified in clonal complexes (CCs). CC1 was the most populated by IMESag-rpsI (more than 95%), mostly of type-A (71%). One CC1 strain (S. agalactiae HRC) was deep-sequenced to understand the rationale underlying type-A IMESag-rpsI enrichment in GBS. Thirteen open reading frames were identified, one of them encoding a protein (MobSag) belonging to the broadly distributed family of relaxases MOBV1. Protein MobSag was purified and, by a newly developed method, shown to cleave DNA at a specific dinucleotide. The S. agalactiae HRC-IMESag-rpsI is able to excise from the chromosome, as shown by the presence of circular intermediates, and it harbours a fully functional mobilization module. Further, the mobSag gene encoded by this mobile element is able to promote plasmid transfer among pneumococcal

  10. Determination of the Concentration of Essential Elements in Pleurotus Ostreatus Cultivated on Valisneria Arthiopica as a Supplementary Substrate to Sawdust using Instrumental Neutron Activation Analyses

    Directory of Open Access Journals (Sweden)

    R.G. Abrefah

    2011-11-01

    Full Text Available Mushrooms are excellent nutritional and medicinal sources in the environment. This study has sought to conduct an analysis of the concentration of the essential elements in the mushroom sample that was cultivated on three supplementary substrate compositions (25% Vallisneria aethiopica and 75% Tripochton scleroxylon, 50% Vallisneria aethiopica and 50% Tripochton scleroxylon and 75% Vallisneria aethiopica and 25% Tripochton scleroxylon using Instrumental Neutron Activation Analysis (INAA at the Ghana Research Reactor-1 facility(GHARR-1. The concentrations of the elements were detected in Pleurotus ostreatus cultivated on three different percentage substrate compositions of a mixture of Vallisneria aethiopica and Triplochiton scleroxylon. The mixture of 50% Vallisneria aethiopica and 50% Tripochton scleroxylon was best for most of the cultivation of oyster mushrooms since most of the elements detected in the samples attained the highest concentration in this substrate. The validity of the INAA technique for determination essential elements was checked by analyses of SRM 1566b (Oyster tisue and Peach leaves 1547, respectively. The mean concentrations of the nutritional elements (Al, Cs, Ca, Cu, Cr, Cl, Zn, Br, Hg, Th, Fe, K, Mg, Mn, Na and V were determined in mushrooms cultivated on three different substrate mixtures.

  11. Functional gene groups are concentrated within chromosomes, among chromosomes and in the nuclear space of the human genome.

    Science.gov (United States)

    Thévenin, Annelyse; Ein-Dor, Liat; Ozery-Flato, Michal; Shamir, Ron

    2014-09-01

    Genomes undergo changes in organization as a result of gene duplications, chromosomal rearrangements and local mutations, among other mechanisms. In contrast to prokaryotes, in which genes of a common function are often organized in operons and reside contiguously along the genome, most eukaryotes show much weaker clustering of genes by function, except for few concrete functional groups. We set out to check systematically if there is a relation between gene function and gene organization in the human genome. We test this question for three types of functional groups: pairs of interacting proteins, complexes and pathways. We find a significant concentration of functional groups both in terms of their distance within the same chromosome and in terms of their dispersal over several chromosomes. Moreover, using Hi-C contact map of the tendency of chromosomal segments to appear close in the 3D space of the nucleus, we show that members of the same functional group that reside on distinct chromosomes tend to co-localize in space. The result holds for all three types of functional groups that we tested. Hence, the human genome shows substantial concentration of functional groups within chromosomes and across chromosomes in space.

  12. SERUM FERRITIN CONCENTRATIONS IN AN IMPAIRED FASTING GLUCOSE POPULATION AND THEIR NORMAL CONTROL GROUP

    Directory of Open Access Journals (Sweden)

    F. Sharifi

    2007-07-01

    Full Text Available Some recent studies have revealed the relationship among excess ferritin, coronary heart disease, and insulin resistance. To assess the association between serum ferritin concentration and impaired fasting glucose, this study was designed. A total of 187 people including 91 impaired fasting glucose (IFG subjects and 96 normal glucose subjects who had been recognized in a large epidemiological study in Zanjan in 2001 were enrolled. The cohorts were well matched for age, sex and BMI. Body mass index and blood pressure of the participants were measured and serum cholesterol, triglyceride and ferritin were evaluated. All the data were analyzed by t-test, x² test and analysis of variance. Serum ferritin was higher in the IFG cohort (85.5 ± 6.6 µg/l vs. 49.4 ± 3.7 µg/l, P = 0.001. A positive correlation was found between fasting plasma glucose and serum ferritin in this study (r: 0.29, P: 0.001. Using multiple regression analysis, we found an association between serum ferritin and BMI (0.06, p: 0.4, blood pressure (0.15, P = 0.01, FPG (0.29, P = 0.001, triglyceride (0.08, P = 0.01 and cholesterol (0.07, P = 0.03. The odd's ratio for the association of IFG in male subjects with the high serum ferritin level was 8.3 (CI 95%:1.211.9, P = 0.01 and for females was 3.06 (C.I 95%: 0.58-15, P: 0.1. Our study, implying that hyperferritinemia occurs before elevation of plasma glucose concentration more than 126 mg/dl. If prospective and interventional studies Confirm an etiologic role of iron overload in the pathogenesis of insulin resistance and type 2 diabetes, reduced dietary iron intake, especially in men with additional risk factors for type 2 diabetes, would appear to be a logical consequence.

  13. Influence of extremely low frequency magnetic field on total protein and –SH groups concentrations in liver homogenates

    Directory of Open Access Journals (Sweden)

    Elżbieta Ciejka

    2014-10-01

    Full Text Available Background: Free radicals are atoms, molecules or their fragments, whose excess leads to the development of oxidative stress, the cause of many neoplastic, neurodegenerative and inflammatory diseases, as well as aging of organisms. Industrial pollution, tobacco smoke, ionizing radiation, ultrasound and magnetic fields are the major exogenous sources of free radicals. The low frequency magnetic field is commonly applied in physiotherapy. The aim of the present study was to evaluate the effect of extremely low frequency magnetic field (ELF-MF on the concentration of sulfhydryl groups (–SH and proteins in liver tissues of experimental animals depending on the time of exposure to the field. Material and Methods: Twenty one Sprague-Dawley male rats, aged 3–4 months were randomly divided into 3 experimental groups (each containing 7 animals: controls (group I, the rats exposed to ELF-MF of 40 Hz, 7 mT (this kind of the ELF-MF is mostly used in magnetotherapy, 30 min/day for 2 weeks (group II and the rats exposed to 40 Hz, 7 mT for 60 min/day for 2 weeks (group III. The concentrations of proteins and sulfhydryl groups in the liver tissues were determined after exposure to magnetic fields. Results: Exposure to low magnetic field: 40 Hz, 7 mT for 30 min/day and 60 min/day for 2 weeks caused a significant increase in the concentration of –SH groups and total protein levels in the liver tissues. Conclusions: The study results suggest that exposure to magnetic fields leads to the development of adaptive mechanisms to maintain the balance in the body oxidation-reduction and in the case of the studied parameters does not depend on the time of exposure. Med Pr 2014;65(5:639–644

  14. A cavity ring-down spectroscopy system for high time resolution measurements of gaseous elemental mercury concentrations

    Science.gov (United States)

    Pierce, Ashley M.

    The global cycling of mercury (Hg), a highly toxic environmental pollutant, currently has many unknowns. There are various sources of Hg to the atmosphere including both anthropogenic and natural sources. Processes involved in the global cycling of Hg include emissions from legacy Hg pools, deposition, re-emission, and chemical and physical transformation processes such as gas-phase oxidation and heterogeneous redox reactions. Gaseous elemental mercury (GEM) can represent >95% of Hg present in the atmosphere. GEM has a relatively long atmospheric lifetime, which allows it to be transported 1000s of km, effectively making it a global pollutant. Once deposited, Hg can be converted to methylmercury, a bioavailable form of Hg known to cause neurological damage in wildlife and humans. Current atmospheric Hg sensors require long analyzing periods for a single sample (minutes to hours), thus a faster-response sensor would improve characterization of surface-atmosphere exchange processes and atmospheric Hg dynamics. The goal of this thesis work was to develop a new, field-deployable sensor for high time resolution measurements of GEM in ambient air using pulsed cavity ring-down spectroscopy (CRDS). In this research, a CRDS system was developed using a pulsed laser (50 Hz pulse repetition rate) emitting wavelengths tunable between 215 and 280 nm (Hg absorbs at 253.65 nm), a high finesse 1-m-long cavity lined with two high reflectivity mirrors. Due to the long path length (˜1 km) produced inside the short cavity, sample volumes could be kept small while measurement sensitivity remained high. By optimizing the CRDS setup and reducing interferences (e.g., ozone concentration fluctuations), the current CRDS sensor was deployed in the field to measure GEM concentrations in ambient air. The sensor was also used for the first-ever GEM flux measurements by the eddy covariance flux method. Results showed that fast GEM fluctuations could be detected by the CRDS sensor and the

  15. Standards for components in concentrating solar thermal power plants - status of the Spanish working group

    Science.gov (United States)

    Sallaberry, Fabienne; Bello, Azucena; Burgaleta, Juan Ignacio; Fernandez-García, Aránzazu; Fernandez-Reche, Jesus; Gomez, Juan Antonio; Herrero, Saioa; Lüpfert, Eckhard; Morillo, Rafael; Vicente, Gema San; Sanchez, Marcelino; Santamaria, Patricia; Ubach, Josep; Terradillos, Jesus; Valenzuela, Loreto

    2016-05-01

    Today Spain is still the worldwide leader in the use of Concentrating Solar Power (CSP) technology with more than 2300 MW installed solar thermal power rated in 2015, compared to the 4600 MW installed worldwide. In order to improve the quality of current plants and require the best quality for future plants, the subcommittee SC 117 "Thermoelectric Solar Energy Systems", which is part of the committee AEN/CTN 206 for electricity production, works on different aspects of the plants since 2010. This paper gives an overview of the state of the publications in draft to qualify the performance and the durability of the main components of the solar field (receiver tubes, solar tracking systems, reflectors, heat transfer fluids, collectors and specific sensors). A summary of the main tests set for each component in the future Spanish standards is presented. The first complete standard drafts will be ready by the end of the current year 2015 and most are expected to be published within the following years.

  16. Temporal variations in gaseous elemental mercury concentrations at a contaminated site: Main factors affecting nocturnal maxima in daily cycles

    Science.gov (United States)

    Esbrí, José M.; Martínez-Coronado, Alba; Higueras, Pablo L.

    2016-01-01

    Mercury is considered to be a global pollutant and it has been globally transported as gaseous elemental mercury (GEM). International networks for the continuous monitoring of mercury, all of which are based on background sites, study the dispersion pattern of this metal and trends in its evolution in time and space. However, information about seasonal and daily cycling of polluted sites is scarce. The aim of the work described here was to cover this gap in knowledge. For this purpose, continuous (GEM) measurements were carried out in Almadén town from November 2011 to September 2013. Meteorological data were also collected during this time. GEM data show an average concentration during the sampling period (2011-2013) of 27.4 ng m-3, with a range of 0.8-686.9 ng m-3. The results highlighted seasonal and daily cycles of GEM in Almadén town, with seasonally higher levels in summer (686.9 ng m-3) and significantly daily higher levels during the night. A multiple linear regression model has established wind speed as the best GEM predictor in all seasons during the night, while the best predictor in winter is relative humidity, temperature in spring, solar radiation in summer and wind speed in autumn during the day. These results provide evidence that, in mining polluted sites like Almadén, photochemical reactions have a negligible impact on GEM levels during the daytime and that meteorological parameters are more relevant. Further studies on diurnal GEM cycling in polluted sites must be carried out to obtain a realistic local risk assessment, taking into account night GEM levels and their importance in each case study.

  17. Major- and Trace-Element Concentrations in Soils from Northern California: Results from the Geochemical Landscapes Project Pilot Study

    Science.gov (United States)

    Morrison, Jean M.; Goldhaber, Martin B.; Holloway, JoAnn M.; Smith, David B.

    2008-01-01

    In 2004, the U.S. Geological Survey (USGS), the Geological Survey of Canada (GSC), and the Mexican Geological Survey (Servicio Geologico Mexicano, or SGM) initiated pilot studies in preparation for a soil geochemical survey of North America called the Geochemical Landscapes Project. The purpose of this project is to provide a better understanding of the variability in chemical composition of soils in North America. The data produced by this survey will be used to construct baseline geochemical maps for regions within the continent. Two initial pilot studies were conducted: (1) a continental-scale study involving a north-south and east-west transect across North America and (2) a regional-scale study. The pilot studies were intended to test and refine sample design, sampling protocols, and field logistics for the full continental soils geochemical survey. Smith and others (2005) reported the results from the continental-scale pilot study. The regional-scale California study was designed to represent more detailed, higher resolution geochemical investigations in a region of particular interest that was identified from the low-sample-density continental-scale survey. A 20,000-km2 area of northern California (fig. 1), representing a wide variety of topography, climate, and ecoregions, was chosen for the regional-scale pilot study. This study area also contains diverse geology and soil types and supports a wide range of land uses including agriculture in the Sacramento Valley, forested areas in portions of the Sierra Nevada, and urban/suburban centers such as Sacramento, Davis, and Stockton. Also of interest are potential effects on soil geochemistry from historical hard rock and placer gold mining in the foothills of the Sierra Nevada, historical mercury mining in the Coast Range, and mining of base-metal sulfide deposits in the Klamath Mountains to the north. This report presents the major- and trace-element concentrations from the regional-scale soil geochemical

  18. Moisture content in Dall's porpoise (Phocoenoides dalli) tissues: a reference base for conversion factors between dry and wet weight trace element concentrations in cetaceans

    Energy Technology Data Exchange (ETDEWEB)

    Yang Jian; Miyazaki, Nobuyuki

    2003-03-01

    Conversion factors were developed for Dall's porpoise tissues to convert trace element concentrations between dry and wet weight basis. - Concentration of trace elements measured by dry weight basis has become more commonly used in recent studies on cetaceans than wet weight basis, which was used more in earlier studies. Because few authors present moisture content data in their papers, it is difficult to compare the concentrations of trace elements between various studies. Therefore, we felt that it would be useful if a reference conversion factor (CF) for tissue types could be found to convert between wet weight and dry weight data on trace element concentrations. We determined the moisture contents of 14 tissues of Dall's porpoise (Phocoenoides dalli), and then, calculated the CF values for those tissues. Because the moisture content of each tissue differs from other tissues, it is necessary to use a specific CF for each tissue rather than a general CF for several tissues. We have also found that CF values for Dall's porpoise tissues are similar to the same tissues in other cetaceans. Therefore CF values from Dall's porpoise can be reliably used to convert between wet and dry weight concentrations for other cetacean tissues as reference data.

  19. Chemo-dynamical evolution model: Enrichment of r-process elements in the Local Group dwarf galaxies

    Science.gov (United States)

    Hirai, Yutaka; Ishimaru, Yuhri; Saitoh, Takayuki R.; Fujii, Michiko S.; Hidaka, Jun; Kajino, Toshitaka

    2016-08-01

    Neutron star mergers are one of the candidate astrophysical site(s) of r-process. Several chemical evolution studies however pointed out that the observed abundance of r-process is difficult to reproduce by neutron star mergers. In this study, we aim to clarify the enrichment of r-process elements in the Local Group dwarf galaxies. We carry out numerical simulations of galactic chemo-dynamical evolution using an N-body/smoothed particle hydrodynamics code, ASURA. We construct a chemo-dynamical evolution model for dwarf galaxies assuming that neutron star mergers are the major source of r-process elements. Our models reproduce the observed dispersion in [Eu/Fe] as a function of [Fe/H] with neutron star mergers with a merger time of 100 Myr. We find that star formation efficiency and metal mixing processes during the first <~ 300 Myr of galaxy evolution are important to reproduce the observations. This study supports that neutron star mergers are a major site of r-process.

  20. First-principles study on the lattice stability of elemental Co, Rh, and Ir in the ⅧB group