WorldWideScience

Sample records for chemical elements

  1. Plants' essential chemical elements

    Science.gov (United States)

    Kevin T. Smith

    2007-01-01

    Every garden center and hardware store sells fertilizer guaranteed to "feed" plants. In a strict sense, we can't feed plants. Food contains an energy source. Green plants capture solar energy and make their own food through photosynthesis! Photosynthesis and other metabolic processes require chemical elements in appropriate doses for plants to survive...

  2. Elements of chemical thermodynamics

    CERN Document Server

    Nash, Leonard K

    2005-01-01

    This survey of purely thermal data in calculating the position of equilibrium in a chemical reaction highlights the physical content of thermodynamics, as distinct from purely mathematical aspects. 1970 edition.

  3. Origin of the chemical elements

    Energy Technology Data Exchange (ETDEWEB)

    Tayler, R J

    1984-05-01

    The subject is discussed in relation to the composition of initially created matter and changes which have occurred during the life history of the universe, with particular reference to our galaxy and nearby galaxies. Headings are: observations of element abundances (stars, gas clouds in our own and nearby galaxies, hot gas in galaxy clusters, the solar system); the originally created matter (Big Bang theory and early nuclear reactions); processes changing observed composition (galactic evolution; nuclear fusion reactions in stellar interiors; chemical composition of a highly evolved massive star); supernovae (production of heavy elements); chemical evolution of the galaxy; production of very heavy elements (s process, r process).

  4. Chemical experiments with superheavy elements.

    Science.gov (United States)

    Türler, Andreas

    2010-01-01

    Unnoticed by many chemists, the Periodic Table of the Elements has been extended significantly in the last couple of years and the 7th period has very recently been completed with eka-Rn (element 118) currently being the heaviest element whose synthesis has been reported. These 'superheavy' elements (also called transactinides with atomic number > or = 104 (Rf)) have been artificially synthesized in fusion reactions at accelerators in minute quantities of a few single atoms. In addition, all isotopes of the transactinide elements are radioactive and decay with rather short half-lives. Nevertheless, it has been possible in some cases to investigate experimentally chemical properties of transactinide elements and even synthesize simple compounds. The experimental investigation of superheavy elements is especially intriguing, since theoretical calculations predict significant deviations from periodic trends due to the influence of strong relativistic effects. In this contribution first experiments with hassium (Hs, atomic number 108), copernicium (Cn, atomic number 112) and element 114 (eka-Pb) are reviewed.

  5. Group theoretical classification of chemical elements

    International Nuclear Information System (INIS)

    Byakov, V.M.; Kulakov, V.I.; Rumer, Y.B.; Fet, A.L.

    1977-01-01

    The method of classification of chemical elements, based on group symmetry principles, is compared with element properties. Elements are considered to be states of a single quantum system, the atomic structure being ignored. Elements treated as states of the system, break down into successively diminishing subsystems, big and small multiplets. The theory, being a group classification, does not describe in detail any of element properties, but leads to a unified qualitative description of all of them simultaneously

  6. Origin of the chemical elements

    Energy Technology Data Exchange (ETDEWEB)

    Tayler, R J [Sussex Univ., Brighton (UK). Astronomy Centre

    1984-11-08

    An account is first given of the observed chemical composition of objects in the Universe (Sun, Solar System, stars, gas clouds) and of important variations of composition from object to object. The initial composition is then discussed in terms of the Hot Big Bang cosmological theory, and the different types of nuclear reaction which are believed to have occurred in stars and to have modified this composition are considered. Finally, an account is given of the interpretation of the present observations in terms of the initial chemical composition and of galactic and stellar formation and evolution.

  7. The origin of the chemical elements

    International Nuclear Information System (INIS)

    Tayler, R.J.

    1984-01-01

    The subject is discussed in relation to the composition of initially created matter and changes which have occurred during the life history of the universe, with particular reference to our galaxy and nearby galaxies. Headings are: observations of element abundances (stars, gas clouds in our own and nearby galaxies, hot gas in galaxy clusters, the solar system); the originally created matter (Big Bang theory and early nuclear reactions); processes changing observed composition (galactic evolution; nuclear fusion reactions in stellar interiors; chemical composition of a highly evolved massive star); supernovae (production of heavy elements); chemical evolution of the galaxy; production of very heavy elements (s process, r process). (U.K.)

  8. Chemical element abundance in K giant atmospheres

    International Nuclear Information System (INIS)

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

    1980-01-01

    With the help of modified method of differential curves of growth studied are physical parameters of atmospheres of giant stars of KO111 spectral class of the NGC 752, M25 and UMa cluster. Observations have been made on reflector of Crimea astrophysical observatory of Academy of Sciences of the USSR in the period from February to May, 1978. Spectograms are obtained for the wave length range from 5000-5500 A. It is shown that the change of chemical content in the wide range in heavy element composition does not influence the star atmosphere structUre. It follows from the results of the investigation that the abundance of chemical elements in stars of various scattered clusters, is the same in the range of errors of measurements and is similar to the abundance of chemical elements in the Sun atmosphere

  9. On-stream chemical element monitor

    International Nuclear Information System (INIS)

    Averitt, O.R.; Dorsch, R.R.

    1979-01-01

    An apparatus and method for on-stream chemical element monitoring are described wherein a multiplicity of sample streams are flowed continuously through individual analytical cells and fluorescence analyses are performed on the sample streams in sequence, together with a method of controlling the time duration of each analysis as a function of the concomitant radiation exposure of a preselected perforate reference material interposed in the sample-radiation source path

  10. Atlantic Forest. A natural reservoir of chemical elements

    International Nuclear Information System (INIS)

    De Franca, E.J.; De Nadai Fernandes, E.A.; Bacchi, M.A.; Elias, C.

    2008-01-01

    The accumulation of chemical elements in biological compartments is one of the strategies of tropical species to adapt to a low-nutrient soil. This study focuses on the Atlantic Forest because of its eco-environmental importance as a natural reservoir of chemical elements. About 20 elements were determined by INAA in leaf, soil, litter and epiphyte compartments. There was no seasonality for chemical element concentrations in leaves, which probably indicated the maintenance of chemical elements in this compartment. Considering the estimated quantities, past deforestation events could have released large amounts of chemical elements to the environment. (author)

  11. Airborne chemical elements in Spanish moss

    Energy Technology Data Exchange (ETDEWEB)

    Shacklette, H.T.; Connor, J.J.

    1973-01-01

    Spanish moss (Tillandsia usneoides L.), collected from its geographic range in Southern United States, was analyzed for 38 chemical elements in 123 samples. Analyses of Spanish moss samples collected at rural, residential, highway, and industrial locations reflected significant differences in concentrations of metals. Samples from industrial and highway locations are characterized as containing greater-than-average amounts of arsenic, cadmium, chromium, cobalt, copper, lead, nickel, and vanadium. The high levels of lead found in some samples from highway locations are especially noteworthy. Many samples from sites near the seashore contained greater-than-average amounts of sodium that is thought to have been derived from ocean spray. Samples from rural locations commonly contain low concentrations of the metal usually associated with industrial or urban activity but may contain large amounts of the elements that are ordinary constituents of soil dust. Four of six samples containing detectable amounts of tin were collected within 50 miles of the only tin smelter in the United States; this result suggests that elemental analyses of Spanish moss samples can provide an economical and rapid method of estimating the kind and relative degree of local atmospheric metal pollution.

  12. Advances in chemical investigations of the heaviest elements

    Directory of Open Access Journals (Sweden)

    Türler Andreas

    2016-01-01

    Full Text Available Although somewhat in the shadow of the discoveries of new elements, experimental chemical investigations of the heaviest elements have made tremendous progress in the last decades. Indeed, it was possible to experimentally determine thermochemical properties of heavy transactinide elements such as copernicium or flerovium. But will it be possible to chemically study all currently known elements of the periodic table up to element 118? While it is experimentally feasible to work with single atoms, the short half-lives of even the longest currently known isotopes of elements 115 through 118 call for new experimental approaches.

  13. Electronic Transmutation (ET): Chemically Turning One Element into Another.

    Science.gov (United States)

    Zhang, Xinxing; Lundell, Katie A; Olson, Jared K; Bowen, Kit H; Boldyrev, Alexander I

    2018-03-08

    The concept of electronic transmutation (ET) depicts the processes that by acquiring an extra electron, an element with the atomic number Z begins to have properties that were known to only belong to its neighboring element with the atomic number Z+1. Based on ET, signature compounds and chemical bonds that are composed of certain elements can now be designed and formed by other electronically transmutated elements. This Minireview summarizes the recent developments and applications of ET on both the theoretical and experimental fronts. Examples on the ET of Group 13 elements into Group 14 elements, Group 14 elements into Group 15 elements, and Group 15 elements into Group 16 elements are discussed. Compounds and chemical bonding composed of carbon, silicon, germanium, phosphorous, oxygen and sulfur now have analogues using transmutated boron, aluminum, gallium, silicon, nitrogen, and phosphorous. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Chemical identification and properties of element 112

    Czech Academy of Sciences Publication Activity Database

    Yakushev, AB.; Zvára, Ivo; Oganessian, YT.; Belozerov, AV.; Dmitriev, S. N.; Eichler, B.; Hubener, S.; Sokol, EA.; Turler, A.; Yeremin, AV.; Buklanov, GV.; Chelnokov, ML.; Chepigin, VI.; Gorshkov, VA.; Gulyaev, AV.; Lebedev, VY.; Malyshev, ON.; Popeko, AG.; Soverna, S.; Szeglowski, Z.; Timokhin, SN.; Tretyakova, SP.; Vasko, VM.; Itkis, MG.

    2003-01-01

    Roč. 91, č. 8 (2003), s. 433-439 ISSN 0033-8230 Institutional research plan: CEZ:AV0Z1048901 Keywords : element 112 * superheavy elements * transactinoids Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 0.940, year: 2003

  15. Chemical analysis of rare earth elements

    International Nuclear Information System (INIS)

    Tsukahara, Ryoichi; Sakoh, Takefumi; Nagai, Iwao

    1994-01-01

    Recently attention has been paid to ICP-AES or ICP-MS, and the reports on the analysis of rare earth elements by utilizing these methods continue to increase. These reports have become to take about 30% of the reports on rare earth analysis, and this is because these methods are highly sensitive to rare earth elements, and also these methods have spread widely. In ICP-AES and ICP-MS, mostly solution samples are measured, therefore, solids must be made into solution. At the time of quantitatively determining the rare earth elements of low concentration, separation and concentration are necessary. Referring to the literatures reported partially in 1990 and from 1991 to 1993, the progress of ICP-AES and ICP-MS is reported. Rare earth oxides and the alloys containing rare earth elements are easily decomposed with acids, but the decomposition of rocks is difficult, and its method is discussed. The separation of the rare earth elements from others in geochemical samples, cation exchange process is frequently utilized. Also solvent extraction process has been studied. For the separation of rare earth elements mutually, chromatography is used. The spectral interference in spectral analysis was studied. The comparison of these methods with other methods is reported. (K.I)

  16. Transuranium elements in organic chemical forms

    International Nuclear Information System (INIS)

    Sakanoue, Masanobu; Yamamoto, Masayoshi

    1987-01-01

    It is very important to achive an understanding what role organic matter plays in the behavior of transuranium elements in the environment. This paper reports the studies on characteristics of fallout Pu and Am in soil closely related to soil organic matter, and interaction of humic acid and Am (III) in aqueous solution. From the results obtained, it was suggested that the humic acids had strong interaction with transuranium elements, but such soluble complexes were removed soon from the solution by coagulation and sorption on soil. (author)

  17. First attempt to chemically identify element 112

    Czech Academy of Sciences Publication Activity Database

    Yakushev, AB.; Buklanov, GV.; Chelnokov, ML.; Chepigin, VI.; Dmitriev, S. N.; Gorshkov, VA.; Hubener, S.; Malyshev, ON.; Oganessian, YT.; Popeko, AG.; Sokol, EA.; Timokhin, SN.; Turler, A.; Vasko, VM.; Yeremin, AV.; Zvára, Ivo

    2001-01-01

    Roč. 89, 11/12 (2001), s. 743-745 ISSN 0033-8230 Institutional research plan: CEZ:AV0Z1048901 Keywords : superheavy elements * actionoid * transactinoids Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 0.660, year: 2001

  18. Exploring the Everyday Context of Chemical Elements: Discovering the Elements of Car Components

    Science.gov (United States)

    Franco-Mariscal, Antonio Joaquín

    2015-01-01

    This paper presents a project about the chemical elements made by 15-year-old Spanish high school students of Chemistry. It focuses on context-based teaching combined with the advantages of creating a large mural which subsequently is exposed in the school. The project consisted of researching the chemical elements in the different materials that…

  19. Measurements of radon and chemical elements: Popocatepetl volcano

    International Nuclear Information System (INIS)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V.; Armienta, M.A.; Valdes, C.; Mena, M.; Seidel, J.L.; Monnin, M.

    2002-01-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  20. An Alternate Graphical Representation of Periodic table of Chemical Elements

    OpenAIRE

    Abubakr, Mohd

    2009-01-01

    Periodic table of chemical elements symbolizes an elegant graphical representation of symmetry at atomic level and provides an overview on arrangement of electrons. It started merely as tabular representation of chemical elements, later got strengthened with quantum mechanical description of atomic structure and recent studies have revealed that periodic table can be formulated using SO(4,2)* SU(2) group. IUPAC, the governing body in Chemistry, doesn't approve any periodic table as a standard...

  1. Three Packets of Minerals of the Periodic Table of Chemical Elements and Chemical Compounds

    OpenAIRE

    Labushev, Mikhail M.

    2013-01-01

    The concepts of alpha- and beta-packets of the periodic table of chemical elements and chemical compounds are defined. The first of the 47 minerals alpha-packets is composed. In it all minerals are arranged in increasing Iav index of proportionality of atomic weights of composing chemical elements, the same way as chemical elements are located in increasing atomic weights in the Periodic table. The packet includes 93 known minerals and two compounds - N2O5 and CO2 - being actually minerals. B...

  2. Chemical elements dynamic in the fermentation process of ethanol producing

    International Nuclear Information System (INIS)

    Nepomuceno, N.; Nadai Fernandes, E.A. de; Bacchi, M.A.

    1994-01-01

    This paper provides useful information about the dynamics of chemical elements analysed by instrumental neutron activation analysis (INAA) and, found in the various segments of the fermentation process of producing ethanol from sugar cane. For this, a mass balance of Ce, Co, Cs, Eu, Fe, Hf, La, Sc, Sm, and Th, terrigenous elements, as well as Br, K, Rb, and Zn, sugar cane plant elements, has been demonstrated for the fermentation vats in industrial conditions of ethanol production. (author). 10 refs, 4 figs, 1 tab

  3. GLOBAL AND REGIONAL GEOCHEMICAL INDEXES OF PRODUCTION OF CHEMICAL ELEMENTS

    Directory of Open Access Journals (Sweden)

    Nikolay S. Kasimov

    2014-01-01

    Full Text Available This paper presents a geochemical assessment of the primary involvement of chemical elements in technogenesis in the world and individual countries. In order to compare the intensity of production of various chemical elements in different countries, the authors have introduced a number of new terms and parameters. The new term is “abstract rock” (AR - an elemental equivalent, whose average composition corresponds to the average chemical composition of the upper continental crust. The new parameters are: “conditional technophility of an element” (TY, “specific technophility” (TYN “regional conditional technophility” (TYR, “specific regional technophility” (TN, and “density of regional conditional technophility” (TS. TY equals to the tons of AR per year necessary for the production of the current level of the element. TY of different elements has been estimated for 2008-2010. The highest TY values are associated with C, S, N, Ra, and Au. TY of many micro- and ultramicroelements is of the order of n•1011t. TYN reflects the volume of AR per the world’s capita. TYN changes from the 1960s to 2010 indicates that the Earth’s population is growing much faster than its demand for many chemical elements. TYR, TN, and TS were used for the integrated assessment of technogenesis at the regional scale; they reflect the intensity of the technogenesis process at the level of individual countries and allow comparing countries with different levels of elements production, population, and areas. The TN and TS levels of the leaders in extraction of natural resources are below these values in other countries due to the large territories (Russia, USA, Canada, Australia, Saudi Arabia, Kazakhstan, Argentina, Bolivia, Venezuela, Colombia, Zambia, Mali, Libya, Mongolia, and Sudan, to the large population (Indonesia, Vietnam, the Philippines, Bangladesh, Nigeria, or to both high spatial and demographic dimensions (India, Brazil, France, Egypt

  4. An Educational Card Game for Learning Families of Chemical Elements

    Science.gov (United States)

    Mariscal, Antonio Joaquin Franco; Martinez, Jose Maria Oliva; Marquez, Serafin Bernal

    2012-01-01

    This paper describes an educational card game designed to help high school students (grade 10, 15-16 years old) "understand," as opposed to memorize, the periodic table. The game may also be used to identify different chemical elements found in daily life objects. As an additional value, students learn the names and symbols of the displayed…

  5. The periodic system of chemical elements: old and new developments

    International Nuclear Information System (INIS)

    Kibler, M.

    1987-09-01

    Some historical facts about the construction of a periodic system of chemical elements are reviewed. The Madelung rule is used to generate an unusual format for the periodic table. Following the work of Byakov, Kulakov, Rumer and Fet, such a format is further refined on the basis of a chain of groups starting with SU(2)xS0(4.2)

  6. Content of Chemical Elements in Wood-Destroying Fungi

    Directory of Open Access Journals (Sweden)

    Strapáč I.

    2016-12-01

    Full Text Available The aim of this study was to examine the content of chemical elements in the dried fruiting bodies of edible wood decaying fungi such as Honey mushrooms (Armillaria mellea, Shiitakes (Lentinus edodes and Oyster mushrooms (Pleurotus ostreatus. Powdered samples of fungi were mineralized in a microwave digestion. Twenty-one (21 chemical elements were detected in the plasma of the device ICP-MS AGILENT 7500c by accredited methods with the aid of calibration curves. The content of individual elements varied within a considerable range. The highest contents of K, Mn, Cu and Cd were found in the fruiting bodies of Honey mushrooms (Armillaria mellea. Shiitakes (Lentinus edodes had the highest content of B and Mo. Significant differences were found in the content of elements in the Oyster mushrooms (Pleurotus ostreatus from Slovakia, Hungary and China. The highest content of Al was found in the Oyster mushrooms (Pleurotus ostreatus from Hungary. The Chinese oysters had a maximum contents of Ca, Mg, Co, Pb, As and U. The Oyster mushrooms (Pleurotus ostreatus from Lemešany (Slovakia had the highest contents of Na, Zn, Fe, Se, Ag, Hg and Cr. The difference of chemical element content could be influenced by the genotype of the fungus and by the composition of substrate on which mushroom grow up.

  7. Chemical behaviour of transuranic elements in the natural environment

    International Nuclear Information System (INIS)

    Kim, J.I.

    1991-01-01

    The chemical behaviour of transuranic elements in natural aquifer systems is governed by a variety of geochemical reactions, such as dissolution reaction (solubility), hydrolysis, complexation with inorganics or organics, redox reaction, colloid formation, geochemical interaction with surfaces of various minerals, coprecipitation, mineralisation etc. This paper reviews the present state of knowledge on some of these particular reactions. The emphasis is placed on how the individual reactions can be appraised for the long-term prediction of the geochemical behaviour of transuranic elements in the natural environment. Of the various reactions, the primary thermodynamic processes of dissolution of transuranic compounds in aquatic solution, complexation with important anions present in groundwater and colloid generation are discussed with notable examples. Various laser spectroscopy in use for the chemical speciation are mentioned briefly as for their spectroscopic capability as well as applicability. The present review discussion is primarily directed to a better understanding of the migration behaviour of transuranic elements in natural aquifer systems. (author) 100 refs

  8. Advanced chemical analysis service for elements, radionuclides and phases

    International Nuclear Information System (INIS)

    Sansoni, B.

    1986-01-01

    A review is given on the structure, organisation and performance of the chemical analysis service of the Central Department for Chemical Analysis at the Kernforschungsanlage Juelich GmbH. The research and development programs together with the infrastructure of the Centre afford to analyse almost all stable elements of the periodical table in almost any material. The corresponding chemical analysis service has been organized according to a new modular system of analytical steps. According to this, the most complicated and, therefore, most general case of an analytical scheme for element and radionuclide analysis in any type of material can be differentiated into about 14 different steps, the modules. They are more or less independent of the special problem. The laboratory is designed and organized according to these steps. (orig./PW) [de

  9. CHEMENGL/CHIMISTE, Chemical and Physical Properties of Elements

    International Nuclear Information System (INIS)

    Levart, Eugene

    2007-01-01

    Description of program or function: Data Base on basic chemical, physical, and nuclear properties of the elements in the Mendeleev Table (118 elements, 4435 nuclides comprising isotopes and isomers). Example: density electric and thermal conductivity, masses of isotopes and isomers, ionisation potential, etc. from H to Ei (Z=118). Both French and English versions are available. In addition, the French version (513 pages) contains other general information about the elements such as mineralogy, industrial applications, toxicity, historical information on discovery of the elements, etc. The latest version contains updates of atomic masses, the names of symbols of transuranium elements have been updated in accordance with the IUPAC recommendations. The values of the abundance of elements in the sun have been corrected according to Grevesse et al. The price of the different elements have been updated, some minor errors have been corrected and the presentation of the cover page has been improved. Several pages have been added to the last chapter of the French version (CHIMISTE), this chapter is not available in the English version (CHEMENGL)

  10. Survey of chemical speciation of trace elements using synchrotron radiation

    International Nuclear Information System (INIS)

    Gordon, B.M.

    1985-01-01

    Information concerning the chemical state of trace elements in biological systems generally has not been available. Such information for toxic elements and metals in metalloproteins could prove extremely valuable in the elucidation of their metabolism and other biological processes. The shielding of core electrons by binding electrons affect the energy required for creating inner-shell holes. Furthermore, the molecular binding and the symmetry of the local environment of an atom affect the absorption spectrum in the neighborhood of the absorption edge. X-ray absorption near-edge structure (XANES) using synchrotron radiation excitation can be used to provide chemical speciation information for trace elements at concentrations as low as 10 ppM. The structure and position of the absorption curve in the region of an edge can yield vital data about the local structure and oxidation state of the trace element in question. Data are most easily interpreted by comparing the observed edge structure and position with those of model compounds of the element covering the entire range of possible oxidation states. Examples of such analyses are reviewed. 14 refs., 1 fig

  11. Chemical and nuclear properties of lawrencium (element 103) and hahnium (element 105)

    International Nuclear Information System (INIS)

    Henderson, R.A.

    1990-01-01

    The chemical and nuclear properties of Lr and Ha have been studied, using 3-minute 260 Lr and 35-second 262 Ha. The crystal ionic radius of Lr 3+ was determined by comparing its elution position from a cation-exchange resin column with those of lanthanide elements having known ionic radii. Comparisons are made to the ionic radii of the heavy actinides, Am 3+ through Es 3+ , obtained by x-ray diffraction methods, and to Md 3+ and Fm 3+ which were determined in the same manner as Lr 3+ . The hydration enthalpy of -3622 kJ/mol was calculated from the crystal ionic radius using an empirical form of the Born equation. Comparisons to the spacings between the ionic radii of the heaviest members of the lanthanide series show that the 2Z spacing between Lr 3+ and Md 3+ is anomalously small, as the ionic radius of Lr 3+ of 0.0886 nm is significantly smaller than had been expected. The chemical properties of Ha were determined relative to the lighter homologs in group 5, Nb and Ta. Group 4 and group 5 tracer activities, as well as Ha, were absorbed onto glass surfaces as a first step toward the determination of the chemical properties of Ha. Ha was found to adsorb on surfaces, a chemical property unique to the group 5 elements, and as such demonstrates that Ha has the chemical properties of a group 5 element. A solvent extraction procedure was adapted for use as a micro-scale chemical procedure to examine whether or not Ha displays eka-Ta-like chemical under conditions where Ta will be extracted into the organic phase and Nb will not. Under the conditions of this experiment Ha did not extract, and does not show eka-Ta-like chemical properties

  12. Chemical composition and mineral elements of edible insects (at ...

    African Journals Online (AJOL)

    The Chemical Composition and Mineral Elements of two edible insects' larvae and termite soldiers were assayed. Their ash content were between 1.01% and 7.50%. The legless larva (LS) had 28.52% fat, while the solider ant had 7.14% and the Legged larva (LG) had 1.50%. The white ant (SA) had 15.61% protein while ...

  13. Fates of Chemical Elements in Biomass during Its Pyrolysis.

    Science.gov (United States)

    Liu, Wu-Jun; Li, Wen-Wei; Jiang, Hong; Yu, Han-Qing

    2017-05-10

    Biomass is increasingly perceived as a renewable resource rather than as an organic solid waste today, as it can be converted to various chemicals, biofuels, and solid biochar using modern processes. In the past few years, pyrolysis has attracted growing interest as a promising versatile platform to convert biomass into valuable resources. However, an efficient and selective conversion process is still difficult to be realized due to the complex nature of biomass, which usually makes the products complicated. Furthermore, various contaminants and inorganic elements (e.g., heavy metals, nitrogen, phosphorus, sulfur, and chlorine) embodied in biomass may be transferred into pyrolysis products or released into the environment, arousing environmental pollution concerns. Understanding their behaviors in biomass pyrolysis is essential to optimizing the pyrolysis process for efficient resource recovery and less environmental pollution. However, there is no comprehensive review so far about the fates of chemical elements in biomass during its pyrolysis. Here, we provide a critical review about the fates of main chemical elements (C, H, O, N, P, Cl, S, and metals) in biomass during its pyrolysis. We overview the research advances about the emission, transformation, and distribution of elements in biomass pyrolysis, discuss the present challenges for resource-oriented conversion and pollution abatement, highlight the importance and significance of understanding the fate of elements during pyrolysis, and outlook the future development directions for process control. The review provides useful information for developing sustainable biomass pyrolysis processes with an improved efficiency and selectivity as well as minimized environmental impacts, and encourages more research efforts from the scientific communities of chemistry, the environment, and energy.

  14. Correlation study of chemical elements in phosphate ores

    International Nuclear Information System (INIS)

    Braganca, Maura Julia Camara da Silva

    1999-07-01

    Geological phenomena, 1) endogenous (volcanism, magmatic flow, metasomatism); 2) metamorphic (resultant of action of high temperature and pressure) and; 3) exogenous (intemperism, contamination) can modify the chemical composition of rocks soils. Thus, chemical elements with little mobility can be used as indicators of the previous geological situation before the occurrence of these phenomena and can sign the chemical composition of the initial formation. The elements with great mobility can already be used as indicators of the characteristic and intensity of the changes, can point out the influence factors and its space and time conditions. In this work the results of the study of phosphated samples ores coming from two alkaline-carbonatitic chimneys (Araxa and Catalao) and from a meta sedimentary rock (Patos de Minas), located phosphate rock deposit, are presented. The results were obtained using the instrumental neutron activation analysis, inductively coupled plasma-mass spectrometry (ICP-MS) and ICP-AES techniques. A comparison of the three types of samples ores, using chemical, crystallographic and statistical methods, shows that the Araxa and Catalao present some geochemical similarities and they are distinguished of Patos de Minas, despite its geographic proximity. (author)

  15. Some Chemical Group Separations of Radioactive Trace Elements

    Energy Technology Data Exchange (ETDEWEB)

    Samsahl, K

    1962-06-15

    As a pretreatment for gamma spectrometric analysis methods have been developed for the chemical separation of traces of P, Sc, Ge, As, Se, Br, Zr, Nb, Ru, Ag, Cd, Sn, Sb, I, Hf, Ta, Re, Os, Au and Hg into 9 different groups. By combining the present methods with already existing chemical group separation methods for traces of Na, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Mo, In, Fe, Cs, Ba, L.a, the rare earths, W and Ir, a complete separation scheme comprising 15 groups of elements has been worked out. The chemical 15-group separation method has been advantageously used in gamma spectrometric routine analysis of biological materials.

  16. Some Chemical Group Separations of Radioactive Trace Elements

    International Nuclear Information System (INIS)

    Samsahl, K.

    1962-06-01

    As a pretreatment for gamma spectrometric analysis methods have been developed for the chemical separation of traces of P, Sc, Ge, As, Se, Br, Zr, Nb, Ru, Ag, Cd, Sn, Sb, I, Hf, Ta, Re, Os, Au and Hg into 9 different groups. By combining the present methods with already existing chemical group separation methods for traces of Na, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Mo, In, Fe, Cs, Ba, L.a, the rare earths, W and Ir, a complete separation scheme comprising 15 groups of elements has been worked out. The chemical 15-group separation method has been advantageously used in gamma spectrometric routine analysis of biological materials

  17. Chemical elements in invertebrate orders for environmental quality studies

    International Nuclear Information System (INIS)

    Magalhaes, Marcelo R.L.; Franca, Elvis J.; Paiva, Jose D.S.; Hazin, Clovis A.; Fonseca, Felipe Y.; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio A.

    2013-01-01

    Among the biomonitors of environmental quality, there is a lack of studies on using invertebrates to evaluate quantitatively chemical elements in ecosystems. This group of animals is quite numerous, widely distributed and adaptable to the most diverse environmental conditions. These features are very useful for the environmental quality assessment, as well as the several occurring insect-plant interactions performing essential functions in ecosystems. The objective of this work is to study the variability of chemical composition of invertebrate orders for using in environmental quality monitoring studies. Instrumental neutron activation analysis - INAA was applied to determine some nutrients and trace elements in invertebrate samples. Sampling by pitfall traps was carried out in riverine ecosystems from the urban area from the Piracicaba Municipality, State of Sao Paulo, Brazil. Invertebrate and reference material samples were irradiated in the nuclear research reactor IEA-R1, Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN. Fragments of a Ni-Cr alloy were irradiated for monitoring the thermal neutron flux. Hymenoptera order was considered the most representative according to the total number of sampled species (about 60%). Significant amounts of Ba, Br, Fe and Sc were found in invertebrates of the order Opiliones. Potassium, rubidium and zinc were highly accumulated in species from Blattodea order, indicating a consistent pattern of accumulation for this invertebrate order. Taking into account the abundance of Hymenoptera order, the chemical composition of its species was significant different at the 95% confidence level for Br and Na in the sampled locals. (author)

  18. Chemical elements in invertebrate orders for environmental quality studies

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Marcelo R.L.; Franca, Elvis J.; Paiva, Jose D.S.; Hazin, Clovis A., E-mail: marcelo_rlm@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: dan-paiva@hotmail.com, E-mail: chazin@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fonseca, Felipe Y.; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio A., E-mail: felipe-yamada@hotmail.com, E-mail: lis@cena.usp.br, E-mail: mabacchi@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    Among the biomonitors of environmental quality, there is a lack of studies on using invertebrates to evaluate quantitatively chemical elements in ecosystems. This group of animals is quite numerous, widely distributed and adaptable to the most diverse environmental conditions. These features are very useful for the environmental quality assessment, as well as the several occurring insect-plant interactions performing essential functions in ecosystems. The objective of this work is to study the variability of chemical composition of invertebrate orders for using in environmental quality monitoring studies. Instrumental neutron activation analysis - INAA was applied to determine some nutrients and trace elements in invertebrate samples. Sampling by pitfall traps was carried out in riverine ecosystems from the urban area from the Piracicaba Municipality, State of Sao Paulo, Brazil. Invertebrate and reference material samples were irradiated in the nuclear research reactor IEA-R1, Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN. Fragments of a Ni-Cr alloy were irradiated for monitoring the thermal neutron flux. Hymenoptera order was considered the most representative according to the total number of sampled species (about 60%). Significant amounts of Ba, Br, Fe and Sc were found in invertebrates of the order Opiliones. Potassium, rubidium and zinc were highly accumulated in species from Blattodea order, indicating a consistent pattern of accumulation for this invertebrate order. Taking into account the abundance of Hymenoptera order, the chemical composition of its species was significant different at the 95% confidence level for Br and Na in the sampled locals. (author)

  19. Method for separating the isotopes of a chemical element

    International Nuclear Information System (INIS)

    Devienne, F.M.

    1977-01-01

    A beam of positive or negative primary ions of at least one compound of a chemical element is accelerated in order to pass through collision boxes placed in series. As a result of inelastic collisions of the ions with the molecules of a neutral target gas within each collision box, a given percentage of primary ions is dissociated into at least two fragments, one of which is a secondary ion in the form of at least two isotopic species. The collision boxes are brought to a potential V 2 so as to trap preferentially one isotopic species which is condensed within each box. 15 claims, 4 figures

  20. Chemical and nuclear properties of Rutherfordium (Element 104)

    International Nuclear Information System (INIS)

    Kacher, C.D.

    1995-01-01

    The chemical-properties of rutherfordium (Rf) and its group 4 homologs were studied by sorption on glass support surfaces coated with cobalt(II)ferrocyanide and by solvent extraction with tributylphosphate (TBP) and triisooctylamine (TIOA). The surface studies showed that the hydrolysis trend in the group 4 elements and the pseudogroup 4 element, lb, decreases in the order Rf>Zr∼Hf>Th. This trend was attributed to relativistic effects which predicted that Rf would be more prone to having a coordination number of 6 than 8 in most aqueous solutions due to a destabilization of the 6d 5/2 shell and a stabilization of the 7p l/2 shell. This hydrolysis trend was confirmed in the TBP/HBr solvent extraction studies which showed that the extraction trend decreased in the order Zr>Hf>Rf?Ti for HBr, showing that Rf and Ti did not extract as well because they hydrolyzed more easily than Zr and Hf. The TIOA/HF solvent extraction studies showed that the extraction trend for the group 4 elements decreased in the order Ti>Zr∼Hf>Rf, in inverse order from the trend of ionic radii Rf>Zr∼Hf>Ti. An attempt was made to produce 263 Rf (a) via the 248 Cm( 22 Ne, α3n) reaction employing thenoyltrifluoroacetone (TTA) solvent extraction chemistry and (b) via the 249 Bk( 18 O,4n) reaction employing the Automated Rapid Chemistry Apparatus (ARCA). In the TTA studies, 16 fissions were observed but were all attributed to 256 Fm. No alpha events were observed in the Rf chemical fraction. A 0.2 nb upper limit production cross section for the 248 Cm( 22 Ne, α3n) 263 Rf reaction was calculated assuming the 500-sec half-life reported previously by Czerwinski et al. [CZE92A

  1. HISTORY OF THE ORIGIN OF THE CHEMICAL ELEMENTS AND THEIR DISCOVERERS

    International Nuclear Information System (INIS)

    Holden, N.E.

    2001-01-01

    What do we mean by a chemical element? A chemical element is matter, all of whose atoms are alike in having the same positive charge on the nucleus and the same number of extra-nuclear electrons. As we shall see in the following elemental review, the origin of the chemical elements show a wide diversity with some of these elements having an origin in antiquity, other elements having been discovered within the past few hundred years and still others have been synthesized within the past fifty years via nuclear reactions on heavy elements since these other elements are unstable and radioactive and do not exist in nature

  2. HISTORY OF THE ORIGIN OF THE CHEMICAL ELEMENTS AND THEIR DISCOVERIES.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN,N.E.

    2001-06-29

    What do we mean by a chemical element? A chemical element is matter, all of whose atoms are alike in having the same positive charge on the nucleus and the same number of extra-nuclear electrons. As we shall see in the following elemental review, the origin of the chemical elements show a wide diversity with some of these elements having an origin in antiquity, other elements having been discovered within the past few hundred years and still others have been synthesized within the past fifty years via nuclear reactions on heavy elements since these other elements are unstable and radioactive and do not exist in nature.

  3. Exposure assessment of a cyclist to particles and chemical elements.

    Science.gov (United States)

    Ramos, C A; Silva, J R; Faria, T; Wolterbeek, T H; Almeida, S M

    2017-05-01

    Cycle paths can be used as a route for active transportation or simply to cycle for physical activity and leisure. However, exposure to air pollutants can be boosted while cycling, in urban environments, due to the proximity to vehicular emissions and elevated breathing rates. The objective of this work was to assess the exposure of a cyclist to particles and to chemical elements by combining real-time aerosol mass concentration reading equipment and biomonitoring techniques. PM 10 and PM 2.5 were measured on three cycle paths located in Lisbon, during weekdays and weekends and during rush hours and off-peak hours resulting in a total of 60 campaigns. Lichens were exposed along cycle paths for 3 months, and their element contents were measured by instrumental neutron activation analysis using the k 0 methodology (k 0 -INAA). Using a bicycle commute route of lower traffic intensity and avoiding rush hours or other times with elevated vehicular congestion facilitate a reduction in exposure to pollutants. The implementation of cycle paths in cities is important to stimulate physical activity and active transportation; however, it is essential to consider ambient air and pollutant sources to create safer infrastructures.

  4. Chemical and nuclear properties of Rutherfordium (Element 104)

    Energy Technology Data Exchange (ETDEWEB)

    Kacher, Christian D. [Univ. of California, Berkeley, CA (United States)

    1995-10-30

    The chemical-properties of rutherfordium (Rf) and its group 4 homologs were studied by sorption on glass support surfaces coated with cobalt(II)ferrocyanide and by solvent extraction with tributylphosphate (TBP) and triisooctylamine (TIOA). The surface studies showed that the hydrolysis trend in the group 4 elements and the pseudogroup 4 element, lb, decreases in the order Rf>Zr≈Hf>Th. This trend was attributed to relativistic effects which predicted that Rf would be more prone to having a coordination number of 6 than 8 in most aqueous solutions due to a destabilization of the 6d5/2 shell and a stabilization of the 7pI/2 shell. This hydrolysis trend was confirmed in the TBP/HBr solvent extraction studies which showed that the extraction trend decreased in the order Zr>Hf>Rf?Ti for HBr, showing that Rf and Ti did not extract as well because they hydrolyzed more easily than Zr and Hf. The TIOA/HF solvent extraction studies showed that the extraction trend for the group 4 elements decreased in the order Ti>Zr≈Hf>Rf, in inverse order from the trend of ionic radii Rf>Zr≈Hf>Ti. An attempt was made to produce 263Rf (a) via the 248Cm(22Ne, α3n) reaction employing thenoyltrifluoroacetone (TTA) solvent extraction chemistry and (b) via the 249Bk(18O,4n) reaction employing the Automated Rapid Chemistry Apparatus (ARCA). In the TTA studies, 16 fissions were observed but were all attributed to 256Fm. No alpha events were observed in the Rf chemical fraction. A 0.2 nb upper limit production cross section for the 248Cm(22Ne, α3n)263Rf reaction was calculated assuming the 500-sec half-life reported previously by Czerwinski et al. [CZE92A].

  5. Matching Element Symbols with State Abbreviations: A Fun Activity for Browsing the Periodic Table of Chemical Elements

    Science.gov (United States)

    Woelk, Klaus

    2009-01-01

    A classroom activity is presented in which students are challenged to find matches between the United States two-letter postal abbreviations for states and chemical element symbols. The activity aims to lessen negative apprehensions students might have when the periodic table of the elements with its more than 100 combinations of letters is first…

  6. [Distribution of chemical elements in whole blood and plasma].

    Science.gov (United States)

    Barashkov, G K; Zaĭtseva, L I; Kondakhchan, M A; Konstantinova, E A

    2003-01-01

    The distribution factor (Fd) of 35 elements of plasma and whole blood in 26 healthy men and women was detected by ICP-OES. Usilig this parameter the elements were subdivided in 3 pools. 9 of them have Fd higher than 1.5 ("elements of plasma"-Ag, Ca, Cu, In, Li, Na, Se, Si, Sr); 6 have lower than 0.5 ("elements of blood cells"-Fe, K, Mn, Ni, V, Zn), other 20-about 1 ("blood elements"). Fd of all elements depends on ionic radius. Elements of 2nd sub-groups of all groups of Mendeleev's periodic table ("heavy metals") depend on the similar law: "with growing of ionic radius the concentration of elements in plasma enhances". In alkaline metals Fd depends on the opposite law:" with growing of ionic radius of alkaline metal the quantity of elements in blood cells enhance". Dependence of Fd on the value of atomic mass in periods or in exterior electronic cloud (s-, p-, d-, f-) was not established. The table of distribution of all detected elements in whole blood in relation to 8 macroelements (Ca, Mg, K, Na, S, P, Fe, Zn,) is presented, as a basic diagnostic criteria in metal-ligand homeostasis disturbance.

  7. Electronic structure and chemical properties of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Pershina, V [Gesellschaft fuer Schwerionenforschung (GSI), Helmholtzzentrum fuer Schwerionenforschung Gmbh (Germany)

    2009-12-31

    Relativistic electronic structure calculations of superheavy elements (Z>=104) are analyzed. Preference is given to those related to experimental research. The role of relativistic effects is discussed.

  8. Chemical elements in egg shell of a commercial strain of domestic ...

    African Journals Online (AJOL)

    A study was conducted to determine the chemical elements of the egg shell of exotic commercial pullets (Lohmann) in their first laying year. A total of 160 eggs from eighty pullets were randomly selected at three-monthly intervals during the production year for the ddermination of chemical elements or the eggshell.

  9. Chemical characteristics and trace element concentration of non ...

    African Journals Online (AJOL)

    The present study investigates the details on the aspects of Coal quality such as proximate, ultimate, calorific value and trace element concentration and its impact on human health. Trace elements are present in very low percentage in coal but their concentration increases manifold after coal combustion and utilization.

  10. Behaviors of chemical elements in the atmosphere, Kawasaki, Japan

    International Nuclear Information System (INIS)

    Oda, K.; Kikawada, Y.; Oi, T.

    2008-01-01

    A total of 19 elements in the samples of atmospheric deposition collected in Kawasaki, Japan, were determined by neutron activation analysis, ICPAES and flame photometry. The amounts of soil dust depositions were larger in springs and those of Sb and Zn depositions were larger in summers than in the other seasons. The values of the enrichment factors were higher for Sb and Zn than for the other elements determined throughout the sampling period. A factor analysis showed that the two elements were characterized as industrial components. Rubber products like tires that contain noncombustibles and rubber accelerators were a possible origin of high concentrations of Sb and Zn in the present samples. (author)

  11. Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Goncalves, Simone, E-mail: wspereira@inb.gov.br [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Coordenacao de Protecao Radiologica. Grupo Multidisciplinar de Radioprotecao; Kelecom, Alphonse [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Biologia. Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos; Morais, Gustavo Ferrari de; Campelo, Emanuele Lazzaretti Cordova [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Coordenacao de Desenvolvimento de Processos; Dores, Luis Augusto de Carvalho Bresser [Unidade de Tratamento de Minerio (UTM/INB), Pocos de Caldas, MG (Brazil). Gerencia de Descomissionamento

    2011-07-01

    The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

  12. Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

    International Nuclear Information System (INIS)

    Pereira, Wagner de Souza; Py Junior, Delcy de Azevedo; Goncalves, Simone; Kelecom, Alphonse; Morais, Gustavo Ferrari de; Campelo, Emanuele Lazzaretti Cordova; Dores, Luis Augusto de Carvalho Bresser

    2011-01-01

    The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

  13. Chemical analysis of useful trace elements in sea water

    International Nuclear Information System (INIS)

    Katoh, Shunsaku; Fujii, Ayako; Miyai, Yoshitaka; Sakane, Kohji; Ogata, Noboru.

    1983-01-01

    The methods for the analysis of useful trace elements in sea water which have been tried so far are reviewed, and these methods are described briefly from the standpoint of studying the collection of resources. Ag and Au can be determined by concentrating sea water by ion-exchange method, solvent extraction method and electrodeposition method, then the elements are measured quantitatively by activation analysis and atomic absorption spectrochemical analysis. Sr, B and Li, which exist in relatively high concentration in sea water, are determined easily by atomic absorption spectrochemical analysis and absorption spectrometry. U, Mo and V are measured suitably by concentrating the elements by coprecipitation or solvent extraction method, and measuring by fluorescence analysis and arsenazo-3 method for U and through graphite-atomic absorption analysis for Mo and V. It has been revealed that the concentration of Ag and Au in sea water is extremely low, accordingly the recovery study is not conducted recently. On the other hand, the adsorption method using hydrated titanium oxide and amidoxim adsorbents for U, Mo and V, the adsorption method using aluminum adsorbent for Li, and the adsorption method using magnesium oxide and zirconium hydroxide and the solvent extraction method for B are hopeful to recover these elements. (Yoshitake, I.)

  14. Investigation of chemical forms of elements in surface waters

    International Nuclear Information System (INIS)

    Varshal, G.M.; Velyukhanova, T.K.; Koshcheeva, I.Ya.; Dorofeeva, V.A.; Buachidze, N.S.; Kasimova, O.G.; Makharadze, G.A.

    1983-01-01

    The main trends in the research of the state of elements in natural waters are examined. The hydrolysis of CU(2), Hg(2), Au(3), Sb(3), Ru(4) over a pH range, specific for natural waters, has been studied by solubility and paper electrophoresis technnques and by filtration through cellulose ionites. The regions of predominating different forms of hydroxo complexes have been found and the thermodynamic constants of hydrolysis equilibria have been calculated. Solubility, filtration through sephadexes and cellulose ionites, paper electrophoresis techniques were used to study the complexation of Cu(2), Hg(2), Au(3), Sb(3), Ru(4) with fulvic acids. Some data have been obtained on the composition, stability and molecular-mass distribution of fulvate complexes of ten elements in different oxidation states. High-molecular anionic fulvate complexes are among main forms of most easily hydrolysed elments in solution. The possibility has been shown of prediction of the ratio of coexisting forms of trace elements in solution by theoretical calculations and experimentally Using fractionation on cellulose ionites and sephadexes

  15. Measurements of radon and chemical elements: Popocatepetl volcano; Mediciones de radon y elementos quimicos: Volcan Popocatepetl

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Segovia, N.; Lopez, B.; Reyes, A.V. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Valdes, C.; Mena, M. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L.; Monnin, M. [UMR 5569 CNRS Hydrosciences, Montpellier (France)

    2002-07-01

    The Popocatepetl volcano is a higher risk volcano located at 60 Km from Mexico City. Radon measurements on soil in two fixed seasons located in the north slope of volcano were carried out. Moreover the radon content, major chemical elements and tracks in water samples of three springs was studied. The radon of soil was determined with solid detectors of nuclear tracks (DSTN). The radon in subterranean water was evaluated through the liquid scintillation method and it was corroborated with an Alpha Guard equipment. The major chemical elements were determined with conventional chemical methods and the track elements were measured using an Icp-Ms equipment. The radon on soil levels were lower, indicating a moderate diffusion of the gas across the slope of the volcano. The radon in subterranean water shown few changes in relation with the active scene of the volcano. The major chemical elements and tracks showed a stable behavior during the sampling period. (Author)

  16. PETROS - Worldwide Databank of Major Element Chemical Analyses of Igneous Rocks

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — PETROS is a worldwide data bank of major element chemical analyses of igneous rocks compiled for research and teaching purposes by Dr. Felix Mutschler and Staff at...

  17. k{sub 0}-INAA for determining chemical elements in bird feathers

    Energy Technology Data Exchange (ETDEWEB)

    Franca, Elvis J., E-mail: ejfranca@usp.b [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil); Fernandes, Elisabete A.N.; Fonseca, Felipe Y. [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil); Antunes, Alexsander Z. [IF, Instituto Florestal do Estado de Sao Paulo, Rua do Horto 931, Horto Florestal 02377-000, Sao Paulo, SP (Brazil); Bardini Junior, Claudiney; Bacchi, Marcio A.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O. [CENA/USP, Centro de Energia Nuclear na Agricultura, Universidade of Sao Paulo, P.O. Box 97, 13400-970, Piracicaba, SP (Brazil)

    2010-10-11

    The k{sub 0}-method instrumental neutron activation analysis (k{sub 0}-INAA) was employed for determining chemical elements in bird feathers. A collection was obtained taking into account several bird species from wet ecosystems in diverse regions of Brazil. For comparison reason, feathers were actively sampled in a riparian forest from the Marins Stream, Piracicaba, Sao Paulo State, using mist nets specific for capturing birds. Biological certified reference materials were used for assessing the quality of analytical procedure. Quantification of chemical elements was performed using the k{sub 0}-INAA Quantu Software. Sixteen chemical elements, including macro and micronutrients, and trace elements, have been quantified in feathers, in which analytical uncertainties varied from 2% to 40% depending on the chemical element mass fraction. Results indicated high mass fractions of Br (max=7.9 mg kg{sup -1}), Co (max=0.47 mg kg{sup -1}), Cr (max=68 mg kg{sup -1}), Hg (max=2.79 mg kg{sup -1}), Sb (max=0.20 mg kg{sup -1}), Se (max=1.3 mg kg{sup -1}) and Zn (max=192 mg kg{sup -1}) in bird feathers, probably associated with the degree of pollution of the areas evaluated. In order to corroborate the use of k{sub 0}-INAA results in biomonitoring studies using avian community, different factor analysis methods were used to check chemical element source apportionment and locality clustering based on feather chemical composition.

  18. Model Experiments on Chemical Properties of Superheavy Elements in Aqueous Solutions

    CERN Document Server

    Szeglowski, Z

    2003-01-01

    This paper presents a brief review of model experiments on investigation of chemical properties of transactinide elements, ranging from 104 to 116. The possibilities of isolation of the nuclei of these elements from nuclear reaction products, using the ion-exchange method, are also considered.

  19. Chemical elements contamination of snow cover in region of coal production 'Karazhyra'

    International Nuclear Information System (INIS)

    Evlampieva, E.P.; Panin, M.S.

    2008-01-01

    Peculiarities of space distribution of chemical elements in hardphase and water-soluble falls of snow cover in region of coal deposit 'Karazhyra' are investigated. The maximal, minimal and background areas of elements accumulation in the snow of this region and distribution of their cumulative rates are determined. The main pollutants of snow cover unto background level are revealed.

  20. Phase distribution of ecologically controlled chemical elements in production of extraction phosphoric acid

    International Nuclear Information System (INIS)

    Kazak, V.G.; Agnelov, A.I.; Zajtsev, P.M.

    1995-01-01

    Content of 16 ecologically controlled chemical element (among them Cd, Sr, Th, U, V, Y) in solid and liquid phases of extraction phosphorus acid (EPA) production is determined. These elements are recommended to control by Scientific research institute of human ecology and environment to establish their extraction coefficients to phosphogypsum and EPA and optimal variant of production of ecologically sate phosphorus fertilizers. X-ray fluorescent, atomic-absorption and polarographic methods are used for analysis these elements

  1. Influences of in-fuel physical-chemical processes on serviceability of energy reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Bibilashvili, Yu K; Nekrasova, G A; Sukhanov, G I

    1989-01-01

    In-fuel physico-chemical processes and their effect on stress corrosion cracking of fuel element zirconium cladding are considered in the review. The mechanism of fission product release from the fuel is studied and the negative role of primarily iodine on the cladding corrosion process is demonstrated. Directions for improving the fuel element claddings and fuel to increase the fuel element serviceability are specified.

  2. Influences of in-fuel physical-chemical processes on serviceability of energy reactor fuel elements

    International Nuclear Information System (INIS)

    Bibilashvili, Yu.K.; Nekrasova, G.A.; Sukhanov, G.I.

    1989-01-01

    In-fuel physico-chemical processes and their effect on stress corrosion cracking of fuel element zirconium cladding are considered in the review. The mechanism of fission product release from the fuel is studied and the negative role of primarily iodine on the cladding corrosion process is demonstrated. Directions for improving the fuel element claddings and fuel to increase the fuel element serviceability are specified

  3. Stellar alchemy: The origin of the chemical elements

    International Nuclear Information System (INIS)

    Norman, E.B.

    1994-01-01

    What makes the stars shine? This question puzzled human beings for thousands of years. Early in this century, chemists and physicists discovered radioactivity; and the nuclear model of the atom was developed. Once nuclear reactions were produced in the laboratory, it did not take long before their role in stellar energy generation was realized. The theory that nuclear fusion is the source of stellar energy was initially developed in the 1930's and was elaborated in detail in the 1950's. Only within the last ten years, however, have astronomical observations provided direct confirmation of these theoretical ideas. In this paper, I describe the sequences of nuclear reactions that are believed to be responsible for the power generation in stars. The ashes of these reactions are the heavy elements that we find on earth and throughout the universe. The evolution and final fates of stars are examined. The key astronomical observations that provide support for these theoretical ideas are presented

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

    International Nuclear Information System (INIS)

    Cantinha, Rebeca S.; Farias, Emerson E.G. de; Magalhaes, Marcelo L.R. de; Franca, Elvis J. de; Cunha, Franklin M. da; Zacarias, Vyvyane L.

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  6. Recent studies of nuclear and chemical properties of elements 103, 104 and 105

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1990-08-01

    Information obtained since 1983 on the nuclear and chemical properties of element 103, the last on the actinide series, and elements 104 and 105, at the beginning of the transactinide series, is reviewed. Their chemical properties are compared with their lanthanide and lighter group 4 and 5 homologs and evidence for possible relativistic effects is discussed. The current knowledge of the nuclear properties of these elements and how these affect of the study of chemical properties is discussed. Some of the challenges involved in the study of short-lived isotopes which can only be produced an ''atom-at-a-time'' at an appropriate accelerator and the prognosis for future studies of these and still heavier elements are considered. 40 refs., 4 figs

  7. Chemical analogy in the case of hydrolysis species of F-elements

    International Nuclear Information System (INIS)

    Hirotake Moriyama; Hajimu Yamana; Kenso Fujiwara

    2001-01-01

    In spite of much importance, some of the thermodynamic data of actinide elements are still lacking, and the chemical behaviour of these elements is often predicted by considering chemical analogy, that is by taking the known data of the same and similar group elements. It is thus quite important to establish the basis and conditions for applying the chemical analogy. In the present study, some topics are discussed which are related with the chemical analogy for the hydrolysis behaviour of actinide ions. Systematic trends of the thermodynamic data of actinide ions, namely the solubility products and hydrolysis constants, are discussed by considering the results of recent measurements and by considering possible contributions of non-electrostatic interactions of actinide ions in addition to those of ordinary electrostatic ones. (authors)

  8. On the occurrence of metallic character in the periodic table of the chemical elements.

    Science.gov (United States)

    Hensel, Friedrich; Slocombe, Daniel R; Edwards, Peter P

    2015-03-13

    The classification of a chemical element as either 'metal' or 'non-metal' continues to form the basis of an instantly recognizable, universal representation of the periodic table (Mendeleeff D. 1905 The principles of chemistry, vol. II, p. 23; Poliakoff M. & Tang S. 2015 Phil. Trans. R. Soc. A 373: , 20140211). Here, we review major, pre-quantum-mechanical innovations (Goldhammer DA. 1913 Dispersion und Absorption des Lichtes; Herzfeld KF. 1927 Phys. Rev. 29: , 701-705) that allow an understanding of the metallic or non-metallic status of the chemical elements under both ambient and extreme conditions. A special emphasis will be placed on recent experimental advances that investigate how the electronic properties of chemical elements vary with temperature and density, and how this invariably relates to a changing status of the chemical elements. Thus, the prototypical non-metals, hydrogen and helium, becomes metallic at high densities; and the acknowledged metals, mercury, rubidium and caesium, transform into their non-metallic forms at low elemental densities. This reflects the fundamental fact that, at temperatures above the absolute zero of temperature, there is therefore no clear dividing line between metals and non-metals. Our conventional demarcation of chemical elements as metals or non-metals within the periodic table is of course governed by our experience of the nature of the elements under ambient conditions. Examination of these other situations helps us to examine the exact divisions of the chemical elements into metals and non-metals (Mendeleeff D. 1905 The principles of chemistry, vol. II, p. 23). © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  9. Cumulative and competitive effects of chemical elements on nuclear glass alteration

    International Nuclear Information System (INIS)

    Arena, Helene

    2016-01-01

    This work takes place in the context of the long-term behavior of nuclear glasses under repository conditions. The main objective is to identify, understand and compare the effects of some chemical elements present in the glass composition and/or in the repository media (Zn, Mg, Ni, Co, Fe, Ca, Gd, Ce, K, Cs, Cr and Ag) on the processes involved in glass alteration by water. The cumulative or competitive nature of the effects of these chemical elements was determined. To reach this goal, a 6 oxides simple glass (ISG) has been altered for more than 500 days in a solution containing one or more of the chemical elements of interest. The results indicate that Zn, Mg, Ni, Co and Fe elements increase glass alteration forming secondary phases with the same structure and stoichiometry (tri-octahedral smectites). To form, these silicates consume chemical elements (Si, Al) from the environment and induce a pH decrease until a limiting value of pH. Beyond this pH the precipitation of secondary phases is inhibited and these chemical elements can be integrated into the gel, replacing Ca whose solubility increases at lower pH. As long as they form secondary phases, the effects of these elements are cumulative. Rare earths Gd and Ce also increase glass alteration forming secondary phases but their effects are lower as they contain less silicon. These elements are not integrated in the gel. Chromium increases glass alteration by precipitating with Ca and leading to a less protective gel, depleted in Ca. Silver precipitates as AgCl and has no effect on the alteration of the glass. The chemical elements K, Cs and Ca limit glass alteration by integrating into the gel and slowing down the transport phenomena therein. This integration is competitive: the order of integration (quantity and effectiveness glass alteration limitation) is the following Ca≥≥Cs≥K. Thus, the increase of glass alteration may be proportional to the quantity of elements promoting the precipitation of

  10. Purposeful synthesis of chemical elements and ecologically pure mobile sources of energy

    International Nuclear Information System (INIS)

    Krivitsky, V. A.; Gareev, F. A.

    2007-01-01

    It is well known [1] that the natural geo-transmutation of chemical elements occurs in the atmosphere and earth in the regions of a strong change in geo-, bio-, acoustic-, and electromagnetic fields. The mineral row materials contain the same accompanying chemical combinations which are independent of mineral deposit [2]. This means that the formation of chemical elements occurs in the same physical and chemical conditions. These conditions were simulated on the fundamental cooperative resonance synchronization principle [1]. The experimental facility was constructed on the basis of our model which provided with the calculated final chemical elements. These experimental results indicate new possibilities for, simulating, inducing and controlling nuclear reactions by low energy external fields. The borrowing from the geo-transmutation mechanisms of chemical elements creates the fundamental directions in low energy nuclear reaction researches for construction of new ecologically pure mobile sources of energy independent of oil, gas and coal, new substances, and technologies. References [1] F.A. Gareev, I.E. Zhidkova, E-print arXiv Nucl-th/0610002 2006. [2] V.A. Krivzskii, Transmutazija ximicheskix elementov v evolyuzii Semli (in Russian), Moscow 2003

  11. Some chemical elements in gamma irradiated adults of the mediterranean fruit fly , Ceratitis Capitata (WIED.)

    International Nuclear Information System (INIS)

    El-akhdar, E.A.H.

    2005-01-01

    The chemical analysis of the elemental compositions of both males and females of the Mediterranean fruit fly, Ceratitis capitata (Wied.), was conducted on adult flies irradiated in the full grown pupae with 50, 70, 90 and 110 Gray at different ages (newly emerged, 7 and 15 days old). The data revealed the presence of ten elements, three of which are major (Na, K and N), four are moderate (P, Ca, Fe and Mg) and three are minors (Zn, Mn and Cu). Their quantities, however, varied according to adult sex, age and radiation dose. In all cases, the major elements remained major, the moderate elements remained moderate and the minor elements remained minor although the elements of each group differed in their arrangement according to changes in their quantities

  12. Soil-leaf transfer of chemical elements for the Atlantic Forest

    International Nuclear Information System (INIS)

    Joacir De Franca, E.; De Nadai Fernandes, E.A.; Bacchi, M.A.; Tagliaferro, F.S.

    2007-01-01

    Soil analysis could improve environmental studies since soil is the main source of chemical elements for plants. In this study, soil samples collected at 0-10 cm depth under tree crown projection were analyzed by INAA. Using the chemical composition of the leaf previously determined, the leaf-soil transfer factors of chemical elements could be estimated for the Atlantic Forest. Despite the variability of the intra-species, the transfer factors were specific for some plant species due to their element accumulation in the leaves. Similar Br-Zn combined transfer factors were obtained for the species grouped according to habitats in relation to their position (understory or dominant species) in the forest canopy. (author)

  13. Chemical element concentrations in four lichens on a transect entering Voyageurs National Park

    Science.gov (United States)

    Bennett, J.; Wetmore, C.M.

    1997-01-01

    A three factor transect study was conducted to test the hypothesis that chemical elements from air emissions in the vicinity of International Falls, Minnesota could not be detected in lichens along a 24 km transect reaching into Voyageurs National Park. It was hypothesized that element concentrations in lichens would decline exponentially downwind and would reach background values at a distance before the park boundary. Four species (Cladina rangiferina, Evernia mesomorpha, Hypogymnia physodes, and Parmelia sulcata) were sampled at ten sites for 3 years and 17 chemical elements were measured. The most notable result was a curvilinear geographic trend for many elements, which decreased from International Falls and then increased towards the park. This trend was significant for many anthropogenic elements, including S, Hg, Cd, and Cr, and for all four species. This type of distribution pattern has been observed in Hypogymnia physodes in other studies downwind of a steel mill and an oil refinery. Cladina, a ground-dwelling lichen, generally had lower tissue concentrations of the elements than the three epiphytic species. Tissue concentrations over the 3 years of sampling declined an average of 12%. Sufficient evidence exists to conclude that lichen tissue element concentrations in the vicinity of International Falls may be related to local air emissions, and that an exponential decline of element concentrations downwind of the sources does not apply to this situation.

  14. The distributions of chemical elements and Caesium-137 in the Northern-Crimean canal ecosystem

    International Nuclear Information System (INIS)

    Lazorenko, G.

    1998-01-01

    The distributions in 1992-1995 of some chemical elements and 137 Cs concentrations in components of the Northern-Crimean Canal (NCC) ecosystem and agricultural fields of the Kherson District and the Northern Crimea irrigated by the Dnieper River water are presented in the work. Five main sampling were selected between the Kakhovka Reservior (at the beginning of the NCC) and the Karkinitsky Bay along the 150 km of the main Canal. Two additional stations were selected in discharge canals to study of the role of irrigated agricultural fields in the accumulation of 137 Cs and chemical elements from water. (author)

  15. HISTORY OF THE ORIGIN OF THE CHEMICAL ELEMENTS AND THEIR DISCOVERIES

    International Nuclear Information System (INIS)

    HOLDEN, N.E.

    2001-01-01

    The origin of the chemical elements show a wide diversity with some of these elements having their origin in antiquity. Still other elements have been synthesized within the past fifty years via nuclear reactions on heavy elements, because these other elements are unstable and radioactive and do not exist in nature. The names of the elements come from many sources including mythological concepts or characters; places, areas or countries; properties of the element or its compounds, such as color, smell or its inability to combine; and the names of scientists. There are also some miscellaneous names as well as some obscure names for particular elements. The claim of discovery of an element has varied over the centuries. Many claims, e.g., the discovery of certain rare earth elements of the lanthanide series, involved the discovery of a mineral ore from which an element was later extracted. The honor of discovery has often been accorded not to the person who first isolated the element but to the person who discovered the original mineral itself, even when the ore was impure and contained many elements. The reason for this is that in the case of these rare earth elements, the ''earth'' now refers to oxides of a metal not to the metal itself. This fact was not realized at the time of their discovery, until the English chemist Humphry Davy showed that earths were compounds of oxygen and metals in 1808. In the early discoveries, the atomic weight of an element and spectral analysis of the element were not available. Later both of these elemental properties would be required before discovery of the element would be accepted. In general, the requirements for discovery claims have tightened through the years and claims that were previously accepted would no longer meet the minimum constraints now imposed. There are cases where the honor of discovery is not given to the first person to actually discover the element but to the first person to claim the discovery in print. If a

  16. HISTORY OF THE ORIGIN OF THE CHEMICAL ELEMENTS AND THEIR DISCOVERIES.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN,N.E.

    2001-06-29

    The origin of the chemical elements show a wide diversity with some of these elements having their origin in antiquity. Still other elements have been synthesized within the past fifty years via nuclear reactions on heavy elements, because these other elements are unstable and radioactive and do not exist in nature. The names of the elements come from many sources including mythological concepts or characters; places, areas or countries; properties of the element or its compounds, such as color, smell or its inability to combine; and the names of scientists. There are also some miscellaneous names as well as some obscure names for particular elements. The claim of discovery of an element has varied over the centuries. Many claims, e.g., the discovery of certain rare earth elements of the lanthanide series, involved the discovery of a mineral ore from which an element was later extracted. The honor of discovery has often been accorded not to the person who first isolated the element but to the person who discovered the original mineral itself, even when the ore was impure and contained many elements. The reason for this is that in the case of these rare earth elements, the ''earth'' now refers to oxides of a metal not to the metal itself. This fact was not realized at the time of their discovery, until the English chemist Humphry Davy showed that earths were compounds of oxygen and metals in 1808. In the early discoveries, the atomic weight of an element and spectral analysis of the element were not available. Later both of these elemental properties would be required before discovery of the element would be accepted. In general, the requirements for discovery claims have tightened through the years and claims that were previously accepted would no longer meet the minimum constraints now imposed. There are cases where the honor of discovery is not given to the first person to actually discover the element but to the first person to claim the

  17. Simultaneous topographic and elemental chemical and magnetic contrast in scanning tunneling microscopy

    Science.gov (United States)

    Rose, Volker; Preissner, Curt A; Hla, Saw-Wai; Wang, Kangkang; Rosenmann, Daniel

    2014-09-30

    A method and system for performing simultaneous topographic and elemental chemical and magnetic contrast analysis in a scanning, tunneling microscope. The method and system also includes nanofabricated coaxial multilayer tips with a nanoscale conducting apex and a programmable in-situ nanomanipulator to fabricate these tips and also to rotate tips controllably.

  18. Chemical form of transuranic elements in underground environment and its effect on adsorption

    International Nuclear Information System (INIS)

    Tanaka, Tomo

    1990-01-01

    Many of the transuranic elements such as Np, Pu and Am contained in high-level radioactive wastes are highly dangerous to humans and have extremely long lives. Therefore, safety evaluation of them is highly important after their disposal into the ground. Particularly important processes include the migration of these transuranic elements in near and far fields. The migration of a nuclide depends largely on its chemical form in the underground environment. The present report first describes various chemical forms of transuranic elements in underground environments and outlines their migration behaviors. Techniques that have recently become available for determining their chemical forms include photo-acoustic spectroscopy, thermal lensing spectroscopy, laser induced fluorescence, photo-acoustic detection of light scattering, auto-correlation photon spectroscopy, and laser-induced time-resolved spectrofluorometry. Chemical forms of these elements are then discussed focusing on underground environmental conditions, pH-Eh diagram, deposition/dissolution, formation of complex, formation of colloid, and organic complexes. Migration is discussed in relation to ions, insoluble matters, and colloids. (N.K.)

  19. Mass spectrographic analysis of selected chemical elements by microbial leaching of zircon

    International Nuclear Information System (INIS)

    Becker, S.; Dietze, H.J.; Bullmann, M.; Iske, U.

    1986-01-01

    Spark source mass spectrometry is a useful method for chemical element analysis of geological and biological samples. This sensitive technique (detection limit down to the ppb-range) is used to analyze leaching processes by means of several microorganisms. The problem of microbial leaching of chemical resistent materials was tested under laboratory conditions with regard to possible analytical and technical applications. Leaching of metals with chemolithotrophic and heterotrophic, organic acids producing microorganisms has been investigated with zircon from the Baltic Shield containing 0.7% rare earth elements and 1.67% hafnium. When zircon is leached with strains of thiobacillus ferrooxidans about 80% of the rare earth elements, Hf, Th and U can be recovered. (orig.) [de

  20. Behavior of radon, chemical compounds and stable elements in underground water

    International Nuclear Information System (INIS)

    Lopez R, N.; Segovia, N.; Lopez, M.B.E.; Pena, P.; Armienta, M.A.; Godinez, L.; Seidel, J.L.

    2001-01-01

    The radon behavior, chemical compounds, major and trace elements in water samples of four springs and three wells of urban and agricultural zones around the Jocotitlan volcano and El Oro region was determined, both of them located in the medium part of the Mexican neo-volcanic axis. The 222 Rn was measured by the liquid scintillation method, the analysis of major components was realized with conventional chemical techniques, while the trace elements were quantified using an Icp-Ms. The average values of the radon concentrations obtained during one year were constant relatively, in an interval from 0.97 to 4.99 Bq/lt indicating a fast transport from the reload area toward the sampling points. the compounds, major and trace elements showed differences which indicate distinct origins of water from the site studies. (Author)

  1. Prompt gamma-ray spectroscopy and its use for the elemental chemical analysis

    International Nuclear Information System (INIS)

    Deconninck, G.; Demortier, G.; Bodart, F.

    The elemental chemical analysis by nuclear techniques has been widely developed since a quarter of century. In this review the analysis by irradiation of the the sample (solid or liquid) of a majority of chemical elements by means of the charged particles and the detection during this irradiation of the gamma photons characteristic of the element are considered. After a brief account of the physical phenomena peculiar to the prompt detection of photons in comparison with the activation methods where a delayed activity is measured, a brief description of the experimental equipment for this kind of analysis is given. A comprehensive critical survey of the recent applications to the analysis of metals, semiconductors and electric insulating substances is presented. The necessary informations for the choice of the nuclear reaction to use for a specific analysis are contained in a set of tables. (AF)

  2. Initial chemical transport of reducing elements and chemical reactions in oxide cathode base metal

    International Nuclear Information System (INIS)

    Roquais, J.M.; Poret, F.; Doze, R. le; Dufour, P.; Steinbrunn, A.

    2002-01-01

    In the present work, the formation of compounds associated to the diffusion of reducing elements (Mg and Al) to the nickel surface of a one-piece oxide cathode has been studied. Those compounds have been evidenced after the annealing steps at high temperature performed on cathode base metal prior to the emitting coating deposition. Therefore, they form the ''initial'' interface between the nickel and the coating, in other words, the interface existing at the beginning of cathode life. Extensive analysis to characterize the nickel base prior to coating deposition has been performed by means of scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), Auger electron spectroscopy (AES), transmission electron microscopy (TEM), and glow discharge optical emission spectroscopy (GDOES). TEM and AES analysis have allowed to identify for the first time a spinel compound of MgAl 2 O 4 . The preferential distribution of the different compounds on the nickel surface has been studied by EDX mapping. Experimental profiles of diffusion of the reducing elements in the nickel have been obtained over the entire thickness of the material by GDOES. The mechanism of formation of these compounds together with a related diffusion model are proposed

  3. Versatile protein recognition by the encoded display of multiple chemical elements on a constant macrocyclic scaffold

    Science.gov (United States)

    Li, Yizhou; De Luca, Roberto; Cazzamalli, Samuele; Pretto, Francesca; Bajic, Davor; Scheuermann, Jörg; Neri, Dario

    2018-03-01

    In nature, specific antibodies can be generated as a result of an adaptive selection and expansion of lymphocytes with suitable protein binding properties. We attempted to mimic antibody-antigen recognition by displaying multiple chemical diversity elements on a defined macrocyclic scaffold. Encoding of the displayed combinations was achieved using distinctive DNA tags, resulting in a library size of 35,393,112. Specific binders could be isolated against a variety of proteins, including carbonic anhydrase IX, horseradish peroxidase, tankyrase 1, human serum albumin, alpha-1 acid glycoprotein, calmodulin, prostate-specific antigen and tumour necrosis factor. Similar to antibodies, the encoded display of multiple chemical elements on a constant scaffold enabled practical applications, such as fluorescence microscopy procedures or the selective in vivo delivery of payloads to tumours. Furthermore, the versatile structure of the scaffold facilitated the generation of protein-specific chemical probes, as illustrated by photo-crosslinking.

  4. Chemical aspects of pellet-cladding interaction in light water reactor fuel elements

    International Nuclear Information System (INIS)

    Olander, D.R.

    1982-01-01

    In contrast to the extensive literature on the mechanical aspects of pellet-cladding interaction (PCI) in light water reactor fuel elements, the chemical features of this phenomenon are so poorly understood that there is still disagreement concerning the chemical agent responsible. Since the earliest work by Rosenbaum, Davies and Pon, laboratory and in-reactor experiments designed to elucidate the mechanism of PCI fuel rod failures have concentrated almost exclusively on iodine. The assumption that this is the reponsible chemical agent is contained in models of PCI which have been constructed for incorporation into fuel performance codes. The evidence implicating iodine is circumstantial, being based primarily upon the volatility and significant fission yield of this element and on the microstructural similarity of the failed Zircaloy specimens exposed to iodine in laboratory stress corrosion cracking (SCC) tests to cladding failures by PCI

  5. An investigation of changes in element distribution and chemical states during differentiation of embryonic stem cells

    International Nuclear Information System (INIS)

    Sugimoto, T.; Ide-Ektessabi, A.; Ishihara, R.; Tanigaki, M.

    2004-01-01

    Metallic elements and their organic compounds have dynamic regulatory functions in cells. In this study, we implemented a new approach to investigate the mechanism of differentiation of embryonic stem cells, by measuring and analyzing the change in distribution and chemical states of intracellular trace elements. We anticipate that trace metal elements and metalloproteins play important roles in the direction of differentiation, both as active centers, and as factors in the death of neural cells in neurodegenerative disorders. The aim of this study is to analyze the distribution and chemical states of trace elements during the process of differentiation of mouse embryonic stem cells, and to understand how these factors relate to the differentiation process. Using the experimental results, some previously unexplained points are considered, namely (1) how the intracellular elements change during the process of neuronal differentiation, and (2) what the optimal conditions of such elements are for neuronal differentiation. The information obtained during this study is relevant to nervous system development and evolution

  6. An investigation of changes in element distribution and chemical states during differentiation of embryonic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, T.; Ide-Ektessabi, A. E-mail: h51167@sakura.kudpc.kyoto-u.ac.jp; Ishihara, R.; Tanigaki, M

    2004-07-01

    Metallic elements and their organic compounds have dynamic regulatory functions in cells. In this study, we implemented a new approach to investigate the mechanism of differentiation of embryonic stem cells, by measuring and analyzing the change in distribution and chemical states of intracellular trace elements. We anticipate that trace metal elements and metalloproteins play important roles in the direction of differentiation, both as active centers, and as factors in the death of neural cells in neurodegenerative disorders. The aim of this study is to analyze the distribution and chemical states of trace elements during the process of differentiation of mouse embryonic stem cells, and to understand how these factors relate to the differentiation process. Using the experimental results, some previously unexplained points are considered, namely (1) how the intracellular elements change during the process of neuronal differentiation, and (2) what the optimal conditions of such elements are for neuronal differentiation. The information obtained during this study is relevant to nervous system development and evolution.

  7. The uses of synchrotron radiation sources for elemental and chemical microanalysis

    International Nuclear Information System (INIS)

    Chen, J.R.; Chao, E.C.T.; Minkin, J.A.; Back, J.M.; Jones, K.W.; Rivers, M.L.; Sutton, S.R.

    1989-08-01

    Synchrotron radiation sources offer important features for the analysis of a material. Among these features is the ability to determine both the elemental composition of the material and the chemical state of its elements. For microscopic analysis synchrotron x-ray fluorescence (SXRF) microprobes now offer spatial resolutions of 10μm with minimum detection limits in the 1--10 ppM range depending on the nature of the sample and the synchrotron source used. This paper describes the properties of synchrotron radiation and their importance for elemental analysis, existing synchrotron facilities and those under construction that are optimum for SXRF microanalysis, and a number of applications including the high energy excitation of the K lines of heavy elements, microtomography, and XANES and EXAFS spectroscopies. 45 refs., 8 figs., 1 tab

  8. The uses of synchrotron radiation sources for elemental and chemical microanalysis

    Science.gov (United States)

    Chen, J.R.; Chao, E.C.T.; Minkin, J.A.; Back, J.M.; Jones, K.W.; Rivers, M.L.; Sutton, S.R.

    1990-01-01

    Synchrotron radiation sources offer important features for the analysis of a material. Among these features is the ability to determine both the elemental composition of the material and the chemical state of its elements. For microscopic analysis synchrotron X-ray fluorescence (SXRF) microprobes now offer spatial resolutions of 10 ??m with minimum detection limits in the 1-10 ppm range depending on the nature of the sample and the synchrotron source used. This paper describes the properties of synchrotron radiation and their importance for elemental analysis, existing synchrotron facilities and those under construction that are optimum for SXRF microanalysis, and a number of applications including the high energy excitation of the K lines of heavy elements, microtomography, and XANES and EXAFS spectroscopies. ?? 1990.

  9. Use of chemical elements of 1A family by tropical tree species

    International Nuclear Information System (INIS)

    Carmo, Andrius M.J.; Paiva, Jose Daniel S. de; Magalhaes, Marcelo R.L. de; Franca, Elvis J. de; Hazin, Clovis A.; Bacchi, Marcio A.; Fernandes, Elisabete A.N.

    2013-01-01

    This study aims to evaluate the distribution of K, Rb and Cs in leaves of trees of the Atlantic Forest through studies of correlation between the chemical elements. For this, we used the Instrumental Neutron Activation Analysis for the quantification of the chemical elements. The concentration ranges found were 6700-24000 mg / kg for K, 16 to 72mg / kg for Rb and 0.08 to 0,92mg / kg for Cs. As Rb has chemical similarity to K, is easily absorbed by plants, leading to a high value (0.9) of the Pearson correlation. For the correlation between K and Cs, no significant values were detected except for some species of the Myrtaceae family. However, average correlations (0.6 < r <0.8) between Rb-Cs were obtained for seven plant species of different families. The absence of a specific pattern using of K, Rb and Cs by plants showed great complexity in the distribution of chemical elements in the ecosystem

  10. Quantitative analysis of chemical elements in single cells using nuclear microprobe and nano-probe

    International Nuclear Information System (INIS)

    Deves, Guillaume

    2010-01-01

    The study of the role of trace elements at cellular level requires the use of state-of-the-art analytical tools that could achieve enough sensitivity and spatial resolution. We developed a new methodology for the accurate quantification of chemical element distribution in single cells based on a combination of ion beam analysis techniques STIM, PIXE and RBS. The quantification procedure relies on the development of a STIM data analysis software (Paparamborde). Validity of this methodology and limits are discussed here. The method allows the quantification of trace elements (μg/g) with a 19.8 % uncertainty in cellular compartments with mass below 0.1 ng. The main limit of the method lies in the poor number of samples that can be analyzed, due to long irradiation times required and limited access to ion beam analysis facilities. This is the reason why we developed a database for cellular chemical composition capitalization (BDC4). BDC4 has been designed in order to use cellular chemical composition as a tracer for biological activities and is expected to provide in the future reference chemical compositions for any cellular type or compartment. Application of the STIM-PIXE-RBS methodology to the study of nuclear toxicology of cobalt compounds is presented here showing that STIM analysis is absolutely needed when organic mass loss appears during PIXE-RBS irradiation. (author)

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

    International Nuclear Information System (INIS)

    Magalhaes, Marcelo L.R.; Santos, Mariana L.O.; Cantinha, Rebeca S.; Souza, Thomas Marques de; Franca, Elvis J. de

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

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

    International Nuclear Information System (INIS)

    Molina, R.

    1961-12-01

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

  14. A study of essential elements in ancient Thai fighting swords by chemical and nuclear techniques

    International Nuclear Information System (INIS)

    Janposri, K.

    1980-01-01

    Four ancient Thai fighting swords from the Bangkok National Museum and iron ore from Kao Tab Kwai, Lopburi were studied by neutron activation analysis, metallography and chemical analysis. The results of these scientific studies show that all of these four swords are made of plain carbon steel, containing trace elements which have no effect on the physical and mechanical properties of the steel. The trace elements which were found in the iron ore are quite similar to those found in one of these swords. This means that the iron in one of the swords may have come from ore found at Kao Tab Kwai, Lopburi

  15. Search for chemical separations of the element 106 homologues in HF and HF-HCl media

    International Nuclear Information System (INIS)

    Trubert, D.; Monroy-Guzman, F.; Hussonnois, M.; Brillard, L.; Le Naour, C.; Constantinescu, O.

    1996-01-01

    In order to study the chemical properties of element 263 106 in aqueous media, fast, efficient and reproducible chromatographic separations were tested on its assumed homologous: Mo, W and U. Corroborative static and dynamic off-line experiments have shown that after fixation of these three elements on anion-exchange resin in HF medium, selective elution could be achieved by using suitable concentration of HCl - HF and HCl solutions. Separations of short-lived W isotopes, produced through heavy ion irradiation were also performed on-line. (author). 27 refs., 14 figs

  16. A historical approach to teaching the concept of the chemical element

    OpenAIRE

    Cachapuz, António; Paixão, Fátima

    2005-01-01

    A novel teaching strategy is described, which was developed to introduce the key notion of chemical elements to 15-year-old Portuguese chemistry pupils. The strategy started from the analysis of the so-called ‘Lavoisier law ’and explored the relationships between macro and micro level chemistry in an innovative way. The key idea was first to explore the macro level (mass conservation) to help pupils consider the existence of indestructible units (elements, micro level) as a logical necessity ...

  17. Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements

    International Nuclear Information System (INIS)

    Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E.; Vandegrift, G.F.; Landsberger, S.

    1995-05-01

    The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration

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

    Science.gov (United States)

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

    2017-01-01

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

  19. Three-dimensionality of space in the structure of the periodic table of chemical elements

    International Nuclear Information System (INIS)

    Veremeichik, T. F.

    2006-01-01

    The effect of the dimension of the 3D homogeneous and isotropic Euclidean space, and the electron spin on the self-organization of the electron systems of atoms of chemical elements is considered. It is shown that the finite dimension of space creates the possibility of periodicity in the structure of an electron cloud, while the value of the dimension determines the number of stable systems of electrons at different levels of the periodic table of chemical elements and some characteristics of the systems. The conditions for the stability of systems of electrons and the electron system of an atom as a whole are considered. On the basis of the results obtained, comparison with other hierarchical systems (nanostructures and biological structures) is performed

  20. INAA application in the assessment of chemical element mass fractions in adult and geriatric prostate glands

    International Nuclear Information System (INIS)

    Zaichick, Vladimir; Zaichick, Sofia

    2014-01-01

    The variation with age of the mass fraction of 37 chemical elements in intact nonhyperplastic prostate of 65 healthy 21–87 year old males was investigated by instrumental neutron activation analysis with high resolution spectrometry of short- and long-lived radionuclides. Mean values (M±SΕΜ) for mass fractions (mg kg −1 , dry mass basis) of the chemical elements studied were: Ag—0.055±0.007, Br—33.2±3.3, Ca—2150±118, Cl—13014±703, Co—0.038±0.003, Cr—0.47±0.05, Fe—99.3±6.1, Hg—0.044±0.006, K—11896±356, Mg—1149±68, Mn—1.41±0.07, Na—10886±339, Rb—12.3±0.6, Sb—0.049±0.005, Sc—0.021±0.003, Se—0.65±0.03, and Zn—795±71. The mass fraction of other chemical elements measured in this study were lower than the corresponding detection limits (mg kg −1 , dry mass basis): As<0.1, Au<0.01, Ba<100, Cd<2, Ce<0.1, Cs<0.05, Eu<0.001, Gd<0.02, Hf<0.2, La<0.5, Lu<0.003, Nd<0.1, Sm<0.01, Sr<3, Ta<0.01, Tb<0.03, Th<0.05, U<0.07, Yb<0.03, and Zr<0.3. This work revealed that there is a significant trend for increase with age in mass fractions of Co (p<0.0085), Fe (p<0.037), Hg (p<0.035), Sc (p<0.015), and Zn (p<0.0014) and for a decrease in the mass fraction of Mn (p<0.018) in prostates, obtained from young adult up to about 60 years, with age. In the nonhyperplastic prostates of males in the sixth to ninth decades, the magnitude of mass fractions of all chemical element were maintained at near constant levels. Our finding of correlation between the prostatic chemical element mass fractions indicates that there is a great variation of chemical element relationships with age. - Highlights: • 37 trace elements were determined in prostate of 65 healthy 21–87 year old males by NAA. • Co, Fe, Hg, Sc, and Zn contents significantly increase with age. • Mn content significantly decreases with age. • All elemental contents in the sixth to ninth decades are near constant level. • There is a great disturbance of chemical element

  1. Finite Element Analysis Modeling of Chemical Vapor Deposition of Silicon Carbide

    Science.gov (United States)

    2014-06-19

    concentrations. This is the method by which species adsorb to the surface of the substrate. The movement resulting from diffusion is governed by...itself. This can be treacherous, however. The mesh is what the entire finite element method is built upon. If the movement of the backbone has... Brownian Motion Algorithm for Tow Scale Modeling of Chemical Vapor Infiltration. Computational Materials Science, 1871-1878. !178 23. Wang, C. & D

  2. Piracicaba River Basin: evaluation of chemical elements in deep sediment profile by INAA

    Energy Technology Data Exchange (ETDEWEB)

    França, Elvis J. de; Santos, Robson A.; Santos, Katarine M. Barbosa; Silva, Gleyce K. A. [Centro Regional de Ciencias Nucleares do Nordeste (DIAMB/CRCN-NE/CNEN-PE), Recife, PE (Brazil). Div, de Monitoração Ambiental; Fernandes, Elisabete A. de Nadai; Rodrigues, Vanessa S.; Cavalca, Isabel P.O., E-mail: ejfranca@cnen.gov.br, E-mail: lis@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2017-07-01

    Many hydrographic basins have been impacted by anthropogenic sources, the Piracicaba River Basin of the State of São Paulo, is one of that. The total concentrations of chemical elements in deep sediments of basin may be indicate those available in ecosystem. Therefore, in this research concentration of chemical elements on deep sediment profile sampled of Piracicaba River Basin was determined by k0-Instrumental Neutron Activation Analysis. After collecting the 60 cm depth profile, samples were obtained by sectioning the sediment profile in 5 cm layers, totalizing 12 samples. Analytical portions were transferred to polyethylene vials for neutron irradiation at the Nuclear Research Reactor IEA-R1 from the Instituto de Pesquisas Energéticas e Nucleares IPEN/CNEN. After waiting for radiation safe levels, irradiated samples were transported to the Radioisotopes Laboratory from the Centro de Energia Nuclear na Agricultura CENA/USP. High Resolution Gamma-Ray Spectrometry using HPGe detectors was applied to measure the induced radioactivity. The chemical element mass fractions and their respective expanded analytical uncertainties (95% confidence level) were determined by k0-INAA using the in-house software Quantu. Geological reference materials were analyzed with samples to evaluate the quality of the analytical procedure. Results indicated the presence of enriched surface sediments (0-10 cm depth) for As, Ba, Ca, Co, Cs, Fe, Sb, Sc, Sr, Yb and Zn, despite no alteration was observed for Eu, Ta and Tb. Therefore, the evaluation of deep sediment profile afford the chemical element dynamics for the Piracicaba Basin. (author)

  3. Piracicaba River Basin: evaluation of chemical elements in deep sediment profile by INAA

    International Nuclear Information System (INIS)

    França, Elvis J. de; Santos, Robson A.; Santos, Katarine M. Barbosa; Silva, Gleyce K. A.

    2017-01-01

    Many hydrographic basins have been impacted by anthropogenic sources, the Piracicaba River Basin of the State of São Paulo, is one of that. The total concentrations of chemical elements in deep sediments of basin may be indicate those available in ecosystem. Therefore, in this research concentration of chemical elements on deep sediment profile sampled of Piracicaba River Basin was determined by k0-Instrumental Neutron Activation Analysis. After collecting the 60 cm depth profile, samples were obtained by sectioning the sediment profile in 5 cm layers, totalizing 12 samples. Analytical portions were transferred to polyethylene vials for neutron irradiation at the Nuclear Research Reactor IEA-R1 from the Instituto de Pesquisas Energéticas e Nucleares IPEN/CNEN. After waiting for radiation safe levels, irradiated samples were transported to the Radioisotopes Laboratory from the Centro de Energia Nuclear na Agricultura CENA/USP. High Resolution Gamma-Ray Spectrometry using HPGe detectors was applied to measure the induced radioactivity. The chemical element mass fractions and their respective expanded analytical uncertainties (95% confidence level) were determined by k0-INAA using the in-house software Quantu. Geological reference materials were analyzed with samples to evaluate the quality of the analytical procedure. Results indicated the presence of enriched surface sediments (0-10 cm depth) for As, Ba, Ca, Co, Cs, Fe, Sb, Sc, Sr, Yb and Zn, despite no alteration was observed for Eu, Ta and Tb. Therefore, the evaluation of deep sediment profile afford the chemical element dynamics for the Piracicaba Basin. (author)

  4. Chemical Abundances of Hydrostatic and Explosive Alpha-elements in Sagittarius Stream Stars

    Science.gov (United States)

    Carlin, Jeffrey L.; Sheffield, Allyson A.; Cunha, Katia; Smith, Verne V.

    2018-05-01

    We analyze chemical abundances of stars in the Sagittarius (Sgr) tidal stream using high-resolution Gemini+GRACES spectra of 42 members of the highest surface-brightness portions of both the trailing and leading arms. Targets were chosen using a 2MASS+WISE color–color selection, combined with the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) radial velocities. In this Letter, we analyze [Fe/H] and α-elements produced by both hydrostatic (O, Mg) and explosive (Si, Ca, Ti) nucleosynthetic processes. The average [Fe/H] for our Sgr stream stars is lower than that for stars in the Sgr core, and stars in the trailing and leading arms show systematic differences in [Fe/H]. Both hydrostatic and explosive elements are depleted relative to Milky Way (MW) disk and halo stars, with a larger gap between the MW trend and Sgr stars for the hydrostatic elements. Chemical abundances of Sgr stream stars show similar patterns to those measured in the core of the Sgr dSph. We explore the ratio of hydrostatic to explosive α-elements [α h/ex] (which we refer to as the “HEx ratio”). Our observed HEx ratio trends for Sgr debris are deficient relative to MW stars. Via simple chemical evolution modeling, we show that these HEx ratio patterns are consistent with a Sgr IMF that lacks the most massive stars. This study provides a link between the chemical properties in the intact Sgr core and the significant portion of the Sgr system’s luminosity that is estimated to currently reside in the streams.

  5. Multielement analysis of reagents used in chemical identification of transuranic elements

    International Nuclear Information System (INIS)

    Montalvan Estrada, A.; Brigido Flores, O.; Maslov, O.D.; Dmitriev, S.N.

    2006-01-01

    For more than 40 years, chemical identification of transuranic elements has been used at the Laboratory of Nuclear Reactions of the Join Institute for Nuclear Research, Dubna, Russia, as a secondary method of identification. Chlorination of transuranic elements obtained by nuclear reactions is an important step of the procedure in order to obtain volatile compounds able to pass through a thermo chromatographic process. To access the quality of the reagents TiCl 4 and SOCl 2 multielement analysis was carried out using both X-rays fluorescence and gamma activation. It was followed the simplest procedure for reagents samples pretreatment, so further interferences from other chemical products were avoided. X-rays fluorescence analysis was performed in a spectrometer with Si(Li) detector with a resolution for Fe (K?) of 190 eV. Both Cd-109 and Am-241 were used as isotopic sources of excitation. Gamma activation analysis was carried out using the compact electron accelerator MT-25, where gamma rays are produced in a stopping target. Among the parameters of the MT-25 are the following: energy range-10-25 MeV, gamma-ray flux-10 14 photon/s, power consumption-20 kw. Measurements of the induced activity were performed with the help of a HPGe detector, thin and coaxial Ge(Li) detectors. There were identified two elements in SOCl 2 -Nickel (3*10 -6 g/g) and Antimony (2*10 -7 g/g), while there were identified three elements in TiCl 4 - Zirconium (8*10 -7 g/g), Arsenic (9*10 -7 g/g) and Antimony (5*10 -7 g/g). Only five elements were detected in trace concentrations in the two analyzed reagents, that is for more than 57 elements capable of being detected using gamma activation analysis with the MT-25 only 5 had concentrations above the detection limits of the method. Not being chemical analogs of the synthesized transuranic elements (Z-104 and 106) and not being able to alpha or fission disintegrations there is not expected any interference from them in the chemical

  6. Genetic interpretations of elemental and chemical differences in a soil chronosequence, California

    Science.gov (United States)

    Harden, J.W.

    1988-01-01

    Soils developed on fluvial terraces in central California have similar parent materials, climatic settings, vegetation cover and slopes but range in age from 40,000 to 3,000,000 years. The soils have chemical compositions that change systematically with increasing age. Such chemical differentiation is most likely the result of long-term weathering and mineralogical transformations that occurred since deposition of terrace fills and stabilization of the geomorphic surfaces. The changes in composition with time closely mimic other studies on mineral weathering, in which alkali and alkali-earth elements are lost more rapidly than transitional elements. The relative rates of element loss were determined by changes in element ratios over time. Net losses and gains of elements in different size fractions were monitored by their concentrations relative to Zr, the most stable constituent. Both sand and finer size fractions have lost considerable amounts of Ca, Mg, Na and K. Aluminum appears to have been lost from the sand fraction and gained in the fine fraction over a 3-million-year-time-span. Although there is no evidence for losses of Fe and Ti from sands, there is a net influx of Fe and Ti into finer fractions, probably gained from undetectable yet significant weathering of sand grains. Etching of sand grains, clay mineralogy, and microprobe analyses also indicate that the soils have undergone these chemical transformations during their formation. Mineralogical analyses also mimic other studies on mineral weathering, in which the pyroxenes weather more rapidly than hornblende, which weathers more rapidly than sphene or zircon. ?? 1988.

  7. Mechanism and degree of chemical elements effect on atmosphere corrosion resistance of steels

    International Nuclear Information System (INIS)

    Vu Din' Vuj

    1991-01-01

    It follows from the proposed regression equations that falourable effect of chemical elements on steel resistance to atmospheric corrosion is determined by their ability to increase interatom bond stability in iron crystal lattice and form corrosion products with high protection properties. Element positive influence on steel corrosion resistance decreases in the following order: S, P, Si, Mn, Cu, Cr, Ni, C in semiurban tropical atmosphere and S, Mn, Sr, Cu, Ni, Cr in coastal atmosphere. In the latter case C increases corrosion in a greater degree as compared to P. Small ammounts of Mo decrease steel resistance in semiurban atmosphere and almost do not influence it in the coastal one. Possible mechanisms of individual element influence on steel corrosion resistance are considered

  8. Pesticides, selected elements, and other chemicals in adult total diet samples October 1979-September 1980

    International Nuclear Information System (INIS)

    Gartrell, M.J.; Craun, J.C.; Podrebarac, D.S.; Gunderson, E.L.

    1985-01-01

    The US Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for adult Total Diet samples collected in 20 cities between October 1979 and September 1980. The average concentration, range of concentrations, and calculated average daily intake of each chemical found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and are within acceptable limits. The results for samples collected during the same period that represent the diets of infants and toddlers are reported separately

  9. Dynamics of chemical elements in the fermentation process of ethanol production

    International Nuclear Information System (INIS)

    Nepomuceno, N.; Fernandes, E.A.N.; Bacchi, M.A.

    1997-01-01

    Brazil has become the largest producer of biomass ethanol derived from sugar cane. The industrial production is based on the fermentation of sugar cane juice by yeast, inside of large volume vats, in a fed-batch process that recycles yeast cells. To study the dynamics of chemical elements in each operating cycle, five stages of the fermentation process were considered: must, yeast suspension, wine, non-yeast wine and yeast cream. For this, a mass balance of the terrigenous elements, Ce, Co, Cs, Eu, Fe, Hf, La, Na, Sc, Sm, and Th, and the sugar cane plant elements, Br, K, Rb, and Zn, were established in fermentation vats of an industrial scale unit, with sampling undertaken during different climatic conditions (dry and rainy periods). A similar distribution of the sugar cane characteristics elements was found for the stages analysed, while for the terrigenous elements a trend of accumulation in the yeast cream was observed. Preferential absorption of Br, K, Rb, and Zn by yeast cells was indicated by the smaller concentrations observed in yeast suspension than in yeast cream. (author)

  10. Features of adsorbed chemical elements and their isotopes distribution in iodine air filters AU-1500 of nuclear power plant

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Dovbnya, A.N.; Dikiy, N.P.; Ledenyov, O.P.; Lyashko, Yu.V.

    2013-01-01

    The main aim of research is to investigate the physical features of spatial distribution of the adsorbed chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU-1500 in the forced-exhaust ventilation at the nuclear power plant. The ?-activation analysis method is applied to accurately characterize the distribution of the adsorbed radioactive chemical elements and their isotopes in the granular filtering medium in the AU-1500 iodine air filter after its long term operation at the nuclear power plant. The typical spectrum of the detected chemical elements and their isotopes in the AU-1500 iodine air filter, which was exposed by the irradiation of bremsstrahlung gamma-quantum producing by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127 I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granules of the type of SKT-3, in the AU-1500 iodine air filter are also researched. The possible influences by the standing wave of air pressure in the iodine air filter on the spatial distribution of the chemical elements and their isotopes in the iodine air filter are discussed. The comprehensive analysis of obtained research results on the distribution of the adsorbed chemical elements and their isotopes in the absorber of iodine air filter is performed.

  11. Distribution and relationships between selected chemical elements in green alga Enteromorpha sp. from the southern Baltic

    International Nuclear Information System (INIS)

    Zbikowski, Radoslaw; Szefer, Piotr; Latala, Adam

    2006-01-01

    The concentrations of heavy metals (Cd, Cu, Ni, Pb, Zn and Mn) and macroelements (K, Na, Ca and Mg) were determined in green alga Enteromorpha sp. from the coastal zone of the southern Baltic including Gulf of Gdansk and Vistula Lagoon in 2000-2003. In order to estimate the degree of accumulation of each element by the green alga, concentration and discrimination factors (CFs) with respect to seawater were calculated. The results of factor analysis (FA) and ANOVA clearly indicate geographical differences between concentrations of chemical elements. Enteromorpha sp. from Vistula Lagoon and the southern Baltic exhibited higher levels of Mn and Ni, and Na and K, respectively. Anthropogenic impact of Cu, Pb and Zn, possibly originated from municipal sewage, was identified in alga samples collected in the Gulf of Gdansk, especially in the vicinity of Gdynia. From comparison our data with those published earlier results that Pb content in Enteromorpha sp. from the Gulf of Gdansk decreased within 1978-2003 reflecting reducing use of leaded petrol in Baltic countries in this period. The alga Enteromorpha sp. can be used for biomonitoring surveys of metal contaminants in coastal areas of the Baltic Sea. - Enteromorpha sp. can be used as efficient biomonitor for chemical elements in coastal areas of the Baltic Sea

  12. Rare Earth and other Chemical Elements Accumulation in Vines of Fogo Island (Cape Verde)

    Science.gov (United States)

    Marques, Rosa; Prudêncio, Maria Isabel; Rocha, Fernando; Dias, Maria Isabel; Franco, Dulce

    2017-04-01

    The Fogo Island is the fourth bigger island of the Cape Verde (central Atlantic Ocean). This archipelago is located 570 kilometres off the coast of West Africa, and is characterized by a semi-arid climate. The volcanic soils of the caldera of this island, with an active volcanism during historical times, have been used for viticulture. The study of uptake of chemical elements by vines - absorption and translocation to grapes - grown in soils developed on alkaline pyroclasts is the main goal of this work. The concentrations of 27 chemical elements in bark, leafs and grapes of two vines, as well as in the corresponding soils ( 50). The bioavailable fraction of Cr and As in these soils may be due to the low percentage of iron oxides (particularly in the form of nanoparticles), which play an important role in the retention of these elements. The factors responsible for the phytoavailability of Sb in soils and its uptake by plants it's still poorly known. Although the Sb concentrations in earth's crust are low, higher concentrations of this element in soils may be related with hydrothermal and volcanic processes. Also, the temperature may influence the accumulation of Sb in plants, with an increase of the Sb uptake by plants at higher temperatures, due to an increased desorption rate of Sb from soil particles. Concerning U, its mobility and dispersion in soils is controlled by its oxidation state, its adsorption capacity in clay minerals or iron oxides, and the ability to form more or less soluble complexes. Although U concentrations in these volcanic soils are low, there is a fraction available for absorption and accumulation by grapes. Concerning the rare earth elements (REE), it should be noted that the light REE are not enriched in any part of the vines studied, and only the heavy REE are enriched in grapes (EF = 20-50); this can be explained by the preferential uptake of the heavy REE, after primary minerals breakdown and the formation of more soluble compounds

  13. Chemical Differentiation of Osseous, Dental, and Non-skeletal Materials in Forensic Anthropology using Elemental Analysis.

    Science.gov (United States)

    Zimmerman, Heather A; Meizel-Lambert, Cayli J; Schultz, John J; Sigman, Michael E

    2015-03-01

    Forensic anthropologists are generally able to identify skeletal materials (bone and tooth) using gross anatomical features; however, highly fragmented or taphonomically altered materials may be problematic to identify. Several chemical analysis techniques have been shown to be reliable laboratory methods that can be used to determine if questionable fragments are osseous, dental, or non-skeletal in nature. The purpose of this review is to provide a detailed background of chemical analysis techniques focusing on elemental compositions that have been assessed for use in differentiating osseous, dental, and non-skeletal materials. More recently, chemical analysis studies have also focused on using the elemental composition of osseous/dental materials to evaluate species and provide individual discrimination, but have generally been successful only in small, closed groups, limiting their use forensically. Despite significant advances incorporating a variety of instruments, including handheld devices, further research is necessary to address issues in standardization, error rates, and sample size/diversity. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  14. Results of the experiment on chemical identification of Db as a decay product of element 115

    International Nuclear Information System (INIS)

    Dmitriev, S.N.; Oganesyan, Yu.Ts.; Utenkov, V.K.

    2004-01-01

    For the first time the chemical identification of Db as the terminal isotope of the decay element 115 produced via the 243 Am( 48 Ca, 3n) 288 115 reaction was realized. The experiment was performed on the U400 cyclotron of FLNR, JINR. The 243 Am target was bombarded with a beam dose of 3.4 · 10 18 48 Ca projectiles at an energy of 247 MeV in the center of the target. The reaction products were collected in the surface of a copper catcher block, which was removed with a lathe and then dissolved in concentrated HNO 3 . The group 5 elements were separated by sorption onto Dowex 50X8 cation-exchange resin with subsequent desorption using 1 M HF, which forms anionic fluoride complexes of group 5 elements. The eluant was evaporated onto 0.4 μm thick polyethylene foils which were placed between a pair of semiconductor detectors surrounded by 3 He neutron counters for measurement of α particles, fission fragments and neutrons. Over the course of the experiment, we observed 15 spontaneous fission events with T 1/2 = 32 -7 +11 h which we attribute to 268 Db. The production cross section for the 243 Am + 48 Ca reaction was 4.2 -1.2 + 1 .6 pb. These results agree with the original element 115 synthesis experiment where 268 Db was first observed as the terminal isotope following the five consecutive α decays from the 288 115 parent nucleus at the Dubna gas-filled separator. The data from the present experiment give independent evidence for the synthesis of element 115 as well as element 113 via the 243 Am + 48 Ca reaction

  15. The General Laws of Chemical Elements Composition Dynamics in the Biosphere

    Science.gov (United States)

    Korzh, Vyacheslav D.

    2013-04-01

    The key point of investigation of the specificity of the biosphere elemental composition formation is determination of patterns of redistribution of elemental average concentrations among various phases, like solid - liquid ( the lithosphere - the hydrosphere), which occurs as a result of a global continuous processing of inert matter by living substances. Our task here is to investigate this process in the system "lithosphere - hydrosphere" in view of the integrated involvement of living material in it. This process is most active in biogeochemical barriers, i.e. in places of "the life condensation" and runs under a nonlinear regularity that has been unknown before. It is established that this process results in a general relative increase in concentrations of chemical elements in the solid phase in proportion as their prevalence in the environment is reduced. This process running in various natural systems has practically the same parameter of nonlinearity (v) approximately equal to 0.7. For proto-lithosphere -"living material" - soil v = 0.75. For river - "living material" - ocean v = 0.67. For the contemporary factual awareness level these estimations of nonlinearity indices are practically negligible. Hence, it is for the first time that the existence of a universal constant of nonlinearity of elemental composition evolution in the biosphere has been proved and its quantitative evaluation has been made. REFERENCES 1. Korzh V.D. 1974. Some general laws governing the turnover of substance within the ocean-atmosphere-continent-ocean cycle. // Journal de Recherches Atmospheriques. Vol. 8. P. 653-660. 2. Korzh V.D. 2008. The general laws in the formation of the elemental composition of the Hydrosphere and Biosphere.// J. Ecologica, Vol. XV, P. 13-21. 3. Korzh V.D. 2012. Determination of general laws of elemental composition in Hydrosphere // Water: chemistry & ecology, Journal of water science and its practical application. # 1, P.56-62.

  16. Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.

    Science.gov (United States)

    Bolsunovsky, Alexander

    2011-09-01

    The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

  17. Atom-scale depth localization of biologically important chemical elements in molecular layers.

    Science.gov (United States)

    Schneck, Emanuel; Scoppola, Ernesto; Drnec, Jakub; Mocuta, Cristian; Felici, Roberto; Novikov, Dmitri; Fragneto, Giovanna; Daillant, Jean

    2016-08-23

    In nature, biomolecules are often organized as functional thin layers in interfacial architectures, the most prominent examples being biological membranes. Biomolecular layers play also important roles in context with biotechnological surfaces, for instance, when they are the result of adsorption processes. For the understanding of many biological or biotechnologically relevant phenomena, detailed structural insight into the involved biomolecular layers is required. Here, we use standing-wave X-ray fluorescence (SWXF) to localize chemical elements in solid-supported lipid and protein layers with near-Ångstrom precision. The technique complements traditional specular reflectometry experiments that merely yield the layers' global density profiles. While earlier work mostly focused on relatively heavy elements, typically metal ions, we show that it is also possible to determine the position of the comparatively light elements S and P, which are found in the most abundant classes of biomolecules and are therefore particularly important. With that, we overcome the need of artificial heavy atom labels, the main obstacle to a broader application of high-resolution SWXF in the fields of biology and soft matter. This work may thus constitute the basis for the label-free, element-specific structural investigation of complex biomolecular layers and biological surfaces.

  18. A class of chemical pinning centers including two elements foreign to HTS

    Energy Technology Data Exchange (ETDEWEB)

    Weinstein, Roy; Sawh, Ravi-Persad

    2003-01-01

    Very small deposits are formed when two foreign elements, A and B, are added to textured (RE)BCO. These deposits increase the J{sub c} of samples and hence the maximum trapped field. Deposit sizes are generally in the range 200-400 nm. Their chemical composition is (A{sub x},B{sub y})(RE)Ba{sub 2}O{sub 6}, where x+y=1 and x=y{+-}0.1. Their structure is double perovskite. The deposits produce two types of pinning, one by refinement (e.g., of the Y211 phase) and the other due to the double perovskite deposits themselves. In those cases tested, the refinement increases J{sub c} by factors exceeding 1.33, and the deposits increase J{sub c} by factors exceeding 2, for a total increase by a factor exceeding 2.66. Element A can be U, W or Mo. Element B can be Pt or Zr. We speculate on possible additional elements in classes A and B.

  19. Adaptive Finite Element Method Assisted by Stochastic Simulation of Chemical Systems

    KAUST Repository

    Cotter, Simon L.; Vejchodský , Tomá š; Erban, Radek

    2013-01-01

    Stochastic models of chemical systems are often analyzed by solving the corresponding Fokker-Planck equation, which is a drift-diffusion partial differential equation for the probability distribution function. Efficient numerical solution of the Fokker-Planck equation requires adaptive mesh refinements. In this paper, we present a mesh refinement approach which makes use of a stochastic simulation of the underlying chemical system. By observing the stochastic trajectory for a relatively short amount of time, the areas of the state space with nonnegligible probability density are identified. By refining the finite element mesh in these areas, and coarsening elsewhere, a suitable mesh is constructed and used for the computation of the stationary probability density. Numerical examples demonstrate that the presented method is competitive with existing a posteriori methods. © 2013 Society for Industrial and Applied Mathematics.

  20. Distribution of some chemical elements between dissolved and particulate phases in the ocean

    International Nuclear Information System (INIS)

    Spencer, D.W.; Bacon, M.P.; Sachs, P.L.; Fleer, A.P.; Shafer, D.K.; Belastock, R.A.; Hammer, T.R.

    1985-01-01

    The long-range goal of our research is to understand the processes that control the distribution and fate of chemical elements in the ocean, with emphasis on the rates at which the governing processes operate. Such an understanding is essential in predicting the fate of substances such as heavy metals and radionuclides that are released to the environment as a consequence of energy-producing activities. In pursuit of this goal we have, during the present contract period, devoted all of our effort to participation in the Shelf-Edge Exchange Processes (SEEP) program. Initial results from SEEP-1 are consistent with our hypothesis of enhanced scavenging of reactive chemical substances in upper slope sediments. During the next year we will complete our analytical work for SEEP-1 and carry out quantitative interpretations of our data with mathematical models to assess the importance of boundary uptake in this region of the continental margin. 8 references, 5 figures, 1 table

  1. A mathematical model for chemical reactions with actinide elements in the aqueous nitric acid solution: REACT

    International Nuclear Information System (INIS)

    Tachimori, Shoichi

    1990-02-01

    A mathematical model of chemical reactions with actinide elements: REACT code, was developed to simulate change of valency states of U, Pu and Np in the aqueous nitric acid solution. Twenty seven rate equations for the redox reactions involving some reductants, disproportionation reactions, and radiolytic growth and decay reaction of nitrous acid were programmed in the code . Eight numerical solution methods such as Porsing method to solve the rate equations were incorporated parallel as options depending on the characteristics of the reaction systems. The present report gives a description of the REACT code, e.g., chemical reactions and their rate equations, numerical solution methods, and some examples of the calculation results. A manual and a source file of the program was attached to the appendix. (author)

  2. Status of chemical elements in Atlantic Forest tree species near an industrial complex

    International Nuclear Information System (INIS)

    Araujo, A.L.L.; Fernandes, E.A.N.; Franca, E.J.; Bacchi, M.A.

    2008-01-01

    Environmental quality assessment studies have been conducted with tree species largely distributed in the Atlantic Forest. Leaf and soil samples were collected in the conservation unit Parque Estadual da Serra do Mar (PESM) nearby the industrial complex of Cubatao, Sao Paulo State, Brazil, and analyzed for chemical elements by instrumental neutron activation analysis. Results were compared to background values obtained in the Parque Estadual Carlos Botelho (PECB). The higher As, Fe, Hg and Zn mass fractions in the tree leaves of PESM indicated anthropogenic influence on this conservation unit. (author)

  3. Determination of the concentration profile of chemical elements in superheater pipes

    International Nuclear Information System (INIS)

    Aldape U, F.; Aspiazu F, J.

    1986-05-01

    This work has for object to determine the profile of concentration of chemical elements at trace level in a superheater pipe of Thermoelectric Plants using the X-ray emission spectroscopy technique induced by protons coming from the Accelerator of the Nuclear Center. In the X-ray detection, a Si Li detector was used. The technique was chosen because it allows a multielemental analysis, of high sensitivity and precision. The results can help to understand the problems that are had in the change of flexibility or of corrosion. This will be from utility to the Federal Electricity Commission (CFE). (Author)

  4. Guidelines for terms related to chemical speciations and fractionation of elements : definitions, structural aspects, and methodological approaches (IUPAC Recommendations 2000)

    NARCIS (Netherlands)

    Templeton, D.M.; Ariese, F.; Cornelis, R.; Danielsson, L.G.; Muntau, H.; Leeuwen, van H.P.; Lobínski, R.

    2000-01-01

    This paper presents definitions of concepts related to speciation of elements, more particularly speciation analysis and chemical species. Fractionation is distinguished from speciation analysis, and a general outline of fractionation procedures is given. We propose a categorization of species

  5. Statistic analysis of grouping in evaluation of the behavior of stable chemical elements and physical-chemical parameters in effluent from uranium mining

    International Nuclear Information System (INIS)

    Pereira, Wagner de S.

    2013-01-01

    The Ore Treatment Unit (UTM) is a uranium mine off. The statistical analysis of clustering was used to evaluate the behavior of stable chemical elements and physico-chemical variables in their effluents. The use of cluster analysis proved effective in the evaluation, allowing to identify groups of chemical elements in physico-chemical variables and group analyzes (element and variables ). As a result, we can say, based on the analysis of the data, a strong link between Ca and Mg and between Al and TR 2 O 3 (rare earth oxides) in the UTM effluents. The SO 4 was also identified as strongly linked to total solids and dissolved and these linked to electrical conductivity. Other associations existed, but were not as strongly linked. Additional collections for seasonal evaluation are required so that assessments can be confirmed. Additional statistics analysis (ordination techniques) should be used to help identify the origins of the groups identified in this analysis. (author)

  6. Determination of chemical elements in Eucalyptus grandis, manured with Ballad's, by neutrons activation analysis

    International Nuclear Information System (INIS)

    Mateus, Natalina de Fatima; Madi Filho, Tufic

    2007-01-01

    The biosolid is a mud resulting from the biological treatment of wasted liquids. It is considered as a profitable alternative and important to minimize the environmental impact generated by the sewage thrown in to sanitary lands, in forest cultures like the Eucalyptus grandis. The objective of this work was to detect which chemical elements are present in Eucalyptus grandis samples, fertilized with different quantities of biosolid. The eucalyptuses of Estacao Experimental de Ciencias Florestais of Itatinga were planted in March of 1998 and collected with five years old. The used biosolid was produced by Station of Treatment of Sewer of Barueri - SP, classified as kind B. For the determination of the presence and quantity of chemical elements in the eucalyptus samples, an analysis technique by neutronic activation (NAA) was used followed by gamma rays spectroscopy. The samples were irradiated in the Nuclear Reactor IEA-R1 of IPEN-SP, followed by the measure of induced gamma rays activity, using a Detector HPGe. The presence, mainly of Br, Mn, Na and K, was detected in all analyzed samples. (author)

  7. The Detailed Chemical Properties of M31 Star Clusters. I. Fe, Alpha and Light Elements

    Science.gov (United States)

    Colucci, Janet E.; Bernstein, Rebecca A.; Cohen, Judith G.

    2014-12-01

    We present ages, [Fe/H] and abundances of the α elements Ca I, Si I, Ti I, Ti II, and light elements Mg I, Na I, and Al I for 31 globular clusters (GCs) in M31, which were obtained from high-resolution, high signal-to-noise ratio >60 echelle spectra of their integrated light (IL). All abundances and ages are obtained using our original technique for high-resolution IL abundance analysis of GCs. This sample provides a never before seen picture of the chemical history of M31. The GCs are dispersed throughout the inner and outer halo, from 2.5 kpc < R M31 < 117 kpc. We find a range of [Fe/H] within 20 kpc of the center of M31, and a constant [Fe/H] ~ - 1.6 for the outer halo clusters. We find evidence for at least one massive GC in M31 with an age between 1 and 5 Gyr. The α-element ratios are generally similar to the Milky Way GC and field star ratios. We also find chemical evidence for a late-time accretion origin for at least one cluster, which has a different abundance pattern than other clusters at similar metallicity. We find evidence for star-to-star abundance variations in Mg, Na, and Al in the GCs in our sample, and find correlations of Ca, Mg, Na, and possibly Al abundance ratios with cluster luminosity and velocity dispersion, which can potentially be used to constrain GC self-enrichment scenarios. Data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

  8. THE DETAILED CHEMICAL PROPERTIES OF M31 STAR CLUSTERS. I. Fe, ALPHA AND LIGHT ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Colucci, Janet E.; Bernstein, Rebecca A. [The Observatories of the Carnegie Institution for Science, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Cohen, Judith G., E-mail: jcolucci@obs.carnegiescience.edu [Palomar Observatory, Mail Stop 105-24, California Institute of Technology, Pasadena, CA 91125 (United States)

    2014-12-20

    We present ages, [Fe/H] and abundances of the α elements Ca I, Si I, Ti I, Ti II, and light elements Mg I, Na I, and Al I for 31 globular clusters (GCs) in M31, which were obtained from high-resolution, high signal-to-noise ratio >60 echelle spectra of their integrated light (IL). All abundances and ages are obtained using our original technique for high-resolution IL abundance analysis of GCs. This sample provides a never before seen picture of the chemical history of M31. The GCs are dispersed throughout the inner and outer halo, from 2.5 kpc < R {sub M31} < 117 kpc. We find a range of [Fe/H] within 20 kpc of the center of M31, and a constant [Fe/H] ∼ – 1.6 for the outer halo clusters. We find evidence for at least one massive GC in M31 with an age between 1 and 5 Gyr. The α-element ratios are generally similar to the Milky Way GC and field star ratios. We also find chemical evidence for a late-time accretion origin for at least one cluster, which has a different abundance pattern than other clusters at similar metallicity. We find evidence for star-to-star abundance variations in Mg, Na, and Al in the GCs in our sample, and find correlations of Ca, Mg, Na, and possibly Al abundance ratios with cluster luminosity and velocity dispersion, which can potentially be used to constrain GC self-enrichment scenarios. Data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope.

  9. Physical--chemical studies of transuranium elements. Progress report, April 1, 1977--March 31, 1978

    International Nuclear Information System (INIS)

    Peterson, J.R.

    1978-01-01

    Major advances in our continuing program to determine, interpret, and correlate the basic chemical and physical properties of the transuranium elements are summarized for the period April 1, 1977, through March 31, 1978. CfCl 2 , EsCl 2 , EsBr 2 , and EsI 2 were synthesized and characterized spectrophotometrically, as were several mixed-valence lanthanide-actinide halides (e.g., GdCf 4 Cl 11 ) and CmF 4 , CfF 4 , and EsF 3 . All samples not containing einsteinium were also examined by X rays. Studies of the chemical consequences of the radioactive decay series 253 Es alpha decaying to 249 Bk beta decaying to 249 Cf have continued and expanded. Elemental Cm-248 has been prepared on the one-half milligram scale and used to synthesize CmP and CmSb. Single crystals of AmTe 2 and AmSe 2 have been grown from a Te melt and by iodine transport, respectively. Our SQUID magnetometer was tested successfully in a preliminary configuration, and the expected sensitivity of the device was confirmed. A new design for the flux sensing coils was incorporated prior to an apparatus calibration experiment with lead. A porous vitreous carbon material was found to make a useful optically transparent electrode for simultaneous electrochemical and absorption spectroscopic investigations. Cyclic voltammograms of UO 2 2+ were obtained prior to a spectroelectrochemical study of the radiation of UO 2 2+ . The major obstacle in our solution microcalorimetry program was overcome by the realization of a leak-free sample container. Calorimeter performance now warrants experiments with transuranium element samples. The electrochemical reductions of Cf(III) and Es(III) have been studied by polarography and/or cyclic voltammetry. The results suggest that both are reduced to the divalent state before being reduced to the amalgam

  10. Clustering of samples and elements based on multi-variable chemical data

    International Nuclear Information System (INIS)

    Op de Beeck, J.

    1984-01-01

    Clustering and classification are defined in the context of multivariable chemical analysis data. Classical multi-variate techniques, commonly used to interpret such data, are shown to be based on probabilistic and geometrical principles which are not justified for analytical data, since in that case one assumes or expects a system of more or less systematically related objects (samples) as defined by measurements on more or less systematically interdependent variables (elements). For the specific analytical problem of data set concerning a large number of trace elements determined in a large number of samples, a deterministic cluster analysis can be used to develop the underlying classification structure. Three main steps can be distinguished: diagnostic evaluation and preprocessing of the raw input data; computation of a symmetric matrix with pairwise standardized dissimilarity values between all possible pairs of samples and/or elements; and ultrametric clustering strategy to produce the final classification as a dendrogram. The software packages designed to perform these tasks are discussed and final results are given. Conclusions are formulated concerning the dangers of using multivariate, clustering and classification software packages as a black-box

  11. Results of the Experiment on Chemical Identification of Db as a Decay Product of Element 115

    CERN Document Server

    Dmitriev, S N; Utyonkov, V K; Shishkin, S V; Eremin, A V; Lobanov, Yu V; Tsyganov, Yu S; Chepigin, V I; Sokol, E A; Vostokin, G K; Aksenov, N V; Hussonnois, M; Itkis, M G; Aggeler, H W; Schumann, D; Bruchertseifer, H; Eichler, R; Shaughnessy, D A; Wilk, P A; Kenneally, J M; Stoyer, M A; Wild, J F

    2004-01-01

    For the first time the chemical identification of Db as the terminal isotope of the decay element 115 produced via the $^{243}{\\text{Am}}(^{48}{\\text{Ca}},3n)^{288}115$ reaction was realized. The experiment was performed on the U400 cyclotron of FLNR, JINR. The $^{243}$Am target was bombarded with a beam dose of $3.4\\cdot 10^{18}$ $^{48}$Ca projectiles at an energy of 247 MeV in the center of the target. The reaction products were collected in the surface of a copper catcher block, which was removed with a lathe and then dissolved in concentrated HNO$_3$. The group 5 elements were separated by sorption onto Dowex 50$\\times$8 cation-exchange resin with subsequent desorption using 1M HF, which forms anionic fluoride complexes of group 5 elements. The eluant was evaporated onto 0.4 $\\mu$m thick polyethylene foils which were placed between a pair of semiconductor detectors surrounded by $^3$He neutron counters for measurement of $\\alpha$ particles, fission fragments and neutrons. Over the course of the experiment...

  12. Effects of chemical elements in the trophic levels of natural salt marshes.

    Science.gov (United States)

    Kamiński, Piotr; Barczak, Tadeusz; Bennewicz, Janina; Jerzak, Leszek; Bogdzińska, Maria; Aleksandrowicz, Oleg; Koim-Puchowska, Beata; Szady-Grad, Małgorzata; Klawe, Jacek J; Woźniak, Alina

    2016-06-01

    The relationships between the bioaccumulation of Na, K, Ca, Mg, Fe, Zn, Cu, Mn, Co, Cd, and Pb, acidity (pH), salinity (Ec), and organic matter content within trophic levels (water-soil-plants-invertebrates) were studied in saline environments in Poland. Environments included sodium manufactures, wastes utilization areas, dumping grounds, and agriculture cultivation, where disturbed Ca, Mg, and Fe exist and the impact of Cd and Pb is high. We found Zn, Cu, Mn, Co, and Cd accumulation in the leaves of plants and in invertebrates. Our aim was to determine the selectivity exhibited by soil for nutrients and heavy metals and to estimate whether it is important in elucidating how these metals are available for plant/animal uptake in addition to their mobility and stability within soils. We examined four ecological plant groups: trees, shrubs, minor green plants, and water macrophytes. Among invertebrates, we sampled breastplates Malacostraca, small arachnids Arachnida, diplopods Diplopoda, small insects Insecta, and snails Gastropoda. A higher level of chemical elements was found in saline polluted areas (sodium manufactures and anthropogenic sites). Soil acidity and salinity determined the bioaccumulation of free radicals in the trophic levels measured. A pH decrease caused Zn and Cd to increase in sodium manufactures and an increase in Ca, Zn, Cu, Cd, and Pb in the anthropogenic sites. pH increase also caused Na, Mg, and Fe to increase in sodium manufactures and an increase in Na, Fe, Mn, and Co in the anthropogenic sites. There was a significant correlation between these chemical elements and Ec in soils. We found significant relationships between pH and Ec, which were positive in saline areas of sodium manufactures and negative in the anthropogenic and control sites. These dependencies testify that the measurement of the selectivity of cations and their fluctuation in soils provide essential information on the affinity and binding strength in these environments. The

  13. On the enrichment of low-abundant isotopes of light chemical elements by gas centrifuges

    International Nuclear Information System (INIS)

    Borisevich, V.D.; Morozov, O.E.; Zaozerskiy, Yu.P.; Shmelev, G.M.; Shipilov, Yu.D.

    2000-01-01

    A brief review of the main areas for the application of the isotopes 15 N and 13 C is made. Separation of the nitrogen isotopes in a single gas centrifuge in the form of pure nitrogen, ammonia, and trifluoride of nitrogen as well as the carbon isotopes in the form of carbon dioxide has been studied by means of numerical simulation. The parameters of the centrifugal machine investigated were close to the parameters of the Iguassu machine. The dependence of the efficiency criterion versus the basic parameters of the separation process has been explored in the computational experiments. Comparisons of the calculated results with the experimental data have shown good agreement. The results obtained have demonstrated the possibility of using gas centrifuge technology to enrich successfully the low-abundant isotopes of light chemical elements

  14. Selected elements and organic chemicals in streambed sediment in the Salem area, Oregon, 1999

    Science.gov (United States)

    Tanner, Dwight Q.

    2002-09-13

    Analysis of streambed sediments in the Salem, Oregon, area showed anomalously large concentrations of some elements and organic chemicals, indicating contamination from anthropogenic and/or geologic sources. The streambed sediment sample from Clark Creek, an urban basin, had large concentrations of polycyclic aromatic hyrdocarbons (PAHs), organochlorines, cadmium, lead, and zinc. The sample from the East Fork of Pringle Creek, which is a mostly urban basin, had the highest concentrations of DDD, DDE, and DDT compounds. Aldrin was detected in streambed sediment at only one site, the East Fork of Pringle Creek. Ten of the 14 sites sampled had exceedances of the sediment quality guidelines of the Canadian Council of Ministers of the Environment (CCME), and 8 sites had exceedances of guidelines from the Puget Sound Dredged Disposal Analysis (PSDDA) Program.

  15. Transformation processes influencing physico-chemical forms of radionuclides and trace elements in natural water systems

    International Nuclear Information System (INIS)

    Salbu, B.; Riise, G.; Oughton, D.H.

    1995-01-01

    In order to assess short and long term consequences of radionuclides and trace elements introduced to aquatic systems, knowledge on source terms, key factors and key processes influencing the speciation is essential. The mobility, bioavailability and subsequent transfer into food chains depend on the physico-chemical forms on radionuclides and trace metals. In addition, transformation processes and especially the interaction with natural organic matter (NOM) influences the distribution pattern. Furthermore, the prevailing climate conditions, e.g. episodic events and temperature are vital for fluxes and for the kinetics of the transformation processes. In the present work processes in catchments and processes associated with acidification, episodic events, climate conditions (temperature) and mixing zone phenomena influencing the speciation of radionuclides and trace metals are highlighted. These processes should be highly relevant for assessing far field consequences of radionuclides potentially released from disposal sites. (authors). 21 refs., 8 figs., 1 tab

  16. Chemical elements in the environment: multi-element geochemical datasets from continental to national scale surveys on four continents

    Science.gov (United States)

    Caritat, Patrice de; Reimann, Clemens; Smith, David; Wang, Xueqiu

    2017-01-01

    During the last 10-20 years, Geological Surveys around the world have undertaken a major effort towards delivering fully harmonized and tightly quality-controlled low-density multi-element soil geochemical maps and datasets of vast regions including up to whole continents. Concentrations of between 45 and 60 elements commonly have been determined in a variety of different regolith types (e.g., sediment, soil). The multi-element datasets are published as complete geochemical atlases and made available to the general public. Several other geochemical datasets covering smaller areas but generally at a higher spatial density are also available. These datasets may, however, not be found by superficial internet-based searches because the elements are not mentioned individually either in the title or in the keyword lists of the original references. This publication attempts to increase the visibility and discoverability of these fundamental background datasets covering large areas up to whole continents.

  17. Chemical elemental distribution and soil DNA fingerprints provide the critical evidence in murder case investigation.

    Directory of Open Access Journals (Sweden)

    Giuseppe Concheri

    Full Text Available BACKGROUND: The scientific contribution to the solution of crime cases, or throughout the consequent forensic trials, is a crucial aspect of the justice system. The possibility to extract meaningful information from trace amounts of samples, and to match and validate evidences with robust and unambiguous statistical tests, are the key points of such process. The present report is the authorized disclosure of an investigation, carried out by Attorney General appointment, on a murder case in northern Italy, which yielded the critical supporting evidence for the judicial trial. METHODOLOGY/PRINCIPAL FINDINGS: The proportional distribution of 54 chemical elements and the bacterial community DNA fingerprints were used as signature markers to prove the similarity of two soil samples. The first soil was collected on the crime scene, along a corn field, while the second was found in trace amounts on the carpet of a car impounded from the main suspect in a distant location. The matching similarity of the two soils was proven by crossing the results of two independent techniques: a elemental analysis via inductively coupled plasma mass spectrometry (ICP-MS and optical emission spectrometry (ICP-OES approaches, and b amplified ribosomal DNA restriction analysis by gel electrophoresis (ARDRA. CONCLUSIONS: Besides introducing the novel application of these methods to forensic disciplines, the highly accurate level of resolution observed, opens new possibilities also in the fields of soil typing and tracking, historical analyses, geochemical surveys and global land mapping.

  18. Natural and anthropogenic sources of chemical elements in sediment profiles from the Admiralty Bay, Antarctica

    International Nuclear Information System (INIS)

    Ribeiro, A.P.; Figueira, R.C.L.; Silva, C.R.A.; Franca, E.J.; Mahiques, M.M.; Bicego, M.C.; Montone, R.C.

    2010-01-01

    Full text: The Antarctic Continent and its surrounding Southern Ocean are the least known regions of the world, mainly due to the most unfavorable climatic conditions, in which sampling for environmental studies are quite difficult to be carried out. Admiralty Bay on the King George Island (Antarctica) hosts three research stations, Arctowski, Ferraz and Macchu Picchu, which are operate by Poland, Brazil and Peru, respectively. Therefore, human activities in this region require the use of fossil fuel as an energy source, which is also considered the main source of pollutants in the area. This work investigated the natural and anthropogenic inputs of chemical elements in sediment samples collected close to Ferraz Station, during the 25 th Brazilian Antarctica Expedition in the 2006/2007 austral summer. Total concentrations of As, Zn and Sc were determined in sediment profiles by using the Instrumental Neutron Activation Analysis (INAA). The analytical technique employed to determine the major elements such as Fe, Al, Ca, Mn and Ti was X-ray fluorescence (XRF) spectroscopy. For estimating the sedimentation rate, High Resolution Gamma Ray Spectrometry was applied to determine 137 Cs, after 30 days, to achieve secular equilibrium. According to the enrichment factor and the geochronology analysis, the most relevant enrichment was observed for As in the sediment samples, suggesting the increasing of its content due to the Brazilian activities in the Admiralty Bay. Despite some evidences of anthropogenic contribution, the study indicated low level of environmental risk for this region. (author)

  19. Physical--chemical studies of transuranium elements. Progress report, April 1, 1976--March 31, 1977

    International Nuclear Information System (INIS)

    Peterson, J.R.

    1977-01-01

    Major advances in our continuing program to determine, interpret, and correlate the basic chemical and physical properties of the transuranium elements are summarized for the period April 1, 1976, through March 31, 1977. Implementation of data reduction programs and acquisition of a CRT time-sharing graphics terminal/stand-alone computer have advanced significantly the handling capabilities of single-beam spectral data obtained by our microscope spectrophotometer. EsCl 3 , EsBr 3 , and EsI 3 have been well characterized spectroscopically, and limited X-ray diffraction data have been obtained from EsBr 3 and EsI 3 . The reduction of mixed Es-lanthanide trihalides has produced what might be Es(II). Dimorphism in BkCl 3 , CfCl 3 , and BkBr 3 has been studied spectrophotometrically and the results confirmed by X-ray analysis. Our solution microcalorimeter was improved by reducing the system-generated electrical noise and developing a novel sample container. The operating sensitivity was determined to be within the desired 0.1 percent precision requirement. The necessary hardware was obtained and software development was initiated for the capability to acquire, store, and analyze the heat of solution data automatically. A very sensitive apparatus (SQUID) for the determination of magnetic susceptibility has been constructed and is being evaluated. Our device should greatly facilitate the study of microgram-sized samples of transuranium elements and compounds

  20. The chemical behavior of the transuranic elements and the barrier function in natural aquifer systems

    International Nuclear Information System (INIS)

    Jewett, J.R.

    1997-01-01

    In a geological repository for long-lived radioactive wastes, such as actinides and certain fission products, most of the stored radionuclides remain immobile in the particular geological formation. If any of these could possibly become mobile, only trace concentrations of a few radionuclides would result. Nevertheless, with an inventory in the repository of many tonnes of transuranic elements, the amounts that could disperse cannot be neglected. A critical assessment of the chemical behavior of these nuclides, especially their migration properties in the aquifer system around the repository site, is mandatory for analysis of the long-term safety. The chemistry requited for this includes many geochemical multicomponent reactions that are so far only partially understood and hich therefore can be quantified only incompletely. A few of these reactions have been discussed in this paper based on present knowledge. If a comprehensive discussion of the subject is impossible because of this ack of information then an attempt to emphasize the importance of the predominant geochemical reactions of the transuranic elements in various aquifer systems should be made

  1. Electronic Structure and Chemical Bond of Ti3SiC2 and Adding Al Element

    Institute of Scientific and Technical Information of China (English)

    MIN Xinmin; LU Ning; MEI Bingchu

    2006-01-01

    The relation among electronic structure, chemical bond and property of Ti3SiC2 and Al-doped was studied by density function and discrete variation (DFT-DVM) method. When Al element is added into Ti3SiC2, there is a less difference of ionic bond, which does not play a leading role to influent the properties. After adding Al, the covalent bond of Al and the near Ti becomes somewhat weaker, but the covalent bond of Al and the Si in the same layer is obviously stronger than that of Si and Si before adding. Therefore, in preparation of Ti3SiC2, adding a proper quantity of Al can promote the formation of Ti3SiC2. The density of state shows that there is a mixed conductor character in both of Ti3SiC2 and adding Al element. Ti3SiC2 is with more tendencies to form a semiconductor. The total density of state near Fermi lever after adding Al is larger than that before adding, so the electric conductivity may increase after adding Al.

  2. Carbon black vs. black carbon and other airborne materials containing elemental carbon: Physical and chemical distinctions

    International Nuclear Information System (INIS)

    Long, Christopher M.; Nascarella, Marc A.; Valberg, Peter A.

    2013-01-01

    Airborne particles containing elemental carbon (EC) are currently at the forefront of scientific and regulatory scrutiny, including black carbon, carbon black, and engineered carbon-based nanomaterials, e.g., carbon nanotubes, fullerenes, and graphene. Scientists and regulators sometimes group these EC-containing particles together, for example, interchangeably using the terms carbon black and black carbon despite one being a manufactured product with well-controlled properties and the other being an undesired, incomplete-combustion byproduct with diverse properties. In this critical review, we synthesize information on the contrasting properties of EC-containing particles in order to highlight significant differences that can affect hazard potential. We demonstrate why carbon black should not be considered a model particle representative of either combustion soots or engineered carbon-based nanomaterials. Overall, scientific studies need to distinguish these highly different EC-containing particles with care and precision so as to forestall unwarranted extrapolation of properties, hazard potential, and study conclusions from one material to another. -- Highlights: •Major classes of elemental carbon-containing particles have distinct properties. •Despite similar names, carbon black should not be confused with black carbon. •Carbon black is distinguished by a high EC content and well-controlled properties. •Black carbon particles are characterized by their heterogenous properties. •Carbon black is not a model particle representative of engineered nanomaterials. -- This review demonstrates the significant physical and chemical distinctions between elemental carbon-containing particles e.g., carbon black, black carbon, and engineered nanomaterials

  3. Chemical Hand Warmer Packet Ingestion: A Case of Elemental Iron Exposure.

    Science.gov (United States)

    Weiland, Jessica L; Sherrow, Leighanne K; Jayant, Deepak A; Katz, Kenneth D

    2017-09-01

    For individuals who work outdoors in the winter or play winter sports, chemical hand warmers are becoming increasingly more commonplace because of their convenience and effectiveness. A 32-year-old woman with a history of chronic pain and bipolar disorder presented to the emergency department complaining of a "warm sensation" in her mouth and epigastrium after reportedly ingesting the partial contents of a chemical hand warmer packet containing between 5 and 8 g of elemental iron. She had been complaining of abdominal pain for approximately 1 month and was prescribed unknown antibiotics the previous day. The patient denied ingestion of any other product or medication other than what was prescribed. A serum iron level obtained approximately 6 hours after ingestion measured 235 micrograms/dL (reference range 40-180 micrograms/dL). As the patient demonstrated no new abdominal complaints and no evidence of systemic iron toxicity, she was discharged uneventfully after education. However, the potential for significant iron toxicity exists depending on the extent of exposure to this or similar products. Treatment for severe iron toxicity may include fluid resuscitation, whole bowel irrigation, and iron chelation therapy with deferoxamine. Physicians should become aware of the toxicity associated with ingestion of commercially available hand warmers. Consultation with a medical toxicologist is recommended. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  4. Stand-Off Chemical Detection Using Photoacoustic Sensing Techniques—From Single Element to Phase Array

    Directory of Open Access Journals (Sweden)

    Deepa Gupta

    2018-01-01

    Full Text Available Technologies that can detect harmful chemicals, such as explosive devices, harmful gas leaks, airborne chemicals or/and biological agents, are heavily invested in by the government to prevent any possible catastrophic consequences. Some key features of such technology are, but not limited to, effective signal-to-noise ratio (SNR of the detected signal and extended distance between the detector and target. In this work, we describe the development of photoacoustic sensing techniques from simple to more complex systems. These techniques include passive and active noise filters, parabolic sound reflectors, a lock-in amplifier, and beam-forming with an array of microphones; using these techniques, we increased detection distance from a few cm in an indoor setting to over 41 feet in an outdoor setting. We also establish a theoretical mathematical model that explains the underlying principle of how SNR can be improved with an increasing number of microphone elements in the phase array. We validate this model with computational simulations as well as experimental results.

  5. Chemical elements in Leucaena leucocephala leaves of riparian zones of the municipality of Piracicaba, São Paulo, Brazil

    International Nuclear Information System (INIS)

    França, Elvis J. de; Fernandes, Elisabete A.N.; Lira, Marcelo G.; Ferreira, Fabiano S.; Cavalca, Isabel P.O.; Rodrigues, Vanessa S.; Camilli, Leandro

    2017-01-01

    The species Leucaena leucocephala can be found in several riparian ecosystems, acting as one of the main invasive and harmful species for the forest restoration of the permanent preservation areas. It has also been studied for the phytoremediation of some chemical elements, due to their potential accumulation of chemical substances. Therefore, the present study aimed to evaluate the accumulation of chemical elements in leaves of Leucaena leucocephala trees by Instrumental Neutronic Activation Analysis - INAA. Samples of leaves were collected in eight samples from riverside areas of the Piracicaba Municipality, São Paulo, Brazil, during the dry and rainy season. After collection, washing with water and drying in a forced circulation oven, the samples were comminuted and encapsulated in polyethylene capsules and subjected to a thermal neutron flux of 10 13 cm -2 s -1 for 8 hours in the Nuclear Research Reactor IEA-R1 of IPEN / CNEN. Thermal neutron flux monitoring was performed by Ni-Cr alloy fragments with known concentrations of the chemical monitors elements. After measurements of radioactivity induced by HPGe detectors, the concentrations of the chemical elements were calculated by the k0 method using the Quantu computer program. Certified reference materials were also analyzed for quality assurance of the analytical procedure. The results indicated high concentrations of La and lanthanoids (Ce, Eu, Sm, Tb and Yb) in leaves of L. leucocephala in both periods analyzed. It was possible to observe a decrease in the concentrations of the chemical elements in the rainy season, probably associated to the washing of the geological material deposited on the leaves of the trees by the rains, except for K, Mo, Rb, Sb and Zn, whose values remained or increased in the leaves collected during the rainy season. Considering the constant leaf production, L. leucocephala can greatly affect the cycling of chemical elements due to its accumulation capacity demonstrated by this

  6. Origin of major element chemical trends in DSDP Leg 37 basalts, Mid-Atlantic Ridge

    Science.gov (United States)

    Byerly, G.R.; Wright, T.L.

    1978-01-01

    In this paper we summarize the major element chemical variation for basalts from the Deep Sea Drilling Project Leg 37 and relate it to stratigraphic position in each of five drilling sites. Least-squares techniques are successfully used to quantify the nature and extent of alteration in these basalts, and to correct the major element analysis back to a magmatic, or alteration-free, composition on the assumption that alteration takes place in two ways: (1) secondary minerals are introduced into veins and vesicles, and (2) CO2 and H2O react with components in the rock to form a simple alteration assemblage. A chemical stratigraphy is defined for these basalts by grouping lavas whose chemistries are related by low-pressure phenocryst-liquid differentiation as identified by least-squares calculation. Major chemical-stratigraphic units are as much as 200 m thick; correlations of these units can be made between the holes at site 332 (about 100 m apart), but not between the other sites. Compositions of parental magmas are calculated by extrapolating low-pressure variations to a constant value of 9% MgO. The differences in these extrapolated compositions reflect high-pressure processes, and suggest that clinopyroxene may be an important phase in either intermediate-level fractionation of basaltic liquids, or as a residual phase during the partial melting which produces these basaltic liquids. Several of the basaltic liquids calculated as parental to the Leg 37 basalts have CaO contents greater than 14% and indicate that the oceanic mantle is richer in CaO and Al2O3 than values used in pyrolite models for the upper mantle. A model for magma generation and eruption beneath the Mid-Atlantic Ridge embodies the following characteristics: 1. (1) Separate magma batches are generated in the mantle. 2. (2) Each of these may be erupted directly or stored at shallow depth where significant fractionation takes place. Common fractionation processes are inferred to be gravitative

  7. Chemical Elements in Mulch and Litterfall of Beech Ecosystems and Their Total Turnover

    Directory of Open Access Journals (Sweden)

    Mariyana I. Lyubenovа

    2011-07-01

    Full Text Available The beech communities on the territory of Bulgaria had been objects of regional, local as well as large scale national investigations aiming their classification, determination of their ecological characteristics, conservation status, habitats etc. They are included as objects of the intensive monitoring of forest ecosystems in Bulgaria also. The investigations of chemical content of the litter – fall in these forests were conducted until now. The novelty of the present research is investigation of these elements in the mulch and the ratio between the established quantities calculation. The main goal is the biological turnover special features characterization of the investigated elements which give us a chance to define the investigated ecosystems state and functioning. The indexes as litter – mulch and acropetal coefficients were used for this aim. The content of macroelements as N, Ca and K and microelements as Pb, Zn, Mn and Fe in soils, mulch and in different litter fall fractions have been calculated. The investigation was carried out on three sample plots. During the investigation was established that the soils are characterized with acid reaction, high content of Fe, N and Mn and low content of Ca and K. The concentration of Zn and Pb are high also. The calculated average store of investigated elements in litter – fall is 81.312 kg.ha1 and in the mulch 314 kg.ha1. According to the acropetal coefficient N is accumulated mainly in the acorns, K – in the annual phytomass fractions and Ca – in the perennial fractions. The leaves and the acorns fraction accumulate Mn, and cupolas Fe. The litter – mulch coefficient vary from 1,6 (Mn to 4,2 (Pb. The tendencies of Zn and Ca turnovers acceleration are discovered, while the turnover of more investigated elements is inhibited. The litter – mulch coefficient for Zn and Ca is 0,8 and 1,4 accordingly, i.е. corresponding to the intensive type of turnovers which is not typical for the

  8. Chemical speciation of trace transition elements and iodine in freshwater at Rokkasho

    International Nuclear Information System (INIS)

    Takaku, Yuichi; Ohtsuka, Yoshihito; Hisamatsu, Shun'ichi

    2007-01-01

    Analytical methods for physicochemical speciation of radioactive and related materials, such as lanthanide, actinide and transition metals in environmental samples, were developed to elucidate behavior of radioactive materials in the environment. An inductively coupled plasma mass spectrometer (ICP-MS) was combined with a high-performance liquid chromatographer with a size exclusion (SEC) column or capillary electrophoresis apparatus (CE). Analytical methods using SEC-ICP-MS and CE-ICP-MS were developed for speciation of transition elements and iodine in environmental water samples in fiscal year 2004. The methods were applied to freshwater samples in Rokkasho; the results are reported here. Freshwater samples were collected from two lakes and three rivers surrounding the large-scale spent nuclear fuel reprocessing plant at Rokkasho. After samples were filtered with a membrane filter with 0.45 μm of pore size, large organic molecules were concentrated 200 times using an ultrafilter with a 10 kDa cutoff size. The concentrated solution was used for molecular size analyses using the SEC-ICP-MS technique. Molecular size chromatograms of all river and lake water samples showed two peaks of UV absorptions and concentrations of all transition elements analyzed: 30 kDa and >700 kDa peaks. Ratios of the transition element concentration in 30 kDa peak to that in both peaks varied greatly depending on the element and season of sample collection. Two valence states of inorganic iodine, I - and IO 3 - , were determined separately using the CE-ICP-MS system with a standard capillary column (150 μm inner φ, 75 cm length) with 30 kV as the extraction voltage. Buffer solution of 5 mM TRIS-HNO 3 (pH 3.0) was used for mobile phase. The method was applied to lake and river water samples collected at Rokkasho. Results indicated that the chemical form of inorganic iodine in all samples was IO 3 - . Additional lake water samples were collected from Lake O-ike-higashi-ko in the Juni

  9. Contents of chemical elements in tissues of European badger (Meles meles affected by ovarian tumour – a case report

    Directory of Open Access Journals (Sweden)

    Karel Bukovjan

    2014-01-01

    Full Text Available Higher concentrations of chemical elements in animal tissues may be associated with tumours and may explain cancerogenity. In this study, selected chemical elements were measured in the liver, kidneys, muscles and tissues affected by tumour in a dead female European badger (Meles meles with a metastatic ovarian carcinoma. Atomic absorption spectroscopy was used for the assessment of concentrations of arsenic, cadmium, chromium, copper, lead, and zinc. AMA 254 analyser was used for the assessment of mercury concentration. Concentrations of heavy metals such as As, Cr, Cu, Zn, Cd, Pb, and total Hg amounted to 0.031, 0.16, 7.74, 44.54, 0.67, 0.67, and 0.36 mg·kg-1 in the tumour tissue. This is the first detection of ovarian tumour in a European badger (Meles meles which was systematically examined for the presence of chemical elements.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bilewicz, A.

    1997-12-31

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

  11. Development of a SISAK extraction system for chemical studies of element 108, hassium

    Energy Technology Data Exchange (ETDEWEB)

    Samadani, F.; Alstad, J.; Bjoernstad, T.; Stavsetra, L.; Omtvedt, J.P. [Oslo Univ. (Germany). Dept. of Chemistry

    2010-07-01

    A liquid-liquid extraction system suitable for studies of chemical properties of Hs (element 108), in the form of HsO{sub 4}, was developed using {gamma}-emitting isotopes of its homologue Os. The system is targeted for the fast on-line extraction system SISAK, which operates in a continuous manner and is suitable for liquid-phase studies of transactinide elements. The distribution of OsO{sub 4} between various dilute NaOH solutions and toluene was studied. Both batch and SISAK on-line experiments were performed to develop an appropriate system. From analysis of the extraction curves equilibrium constants for the formation of the presumed complexes, Na[OsO{sub 4}(OH)] and Na{sub 2}[OsO{sub 4}(OH){sub 2}], were obtained: K{sub 1} = (1 {+-} 0.5) x 10{sup 4} and K{sub 2} = 12 {+-} 8, respectively. The SISAK system includes a liquid-scintillation detection system for {alpha} measurements. Due to quenching effects it is not possible to perform direct measurement of the aqueous phase {alpha}'s. Therefore, a two-stage extraction method that provides an indirect measurement of the activity in the aqueous phase was developed as part of the proposed system for Hs: Acidification of the raffinate from the first stage result in recovery of OsO{sub 4}, which is highly extractable into toluene. The yield of extraction in the second step, from 0.01 M NaOH solution after acidification with H{sub 2}SO{sub 4} solution, was (90 {+-} 3)%. (orig.)

  12. Development of a SISAK extraction system for chemical studies of element 108, hassium

    International Nuclear Information System (INIS)

    Samadani, F.; Alstad, J.; Bjoernstad, T.; Stavsetra, L.; Omtvedt, J.P.

    2010-01-01

    A liquid-liquid extraction system suitable for studies of chemical properties of Hs (element 108), in the form of HsO 4 , was developed using γ-emitting isotopes of its homologue Os. The system is targeted for the fast on-line extraction system SISAK, which operates in a continuous manner and is suitable for liquid-phase studies of transactinide elements. The distribution of OsO 4 between various dilute NaOH solutions and toluene was studied. Both batch and SISAK on-line experiments were performed to develop an appropriate system. From analysis of the extraction curves equilibrium constants for the formation of the presumed complexes, Na[OsO 4 (OH)] and Na 2 [OsO 4 (OH) 2 ], were obtained: K 1 = (1 ± 0.5) x 10 4 and K 2 = 12 ± 8, respectively. The SISAK system includes a liquid-scintillation detection system for α measurements. Due to quenching effects it is not possible to perform direct measurement of the aqueous phase α's. Therefore, a two-stage extraction method that provides an indirect measurement of the activity in the aqueous phase was developed as part of the proposed system for Hs: Acidification of the raffinate from the first stage result in recovery of OsO 4 , which is highly extractable into toluene. The yield of extraction in the second step, from 0.01 M NaOH solution after acidification with H 2 SO 4 solution, was (90 ± 3)%. (orig.)

  13. Determination of chemical state of Al doping element in ZnO layer

    International Nuclear Information System (INIS)

    Csik, A.; Toth, J.; Lovics, R.; Takats, V.; Hakl, J.; Vad, K.

    2011-01-01

    Complete text of publication follows. Transparent and conducting oxides (TCO) thin films are very important from the scientific and technological point of view. The coexistence of electrical conductivity and optical transparency in these materials makes it possible to use them in modern technologies: transparent electrodes for flat panel displays and photovoltaic cells, low emissivity windows, transparent thin films transistors, light emitting diodes. One of the important TCO semiconductors is the impurity-doped zinc-oxide (ZnO) layer, for example aluminium doped zinc-oxide layer (AZO), due to its unique physical and chemical properties. It has wide band gap (3.44 eV) and large exciton binding energy (60 meV). ZnO thin layers have a great interest for potential applications in optical and optoelectronic devices. Furthermore, high quality single crystal ZnO wafers has already been available as a result of new developments in ZnO growth technologies with the capability to scale up wafer size, which is an important factor for increasing efficiency of solar cells. Nonetheless, in order to enable the use of ZnO layers with enhanced electrical properties, higher conductivities can be obtained by doping with donor elements such as aluminium, gallium, indium, boron or fluorine. Investigation of p-type doping possibilities, diffusion processes and thermal stability of these layers are in the focus of interest in the interpretation of their optical and electrical properties, and the prediction of their lifetime. In our SNMS/SIMS-XPS laboratory, experiments on TCO layered structures were carried on. Depth profile and chemical state analyses of ZnO/AlO/ZnO layered structures were performed by Secondary Neutral Mass Spectrometry (SNMS) and X-ray photoelectron spectroscopy (XPS). The samples were produced by atomic layer deposition technique with the following layered structure: between a few hundred atomic layers of ZnO was an AlO atomic layer. The SNMS was used for depth

  14. Hard X-ray Microscopy with Elemental, Chemical and Structural Contrast

    International Nuclear Information System (INIS)

    Schroer, C.G.; Boye, P.; Feldkamp, J.P.

    2010-01-01

    We review hard X-ray microscopy techniques with a focus on scanning microscopy with synchrotron radiation. Its strength compared to other microscopies is the large penetration depth of hard x rays in matter that allows one to investigate the interior of an object without destructive sample preparation. In combination with tomography, local information from inside of a specimen can be obtained, even from inside special non-ambient sample environments. Different X-ray analytical techniques can be used to produce contrast, such as X-ray absorption, fluorescence, and diffraction, to yield chemical, elemental, and structural information about the sample, respectively. This makes X-ray microscopy attractive to many fields of science, ranging from physics and chemistry to materials, geo-, and environmental science, biomedicine, and nanotechnology. Our scanning microscope based on nanofocusing refractive X-ray lenses has a routine spatial resolution of about 100 nm and supports the contrast mechanisms mentioned above. In combination with coherent X-ray diffraction imaging, the spatial resolution can be improved to the 10 nm range. The current state-of-the-art of this technique is illustrated by several examples, and future prospects of the technique are given. (author)

  15. Plant absorption of trace elements in sludge amended soils and correlation with soil chemical speciation

    Energy Technology Data Exchange (ETDEWEB)

    Torri, Silvana, E-mail: torri@agro.uba.ar [Catedra de Fertilidad y Fertilizantes, Facultad de Agronomia, UBA, Avda San Martin 4453, Buenos Aires (C1417 DSE) (Argentina); Lavado, Raul [Catedra de Fertilidad y Fertilizantes, Facultad de Agronomia, UBA, Avda San Martin 4453, Buenos Aires (C1417 DSE) (Argentina)

    2009-07-30

    The aim of the present study was to investigate the relationship between Lolium perenne L. uptake of Cd, Cu, Pb, and Zn in sludge amended soils and soil availability of these elements assessed by soil sequential extraction. A greenhouse experiment was set with three representative soils of the Pampas Region, Argentina, amended with sewage sludge and sewage sludge enriched with its own incinerated ash. After the stabilization period of 60 days, half of the pots were sampled for soil analysis; the rest of the pots were sown with L. perenne and harvested 8, 12, 16 and 20 weeks after sowing, by cutting just above the soil surface. Cadmium and Pb concentrations in aerial tissues of L. perenne were below detection limits, in good agreement with the soil fractionation study. Copper and Zn concentration in the first harvest were significantly higher in the coarse textured soil compared to the fine textured soil, in contrast with soil chemical speciation. In the third harvest, there was a positive correlation between Cu and Zn concentration in aerial biomass and soil fractions usually considered of low availability. We conclude that the most available fractions obtained by soil sequential extraction did not provide the best indicator of Cu and Zn availability to L. perenne.

  16. Plant absorption of trace elements in sludge amended soils and correlation with soil chemical speciation

    International Nuclear Information System (INIS)

    Torri, Silvana; Lavado, Raul

    2009-01-01

    The aim of the present study was to investigate the relationship between Lolium perenne L. uptake of Cd, Cu, Pb, and Zn in sludge amended soils and soil availability of these elements assessed by soil sequential extraction. A greenhouse experiment was set with three representative soils of the Pampas Region, Argentina, amended with sewage sludge and sewage sludge enriched with its own incinerated ash. After the stabilization period of 60 days, half of the pots were sampled for soil analysis; the rest of the pots were sown with L. perenne and harvested 8, 12, 16 and 20 weeks after sowing, by cutting just above the soil surface. Cadmium and Pb concentrations in aerial tissues of L. perenne were below detection limits, in good agreement with the soil fractionation study. Copper and Zn concentration in the first harvest were significantly higher in the coarse textured soil compared to the fine textured soil, in contrast with soil chemical speciation. In the third harvest, there was a positive correlation between Cu and Zn concentration in aerial biomass and soil fractions usually considered of low availability. We conclude that the most available fractions obtained by soil sequential extraction did not provide the best indicator of Cu and Zn availability to L. perenne.

  17. Selected elements and organic chemicals in bed sediment and fish tissue of the Tualatin River basin, Oregon, 1992-96

    Science.gov (United States)

    Bonn, Bernadine A.

    1999-01-01

    A variety of elements and organic compounds have entered the environment as a result of human activities. Such substances find their way to aquatic sediments from direct discharges to waterways, atmospheric emissions, and runoff. Some of these chemicals are known to harm fish or wildlife, either by direct toxicity, by reducing viability, or by limiting reproductive success. In aquatic systems, sediments become the eventual sink for most of these chemicals. Analyzing the sediments provides a first step in a chemical inventory that can lead to an assessment of potential biological impacts (Kennicutt and others, 1994).

  18. Understanding the Idea of Chemical Elements and Their Periodic Classification in Spanish Students Aged 16-18 Years

    Science.gov (United States)

    Franco-Mariscal, Antonio-Joaquín; Oliva-Martínez, José María; Almoraima Gil, M. L.

    2016-01-01

    The work reported here involved a comparative study regarding the understanding that high school students (16-18 years) have of the concept of chemical elements and their periodic classification. More specifically, the level of knowledge on this topic was compared before and after the completion of baccalaureate studies in a sample of Spanish…

  19. Bacterial Disproportionation of Elemental Sulfur Coupled to Chemical Reduction of Iron or Manganese

    Science.gov (United States)

    Thamdrup, Bo; Finster, Kai; Hansen, Jens Würgler; Bak, Friedhelm

    1993-01-01

    A new chemolithotrophic bacterial metabolism was discovered in anaerobic marine enrichment cultures. Cultures in defined medium with elemental sulfur (S0) and amorphous ferric hydroxide (FeOOH) as sole substrates showed intense formation of sulfate. Furthermore, precipitation of ferrous sulfide and pyrite was observed. The transformations were accompanied by growth of slightly curved, rod-shaped bacteria. The quantification of the products revealed that S0 was microbially disproportionated to sulfate and sulfide, as follows: 4S0 + 4H2O → SO42- + 3H2S + 2H+. Subsequent chemical reactions between the formed sulfide and the added FeOOH led to the observed precipitation of iron sulfides. Sulfate and iron sulfides were also produced when FeOOH was replaced by FeCO3. Further enrichment with manganese oxide, MnO2, instead of FeOOH yielded stable cultures which formed sulfate during concomitant reduction of MnO2 to Mn2+. Growth of small rod-shaped bacteria was observed. When incubated without MnO2, the culture did not grow but produced small amounts of SO42- and H2S at a ratio of 1:3, indicating again a disproportionation of S0. The observed microbial disproportionation of S0 only proceeds significantly in the presence of sulfide-scavenging agents such as iron and manganese compounds. The population density of bacteria capable of S0 disproportionation in the presence of FeOOH or MnO2 was high, > 104 cm-3 in coastal sediments. The metabolism offers an explanation for recent observations of anaerobic sulfide oxidation to sulfate in anoxic sediments. PMID:16348835

  20. Black poplar-tree (Populus nigra L.) bark as an alternative indicator of urban air pollution by chemical elements

    International Nuclear Information System (INIS)

    Berlizov, A.N.; Malyuk, I.A.; Tryshyn, V.V.

    2008-01-01

    Capabilities of black poplar-tree (Populus nigra L.) bark as a biomonitor of atmospheric air pollution by chemical elements were tested against epiphytic lichens Xanthoria parietina (L.) and Physcia adscendens (Fr.). Concentrations of 40 macro and trace elements were determined using epicadmium and instrumental NAA. The data obtained were processed using non-parametric tests. A good correlation was found between concentrations of majority of elements in bark and lichens. On the accumulation capability bark turned out to be competitive with both lichens examined. The main inorganic components of black poplar-tree bark were revealed. A substrate influence on the concentrations of some elements in epiphytic lichens was established. An optimized procedure of bark pre-irradiation treatment was suggested. (author)

  1. Chemical portioning and speciation of some trace elements in soil and street dust from Khartoum state, Sudan

    International Nuclear Information System (INIS)

    Ahmed, Amel Yousif

    2000-09-01

    In this study, surface soil and street dust samples were collected from Khartoum State, from areas exposed to industrial and traffic emission and from areas expected to be free from elemental emission to serve as control. Samples were digested using wet digestion method to determine the total concentration of Na, K, Cr, Mn, Fe, Cu, Zn and Pb using Atomic Absorption spectrophotometer (Aas), X-Ray fluorescence and flame photometer. Also samples were chemically fractionated using chemical specification method, and the solutions analyzed using Aas to determine the chemical form of the elements. Quality assurance of the data was achieved through the analysis of certified reference material. The range of the total concentration for Na, K, Mn, Fe, Cu, Zn and Pb are 400-5175, 220-4690, 0.07-315.25, 20-250, 2050.8-46000, 0.5-2305, 4.5-280, 9.5-6200 mg/kg respectively. results obtained agree with expected emission profile as inferred from the emitting source locations. Distribution of elements from emitting source locations and control samples in different chemical fractions was carried out, and the findings reinforced by enrichment factors calculations as well by the results obtained by statistical multi-variate analysis methods such as principle compared with previous literature.(Author)

  2. Reconstruction of centennial-scale fluxes of chemical elements in the Australian coastal environment using seagrass archives

    KAUST Repository

    Serrano, Oscar; Davis, Grace; Lavery, Paul S.; Duarte, Carlos M.; Martinez-Cortizas, Antonio; Mateo, Miguel Angel; Masqué , Pere; Arias-Ortiz, Ariane; Rozaimi, Mohammad; Kendrick, Gary A.

    2015-01-01

    The study of a Posidonia australis sedimentary archive has provided a record of changes in element concentrations (Al, Fe, Mn, Pb, Zn, Cr, Cd, Co, As, Cu, Ni and S) over the last 3000 years in the Australian marine environment. Human-derived contamination in Oyster Harbor (SW Australia) started ~. 100 years ago (AD ~. 1900) and exponentially increased until present. This appears to be related to European colonization of Australia and the subsequent impact of human activities, namely mining, coal and metal production, and extensive agriculture. Two contamination periods of different magnitude have been identified: Expansion period (EXP, AD ~. 1900-1970) and Establishment period (EST, AD ~. 1970 to present). Enrichments of chemical elements with respect to baseline concentrations (in samples older than ~. 115 cal. years BP) were found for all elements studied in both periods, except for Ni, As and S. The highest enrichment factors were obtained for the EST period (ranging from 1.3-fold increase in Cu to 7.2-fold in Zn concentrations) compared to the EXP period (1.1-fold increase for Cu and Cr to 2.4-fold increase for Pb). Zinc, Pb, Mn and Co concentrations during both periods were 2- to 7-fold higher than baseline levels. This study demonstrates the value of Posidonia mats as long-term archives of element concentrations and trends in coastal ecosystems. We also provide preliminary evidence on the potential for Posidonia meadows to act as significant long-term biogeochemical sinks of chemical elements.

  3. Reconstruction of centennial-scale fluxes of chemical elements in the Australian coastal environment using seagrass archives

    KAUST Repository

    Serrano, Oscar

    2015-10-02

    The study of a Posidonia australis sedimentary archive has provided a record of changes in element concentrations (Al, Fe, Mn, Pb, Zn, Cr, Cd, Co, As, Cu, Ni and S) over the last 3000 years in the Australian marine environment. Human-derived contamination in Oyster Harbor (SW Australia) started ~. 100 years ago (AD ~. 1900) and exponentially increased until present. This appears to be related to European colonization of Australia and the subsequent impact of human activities, namely mining, coal and metal production, and extensive agriculture. Two contamination periods of different magnitude have been identified: Expansion period (EXP, AD ~. 1900-1970) and Establishment period (EST, AD ~. 1970 to present). Enrichments of chemical elements with respect to baseline concentrations (in samples older than ~. 115 cal. years BP) were found for all elements studied in both periods, except for Ni, As and S. The highest enrichment factors were obtained for the EST period (ranging from 1.3-fold increase in Cu to 7.2-fold in Zn concentrations) compared to the EXP period (1.1-fold increase for Cu and Cr to 2.4-fold increase for Pb). Zinc, Pb, Mn and Co concentrations during both periods were 2- to 7-fold higher than baseline levels. This study demonstrates the value of Posidonia mats as long-term archives of element concentrations and trends in coastal ecosystems. We also provide preliminary evidence on the potential for Posidonia meadows to act as significant long-term biogeochemical sinks of chemical elements.

  4. Sampling procedure in a willow plantation for chemical elements important for biomass combustion quality

    DEFF Research Database (Denmark)

    Liu, Na; Nielsen, Henrik Kofoed; Jørgensen, Uffe

    2015-01-01

    clone ‘Tordis’, and to reveal the relationship between sampling position, shoot diameters, and distribution of elements. Five Tordis willow shoots were cut into 10–50 cm sections from base to top. The ash content and concentration of twelve elements (Al, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, P, Si, and Zn......Willow (Salix spp.) is expected to contribute significantly to the woody bioenergy system in the future, so more information on how to sample the quality of the willow biomass is needed. The objectives of this study were to investigate the spatial variation of elements within shoots of a willow......) in each section were determined. The results showed large spatial variation in the distribution of most elements along the length of the willow shoots. Concentrations of elements in 2-year old shoots of the willow clone Tordis were fairly stable within the range of 100–285 cm above ground and resembled...

  5. Instrumental Neutron Activation Analysis applied to the study of chemical element accumulation in organs of Rhinella schneideri (Werner, 1894)

    Energy Technology Data Exchange (ETDEWEB)

    Bardini Junior, Claudiney; Fernandes, Elisabete A. de Nadai, E-mail: lis@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Santos, Katarine M. Barbosa; Silva Neto, Luiz J. da; Santos, Robson A. dos; Silva, Karolayne E.M.; França, Elvis J. de, E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciências Nucleares do Nordeste (DIAMB/CRCN-NE/CNEN-PE), Recife, PE (Brazil). Div. de Monitoração Ambiental

    2017-07-01

    Instrumental Neutron Activation Analysis (INAA) is a multielementar technique with high sensitivity, and can be applied to study small samples. Therefore, this research proposes using the INAA for quantifying the accumulation of chemical elements in organs of anuran amphibians Rhinella schneideri (Werner, 1894). Male individuals were collected on areas with anthropogenic influence close to water resources on the campus of ESALQ/USP in 2009. The animals were sacrificed in a cold chamber and dissected to separate their kidneys, livers, lungs and skins. After cleaning, the organs were lyophilized and pulverized. Samples weighing from 200 to 500 mg were placed in polyethylene capsules to be irradiated. The INAA technique, based on the bombardment of samples with neutrons for the production of radionuclides, was applied using the Nuclear Research Reactor of the Nuclear and Energy Research Institute. Portions of certified reference materials were used to evaluate the quality of the analytical procedure. The mass fractions were quantified by the k0 method, and the results indicated differences among the As, Br, Co, Cr, Fe, Hg, Sc, Se and Zn concentrations in the analyzed organs. Therefore, it was possible to calculate the bioaccumulation indexes relative to these chemical elements for the species. In addition, it was possible to infer the contamination pathways: As, Br, Co, Cr and Se by ingestion and Co, Fe, Hg, Sc and Zn by contact, which corroborated the usage of R. schneideri anuran as a biomonitor of chemical elements. (author)

  6. Determination of chemical elements in africanized Apis mellifera (Hymenoptera: Apidae honey samples from the State of Piauí, Brazil

    Directory of Open Access Journals (Sweden)

    Geni da Silva Sodré

    2007-08-01

    Full Text Available Honey is a food used since the most remote times, appreciated for its characteristic flavor, considerable nutritional value and medicinal properties; however, little information exists about the presence of chemical elements in it. The objectives of this work were to determine the chemical elements present in 38 honey samples, collected directly from beekeepers from the State of Piauí, Brazil and to verify whether they presented any contamination. The chemical elements were determined by means of Total Reflection X-ray Fluorescence. The means of three replicates were: K (109.671 ± 17.487, Ca (14.471 ± 3.8797, Ti (0.112 ± 0.07, Cr (0.196 ± 0.11, Mn (0.493 ± 0.103, Fe (1.722 ± 0.446, Co (0.038, Ni (0.728 ± 0.706, Cu (0.179 ± 0.0471, Zn (0.967 ± 0.653, Se (not detected, Br (not detected, Rb (0.371 ± 0.097, Sr (0.145 ± 0.45, Ba (11.681, Hg (not detected, and Pb (0.863 µg g-1.

  7. Total reflection X-ray fluorescence applied to the chemical elements analysis of the mate tea infusion (Ilex-paraguariensis)

    International Nuclear Information System (INIS)

    Lopes, Fabio; Appoloni, Carlos R.; Cunha, Richard M. da Silva e; Nascimento Filho, Virgilio Franco do

    2002-01-01

    The purpose was to evaluate simultaneously the chemical element concentrations from K to Sr (19≤Z≤38) range in six samples of mate tea (Ilex paraguariensis) infusion, commercially available in Paraguay and South of Brazil. The chemical analysis of this beverage has a great nutritional importance for the native people of these areas, due to their large daily consumption. For the determination of these elements the dry-ashing and total reflection X-rays fluorescence (TXRF) were used. The methodology showed limits of detection among 81 ng.mL-1 for K to 10 ng.mL -1 for Zn. Six infusion samples were prepared in triplicate, and the concentration was 3,8 to 10,2 μg.mL -1 for K, Ca and Mn, 0,21 to 1,07 μg. mL -1 for Fe and Zn and 0.03 to 0,17 μg.mL -1 for Ni, Cu, Br, Rb and Sr. The Mn and Ni concentrations are above the maximum permissible values for drinking water established by World Health Organization and Brazilian legislation (these organisms do not regulate the maximum permissible values for chemical elements in mate tea infusion). (author)

  8. Instrumental Neutron Activation Analysis applied to the study of chemical element accumulation in organs of Rhinella schneideri (Werner, 1894)

    International Nuclear Information System (INIS)

    Bardini Junior, Claudiney; Fernandes, Elisabete A. de Nadai; Santos, Katarine M. Barbosa; Silva Neto, Luiz J. da; Santos, Robson A. dos; Silva, Karolayne E.M.; França, Elvis J. de

    2017-01-01

    Instrumental Neutron Activation Analysis (INAA) is a multielementar technique with high sensitivity, and can be applied to study small samples. Therefore, this research proposes using the INAA for quantifying the accumulation of chemical elements in organs of anuran amphibians Rhinella schneideri (Werner, 1894). Male individuals were collected on areas with anthropogenic influence close to water resources on the campus of ESALQ/USP in 2009. The animals were sacrificed in a cold chamber and dissected to separate their kidneys, livers, lungs and skins. After cleaning, the organs were lyophilized and pulverized. Samples weighing from 200 to 500 mg were placed in polyethylene capsules to be irradiated. The INAA technique, based on the bombardment of samples with neutrons for the production of radionuclides, was applied using the Nuclear Research Reactor of the Nuclear and Energy Research Institute. Portions of certified reference materials were used to evaluate the quality of the analytical procedure. The mass fractions were quantified by the k0 method, and the results indicated differences among the As, Br, Co, Cr, Fe, Hg, Sc, Se and Zn concentrations in the analyzed organs. Therefore, it was possible to calculate the bioaccumulation indexes relative to these chemical elements for the species. In addition, it was possible to infer the contamination pathways: As, Br, Co, Cr and Se by ingestion and Co, Fe, Hg, Sc and Zn by contact, which corroborated the usage of R. schneideri anuran as a biomonitor of chemical elements. (author)

  9. A Colorful Demonstration to Visualize and Inquire into Essential Elements of Chemical Equilibrium

    Science.gov (United States)

    Eilks, Ingo; Gulacar, Ozcan

    2016-01-01

    One of the topics that chemistry teachers have a great challenge introducing is chemical equilibrium. When being introduced to chemical equilibrium, many students have difficulties in understanding that some reactions do not go to completion, as this contrasts most of their supposed prior experiences in chemistry lessons. Students may also…

  10. Gas phase chemical studies of superheavy elements using the Dubna gas-filled recoil separator - Stopping range determination

    International Nuclear Information System (INIS)

    Wittwer, D.; Abdullin, F.Sh.; Aksenov, N.V.; Albin, Yu.V.; Bozhikov, G.A.; Dmitriev, S.N.; Dressler, R.; Eichler, R.; Gaeggeler, H.W.; Henderson, R.A.; Huebener, S.; Kenneally, J.M.; Lebedev, V.Ya.; Lobanov, Yu.V.; Moody, K.J.; Oganessian, Yu.Ts.; Petrushkin, O.V.; Polyakov, A.N.; Piguet, D.; Rasmussen, P.

    2010-01-01

    Currently, gas phase chemistry experiments with heaviest elements are usually performed with the gas-jet technique with the disadvantage that all reaction products are collected in a gas-filled thermalisation chamber adjacent to the target. The incorporation of a physical preseparation device between target and collection chamber opens up the perspective to perform new chemical studies. But this approach requires detailed knowledge of the stopping force (STF) of the heaviest elements in various materials. Measurements of the energy loss of mercury (Hg), radon (Rn), and nobelium (No) in Mylar and argon (Ar) were performed at low kinetic energies of around (40-270) keV per nucleon. The experimentally obtained values were compared with STF calculations of the commonly used program for calculating stopping and ranges of ions in matter (SRIM). Using the obtained data points an extrapolation of the STF up to element 114, eka-lead, in the same stopping media was carried out. These estimations were applied to design and to perform a first chemical experiment with a superheavy element behind a physical preseparator using the nuclear fusion reaction 244 Pu( 48 Ca; 3n) 289 114. One decay chain assigned to an atom of 285 112, the α-decay product of 289 114, was observed.

  11. An assessment study in the determination of chemical elements in sediments and fish in the Zarka River and King Talal Dam, Jordan

    International Nuclear Information System (INIS)

    Alsabbagh, A.; Khalayleh, L.; Dbissi, M.; Landsberger, S.

    2017-01-01

    Concentrations of several trace elements were detected in the sediments at King Talal Dam and at different locations along the Zarka River, Jordan. Chemical elements were also detected in the edible part of common fish types existing at the dam. Elemental concentrations were determined using neutron activation analysis (NAA). The results showed that the concentration of chemical elements in the sediments decreases as one moves away from the Khirbet Al Samra waste water treatment plant. The results also revealed that most of the elements had higher concentrations in Tilapia fish compared to the Catfish. (author)

  12. Trace-element analysis of Antarctic H chondrites: Chemical weathering and comparisons with their non-Antarctic counterparts

    International Nuclear Information System (INIS)

    Kwok, J.E.

    1986-01-01

    Large numbers of meteorites have been discovered in Antarctica over the last decade (7000 fragments probably representing over 1200 separate events). They are important for their numbers and for their complement of unique or rare specimens; they also have long terrestrial ages (up to 1,000,000 years) compared to non-Antarctic falls (usually < 200 years). We report compositional data for mobile/volatile trace elements Ag, Au, Bi, Cd, Co, Cs, In, Rb, Sb, Se, Te, Ti, U, and Zn in a suite of Antarctic H chondrites. Our data show that heavily oxidized H chondrites are leached of a portion of their trace elements and, therefore, have been chemically compromised by their stay in Antarctica. The less oxidized specimens seem to have retained their chemical integrity. We suggest possibilities for using chemical data to measure the degree of a chondrite's chemical weathering. We compare our data to that obtained previously for non-Antarctic H chondrites (Linger et al., 1986), by petrologic type (H4, H5, H6, H4-6) and shock-loading (moderately shocked facies a-c, heavily shocked facies d-f). Many statistically significant differences are found between non-Antarctic and Victoria Land, Antarctica H chondrites of each petrologic type and of shock facies d-f

  13. Simultaneous speciation of trace elements using chemical separation and neutron activation

    International Nuclear Information System (INIS)

    Chatt, A.

    2003-01-01

    Speciation neutron activation analysis (SNAA) is a sophisticated analytical technique which can be developed for studying the simultaneous speciation of a number of elements in a variety of matrices. The advantages of SNAA are demonstrated with typical examples such as (i) arsenic speciation in sea foods and water, and simultaneous speciation of (ii) arsenic, antimony and selenium in water, (iii) chlorine, bromine and iodine in fish, (iv) lanthanides in simulated vitrified waste, and (v) trace elements bound to proteins. (author)

  14. Finite element modeling of contaminant transport in soils including the effect of chemical reactions.

    Science.gov (United States)

    Javadi, A A; Al-Najjar, M M

    2007-05-17

    The movement of chemicals through soils to the groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. Recent studies have shown that the current models and methods are not able to adequately describe the leaching of nutrients through soils, often underestimating the risk of groundwater contamination by surface-applied chemicals, and overestimating the concentration of resident solutes. Furthermore, the effect of chemical reactions on the fate and transport of contaminants is not included in many of the existing numerical models for contaminant transport. In this paper a numerical model is presented for simulation of the flow of water and air and contaminant transport through unsaturated soils with the main focus being on the effects of chemical reactions. The governing equations of miscible contaminant transport including advection, dispersion-diffusion and adsorption effects together with the effect of chemical reactions are presented. The mathematical framework and the numerical implementation of the model are described in detail. The model is validated by application to a number of test cases from the literature and is then applied to the simulation of a physical model test involving transport of contaminants in a block of soil with particular reference to the effects of chemical reactions. Comparison of the results of the numerical model with the experimental results shows that the model is capable of predicting the effects of chemical reactions with very high accuracy. The importance of consideration of the effects of chemical reactions is highlighted.

  15. 18 Sco: A solar twin rich in refractory and neutron-capture elements. Implications for chemical tagging

    Energy Technology Data Exchange (ETDEWEB)

    Meléndez, Jorge; Monroe, TalaWanda R.; Tucci Maia, Marcelo; Freitas, Fabrício C. [Departamento de Astronomia do IAG/USP, Universidade de São Paulo, Rua do Matão 1226, 05508-900 São Paulo, SP (Brazil); Ramírez, Iván [McDonald Observatory and Department of Astronomy, University of Texas at Austin (United States); Karakas, Amanda I.; Yong, David; Asplund, Martin [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT 2611 (Australia); Bedell, Megan; Bean, Jacob [Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Bergemann, Maria [Institute of Astronomy, University of Cambridge, Madingley Road, CB3 0HA, Cambridge (United Kingdom); Do Nascimento, José-Dias Jr.; Castro, Matthieu [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN (Brazil); Bazot, Michael [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Alves-Brito, Alan, E-mail: jorge.melendez@iag.usp.br [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, Porto Alegre, RS (Brazil)

    2014-08-10

    We study with unprecedented detail the chemical composition and stellar parameters of the solar twin 18 Sco in a strictly differential sense relative to the Sun. Our study is mainly based on high-resolution (R ∼ 110,000), high signal-to-noise ratio (800-1,000) Very Large Telescope UVES spectra, which allow us to achieve a precision of about 0.005 dex in differential abundances. The effective temperature and surface gravity of 18 Sco are T{sub eff} = 5823 ± 6 K and log g = 4.45 ± 0.02 dex, i.e., 18 Sco is 46 ± 6 K hotter than the Sun and log g is 0.01 ± 0.02 dex higher. Its metallicity is [Fe/H] = 0.054 ± 0.005 dex, and its microturbulence velocity is +0.02 ± 0.01 km s{sup –1} higher than solar. Our precise stellar parameters and differential isochrone analysis show that 18 Sco has a mass of 1.04 ± 0.02 M{sub ☉} and that it is ∼1.6 Gyr younger than the Sun. We use precise High Accuracy Radial velocity Planet Searcher (HARPS) radial velocities to search for planets, but none are detected. The chemical abundance pattern of 18 Sco displays a clear trend with condensation temperature, thus showing higher abundances of refractories in 18 Sco than in the Sun. Intriguingly, there are enhancements in the neutron-capture elements relative to the Sun. Despite the small element-to-element abundance differences among nearby n-capture elements (∼0.02 dex), we successfully reproduce the r-process pattern in the Solar System. This is independent evidence for the universality of the r process. Our results have important implications for chemical tagging in our Galaxy and nucleosynthesis in general.

  16. Fractionation of chemical elements including the REEs and 226Ra in stream contaminated with coal-mine effluent

    International Nuclear Information System (INIS)

    Centeno, L.M.; Faure, G.; Lee, G.; Talnagi, J.

    2004-01-01

    Water draining from abandoned open-pit coal mines in southeastern Ohio typically has a low pH and high concentrations of Fe, Al and Mn, as well as of trace metals (Pb, Cu, Zn, Ni, Co, etc.) and of the rare earth elements (REEs). The cations of different elements are sorbed selectively by Fe and Al hydroxide precipitates which form with increasing pH. As a result, the trace elements are separated from each other when the hydroxide precipitates are deposited in the channel of a flowing stream. Therefore, the low-energy environment of a stream contaminated by mine effluent is a favorable site for the chemical fractionation of the REEs and of other groups of elements with similar chemical properties. The interpretation of chemical analyses of water collected along a 30-km-stretch of Rush Creek near the town of New Lexington, Perry County, Ohio, indicates that the abundances of the REEs in the water appear to change downstream when they are normalized to the REE concentrations of the mine effluent. In addition, the Ce/La ratios (and those of all REEs) in the water decrease consistently downstream. The evidence indicates that the REEs which remain in solution are enriched La and Ce because the other REEs are sorbed more efficiently. The solid Fe(OH) 3 precipitates in the channel of Rush Creek upstream of New Lexington also contain radioactive 226 Ra that was sorbed from the water. This isotope of Ra is a decay product of 238 U which occurs in the Middle Pennsylvanian (Upper Carboniferous) coal and in the associated shale of southeastern Ohio. The activity of 226 Ra of the Fe(OH) 3 precipitates increases with rising pH, but then declines farther downstream as the concentration of Ra remaining in the water decreases

  17. Chemical elements in soils of riverside areas of the Piracicaba river basin, São Paulo, Brazil

    International Nuclear Information System (INIS)

    França, Elvis J.; Lira, Marcelo B.G.; Paiva, José D.S.; Fernandes, Elisabete A. de N.; Fonseca, Felipe Y.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O.; Camilli, Leandro

    2017-01-01

    The monitoring of the soil quality of the Piracicaba River Basin, located in the State of São Paulo, is of extreme environmental importance, as it ensures the functionality of the basin ecosystems and environmental protection. However, there are few studies focused on the concentration of chemical elements in soils of environmental protection zones of highly populated riverside regions. In view of the above, this work aims to determine the concentration of chemical elements in the soils located on the banks of the Piracicaba River by the Instrumental Neutronic Activation Analysis - INAA. Soil samples were collected in the 0-5 cm, 5-10 cm and 10-15 cm profiles. Subsequently, the samples were dried in an oven at 80 deg C and comminuted with the aid of mortar and pistil. 250 mg portions were transferred to polyethylene capsules and irradiated in 10 13 cm -2 .s -1 neutron flux for 4 hours at the IEA-R1 Nuclear Research Reactor of the Nuclear and Energy Research Institute -IPEN / SP, Brazil. The determination of the chemical elements was conducted by the k0-INAA method from the Quantu program. Comparing the results obtained with the soil values of an untouched area of Atlantic Forest - Carlos Botelho State Park, the maximum values obtained of As (29 mg / kg) and Zn (185 mg / kg) were about 5 times greater. However, concentrations of terrigenous elements such as Fe and Sc were also high in some cases, indicating that there is also a contribution of the source material (rocks) to the high concentrations observed in the riverside soils

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

    International Nuclear Information System (INIS)

    Sanches, Thalita Pinheiro; Saiki, Mitiko

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    Sanches, Thalita Pinheiro

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  1. Mapping chemical elements on the surface of orthodontic appliance by SEM-EDX.

    Science.gov (United States)

    Mikulewicz, Marcin; Wołowiec, Paulina; Michalak, Izabela; Chojnacka, Katarzyna; Czopor, Wojciech; Berniczei-Royko, Adam; Vegh, Andras; Gedrange, Thomas

    2014-05-25

    During orthodontic treatment, the various elements that constitute the fixed appliance undergo different processes. As a result of a change of the surface, elution/coverage of metals on the surface can be observed in the process of corrosion/passivation. Scanning electron microscopy with an energy-dispersive X-ray analytical system (SEM-EDX) was used to analyze the composition of stainless steel elements of orthodontic fixed appliances (before and after orthodontic treatment), to obtain the composition of the surface of the elements. The analyzed elements were: brackets (Victory Series APC PLUS 022, 3M Unitek, Monrovia, CA, USA); wires (0.017×0.025, 3M Unitek, Monrovia, CA, USA); and bands (37+, 3M Unitek, Monrovia, CA, USA). The results showed a decrease of chromium and iron contribution to the surface, with increase of oxygen content in used vs. new elements of the appliance. Our results confirm the formation of oxides (passivation layer) on the surface of stainless steel as a result of the presence of the orthodontic appliance in patients' oral cavities.

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

    Directory of Open Access Journals (Sweden)

    Changyi Shi

    2011-04-01

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

  3. Nipponium, the element ascribable to rhenium from the modern chemical viewpoint

    Energy Technology Data Exchange (ETDEWEB)

    Yoshihara, H.K. [Japan Isotope Data Inst., Sendai (Japan)

    1997-11-01

    Though the discovery of nipponium by Ogawa in 1908 was judged to be false and his work was forgotten for many years, the new element he believed to have found should be ascribed to rhenium (z = 75) by the following reasons: (1) the spectral line of 4882 A agrees well with the present data of rhenium, (2) recalculation of the atomic weight of the element supports the value in the neighbourhood of 185 which is very close to the present value 186.2 of rhenium, and (3) rhenium is actually present in Japanese molybdenite he studied. Therefore, it is concluded that his discovery of the `new` element was correct, but assignment of z = 43 was wrong. (orig.)

  4. Study of the physico-chemical behavior of transuranian elements in radioactive waste repositories

    International Nuclear Information System (INIS)

    Vitorge, P.; Billon, A.; Dautel, C.; Michau, O.; Quevrin, M.; Delorme, P.; Berthoud, T.; Mauchien, P.

    1986-01-01

    Transuranian chemistry is being studied in the geochemical context of the geological disposal of radioactive waste. The transuranians considered are plutonium, neptunium and americium. The first part, devoted to the chemistry of these elements in aqueous solutions, consists of a critical compilation of literature data with a view to resulting in producing the E h -pH diagrams of transuranians in a complexing environment. The study of the retention by constituents of artificial clay barriers (bentonite and attapulgite) is the subject of the second part. The third part concerns the development of a measurement technique for transuranian elements at trace levels by the thermal lensing method

  5. Mineralogy and chemical composition and distribution of rare earth elements of clay-rich sediments, Central Uganda

    International Nuclear Information System (INIS)

    Nyakairu, G.W.A.

    2001-02-01

    In Uganda, Precambrian rocks are extensively weathered to sediments, which are locally altered to form considerable clay deposits. Clay-rich sediment samples were collected from the Kajjansi, Kitiko, Kitetika, and Ntawo valleys (central Uganda), all of which are currently used for traditional brick, tile, and pottery manufacture. The mineralogical and chemical characteristics, and source rocks of these clay-rich sediments is not well understood. A study using modern analytical techniques, such as XRD, to obtain the bulk mineralogical composition, and XRF and INAA analyses for whole rock major and trace element abundances was performed. The results show that the sediments are dominated by kaolinite and quartz, and minor phases include smectite, chlorite, and illite/muscovite. Whole rock chemistry shows that sediment samples rich in SiO2 have low Al, Fe, Sc and Cr contents. The high chemical index of alteration (CIA) values (87 to 96), chemical index of weathering (CIW) values around 98 and low contents of the alkali and alkali earth elements of the clay-rich sediments suggest a relatively more intense weathering source area. The clay-rich sediments as raw materials for industry were classified as silty clays from grain size analysis. The chemical and mineralogical composition results show that, taken as a whole, the clay-rich sediments possess characteristics satisfactory for brick production. The chondrite-normalized rare earth elements (REE) patterns of the clay-rich sediments show LREE enrichments and a negative Eu anomaly. The high chondrite-normalized La/Yb ratios, and Gd/Yb ratios lower than 2.0, confirm that the sediments are enriched in the LREEs. The mineralogical composition, REE contents, and elemental ratios in these sediments suggest a provenance from mainly felsic rocks, with only minor contributions from basic sources. The basic sediments were most likely derived from metasedimentary rocks, such as muscovite-biotite schists, which are characteristic

  6. Speciation of trace elements in biological samples by nuclear analytical and related techniques coupled with chemical and biochemical separation

    International Nuclear Information System (INIS)

    Chen, C.Y.; Gao, Y.X.; Li, B.; Yu, H.W.; Li, Y.F.; Sun, J.; Chai, Z.F.

    2005-01-01

    In the past, most analytical problems relating to biological systems were addressed by measuring the total concentrations of elements. Now there is increasing interest of the importance of their chemical forms, in which an element is present in biological systems, e.g., the oxidation state, the binding state with macromolecules, or even the molecular structure. The biological effects of chromium, which is classified as an essential nutrient, are dependent upon its oxidation. state. In general, trivalent chromium is biochemically active, whereas hexavalent chromium is considered to be toxic. Mercury is one of serious environmental persistent pollutants. However, organic forms of mercury are known to possess much higher toxicity than inorganic mercury. Therefore, information on speciation is critically required in order to better understanding of their bioavailability, metabolism, transformation, and toxicity in vivo. Recently, chemical speciation of selenium, mercury, copper, zinc, iron, and so on, has been investigated by INAA, ICP-MS, XRF, EXAFS and related techniques combined with chemical and biochemical separation (extraction, chromatography, gel electrophoresis, etc.). INAA, XRF, and ICP-MS have superior advantages in aspect of multielemental analysis with high accuracy and sensitivity, which render the possibility of analyzing various elements of interest simultaneously. These offline or online techniques have been flexibly applied to different biological matrixes, such as human hair, serum, urine, various tissues and organs in our researches. In addition, EXAFS provides structural information about the moiety of metal centers up to a distance of approximately 4-5 Anstrom. For instance, hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Imbalance of elements, such as Se, Zn, Fe, Cu, Cd, Ca, etc., has been found in the whole blood or serum of patients with HCC. We found that the profiles of Se, Cd, Fe, Zn and Cu-containing proteins

  7. An x ray scatter approach for non-destructive chemical analysis of low atomic numbered elements

    Science.gov (United States)

    Ross, H. Richard

    1993-01-01

    A non-destructive x-ray scatter (XRS) approach has been developed, along with a rapid atomic scatter algorithm for the detection and analysis of low atomic-numbered elements in solids, powders, and liquids. The present method of energy dispersive x-ray fluorescence spectroscopy (EDXRF) makes the analysis of light elements (i.e., less than sodium; less than 11) extremely difficult. Detection and measurement become progressively worse as atomic numbers become smaller, due to a competing process called 'Auger Emission', which reduces fluorescent intensity, coupled with the high mass absorption coefficients exhibited by low energy x-rays, the detection and determination of low atomic-numbered elements by x-ray spectrometry is limited. However, an indirect approach based on the intensity ratio of Compton and Rayleigh scattered has been used to define light element components in alloys, plastics and other materials. This XRS technique provides qualitative and quantitative information about the overall constituents of a variety of samples.

  8. A sampling strategy for estimating plot average annual fluxes of chemical elements from forest soils

    NARCIS (Netherlands)

    Brus, D.J.; Gruijter, de J.J.; Vries, de W.

    2010-01-01

    A sampling strategy for estimating spatially averaged annual element leaching fluxes from forest soils is presented and tested in three Dutch forest monitoring plots. In this method sampling locations and times (days) are selected by probability sampling. Sampling locations were selected by

  9. 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 combus...

  10. Periodic Table Target: A Game that Introduces the Biological Significance of Chemical Element Periodicity

    Science.gov (United States)

    Sevcik, Richard S.; McGinty, Ragan L.; Schultz, Linda D.; Alexander, Susan V.

    2008-01-01

    Periodic Table Target, a game for middle school or high school students, familiarizes students with the form of the periodic table and the biological significance of different elements. The Periodic Table Target game board is constructed as a class project, and the game is played to reinforce the content. Students are assigned several elements…

  11. Bacterial disproportionation of elemental sulfur coupled to chemical reduction of iron or manganese

    DEFF Research Database (Denmark)

    Thamdrup, Bo; Finster, Kai; Hansen, Jens Würgler

    1993-01-01

    A new chemolithotrophic bacterial metabolism was discovered in anaerobic marine enrichment cultures. Cultures in defined medium with elemental sulfur (S) and amorphous ferric hydroxide (FeOOH) as sole substrates showed intense formation of sulfate. Furthermore, precipitation of ferrous sulfide an...

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

    Czech Academy of Sciences Publication Activity Database

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

    2011-01-01

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

  13. Elemental chemical characterization of coins of currently national circulating by X-ray fluorescence non-destructive techniques

    International Nuclear Information System (INIS)

    Olivera, Paula; Calcina, Esly

    2013-01-01

    Given the frequent counterfeit bills and coins is proposed in this paper to identify the elemental chemical composition; for now, the current official currencies circulating in our country, by Energy Dispersive X-ray Fluorescence technique and non-destructive methods, the goal is to compare with the false and establish the differences that could help identify them immediately taking advantage of the fast response of this technique. Have been identified the elements Al in the coins of 5 cents, Cu and Zn for 10 and 20 cents, Ni, Cu and Zn for 50 cents and a Un Nuevo Sol and Cr, Cu and Zn 2 coins 5 Nuevos Soles. 57 Peruvian coins of different production years and a counterfeit coin of 5 Nuevos Soles have been analyzed, finding Cu and Zn in central part and Fe in circulating edge ring, looking for this one the absence of Ni and Cr, which in the official currency was found. (authors).

  14. Chemical evolution with rotating massive star yields - I. The solar neighbourhood and the s-process elements

    Science.gov (United States)

    Prantzos, N.; Abia, C.; Limongi, M.; Chieffi, A.; Cristallo, S.

    2018-05-01

    We present a comprehensive study of the abundance evolution of the elements from H to U in the Milky Way halo and local disc. We use a consistent chemical evolution model, metallicity-dependent isotopic yields from low and intermediate mass stars and yields from massive stars which include, for the first time, the combined effect of metallicity, mass loss, and rotation for a large grid of stellar masses and for all stages of stellar evolution. The yields of massive stars are weighted by a metallicity-dependent function of the rotational velocities, constrained by observations as to obtain a primary-like 14N behaviour at low metallicity and to avoid overproduction of s-elements at intermediate metallicities. We show that the Solar system isotopic composition can be reproduced to better than a factor of 2 for isotopes up to the Fe-peak, and at the 10 per cent level for most pure s-isotopes, both light ones (resulting from the weak s-process in rotating massive stars) and the heavy ones (resulting from the main s-process in low and intermediate mass stars). We conclude that the light element primary process (LEPP), invoked to explain the apparent abundance deficiency of the s-elements with A values of ^{12}C/^{13}C in halo red giants, which is rather due to internal processes in those stars.

  15. Effect of Gamma Irradiation Doses and Micro Elements on Some Physical, Chemical and Crop Parameters of Vigna sinensis

    International Nuclear Information System (INIS)

    Hussein, L.O.S.; Saleh, O.I.; Abdullah, M.I.

    2011-01-01

    The present work aim to expose Vigna sinensis L. (cowpea) seeds to gamma rays at dose levels 40, 80 and 120 Gy and to spray the growing plants with micro elements; boron (B) and zinc (Zn) after one month of planting; until harvest date, for increasing crop quality and quantity. Some physical parameters, some chemical analysis, the yield and net percentage of the produced crop were evaluated. The result obtained refer that, the 40 Gy dose enhanced most of physical, chemical and yield parameters of cowpea crop. Moreover, the harvested crop was increased and improved in case of those produced from plants sprayed with different concentrations of B or Zn plus 40 Gy dose as compared with the other treatments used followed by the dose of 80 Gy. Meanwhile, the dose of 120 Gy gave the least enhancement on the quality and quantity of the aforementioned treatments in cowpea crop

  16. Physical-chemical studies of transuranium elements: Progress report for the period April 1, 1985-March 31, 1988

    International Nuclear Information System (INIS)

    Peterson, J.R.

    1987-01-01

    New knowledge is being accumulated in the role of the 5f electrons in the bonding in actinide elements and compounds, the relationships of metallic structures to metallic valence and radius, the extent and magnitude of the actinide contraction, the magnetic, thermodynamic, spectroscopic, and crystallographic properties of these materials as related to general theories, the effect of self-irradiation on chemical and physical properties, the chemical and physical consequences of radioactive decay in the bulk-phase solid state, and in general, the range of validity of the actinide hypothesis. Separate reports are given on: spectrophotometric studies of Cf(III) ions in lanthanide trihalide hosts, new ternary transplutonium chalcogenide halides, Raman spectrometric studies of lanthanide trihalides as function of T or P, and solution calorimetry of californium halides

  17. Chemical evolution of soil profile from humid regions: The role of the rare elements

    Directory of Open Access Journals (Sweden)

    Yu.N. Vodyanitskii

    2016-06-01

    Full Text Available Eluvial-illuvial distribution of rare metals in forest soils is expressed more vividly than the distribution of Fe and Al the more. This is applies primarily to lanthanides: Y, La, Ce. In particular, this difference is noticeable in light Al–Fe-humus podzols, where highly differentiated elements of platinum group. The type of metals exposed to eluvial-illuvial distribution depends on the mineralogical composition of the parent rock and has a pronounced regional dimension.

  18. Biorefine: Recovery of nutrients and metallic trace elements from different wastes by chemical and biochemical processes

    OpenAIRE

    Tarayre, Cédric; Fischer, Christophe; De Clercq, Lies; Michels, Evi; Meers, Erik; Buysse, Jeroen; Delvigne, Frank; Thonart, Philippe

    2014-01-01

    At present, most waste processing operations are not oriented towards the valorization of valuable reusable components such as nitrogen, phosphorus, potassium and even Metallic Trace Elements (MTEs). Currently, sewage sludge, for example is usually used as a fertilizer in agriculture, in energy production or in the field of construction. Ashes originating from sludge incineration contain heavy metals and minerals in large quantities. Manure is mainly used in agriculture, although considerable...

  19. Evaluation of chemical elements migration from food packaging plastics into food

    International Nuclear Information System (INIS)

    Kamiya, Adriana M.; Fulfaro, Roberto; Saiki, Mitiko

    2000-01-01

    This work presents results of As, Cd, Co, Cr, Sb, Se, Sn, and Zn obtained in the analysis of plastics from food packing materials by instrumental neutron activation analysis. The radiometric method was also applied to evaluate the migration of Co and Sb from the plastic into the food simulant. The possible sources of the toxic elements in plastic materials and the advantages of radiometric method in the migration evaluation are discussed. (author)

  20. Chemical elements in common vegetable components of Portuguese diets, determined by k 0-INAA

    International Nuclear Information System (INIS)

    Pacheco, A.M.G.; Freitas, M.C.; Ventura, M.G.; Dionisio, I.; Ermakova, E.

    2006-01-01

    Vegetables play an important role in national diets, as a side dish to many a main-course fare the whole year round, and, especially in what concerns raw lettuce and tomato, with a higher seasonal rate of consumption during summer months, as associated to the traditional charcoal-grilled sardines. In March 2004, lettuces, tomatoes, carrots and cabbages of Portuguese origin (except for the carrots from one site) were purchased from large commercial areas or central markets of two central and southern regional hubs, respectively Coimbra and Evora. Even if from different growers, all vegetables had come from horticultural plots in the same general area of western Portugal, north of Lisboa. For lettuce plants, the inner leaves were separated from the external ones and processed as different samples for further analysis. In this work, the reactor and detector parameters were re-evaluated for the new IAEA k 0 -INAA software. Quality assessment was obtained through analysis of IAEA-359 (cabbage material) and BCR-679 (Bowen's kale). Traces of hazardous elements-namely, antimony, arsenic and bromine-could be found throughout, and, for lettuce samples, the overall results indicate that outer leaves feature higher concentrations than inner ones. Interestingly enough, vegetables from Coimbra and Evora appeared to differ from each other in their elemental levels, even if originally grown at relatively close range. Concentrations of trace elements are compared to available data from other countries' cultivars

  1. Ab initio quantum chemical calculations of the interaction between radioactive elements and imidazolium based ionic liquids

    Science.gov (United States)

    Saravanan, A. V. Sai; Abishek, B.; Anantharaj, R.

    2018-04-01

    The fundamental natures of the molecular level interaction and charge transfer between specific radioactive elements and ionic liquids of 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([BMIM]+[NTf2]-), 1-Butyl-3-methylimidazolium ethylsulfate ([BMIM]+[ES]-) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]+[BF4]-) were investigated utilising HF theory and B3LYP hybrid DFT. The ambiguity in reaction mechanism of the interacting species dictates to employ Effective Core Potential (ECP) basis sets such as UGBS, SDD, and SDDAll to account for the relativistic effects of deep core electrons in the system involving potential, heavy and hazardous radioactive elements present in nuclear waste. The SCF energy convergence of each system validates the characterisation of the molecular orbitals as a linear combination of atomic orbitals utilising fixed MO coefficients and the optimized geometry of each system is visualised based on which Mulliken partial charge analysis is carried out to account for the polarising behaviour of the radioactive element and charge transfer between the IL phase by comparison with the bare IL species.

  2. Chemical analysis of the elements in UZrNb alloy at CDTN: preliminary investigation

    International Nuclear Information System (INIS)

    Ferraz, Wilmar Barbosa; Palmieri, Helena Eugenia L.; Reis, Sergio Carneiro dos; Santos, Ana Maria Matildes dos; Souza, Adalberto Leles de

    2012-01-01

    The complete determination of major, minor, and impurity element contents in nuclear fuel is essential for quality assurance in the production of nuclear fuels. The control over all the stages of the development of nuclear fuel involves a combination of different analytical methods such as spectrometric methods. The goal of our investigation is to develop and evaluate procedures for the determination of main elements and carbon impurity present in some uranium alloys. In this paper the element contents in U2.5Zr7.5Nb, U3Zr9Nb alloys and U6Nb, in weight percent, were investigated by means of scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), inductively coupled plasma mass spectrometry (ICP-MS), wavelength dispersive fluorescence spectrometry (XRF/WDS) and energy-dispersive X-ray spectroscopy (EDX). The total carbon was determined using a carbon analyzer in which the sample is oxidized to carbon dioxide (IR absorption). It was observed a satisfactory correlation between the results obtained by employed methods. (author)

  3. On the Necessity of Using Element No.155 in the Chemical Physical Calculations: Again on the Upper Limit in the Periodic Table of Elements

    Directory of Open Access Journals (Sweden)

    Khazan A.

    2010-10-01

    Full Text Available It is shown how the properties of different elements of the Periodic System of Elements can be obtained using the properties of the theoretically predicted heaviest element No.155 (it draws the upper principal limit of the Table, behind which stable elements cannot exist. It is suggested how the properties of element No.155 can be used in the synthesis of superheavy elements. An analysis of nuclear reactions is also produced on the same basis.

  4. Semiquantitative and quantitative measurements for EDXRF in elemental chemical composition of pigments

    International Nuclear Information System (INIS)

    Costa, Elizabeth Cristina Soares da

    2005-02-01

    X-Ray fluorescence technique is largely used in the characterization of art and archaeological objects for restoration and conservation, allowing a multi-elemental, simultaneous and non destructive analysis. In this work it was used a portable XRF equipment of XRF that consists of a 238 Pu source ( 13,6 and 17,2 keV; 95 mCi) and a SI-PIN detector coupled to a 8 k multichannel analyser. The results were collected by a palmtop computer and later analysed in a PC, through the program AXIL-QXAS. The acquisition time for each measurement was 500 s. The measurements were accomplished in a wood sculpture (Santa Luzia image, number 164) from the collection of the Museu de Etnologia da Universidade de Sao Paulo (MAE-USP), in the following regions: (STL1) inferior side of the wood base exposed without finishing, (STL2) frontal inferior base of the pedestal (dark blue) (STL3), inferior part of the frontal dress (gold), (STL4) medium part of the dress (clear blue) (STL5) mantle (red), (STL6) back central lock of the hair in the backs (black), (STL7) right cheek (flesh-coloured) and (STL8) mantle (gold). The elements found in the STL1 region were: Al, Ca, Fe and a high concentration of Zn. In the region STL2 were found Al, C, Fe, Zn and the key element Cu. In the region STL3 - Ca, Zn and the key element Au. In the region STL4 it was found Zn and the key element Cu. In the region STL5 the key element S and Hg. In the region STL6 were found Fe, Ca, S and Hg. In the region STL 7 were found Al, Cu, Hg and Zn. In the region STL8 were found Ca, Al and Au, with high concentration. It was concluded that the possible pigments would be: STL2 and STL4 - CuCO 3 . Cu(OH) 2 + ZnO; STL3 and STL8 - Au; STL5 - HgS, STL6 - HgS mixed with other oxides, possibly of Fe and Mn, and STL 7 - HgS + ZnO. Standard samples of wood painted with pigments of the colors white, blue, red, rose, flesh color and green were also made. Through the XRF method it was verified that the white pigment is TiO 2 , the

  5. Chemical modelling of trace elements in pore water from PFBC residues containing ammonia

    International Nuclear Information System (INIS)

    Karlsson, L.G.; Brandberg, F.

    1993-01-01

    Ammonia is added to the PFBC process with the purpose to reduce the emissions of NO x in the stack gases. The design of the system for cleaning the stack gases will lead to an increased adsorption of ammonia and an accumulation of soluble ammonium salts in the cyclone ash from PFBC processes. This can be an environmental problem since the amounts will increase over the coming years and there will be a need to dispose the residues. When infiltrating rainwater penetrates the disposed residues ammonia and ammonium salts result in a contamination of the pore water with ammonia in the disposed residues. This entail the solubility of several trace elements in the residues that form soluble complexes with ammonia will increase and cause an increased contamination of groundwater and surface water. In this study the increased solubilities is calculated for the trace elements cadmium, cobalt, copper, mercury, nickel, silver and zinc in the residues using thermodynamical data. The calculations have been performed with probable solid phases of the trace elements at oxidizing and reducing conditions as a function of pH and at varying concentration of ammonia in the pore water. The thermodynamic calculations have been performed with the geochemical code EQ3NR. The results from the calculations show that as a concentration of 17 mg NH 3 /l in the pore water of the residues increases the solubilities for copper and silver. If the concentration of ammonia increases to 170 mg NH 3 /l will the solubilities increase also for cadmium, nickel and zinc. (12 refs., 39 figs.)

  6. Determination of isotope ratio of elements by mass distribution in molecules of varied chemical compounds

    International Nuclear Information System (INIS)

    Gladkikh, I.S.; Babichev, A.P.

    1999-01-01

    The procedure and program for calculation of isotope ratio of elements involving in the compound being studied using data of mass spectrometry were elaborated. The methods developed for the O 2 , SiH 4 , Cd(CH 3 ) 2 molecules were demonstrated for the illustration. The results of calculation provide support for the efficiency of the program and satisfactory reliability of the results during calculation of the isotope and complex compound concentrations. The program may be used for the estimation of the degree of nonequilibrium isotope distributions, it may indicate on the errors of the mass spectroscopy results [ru

  7. Elemental concentration and chemical parameters of drinking water of Patiala City, India

    International Nuclear Information System (INIS)

    Sharma, H.K.; Singh, B.; Mittal, V.K.; Sahota, H.S.

    1989-01-01

    Neutron activation analysis and energy dispersive x-ray fluorescence techniques have been used to determine 28 major and trace element concentrations in drinking water. Conductivity, pH, hardness, alkalinity, chlorides and sulphates were also measured. The majority of the concentrations are well below the ISI/WHO recommended values. However cadmium, mercury, total dissolved solids (TDS) conductivity and alkalinity were found to be higher in about half the cases compared to ISI/WHO recommended values, whereas sodium was found to be higher in almost all the cases. A linear relationship was observed between TDS and conductivity. (author)

  8. Chemical and sewage sludge co-incineration in a full-scale MSW incinerator: toxic trace element mass balance.

    Science.gov (United States)

    Biganzoli, Laura; Grosso, Mario; Giugliano, Michele; Campolunghi, Manuel

    2012-10-01

    Co-incineration of sludges with MSW is a quite common practice in Europe. This paper illustrates a case of co-incineration of both sewage sludges and chemical sludges, the latter obtained from drinking water production, in a waste-to-energy (WTE) plant located in northern Italy and equipped with a grate furnace, and compares the toxic trace elements mass balance with and without the co-incineration of sludges. The results show that co-incineration of sewage and chemical sludges does not result in an increase of toxic trace elements the total release in environment, with the exception of arsenic, whose total release increases from 1 mg t(fuel) (-1) during standard operation to 3 mg t(fuel) (-1) when sludges are co-incinerated. The increase of arsenic release is, however, attributable to the sole bottom ashes, where its concentration is five times higher during sludge co-incineration. No variation is observed for arsenic release at the stack. This fact is a further guarantee that the co-incineration of sludges, when performed in a state-of-the-art WTE plant, does not have negative effects on the atmospheric environment.

  9. Native bromeliads as biomonitors of airborne chemical elements in a Brazilian restinga forest

    Energy Technology Data Exchange (ETDEWEB)

    Elias, C; Fernandes, E A.N.; Franca, E J; Bacchi, M A; Tagliaferro, F S [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba, SP (Brazil)

    2008-11-15

    Epiphytic bromeliads have been used as biomonitors of air pollution since they have specialized structures in leaves for absorbing humidity and nutrients available in the atmosphere. Leaves of five bromeliad species were collected in the conservation unit Parque Estadual Ilha do Cardoso, Sao Paulo State, Brazil, and analyzed by INAA. Vriesea carinata was the species showing most accumulation, with the highest mass fractions of K, Na, Rb and Zn. Similar results were previously found for the same species collected in the dense ombrophilous forest. Chemical composition of bromeliads provided an indication of the atmosphere status in the conservation unit. (author)

  10. Native bromeliads as biomonitors of airborne chemical elements in a Brazilian restinga forest

    International Nuclear Information System (INIS)

    Elias, C.; Fernandes, E.A.N.; Franca, E.J.; Bacchi, M.A.; Tagliaferro, F.S.

    2008-01-01

    Epiphytic bromeliads have been used as biomonitors of air pollution since they have specialized structures in leaves for absorbing humidity and nutrients available in the atmosphere. Leaves of five bromeliad species were collected in the conservation unit Parque Estadual Ilha do Cardoso, Sao Paulo State, Brazil, and analyzed by INAA. Vriesea carinata was the species showing most accumulation, with the highest mass fractions of K, Na, Rb and Zn. Similar results were previously found for the same species collected in the dense ombrophilous forest. Chemical composition of bromeliads provided an indication of the atmosphere status in the conservation unit. (author)

  11. Micro-PIXE for the quantitative imaging of chemical elements in single cells

    International Nuclear Information System (INIS)

    Ortega, R.

    2013-01-01

    Full text: The knowledge of the intracellular distribution of biological relevant metals is important to understand their mechanisms of action in cells, either for physiological, toxicological or pathological processes. However, the direct detection of trace metals in single cells is a challenging task that requires sophisticated analytical developments. The aim of this seminar will be to present the recent achievements in this field using micro-PIXE analysis. The combination of micro-PIXE with RBS (Rutherford Backscattering Spectrometry) and STIM (Scanning Transmission lon Microscopy) allows the quantitative determination of trace metal content within sub-cellular compartments. The application of STlM analysis will be more specifically highlighted as it provides high spatial resolution imaging (<200 nm) and excellent mass sensitivity (<0.1 ng). Application of the STIM-PIXE-RBS methodology is absolutely needed when organic mass loss appears during PIXE-RBS irradiation. This combination of STIM-PIXE-RBS provides fully quantitative determination of trace element content, expressed in μg/g, which is a quite unique capability for micro-PIXE compared to other micro-analytical methods such as the electron and synchrotron X-ray fluorescence or the techniques based on mass spectrometry. Examples of micro-PIXE studies for subcellular imaging of trace elements in the various fields of interest will be presented such as metal-based toxicology, pharmacology, and neuro degeneration [1] R. Ortega, G. Devés, A. Carmona. J. R. Soc. Interface, 6, (2009) S649-S658. (author)

  12. Dispersion of chemical elements in an industrial environment studied by biomonitoring using Parmelia sulcata

    International Nuclear Information System (INIS)

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

    2000-01-01

    Transplants of the lichen Parmelia sulcata Taylor were suspended in nylon bags within a rectangle of 15 km wide and 25 km long on a grid 2.5 km x 2.5 km, centred in a power station. In all of the 47 places two sets of four transplants each were hanged, one facing the wind and the other opposing the wind. Care was taken (1) in covering the two sets with a polyethylene roof to prevent leaching of elements in the lichen, (2) in building a hanging system that could rotate according to the wind direction, and (3) in orienting one set towards the wind and the other set opposite the wind. During a one-year period, one transplant of each set was taken for analysis after a 3 month exposure. Some results of the second campaign (after a 6 month exposure) obtained by INAA are shown and compared with the first campaign (after a 3 month exposure). Elemental contents are mapped and discussed. (author)

  13. PIXE and ICP analysis of chemical elements in the downer cow syndrome

    International Nuclear Information System (INIS)

    Dima, G.; Stihi, C.; Popescu, I. V.; Badica, T.; Olariu, A.; Petre, M.; Jianu, E. D.

    2001-01-01

    The aim of this study was the microelemental analysis of blood serum samples collected from healthy and ill cows (downer cow syndrome DCS). The origin of this syndrome is uncertain but the clinical experience denotes that the DCS is advanced by the hypocalcaemic paresis of parturition. The diminution of some nutritive elements from food can be a cause of DCS. The cows are more sensitive to the diminution of P in food in comparison with the diminution of Ca. Another interesting aspect about the origin of DCS is the ratio Ca/P in food. The samples were collected from cows at some animal farms: 20 healthy cows and 12 DCS cows breeds on the same conditions. Concentrations of P, Cl, K, Ca and Fe elements were obtained by using particle induced X - ray emission (PIXE) and inductively coupled plasma (ICP). The mineral concentrations in the serum have values in normal limits for healthy cows even during the winter, when the mineral content of dry food is very poor. On the other hand, we can observe important decreases under the normal limits of the amount of Ca, P and Mg in the blood serum of DCS cows. It is easy to see the tendency of the DCS animals to have hypocalcemia and hypophosphataemia. Those perturbations can be the causes of the installations of the ill cows in the lypostatic and decubital attitudes. (authors)

  14. Elemental and chemical characterization of dolphin enamel and dentine using X-ray and Raman microanalyzes (Cetacea: Delphinoidea and Inioidea).

    Science.gov (United States)

    Loch, Carolina; Swain, Michael V; Fraser, Sara J; Gordon, Keith C; Kieser, Jules A; Fordyce, R Ewan

    2014-01-01

    Dolphins show increased tooth number and simplified tooth shape compared to most mammals, together with a simpler ultrastructural organization and less demanding biomechanical function. However, it is unknown if these factors are also reflected in the chemical composition of their teeth. Here, the bulk chemical composition and elemental distribution in enamel and dentine of extant dolphins were characterized and interpreted using X-ray and spectroscopy techniques. Teeth of 10 species of Delphinida were analyzed by WDX, EDX and Raman spectroscopy. For most of the species sampled, the mineral content was higher in enamel than in dentine, increasing from inner towards outer enamel. The transition from dentine to enamel was marked by an increase in concentration of the major components Ca and P, but also in Na and Cl. Mg decreased from dentine to enamel. Concentrations of Sr and F were often low and below detection limits, but F peaked at the outer enamel region for some species. Raman spectroscopy analyzes showed characteristics similar to carbonated hydroxyapatite, with the strongest peak for the phosphate PO4(3-) stretching mode at 960-961cm(-1). Dentine samples revealed a higher diversity of peaks representative of organic components and proteins than enamel. The similar distribution pattern and small variation in average concentration of major and minor elements in dentine and enamel of dolphins suggest that they are subject to strong physiological control. A clear trend of the elemental variations for all dolphin species sampled suggests that the general pattern of tooth chemistry is conserved among the Mammalia. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Comparative study of the chemical composition and mineral element content of Artocarpus heterophyllus and Treculia africana seeds and seed oils.

    Science.gov (United States)

    Ajayi, Ibironke Adetolu

    2008-07-01

    A comparative study of Artocarpus heterophyllus and Treculia africana seeds, both of Moraceae family, was carried out to establish their chemical compositions and evaluate their mineral element content in order to investigate the possibility of using them for human and or animal consumption and also to examine if there is a relationship between the properties of these seeds. A. heterophyllus and T. africana are rich in protein; their protein contents are higher than those from high protein animal sources such as beef and marine fishes. Both seeds have high carbohydrate content and could act as source of energy for animals if included in their diets. The oil contents of the seeds are 11.39% and 18.54% for A. heterophyllus and T. africana, respectively. The oils are consistently liquid at room temperature. The results of the physicochemical properties of the two seeds are comparable to those of conventional oil seeds such as groundnut and palm kernel oils and could be useful for nutritional and industrial purposes. The seeds were found to be good sources of mineral elements. The result revealed potassium to be the prevalent mineral elements which are 2470.00 ppm and 1680.00 ppm for A. heterophyllus and T. africana, respectively followed by sodium, magnesium and then calcium. They also contain reasonable quantity of iron, in particular A. heterophyllus 148.50 ppm.

  16. Quantification of chemical elements in blood of patients affected by multiple sclerosis.

    Science.gov (United States)

    Forte, Giovanni; Visconti, Andrea; Santucci, Simone; Ghazaryan, Anna; Figà-Talamanca, Lorenzo; Cannoni, Stefania; Bocca, Beatrice; Pino, Anna; Violante, Nicola; Alimonti, Alessandro; Salvetti, Marco; Ristori, Giovanni

    2005-01-01

    Although some studies suggested a link between exposure to trace elements and development of multiple sclerosis (MS), clear information on their role in the aetiology of MS is still lacking. In this study the concentrations of Al, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Ni, Pb, Sb, Si, Sn, Sr, Tl, V, W, Zn and Zr were determined in the blood of 60 patients with MS and 60 controls. Quantifications were performed by inductively coupled plasma (ICP) atomic emission spectrometry and sector field ICP mass spectrometry. When the two groups were compared, an increased level of Co, Cu and Ni and a decrement of Be, Fe, Hg, Mg, Mo, Pb and Zn in blood of patients were observed. In addition, the discriminant analysis pointed out that Cu, Be, Hg, Co and Mo were able to discriminate between MS patients and controls (92.5% of cases correctly classified).

  17. Protein energetic conformational analysis from NMR chemical shifts (PECAN) and its use in determining secondary structural elements

    Energy Technology Data Exchange (ETDEWEB)

    Eghbalnia, Hamid R.; Wang Liya; Bahrami, Arash [National Magnetic Resonance Facility at Madison, Biochemistry Department (United States); Assadi, Amir [University of Wisconsin-Madison, Mathematics Department (United States); Markley, John L. [National Magnetic Resonance Facility at Madison, Biochemistry Department (United States)], E-mail: eghbalni@nmrfam.wisc.edu

    2005-05-15

    We present an energy model that combines information from the amino acid sequence of a protein and available NMR chemical shifts for the purposes of identifying low energy conformations and determining elements of secondary structure. The model ('PECAN', Protein Energetic Conformational Analysis from NMR chemical shifts) optimizes a combination of sequence information and residue-specific statistical energy function to yield energetic descriptions most favorable to predicting secondary structure. Compared to prior methods for secondary structure determination, PECAN provides increased accuracy and range, particularly in regions of extended structure. Moreover, PECAN uses the energetics to identify residues located at the boundaries between regions of predicted secondary structure that may not fit the stringent secondary structure class definitions. The energy model offers insights into the local energetic patterns that underlie conformational preferences. For example, it shows that the information content for defining secondary structure is localized about a residue and reaches a maximum when two residues on either side are considered. The current release of the PECAN software determines the well-defined regions of secondary structure in novel proteins with assigned chemical shifts with an overall accuracy of 90%, which is close to the practical limit of achievable accuracy in classifying the states.

  18. Protein energetic conformational analysis from NMR chemical shifts (PECAN) and its use in determining secondary structural elements

    International Nuclear Information System (INIS)

    Eghbalnia, Hamid R.; Wang Liya; Bahrami, Arash; Assadi, Amir; Markley, John L.

    2005-01-01

    We present an energy model that combines information from the amino acid sequence of a protein and available NMR chemical shifts for the purposes of identifying low energy conformations and determining elements of secondary structure. The model ('PECAN', Protein Energetic Conformational Analysis from NMR chemical shifts) optimizes a combination of sequence information and residue-specific statistical energy function to yield energetic descriptions most favorable to predicting secondary structure. Compared to prior methods for secondary structure determination, PECAN provides increased accuracy and range, particularly in regions of extended structure. Moreover, PECAN uses the energetics to identify residues located at the boundaries between regions of predicted secondary structure that may not fit the stringent secondary structure class definitions. The energy model offers insights into the local energetic patterns that underlie conformational preferences. For example, it shows that the information content for defining secondary structure is localized about a residue and reaches a maximum when two residues on either side are considered. The current release of the PECAN software determines the well-defined regions of secondary structure in novel proteins with assigned chemical shifts with an overall accuracy of 90%, which is close to the practical limit of achievable accuracy in classifying the states

  19. Trace element distribution in different chemical fractions of False Bay sediments

    International Nuclear Information System (INIS)

    Rosental, R.

    1984-05-01

    Trace metals in the aquatic environment are generally concentrated on solid geochemical phases which eventually become incorporated into estuarine and marine sediments. The mechanism of trace metal concentration is believed to be adsorption on various geochemical phases, such as hydrous metal oxides, clays and organic matter. Metals in estuarine sediments can thus be expected to be partitioned between different phases, depending on the concentration of the phase and the strength of the adsorption bond. The bioavailability of sediment-bound metals to deposit-feeding organisms will depend on trace metal partitioning and the kinetics of biological metal uptake from each geochemical phase. The major objective of this study was to establish an analytical procedure involving sequential chemical extractions for the partitioning of particulate trace metals in sediment samples, collected from False Bay. Eight metals were examined, i.e. Cd, Cu, Cr, Fe, Mn, Ni, Pb and Zn. X-ray diffraction was also used in the study

  20. Separation and sampling technique of light element isotopes by chemical exchange process

    International Nuclear Information System (INIS)

    Kato, Shunsaku; Oi, Kenta; Takagi, Norio; Hirotsu, Takafumi; Kano, Hirofumi; Sonoda, Akinari; Makita, Yoji

    2000-01-01

    Lithium and boron isotope separation technique were studied. Granulation of lithium isotope separation agent was carried out by cure covering in solution. Separation of lithium isotope was stepped up by ammonium carbonate used as elusion agent. Styrene and ester resin derived three kinds of agents such as 2-amino-1, 3-propanediol (1, 3-PD), 2-amino-2-methyl-1, 3-propanediol (Me-1,3-PD) and tris(2-hydroxyethyl)amine (Tris) were used as absorbent.The ester resin with Tris showed larger amount of adsorption (1.4 mmol/g) than other resins. However, all resins with agent indicated more large adsorption volume of boron than the objective value (0.5 mmol/g). Large isotope shift was shown by the unsymmetrical vibration mode of lithium ion on the basis of quantum chemical calculation of isotope effect on dehydration of hydrated lithium ion. (S.Y.)

  1. High sensitivity detection and characterization of the chemical state of trace element contamination on silicon wafers

    CERN Document Server

    Pianetta, Piero A; Baur, K; Brennan, S; Homma, T; Kubo, N

    2003-01-01

    Increasing the speed and complexity of semiconductor integrated circuits requires advanced processes that put extreme constraints on the level of metal contamination allowed on the surfaces of silicon wafers. Such contamination degrades the performance of the ultrathin SiO sub 2 gate dielectrics that form the heart of the individual transistors. Ultimately, reliability and yield are reduced to levels that must be improved before new processes can be put into production. It should be noted that much of this metal contamination occurs during the wet chemical etching and rinsing steps required for the manufacture of integrated circuits and industry is actively developing new processes that have already brought the metal contamination to levels beyond the measurement capabilities of conventional analytical techniques. The measurement of these extremely low contamination levels has required the use of synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) where sensitivities 100 times better than conv...

  2. Theoretical study of the electronic structure of f-element complexes by quantum chemical methods

    International Nuclear Information System (INIS)

    Vetere, V.

    2002-09-01

    This thesis is related to comparative studies of the chemical properties of molecular complexes containing lanthanide or actinide trivalent cations, in the context of the nuclear waste disposal. More precisely, our aim was a quantum chemical analysis of the metal-ligand bonding in such species. Various theoretical approaches were compared, for the inclusion of correlation (density functional theory, multiconfigurational methods) and of relativistic effects (relativistic scalar and 2-component Hamiltonians, relativistic pseudopotentials). The performance of these methods were checked by comparing computed structural properties to published experimental data, on small model systems: lanthanide and actinide tri-halides and on X 3 M-L species (X=F, Cl; M=La, Nd, U; L = NH 3 , acetonitrile, CO). We have thus shown the good performance of density functionals combined with a quasi-relativistic method, as well as of gradient-corrected functionals associated with relativistic pseudopotentials. In contrast, functionals including some part of exact exchange are less reliable to reproduce experimental trends, and we have given a possible explanation for this result . Then, a detailed analysis of the bonding has allowed us to interpret the discrepancies observed in the structural properties of uranium and lanthanides complexes, based on a covalent contribution to the bonding, in the case of uranium(III), which does not exist in the lanthanide(III) homologues. Finally, we have examined more sizeable systems, closer to experimental species, to analyse the influence of the coordination number, of the counter-ions and of the oxidation state of uranium, on the metal-ligand bonding. (author)

  3. Effect of leafhopper Arboridiakurdistanisp.nov on the some grape leaves elements and its chemical control

    Science.gov (United States)

    Amin, Abdulbaset Mohammed; Younis, Sara Dasco

    2017-09-01

    The leafhopper Arboridiakurdistanisucking leaves sap and causes decrease of nitrogen in leaves and lead to inhabiting the chlorophyll then decrease the rate of photosynthesis and drying of the leaf. Chemical analysis of plant leaves showed the decreasing of Nitrogen content and gave the means in July, August and September 2.699%, 2.531% and 2.063% respectively, The phosphors rate is decrease in infested leaves, the mean of phosphors content in infested leaves in July, August and September were 0.532ppm, 0.496ppm and 0.361ppm respectively. At the time of protein is decreased in grape leaves the plants should delay in growth, the proteins content were 16.865%, 15.814% and 14.689%, while the potassium content in infested grape leave in July, August and September were 0.509%, 0.509% and 0.394% respectively. The chemical control showed that the best insecticide was Actara which gave 23.33% mortality for 48hours at 0.5gm/gallon water and raised to 90.00% at rate of 1.5gm/gallon water, Marshal gave 13.33% and 80.00% after 48 hours at rate of 0.5 and 1.5gm/gallon water respectively, but Spear gave 6.67% and 33.33% after 48 hours at 0.5% and 1.5gm/gallon water respectively. Based on LC50 Value, Actara proved to be more effective than Marshal and Spear.

  4. Assessment of chemical element migration in soil-plant complex of Urov endemic localities of East Transbaikalia

    Science.gov (United States)

    Vadim V., Ermakov; Valentina, Danilova; Sabsbakhor, Khushvakhtova; Aklexander, Degtyarev; Sergey, Tyutikov; Victor, Berezkin; Elena, Karpova

    2014-05-01

    The comparative evaluation of the levels of biologically active chemical elements and their migration in the soil-plant complex of two Urov endemic locations in East Transbaikalia (Zolinsky and Uryumkansky) and background areas (Western Baikal region and the western area of the Trans-Baikal region) was conducted. The predominant soil-forming rocks in East Transbaikalia are weathering products of Proterozoic carbonated granitoids PR2. The surface rocks consist from granite, granodiorite, diorite quartz diorite, gabbro, norite, gabbro-norite and other. Soils - mountain and cryogenic meadow forests, mountain permafrost taiga podzolised, meadow alluvial, peaty meadow [2]. The paludification of narrow valleys and thermokarst phenomena are typical in Urov endemic localities. It reflects on the spotted of soil and differentiation of chemical composition of soils and plants. Most of the chemical elements in soils were determined by means of X-ray fluorescence, and trace elements in soils and plants - by atomic absorption spectrometry. The selenium content was measured by spectrofluorimetric method [3]. The research processed by methods of variation statistics. It was found that the soils of two locations of the Urov subregion of the biosphere were more enriched with iron, barium, calcium, uranium, thorium, phosphorus, and to a lesser extent strontium compared to background soils. The ratio of Ca: P was significantly higher in the soil of background areas, and Ca: Sr, on the contrary, in endemic soils. In assessing the migration of trace elements in soil-plant complex by means of the total content of trace elements and biological absorption coefficient found a marked accumulation by plants manganese, chromium, arsenic and weak plants accumulation of cobalt and nickel. Soil landscape is not much different in content of selenium, but its migration in plants was reduced in places of spread of Urov disease [1]. The concentrators of cadmium (leaves of different species of willow

  5. Dialkyldithiophosphoric acids - chemical properties and 5f and 4f elements ions extraction

    International Nuclear Information System (INIS)

    Pattee, D.

    1987-09-01

    This work is a contribution to the study of the properties of the dialkyldithiophosphoric acids and of the extraction of the 4f and 5f ions from weakly acidic nitrate and phosphate media. Following a complete bibliographic study, synthesis and purification of the di-2-ethylhexyl-dithiophosphoric acid (HDEHDTP) is studied. It is identified with chemical methods and spectroscopic methods (I.R., N.M.R., V.P.C.); its by products, the di-2-ethylhexyl (monothio) phosphoric acids (HDEHTP, HDEHP) are also identified and characterized. Stability against hydrolysis and radiolysis is determined. The extractive properties are studied for the 4f and 5f ions. The presence of a sulfur donor atom in HDEHDTP makes it inefficient for the extraction of trivalent lanthanides and actinides but brings out a certain selectivity for americium. For HDEHTP, the presence of an oxygen donor atom rubs out any selectivity and the extraction constants are greater. Selectivity of HDEHDTP is increased by TBP (tri-n-butylphosphate) in synergistic mixtures. The mechanism of extraction of hexavalent uranium from phosphoric medium is elucidated. A model is developed by NMR for the micellisation of the sodium salts of HDEHDTP, HDEHTP and HDEHP, and extrapolated it to the trivalent rare earth salts of the acids. The structures are verified by light scattering and low angle X-ray diffraction [fr

  6. Bacterial disproportionation of elemental sulfur coupled to chemical reduction of iron or manganese

    DEFF Research Database (Denmark)

    Thamdrup, Bo; Finster, Kai; Hansen, Jens Würgler

    1993-01-01

    and pyrite was observed. The transformations were accompanied by growth of slightly curved, rod-shaped bacteria. The quantification of the products revealed that S was microbially disproportionated to sulfate and sulfide, as follows: 4S + 4H(2)O --> SO(4) + 3H(2)S + 2H. Subsequent chemical reactions between...... reduction of MnO(2) to Mn. Growth of small rod-shaped bacteria was observed. When incubated without MnO(2), the culture did not grow but produced small amounts of SO(4) and H(2)S at a ratio of 1:3, indicating again a disproportionation of S. The observed microbial disproportionation of S only proceeds...... significantly in the presence of sulfide-scavenging agents such as iron and manganese compounds. The population density of bacteria capable of S disproportionation in the presence of FeOOH or MnO(2) was high, > 10 cm in coastal sediments. The metabolism offers an explanation for recent observations of anaerobic...

  7. Effects of chemical functional groups on elemental mercury adsorption on carbonaceous surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jing, E-mail: liujing27@mail.hust.edu.cn [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Cheney, Marcos A. [Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD 21853 (United States); Wu Fan; Li Meng [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China)

    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{sup 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{sup 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{sup 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.

  8. Study of chemical and electrochemical properties of some elements in molten NaAlCl

    International Nuclear Information System (INIS)

    Bermond, Alain

    1976-01-01

    We describe a study of the electrochemical and chemical properties in molten mixtures of Aluminium Chloride-Sodium chloride, at 210 deg. C and the concept of acidity, related to chloride activity, is previously summarized. In a first part, the study of Mercury and Cadmium by means of electro-analytical techniques, states the Hg 2+ 2 , Hg 2+ , Cd 2+ 2 and Cd 2+ ions and their acid properties. Some diagrams Equilibrium potential vs acidity are the synthesis of these results. In a second part, it is shown that a nickel electrode is an indicator of the presence of oxide ions; from interpretation of electrochemical results, O 2 appears to behave, in terms of the chloro-acido-basicity concept, as a strong di-base, giving the solvated form AlOCl - 2 , or a strong tri-base giving AlOCl. A saturation effect by Al 2 O 3 appears when the oxide concentration is increased; the solubility of Al 2 O 3 versus acidity is determined from the electrochemical results. In a third part, results for the Ni/Ni(II) or HCl/H 2 O systems are related to dissolved oxide ion presence in chloroaluminate melts; elimination of oxide ions, through H 2 O formation, by reaction with HCl is noteworthy. (author) [fr

  9. The role of mineral elements and other chemical compounds used in balneology: data from double-blind randomized clinical trials

    Science.gov (United States)

    Morer, Carla; Roques, Christian-François; Françon, Alain; Forestier, Romain; Maraver, Francisco

    2017-12-01

    The aims of this study were to conduct a systematic literature review on balneotherapy about the specific therapeutic role of mineral elements and other chemical compounds of mineral waters and derivate peloids/muds and to discuss the study methods used to evaluate it (in musculoskeletal conditions). We searched Medline by PubMed using the following key words: "spa therapy" "balneotherapy" "mud" "peloid" "mud pack Therapy" in combination with "randomized controlled trial" "double blind trial." We also reviewed the reference list of articles retrieved by the Medline search. We selected the double-blind randomized clinical trials that assessed the effects of mineral water or mud treatments compared to tap water, attenuated peloid/mud therapy or similar treatments without the specific minerals or chemical compounds of the treatment group ("non-mineral"). We evaluated the internal validity and the quality of the statistical analysis of these trials. The final selection comprised 27 double-blind randomized clinical trials, 20 related to rheumatology. A total of 1118 patients with rheumatological and other musculoskeletal diseases were evaluated in these studies: 552 of knee osteoarthritis, 47 of hand osteoarthritis, 147 chronic low back pain, 308 of reumathoid arthritis, and 64 of osteoporosis; 293 of these participants were assigned to the experimental groups of knee osteoarthritis, 24 in hand osteoarthritis, 82 of low back pain, 152 with reumathoid arthritis, and 32 with osteoporosis. They were treated with mineral water baths and/or mud/peloid (with or without other forms of treatment, like physical therapy, exercise…). The rest were allocated to the control groups; they received mainly tap water and/or "non-mineral" mud/peloid treatments. Mineral water or mud treatments had better and longer improvements in pain, function, quality of life, clinical parameters, and others in some rheumatologic diseases (knee and hand osteoarthritis, chronic low back pain

  10. Chemical composition of arctic snow: concentration levels and regional distribution of major elements.

    Science.gov (United States)

    de Caritat, Patrice; Hall, Gwendy; Gìslason, Sigurdur; Belsey, William; Braun, Marlene; Goloubeva, Natalia I; Olsen, Hans Kristian; Scheie, Jon Ove; Vaive, Judy E

    2005-01-05

    At the end of the northern winter 1996/1997, 21 snow samples were collected from 17 arctic localities in Norway, Sweden, Finland, Svalbard, Russia, Alaska, Canada, Greenland and Iceland. Major element concentrations of the filtered (0.45 mum) melted snow indicate that most samples are consistent with a diluted seawater composition. Deviations from this behaviour indicate additional SO(4)(2-) and Cl(-) relative to seawater, suggesting a minor contribution from (probably local) coal combustion emissions (Alaska, Finland, Sweden, Svalbard). The samples with the highest Na and Cl(-) content (Canada, Russia) also have higher Na/SO(4)(2-) and Cl(-)/SO(4)(2-) ratios than seawater, suggesting a slight contamination from (probably local) deicing activities. Local soil or rock dust inputs in the snow are indicated by 'excess' Ca contents (Alaska, Svalbard, Greenland, Sweden). No overall relationship was found between pH (range: 4.6-6.1) and total or non-seasalt SO(4)(2-) (NSS), suggesting that acidification due to long-range transport of SO(2) pollution is not operating on an arctic-wide scale. In a few samples (Alaska, Finland, Sweden, Svalbard), a significant proportion (>50%) of SO(4)(2-) is non-marine in origin. Sources for this non-marine SO(4)(2-) need not all be found in long-range atmospheric transport and more likely sources are local industry (Finland, Sweden), road traffic (Alaska) or minor snow-scooting traffic (one Svalbard locality). A few samples from northern Europe show a relatively weak trend of decreasing pH with increasing NO(3)(-).

  11. Coprecipitation experiment with Sm hydroxide using a multitracer produced by nuclear spallation reaction: A tool for chemical studies with superheavy elements

    International Nuclear Information System (INIS)

    Kasamatsu, Yoshitaka; Yokokita, Takuya; Toyomura, Keigo; Shigekawa, Yudai; Haba, Hiromitsu; Kanaya, Jumpei; Huang, Minghui; Ezaki, Yutaka; Yoshimura, Takashi; Morita, Kosuke; Shinohara, Atsushi

    2016-01-01

    To establish a new methodology for superheavy element chemistry, the coprecipitation behaviors of 34 elements with samarium hydroxide were investigated using multitracer produced by a spallation of Ta. The chemical reactions were rapidly equilibrated within 10 s for many elements. In addition, these elements exhibited individual coprecipitation behaviors, and the behaviors were qualitatively related to their hydroxide precipitation behaviors. It was demonstrated that the ammine and hydroxide complex formations of superheavy elements could be investigated using the established method. - Highlights: • We established a new methodology for superheavy element (SHE) chemistry. • Coprecipitation behaviors of 34 elements with Sm hydroxide could be simultaneously investigated by using multitracer. • The complex formations were investigated from the coprecipitation behaviors. • The established method will lead to the study on various precipitates of SHEs.

  12. Diversity of Chemical Bonding and Oxidation States in MS4 Molecules of Group 8 Elements.

    Science.gov (United States)

    Huang, Wei; Jiang, Ning; Schwarz, W H Eugen; Yang, Ping; Li, Jun

    2017-08-04

    The geometric and electronic ground-state structures of 30 isomers of six MS 4 molecules (M=Group 8 metals Fe, Ru, Os, Hs, Sm, and Pu) have been studied by using quantum-chemical density functional theory and correlated wavefunction approaches. The MS 4 species were compared to analogous MO 4 species recently investigated (W. Huang, W.-H. Xu, W. H. E. Schwarz, J. Li, Inorg. Chem. 2016, 55, 4616). A metal oxidation state (MOS) with a high value of eight appeared in the low-spin singlet T d geometric species (Os,Hs)S 4 and (Ru,Os,Hs)O 4 , whereas a low MOS of two appeared in the high-spin septet D 2d species Fe(S 2 ) 2 and (slightly excited) metastable Fe(O 2 ) 2 . The ground states of all other molecules had intermediate MOS values, with S 2- , S 2 2- , S 2 1- (and O 2- , O 1- , O 2 2- , O 2 1- ) ligands bonded by ionic, covalent, and correlative contributions. The known tendencies toward lower MOS on going from oxides to sulfides, from Hs to Os to Ru, and from Pu to Sm, and the specific behavior of Fe, were found to arise from the different atomic orbital energies and radii of the (n-1)p core and (n-1)d and (n-2)f valence shells of the metal atoms in row n of the periodic table. The comparative results of the electronic and geometric structures of the MO 4 and MS 4 species provides insight into the periodicity of oxidation states and bonding. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Chemical fractionation and mobility of traffic-related elements in road environments.

    Science.gov (United States)

    Adamiec, Ewa

    2017-12-01

    Due to considerable progress in exhaust control emission technology and extensive regulatory work regarding this issue, non-exhaust sources of air pollution have become a growing concern. This research involved studying three types of road environment samples such as road dust, sludge from storm drains and roadside soil collected from heavily congested and polluted cities in Poland (Krakow, Warszawa, Opole and Wroclaw). Particles below 20 µm were examined since it was previously estimated that this fine fraction of road dust is polluted mostly by metals derived from non-exhaust sources of pollution such as brake linings wear. Chemical analysis of all samples was combined with a fractionation study using BCR protocol. It was concluded that the finest fractions of road environment samples were significantly contaminated with all of the investigated metals, in particular with Zn, Cu, both well-known key tracers of brake and tire wear. In Warszawa, the pollution index for Zn was on average 15-18 times the background value, in Krakow 12 times, in Wroclaw 8-12 times and in Opole 6-9 times the background value. The pollution index for Cu was on average 6-14 times the background in Warszawa, 7-8 times in Krakow, 4-6 times in Wroclaw and in Opole 5 times the background value. Fractionation study revealed that mobility of examined metals decreases in that order: Zn (43-62%) > Cd (25-42%) > Ni (6-16%) > Cu (3-14%) > Pb (1-8%). It should, however, be noted that metals even when not mobile in the environment can become a serious health concern when ingested or inhaled.

  14. Consideration on thermodynamic data for predicting solubility and chemical species of elements in groundwater. Part 1: Tc, U, Am

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Tetsuji; Takeda, Seiji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-01-01

    The solubility determines the release of radionuclides from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Complexations of radionuclides by ligands in groundwater affect the interaction between radionuclides and geologic media, thus affect their migration behavior. Thermodynamic data for Tc, Am and U were reviewed and compiled to be used for predicting the solubility and chemical species in groundwater. Thermodynamic data were reviewed with emphasis on the hydrolysis and carbonate complexation that can dominate the speciation in typical groundwater. Thermodynamic data for other species were selected based on existing database. Thermodynamic data for other important elements are under investigation, thus shown in an appendix for temporary use. (author)

  15. Consideration on thermodynamic data for predicting solubility and chemical species of elements in groundwater. Part 2: Np, Pu

    International Nuclear Information System (INIS)

    Yamaguchi, Tetsuji

    2000-11-01

    The solubility determines the release of a radionuclide from waste form and is used as a source term in radionuclide migration analysis in performance assessment of radioactive waste repository. Complexations of the radionuclide by ligands in groundwater affect the interaction between radionuclides and geologic media, thus affect their migration behavior. It is essential to estimate the solubility and to predict the chemical species for the radionuclide based on thermodynamic data. The thermodynamic data of aqueous species and compounds were reviewed and compiled for Np and Pu. Thermodynamic data were reviewed with emphasis on the hydrolysis and carbonate complexation that can dominate the speciation in groundwater. Thermodynamic data for other species were selected based on existing databases. Thermodynamic data for other important elements are under investigation, thus shown in an appendix for temporary use. (author)

  16. LAD Prize Talk: Lab Astro and the Origins of the Chemical Elements

    Science.gov (United States)

    Lawler, James E.

    2017-06-01

    Only a few of the lightest or primordial nuclei were made just after the Big Bang. Other light nuclei up to the Fe-group are made by fusion in stars. Heavier nuclei are made primarily via r(apid)-process and s(low)-process n(eutron)-capture events. Although the s-process n-capture is fairly well understood, the r-process n-capture events remain poorly understood. The relative role of Core Collapse SNe and n-star mergers will likely be understood in the next few decades. I will discuss recent studies of old Metal-Poor stars that are revealing some new details of nucleosynthesis. This progress is due to the availability of high resolution spectra from large ground based telescopes, access to the UV via HST, and better laboratory data. Our laboratory astrophysics program has focused primarily on the measurement of transition probabilities by combining radiative lifetimes with emission branching fractions. The use of Time Resolved Laser Induced Fluorescence (TRLIF) to measure radiative lifetimes in metallic atoms and ions provides an absolute scale for transition probabilities accurate to a few percent [e.g. 1]. The development and application of TRLIF to neutral and ionized atoms of nearly all elements is due to a simple, versatile, and reliable atom/ion beam source based on a hollow cathode discharge [2, 3]. Fourier transform spectrometers (FTSs) are essential in the measurement of emission branching fractions for atoms and ions with dense spectra such as the rare earths [e.g. 4, 5]. A 3 m focal length echelle spectrometer is important to the measurement of weak branches which might otherwise be obscured by multiplex noise in FTS data [6, 7]. References: [1] E. A. Den Hartog et al., ApJS 194: 35 (2011). [2] D. W. Duquette et al., Phys. Rev. A24, 2847 (1981). [3] S. Salih & J. E. Lawler, Phys. Rev. A29, 3753, (1983). [4] J. W. Brault, J. Opt. Soc. Am. 66, 1081 (1976). [5] J. E. Lawler et al., ApJS 182, 51 (2009). [6] M. P. Wood & J. E. Lawler, Appl. Opt. 51, 8407

  17. Investigation of Chemical and Physical Changes to Bioapatite During Fossilization Using Trace Element Geochemistry, Infrared Spectroscopy and Stable Isotopes

    Science.gov (United States)

    Suarez, C. A.; Kohn, M. J.

    2013-12-01

    Bioapatite in the form of vertebrate bone can be used for a wide variety of paleo-proxies, from determination of ancient diet to the isotopic composition of meteoric water. Bioapatite alteration during diagenesis is a constant barrier to the use of fossil bone as a paleo-proxy. To elucidate the physical and chemical alteration of bone apatite during fossilization, we analyzed an assortment of fossil bones of different ages for trace elements, using LA-ICP-MS, stable isotopes, and reflected IR spectroscopy. One set of fossil bones from the Pleistocene of Idaho show a diffusion recrystallization profile, however, rare earth element (REE) profiles indicate diffusion adsorption. This suggests that REE diffusion is controlled by changing (namely decreasing) boundary conditions (i.e. decreasing concentration of REE in surrounding pore fluids). Reflected IR analysis along this concentration profile reveal that areas high in U have lost type A carbonate from the crystal structure in addition to water and organics. Stable isotopic analysis of carbon and oxygen will determine what, if any, change in the isotopic composition of the carbonate component of apatite has occurred do to the diffusion and recrystallization process. Analysis of much older bone from the Cretaceous of China reveal shallow REE and U concentration profiles and very uniform reflected IR spectra with a significant loss of type A carbonate throughout the entire bone cortex. Analysis of stable isotopes through the bone cortex will be compared to the stable isotopes collected from the Pleistocene of Idaho.

  18. Chemical Composition and Amounts of Mineral Elements in Honeybee-Collected Pollen in Relation to Botanical Origin

    Directory of Open Access Journals (Sweden)

    Taha El-Kazafy Abdou

    2015-06-01

    Full Text Available This study was conducted at the apiary of the Agricultural and Veterinary Training and Research Station, King Faisal University, Al-Ahsa, Saudi Arabia. The purpose was to study the relationship between the botanical origin and chemical composition of bee-collected pollen. The amount of mineral elements present in bee-collected pollen was also studied. The composition of pollen loads showed the maximum contents of dry matter, ash, glucose, fructose, magnesium (Mg, phosphorus (P, and manganese (Mn for the date palm; the maximum contents of protein, calcium (Ca, and zinc (Zn for alfalfa; the maximum contents of fiber, and copper (Cu for the sunflower; the maximum contents of the lipids and iron (Fe for summer squash; and the maximum contents of sodium (Na, and potassium (K for rape. Calcium was found to be correlated in a significantly (p<0.01 positive way with K, Na, Mg, P, Mn, and Zn. Copper, though, was correlated in a significantly (p<0.01 negative way with Ca, Mg, P, Mn, and Zn. The high levels of protein, ash, glucose, and fructose, and low lipid content found in bee-pollen from the date palm and from alfalfa, mean that pollen from the date palm and from alfalfa make an excellent food supplement. It was concluded, that the chemical composition of beecollected pollen can be correlated with the plant species from which pollen was collected.

  19. Characterization of chemical elements of fruits of Leucaena leucocephala in riverside areas of the Piracicaba River Basin, São Paulo, Brazil

    International Nuclear Information System (INIS)

    França, Elvis J.; Magalhães, Marcelo R.L. de; Ferreira, Fabiano S.; Fernandes, Elisabete A. de N.; Fonseca, Felipe Y.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O.; Camilli, Leandro; Silva, Bruno F.

    2017-01-01

    The species Leucaena leucocephala is present in several environments. Its fruit is widely used in cattle feed. However, it is classified as an invasive species, causing problems in the restoration of impacted areas. The Piracicaba River Basin is heavily affected by urbanization and industrialization, which shows the proliferation of this species. Considering the importance of this tree species for Brazil, the present study quantifies chemical elements in fruits of this species by applying Instrumental Neutronic Activation Analysis, method k 0 . Samples were collected in riverside areas of the Piracicaba Municipality, São Paulo, Brazil, at different periods (dry and rainy season). After collection, the samples were shattered and transferred to polyethylene capsules and irradiated with neutrons. Certified reference materials were used to evaluate the quality of the analytical procedure, all material was irradiated under a thermal neutron flux of 10 13 cm-2s-1 for 8 hours. Ni-Cr alloy was used for the monitoring of thermal neutron flux. High Resolution Range Spectrometry with HPG detectors was employed for the measurement of the induced radioactivity, allowing the quantification of the chemical elements. Compared with available results of chemical analysis of pods, the chemical elements Ca, K, Ba, Cr and Se presented high concentrations. We also quantified chemical elements of environmental relevance such as As, Hg, Br, Ce, Cs, Eu, Hf, La, Rb, Sb, Sc, Sm, Ta, Tb, Th and Yb, indicating the need for element dynamics studies in the environments occupied by this invasive species

  20. Sea spray aerosol chemical composition: elemental and molecular mimics for laboratory studies of heterogeneous and multiphase reactions.

    Science.gov (United States)

    Bertram, Timothy H; Cochran, Richard E; Grassian, Vicki H; Stone, Elizabeth A

    2018-04-03

    Sea spray aerosol particles (SSA), formed through wave breaking at the ocean surface, contribute to natural aerosol particle concentrations in remote regions of Earth's atmosphere, and alter the direct and indirect effects of aerosol particles on Earth's radiation budget. In addition, sea spray aerosol serves as suspended surface area that can catalyze trace gas reactions. It has been shown repeatedly that sea spray aerosol is heavily enriched in organic material compared to the surface ocean. The selective enrichment of organic material complicates the selection of representative molecular mimics of SSA for laboratory or computational studies. In this review, we first provide a short introduction to SSA formation processes and discuss chemical transformations of SSA that occur in polluted coastal regions and remote pristine air. We then focus on existing literature of the chemical composition of nascent SSA generated in controlled laboratory experiments and field investigations. We combine the evidence on the chemical properties of nascent SSA with literature measurements of SSA water uptake to assess SSA molecular composition and liquid water content. Efforts to speciate SSA organic material into molecular classes and specific molecules have led to the identification of saccharides, alkanes, free fatty acids, anionic surfactants, dicarboxylic acids, amino acids, proteinaceous matter, and other large macromolecules. However to date, less than 25% of the organic mass of nascent SSA has been quantified at a molecular level. As discussed here, quantitative measurements of size resolved elemental ratios, combined with determinations of water uptake properties, provides unique insight on the concentration of ions within SSA as a function of particle size, pointing to a controlling role for relative humidity and the hygroscopicity of SSA organic material at small particle diameters.

  1. chemical studies on the reactivity of some organic extractants for extraction and separation of certain elements from aqueous solutions

    International Nuclear Information System (INIS)

    Aly, M.M.I.

    2010-01-01

    Lanthanide elements such as lanthanum and neodymium are important elements in photo-electronic and metallurgical industries as well as in nuclear technology. The main constituents of the spent nuclear fuel are actinides like uranium, thorium and various fission products including lanthanides. The co-ordination compounds of the trivalent lanthanum and neodymium continues to be an active research area, which includes the specific spectroscopic and magnetic properties of rare earth ions and their applications as super molecular device, contrast-enhancing agents in magnetic resonance imaging, optical signal amplifiers and electroluminescent (EL) devices. Hence, the separation and purification of these elements is of great concern. Solvent extraction technique is employed to separate and purify rare earth elements in an industrial scale, but the separation of lanthanum and neodymium is a difficult task, as lanthanide ions exhibit similar chemical and physical properties. They have generally common and stable +3 oxidation state that requires synthesis of certain extractants which are able to extract them from different aqueous solutions. During the last twenty years, different publications have pointed out the remarkable properties of alkyl amide in the field of separation chemistry. These extractants are able to form stable co-ordination compounds with different metallic ions. In this concern, this thesis deals with the synthesis of different amide extractants namely N, N diethylacetoamide (DEAA), N, N Teteraphenyl malonamide (TPMA), N, N diphenylbenzamide (DPBA), N, N' diphenylacetoamide (DPAA), and N, N' Teteraethyl malonamide (TEMA), which were synthesized, characterized and compared with Aliquat-336 in kerosene for extraction and separation of La (III) and Nd (III). The effect of the different parameters affecting the extraction of these metals from aqueous nitric acid medium in the different systems has been studied in terms of shaking time, nitric acid, hydrogen

  2. The partition behavior and the chemical speciation of selected trace elements in a typical coal sample during pyrolysis / Tivo Bafana Hlatshwayo

    OpenAIRE

    Hlatshwayo, Tivo Bafana

    2008-01-01

    Sasol is by far the world's leading company in upgrading of low-grade coal into high value chemicals and fuels. Such plants also utilise fine particles or pulverised coal in the combustion process to generate steam and electricity for their processes. Certain trace elements released from coal during utilisation may be of environmental concern. From the literature findings it appears that the elements of interest are mercury, arsenic and selenium due to their potential health hazard and as...

  3. Application of chemical fractionation for monitoring some trace elements in street and industrial dust from Wadmedani, Sudan

    International Nuclear Information System (INIS)

    Mohamed, Ibtihag El hassan

    2000-09-01

    This study monitors some trace elements concentration in street and industrial dust from Wad Medani city, Gezira State in central Sudan. A total of 20 samples of dust were collected from crowded and non-crowded streets, material processing workshop and a tannery. Samples were treated by sequential chemical extraction in five fractions, which termed as exchangeable fraction, carbonate fraction, Fe-Mn oxides fraction, organic matter fraction and residual fraction. The same samples were digested by wet method. The obtained solutions were analyzed for Cr, Fe, Ni, Cu, Zn, and Pb content using Atomic Absorption Spectrometer (AAS) and for Na and K content using Flame Emission Spectrometer (FES). X-Ray Fluorescence Spectrometer (XRF) was used to determine the total content of Na, K, Cr, Fe, Ni, Cu, Zn and Pb in the bulk sample. Results of total content, which obtained by AAS, FES and XRF spectrometry, were compared with each other and with total content for the fractionated samples. Certified reference materials from IAEA were analyzed to make sure of the data obtained. The ranges of concentrations obtained are 113-3900 μg/g for Cr, 0.3-110.4 mg/g for Fe, 27-500 μg/g for Ni, 34.7-4390 μ/g for Cu, 62-1320 μg/g for Zn and 40-1250 μg/g for Pb dry weight. The obtained results were analyzed statistically using multivariate methods that include Correlation Matrices, Principal Component Analysis (PCA) and cluster analysis. The concentrations of trace elements in street and industrial dust of Wad Medani were compared with those values in literature. It has been observed that the dust from street and industrial area of wad Medani is slightly affected by anthropogenic sources.(Author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-20

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

  5. ELEMENTAL ABUNDANCES AND THEIR IMPLICATIONS FOR THE CHEMICAL ENRICHMENT OF THE BOÖTES I ULTRAFAINT GALAXY

    International Nuclear Information System (INIS)

    Gilmore, Gerard; Norris, John E.; Yong, David; Monaco, Lorenzo; Wyse, Rosemary F. G.; Geisler, D.

    2013-01-01

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

  6. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  7. Chemical sensor

    Science.gov (United States)

    Rauh, R. David (Inventor)

    1990-01-01

    A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.

  8. A simple chemical method for the separation of phosphorus interfering the trace element determinations by neutron activation analysis in high doped silicon wafers

    International Nuclear Information System (INIS)

    Wagler, H.; Flachowsky, J.

    1986-01-01

    Neutron activation analysis is one of the most available method for the determination of trace elements, but in the case of P-doped silicon wafers the 32 P-activity interferes the gamma spectrometry. It is not possible to determine the trace elements without chemical manipulations. On the other hand, time consuming chemical separations should be avoided. Therefore, a simple and rapid P-separation method has to be developed, in which the following twelve trace elements should be taken into consideration: Ag, As, Au, Co, Cr, Cu, Fe, Mo, Na, Sb, W, and Zn. After acid oxidative dissolution of the activated sample, P is present as phosphate ion. The phosphate ion is removed by precipitation as BiPO 4 . (author)

  9. Characterization of chemical elements in soil submitted to different systems use and management by energy dispersive x-ray fluorescence spectrometry (EDXRF)

    International Nuclear Information System (INIS)

    Wastowski, Arci Dirceu; Rosa, Genesio Mario da; Cherubin, Mauricio Roberto; Rigon, Joao Paulo Gonsiorkiewicz

    2010-01-01

    This study aimed to evaluate the chemical elements levels in soil, submitted to different management systems and use by the Energy Dispersive X-Ray Fluorescence Spectrometry - EDXRF. The systems were T1 - agroforestry (SAF), T2 - native field (CN), T3 - native forest (NM), T4 - tillage forest (PF); T5 - conventional tillage system (SPC) and T6 - system tillage (NT). Samples were collected at 0-10 and 10-20 cm, dried and ground for analysis in EDX-720. The soil showed no difference in the average concentrations of chemical elements analyzed in the profiles, but the systems presented different concentrations of metal elements, and T3 had the highest K, Ca and Zn at 0-10 cm and higher contents of K, Ca, Cu, Zn and Mn in the layer of 10-20 cm. (author)

  10. Behavior of radon, chemical compounds and stable elements in underground water; Comportamiento de radon, compuestos quimicos y elementos estables en agua subterranea

    Energy Technology Data Exchange (ETDEWEB)

    Lopez R, N.; Segovia, N.; Lopez, M.B.E.; Pena, P. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Armienta, M.A.; Godinez, L. [IGFUNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Seidel, J.L. [ISTEEM, M.S.E. Montpellier (France)

    2001-07-01

    The radon behavior, chemical compounds, major and trace elements in water samples of four springs and three wells of urban and agricultural zones around the Jocotitlan volcano and El Oro region was determined, both of them located in the medium part of the Mexican neo-volcanic axis. The {sup 222} Rn was measured by the liquid scintillation method, the analysis of major components was realized with conventional chemical techniques, while the trace elements were quantified using an Icp-Ms. The average values of the radon concentrations obtained during one year were constant relatively, in an interval from 0.97 to 4.99 Bq/lt indicating a fast transport from the reload area toward the sampling points. the compounds, major and trace elements showed differences which indicate distinct origins of water from the site studies. (Author)

  11. Partitioning of Trace Elements Between Hydrous Minerals and Aqueous Fluids : a Contribution to the Chemical Budget of Subduction Zones

    Science.gov (United States)

    Daniel, I.; Koga, K. T.; Reynard, B.; Petitgirard, S.; Chollet, M.; Simionovici, A.

    2006-12-01

    Subduction zones are powerful chemical engines where the downgoing lithosphere reacts with asthenospheric mantle and produces magmas. Understanding this deep recycling system is a scientific challenge requiring multiple approaches. Among those, it appears that we lack basic information on the composition of the fluid that begins the process of material transfer in subduction zones. Indeed, no pristine fluid sample has yet been collected from this particular environment. Albeit challenging, the alternative would be experimental study of fluids under the appropriate conditions. Consequently, we developed an experimental protocol to measure the concentration of aqueous fluids equilibrated with minerals up to pressures (P) of 5 GPa, at least and temperatures (T) of 550 C. This includes syntheses at high-P and -T conditions, and determination of the fluid composition. Syntheses were performed in a large volume belt-type press at the conditions, 2-5 GPa and ca. 550 C. Oxides or minerals were loaded with water in a gold capsule sealed afterwards. Presence of free fluid during experiments could be confirmed by direct observation of fluid release from the sealed capsule upon puncturing. The composition in trace elements of the fluids that were equilibrated at high-P and -T with minerals was reconstructed from that of the precipitates deposited at the surface of minerals after evaporation of the capsule. The precipitates were dissolved and analyzed by a leaching technique detailed in Koga et al. (2005). Two hydrous minerals of prime interest for subductions were sofar investigated: the high-pressure variety of serpentine, antigorite, and talc. The partitioning coefficients of a series of trace-elements will be presented, as well as their evolution as a function of pressure. Consequences for the composition of the fluids released during the dehydration of hydrous metamorphic minerals will be drawn. Those measurements are unlikely to be feasible at pressures in excess of 5 GPa

  12. Elemental Abundances and their Implications for the Chemical Enrichment of the Boötes I Ultrafaint Galaxy

    Science.gov (United States)

    Gilmore, Gerard; Norris, John E.; Monaco, Lorenzo; Yong, David; Wyse, Rosemary F. G.; Geisler, D.

    2013-01-01

    We present a double-blind analysis of high-dispersion spectra of seven red giant members of the Boötes I ultrafaint dwarf spheroidal galaxy, complemented with re-analysis of a similar spectrum of an eighth-member star. The stars cover [Fe/H] from -3.7 to -1.9 and include a CEMP-no star with [Fe/H] = -3.33. We conclude from our chemical abundance data that Boötes I has evolved as a self-enriching star-forming system, from essentially primordial initial abundances. This allows us uniquely to investigate the place of CEMP-no stars in a chemically evolving system, in addition to limiting the timescale of star formation. The elemental abundances are formally consistent with a halo-like distribution, with enhanced mean [α/Fe] and small scatter about the mean. This is in accord with the high-mass stellar initial mass function in this low-stellar-density, low-metallicity system being indistinguishable from the present-day solar neighborhood value. There is a non-significant hint of a decline in [α/Fe] with [Fe/H]; together with the low scatter, this requires low star formation rates, allowing time for supernova ejecta to be mixed over the large spatial scales of interest. One star has very high [Ti/Fe], but we do not confirm a previously published high value of [Mg/Fe] for another star. We discuss the existence of CEMP-no stars, and the absence of any stars with lower CEMP-no enhancements at higher [Fe/H], a situation that is consistent with knowledge of CEMP-no stars in the Galactic field. We show that this observation requires there be two enrichment paths at very low metallicities: CEMP-no and "carbon-normal." Based on observations collected at the European Southern Observatory, Paranal, Chile (Proposal P82.182.B-0372, PI: G. Gilmore).

  13. Content of chemical elements in tree rings of lodgepole pine and whitebark pine from a subalpine Sierra Nevada forest

    Science.gov (United States)

    David L. Peterson; Darren R. Anderson

    1990-01-01

    The wood of lodgepole pines and whitebark pines from a high elevation site in the east central Sierra Nevada of California was analyzed for chemical content to determine whether there were any temporal patterns of chemical distribution in tree rings. Cores were taken from 10 trees of each species and divided into 5-year increments for chemical analysis. Correlation...

  14. Use of chemical elements of 1A family by tropical tree species; Uso de elementos quimicos da familia 1A por especies arboreas tropicais

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Andrius M.J.; Paiva, Jose Daniel S. de; Magalhaes, Marcelo R.L. de; Franca, Elvis J. de; Hazin, Clovis A., E-mail: ejfranca@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Bacchi, Marcio A.; Fernandes, Elisabete A.N., E-mail: mabacchi@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil).

    2013-07-01

    This study aims to evaluate the distribution of K, Rb and Cs in leaves of trees of the Atlantic Forest through studies of correlation between the chemical elements. For this, we used the Instrumental Neutron Activation Analysis for the quantification of the chemical elements. The concentration ranges found were 6700-24000 mg / kg for K, 16 to 72mg / kg for Rb and 0.08 to 0,92mg / kg for Cs. As Rb has chemical similarity to K, is easily absorbed by plants, leading to a high value (0.9) of the Pearson correlation. For the correlation between K and Cs, no significant values were detected except for some species of the Myrtaceae family. However, average correlations (0.6 chemical elements in the ecosystem.

  15. Mobility of plume-derived volcanogenic elements in meteoric water at Nyiragongo volcano (Congo) inferred from the chemical composition of single rainfall events

    Science.gov (United States)

    Liotta, Marcello; Shamavu, Patient; Scaglione, Sarah; D'Alessandro, Walter; Bobrowski, Nicole; Bruno Giuffrida, Giovanni; Tedesco, Dario; Calabrese, Sergio

    2017-11-01

    The chemical composition of single rainfall events was investigated at Nyiragongo volcano (Democratic Republic of Congo) with the aim of determining the relative contributions of plume-derived elements. The different locations of the sampling sites allowed both plume-affected samples (hereafter referred to as ;fumigated samples;) and samples representative of the local background to be collected. The chemical composition of the local background reflects the peculiar geographic features of the area, being influenced by biomass burning, geogenic dust, and biological activity. Conversely, fumigated samples contain large amounts of volcanogenic elements that can be clearly distinguished from the local background. These elements are released into the atmosphere from the persistently boiling lava lake of the Nyiragongo crater and from the neonate lava lake of Nyamulagira. These emissions result in a volcanic plume that includes solid particles, acidic droplets, and gaseous species. The chemical signature of the volcanic emissions appears in falling raindrops as they interact with the plume. HCl and HBr readily dissolve in water, and so their ratio in rain samples reflects that of the volcanic plume. The transport of HF is mediated by the large amount of silicate particles generated at the magma-air interface. SO2 is partially converted into SO42- that dissolves in water. The refractory elements dissolved in rain samples derive from the dissolution of silicate particles, and most of them (Al, Mg, Ca, and Sr) are present at exactly the same molar ratios as in the rocks. In contrast, elements such as Na, K, Rb, Cu, and Pb are enriched relative to the whole-rock composition, suggesting that they are volatilized during magma degassing. After correcting for the dissolution of silicate particles, we can define that the volatility of the elements decreases in the following order: Pb ≫ Rb > K > Na. This finding, which is the first for a volcanic plume, is consistent with

  16. Mechanical properties investigation on single-wall ZrO2 nanotubes: A finite element method with equivalent Poisson's ratio for chemical bonds

    Science.gov (United States)

    Yang, Xiao; Li, Huijian; Hu, Minzheng; Liu, Zeliang; Wärnå, John; Cao, Yuying; Ahuja, Rajeev; Luo, Wei

    2018-04-01

    A method to obtain the equivalent Poisson's ratio in chemical bonds as classical beams with finite element method was proposed from experimental data. The UFF (Universal Force Field) method was employed to calculate the elastic force constants of Zrsbnd O bonds. By applying the equivalent Poisson's ratio, the mechanical properties of single-wall ZrNTs (ZrO2 nanotubes) were investigated by finite element analysis. The nanotubes' Young's modulus (Y), Poisson's ratio (ν) of ZrNTs as function of diameters, length and chirality have been discussed, respectively. We found that the Young's modulus of single-wall ZrNTs is calculated to be between 350 and 420 GPa.

  17. Experimental research on the contrast production of the chemical elements with the atomic numbers 1-83 in a computer-totalbody-tomogram

    International Nuclear Information System (INIS)

    Kirschner, H.; Burmester, U.; Stringaris, K.

    1979-01-01

    The contrast production for the chemical elements with the atomic numbers Z=1-83 were determined by computer-tomography. With the formula relation of the Δ-number and the atomic number can one compute the contrast production of any chosen chemical compound. Iodine-free and inorganic iodine-containing contrast media are examined for their contrast production and compared with presently used organic iodine-containing contrast media. The contrast enhancement of organic contrast media in tissue are discussed. (orig.) [de

  18. Identifying Military Impacts on Archaeological Deposits Based on Differences in Soil Organic Carbon and Chemical Elements at Soil Horizon Interfaces

    Science.gov (United States)

    2012-03-01

    Robotic pH meter (AS-3000 Dual pH Analyzer, LabFit, Burswood, Australia) using a 1:1 soil / solution ratio (0.01 M CaCl2) (Kissel et al., 2009). Soil lime...displacement of elements in the soil profile, and alterations in mineralization processes which affect the leachable element concentration in soil solution . Leachable

  19. Plant-beneficial elements status assessment in soil-plant system in the vicinity of a chemical industry complex: shedding light on forage grass safety issues.

    Science.gov (United States)

    Anjum, Naser A; Duarte, Armando C; Pereira, Eduarda; Ahmad, Iqbal

    2015-02-01

    Human health is closely linked with soils via plants, grazers, or plant-based products. This study estimated plant-beneficial elements (macronutrients: K, P; secondary macronutrients: Ca, Mg; micronutrients: Mo, Mn, Na, Ni, Se) in both soils and shoots of two forage grass species (Eriophorum angustifolium and Lolium perenne) prevalent in the vicinity of a chemical industry complex (Estarreja, Portugal). Both soils and plants from the chemical industrial areas exhibited differential concentrations of the studied elements. In soils, the role of contamination was evidenced as insignificant in context of its impact on all the tested macro and secondary macronutrients except P, and micronutrients such as Mo and Ni. In forage grass plant shoots, the role of contamination was evidenced as insignificant in relation to its impact on all the tested macro and secondary macronutrients except K. Between the two forage grass plants, high Se-harboring L. perenne cannot be recommended for its use as animal feed.

  20. Transactinide elements

    International Nuclear Information System (INIS)

    Hemingway, J.D.

    1975-01-01

    The review is covered in sections, entitled: predicted nuclear properties - including closed shells, decay characteristics; predicted chemical properties - including electronic structure and calculated properties, X-radiation, extrapolated chemical properties, separation chemistry; methods of synthesis; the natural occurrence of superheavy elements. (U.K.)

  1. The Natural Selection of the Chemical Elements (by R. J. P. Williams and J. J. R. Fraústo da Silva)

    Science.gov (United States)

    Kauffman, George B.

    1998-12-01

    Clarendon: New York, 1996. xxvi + 646 pp. Figs., tables. 20.5 x 25.6 cm. ISBN 0-19-855843-0. $80.00. R. J. P. Williams, Royal Society Research Professor Emeritus at Wadham College, Oxford University, and J. J. R. Fraústo da Silva, Professor of Analytical Chemistry at the Instituto Superior Técnico, Universidade Técnica de Lisboa, have collaborated on two previous volumes: New Trends in Bio-inorganic Chemistry (1978) and The Biological Chemistry of the Elements (3rd printing, 1994). Their latest collaborative effort is a book whose ambitious objective is "to show the relationship of every kind of material around us, living and nonliving, to the properties of the chemical elements of the periodic table." The "natural selection" of the chemical elements results from a number of factors, all of which are described in detail. Among these are chemical affinity related to the electronic configuration of their atoms, thermodynamic and kinetic stability, and "functional value to an organisation such as a living system". The physicist's approach to material through phase structure and the phase rule is stressed rather than the chemist's approach through bonding theories. The entire book possesses a strong environmental and interdisciplinary emphasis.

  2. Alguns aspectos históricos da classificação periódica dos elementos químicos Some historical aspects of the periodic classification of the chemical elements

    Directory of Open Access Journals (Sweden)

    Mario Tolentino

    1997-02-01

    Full Text Available A history of the periodic table of the elements is presented, from the first tentative classifications, passing through Meyer and Mendeleev, up to recent speculations on super-heavy elements still to be synthesized. Many of the discussions and discoveries related to chemical elements and their proper periodic classification are also presented.

  3. Distribution of chemical elements in attic dust as reflection of their geogenic and anthropogenic sources in the vicinity of the copper mine and flotation plant.

    Science.gov (United States)

    Balabanova, Biljana; Stafilov, Trajče; Sajn, Robert; Bačeva, Katerina

    2011-08-01

    The main aim of this article was to assess the atmospheric pollution with heavy metals due to copper mining Bučim near Radoviš, the Republic of Macedonia. The open pit and mine waste and flotation tailings are continually exposed to open air, which leads to winds carrying the fine particles into the atmosphere. Samples of attic dust were examined as historical archives of mine emissions, with the aim of elucidating the pathways of pollution. Dust was collected from the attics of 29 houses, built between 1920 and 1970. Nineteen elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Li, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn) were analyzed by atomic emission spectrometry with inductively coupled plasma. The obtained values of the investigated elements in attic dust samples were statistically processed using nonparametric and parametric analysis. Factor analysis revealed three factors governing the source of individual chemical elements. Two of them grouping Ca, Li, Mg, Mn, and Sr (Factor 1) and Co, Cr, and Ni (Factor 2) can be characterized as geogenic. The third factor grouping As, Cu, and Pb is anthropogenic and mirrors dust fallout from mining operation and from flotation tailings. Maps of areal deposition were prepared for this group of elements, from which correlation of these anthropogenic born elements was confirmed.

  4. Sampling strategy and analysis of trace element concentrations by inductively coupled plasma mass spectrometry on medieval human bones--the concept of chemical life history.

    Science.gov (United States)

    Skytte, Lilian; Rasmussen, Kaare Lund

    2013-07-30

    Medieval human bones have the potential to reveal diet, mobility and treatment of diseases in the past. During the last two decades trace element chemistry has been used extensively in archaeometric investigations revealing such data. Many studies have reported the trace element inventory in only one sample from each skeleton - usually from the femur or a tooth. It cannot a priori be assumed that all bones or teeth in a skeleton will have the same trace element concentrations. Six different bone and teeth samples from each individual were carefully decontaminated by mechanical means. Following dissolution of ca. 20 mg sample in nitric acid and hydrogen peroxide the assays were performed using inductively coupled plasma mass spectrometry (ICPMS) with quadropole detection. We describe the precise sampling technique as well as the analytical methods and parameters used for the ICPMS analysis. The places of sampling in the human skeleton did exhibit varying trace element concentrations. Although the samples are contaminated by Fe, Mn and Al from the surrounding soil where the bones have been residing for more than 500 years, other trace elements are intact within the bones. It is shown that the elemental ratios Sr/Ca and Ba/Ca can be used as indicators of provenance. The differences in trace element concentrations can be interpreted as indications of varying diet and provenance as a function of time in the life of the individual - a concept which can be termed chemical life history. A few examples of the results of such analyses are shown, which contains information about provenance and diagenesis. Copyright © 2013 John Wiley & Sons, Ltd.

  5. Chemical properties of some elements in a molten lithium chloride, potassium chloride eutectic (1962); Proprietes chimiques de quelques elements dans l'eutectique chlorure de lithium-chlorure de potassium fondu (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-12-15

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

  6. The Effect of Risk Factors on the Levels of Chemical Elements in the Tibial Plateau of Patients with Osteoarthritis following Knee Surgery

    Directory of Open Access Journals (Sweden)

    Natalia Lanocha-Arendarczyk

    2015-01-01

    Full Text Available The aim of this study was to evaluate the aforementioned chemical elements in tibial plateau samples obtained during knee arthroplasty. The gender-specific analysis of chemical element levels in the bone samples revealed that there were statistically significant differences in the concentration of Pb and Se/Pb ratio. The contents of elements in the tibial plateau in the patients with osteoarthritis (OA can be arranged in the following descending order: F− > K > Zn > Fe > Sr > Pb > Mn > Se > Cd > THg. We observed statistical significant effects of environmental factors including smoking, seafood diet, and geographical distribution on the levels of the elements in tibial bone. Significant positive correlation coefficients were found for the relationships K-Cd, Zn-Sr, Zn-F−, THg-Pb, Pb-Cd, Se-Se/Pb, Se-Se/Cd, Se/Pb-Se/Cd, Pb-Cd/Ca, Cd-Cd/Ca, and F−-F−/Ca·1000. Significant negative correlations were found for the relationships THg-Se/Pb, Pb-Se/Pb, Cd-Se/Pb, K-Se/Cd, Pb-Se/Cd, Cd-Se/Cd, THg-Se/THg, Pb-Se/THg, Se-Pb/Cd, Zn-Cd/Ca, and Se/Cd-Cd/Ca. The results reported here may provide a basis for establishing reference values for the tibial plateau in patients with OA who had undergone knee replacement surgery. The concentrations of elements in the bone with OA were determined by age, presence of implants, smoking, fish and seafood diet, and sport activity.

  7. Assessment of atmospheric pollution of chemical elements by epiphytic lichen analysis at the Campus of the Sao Paulo University

    International Nuclear Information System (INIS)

    Rocha, Rosiana Rocho

    2015-01-01

    Air pollution has been a frequent topic of research, due to the effects that it can cause on the health of living organisms, environment and climate. In order to identify pollution sources and their effects, biomonitoring has been studied due to its low cost and possibility of sampling in wide geographic areas. In this study for passive biomonitoring of air pollution levels at the Cidade Universitaria Armando Salles de Oliveira (CUASO), University of Sao Paulo campus, epiphytic lichens of Canoparmelia texana species were used. The lichens collected from tree barks at different sampling sites in the CUASO were cleaned, freeze-dried and ground for analyses. Lichen samples were analyzed by X - ray fluorescence spectrometry (XRFS) and neutron activation analysis (NAA). For XRFS, cylindrical pellets of samples were prepared to determine As, Br, Ca, Cl, Cr, Cu, Fe, K, Mn, Rb, S, Sr and Zn. For NAA, lichen sample aliquots along with synthetic elemental standards were irradiated both for short and long periods at the IEA-R1 nuclear research reactor. The induced activities were measured by a gamma ray spectrometer to determine As, Br, Ca Cd, Cl, Co, Cr, Cs, Cu, Fe, K, La, Mg, Mn, Rb, Sb, Sc, Se, U, V and Zn. The precision and accuracy of the results were evaluated by the analysis of certified reference materials (MRCs). Their results of relative errors and standard deviations were below 15% for most of the elements. The standardized difference or En score values were lower than |1| indicating satisfactory results. Replicate analyses of a lichen sample by XRFS and NAA, indicated good homogeneity of the sample for the elements determined. The lichen results showed that the mean concentrations of As, Br, Ca, Cd, Co, Cr, Cs, Rb, Sb, Se and U were higher in samples from CUASO than those from regions considered unpolluted. For Fe, K, La, S, V and Zn, they were of the same order of magnitude. The correlation study between the elements showed high correlation (r > 0.7) for elements

  8. Chemical elements in pearl oysters (Paxyodon ponderosus), phytoplankton and estuarine sediments from eastern Amazon (Northern Brazil): Bioaccumulation factors and trophic transfer factors

    Science.gov (United States)

    Vilhena, Maria P. S. P.; Costa, Marcondes L.; Berrêdo, José F.; Paiva, Rosildo S.; Souza, Crisvaldo C. S.

    2016-04-01

    The current study was conducted near Barcarena County, which is a mid-sized urban center where aluminum ore processing industries (bauxite) and Vila do Conde cargo terminal are located. It aims to discuss the bioaccumulation factors as well as factors related to the trophic transfer of chemical elements in water, oyster, phytoplankton and bottom sediments from an estuary in the Brazilian Northern coast. The bioaccumulation factor (BAF), trophic transfer factor (TTF) and biota-sediment-water were used to correlate the contents of chemical elements found in organisms. The sediment, surface water, phytoplankton and pearl oysters chemical composition was analyzed by ICP-OES and ICP-MS. Pearl oysters showed K, Ca, Mg, P, Mn, Fe, Zn, Al, Ba and Pb accumulation, which concentration increase is associated with their diet (phytoplankton). Al concentrations are 14 times higher in pearl oysters (Paxyodon ponderosus), assuming that they are associated with wastewater emissions and with industrialization processes in the area. BAF and BSAF values are 1000 times higher than the metal concentrations in water and bioavailable fraction concentrations. The oyster-phytoplankton trophic transfer factor indicates that P, Ba, Ca, Na, Cd and Zn showed the largest transfers (from 5 to 19). These trophic transfers may be sufficient to cause significant ecotoxicological effects on the region biota.

  9. The use of neutron activation analysis for particle size fractionation and chemical characterization of trace elements in urban air particulate matter

    International Nuclear Information System (INIS)

    Rizzio, E.; Bergamaschi, G.; Profumo, A.; Gallorini, M.

    2001-01-01

    The concentration of more than 25 trace elements have been determined in total air particulate matter and in the size segregated fractions from the urban area of Pavia (North Italy). The PM10 fraction was also collected and analyzed. A study of the solubility in water and in physiological solution of the trace elements contained in the PM10 was also carried out. The resulting solutions were further submitted to column chromatography using Chelex 100 to perform a preliminary chemical characterization. INAA was used as the main analytical technique. ET-AAS was used for all Pb and Cd measurements and, in some cases, for the analysis of V, Mn, Cu and Ni. (author)

  10. Integrated chemical sensor array platform based on a light emitting diode, xerogel-derived sensor elements, and high-speed pin printing

    International Nuclear Information System (INIS)

    Cho, Eun Jeong; Bright, Frank V.

    2002-01-01

    We report a new, solid-state, integrated optical array sensor platform. By using pin printing technology in concert with sol-gel-processing methods, we form discrete xerogel-based microsensor elements that are on the order of 100 μm in diameter and 1 μm thick directly on the face of a light emitting diode (LED). The LED serves as the light source to excite chemically responsive luminophores sequestered within the doped xerogel microsensors and the analyte-dependent emission from within the doped xerogel is detected with a charge coupled device (CCD). We overcome the problem of background illumination from the LED reaching the CCD and the associated biasing that results by coating the LED first with a thin layer of blue paint. The thin paint layer serves as an optical filter, knocking out the LEDs red-edge spectral tail. The problem of the spatially-dependent fluence across the LED face is solved entirely by performing ratiometric measurements. We illustrate the performance of the new sensor scheme by forming an array of 100 discrete O 2 -responsive sensing elements on the face of a single LED. The combination of pin printing with an integrated sensor and light source platform results in a rapid method of forming (∼1 s per sensor element) reusable sensor arrays. The entire sensor array can be calibrated using just one sensor element. Array-to-array reproducibly is <8%. Arrays can be formed using single or multiple pins with indistinguishable analytical performance

  11. Examination of chemical elements partitioning between the γ and γ′ phases in CMSX-4 superalloy using EDS microanalysis and electron tomography

    Directory of Open Access Journals (Sweden)

    Kruk Adam

    2014-01-01

    Full Text Available In the present study, the partition of chemical elements between γ and γ′ phases in CMSX-4 was investigated using EDS microanalysis and electron tomography (FIB-SEM and STEM-EDS methods. The investigation has been performed for the superalloy after standard heat treatment and the ex-service CMSX-4 turbine blade after operation for 12 700 hours and 200 starts in industrial gas turbine. The results have shown that Co, Cr and Re partition to the γ matrix, Ni and W are present in both γ and γ′ phases, while Al, Ti and Ta strongly partition to the γ′ phase. The results show the abilities of new analytical electron microscopy and electron tomography methods to characterize the microstructure and chemical composition of single crystal superalloys at the nanoscale.

  12. The study of chemical composition and elemental mappings of colored over-glaze porcelain fired in Qing Dynasty by micro-X-ray fluorescence

    International Nuclear Information System (INIS)

    Cheng Lin; Li Meitian; Kim Youshi; Fan Changsheng; Wang Shanghai; Pan Qiuli; Liu Zhiguo; Li Rongwu

    2011-01-01

    It is very difficult to measure the chemical composition of colored pigments of over-glaze porcelain by X-ray fluorescence because it contains high concentration of Pb. One of the disadvantages of our polycapillary optics is that it has low transmission efficiency to the high energy X-ray. However, it is beneficial to measure the chemical compositions of rich Pb sample. In this paper, we reported the performances of a tabletop setup of micro-X-ray fluorescence system base on slightly focusing polycapillary and its applications for analysis of rich Pb sample. A piece of Chinese ancient over-glaze porcelain was analyzed by micro-X-ray fluorescence. The experimental results showed that the Cu, Fe and Mn are the major color elements. The possibilities of the process of decorative technology were discussed in this paper, also.

  13. Physical-chemical modeling of elements' behavior in mixing sea and fresh waters of minor rivers in the White Sea catchment area.

    Science.gov (United States)

    Maksimova, Victoria V; Mazukhina, Svetlana I; Cherepanova, Tatiana A; Gorbacheva, Tamara T

    2017-07-29

    The physical-chemical stage of marginal filters in minor rivers of the White Sea catchment area by the example of the Umba River, flowing to Kandalaksha Gulf, has been explored. Application of the method of physical-chemical modeling on the basis of field data allowed establishing migration forms of a number of elements in the "river-sea" system and deposition of solid phases when mixing waters. The mixing of river and sea water is accompanied by the sedimentation of predominantly goethite, hydromuscovite, and hydroxylapatite. Sediments in mixing river and sea waters were found to be mainly composed by goethite, hydromuscovite, and hydroxylapatite. The research has added to the knowledge of the role of the abiotic part in the marginal filters of small rivers in the Arctic.

  14. The study of chemical composition and elemental mappings of colored over-glaze porcelain fired in Qing Dynasty by micro-X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Lin, E-mail: chenglin@bnu.edu.c [Beijing Normal University, Beijing 100875 (China); Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Radiation Center, Beijing 100875 (China); Li Meitian; Kim Youshi [Beijing Normal University, Beijing 100875 (China); Fan Changsheng; Wang Shanghai [Jiangxi Provincial Institute of Archaeology, Jiangxi Province 330025 (China); Pan Qiuli; Liu Zhiguo [Beijing Normal University, Beijing 100875 (China); Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Radiation Center, Beijing 100875 (China); Li Rongwu [Beijing Normal University, Beijing 100875 (China)

    2011-02-01

    It is very difficult to measure the chemical composition of colored pigments of over-glaze porcelain by X-ray fluorescence because it contains high concentration of Pb. One of the disadvantages of our polycapillary optics is that it has low transmission efficiency to the high energy X-ray. However, it is beneficial to measure the chemical compositions of rich Pb sample. In this paper, we reported the performances of a tabletop setup of micro-X-ray fluorescence system base on slightly focusing polycapillary and its applications for analysis of rich Pb sample. A piece of Chinese ancient over-glaze porcelain was analyzed by micro-X-ray fluorescence. The experimental results showed that the Cu, Fe and Mn are the major color elements. The possibilities of the process of decorative technology were discussed in this paper, also.

  15. Serum levels of chemical elements in esophageal squamous cell carcinoma in Anyang, China: a case-control study based on machine learning methods.

    Science.gov (United States)

    Lin, Tong; Liu, Tiebing; Lin, Yucheng; Zhang, Chaoting; Yan, Lailai; Chen, Zhongxue; He, Zhonghu; Wang, Jingyu

    2017-09-24

    Esophageal squamous cell carcinoma (ESCC) is the predominant form of esophageal carcinoma with extremely aggressive nature and low survival rate. The risk factors for ESCC in the high-incidence areas of China remain unclear. We used machine learning methods to investigate whether there was an association between the alterations of serum levels of certain chemical elements and ESCC. Primary healthcare unit in Anyang city, Henan Province of China. 100 patients with ESCC and 100 healthy controls matched for age, sex and region were included. Primary outcome was the classification accuracy. Secondary outcome was the p Value of the t-test or rank-sum test. Both traditional statistical methods of t-test and rank-sum test and fashionable machine learning approaches were employed. Random Forest achieves the best accuracy of 98.38% on the original feature vectors (without dimensionality reduction), and support vector machine outperforms other classifiers by yielding accuracy of 96.56% on embedding spaces (with dimensionality reduction). All six classifiers can achieve accuracies more than 90% based on the single most important element Sr. The other two elements with distinctive difference are S and P, providing accuracies around 80%. More than half of chemical elements were found to be significantly different between patients with ESCC and the controls. These results suggest clear differences between patients with ESCC and controls, implying some potential promising applications in diagnosis, prognosis, pharmacy and nutrition of ESCC. However, the results should be interpreted with caution due to the retrospective design nature, limited sample size and the lack of several potential confounding factors (including obesity, nutritional status, and fruit and vegetable consumption and potential regional carcinogen contacts). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted

  16. Determination of the concentration profile of chemical elements in superheater pipes; Determinacion del perfil de concentracion de elementos quimicos en tubos de sobrecalentadores

    Energy Technology Data Exchange (ETDEWEB)

    Aldape U, F; Aspiazu F, J [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1986-05-15

    This work has for object to determine the profile of concentration of chemical elements at trace level in a superheater pipe of Thermoelectric Plants using the X-ray emission spectroscopy technique induced by protons coming from the Accelerator of the Nuclear Center. In the X-ray detection, a Si Li detector was used. The technique was chosen because it allows a multielemental analysis, of high sensitivity and precision. The results can help to understand the problems that are had in the change of flexibility or of corrosion. This will be from utility to the Federal Electricity Commission (CFE). (Author)

  17. Growth mechanism and elemental distribution of beta-Ga2O3 crystalline nanowires synthesized by cobalt-assisted chemical vapor deposition.

    Science.gov (United States)

    Wang, Hui; Lan, Yucheng; Zhang, Jiaming; Crimp, Martin A; Ren, Zhifeng

    2012-04-01

    Long beta-Ga2O3 crystalline nanowires are synthesized on patterned silicon substrates using chemical vapor deposition technique. Advanced electron microscopy indicates that the as-grown beta-Ga2O3 nanowires are consisted of poly-crystalline (Co, Ga)O tips and straight crystalline beta-Ga2O3 stems. The catalytic cobalt not only locates at the nanowire tips but diffuses into beta-Ga2O3 nanowire stems several ten nanometers. A solid diffusion growth mechanism is proposed based on the spatial elemental distribution along the beta-Ga2O3 nanowires at nanoscale.

  18. Studies on the Elemental and Chemical Constituent of Some Myanmar Indigenous Medicinal Plants used for the Treatment of Hypertension

    International Nuclear Information System (INIS)

    Myatt Hla Wai; Kyaw Naing; Hla Ngwe; Hnin Pwint Aung; Myint U; Maung Maung Htay

    2004-06-01

    Study of Myanmar indigenous medicinal plants used for the treatment of hypertension was conducted. The samples studied were Gant-ka-lar (Gisekia pharnaceoides), Dan-da-lun (Moringa oleifera), Egayit (Millingtonia hortensis), Sue-pan (Carthumas tinctarius), Kauk-yoe-new (Oxystelma esculentum), Shauk (Citrus medica), Kyet-lei-san (Vitex glabrata), Sin-ngo-myet (Eleusine indica). In all these samples, qualitative determination of potassium had been determined by High Purity Germanium gamma counter and quantitative determination had been accomplished by NaI (Tl) gamma scintillation counting and ''Aloka'' gross gamma counting methods. In addition, quantitative determination of the elements in these samples was carried out by Atomic Absorption Spectrophotometry and Flame photometry. Relative quantitative elemental analysis of these samples was carried out by using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometry

  19. Some Chemical Elements in Gamma Irradiated Adults of the Mediterranean Fruit Fly, Ceratitis capitata (Wied.) Fed on Different Diets

    International Nuclear Information System (INIS)

    Elakhdar, E.A.H.

    2013-01-01

    The elemental composition of four yeast diets differ in protein composition and mixed with sugar as a carbohydrate source were compared with a standard yeast diet used for the mass rearing of med fly C. capitata. The cost availability and the effects on the quality of reared flies were the main measures for these comparisons. Moreover, the elemental composition of reared flies on the tested diets either irradiated to gamma radiation or normal beside full grown pupae (F1) were detected and compared with those reared on standard diet . Data obtained revealed that ten elements (K, N, Na, P, Ca, Fe, Mg, Zn, Mn and Cu) were detected and classified according to their quantities .However those quantities varied according to the type of used yeast ,insect stage , insect sex and irradiated dose. The major group (K, N, Na and P), moderate group (Ca, Fe and Mg) and minor group (Zn, Mn and Cu) remained unchanged although their quantities were changed inside each group. In addition, a significant increase in K, N, Na, P and Ca when diet No.4 (D4) was used to feed flies. These findings may enhance the opportunity of sterile insect technique (SIT). However Fe and Zn ions were decreased with changing the standard yeast and this is may contradict SIT. Also when normal females fed on all tested yeasts, the concentrations of the ten elements increased as compared to those fed on standard diet. These results may increase the efficiency of sterilized reared insects to compete with the native insects in the field

  20. Multi trace element analysis of dry biological materials by neutron activation analysis including a chemical group separation

    International Nuclear Information System (INIS)

    Weers, C.A.

    1980-07-01

    Multi-element analysis of dry biological material by neutron activation analysis has to include radiochemical separation. The evaporation process is described in terms of the half-volume. The pretreatment of the samples and the development of the destruction-evaporation apparatus are described. The successive adsorption steps with active charcoal, Al 2 O 3 and coprecipitation with Fe(OH) 3 are described. Results obtained for standard reference materials are summarized. (G.T.H.)

  1. Chemical Identification of Dubnium as a Decay Product of Element 115 Produced in the Reaction $\\rm {^{48}Ca}+{^{243}Am}$

    CERN Document Server

    Dmitriev, S N; Utyonkov, V K; Shishkin, S V; Eremin, A V; Lobanov, Yu V; Chepigin, V I; Sokol, E A; Tsyganov, Yu S; Vostokin, G K; Aksenov, N V; Hussonnois, M; Itkis, M G; Aggeler, H W; Schumann, D; Bruchertseifer, H; Eichler, R; Shaughnessy, D A; Wilk, P A; Kenneally, J M; Stoyer, M A; Wild, J F

    2004-01-01

    The results of an experiment designed to identify $^{268}$Db as the terminal isotope in the $\\alpha $-decay chain of element 115 produced via the ${\\rm {^{243}Am}}({\\rm {^{48}Ca}},3n){\\rm {^{288}115}}$ reaction are presented. The $^{243}$Am target was bombarded with a beam dose of $3.4\\cdot 10^{18}$ $^{48}$Ca projectiles at an energy of 247 MeV at the center of the target. The reaction products were collected in the surface layer of a copper catcher block, which was removed with a lathe and then dissolved in concentrated HNO$_{3}$. The group-5 elements were separated by sorption onto Dowex $50{\\times} 8$ cation-exchange resin with subsequent desorption using 1 M HF, which forms anionic fluoride complexes of group-5 elements. The eluent was evaporated onto a 0.4 $\\mu$m thick polyethylene foil that was placed between a pair of semiconductor detectors surrounded by $^{3}$He neutron counters for measurement of $\\alpha$ particles, fission fragments, and neutrons. In the course of the experiment, we observed 15 spo...

  2. Analysis of the chemical elements behavior in leaves infected with fumagina employing X-ray fluorescence technique

    International Nuclear Information System (INIS)

    Blonski, Maria Selia

    2002-02-01

    Fumagina is produced by the Capnodium fungi, a mushroom from Dothideales order, that lives associated with the yellow aphid (Monelliopsis pecanis), excreting a heavy load of a sugared substance that provides the sooty fungus development, covering, in some cases the totality, of leaves, fruits and branches surfaces. One of the big problems caused by this disease is the physic photosynthesis stuckness, reducing in 98% the active photosynthesis radiation and in 70% the net photosynthesis. This photosynthesis reduction affects the plants carbohydrate reservoirs, resulting in reduced and bad qualified crops. It was employed the Energy Dispersion X-Ray Fluorescence Technique (EDXRF) to study the fumagina disease. The measurements were realized with infected and healthy leaves of citric plants (orange and lemon trees), collected at the Farm School of the State University of Londrina, and also leaves of icsora plant from Piracicaba-SP. Through this technique it was observed a metabolic disorder related to Fe and Ca elements. By comparing the EDXRF spectra of the healthy plant leaves with the infected ones, it was verified that the concentration of Ca is higher than the concentration Fe in leaves of healthy plants, while for the leaves of plants infected with fumagina, it was observed a higher concentration of Fe. Employing EDXRF and the emission/transmission method for the matrix effect correction, samples of the citric plants were also analysed in pellet. The elements K, Ca, Ti, Mn , Fe, Cu and Zn were quantified. It was verified a higher Fe concentration in fumagina samples compared to the samples without fumagina. For all the elements of interest the minimum level of detection found was at the order of μg g -1 . (author)

  3. Determination of elemental and physico-chemical quality of well waters and assessment of their impacts on public health

    International Nuclear Information System (INIS)

    Randriamanivo, L.V.; Rasolofonirina, M.; Rakotondramanana, H.T.; Rasoazanany, E.O.; Razafy Andrianarivo, R.

    2001-01-01

    Water is one the most important constituents of the human environment. The relevance of determining pollutants in drinking water is obvious because it is among the pathways of contaminants to enter the organism. The aim of this work is to determine water quality and thus to assess the effects on humans. Total Reflection X-Ray Fluorescence analysis method (TXRF) has been applied for the measurements of trace elements in drinking water. The analyses were performed without any pre-concentration of samples. Colorimetric method was used for the analysis of major components of water. The samples were collected in the regions towards southern Antananarivo. Well waters were sampled because they are the type of drinking water consumed by the population in these regions. Analytical results showed that the determined concentrations of toxic elements such as chromium and lead are largely lower than the maximum allowed values, except two sites were lead concentration exceeds it. For Fe, five sites showed water samples having iron concentrations higher than Recommended Value (50 μg.L -1 ) fixed by the European Union. The mean values for barium and manganese were above the maximum allowed value established by law in some sites. This is mainly due to the geology of the terrain. Concerning nitrate, three sites showed higher concentration than the maximum allowed value.

  4. Linking chemical elements in forest floor humus (Oh-horizon) in the Czech Republic to contamination sources

    International Nuclear Information System (INIS)

    Sucharova, Julie; Suchara, Ivan; Hola, Marie; Reimann, Clemens; Boyd, Rognvald; Filzmoser, Peter; Englmaier, Peter

    2011-01-01

    While terrestrial moss and other plants are frequently used for environmental mapping and monitoring projects, data on the regional geochemistry of humus are scarce. Humus, however, has a much larger life span than any plant material. It can be seen as the 'environmental memory' of an area for at least the last 60-100 years. Here concentrations of 39 elements determined by ICP-MS and ICP AES, pH and ash content are presented for 259 samples of forest floor humus collected at an average sample density of 1 site/300 km 2 in the Czech Republic. The scale of anomalies linked to known contamination sources (e.g., lignite mining and burning, metallurgical industry, coal fired power plants, metal smelters) is documented and discussed versus natural processes influencing humus quality. Most maps indicate a local impact from individual contamination sources: often more detailed sampling than used here would be needed to differentiate between likely sources. - Highlights: → Concentrations of 39 elements in forest floor humus are provided. → The capabilities of humus sampling for bio-monitoring purposes are demonstrated. → Geochemical anomalies are linked to known contamination sources. → The study shows the importance of scale for geochemical mapping projects. → Humus provides a picture of the long term contamination history of a country. - Forest floor humus, the atmosphere-biosphere-pedosphere interface, archives an environmental contamination signal over long time periods.

  5. Study of the composition of chemical elements of contaminated soils in the Bibi-Heybat oil production field

    International Nuclear Information System (INIS)

    Jafarov, E.S; Abbasova, D.R; Rzaguliyev, E.E

    2010-01-01

    Full text:Full text:More attention is given to the study of the results of pollution of the environment with heavy metals in recent years. Occurrence of the disease among the population living near the industrial zone contaminated with Cd element stimulated to this process. It became clear that the cause of this incident, the above-mentioned item in a c ontaminated land - an area formed in the plan into the human body was acting on the food chain. Was determined that the highly toxic cadmium feature to have if it can create a lot of sulfur compounds in close contact. Idea about absolute toxicity in the heavy metals is wrong. On the contrary, this group of the Cu, Zn, Mn, Fe and others, certain quantity of metals, such as living a life that is very important for the activity. Being many of Ca elements in these lands is of special interest. The reason for this, perhaps, of having a high salinity land is dominated by Ca salts.

  6. Linking chemical elements in forest floor humus (O{sub h}-horizon) in the Czech Republic to contamination sources

    Energy Technology Data Exchange (ETDEWEB)

    Sucharova, Julie; Suchara, Ivan; Hola, Marie [Silva Tarouca Research Institute for Landscape and Ornamental Gardening, Kvetnove namesti 391, 252 43 Pruhonice (Czech Republic); Reimann, Clemens, E-mail: Clemens.Reimann@ngu.no [Geological Survey of Norway, P.O. Box 6315 Sluppen, 7491 Trondheim (Norway); Boyd, Rognvald [Geological Survey of Norway, P.O. Box 6315 Sluppen, 7491 Trondheim (Norway); Filzmoser, Peter [Institute for Statistics and Probability Theory, Vienna University of Technology, Wiedner Hauptstrasse 8-10, 1040 Wien (Austria); Englmaier, Peter [Faculty of Life Science, University of Vienna, Althanstr. 14, A-1090 Vienna (Austria)

    2011-05-15

    While terrestrial moss and other plants are frequently used for environmental mapping and monitoring projects, data on the regional geochemistry of humus are scarce. Humus, however, has a much larger life span than any plant material. It can be seen as the 'environmental memory' of an area for at least the last 60-100 years. Here concentrations of 39 elements determined by ICP-MS and ICP AES, pH and ash content are presented for 259 samples of forest floor humus collected at an average sample density of 1 site/300 km{sup 2} in the Czech Republic. The scale of anomalies linked to known contamination sources (e.g., lignite mining and burning, metallurgical industry, coal fired power plants, metal smelters) is documented and discussed versus natural processes influencing humus quality. Most maps indicate a local impact from individual contamination sources: often more detailed sampling than used here would be needed to differentiate between likely sources. - Highlights: > Concentrations of 39 elements in forest floor humus are provided. > The capabilities of humus sampling for bio-monitoring purposes are demonstrated. > Geochemical anomalies are linked to known contamination sources. > The study shows the importance of scale for geochemical mapping projects. > Humus provides a picture of the long term contamination history of a country. - Forest floor humus, the atmosphere-biosphere-pedosphere interface, archives an environmental contamination signal over long time periods.

  7. Geophagy practices and the content of chemical elements in the soil eaten by pregnant women in artisanal and small scale gold mining communities in Tanzania.

    Science.gov (United States)

    Nyanza, Elias C; Joseph, Mary; Premji, Shahirose S; Thomas, Deborah Sk; Mannion, Cynthia

    2014-04-15

    Geophagy, a form of pica, is the deliberate consumption of soil and is relatively common across Sub-Saharan Africa. In Tanzania, pregnant women commonly eat soil sticks sold in the market (pemba), soil from walls of houses, termite mounds, and ground soil (kichuguu). The present study examined geophagy practices of pregnant women in a gold mining area of Geita District in northwestern Tanzania, and also examined the potential for exposure to chemical elements by testing soil samples. We conducted a cross sectional study using a convenience sample of 340 pregnant women, ranging in age from 15-49 years, who attended six government antenatal clinics in the Geita District, Tanzania. Structured interviews were conducted in June-August, 2012, to understand geophagy practices. In addition, soil samples taken from sources identified by pregnant women practicing geophagy were analysed for mineral element content. Geophagy was reported by 155 (45.6%) pregnant women with 85 (54.8%) initiating the practice in the first trimester. A total of 101 (65%) pregnant women reported eating soil 2 to 3 times per day while 20 (13%) ate soil more than 3 times per day. Of 155 pregnant women 107 (69%) bought pemba from local shops, while 48 (31%) consumed ground soil kichuguu. The estimated mean quantity of soil consumed from pemba was 62.5 grams/day. Arsenic, chromium, copper, iron, manganese, nickel and zinc levels were found in both pemba and kichuguu samples. Cadmium and mercury were found only in the kichuguu samples. Based on daily intake estimates, arsenic, copper and manganese for kichuguu and copper and manganese for pemba samples exceed the oral Minimum Risk Levels designated by the U.S. Agency for Toxic Substance and Disease Registry. Almost 50% of participants practiced geophagy in Geita District consistent with other reports from Africa. Both pemba and kichuguu contained chemical elements at varying concentration, mostly above MRLs. As such, pregnant women who eat soil in Geita

  8. [Spatial distribution of birth defects among children aged 0 to 5 years and its relationship with soil chemical elements in Chongqing].

    Science.gov (United States)

    Dong, Yan; Zhong, Zhao-hui; Li, Hong; Li, Jie; Wang, Ying-xiong; Peng, Bin; Zhang, Mao-zhong; Huang, Qiao; Yan, Ju; Xu, Fei-long

    2013-10-01

    To explore the correlation between the incidence of birth defects and the contents of soil elements so as to provide a scientific basis for screening the related pathogenic factors that inducing birth defects for the development of related preventive and control strategies. MapInfo 7.0 software was used to draw the maps on spatial distribution regarding the incidence rates of birth defects and the contents of 11 chemical elements in soil in the 33 studied areas. Variables on the two maps were superposed for analyzing the spatial correlation. SAS 8.0 software was used to analyze single factor, multi-factors and principal components as well as to comprehensively evaluate the degrees of relevance. Different incidence rates of birth defects showed in the maps of spatial distribution presented certain degrees of negative correlation with anomalies of soil chemical elements, including copper, chrome, iodine, selenium, zinc while positively correlated with the levels of lead. Results from the principal component regression equation indicating that the contents of copper(0.002), arsenic(-0.07), cadmium(0.05), chrome (-0.001), zinc (0.001), iodine(-0.03), lead (0.08), fluorine(-0.002)might serve as important factors that related to the prevalence of birth defects. Through the study on spatial distribution, we noticed that the incidence rates of birth defects were related to the contents of copper, chrome, iodine, selenium, zinc, lead in soil while the contents of chrome, iodine and lead might lead to the occurrence of birth defects.

  9. Evaluation of Wet Chemical ICP-AES Elemental Analysis Methods using Simulated Hanford Waste Samples-Phase I Interim Report

    International Nuclear Information System (INIS)

    Coleman, Charles J.; Edwards, Thomas B.

    2005-01-01

    The wet chemistry digestion method development for providing process control elemental analyses of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Melter Feed Preparation Vessel (MFPV) samples is divided into two phases: Phase I consists of: (1) optimizing digestion methods as a precursor to elemental analyses by ICP-AES techniques; (2) selecting methods with the desired analytical reliability and speed to support the nine-hour or less turnaround time requirement of the WTP; and (3) providing baseline comparison to the laser ablation (LA) sample introduction technique for ICP-AES elemental analyses that is being developed at the Savannah River National Laboratory (SRNL). Phase II consists of: (1) Time-and-Motion study of the selected methods from Phase I with actual Hanford waste or waste simulants in shielded cell facilities to ensure that the methods can be performed remotely and maintain the desired characteristics; and (2) digestion of glass samples prepared from actual Hanford Waste tank sludge for providing comparative results to the LA Phase II study. Based on the Phase I testing discussed in this report, a tandem digestion approach consisting of sodium peroxide fusion digestions carried out in nickel crucibles and warm mixed-acid digestions carried out in plastic bottles has been selected for Time-and-Motion study in Phase II. SRNL experience with performing this analytical approach in laboratory hoods indicates that well-trained cell operator teams will be able to perform the tandem digestions in five hours or less. The selected approach will produce two sets of solutions for analysis by ICP-AES techniques. Four hours would then be allocated for performing the ICP-AES analyses and reporting results to meet the nine-hour or less turnaround time requirement. The tandem digestion approach will need to be performed in two separate shielded analytical cells by two separate cell operator teams in order to achieve the nine-hour or less turnaround

  10. Rice flakes produced from commercial wild rice: Chemical compositions, vitamin B compounds, mineral and trace element contents and their dietary intake evaluation.

    Science.gov (United States)

    Sumczynski, Daniela; Koubová, Eva; Šenkárová, Lenka; Orsavová, Jana

    2018-10-30

    Non-traditional wild rice flakes were analysed for chemical composition, vitamin B compounds, α-tocopherol, mineral and trace elements. Dietary intakes of vitamins, minerals and trace elements were evaluated using FAO/WHO and Institute of Medicine regulations. Wild rice flakes proved to be significant contributors of pyridoxine, pantothenic and folic acids, niacin, thiamine, chromium, magnesium, manganese, phosphorus, zinc, copper, molybdenum and iron to essential dietary intakes values. Toxic dietary intake values for aluminium, cadmium, tin and mercury were less than 33%, which complies the limits for adults set by FAO/WHO for toxic elements intake related to the body weight of 65 kg for females and 80 kg for males taking 100 g of flakes as a portion. However, concentrations of Hg reaching between 3.67 and 12.20 µg/100 g in flakes exceeded the average Hg value of 0.27-1.90 μg/100 g in cereals consumed in the EU. It has to be respected in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Multi trace element analysis of dry biological materials by neutron activation analysis including a chemical group separation

    International Nuclear Information System (INIS)

    Weers, C.A.

    1980-01-01

    The principles of activation analysis and the practical aspects of neutron activation analysis are outlined. The limits which are set to accuracy and precision are defined. The description of the evaporation process is summarised in terms of the half-volume. This quantity is then used to define the resolving power. The formulation is checked by radiotracer experiments. Dried animal blood is used as the testing material. The pretreatment of the samples and (the development of) the destruction-evaporation apparatus is described. Four successive devices were built and tested. The development of the successive adsorption steps with active charcoal, Al 2 O 3 and coprecipitation with Fe(OH) 3 is presented. Seven groups of about 25 elements in total can be determined this way. The results obtained for standard reference materials are summarized and compared with literature data. (Auth.)

  12. Synthesis and evaluation of germanium organometallic compounds as precursors for chemical vapor deposition (CVD) and for obtaining nanoparticles of elemental germanium

    International Nuclear Information System (INIS)

    Ballestero Martinez, Ernesto

    2014-01-01

    The interest in the development of materials having applications such as electronics areas or biomarkers has affected the synthesis of new compounds based on germanium. This element has had two common oxidation states, +4 and +2, of them, +2 oxidation state has been the least studied and more reactive. Additionally, compounds of germanium (II) have had similarities with carbenes regarding the chemical acid-base Lewis. The preparation of compounds of germanium (II) with ligands β-decimations has enabled stabilization of new chemical functionalities and, simultaneously, provided interesting thermal properties to develop new preparation methodologies of materials with novel properties. The preparation of amides germanium(II) L'Ge(NHPh) [1, L' = {HC (CMeN-2,4,6-Me 3 C 6 H 2 ) 2 }], L'Ge(4-NHPy) [2] L'Ge(2-NHPy) [3] and LGe(2-NHPy) [4, L = {HC(CMeN-2,6- i Pr 2 C 6 H 3 ) 2 }]; the structural chemical composition were determined using techniques such as nuclear magnetic resonance ( 1 H, 13 C), other techniques are treated: elemental analysis, melting point, infrared spectroscopy, X-ray diffraction of single crystal and thermal gravimetric analysis (TGA). The TGA has showed that 4-1 have experimented a thermal decomposition; therefore, these compounds could be considered as potential starting materials for obtaining germanium nitride (GeN x ). Certainly, the availability of nitrogen coordinating atoms in the chemical composition in 2-4 have been interesting because it could act as ligands in reactions with transition metal complexes. That way, information could be obtained at the molecular level for some reactions and interactions that in surface chemistry have used similar link sites, for example, chemical functionalization of silicon and germanium substrates. The synthesis and structural characterization of germanium chloride compound(II) L''GeCl [5, L'' = HC{(CMe) (N-2,6-Me 2 C 6 H 3 )} 2 ], which could be used later for the

  13. A finite element analysis of the effects of geometrical shape on the elastic properties of chemical vapor deposited diamond nanowire

    Directory of Open Access Journals (Sweden)

    Garuma Abdisa Denu

    2017-01-01

    Full Text Available We report the effect of geometrical shape of diamond nanowire on its mechanical properties. Finite element modeling using COMSOL Multiphysics software is used to simulate various diamond nanowire with circular, square, rectangular, hexagonal and triangular cross-sections. A bending test under concentrated load applied at one of the free ends is simulated using FEM. The force response of the nanowire under different loading is studied for the various cross-sections. The dimensions of each cross-section is chosen so that material properties such as Young’s modulus can be kept constant for comparison in all the cross-sections. It is found out that the bending capability of a triangular nanowire is higher compared to other cross-sections due to its lowest second moment. Circular and hexagonal cross-section show highest stiffness. The study of mechanical property of diamond nanowires is useful for optimal nanomechanical designs where the effect of cross-section has to be taken into account.

  14. Linking chemical elements in forest floor humus (Oh-horizon) in the Czech Republic to contamination sources.

    Science.gov (United States)

    Sucharova, Julie; Suchara, Ivan; Hola, Marie; Reimann, Clemens; Boyd, Rognvald; Filzmoser, Peter; Englmaier, Peter

    2011-05-01

    While terrestrial moss and other plants are frequently used for environmental mapping and monitoring projects, data on the regional geochemistry of humus are scarce. Humus, however, has a much larger life span than any plant material. It can be seen as the "environmental memory" of an area for at least the last 60-100 years. Here concentrations of 39 elements determined by ICP-MS and ICP AES, pH and ash content are presented for 259 samples of forest floor humus collected at an average sample density of 1 site/300 km2 in the Czech Republic. The scale of anomalies linked to known contamination sources (e.g., lignite mining and burning, metallurgical industry, coal fired power plants, metal smelters) is documented and discussed versus natural processes influencing humus quality. Most maps indicate a local impact from individual contamination sources: often more detailed sampling than used here would be needed to differentiate between likely sources. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Assessment of chemicals released in the marine environment by dielectric elastomers useful as active elements in wave energy harvesters.

    Science.gov (United States)

    Zaltariov, Mirela-Fernanda; Bele, Adrian; Vasiliu, Lavinia; Gradinaru, Luiza; Vornicu, Nicoleta; Racles, Carmen; Cazacu, Maria

    2018-01-05

    A series of elastomers, either natural or synthetic (some of them commercial, while others prepared in the laboratory), suitable for use as active elements in devices for wave energy harvesting, were evaluated concerning their behavior and effects on the marine environment. In this aim, the elastomer films, initially evaluated regarding their aspect, structure, surface wettability, and tolerance of microorganisms growth, were immersed in synthetic seawater (SSW) within six months for assessing compounds released. There were analyzed the changes occurred both in the elastomers and salt water in which they were immersed. For this, water samples taken at set time intervals were analyzed by using a sequence of sensitive spectral techniques: UV-vis, IR, and in relevant cases 1 H NMR and electrospray ionization mass spectrometry (ESI-MS), able to detect and identify organic compounds, while after six months, they were also investigated from the point of view of aspect, presence of metal traces, pH, and biological activity. The changes in aspect, structure and morphology of the dielectric films at the end of the dipping period were also evaluated by visual inspection, IR spectroscopy by using spectral subtraction method, and SEM-EDX technique. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Lattice parameters and stability of the spinel compounds in relation to the ionic radii and electronegativities of constituting chemical elements.

    Science.gov (United States)

    Brik, Mikhail G; Suchocki, Andrzej; Kamińska, Agata

    2014-05-19

    A thorough consideration of the relation between the lattice parameters of 185 binary and ternary spinel compounds, on one side, and ionic radii and electronegativities of the constituting ions, on the other side, allowed for establishing a simple empirical model and finding its linear equation, which links together the above-mentioned quantities. The derived equation gives good agreement between the experimental and modeled values of the lattice parameters in the considered group of spinels, with an average relative error of about 1% only. The proposed model was improved further by separate consideration of several groups of spinels, depending on the nature of the anion (oxygen, sulfur, selenium/tellurium, nitrogen). The developed approach can be efficiently used for prediction of lattice constants for new isostructural materials. In particular, the lattice constants of new hypothetic spinels ZnRE2O4, CdRE2S4, CdRE2Se4 (RE = rare earth elements) are predicted in the present Article. In addition, the upper and lower limits for the variation of the ionic radii, electronegativities, and their certain combinations were established, which can be considered as stability criteria for the spinel compounds. The findings of the present Article offer a systematic overview of the structural properties of spinels and can serve as helpful guides for synthesis of new spinel compounds.

  17. Linking chemical elements in forest floor humus (O-h-horizon) in the Czech Republic to contamination sources

    Energy Technology Data Exchange (ETDEWEB)

    Sucharova, J.; Suchara, I.; Hola, M.; Reimann, C.; Boyd, R.; Filzmoser, P.; Englmaier, P. [Geological Survey of Norway, Trondheim (Norway)

    2011-05-15

    While terrestrial moss and other plants are frequently used for environmental mapping and monitoring projects, data on the regional geochemistry of humus are scarce. Humus, however, has a much larger life span than any plant material. It can be seen as the 'environmental memory' of an area for at least the last 60-100 years. Here concentrations of 39 elements determined by ICP-MS and ICP AES, pH and ash content are presented for 259 samples of forest floor humus collected at an average sample density of 1 site/300 km{sup 2} in the Czech Republic. The scale of anomalies linked to known contamination sources (e.g., lignite mining and burning, metallurgical industry, coal fired power plants, metal smelters) is documented and discussed versus natural processes influencing humus quality. Most maps indicate a local impact from individual contamination sources: often more detailed sampling than used here would be needed to differentiate between likely sources.

  18. Trace elements in bivalves from the Rio Cruces, Chile, trace watershed evolution after a major earthquake and challenge a postulated chemical spill from a pulp plant

    Science.gov (United States)

    Risk, M.; Burchell, M.; Nairn, R.; Tubrett, M.; Forsterra, G.

    2009-05-01

    In May, 1960, the largest recorded earthquake in the history of the planet hit southern Chile, dropping part of the course of the Rio Cruces by 2m and creating an extensive wetland. The Brazilian Waterweed Egeria densa colonised the area, and became a primary food source for large populations of the Black-necked Swan, Cygnus melancoryphus. In 2004, a large pulp mill commenced operations upstream on the river. According to local reports, immediately after the opening of the plant, the weed died and the swans left. There was public outcry, and a search for a cause or a culprit. It was postulated that some sort of chemical spill from the plant caused the weed to die, resulting in departure of the swans. In 2008, we collected specimens of the bivalve Diplodon chilensis from several locations downstream from the Plant and towards the wetland to see if there was evidence of a chemical spill recorded in the shells. We prepared thin-sections of the shells to observe growth line development and patterns. Additionally, shell samples were analysed for stable oxygen isotopes and trace elements, using LA-ICP/MS. Based on annual growth lines, some of the bivalves were long-lived, with an age of more than 50 years. These individuals settled in the river shortly after the earthquake, and have lived there continuously ever since. Annual and sub-annual banding was clear, and the annual cyclicity of the major bands was verified with oxygen isotope analysis. There are no changes in growth corresponding to 2004. Trace element scans provided a wealth of information on the evolution of this earthquake-impacted wetland. Barium, Strontium and Manganese all showed strong annual cyclicity. From the analysis of older specimens, we interpret the high peaks of the Ba signal as reflecting soil erosion-Ba peaks are large immediately after the earthquake, then they diminish through time. Sr is likely a temperature signal, and Mn reflects runoff. Minor peaks in Cu, As and Pb probably reflect

  19. Diversity of Chemical Bonding and Oxidation States in MS 4 Molecules of Group 8 Elements

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Wei [Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084 P.R. China; Jiang, Ning [Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084 P.R. China; Schwarz, W. H. Eugen [Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084 P.R. China; Physical and Theoretical Chemistry, University of Siegen, Siegen 57068 Germany; Yang, Ping [Theoretical Division, Los Alamos National Laboratory, Los Alamos New Mexico 87545 USA; Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland Washington 953002 USA; Li, Jun [Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084 P.R. China; Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland Washington 953002 USA

    2017-07-11

    The geometric and electronic ground-state structures of six MS4 molecules (M = group-8 metals Fe, Ru, Os, Hs, Sm, and Pu) have been studied by using quantum-chemical density-functional and correlated wave-function approaches. The MS4 species are compared to analogous MO4 species recently investi-gated (Inorg. Chem. 2016, 55: 4616). Metal oxidation state (MOS) of high value VIII appears in low- spin singlet Td geometric species (Os,Hs)S4 and (Ru,Os,Hs)O4, whereas low MOS=II appears in high- spin septet D2d species Fe(S2)2 and (slightly excited) metastable Fe(O2)2. The ground states of all other molecules have intermediate MOS values, containing S2-, S22-, S21- (and resp. O2--, O1-, O22-, O21-) ligands, bonded by ionic, covalent and correlative contributions.

  20. Synthesis and evaluation of germanic organometallic compounds as precursors for chemical vapor deposition (CVD) and for obtaining nanoparticles of elemental germanium

    International Nuclear Information System (INIS)

    Ballestero Martinez, Ernesto

    2014-01-01

    The interest in the development of materials that have applications in areas such as electronics or biomarkers has affected the synthesis of new compounds based on germanium. This element has two states of common oxidation, +4 and +2, of them, the +2 oxidation state is the least studied and more reactive. Additionally, compounds of germanium (II) have similarities to carbenes in terms Lewis'acid base chemistry. The preparation of compounds of germanium (II) with ligands β-diketiminates has made possible the stabilization of new chemical functionalities and, simultaneously, it has provided interesting thermal properties to develop new methods of preparation of materials with novel properties. The preparation of amides germanium (II) L'Ge (NHPh) [1, L'= {HC (CMeN-2,4,6-Me 3 C 6 H 2 ) 2 } - ], L'Ge (4-NHPy) [2], L'Ge (2-NHPy) [3] and LGe(2-NHPy) [4, L = {HC (CMeN-2,6- i Pr 2 C 6 H 3 ) 2 ] - ] are presented, the chemical and structural composition was determined by using techniques such as nuclear magnetic resonance ( 1 H, 13 C), elemental analysis, melting point, infrared spectroscopy, X-ray diffraction of single crystal and thermogravimetric analysis (TGA). The TGA has demonstrated that 1-4 experience a thermal decomposition, therefore, these compounds could be considered as potential starting materials for the obtaining of germanium nitride (GeN x ). Certainly, the availability of coordinating nitrogen atoms in the chemical composition in 2-4 have been interesting given that it could act as ligands in reactions with transition metal complexes. Thus, relevant information to molecular level could be obtained for some reactions and interactions that have used similar link sites in surface chemistry, for example, the chemical functionalization of silicon and germanium substrate. Additionally, the synthesis and structural characterization of germanium chloride compound (II) L G eCl [5, L' = HC{(CMe) (N-2,6-Me 2 C 6 H 3 )} 2 - ] is reported

  1. Trace Elements and Physico-Chemical Quality of the Well Waters in Mahitsy, Province of Antananarivo, Madagascar

    International Nuclear Information System (INIS)

    Rasolofonirina, M.; Randriamanivo, L.V.; Andrianarilala, M.T.; Raoelina Andriambololona

    2004-01-01

    The proposed study area of Mahitsy is located in the province of Antananarivo. Only 14.38% of the population in the rural zone has access to safe drinking water. Most of human population use wells or springs as the main source of drinking water. Wells are generally less than 20 meters deep and they are not properly sealed. Well waters investigated in January 2004 have a very large range of trace constituent and chemical composition in the zone of interest. Manganese concentrations range is 8μg.L -1 -1115 μg.L -1 and concentrations of barium vary in the range of 55μg.L -1 - 4967 μg.L -1 . 67% of monitored well waters are of manganese concentration higher than 50μg.L -1 and 44% contain barium with a concentration higher than 700μg.L -1 . Total dissolved solids vary between 8 mg.L -1 and 881 mg.L -1 and well water pHs are acidic (4.28 - 5.94). Nitrate concentrations monitored in Mahitsy groundwaters show that, 54% of the well water samples exceed 50 mg.L -1 (WHO guidelines value) and 84% exceed 13.5 mg.L -1 (indicative value of human activities). The nitrate content ranges from 4 to 489 mg.L -1 . Groundwater nitrate correlates positively with chloride and potassium. That would suggest that the high content of nitrate may result from the septic tank, the cesspool and the animal wastes storage, located next to the well. However, people draw water from groundwater for domestic purposes, as the water infrastructure remains undeveloped in the studied area. The measurement of trace constituents are performed using Total Relflection X-ray Fluorescence (TXRF) analytical method and the major ions are determined by Ion Chromatograph (IC) system.

  2. Optical properties, morphology and elemental chemical composition of atmospheric particles at T1 supersite on MILAGRO campaign

    Science.gov (United States)

    Carabali, G.; Mamani-Paco, R.; Castro, T.; Peralta, O.; Herrera, E.; Trujillo, B.

    2011-05-01

    Atmospheric particles were sampled at T1 supersite (19°43' N latitude, 98°58' W longitude, and 2340 m above sea level) during MILAGRO campaign. T1 was located at the north of Mexico City Metropolitan Area (MCMA). Aerosol sampling was done by placing transmission electron microscope (TEM) copper grids on the last 5 stages of an 8-stage MOUDI cascade impactor (d50 = 1.8, 1.0, 0.56, 0.32, and 0.18 μm). Samples were obtained at morning (06:00-09:00), noon (11:00-14:00), afternoon (16:00-19:00) and evening (21:00-24:00) local time. Absorption and scattering coefficients, and particles concentration (0.01-3 μm aerodynamic diameter) were measured simultaneously using a PASP absorption photometer (operated at 550 nm), a portable integrating nephelometer (at 530 nm) and a CNI particle counter. TEM images of particles were acquired at different magnifications using a CM 200 Phillips TEM-EDAX system. The morphology of atmospheric particles for two aerodynamic diameters (0.18 and 1.8 μm) was compared using border-based fractal dimension. Particles sampled under Mexico City pollution influence showed not much variability, suggesting the presence of more compact particles in smaller sizes (d50 = 1.8 μm) at the site. The presence of higher numbers of compact particles can be attributed to aerosol aging and secondary aerosol formation, among others. Under early morning conditions, smaller particles (d50 = 0.18 μm) had more irregular features resulting in a higher average fractal dimension. Energy dispersive X-ray spectroscopy (EDS) was used to determine the elemental composition of particles. EDS analysis in particles with d50 = 0.18 μm showed a higher content of carbonaceous material and relevant amounts of Si, Fe, K, and Co. This may indicate an impact from industrial and vehicle's emissions on atmospheric particles.

  3. Seasonal changes in chemical and mineralogical composition of sewage sludge incineration residues and their potential for metallic elements and valuable components recovery

    Science.gov (United States)

    Kasina, Monika; Kowalski, Piotr R.; Michalik, Marek

    2017-04-01

    Increasing energy needs, the implementation of the circular economy principles and rising environmental awareness caused that waste management is becoming a major social and economic issue. The EU Member States have committed to a significant reduction in the amount of waste produced and landfilled and to use their inherent energy and raw materials potential. One of the most reasonable option to fulfil these commitments is waste incineration. The aim of the waste incineration is to reduce their volume and toxicity by disinfection and detoxification at high temperatures. Thermal process and reduction of volume allows the recovery of minerals and metallic elements from residues as well as the energy production (waste-to-energy strategy) during incineration. As a result of waste incineration a variety of solid residues (bottom ash, fly ash, air pollution control residues) and technological waste (gas waste, wastewater) are produced. The goal of this study is to characterize fly ash and air pollution control (APC) residues formed as a result of municipal sewage sludge incineration in terms of their chemical and mineral composition and their extractive potential. Residues were sampled quarterly to study their seasonal changes in composition. The fly ash was a Si-P-C-Fe-Al dominated material, whereas the APC residues composition was dominated by Na-rich soluble phases. The removal of soluble phase ( 98% of the material) from the APC residues by dissolution in deionised water caused significant mass reduction and concentration of non-soluble elements. The main mineral phases in fly ash were quartz, hematite, Fe-PO4, whitlockite and feldspar, while in APC thenardite, and in lower amount calcite, apatite and quartz were present. The chemical composition of fly ash was practically invariable in different seasons, but significant differences were observed in APC residues. The lowest concentrations of all elements and the highest TOC content were measured in the samples

  4. Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore.

    Science.gov (United States)

    Zakrzewska-Koltuniewicz, Grażyna; Herdzik-Koniecko, Irena; Cojocaru, Corneliu; Chajduk, Ewelina

    2014-06-30

    The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P=5 bar, T=120 °C and t=90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th). Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Processing of spent Ni-MH batteries for the recovery of cobalt, nickel and rare earth elements bearing materials by means of a chemical and electrochemical sequential process

    Science.gov (United States)

    Delvasto, P.; Orta Rodríguez, R.; Blanco, S.

    2016-02-01

    Rechargeable Ni-MH batteries contain strategic metal values which are worth to be recovered. In the present work, a preliminary sequential chemical and electrochemical procedure is proposed, in order to reclaim materials bearing Ni, Co and rare earth elements (REE) from Ni-MH spent batteries. Initially, spent batteries are disassembled to separate the electrode materials (anode and cathode), which are then leached with an aqueous solution of 5w% sulphuric acid. The metal content of this solution is checked by atomic absorption spectrometry techniques. The obtained solution is pH-adjusted (with NaOH), until pH is between 4.0 and 4.3; then, it is heated up to 70°C to precipitate a rare earth elements sulphate (Nd, La, Pr, Ce), as determined by means of x-ray fluorescence techniques. The solids-free solution is then electrolyzed, in order to recover a Ni-Co alloy. The electrolysis conditions were established through a cyclic voltammetry technique.

  6. Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere.

    Science.gov (United States)

    Lü, Senlin; Zhang, Rui; Yao, Zhenkun; Yi, Fei; Ren, Jingjing; Wu, Minghong; Feng, Man; Wang, Qingyue

    2012-01-01

    Ambient coarse particles (diameter 1.8-10 microm), fine particles (diameter 0.1-1.8 microm), and ultrafine particles (diameter Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 +/- 2.18, 8.82 +/- 3.52, and 2.02 +/- 0.41 microg/m3, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.

  7. Application of INAA for chemical quality control analysis of C-C composite and high purity graphite by determining trace elemental concentrations

    International Nuclear Information System (INIS)

    Shinde, Amol D.; Reddy, A.V.R.; Acharya, R.; Venugopalan, Ramani

    2015-01-01

    Carbon based materials like graphite and C-C composites are used for various scientific and technological applications. Owing to its low neutron capture cross section and good moderating properties, graphite is used as a moderator or reflector in nuclear reactors. For high temperature reactors like CHTR, graphite and C-C composites are proposed as structural materials. Studies are in progress to use C-C composites as prospective candidate instead of graphite due to their excellent mechanical and thermal properties. The advantage of carbon-carbon composite is that the microstructure and the properties can be tailor made. Impurities like rare earth elements and neutron poisons which have high neutron absorption cross section and elements whose activation products of have longer half-lives like 60 Co (5.27 y), 65 Zn (244.3 d) and 59 Fe (44.5 d) are not desired in structural materials. For chemical quality control (CQC) it is necessary to evaluate accurately the impurity concentrations using a suitable non-destructive analytical technique. In the present work, two carbon/carbon composite samples and two high purity graphite samples were analyzed by Instrumental Neutron Activation Analysis (INAA) using high-flux reactor neutrons. Samples, sealed in Al foil, were irradiated in tray-rod position of Dhruva reactor, BARC at a neutron flux of ∼ 5 x 10 13 cm -2 s -1 . Radioactive assay was carried out using high resolution gamma ray spectrometry using 40% HPGe detector

  8. Method for the elucidation of the elemental composition of low molecular mass chemicals using exact masses of product ions and neutral losses: application to environmental chemicals measured by liquid chromatography with hybrid quadrupole/time-of-flight mass spectrometry.

    Science.gov (United States)

    Suzuki, Shigeru; Ishii, Tetsuko; Yasuhara, Akio; Sakai, Shinichi

    2005-01-01

    A method for elucidating the elemental compositions of low molecular weight chemicals, based primarily on mass measurements made using liquid chromatography (LC) with time-of-flight mass spectrometry (TOFMS) and quadrupole/time-of-flight mass spectrometry (LC/QTOFMS), was developed and tested for 113 chemicals of environmental interest with molecular masses up to approximately 400 Da. As the algorithm incorporating the method is not affected by differences in the instrument used, or by the ionization method and other ionization conditions, the method is useful not only for LC/TOFMS, but also for all kinds of mass spectra measured with higher accuracy and precision (uncertainties of a few mDa) employing all ionization methods and on-line separation techniques. The method involves calculating candidate compositions for intact ionized molecules (ionized forms of the sample molecule that have lost or gained no more than a proton, i.e., [M+H](+) or [M-H](-)) as well as for fragment ions and corresponding neutral losses, and eliminating those atomic compositions for the molecules that are inconsistent with the corresponding candidate compositions of fragment ions and neutral losses. Candidate compositions were calculated for the measured masses of the intact ionized molecules and of the fragment ions and corresponding neutral losses, using mass uncertainties of 2 and 5 mDa, respectively. Compositions proposed for the ionized molecule that did not correspond to the sum of the compositions of a candidate fragment ion and its corresponding neutral loss were discarded. One, 2-5, 6-10, 11-20, and >20 candidate compositions were found for 65%, 39%, 1%, 1%, and 0%, respectively, for the 124 ionized molecules formed from the 113 chemicals tested (both positive and negative ions were obtained from 11 of the chemicals). However, no candidate composition was found for 2% of the test cases (i.e., 3 chemicals), for each of which the measured mass of one of the product ions was in

  9. Selecting chemical and ecotoxicological test batteries for risk assessment of trace element-contaminated soils (phyto)managed by gentle remediation options (GRO).

    Science.gov (United States)

    Kumpiene, Jurate; Bert, Valérie; Dimitriou, Ioannis; Eriksson, Jan; Friesl-Hanl, Wolfgang; Galazka, Rafal; Herzig, Rolf; Janssen, Jolien; Kidd, Petra; Mench, Michel; Müller, Ingo; Neu, Silke; Oustriere, Nadège; Puschenreiter, Markus; Renella, Giancarlo; Roumier, Pierre-Hervé; Siebielec, Grzegorz; Vangronsveld, Jaco; Manier, Nicolas

    2014-10-15

    During the past decades a number of field trials with gentle remediation options (GRO) have been established on trace element (TE) contaminated sites throughout Europe. Each research group selects different methods to assess the remediation success making it difficult to compare efficacy between various sites and treatments. This study aimed at selecting a minimum risk assessment battery combining chemical and ecotoxicological assays for assessing and comparing the effectiveness of GRO implemented in seven European case studies. Two test batteries were pre-selected; a chemical one for quantifying TE exposure in untreated soils and GRO-managed soils and a biological one for characterizing soil functionality and ecotoxicity. Soil samples from field studies representing one of the main GROs (phytoextraction in Belgium, Sweden, Germany and Switzerland, aided phytoextraction in France, and aided phytostabilization or in situ stabilization/phytoexclusion in Poland, France and Austria) were collected and assessed using the selected test batteries. The best correlations were obtained between NH4NO3-extractable, followed by NaNO3-extractable TE and the ecotoxicological responses. Biometrical parameters and biomarkers of dwarf beans were the most responsive indicators for the soil treatments and changes in soil TE exposures. Plant growth was inhibited at the higher extractable TE concentrations, while plant stress enzyme activities increased with the higher TE extractability. Based on these results, a minimum risk assessment battery to compare/biomonitor the sites phytomanaged by GROs might consist of the NH4NO3 extraction and the bean Plantox test including the stress enzyme activities. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Early diagenesis of mangrove leaves in a tropical estuary: Bulk chemical characterization using solid-state 13C NMR and elemental analyses

    Science.gov (United States)

    Benner, Ronald; Hatcher, Patrick G.; Hedges, John I.

    1990-07-01

    Changes in the chemical composition of mangrove ( Rhizophora mangle) leaves during decomposition in tropical estuarine waters were characterized using solid-state 13C nuclear magnetic resonance (NMR) and elemental (CHNO) analysis. Carbohydrates were the most abundant components of the leaves accounting for about 50 wt% of senescent tissues. Tannins were estimated to account for about 20 wt% of leaf tissues, and lipid components, cutin, and possibly other aliphatic biopolymers in leaf cuticles accounted for about 15 wt%. Carbohydrates were generally less resistant to decomposition than the other constituents and decreased in relative concentration during decomposition. Tannins were of intermediate resistance to decomposition and remained in fairly constant proportion during decomposition. Paraffinic components were very resistant to decomposition and increased in relative concentration as decomposition progressed. Lignin was a minor component of all leaf tissues. Standard methods for the colorimetric determination of tannins (Folin-Dennis reagent) and the gravimetric determination of lignin (Klason lignin) were highly inaccurate when applied to mangrove leaves. The N content of the leaves was particularly dynamic with values ranging from 1.27 wt% in green leaves to 0.65 wt% in senescent yellow leaves attached to trees. During decomposition in the water the N content initially decreased to 0.51 wt% due to leaching, but values steadily increased thereafter to 1.07 wt% in the most degraded leaf samples. The absolute mass of N in the leaves increased during decomposition indicating that N immobilization was occurring as decomposition progressed.

  11. Investigation on fuel-cladding chemical interaction in metal fuel for FBR. Reaction of rare earth elements with Fe-Cr alloy

    International Nuclear Information System (INIS)

    Inagaki, Kenta; Ogata, Takanari

    2010-01-01

    Rare-earth fission product (FP) elements generated in the metal fuel interact with cladding alloy and result in the wastage of the cladding (Fuel-Cladding Chemical Interaction (FCCI)). To evaluate FCCI quantitatively, several influential factors must be considered. They are temperature, temperature gradient, time, composition of the cladding and the behavior of rare-earth FP. In this research, the temperature and time dependencies are investigated with tests in the simplified system. Fe-12wt%Cr was used as stimulant material of cladding and rare-earth alloy 13La -24Ce -12Pr -39Nd -12Sm (RE) as a rare-earth FP. A diffusion couple Fe-Cr/RE was made and annealed at 923K, 853K, 773K or 693K. The structures of reaction layers were analyzed with Electron Probe Micro Analyzer (EPMA) and the details of the structures were clarified. The width of the reaction layer in the Fe-Cr alloy grew in proportion to the square root of time. The reaction rate constants K=(square of the width of reaction layer / time) were evaluated. It was confirmed that the relation between K and the inverse of the temperature showed linearity above 773 K. (author)

  12. Vertical exchange and chemical conversion of trace elements over topographically complex terrain; Vertikaler Austausch und chemische Umwandlung von Spurenstoffen ueber topographisch gegliedertem Gelaende

    Energy Technology Data Exchange (ETDEWEB)

    Kuntze, K.

    2001-10-01

    The influence of topography on the vertical exchange of trace elements was investigated with the aid of a numeric simulation model. It is a couopled 3D model consisting of the mesoscale model KAMM and the dispersion model DRAIS, extended by the gaseous phase mechanism of the RADM model. This way, both meteorological and chemical processes can be analyzed in a preselected time and spatial resolution. The simulations were validated by a comparison with measurements made during the TRACT campaign. Satisfactory agreement between the two was established. [German] In der vorliegenden Arbeit wurde der Einfluss der Topographie auf den vertikalen Austausch von Spurenstoffen mit Hilfe eines numerischen Simulationsmodells untersucht. Bei dem Simulationsmodell handelt es sich um ein dreidimensionales gekoppeltes Modell, welches aus dem mesoskaligen Modell KAMM und dem um den Gasphasenmechanismus des RADM-Modells erweiterten Ausbreitungsmodell DRAIS besteht. Mit diesem Modellsystem war es moeglich, sowohl meterologische als auch chemische Prozesse in einer vorher gewaehlten zeitlichen und raeumlichen Aufloesung zu betrachten. Um die Qualitaet der Simulation und damit deren Verwendbarkeit fuer die Untersuchungen festzustellen, wurde ein Vergleich mit Messungen durchgefuehrt. Dazu wurden berechnete meterologische und chemische Groessen mit den waehrend der Feldmesskampagne TRACT gemessenen Groessen verglichen. Der Vergleich der simulierten Groessen sowohl mit Radiosondenaufstiegen als auch mit Zeitreihen und Flugzeugmessungen lieferte eine gute Uebereinstimmung. (orig.)

  13. Absorption of metals and characterization of chemical elements present in three species of Gracilaria (Gracilariaceae Greville: a genus of economical importance

    Directory of Open Access Journals (Sweden)

    Angela P. Tonon

    2011-04-01

    Full Text Available Gracilaria Greville is a genus of seaweed that is economically explored by the cosmetic, pharmaceutical and food industries. One of the biggest problems associated with growing Gracilaria is the discharge of heavy metals into the marine environment. The absorption of heavy metals was investigated with the macroalga Gracilaria tenuistipitata Zhang et Xia, cultivated in a medium containing copper (Cu and cadmium (Cd. In biological samples, EC50 concentrations of 1 ppm for cadmium and 0.95 ppm for copper were used. These concentrations were based on seaweed growth curves obtained over a period of six days in previous studies. ICP-AES was used to determine the amount of metal that seaweeds absorbed during this period. G. tenuistipitata was able to bioaccumulate both metals, about 17% of copper and 9% of cadmium. Basal natural levels of Cu were found in control seaweeds and in G. tenuistipitata exposed to Cd. In addition, the repertoire of other important chemical elements, as well as their concentrations, was determined for G. tenuistipitata and two other important seaweeds, G. birdiae Plastino & Oliveira and G. domingensis (Kützing Sonder ex Dickie, collected in natural environments on the Brazilian shore.

  14. XIII International science and technology conference High-tech chemical technologies-2010 with elements of Scientific school for young people Innovations in chemistry: achievements and prospects. Summaries of reports

    International Nuclear Information System (INIS)

    2010-01-01

    Materials of the XIII International science and technology conference High-tech chemical technologies-2010 with elements of Scientific school for young people Innovations in chemistry: achievements and prospects (29 June-2 July 2010, Ivanovo) are presented. During the conference the following areas: theoretical aspects of chemical technology; technology of deep oil refining and the production of organic substances; technology of drugs and biologically active substances; technology of inorganic materials, polymers and composites based on them - the technological principles and methods of synthesis, modification, and processing; environmental and economic problems of chemical technologies and their solutions are considered [ru

  15. Rare earth, major, and trace element composition of Monterey and DSDP chert and associated host sediment: Assessing the influence of chemical fractionation during diagenesis

    Science.gov (United States)

    Murray, R.W.; Buchholtz ten Brink, Marilyn R.; Gerlach, David C.; Russ III, G. Price; Jones, David L.

    1992-01-01

    Chert and associated host sediments from Monterey Formation and Deep Sea Drilling Project (DSDP) sequences were analyzed in order to assess chemical behavior during diagenesis of biogenic sediments. The primary compositional contrast between chert and host sediment is a greater absolute SiO2 concentration in chert, often with final SiO2 ≥ 98 wt%. This contrast in SiO2 (and SiAl">SiAl) potentially reflects precursor sediment heterogeneity, diagenetic chemical fractionation, or both. SiO2 concentrations and SiAl">SiAl ratios in chert are far greater than in modern siliceous oozes, however and often exceed values in acid-cleaned diatom tests. Compositional contrasts between chert and host sediment are also orders-of-magnitude greater than between multiple samples of the host sediment. Calculations based on the initial composition of adjacent host, observed porosity reductions from host to chert and a postulated influx of pure SiO2, construct a chert composition which is essentially identical to observed SiO2 values in chert. Thus, precursor heterogeneity does not seem to be the dominant factor influencing the current chert composition for the key elements of interest. In order to assess the extent of chemical fractionation during diagenesis, we approximate the precursor composition by analyzing host sediments adjacent to the chert.The SiO2 concentration contrast seems caused by biogenic SiO2 dissolution and transport from the local adjacent host sediment and subsequent SiO2reprecipitation in the chert. Along with SiO2, other elements are often added (with respect to Al) to Monterey and DSDP chert during silicification, although absolute concentrations decrease. The two Monterey quartz chert nodules investigated, in contrast to the opal-CT and quartz chert lenses, formed primarily by extreme removal of carbonate and phosphate, thereby increasing relative SiO2 concentrations. DSDP chert formed by both carbonate/phosphate dissolution and SiO2 addition from

  16. Development of constraint algorithm for the number of electrons in molecular orbitals consisting mainly 4f atomic orbitals of rare-earth elements and its introduction to tight-binding quantum chemical molecular dynamics method

    International Nuclear Information System (INIS)

    Endou, Akira; Onuma, Hiroaki; Jung, Sun-ho

    2007-01-01

    Our original tight-binding quantum chemical molecular dynamics code, Colors', has been successfully applied to the theoretical investigation of complex materials including rare-earth elements, e.g., metal catalysts supported on a CeO 2 surface. To expand our code so as to obtain a good convergence for the electronic structure of a calculation system including a rare-earth element, we developed a novel algorithm to provide a constraint condition for the number of electrons occupying the selected molecular orbitals that mainly consist of 4f atomic orbitals of the rare-earth element. This novel algorithm was introduced in Colors. Using Colors, we succeeded in obtaining the classified electronic configurations of the 4f atomic orbitals of Ce 4+ and reduced Ce ions in a CeO 2 bulk model with one oxygen defect, which makes it difficult to obtain a good convergence using a conventional first-principles quantum chemical calculation code. (author)

  17. Potential in using elemental concentrations in radial increments of old growth eastern red cedar to examine the chemical history of the environment

    International Nuclear Information System (INIS)

    Guyette, R.; McGinnes, E.A. Jr.

    1987-01-01

    Research examines the potential of utilizing elemental concentrations in the wood of eastern red cedar (Juniperus virginiana L.) to make inferences about past changes in atmospheric and site chemistry. Crossdated growth increments from live trees and remnant wood are analyzed by neutron activation analysis (NAA) and inductively coupled plasma optical emission spectroscopy (ICP Scan) for elements with potential environmental information. Radial heartwood ring series from 300 to 700 years in length are analyzed in 20 year increments for 37 different elements. Evidence for minimal radial translocation of elements in the heartwood is presented. The radial concentration of elements in the bole is found to be coincident with early smelting activities. 7 references, 4 figures

  18. Deciphering open space in urban contexts: Geophysical survey, soil multi-element chemical analysis, and artifact distributions at the 15th–16th-century AD Swahili settlement of Songo Mnara

    DEFF Research Database (Denmark)

    Fleisher, Jeffrey; Sulas, Federica

    2015-01-01

    to map artifact and geochemical distributions across these areas. These data provided a means to distinguish a ‘public space’ at the site: correlations were found between anomalies, daub, certain chemical elements (Fe, P, K, Mn) while areas without anomalies—the ‘public space’—correlated with more...... at this Swahili site contained defined and protected public areas where small-scale production may have occurred....

  19. The distribution of mercury and other trace elements in the bones of two human individuals from medieval Denmark – the chemical life history hypothesis

    DEFF Research Database (Denmark)

    Rasmussen, Kaare Lund; Skytte, Lilian; Pilekær, Christian

    2013-01-01

    performed on a single sample from a tooth or a long bone. In this paper we investigate how a suite of elements (Mg, Al, Ca, Mn, Fe, Zn, As, Sr, Ba, Hg and Pb) are distributed in two medieval skeletons excavated at the laymen cemetery at the Franciscan Friary in Svendborg, Denmark.The analyses have been...... individuals can be clearly distinguished by Principal Component Analysis of all the measured trace elements.Our data support a previously published hypothesis that the elemental ratios Sr/Ca, Ba/Ca and Mg/Ca are indicative of provenance. Aluminium, Fe and Mn can be attributed to various forms of diagenesis...

  20. A study on monitoring methodology for trace elements in the environment through chemical analysis of hair. Part of a coordinated programme on nuclear methods in health-related monitoring of trace element pollutants

    International Nuclear Information System (INIS)

    Fukushima, I.

    1981-06-01

    An attempt was made to monitor community exposure to environmental As, Cd, Cr, Hg, Mn, Pb and Se using hair analysis by instrumental neutron activation analysis and atomic absorption spectroscopy. Hair samples were collected from male and female subjects from six Japanese localities. Samples from each locality were respectively mixed and analysed for elements of interest. The results indicated that this approach was effective in revealing geographical differences of hair elemental levels. The method is suitable for a routine monitoring programme of community exposure to environmental metal pollutants

  1. Elemental Food for Thought

    Science.gov (United States)

    Cady, Susan

    2005-01-01

    One of the first tasks students learn in chemistry is to pronounce and spell the names of elements and learn their corresponding chemical symbols. Repetitive oral recitation is commonly used to learn this information, but games and puzzles can make this task creative, variable, and fun. Elemental Food for Thought is a puzzlelike activity that…

  2. Proceedings of transuranium elements

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    The identification of the first synthetic elements was established by chemical evidence. Conclusive proof of the synthesis of the first artificial element, technetium, was published in 1937 by Perrier and Segre. An essential aspect of their achievement was the prediction of the chemical properties of element 43, which had been missing from the periodic table and which was expected to have properties similar to those of manganese and rhenium. The discovery of other artificial elements, astatine and francium, was facilitated in 1939-1940 by the prediction of their chemical properties. A little more than 50 years ago, in the spring of 1940, Edwin McMillan and Philip Abelson synthesized element 93, neptunium, and confirmed its uniqueness by chemical means. On August 30, 1940, Glenn Seaborg, Arthur Wahl, and the late Joseph Kennedy began their neutron irradiations of uranium nitrate hexahydrate. A few months later they synthesized element 94, later named plutonium, by observing the alpha particles emitted from uranium oxide targets that had been bombarded with deuterons. Shortly thereafter they proved that is was the second transuranium element by establishing its unique oxidation-reduction behavior. The symposium honored the scientists and engineers whose vision and dedication led to the discovery of the transuranium elements and to the understanding of the influence of 5f electrons on their electronic structure and bonding. This volume represents a record of papers presented at the symposium

  3. The chemical speciation and analysis of trace elements in sediment with Neutron Activation Analytical method(NAA) and atomic mass spectrometry

    International Nuclear Information System (INIS)

    Nam, Sang-Ho; Kim, Jae-Jin; Chung, Yong-Sam; Kim, Sun-Ha

    2003-01-01

    In this research, first of all, the analytical methods for the determination of major elements in sediment have been developed with ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The analytical results of major elements (Al, Ca, K, Fe, Mg) with Cool ICP-MS were much better than those with normal ICP-MS. The analytical results were compared with those of NAA (Neutron Activation Analysis). NAA were a little superior to ICP-MS for the determination of major elements in sediment as a non-destructive trace analytical trace analytical method. The analytical methods for the determination of minor elements (Cr, Ce, U, Co, Pb, As, Se) have been also developed with ICP-MS. The analytical results by standard calibration curve with ICP-MS were not accurate due to the matrix interferences. Thus, the internal standard method was applied, then the analytical results for minor elements with ICP-MS were greatly improved. The analytical results obtained by ICP-MS were compared with those obtained by NAA. It showed that the two analytical methods have great capabilities for the determination of minor elements in sediments. Accordingly, the NAA will plan an important role in analysis of environment sample with complex matrix. ICP-MS also will play an important role because it has a great capability for the determination of Pb that could not be determined by NAA

  4. Statistic analysis of grouping in evaluation of the behavior of stable chemical elements and physical-chemical parameters in effluent from uranium mining; Analise de agrupamento na avaliacao do comportamento de elementos quimicos estaveis e parametros fisico-quimicos em efluente de mineracao de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de S., E-mail: wspereira@inb.gov.br, E-mail: pereirarsj@gmail.com [Universidade Federal Fluminense (GETA/LARARA-PLS/UFF), Niteroi, RJ (Brazil). Grupo de Estudos em Temas Ambientais. Laboratorio de Radiobiologia e Radiometria Pedro Lopes dos Santos; Py Junior, Delcy de A.; Dores, Luis A. de C.B.; Campelo, Emanuele L.C.; Morais, Gustavo F. de; Kelecom, Alphonse, E-mail: delcy@inb.gov.br, E-mail: kclecom@uol.com.br [lndustrias Nucleares do Brasil (UTM/INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerios; Pereira, Juliana R. de S., E-mail: pereirarsj@gmail.com [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil)

    2013-10-01

    The Ore Treatment Unit (UTM) is a uranium mine off. The statistical analysis of clustering was used to evaluate the behavior of stable chemical elements and physico-chemical variables in their effluents. The use of cluster analysis proved effective in the evaluation, allowing to identify groups of chemical elements in physico-chemical variables and group analyzes (element and variables ). As a result, we can say, based on the analysis of the data, a strong link between Ca and Mg and between Al and TR{sub 2}O{sub 3} (rare earth oxides) in the UTM effluents. The SO{sub 4} was also identified as strongly linked to total solids and dissolved and these linked to electrical conductivity. Other associations existed, but were not as strongly linked. Additional collections for seasonal evaluation are required so that assessments can be confirmed. Additional statistics analysis (ordination techniques) should be used to help identify the origins of the groups identified in this analysis. (author)

  5. The size distribution of chemical elements of atmospheric aerosol at a semi-rural coastal site in Venice (Italy). The role of atmospheric circulation.

    Science.gov (United States)

    Masiol, Mauro; Squizzato, Stefania; Ceccato, Daniele; Pavoni, Bruno

    2015-01-01

    The concentrations of selected elemental tracers were determined in the aerosol of a semi-rural coastal site near Venice (Italy). Size-segregated aerosol samples were collected using an 8-stage cascade impactor set at 15m above ground, during the cold season (late autumn and winter), when high levels of many pollutants are known to cause risks for human health. From the experimental data, information was extracted on potential pollutant sources by investigating the relationships between elements in the different size fractions. Moreover, an approach to highlight the importance of local atmospheric circulation and air mass origin in influencing the PM composition and fractional distribution is proposed. Anthropogenic elements are strongly inter-correlated in the submicrometric (4 μm) Fe and Zn are well correlated and are probably linked to tire and brake wear emissions. Regarding atmospheric circulation, results show increasing levels of elements related to pollution sources (S, K, Mn, Ni, Cu, Zn) when air masses come from Central and Eastern Europe direction and on the ground wind blows from NWN-N-NE (from mainland Venice). Low wind speed and high percentage of wind calm hours favor element accumulation in the submicrometric and intermediate modes. Furthermore, strong winds favor the formation of sea-spray and the increase of Si in the coarse mode due to the resuspension of sand fine particles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Distribution of chemical elements in soils and stream sediments in the area of abandoned Sb–As–Tl Allchar mine, Republic of Macedonia

    Energy Technology Data Exchange (ETDEWEB)

    Bačeva, Katerina [Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, POB 162, 1000 Skopje (Macedonia, The Former Yugoslav Republic of); Stafilov, Trajče, E-mail: trajcest@pmf.ukim.mk [Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, POB 162, 1000 Skopje (Macedonia, The Former Yugoslav Republic of); Šajn, Robert [Geological Survey of Slovenia, Ljubljana (Slovenia); Tănăselia, Claudiu [INCDO-INOE 2000 Research Institute for Analytical Instrumentation (ICIA), Cluj-Napoca (Romania); Makreski, Petre [Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Ss. Cyril and Methodius University, POB 162, 1000 Skopje (Macedonia, The Former Yugoslav Republic of)

    2014-08-15

    The aim of this study was to investigate the distribution of some toxic elements in topsoil and subsoil, focusing on the identification of natural and anthropogenic element sources in the small region of rare As–Sb–Tl mineralization outcrop and abandoned mine Allchar known for the highest natural concentration of Tl in soil worldwide. The samples of soil and sediments after total digestion were analyzed by inductively coupled plasma–mass spectrometry (ICP–MS) and inductively coupled plasma–atomic emission spectrometry (ICP–AES). Factor analysis (FA) was used to identify and characterize element associations. Six associations of elements were determined by the method of multivariate statistics: Rb–Ta–K–Nb–Ga–Sn–Ba–Bi–Li–Be–(La–Eu)–Hf–Zr–Zn–In–Pd–Ag–Pt–Mg; Tl–As–Sb–Hg; Te–S–Ag–Pt–Al–Sc–(Gd–Lu)–Y; Fe–Cu–V–Ge–Co–In; Pd–Zr–Hf–W–Be and Ni–Mn–Co–Cr–Mg. The purpose of the assessment was to determine the nature and extent of potential contamination as well as to broadly assess possible impacts to human health and the environment. The results from the analysis of the collected samples in the vicinity of the mine revealed that As and Tl elements have the highest median values. Higher median values for Sb are obviously as a result of the past mining activities and as a result of area surface phenomena in the past. - Highlights: • Soil and river sediments were analyzed from Sb–As–Tl Allchar locality. • An increased content of certain toxic elements for environment was determined. • Highest As and Tl contents are obtained in the close vicinity of Allchar mine. • River sediments portray 160 times higher content of Sb than EU values. • The results classify Allchar as probably the highest natural Tl-deposit worldwide.

  7. Physical and chemical investigation of water and sediment of the Keban Dam Lake, Turkey. Part 2. Distribution of radioactivity, heavy metals and major elements

    International Nuclear Information System (INIS)

    Kulahci, F.; Dogru, M.

    2006-01-01

    Thirtynine surface water and 20 deep sediment samples were taken in different locations in Keban Dam Lake (Elazig, Turkey) to identify major sources and assess major elements, heavy metals, 137 Cs, 90 Sr, total alpha- and, total beta-distribution in 2003 and 2004 in four seasons each year. As a preliminary study heavy metal (Zn, Fe, Mn, Ni, Cu, Cr, and Co), major element (Mg, Ca, Na, K) and radioactivity concentrations of 137 Cs, 90 Sr, total-α and total-β in the surface water and deep sediments were determined. (author)

  8. Elements beyond uranium

    International Nuclear Information System (INIS)

    Seaborg, G.T.; Loveland, W.D.

    1990-01-01

    This book is the 12th volume in a series on transuranium elements. Varied techniques for production of these elements, the methods used in the identification, and the exquisitely refined microchemical techniques required to deal wth samples sometimes involving only a few atoms are described in detail. The chapter on synthesis of the new elements is liberally laced with reminiscences of the proud progenitors as well as the criteria for the discovery of a new chemical element. The authors lament that the superheavy elements (elements in the region of atomic number 114) still elude detection even though their creation should be possible, and some, at least, should survive long enough to be detected. One chapter in the book is devoted to practical applictions of uranium, and the transuranic elements

  9. Standard elements; Elements standards

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

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

  10. Сomposition and ratio of the chemical elements on the surfaces different by height of reindeer lichen podetia Cladonia rangiferina

    Directory of Open Access Journals (Sweden)

    Byazrov Lev

    2016-06-01

    Full Text Available In the paper the composition of 21 elements – Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Ba, Pb – was compared in the upper, central, and lower parts of podetia surfaces of the reindeer lichen Cladonia rangiferina, sampled on the slope of Barguzinsky chain. For the measurement of the elements content (%, a sample-nondestructive μ-XRF spectrometer was used. It was stated that the share (% of the most elements, except for Cu and Zn, was highly variable. The content of the elements on the surfaces differs significantly between the studied parts of C. rangiferina podetia: mean values of the content of P, S, Cl, and K were statistically higher on the surface of the upper part of podetia, while those of Al, Si, Ca, Ti, Cr, Mn, Fe, Cu, Zn, Co, and the total content – on the surface of the lower part of podetia. On all the parts of podetia very high value of the enrichment factor for As and Pb was established, and It was increased for P, Co, Ni, Cu, Zn.

  11. Nuclear toxicology file: cell response to the steady or radioactive chemical elements exposure; Dossier toxicologie nucleaire: reponse cellulaire a l'exposition aux elements chimiques stables ou radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, B.S.; Saintigny, Y. [Centre National de la Recherche Scientifique (CNRS), Sciences du Vivant, UMR 217, 92 - Fontenay aux Roses (France); CEA Fontenay aux Roses, IRCM, UMR 217, 92 (France); Adam, Ch. [Institut de Radioprotection et de Surete Nucleaire (IRSN:DEI/SECRE), Lab. de Radioecologie et d' Ecotoxicologie, 13 - Saint-Paul-lez-Durance (France)

    2008-09-15

    The cellular response to an exposure in a toxic element is made at different levels. The first level is the agent detoxication by its elimination or its neutralization. The second level is the repair of the damages caused by this agent (for example the DNA repair). The third level is the control of the cellular death programmed to eliminate the irreparably damaged cells.Finally, the hurt cell can inform the nearby cells by producing molecular effectors inducing an abscopal or bystander effect. (N.C.)

  12. Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars: II. Ages, metallicities, detailed elemental abundances, and connections to the Galactic thick disc

    NARCIS (Netherlands)

    Bensby, T.; Feltzing, S.; Johnson, J.A.; Gould, A.; Adén, D.; Asplund, M.; Meléndez, J.; Gal-Yam, A.; Lucatello, S.; Sana, H.; Sumi, T.; Miyake, N.; Suzuki, D.; Han, C.; Bond, I.; Udalski, A.

    2010-01-01

    Context. The Bulge is the least understood major stellar population of the Milky Way. Most of what we know about the formation and evolution of the Bulge comes from bright giant stars. The underlying assumption that giants represent all the stars, and accurately trace the chemical evolution of a

  13. Study of the chemical elements and polycyclic aromatic hydrocarbons in atmospheric particles of PM 10 and PM 2.5 in the urban and rural areas of South Brazil

    Science.gov (United States)

    Dallarosa, Juliana; Calesso Teixeira, Elba; Meira, Lindolfo; Wiegand, Flavio

    2008-07-01

    The purpose of this work is to study the chemical elements and PAHs associated with atmospheric particulate in samples of PM 10 collected in the Metropolitan Area of Porto Alegre—MAPA, Rio Grande do Sul, Brazil. In addition, to study the chemical elements associated with particles of different fractions of PM 10-2.5 and PM 2.5 using dichotomous sampling, in urban (MAPA) and rural areas. Two types of samplers were used: HV PM 10 and Dichotomous (PM 10-2.5 and PM 2.5). Samples were collected during 2002 and 2005. The concentration of the elements Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, and Zn was determined by PIXE (Particle-Induced X-ray Emission), while the concentrations of 16 major PAHs were determined according to EPA with a gas chromatograph coupled to a mass spectrometer (GS/MS). Results showed that elements of anthropogenic origin (V, Zn, Cr, Ni, Cu, and S) were mainly associated with the fraction PM 2.5, while the soil dust (Si, Al, Ti and Fe) were found mainly on fraction PM 10-2.5. In samples of PM 10, the most frequent PAHs found were Bgp, Flt, BaA, Chr, B(b + k)F, BaP and Dba. The types of emission and their association with the atmospheric parameters were studied applying the statistical analysis of the principal component method. The main sources found in the area under study were vehicles, industries (steel mills and a coal-fired power station), dust, sea breeze, and burning.

  14. Chemistry of superheavy elements

    International Nuclear Information System (INIS)

    Schaedel, M.

    2012-01-01

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  15. Chemical functionalization and edge doping of zigzag graphene nanoribbon with L-(+)-leucine and group IB elements-A DFT study

    Science.gov (United States)

    Janani, K.; John Thiruvadigal, D.

    2017-10-01

    First-principles based density functional theory (DFT) calculations have been carried out on the chemically functionalized pure and Cu, Ag and Au doped zigzag graphene nanoribbon (ZGNR(6,0)) with the use of the branched chain amino acid L-(+)-Leucine named as LLZGNR(6,0), LLCuZGNR(6,0), LLAgZGNR(6,0) and LLAuZGNR(6,0) respectively. The structural stability for minimum total energy was confirmed by perturbating the geometry of the relaxed structures. The physical and chemical properties, such as band gap, chemical potential, transmission spectrum, charge transfer, bonding character and Gibb's free energy of solvation were analysed for all the four systems. It has been observed that the edge doping assisted functionalized systems (LLCuZGNR(6,0), LLAgZGNR(6,0) and LLAuZGNR(6,0)) without the inclusion of spin polarisation are semiconducting in nature. Whereas, barely functionalized system is found to be semi-metallic. An effective space charge polarisation in functionalized graphene nanoribbon has been revealed through charge transfer studies. Hence, it signifies the effective solubility of the nanoribbon in aqueous media. The results indicate the possibility of using such system as nanocarriers in targeted drug delivery applications.

  16. Theoretical study of the electronic structure of f-element complexes by quantum chemical methods; Analyse de la structure electronique des complexes contenant des elements F par des methodes de la chimie quantique

    Energy Technology Data Exchange (ETDEWEB)

    Vetere, V

    2002-09-15

    This thesis is related to comparative studies of the chemical properties of molecular complexes containing lanthanide or actinide trivalent cations, in the context of the nuclear waste disposal. More precisely, our aim was a quantum chemical analysis of the metal-ligand bonding in such species. Various theoretical approaches were compared, for the inclusion of correlation (density functional theory, multiconfigurational methods) and of relativistic effects (relativistic scalar and 2-component Hamiltonians, relativistic pseudopotentials). The performance of these methods were checked by comparing computed structural properties to published experimental data, on small model systems: lanthanide and actinide tri-halides and on X{sub 3}M-L species (X=F, Cl; M=La, Nd, U; L = NH{sub 3}, acetonitrile, CO). We have thus shown the good performance of density functionals combined with a quasi-relativistic method, as well as of gradient-corrected functionals associated with relativistic pseudopotentials. In contrast, functionals including some part of exact exchange are less reliable to reproduce experimental trends, and we have given a possible explanation for this result . Then, a detailed analysis of the bonding has allowed us to interpret the discrepancies observed in the structural properties of uranium and lanthanides complexes, based on a covalent contribution to the bonding, in the case of uranium(III), which does not exist in the lanthanide(III) homologues. Finally, we have examined more sizeable systems, closer to experimental species, to analyse the influence of the coordination number, of the counter-ions and of the oxidation state of uranium, on the metal-ligand bonding. (author)

  17. The Chemistry of Superheavy Elements

    CERN Document Server

    Schädel, M

    2003-01-01

    The chemistry of transactinide or superheavy elements has reached element 108. Preparations are under way to leap to element 112 and beyond. The current status of this atom-at-a-time chemical research and its future perspectives are reviewed from an experimental point of view together with some of the interesting results from n -rich nuclides near and at the N=162 neutron shell. Experimental techniques and important results enlightening typical chemical properties of elements 104 through 108 are presented in an exemplary way. From the results of these experiments it is justified to place these elements in the Periodic Table of the Elements in to groups 4 through 8, respectively. However, mainly due to the influence of relativistic effects, it is no longer possible to deduce detailed chemical properties of these superheavy elements simply from this position.

  18. The solar element

    DEFF Research Database (Denmark)

    Kragh, Helge

    2009-01-01

    of the nineteenth century. In the modest form of a yellow spectral line known as D3, 'helium' was sometimes supposed to exist in the Sun's atmosphere, an idea which is traditionally ascribed to J. Norman Lockyer. Did Lockyer discover helium as a solar element? How was the suggestion received by chemists, physicists...... and astronomers in the period until the spring of 1895, when William Ramsay serendipitously found the gas in uranium minerals? The hypothetical element helium was fairly well known, yet Ramsay's discovery owed little or nothing to Lockyer's solar element. Indeed, for a brief while it was thought that the two...... elements might be different. The complex story of how helium became established as both a solar and terrestrial element involves precise observations as well as airy speculations. It is a story that is unique among the discovery histories of the chemical elements....

  19. Galvanic element. Galvanisches Element

    Energy Technology Data Exchange (ETDEWEB)

    Sprengel, D.; Haelbig, H.

    1980-01-03

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

  20. Semiquantitative and quantitative measurements for EDXRF in elemental chemical composition of pigments; Medidas semi-quantitativas e quantitativas por EDXRF em composicao quimica elementar de pigmentos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Elizabeth Cristina Soares da

    2005-02-15

    X-Ray fluorescence technique is largely used in the characterization of art and archaeological objects for restoration and conservation, allowing a multi-elemental, simultaneous and non destructive analysis. In this work it was used a portable XRF equipment of XRF that consists of a {sup 238} Pu source ( 13,6 and 17,2 keV; 95 mCi) and a SI-PIN detector coupled to a 8 k multichannel analyser. The results were collected by a palmtop computer and later analysed in a PC, through the program AXIL-QXAS. The acquisition time for each measurement was 500 s. The measurements were accomplished in a wood sculpture (Santa Luzia image, number 164) from the collection of the Museu de Etnologia da Universidade de Sao Paulo (MAE-USP), in the following regions: (STL1) inferior side of the wood base exposed without finishing, (STL2) frontal inferior base of the pedestal (dark blue) (STL3), inferior part of the frontal dress (gold), (STL4) medium part of the dress (clear blue) (STL5) mantle (red), (STL6) back central lock of the hair in the backs (black), (STL7) right cheek (flesh-coloured) and (STL8) mantle (gold). The elements found in the STL1 region were: Al, Ca, Fe and a high concentration of Zn. In the region STL2 were found Al, C, Fe, Zn and the key element Cu. In the region STL3 - Ca, Zn and the key element Au. In the region STL4 it was found Zn and the key element Cu. In the region STL5 the key element S and Hg. In the region STL6 were found Fe, Ca, S and Hg. In the region STL 7 were found Al, Cu, Hg and Zn. In the region STL8 were found Ca, Al and Au, with high concentration. It was concluded that the possible pigments would be: STL2 and STL4 - CuCO{sub 3}. Cu(OH){sub 2} + ZnO; STL3 and STL8 - Au; STL5 - HgS, STL6 - HgS mixed with other oxides, possibly of Fe and Mn, and STL 7 - HgS + ZnO. Standard samples of wood painted with pigments of the colors white, blue, red, rose, flesh color and green were also made. Through the XRF method it was verified that the white pigment is

  1. Methodological study of air quality using lichens as ecological bio-indicators, chemical element bio-accumulators and oxidative stress bio-markers; Etude methodologique de la qualite de l'air en Lorraine-Nord par les lichens: contribution en tant que bioindicateurs ecologiques, bioaccumulateurs d'elements chimiques et biomarqueurs du stress oxydant

    Energy Technology Data Exchange (ETDEWEB)

    Signoret, J.

    2002-11-15

    The objective of this thesis was to contribute to a better understanding of the impact of the atmospheric pollutions on lichens in experimental conditions of field (Lorraine region, France). Techniques of sampling areas analysis for epiphytic lichens were little developed in bio-indication. Without a precise method and a solid validation of the choices of the surface of sampling, survey analysis continue to be subjective and comparative studies and hypotheses testing are rough. To examine this problem, we tested an operational technique of sampling and spatial analysis, based on digitized and geo-referenced data, which makes more objective the lichen covering and frequency assessment. We present a simple example to demonstrate how our investigations will allow to do the link between survey and air quality diagnosis, with perspectives on i) stratified random sampling techniques of lichen communities based on the image interpretation, ii) multi-scale sampling techniques to estimate the efficiency of the sampling grid classically used in bio-monitoring and iii) GIS (Geographical Information Systems) and geostatistical techniques to study floristic and ecological variations at every sampling point. The transplantation is a field technique used for the study air pollution effects and chemical elements accumulation on the lichen symbiosis. Precipitation is known to play an important role in the uptake and release of chemical elements by lichen thalli, but few information was available on their roles in the lichen resistance exposed to photo-oxidizing pollutants. We used this technique to study the effects of gas pollutants and airborne chemical elements on the lichen physiology exposed or not at precipitation. To analyze these interactions, the lichen Hypogymnia physodes (L.) Nyl. was transplanted to 5 locations of the Moselle valley with different levels of air pollution for 14, 34 and 68 days (summer 2001). In each of these sites, 6 transplantation designs, covered or

  2. The distribution of some chemical elements between dissolved and particulate phases in the ocean: Progress report, 1 April 1987-31 March 1988

    International Nuclear Information System (INIS)

    Spencer, D.W.; Bacon, M.P.; Sachs, P.L.; Fleer, A.P.; Shafer, D.K.; Belastock, R.A.; Hammar, T.R.

    1988-01-01

    The long-range goal of our research under this contract is an understanding of the processes that control the distribution and fate of chemical species in the ocean, with a particular emphasis on species which are reactive with respect to uptake by marine particulate matter. Such an understanding is essential in predicting the fate of reactive pollutants, such as heavy metals and radionuclides, that are released to the environment as a consequence of energy-producing activities. In pursuit of this goal we have, during the present contract period, been devoting all of our effort to participation in the Shelf-Edge Exchange Processes (SEEP) program. 23 refs., 7 figs., 4 tabs

  3. Study the chemical composition and biological outcomes resulting from the interaction of the hormone adrenaline with heavy elements: Infrared, Raman, electronic, 1H NMR, XRD and SEM studies

    Science.gov (United States)

    Ibrahim, Omar B.; Mohamed, Mahmoud A.; Refat, Moamen S.

    2014-01-01

    Heavy metal adrenaline complexes formed from the reaction of adrenaline with Al3+, Zn2+, Sn2+, Sb3+, Pb2+and Bi3+ ions in methanolic solvent at 60 °C. The final reaction products have been isolated and characterization using elemental analyses (% of carbon, hydrogen and nitrogen), conductivity measurements, mid infrared, Raman laser, UV-Vis, 1H NMR spectra, X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX). Upon the spectroscopic, conductivity and elemental analyses, the stoichiometric reactions indicated that the data obtained refer to 1:2 (M:L) for Zn2+, Sn2+, Pb2+and Bi3+ complexes [Zn(Adr)2(Cl)2], [Sn(Adr)2]Cl2, [Pb(Adr)2](NO3)2 and [Bi(Adr)2(Cl)2]Cl, while the molar ratio 1:3 (M:L) for Al3+ and Sb3+ with formulas [Al(Adr)3](NO3)3 and [Sb(Adr)3]Cl3. The infrared and Raman laser spectra interpreted the mode of interactions which associated through the two phenolic groups of catechol moiety. The adrenaline chelates have been screened for their in vitro antibacterial activity against four bacteria, Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two strains of fungus (Aspergillus flavus and Candida albicans). The metal chelates were shown to possess more antibacterial and antifungal activities than the free adrenaline chelate.

  4. A view of the H-band light-element chemical patterns in globular clusters under the AGB self-enrichment scenario

    Science.gov (United States)

    Dell'Agli, F.; García-Hernández, D. A.; Ventura, P.; Mészáros, Sz; Masseron, T.; Fernández-Trincado, J. G.; Tang, B.; Shetrone, M.; Zamora, O.; Lucatello, S.

    2018-04-01

    We discuss the self-enrichment scenario by asymptotic giant branch (AGB) stars for the formation of multiple populations in globular clusters (GCs) by analysing data set of giant stars observed in nine Galactic GCs, covering a wide range of metallicities and for which the simultaneous measurements of C, N, O, Mg, Al, and Si are available. To this aim, we calculated six sets of AGB models, with the same chemical composition as the stars belonging to the first generation of each GC. We find that the AGB yields can reproduce the set of observations available, not only in terms of the degree of contamination shown by stars in each GC but, more important, also the observed trend with metallicity, which agrees well with the predictions from AGB evolution modelling. While further observational evidences are required to definitively fix the main actors in the pollution of the interstellar medium from which new generation of stars formed in GCs, the present results confirm that the gas ejected by stars of mass in the range 4 M_{⊙} ≤ M ≤ 8 M_{⊙} during the AGB phase share the same chemical patterns traced by stars in GCs.

  5. Chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation - Part 2: Alkaline earth elements as tracers of watershed hydrochemistry and provenance

    Science.gov (United States)

    Brügmann, G.; Krause, J.; Brachert, T. C.; Stoll, B.; Weis, U.; Kullmer, O.; Ssemmanda, I.; Mertz, D. F.

    2012-11-01

    This study demonstrates that alkaline earth elements in enamel of hippopotamids, in particular Ba and Sr, are tracers for water provenance and hydrochemistry in terrestrial settings. The studied specimens are permanent premolar and molar teeth found in modern and fossil lacustrine sediments of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi) and from modern fluvial environments of the Nile River. Concentrations in enamel vary by two orders of magnitude for Ba (120-9336 μg g-1) as well as for Sr (9-2150 μg g-1). The variations are partially induced during post-mortem alteration and during amelogenesis, but the major contribution originates ultimately from the variable water chemistry in the habitats of the hippopotamids which is controlled by the lithologies and weathering processes in the watershed areas. Amelogenesis causes a distinct distribution of MgO, Ba and Sr in modern and fossil enamel, in that element concentrations increase along profiles from the outer rim towards the enamel-dentin junction by a factor of 1.3-1.9. These elements are well correlated in single specimens, thus suggesting that their distribution is determined by a common, single process, which can be described by closed system Rayleigh crystallization of bioapatite in vivo. Enamel from most hippopotamid specimens has Sr/Ca and Ba/Ca which are typical for herbivores. However, Ba/Sr ranges from 0.1 to 3 and varies on spatial and temporal scales. Thus, Sr concentrations and Ba/Sr in enamel differentiate between habitats having basaltic mantle rocks or Archean crustal rocks as the ultimate sources of Sr and Ba. This provenance signal is modulated by climate change. In Miocene to Pleistocene enamel from the Lake Albert region, Ba/Sr decreases systematically with time from 2 to 0.5. This trend can be correlated with changes in climate from humid to arid, in vegetation from C3 to C4 biomass as well as with increasing evaporation of the lake water

  6. Reconstruction of the diet of a pre hispanic population sector of Cuauhnahuac, Morelos by means of the chemical elements analysis in skeletal rests

    International Nuclear Information System (INIS)

    Brito, L.; Garza, I.; Banos, L.; Chaire, F.

    2004-01-01

    The goal of this work was diet reconstruction of 25 pre hispanic residents of Cuauhnahuac, tributary town of the mexicas, during the Late Pos classic period (1350-1521 a.C.). The analysis included human skull samples proceeding from human femur, tibia and fibula. The applied technique was X-ray fluorescence spectrometry (XRF) to know the mineral concentrations, which are closely related with the quality and quantity of the consumed food. The main indicative elements are strontium (Sr), that denotes the consumption of vegetables, zinc (Zn), that shows the consumption of animal proteins, and magnesium (Mg), associated with Meso american food resources. The results indicate the existence of differences in the diet among the same population's individuals, probably because social stratification determined the power resources acquisition. (Author) 28 refs., 7 tabs., 2 figs

  7. Elemental diffusion in stars

    International Nuclear Information System (INIS)

    Michaud, Georges; Montmerle, Thierry

    1977-01-01

    This paper is dealing with the origin of the elements in the universe. The scheme of nucleosynthesis is kept to explain the stellar generation of helium, carbon, etc... from the initial hydrogen; but a nonlinear theory is then elaborated to account for the anomalous abundances which were observed. The chemical elements would diffuse throughout the outer layers of a star under the action of the opposite forces of gravitation and radiation. This theory, with completing the nucleosynthesis, would contribute to give a consistent scheme of the elemental origin and abundances [fr

  8. Chemically enhanced phytoextraction of risk elements from a contaminated agricultural soil using Zea mays and Triticum aestivum: performance and metal mobilization over a three year period.

    Science.gov (United States)

    Neugschwandtner, Reinhard W; Tlustos, Pavel; Komárek, Michael; Száková, Jirina; Jakoubková, Lucie

    2012-09-01

    Enhanced phytoextraction using EDTA for the remediation of an agricultural soil contaminated with less mobile risk elements Cd and Pb originating from smelting activities in Príbram (Czech Republic) was assessed on the laboratory and the field scale. EDTA was applied to the first years crop Zea mays. Metal mobilization and metal uptake by the plants in the soil were monitored for two additional years when Triticum aestivum was planted. The application ofEDTA effectively increased water-soluble Cd and Pb concentrations in the soil. These concentrations decreased over time. Anyhow, increased concentrations could be still observed in the third experimental year indicating a low possibility of groundwater pollution after the addition of EDTA during and also after the enhanced phytoextraction process under prevailing climatic conditions. EDTA-applications caused phytotoxicity and thereby decreased biomass production and increased Cd and Pb uptake by the plants. Phytoextraction efficiency and phytoextraction potential were too low for Cd and Pb phytoextraction in the field in a reasonable time frame (as less than one-tenth of a percent of total Cd and Pb could be removed). This strongly indicates that EDTA-enhanced phytoextraction as implemented in this study is not a suitable remediation technique for risk metal contaminated soils.

  9. Quantum chemical study of the interaction of elemental Hg with small neutral, anionic and cationic Aun (n = 1–6) clusters

    International Nuclear Information System (INIS)

    Siddiqui, Shamoon Ahmad; Bouarissa, Nadir; Rasheed, Tabish; Al-Assiri, M.S.

    2013-01-01

    Graphical abstract: Binding energies as a function of cluster size for Au n Hg, Au n Hg + and Au n Hg − complexes. Highlights: ► Hg adsorption of neutral and charged Au n (n = 1–6) clusters has been discussed. ► Size and charged state of cluster significantly affect the Hg adsorption. ► Transfer of electron mainly found from s orbital of Hg to s orbital of Au. - Abstract: Adsorption of elemental mercury (Hg) on small neutral, cationic and anionic gold clusters (Au n , n = 1–6) has been studied by using the density functional theory (DFT). Results of this investigation show that frontier molecular orbital theory is a useful tool to predict the selectivity of Hg adsorption. It is found that adsorption of Hg on neutral, cationic and anionic Au n (n = 1–6) clusters are thermodynamically favorable. The binding energies of Hg on the cationic Au n clusters are greater than those on the neutral and anionic clusters. Natural bond orbital (NBO) analysis indicates that the flow of electrons in the neutral and charged clusters is mainly due to the s orbitals of Hg and Au. Results of NBO analysis also indicate that the binding energy of Hg with Au n clusters is directly proportional to the charge transfer, i.e. greater is the charge transfer, higher is the binding energy

  10. Weather elements, chemical air pollutants and airborne pollen influencing asthma emergency room visits in Szeged, Hungary: performance of two objective weather classifications.

    Science.gov (United States)

    Makra, László; Puskás, János; Matyasovszky, István; Csépe, Zoltán; Lelovics, Enikő; Bálint, Beatrix; Tusnády, Gábor

    2015-09-01

    Weather classification approaches may be useful tools in modelling the occurrence of respiratory diseases. The aim of the study is to compare the performance of an objectively defined weather classification and the Spatial Synoptic Classification (SSC) in classifying emergency department (ED) visits for acute asthma depending from weather, air pollutants, and airborne pollen variables for Szeged, Hungary, for the 9-year period 1999-2007. The research is performed for three different pollen-related periods of the year and the annual data set. According to age and gender, nine patient categories, eight meteorological variables, seven chemical air pollutants, and two pollen categories were used. In general, partly dry and cold air and partly warm and humid air aggravate substantially the symptoms of asthmatics. Our major findings are consistent with this establishment. Namely, for the objectively defined weather types favourable conditions for asthma ER visits occur when an anticyclonic ridge weather situation happens with near extreme temperature and humidity parameters. Accordingly, the SSC weather types facilitate aggravating asthmatic conditions if warm or cool weather occur with high humidity in both cases. Favourable conditions for asthma attacks are confirmed in the extreme seasons when atmospheric stability contributes to enrichment of air pollutants. The total efficiency of the two classification approaches is similar in spite of the fact that the methodology for derivation of the individual types within the two classification approaches is completely different.

  11. High and low oxidation states and special bonding situations. An investigation of f-elements, xenon and fluorine by matrix-isolation spectroscopy and quantum-chemical calculations

    Energy Technology Data Exchange (ETDEWEB)

    Vent-Schmidt, Thomas

    2015-11-30

    During this thesis, the matrix-isolation technique in conjuction with quantum-chemical calculations has been employed in order to synthesize and characterize new compounds. The focus of the study were new species of the actinide and lanthanide series, but the photochemistry of XeO{sub 4} and the polyfluorides were also investigated. Based on the experience of laser ablated uranium and thorium atoms with H{sub 2} and F{sub 2} the reaction of these actinide atoms with HF has been investigated. The main products in these experiments are HThF and HUF which contain an actinide metal in the rather scarce +II oxidation state. In addition, the deuterated compounds have also been prepared and the isotopic shifts support the assignment. The higher hydride fluorides of thorium such as HThF{sub 3}, H{sub 2}ThF{sub 2} and H{sub 3}ThF have also been observed, whereas there is only little evidence for higher uranium hydride fluorides. The different behavior of the two metals under similar reaction conditions has been investigated theoretically. Besides the hydride fluorides, the reaction of the actinide atoms with HF gives also rise to the low valent fluorides and hydrides such as AnH and AnF (An = U, Th). These compounds have already been identified in experiments using fluorine or hydrogen as reagent, but a more reliable assignment can be made in these experiments due to the lower concentration of H or F. In addition, ThF{sub 2} has been observed in these experiments and there is evidence for the unknown difluoride of uranium, which will be addressed in a future paper. Experiments with laser ablated uranium and thorium atoms were extended to the reaction of these metals with H{sub 2}Se. Previous experiments using H{sub 2}O and H{sub 2}S instead of H{sub 2}Se yielded H{sub 2}AnX (An = U, Th; X = O, S) compounds which show evidence for an actinide-chalcogenide multiple bond. The new synthesized species H{sub 2}ThSe and H{sub 2}USe are characterized by their symmetric and

  12. Effects of Non Process Elements in the chemical recovery system of paper mills; Effekter av PFG foer integrerade pappersbruk vid indunstning och foerbraenning av bioslam i sodapannan

    Energy Technology Data Exchange (ETDEWEB)

    Dahlbom, Johan [AaF Process AB, Stockholm (Sweden); Wadsborn, Rickard [STFI-Packforsk AB, Stockholm (Sweden)

    2005-09-01

    Effluent treatment of pulp and paper mills generates a biological sludge that according to Swedish implementation of EU-directives from 2005 has to be taken care of by incineration or by production of soil for agriculture or ground cover. An alternative way to take care of the sludge is incineration in the recovery boiler. This method is used in two Finish and two Swedish pulp mills with good results. The purpose of this project is to investigate the consequences for integrated pulp and paper mills when the biological sludge is incinerated in the recovery boiler. The biological sludge contents Non Process Elements, NPE, which increase the risks of incrustations in the system and increase the need of make up lime. This study comprises the following NPE: aluminum, silicon, phosphorus, chloride, potassium, manganese, magnesium, iron, copper, barium and calcium. The simulation program WinGEMS 5.0 (Pacific Simulation) was used in the study to predict the levels of NPE in the recovery system of the Kraft mills. Three different pulp and paper mills were selected for the study, Billerud Skaerblacka, ASSI Domaen Froevi and SCA Obbola. The mills are different concerning raw materials, process, degree of own produced pulp and paper products. All three the mills have effluent treatment and use the method of activated sludge that generates a surplus of biological sludge. The results of the study proved that for Skaerblacka mill the method is applicable. For Obbola the prerequisites are somewhat more complicated, the effluent treatment generates considerably higher amount of sludge per ton pulp produced due to the treatment technique and use of waste paper (40 %) for the paper machine. The high input of aluminum with the sludge will give troublesome incrustations of sodium-aluminum-silicate on the heat surfaces in the evaporation plant. To eliminate the aluminum from the system magnesium can be added to the black liquor which will precipitate as the double salt hydrotalcite in

  13. Characterization of chemical elements of fruits of Leucaena leucocephala in riverside areas of the Piracicaba River Basin, São Paulo, Brazil; Caracterização de elementos químicos de frutos de Leucaena leucocephala em áreas ribeirinhas da Bacia do Rio Piracicaba, São Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    França, Elvis J.; Magalhães, Marcelo R.L. de; Ferreira, Fabiano S., E-mail: ejfranca@cnen.gov.br, E-mail: marcelo_rlm@hotmail.com, E-mail: biologofabiano10@gmail.com [Centro de Ciência Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fernandes, Elisabete A. de N.; Fonseca, Felipe Y.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O.; Camilli, Leandro, E-mail: lis@cena.usp.br, E-mail: vsrodrigues89@gmail.com, E-mail: i-cavalcante@uol.com.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Silva, Bruno F., E-mail: brunodasilva1996@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2017-07-01

    The species Leucaena leucocephala is present in several environments. Its fruit is widely used in cattle feed. However, it is classified as an invasive species, causing problems in the restoration of impacted areas. The Piracicaba River Basin is heavily affected by urbanization and industrialization, which shows the proliferation of this species. Considering the importance of this tree species for Brazil, the present study quantifies chemical elements in fruits of this species by applying Instrumental Neutronic Activation Analysis, method k{sup 0}. Samples were collected in riverside areas of the Piracicaba Municipality, São Paulo, Brazil, at different periods (dry and rainy season). After collection, the samples were shattered and transferred to polyethylene capsules and irradiated with neutrons. Certified reference materials were used to evaluate the quality of the analytical procedure, all material was irradiated under a thermal neutron flux of 10{sup 13} cm-2s-1 for 8 hours. Ni-Cr alloy was used for the monitoring of thermal neutron flux. High Resolution Range Spectrometry with HPG detectors was employed for the measurement of the induced radioactivity, allowing the quantification of the chemical elements. Compared with available results of chemical analysis of pods, the chemical elements Ca, K, Ba, Cr and Se presented high concentrations. We also quantified chemical elements of environmental relevance such as As, Hg, Br, Ce, Cs, Eu, Hf, La, Rb, Sb, Sc, Sm, Ta, Tb, Th and Yb, indicating the need for element dynamics studies in the environments occupied by this invasive species.

  14. Chemical elements in Leucaena leucocephala leaves of riparian zones of the municipality of Piracicaba, São Paulo, Brazil; Elementos químicos em folhas de Leucaena leucocephala de zonas ripárias do município de Piracicaba, São Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    França, Elvis J. de; Fernandes, Elisabete A.N.; Lira, Marcelo G.; Ferreira, Fabiano S.; Cavalca, Isabel P.O.; Rodrigues, Vanessa S.; Camilli, Leandro, E-mail: ejfranca@yahoo.com.br, E-mail: liramarcelo@hotmail.com, E-mail: biologofabiano10@gmail.com [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-07-01

    The species Leucaena leucocephala can be found in several riparian ecosystems, acting as one of the main invasive and harmful species for the forest restoration of the permanent preservation areas. It has also been studied for the phytoremediation of some chemical elements, due to their potential accumulation of chemical substances. Therefore, the present study aimed to evaluate the accumulation of chemical elements in leaves of Leucaena leucocephala trees by Instrumental Neutronic Activation Analysis - INAA. Samples of leaves were collected in eight samples from riverside areas of the Piracicaba Municipality, São Paulo, Brazil, during the dry and rainy season. After collection, washing with water and drying in a forced circulation oven, the samples were comminuted and encapsulated in polyethylene capsules and subjected to a thermal neutron flux of 10{sup 13} cm{sup -2}s{sup -1} for 8 hours in the Nuclear Research Reactor IEA-R1 of IPEN / CNEN. Thermal neutron flux monitoring was performed by Ni-Cr alloy fragments with known concentrations of the chemical monitors elements. After measurements of radioactivity induced by HPGe detectors, the concentrations of the chemical elements were calculated by the k0 method using the Quantu computer program. Certified reference materials were also analyzed for quality assurance of the analytical procedure. The results indicated high concentrations of La and lanthanoids (Ce, Eu, Sm, Tb and Yb) in leaves of L. leucocephala in both periods analyzed. It was possible to observe a decrease in the concentrations of the chemical elements in the rainy season, probably associated to the washing of the geological material deposited on the leaves of the trees by the rains, except for K, Mo, Rb, Sb and Zn, whose values remained or increased in the leaves collected during the rainy season. Considering the constant leaf production, L. leucocephala can greatly affect the cycling of chemical elements due to its accumulation capacity

  15. Chemistry of the superheavy elements.

    Science.gov (United States)

    Schädel, Matthias

    2015-03-13

    The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently 'known' SHEs (11 are officially 'discovered' and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe 'relativistically' influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  16. Transplutonium elements

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishnan, C. K.; Jadhav, A. V.; Reghuraman, K.; Mathew, K. A.; Nair, P. S.; Ramaniah, M. V.

    1973-07-01

    Research progress is reported on studies of the transplutonium elements including recovery and purification of americium, preparation of /sup 238/Pu, extraction studies using diethylhexyl phosphate. (DHM)

  17. Chemistry of the transactinide elements

    International Nuclear Information System (INIS)

    Schaedel, M.

    1995-01-01

    The experimentally known chemical properties of the transactinide elements 104 and 105, and the experimental techniques used to study these properties on an atom-at-a-time base, are reviewed. The production of transactinides in heavy ion reactions and the specific aspects of chemical separations with single atoms is briefly discussed. The chemical properties of the first two transactinide elements are compared with the lighter element homologs in group 4 and 5 of the Periodic Table and with the expected behaviour obtained from most recent atomic and molecular calculations which take the increasingly strong relativistic effect into account. Elements 104 and 105 behave as transactinide elements and, in general, exhibit properties characteristic of their position in group 4 and 5 of the Periodic Table. However, surprising deviations of the chemical properties from expectations based on simple extrapolations have been observed. It is shown that the chemical properties of the heaviest elements cannot reliably be predicted by simple extrapolations. Prospects to extend our chemical knowledge at the top end of the Periodic Table are discussed. (orig.)

  18. Toxic Elements

    DEFF Research Database (Denmark)

    Hajeb, Parvaneh; Shakibazadeh, Shahram; Sloth, Jens Jørgen

    2016-01-01

    Food is considered the main source of toxic element (arsenic, cadmium, lead, and mercury) exposure to humans, and they can cause major public health effects. In this chapter, we discuss the most important sources for toxic element in food and the foodstuffs which are significant contributors to h...

  19. Chemistry of the heaviest elements

    International Nuclear Information System (INIS)

    Schaedel, M.

    1992-08-01

    The experimentally known chemical properties of elements 103,104, and 105, and the experimental techniques to obtain these properties on a one-atom- at-a-time base, are summarized. The chemical properties are compared with the lighter group 3,4 and 5 homologs and with the expected behaviour as obtained from theoretical calculations. In this transition region from the last actinide element to the beginning of the transactinide series one may expect to find evidence for increasingly strong relativistic effects altering the chemical behaviour. (orig.)

  20. The Origin of the Chemical Elements, 1

    Science.gov (United States)

    Selbin, Joel

    1973-01-01

    The problem of the origin is inextricably interwoven with such matters as the origin of the universe, the structure and evolution of galaxies, stars and other astronomical objects, and with nuclear physics. (Author/DF)

  1. Periodic table of elements

    International Nuclear Information System (INIS)

    Fluck, E.; Heumann, K.G.

    1985-01-01

    Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF) [de

  2. Fuel element

    International Nuclear Information System (INIS)

    Armijo, J.S.

    1976-01-01

    A fuel element for nuclear reactors is proposed which has a higher corrosion resisting quality in reactor operations. The zirconium alloy coating around the fuel element (uranium or plutonium compound) has on its inside a protection layer of metal which is metallurgically bound to the substance of the coating. As materials are namned: Alluminium, copper, niobium, stainless steel, and iron. This protective metallic layer has another inner layer, also metallurgically bound to its surface, which consists usually of a zirconium alloy. (UWI) [de

  3. Transplutonium elements - a literature survey

    International Nuclear Information System (INIS)

    Sivaramakrishnan, C.K.; Jadhav, A.V.

    1974-01-01

    The report surveys reported work on the discovery of transplutonium elements and their production through various methods like bombardment of heavy elements with charged ions, successive neutron captures on heavy elements in reactors and multiple neutron captures by heavy elements during nuclear explosions. Estimated yields of transplutonium elements in special targets irradiated in reactors, and also as byproducts from spent power reactor fuels are quoted. Various chemical procedures adopted for recovery of these elements from irradiated target and also from power reactor fuel reprocessing streams are described. A brief survey of shielded facilities available at various centres for transplutonium programmes is also included. Major uses of some of these heavy elements are described. (author)

  4. Nuclear fuel element

    International Nuclear Information System (INIS)

    Penrose, R.T.; Thompson, J.R.

    1976-01-01

    A method of protecting the cladding of a nuclear fuel element from internal attack and a nuclear fuel element for use in the core of a nuclear reactor are disclosed. The nuclear fuel element has disposed therein an additive of a barium-containing material and the barium-containing material collects reactive gases through chemical reaction or adsorption at temperatures ranging from room temperature up to fuel element plenum temperatures. The additive is located in the plenum of the fuel element and preferably in the form of particles in a hollow container having a multiplicity of gas permeable openings in one portion of the container with the openings being of a size smaller than the size of the particles. The openings permit gases and liquids entering the plenum to contact the particles. The additive is comprised of elemental barium or a barium alloy containing one or more metals in addition to barium such as aluminum, zirconium, nickel, titanium and combinations thereof. 6 claims, 3 drawing figures

  5. Use of analog elements to predict the equilibrium and behavior of transuranic elements in the environment

    International Nuclear Information System (INIS)

    Weimer, W.C.; Laul, J.C.; Kutt, J.C.

    1978-01-01

    Several naturally-occurring elements with chemical properties similar to those of selected transuranic elements have been chosen and are being examined as potential predictors of transuranic geochemical behaviors. This approach may allow the estimation of the long-term behaviors of transuranic elements in the environment by analyses of the steady-state behaviors of their analog elements. The elements receiving principal attention are the transuranics Am and Cm and their proposed lanthanide element analog Nd

  6. Chemical Peels

    Science.gov (United States)

    ... care Kids’ zone Video library Find a dermatologist Chemical peels Overview Chemical peels: Overview Also called chemexfoliation , derma peeling Do ... Overview Chemical peels: FAQs Chemical peels: Preparation FAQs Chemical peels: FAQs To help you decide whether this ...

  7. Trace element emissions from coal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-09-15

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

  8. PELTIER ELEMENTS

    CERN Document Server

    Tani, Laurits

    2015-01-01

    To control Peltier elements, temperature controller was used. I used TEC-1091 that was manufactured my Meerstetter Engineering. To gain control with the temperature controller, software had to be intalled on a controlling PC. There were different modes to control the Peltier: Tempererature controller to control temperature, Static current/voltage to control voltage and current and LIVE ON/OFF to auto-tune the controller respectively to the system. Also, since near the collision pipe there is much radiation, radiation-proof Peltier elements have to be used. To gain the best results, I had to find the most efficient Peltier elements and try to get their cold side to -40 degrees Celsius.

  9. Characterization of chemical elements in soil submitted to different systems use and management by energy dispersive x-ray fluorescence spectrometry (EDXRF); Caracterizacao dos niveis de elementos quimicos em solo, submetido a diferentes sistemasde uso e manejo, utilizando espectrometria de fluorescencia de raios-X por energia dispersiva (EDXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Wastowski, Arci Dirceu; Rosa, Genesio Mario da; Cherubin, Mauricio Roberto; Rigon, Joao Paulo Gonsiorkiewicz, E-mail: wastowski@smail.ufsm.b [Universidade Federal de Santa Maria (UFSM), Frederico Westphalen, RS (Brazil). Centro de Educacao Superior Norte do Rio Grande do Sul

    2010-07-01

    This study aimed to evaluate the chemical elements levels in soil, submitted to different management systems and use by the Energy Dispersive X-Ray Fluorescence Spectrometry - EDXRF. The systems were T1 - agroforestry (SAF), T2 - native field (CN), T3 - native forest (NM), T4 - tillage forest (PF); T5 - conventional tillage system (SPC) and T6 - system tillage (NT). Samples were collected at 0-10 and 10-20 cm, dried and ground for analysis in EDX-720. The soil showed no difference in the average concentrations of chemical elements analyzed in the profiles, but the systems presented different concentrations of metal elements, and T3 had the highest K, Ca and Zn at 0-10 cm and higher contents of K, Ca, Cu, Zn and Mn in the layer of 10-20 cm. (author)

  10. Caracterização dos níveis de elementos químicos em solo, submetido a diferentes sistemas de uso e manejo, utilizando espectrometria de fluorescência de raios-x por energia dispersiva (EDXRF Characterization of chemical elements in soil submitted to different systems use and management by energy dispersive x-ray fluorescence spectrometry (EDXRF

    Directory of Open Access Journals (Sweden)

    Arci Dirceu Wastowski

    2010-01-01

    Full Text Available This study aimed to evaluate the chemical elements levels in soil, submitted to different management systems and use by the Energy Dispersive X-Ray Fluorescence Spectrometry - EDXRF. The systems were T1 - agro forestry (SAF, T2 - Native Field (CN, T3 - Native Forest (NM, T4 - Tillage Forest (PF; T5 - conventional tillage system (SPC and T6 - System tillage (NT. Samples were collected at 0-10 and 10-20 cm, dried and ground for analysis in EDX-720. The soil showed no difference in the average concentrations of chemical elements analyzed in the profiles, but the systems presented different concentrations of metal elements, and T3 had the highest K, Ca and Zn at 0-10 cm and higher contents of K, Ca, Cu, Zn and Mn in the layer of 10-20 cm.

  11. Chemistry of the heaviest elements

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1996-01-01

    Studies of the chemical properties of the elements at the uppermost end of the periodic table are discussed. Some historical perspective is given, but major emphasis is on recent studies. Isotopes of these elements are short-lived and, therefore, must be studied near the site of production. They must be produced with charged-particle beams at accelerators rather than via neutron capture. The use of radioactive heavy actinide targets is often required and the number of atoms produced is so small that any chemistry to be performed must be done on an ''atom-at-a-time'' basis. Furthermore, a knowledge of their nuclear properties is required in order to identify and detect them. To date, both gas and aqueous phase properties of elements as heavy as element 104 (rutherfordium) and element 105 (hahnium) have been investigated, even though their longest-lived known isotopes have half-lives of only 65 and 35 seconds, respectively. The experimental results show that their chemical properties cannot be simply extrapolated from the known properties of their lighter homologs in the periodic table, emphasizing the importance of obtaining additional experimental information for the heaviest elements to compare with predictions and help assess the influence of relativistic effects. The feasibility of the extension of chemical studies to still heavier elements is also discussed. (orig.)

  12. Superheavy Elements Challenge Experimental and Theoretical Chemistry

    CERN Document Server

    Zvára, I

    2003-01-01

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

  13. Fuel element

    International Nuclear Information System (INIS)

    Kennedy, S.T.

    1982-01-01

    A nuclear reactor fuel element wherein a stack of nuclear fuel is prevented from displacement within its sheath by a retainer comprising a tube member which is radially expanded into frictional contact with the sheath by means of a captive ball within a tapered bore. (author)

  14. The origin of the elements. Chapter 3

    International Nuclear Information System (INIS)

    Tayler, R.J.

    1980-01-01

    The paper is concerned with the questions: how the present chemical composition is related to the original composition of the Universe, and what was the nature of that original composition. In particular, the chemical evolution of the Galaxy is discussed. Section headings are: observations of chemical composition (stars, cosmic gases, galaxies, element abundance); theoretical considerations (nucleosynthesis); cosmological element production (the Hot Big Bang theory); galactic nucleosynthesis. (U.K.)

  15. I. Forensic data analysis by pattern recognition. Categorization of white bond papers by elemental composition. II. Source identification of oil spills by pattern recognition analysis of natural elemental composition. III. Improving the reliability of factor analysis of chemical measured analytical data by utilizing the measured analytical uncertainity. IV. Elucidating the structure of some clinical data

    International Nuclear Information System (INIS)

    Duewer, D.L.

    1977-01-01

    Pattern recognition techniques are applied to the analysis of white bond papers and the problem of determining the source of an oil spill. In each case, an elemental analysis by neutron activation is employed. For the determination of source of oil spills, the field sample was weathered prior to activation analysis. A procedure for including measured analytical uncertainty into data analysis methodology is discussed, with particular reference to factor analysis. The suitability of various dispersion matrices and matrix rank determination criteria for data having analytical uncertainty is investigated. A criterion useful for judging the number of factors insensitive to analytical uncertainty is presented. A model data structure for investigating the behavior of factor analysis techniques in a known, controlled manner is described and analyzed. A chemically interesting test data base having analytical uncertainty is analyzed and compared with the model data. The data structure of 22 blood constituents in three categories of liver disease (viral or toxic hepatitis, alcoholic liver diseases and obstructive processes) is studied using various statistical and pattern recognition techniques. Comparison of classification results on the original data, in combination with principal component analysis, suggests a possible underlying structure for the data. This model structure is tested by the application of two simple data transformations. Analysis of the transformed data appears to confirm that some basic understanding of the studied data has been achieved

  16. New elements

    International Nuclear Information System (INIS)

    Flerov, G.

    1976-01-01

    The history is briefly described of the investigation of superheavy elements at the Joint Institute for Nuclear Research at Dubna. The significance of the investigation is assessed from the point of view of the nuclear structure study and major problems encountered in experimental efforts are indicated. Current experimental methods aiming at the discovery or the production of superheavy nuclei with Z approximately 114 are listed. (I.W.)

  17. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  18. Nuclear chemistry of transactinide elements

    Energy Technology Data Exchange (ETDEWEB)

    Nagame, Yuichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    The current status on the nuclear chemistry studies of transactinide elements is reviewed. The production of transactinides in heavy ion reactions is briefly discussed, and nuclear properties on the stability of transactinides are presented. Chemical properties of the trans-actinide elements 104, 105 and 106, and a typical experimental technique used to study these properties on an atom-at-a-time base are introduced. (author)

  19. Radiographic element

    International Nuclear Information System (INIS)

    Abbott, T.I.; Jones, C.G.

    1984-01-01

    Radiographic elements are disclosed comprised of first and second silver halide emulsion layers separated by an interposed support capable of transmitting radiation to which the second image portion is responsive. At least the first imaging portion contains a silver halide emulsion in which thin tubular silver halide grains of intermediate aspect ratios (from 5:1 to 8:1) are present. Spectral sensitizing dye is adsorbed to the surface of the tubular grains. Increased photographic speeds can be realized at comparable levels of crossover. (author)

  20. Recommended inorganic chemicals for calibration

    International Nuclear Information System (INIS)

    Moody, J.R.; Greenberg, R.R.; Pratt, K.W.; Rains, T.C.

    1988-01-01

    All analytical techniques depend on the use of calibration chemicals to relate analyte concentration to an instrumental parameter. A fundamental component in the preparation of calibration solutions is the weighing of a pure chemical or metal before preparing a solution standard. The analyst must be assured that the purity, stoichiometry, and assay of the chemical are known. These terms have different meanings, and each has an important influence. This report is intended to assist the analyst in the selection and use of chemical standards for instrumental calibration. Purity, stoichiometry, and preparation of solutions for different purposes are discussed, and a critical evaluation of the best materials available for each element is presented for use in preparing solutions or calibration standards. Information on the chemical form, source, purity, drying, and appropriate precautions is given. In some cases, multiple sources or chemical forms are available. Certain radioactive elements, the transuranic elements, and the noble gases are not considered

  1. Superheavy elements

    CERN Document Server

    Hofmann, S

    1999-01-01

    The outstanding aim of experimental investigations of heavy nuclei is the exploration of spherical 'SuperHeavy Elements' (SHEs). On the basis of the nuclear shell model, the next double magic shell-closure beyond sup 2 sup 0 sup 8 Pb is predicted at proton numbers between Z=114 and 126 and at neutron number N=184. All experimental efforts aiming at identifying SHEs (Z>=114) were negative so far. A highly sensitive search experiment was performed in November-December 1995 at SHIP. The isotope sup 2 sup 9 sup 0 116 produced by 'radiative capture' was searched for in the course of a 33 days irradiation of a sup 2 sup 0 sup 8 Pb target with sup 8 sup 2 Se projectiles, however, only cross-section limits were measured. Positive results were obtained in experiments searching for elements from 110 to 112 using cold fusion and the 1n evaporation channel. The produced isotopes were unambiguously identified by means of alpha-alpha correlations. Not fission, but alpha emission is the dominant decay mode. The measurement ...

  2. Risk from environmental chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Somers, E [Environmental Health Directorate, Health Protection Branch, Health and Welfare Canada, Ontario

    1982-01-01

    The elements of risk assessment, namely risk identification, risk estimation, risk evaluation and risk management, are described with respect to the control of environmental chemicals. The methodology of risk estimation is outlined and examples given of its application to regulatory decision-making for a number of chemicals in Canada. Finally, the extent and limitations of the process of risk evaluation are considered together with the need to recognize the importance of the public's perception of the level of risk.

  3. Fuel element

    International Nuclear Information System (INIS)

    Hirose, Yasuo.

    1982-01-01

    Purpose: To increase the plenum space in a fuel element used for a liquid metal cooled reactor. Constitution: A fuel pellet is secured at one end with an end plug and at the other with a coil spring in a tubular container. A mechanism for fixing the coil spring composed of a tubular unit is mounted by friction with the inner surface of the tubular container. Accordingly, the recoiling force of the coil spring can be retained by fixing mechanism with a small volume, and since a large amount of plenum space can be obtained, the internal pressure rise in the cladding tube can be suppressed even if large quantities of fission products are discharged. (Kamimura, M.)

  4. Trace elements in brazilian soils

    International Nuclear Information System (INIS)

    Rocha, Geraldo Cesar

    1995-01-01

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

  5. Superheavy element chemistry. Achievements and perspectives

    International Nuclear Information System (INIS)

    Schaedel, M.

    2007-01-01

    Superheavy elements have been synthesized and chemically characterized one-atom-at-a-time up to element 108. Presently, the quest for element 112 is one of the hottest topics in this field. The transactinide elements 104 to 108 are members of group 4 to 8 of the Periodic Table and element 112 belongs into group 12. Chemical properties of some of these elements, like elements 104 and 105, show stunning deviations from simple extrapolations within their respective group while others exhibit great similarities with their lighter homologues elements. First experiments to investigate seaborgium (Sg, element 106) in aqueous solution were performed. Again, in large international collaborations at the GSI, several gas-phase chemistry experiments were performed with hassium (Hs, element 108). Recently, the highly efficient and very clean separation of Hs was applied for nuclear studies of various Hs nuclides investigating their cross section and their nuclear decay properties in the region of the doubly-magic 270 Hs (Z=108, N=162). To overcome certain limitations of the presently used on-line chemical separations the new TransActinide Separation and Chemistry Apparatus (TASCA) - with a gas-filled recoil separator as a front-end tool - was designed and built at the GSI in a collaborative effort. Presently in its commissioning phase, TASCA shall be a key instrument for a big leap into quantitatively and qualitatively new experiments in the region of superheavy elements. (author)

  6. Total reflection X-ray fluorescence applied to the chemical elements analysis of the mate tea infusion (Ilex-paraguariensis); Fluorescencia de raios-X por reflexao total aplicada a analise de elementos quimicos em cha de erva-mate (Ilex-paraguariensis)

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Fabio; Appoloni, Carlos R. [Universidade Estadual de Londrina, PR (Brazil). Lab. de Fisica Nuclear Aplicada; Cunha, Richard M. da Silva e; Nascimento Filho, Virgilio Franco do [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear

    2002-07-01

    The purpose was to evaluate simultaneously the chemical element concentrations from K to Sr (19{<=}Z{<=}38) range in six samples of mate tea (Ilex paraguariensis) infusion, commercially available in Paraguay and South of Brazil. The chemical analysis of this beverage has a great nutritional importance for the native people of these areas, due to their large daily consumption. For the determination of these elements the dry-ashing and total reflection X-rays fluorescence (TXRF) were used. The methodology showed limits of detection among 81 ng.mL-1 for K to 10 ng.mL{sup -1} for Zn. Six infusion samples were prepared in triplicate, and the concentration was 3,8 to 10,2 {mu}g.mL{sup -1} for K, Ca and Mn, 0,21 to 1,07 {mu}g. mL{sup -1} for Fe and Zn and 0.03 to 0,17 {mu}g.mL{sup -1} for Ni, Cu, Br, Rb and Sr. The Mn and Ni concentrations are above the maximum permissible values for drinking water established by World Health Organization and Brazilian legislation (these organisms do not regulate the maximum permissible values for chemical elements in mate tea infusion). (author)

  7. Chemical analysis report 2014

    International Nuclear Information System (INIS)

    Elbouzidi, Saliha; Elyahyaoui, Adil; Ghassan, Acil; Marah, Hamid

    2014-01-01

    This report highlights the results of chemical analyzes related to Major elements, traces and heavy metals carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 120 samples. The report presents the analytical techniques used (parameters and methods), a legend and the results tables.

  8. Automated rapid chemistry in heavy element research

    International Nuclear Information System (INIS)

    Schaedel, M.

    1994-01-01

    With the increasingly short half-lives of the heavy element isotopes in the transition region from the heaviest actinides to the transactinide elements the demand for automated rapid chemistry techniques is also increasing. Separation times of significantly less than one minute, high chemical yields, high repetition rates, and an adequate detection system are prerequisites for many successful experiments in this field. The development of techniques for separations in the gas phase and in the aqueous phase for applications of chemical or nuclear studies of the heaviest elements are briefly outlined. Typical examples of results obtained with automated techniques are presented for studies up to element 105, especially those obtained with the Automated Rapid Chemistry Apparatus, ARCA. The prospects to investigate the properties of even heavier elements with chemical techniques are discussed

  9. On the Geometry of the Periodic Table of Elements

    Directory of Open Access Journals (Sweden)

    Khazan A.

    2010-10-01

    Full Text Available The presented analytical research manifests a geometrical connexion existing among the elements of the Periodic Table of Elements, in addition to the known physical chemical connexion.

  10. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  11. Chemical elements in soils of riverside areas of the Piracicaba river basin, São Paulo, Brazil; Elementos químicos em solos de áreas ribeirinhas da bacia hidrográfica do rio Piracicaba, São Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    França, Elvis J.; Lira, Marcelo B.G.; Paiva, José D.S., E-mail: ejfranca@cnen.gov.br, E-mail: liramarcelo@hotmail.com, E-mail: paivajds@gmail.com [Centro Regional de Ciências Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fernandes, Elisabete A. de N.; Fonseca, Felipe Y.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O.; Camilli, Leandro, E-mail: lis@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2017-07-01

    The monitoring of the soil quality of the Piracicaba River Basin, located in the State of São Paulo, is of extreme environmental importance, as it ensures the functionality of the basin ecosystems and environmental protection. However, there are few studies focused on the concentration of chemical elements in soils of environmental protection zones of highly populated riverside regions. In view of the above, this work aims to determine the concentration of chemical elements in the soils located on the banks of the Piracicaba River by the Instrumental Neutronic Activation Analysis - INAA. Soil samples were collected in the 0-5 cm, 5-10 cm and 10-15 cm profiles. Subsequently, the samples were dried in an oven at 80 deg C and comminuted with the aid of mortar and pistil. 250 mg portions were transferred to polyethylene capsules and irradiated in 10{sup 13} cm{sup -2}.s{sup -1} neutron flux for 4 hours at the IEA-R1 Nuclear Research Reactor of the Nuclear and Energy Research Institute -IPEN / SP, Brazil. The determination of the chemical elements was conducted by the k0-INAA method from the Quantu program. Comparing the results obtained with the soil values of an untouched area of Atlantic Forest - Carlos Botelho State Park, the maximum values obtained of As (29 mg / kg) and Zn (185 mg / kg) were about 5 times greater. However, concentrations of terrigenous elements such as Fe and Sc were also high in some cases, indicating that there is also a contribution of the source material (rocks) to the high concentrations observed in the riverside soils.

  12. A study on chemical element determinations in human nails by neutron activation analysis; Estudo sobre determinacao de elementos quimicos em unhas humanas pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Sanches, Thalita Pinheiro

    2012-07-01

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

  13. Elemental Etymology: What's in a Name?

    Science.gov (United States)

    Ball, David W.

    1985-01-01

    Examines the origin of the names (or etymologies) of the chemical elements. Includes tables listing elements: (1) with names of obscure origin; (2) named for colors; (3) named after real or mythical people; (4) named after places; (5) named after heavenly bodies; and (6) having names of miscellaneous origin. (JN)

  14. Chemistry gains a new element: Z=106

    International Nuclear Information System (INIS)

    Gaeggeler, H.W.; Eichler, B.; Tuerler, A.

    1997-01-01

    Even though 112 chemical elements are presently known, for elements with atomic numbers above 105 only nuclear decay properties have been investigated so far. Such data allow to proof the existence of a given nuclide, but they do not yield any information with respect to the position of a chemical element in the Periodic Table. We have performed ever first chemical investigations of element 106. According to the Periodic Table element 106 should be a member of group 6, having similar chemical properties as W, Mo and Cr. Two different techniques were applied to separate and identify element 106: a liquid chromatography system (ARCA = Automated Rapid Chemistry Apparatus) and a continuous isothermal chromatography device (OLGA = On-Line Gaschemistry Apparatus). With ARCA about 5'000 separations on small cation exchange columns (Aminex A6) with a 0.1 M HNO 3 /5.10 -4 M Hf solution were performed and with OLGA the gas adsorption behaviour of oxychlorides on quartz columns using Cl 2 /SOCl 2 /O 2 as reactive gas were studied. On the basis of only ten detected atoms, it was possible to proof that element 106 forms complexes which are eluted at positions similar to those of Mo and W. In addition, in the gas phase element 106 forms oxychlorides of lower volatility compared to those of Mo and W. (author) 1 ref

  15. Chemical process hazards analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  16. Assessment of atmospheric pollution of chemical elements by epiphytic lichen analysis at the Campus of the Sao Paulo University; Avaliacao da poluicao atmosferica de elementos quimicos pela analise de liquen epifitico no Campus da Cidade Universitaria de Sao Paulo

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Rosiana Rocho

    2015-07-01

    Air pollution has been a frequent topic of research, due to the effects that it can cause on the health of living organisms, environment and climate. In order to identify pollution sources and their effects, biomonitoring has been studied due to its low cost and possibility of sampling in wide geographic areas. In this study for passive biomonitoring of air pollution levels at the Cidade Universitaria Armando Salles de Oliveira (CUASO), University of Sao Paulo campus, epiphytic lichens of Canoparmelia texana species were used. The lichens collected from tree barks at different sampling sites in the CUASO were cleaned, freeze-dried and ground for analyses. Lichen samples were analyzed by X - ray fluorescence spectrometry (XRFS) and neutron activation analysis (NAA). For XRFS, cylindrical pellets of samples were prepared to determine As, Br, Ca, Cl, Cr, Cu, Fe, K, Mn, Rb, S, Sr and Zn. For NAA, lichen sample aliquots along with synthetic elemental standards were irradiated both for short and long periods at the IEA-R1 nuclear research reactor. The induced activities were measured by a gamma ray spectrometer to determine As, Br, Ca Cd, Cl, Co, Cr, Cs, Cu, Fe, K, La, Mg, Mn, Rb, Sb, Sc, Se, U, V and Zn. The precision and accuracy of the results were evaluated by the analysis of certified reference materials (MRCs). Their results of relative errors and standard deviations were below 15% for most of the elements. The standardized difference or En score values were lower than |1| indicating satisfactory results. Replicate analyses of a lichen sample by XRFS and NAA, indicated good homogeneity of the sample for the elements determined. The lichen results showed that the mean concentrations of As, Br, Ca, Cd, Co, Cr, Cs, Rb, Sb, Se and U were higher in samples from CUASO than those from regions considered unpolluted. For Fe, K, La, S, V and Zn, they were of the same order of magnitude. The correlation study between the elements showed high correlation (r > 0.7) for elements

  17. Status of transuranium element production

    International Nuclear Information System (INIS)

    King, L.J.

    1985-01-01

    The Transuranium Processing Plant at Oak Ridge National Laboratory has been the production, storage, and distribution center for the heavy-element research program of the US Department of Energy since 1966. During the past four years, annual production rates of transcurium elements have been relatively stable, averaging 34 mg of 249 Bk, 369 mg of 252 Cf, 1.4 mg of 253 Es, and 0.7 pg of 257 Fm. The extensive provisions for changing and modifying equipment have allowed continual updating of the plant to include new concepts in chemical processes and equipment design. 21 refs., 4 figs., 2 tabs

  18. The chemical evolution of galaxies

    International Nuclear Information System (INIS)

    Chiosi, Cesare

    1986-01-01

    The chemical evolution of galaxies is reviewed with particular attention to the theoretical interpretation of the distribution and abundances of elements in stars and the interstellar medium. The paper was presented to the conference on ''The early universe and its evolution'', Erice, Italy, 1986. The metallicity distribution of the solar vicinity, age metallicity relationship, abundance gradients in the galaxy, external galaxies, star formation and evolution, major sites of nucleosynthesis, yields of chemical elements, chemical models, and the galactic disk, are all discussed. (U.K.)

  19. Heavy-element research

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The status is reported of studies on the solid-state chemistry of the actinides and lanthanides, spectroscopy of actinide compounds, and dynamic chemical description of actinide elements in solution. Phase studies were done on Rb 2 UO 4 , K 2 UO 4 , Li 2 UO 4 , and Es 2 U 2 O 7 . The lithium neptunate (VI) system was investigated and the existence of Li 2 NpO 4 was established. In oxidation-reduction studies it was shown that Am(III) can be electrolytically oxidized to Am(IV) in strong H 3 PO 4 , but Cf(III) and Pr(III) do not oxidize. The low-temperature absorption spectrum of thin films of NpBr 3 was investigated. (U.S.)

  20. Chemical Solitaire

    Science.gov (United States)

    Philippof, Joanna; Seraphin, Kanesa Duncan; Seki, Jennifer; Kaupp, Lauren

    2015-01-01

    The periodic table does more than provide information about the elements. The periodic table also helps us make predictions about how the elements behave. Understanding the atomic structure of matter and periodic properties of the elements, as shown in the periodic table, is fundamental to many scientific disciplines. Unfortunately, high school…

  1. Heavy-element nucleosynthesis

    International Nuclear Information System (INIS)

    Mathews, G.J.

    1990-01-01

    New measurements and theoretical studies of nuclear properties, together with new astronomical data on the growth of heavy-element abundances during the early history of the Galaxy, now provide a clearer picture of where in nature the elements heavier than iron are produced by rapid (r-process) and show (s-process) neutron capture reactions. The nuclear data suggest that the r-process involves a high-neutron-density beta-flow equilibrium environment and that the s-process may have occurred at a temperature and neutron density consistent with a 13 C(α,n) 16 0 neutron source. The astronomical data, when compared with simple galactic chemical evolution modes, suggests that the r-process is associated with type II supernovae and that the neutron source must be manufactured by the star. Low-mass type II supernovae are proposed as the most important contributors to the r-process. A 13 C neutron source in intermediate-mass stars is proposed for the s-process. 64 refs., 7 figs

  2. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    1980-01-01

    The invention is of a nuclear fuel element which comprises a central core of a body of nuclear fuel material selected from the group consisting of compounds of uranium, plutonium, thorium and mixtures thereof, and an elongated composite cladding container comprising a zirconium alloy tube containing constituents other than zirconium in an amount greater than about 5000 parts per million by weight and an undeformed metal barrier of moderate purity zirconium bonded to the inside surface of the alloy tube. The container encloses the core so as to leave a gap between the container and the core during use in a nuclear reactor. The metal barrier is of moderate purity zirconium with an impurity level on a weight basis of at least 1000ppm and less than 5000ppm. Impurity levels of specific elements are given. Variations of the invention are also specified. The composite cladding reduces chemical interaction, minimizes localized stress and strain corrosion and reduces the likelihood of a splitting failure in the zirconium alloy tube. Other benefits are claimed. (U.K.)

  3. Molecular activation analysis for chemical speciation studies

    International Nuclear Information System (INIS)

    Chai-Chifang

    1998-01-01

    The term of Molecular Activation Analysis (MAA) refers to an activation analysis method that is able to provide information about the chemical species of elements in system of interests, though its definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the total concentrations are often without any meaning when assessing health or environmental risks of trace elements.In practice, the MAA is a combination of conventional instrumental or radiochemical activation analysis and physical, chemical or biochemical separation techniques. The MAA is able to play a particular role in speciation studies. However, the critical point in the MAA is that it is not permitted to change the primitive chemical species of elements in systems, or the change has to be under control; in the meantime it is not allowed to form the 'new artifact' originally not present in systems. Some practical examples of MAA for chemical species research performed recently in our laboratory will be presented as follows: Chemical species of platinum group elements in sediment; Chemical species of iodine in marine algae; Chemical species of mercury in human tissues; Chemical species of selenium in corn; Chemical species of rare earth elements in natural plant, etc. The merits and limitations of MAA will be described as well. (author)

  4. Frontiers of heavy element nuclear and radiochemistry

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1999-01-01

    The production and half-lives of the heaviest chemical elements, now known through Z=112, are reviewed. Recent experimental evidence for the stabilization of heavy element isotopes due to proximity to deformed nuclear shells at Z=108 and N=162 is compared with the theoretical predictions. The possible existence of isotopes of elements 107-110 with half-lives of seconds or longer, and production reactions and experimental techniques for increasing the overall yields of such isotopes in order to study both their nuclear and chemical properties are discussed. The present status of studies of the chemical properties of Rf, Ha, and Sg is briefly summarized and prospects for extending chemical studies beyond Sg are considered. (author)

  5. Chemical Peels

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Chemical Peels Uses for Chemical Peels Learn more ...

  6. Chemical Oscillations

    Indian Academy of Sciences (India)

    IMTECH),. Chandigarh. Praveen Kumar is pursuing his PhD in chemical dynamics at. Panjab University,. Chandigarh. Keywords. Chemical oscillations, autoca-. talYSis, Lotka-Volterra model, bistability, hysteresis, Briggs-. Rauscher reaction.

  7. Chemical evolution of galaxies

    International Nuclear Information System (INIS)

    Vigroux, Laurent

    1979-01-01

    This research thesis addresses theories on the chemical evolution of galaxies which aim at explaining abundances of different elements in galaxies, and more particularly aims at improving the model by modifying hypotheses. After a description of the simple model and of its uncertainties, the author shows how it is possible to understand the evolution of the main elements. Predictions obtained with this model are then compared with the present knowledge on galaxies by considering them according to an increasing complexity: Sun's neighbourhood, our galaxy, other spiral galaxies, elliptical galaxies, and finally galaxy clusters. A specific attention is given to irregular galaxies which are the simplest systems [fr

  8. Chemical ecotoxicology

    International Nuclear Information System (INIS)

    Paasivirta, J.

    1991-01-01

    This book discusses risk assessment, chemical cycles, structure-activity relations, organohalogens, oil residues, mercury, sampling and analysis of trace chemicals, and emissions from the forestry industry. Topics include: Cycles of chemicals in the environment. Rick assessment and management, strucuture and toxicity, sampling and analysis of trace chemicals in environment, interpretation of the environmental analysis results, mercury in the environment, organohalogen compounds in the environment, emissions from forestry industry, oil residues in the environment: oil spills in the marine environment

  9. Transuranium elements: Past, present, and future

    International Nuclear Information System (INIS)

    Seaborg, G.T.

    1995-01-01

    In this illustrative Account the authors shall concentrate on four of these elements, chosen for their current interest or pivotal role. The story of plutonium is one of the most dramatic in the history of science, and today, plutonium is at the focus of an extraordinary dilemma. Mendelevium (element 101) has played a pivotal role in blazing the trail for the discovery of the heaviest elements on the basis of open-quotes one atom at a timeclose quotes production. Seaborgium (element 106) was recently named in my honor by the discoverers and may be the last element, at least for some time, for which it will be possible to determine many chemical properties. And element 110 represents recent evidence, after a lapse of 10 years, for the discovery of a chemical element. Recent (1994) recommendations of the IUPAC Commission on the Nomenclature of Inorganic Chemistry for the renaming of elements 104-108 have met with widespread rejection. The author is using the names proposed by the acknowledged discoverers (elements 106-109) or, in the case of the disputed elements 104 and 105, the most logical names. 21 refs., 5 figs

  10. EVALUATION OF PHYSICO-CHEMICAL PARAMETERS OF AGRICULTURAL SOILS IRRIGATED BY THE WATERS OF THE HYDROLIC BASIN OF SEBOU RIVER AND THEIR INFLUENCES ON THE TRANSFER OF TRACE ELEMENTS INTO SUGAR CROPS (THE CASE OF SUGAR CANE

    Directory of Open Access Journals (Sweden)

    N. Benlkhoubi

    2016-05-01

    Full Text Available This research was conducted in Kenitra (northwestern Morocco to determine the physicochemical parameters and metallic concentrations at three levels: surface water of Sebou and Beht intended for irrigation, agricultural soils and sugarcane. The spectrometric analysis of source plasma emission (ICP has identified eight trace elements contained in the materials taken from zone 1 (As, Cd, Co, Zn, Ni, Pb, Cu and Cr.The obtained results showed that the interaction between the different physicochemical parameters of agricultural soils decides the transfer of the metal elements to the plants. Indeed, for the soil which is used in this agriculture (for sugar cane, its irrigation water, and the contents of Cr, Cd and As exceeds the accepted standards.The principal component analysis of the levels of trace metal supports in area 1, allowed to distinguish between the items with a high tolerance for bagasse (Zn, Cu, Ni, Cd and Pb, compared to Cr, Co, and As.

  11. Studies of the physico-chemical properties on the transuranian elements in connection with the migration phenomenon in the geosphere. Task 3 Characterization of radioactive waste forms. A series of final reports (1985-89)

    International Nuclear Information System (INIS)

    Vitorge, P.; Oliver, J.; Mangin, J.P.; Billon, A.

    1991-01-01

    In the first part, the properties of the transuranium elements (TRU) mainly Pu Np Am have been investigated in terms of complexation by OH and CO3 ligands in aqueous solution. The species which are formed in given physicochemical conditions (ionic strength, concentrations...) are studied with no direct reference to well defined ground waters. Equilibrium constants of complexes and redox potential values are useful in the drawing up of Pourbaix's diagrams. Areas of stability of species in function of Eh pH pCO2 are given for the different elements in a few cases. The second part of this report deals with the study of the transfer of tritiated water cesium and strontium through highly compacted clay (diffusion coefficient). In a third part a code for the computation of ion migration and diffusion in areas close to radwaste storage facilities has been developed. This type of application was found to require a mesh pattern and boundary conditions different from the usual, which justifies the writing of a new code called CONDIMENT. (Convection and Diffusion of elements) 49 figs.; 18 tabs.; 21 refs

  12. Fuel element tomography by gammametry

    International Nuclear Information System (INIS)

    Simonet, G.; Pineira, T.

    1982-03-01

    As from transversal gamma determinations of a cylindrical fuel element, the TOMOGAM program reconstitutes the distribution of fission products in a section. This direct, fast and non destructive method, makes it possible to have access to the behaviour of the fuel at any time: - the soluble fission products in the matrix represent the fuel itself and the distribution of the fissions, - the migrating elements inform on the temperature reached in accordance with the permitted powers, - the volatile nuclides build up in particular points where physical-chemical phenomena of fuel-cladding interaction are liable to corrode the latter. Hence, gamma spectrometry extends its possibilities of analysis relative to the performance of reactor elements [fr

  13. Cosmic Feast of the Elements

    Science.gov (United States)

    Morisset, C.; Delgado-Inglada, G.; García-Rojas, J.

    2017-11-01

    In the past few decades most of our understanding of the history and chemical evolution of galaxies has been guided by the study of their stars and gaseous nebulae. Nebulae, thanks to their bright emission lines, are especially useful tracers of chemical elements from the very center to the outskirts of galaxies. In order to pin down the chemical abundances in nebulae, we must rely on careful analysis of emission lines combined with detailed models of the microscopic physical processes inside nebulae and state-of-the-art atomic data. Another important piece of the puzzle is the interplay between galaxy evolution and the activity of their central engines either as optical AGNs or radio jets. Last but not least, let us not forget the huge population of lineless, retired galaxies ionized by hot low-mass evolved stars: after nuclear and star formation activity quiets down, retired galaxies are the natural consequence of galaxy evolution. Grażyna Stasińska has made important contributions to each and every one of those aspects. This conference is to honor her work. We invite you to take part and share the latest news on this cosmic feast that transmutes chemical species, the onward journey of elements inside and outside galaxies either as lonely atoms or gregarious molecules and crystals, and their recycling in stars, which starts the cosmic feast all over again.

  14. Analysis of the chemical elements behavior in leaves infected with fumagina employing X-ray fluorescence technique; Analise do comportamento de elementos quimicos em folhas infectadas com fumagina atraves da tecnica de fluorescencia de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Blonski, Maria Selia

    2002-02-01

    Fumagina is produced by the Capnodium fungi, a mushroom from Dothideales order, that lives associated with the yellow aphid (Monelliopsis pecanis), excreting a heavy load of a sugared substance that provides the sooty fungus development, covering, in some cases the totality, of leaves, fruits and branches surfaces. One of the big problems caused by this disease is the physic photosynthesis stuckness, reducing in 98% the active photosynthesis radiation and in 70% the net photosynthesis. This photosynthesis reduction affects the plants carbohydrate reservoirs, resulting in reduced and bad qualified crops. It was employed the Energy Dispersion X-Ray Fluorescence Technique (EDXRF) to study the fumagina disease. The measurements were realized with infected and healthy leaves of citric plants (orange and lemon trees), collected at the Farm School of the State University of Londrina, and also leaves of icsora plant from Piracicaba-SP. Through this technique it was observed a metabolic disorder related to Fe and Ca elements. By comparing the EDXRF spectra of the healthy plant leaves with the infected ones, it was verified that the concentration of Ca is higher than the concentration Fe in leaves of healthy plants, while for the leaves of plants infected with fumagina, it was observed a higher concentration of Fe. Employing EDXRF and the emission/transmission method for the matrix effect correction, samples of the citric plants were also analysed in pellet. The elements K, Ca, Ti, Mn , Fe, Cu and Zn were quantified. It was verified a higher Fe concentration in fumagina samples compared to the samples without fumagina. For all the elements of interest the minimum level of detection found was at the order of {mu}g g{sup -1}. (author)

  15. Relativistic quantum chemistry of the superheavy elements. Closed-shell element 114 as a case study

    International Nuclear Information System (INIS)

    Schwerdtfeger, Peter; Seth, Michael

    2002-01-01

    The chemistry of superheavy element 114 is reviewed. The ground state of element 114 is closed shell [112]7s 2 7p 1/2 2 and shows a distinct chemical inertness (low reactivity). This inertness makes it rather difficult to study the atom-at-a-time chemistry of 114 in the gas or liquid phase. (author)

  16. [Chemical weapons and chemical terrorism].

    Science.gov (United States)

    Nakamura, Katsumi

    2005-10-01

    Chemical Weapons are kind of Weapons of Mass Destruction (WMD). They were used large quantities in WWI. Historically, large quantities usage like WWI was not recorded, but small usage has appeared now and then. Chemical weapons are so called "Nuclear weapon for poor countrys" because it's very easy to produce/possession being possible. They are categorized (1) Nerve Agents, (2) Blister Agents, (3) Cyanide (blood) Agents, (4) Pulmonary Agents, (5) Incapacitating Agents (6) Tear Agents from the viewpoint of human body interaction. In 1997 the Chemical Weapons Convention has taken effect. It prohibits chemical weapons development/production, and Organization for the Prohibition of Chemical Weapons (OPCW) verification regime contributes to the chemical weapons disposal. But possibility of possession/use of weapons of mass destruction by terrorist group represented in one by Matsumoto and Tokyo Subway Sarin Attack, So new chemical terrorism countermeasures are necessary.

  17. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.

  18. Alarms, Chemical

    Science.gov (United States)

    cited in applicable qualitative materiel requirements, small development requirements, technical characteristics, and other requirements and documentation that pertain to automatic chemical agent alarms.

  19. Chemical oceanography

    National Research Council Canada - National Science Library

    Millero, F.J

    1996-01-01

    Chemical Oceanography presents a comprehensive examination of the chemistry of oceans through discussions of such topics as descriptive physical oceanography, the composition of seawater and the major...

  20. On-line gas chemistry experiments with trans actinide elements

    International Nuclear Information System (INIS)

    Turler, A.; Gaguller, B.; Jost, D.T.

    1993-01-01

    The latest achievements in the gas phase chemistry studies of elements 104 and 105 and their lighter homologs are reviewed. Experimental techniques employed in the studies are described. Experimental data on chlorides and bromides of the groups 4, 5 elements and elements 104, 105 are compared with their theoretically predicted chemical properties. 45 refs

  1. Chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 2: Alkaline earth elements as tracers of watershed hydrochemistry and provenance

    Directory of Open Access Journals (Sweden)

    I. Ssemmanda

    2012-11-01

    Full Text Available This study demonstrates that alkaline earth elements in enamel of hippopotamids, in particular Ba and Sr, are tracers for water provenance and hydrochemistry in terrestrial settings. The studied specimens are permanent premolar and molar teeth found in modern and fossil lacustrine sediments of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi and from modern fluvial environments of the Nile River. Concentrations in enamel vary by two orders of magnitude for Ba (120–9336 μg g−1 as well as for Sr (9–2150 μg g−1. The variations are partially induced during post-mortem alteration and during amelogenesis, but the major contribution originates ultimately from the variable water chemistry in the habitats of the hippopotamids which is controlled by the lithologies and weathering processes in the watershed areas. Amelogenesis causes a distinct distribution of MgO, Ba and Sr in modern and fossil enamel, in that element concentrations increase along profiles from the outer rim towards the enamel–dentin junction by a factor of 1.3–1.9. These elements are well correlated in single specimens, thus suggesting that their distribution is determined by a common, single process, which can be described by closed system Rayleigh crystallization of bioapatite in vivo. Enamel from most hippopotamid specimens has Sr/Ca and Ba/Ca which are typical for herbivores. However, Ba/Sr ranges from 0.1 to 3 and varies on spatial and temporal scales. Thus, Sr concentrations and Ba/Sr in enamel differentiate between habitats having basaltic mantle rocks or Archean crustal rocks as the ultimate sources of Sr and Ba. This provenance signal is modulated by climate change. In Miocene to Pleistocene enamel from the Lake Albert region, Ba/Sr decreases systematically with time from 2 to 0.5. This trend can be correlated with changes in climate from humid to arid, in vegetation from C3 to C4 biomass as well as with increasing

  2. Discrete Element Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J; Johnson, S

    2007-12-03

    The Distinct Element Method (also frequently referred to as the Discrete Element Method) (DEM) is a Lagrangian numerical technique where the computational domain consists of discrete solid elements which interact via compliant contacts. This can be contrasted with Finite Element Methods where the computational domain is assumed to represent a continuum (although many modern implementations of the FEM can accommodate some Distinct Element capabilities). Often the terms Discrete Element Method and Distinct Element Method are used interchangeably in the literature, although Cundall and Hart (1992) suggested that Discrete Element Methods should be a more inclusive term covering Distinct Element Methods, Displacement Discontinuity Analysis and Modal Methods. In this work, DEM specifically refers to the Distinct Element Method, where the discrete elements interact via compliant contacts, in contrast with Displacement Discontinuity Analysis where the contacts are rigid and all compliance is taken up by the adjacent intact material.

  3. Corrigendum to "Chemical composition and acidity of size-fractionated inorganic aerosols of 2013-14 winter haze in Shanghai and associated health risk of toxic elements" [Atmos. Environ. (2015) 259-271

    Science.gov (United States)

    Behera, Sailesh N.; Cheng, Jinping; Huang, Xian; Zhu, Qiongyu; Liu, Ping; Balasubramanian, Rajasekhar

    2018-03-01

    The authors regret that the sources from which the RfC (reference concentration) and the IUR (inhalation unit risk) values were obtained for estimation of RfD (reference dose, presented in Table 2) and SF (slope factor, presented in Table 3) were not clearly indicated in the published article due to an oversight. The revised tables with improved clarity are given below. a The Risk Assessment Information System (https://rais.ornl.gov/) b USEPA Integrated Risk Information System (IRIS) (http://www.epa.gov/iris) c The California EPA, the office of Environmental Health Hazard Assessment (OEHHA) (https://www.oehha.gov.gov/) d Behera, S.N., Xian, H. and Balasubramanian, R., 2014. Human health risk associated with exposure to toxic elements in mainstream and sidestream cigarette smoke. Science of the Total Environment, 472, pp.947-956.

  4. The elements of life and medicines.

    Science.gov (United States)

    Chellan, Prinessa; Sadler, Peter J

    2015-03-13

    Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.

  5. Chemical shift imaging: a review

    International Nuclear Information System (INIS)

    Brateman, L.

    1986-01-01

    Chemical shift is the phenomenon that is seen when an isotope possessing a nuclear magnetic dipole moment resonates at a spectrum of resonance frequencies in a given magnetic field. These resonance frequencies, or chemical shifts, depend on the chemical environments of particular nuclei. Mapping the spatial distribution of nuclei associated with a particular chemical shift (e.g., hydrogen nuclei associated with water molecules or with lipid groups) is called chemical shift imaging. Several techniques of proton chemical shift imaging that have been applied in vivo are presented, and their clinical findings are reported and summarized. Acquiring high-resolution spectra for large numbers of volume elements in two or three dimensions may be prohibitive because of time constraints, but other methods of imaging lipid of water distributions (i.e., selective excitation, selective saturation, or variations in conventional magnetic resonance imaging pulse sequences) can provide chemical shift information. These techniques require less time, but they lack spectral information. Since fat deposition seen by chemical shift imaging may not be demonstrated by conventional magnetic resonance imaging, certain applications of chemical shift imaging, such as in the determination of fatty liver disease, have greater diagnostic utility than conventional magnetic resonance imaging. Furthermore, edge artifacts caused by chemical shift effects can be eliminated by certain selective methods of data acquisition employed in chemical shift imaging

  6. Mendeleev's principle against Einstein's relativity: news from the chemistry of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Gaeggeler, Heinz W [Department of Chemistry and Biochemistry, University of Bern, Bern (Switzerland)

    2009-12-31

    The review briefly considers the problems of synthesis and chemical identification of superheavy elements. The specific features of their properties are determined by the relativistic effects. The synthesis and chemical investigations into bohrium and element 112 are discussed as examples.

  7. Chemical Emergencies - Multiple Languages

    Science.gov (United States)

    ... Chemical Emergencies - bosanski (Bosnian) PDF Chemical Emergencies - English MP3 Chemical Emergencies - bosanski (Bosnian) MP3 Chemical Emergencies - English MP4 Chemical Emergencies - bosanski (Bosnian) ...

  8. Chemistry of the elements

    International Nuclear Information System (INIS)

    Greenwood, N.N.; Earnshaw, A.

    1984-01-01

    This textbook presents an account of the chemistry of the elements for both undergraduate and postgraduate students. It covers not only the 'inorganic' chemistry of the elements, but also analytical, theoretical, industrial, organometallic;, bio-inorganic and other areas of chemistry which apply. The following elements of special nuclear interest are included: Rb, Cs, Fr, Sr, Ba, Ra, Po, At, Rn, Sc, Y, Zr, Hf, V, Nb, Ta, Mo, Tc, Ru, the Lanthanide Elements, the Actinide Elements. (U.K.)

  9. PIXE - a new method for elemental analysis

    International Nuclear Information System (INIS)

    Johansson, S.A.E.

    1983-01-01

    With elemental analysis we mean the determination of which chemical elements are present in a sample and of their concentration. This is an old and important problem in chemistry. The earliest methods were purely chemical and many such methods are still used. However, various methods based on physical principles have gradually become more and more important. One such method is neutron activation. When the sample is bombarded with neutrons it becomes radioactive and the various radioactive isotopes produced can be identified by the radiation they emit. From the measured intensity of the radiation one can calculate how much of a certain element that is present in the sample. Another possibility is to study the light emitted when the sample is excited in various ways. A spectroscopic investigation of the light can identify the chemical elements and allows also a determination of their concentration in the sample. In the same way, if a sample can be brought to emit X-rays, this radiation is also characteristic for the elements present and can be used to determine the elemental concentration. One such X-ray method which has been developed recently is PIXE. The name is an acronym for Particle Induced X-ray Emission and indicates the principle of the method. Particles in this context means heavy, charged particles such as protons and a-particles of rather high energy. Hence, in PIXE-analysis the sample is irradiated in the beam of an accelerator and the emitted X-rays are studied. (author)

  10. Hazardous Chemicals

    Centers for Disease Control (CDC) Podcasts

    2007-04-10

    Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

  11. Radiological and related Chemical Health Impact Assessments of ...

    African Journals Online (AJOL)

    Ogunjo Samuel

    concentrations obtained and the relation from United State Environmental Protection Agency (USEPA), the chemical ... radioactive elements uranium-238 and thorium-232 decay .... Using Equation 2, the elemental concentrations in pipe.

  12. Chemistry of the transactinide elements

    International Nuclear Information System (INIS)

    Schaedel, Matthias

    1996-01-01

    Synthesis and decay of elements in the upper end of periodic table (z=104 to 111) are described. In view of very short half-life of about 1 s, the production of the transactinide isotopes and their transport to the separation and detection chamber are to be necessarily carried out employing fast and reliable techniques. Advances in microchemical separation techniques such as OLGA-II, HEVI, ARCA-II and SISAK, coupled to sensitive detection methods enable the detection of these heavier transactinide elements at atomic level. Their position in the periodic table and similarities, if any, with the corresponding lighter homologs are discussed based on their predicted and observed chemical behaviour. (author). 70 refs., 15 figs

  13. Utilization of chemical derivatives in activation analysis

    International Nuclear Information System (INIS)

    Ehmann, W.D.

    1990-01-01

    Derivative activation analysis (DAA) is a method to enhance the sensitivity of nuclear activation analysis for the more elusive elements. It may also allow a degree of chemical speciation for the element of interest. DAA uses a preirradiation chemical reaction on the sample to initiate the formation of, or an exchange with, a chemical complex which contains a surrogate element, M. As a result, the amount of the element or the chemical species to be determined, X, is now represented by measurement of the amount of the surrogate element, M, that is made part of, or released by the complex species. The surrogate element is selected for its superior properties for nuclear activation analysis and the absence of interference reaction in its final determination by instrumental neutron activation analysis (INAA) after some preconcentration or separation chemistry. Published DAA studies have been limited to neutron activation analysis. DAA can offer the analyst some important advantages. It can determine elements, functional groups, or chemical species which cannot be determined directly by INAA, fast neutron activation analysis (FNAA), prompt gamma neutron activation analysis (PGNAA), or charged particle activation analysis (CPAA) procedures. When compared with conventional RNAA, there are fewer precautions with respect to handling of intensely radioactive samples, since the chemistry is done before the irradiation. The preirradiation chemistry may also eliminate many interferences that might occur in INAA and, through use of an appropriate surrogate element, can place the analytical gamma-ray line in an interference-free region of the gamma-ray spectrum

  14. Chemical Peel

    Science.gov (United States)

    ... your expectations. Talk with your doctor about your motivations and expectations, as well as the potential risks. ... the sun permanently to prevent changes in skin color. Keep in mind that chemical peel results might ...

  15. Chemical carcinogens

    National Research Council Canada - National Science Library

    Searle, Charles E

    1976-01-01

    Cancer causing agents are now known to exist throughout the environment-in polluted air and tobacco smoke, in various plants and foods, and in many chemicals that are used in industry and laboratories...

  16. Trace elements in wild and orchard honeys

    Energy Technology Data Exchange (ETDEWEB)

    Almeida-Silva, M.; Canha, N.; Galinha, C.; Dung, H.M. [Instituto Tecnologico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Freitas, M.C., E-mail: cfreitas@itn.pt [Instituto Tecnologico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Sitoe, T. [Instituto Tecnologico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal)

    2011-11-15

    The present study aims the identification and quantification of trace elements in two types of honey samples: Orchard honey and Wild honey from mainland Portugal. Chemical elements content was assessed by Instrumental Neutron Activation Analysis (INAA). Concentrations were determinated for Ag, As, Br, Ca, Cl, Cs, Cu, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, U, V and Zn. The nutritional values of both honey types were evaluated since this product contains some elements that are essential dietary nutrients for humans. Physical properties of the honey samples, such as electrical conductivy and pH, were assessed as well.

  17. Recent research on the heavy transuranium elements

    International Nuclear Information System (INIS)

    Seaborg, G.T.

    1988-09-01

    This review is devoted to recent research (performed in the 1980s) on the heavy members of the group, defined as the transcurium elements (with a few references to related work on lighter elements). It covers the discovery of the three heaviest elements, the discovery of new isotopes, investigation of interesting decay properties of some previously known isotopes, investigations of some heavy ion reaction mechanisms in this region, and recent investigations of nuclear and chemical properties. It is not exhaustive in its coverage, is necessarily succinct, and inevitably places emphasis on those aspects with which the author is most familiar. 92 refs., 3 figs

  18. Element 74, the Wolfram Versus Tungsten Controversy

    Energy Technology Data Exchange (ETDEWEB)

    Holden,N.E.

    2008-08-11

    Two and a quarter centuries ago, a heavy mineral ore was found which was thought to contain a new chemical element called heavy stone (or tungsten in Swedish). A few years later, the metal was separated from its oxide and the new element (Z=74) was called wolfram. Over the years since that time, both the names wolfram and tungsten were attached to this element in various countries. Sixty years ago, IUPAC chose wolfram as the official name for the element. A few years later, under pressure from the press in the USA, the alternative name tungsten was also allowed by IUPAC. Now the original, official name 'wolfram' has been deleted by IUPAC as one of the two alternate names for the element. The history of this controversy is described here.

  19. Periodic Table of the Elements in the Perspective of Artificial Neural Networks

    Science.gov (United States)

    Lemes, Mauricio R.; Dal Pino, Arnaldo

    2011-01-01

    Although several chemical elements were not known by end of the 19th century, Mendeleev came up with an astonishing achievement, the periodic table of elements. He was not only able to predict the existence of (then) new elements, but also to provide accurate estimates of their chemical and physical properties. This is a profound example of the…

  20. Data Element Registry Services

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data Element Registry Services (DERS) is a resource for information about value lists (aka code sets / pick lists), data dictionaries, data elements, and EPA data...

  1. Reactivity of Dual-Use Decontaminants with Chemical Warfare Agents

    Science.gov (United States)

    2016-07-01

    REACTIVITY OF DUAL-USE DECONTAMINANTS WITH CHEMICAL WARFARE AGENTS ECBC-TR-1384... Decontaminants with Chemical Warfare Agents 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Willis, Matthew P...extraction) of chemical warfare agents from materials. 15. SUBJECT TERMS GD HD Decontamination Hazard mitigation VX Chemical warfare agent Liquid-phase

  2. Basic Finite Element Method

    International Nuclear Information System (INIS)

    Lee, Byeong Hae

    1992-02-01

    This book gives descriptions of basic finite element method, which includes basic finite element method and data, black box, writing of data, definition of VECTOR, definition of matrix, matrix and multiplication of matrix, addition of matrix, and unit matrix, conception of hardness matrix like spring power and displacement, governed equation of an elastic body, finite element method, Fortran method and programming such as composition of computer, order of programming and data card and Fortran card, finite element program and application of nonelastic problem.

  3. Chemical properties of mendelevium

    International Nuclear Information System (INIS)

    Hulet, E.K.

    1980-01-01

    The isotope 256 Md is nearly always employed for chemical studies of this element. This nuclide can be made by bombardment of fractions of a microgram of 254 Es with intense alpha-particle beams which will produce about 10 6 atoms of 256 Md with a half-life of 77 minutes. Even with the most intense ion beams and the largest available quantities of target isotope, about 10 6 atoms at a time is all the Md that can be produced for chemical studies. This lack of sufficient sample size coupled with the very short lifetimes of the few atoms produced has severly restricted the gathering and broadening of our knowledge concerning the properties of Md and the heavier elements. To illustrate, the literature contains a mere eleven references to the chemical studies of Md, and none of these deal with bulk properties associated with element found in solid phases. Some of these findings are: Md was found to be more volatile than other actinide metals which lead to the belief that it is divalent in the metallic state; separation of Md from the other actinides can be accomplished either by reduction of Md to the divalent state or by chromatographic separations with Md remaining in the tripositive state; extraction of Md with bis(2-ethylhexyl)phosphoric acid is much poorer than the extraction of the neighboring tripositive actinides; attempts to oxidize Md wih sodium bismuthate failed to show any evidence of Md 4+ ; standard reduction potential of Md 3+ was found to be close to -0.1 volt; Md 3+ can be reduced to Md(Hg) by sodium amalgams and by electrolysis; the electrochemical behavior of Md is very similar to that of Fm and can be summarized in the equation, Md 2+ + 2e - = Md(Hg), and E 0 = 1.5 V

  4. Chemical sensors

    International Nuclear Information System (INIS)

    Hubbard, C.W.; Gordon, R.L.

    1987-05-01

    The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section

  5. Radiolabelled cellular blood elements

    International Nuclear Information System (INIS)

    Sinzinger, H.

    1990-01-01

    This book reports on radiolabelled cellular blood elements, covering new advances made during the past several years, in particular the use of Tc-99 as a tracer for blood elements. Coverage extends to several radiolabelled monoclonal antibodies that are specific for blood components and may label blood elements in vivo

  6. Environmental mineralogy - Understanding element behavior in ecosystems

    International Nuclear Information System (INIS)

    Brown Jr, G.E.; Calas, G.

    2011-01-01

    Environmental Mineralogy has developed over the past decade in response to the recognition that minerals are linked in many important ways with the global ecosystem. Minerals are the main repositories of the chemical elements in Earth's crust and thus are the main sources of elements needed for the development of civilization, contaminant and pollutant elements that impact global and local ecosystems, and elements that are essential plant nutrients. These elements are released from minerals through natural processes, such as chemical weathering, and anthropogenic activities, such as mining and energy production, agriculture and industrial activities, and careless waste disposal. Minerals also play key roles in the biogeochemical cycling of the elements, sequestering elements and releasing them as the primary minerals in crustal rocks undergo various structural and compositional transformations in response to physical, chemical, and biological processes that produce secondary minerals and soils. These processes have resulted in the release of toxic elements such as arsenic in groundwater aquifers, which is having a major impact on the health of millions of people in South and Southeast Asia. The interfaces between mineral surfaces and aqueous solutions are the locations of most chemical reactions that control the composition of the natural environment, including the composition of natural waters. The nuclear fuel cycle, from uranium mining to the disposition of high-level nuclear waste, is also intimately related to minerals. A fundamental understanding of these processes requires molecular-scale information about minerals, their bulk structures and properties such as solubility, their surfaces, and their interactions with aqueous solutions, atmospheric and soil gases, natural organic matter, and biological organisms. Gaining this understanding is further complicated by the presence of natural, incidental, and manufactured nano-particles in the environment, which

  7. Chemical and petrochemical industry

    Science.gov (United States)

    Staszak, Katarzyna

    2018-03-01

    The potential sources of various metals in chemical and petrochemical processes are discussed. Special emphasis is put on the catalysts used in the industry. Their main applications, compositions, especially metal contents are presented both for fresh and spent ones. The focus is on the main types of metals used in catalysts: the platinum-group metals, the rare-earth elements, and the variety of transition metals. The analysis suggested that chemical and petrochemical sectors can be considered as the secondary source of metals. Because the utilization of spent refinery catalysts for metal recovery is potentially viable, different methods were applied. The conventional approaches used in metal reclamation as hydrometallurgy and pyrometallurgy, as well as new methods include bioleaching, were described. Some industrial solutions for metal recovery from spent solution were also presented.

  8. The chemistry of transactinide elements. Experimental achievements and perspectives

    International Nuclear Information System (INIS)

    Schaedel, M.

    2002-01-01

    The chemistry of transactinides and superheavy elements has reached element 108. Preparations are under way to leap to element 112 and beyond. This development, its current status and future perspectives are reviewed from an experimental point of view. The atom-at-a-time situation of transactinide chemistry is briefly outlines. Experimental techniques and important results enlightening the chemical properties of elements 104 through 108 are presented in an exemplary way with emphasis on the aqueous chemistry of the lighter ones. From the results of these experiments it is justified to place these elements in the Periodic Table of the Elements into groups 4 through 8, respectively. However, strongly due to the influence of relativistic effects, it is no longer possible to deduce detailed chemical properties of these superheavy elements from this position. Perspectives for future research programs are given. (author)

  9. Pyrometallurgical partitioning of uranium and transuranic elements from rare earth elements by electrorefining and reductive extraction

    International Nuclear Information System (INIS)

    Uozumi, Koichi; Kinoshita, Kensuke; Inoue, Tadashi; Storvick, T.S.; Krueger, C.L.; Nabelek, C.R.

    2001-01-01

    High-level liquid waste generated from PUREX reprocessing contains a small amount of transuranic elements, such as Np, Pu, Am, and Cm, with long-lived radioactivities. A pyrometallurgical partitioning process is being developed to recover transuranic elements from such waste. Small amounts of U contained in the high-level liquid waste are also recovered in the process. A key issue for developing the process is effective separation of U and the transuranic elements from the rare-earth elements, because the two elemental groups are chemically analogous. A series of process tests were carried out in the present study to demonstrate that a combination of electrorefining and reductive extraction is useful for separating U and transuranic elements from the rare-earth elements. The results indicate that 99% of U and each transuranic elements is recovered by the combination process as a product, and that the quantity of rare-earth elements contained in the product is smaller than the transuranic elements by weight. The overall mass balance of U and transuranic elements in the system ranged within the experimental errors assigned to sampling and analysis. (author)

  10. Rare (Earth Elements [score

    Directory of Open Access Journals (Sweden)

    Camilo Méndez

    2014-12-01

    Full Text Available Rare (Earth Elements is a cycle of works for solo piano. The cycle was inspired by James Dillon’s Book of Elements (Vol. I-V. The complete cycle will consist of 14 pieces; one for each selected rare (earth element. The chosen elements are Neodymium, Erbium, Tellurium, Hafnium, Tantalum, Technetium, Indium, Dysprosium, Lanthanium, Cerium, Europium, Terbium, Yttrium and Darmstadtium. These elements were selected due to their special atomic properties that in many cases make them extremely valuable for the development of new technologies, and also because of their scarcity. To date, only 4 works have been completed Yttrium, Technetium, Indium and Tellurium.

  11. Generalized finite elements

    International Nuclear Information System (INIS)

    Wachspress, E.

    2009-01-01

    Triangles and rectangles are the ubiquitous elements in finite element studies. Only these elements admit polynomial basis functions. Rational functions provide a basis for elements having any number of straight and curved sides. Numerical complexities initially associated with rational bases precluded extensive use. Recent analysis has reduced these difficulties and programs have been written to illustrate effectiveness. Although incorporation in major finite element software requires considerable effort, there are advantages in some applications which warrant implementation. An outline of the basic theory and of recent innovations is presented here. (authors)

  12. Light element thermodynamics related to actinide separations

    International Nuclear Information System (INIS)

    Johnson, I.; Johnson, C.E.

    1997-01-01

    The accumulation of waste from the last five decades of nuclear reactor development has resulted in large quantities of materials of very diverse chemical composition. An electrometallurgical (EM) method is being developed to separate the components of the waste into several unique streams suitable for permanent disposal and an actinide stream suitable for retrievable storage. The principal types of nuclear wastes are spent oxide or metallic fuel. Since the EM module requires a metallic feed, and oxygen interferes with its operation, the oxide fuel has to be reduced prior to EM treatment. Further, the wastes contain, in addition to oxygen, other light elements (first- and second-row elements) that may also interfere with the operation of the EM module. The extent that these light elements interfere with the operation of the EM module has been determined by chemical thermodynamic calculations. (orig.)

  13. Chemical pneumonitis

    Science.gov (United States)

    ... cleaning materials such as chlorine bleach, during industrial accidents, or near swimming pools) Grain and fertilizer dust ... and the A.D.A.M. Editorial team. Chemical Emergencies ... about A.D.A.M.'s editorial policy , editorial process and privacy policy . A.D.A.M. is ...

  14. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil

  15. Chemical analysis of the Fornax Dwarf galaxy

    NARCIS (Netherlands)

    Letarte, Bruno

    2007-01-01

    This thesis is entitled “Chemical Analysis of the Fornax Dwarf Galaxy”, and it’s main goal is to determine what are the chemical elements present in the stars of this galaxy in order to try and understand it’s evolution. Galaxies are not “static” objects, they move, form stars and can interact with

  16. Limitless Analytic Elements

    Science.gov (United States)

    Strack, O. D. L.

    2018-02-01

    We present equations for new limitless analytic line elements. These elements possess a virtually unlimited number of degrees of freedom. We apply these new limitless analytic elements to head-specified boundaries and to problems with inhomogeneities in hydraulic conductivity. Applications of these new analytic elements to practical problems involving head-specified boundaries require the solution of a very large number of equations. To make the new elements useful in practice, an efficient iterative scheme is required. We present an improved version of the scheme presented by Bandilla et al. (2007), based on the application of Cauchy integrals. The limitless analytic elements are useful when modeling strings of elements, rivers for example, where local conditions are difficult to model, e.g., when a well is close to a river. The solution of such problems is facilitated by increasing the order of the elements to obtain a good solution. This makes it unnecessary to resort to dividing the element in question into many smaller elements to obtain a satisfactory solution.

  17. The synthetic elements

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.C.

    1990-05-01

    Prior to 1940, the heaviest element known was uranium, discovered in 1789. Since that time the elements 93 through 109 have been synthesized and identified and the elements 43, 61, 85, and 87 which were missing form the periodic tables of the 1930's have been discovered. The techniques and problems involved in these discoveries and the placement of the transuranium elements in the periodic table will be discussed. The production and positive identification of elements heavier than Md (Z=101), which have very short half-lives and can only be produced an atom-at-a-time, are very difficult and there have been controversies concerning their discovery. Some of the new methods which have been developed and used in these studies will be described. The prospects for production of still heavier elements will be considered.

  18. The synthetic elements

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    1990-05-01

    Prior to 1940, the heaviest element known was uranium, discovered in 1789. Since that time the elements 93 through 109 have been synthesized and identified and the elements 43, 61, 85, and 87 which were missing form the periodic tables of the 1930's have been discovered. The techniques and problems involved in these discoveries and the placement of the transuranium elements in the periodic table will be discussed. The production and positive identification of elements heavier than Md (Z=101), which have very short half-lives and can only be produced an atom-at-a-time, are very difficult and there have been controversies concerning their discovery. Some of the new methods which have been developed and used in these studies will be described. The prospects for production of still heavier elements will be considered

  19. Rare-earth elements

    Science.gov (United States)

    Van Gosen, Bradley S.; Verplanck, Philip L.; Seal, Robert R.; Long, Keith R.; Gambogi, Joseph; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    The rare-earth elements (REEs) are 15 elements that range in atomic number from 57 (lanthanum) to 71 (lutetium); they are commonly referred to as the “lanthanides.” Yttrium (atomic number 39) is also commonly regarded as an REE because it shares chemical and physical similarities and has affinities with the lanthanides. Although REEs are not rare in terms of average crustal abundance, the concentrated deposits of REEs are limited in number.Because of their unusual physical and chemical properties, the REEs have diverse defense, energy, industrial, and military technology applications. The glass industry is the leading consumer of REE raw materials, which are used for glass polishing and as additives that provide color and special optical properties to the glass. Lanthanum-based catalysts are used in petroleum refining, and cerium-based catalysts are used in automotive catalytic converters. The use of REEs in magnets is a rapidly increasing application. Neodymium-iron-boron magnets, which are the strongest known type of magnets, are used when space and weight are restrictions. Nickel-metal hydride batteries use anodes made of a lanthanum-based alloys.China, which has led the world production of REEs for decades, accounted for more than 90 percent of global production and supply, on average, during the past decade. Citing a need to retain its limited REE resources to meet domestic requirements as well as concerns about the environmental effects of mining, China began placing restrictions on the supply of REEs in 2010 through the imposition of quotas, licenses, and taxes. As a result, the global rare-earth industry has increased its stockpiling of REEs; explored for deposits outside of China; and promoted new efforts to conserve, recycle, and substitute for REEs. New mine production began at Mount Weld in Western Australia, and numerous other exploration and development projects noted in this chapter are ongoing throughout the world.The REE-bearing minerals are

  20. Molecular activation analysis for chemical species studies

    International Nuclear Information System (INIS)

    Chai Zhifang; Mao Xueying; Wang Yuqi; Sun Jingxin; Qian Qingfang; Hou Xiaolin; Zhang Peiqun; Chen Chunying; Feng Weiyu; Ding Wenjun; Li Xiaolin; Li Chunsheng; Dai Xiongxin

    2001-01-01

    The Molecular Activation Analysis (MAA) mainly refers to an activation analysis method that is able to provide information about the chemical species of elements in systems of interest, though its exact definition has remained to be assigned. Its development is strongly stimulated by the urgent need to know the chemical species of elements, because the bulk contents or concentrations are often insignificant for judging biological, environmental or geochemical effects of elements. In this paper, the features, methodology and limitation of MAA were outlined. Further, the up-to-date MAA progress made in our laboratory was introduced as well. (author)

  1. Fuel element loading system

    International Nuclear Information System (INIS)

    Arya, S.P; s.

    1978-01-01

    A nuclear fuel element loading system is described which conveys a plurality of fuel rods to longitudinal passages in fuel elements. Conveyor means successively position the fuel rods above the longitudinal passages in axial alignment therewith and adapter means guide the fuel rods from the conveyor means into the longitudinal passages. The fuel elements are vibrated to cause the fuel rods to fall into the longitudinal passages through the adapter means

  2. Elements in biological AMS

    International Nuclear Information System (INIS)

    Vogel, J.S.; McAninch, J.; Freeman, S.

    1996-08-01

    AMS (Accelerator Mass Spectrometry) provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. 14 C is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth's biosphere. Thirty-three elements in the main periodic table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. Overlap of biologically interesting heavy elements and possible AMS tracers is discussed

  3. Origin and Evolution of the Elements

    Science.gov (United States)

    McWilliam, Andrew; Rauch, Michael

    2004-09-01

    Introduction; List of participants; 1. Mount Wilson Observatory contributions to the study of cosmic abundances of the chemical elements George W. Preston; 2. Synthesis of the elements in stars: B2FH and beyond E. Margaret Burbidge; 3. Stellar nucleosynthesis: a status report 2003 David Arnett; 4. Advances in r-process nucleosynthesis John J. Cowan and Christopher Sneden; 5. Element yields of intermediate-mass stars Richard B. C. Henry; 6. The impact of rotation on chemical abundances in red giant branch stars Corinne Charbonnel; 7. s-processing in AGB stars and the composition of carbon stars Maurizio Busso, Oscar Straniero, Roberto Gallino, and Carlos Abia; 8. Models of chemical evolution Francesca Matteucci; 9. Model atmospheres and stellar abundance analysis Bengt Gustafsson; 10. The light elements: lithium, beryllium, and boron Ann Merchant Boesgaard; 11. Extremely metal-poor stars John E. Norris; 12. Thin and thick galactic disks Poul E. Nissen; 13. Globular clusters and halo field stars Christopher Sneden, Inese I. Ivans and Jon P. Fulbright; 14. Chemical evolution in ω Centauri Verne V. Smith; 15. Chemical composition of the Magellanic Clouds, from young to old stars Vanessa Hill; 16. Detailed composition of stars in dwarf spheroidal galaxies Matthew D. Shetrone; 17. The evolutionary history of Local Group irregular galaxies Eva K. Grebel; 18. Chemical evolution of the old stellar populations of M31 R. Michael Rich; 19. Stellar winds of hot massive stars nearby and beyond the Local Group Fabio Bresolin and Rolf P. Kudritzki; 20. Presolar stardust grains Donald D. Clayton and Larry R. Nittler; 21. Interstellar dust B. T. Draine; 22. Interstellar atomic abundances Edward B. Jenkins; 23. Molecules in the interstellar medium Tommy Wiklind; 24. Metal ejection by galactic winds Crystal L. Martin; 25. Abundances from the integrated light of globular clusters and galaxies Scott C. Trager; 26. Abundances in spiral and irregular galaxies Donald R. Garnett; 27

  4. Chemical radioprotection

    International Nuclear Information System (INIS)

    Siegel, G.

    1979-01-01

    A reivew of the problems and progress in the field of chemical radioprotection is given. After defining the field of research, the practical significance of radioprotective substances and the requirements for a utilizable radioprotective preparation are presented. Trends of development of this field of research, the state of the art, and resulting conclusions for the future development of radioprotective substances of practical value are discussed. (author)

  5. Data sheets on selected toxic elements

    International Nuclear Information System (INIS)

    Jaworski, J.F.

    1982-01-01

    The chemical elements considered in this volume have been identified as toxic to animal and vegetable life forms; however, these elements have not been studied as intensely as lead, mercury, cadmium, etc. Since, in most cases, existing data are insufficient to permit discussion and comparisons of relative quality, it was decided to present what quantitative data there are in as concise a manner as possible. The resulting data sheets present what is considered to be the best available information on the environmental levels, emissions and toxicology of these elements and some of their compounds. Reference is made to the article or review in which the datum appears and which may contain any discussion of the datum and the methods whereby it was obtained. Elements considered in this volume are antimony, barium, beryllium, bismuth, boron, cesium, gallium, germanium, indium, molybdenum, silver, tellurium, thallium, tin, uranium and zirconium

  6. Analogs for transuranic elements

    International Nuclear Information System (INIS)

    Weimer, W.C.; Laul, J.C.; Kutt, J.C.

    1981-01-01

    A combined theoretical and experimental approach is being used to estimate the long-term environmental and biogeochemical behaviors of selected transuranic elements. The objective of this research is to estimate the effect that long-term (hundreds of years) environmental weathering has on the behavior of the transuranic elements americium and curium. This is achieved by investigating the actual behavior of naturally occurring rare earth elements, especially neodymium, that serve as transuranic analogs. Determination of the analog element behavior provides data that can be used to estimate the ultimate availability to man of transuranic materials released into the environment

  7. A preliminary assessment of the chemical and microbial water ...

    African Journals Online (AJOL)

    A preliminary assessment of the chemical and microbial water quality of the Chunies River - Limpopo: short communication. ... For this purpose sampling was undertaken on 25 and 26 May 2002, and a range of chemical (macro-elements, micro-elements and heavy metals) and microbial variables (HPC, total coliforms and ...

  8. Elemental abundances of solar sibling candidates

    International Nuclear Information System (INIS)

    Ramírez, I.; Lambert, D. L.; Endl, M.; Cochran, W. D.; MacQueen, P. J.; Bajkova, A. T.; Bobylev, V. V.; Roederer, I. U.; Wittenmyer, R. A.

    2014-01-01

    Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high-resolution, high signal-to-noise ratio spectra for 30 of these objects to determine, using detailed elemental abundance analysis, if they could be true solar siblings. Only two of the candidates are found to have solar chemical composition. Updated modeling of the stars' past orbits in a realistic Galactic potential reveals that one of them, HD 162826, satisfies both chemical and dynamical conditions for being a sibling of the Sun. Measurements of rare-element abundances for this star further confirm its solar composition, with the only possible exception of Sm. Analysis of long-term high-precision radial velocity data rules out the presence of hot Jupiters and confirms that this star is not in a binary system. We find that chemical tagging does not necessarily benefit from studying as many elements as possible but instead from identifying and carefully measuring the abundances of those elements that show large star-to-star scatter at a given metallicity. Future searches employing data products from ongoing massive astrometric and spectroscopic surveys can be optimized by acknowledging this fact.

  9. THE RAVE CATALOG OF STELLAR ELEMENTAL ABUNDANCES: FIRST DATA RELEASE

    International Nuclear Information System (INIS)

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

    2011-01-01

    We present chemical elemental abundances for 36,561 stars observed by the RAdial Velocity Experiment (RAVE), an ambitious spectroscopic survey of our Galaxy at Galactic latitudes |b| > 25° and with magnitudes in the range 9 DENIS 2 minimization technique. We plan to extend this pipeline to include estimates for other elements, such as oxygen and sulfur, in future data releases.

  10. Comparison of trace element contamination levels (Cu, Zn, Fe, Cd ...

    African Journals Online (AJOL)

    SERVER

    2008-03-18

    Mar 18, 2008 ... Chemical analysis of the trace elements in the soft tissues. The trace elements of interest (Cu, Zn, Fe, Pb, Cd) were then determined in the digested solutions, using Thermoelemental type. M6 brand of an atomic absorption Spectrometer equipped with a flame operated atomisation system and a deuterium ...

  11. Contamination of Kallar Kahar Lake by Inorganic Elements and ...

    African Journals Online (AJOL)

    The present study was conducted to find out the contamination of Kallar Kahar Lake by inorganic elements and heavy metals and the temporal variation of these chemicals in the lake water. Water samples were collected on monthly basis during December 2001 to November 2002. Concentration of 10 inorganic elements ...

  12. Probing Trace-elements in Bitumen by Neutron Activation Analysis

    NARCIS (Netherlands)

    Nahar, S.N.; Schmets, A.J.M.; Scarpas, Athanasios

    Trace elements and their concentrations play an important role in both chemical and physical properties of bitumen. Instrumental Neutron Activation Analysis (INAA) has been applied to determine the concentration of trace elements in bitumen. This method requires irradiation of the material with

  13. Boiling points of the superheavy elements 117 and 118

    International Nuclear Information System (INIS)

    Takahashi, N.

    2001-01-01

    It has been shown that the relativistic effect on the electrons reveal in the heavy element region. What kind of changes will appear in the heavy elements because of the relativistic effects? Can we observe the changes? We observed that the boiling points of astatine and radon are lower than that extrapolated values from lighter elements in the same groups. Systematic behavior of the elements on the boiling point was examined and a new method for the estimation of the boiling points of the superheavy elements in the halogen and rare gases has been found. The estimated values of the elements 117 and 118 are 618 and 247 K, respectively which are considerably lower than those obtained until now. If these values are correct the production of the superheavy elements with heavy ions reaction may be affected. Further, the chemical properties may be fairly different from the lighter elements. (author)

  14. Household Chemical Emergencies

    Science.gov (United States)

    ... Content Home Be Informed Household Chemical Emergencies Household Chemical Emergencies Although the risk of a chemical accident ... reduce the risk of injury. Before a Household Chemical Emergency It is critical to store household chemicals ...

  15. Isotopic composition of chemical elements in natural cycles

    International Nuclear Information System (INIS)

    Wetzel, K.

    1977-12-01

    Mathematical models developed for planning and evaluating tracer experiments have been applied in investigations of the isotopic composition of carbon in its natural cycle through various periods of the last billion years. The influence on the natural isotope ratio due to industrial combustion of fossil fuels is shown. In order to describe regional differences from the global behaviour of carbon a parameter has been introduced, which represents the time needed for one total exchange of the atmosphere in a certain region with the global atmosphere

  16. Physiological Effects of Trace Elements and Chemicals in Water

    Science.gov (United States)

    Varma, M. M.; And Others

    1976-01-01

    The physiological effects on humans and animals of trace amounts of organic and unorganic pollutants in natural and waste waters are examined. The sensitivity of particular organs and species is emphasized. Substances reviewed include mercury, arsenic, cadmium, lead, chromium, fluorides, nitrates and organics, including polychlounated biphenyls.…

  17. Stars, Galaxies, and the Origin of Chemical Elements

    Science.gov (United States)

    Peter, Ulmschneider

    "That I am mortal I know, and that my days are numbered, but when in my mind I follow the multiply entwined orbits of the stars, then my feet do no longer touch the Earth. At the table of Zeus himself do I eat Ambrosia, the food of the Gods". These words by Ptolemy from around 125 A.D. are handed down together with his famous book The Almagest, the bible of astronomy for some 1500 years. They capture mankind's deep fascination with the movements of the heavens, and the miracles of the biological world. After the Babylonians observed the motions of the Sun, Moon, and planets for millennia, the ancient Greeks were the first to speculate about the nature of these celestial bodies. Yet it is only as a consequence of developments in the last 150 years that a much clearer picture of the physical universe has begun to emerge. Among the most important discoveries have been the stellar parallax, confirming Copernicus's heliocentric system, the realization that galaxies are comprised of billions of stars, the awareness of the size of the universe, and the evolutionary nature of living organisms.

  18. Element by element review of their atomic weights

    International Nuclear Information System (INIS)

    Peiser, H.S.; Holden, N.E.; Bievre, P. de

    1984-01-01

    The IUPAC 'standard' atomic weights of the terrestrially occurring chemical elements are individually reviewed tracing changes during the past 25 years. Emphasized is the relevant published scientific evidence which in each case constitutes the basis for the expert judgment by the responsible IUPAC Commission. It biennially reports on, recommends, and tabulates the best values of these atomic weights with an implied judgment of their individual reliability. In the introductory part of this Review the history of atomic-weight determinations is sketched. The IUPAC leadership in this data-evaluation project is described as it benefits science, technology, and trade. The remaining experimental uncertainties and natural variabilities are discussed. The treatment of abnormal materials is explained. The principal techniques for determining atomic weights are outlined. The effects of naturally occurring radioactive nuclides are characterized in their essentials. (author)

  19. General geochemical properties and abundances of the rare earth elements

    International Nuclear Information System (INIS)

    Henderson, P.

    1984-01-01

    This chapter reviews some of the fundamental aspects of rare earth elements (REE) geochemistry and gives data on abundances in the solar system, the bulk Earth and the Earth's crust. It describes the state of knowledge on the partitioning of the REE, especially in igneous rock systems, and cites reference works concerned with the REE. Several chemical properties of REE are discussed (oxidation states; redox conditions; element coordination and ionic radii; element substitution). (Auth.)

  20. Seagrass leaf element content

    NARCIS (Netherlands)

    Vonk, J.A.; Smulders, Fee O.H.; Christianen, Marjolijn J.A.; Govers, Laura L.

    2017-01-01

    Knowledge on the role of seagrass leaf elements and in particular micronutrients and their ranges is limited. We present a global database, consisting of 1126 unique leaf values for ten elements, obtained from literature and unpublished data, spanning 25 different seagrass species from 28 countries.

  1. Berkeley new element program

    International Nuclear Information System (INIS)

    Ghiorso, A.

    1975-09-01

    The work done with element 106 is reviewed, and a new experiment which bears on the properties of the isotope of mass 260 with atomic number 104 is discussed. It is noted that in the case of element 106 a link is demonstrated to the granddaughter as well as the daughter

  2. Nuclear fuel element

    International Nuclear Information System (INIS)

    Mogard, J.H.

    1977-01-01

    A nuclear fuel element is disclosed for use in power producing nuclear reactors, comprising a plurality of axially aligned ceramic cylindrical fuel bodies of the sintered type, and a cladding tube of metal or metal alloys, wherein said cladding tube on its cylindrical inner surface is provided with a plurality of slightly protruding spacing elements distributed over said inner surface

  3. Assessment of elemental composition and distribution of some ...

    African Journals Online (AJOL)

    Nigerian Journal of Physics ... The MOP fertilizer has the highest mean concentration levels for both As and Pb, followed by SSP fertilizer, which recorded As and Pb concentration level s of 161±50 ppm and 231±68 ppm, respectively. ... Keywords: chemical elements, fertilizers, concentration levels, PBTs, chemical toxicity ...

  4. Chemical cosmology

    CERN Document Server

    Boeyens, Jan CA

    2010-01-01

    The composition of the most remote objects brought into view by the Hubble telescope can no longer be reconciled with the nucleogenesis of standard cosmology and the alternative explanation, in terms of the LAMBDA-Cold-Dark-Matter model, has no recognizable chemical basis. A more rational scheme, based on the chemistry and periodicity of atomic matter, opens up an exciting new interpretation of the cosmos in terms of projective geometry and general relativity. The response of atomic structure to environmental pressure predicts non-Doppler cosmical redshifts and equilibrium nucleogenesis by alp

  5. Chemical characterization of atmospheric particles

    International Nuclear Information System (INIS)

    Adams, F.

    2002-01-01

    In the characterisation of complex environmental materials such as atmospheric particulate matter, analytical specificity is required to account for the many dimensions of information present in the sample. These dimensions include size, morphology, elemental composition, inorganic and organic chemical speciation, all to be performed on either single particles or on the population (or bulk sample) basis. Various techniques were developed for such measurements, including a number of bulk analysis procedures, methodologies for microscopical analysis of individual particles, and a variety of procedures for organic/inorganic chemical speciation. (author)

  6. Effort problem of chemical pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Okrajni, J.; Ciesla, M.; Mutwil, K. [Silesian Technical University, Katowice (Poland)

    1998-12-31

    The problem of the technical state assessment of the chemical pipelines working under mechanical and thermal loading has been shown in the paper. The pipelines effort after the long time operating period has been analysed. Material geometrical and loading conditions of the crack initiation and crack growth process in the chosen object has been discussed. Areas of the maximal effort have been determined. The material structure charges after the long time operating period have been described. Mechanisms of the crack initiation and crack growth in the pipeline elements have been analysed and mutual relations between the chemical and mechanical influences have been shown. (orig.) 16 refs.

  7. Trace element analysis in soy sauce

    International Nuclear Information System (INIS)

    Haruyama, Yoichi; Saito, Manabu; Tomiya, Michio

    1993-01-01

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

  8. Stability and `volatility ` of element 104 oxychloride

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-09-01

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

  9. Tests on the synthesis of superheavy elements

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The article briefly summarizes the study of superheavy elements, starting with speculations on the existence of relatively long-living nuclei via theoretical works to nuclear properties and chemical properties, search for the longest-living nuclei of the calculated stability island in nature, up to the attempts to produce such superheavy elements in large heavy ion accelerators (Berkely, Dubna, Darmstadt, Orsay). Principle and problems of the two methods to achieve a synthesis of such heavy nuclei, i. e. fusion reactions and transfer reactions, are briefly discussed. (RB) [de

  10. Elemental transport coefficients in viscous plasma flows near local thermodynamic equilibrium

    International Nuclear Information System (INIS)

    Orsini, Alessio; Kustova, Elena V.

    2009-01-01

    We propose a convenient formulation of elemental transport coefficients in chemically reacting and plasma flows locally approaching thermodynamic equilibrium. A set of transport coefficients for elemental diffusion velocities, heat flux, and electric current is introduced. These coefficients relate the transport fluxes with the electric field and with the spatial gradients of elemental fractions, pressure, and temperature. The proposed formalism based on chemical elements and fully symmetric with the classical transport theory based on chemical species, is particularly suitable to model mixing and demixing phenomena due to diffusion of chemical elements. The aim of this work is threefold: to define a simple and rigorous framework suitable for numerical implementation, to allow order of magnitude estimations and qualitative predictions of elemental transport phenomena, and to gain a deeper insight into the physics of chemically reacting flows near local equilibrium.

  11. Photodisintegration of the heavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, R W; Collie, C H

    1950-08-01

    The photothresholds for the emission of neutrons by the following elements have been determined; the threshold in MeV is given in the brackets following the symbol: Pt(6.1 +- 0.1), Au(8.1 +- 0.1), Hg(6.6 +- 0.2), Tl(7.3 +- 0.25), Pb(6.9 +- 0.1), Bi(7.2 +- 0.1), Th(6.9 +- 0.15), U(5.8 +- 0.15). The neutrons were detected by the Szilard-Chalmers method of chemical concentration and the ..gamma.. rays were obtained from a small betatron. Rough values of the total cross sections can be estimated from the results.

  12. STATUS OF RADIOACTIVE ELEMENTS IN THE ATOMIC WEIGHTS TABLE

    International Nuclear Information System (INIS)

    HOLDEN, N.E.

    2003-01-01

    During discussions within the Inorganic Chemistry Division Committee, that dealt with the Periodic Table of the Chemical Elements and the official IUPAC position on its presentation, the following question was raised. When the various chemical elements are presented, each with their appropriate atomic weight value, how should the radioactive elements be presented? The Atomic Weights Commission has treated this question in a number of different ways during the past century, almost in a random manner. This report reviews the position that the Commission has taken as a function of time, as a prelude to a discussion in Ottawa about how the Commission should resolve this question for the future

  13. The production of transplutonium elements in France

    International Nuclear Information System (INIS)

    Koehly, G.; Bourges, J.; Madic, C.; Sontag, R.; Kertesz, C.

    1980-08-01

    The development of the program for the production of transplutonium elements, 241 Am, 243 Am and 244 Cm, in France, required a major effort from the technological and chemical standpoints. Pre-existing hot cells were reconditioned and others specially built for these production operations. From the chemical standpoint, the development of extractive chromatography on the preparative scale has allowed the definition of simple processes. This type of process, initially developed for the treatment of Pu/Al targets, is ideal for the treatment of industrial wastes for their decontamination and for the production of 241 Am

  14. Platinum-group elements

    Science.gov (United States)

    Zientek, Michael L.; Loferski, Patricia J.; Parks, Heather L.; Schulte, Ruth F.; Seal, Robert R.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    The platinum-group elements (PGEs)—platinum, palladium, rhodium, ruthenium, iridium, and osmium—are metals that have similar physical and chemical properties and tend to occur together in nature. PGEs are indispensable to many industrial applications but are mined in only a few places. The availability and accessibility of PGEs could be disrupted by economic, environmental, political, and social events. The United States net import reliance as a percentage of apparent consumption is about 90 percent.PGEs have many industrial applications. They are used in catalytic converters to reduce carbon monoxide, hydrocarbon, and nitrous oxide emissions in automobile exhaust. The chemical industry requires platinum or platinum-rhodium alloys to manufacture nitric oxide, which is the raw material used to manufacture explosives, fertilizers, and nitric acid. In the petrochemical industry, platinum-supported catalysts are needed to refine crude oil and to produce aromatic compounds and high-octane gasoline. Alloys of PGEs are exceptionally hard and durable, making them the best known coating for industrial crucibles used in the manufacture of chemicals and synthetic materials. PGEs are used by the glass manufacturing industry in the production of fiberglass and flat-panel and liquid crystal displays. In the electronics industry, PGEs are used in computer hard disks, hybridized integrated circuits, and multilayer ceramic capacitors.Aside from their industrial applications, PGEs are used in such other fields as health, consumer goods, and finance. Platinum, for example, is used in medical implants, such as pacemakers, and PGEs are used in cancer-fighting drugs. Platinum alloys are an ideal choice for jewelry because of their white color, strength, and resistance to tarnish. Platinum, palladium, and rhodium in the form of coins and bars are also used as investment commodities, and various financial instruments based on the value of these PGEs are traded on major exchanges

  15. Discovery of element 112

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, S. [GSI, Darmstadt (Germany)

    1996-12-31

    The new elements 110, 111, and 112 were synthesized and unambiguously identified in experiments at SHIP. Due to strong shell effects the dominant decay mode is not fission, but emission of alpha particles. Theoretical investigations predict that maximum shell effects should exist in nuclei near proton number 114 and neutron number 184. Measurements give hope that isotopes of element 114 close to the island of spherical Superheavy Elements could be produced by fusion reactions using {sup 118}Pb as target. systematic studies of the reaction cross-sections indicate that transfer of nucleons is the important process to initiate the fusion.

  16. Nuclear fuel element

    International Nuclear Information System (INIS)

    Grossman, L.N.; Levin, H.A.

    1975-01-01

    A nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of particles in a hollow gas permeable container having a multiplicity of openings of size smallr than the size of the particles. The container is preferably held in the spring in the plenum of the fuel element. (E.C.B.)

  17. The Chemical Composition of Mercury

    OpenAIRE

    Nittler, Larry R.; Chabot, Nancy L.; Grove, Timothy L.; Peplowski, Patrick N.

    2017-01-01

    The chemical composition of a planetary body reflects its starting conditions modified by numerous processes during its formation and geological evolution. Measurements by X-ray, gamma-ray, and neutron spectrometers on the MESSENGER spacecraft revealed Mercury's surface to have surprisingly high abundances of the moderately volatile elements sodium, sulfur, potassium, chlorine, and thorium, and a low abundance of iron. This composition rules out some formation models for which high temperatur...

  18. Cantilevered probe detector with piezoelectric element

    Science.gov (United States)

    Adams, Jesse D; Sulchek, Todd A; Feigin, Stuart C

    2013-04-30

    A disclosed chemical detection system for detecting a target material, such as an explosive material, can include a cantilevered probe, a probe heater coupled to the cantilevered probe, and a piezoelectric element disposed on the cantilevered probe. The piezoelectric element can be configured as a detector and/or an actuator. Detection can include, for example, detecting a movement of the cantilevered probe or a property of the cantilevered probe. The movement or a change in the property of the cantilevered probe can occur, for example, by adsorption of the target material, desorption of the target material, reaction of the target material and/or phase change of the target material. Examples of detectable movements and properties include temperature shifts, impedance shifts, and resonant frequency shifts of the cantilevered probe. The overall chemical detection system can be incorporated, for example, into a handheld explosive material detection system.

  19. Ecological effect of rare earth elements

    International Nuclear Information System (INIS)

    Hu Aitang; Zhou Quansuo; Zheng Shaojian; Zhai Hai; Zhao Xiulan; Pang Yonglin; Wang Yuqi; Sun Jingxin; Zhang Shen; Wang Lijun

    1997-01-01

    Water and soil culture were carried out to study the ecological effect of rare earth elements (REEs) in the aspect of plant-soil system. Contents of REEs were determined by instrumental neutron activation analysis (INAA). There was a limit to REEs-tolerance of crops, which differed with the development periods of plant and soil types. The REEs concentration in plant, especially in root, was marked related to the concentration in culture material. Beyond the concentration-limit appeared phototoxicity. The chemical behavior of REEs in plants and soils varied with soil types and elements. The bio-availability of REEs in soil mainly depended on the exchangeable fraction of REEs affected strongly by the physi-chemical properties of soils

  20. Bridge element deterioration rates.

    Science.gov (United States)

    2008-10-01

    This report describes the development of bridge element deterioration rates using the NYSDOT : bridge inspection database using Markov chains and Weibull-based approaches. It is observed : that Weibull-based approach is more reliable for developing b...