WorldWideScience

Sample records for chemical elements by group and name

  1. Study on the chemical species of platinum group elements in geological samples by molecular activation analysis

    International Nuclear Information System (INIS)

    The chemical species of platinum group elements in some upper mantle-derived xenoliths from Eastern China are studied by molecular activation analysis, in which the chemical stepwise dissolution, nickel fire assay preconcentration and neutron activation analysis are jointly applied. The weighted sums of platinum group elements in 6 phases are in agreement with their total contents. The distribution patterns of platinum group elements in sulphides show that sulphide segregation is one of the important mechanisms for the fractionation of platinum group elements in upper mantle-derived material during partial melting

  2. A Group-Theoretical Approach to the Periodic Table of Chemical Elements: Old and New Developments

    OpenAIRE

    Kibler, M. R.

    2005-01-01

    This paper is a companion article to the review paper by the present author devoted to the classification of matter constituents (chemical elements and particles) and published in the first part of the proceedings of The Second Harry Wiener International Memorial Conference (see quant-ph/0310155). It is mainly concerned with a group-theoretical approach to the Periodic Table of the neutral elements based on the noncompact group SO(4,2)xSU(2).

  3. Sobre os nomes dos elementos químicos, inclusive dos transférmios About the names of the chemical elements, including the transfermium elements

    OpenAIRE

    Rocha-Filho, Romeu C.; Aécio Pereira Chagas

    1999-01-01

    The names of the chemical elements in Brazilian portuguese are presented, including a discussion of corresponding Brazilian nomenclature rules and translation of some parts of the pertinent IUPAC rules. The rules for naming groups of elements in the periodic table, as well as those for the symbolic indication of atomic number, mass number and electric charge of atoms, are also presented.

  4. Analysis Of Names Of Organic Chemical Compounds By Using Parser Combinators And The Generative Lexicon Theory

    OpenAIRE

    Márcio de Souza Dias; Rita Maria Silva Julia; Eduardo Costa Pereira

    2011-01-01

    This work proposes OCLAS (Organic Chemistry Language Ambiguity Solver), an automatic system to analyze syntactically and semantically Organic Chemistry compound names and to generate the pictures of their chemical structures. If both parses detect that the input name corresponds to a theoretically possible organic chemical compound, the system generates its molecular structure picture, whether or not the name respects the current official nomenclature. This capacity of treating ev...

  5. Chemical named entity recognition in patents by domain knowledge and unsupervised feature learning.

    Science.gov (United States)

    Zhang, Yaoyun; Xu, Jun; Chen, Hui; Wang, Jingqi; Wu, Yonghui; Prakasam, Manu; Xu, Hua

    2016-01-01

    Medicinal chemistry patents contain rich information about chemical compounds. Although much effort has been devoted to extracting chemical entities from scientific literature, limited numbers of patent mining systems are publically available, probably due to the lack of large manually annotated corpora. To accelerate the development of information extraction systems for medicinal chemistry patents, the 2015 BioCreative V challenge organized a track on Chemical and Drug Named Entity Recognition from patent text (CHEMDNER patents). This track included three individual subtasks: (i) Chemical Entity Mention Recognition in Patents (CEMP), (ii) Chemical Passage Detection (CPD) and (iii) Gene and Protein Related Object task (GPRO). We participated in the two subtasks of CEMP and CPD using machine learning-based systems. Our machine learning-based systems employed the algorithms of conditional random fields (CRF) and structured support vector machines (SSVMs), respectively. To improve the performance of the NER systems, two strategies were proposed for feature engineering: (i) domain knowledge features of dictionaries, chemical structural patterns and semantic type information present in the context of the candidate chemical and (ii) unsupervised feature learning algorithms to generate word representation features by Brown clustering and a novel binarized Word embedding to enhance the generalizability of the system. Further, the system output for the CPD task was yielded based on the patent titles and abstracts with chemicals recognized in the CEMP task.The effects of the proposed feature strategies on both the machine learning-based systems were investigated. Our best system achieved the second best performance among 21 participating teams in CEMP with a precision of 87.18%, a recall of 90.78% and aF-measure of 88.94% and was the top performing system among nine participating teams in CPD with a sensitivity of 98.60%, a specificity of 87.21%, an accuracy of 94.75%, a

  6. Chemical named entity recognition in patents by domain knowledge and unsupervised feature learning

    Science.gov (United States)

    Zhang, Yaoyun; Xu, Jun; Chen, Hui; Wang, Jingqi; Wu, Yonghui; Prakasam, Manu; Xu, Hua

    2016-01-01

    Medicinal chemistry patents contain rich information about chemical compounds. Although much effort has been devoted to extracting chemical entities from scientific literature, limited numbers of patent mining systems are publically available, probably due to the lack of large manually annotated corpora. To accelerate the development of information extraction systems for medicinal chemistry patents, the 2015 BioCreative V challenge organized a track on Chemical and Drug Named Entity Recognition from patent text (CHEMDNER patents). This track included three individual subtasks: (i) Chemical Entity Mention Recognition in Patents (CEMP), (ii) Chemical Passage Detection (CPD) and (iii) Gene and Protein Related Object task (GPRO). We participated in the two subtasks of CEMP and CPD using machine learning-based systems. Our machine learning-based systems employed the algorithms of conditional random fields (CRF) and structured support vector machines (SSVMs), respectively. To improve the performance of the NER systems, two strategies were proposed for feature engineering: (i) domain knowledge features of dictionaries, chemical structural patterns and semantic type information present in the context of the candidate chemical and (ii) unsupervised feature learning algorithms to generate word representation features by Brown clustering and a novel binarized Word embedding to enhance the generalizability of the system. Further, the system output for the CPD task was yielded based on the patent titles and abstracts with chemicals recognized in the CEMP task. The effects of the proposed feature strategies on both the machine learning-based systems were investigated. Our best system achieved the second best performance among 21 participating teams in CEMP with a precision of 87.18%, a recall of 90.78% and a F-measure of 88.94% and was the top performing system among nine participating teams in CPD with a sensitivity of 98.60%, a specificity of 87.21%, an accuracy of 94.75%, a

  7. Some Chemical Group Separations of Radioactive Trace Elements

    International Nuclear Information System (INIS)

    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

  8. Properties of Group Five and Group Seven transactinium elements

    OpenAIRE

    Wilk, Philip A.

    2001-01-01

    The detection and positive identification of the short-lived, low cross section isotopes used in the chemical studies of the heaviest elements are usually accomplished by measuring their alpha-decay, thus the nuclear properties of the heaviest elements must be examined simultaneously with their chemical properties. The isotopes 224 Pa and 266,267 Bh have been studied extensively as an integral part of the investigation of the heaviest members of the groups five and seven of the periodic...

  9. 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)

    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 TR2O3 (rare earth oxides) in the UTM effluents. The SO4 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)

  10. 3D Chemical and Elemental Imaging by STXM Spectrotomography

    International Nuclear Information System (INIS)

    Spectrotomography based on the scanning transmission x-ray microscope (STXM) at the 10ID-1 spectromicroscopy beamline of the Canadian Light Source was used to study two selected unicellular microorganisms. Spatial distributions of sulphur globules, calcium, protein, and polysaccharide in sulphur-metabolizing bacteria (Allochromatium vinosum) were determined at the S 2p, C 1s, and Ca 2p edges. 3D chemical mapping showed that the sulphur globules are located inside the bacteria with a strong spatial correlation with calcium ions (it is most probably calcium carbonate from the medium; however, with STXM the distribution and localization in the cell can be made visible, which is very interesting for a biologist) and polysaccharide-rich polymers, suggesting an influence of the organic components on the formation of the sulphur and calcium deposits. A second study investigated copper accumulating in yeast cells (Saccharomyces cerevisiae) treated with copper sulphate. 3D elemental imaging at the Cu 2p edge showed that Cu(II) is reduced to Cu(I) on the yeast cell wall. A novel needle-like wet cell sample holder for STXM spectrotomography studies of fully hydrated samples is discussed.

  11. CHEMDNER: The drugs and chemical names extraction challenge

    OpenAIRE

    Krallinger, M.; Leitner, F.; Rabal, O.; Vazquez, M.; Oyarzabal, J.; Valencia, A.

    2015-01-01

    Natural language processing (NLP) and text mining technologies for the chemical domain (ChemNLP or chemical text mining) are key to improve the access and integration of information from unstructured data such as patents or the scientific literature. Therefore, the BioCreative organizers posed the CHEMDNER (chemical compound and drug name recognition) community challenge, which promoted the development of novel, competitive and accessible chemical text mining systems. This task allowed a comp...

  12. Analysis of Names and Relationships Among Data Elements

    OpenAIRE

    C. S. Sankar

    1985-01-01

    When making decisions, managers like to obtain pertinent information quickly and accurately from the information systems in an organization. But, often, different answers are obtained, depending on how the information request is phrased or from which information system the information is requested. In order to correct this problem, the system analyst and data base administrator have to resolve any conflicts in defining elements, their names and their relationships before computerized informat...

  13. CHEMDNER: The drugs and chemical names extraction challenge.

    Science.gov (United States)

    Krallinger, Martin; Leitner, Florian; Rabal, Obdulia; Vazquez, Miguel; Oyarzabal, Julen; Valencia, Alfonso

    2015-01-01

    Natural language processing (NLP) and text mining technologies for the chemical domain (ChemNLP or chemical text mining) are key to improve the access and integration of information from unstructured data such as patents or the scientific literature. Therefore, the BioCreative organizers posed the CHEMDNER (chemical compound and drug name recognition) community challenge, which promoted the development of novel, competitive and accessible chemical text mining systems. This task allowed a comparative assessment of the performance of various methodologies using a carefully prepared collection of manually labeled text prepared by specially trained chemists as Gold Standard data. We evaluated two important aspects: one covered the indexing of documents with chemicals (chemical document indexing - CDI task), and the other was concerned with finding the exact mentions of chemicals in text (chemical entity mention recognition - CEM task). 27 teams (23 academic and 4 commercial, a total of 87 researchers) returned results for the CHEMDNER tasks: 26 teams for CEM and 23 for the CDI task. Top scoring teams obtained an F-score of 87.39% for the CEM task and 88.20% for the CDI task, a very promising result when compared to the agreement between human annotators (91%). The strategies used to detect chemicals included machine learning methods (e.g. conditional random fields) using a variety of features, chemistry and drug lexica, and domain-specific rules. We expect that the tools and resources resulting from this effort will have an impact in future developments of chemical text mining applications and will form the basis to find related chemical information for the detected entities, such as toxicological or pharmacogenomic properties. PMID:25810766

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

    OpenAIRE

    BOLSHAKOV V. I.; Savin, Yu. L.; O. P. Prykhodko; L. S. Savin; Kulbashnyi, V. M.

    2007-01-01

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

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

    OpenAIRE

    BOLSHAKOV V. I.; Savin, Yu. L.; O. P. Prykhodko; L. S. Savin; Kulbashnyi, V. M.

    2008-01-01

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

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

    International Nuclear Information System (INIS)

    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, Al2O3 and coprecipitation with Fe(OH)3 are described. Results obtained for standard reference materials are summarized. (G.T.H.)

  17. Chemical named entities recognition: a review on approaches and applications.

    Science.gov (United States)

    Eltyeb, Safaa; Salim, Naomie

    2014-01-01

    The rapid increase in the flow rate of published digital information in all disciplines has resulted in a pressing need for techniques that can simplify the use of this information. The chemistry literature is very rich with information about chemical entities. Extracting molecules and their related properties and activities from the scientific literature to "text mine" these extracted data and determine contextual relationships helps research scientists, particularly those in drug development. One of the most important challenges in chemical text mining is the recognition of chemical entities mentioned in the texts. In this review, the authors briefly introduce the fundamental concepts of chemical literature mining, the textual contents of chemical documents, and the methods of naming chemicals in documents. We sketch out dictionary-based, rule-based and machine learning, as well as hybrid chemical named entity recognition approaches with their applied solutions. We end with an outlook on the pros and cons of these approaches and the types of chemical entities extracted. PMID:24834132

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

    DEFF Research Database (Denmark)

    Zhou, Chunfang

    2015-01-01

    As the recent studies have discussed Problem-Based Learning (PBL) as popular model of fostering creativity, this paper aims to provide a theoretical framework bridging creativity and student group context by elements of PBL. According to the literature review, the elements at least include group...... learning, problem solving, interdisciplinary learning, project management and facilitation. The main five elements construct PBL as a suitable learning environment to develop individual creativity and to stimulate interplay of individual creativity and group creativity. Thus, a theoretical model will be...... built for understanding that how PBL influences creativity by its elements that underpins a systematic view to PBL and creativity which also indicates both theoretical and practical significances....

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

    Directory of Open Access Journals (Sweden)

    V. I. Bolshakov

    2007-11-01

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

  20. Physical and chemical parameters of sediment extraction and fractionation that influence toxicity, as evaluated by microtox (trade name)

    International Nuclear Information System (INIS)

    Several physical and chemical parameters of sediment extraction and fractionation of organic compounds that influence bioassay results were evaluated. Each parameter was evaluated with a photoluminescent bacterial bioassay (Microtox) as an end point. Three solvents (acetonitrile, acetone, and methanol) were studied for their ability to extract toxic organic components from marine sediments. Acetone extracted the most toxicity, with no difference between acetonitrile and methanol. Two methods of fractionating sediment extracts (silica-gel-column chromatography (SGCC) and acid-base fractionation) were compared. SGCC was more useful because it resulted in a wider range of responses and was faster to perform than acid-base fractionation. Microtox was used to rank four marine sediments with respect to toxicity and to determine if one chemical class (or fraction) was consistently more toxic among different sediments. With some caveats, Microtox results agreed with general chemical concentration trends and other bioassay results in distinguishing between contaminated and noncontaminated sediments. Although results indicated there was not a consistently most toxic fraction among sediments, there was a consistently least toxic fraction. The effect of sediment storage time on toxicity was also evaluated. Results indicated that the most stable chemical fraction (containing nonpolar hydrocarbons) did not change toxicologically for 30 weeks, whereas the more chemically active fraction (containing ketones, quinones, and carboxyls) changed as soon as one week

  1. A new-generation density functional towards chemical accuracy for chemistry of main group elements

    CERN Document Server

    Zhang, Igor Ying

    2013-01-01

    A New-Generation Density Functional: Towards Chemical Accuracy for Chemistry of Main Group Elements covers the most recent progress in the development of a new generation of density functional theory (DFT) for accurate descriptions of thermochemistry, thermochemical kinetics, and nonbonded interactions of main group molecules.

  2. On a group-theoretical approach to the periodic table of chemical elements

    OpenAIRE

    Kibler, Maurice

    2004-01-01

    This paper is concerned with the application of the group SO(4,2)xSU(2) to the periodic table of chemical elements. It is shown how the Madelung rule of the atomic shell model can be used for setting up a periodic table that can be further rationalized via the group SO(4,2)xSU(2) and some of its subgroups. Qualitative results are obtained from the table and the general lines of a programme for a quantitative approach to the properties of chemical elements are developed on the basis of the gro...

  3. Properties of Group Five and Group Seven transactinium elements

    International Nuclear Information System (INIS)

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

  4. Properties of Group Five and Group Seven transactinium elements

    Energy Technology Data Exchange (ETDEWEB)

    Wilk, Philip A.

    2001-05-01

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

  5. 化学元素周期表中以神话人物名称命名的化学元素英文名称分析%Analysis of the English Name of the Chemical Element in the Periodic Table of Chemical Elements Named after the Name of the Mythological Figure

    Institute of Scientific and Technical Information of China (English)

    王琦

    2012-01-01

    欧洲各国神话尤其是希腊罗马神话,对现代社会文明历史的影响是多方面的,在化学史上对化学元素的命名方面,其影响也不容小视,因此了解以神话人物名称对元素命名的方法,有助于加深对元素周期表的了解,有助于更好地理解欧洲各国古代神话对西方社会文化的影响。%European mythology, especially Greek and Roman mythology, the influence in history of modem society civili- zation is various, its influence can not be overlooked in the naming of the chemical history of the chemical elements, and therefore understand the name of the mythological figure named elements, help deepen the understanding of the periodic tab le, and contribute to a better understanding of the ancient myths of Western society and culture in European countries.

  6. Nuclear and chemical properties of the transactinide elements

    International Nuclear Information System (INIS)

    Transactinide elements, whose atomic number larger than 104 and classified as 6d-transition elements in the periodic table, have seldom been studied of the chemical nature in spite of much interest in the possible relativistic effects of these superheavy nuclides. This report briefly reviews recent topics in the advancement for the superheavy (Z > 104) nuclide synthesis by means of cold fusion with varying combinations of incident and target atoms using ion accelerators, for example, at GSI, Darmstadt, and at JINR, Dubna. It also reviews recent progress in their nuclear and chemical properties studied by a world-wide cooperative research group working at GSI, Mainz University, Bern University, PSI, Uppsala University, Dubna and LBL groups into which JAERI group has joined since 1998. Moreover, expectation is stated for the successful synthesis of superheavy elements on employment of radioactive beams consisting of neutron-excess nuclides. (Ohno, S.)

  7. Concentration and distribution of platinum-group elements (PGE) in soils. Platinum emission by attrition of automobile exhaust catalysts

    International Nuclear Information System (INIS)

    In Germany automobile exhaust control by platinum-group element (PGE) loaded catalysts is now well established. By mechanical or chemical attrition, these catalysts could act as a potential source for a significant increase of PGE abundances in the environment. During a recent research program concentrations and distributions of PGE in different soils were measured along the highway A66 Frankfurt - Wiesbaden. 71 nearsurface soil samples were analysed by graphite furnace atomic absorption spectrometry (GFAAS). The results revealed average abundances of 10 ppb platinum and 3 ppb ruthenium. Palladium as well as rhodium were below the analytical detection limit of 2 ppb. With increasing distance from the highway edge PGE values gradually decreased. Only the upmost soil layer, down to 20 cm depth, contains measurable PGE concentrations. Results: There are irregular PGE concentrations of anthropogenic origin in different soils along the highway A66 Frankfurt -Wiesbaden possibly arising from automobile exhaust catalysts. Further monitoring could help to avoid potential environmental hazards. (orig.)

  8. Extra- and intra-cellular accumulation of platinum group elements by the marine microalga, Chlorella stigmatophora.

    Science.gov (United States)

    Shams, Leyla; Turner, Andrew; Millward, Geoffrey E; Brown, Murray T

    2014-03-01

    To better understand the marine biogeochemistry of the platinum group elements (PGE), Rh(III), Pd(II) and Pt(IV) were added in combination and at ppb concentrations to cultures of the marine microalga, Chlorella stigmatophora, maintained in sea water at 15 °C and under 60 μmol m(-2) s(-1) PAR. The accumulation of PGE was established in short-term (24-h) exposures, and under varying conditions of algal biomass and PGE concentration, and in a longer-term exposure (156-h) by ICP-MS analysis of sea water and nitric acid digests and EDTA washes of the alga. In short-term exposures, and under all conditions, the extent of accumulation by C. stigmatophora was in the order: Rh > Pd > Pt; and Pd was internalised (or resistant to EDTA extraction) to a considerably greater extent than Rh and Pt. Accumulation isotherms were quasi-linear up to added PGE concentrations of 30 μg L(-1) and all metals displayed a significant reduction in accumulation on a weight-normalised basis with increasing density (biomass) of C. stigmatophora, an effect attributed to the production of exudates able to stabilise metals in sea water through complexation. In the longer-term exposure, kinetic constraints on the reactivities of Rh and, in particular, Pt, resulted in final degrees of accumulation and internalisation by C. stigmatophora that were greatest for Rh and similar between Pd and Pt. Among the PGE, therefore, Rh is predicted to participate in biological removal and transport processes in the marine environment to the greatest extent while decoupling in the biogeochemistries of Pd and Pt is predicted in shorter-term or more transient processes. PMID:24268058

  9. Liquid-liquid extraction and separation of VIII group elements, especially ruthenium, by synergic combinations or aromatic polyimines and micellar cationic exchangers

    International Nuclear Information System (INIS)

    This thesis aims to characterize and to quantify the chemical equilibria involved in d-elements liquid-liquid extraction systems, especially elements belonging to the VIII group (Fe, Ni, Co, Ru, Rh, Pd, Pt). These systems are composed of synergic combination of aromatic polyimines and micellar cationic exchangers. Substitutions are first performed in aqueous acidic media by aromatic polyimines; then extractions are operated using micellic canionic exchangers. Chemical equilibria, selectivity effects, especially those due to ion-pair formations, kinetics, extractant behaviour are analysed and quantified

  10. Chemical named entities recognition: a review on approaches and applications

    OpenAIRE

    Eltyeb, Safaa; Salim, Naomie

    2014-01-01

    The rapid increase in the flow rate of published digital information in all disciplines has resulted in a pressing need for techniques that can simplify the use of this information. The chemistry literature is very rich with information about chemical entities. Extracting molecules and their related properties and activities from the scientific literature to “text mine” these extracted data and determine contextual relationships helps research scientists, particularly those in drug developmen...

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

    International Nuclear Information System (INIS)

    The chemical and nuclear properties of Lr and Ha have been studied, using 3-minute 260Lr and 35-second 262Ha. The crystal ionic radius of Lr3+ 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, Am3+ through Es3+, obtained by x-ray diffraction methods, and to Md3+ and Fm3+ which were determined in the same manner as Lr3+. 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 Lr3+ and Md3+ is anomalously small, as the ionic radius of Lr3+ 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 characterization of element 112.

    Science.gov (United States)

    Eichler, R; Aksenov, N V; Belozerov, A V; Bozhikov, G A; Chepigin, V I; Dmitriev, S N; Dressler, R; Gäggeler, H W; Gorshkov, V A; Haenssler, F; Itkis, M G; Laube, A; Lebedev, V Ya; Malyshev, O N; Oganessian, Yu Ts; Petrushkin, O V; Piguet, D; Rasmussen, P; Shishkin, S V; Shutov, A V; Svirikhin, A I; Tereshatov, E E; Vostokin, G K; Wegrzecki, M; Yeremin, A V

    2007-05-01

    The heaviest elements to have been chemically characterized are seaborgium (element 106), bohrium (element 107) and hassium (element 108). All three behave according to their respective positions in groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties. However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties. The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12. Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury. However, the production and identification methods used cast doubt on the validity of this result. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of (283)112 through the alpha decay of the short-lived (287)114 (which itself forms in the nuclear fusion reaction of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of (283)112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides. PMID:17476264

  13. Chemical characterization of element 112

    Science.gov (United States)

    Eichler, R.; Aksenov, N. V.; Belozerov, A. V.; Bozhikov, G. A.; Chepigin, V. I.; Dmitriev, S. N.; Dressler, R.; Gäggeler, H. W.; Gorshkov, V. A.; Haenssler, F.; Itkis, M. G.; Laube, A.; Lebedev, V. Ya.; Malyshev, O. N.; Oganessian, Yu. Ts.; Petrushkin, O. V.; Piguet, D.; Rasmussen, P.; Shishkin, S. V.; Shutov, A. V.; Svirikhin, A. I.; Tereshatov, E. E.; Vostokin, G. K.; Wegrzecki, M.; Yeremin, A. V.

    2007-05-01

    The heaviest elements to have been chemically characterized are seaborgium (element 106), bohrium (element 107) and hassium (element 108). All three behave according to their respective positions in groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties. However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties. The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12. Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury. However, the production and identification methods used cast doubt on the validity of this result. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of 283112 through the alpha decay of the short-lived 287114 (which itself forms in the nuclear fusion reaction of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of 283112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides.

  14. Naming and nurturing reality from a heart renewed by grace

    Directory of Open Access Journals (Sweden)

    Fritz W. de Wet

    2015-02-01

    Full Text Available This contribution investigates the unbearable tension between the homiletical act of naming reality (with the promise of exposing, challenging and/or triggering creative forces in it on the one hand, and neglecting this same reality on the other hand, thereby causing it to return to an ignored, unchallenged and degenerated state. The author focuses on tension fields that are generated when preachers embark on the activity of naming realities in their proximate contexts and how they position, withdraw or distance themselves in a certain way when problematic elements (for instance the glaring and seemingly unbridgeable inequality in the situation of Dalits are opened up by the act of naming. By means of a theological reflection on the renewal of the heart by God’s act of grace in Christ, the author attempts to identify key markers for a homiletic theory that will be able to link the act of naming reality with the act of nurturing (rather than neglecting this named reality.

  15. Chemical identification and properties of element 112

    CERN Document Server

    Yakushev, A B; Zvára, I

    2002-01-01

    The second experiment on the chemical identification of element 112 performed at the FLNR (Dubna) is reported. Similar to the first test in 2000, the 2 mg/cm sup 2 sup n sup a sup t U target was bombarded with the 262-MeV sup 4 sup 8 Ca ions aiming at the production of sup 2 sup 8 sup 3 112, which as reported earlier decays by SF with a half-life of 3 min. The bombardment products recoiling from the target were thermalized in flowing helium and transported by the gas to detectors 25 m apart. Of all the heavy elements, the reaction products, only Hg, Rn and At were efficiently transported and thus selectively isolated. This time the beam dose was much higher (2.8 centre dot 10 sup 1 sup 8) and two different devices for detecting fission fragments and alpha particles were employed. The device used earlier was an assembly of sixteen PIPS detectors coated with Au to detect 'Hg-like' nuclides being adsorbed on Au at ambient temperature. The new one was a flow-through ionization chamber, 5000 cm sup 3 in volume, wh...

  16. Chemical Elements at High and Low Redshifts

    CERN Document Server

    Pettini, M

    2006-01-01

    The past few years have seen a steady progress in the determination of element abundances at high redshifts, with new and more accurate measures of metallicities in star-forming galaxies, in QSO absorbers, and in the intergalactic medium. We have also become more aware of the limitations of the tools at our disposal in such endeavours. I summarise these recent developments and--in tune with the theme of this meeting--consider the clues which chemical abundance studies offer to the links between the high redshift galaxy populations and today's galaxies. The new data are `fleshing out' the overall picture of element abundances at redshifts z = 2 - 3 which has been gradually coming into focus over the last decade. In particular, we can now account for at least 40% of the metals produced by the global star formation activity in the universe from the Big Bang to z = 2.5, and we have strong indications of where the remainder are likely to be found.

  17. Toxic Release Inventory Chemicals by Groupings

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Toxics Release Inventory (TRI) makes available information for more than 600 toxic chemicals that are being used, manufactured, treated, transported, or...

  18. Thermodynamic and kinetic studies of some Group III and Group V elements and alloys by solid state electrochemical techniques

    International Nuclear Information System (INIS)

    The Gibbs free energy of forming gallium sesquioxide and indium sesquioxide are measured using a CO2--CO--O2 gas reference electrode and calcia stabilized zirconia as the solid electrolyte. The free energies are: ΔG0/sub f/(β-Ga2O3(c)) equals -(265,309 +- 152) + (82.47 +- 0.16) (T/K) cal mol-1 and ΔG0/sub f/(In2O3 (c)) equals -(223,160 +- 137) + (79.47 +- 0.12) (T/K) cal mol-.1 A solid state galvanic cell is employed to measure gallium activities in Ga--Sb liquid alloys. Results show moderate negative deviations from ideality in the composition range 0.039 less than x/sub Ga/ less than 0.833. Partial molar enthalpies and entropies are calculated, and agree wih calorimetric data. Results are combined with calorimetric data to calculate the liquidus temperatures of the Ga--Sb system, which are in excellent agreement with measurements. Effect of short-range ordering is also investigated. Coulometric titration techniques are used to investigate the solubility and diffusivity of oxygen in liquid indium. Dissolved atomic oxygen is found to follow Henry's law and a saturation solubility of x0/sup sat/ equals 3.3 x 10-3 is determined at 9080K. From a galvanostatic response of an indium electrode, an oxygen diffusivity of 2.2 x 10-6 cm2 s-1 is found, in good agreement with other available data

  19. Replacement names and nomenclatural comments for problematic species-group names in Europe's Neogene freshwater Gastropoda. Part 2

    Directory of Open Access Journals (Sweden)

    Thomas Neubauer

    2014-07-01

    Full Text Available In the course of a new database project on Miocene to Recent freshwater gastropods of Europe, a great many of primary and secondary homonyms were revealed. Such nomenclatural issues need clarification in order to avoid misunderstandings and wrong statements about geographical distributions and temporal ranges. The following 16 new names are introduced to replace existing homonyms: Theodoxus militaris jurisicpolsakae nom. n., Viviparus stevanovici nom. n., Melanopsis haueri ripanjensis nom. n., Melanopsis wolfgangfischeri nom. n., Micromelania ramacanensis nom. n., Pseudamnicola welterschultesi nom. n., Muellerpalia haszprunari nom. n., Muellerpalia pseudovalvatoides nom. n., Lithoglyphus gozhiki nom. n., Valvata heidemariae willmanni nom. n., Radix macaleti nom. n., Gyraulus okrugljakensis nom. n., Gyraulus rasseri nom. n., Gyraulus vrapceanus nom. n., Planorbarius halavatsi nom. n., and Segmentina mosbachensis nom. n. Additionally, six cases of homonyms are discussed that are not replaced by new names, because they are considered junior synonyms.

  20. Formation of intermetallic compound at interface between rare earth elements and ferritic-martensitic steel by fuel cladding chemical interaction

    Institute of Scientific and Technical Information of China (English)

    Jun Hwan Kim; Byoung Oon Lee; Chan Bock Lee; Seung Hyun Jee; Young Soo Yoon

    2012-01-01

    The intermetallic compounds formation at interface between rare earth elements and clad material were investigated to demonstrate the effects of rare earth elements on fuel-cladding chemical interaction (FCCI) behavior.Mischmetal (70Ce-30La) and Nd were prepared as rare earth elements.Diffusion couple testing was performed on the rare earth elements and cladding (9Cr2W steel) near the operation temperature of(sodium-cooled fast reactor) SFR fuel.The performance of a diffusion barrier consisting of Zr and V metallic foil against the rare earth elements was also evaluated.Our results showed that Ce and Nd in the rare earth elements and Fe in the clad material interdiffused and reacted to form intermetallic species according to the parabolic rate law,describing the migration of the rare earth element.The diffusion of Fe limited the reaction progress such that the entire process was governed by the cubic rate law.Rare earth materials could be used as a surrogate for high burnup metallic fuels,and the performance of the barrier material was demonstrated to be effective.

  1. On the maximally clustered elements of Coxeter groups

    OpenAIRE

    Green, R M.

    2007-01-01

    We continue the study of the maximally clustered elements for simply laced Coxeter groups which were recently introduced by Losonczy. Such elements include as a special case the freely braided elements of Losonczy and the author, which in turn constitute a superset of the $iji$-avoiding elements of Fan. Our main result is to classify the MC-finite Coxeter groups, namely those Coxeter groups having finitely many maximally clustered elements. Remarkably, any simply laced Coxeter group having fi...

  2. Effects of responding to a name and group call on preschoolers' compliance.

    Science.gov (United States)

    Beaulieu, Lauren; Hanley, Gregory P; Roberson, Aleasha A

    2012-01-01

    We assessed teacher-child relations with respect to children's name calls, instructions, and compliance in a preschool classroom. The most frequent consequence to a child's name being called was the provision of instructions. We also observed a higher probability of compliance when children attended to a name call. Next, we evaluated the effects of teaching preschoolers to attend to their names and a group call on their compliance with typical instructions. We used a multiple baseline design across subjects and a control-group design to evaluate whether gains in compliance were a function of treatment or routine experience in preschool. Results showed that compliance increased as a function of teaching precursors for all children in the experimental group, and the effects on compliance were maintained despite a reduction of the occurrence of precursors. Moreover, it appeared that precursor teaching, not routine preschool experience, was responsible for the changes in compliance. PMID:23322926

  3. 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...

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

  6. Structure and Ionic Conductivity of Halocomplexes of Main Group Metallic Elements Studied by NMR and NQR

    International Nuclear Information System (INIS)

    Li3InBr6 undergoes phase transition to a lithium superionic conductor at Ttr = 314 K (σ = 5.0 x 10-4 S cm-1 at 330 K). The Rietveld analysis and the DSC measurement suggested that the positional disorder is introduced at the cationic sites above Ttr. The X-ray powder diffraction pattern at the superionic phase changes gradually with temperature and finally shows a simple powder pattern at 420 K which is quite similar to that of LiBr. This rock salt structure contains intrinsic vacancies because one In3+ and two vacancies substitute for three Li+. 7Li and 115In NMR support the rapid diffusion of the Li+ and the introduction of the In3+ into the rock salt structure. On the other hand, the ionic conductivity for Na3InCl6 was 10-5 S cm-1 even at 500 K. Conduction path for the sodium ions could be proposed by means of the Rietveld analysis and the NMR experiment using a single crystal.

  7. Steacyite, a new name, and a re-evaluation of the nomenclature of 'ekanite'-group minerals

    International Nuclear Information System (INIS)

    Ekanite from the type locality (Sri Lanka), ThCa2Si8O20, is metamict and gives only a very poor Debye-Scherrer diagram; heated Sri Lanka ekanite is body-centred tetragonal, with a 7.46, c 14.96 A. Natural ekanite from the Tombstone Mountains, Yukon Territory (Symanski et al. 1982) has the same chemical composition and gives a powder pattern that matches that of heated ekanite from Sri Lanka. The crystal structure of ekanite is characterized by Si8O20 sheets, space group I422, a 7.483(3), c 14.893(6) A. Steacyite corresponds to Th(Na,Ca)sub(2)(Ksub(1-) blocksub(z))Sisub(8)0sub(20), z = 0.39, described by Perrault β Richard (1973) under the name 'ekanite'. The crystal structure of steacyite is characterized by discrete pseudocubic arrangments of Si8O20, space group P4/mcc, a 7.58(1), c 14.77(2) A, Z=2. Powder diagrams of ekanite and steacyite show significant diffrences. A Th-Ca-K silicate from central Asia was described by Ginzburg et al. (1965) under the name 'ekanite'; it corresponds to Th(Ca,Na)sub( 2)(Ksub(1-z)blocksub(z)) Sisub(8)Osub(20) with z between 0.23 and 0.40. Space group, cell dimensions and powder pattern are essentially identical to those of steacyite; this mineral should receive a name other than ekanite. These two minerals may define a continuous series. The name honours H.R. Steacy of the Geological Survey of Canada. Iraqite (Livingston et al. 1976) gives a powder pattern identical to that of steacyite and is presumed isotructural. It corresponds to (RE,Th)Casub(2)(Ksub(1-z)blocksub(z)) Sisub(8)0sub(20), with z = 0.47

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

    International Nuclear Information System (INIS)

    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)

  9. Incorporating domain knowledge in chemical and biomedical named entity recognition with word representations

    OpenAIRE

    Munkhdalai, Tsendsuren; Li, Meijing; Batsuren, Khuyagbaatar; Park, Hyeon Ah; Choi, Nak Hyeon; Ryu, Keun Ho

    2015-01-01

    Background Chemical and biomedical Named Entity Recognition (NER) is an essential prerequisite task before effective text mining can begin for biochemical-text data. Exploiting unlabeled text data to leverage system performance has been an active and challenging research topic in text mining due to the recent growth in the amount of biomedical literature. We present a semi-supervised learning method that efficiently exploits unlabeled data in order to incorporate domain knowledge into a named...

  10. Judy Riffle named American Chemical Society Fellow

    OpenAIRE

    Doss, Catherine

    2010-01-01

    Judy S. Riffle, professor of chemistry and director of Virginia Tech's interdisciplinary Macromolecular Science and Engineering Ph.D. education program, has been named a Fellow of the American Chemical Society.

  11. Chemistry union unveils names of four new elements

    Science.gov (United States)

    Johnston, Hamish

    2016-07-01

    The periodic table could soon be graced by four new symbols – Nh, Mc, Ts and Og – after the International Union of Pure and Applied Chemistry (IUPAC) unveiled its proposed names for the four most recently discovered elements.

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

    International Nuclear Information System (INIS)

    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 7pl/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

  13. Analytical quality control of chemical element contents in human hair determined by INAA, ICP-ES and ICP-MS

    International Nuclear Information System (INIS)

    Full text: Human hair analysis is often used in studies of exposure of such elements as As, Hg, Pb, Cd and in estimation of nutritional status of many chemical elements too. Estimation of precision and accuracy of analytical determination or chemical element contents in human hair samples by combination of four methods: 1) instrumental neutron activation analysis with registration ol short-lived radionuclides radiations (INAA-SL), 2) instrumental neutron activation analysis with using long-lived radionuclides (INAA-LL), 3) atomic emission spectrometry and 4) mass-spectrometry with inductively coupled plasma (ICP-AES and ICP-MS respectively) was made using certified reference materials (CRM) NIES No 13 (human hair, Japan) and GBW09101 (human hair, China) as the subject. For estimation of repeatability of the results 10 samples weighting around 50 mg were Measured by one sample per one labor shift during 10 labor shifts. Two operators carried out the measurements alternately. It was shown that no less than 38 elements were available for analysis in human hair samples by INAA: Ag, As, Au, Ba, Br, Ca, Cd, Ce, Cl, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, I, K, La, Lu, Mg, Mn, Na, Nd, Rb, S, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Tm, Yb, Zn. For ICP-AES coupled with ICP-MS the maximum available elements were 40: Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Ge, Hg, I, K, La, Li, Mg, Mn, Mo, Ni, P, Pb, Pt, Rb, Sb, Se, Si, Sn, Sr, Ti, Tl, V, W, Zn, Zr. All together the complex of four methods allow detect in human hair 58 different elements: Ag, Al, As, Au, B, Ba, Be, Bi, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Cs, Eu, Fe, Ga, Gd, Ge, Hf, Hg, I, K, La, Li, Lu, Mg, Mn, Mo, Na, Nd, Ni, P, Pb, Pt, Rb, S, Sb, Sc, Se, Si, Sm, Sn, Sr, Ta, Tb, Th, Ti, Tl, Tm, V, W, Yb, Zn, and Zr. However: 1) INAA-SL of single sample with relative uncertainty (determined as ±2 RSD) less than ±10% allows to estimate mass fractions of no one element; within range from ±10% to <±20% - only Cl; within range

  14. Family-Group Names In Coleoptera (Insecta

    Directory of Open Access Journals (Sweden)

    Patrice Bouchard

    2011-04-01

    Full Text Available We synthesize data on all known extant and fossil Coleoptera family-group names for the first time. A catalogue of 4887 family-group names (124 fossil, 4763 extant based on 4707 distinct genera in Coleoptera is given. A total of 4492 names are available, 183 of which are permanently invalid because they are based on a preoccupied or a suppressed type genus. Names are listed in a classification framework. We recognize as valid 24 superfamilies, 211 families, 541 subfamilies, 1663 tribes and 740 subtribes. For each name, the original spelling, author, year of publication, page number, correct stem and type genus are included. The original spelling and availability of each name were checked from primary literature. A list of necessary changes due to Priority and Homonymy problems, and actions taken, is given. Current usage of names was conserved, whenever possible, to promote stability of the classification. New synonymies (family-group names followed by genus-group names: Agronomina Gistel, 1848 syn. n. of Amarina Zimmermann, 1832 (Carabidae, Hylepnigalioini Gistel, 1856 syn. n. of Melandryini Leach, 1815 (Melandryidae, Polycystophoridae Gistel, 1856 syn. n. of Malachiinae Fleming, 1821 (Melyridae, Sclerasteinae Gistel, 1856 syn. n. of Ptilininae Shuckard, 1839 (Ptinidae, Phloeonomini Ádám, 2001 syn. n. of Omaliini MacLeay, 1825 (Staphylinidae, Sepedophilini Ádám, 2001 syn. n. of Tachyporini MacLeay, 1825 (Staphylinidae, Phibalini Gistel, 1856 syn. n. of Cteniopodini Solier, 1835 (Tenebrionidae; Agronoma Gistel 1848 (type species Carabus familiaris Duftschmid, 1812, designated herein syn. n. of Amara Bonelli, 1810 (Carabidae, Hylepnigalio Gistel, 1856 (type species Chrysomela caraboides Linnaeus, 1760, by monotypy syn. n. of Melandrya Fabricius, 1801 (Melandryidae, Polycystophorus Gistel, 1856 (type species Cantharis aeneus Linnaeus, 1758, designated herein syn. n. of Malachius Fabricius, 1775 (Melyridae, Sclerastes Gistel, 1856 (type species

  15. The elements Church, Kirk and Kir(kby in English place-names and their distribution

    Directory of Open Access Journals (Sweden)

    Toshiko Yamaguchi

    1997-12-01

    Full Text Available From the linguistic point of view, English place-names are rather heterogeneous material. This heterogeneity finds its explanation in the various relationships between different peoples of differing linguistic background who came to the British Isles and settled there. The linguistic formations of the place-names and their distribution often offer a clue as to how this heterogeneity has been formed, i. e. how various may have been the human contact of the peoples in a new land. The place-names containing church, kirk and kir(kby will be, like many other names, plain indicators of such English and Scandinavian interrelations.

  16. The origins of light and heavy r-process elements identified by chemical tagging of metal-poor stars

    CERN Document Server

    Tsujimoto, Takuji

    2014-01-01

    Growing interests in neutron star (NS) mergers as the origin of r-process elements have sprouted since the discovery of evidence for the ejection of these elements from a short-duration gamma-ray burst. The hypothesis of a NS merger origin is reinforced by a theoretical update of nucleosynthesis in NS mergers successful in yielding r-process nuclides with A>130. On the other hand, whether the origin of light r-process elements are associated with nucleosynthesis in NS merger events remains unclear. We find a signature of nucleosynthesis in NS mergers from peculiar chemical abundances of stars belonging to the Galactic globular cluster M15. This finding combined with the recent nucleosynthesis results implies a potential diversity of nucleosynthesis in NS mergers. Based on these considerations, we are successful in the interpretation of an observed correlation between [light r-process/Eu] and [Eu/Fe] among Galactic halo stars and accordingly narrow down the role of supernova nucleosynthesis in the r-process pr...

  17. Chemical characterization of bohrium (element 107)

    Science.gov (United States)

    Eichler; Bruchle; Dressler; Dullmann; Eichler; Gaggeler; Gregorich; Hoffman; Hubener; Jost; Kirbach; Laue; Lavanchy; Nitsche; Patin; Piguet; Schadel; Shaughnessy; Strellis; Taut; Tobler; Tsyganov; Turler; Vahle; Wilk; Yakushev

    2000-09-01

    The arrangement of the chemical elements in the periodic table highlights resemblances in chemical properties, which reflect the elements' electronic structure. For the heaviest elements, however, deviations in the periodicity of chemical properties are expected: electrons in orbitals with a high probability density near the nucleus are accelerated by the large nuclear charges to relativistic velocities, which increase their binding energies and cause orbital contraction. This leads to more efficient screening of the nuclear charge and corresponding destabilization of the outer d and f orbitals: it is these changes that can give rise to unexpected chemical properties. The synthesis of increasingly heavy elements, now including that of elements 114, 116 and 118, allows the investigation of this effect, provided sufficiently long-lived isotopes for chemical characterization are available. In the case of elements 104 and 105, for example, relativistic effects interrupt characteristic trends in the chemical properties of the elements constituting the corresponding columns of the periodic table, whereas element 106 behaves in accordance with the expected periodicity. Here we report the chemical separation and characterization of six atoms of element 107 (bohrium, Bh), in the form of its oxychloride. We find that this compound is less volatile than the oxychlorides of the lighter elements of group VII, thus confirming relativistic calculations that predict the behaviour of bohrium, like that of element 106, to coincide with that expected on the basis of its position in the periodic table. PMID:10993071

  18. Chemical characterization of bohrium (element 107)

    Science.gov (United States)

    Eichler, R.; Brüchle, W.; Dressler, R.; Düllmann, Ch. E.; Eichler, B.; Gäggeler, H. W.; Gregorich, K. E.; Hoffman, D. C.; Hübener, S.; Jost, D. T.; Kirbach, U. W.; Laue, C. A.; Lavanchy, V. M.; Nitsche, H.; Patin, J. B.; Piguet, D.; Schädel, M.; Shaughnessy, D. A.; Strellis, D. A.; Taut, S.; Tobler, L.; Tsyganov, Y. S.; Türler, A.; Vahle, A.; WiIk, P. A.; Yakushev, A. B.

    2000-09-01

    The arrangement of the chemical elements in the periodic table highlights resemblances in chemical properties, which reflect the elements' electronic structure. For the heaviest elements, however, deviations in the periodicity of chemical properties are expected: electrons in orbitals with a high probability density near the nucleus are accelerated by the large nuclear charges to relativistic velocities, which increase their binding energies and cause orbital contraction. This leads to more efficient screening of the nuclear charge and corresponding destabilization of the outer d and f orbitals: it is these changes that can give rise to unexpected chemical properties. The synthesis of increasingly heavy elements, now including that of elements 114, 116 and 118, allows the investigation of this effect, provided sufficiently long-lived isotopes for chemical characterization are available. In the case of elements 104 and 105, for example, relativistic effects interrupt characteristic trends in the chemical properties of the elements constituting the corresponding columns of the periodic table, whereas element 106 behaves in accordance with the expected periodicity. Here we report the chemical separation and characterization of six atoms of element 107 (bohrium, Bh), in the form of its oxychloride. We find that this compound is less volatile than the oxychlorides of the lighter elements of group VII, thus confirming relativistic calculations that predict the behaviour of bohrium, like that of element 106, to coincide with that expected on the basis of its position in the periodic table.

  19. Provenance determination of copper artefacts by the application of platinum group element and lead isotope geochemistry to the corrosion products

    International Nuclear Information System (INIS)

    Metal core and corrosion rind from four corroded copper artefacts from Tell Ahmar in Syria were analysed for PGE - platinum group elements (Pd, Pt, Ir and Ru) and gold via NiS fire assay preconcentration radiochemical neutron activation analysis (RNAA) and for Pb isotopes via thermal ionisation mass spectrometry (TIMS). The Pb isotopic signature was indistinguishable for all four samples, suggesting that the copper used came from a single ore deposit in Cyprus. The Pb isotopic signature for the Tell Ahmar artefacts and their associated corrosion products range between 2.075 to 2.085 208-Pb/206-Pb and 0.833 to 0.846 207-Pb/206-Pb, while the Cypriot Pb isotope field ranges between 2.067 to 2.085 208-Pb/206-Pb and 0.833 to 0.847 207-Pb/206-Pb. The data suggests that the corrosion products of an artefact can be used to identify the source ore deposit as both the metal and associated corrosion have the same or similar Pb isotopic signature. Additionally, synthetic artefacts were produced by smelting examples of Australian orebodies and artificially corroding them in order to determine whether selected geochemical elements, ratios and isotopes could be used as tracers in provenance studies. In particular the platinum group metals, gold, silver, cobalt and nickel in the ore, smelted copper produced from the ore, and the associated corrosion were determined. The PGEs were selected for trace element studies because, although they are only present in the parts per trillion to parts per billion range in copper ores, they are chalcophile and spatially and petrologically associated with copper minerals in most ore deposits. During smelting to produce the copper, the PGEs do not fractionate and so follow the copper into the melt. Gold, silver, cobalt and nickel, like the PGEs, also partition strongly into the melt, regardless of smelting method. Preliminary investigations suggest that chondrite normalised PGE patterns, coupled with Pb isotopic ratios and base metal data, may be

  20. Search for new chemical elements and possibilities to synthesize transactinide isotopes for chemical studies

    International Nuclear Information System (INIS)

    Elements up to Z=112 as well as 114 and 116 are officially recognized as discovered and have been named. The current literature contains reports about the synthesis of all elements up to Z=118, meaning that more than 10% of all elements are members of the transactinide series with Z=104-118. Therefore, search experiments for the new elements with Z=119 and Z=120 have been performed. An important question for such experiments concerns the optimum choice of the nuclear reaction. While only one experiment has been conducted so far with the aim of discovering Z=119, already four experiments on the synthesis of Z=120 have been performed, all employing different reactions. Still, Z=119 and 120 are not yet announced as discovered. The situation using the TASCA experiments as an example and the perspectives for the discovery of new elements are studied. The optimum reactions leading to the relatively long-lived isotopes of the transactinides as they are frequently used in chemical studies of these elements, including elements which were not studied chemically to date are discussed

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

    International Nuclear Information System (INIS)

    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

  2. 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

  3. Research on separation and extraction technology of the light element isotopes by the chemical exchange process

    International Nuclear Information System (INIS)

    It was clarified that the separation coefficient became 1.036, and succeeded in the development of the new, efficient lithium separator (Sodium Super-Ionic Conductor: NASICON) which is the elution liquid in the acid processed phosphate system for the lithium isotope separation technology. NASICON can be used in the column for the isotope separation, repeatedly if the nitric acid is used for the elution liquid and the hydroxide lithium or the acetic acid lithium solution as an adsorption solution of the lithium. Furthermore, the separation coefficient of 1.029 was obtained using the glucamine resin of the ester system for the boron isotope separation technology. (H. Katsuta)

  4. Some features of group separation process of transplutonium and rare earth elements by extraction with HDEHP from solutions containing DTPA

    International Nuclear Information System (INIS)

    The effect of concentration of separable elements in case of transplutonium and rare earth elements extraction with di-2-ethylhexylphosphoric acid (D2EHPA) from solutions containing diethylenetriaminepentaacetic acid (DTPA) on their distribution coefficients and separation at a relatively low concentration of the extracting agent (0.2-0.5 mol/l) and complexon (0.01-0.1 mol/l) is studied. It is shown that the changes in metal distribution at the change of its concentration to a great extent is determined by the distribution coefficient (DC) of the element microamounts. In case of small DC values the increase of metal concentration decreases the equilibrium complexon concentration. This causes the increase of DC metal. At high DC values dominates the effect of the decrease of extracting agent equilibrium concentration which results in the DC decrease. Another peculiarity of the studied system is slow attainment of transplutonium and rare earth elements extraction equilibrium. The process rate depends on the intensity of mixing solutions reagent concentration and admixtures. With the increase of DTPA concentration and pH-value of solution the process rate constantly decreases. Introduction of citric or other carbonic acids in the system permits to accelerate the mass exchange. With increase of atomic number of the distributable element in the RE and TPE series the process rate constantly decreacses. Approximate relations reflecting the effect of the studied factors have been found, the program of coefficients of computerized distribution is developed

  5. Determination of OH groups by wet chemical methods

    Czech Academy of Sciences Publication Activity Database

    Kuráň, P.; Janoš, P.; Madronová, L.; Novák, František

    New York : Nova Science Publisher, 2011 - (Madronová, L.), s. 47-60 ISBN 978-1-61668-965-0. - (Chemistry Research and Applications) Institutional research plan: CEZ:AV0Z60660521 Keywords : determination * OH groups * wet chemical methods Subject RIV: CB - Analytical Chemistry, Separation

  6. Swayed by the Logo and Name: Does University Branding Work?

    Science.gov (United States)

    Idris, Muhammad Zaffwan; Whitfield, T. W. Allan

    2014-01-01

    Over the last decade, many universities attempted to improve their public image by changing their corporate visual identity (CVI) and/or name. Despite the prevalence of such practices, little research has been conducted into their effectiveness. The research reported here focused upon one facet of the higher education branding debate, that of the…

  7. ACCUMULATION OF CHEMICAL ELEMENTS BY ORGANS OF SPARGANIUM ERECTUM L. AND THEIR POTENTIAL USE IN PHYTOREMEDIATION PROCESS

    Directory of Open Access Journals (Sweden)

    Agnieszka Edyta Parzych

    2016-01-01

    Full Text Available The study of bottom sediments and organs of Sparganium erectum carried out in the summer of 2014 in the city of Lębork, located in Northern Poland. The aim of this study was to evaluate the content of macroelements and heavy metals in the leaves, rhizomes and roots S. erectum and in bottom sediments of the Łeba River as well as comparison of accumulation and translocation factors of N, P, K, Mg, Ca, Zn, Ni, Cu, Mn, Fe, Cd and Cr in researched organs of aquatic plant. The use of S. erectum for biomonitoring and phytoremediation has also been considered. The results of Mann Whitney U test showed a number of statistically significant differences in the content of chemical elements in the leaves, rhizomes, roots and in bottom sediments. The macroelements are mainly accumulated in leaves and heavy metals are accumulated in roots and rhizomes of S. erectum. Increased Mn and Fe content in roots and rhizomes of S. erectum, in relation this physiological needs, refers to the beneficial effects of this species in the water treatment and sludge from the bottom sediment of manganese and iron compounds. The obtained bioconcentration and translocation factors values allowed to state that S. erectum can be used for phytoremediation of contaminated bottom sediments because retains metals in their roots and limit Mn and Fe mobility from roots and rhizomes to leaves once absorbed by roots of plant.

  8. Synthesis of the heaviest chemical elements - results and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, G.

    1988-11-01

    All 17 artificially produced elements heavier than uranium were discovered by nuclear-chemical synthesis. The three heaviest ones - elements 107, 108 and 109 - were snythesized at the heavy-ion accelerator UNILAC in Darmstadt by nuclear fusion from the heaviest stable nuclei, lead-208 and bismuth-209, and the most neutron-rich stable isotopes of chromium and iron: element 107 from bismuth-209 (atomic number Z=83) and chromium-54 (Z=24), element 108 from lead-208 (Z=82) and iron-58 (Z=26), and element 109 from bismuth-209 and iron-58. The first isotopes detected were those with mass numbers 262 (Z=107), 265 (Z=108) and 266 (Z=109); these nuclei are short-lived ed -emitters with half-lives of 8.2 ms, 1.8 ms and 3.4 ms, respectively. The yields of these reactions are extremely small; only three atoms of element 109 have ever been observed. Experiments to synthesize element 110 have given ambiguous results. All attempts to detect the 'superheavy' elements with proton numbers near Z=114 and neutron numbers near N=184 have thus far failed. These elements have been predicted theoretically, and many attempts to synthesize them have been made, e.g. at UNILAC by fusion of calcium-48 (Z=20) with curium-248 (Z=96), or by transference of protons in the collision of two very heavy nuclei such as uranium-238 (Z=92). Surprisingly, the heaviest known nuclei are far more stable toward spontaneous fission into two fragments than was expected, but their synthesis is strongly hindered - much more than was initially anticipated. It is this hindrance rather than the decreasing nuclear stability which seems to presently limit the extent of the periodic table: even heavier elements should be able to exist, but no way has yet been found to produce them.

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

    Science.gov (United States)

    Houtkamp, Roos; Roelfsema, Pieter R.

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Selig, W.

    1977-11-08

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    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

  13. 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.

  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 properties of element 106 (seaborgium)

    International Nuclear Information System (INIS)

    The synthesis, via nuclear fusion reactions, of elements heavier than the actinides, allows one to prove the limits of the periodic table as a means of classifying the elements. In particular, deviations in the periodicity of chemical properties for the heaviest elements are predicted as a consequence of increasingly strong relativistic effects on the electronic shell structure. The transactinide elements have now been extended up to element 112, but the chemical properties have been investigated only for the first two of the transactinide elements, 104 and 105. Those studies showed that relativistic effect render these two elements chemically different from their lighter homologues in the same columns of the periodic table. Here we report the chemical separation of element 106 (seaborgium, Sg) and investigations of its chemical behaviour in the gas phase and in aqueous solution. The methods that we use are able to probe the reactivity of individual atoms, and are based on the detection of just seven atoms of seaborgium we find that it exhibits properties characteristic of the group 6 homologues molybdenum and tungsten. Thus seaborgium appears to restore the trends of the periodic table disrupted by relativistic effects in elements 104 and 105. (Author)

  16. Measurements of radon and chemical elements: Popocatepetl volcano

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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

  18. The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, S.; Plimer, I. R. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs.

  19. The platinum group elements and gold: analysis by radiochemical and instrumental neutron activation analysis and relevance to geological exploration and related problems

    International Nuclear Information System (INIS)

    This paper presents an overview of research conducted with the support of the Australian Institute of Nuclear Science and Engineering, at the University of Melbourne, School of Earth Sciences, Radiochemical Neutron Activation Laboratory. The primary objective of this research is to realize the high potential of the platinum group elements (PGE) and gold to the solution of petrogenetic problems, the study of magma generation and magmatic processes in mafic/ultramafic rock suites, as tracers in hydrothermal ore formation. The PGEs (Os, Ru, Ir, Pt, Pd and Rh) are among the least abundant of all elements on earth with unique properties such as high melting points, high electrical and thermal conductivity, high density, strength and toughness as alloys. They exhibit both siderophile and chalcophile characteristics and are valuable tools in providing information about magmatic processes, in particular S-saturation, as well as crystal fractionation trends. Two distinct groups of PGEs are discerned; the IPGEs (Ru, Os, Ir) and the PPGEs (Pt, Pd, Rh, Au) on the basis of their behaviour during fractionation processes. Using chondrite normalized PGE patterns it is possible to distinguish between sulphides that segregated from primitive magmas, such as komatiites, and sulphides which segregated from more fractionated magmas, such as tholeiites. It is critical to the understanding of these processes to be able to analyse key elements, such as the PGE and gold, in the parts per billion to parts per trillion range. Platinum group elements and Au were determined by radiochemical neutron activation analysis using a modified NiS fire-assay preconcentration technique, adapted from procedures first used by Robert, R.V. D. and van Wyk, E. (1975) . Detection limits are generally 0.005-0.01 ppb (Au and Ir), 0.1-0.2 ppb (Pd and Pt), and 0.1-0.5 ppb for Ru. 9 refs

  20. 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)

    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)

  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. 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.

    OpenAIRE

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

    2014-01-01

    Background 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 sample...

  3. Determination of trace and platinum-group elements in high ionic-strength volcanic fluids by sector-field inductively coupled plasma mass spectrometry (ICP-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, T.P.; O`Day, P.A. [Arizona State Univ., Tempe, AZ (United States). Dept. of Geology; Shuttleworth, S. [Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130 (United States)

    1998-11-01

    The accurate measurement of ultra-trace concentrations of rare metals and platinum group elements in volcanic fluids is complicated by interferences, complex matrices, and preferential element partitioning. We analyzed condensed, high-temperature magmatic fluids collected from Kudryavy volcano (Kurile Islands, Russia) for Be, B, Rb, Sr, Mo, Ru, Rh, Pd, Cd, W, Re, Pt, Pb, Bi, and U using ICP-MS. The samples had three different matrices: 5 mol L{sup -1} sodium hydroxide (NaOH, pH = 11), gas condensates of sulfuric acid (H{sub 2}SO{sub 4}, pH = 0), and solid elemental sulfur. Interferences and suppression/enhancement effects were investigated using standards in concentrated NaOH and H{sub 2}SO{sub 4} solutions to determine adequate dilution for sample analyses, which then required very low levels of element detection (< 1 {mu}g L{sup -1} for most elements). Depending on the field sampling technique of volcanic gas vents, our results show significant differences in concentrations of some trace elements due to the precipitation of solid sulfur during gas condensation and variations in element volatility as a function of temperature. (orig.) With 4 figs., 9 tabs., 15 refs.

  4. Lab Astro and the Origins of the Chemical Elements

    Science.gov (United States)

    Lawler, James E.

    2010-03-01

    Interpretation of the spectra of metal-poor Galactic halo stars is dependent on AMO laboratory data [1,2]. Metal-poor Galactic halo stars were born when the Milky Way was young and they provide a record of the chemical evolution of the Galaxy. Elements heavier than iron are produced via r(apid)-process and s(low)-process n(eutron)-capture mechanisms. The s-process mechanism, which occurs in certain AGB stars, is relatively well understood. The explosive r-process is not well understood. The r-process n-capture mechanism was dominant early in the Galaxy's history [3]. New large aperture telescopes make it possible to record high-resolution spectra with high signal-to-noise ratios on a growing number of metal-poor stars. In addition to mapping the chemical evolution of the Galaxy, these studies are yielding an increasingly well-defined r-process elemental abundance pattern which constrains models of r-process nucleosynthesis [1]. The next phase of this ongoing research will address challenges in modeling stellar photospheres. Peculiar trends in abundances of specific Fe-group elements as a function of stellar age or metallicity may be due to limitations in traditional one dimensional (1d) local thermodynamic equilibrium (LTE) models of stellar photospheres or may be due to poorly understood nucleosynthesis [4]. Efforts are now underway to test the Saha or ionization equilibrium in a variety of stellar atmospheres for several Fe-group elements using the best available spectroscopic data for selected transitions. More comprehensive spectroscopic data of improved accuracy and accurate collisional data, especially for inelastic collisions of H atoms with metal atoms and ions, will be needed to fully develop 3d/non-LTE models of photospheres [e.g. 5]. [4pt] [1] C. Sneden, J. E. Lawler, J. J. Cowan, I. I. Ivans, and E. A. Den Hartog, Astrophys. J. Suppl. Ser. 182, 80-96 (2009). [0pt] [2] J. E. Lawler, C. Sneden, J. J. Cowan, I. I. Ivans, and E. A. Den Hartog, Astrophys. J

  5. Correlation Between Chemical Element Contents in Tree Rings and Soils

    Institute of Scientific and Technical Information of China (English)

    QIANJUN-LONG; KESHAN-ZHE; 等

    1993-01-01

    The annual growth rings of ten trees and the soils near the tree roots were sampled from the mining ares of lead-and zinc-dominant metals in the Xixia Mountain,Nanjing,for the determination of chemical element contents.The study results showed that the elemental contents in the tree rings were correlated with those in the soils,i.e.,the elemental contents in the tree rings increased with those in the soils,even in the cases of different environments and different tree species.Therefore,a time-concentration sequence could be set up on the basis of determining the elemental contents in the successive annual growth rings of trees to qualitatively reflect the annual variations of relevant elements in the soils,and a time-concentration sequence of elemental contents in soils could also be established in terms of related model to reproduce the dynamic changes of the surroundings.

  6. Enhancing of chemical compound and drug name recognition using representative tag scheme and fine-grained tokenization

    OpenAIRE

    Dai, Hong-Jie; Lai, Po-Ting; Chang, Yung-Chun; Tsai, Richard Tzong-Han

    2015-01-01

    Background The functions of chemical compounds and drugs that affect biological processes and their particular effect on the onset and treatment of diseases have attracted increasing interest with the advancement of research in the life sciences. To extract knowledge from the extensive literatures on such compounds and drugs, the organizers of BioCreative IV administered the CHEMical Compound and Drug Named Entity Recognition (CHEMDNER) task to establish a standard dataset for evaluating stat...

  7. Platinum group elements in mantle melts and mantle samples

    Science.gov (United States)

    Barnes, Stephen J.; Mungall, James E.; Maier, Wolfgang D.

    2015-09-01

    A large data compilation has been assembled of platinum group element (PGE) analyses in mantle melts and mantle rocks, the latter including an assortment of xenoliths and obducted mantle massifs. The degree of correlation has been investigated among the PGEs and with other major element variables such as Al2O3, TiO2 and Mg number, and the results are considered in the context of the current paradigm for the behaviour of highly siderophile elements in the silicate Earth. Primitive mantle melts have a wide range of PGE contents. Komatiites have the highest abundances of all the PGEs, show the strongest correlations between Pt and Rh, Pt and Pd and between the iridium-group PGEs Ir, Ru and Os (IPGEs). Most basalts of all affinities have lower levels of Pt and Pd and much lower levels of Ir, Ru and Os than komatiites. Within the basalt grouping Rh has stronger affinities with the IPGEs. Picrites and Archaean basalts are intermediate between these two groups. MORBs and a small proportion of continental LIP basalts show strong depletions in all PGEs attributable to retention of sulfide in their mantle source rocks, or sulfide liquid fractionation on ascent. The degree of PGE depletion in other basalts is probably attributable to equilibration with sulfide, but is less than would be expected under conventional models of sulfide extraction, and is instead attributed to mixing of magmas generated at variable depths incorporating both sulfide-saturated and undersaturated components. Basalts with Pt and Pd contents higher than typical komatiites are rare, a notable example being B1-type parent magmas to the Bushveld Complex, which have komatiite-like relative PGE abundances and Pt, Pd and Rh abundances up to a factor of two higher than komatiites for comparable Ti contents. The mantle composition array as a whole is characterized by variable degrees of depletion of Pt, Pd and Rh in Al-poor, melt-depleted harzburgite/dunite lithologies; lack of depletion in these elements in

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

    International Nuclear Information System (INIS)

    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)

  9. 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)

  10. Re-187 Os-187 Isotopic and Highly Siderophile Element Systematics of Group IVB Irons

    Science.gov (United States)

    Honesto, J.; McDonough, W. F.; Walker, R. J.; McCoy, T. J.; Ash, R. D.

    2005-01-01

    Study of the magmatic iron meteorite groups permits constraints to be placed on the chemical and isotopic composition of parent bodies, and the timing of, and crystal-liquid fractionation processes involved in the crystallization of asteroidal cores. Here we examine Re-Os isotopic and trace elemental systematics of group IVB irons. Compared to most irons, the irons comprising this group are enriched in some of the most refractory siderophile elements, yet highly-depleted in most volatile siderophile elements. These characteristics have been attributed to processes such as high temperature condensation of precursor materials and oxidation in the parent body. Most recently it has been suggested that both processes may be involved in the chemical complexity of the group. Here, high precision isotopic and highly siderophile element (HSE) concentrations are used to further examine these possible origins, and the crystallization history of the group. In addition, we have begun to assess the possibility of relating certain ungrouped irons with major groups via multi-element, trace element modeling. In a companion abstract, the isotopic and trace element systematics of the ungrouped iron Tishomingo are compared with the IVB irons.

  11. Broadening and shift of the intercombination spectral line of the second group elements (Hg, Cd and Zn) perturbed by inert gases

    International Nuclear Information System (INIS)

    The Van der Waals and Lennard - Jones potential parameters for the ground and exited states of the second group elements (Hg, Cd and Zn) perturbed by inert gases (Xe, Kr, Ar, Ne and He) have been calculated using coulomb approximation. The basis of the Lindholm -Foley impact theory and the calculated potential parameters are used for calculating the collision broadening and shift coefficients β and δ for the intercombination lines 253.7, 326.1 and 307.6 nm of Hg, Cd and Zn atoms respectively when they are colliding with inert gas atoms . The calculating coefficients of β and δ are compared with their corresponding experimental values, taken from literatures

  12. Flow-by-flow chemical stratigraphy and evolution of thirteen Serra Geral Group basalt flows from Vista Alegre, southernmost Brazil

    Directory of Open Access Journals (Sweden)

    Viter M Pinto

    2011-06-01

    Full Text Available The geochemical characterization of thirteen Serra Geral Group flows in the Vista Alegre region (RS-SC, southern Brazil, displays the homogeneous basaltic composition near 50 wt.% SiO2. Each of the five basal flows (Pitanga-type, high-Ti/Y ~600, TiO2 > 3 wt.% and eight upper flows (Paranapanema-type, medium Ti/Y ~400, TiO2 > 2 wt.% can be identified from their chemical composition; sets of flows have parallel variation in chemical composition. The flow-by-flowcorrelation in four sections shows the horizontal position of the flows in three profiles and an approximately 200-m downdrop of the Itapiranga block with respect to the Frederico Westphalen block. The world-class amethyst geode mineralization and the systematic presence of native copper in the basalts make the correlation of great geological and economic significance.A caracterização geoquímica de treze derrames do Grupo Serra Geral na região de Vista Alegre (RS e SC, sul do Brasil, exibe uma composição basáltica homogênea próxima a 50% de SiO2. Os cinco derrames basais são classificados quimicamente como tipo Pitanga (alto Ti/Y ~600 e TiO2 > 3 em peso percentual, os demais oito derrames possuem médio Ti/Y ~400 com TiO2 ~2.5 em peso percentual, sendo classificados como magma tipo Paranapanema. Cada derrame pode ser identificado através de sua composição química e correlacionado, com variação paralela entre os perfis estudados. A correlação derrame a derrame nos quatro perfis demonstra uma posição horizontal em três perfis e um rejeito vertical de aproximadamente 200 m do bloco Itapiranga em relação ao bloco Frederico Westphalen. A presença de jazidas de ametista em geodos e a sistemática ocorrência de cobre nativo nos basaltos da região tornam a correlação de grande significado geológico e econômico.

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

    International Nuclear Information System (INIS)

    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

  14. Classifying chemical elements and particles: from the atomic to the sub-atomic world

    OpenAIRE

    Kibler, Maurice

    2003-01-01

    published in the book "The Periodic Table: Into the 21st Century", edited by D.H. Rouvray and R.B. King (Research Studies Press, Baldock, UK, 2004) pp. 297-329. This paper presents two facets. First, we show that the periodic table of chemical elements can be described, understood and modified (as far as its format is concerned) on the basis of group theory and more specifically by using the group SO(4,2)xSU(2). Second, we show that "periodic tables" also exist in the sub-atomic and sub-nu...

  15. A simple and general method for solving detailed chemical evolution with delayed production of iron and other chemical elements

    OpenAIRE

    Vincenzo, Fiorenzo; Matteucci, Francesca; Spitoni, Emanuele

    2016-01-01

    In this Letter, we present a new theoretical method for solving the chemical evolution of galaxies, by assuming the instantaneous recycling approximation for chemical elements restored by massive stars and the Delay Time Distribution formalism for the delayed chemical enrichment by Type Ia Supernovae. The galaxy gas mass assembly history, together with the assumed stellar yields and initial mass function, represent the starting point of this method. We derive a very simple and general equatio...

  16. FINITE ELEMENT METHOD AND ANALYSIS FOR CHEMICAL-FLOODING SIMULATION

    Institute of Scientific and Technical Information of China (English)

    YUAN Yirang

    2000-01-01

    This article discusses the enhanced oil recovery numerical simulation of the chemical-flooding (such as surfactants, alcohol, polymers) composed of three-dimensional multicomponent, multiphase and incompressible mixed fluids. The mathematical model can be described as a coupled system of nonlinear partial differential equations with initialboundary value problems. From the actual conditions such as the effect of cross interference and the three-dimensional characteristic of large-scale science-engineering computation, this article puts forward a kind of characteristic finite element fractional step schemes and obtain the optimal order error estimates in L2 norm. Thus we have thoroughly solved the well-known theoretical problem proposed by a famous scientist, R. E. Ewing.

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

    CERN Document Server

    Wahl, Ulrich; Decoster, Stefan; Mendonça, Tânia

    2009-01-01

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

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

    CERN Document Server

    Wahl, U; Decoster, S; Mendonca, T

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

  20. Chemical bioimaging for the subcellular localization of trace elements by high contrast TEM, TEM/X-EDS, and NanoSIMS.

    Science.gov (United States)

    Penen, Florent; Malherbe, Julien; Isaure, Marie-Pierre; Dobritzsch, Dirk; Bertalan, Ivo; Gontier, Etienne; Le Coustumer, Philippe; Schaumlöffel, Dirk

    2016-09-01

    Chemical bioimaging offers an important contribution to the investigation of biochemical functions, biosorption and bioaccumulation processes of trace elements via their localization at the cellular and even at the subcellular level. This paper describes the combined use of high contrast transmission electron microscopy (HC-TEM), energy dispersive X-ray spectroscopy (X-EDS), and nano secondary ion mass spectrometry (NanoSIMS) applied to a model organism, the unicellular green algae Chlamydomonas reinhardtii. HC-TEM providing a lateral resolution of 1nm was used for imaging the ultrastructure of algae cells which have diameters of 5-10μm. TEM coupled to X-EDS (TEM/X-EDS) combined textural (morphology and size) analysis with detection of Ca, P, K, Mg, Fe, and Zn in selected subcellular granules using an X-EDS probe size of approx. 1μm. However, instrumental sensitivity was at the limit for trace element detection. NanoSIMS allowed chemical imaging of macro and trace elements with subcellular resolution (element mapping). Ca, Mg, and P as well as the trace elements Fe, Cu, and Zn present at basal levels were detected in pyrenoids, contractile vacuoles, and granules. Some metals were even localized in small vesicles of about 200nm size. Sensitive subcellular localization of trace metals was possible by the application of a recently developed RF plasma oxygen primary ion source on NanoSIMS which has shown good improvements in terms of lateral resolution (below 50nm), sensitivity, and stability. Furthermore correlative single cell imaging was developed combining the advantages of TEM and NanoSIMS. An advanced sample preparation protocol provided adjacent ultramicrotome sections for parallel TEM and NanoSIMS analyses of the same cell. Thus, the C. reinhardtii cellular ultrastructure could be directly related to the spatial distribution of metals in different cell organelles such as vacuoles and chloroplast. PMID:27288221

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

    CERN Document Server

    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. Beta-packet of oxides and hydroxides minerals includes 88 known minerals and five chemical compounds - N2O5, CO2, CO, SO3 and SO2. Two minerals of the packet have not been determined yet. Besides, beta-packet of minerals with sulfur, selenium or arsenic is composed, with one mineral not defined yet. The results of the calculations can be used for further development of the Periodic Table of Chemical Elements and Chemical Compounds and their properties investigation.

  2. Chemical Identification of Archaeological Obsidian from Lagartero, Chiapas, Mexico, Using Main and Trace Elements Determined by PIXE. Chapter 10

    International Nuclear Information System (INIS)

    Proton induced X ray emission (proton PIXE) analysis has been used for determination of minor and trace element concentrations of archaeological obsidian samples, which were collected at the site at Lagartero, Chiapas, Mexico. Samples of Mexican and Guatemalan sources were also analysed. Statistical treatments such as principal component analyses were applied to the data set. Obsidians from Lagartero were identified as coming from the Guatemalan sources of Ixtepeque and El Chayal, with one sample from Ucareo/Zinapecuaro, Mexico. These results indicate that there was contact between the population of Lagartero and other Mayans or Mesoamericans. (author)

  3. Grouping and analysis of chair quality and their basic elements

    Directory of Open Access Journals (Sweden)

    Skakić Dušan

    2009-01-01

    Full Text Available Both the scientific experience and the engineering practice indicate that the decision making processes in the course of solving complex designing problems require an analysis of a great number of different construction variants. These types of decision-making processes are time consuming and do not always result in the selection of an optimal solution. That is why the methods of numerical optimization are applied in a wide range of technical sciences to assist in the selection of the best solution. The first step in solving the problem by using the Finite element method is to determine the type of chair earmarked for modeling, and to determine the dimensions of the chair elements.

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

    International Nuclear Information System (INIS)

    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

  5. 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)

    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.

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

    Science.gov (United States)

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

    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.

  7. KASCADE measurements of energy spectra for elemental groups of cosmic rays: Results and open problems

    CERN Document Server

    Antoni, T; Antoni, T; Apel, W D; Badea, F; Bekk, K; Bercuci, A; Blümer, H; Bozdog, H; Brancus, I M; Büttner, C; Chilingarian, A A; Daumiller, K; Doll, P; Engel, R; Engler, J; Fessler, F; Gils, H J; Glasstetter, R; Haungs, A; Heck, D; Hörandel, J R; Klages, H O; Maier, G; Mathes, H J; Mayer, H J; Milke, J; Müller, M; Obenland, R; Oehlschläger, J; Ostapchenko, S; Petcu, M; Plewnia, S; Rebel, H; Risse, A; Risse, M; Roth, M; Schatz, G; Schieler, H; Scholz, J; Stumpert, M; Thouw, T; Ulrich, H; Van Buren, J; Vardanyan, A; Weindl, A; Wochele, J; Zabierowski, J; Zagromski, S

    2005-01-01

    A composition analysis of KASCADE air shower data is performed by means of unfolding the two-dimensional frequency spectrum of electron and muon numbers. Aim of the analysis is the determination of energy spectra for elemental groups representing the chemical composition of primary cosmic rays. Since such an analysis depends crucially on simulations of air showers the two different hadronic interaction models QGSJet and SIBYLL are used for their generation. The resulting primary energy spectra show that the knee in the all particle spectrum is due to a steepening of the spectra of light elements but, also, that neither of the two simulation sets is able to describe the measured data consistently over the whole energy range with discrepancies appearing in different energy regions.

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  9. Solution of the diffusion equations for several groups by the finite elements method

    International Nuclear Information System (INIS)

    The code DELFIN has been implemented for the solution of the neutrons diffusion equations in two dimensions obtained by applying the approximation of several groups of energy. The code works with any number of groups and regions, and can be applied to thermal reactors as well as fast reactor. Providing it with the diffusion coefficients, the effective sections and the fission spectrum we obtain the results for the systems multiplying constant and the flows of each groups. The code was established using the method of finite elements, which is a form of resolution of the variational formulation of the equations applying the Ritz-Galerkin method with continuous polynomial functions by parts, in one case of the Lagrange type with rectangular geometry and up to the third grade. The obtained results and the comparison with the results in the literature, permit to reach the conclusion that it is convenient, to use the rectangular elements in all the cases where the geometry permits it, and demonstrate also that the finite elements method is better than the finite differences method. (author)

  10. 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.

  11. Glossary of class names of polymers based on chemical structure and molecular architecture (IUPAC Recommendations 2009)

    Czech Academy of Sciences Publication Activity Database

    Baron, M.; Hellwich, K. H.; Hess, M.; Horie, K.; Jenkins, A.D.; Jones, R. G.; Kahovec, Jaroslav; Kratochvíl, Pavel; Metanomski, W. V.; Mormann, W.; Stepto, R. F. T.; Vohlídal, J.; Wilks, E. S.

    2009-01-01

    Roč. 81, č. 6 (2009), s. 1131-1183. ISSN 0033-4545 R&D Projects: GA MŠk(CZ) LA09028 Keywords : IUPAC Polymer Division * macromolecule architecture * polymer class names Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.289, year: 2009

  12. A simple and general method for solving detailed chemical evolution with delayed production of iron and other chemical elements

    CERN Document Server

    Vincenzo, Fiorenzo; Spitoni, Emanuele

    2016-01-01

    In this Letter, we present a new theoretical method for solving the chemical evolution of galaxies, by assuming the instantaneous recycling approximation for chemical elements restored by massive stars and the Delay Time Distribution formalism for the delayed chemical enrichment by Type Ia Supernovae. The galaxy gas mass assembly history, together with the assumed stellar yields and initial mass function, represent the starting point of this method. We derive a very simple and general equation which closely relates the Laplace transforms of the galaxy gas accretion and star formation history, which can be used to simplify the problem of retrieving these quantities in most of current galaxy evolution models. We find that - once the galaxy star formation history has been reconstructed from our assumptions - the differential equation for the evolution of the chemical element $X$ can be suitably solved with classical methods. We apply our model to reproduce the $[\\text{O/Fe}]$ and $[\\text{Si/Fe}]$ vs. $[\\text{Fe/...

  13. Cosmic rays interactions and the abundances of the chemical elements

    International Nuclear Information System (INIS)

    Our Galaxy is the largest nuclear interaction experiment which we know, because of the interaction between cosmic ray particles and the interstellar material. Cosmic rays are particles, which have been accelerated in the Galaxy or in extragalactic space. Cosmic rays come as protons, electrons, heavier nuclei, and their antiparticles. Up to energies up to some tens of TeV of particle energy it is possible to derive chemical abundances of cosmic rays. It has been proposed that cosmic ray particles can be attributed to three main sites of origin and acceleration, a) supernova shocks in the interstellar medium, b) supernova shocks in a stellar wind of the predecessor star, and c) powerful radio galaxies. This proposal leads to quantitative tests, which are encouraging so far. Quantitative models for transport and interaction appear to be consistent with the data. Li, Be, B are secondary in cosmic rays, as are many of the odd-Z elements, as well as the sub-Fe elements. At very low energies, cosmic ray particles are subject to ionization losses, which produce a steep low energy cutoff; all particles below the cutoff are moved into the thermal material population, and the particles above it remain as cosmic rays. This then changes the chemical abundances in the interstellar medium, and is a dominant process for many isotopes of Li, Be, B. With a quantitative theory for the origin of cosmic rays proposed, it appears worthwhile to search for yet better spallation cross sections, especially near threshold. With such an improved set of cross sections, the theory of the interstellar medium and its chemical abundances, both in thermal and in energetic particles, could be taken a large step forward. (author)

  14. Autism by Another Name? Semantic and Pragmatic Impairments in Children.

    Science.gov (United States)

    Brook, Sarah Lister; Bowler, Dermot M.

    1992-01-01

    A review of the literature on children with language disorders characterized by semantic and pragmatic impairments suggests that some of these conditions may stem from the same fundamental cognitive and interpersonal difficulties found in early childhood autism. A summary of recent research and theory in autism is also presented. (Author/DB)

  15. The impact of the properties of the heaviest elements on the chemical and physical sciences

    International Nuclear Information System (INIS)

    The unique role of the heaviest elements in chemical and physical sciences is discussed. With the actinide series (Z = 90-103) and the superactinide series (Z = 122-155), the heaviest elements have significantly shaped the architecture of the Periodic Table of the elements. Relativistic effects in the electron shells of the heaviest elements change the chemical properties in a given group in a non-linear fashion. Relativistically stabilized sub-shell closures give rise to a new category of elements in the Periodic Table: volatile metals. The prototype for this property is element 114 which, due to the relativistic stabilization of its 7s27p1/22 electron configuration, is volatile in its elementary state, but, in contrast to a noble gas, exhibits a marked metal-metal interaction with a gold surface at room temperature. Nuclear shell effects dominate the physical properties of the transuranium elements. These give rise to superdeformed shape isomers (fission isomers) in the actinides (U-Bk). Superheavy elements (Z ≥ 104) owe their existence solely to nuclear shell effects at N = 152, 162, and 184. At this time, a building lot is the location of the next spherical proton shell closure as there is evidence that the center of the 'island of stability' is not at Z = 114. This needs urgently further theoretical and experimental efforts. The cross sections for the syntheses of elements 119 and 120 will give us important information on the 'upper end of the Periodic Table of the elements'. (orig.)

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

    KAUST Repository

    Cotter, Simon L.

    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.

  17. 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)

    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 60Co (5.27 y), 65Zn (244.3 d) and 59Fe (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 1013cm-2s-1. Radioactive assay was carried out using high resolution gamma ray spectrometry using 40% HPGe detector

  18. Multi-element trace determinations in pure alkaline earth fluoride powders by high-resolution ICP-MS using wet-chemical sample preparation and laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Tibi, Markus; Heumann, Klaus G. [Institute of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg-University Mainz, Duesbergweg 10-14, 55099, Mainz (Germany)

    2003-09-01

    Four alternative analytical procedures for the determination of ten important trace impurities (Mg, Cr, Fe, Cu, Zn, Sr, Zr, Cd, Ba, and Pb) in pure alkaline earth fluoride powders were applied using high-resolution inductively coupled plasma mass spectrometry (ICP-MS). Two procedures are based on a wet-chemical microwave digestion with boric acid and quantification by the standard addition technique and isotope dilution mass spectrometry (IDMS), respectively. In addition, analyses are also performed by laser ablation as a direct solid sampling technique applying matrix-matched external calibration as well as isotope dilution of the powdered sample. For most elements good agreement between the different methods is found. Detection limits for laser ablation vary between 0.05 ng g{sup -1} for Zr and 20 ng g{sup -1} for Mg. They are about one to two orders of magnitude lower than those of the wet-chemical procedures, which is mainly due to the high dilution factor during the sample preparation step. Advantages and restrictions of the different analytical procedures are discussed with respect to their routine applicability. Due to its relatively high accuracy, low detection limits, and time-efficiency LA-ICP-IDMS is the preferred choice if no standard reference materials are available. (orig.)

  19. Determination of rare earth elements in Taiwan monazite by chemical neutron activation analysis

    International Nuclear Information System (INIS)

    Taiwan monazite is a unique mineral obtained from the heavy sand found in the river floor of Tzuo-suei river and En-suei river. Both rivers are flowing parallel with separated narrow area into the sea at southwestern coast of Taiwan. The characteristic of monazite is that it contains considerable rare earth elements (REEs). REEs are considered very useful elements in the local industries and scientific researches such as ceramic, semiconductors, and glass optics. In this study, chemical neutron activation analysis (CNAA) was used to determine the contents of REEs in Taiwan monazite. A few milligram of monazite was digested in the microwave oven for 25 minutes with mixed acid (conc. HNO3 and HClO4). REEs were preconcentrated by hydrated magnesium oxide and CNAA was performed. (author)

  20. The TSCA interagency testing committee`s approaches to screening and scoring chemicals and chemical groups: 1977-1983

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.D. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    This paper describes the TSCA interagency testing committee`s (ITC) approaches to screening and scoring chemicals and chemical groups between 1977 and 1983. During this time the ITC conducted five scoring exercises to select chemicals and chemical groups for detailed review and to determine which of these chemicals and chemical groups should be added to the TSCA Section 4(e) Priority Testing List. 29 refs., 1 fig., 2 tabs.

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

    Science.gov (United States)

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

    2014-05-01

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

  2. Induction by Coinduction and Control Operators in Call-by-Name

    Directory of Open Access Journals (Sweden)

    Yoshihiko Kakutani

    2013-09-01

    Full Text Available This paper studies emulation of induction by coinduction in a call-by-name language with control operators. Since it is known that call-by-name programming languages with control operators cannot have general initial algebras, interaction of induction and control operators is often restricted to effect-free functions. We show that some class of such restricted inductive types can be derived from full coinductive types by the power of control operators. As a typical example of our results, the type of natural numbers is represented by the type of streams. The underlying idea is a counterpart of the fact that some coinductive types can be expressed by inductive types in call-by-name pure language without side-effects.

  3. [Naming and classification of steroids and human stress ulcers. Articles of historic significance published by Hans Selye 70 years ago].

    Science.gov (United States)

    Szabó, Sándor; Gyires, Klára

    2015-08-30

    The name of Hans Selye is mostly known worldwide as the discoverer of stress reaction. Yet, he made numerous other seminal and clinically relevant discoveries. Namely, since he had a focused research on steroid hormones originating from the adrenal cortex that play a crucial role in stress response, he was the first who introduced about 70 years ago the first classification of steroids that is still valid nowadays. This is based on three objective facts: (a) the names of steroid groups are identical with their organ of origin (e.g., corticoids from the adrenal cortex, testoids/androgens from the testis); (b) chemical structures of the steroids are identical within a group (e.g., all corticoids have pregnane nucleus with 21 carbon atoms); and (c) the biological effects are homogenous within a group (e.g., all glucocorticoids exert catabolic effect, while androgens are anabolic). It should be emphasized that Selye also discovered in animal models the pro-inflammmatory effect of mineralocorticoids and the anti-inflammatory properties of glucocorticoids, about 8-10 years before Nobel Prize was awarded to a physician for the first clinical use of adrenocorticotrop hormone and cortisone. Last, but not least, Selye was the first who recognized about 70 years ago the occurence of stress ulcers in humans, based on clinical reports on the huge increase in the number of perforated gastric anti-duodenal ulcers during bombings of London in World War II. The subsequent ulcer research by Selye`s former students and their contemporaries resulted in the recognition of anti-duodenal ulcer effect of dopamine, and the central gastroprotective actions of thyreotrop releasing hormone and endogenous opioids. Thus, Hans Selye made much more contributions to medical science and clinical practice than 'just' the discoverer of biologic stress response. PMID:26299832

  4. Genetic Diversity of Two Important Groups of Maize Landraces with Same Name in China Revealed by M13 Tailed-Primer SSRs

    Institute of Scientific and Technical Information of China (English)

    LIU Zhi-zhai; GUO Rong-hua; ZHAO Jiu-ran; CAI Yi-lin; WANG Feng-ge; CAO Mo-ju; WANG Rong-huan; SHI Yun-su; SONG Yan-chun; WANG Tian-yu; LI Yu

    2009-01-01

    Maize landraces White Dent and Golden Queen played a very important role in the pre-hybrid era of maize production in China. However, dozens of accessions with the same names of White Dent and Golden Queen are preserved in China National Genebank (CNG). The present study investigated the genetic diversity of these two important groups of maize landraces, as well as the relationships within and among them. Thirty-four landrace accessions with the name of White Dent and 10 with Golden Queen preserved in CNG were fingerprinted with 52 simple sequence repeats with tailed primer M13. Summary statistics including average number of alleles per locus, gene diversity/expected heterozygosity, and observed heterozygosity were carried out using PowerMarker ver. 3.25 software. The test of Hardy-Weinberg equilibrium (HWE) and linkage disequilibrium (LD) of all the 44 maize landrace accessions were also performed by PowerMarker. We observed a significant differentiation in terms of the average number of alleles between White Dent and Golden Queen (6.44 alleles per locus in White Dent, 4.48 in Golden Queen), while both groups of maize landraces had a relatively high but similar gene diversity (0.61 of White Dent, 0.63 of Golden Queen). The fixation index (FST) was only 0.0044, while the percentage of loci deviated from Hardy-Weinberg equilibrium within these two groups of White Dent and Golden Queen was 32.69 and 3.92%, respectively. The rather high genetic diversity and average number of alleles per locus confirmed that both groups of landraces had a rather broad germplasm base. The extremely low fixation index showed that there was little genetic variation between White Dent and Golden Queen and the molecular variation within these two groups was remarkably high, indicating no genetic drift between White Dent and Golden Queen and suggesting different improvement approaches to these two important groups of landraces. Hardy-Weinberg equilibrium test revealed that the group of

  5. Application of INAA to ancient bricks for grouping study using trace elements

    International Nuclear Information System (INIS)

    The paper presents the chemical composition analysis results of 57 ancient clay bricks obtained from Buddhist sites of two major locations of Andhra Pradesh, India. Samples were analyzed by instrumental neutron activation analysis (INAA) using high flux reactor neutrons and high resolution gamma ray spectrometry. Major, minor and trace concentrations of 23 elements were determined by relative method of NAA. For the grouping/provenance study, statistical cluster analysis was performed using concentrations of 14 selected elements namely Sc, Cr, Fe, Co, Zn, Cs, La, Ce, Eu, Tb, Yb, Lu, Ta and Th. The cluster analysis results indicated two major groups, which are in good agreement with the collection history of samples. Accuracy of the method was evaluated by analyzing two IAEA reference materials, RMs SL-1 and Soil-7. (author)

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

    International Nuclear Information System (INIS)

    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. Nuclear process and the heaviest chemical elements in the magnetic stars

    International Nuclear Information System (INIS)

    Full text : In the base of investigate isotopic shifts in the lines it was obtained that several lanthanides (rare earths) and actinides (Thand U) is present in the atmosphere of magnetic chemical peculiar stars. Isotopic shifts in the lines of the heavy elements in MCP stars point to the fact it is observed mainly the products of rapid neutron capture. Isotopic shifts in the lines of the heavy elements in MCP stars and it is known that large majority chemically elements may be generated by the nuclear reactions, in particular in a stars

  8. 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

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

    International Nuclear Information System (INIS)

    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 1012 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 HNO3 solution may cause sample dissolution. Sample homogeneity was verified by analysis of a sample in replicate. A comparison

  10. ON GENERIC TYPE SPECIES INDICATED BY MISAPPLIED NAMES

    Directory of Open Access Journals (Sweden)

    M. A. DONK

    2015-11-01

    Full Text Available When the type method was introduced in the "International Rules of Botanical Nomenclature," it was stated that "a nomenclatural type is that constituent element to which the name of a group is permanently attached" and, further, that "the type of .. . a generic name is a species and that of a species .. . is usually a specimen or preparation. In some species, however, the type is a description or figure given by a previous 1 author" (Art. 18 . No doubt, the type of a generic name is a species and that of a specific name a specimen (or its substitute. A species may be variously interpreted as to its limits; it may be narrowly or broadly conceived. It may receive a name, but it remains a species even if it has no name. It frequently occurs that a specific name is misapplied to a quite different species. Hence it is also evident that a species and a specific name are two intrinsically different notions, not at all identical and interchangeable. As quoted above, Art. 18 positively says that the type of a generic name is a species and does not refer to specific names. I believe this article really states what it wanted to convey in this respect, and is not an instance of unfortunate wording. A species comprises a vast number of 'individuals plants' and of these some are preserved often only in part, or are subject to taxonomic study without preservation, and represent the 'specimens' of the Rules; when the species is given a name, one of these is or afterwards becomes the 'type specimen.' Thus a (type species and a (type specimen are different notions. In the binomial system a specific name is a combination of two words. The first part, or generic appellation, stands for a generic description, 2 the second part, or specific epithet, for a specific description : a specific name roots in two different descriptions. Far more often than not these two are published on different occasions by different authors.

  11. Real Elements and Schur Indices of a Group

    CERN Document Server

    Kulshrestha, Amit

    2011-01-01

    In this article we try to explore the relation between real conjugacy classes and real characters of finite groups at more refined level. This refinement is in terms of properties of groups such as strong reality and total orthogonality. In this connection we raise several questions and record several examples which have motivated those questions.

  12. Democratic elements in group and project organized PBL

    DEFF Research Database (Denmark)

    Qvist, Palle

    2006-01-01

    Students in a democratic learning system as the Aalborg Model knows of and uses democratics skills as e.g. the ability to discuss and accept other points of view, negotiate, compromise, reach consensus or accept the result of a vote in striving to reach specific common or personal learning goals...... beyond it to the school and the community” (Marris, 2003:274) then implementing democratic learning systems as The Aalborg Model are important for supporting and promote democratic bildung of students in higher education. This article defines at a – start - what should be understood by a democratic...... learning system. It contrasts it to an authoritarian or elitist systems. Then it brings the results from an investigation of 9 process analyses’ written at the end of the second semester 2005 by project groups from The Technical Natural Scientific Basic Year at Aalborg University and concludes that...

  13. LLNL Chemical Kinetics Modeling Group

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, W J; Westbrook, C K; Mehl, M; Herbinet, O; Curran, H J; Silke, E J

    2008-09-24

    The LLNL chemical kinetics modeling group has been responsible for much progress in the development of chemical kinetic models for practical fuels. The group began its work in the early 1970s, developing chemical kinetic models for methane, ethane, ethanol and halogenated inhibitors. Most recently, it has been developing chemical kinetic models for large n-alkanes, cycloalkanes, hexenes, and large methyl esters. These component models are needed to represent gasoline, diesel, jet, and oil-sand-derived fuels.

  14. Structure and magnetism in novel group IV element-based magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, Frank [Univ. of North Carolina, Chapel Hill, NC (United States)

    2013-08-14

    The project is to investigate structure, magnetism and spin dependent states of novel group IV element-based magnetic thin films and heterostructures as a function of composition and epitaxial constraints. The materials systems of interest are Si-compatible epitaxial films and heterostructures of Si/Ge-based magnetic ternary alloys grown by non-equilibrium molecular beam epitaxy (MBE) techniques, specifically doped magnetic semiconductors (DMS) and half-metallic Heusler alloys. Systematic structural, chemical, magnetic, and electrical measurements are carried out, using x-ray microbeam techniques, magnetotunneling spectroscopy and microscopy, and magnetotransport. The work is aimed at elucidating the nature and interplay between structure, chemical order, magnetism, and spin-dependent states in these novel materials, at developing materials and techniques to realize and control fully spin polarized states, and at exploring fundamental processes that stabilize the epitaxial magnetic nanostructures and control the electronic and magnetic states in these complex materials. Combinatorial approach provides the means for the systematic studies, and the complex nature of the work necessitates this approach.

  15. Pesticides, selected elements, and other chemicals in infant and toddler total diet samples, October 1980-March 1982

    Energy Technology Data Exchange (ETDEWEB)

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

    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 infant and toddler Total Diet samples collected in 13 cities between October 1980 and March 1982. 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 generally are within acceptable limits. The results for samples collected during the same period that represent the adult diet are reported separately.

  16. Analysis of the platinum group elements in environmental materials by ICP-MS

    International Nuclear Information System (INIS)

    Complete text of publication follows. Platinum group elements (PGEs) can be naturally found only at very low concentration in the earth crust. However, the uses of PGEs in vehicle exhaust catalysts (VECs), in addition to some other applications cause their anthropogenic emission and spread in the environment. PGE contamination initially occurs in airborne particulate matter (PM), roadside dust, soil, sludge and water, etc.; which finally results in bioaccumulation of these elements in the living organisms. The metallic form of these elements is generally considered to be inert as regards biological reactions. On the contrary, some of their compounds are very toxic and allergenic. The accurate determination of PGEs has been one of the difficult tasks in analytical chemistry because of their ultra-trace concentration in most geological, environmental and biological samples (typically 1-100 ng g-1). Methods like ETAAS and ICP-OES do not provide sufficient sensitivity and detection limits for the direct determination of these elements in such samples. ICP-MS is one of the most sensitive analytical techniques presently available for PGEs determination at trace levels generally having detection limits in the order of ng g-1. However, determination by ICP-MS is hampered by spectral interferences from monoatomic and polyatomic ions produced in the plasma from matrix constituents. Selected PGEs (Pt, Pd and Rh) were determined in the environmental samples (soils and airborne particulate matter) collected from areas strongly affected by automobile traffic and reference samples from unaffected sites. Several spectral overlap interferences (HfO+ in 195Pt determination, ArCu+, ArGa+ and YO+ on 105Pd determination and ArCu+, RbO+, SrO+ and Pb2+ on 103Rh determination) were corrected by means of the mathematical corrections. The samples were digested in aqua regia. Reference material SARM-7 was analysed as well. The results show a significant increase of PGE concentration in

  17. Migration of chemical elements in food chains and ontogeny phases of meadow moth in the remote migration of butterflies

    Science.gov (United States)

    Knorr, I. B.; Naumova, E. N.; Trounova, V. A.; Zolotarev, K. V.

    1998-02-01

    To study the complex problem of the remote migrations of insects SR XRF analysis seems to be most promising. It provides fast and exact determination of elemental composition of biosamples. The presence-absence of "marking" elements and groups of elements allows one to identify geographical populations (origin) of insects. This work is based on the planned and specially performed laboratory experiments which should answer the questions on assimilation of different chemical elements, migration of these elements atontogeny phases and accumulation or the release of some elements at the final developmental stages.

  18. Naming names

    Science.gov (United States)

    The tiny, 1.5-km wide moon that NASA's Galileo mission discovered and photographed around the asteroid Ida no longer has to go by the nondescript appellation of “it.” The International Astronomical Union (IAU) has formally bestowed the name of Dactyl on Ida's moon. Dactyl is derived from the Dactyli, a group of mythological beings who lived on Mount Ida, where the infant Zeus was hidden by the nymph Ida and protected by the Dactyli, according to some mythological accounts. The IAU, which is responsible for naming all solar system bodies, also approved names for the surface features on another asteroid called Gaspra, which was visited by Galileo in October of 1991. Gaspra was the first asteroid to be visited by a spacecraft.

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

    International Nuclear Information System (INIS)

    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

  20. Rapid Neutron Capture Process in Supernovae and Chemical Element Formation

    Indian Academy of Sciences (India)

    Rulee Baruah; Kalpana Duorah; H. L. Duorah

    2009-09-01

    The rapid neutron capture process (r-process) is one of the major nucleosynthesis processes responsible for the synthesis of heavy nuclei beyond iron. Isotopes beyond Fe are most exclusively formed in neutron capture processes and more heavier ones are produced by the r-process. Approximately half of the heavy elements with mass number ≻ 70 and all of the actinides in the solar system are believed to have been produced in the r-process. We have studied the r-process in supernovae for the production of heavy elements beyond = 40 with the newest mass values available. The supernova envelopes at a temperature ≻ 109 K and neutron density of 1024 cm-3 are considered to be one of the most potential sites for the r-process. The primary goal of the r-process calculations is to fit the global abundance curve for solar system r-process isotopes by varying time dependent parameters such as temperature and neutron density. This method aims at comparing the calculated abundances of the stable isotopes with observation.We have studied the r-process path corresponding to temperatures ranging from 1.0 × 109 K to 3.0 × 109 K and neutron density ranging from 1020 cm-3 to 1030 cm-3. With temperature and density conditions of 3.0 × 109 K and 1020 cm-3 a nucleus of mass 273 was theoretically found corresponding to atomic number 115. The elements obtained along the r-process path are compared with the observed data at all the above temperature and density range.

  1. Applicative Bisimilarities for Call-by-Name and Call-by-Value λμ-Calculus

    OpenAIRE

    Biernacki, Dariusz; Lenglet, Sergueï

    2014-01-01

    We propose the first sound and complete bisimilarities for the call-by-name and call-by-value untyped λµ-calculus, defined in the applicative style. We give equivalence examples to illustrate how our relations can be used; in particular, we prove David and Py's counter-example, which cannot be proved with Lassen's preexisting normal form bisimilarities for the λµ-calculus.

  2. Phases of Environmental Evolution Indicated by Primary Chemical Elements and Paleontological Records in the Upper Pleistocene-Holocene Series for the Salawusu River Valley, China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Studies of lithology, sedimentary facies and the distribution regularity of SiO2 and Al2O3 contents and Al2O3/SiO2 ratio allow us to divide the Upper Pleistocene-Holocene Series represented by the Milanggouwan section in China's Salawusu River valley into six segments: MGS1, MGS2, MGS3,MGS4, MGS5 and MGS6. The boundary ages for MGS1 (the Dishaogouwan and Dagouwan Formations), MGS2 (the upper Chengchuan Formation), MGS3 (the middle Chengchuan Formation),MGS4 (the lower Chengchuan Formation), MGS5 (most strata of the Salawusu Formation) and MGS6 (the bottom of the Salawusu Formation and the top of the Lishi Formation) correspond to those of MIS1, MIS2, MIS3, MIS4, MIS5 and MIS6, respectively, from deep sea sediments or continental glaciers. MGS5 can be subdivided into five subsegments (MGS5a, MGS5b, MGS5c,MGS5d and MGS5e) and the boundary ages of these subsegments correspond to those of MIS5a,MIS5b, MIS5c, MIS5d and MIS5e, respectively. Based on the paleoenvironment and paleoecology indicated by the primary chemical elements, fossil vertebrates, mollusks and pollen grains, we hypothesize that MGS1, MGS2, MGS3, MGS4, MGS5 and MGS6 and the subsegments of MGS5 match the corresponding stages for oxygen isotopes in the deep sea sediments and continental glaciers,and the substages of MIS5 in terms of climatic characters, further explaining the phenomena that determined the formation of the late Quaternary strata and the paleontology of the Salawusu River valley. These phenomena relate to fluctuations in the global climate (and particularly in the East Asian monsoon) during the glacial and interglacial periods.

  3. Atlantic Forest. A natural reservoir of chemical elements

    International Nuclear Information System (INIS)

    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)

  4. Chemical and elemental comparison of two formulations of oleoresin capsicum.

    Science.gov (United States)

    Haas, J S; Whipple, R E; Grant, P M; Andresen, B D; Volpe, A M; Pelkey, G E

    1997-01-01

    In-custody deaths following the application of pepper spray weaponry by law enforcement personnel have increased in California over the last few years. Oleoresin capsicum (OC), an oily extract of hot peppers, is the active ingredient in the spray, but little detailed information on product mixtures is available. Since OC extracts contain a multitude of natural compounds at irregular concentrations, there could be considerable, variation in overall chemical composition among the different formulations of both 'natural' and 'synthetic' OC preparations. This was confirmed by organic and inorganic analyses performed on OC sprays produced by two manufacturers licensed for distribution within the state of California. The results indicated that the differences could lead to considerable inconsistency in weapon effectiveness, and suggested that more comprehensive studies are warranted. PMID:9022856

  5. Chemical Elements Abundance in the Universe and the Origin of Life

    CERN Document Server

    Valkovic, Vlado

    2016-01-01

    Element synthesis which started with p-p chain has resulted in several specific characteristics including lack of any stable isotope having atomic masses 5 or 8. The carbon to oxygen ratio is fixed early by the chain of coincidences. These, remarkably fine-tuned, conditions are responsible for our own existence and indeed the existence of any carbon based life in the Universe. Chemical evolution of galaxies reflects in the changes of chemical composition of stars, interstellar gas and dust. The evolution of chemical element abundances in a galaxy provides a clock for galactic aging. On the other hand, the living matter on the planet Earth needs only some elements for its existence. Compared with element requirements of living matter a hypothesis is put forward, by accepting the Anthropic Principle, which says: life as we know, (H-C-N-O) based, relying on the number of bulk and trace elements originated when two element abundance curves, living matter and galactic, coincided. This coincidence occurring at part...

  6. 2010 Chemical Working Group Status

    Science.gov (United States)

    Reid, Concha M.

    2010-01-01

    The Steering Group for the Interagency Advanced Power Group (IAPG) held their business meeting on November 30-December 1st in McLean, Virginia. Status reports were presented from each of the IAPG's Working Groups. These charts contain a brief summary of the IAPG Chemical Working Group's activities during 2010 and its plans for 2011.

  7. Chemical Evolution models of Local Group galaxies

    OpenAIRE

    Tosi., M

    2003-01-01

    Status quo and perspectives of standard chemical evolution models of Local Group galaxies are summarized, discussing what we have learnt from them, what we know we have not learnt yet, and what I think we will learn in the near future. It is described how Galactic chemical evolution models have helped showing that: i) stringent constraints on primordial nucleosynthesis can be derived from the observed Galactic abundances of the light elements, ii) the Milky Way has been accreting external gas...

  8. Elements with Square Roots in Finite Groups

    Institute of Scientific and Technical Information of China (English)

    M.S. Lucido; M.R. Pournaki

    2005-01-01

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

  9. Chemical analysis of solid materials by a LIMS instrument designed for space research: 2D elemental imaging, sub-nm depth profiling and molecular surface analysis

    Science.gov (United States)

    Moreno-García, Pavel; Grimaudo, Valentine; Riedo, Andreas; Neuland, Maike B.; Tulej, Marek; Broekmann, Peter; Wurz, Peter

    2016-04-01

    Direct quantitative chemical analysis with high lateral and vertical resolution of solid materials is of prime importance for the development of a wide variety of research fields, including e.g., astrobiology, archeology, mineralogy, electronics, among many others. Nowadays, studies carried out by complementary state-of-the-art analytical techniques such as Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), Secondary Ion Mass Spectrometry (SIMS), Glow Discharge Time-of-Flight Mass Spectrometry (GD-TOF-MS) or Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) provide extensive insight into the chemical composition and allow for a deep understanding of processes that might have fashioned the outmost layers of an analyte due to its interaction with the surrounding environment. Nonetheless, these investigations typically employ equipment that is not suitable for implementation on spacecraft, where requirements concerning weight, size and power consumption are very strict. In recent years Laser Ablation/Ionization Mass Spectrometry (LIMS) has re-emerged as a powerful analytical technique suitable not only for laboratory but also for space applications.[1-3] Its improved performance and measurement capabilities result from the use of cutting edge ultra-short femtosecond laser sources, improved vacuum technology and fast electronics. Because of its ultimate compactness, simplicity and robustness it has already proven to be a very suitable analytical tool for elemental and isotope investigations in space research.[4] In this contribution we demonstrate extended capabilities of our LMS instrument by means of three case studies: i) 2D chemical imaging performed on an Allende meteorite sample,[5] ii) depth profiling with unprecedented sub-nm vertical resolution on Cu electrodeposited interconnects[6,7] and iii) preliminary molecular desorption of polymers without assistance of matrix or functionalized substrates.[8] On the whole

  10. A family of names: rune-names and ogam-names and their relation to alphabet letter-names

    OpenAIRE

    Griffiths, Alan

    2013-01-01

    The current consensus is that vernacular names assigned to the runes of the Germanic fuþark and to Irish ogam characters are indigenous creations independent of Mediterranean alphabet traditions. I propose, however, that ogam-names are based on interpretations of Hebrew, Greek or Latin letter-names given by Jerome, Ambrose and others, and introduced into Ireland by Christian missionaries (fifth to sixth centuries). Subsequently, under the influence of Irish Christian missionaries in northern ...

  11. Bioaccumulation of elements and radionuclides by macrofungi. Review for the territory of Poland

    International Nuclear Information System (INIS)

    A bibliographic review is presented on publications related to bioaccumulation of elements, specially metals and radionuclides in fruiting bodies of higher mushrooms collected at the territory of Poland. In the paper apart from the list of references in tables is given, chronologically, name of the first author, year of publication, site, the type of work (in situ, commercial source, field experiment, laboratory study), chemical symbols of the elements and the abbreviations of the latin names of the mushroom species under study. (author)

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

    International Nuclear Information System (INIS)

    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)

  13. Features of adsorbed radioactive chemical elements and their isotopes distribution in iodine air filters AU-1500 at nuclear power plants

    CERN Document Server

    Neklyudov, I M; 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 radioactive chemical elements and their isotopes in the granular filtering medium in the iodine air filters of the type of AU1500 in the forced exhaust ventilation systems at the nuclear power plant. The gamma 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 AU1500 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 AU1500 iodine air filter, which was exposed to the bremsstrahlung gamma quantum irradiation, produced by the accelerating electrons in the tantalum target, are obtained. The spatial distributions of the detected chemical element 127I and some other chemical elements and their isotopes in the layer of absorber, which was made of the cylindrical coal granule...

  14. Features of a Spatial Distribution of Dust Masses and Adsorbed Chemical Elements in Filters of NPPs

    International Nuclear Information System (INIS)

    The features of an adsorption from air of chemical elements and their isotopes in carbon filters AU-1500 of atomic power plants are clarified. It is shown that the nonuniform allocation of elements inside a filter retrieved earlier by a method of a gamma-activation analysis, well correlates with features of allocation of dust masses researched by the authors. This circumstance indicates the important role of dust fractions of adsorbent placed in a filter, in an adsorption of elements and their isotopes. The physical reasons resulting in to such character of interaction by portable air elements with dust accumulations are surveyed. The analysis of influence of these processes on serviceability of filters and saving of the accumulated material are considered

  15. Group behaviour in physical, chemical and biological systems

    Indian Academy of Sciences (India)

    Cihan Saçlioğlu; Önder Pekcan; Vidyanand Nanjundiah

    2014-04-01

    Groups exhibit properties that either are not perceived to exist, or perhaps cannot exist, at the individual level. Such `emergent’ properties depend on how individuals interact, both among themselves and with their surroundings. The world of everyday objects consists of material entities. These are, ultimately, groups of elementary particles that organize themselves into atoms and molecules, occupy space, and so on. It turns out that an explanation of even the most commonplace features of this world requires relativistic quantum field theory and the fact that Planck’s constant is discrete, not zero. Groups of molecules in solution, in particular polymers (`sols’), can form viscous clusters that behave like elastic solids (`gels’). Sol-gel transitions are examples of cooperative phenomena. Their occurrence is explained by modelling the statistics of inter-unit interactions: the likelihood of either state varies sharply as a critical parameter crosses a threshold value. Group behaviour among cells or organisms is often heritable and therefore can evolve. This permits an additional, typically biological, explanation for it in terms of reproductive advantage, whether of the individual or of the group. There is no general agreement on the appropriate explanatory framework for understanding group-level phenomena in biology.

  16. Group behaviour in physical, chemical and biological systems.

    Science.gov (United States)

    Saçlioğlu, Cihan; Pekcan, Önder; Nanjundiah, Vidyanand

    2014-04-01

    Groups exhibit properties that either are not perceived to exist, or perhaps cannot exist, at the individual level. Such 'emergent' properties depend on how individuals interact, both among themselves and with their surroundings. The world of everyday objects consists of material entities. These are, ultimately, groups of elementary particles that organize themselves into atoms and molecules, occupy space, and so on. It turns out that an explanation of even the most commonplace features of this world requires relativistic quantum field theory and the fact that Planck's constant is discrete, not zero. Groups of molecules in solution, in particular polymers ('sols'), can form viscous clusters that behave like elastic solids ('gels'). Sol-gel transitions are examples of cooperative phenomena. Their occurrence is explained by modelling the statistics of inter-unit interactions: the likelihood of either state varies sharply as a critical parameter crosses a threshold value. Group behaviour among cells or organisms is often heritable and therefore can evolve. This permits an additional, typically biological, explanation for it in terms of reproductive advantage, whether of the individual or of the group. There is no general agreement on the appropriate explanatory framework for understanding group-level phenomena in biology. PMID:24736152

  17. Numerical simulation of isothermal chemical vapor infiltration process in fabrication of carbon-carbon composites by finite element method

    Institute of Scientific and Technical Information of China (English)

    李克智; 李贺军; 姜开宇

    2000-01-01

    The chemical vapor infiltration process in fabrication of carbon-carbon composites is highly inefficient and requires long processing time. These limitations add considerably to the cost of fabrication and restrict the application of this material. Efforts have been made to study the CVI process in fabrication of carbon-carbon composites by computer simulation and predict the process parameters, density, porosity, etc. According to the characteristics of CVI process, the basic principle of FEM and mass transport, the finite element model has been established. Incremental finite element equations and the elemental stiffness matrices have been derived for the first time. The finite element program developed by the authors has been used to simulate the ICVI process in fabrication of carbon-carbon composites. Computer color display of simulated results can express the densification and distributions of density and porosity in preform clearly. The influence of process parameters on the densification of prefo

  18. Response to the Report of the Transfermium Working Group ''Discovery of the Transfermium Elements''

    International Nuclear Information System (INIS)

    In the opinion of the authors the report of the Transfermium Working Group (TWG) ''Discovery of the Transfermium Elements'' is riddled with errors of omission and commission. Many relevant references and much relevant data were omitted as a result of the selective use of references and data. There were only two members representing the International Union of Applied Chemistry (IUPAC) on the TWG ( and these were not nuclear chemists) while there were seven members representing the International Union of Applied Physics (IUPAP). Much of the experimental evidence is of a basically chemical nature and its proper evaluation would have benefited from the presence of more nuclear chemists on the TWG. Especially grievous is the rejection of the Berkeley claim to the 1955 discovery of element 101 which was based on a clear-cut chemical identification. Our most serious quarrel with the TWG report is their treatment of the discovery of element 104. It is clearly a waste of time and effort to reopen the cases of elements 102 and 103, which were discovered more than 30 years ago with the approval of the suggested names by the IUPAC according to the standards of that era. (Author)

  19. Elemental diffusion during the droplet epitaxy growth of In(Ga)As/GaAs(001) quantum dots by metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z. B.; Chen, B.; Wang, Y. B.; Liao, X. Z., E-mail: xiaozhou.liao@sydney.edu.au [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Lei, W. [School of Electrical, Electronic and Computer Engineering, The University of Western Australia, Perth, WA 6009 (Australia); Tan, H. H.; Jagadish, C. [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Zou, J. [Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, QLD 4072 (Australia); Ringer, S. P. [School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia)

    2014-01-13

    Droplet epitaxy is an important method to produce epitaxial semiconductor quantum dots (QDs). Droplet epitaxy of III-V QDs comprises group III elemental droplet deposition and the droplet crystallization through the introduction of group V elements. Here, we report that, in the droplet epitaxy of InAs/GaAs(001) QDs using metal-organic chemical vapor deposition, significant elemental diffusion from the substrate to In droplets occurs, resulting in the formation of In(Ga)As crystals, before As flux is provided. The supply of As flux suppresses the further elemental diffusion from the substrate and promotes surface migration, leading to large island formation with a low island density.

  20. Elemental diffusion during the droplet epitaxy growth of In(Ga)As/GaAs(001) quantum dots by metal-organic chemical vapor deposition

    International Nuclear Information System (INIS)

    Droplet epitaxy is an important method to produce epitaxial semiconductor quantum dots (QDs). Droplet epitaxy of III-V QDs comprises group III elemental droplet deposition and the droplet crystallization through the introduction of group V elements. Here, we report that, in the droplet epitaxy of InAs/GaAs(001) QDs using metal-organic chemical vapor deposition, significant elemental diffusion from the substrate to In droplets occurs, resulting in the formation of In(Ga)As crystals, before As flux is provided. The supply of As flux suppresses the further elemental diffusion from the substrate and promotes surface migration, leading to large island formation with a low island density

  1. Naming Me, Naming You. Personal Names, Online Signatures and Cultural Meaning

    Directory of Open Access Journals (Sweden)

    Charlotte Hagström

    2012-08-01

    Full Text Available Every day we talk and speak and chat to people. We write and listen to each other, refer to each other, describe to each other what we and others have done and said. Doing this, we sometimes use our given names, sometimes we go by our nicknames, which often indicate or clarify who we are or are made up by ourselves to draw other people's attention. Nicknames can be official or informal, known by many or only by a few, real monikers or made up pseudonyms or signatures. Where ever there are people there are names, since names are and have always been part of human life. Sociologist Richard D. Alford states that ethnographic research has not found a single society whose members do not have names (Alford, 1988, 1. Names are cultural universals, something all humans have in common, no matter where or when they live. This article focuses on personal names and naming from a cultural ethnographic perspective. It begins with reflections on the link between name and self, continues with a discussion of how names are used to culturally structure our surroundings and interpret the world, and con- cludes with an analysis of names used in virtual settings. The virtual field has hitherto not received much interest among name researchers. In online games, chat rooms and web communities, names are not only useful and applicable, as they are in the so called real world; they are even more essential and important as it is mainly through their names participants recognise and identify each other.

  2. Adapting Web content for low-literacy readers by using lexical elaboration and named entities labeling

    Science.gov (United States)

    Watanabe, W. M.; Candido, A.; Amâncio, M. A.; De Oliveira, M.; Pardo, T. A. S.; Fortes, R. P. M.; Aluísio, S. M.

    2010-12-01

    This paper presents an approach for assisting low-literacy readers in accessing Web online information. The "Educational FACILITA" tool is a Web content adaptation tool that provides innovative features and follows more intuitive interaction models regarding accessibility concerns. Especially, we propose an interaction model and a Web application that explore the natural language processing tasks of lexical elaboration and named entity labeling for improving Web accessibility. We report on the results obtained from a pilot study on usability analysis carried out with low-literacy users. The preliminary results show that "Educational FACILITA" improves the comprehension of text elements, although the assistance mechanisms might also confuse users when word sense ambiguity is introduced, by gathering, for a complex word, a list of synonyms with multiple meanings. This fact evokes a future solution in which the correct sense for a complex word in a sentence is identified, solving this pervasive characteristic of natural languages. The pilot study also identified that experienced computer users find the tool to be more useful than novice computer users do.

  3. Contents of chemical elements in stomach during prenatal development: different age-dependent dynamical changes and their significance

    Institute of Scientific and Technical Information of China (English)

    Shao-Fan Hou; Hai-Rong Li; Li-Zhen Wang; De-Zhu Li; Lin-Sheng Yang; Chong-Zheng Li

    2003-01-01

    AIM: To observe dynamic of different chemical elements in stomach tissue during fetal development.METHODS: To determine contents of the 21 chemical elements in each stomach samples from fetus aging four to ten months. The content values were compared to those from adult tissue samples, and the values for each month group were also analyzed for dynamic changes.RESULTS: Three representations were found regarding the relationship between contents of the elements and ages of the fetus, including the positive correlative (K), reversely correlative (Na, Ca, P, Al, Cu, Zn, Fe, Mn, Cr, Sr, Li, Cd, Ba,Se ) and irrelevant groups (Mg, Co, Ni, V, Pb, Ti).CONCLUSION: The chemical elements' contents in stomach tissues were found to change dynamically with the stomach weights. The age-dependent representations for different chemical elements during the prenatal development may be of some significance for assessing development of fetal stomach and some chemical elements. The data may be helpful for the nutritional balance of fetus and mothers during prenatal development and even the perinatal stages.

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

    International Nuclear Information System (INIS)

    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

  5. Influence of ironworks on distribution of chemical elements in Bosnia and Herzegovina and Slovenia

    Directory of Open Access Journals (Sweden)

    Jasminka Alijagić

    2006-06-01

    Full Text Available The objective of this work is the study of the distribution of chemical elements in attic dust and topsoil for the identification of anthropogenic and geogenic element sources in an old metallurgic area in Bosnia and Herzegovina and Slovenia (Slo – BiH bilateral project “Heavy metals in environment as consequences of mining and smelting in the past”. Samples of attic dust and topsoil were collected in localities in BiH (Zenica, Vareš and Ilijaš and Slovenia (Jesenice, Štore and Ravne.Analysis for 42 chemical elements was performed. Based on a comparison of statistical parameters, spatial distribution of particular elements and results of cluster analysis one natural and two anthropogenic geochemical associations were identified. The natural geochemical association (Al-K-La-Sc-Th-Ti is influenced mainly by lithology. The anthropogenic association (Co-Cr-Mo-Ni-V-W is the result of iron metallurgy in the past. The second anthropogenic association (Ag-As-Cd-Fe-Hg-Mn-Pb-Sb-Sn-Zn is the result of high level of sulphide phase in iron ore (Vareš and zinc and sulphuric acid production in the Celje area.

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

    International Nuclear Information System (INIS)

    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)

  7. SHIP, the Separator for Heavy Ion Reaction Products, and the making of the heaviest atomic nuclei. Roentgenium - a new chemical element

    International Nuclear Information System (INIS)

    Ever since the foundation of the GSI, the Darmstadt-based Gesellschaft fuer Schwerionenforschung, in the 1970s, physicists of the Justus-Liebig-University of Giessen have been at the frontiers of research work examining the behaviour of nuclear matter under critical stability conditions. The article in this edition of ''Spiegel der Forschung'', the scientific journal of the university, highlights the results of the last twenty years of research activities with the velocity separator named SHIP, Separator for Heavy Ion Reaction Products. With this instrument, developed by members of the university's II. Institute of Physics and built and operated by members of the GSI in Darmstadt, the scientists were able to generate the six heaviest of the currently known chemical elements, with atomic numbers ranging from 107 to 112. The element with the atomic number 111 will be named ''Roentgenium'', in honour of the famous physicist and Nobel prize winner Wilhelm Conrad Roentgen

  8. Recognition of cigarette brand names and logos by young children in Hong Kong

    OpenAIRE

    Peters, J.; Betson, C. L.; Hedley, A. J.; Lam, T. H.; Ong, S. G.; C. M. Wong; Fielding, R.

    1995-01-01

    Objective-To examine the recognition of cigarette brand names and logos by Hong Kong primary school children. Design - Cross-sectional survey with self-completed questionnaires examining smoking behaviour and recognition of 13 food, drink, cigarette, and toothpaste brand names and logos. Subjects - A total of 9591 primary school children (mean age =10.3; SD = 1.29) living in two districts of Hong Kong included in 1991 as part of a four-year respiratory health, smoking, and air pollution s...

  9. Distribution of chemical elements in calc-alkaline igneous rocks, soils, sediments and tailings deposits in northern central Chile

    Science.gov (United States)

    Oyarzún, Jorge; Oyarzun, Roberto; Lillo, Javier; Higueras, Pablo; Maturana, Hugo; Oyarzún, Ricardo

    2016-08-01

    This study follows the paths of 32 chemical elements in the arid to semi-arid realm of the western Andes, between 27° and 33° S, a region hosting important ore deposits and mining operations. The study encompasses igneous rocks, soils, river and stream sediments, and tailings deposits. The chemical elements have been grouped according to the Goldschmidt classification, and their concentrations in each compartment are confronted with their expected contents for different rock types based on geochemical affinities and the geologic and metallogenic setting. Also, the element behavior during rock weathering and fluvial transport is here interpreted in terms of the ionic potentials and solubility products. The results highlight the similarity between the chemical composition of the andesites and that of the average Continental Crust, except for the higher V and Mn contents of the former, and their depletion in Mg, Ni, and Cr. The geochemical behavior of the elements in the different compartments (rocks, soils, sediments and tailings) is highly consistent with the mobility expected from their ionic potentials, their sulfates and carbonates solubility products, and their affinities for Fe and Mn hydroxides. From an environmental perspective, the low solubility of Cu, Zn, and Pb due to climatic, chemical, and mineralogical factors reduces the pollution risks related to their high to extremely high contents in source materials (e.g., rocks, altered zones, tailings). Besides, the complex oxyanions of arsenic get bound by colloidal particles of Fe-hydroxides and oxyhydroxides (e.g., goethite), thus becoming incorporated to the fine sediment fraction in the stream sediments.

  10. Photochemistry and charge transfer chemistry of the platinum group elements

    Energy Technology Data Exchange (ETDEWEB)

    Eisenberg, R.

    1992-12-01

    During the past 3 years, progress was made in elucidating the excited state structures of Pt(diimine)(dithiolate) complexes, while more recent efforts focused on the photochemistry of these complexes and electronic structure of other dithiolate systems. A carbonyl-Ir-maleonitrile dithiolate complex is also studied.

  11. Chemical substructure and inhomogeneous mixing in Local Group dwarf galaxies

    Science.gov (United States)

    Venn, K. A.

    Evidence for inhomogeneous mixing in the Carina, Draco, and Sculptor dwarf galaxies is examined from chemical abundance patterns. Inhomogeneous mixing at early times is indicated in the classical dwarf galaxies, though cannot be ascertained in ultra faint dwarfs. Mixing efficiencies can affect the early metallicity distribution function, the pre-enrichment levels in globular clusters, and also have an impact on the structure of dwarf systems at early times. Numerical models that include chemical evolution explicitly do a better job in reproducing the observations, and make interesting predictions for the nature of dwarf galaxies and their first stars at the earliest times.

  12. Population Signatures in Planetary Nebulae from Abundances of Fe-group and Neutron-Capture Elements

    Science.gov (United States)

    Dinerstein, Harriet L.; Geballe, Thomas R.; Sterling, N. C.

    2015-08-01

    There are two categories of elements for which abundances are measured in planetary nebulae (PNe). The first are species whose abundances may be modified by nuclear reactions in the star prior to PN formation, such as He, C, N, and nuclei made by slow neutron captures (Karakas & Lattanzio 2014, PASA, 31, 30). In contrast, elements unaffected by evolution should indicate the star’s initial composition. These include S, Ar, Cl, and (with certain exceptions) O and Ne, most of which are alpha species. A long-missing piece of the puzzle has been the abundances of the Fe-group elements. We cannot determine a meaningful elemental abundance from the gas-phase Fe lines seen in PNe, since Fe is heavily depleted into dust. Another approach is to use a different element as a proxy for Fe. Dinerstein & Geballe (2001, ApJ, 562, 515) identified a line at 3.625 μm as due to Zn, the least refractory Fe-group element. Observations of this line in Milky Way PNe yield -1 ≤ [Zn/H] ≤ 0 (Smith, Zijlstra, & Dinerstein 2014, MNRAS, 441, 3161; Dinerstein et al. 2015, in preparation). Substituting Zn for Fe, PNe can be placed in the [alpha/Fe] vs. [Fe/H] diagram used to characterize stellar populations. Dividing our sample into probable thin and thick disk members using the kinematic criterion of Peimbert’s Type II and III classes (1978, IAU Symp. 76, 215), we find that they occupy similar regions in [alpha/Fe] vs. [Fe/H] phase space as the stars of those populations. Elevated [alpha/Fe] values at subsolar [Fe/H], which tend to be higher for thick than thin disk PNe, cause degeneracies that make alpha species ambiguous metallicity indicators. This is important for self-enrichment studies, since if the initial abundance of an element is lower than projected from an alpha species, internal synthesis may be required to produce even a solar final abundance. Low observed abundances of the n-capture element Se suggest that many Type III PNe may have subsolar initial abundances of n

  13. Provenance determination of pottery by trace element analysis. Problems, solutions and applications

    International Nuclear Information System (INIS)

    Provenance determinations of pottery by chemical analysis is reviewed and shown to work well. Since pottery is produced from a well homogenized clay paste according to a certain recipe, sharp elemental patterns are expected for a series of products having the same origin. To obtain such patterns when forming compositional groups of pottery, a consideration of experimental errors, a correction for dilution and a choice of only stable elements is necessary. The patterns thus obtained will have low probability of overlap with groups of different origin. Examples for well defined groups of German stonewares and of Mycenaean wares from the Peloponnese are recorded. (author)

  14. The chemical thermodynamics of actinide elements and compounds

    International Nuclear Information System (INIS)

    This compilation forms the twelfth part of a comprehensive assessment and selection of actinide thermodynamic data. The other parts of the compilation deal mostly with actinide elements and compounds. This part, which is the last one to be published in this Series, concerns inorganic actinide complexes in aqueous solution. The properties considered include the stability constant as a function of ionic strength and temperature and, whenever possible, enthalpy and entropy values. The present assessment is based on a literature survey that was terminated in early 1989. In tabulating literature data, only experimental results were used; estimates as well as recalculated data were ignored. Unlike in previous assessments of this kind in this assessment the selection of a best value is discussed and justified, and reasons are given for the rejection of data. In addition, our estimates of the thermodynamic properties, based on interrelationships between analogous systems, are given when this can be done reliably. Another essential aim of this assessment is to indicate those areas in which additional research is required. Refs

  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. Thermal stability and thermodynamical characteristics of aluminium hydrides elements of II A group

    International Nuclear Information System (INIS)

    The purpose of this work is studying of de solvation processes, thermal decomposition of solvated tetra-hydro-aluminates elements of II A group and determination of thermodynamical characteristics of these processes

  17. Nuclear lattice model and the electronic configuration of the chemical elements

    OpenAIRE

    Garai, Jozsef

    2011-01-01

    The fundamental organizing principle resulting in the periodic table is the nuclear charge. Arranging the chemical elements in an increasing atomic number order, a symmetry pattern known as the Periodic Table is detectable. The correlation between nuclear charge and the Periodic System of the Chemical Elements (PSCE) indicates that the symmetry emerges from the nucleus. Nuclear symmetry can only exist if the relative positions of the nucleons in the nucleus are invariant. Pauli exclusion prin...

  18. Uptake, translocation, accumulation, and phytotoxicity of platinum group elements (PGE) on potato, lettuce, and barley.

    OpenAIRE

    Aboughalma, Hassan

    2004-01-01

    The transition elements platinum, palladium, and rhodium are widely used in the automobile industry. Production of catalytic converters is the principal application field of the so called Platinum Group Elements (PGE). Since the introduction of autocatalysts to reduce the emission of the greenhouse gases; CO, NOX, and HC, the concentration of PGE in environmental samples such as road dusts, soils, and plants is steadily increasing. The uptake pathways, accumulation, and t...

  19. Group separation of transplutonium and rare earth elements by liquid chromatography with free stationary phase using 2,4,6-tris[ditolylphosphoryl] - 1,3,5 - triazine as extractant

    International Nuclear Information System (INIS)

    Methods of group separation of trace amounts of transplutonium elements (TPE) and weight amounts of rare earth elements (REE) in the systems on the basis of bifunctional neutral organophosphoric compounds by the method of liquid chromatography with a free stationary phase have been developed. When solution of 2,4,6 - tris[ditolylphosphoryl] - 1,3,5 - triazine in chloroform was used as stationary phase, REE were the first to be washed out by 0.5 mol/l NH4SCN-1 mol/l HCl solution, then TPE - by 0.025 mol/l of oxyethylidenediphosphonic acid in water. the fractions contained about 100% of one of the groups without impurity of the other. 7 refs.; 6 figs

  20. 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.

  1. Reactivity calculations for the fuel elements of I.T.U. TRIGA MARK-II reactor by means of one-group perturbation theory

    International Nuclear Information System (INIS)

    The reactivities of the fuel elements of I.T.U. TRIGA MARK-II reactor has been calculated by using both one-group perturbation theory and a one-dimensional, two-group diffusion computer code TRIGAP. For each fuel element, reactivities calculated by both methods are compared with those measured experimentally. It is seen that the reactivity calculations made by using the one-group perturbation theory give the results with better accuracy in comparison to TRIGAP. One-group perturbation theory can be easily applied to the reactivity calculations of fuel elements of TRIGA type reactors in acceptable range (orig.)

  2. Relationship between the types of binary alloy phase diagrams of VIII and IB group elements and the Mendeleev numbers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The relationship between the types of binary alloy phase diagrams of Vlll and IB group elements and the Men deleev numbers was discussed for the first time using the Vlll and IB group elements as solvent metals (A) and the other elements as solute metals (B), basesd on their alloy phase diagram types. The Mendeleev numbers of the solvent metals and the solute metals were expressed as Ma and MB, respectively. A two-dimension map of MdMB was drawn. It is indicated that there is an oblique line in the map, which divides the binary alloy phase diagram types of solvent metals into two symmetry parts, the phase diagram types of the other elements with solvent metals located at the above or down of the line respectively, while on the line, AM= 0. The phase diagrams between the solvent metals basically are simple systems, mainly belong to the types of continues solid solution and the peritectic (about 40% for each type). The solvent metals can be divided into three groups: Co, Ir, Rh, Ni, Pt, and Pd as the first group; Ag, Au, and Cu as the second group;and Fe, Os, and Ru as the third group. The characteristics of the phase diagrams formed between the elements in each group were discussed. About 80% phase diagrams belong to complex systems and less than 20% belong to the simple systems. The regular variation of the chemical scale, the metallic radii of the atoms, the number of valence electrons, and the first ionization energy with the Mendeleev numbers and the crystal structure were introduced as well.

  3. On-line investigation of short-lived Os and Re isotopes as a test for chemical studies of 108 (Hs) and 107 (Bh) elements in HCl solutions by continuous chromatography

    International Nuclear Information System (INIS)

    On-line chemistry studies of short-lived isotopes of Os and Re, as homologs of 108 (Hs) and 107 (Bh), respectively, produced in the nuclear reactions at the (LNR, Dubna) cyclotron have been carried out. It was shown, that Os and Re are not sorbed on cation exchangers, but very strongly sorbed on anion exchangers from diluted HCl solutions. Re is also retained by a TOPO containing sorbent and may be separated from Os. The possibilities of chemical species and oxidation states investigation of short-lived transactinide elements by continuous chromatography have been shown. (author)

  4. Predicion of Chemical Element Contents in Soils

    Institute of Scientific and Technical Information of China (English)

    KESHAN-ZHE; QIANJUN-LONG; 等

    1994-01-01

    Assuming that the regularity for the dynamic changes of the chrono-sequences of chemical element contents in tree rings follows a k-order constant coefficient differential equation and substituting the differential with the difference,we could obtain the inferred value ym+k+1 by the formula:ym+k+1=c1ym+1+c2Ym+2+…ckym+kEach coefficient ci in the formula may be ascertained by use of the measured data in the chrono-sequences,Extending the chrono-sequences on the assumption that the regularity of dynamic changes wouldn't change in the near future,the contents of chemical elements in the soils may be predicted in terms of a logarithmic linear correlation model.Also,this extension method could be used for the reproduction of the contents of chemical elemets in soils during different periods of time in the past.

  5. Climbing elements in finite coxeter groups

    OpenAIRE

    Brady, Thomas; Kenny, Aisling; Watt, And Colum

    2010-01-01

    We define the notion of a climbing element in a finite real reflection group relative to a total order on the reflection set and we characterise these elements in the case where the total order arises from a bipartite Coxeter element.

  6. Universal algebra of a Hom-Lie algebra and group-like elements

    OpenAIRE

    Laurent-Gengoux, Camille; Makhlouf, Abdenacer; Teles, Joana

    2016-01-01

    We construct the universal enveloping algebra of a Hom-Lie algebra and endow it with a Hom-Hopf algebra structure. We discuss group-like elements that we see as a Hom-group integrating the initial Hom-Lie algebra.

  7. Universal Algebra of a Hom-Lie Algebra and group-like elements

    OpenAIRE

    Laurent-Gengoux, Camille; Makhlouf, Abdenacer; Teles, Joana

    2015-01-01

    We construct the universal enveloping algebra of a Hom-Lie algebra and endow it with a Hom-Hopf algebra structure. We discuss group-like elements that we see as a Hom-group integrating the initial Hom-Lie algebra.

  8. Determination of copper, scandium, molybdenum, tin, lead, and iron group elements in lunar surface materials

    Science.gov (United States)

    Pavlenko, L. I.; Simonova, L. V.; Karyakin, A. V.

    1974-01-01

    Distribution regularities of copper, scandium, molybdenum, tin, lead, and iron group elements were investigated in basaltoid rocks of lunar and terrestrial origin. Samples of various regolith zones taken in the area of the Sea of Fertility were analyzed, along with samples of basic and ultrabasic rocks of the East African Rift for their content of the trace admixtures listed. Data obtained on the abundance of copper, scandium, molybdenum, tin, lead, cobalt, nickel, chromium, and vanadium in Luna 16 lunar surface material were compared with the abundance of these elements in samples of lunar rocks returned by Apollo 11, Apollo 12, and Apollo 14, with the exception of scandium; its content in the latter samples was considerably higher.

  9. 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.

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

    CERN Document Server

    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 periodic table. The only specific recommendation provided by IUPAC is that the periodic table should follow the 1 to 18 group numbering. In this technical paper, we describe a new graphical representation of periodic table, referred as 'Circular form of Periodic table'. The advantages of circular form of periodic table over other representations are discussed along with a brief discussion on history of periodic tables.

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

    International Nuclear Information System (INIS)

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

    Energy Technology Data Exchange (ETDEWEB)

    Zbikowski, Radoslaw [Department of Food Sciences, Medical University of Gdansk, al. Gen. J Hallera 107, PL 80-416 Gdansk (Poland); Institute of Oceanography, University of Gdansk, Av. Pilsudskiego 46, PL 81-378 Gdynia (Poland); Szefer, Piotr [Department of Food Sciences, Medical University of Gdansk, al. Gen. J Hallera 107, PL 80-416 Gdansk (Poland)]. E-mail: pszef@amg.gda.pl; Latala, Adam [Institute of Oceanography, University of Gdansk, Av. Pilsudskiego 46, PL 81-378 Gdynia (Poland)

    2006-10-15

    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.

  13. 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...

  14. A new comprehensive set of elemental abundances in DLAs - II. Data analysis and chemical variation studies

    CERN Document Server

    Dessauges-Zavadsky, M; D'Odorico, S; Calura, F; Matteucci, F

    2005-01-01

    We present new elemental abundance studies of seven damped Lyman-alpha systems (DLAs). Together with the four DLAs analyzed in Dessauges-Zavadsky et al. (2004), we have a sample of eleven DLA galaxies with uniquely comprehensive and homogeneous abundance measurements. These observations allow one to study the abundance patterns of 22 elements and the chemical variations in the interstellar medium of galaxies outside the Local Group. Comparing the gas-phase abundance ratios of these high redshift galaxies, we found that they show low RMS dispersions, reaching only up 2-3 times the statistical errors for the majority of elements. This uniformity is remarkable given that the quasar sightlines cross gaseous regions with HI column densities spanning over one order of magnitude and metallicities ranging from 1/55 to 1/5 solar. The gas-phase abundance patterns of interstellar medium clouds within the DLA galaxies detected along the velocity profiles show, on the other hand, a high dispersion in several abundance rat...

  15. Scientific Realism and the Periodic Table of Chemical Elements

    OpenAIRE

    Sides, Jonathan David

    2006-01-01

    The periodic table poses a difficulty for both scientific realists and anti-realists. The antirealist has difficulty accounting for the success of the table during a period in chemistry when many theories and concepts changed; the spatial relations of current tables in use do not show fundamental changes from the original tables proposed by Mendeleev. Yet, most versions of scientific realism are based upon the understanding that theories are some collection of written propositi...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Extended Functional Groups (EFG: An Efficient Set for Chemical Characterization and Structure-Activity Relationship Studies of Chemical Compounds

    Directory of Open Access Journals (Sweden)

    Elena S. Salmina

    2015-12-01

    Full Text Available The article describes a classification system termed “extended functional groups” (EFG, which are an extension of a set previously used by the CheckMol software, that covers in addition heterocyclic compound classes and periodic table groups. The functional groups are defined as SMARTS patterns and are available as part of the ToxAlerts tool (http://ochem.eu/alerts of the On-line CHEmical database and Modeling (OCHEM environment platform. The article describes the motivation and the main ideas behind this extension and demonstrates that EFG can be efficiently used to develop and interpret structure-activity relationship models.

  18. Physical and chemical behavior of elements in uranium waste. 3

    International Nuclear Information System (INIS)

    Thermodynamic behavior of UF6 conversion was studied. From the results of theoretical calculations on the conversion from UF6 to UO2, the following reactions were thought to generate; UF6 + 2H2O = UO2F2 + 4HF (a), UO2F2 + H2 = 1/2UF4 + 1/2UO2 + H2O (b) and 1/2UF4 + H2O 1/2UO2 + 2HF (c) instead of UF6 + 2H2O = UO2F2 + 4HF (1), UO2 + H2O UO3 + 2HF (2) and UO3 + H2 = UO2 + H2O (3). UO2F2 is obtained easily by the hydrolysis of UF6. The appropriate temperature for hydrogen reduction of UO2F2 and water vapor oxidation of UF4 is more than 500 K and 950 K, respectively. Some experiments were carried out by a small reactor in order to confirm the above reaction (b). However, UO3 was produced without UO2 and UF4. This fact showed existence of oxygen. UO2F2 is hygroscopic and deliquescent. When UO2F2 was feed to the reactor, it contacted with air and UO2 was oxidized to UO3. (S.Y.)

  19. Fe-Group Elements in the Metal-Poor Star HD 84937: Abundances and their Implications

    Science.gov (United States)

    Sneden, Chris; Cowan, John J.; Kobayashi, Chiaki; Pignatari, Marco; Lawler, James E.; Den Hartog, Elizabeth; Wood, Michael P.

    2016-01-01

    We have derived accurate relative abundances of the Fe-group elements Sc through Zn in the very metal-poor main-sequence turnoff star HD 84937. For this study we analyzed high resolution, high signal-to-noise HST/STIS and VLT/UVES spectra over a total wavelength range 2300-7000 Å. We employed only recent or newly-applied reliable laboratory transition data for all species. Abundances from more than 600 lines of non-Fe species were combined with about 550 Fe lines in HD 84937 to yield abundance ratios of high precision. From parallel analyses of solar photospheric spectra we also derived new solar abundances of these elements. This in turn yielded internally-consistent relative HD 84937 abundances with respect to the Sun. For seven of the ten Fe-group elements the HD 84937 abundances were from both neutral and ionized transitions. In all of these cases the neutral and ionized species yield the same abundances within the measurement uncertainties. Therefore standard Saha ionization balance appears to hold in the HD 84937 atmosphere. We derived metallicity [Fe/H] = -2.32 with sample standard deviation of 0.06. Solid evidence is seen for departures from the solar abundance mix in HD 84937, for example [Co/Fe] = +0.14, [Cu/Fe] = -0.83, and = +0.31. Combining our Sc, Ti, and V abundances for this star with those from large-sample spectroscopic surveys suggests that these elements are positively correlated in stars with [Fe/H] analysis strongly suggests that different types of supernovae with a large scatter of explosion energies and asymmetries contributed to the creation of the Fe-group elements early in the Galaxy's history.This work has been supported in part by NASA grant NNX10AN93G (J.E.L.), by NSF grants AST-1211055 (J.E.L.), AST-1211585 (C.S.), PHY-1430152 (through JINA, J.J.C. and M.P.), EU MIRGCT-2006-046520 (M.P.), and by the ``Lendlet-2014'' Programme of the Hungarian Academy of Sciences (M.P.) and from SNF (Switzerland, M.P.).

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

    International Nuclear Information System (INIS)

    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).

  1. 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 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.

  2. 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.

  3. Epitaxial growth of group IV materials by chemical vapor deposition for Germanium Metal Oxide Semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, Benjamin; Loo, Roger; Caymax, Matty [imec, Kapeldreef 75, B-3001 Leuven (Belgium)

    2011-07-01

    Over the past 5-10 years, germanium has attracted a lot of interest to replace Silicon as a high carrier mobility material in future p-Metal Oxide Semiconductors transistors. This paper reviews developments of epitaxial Group IV materials (silicon, germanium, tin and alloys) by means of Reduced Pressure Chemical Vapor Deposition for use as Channel, Gate stack and Source/Drain in high performance Germanium transistors. We first describe Germanium growth on standard Silicon wafers. Selective epitaxial growth within Shallow Trench Isolation structures allows seamless integration of Germanium channels in Si platform with a significant defect reduction down to levels required for state-of-the-art VLSI technology. Next we focus on the most successful passivation approach for Germanium MOS interfaces by means of ultrathin epitaxial Si capping layers. This moves the problem of gate stack formation from a germanium surface to a silicon surface. We discuss novel extremely low temperature CVD processes involving innovative precursors, and impacts of point defects, strain relaxation and Silicon-Germanium intermixing on Germanium device performance. Finally, the implementation of Germanium-Tin alloys in embedded Source/Drain regions in Germanium transistors is proposed as an innovative architecture to implement strain in Germanium channels.

  4. Dietary intakes of essential and toxic elements in several groups of Nigerians consuming food exposed to specific industrial pollution sources

    International Nuclear Information System (INIS)

    Dietary intakes of essential and toxic trace elements in various groups of the population consuming food exposed to specific industrial pollutants will be assessed. Industries with clear-cut marker elemental pollutants and which have been in operation for many years are selected. For the first year of study, the tin and lead smelting industry in Jos, Plateau state of Nigeria will be the focus. The common food products (and total diets) that are grown within the locality will be surveyed, sampled and analysed for the marker elemental pollutants. Other essential trace elements which could influence the absorption and metabolism of the marker pollutants will also be studied. Trace element analysis will be carried out mainly by the IAEA-donated TR-XRF system in our laboratory. Afterwards, food frequency questionnaires will be administered to 30 subjects each from 16 sub-groups of the population and their dietary intakes of the various elements of interest will be assessed. The sub-groups are chosen to take care of sociological differences in feeding habits as well as possible variation in the biological tolerance of toxic trace elements. For 5 subjects from each group, blood and headhair samples will be collected and analysed for the elements of interest. Previously obtained results from preliminary studies are presented. (author)

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

    Indian Academy of Sciences (India)

    Ram Seshadri

    2001-10-01

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

  6. THE EFFECT OF DRAINAGE ON CHEMICAL ELEMENTS CONTENT OF MARSH

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper takes marsh in the Sanjiang Plain as an example in order to research the effect of draining on the chemical elements in marsh. The Sanjiang Ecological Test Station of Mire and Uetland serves as the resarch base. The authors selected soil samples in the Sanjiang Plain (the top and the end of the drain, marsh soil and degeneration marsh soil), mainly analyzed contents of main ions (HCO3-, Cl-, SO42-and NO3-), main heavy metals (Fe, Mn, Znand Cu), nutritive elements (N, P,K), organic matter and pH value. By testing these samples as above, the paper initially researches the effect on chemical elements content by draining by the means of the contrast of chemical elements contents between marsh soil and degenerative marsh soil and different characteristics of marsh soil elements. Results show that a lot of chemical elements had been lost because of draining.

  7. Multiple complexation of CO and related ligands to a main-group element.

    Science.gov (United States)

    Braunschweig, Holger; Dewhurst, Rian D; Hupp, Florian; Nutz, Marco; Radacki, Krzysztof; Tate, Christopher W; Vargas, Alfredo; Ye, Qing

    2015-06-18

    The ability of an atom or molecular fragment to bind multiple carbon monoxide (CO) molecules to form multicarbonyl adducts is a fundamental trait of transition metals. Transition-metal carbonyl complexes are vital to industry, appear naturally in the active sites of a number of enzymes (such as hydrogenases), are promising therapeutic agents, and have even been observed in interstellar dust clouds. Despite the wealth of established transition-metal multicarbonyl complexes, no elements outside groups 4 to 12 of the periodic table have yet been shown to react directly with two or more CO units to form stable multicarbonyl adducts. Here we present the synthesis of a borylene dicarbonyl complex, the first multicarbonyl complex of a main-group element prepared using CO. The compound is additionally stable towards ambient air and moisture. The synthetic strategy used--liberation of a borylene ligand from a transition metal using donor ligands--is broadly applicable, leading to a number of unprecedented monovalent boron species with different Lewis basic groups. The similarity of these compounds to conventional transition-metal carbonyl complexes is demonstrated by photolytic liberation of CO and subsequent intramolecular carbon-carbon bond activation. PMID:26085273

  8. Multiple complexation of CO and related ligands to a main-group element

    Science.gov (United States)

    Braunschweig, Holger; Dewhurst, Rian D.; Hupp, Florian; Nutz, Marco; Radacki, Krzysztof; Tate, Christopher W.; Vargas, Alfredo; Ye, Qing

    2015-06-01

    The ability of an atom or molecular fragment to bind multiple carbon monoxide (CO) molecules to form multicarbonyl adducts is a fundamental trait of transition metals. Transition-metal carbonyl complexes are vital to industry, appear naturally in the active sites of a number of enzymes (such as hydrogenases), are promising therapeutic agents, and have even been observed in interstellar dust clouds. Despite the wealth of established transition-metal multicarbonyl complexes, no elements outside groups 4 to 12 of the periodic table have yet been shown to react directly with two or more CO units to form stable multicarbonyl adducts. Here we present the synthesis of a borylene dicarbonyl complex, the first multicarbonyl complex of a main-group element prepared using CO. The compound is additionally stable towards ambient air and moisture. The synthetic strategy used--liberation of a borylene ligand from a transition metal using donor ligands--is broadly applicable, leading to a number of unprecedented monovalent boron species with different Lewis basic groups. The similarity of these compounds to conventional transition-metal carbonyl complexes is demonstrated by photolytic liberation of CO and subsequent intramolecular carbon-carbon bond activation.

  9. Numerical kinetic model including equilibrium and rate equations for chemical reactions of actinide elements

    International Nuclear Information System (INIS)

    Numerical simulation method was examined for chemical reactions of actinide elements U, Pu, Np, and Tc etc. in an aqueous nitric acid solution. It is known that the numerical calculation for the Purex process with chemical reactions and liquid flow becomes stiff, because time constant for the chemical reactions is two to three order of magnitude smaller due to the very fast reactions than that of mass transfer or of reaching distribution equilibrium. Recently in order to increase a time step Δt the partial equilibrium (P.E.) model, in which some very fast reactions are treated by the equilibrium law whereas other reactions are by the rate law, has been proposed. In the present study concentration change of the solutes in an aqueous solution with 30 chemical reactions, of which 4 are expressed by equilibrium equations, has been calculated. Description of the P.E. model and the comparison of the results and cpu time between the kinetic and the P.E. models are given. (author)

  10. Common Data Elements for Pediatric Traumatic Brain Injury: Recommendations from the Working Group on Demographics and Clinical Assessment

    OpenAIRE

    Adelson, P. David; Pineda, Jose; Bell, Michael J.; Nicholas S. Abend; Berger, Rachel P.; Giza, Christopher C.; Hotz, Gillian; Mark S Wainwright

    2012-01-01

    The Common Data Elements (CDEs) initiative is a National Institutes of Health (NIH) interagency effort to standardize naming, definitions, and data structure for clinical research variables. Comparisons of the results of clinical studies of neurological disorders have been hampered by variability in data coding, definitions, and procedures for sample collection. The CDE project objective is to enable comparison of future clinical trials results in major neurological disorders, including traum...

  11. Numerical simulation of isothermal chemical vapor infiltration process in fabrication of carbon-carbon composites by finite element method

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The chemical vapor infiltration process in fabrication of carbon-carbon composites is highly inefficient and requires long processing time. These limitations add considerably to the cost of fabrication and restrict the application of this material. Efforts have been made to study the CVI process in fabrication of carbon-carbon composites by computer simulation and predict the process parameters, density, porosity, etc. According to the characteristics of CVI process, the basic principle of FEM and mass transport, the finite element model has been established. Incremental finite element equations and the elemental stiffness matrices have been derived for the first time. The finite element program developed by the authors has been used to simulate the ICVI process in fabrication of carbon-carbon composites. Computer color display of simulated results can express the densification and distributions of density and porosity in preform clearly. The influence of process parameters on the densification of preform has been analyzed. The numerically simulated and experimental results give a good agreement.

  12. Anomalous Behaviour of a Protein During Sds/Page Corrected by Chemical Modification of Carboxylic Groups

    OpenAIRE

    Matagne, André; Joris, Bernard; Frère, Jean-Marie

    1991-01-01

    The 29,000-Mr Actinomadura R39 beta-lactamase exhibited a remarkably low electrophoretic mobility on SDS/PAGE, yielding an Mr value almost twice that computed from the corresponding gene sequence. We showed that chemical modification of the carboxylic groups of glutamic acid and aspartic acid residues restored a normal electrophoretic mobility and that the anomalous behaviour of that protein on SDS/PAGE was due to its very large negative charge at neutral pH. We also compared the behaviour of...

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

    CERN Document Server

    Van Kortryk, T S

    2015-01-01

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

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

    CERN Document Server

    Haaland, Arne

    2008-01-01

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

  15. Tough by name, tough by nature.

    Science.gov (United States)

    Baillie, Jonathan

    2015-04-01

    Few beds, one would imagine, could withstand three-quarters of a ton landing on them, but this was the challenge successfully met by a box bed from a furniture manufacturer for challenging behaviour environments, Tough Furniture, when, to reassure a customer that the bed could accommodate 30-stone patients, 13 of the company's staff jumped repeatedly on it to ensure that it would survive intact in a real-world setting. Such testing may seem extreme, but is vital, since much of the company's furniture is destined for environments where patients will abuse, and indeed attempt to destroy, components. As MD David Vesty explained to HEJ editor, Jonathan Baillie, when he visited the company's Shropshire headquarters, it is through manufacturing premium quality cabinet furniture that is both attractive and distinctly non-institutional, but will equally withstand the harshest use, that the company has ensured that its products can live up to the brand name. PMID:26281428

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

    Science.gov (United States)

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

    2007-01-01

    The major element relationships in ferromanganese (Fe-Mn) crusts from Afanasiy-Nikitin seamount (ANS), eastern equatorial Indian Ocean, appear to be atypical. High positive correlations (r = 0.99) between Mn/Co and Fe/Co ratios, and lack of correlation of those ratios with Co, Ce, and Ce/Co, indicate that the ANS Fe-Mn crusts are distinct from Pacific seamount Fe-Mn crusts, and reflect region-specific chemical characteristics. The platinum group elements (PGE: Ir, Ru, Rh, Pt, and Pd) and Au in ANS Fe-Mn crusts are derived from seawater and are mainly of terrestrial origin, with a minor cosmogenic component. The Ru/Rh (0.5-2) and Pt/Ru ratios (7-28) are closely comparable to ratios in continental basalts, whereas Pd/Ir ratios exhibit values ( 0.75) correlations between water depth and Mn/Co, Fe/Co, Ce/Co, Co, and the PGEs. Fractionation of the PGE-Au from seawater during colloidal precipitation of the major-oxide phases is indicated by well-defined linear positive correlations (r > 0.8) of Co and Ce with Ir, Ru, Rh, and Pt; Au/Co with Mn/Co; and by weak or no correlations of Pd with water depth, Co-normalized major-element ratios, and with the other PGE (r fractionation of PGE-Au and their positive association with redox sensitive Co and Ce may have applications in reconstructing past-ocean redox conditions and water masses.

  17. Finite element analysis of second order wave radiation by a group of cylinders in the time domain

    Institute of Scientific and Technical Information of China (English)

    WANG Chi-zhong; MITRA Santanu; HUANG Hao-cai; KHOO Boo-cheong

    2013-01-01

    A finite element based numerical method is employed to analyze the wave radiation by multiple or a group of cylinders in the time domain.The nonlinear free surface and body surface boundary conditions are satisfied based on the perturbation method up to the second order.The first-and second-order velocity potential problems at each time step are solved through a Finite Element Method (FEM).The matrix equation of the FEM is solved through iteration and the initial solution is obtained from the result at the previous time step.The three-dimensional (3-D) mesh required is generated based on a two-dimensional (2-D) hybrid mesh on a horizontal plane and its extension in the vertical direction.The hybrid mesh is generated by combining an unstructured grid away from cylinders and two structured grids near the cylinder and the artificial boundary.The fluid velocity on the free surface and the cylinder surface are calculated by using a differential method.Results for various configurations including the cases of two cylinders and four cylinders and a group of eighteen cylinders are obtained to show the joint influences of cylinders on the first-and secondorder waves and forces,including the effects of spacing ratios and wave frequency on the second order waves and the mean force,in particular.

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

    Indian Academy of Sciences (India)

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

    2007-02-01

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

  19. Chemical Nomenclature and Terminology in the Light of Nationalism

    OpenAIRE

    Raos N.

    2015-01-01

    Chemical nomenclature and terminology are not only determined by the development of chemistry, but also by linguistic policies of the nation which uses them. The first modern chemical nomenclature, developed in France at the end of the 18th century, had been intended for international usage, and thus the names of new elements were developed from Greek and Latin roots. Conversely, in Germany the names of elements were coined in strict reference to the German language. In Croatia, both tende...

  20. Localizing chemical groups while imaging single native proteins by high-resolution atomic force microscopy.

    Science.gov (United States)

    Pfreundschuh, Moritz; Alsteens, David; Hilbert, Manuel; Steinmetz, Michel O; Müller, Daniel J

    2014-05-14

    Simultaneous high-resolution imaging and localization of chemical interaction sites on single native proteins is a pertinent biophysical, biochemical, and nanotechnological challenge. Such structural mapping and characterization of binding sites is of importance in understanding how proteins interact with their environment and in manipulating such interactions in a plethora of biotechnological applications. Thus far, this challenge remains to be tackled. Here, we introduce force-distance curve-based atomic force microscopy (FD-based AFM) for the high-resolution imaging of SAS-6, a protein that self-assembles into cartwheel-like structures. Using functionalized AFM tips bearing Ni(2+)-N-nitrilotriacetate groups, we locate specific interaction sites on SAS-6 at nanometer resolution and quantify the binding strength of the Ni(2+)-NTA groups to histidine residues. The FD-based AFM approach can readily be applied to image any other native protein and to locate and structurally map histidine residues. Moreover, the surface chemistry used to functionalize the AFM tip can be modified to map other chemical interaction sites. PMID:24766578

  1. Recognition of cigarette brand names and logos by primary schoolchildren in Ankara, Turkey

    OpenAIRE

    Emri, S; Bagci, T.; Karakoca, Y.; Baris, E

    1998-01-01

    OBJECTIVE—To assess the smoking behaviour of primary schoolchildren and their ability to recognise brand names and logos of widely advertised cigarettes, compared with other commercial products intended for children.
DESIGN—Cross-sectional survey in classroom settings using a questionnaire designed to measure attitudes towards smoking and the recognition of brand names and logos for 16 food, beverage, cigarette, and toothpaste products.
SETTING—Ankara, Turkey.
SUBJECTS—1093 children (54.6% bo...

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

    CERN Document Server

    Wahl, Ulrich; Mendonça, Tânia; Decoster, Stefan

    2010-01-01

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

  3. First principles calculation of material properties of group IV elements and III-V compounds

    OpenAIRE

    Malone, Brad Dean

    2012-01-01

    This thesis presents first principles calculations on the properties of group IV elements and group III-V compounds. It includes investigations into what structure a material is likely to form in, and given that structure, what are its electronic, optical, and lattice dynamical properties as well as what are the properties of defects that might be introduced into the sample. The thesis is divided as follows:Chapter 1 contains some of the conceptual foundations used in the present work. These ...

  4. Ubiquitous place names Standardization and study in Indonesia

    Directory of Open Access Journals (Sweden)

    Allan F. Lauder

    2015-07-01

    Full Text Available Place names play a vital role in human society. Names exist in all languages and place names are an indispensible part of international communication. This has been acknowledged by the establishment of the United Nations Group of Experts on Geographical Names (UNGEGN. One of UNGEGN’s tasks is to coordinate international efforts on the proper use of place names. Indonesia supports this effort and through its National Geospatial Agency (BIG. Place names are also of interest as an object of study in themselves. Academic studies into place names are found in linguistics, onomastics, philosophy and a number of other academic disciplines. This article looks at these two dimensions of place names, standardization efforts under the auspices of international and national bodies, and academic studies of names, with particular reference to the situation in Indonesia.

  5. Grace by Any Other Name.

    Science.gov (United States)

    Atkinson, Robert

    1981-01-01

    Explores how conscious effort often precipitates grace, insight and peak experiences which encourage growth and development. Suggests counselors encourage the expression of attitudes and feelings but refrain from making judgements too quickly and imposing their own moral system on the client. (JAC)

  6. A family of names : rune-names and ogam-names and their relation to alphabet letter-names

    NARCIS (Netherlands)

    Griffiths, Alan

    2013-01-01

    The current consensus is that vernacular names assigned to the runes of the Germanic fuþark and to Irish ogam characters are indigenous creations independent of Mediterranean alphabet traditions. I propose, however, that ogam-names are based on interpretations of Hebrew, Greek or Latin letter-names

  7. Element-by-element and implicit-explicit finite element formulations for computational fluid dynamics

    Science.gov (United States)

    Tezduyar, T. E.; Liou, J.

    1988-01-01

    Preconditioner algorithms to reduce the computational effort in FEM analyses of large-scale fluid-dynamics problems are presented. A general model problem is constructed on the basis of the convection-diffusion equation and the two-dimensional vorticity/stream-function formulation of the Navier-Stokes equations; this problem is then analyzed using element-by-element, implicit-explicit, and adaptive implicit-explicit approximation schemes. Numerical results for the two-dimensional advection and rigid-body rotation of a cosine hill, flow past a circular cylinder, and driven cavity flow are presented in extensive graphs and shown to be in good agreement with those obtained using implicit methods.

  8. The XPS study of physical and chemical forms of neptunium group on the surface of minerals

    Directory of Open Access Journals (Sweden)

    Teterin Anton Yu.

    2010-01-01

    Full Text Available The sorption behavior and the physical and chemical forms of neptunium on the surface of minerals of the two chlorate samples, biotite and kaolin, with different contents of Fe(II was studied. The liquid-liquid extraction and the X-ray photoelectron spectroscopy were employed to identify the valence forms of neptunium. On the basis of the obtained data the quantitative elemental composition of the surface of the studied minerals, as well as the ionic composition of the formed neptunium complexes was determined. It was shown that the Np(IV and Np(VI containing compounds did not form, while the complexes Np(VO+ -hydroxyl did form on the surface. The oxygen ions bonded with iron and oxygen belonging to water and/or of carboxyl were suggested to be present in the equatorial plane of the neptunyl group NpO+.

  9. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    through using mathematical names for the numbers such as one-ten-one for 11 and five-ten-six for 56. The project combines the renaming of numbers with supporting the teaching with the new number names. Our hypothesis is that Danish children have more difficulties learning and working with numbers, because...... the Danish number names are more complicated than in other languages. Keywords: A research project in grade 0 and 1th in a Danish school, Base-10 system, two-digit number names, semiotic, cognitive perspectives....

  10. Variation of fine structure constant and nuclear size from isotope shift of Group III elements

    International Nuclear Information System (INIS)

    Interpretation of precise isotope-shift (IS) theory is formalism dependent, and care must be exercised in interpreting these results and those obtained from relativistic many-electron ab-initio calculations. Here nuclear size or specifically, nuclear charge radii have been estimated with high accuracy. Important consequence of IS is shifting of spectral lines which is observed in quasar medium. Accurate calculation of IS will provide light on the variation of fine structure constant α as shifting depends on both. Now interestingly both of the phenomena have same magnitude of effects. So without highly accurate study of IS, nobody can comment on α variation. The study of particle physics beyond standard model demands precise calculation of Parity non-conservation (PNC) effect. PNC effect depends on the charge distribution of the nucleus. The shifting of the energy levels due to the change of the model of the nucleus from point type to Fermi distribution type is a great tool to calculate the most realistic rms radius of the nucleus. This shifting is called the Volume Shift or Field Shift (FS). So calculations with higher accuracy of volume shift take important role in these studies. A large number of researchers involved in this field since last two decades. They used different theories but none of them are all order method, which is extremely necessary for Specific Mass Shift (SMS) Calculations. We are applying here the relativistic coupled cluster (RCC) theory in self-consistent way. RCC is well known as highly correlated all order method. Here we present the IS- study on a few Group III elements. The group III elements are single valence elements. P1/2 state is their ground state and P3/2 state is their first excited state which is a metastable state. We study how the lifetime of this metastable state is effected by all three parts of the IS which are SMS, NMS and FS. The most abundant isotopes of the elements of this group such as 11B, 27AI, 69Ga etc. possess a

  11. Dimetallaheteroborane clusters containing group 16 elements: A combined experimental and theoretical study

    Indian Academy of Sciences (India)

    Kiran Kumarvarma Chakrahari; Rongala Ramalakshmi; Dudekula Sharmila; Sundargopal Ghosh

    2014-09-01

    Recently we described the synthesis and structural characterization of various dimetallaherteroborane clusters, namely nido-[(Cp∗Mo)2B4EClH6−], 1-3; (1: E = S, x = 0; 2: E = Se, x = 0; 3: E = Te, x = 1). A combined theoretical and experimental study was also performed, which demonstrated that the clusters 1-3 with their open face are excellent precursors for cluster growth reaction. In this investigation process on the reactivity of dimetallaheteroboranes with metal carbonyls, in addition to [(Cp∗Mo)2B4H6EFe(CO)3] (4: E = S, 6: E = Te) reported earlier, reaction of 2 with [Fe2(CO)9] yielded mixed-metallaselenaborane [(Cp∗Mo)2B4H6SeFe(CO)3], 5 in good yield. The quantum chemical calculation using DFT method has been carried out to probe the bonding, NMR chemical shifts and electronic properties of dimolybdaheteroborane clusters 4-6.

  12. Call-by-name, call-by-value, call-by-need and the linear lambda calculus

    OpenAIRE

    Maraist, J.; Odersky, M.; Turner, D.N.; Wadler, P.

    1999-01-01

    Girard described two translations of intuitionistic logic into linear logic, one where A→B maps to (!A⊸B) and another where it maps to !(A⊸B). We detail the action of these translations on terms and show that the first corresponds to a call-by-name calculus, while the second corresponds to call-by-value. We further show that if the target of the translation is taken to be an affine calculus, where! controls contraction but weakening is allowed everywhere, then the second translation correspon...

  13. Call-by-name, Call-by-value, Call-by-need, and the Linear Lambda Calculus

    OpenAIRE

    Maraist, John; Odersky, Martin; Turner, David N.; Wadler, Philip

    1995-01-01

    Girard described two translations of intuitionistic logic into linear logic, one where A -> B maps to (!A) -o B, and another where it maps to !(A -o B). We detail the action of these translations on terms, and show that the first corresponds to a call-by-name calculus, while the second corresponds to call-by-value. We further show that if the target of the translation is taken to be an affine calculus, where ! controls contraction but weakening is allowed everywhere, then the second transl...

  14. meeting) structurally related to a subgroup of substances within the group of ‘ Furfuryl and furan derivatives with and without additional side - chain substituents and heteroatoms from chemical group 14’ evaluated by JECFA in FGE.13Rev2 (2011)

    DEFF Research Database (Denmark)

    Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further...... evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The substances are evaluated through a stepwise approach that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism and...... toxicity. FGE.65 concerns a group of 33 sulfur-substituted furan derivatives evaluated by the JECFA at their 59th meeting. The Panel concluded in FGE.65 that the evaluation could not be finalised for four of the 33 substances [FL-no: 13.056, 13.160, 13.193 and 13.194] due to lack of toxicity data. In the...

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

    International Nuclear Information System (INIS)

    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

  16. Call-by-Value and Call-by-Name Dual Calculi with Inductive and Coinductive Types

    OpenAIRE

    Kimura, Daisuke; Tatsuta, Makoto

    2013-01-01

    This paper extends the dual calculus with inductive types and coinductive types. The paper first introduces a non-deterministic dual calculus with inductive and coinductive types. Besides the same duality of the original dual calculus, it has the duality of inductive and coinductive types, that is, the duality of terms and coterms for inductive and coinductive types, and the duality of their reduction rules. Its strong normalization is also proved, which is shown by translating it into a seco...

  17. Aboriginal Placenames : Naming and re-naming the Australian landscape

    OpenAIRE

    Hercus, Luise; Koch, Harold

    2009-01-01

    Aboriginal approaches to the naming of places across Australia differ radically from the official introduced Anglo-Australian system. However, many of these earlier names have been incorporated into contemporary nomenclature, with considerable reinterpretations of their function and form. Recently, state jurisdictions have encouraged the adoption of a greater number of Indigenous names, sometimes alongside the accepted Anglo-Australian terms, around Sydney Harbour, for example. In some cases,...

  18. The Ekamanganese elements

    International Nuclear Information System (INIS)

    A recent study tends to revalidate the search for element 43 done in 1925. In ores with properties similar to the hypothetical chemical properties of the missing elements 43 and 75, the unknown elements were concentrated by chemical means. Roentgen-ray spectroscopy was applied in order to observe the characteristic Roentgen L lines for element 75 and K lines for element 43. Element 43 was observed in sperrylith, gadolinit, fergusonit and columbit. The name masurium was proposed. Similarly, element 75 was observed in tantalit, wolframit and platinit. The name rhenium was chosen. (MCB)

  19. The origin of the chemical elements

    International Nuclear Information System (INIS)

    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.)

  20. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    This paper concerns the results from the first year of a three-year research project involving the relationship between Danish number names and their corresponding digits in the canonical base 10 system. The project aims to develop a system to help the students’ understanding of the base 10 system...... through using mathematical names for the numbers such as one-ten-one for 11 and five-ten-six for 56. The project combines the renaming of numbers with supporting the teaching with the new number names. Our hypothesis is that Danish children have more difficulties learning and working with numbers, because...... the Danish number names are more complicated than in other languages. Keywords: A research project in grade 0 and 1th in a Danish school, Base-10 system, two-digit number names, semiotic, cognitive perspectives....

  1. Synthesis, structural features and physical properties of antimonites of the third group of elements

    International Nuclear Information System (INIS)

    Crystallization in the Sb2-O3-Me2O3-R-H2O systems (Me=Ine Sc, Y, La, Pr Tb, Yb; R=KF, CsF, KHF2) has been investigated and conditions of the reactions of the In3Sb5O12, Sc3Sb5O12, La3Sb5O13, Pr3Sb5O12. Tb3Sb5O12 and Yb3Sb5O12 monocrystal formation are analyzed. It is shown that antimonites of the third group elements are characterized by the presence of phase transformations and some of them possess pyroelectric and electroacoustic properties valuable for engineering

  2. "What's Your Name?": Names, Naming Practices, and Contextualized Selves of Young Korean American Children

    Science.gov (United States)

    Kim, Jinhee; Lee, Kyunghwa

    2011-01-01

    This study examined how young Korean American children and the adults around these children perform naming practices and what these practices mean to the children. As part of a large ethnographic study on Korean American children's peer culture in a heritage language school in the United States, data were collected by observing 11 prekindergarten…

  3. Spontaneous Double Hydrometallation Induced by N→M Coordination in Organometallic Hydrides of Group 14 Elements.

    Science.gov (United States)

    Novák, Miroslav; Dostál, Libor; Turek, Jan; Alonso, Mercedes; De Proft, Frank; Růžička, Aleš; Jambor, Roman

    2016-04-11

    Our attempts to synthesise N→M intramolecularly coordinated diorganometallic hydrides L2 MH2 [M=Si (4), Ge (5), Sn (6)] containing the CH=N imine group (in which L is C,N-chelating ligand {2-[(2,6-iPr2 C6 H3 )N=CH]C6 H4 }(-) ) yielded 1,1'-bis(2,6-diisopropylphenyl)-2,2'-spriobi[benzo[c][1,2]azasilole] (7), 1,1'-bis(2,6-diisopropylphenyl)-2,2'-spriobi[benzo[c][1,2]azagermole] (8) and C,N-chelated homoleptic stannylene L2 Sn (10), respectively. Compounds 7 and 8 are an outcome of a spontaneous double hydrometallation of the two CH=N imine moieties induced by N→M intramolecular coordination (M=Si, Ge) in the absence of any catalyst. In contrast, the diorganotin hydride L2 SnH2 (6) is redox-unstable and the reduction of the tin centre with the elimination of H2 provided the C,N-chelated homoleptic stannylene L2 Sn (10). Compounds 7 and 8 were characterised by NMR spectroscopy and X-ray diffraction analysis. Because the proposed N→M intramolecularly coordinated diorganometallic hydrides L2 MH2 [M=Si (4), Ge (5), Sn (6)] revealed two different types of reduction reactions, DFT calculations were performed to gain an insight into the structures and bonding of the non-isolable diorganometallic hydrides as well as the products of their subsequent reactions. Furthermore, the thermodynamic profiles of the different reaction pathways with respect to the central metal atom were also investigated. PMID:26934563

  4. [Structure and evolutionary role of the Penelope mobile element in Drosophila species of the virilis group].

    Science.gov (United States)

    Lezin, G T; Makarova, K V; Velikodvorskaia, V V; Zelentsova, E S; Kechumian, R R; Kidwell, M G; Kunin, E V; Evgen'ev, M B

    2001-01-01

    The mobile element Penelope is activated and mobilizes several other transposons in dysgenic crosses in Drosophila virilis. Its structure proved to be complex and to vary greatly in all examined species of the virilis group. Phylogenetic analysis of the reverse transcriptase (RT) domain assigned Penelope to a new branch, rather than to any known family, of LTR-lacking retroelements. Amino acid sequence analysis showed that the C-terminal domain of the Penelope polyprotein is an active endonuclease, which is related to intron-encoded endonucleases and to bacterial repair endonuclease UrvC, and may act as an integras. Retroelements coding for a putative endonuclease that differs from typical integrase have thus far not been known. The N-terminal domain of the Penelope polyprotein was shown to contain a protease with significant homology to HIV-1 protease. Phylogenetic analysis divided the Penelope copies from several virilis species into two subfamilies, one including virtually identical full-length copies, and the other comprising highly divergent defective copies. The results suggest both vertical and horizontal transfer of the element. Possibly, Penelope invasion recurred during evolution and contributed to genome rearrangement in the virilis species. Chromosome aberrations detected in D. virilis, which is now being invaded by Penelope, is direct evidence for this assumption. PMID:11605533

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

    International Nuclear Information System (INIS)

    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 X3M-L species (X=F, Cl; M=La, Nd, U; L = NH3, 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)

  6. Psychological Impact of First Names:Individual Level and Group Level Evidence%名字的心理效应:来自个体层面和群体层面的证据

    Institute of Scientific and Technical Information of China (English)

    苏红; 任孝鹏

    2015-01-01

    First name, a typical term used for identification, plays an extremely important role in social interactions. First names are among the earliest information available to people, given how quite often these are very first data exchanged during interpersonal communication. Recently, the rapid development of Internet, which is not necessarily inclusive of “face to face” contacts, has made the first names even more increasingly prominent and important in the initial interpersonal interaction stages. We have systematically reviewed relevant studies in psychology about first names at individual level and group level. At the individual level, researchers focused on the relations between first names and other psychological variables, like the relation between first names and self-identity of those who possess the names or the relation between first names and others’ evaluations of name-possessors. Studies revealed that first names can influence individual’s psychological state as well as name-possessors’ behavior. At the group level, as cultural products, first names have been used to examine the cultural evolution and cultural identity, which was mainly done by analyzing the frequency change of first names. Previous studies mostly focused on Western culture and respective first names practices, while little focus was placed on empirically exploring the distinctiveness of Chinese names. Since Chinese culture has its own cultural particularities, including the naming practices, psychologist should look further into these. Future empirical research should focus more on indigenous first names, like exploring changes in Chinese cross-generational individuality by using the percentage of Chinese popular names, or exploring the relation between masculine/feminine names and job-hunting or online-dating.%作为典型的标识符号名字在社会认知过程中发挥着重要的识别功能,随着互联网对人际互动方式的影响更加突出,名字作为交往

  7. Cortical distribution of speech and language errors investigated by visual object naming and navigated transcranial magnetic stimulation.

    Science.gov (United States)

    Krieg, Sandro M; Sollmann, Nico; Tanigawa, Noriko; Foerschler, Annette; Meyer, Bernhard; Ringel, Florian

    2016-05-01

    Navigated transcranial magnetic stimulation (nTMS) gains increasing importance in presurgical language mapping. Although bipolar direct cortical stimulation (DCS) is regarded as the gold standard for intraoperative mapping of language-related areas, it cannot be used to map the healthy human brain due to its invasive character. Therefore, the present study employed a non-invasive virtual-lesion modality to provide a causality-confirmed cortical language map of the healthy human brain by repetitive nTMS (rTMS) with functional specifications beyond language-positive/language-negative distinction. Fifty right-handed healthy volunteers underwent rTMS language mapping of the left hemisphere combined with an object-naming task. The induced errors were categorized and frequency maps were calculated. Moreover, a principal component analysis (PCA) was performed on the basis of language-positive cortical regions for each error category. The left hemisphere was stimulated at 258-789 sites (median: 361.5 sites), and 12-241 naming errors (median: 72.5 errors) were observed. In male subjects, a total number of 2091 language errors were elicited by 9579 stimulation trains, which is equal to an error rate of 21.8 %. Within females, 10,238 stimulation trains elicited 2032 language errors (19.8 %). PCA revealed that the inferior parietal lobe (IPL) and middle frontal gyrus (MFG) were causally involved in object naming as a semantic center and an executive control center. For the first time, this study provides causality-based data and a model that approximates the distribution of language-related cortical areas grouped for different functional aspects of single-word production processes by PCA. PMID:25894631

  8. Meeting of October 20, 2005 of the working group about the division by 4 of greenhouse gas emissions of France at the 2050 prospects, named 'factor 4'

    International Nuclear Information System (INIS)

    This document gathers 4 presentations given at this meeting of the 'Factor 4' working group: the first presentation (C. Parent) presents the 2050 prospective of transports demand and the transport offer variables (world context, specific European actions, French context and taxation, impact of the different scenarios on road traffic, energy consumption and CO2 emissions). The second presentation (P. Aussourd) treats of the energy approaches of the transport prospective for 2050 (definition of 4 scenarios, global consequences in terms of fiscal income, energy consumption and CO2 emissions, lessons gained, possibility of an incremental scenario with chargeable hybrid vehicles, use of short crises for a long-term action in the change of life styles). The third presentation (R. Lavergne) deals with the energy prospective for the energy demand in France at the 2050 prospects (definition of a reference scenario, sectoral analysis, main hypotheses, critical points). The last presentation (H. Prevot) explains how it is possible for France to divide by 2 or 3 the CO2 emissions with keeping the same energy consumption as for the year 2000 (optimum combination of energy sources, use of biomass and solar space heating, power generation by nuclear energy, coal with CO2 sequestration and wind energy, evolution of fuel prices, role of the public action and of the government, convincing the decision makers). (J.S.)

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

    International Nuclear Information System (INIS)

    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)

  10. Geophysical Imaging of the Stillwater and Bushveld Complexes and Relation to Platinum-group Element Exploration

    Science.gov (United States)

    Finn, C.; Bedrosian, P.; Zientek, M. L.; Cole, J.; Webb, S. J.; Bloss, B. R.

    2015-12-01

    Exploring for platinum-group elements (PGEs) relies on understanding the geophysical signature of the entire magmatic system in which they form, from bottom to top. New potential field and electromagnetic data and methods effectively map internal structures of layered intrusions that host PGE-bearing magmatic ore deposits, the volume of the intrusion and its extent under cover, and locations of sulfide mineralization. High resolution aeromagnetic data can image fine scale linear anomalies related to layering in the Stillwater and Bushveld Complexes. At Stillwater, the aeromagnetic anomalies relate to boundaries between major stratigraphic units and olivine-bearing rock layers altered to a mixture of serpentine and magnetite. The PGE-enriched sulfide mineralization hosted by olivine-bearing rocks in the Stillwater Complex produces a distinct linear magnetic high. In the Upper Zone of the Bushveld Complex, primary magnetite layers generate linear magnetic highs. Electromagnetic (EM) data over the Stillwater Complex highlight contact-type mineralization which contain low resistivity sulfide minerals. Stochastic inversions reveal a low resistivity zone along the southern edge of the Stillwater Complex corresponding to mineralization in banded iron formation or contact-type sulfide mineralization in the Basal zone. Gravity highs characterize the exposed and interpreted buried extent of the Stillwater and Bushveld complexes. A 3D inversion of gravity data of the Sillwater Complex indicates that the complex extends 30 km north and 40 km east of its outcrop beneath Phanerozoic cover. Geophysical models image the 3D geometry of the Bushveld Complex north of the Thabazimbi-Murchison Lineament (TML), critical for understanding the origin of the world's largest layered mafic intrusion and associated platinum- group element deposits, as a ~4 km thick, 160 km x ~125 km body underlying ~1-2 km of cover. Locally thick regions in the TML portion of the model may represent feeders

  11. Room temperature ferromagnetism in Ist group elements codoped ZnO:Fe nanoparticles by co-precipitation method

    Science.gov (United States)

    Pazhanivelu, V.; Paul Blessington Selvadurai, A.; Kannan, R.; Murugaraj, R.

    2016-04-01

    In this paper, we report on the structural, vibrational and magnetic behavior of Ist group elements (Li+, Na+ and K+) codoping effect in ZnO:Fe nanoparticles (NPs) prepared by co-precipitation method. The single crystalline phase of the prepared NPs was identified as Wurtizite structure and the Raman spectra expressed the local structural change and the presence of complex lattice defects such as Zinc interstitial (Zni) and Oxygen vacanvy (V+o) defects in the NPs. The presence of functional groups was confirmed by FT-IR spectral analysis. The optical absorption properties of the prepared NPs were characterised by UV-Drs spectroscopy. The valance state of Zinc ions and the role of Oxygen related defects were analysed from x-ray photoelectron spectroscopy (XPS) spectra. The electron paramagnetic resonance (EPR) spectral line illustrated the presence of complex defects such as Zinc interstitial (Zni) and oxygen vacancy (V+o) defects in the sample. The observed room temperature ferromagnetism (RTFM) in the prepared sample was induced by lattice defects. The observed results are discussed and reported.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 25th 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 137Cs, 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)

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

    International Nuclear Information System (INIS)

    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)

  15. Science, names giving and names calling: Change NDM-1 to PCM

    Directory of Open Access Journals (Sweden)

    Ajai R Singh

    2011-03-01

    Full Text Available A journal editor recently apologised for publishing a 2010 paper in which authors designated an enzyme as New Delhi metallo-β-lactamase-1 (NDM-1 and its related gene blaNDM-1 after a city, New Delhi. This name had raised an outcry in India, with health authorities, media and medical practitioners demanding New Delhi be dropped from the name. The name was actually first given in another 2009 paper, whose corresponding author remains the same as the 2010 paper. There is a tradition of eponymous names in science. But those found derogatory to races, groups, cities, and countries have been changed. For example, "Mongolism" was changed to Down's syndrome; "Australia" antigen to HBsAg; "Mexican" Swine flu to H1N1; "GRID" (Gay Related Immune Deficiency and 4H-Disease (Haitians, Homosexuals, Haemophiliacs and Heroin Users Disease to AIDS. It is necessary that NDM-1 also be changed to a name based on scientific characteristics. NDM-1 must be changed to PCM (plasmid-encoding carbapenemase-resistant metallo-β-lactamase. It is also necessary to review the tradition of naming organisms, diseases, genes, etc. after cities, countries and races. Often, such names giving amounts to names calling. It needs to be discarded by scientists in all new names giving from now on. "Geographical" and "racial" names giving must be replaced by "scientific" names giving. Journal editors must ensure that such scientific names giving is laid down as standard guideline in paper submissions. All such names still in currency need to be phased out by replacing them with names based on scientific characteristics, or in honour of their pioneering scientist/s or institutions. The lead author of the above 2010 paper has said he was not consulted about the final draft and did not agree with the conclusions of the paper. To ensure that corresponding authors do not ride roughshod over co-authors, and lead and other authors do not backtrack on papers, editors must ensure written

  16. Science, Names Giving and Names Calling: Change NDM-1 to PCM

    Science.gov (United States)

    Singh, Ajai R.

    2011-01-01

    A journal editor recently apologised for publishing a 2010 paper in which authors designated an enzyme as New Delhi metallo-β-lactamase-1 (NDM-1) and its related gene blaNDM-1 after a city, New Delhi. This name had raised an outcry in India, with health authorities, media and medical practitioners demanding New Delhi be dropped from the name. The name was actually first given in another 2009 paper, whose corresponding author remains the same as the 2010 paper. There is a tradition of eponymous names in science. But those found derogatory to races, groups, cities, and countries have been changed. For example, “Mongolism” was changed to Down’s syndrome; “Australia” antigen to HBsAg; “Mexican” Swine flu to H1N1; “GRID” (Gay Related Immune Deficiency) and 4H-Disease (Haitians, Homosexuals, Haemophiliacs and Heroin Users Disease) to AIDS. It is necessary that NDM-1 also be changed to a name based on scientific characteristics. NDM-1 must be changed to PCM (plasmid-encoding carbapenem-resistant metallo-β-lactamase). It is also necessary to review the tradition of naming organisms, diseases, genes, etc. after cities, countries and races. Often, such names giving amounts to names calling. It needs to be discarded by scientists in all new names giving from now on. “Geographical” and “racial” names giving must be replaced by “scientific” names giving. Journal editors must ensure that such scientific names giving is laid down as standard guideline in paper submissions. All such names still in currency need to be phased out by replacing them with names based on scientific characteristics, or in honour of their pioneering scientist/s or institutions. The lead author of the above 2010 paper has said he was not consulted about the final draft and did not agree with the conclusions of the paper. To ensure that corresponding authors do not ride roughshod over co-authors, and lead and other authors do not backtrack on papers, editors must ensure

  17. Science, names giving and names calling: Change NDM-1 to PCM

    Directory of Open Access Journals (Sweden)

    Singh Ajai

    2011-01-01

    Full Text Available A journal editor recently apologised for publishing a 2010 paper in which authors designated an enzyme as New Delhi metallo-β-lactamase-1 (NDM-1 and its related gene blaNDM-1 after a city, New Delhi. This name had raised an outcry in India, with health authorities, media and medical practitioners demanding New Delhi be dropped from the name. The name was actually first given in another 2009 paper, whose corresponding author remains the same as the 2010 paper. There is a tradition of eponymous names in science. But those found derogatory to races, groups, cities, and countries have been changed. For example, "Mongolism" was changed to Down′s syndrome; "Australia" antigen to HBsAg; "Mexican" Swine flu to H1N1; "GRID" (Gay Related Immune Deficiency and 4H-Disease (Haitians, Homosexuals, Haemophiliacs and Heroin Users Disease to AIDS. It is necessary that NDM-1 also be changed to a name based on scientific characteristics. NDM-1 must be changed to PCM (plasmid-encoding carbapenem-resistant metallo-β-lactamase. It is also necessary to review the tradition of naming organisms, diseases, genes, etc. after cities, countries and races. Often, such names giving amounts to names calling. It needs to be discarded by scientists in all new names giving from now on. "Geographical" and "racial" names giving must be replaced by "scientific" names giving. Journal editors must ensure that such scientific names giving is laid down as standard guideline in paper submissions. All such names still in currency need to be phased out by replacing them with names based on scientific characteristics, or in honour of their pioneering scientist/s or institutions. The lead author of the above 2010 paper has said he was not consulted about the final draft and did not agree with the conclusions of the paper. To ensure that corresponding authors do not ride roughshod over co-authors, and lead and other authors do not backtrack on papers, editors must ensure written

  18. A scalable machine-learning approach to recognize chemical names within large text databases

    OpenAIRE

    Wren Jonathan D

    2006-01-01

    Abstract Motivation The use or study of chemical compounds permeates almost every scientific field and in each of them, the amount of textual information is growing rapidly. There is a need to accurately identify chemical names within text for a number of informatics efforts such as database curation, report summarization, tagging of named entities and keywords, or the development/curation of reference databases. Results A first-order Markov Model (MM) was evaluated for its ability to disting...

  19. Main Group Element Chemistry in Service of Hydrogen Storage and Activation. Final report

    International Nuclear Information System (INIS)

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an 'endless' hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular weight

  20. Final Report: Main Group Element Chemistry in Service of Hydrogen Storage and Activation

    Energy Technology Data Exchange (ETDEWEB)

    David A. Dixon; Anthony J. Arduengo, III

    2010-09-30

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an “endless” hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular

  1. Identification and Determination of Trace Elements in Rice Seeds by Neutron Activation Analysis

    International Nuclear Information System (INIS)

    In rice seeds, the high activities of 42K, 38Cl and other radioisotopes induced by neutron irradiation make it impossible to identify most of the trace elements directly by gamma-ray spectrometry. To overcome this difficulty, fast and selective radiochemical group-separation methods have been developed which allow the identification of various trace elements such as Ba, Sr, As, Sb, Fe, Cu, Zn and Cd. Neutron activation analysis has also been used to determine six elements existing in quantities of the order of milligrams or traces. In these cases, after the addition of appropriate carrier elements, the radioisotopes were separated individually by standard radiochemical procedures, and chemical yields were determined. The experimental procedures are described. Amongst the seeds analysed, four varieties, Spanish and Korean, were included that were selected by the Institutes of Agricultural Research of Spain and Korea, and were of known origin. Wide differences in trace-element concentrations were observed. Measurements on whole seeds and seeds without cortex showed that the trace element contents of the former are two or three times those of the latter. This suggests an enrichment of trace elements in the seed cortex. The concentration ranges observed were: 6 to 50 ppm for Mn, 1 to 4 ppm for Cu, 7 to 45 ppm for Na, 0.2 to 1 ppm for Br, 1000 to 4800 ppm for K and 200 to 2500 ppm for CI. (author)

  2. Trace-element composition and zoning in clinopyroxene- and amphibole-group minerals: Implications for element partitioning and evolution of carbonatites

    Science.gov (United States)

    Reguir, Ekaterina P.; Chakhmouradian, Anton R.; Pisiak, Laura; Halden, Norman M.; Yang, Panseok; Xu, Cheng; Kynický, Jindřich; Couëslan, Chris G.

    2012-01-01

    The present work is a first comprehensive study of the trace-element composition and zoning in clinopyroxene- and amphibole-group minerals from carbonatites, incorporating samples from 14 localities worldwide (Afrikanda, Aley, Alnö, Blue River, Eden Lake, Huayangchuan, Murun, Oka, Ozernaya Varaka, Ozernyi, Paint Lake, Pinghe, Prairie Lake, Turiy Mys). The new electron-microprobe data presented here significantly extend the known compositional range of clinopyroxenes and amphiboles from carbonatites. These data confirm that calcic and sodic clinopyroxenes from carbonatites are not separated by a compositional gap, instead forming an arcuate trend from nearly pure diopside through intermediate aegirine-augite compositions confined to a limited range of CaFeSi 2O 6 contents (15-45 mol%) to aegirine with magnesio-ferrikatophorite, richterite, magnesioriebeckite, ferri-nyböite and (potassic-)magnesio-arfvedsonite. In comparison with the clinopyroxenes, the amphiboles contain similar levels of tetravalent high-field-strength elements (Ti, Zr and Hf) and compatible transition elements (Cr, Co and Ni), but are capable of incorporating much higher concentrations of Sc and incompatible elements (up to 500 ppm Sc, 43 ppm Rb, 1470 ppm Sr, 1230 ppm Ba, 80 ppm Pb, 1070 ppm REE, 140 ppm Y, and 180 ppm Nb). In some carbonatites, amphiboles contribute as much as 25% of the Zr + Hf, 15% of the Sr and 35% of the Rb + Ba whole-rock budget. Both clinopyroxenes and amphiboles may also host a significant share (~ 10%) of the bulk heavy-REE content. Our trace-element data show that the partitioning of REE between clinopyroxene (and, in some samples, amphibole) and the melt is clearly bimodal and requires a revision of the existing models assuming single-site REE partitioning. Clinopyroxenes and amphiboles from carbonatites exhibit a diversity of zoning patterns that cannot be explained exclusively on the basis of crystal chemistry and relative compatibility of different trace-element in

  3. Contextual Equivalences in Call-by-Need and Call-By-Name Polymorphically Typed Calculi (Preliminary Report)

    OpenAIRE

    Schmidt-Schauß, Manfred; Sabel, David

    2014-01-01

    This paper presents a call-by-need polymorphically typed lambda-calculus with letrec, case, constructors and seq. The typing of the calculus is modelled in a system-F style. Contextual equivalence is used as semantics of expressions. We also define a call-by-name variant without letrec. We adapt several tools and criteria for recognizing correct program transformations to polymorphic typing, in particular an inductive applicative simulation.

  4. INVESTIGATION OF BRAND NAME-COUNTRY OF ORIGIN PREFERENCE IN FOUR DIFFERENT PRODUCT GROUPS WITH RESPECT TO CONSPICUOUS CONSUMPTION TENDENCY

    Directory of Open Access Journals (Sweden)

    Volkan Doğan

    2013-10-01

    Full Text Available The aim of this study is to examine different preferences for brand name–country of origin shaped in line with levels of conspicuous consumption tendency and to determine Turkish consumers’ preferences for brand name–country of origin combinations in different product groups. The study was conducted in Eskisehir (Turkey with a sample of 413 people chosen through convenience sampling. The study data were collected with a questionnaire and face-face-to interviews. The participants’ preferences for brand name-country of origin combinations were determined separately based on four different product groups(hedonic, utilitarian, durable and non-durable. The study showed that, for all the four product groups, the participants preferred the products with a Turkish brand name and Turkey as the country of origin most, followed by the products with a French brand name and France as the country of origin. This finding suggests that, with respect to the four product groups in the study, Turkish consumers preferred domestic products over foreign products. Also, the participants who preferred French brand name-France as the country of origin for the hedonic product, French brand name-Turkey as the country of origin for the utilitarian product, French brand name-Turkey as the country of origin for the durable product and French brand name-France as the country of origin for the non-durable product were found to have highest tendency of conspicuous consumption in the corresponding product groups. In other words, as the level of conspicuous consumption increased, the participants tended to prefer French brand name-France as the country of origin for the hedonic product, French brand name-Turkey as the country of origin for the utilitarian product, French brand name-Turkey as the country of origin for the durable product and French brand name-France as the country of origin for the non-durable product.

  5. Frontiers of the heaviest elements - towards an understanding of the physical and chemical behaviour of the elements

    International Nuclear Information System (INIS)

    The description of the chemical behaviour of the heaviest elements has directly to do with a good relativistic description. In the limit of very low charges (at the beginning of the Periodic System) the non-relativistic description looks of course very much like the relativistic description and the problem is that we have learned to think in terms of the solution of the non-relativistic Schroedinger equation. In the first part I will therefore try to discuss the difference between the non-relativistic and the relativistic description. The talk has been structured as follows: first a brief discussion is given for the relativistic effects of 1-electron atoms which then will be extended to many-electron atoms. In the third section relativistic calculations of molecules will be discussed. (author)

  6. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    Energy Technology Data Exchange (ETDEWEB)

    Elen, Ken [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Strategisch Initiatief Materialen (SIM), SoPPoM Program (Belgium); Capon, Boris [Strategisch Initiatief Materialen (SIM), SoPPoM Programm (Belgium); Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); De Dobbelaere, Christopher [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Dewulf, Daan [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Peys, Nick [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw, Kapeldreef 75, B-3001 Heverlee (Belgium); Detavernier, Christophe [Coating and Contacting of Nanostructures, Ghent University, Krijgslaan 281 S1, B-9000 Ghent (Belgium); Hardy, An [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium); Van Bael, Marlies K., E-mail: marlies.vanbael@uhasselt.be [Inorganic and Physical Chemistry, Institute for Materials Research, Hasselt University, Agoralaan Building D, B-3590 Diepenbeek (Belgium); IMEC vzw division IMOMEC, Agoralaan Building D, B-3590 Diepenbeek (Belgium)

    2014-03-31

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum.

  7. Transparent conducting oxide films of group V doped titania prepared by aqueous chemical solution deposition

    International Nuclear Information System (INIS)

    Transparent conducting oxide (TCO) films of titania doped with vanadium (V), niobium (Nb) and tantalum (Ta) are obtained by aqueous Chemical Solution Deposition (CSD). The effect of the dopant on the crystallization and microstructure of the resulting films is examined by means of X-ray diffraction and electron microscopy. During annealing of the thin films, in-situ characterization of the crystal structure and sheet resistance is carried out. Niobium doped anatase films, obtained after annealing in forming gas, show a resistivity of 0,28 Ohm cm, which is the lowest resistivity reported for a solution deposited anatase-based TCO so far. Here, we demonstrate that aqueous CSD may provide a strategy for scalable TCO production in the future. - Highlights: • Aqueous chemical solution deposition of doped titanium dioxide • Doping delays the phase transition from anatase to rutile • Lowest resistivity after doping with niobium and annealing in Forming Gas • Transparency higher than 80% in the visible range of optical spectrum

  8. Validation and quality assurance applied to goat milk chemical composition: minerals and trace elements measurements

    OpenAIRE

    Trancoso, Inês; Roseiro, Luísa; Martins, António P. L.; Trancoso, Maria Ascensão

    2009-01-01

    In the present study, quality assurance programmes were implemented to validate and control the analytical methodologies used for the characterization of minerals and trace elements in goat milk from Portuguese breeds. With the exception of chloride that was determined by potentiometric titration, all the other elements were determined by spectroscopic techniques after different sample decomposition: P was measured by ultraviolet-visible molecular absorption spectrometry, Ca, Fe, K, Mg, Mn, N...

  9. Retrieving episodic memories when recognizing familiar faces and names.

    OpenAIRE

    Barsics, Catherine; Brédart, Serge

    2009-01-01

    This study was aimed at investigating whether the recognition of familiar faces is more likely to be associated with an experience of Remembering than the recognition of familiar names. Using the Remember/Know paradigm the proportions of episodic memories recalled following the recognition of famous faces and names (Conditions) were assessed. Presented faces and names were previously judged by an independent group of participants as eliciting an equivalent level of familiarity. Nevertheless s...

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

    Directory of Open Access Journals (Sweden)

    F. P. Agterberg

    2012-01-01

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

  11. Assessing the Amount of Chemical Elements in Biodegradable Agricultural Wastes and ASH

    Directory of Open Access Journals (Sweden)

    Rasa Kvasauskienė

    2011-02-01

    Full Text Available Biodegradable agricultural wastes such as manure, has long been used as an organic fertilizer that improves soil structure, enriches the soil with micro-organisms and micro-elements necessary for plants and promotes humus formation. Manure can also be successfully used as a renewable energy source directly combusting and extracting energy. The carried out investigation showed that the incineration of manure remaining in ashes could also be used as a fertilizer. Waste combustion reduces its volume to 80–90%. Also, the investigation revealed that the amount of chemical elements (Na, Mg, Si, P, K, Ca, Ti, Mn, Fe decreased after combustion. However, the concentration of these elements in ashes is higher than that in raw manure. Article in Lithuanian

  12. RADIOACTIVE CHEMICAL ELEMENTS IN THE ATOMIC TABLE

    International Nuclear Information System (INIS)

    In the 1949 Report of the Atomic Weights Commission, a series of new elements were added to the Atomic Weights Table. Since these elements had been produced in the laboratory and were not discovered in nature, the atomic weight value of these artificial products would depend upon the production method. Since atomic weight is a property of an element as it occurs in nature, it would be incorrect to assign an atomic weight value to that element. As a result of that discussion, the Commission decided to provide only the mass number of the most stable (longest-lived) known isotope as the number to be associated with these entries in the Atomic Weights Table. As a function of time, the mass number associated with various elements has changed as longer-lived isotopes of a particular elements has been found in nature, or as improved half-life values of an element's isotopes might cause a shift in the longest-lived isotope from one mass number to another. In the 1957 Report of the Atomic Weights Commission, it was decided to discontinue the listing of the mass number in the Atomic Weights Table on the grounds that the kind of information supplied by the mass number is inconsistent with the primary purpose of the Table, i.e., to provide accurate values of ''these constants'' for use in chemical calculations. In addition to the Table of Atomic Weights, the Commission included an auxiliary Table of Radioactive Elements for the first time, where the entry would be the isotope of that element which was most stable, i.e., it had the longest known half-life. In their 1973 report, the Commission noted that the users of the Atomic Weights Table were dissatisfied with the omission of values in the Table for some elements and it was decided to reintroduce the mass number for elements. In their 1983 report, the Commission decided that radioactive elements were considered to lack a characteristic terrestrial isotopic composition, from which an atomic weight value could be calculated to

  13. Elements and cyclic subgroups of finite order of the Cremona group

    OpenAIRE

    Blanc, Jérémy

    2008-01-01

    We give the classification of elements - respectively cyclic subgroups - of finite order of the Cremona group, up to conjugation. Natural parametrisations of conjugacy classes, related to fixed curves of positive genus, are provided.

  14. Changing the Family Name by Administrative Means

    Directory of Open Access Journals (Sweden)

    Duret Nicu

    2009-06-01

    Full Text Available In the Roman law, changing the name was possible except for the case in which this changewould have been fraudulent. This possibility was kept also in the Middle Age but with some restrictions:the handicraftsmen were not allowed to change their name when it served as a factory brand, the notarycould not change his name without having an authorization, and neither could he change his normalsignature. Gradually, the monarchy increased its control in this matter, tending to transform a socialinstitution into a police one.

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

    CERN Document Server

    Radamson, Henry

    2014-01-01

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

  16. Meeting of November 10, 2005 of the working group about the division by 4 of greenhouse gas emissions of France at the 2050 prospects, named 'factor 4'

    International Nuclear Information System (INIS)

    This document gathers 3 presentations given at this meeting of the 'factor 4' working group: the first presentation (P. Radanne) defines the bases of the problem of abatement of greenhouse gases emissions (economic growth, energy consumption in France, CO2 emissions, sectoral analysis of solutions (residential, industry, transports), development of renewable energy sources, economical mechanisms). The second presentation (T. Salomon) gives the vision of the Negawatt association of what should be an efficient energy policy: better consuming thanks to energy savings and to a better energy efficiency, and development of renewable energy sources. An illustration of an efficient urban energy and environmental policy is given with the example of Freiburg-um-Brisgau city (Germany). The third presentation (J. Sivardiere) analyses the positive impact of modal transfers in the transportation sector (change of habits) and the need for strong incentives (taxes) to reach this goal. (J.S.)

  17. The early chemical enrichment histories of two Sculptor group dwarf galaxies as revealed by RR lyrae variables

    International Nuclear Information System (INIS)

    We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys on board the Hubble Space Telescope, we have identified a sample of RRL candidates in both dTrans galaxies (219 RRab (RR0) and 13 RRc (RR1) variables in ESO294-G010; 225 RRab and 44 RRc stars in ESO410-G005). The metallicities of the individual RRab stars are calculated via the period-amplitude-[Fe/H] relation derived by Alcock et al. This yields mean metallicities of ([Fe/H])ESO294 = –1.77 ± 0.03 and ([Fe/H])ESO410 = –1.64 ± 0.03. The RRL metallicity distribution functions (MDFs) are investigated further via simple chemical evolution models; these reveal the relics of the early chemical enrichment processes for these two dTrans galaxies. In the case of both galaxies, the shapes of the RRL MDFs are well described by pre-enrichment models. This suggests two possible channels for the early chemical evolution for these Sculptor group dTrans galaxies: (1) the ancient stellar populations of our target dwarf galaxies might have formed from the star forming gas which was already enriched through 'prompt initial enrichment' or an 'initial nucleosynthetic spike' from the very first massive stars, or (2) this pre-enrichment state might have been achieved by the end products from more evolved systems of their nearest neighbor, NGC 55. We also study the environmental effects of the formation and evolution of our target dTrans galaxies by comparing their properties with those of 79 volume limited (D ☉ < 2 Mpc) dwarf galaxy samples in terms of the luminosity-metallicity relation and the H I gas content. The presence of these RRL stars strongly supports the idea that although the Sculptor Group galaxies have a considerably

  18. Reconstructing the cosmic evolution of the chemical elements

    CERN Document Server

    Frebel, Anna

    2014-01-01

    The chemical elements are created in nuclear fusion processes in the hot and dense cores of stars. The energy generated through nucleosynthesis allows stars to shine for billions of years. When these stars explode as massive supernovae, the newly made elements are expelled, chemically enriching the surrounding regions. Subsequent generations of stars are formed from gas that is slightly more element enriched than that from which previous stars formed. This chemical evolution can be traced back to its beginning soon after the Big Bang by studying the oldest and most metal-poor stars still observable in the Milky Way today. Through chemical analysis, they provide the only available tool for gaining information about the nature of the short-lived first stars and their supernova explosions more than thirteen billion years ago. These events set in motion the transformation of the pristine universe into a rich cosmos of chemically diverse planets, stars, and galaxies.

  19. INDUCTION OF HEME OXYGENASE-1 EXPRESSION IN MACROPHAGES BY DIESEL EXHAUST PARTICLE CHEMICALS AND QUINONES VIA THE ANTIOXIDANT-RESPONSIVE ELEMENT. (R827352C001)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Nuclear analytical methods for platinum group elements

    International Nuclear Information System (INIS)

    Platinum group elements (PGE) are of special interest for analytical research due to their economic importance like chemical peculiarities as catalysts, medical applications as anticancer drugs, and possible environmental detrimental impact as exhaust from automobile catalyzers. Natural levels of PGE are so low in concentration that most of the current analytical techniques approach their limit of detection capacity. In addition, Ru, Rh, Pd, Re, Os, Ir, and Pt analyses still constitute a challenge in accuracy and precision of quantification in natural matrices. Nuclear analytical techniques, such as neutron activation analysis, X ray fluorescence, or proton-induced X ray emission (PIXE), which are generally considered as reference methods for many analytical problems, are useful as well. However, due to methodological restrictions, they can, in most cases, only be applied after pre-concentration and under special irradiation conditions. This report was prepared following a coordinated research project and a consultants meeting addressing the subject from different viewpoints. The experts involved suggested to discuss the issue according to the (1) application, hence, the concentration levels encountered, and (2) method applied for analysis. Each of the different fields of application needs special consideration for sample preparation, PGE pre-concentration, and determination. Additionally, each analytical method requires special attention regarding the sensitivity and sample type. Quality assurance/quality control aspects are considered towards the end of the report. It is intended to provide the reader of this publication with state-of-the-art information on the various aspects of PGE analysis and to advise which technique might be most suitable for a particular analytical problem related to platinum group elements. In particular, many case studies described in detail from the authors' laboratory experience might help to decide which way to go. As in many cases

  1. Trivalent f-element intra-group separation by solvent extraction with CMPO-complexant system

    International Nuclear Information System (INIS)

    For trivalent actinide and lanthanide separation, the solvent extraction system which employs neutral bifunctional extractant n-octyl(phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and aminopolyacetic acid was investigated. The system is based on CMPO-tri-n-butylphosphate (TBP) mixed solvent and diethylenetriaminepentaacetic acid (DTPA)-sodium nitrate solution. The separation is achieved by complexing trivalent actinide preferentially with DTPA in aqueous phase and extracting lanthanide into organic phase. Mutual separation between light lanthanide, Am and Cm was mainly governed by complex formation with DTPA. The acidity is most affecting parameter for partitioning and its increase results in decrease of distribution ratio. For selective stripping of trivalent actinide from 0.2M CMPO-1.0M TBP in n-dodecane at room temperature, 0.05M DTPA and 2-4M sodium nitrate solution (pH 2) is useful. From the observed distribution behavior, a basic flow sheet which is composed of four steps was proposed. In batchwise experiments with radioactive nuclides, separation factor of larger than 13 and 27 for Ce/Am and Cm/Eu, respectively, were obtained and the applicability of the system was indicated. (author)

  2. Modern alchemy: Fred Hoyle and element building by neutron capture

    Science.gov (United States)

    Burbidge, E. Margaret

    Fred Hoyle's fundamental work on building the chemical elements by nuclear processes in stars at various stages in their lives began with the building of elements around iron in the very dense hot interiors of stars. Later, in the paper by Burbidge, Burbidge, Fowler and Hoyle, we four showed that Hoyle's "equilibrium process" is one of eight processes required to make all of the isotopes of all the elements detected in the Sun and stars. Neutron capture reactions, which Fred had not considered in his epochal 1946 paper, but for which experimental data were just becoming available in 1957, are very important, in addition to the energy-generating reactions involving hydrogen, helium, carbon, nitrogen and oxygen, for building all of the elements. They are now providing clues to the late stages of stellar evolution and the earliest history of our Galaxy. I describe here our earliest observational work on neutron capture processes in evolved stars, some new work on stars showing the results of the neutron capture reactions, and data relating to processes ending in the production of lead, and I discuss where this fits into the history of stars in our own Galaxy.

  3. Determination of platinum group elements and gold in reference materials by instrumental neutron activation analysis and inductively coupled plasma-mass spectrometry with nickel sulphide fire-assay collection

    International Nuclear Information System (INIS)

    Instrumental Neutron Activation Analysis (INAA) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) after NiS fire assay were used to determine platinum group elements (PGE) and Au in the geological reference materials peridotite GPt-3 and pyroxene peridotite GPt-4 (IGGE, China). INAA has been one of the most useful analytical techniques for PGEs and Au determination, due to its high sensitivity and accuracy. After the fire assay, the NiS button is dissolved in concentrated hydrochloric acid, leaving a residue of insoluble PGE sulphides; the solution is filtered and the filter is directly irradiated with neutrons. In more recent years, ICP-MS with nickel fire assay collection and tellurium coprecipitation has been used as a mean of analysing PGE, with the main advantage of avoiding problems of losses of PGE during the HCl digestion of the NiS button. Buttons were prepared by mixing the sample (10-15 g) with fluxes, nickel and sulphur in a fire clay crucible and fused at temperatures around 1000 deg C. For NAA, the filters containing the PGEs and Au were irradiated at the IEA-R1 research nuclear reactor at IPEN. The measurements of the induced gamma-ray activity were carried out in an hyperpure Ge detector. In general, the results obtained by the two techniques were in good agreement with recommended values. INAA results exhibited higher values than the recommended values for Pd and Pt in GPt-3, while the opposite effect was observed for GPt-4 sample. Ru was not detected by INAA. On the other hand, Rh and Ir were determined more accurately by INAA (relative errors better than 10%). The ICP-MS analytical technique showed better detection limits, and all the PGE were determined. Results obtained for Pt and Pd presented accuracy better than 5% while losses were observed for Os and Ir. (author)

  4. Eunice E. Santos named to elite defense science group

    OpenAIRE

    Trulove, Susan

    2005-01-01

    Eunice E. Santos, director of the Laboratory for Computation, Information, and Distributed Processing and associate professor of computer science in the College of Engineering at Virginia Tech, has been appointed to the Defense Science Study Group (DSSG), a program that introduces outstanding scientists and engineers to the challenges that face national security.

  5. 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.

  6. Minimal length elements of finite Coxeter groups

    OpenAIRE

    He, Xuhua; Nie, Sian

    2012-01-01

    We give a geometric proof that any minimal length element in a (twisted) conjugacy class of a finite Coxeter group $W$ has remarkable properties with respect to conjugation, taking powers in the associated braid monoid and taking the centralizer in $W$ .

  7. Semantic Web Compatible Names and Descriptions for Organisms

    Science.gov (United States)

    Wang, H.; Wilson, N.; McGuinness, D. L.

    2012-12-01

    Modern scientific names are critical for understanding the biological literature and provide a valuable way to understand evolutionary relationships. To validly publish a name, a description is required to separate the described group of organisms from those described by other names at the same level of the taxonomic hierarchy. The frequent revision of descriptions due to new evolutionary evidence has lead to situations where a single given scientific name may over time have multiple descriptions associated with it and a given published description may apply to multiple scientific names. Because of these many-to-many relationships between scientific names and descriptions, the usage of scientific names as a proxy for descriptions is inevitably ambiguous. Another issue lies in the fact that the precise application of scientific names often requires careful microscopic work, or increasingly, genetic sequencing, as scientific names are focused on the evolutionary relatedness between and within named groups such as species, genera, families, etc. This is problematic to many audiences, especially field biologists, who often do not have access to the instruments and tools required to make identifications on a microscopic or genetic basis. To better connect scientific names to descriptions and find a more convenient way to support computer assisted identification, we proposed the Semantic Vernacular System, a novel naming system that creates named, machine-interpretable descriptions for groups of organisms, and is compatible with the Semantic Web. Unlike the evolutionary relationship based scientific naming system, it emphasizes the observable features of organisms. By independently naming the descriptions composed of sets of observational features, as well as maintaining connections to scientific names, it preserves the observational data used to identify organisms. The system is designed to support a peer-review mechanism for creating new names, and uses a controlled

  8. Feature Names and Identity in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Emmanuel Chabata

    2012-08-01

    Full Text Available This paper is about feature names in Zimbabwe. It focuses on the role played by place names in defining Zimbabwe, both as a physical entity and as a community of speakers with a remarkable history and a sense of nationhood. The paper thus focuses on two types of place names, that is, those that refer to the natural landscape, such as mountains and rivers, as well as those that refer to man-made features such as roads and streets, hospitals and schools. Regarding names that are bestowed onto the features of the natural landscape, we will look at how some place names vividly describe the outstanding features or characteristics of particular geographical features, that is, the extent to which the names are used as tools in describing the features; the way the eye meets the landscape. We will also look at how some names of physical features are coined in response to the landscape's 'behaviour' or in relation to the link the landscape has with historical event(s. The paper will also look at how the bestowal of commemorative names on Zimbabwean features has been used in concretising the Zimbabwean people's link with the country's history, that is, how Zimbabweans have tried to define themselves as a people through naming some of their popular places after names of the country's heroes and heroines, both living and dead.

  9. Physical features of accumulation and distribution processes of small disperse coal dust precipitations and absorbed radioactive chemical elements in iodine air filter at nuclear power plant

    CERN Document Server

    Ledenyov, Oleg P; Poltinin, P Ya; Fedorova, L I

    2012-01-01

    The physical features of absorption process of radioactive chemical elements and their isotopes in the iodine air filters of the type of AU-1500 at the nuclear power plants are researched. It is shown that the non-homogenous spatial distribution of absorbed radioactive chemical elements and their isotopes in the iodine air filter, probed by the gamma-activation analysis method, is well correlated with the spatial distribution of small disperse coal dust precipitations in the iodine air filter. This circumstance points out to an important role by the small disperse coal dust fractions of absorber in the absorption process of radioactive chemical elements and their isotopes in the iodine air filter. The physical origins of characteristic interaction between the radioactive chemical elements and the accumulated small disperse coal dust precipitations in an iodine air filter are considered. The analysis of influence by the researched physical processes on the technical characteristics and functionality of iodine ...

  10. A thermodynamic force generated by chemical gradient and adsorption reaction

    CERN Document Server

    Sugawara, Takeshi

    2009-01-01

    Biological units such as macromolecules, organelles, and cells are directed to a proper location under gradients of relevant chemicals. By considering a macroscopic element that has binding sites for a chemical adsorption reaction to occur on its surface, we show the existence of a thermodynamic force that is generated by the gradient and exerted on the element. By assuming local equilibrium and adopting the grand potential from thermodynamics, we derive a formula for such a thermodynamic force, which depends on the chemical potential gradient and Langmuir isotherm. The conditions under which the formula can be applied are demonstrated to hold in intracellular reactions. The role of the force in the partitioning of bacterial chromosome/plasmid during cell division is discussed.

  11. Study on Model of Correlation Between Chemical Element Contents in Tree Rings and Soils near Tree Roots

    Institute of Scientific and Technical Information of China (English)

    KESHAN-ZHE; QIANJUN-LONG; 等

    1994-01-01

    The chemical element contents in tree rings are correlated with those in the soils near the tree roots,The results in the present study showed that the correlation between them could be described using the following logarithmic linear correlation model:lgC'(Z)=a(Z)+b(Z)lgC(Z).Therefor,by determining the chrono-sequence C(Z,t),where Z is the atomic number and t the year,of elemental contents in the annual growth rings of trees,we could get the chrono-sequence C'(Z,t) of elemental contents in the soil,thus inferring the dynaminc variations of relevant elemental contents in the soil.

  12. 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)

  13. Chemical elements in invertebrate orders for environmental quality studies

    International Nuclear Information System (INIS)

    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)

  14. Chemical analysis of CH stars - II: atmospheric parameters and elemental abundances

    CERN Document Server

    Karinkuzhi, Drisya

    2014-01-01

    We present detailed chemical analyses for a sample of twelve stars selected from the CH star catalogue of Bartkevicius (1996). The sample includes two confirmed binaries, four objects that are known to show radial velocity variations and the rest with no information on the binary status. A primary objective is to examine if all these objects exhibit chemical abundances characteristics of CH stars, based on detailed chemical composition study using high resolution spectra. We have used high resolution (R ~ 42000) spectra from the ELODIE archive. These spectra cover 3900 to 6800 Angstrom in the wavelength range. We have estimated the stellar atmospheric parameters, the effective temperature Teff, the surface gravity log g, and metallicity [Fe/H] from LTE analysis using model atmospheres. Estimated temperatures of these objects cover a wide range from 4200 K to 6640 K, the surface gravity from 0.6 to 4.3 and metallicity from -0.13 to -1.5. We report updates on elemental abundances for several heavy elements, Sr,...

  15. Determination of boron concentration in borosilicate glass, boron carbide and graphite samples by conventional wet-chemical and nuclear analytical methods

    International Nuclear Information System (INIS)

    Boron is an important element in nuclear technology. A comparative study was carried out for the determination of boron in borosilicate glass, boron carbide and graphite samples by wet-chemical and nuclear analytical methods. Wet chemical methods namely titrimetry, Inductively Coupled Plasma Mass Spectrometry and ICP Optical Emission Spectrometry and nuclear analytical methods namely Particle Induced Gamma-Ray Emission and Nuclear Reaction Analysis were used. Boron concentrations were in trace (mg kg-1) level in graphite and percentage level in borosilicate glass and boron carbide. (author)

  16. Strength of the pnicogen bond in complexes involving group Va elements N, P, and As.

    Science.gov (United States)

    Setiawan, Dani; Kraka, Elfi; Cremer, Dieter

    2015-03-01

    A set of 36 pnicogen homo- and heterodimers, R3E···ER3 and R3E···E′R′3, involving differently substituted group Va elements E = N, P, and As has been investigated at the ωB97X-D/aug-cc-pVTZ level of theory to determine the strength of the pnicogen bond with the help of the local E···E′ stretching force constants k(a). The latter are directly related to the amount of charge transferred from an E donor lone pair orbital to an E′ acceptor σ* orbital, in the sense of a through-space anomeric effect. This leads to a buildup of electron density in the intermonomer region and a distinct pnicogen bond strength order quantitatively assessed via k(a). However, the complex binding energy ΔE depends only partly on the pnicogen bond strength as H,E-attractions, H-bonding, dipole-dipole, or multipole-multipole attractions also contribute to the stability of pnicogen bonded dimers. A variation from through-space anomeric to second order hyperonjugative, and skewed π,π interactions is observed. Charge transfer into a π* substituent orbital of the acceptor increases the absolute value of ΔE by electrostatic effects but has a smaller impact on the pnicogen bond strength. A set of 10 dimers obtains its stability from covalent pnicogen bonding whereas all other dimers are stabilized by electrostatic interactions. The latter are quantified by the magnitude of the local intermonomer bending force constants XE···E′. Analysis of the frontier orbitals of monomer and dimer in connection with the investigation of electron difference densities, and atomic charges lead to a simple rationalization of the various facets of pnicogen bonding. The temperature at which a given dimer is observable under experimental conditions is provided. PMID:25325889

  17. Carcinogenesis and Chemotherapy Viewed from the Perspective of Stoichiometric Network Analysis (SNA: What Can the Biological System of the Elements Contribute to an Understanding of Tumour Induction by Elemental Chemical Noxae (e.g., Ni2+, Cd2+ and to an Understanding of Chemotherapy?

    Directory of Open Access Journals (Sweden)

    Stefan Franzle

    2003-01-01

    Full Text Available The biological application of stoichiometric network analysis (SNA permits an understanding of tumour induction, carcinogenesis, and chemotherapy. Starting from the Biological System of the Elements, which provides a comprehensive treatment of the functions and distributions of chemical (trace elements in biology, an attempt is made to interrelate the essential feature of biology and — regrettably — of tumour genesis by superimposing SNA reasoning on common features of all crucial biological processes. For this purpose, aspects, effects and drawbacks of autocatalysis (identical reproduction which can occur either under control or without control [in tumours] are linked with the known facts about element distributions in living beings and about interference of metals with tumours (in terms of both chemotherapy and carcinogenesis. The essential role of autocatalysis in biology and the drawbacks of either controlled or spontaneous cell division can be used to understand crucial aspects of carcinogenesis and chemotherapy because SNA describes and predicts effects of autocatalysis, including phase effects that may be due to some kind of intervention. The SNA-based classifications of autocatalytic networks in cell biology are outlined here to identify new approaches to chemotherapy.

  18. Development and Analysis of Group Contribution Plus Models for Property Prediction of Organic Chemical Systems

    DEFF Research Database (Denmark)

    Mustaffa, Azizul Azri

    and further development of the GCPlus approach for predicting mixture properties to be called the UNIFAC-CI model. The contributions of this work include an analysis of the developed Original UNIFAC-CI model in order to investigate why the model does not perform as well as the reference UNIFAC model......Prediction of properties is important in chemical process-product design. Reliable property models are needed for increasingly complex and wider range of chemicals. Group-contribution methods provide useful tool but there is a need to validate them and improve their accuracy when complex chemicals...... are present in the mixtures. In accordance with that, a combined group-contribution and atom connectivity approach that is able to extend the application range of property models has been developed for mixture properties. This so-called Group-ContributionPlus (GCPlus) approach is a hybrid model which...

  19. Traffic related distribution of platinum group elements in urban environment

    International Nuclear Information System (INIS)

    Complete text of publication follows. Environmental concentrations of platinum, palladium and rhodium (platinum group elements, PGE) have increased dramatically over the past two decades, because of their use in the catalytic converter of motor vehicles. Cars fitted with exhaust catalysts containing PGE significantly minimize toxic gas emission produced during gas combustion. Through physical and chemical stress of wash coat layer of catalyst PGE are emitted as particulate matter at rates up to some ng per km per vehicle. PGE are subsequently dispersed by the atmosphere or subjected to localized accumulation in road dust and urban soil and enter the aquatic environment. Platinum group elements are relatively new group of anthropogenic pollutants. Traffic is the main source of PGE contamination in urban areas. There is increasing concern about the hazardous effects of them for people and for other living organisms in these areas. In the contribution we will present data from a first study of PGE levels in environment matrices in Czech Republic, where over the last two decades number of motor vehicles increased significantly. In urban agglomerations road traffic becomes one of the dominant polluters. The distribution of PGE in urban samples matrices was studied. Airborne, road and tunnel dusts as well as soils and run/off waters were collected at locations in Brno. Sampling was made at different sites with varying traffic volumes and driving styles (stop/start vs. constant speed). Samples were taken with different sampling devices/techniques in years from 2002 to 2007. The content of PGE in environmental samples was analyzed using ICP-MS. The accuracy was checked using the standard reference material BCR 723 (road dust) and NIST 1648a (urban particulate matter). Although the results show especially the increase of PGE in environmental samples, they still stay in the area of trace element analysis.

  20. Analysis of liquid evaporation system containing uranium and others chemical elements according to laws and standards in force

    International Nuclear Information System (INIS)

    Liquid evaporation has been world-wide sanctioned in the nuclear industry as a volume reduction technique for laboratory effluents or rad wastes. This fast technique has showed efficiency for non volatile chemical elements concentration. The resulting mud is chemically stable, physically homogeneous and biologically inhert. It is common that low radiation level liquids, containing uranium undergo evaporation, although its quantity in the mud can be not the limiting factor for the final deposition. It often occurs that depending on liquids to be evaporated other chemical elements as flour or heavy metals could avoid the deposition of the mud in the environment. The proposed evaporator works with solar heating, although electric energy could be used, and allow to evaporate 50 L of liquids per day. Volume reduction factor can reach 95% and the construction cost is very low. In this work there are analyzed evaporator characteristics and the limiting values established by Brazilian laws and standards, for those elements that are present in the resulting mud. The aim is to justify why zero discharge is preferred instead the deposition of the concentrate in the environment. (author)

  1. Proposal for the systematic naming of mesons and baryons

    International Nuclear Information System (INIS)

    Twenty years ago, the Particle Data Group adopted a systematic naming convention for baryons: the symbols N, Δ, Λ, Σ, Ψ, and Ω were to identify the isospin and strangeness, The mesons, by contrast, have become an alphabet soup of uninformative names - theta, iota, xi, zeta, g/sub T/, g/sub s/, H, E, delta, h, g, r, kappa, etc. -, and in some cases identical names are used for mesons with different quantum numbers (A, B, and D). Furthermore, experimentalists are now discovering baryons that contain heavy quarks. It is therefore timely to consider systematic naming conventions both for mesons and for baryons with heavy quarks. The Particle Data Group is circulating this proposal in the hope of generating feedback, and we attach a sheet for responses. It should be emphasized that the Particle Tables would show both the old and new names for some time

  2. Airborne particulate matter, platinum group elements and human health: a review of recent evidence.

    Science.gov (United States)

    Wiseman, Clare L S; Zereini, Fathi

    2009-04-01

    Environmental concentrations of the platinum group elements (PGE) platinum (Pt), palladium (Pd) and rhodium (Rh) have been on the rise, due largely to the use of automobile catalytic converters which employ these metals as exhaust catalysts. It has generally been assumed that the health risks associated with environmental exposures to PGE are minimal. More recent studies on PGE toxicity, environmental bioavailability and concentrations in biologically relevant media indicate however that environmental exposures to these metals may indeed pose a health risk, especially at a chronic, subclinical level. The purpose of this paper is to review the most recent evidence and provide an up-to-date assessment of the risks related to environmental exposures of PGE, particularly in airborne particulate matter (PM). This review concludes that these metals may pose a greater health risk than once thought for several reasons. First, emitted PGE may be easily mobilised and solubilised by various compounds commonly present in the environment, thereby enhancing their bioavailability. Second, PGE may be transformed into more toxic species upon uptake by organisms. The presence of chloride in lung fluids, for instance, may lead to the formation of halogenated PGE complexes that have a greater potential to induce cellular damage. Third, a significant proportion of PGE found in airborne PM is present in the fine fraction that been found to be associated with increases in morbidity and mortality. PGE are also a concern to the extent that they contribute to the suite of metals found in fine PM suspected of eliciting a variety of health effects, especially in vulnerable populations. All these factors highlight the need to monitor environmental levels of PGE and continue research on their bioavailability, behaviour, speciation and associated toxicity to enable us to better assess their potential to elicit health effects in humans. PMID:19181366

  3. The Early Chemical Enrichment Histories of Two Sculptor Group Dwarf Galaxies as Revealed by RR Lyrae Variables

    Science.gov (United States)

    Yang, Soung-Chul; Wagner-Kaiser, Rachel; Sarajedini, Ata; Kim, Sang Chul; Kyeong, Jaemann

    2014-03-01

    We present the results of our analysis of the RR Lyrae (RRL) variable stars detected in two transition-type dwarf galaxies (dTrans), ESO294-G010 and ESO410-G005 in the Sculptor group, which is known to be one of the closest neighboring galaxy groups to our Local Group. Using deep archival images from the Advanced Camera for Surveys on board the Hubble Space Telescope, we have identified a sample of RRL candidates in both dTrans galaxies (219 RRab (RR0) and 13 RRc (RR1) variables in ESO294-G010; 225 RRab and 44 RRc stars in ESO410-G005). The metallicities of the individual RRab stars are calculated via the period-amplitude-[Fe/H] relation derived by Alcock et al. This yields mean metallicities of lang[Fe/H]rangESO294 = -1.77 ± 0.03 and lang[Fe/H]rangESO410 = -1.64 ± 0.03. The RRL metallicity distribution functions (MDFs) are investigated further via simple chemical evolution models; these reveal the relics of the early chemical enrichment processes for these two dTrans galaxies. In the case of both galaxies, the shapes of the RRL MDFs are well described by pre-enrichment models. This suggests two possible channels for the early chemical evolution for these Sculptor group dTrans galaxies: (1) the ancient stellar populations of our target dwarf galaxies might have formed from the star forming gas which was already enriched through "prompt initial enrichment" or an "initial nucleosynthetic spike" from the very first massive stars, or (2) this pre-enrichment state might have been achieved by the end products from more evolved systems of their nearest neighbor, NGC 55. We also study the environmental effects of the formation and evolution of our target dTrans galaxies by comparing their properties with those of 79 volume limited (D ⊙ giant host galaxies, loosely bound and very low local density), they share a common epoch of early star formation with the dwarf satellite galaxies in the Local Group.

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

    International Nuclear Information System (INIS)

    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

  5. Chemical composition, stratigraphy, and depositional environments of the Black River Group (Middle Ordovician), southwestern Ohio.

    Science.gov (United States)

    Stith, David A.

    1981-01-01

    The chemical composition and stratigraphy of the Black River Group in southwestern Ohio were studied. Chemical analyses were done on two cores of the Black River from Adams and Brown Counties, Ohio. These studies show that substantial reserves of high-carbonate rock are present in the Black River at depths of less than 800 ft, in proximity to Cincinnati and the Ohio River. Stratigraphic studies show that the Black River Group has eight marker beds in its middle and upper portions and three distinct lithologic units in its lower portion; these marker beds and units are present throughout southwestern Ohio. The Black River Group correlates well with the High Bridge Group of Kentucky. Depositional environments of the Black River are similar to those of the High Bridge and to present-day tidal flats in the Bahamas.-Author

  6. Nested symmetric representation of elements of the Suzuki chain groups

    Directory of Open Access Journals (Sweden)

    Mohamed Sayed

    2003-11-01

    Full Text Available We demonstrate an economic and concise method for representing the elements of groups involved in the Suzuki chain. For example, we represent each element of Suz:2 by a permutation on 14 letters from L3(2:2 followed by four words, each of length at most two, in 14, 36, 100, and 416 involutory symmetric generators, respectively. Such expressions will have an obvious advantage over permutations on 1782 provided that it is reasonably simple to multiply and invert them. We refer to this as nested symmetric representation of an element of the group.

  7. Report of the IAU/IAG Working Group on cartographic coordinates and rotational elements: 2006

    Science.gov (United States)

    Seidelmann, P.K.; Archinal, B.A.; A'Hearn, M.F.; Conrad, A.; Consolmagno, G.J.; Hestroffer, D.; Hilton, J.L.; Krasinsky, G.A.; Neumann, G.; Oberst, J.; Stooke, P.; Tedesco, E.F.; Tholen, D.J.; Thomas, P.C.; Williams, I.P.

    2007-01-01

    Every three years the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report introduces improved values for the pole and rotation rate of Pluto, Charon, and Phoebe, the pole of Jupiter, the sizes and shapes of Saturn satellites and Charon, and the poles, rotation rates, and sizes of some minor planets and comets. A high precision realization for the pole and rotation rate of the Moon is provided. The expression for the Sun's rotation has been changed to be consistent with the planets and to account for light travel time ?? 2007 Springer Science+Business Media B.V.

  8. NMR chemical shifts in amino acids: Effects of environments, electric field, and amine group rotation

    International Nuclear Information System (INIS)

    The authors present calculations of NMR chemical shifts in crystalline phases of some representative amino acids such as glycine, alanine, and alanyl-alanine. To get an insight on how different environments affect the chemical shifts, they study the transition from the crystalline phase to completely isolated molecules of glycine. In the crystalline limit, the shifts are dominated by intermolecular hydrogen-bonds. In the molecular limit, however, dipole electric field effects dominate the behavior of the chemical shifts. They show that it is necessary to average the chemical shifts in glycine over geometries. Tensor components are analyzed to get the angle dependent proton chemical shifts, which is a more refined characterization method

  9. What's in a Screen Name? Attractiveness of Different Types of Screen Names Used by Online Daters

    OpenAIRE

    Monica T. Whitty; Tom Buchanan

    2010-01-01

    This paper examined whether different types of screen names offer advantages when it comes to attracting a partner on dating sites. In the pilot study, we conducted a content analysis of real screen names to develop a typology of screen names. In the main study, we explored whether the typology predicted online daters' ratings of names, and compared the types of names that appealed to men and to women. Men more than women were attracted to screen names that indicated physical attractiveness, ...

  10. Stellar substructures in the solar neighbourhood. II. Abundances of neutron-capture elements in the kinematic Group 3 of the Geneva-Copenhagen survey

    CERN Document Server

    Stonkutė, Edita; Nordström, Birgitta; Ženovienė, Renata; 10.1051/0004-6361/201321437

    2013-01-01

    The evolution of chemical elements in a galaxy is linked to its star formation history. Variations in star formation history are imprinted in the relative abundances of chemical elements produced in different supernova events and asymptotic giant branch stars. We determine detailed elemental abundances of s- and r-process elements in stars belonging to Group3 of the Geneva-Copenhagen survey and compare their chemical composition with Galactic disc stars. The aim is to look for possible chemical signatures that might give information about the formation history of this kinematic group of stars, which is suggested to correspond to remnants of disrupted satellites. High-resolution spectra were obtained with the FIES spectrograph at the Nordic Optical Telescope, La Palma, and were analysed with a differential model atmosphere method. Comparison stars were observed and analysed with the same method. Abundances of chemical elements produced mainly by the s-process are similar to those in the Galactic thin-disc dwar...

  11. Determination of minor-and trace elements in magnesite samples, by activation analysis

    International Nuclear Information System (INIS)

    A method employing activation analysis with thermal neutron was developed for the determination of minor and trace elements in magnesite samples from the states of Ceara and Bahia (Brazil). Ten samples were analyzed. A qualitative analysis of the samples indicated the presence of Mn, Fe, Sc, Ca, Cu, Co and some of the lanthanides. The experimental part includes a non-destructive analysis of manganese and analysis with chemical separation of the other elements, individually or in groups, after sample dissolution, The dissolutions were made with concentrated HCl and the further separations were carried out in 8 N HCl medium. Iron was separated by means of an extraction of HFeCl4 with isopropyl ether. Scandium and calcium were determined by retention of scandium with di-(2-ehylhexyl) phosphoric acid (HDEHP). The activities of 46Sc and 47Sc (a 47Ca descendant) were employed for the analysis of scandium and calcium in the sample. In the effluent of the kieselguhr column copper and cobalt were determined, after retention in an anionic resin of the CuCl-3 and CoCl-3 complexes. Finally, in the effluent of the resin, the lanthanide group was separated by oxalate precipitation. In the gamma-ray spectrum of this precipitate the elements europium, cerium, samarium and lanthanum were determined. A detailed study of the possible interferences in the neutron activation analysis of the elements analysed was also made. The precision and accuracy of the results obtained and the sensitivity of the method are discussed. (Author)

  12. Adaptive finite element method assisted by stochastic simulation of chemical systems

    Czech Academy of Sciences Publication Activity Database

    Cotter, S.L.; Vejchodský, Tomáš; Erban, R.

    2013-01-01

    Roč. 35, č. 1 (2013), B107-B131. ISSN 1064-8275 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional support: RVO:67985840 Keywords : chemical Fokker-Planck * adaptive meshes * stochastic simulation algorithm Subject RIV: BA - General Mathematics Impact factor: 1.940, year: 2013 http://epubs.siam.org/doi/abs/10.1137/120877374

  13. Technology for Anonymity: Names By Other Nyms.

    Science.gov (United States)

    Wayner, Peter

    1999-01-01

    Provides a summary of some of the technical solutions for producing anonymous communication on the Internet and presents an argument that anonymity is as much a part of crime prevention as requiring people to provide their names. Discusses identity theft; the three major techniques that make anonymous cash possible; and anonymizing Internet…

  14. Internet Naming and Discovery Architecture and Economics

    CERN Document Server

    Khoury, Joud S

    2013-01-01

    Naming is an integral building block within data networks and systems and is becoming ever more important as complex data-centric usage models emerge. Internet Naming and Discovery is timely in developing a unified model for studying the topic of naming and discovery. It details the architectural and economic tools needed for designing naming and discovery schemes within the broader context of internetwork architecture.   Readers will find in this book a historic overview of the Internet and a comprehensive survey of the literature, followed by and an in-depth examination of naming and discovery. Specific topics covered include: ·         formal definitions of name, address, identifier, locator, binding, routing, discovery, mapping, and resolution; ·         a discussion of the properties of names and bindings, along with illustrative case studies; ·         taxonomy that helps in organizing the solution space, and more importantly in identifying new avenues for contributing to the...

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

    Science.gov (United States)

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

    2010-01-01

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

  16. Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009

    Science.gov (United States)

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

    2011-02-01

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

  17. Separation of W from Ta, Hf, Lu and Mo by BPHA-C5H11OH/HCl extraction system (Model experiments for chemical study of seaborgium, the 106th element)

    International Nuclear Information System (INIS)

    In the batch experiment with W, Ta, Hf, Lu and Mo as radiotracers, a new rapid radiochemical isolation procedure for element tungsten has been developed by using radiochemical separation method and γ spectrum measurement technique. With Voltalef powder carried 2% (W/V) BPHA (Benzoyl-phenyl-hydroxyl-amine)-C5H11OH (iso-amyl-alcohol) organic solution, radioactive W was adsorbed on the Voltalef column in the 4 mol/L hydrochloric acid system. Hf, Lu and Mo fractions passed through the Voltalef column rapidly and partial Ta activities retained on the Voltalef column, respectively. Following this, W fraction was eluted completely with 1%Na3C6H5O7 (sodium citrate)-5%(W/V) NH4OH solution and no Hf, Lu, Ta and Mo activities passed through the Voltalef extraction chromatographic column. The procedure was simultaneously used to isolate W from Er target bombarded with a low energy 12C beams. By means of this separation system, it is one of the possible way to develop an isolation procedure of Sg, supposing the chemical property of Sg is similar to that of tungsten

  18. DNA-Bank of the Siberian Group Chemical Enterprises workers and Seversk city residents

    International Nuclear Information System (INIS)

    According to the mostr common definition a DNA-bank is a system of a genetic material storage. Applying to nuclear-chemical plant workers, DNA-bank creation is determined by the necessity to preserve a hereditary material of these people and their descendants for the further evaluation of consequences fo technogenic factors action on human genome using a contemporary conceptual and applied advances of genetics. In the frameworks of the study of technogenic factors indluence on human genome and genetic-caused disorders development the Seversk Biophysical Research Center is being created DNA-bank of Siberian Group of Chemical Enterprises workers exposed to radiation, their descendants, and ZATO Seversk and Tomsk city inhabitants. The DNA-bank will be a basis for all major research laboratory projects: analysis of molecular basis of individual radiosensitivity; analysis of technogenic factors role in congenital malformations and hereditary diseases development in nuclear-chemical plant workers offspring; elaboration of genotype-specific tes-systems of cancer prognosis and development of cardiovascular and other common disorders connected with the effect of technogenic factors. The DNA-bank creation is a technological issue aggravated by ethical problems. Whereas the DNA isolation is not a problem today, ethical complication id debated widely in the world. These questions strongly arise in a view of advances of Human Genome Project. Information consent on DNA usage is imperative today. Also questions on DNA property (who is its owner a doner or a banker) and of a confidentiality, which maintenance is a doubtable question in a case of multiple genetic testing, are not solved today. At present, the Genomic Medicine Laboratory disposes the DNA samples of more than 400 Sevesk and Tomsk inhabitants affected with breast and lung cancer. More than 800 blood samples of main manufacture of the Siberian Group of Chemical Enterprises workers are collected. About 1500 DNA samples

  19. Chemical composition of the ore and occurrence state of the elements in Jingbaoshan platinum- palladium deposit

    Institute of Scientific and Technical Information of China (English)

    SONG Huanbin; HE Mingqin; ZHANG Shangzhong; YI Fenghuang

    2008-01-01

    The Jingbaoshan platinum-palladium deposit is China's largest independent PGM (platinum-group metals) deposit so far discovered. There are eleven kinds of useful components in the ore: Pt, Pd, Os, Ir, Ru, Rh, Au, Ag, Cu, Ni, and Co. The platinum-group elements, gold and silver occur in the form of minerals in ores. twenty-five kinds of precious metal minerals have been found, of which twenty one belong to the platinum-group minerals. The minerals are very small in grain size. Copper occurs mainly as copper sulfide with a small amount of free copper oxide, and the beneficiated copper accounts for 95.21%. Nickel occurs mainly as nickel sulfide, and some nickel silicate and nickel oxide occur in the ore. The beneficiated nickel accounts for 72.03%. Cobalt occurs mainly as cobalt sulfide, and there are some cobalt oxide and other kinds of cobalt. The beneficiated cobalt accounts for 77.58%.

  20. Inhibition of Synaptosomal Biogenic Amine Transport by a Diverse Group of Neurotoxic Chemicals

    OpenAIRE

    Bracken, William M.

    1980-01-01

    Synaptosomal membrane functions were monitored, after in vitro exposure to select environmental pollutants, in synaptosomal preparations originating from rat cerebral cortices. The uptake of NE and 5HT into the synaptosomes was monitored as was the K+-dependent phosphate activity of the membrane. CH3HgCl, Hg(NO3)2, CdCl2, diisopropylfluorophosphate (DFP), paraoxon, acrylamide and Kepone were the test chemicals whose effects were studied. CH3HgCl, Hg(NO3)2 and Kepone had the greatest inhibi...

  1. Chemical analysis of CH stars - I: atmospheric parameters and elemental abundances

    CERN Document Server

    Karinkuzhi, Drisya

    2014-01-01

    Results from high-resolution spectral analyses of a selected sample of CH stars are presented. Detailed chemical composition studies of these objects, which could reveal abundance patterns that in turn provide information regarding nucleosynthesis and evolutionary status, are scarce in the literature. We conducted detailed chemical composition studies for these objects based on high resolution (R ~ 42000) spectra. The spectra were taken from the ELODIE archive and cover the wavelength range from 3900 to 6800 A, in the wavelength range. We estimated the stellar atmospheric parameters, the effective temperature Teff, the surface gravity log g, and metallicity [Fe/H] from Local thermodynamic equilibrium analyses using model atmospheres. Estimated temperatures of these objects cover a wide range from 4550 K to 6030 K, the surface gravity from 1.8 to 3.8 and metallicity from -0.18 to -1.4. We report updates on elemental abundances for several heavy elements and present estimates of abundance ratios of Sr, Y, Zr, B...

  2. Distribution of chemical elements in marine algae

    International Nuclear Information System (INIS)

    The analytical data on the distribution of chemical elements in the biosphere is promptly increasing in numbers. A method of data analysis which can arrange these data in accordance with a definite principle has been proposed. In our laboratory, systematic study of chemical elements in various Japanese seaweeds has been carried out and a relationship between the concentration factor for elements on a seaweed and its oceanic residence time emerged from the results: the logarithm of the concentration factor(y) tends to be inversely proportional to the logarithm of the residence time(x). Consequently the following rormula can be assumed: log y = log a + b log x. The values of log a, b, and the correlation coefficient r are calculated from the individual data. Usually the value of +r+ was more than 0.8. And in general the larger value of log a the sample has, the larger one of +b+ it has. This regularity between residence time and concentration factor was observed also in other phyla of marine organisms such as marine zoo plankton. Furthermore, since the ocean is closely connected with each of geochemical spheres, there is a tendency that the value of oceanic residence time has similar relation with the concentration ratio of many other geochemical abundance to oceanic chemical abundance as well as with concentration factor of marine organisms. In connection with these results it was found that there is close correlation between the two of each ratio of geochemical abundance to oceanic abundance. On the other hand, it was seen that there are no close correlation between ratios of geochemical abundance to crustal chemical abundance or other ones. Therefore it is again presumed that the ocean gives important contributions on the distribution of chemical elements in many kinds of substances in biosphere. (author)

  3. Distribution of cesium 137 and other chemical elements on the physical chemical barriers of a boundary zone of the Belarus Poles'e marsh

    International Nuclear Information System (INIS)

    An effect of the physical chemical barriers on distribution of cesium-137 and other chemical elements has been considered on the example of landscape-geochemical profile 'White Marsh' formed under conditions typical of Poles'e landscape-geochemical characteristics of the profile is presented. (authors). 2 figs., 1 tab., 7 refs

  4. Deposition and mobility of chemical elements in forest and wetland environments

    International Nuclear Information System (INIS)

    A preliminary study has been initiated to observe organic-rich natural system such as forest litter, bogs, wetlands, marshlands, and rivers to evaluate the role organic matter plays in retaining chemical elements from fallout. We have found that 210Pb can be used to date the layers of certain types of wetlands over the past 150 years. The dating method also provides quantitative information on the rate of aerobic oxidation of the upper layers from the change in organic carbon. Several sites have shown that during the first 40 years, one-half of the initially deposited litter decomposes; after this time the rate of decomposition is much slower. The 137Cs has limited mobility after deposition; infiltration penetrates ≤ 20cm. The 137Cs is much more mobile in the organic-rich marshlands than in the clay-silt rich lake sediments. 239,240Pu is also mobilized, possibly as organic complexes. (author)

  5. Constrained positive matrix factorization: Elemental ratios, spatial distinction, and chemical transport model source contributions

    Science.gov (United States)

    Sturtz, Timothy M.

    Source apportionment models attempt to untangle the relationship between pollution sources and the impacts at downwind receptors. Two frameworks of source apportionment models exist: source-oriented and receptor-oriented. Source based apportionment models use presumed emissions and atmospheric processes to estimate the downwind source contributions. Conversely, receptor based models leverage speciated concentration data from downwind receptors and apply statistical methods to predict source contributions. Integration of both source-oriented and receptor-oriented models could lead to a better understanding of the implications sources have on the environment and society. The research presented here investigated three different types of constraints applied to the Positive Matrix Factorization (PMF) receptor model within the framework of the Multilinear Engine (ME-2): element ratio constraints, spatial separation constraints, and chemical transport model (CTM) source attribution constraints. PM10-2.5 mass and trace element concentrations were measured in Winston-Salem, Chicago, and St. Paul at up to 60 sites per city during two different seasons in 2010. PMF was used to explore the underlying sources of variability. Information on previously reported PM10-2.5 tire and brake wear profiles were used to constrain these features in PMF by prior specification of selected species ratios. We also modified PMF to allow for combining the measurements from all three cities into a single model while preserving city-specific soil features. Relatively minor differences were observed between model predictions with and without the prior ratio constraints, increasing confidence in our ability to identify separate brake wear and tire wear features. Using separate data, source contributions to total fine particle carbon predicted by a CTM were incorporated into the PMF receptor model to form a receptor-oriented hybrid model. The level of influence of the CTM versus traditional PMF was

  6. Isotope Anomalies in the Fe-group Elements in Meteorites and Connection to Nucleosynthesis in AGB Stars

    CERN Document Server

    Wasserburg, Gerald J; Busso, Maurizio

    2015-01-01

    We study the effects of neutron captures in AGB stars on \\oq Fe-group\\cqb elements, with an emphasis on Cr, Fe, and Ni. These elements show anomalies in $^{54}$Cr, $^{58}$Fe, and $^{64}$Ni in solar-system materials, which are commonly attributed to SNe. However, as large fractions of the interstellar medium (ISM) were reprocessed in AGB stars, these elements were reprocessed, too. We calculate the effects of such reprocessing on Cr, Fe, and Ni through 1.5\\msb and 3\\msb AGB models, adopting solar and 1/3 solar metallicities. All cases produce excesses of $^{54}$Cr, $^{58}$Fe, and $^{64}$Ni, while the other isotopes are little altered; hence, the observations may be explained by AGB processing. The results are robust and not dependent on the detailed initial isotopic composition. Consequences for other \\oq Fe group\\cqb elements are then explored. They include $^{50}$Ti excesses, and some production of $^{46,47,49}$Ti. In many circumstellar condensates, Ti quantitatively reflects these effects of AGB neutron cap...

  7. Naming Speed in Dyslexia and Dyscalculia

    Science.gov (United States)

    Willburger, Edith; Fussenegger, Barbara; Moll, Kristina; Wood, Guilherme; Landerl, Karin

    2008-01-01

    In four carefully selected samples of 8- to 10-year old children with dyslexia (but age adequate arithmetic skills), dyscalculia (but age adequate reading skills), dyslexia/dyscalculia and controls a domain-general deficit in rapid automatized naming (RAN) was found for both dyslexia groups. Dyscalculic children exhibited a domain-specific deficit…

  8. 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 and Cs by plants showed great complexity in the distribution of chemical elements in the ecosystem.

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

    International Nuclear Information System (INIS)

    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

  10. 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

  11. Plants and geographical names in Croatia.

    Science.gov (United States)

    Cargonja, Hrvoje; Daković, Branko; Alegro, Antun

    2008-09-01

    The main purpose of this paper is to present some general observations, regularities and insights into a complex relationship between plants and people through symbolic systems like geographical names on the territory of Croatia. The basic sources of data for this research were maps from atlas of Croatia of the scale 1:100000. Five groups of maps or areas were selected in order to represent main Croatian phytogeographic regions. A selection of toponyms from each of the map was made in which the name for a plant in Croatian language was recognized (phytotoponyms). Results showed that of all plant names recognized in geographical names the most represented are trees, and among them birch and oak the most. Furthermore, an attempt was made to explain the presence of the most represented plant species in the phytotoponyms in the light of general phytogeographical and sociocultural differences and similarities of comparing areas. The findings confirm an expectation that the genera of climazonal vegetation of particular area are the most represented among the phytotoponyms. Nevertheless, there are ample examples where representation of a plant name in the names of human environment can only be ascribed to ethno-linguistic and socio-cultural motives. Despite the reductionist character of applied methodology, this research also points out some advantages of this approach for ethnobotanic and ethnolinguistic studies of greater areas of human environment. PMID:18982772

  12. Modifications of chemical functional groups of Pandanus amaryllifolius Roxb and its effect towards biosorption of heavy metals

    Science.gov (United States)

    Abdullah, Mohd. Zamri; Ismail, Siti Salwa

    2015-07-01

    The utilization of non-living biomass as an alternative biosorbent for heavy metal removal has gain a tremendous consideration through the years. Pandanus amaryllifolius Roxb or pandan leaves, which is widely used as food additives in the South East Asia region, has been selected for its viability in the said effort due to the presence of chemical functional groups on its cellular network that enables the sorption to occur. In order to elucidate the possible mechanisms participated during the heavy metal removal process, the biosorbent undergone a series of modification techniques to alter the chemical functional groups present on its constituent. From the outcome of the chemically-modified biosorbent being subjected to the contact with metal cations, nitrogen- and oxygen-containing groups present on the biosorbent are believed to be responsible for the metal uptake to occur through complexation mechanism. Modifying amine groups causes 14% reduction of Cu(II) uptake, whereas removing protein element increases the uptake to 26% as compared to the unmodified biosorbent. Also, scanning electron micrographs further suggested that the adsorption mechanism could perform in parallel, as attributed to the evidence of porous structure throughout the biosorbent fibrous nature.

  13. Modifications of chemical functional groups of Pandanus amaryllifolius Roxb and its effect towards biosorption of heavy metals

    International Nuclear Information System (INIS)

    The utilization of non-living biomass as an alternative biosorbent for heavy metal removal has gain a tremendous consideration through the years. Pandanus amaryllifolius Roxb or pandan leaves, which is widely used as food additives in the South East Asia region, has been selected for its viability in the said effort due to the presence of chemical functional groups on its cellular network that enables the sorption to occur. In order to elucidate the possible mechanisms participated during the heavy metal removal process, the biosorbent undergone a series of modification techniques to alter the chemical functional groups present on its constituent. From the outcome of the chemically-modified biosorbent being subjected to the contact with metal cations, nitrogen- and oxygen-containing groups present on the biosorbent are believed to be responsible for the metal uptake to occur through complexation mechanism. Modifying amine groups causes 14% reduction of Cu(II) uptake, whereas removing protein element increases the uptake to 26% as compared to the unmodified biosorbent. Also, scanning electron micrographs further suggested that the adsorption mechanism could perform in parallel, as attributed to the evidence of porous structure throughout the biosorbent fibrous nature

  14. Modifications of chemical functional groups of Pandanus amaryllifolius Roxb and its effect towards biosorption of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, Mohd Zamri, E-mail: zamriab@petronas.com.my; Ismail, Siti Salwa [Chemical Engineering Department, Universiti Teknologi PETRONAS, 31750 Bandar Seri Iskandar, Perak (Malaysia)

    2015-07-22

    The utilization of non-living biomass as an alternative biosorbent for heavy metal removal has gain a tremendous consideration through the years. Pandanus amaryllifolius Roxb or pandan leaves, which is widely used as food additives in the South East Asia region, has been selected for its viability in the said effort due to the presence of chemical functional groups on its cellular network that enables the sorption to occur. In order to elucidate the possible mechanisms participated during the heavy metal removal process, the biosorbent undergone a series of modification techniques to alter the chemical functional groups present on its constituent. From the outcome of the chemically-modified biosorbent being subjected to the contact with metal cations, nitrogen- and oxygen-containing groups present on the biosorbent are believed to be responsible for the metal uptake to occur through complexation mechanism. Modifying amine groups causes 14% reduction of Cu(II) uptake, whereas removing protein element increases the uptake to 26% as compared to the unmodified biosorbent. Also, scanning electron micrographs further suggested that the adsorption mechanism could perform in parallel, as attributed to the evidence of porous structure throughout the biosorbent fibrous nature.

  15. Configuration interaction matrix elements. I. Algebraic approach to the relationship between unitary group generators and permutations

    International Nuclear Information System (INIS)

    Matrix elements of unitary group generators between spin-adapted antisymmetric states are shown to be proportional to spin matrix elements of so-called line-up permutations. The proportionality factor is given explicitly as a simple function of the orbital occupation numbers. If one bases the theory on ordered orbital products, the line-up permutations are given a priori. The final formulas have a very simple structure; this property is a direct consequence of the fact that the spin functions have been taken to be geminally antisymmetric. 1 table

  16. What's in a Screen Name? Attractiveness of Different Types of Screen Names Used by Online Daters

    Directory of Open Access Journals (Sweden)

    Monica T. Whitty

    2010-01-01

    Full Text Available This paper examined whether different types of screen names offer advantages when it comes to attracting a partner on dating sites. In the pilot study, we conducted a content analysis of real screen names to develop a typology of screen names. In the main study, we explored whether the typology predicted online daters' ratings of names, and compared the types of names that appealed to men and to women. Men more than women were attracted to screen names that indicated physical attractiveness, and women more than men were attracted to screen names that indicated intelligence or were neutral. Similarly, men more than women were motivated to contact screen names which indicated physical attractiveness and women more than men were more motivated to contact screen names which indicated intellectual characteristics or were neutral. These findings indicate that different types of screen names may elicit different reactions.

  17. Should general practitioners call patients by their first names?

    OpenAIRE

    McKinstry, B

    1990-01-01

    OBJECTIVE--To assess the acceptability to patients of the use of patients' first names by doctors and doctors' first names by patients in general practice. DESIGN--An administered questionnaire survey. SETTING--5 General practices in Lothian. PATIENTS--475 Patients consulting 30 general practitioners. MAIN OUTCOME MEASURE--Response by patients to questionnaire on attitude to use of first names. RESULTS--Most of the patients either liked (223) or did not mind (175) being called by their first ...

  18. Lanthanides and actinides among other groups of elements of the D.I. Mendeleev's Periodic Table

    International Nuclear Information System (INIS)

    The extent to which actinides are similar to other elements of the periodic table is discussed. Actinides show certain similarity with transition metals in trends in variation of stability of the highest and lowest oxidation states with increasing atomic number. Similarity between elements of the first half of the lanthanide family and those of the second half of the actinides family is demonstrated. In the lowest oxidation states, actinides and lanthanide are analogs of alkali and alkaline-earth elements, and in the tetravalent state they start to exhibit noticeable similarity with d elements. The formation of Pu(VIII) is suggested on the basis of essentially similar volatility of oxides of Os and Ru with that of Pu. Bivalent actinides and lanthanide ions with one d electron are of particular interest. Being analogs of bivalent elements, they form various types of clusters

  19. Neutron noise simulation by GFEM and unstructured triangle elements

    International Nuclear Information System (INIS)

    Highlights: ► We develop a 2-D, 2-group neutron noise simulator based on GFEM. ► The spatial discretization is performed using unstructured triangle elements. ► The effects of fluctuations in diffusion coefficient on results are investigated. ► The developed code can be applied for both rectangular and hexagonal reactor cores. ► We find that the developed code is reliable tool for neutron noise calculation. - Abstract: In the present study, the neutron noise, i.e. the stationary fluctuation of the neutron flux around its mean value, is calculated in 2-group forward and adjoint diffusion theory for both hexagonal and rectangular reactor cores. To this end, the static neutron calculation is performed at the first stage. The spatial discretization of equations is based on linear approximation of Galerkin Finite Element Method (GFEM) using unstructured triangle elements. Using power iteration method, forward and adjoint fluxes with the corresponding eigenvalues are obtained. The results are then benchmarked against the valid results for BIBLIS-2D and IAEA-2D benchmark problems and DONJON computer code. The dynamic calculations are performed in the frequency domain which leads to reducing the dimension of the variable space of the noise equations. The forward/adjoint noise in two energy group is obtained by assuming the neutron noise source as an absorber of variable strength type. The neutron noise induced by a vibrating absorber type of noise source is also obtained from the calculated adjoint Green's function. Comparison of the calculated neutron noise at zero frequency with the results of static calculation, and utilizing the results of adjoint noise calculations are two different procedures to validate the neutron noise calculations.

  20. Determination of the platinum - group elements (PGE) and gold (Au) in the manganese nodule reference samples by nickel sulfide fire-assay and Te coprecipitation with ICP-MS

    Digital Repository Service at National Institute of Oceanography (India)

    Balaram, V.; Mathur, R.; Banakar, V.K.; Hein, J.R.; Rao, C.R.M.; Rao, T.G.; Dasaram, B.

    was transferred to a fire clay crucible and fused in a muffle furnace at 1100oC for an hour. The molten sample was swirled to ensure proper mixing and heated for one more hour. The melt was then quickly poured into an iron mould and allowed to cool... coprecipitation with inductively coupled plasma mass-spectrometry (ICP-MS), Chem. Geol., 157 (1999) 189-197. 11 Balaram V & Gnaneswara Rao T, Rapid determination of REEs and other trace elements in geological samples by microwave acid digestion and ICP-MS, At...

  1. Attempts to chemically investigate element 112

    International Nuclear Information System (INIS)

    Two experiments aiming at the chemical investigation of element 112 produced in the heavy ion induced nuclear fusion reaction of 48Ca with 238U were performed at the Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt, Germany. Both experiments were designed to determine the adsorption enthalpy of element 112 on a gold surface using a thermochromatography setup. The temperature range covered in the thermochromatography experiments allowed the adsorption of Hg at about 35 C and of Rn at about -180 C. Reports from the Flerov Laboratory for Nuclear Reactions (FLNR), Dubna, Russia claim production of a 5-min spontaneous fission (SF) activity assigned to 283112 for the 238U(48Ca,3n) 283112 reaction. Hence, experiment 1 was designed to detect spontaneously fissioning (SF) isotopes of element 112 with half-lives (t1/2) longer than about 20 s. 11 high-energy events were detected. 7 events exhibit a deposition pattern resembling a chromatographic peak in the vicinity of Rn deposition. However, the energy of the events observed in experiment 2 was lower than expected for a SF-decay of 283112. Therefore, these events could not be unambiguously attributed to the decay of 283112. In contradiction with earlier publications newer reports from FLNR Dubna claim that 283112 decays by α-particle emission (Eα = 9.5 MeV) with t1/2 = 4 s followed by a SF-decay of 279Ds (t1/2 = 0.2 s). Therefore, experiment 2 was designed to be sensitive to both claimed decay properties of 283112. However, during this experiment neither short α-SF correlations nor SF co-incidences were detected. The conclusion is that 283112 was not unambiguously detected, neither in experiment 1 nor in experiment 2. (orig.)

  2. Xingfa Group: To Be World-Famous Phosphorus Chemical Enterprise

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ As the biggest fine phosphorus chemical producer in China, Hubei Xingfa Chemicals Co., Ltd. (Xingfa Group, SH: 600141) is mainly engaged in the production and sales of phosphorus chemicals and fine chemicals.

  3. Predicting Anatomical Therapeutic Chemical (ATC classification of drugs by integrating chemical-chemical interactions and similarities.

    Directory of Open Access Journals (Sweden)

    Lei Chen

    Full Text Available The Anatomical Therapeutic Chemical (ATC classification system, recommended by the World Health Organization, categories drugs into different classes according to their therapeutic and chemical characteristics. For a set of query compounds, how can we identify which ATC-class (or classes they belong to? It is an important and challenging problem because the information thus obtained would be quite useful for drug development and utilization. By hybridizing the informations of chemical-chemical interactions and chemical-chemical similarities, a novel method was developed for such purpose. It was observed by the jackknife test on a benchmark dataset of 3,883 drug compounds that the overall success rate achieved by the prediction method was about 73% in identifying the drugs among the following 14 main ATC-classes: (1 alimentary tract and metabolism; (2 blood and blood forming organs; (3 cardiovascular system; (4 dermatologicals; (5 genitourinary system and sex hormones; (6 systemic hormonal preparations, excluding sex hormones and insulins; (7 anti-infectives for systemic use; (8 antineoplastic and immunomodulating agents; (9 musculoskeletal system; (10 nervous system; (11 antiparasitic products, insecticides and repellents; (12 respiratory system; (13 sensory organs; (14 various. Such a success rate is substantially higher than 7% by the random guess. It has not escaped our notice that the current method can be straightforwardly extended to identify the drugs for their 2(nd-level, 3(rd-level, 4(th-level, and 5(th-level ATC-classifications once the statistically significant benchmark data are available for these lower levels.

  4. Molecular clusters of the main group elements

    CERN Document Server

    Driess, Matthias

    2008-01-01

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

  5. Spinel from Apollo 12 Olivine Mare Basalts: Chemical Systematics of Selected Major, Minor, and Trace Elements

    Science.gov (United States)

    Papike, J. J.; Karner, J. M.; Shearer, C. K.; Spilde, M. N.

    2002-01-01

    Spinels from Apollo 12 Olivine basalts have been studied by Electron and Ion microprobe techniques. The zoning trends of major, minor and trace elements provide new insights into the conditions under which planetary basalts form. Additional information is contained in the original extended abstract.

  6. Establishment of natural background concentration of some elements in soils from Zaria and environ by INAA using NIRR-1

    International Nuclear Information System (INIS)

    Source profile of chemical elements is important both for determination of natural baseline and anthropogenic input into soil characteristics. Undisturbed soils in Zaria and environ were sampled at six locations namely Bassawa, Kufena, TSibiri, Palladan, Kamphaghi and Kudingi based on the geology of the area. The soil samples were analyzed for sixteen (16) elements using Instrumental Neutron Activation Analysis (INAA) Technique. The elements determined were AI, Mn, Dy, K, Br, La, Sc, Cr, Fe, Co, Rb, Cs, Ba, Eu, Lu and Ta. Analysis of the data revealed that concentration of most of the elements determined increases with depth indicating that natural sources account for the distribution pattern. In addition, soil samples collected in areas underlain by igneous rocks contain high concentrations of AI and Dy in 0-15 cm fraction and K, La, Rb and Mn in 0-30 cm fraction when compared with soil samples collected in areas underlain by metamorphic rocks. On the other hand, soil collected from the areas underlain by metamorphic rocks are more enriched in Sc and Cr in the 0-15 cm fraction and Sc and Co in the 0-30 cm fraction compared with soil collected from areas underlain by igneous rocks. The general variations in the elemental concentration of the various soil samples is attributed to the differences in parent rock chemistry and constituent minerals, local variation in Eh-pH conditions of the environment and continued alterations by other soil forming factors.

  7. Effect of Organic Matter on Soil Chemical Properties and Corn Yield and Elemental Uptake

    OpenAIRE

    M. Afyuni; Y. Rezaenejad

    2001-01-01

    Due to high production of organic residues such as sewage sludge and compost, land application is probably the best way to prevent accumulated residues in the environment. However, the risk involved in the land application of organic residues should be evaluated prior to the assessment of their economic and fertilizer values. The objective of this study was to evaluate the effect of organic residues on soil chemical properties, yield and uptake of heavy metals and nutrients by corn (Zea mays ...

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

    International Nuclear Information System (INIS)

    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

  9. Functional groups and elemental analyses of cuticular morphotypes of Cordaites principalis (Germar) Geinitz, Carboniferous Maritimes Basin, Canada

    Science.gov (United States)

    Zodrow, E.L.; Mastalerz, Maria; Orem, W.H.; Simunek, Z.; Bashforth, A.R.

    2000-01-01

    Well-preserved cuticles were isolated from Cordaites principalis (Germar) Geinitz leaf compressions, i.e., foliage from extinct gymnosperm trees Coniferophyta: Order Cordaitales. The specimens were collected from the Sydney. Stellarton and Bay St. George subbasins of the once extensive Carboniferous Maritimes Basin of Atlantic Canada. Fourier transformation of infrared spectra (FTIR) and elemental analyses indicate that the ca. 300-306-million-year-old fossil cuticles share many of the functional groups observed in modern cuticles. The similarities of the functional groups in each of the three cuticular morphotypes studied support the inclusion into a single cordaite-leaf taxon, i.e., C. principalis (Germar), confirming previous morphological investigations. Vitrinite reflectance measurements on coal seams in close proximity to the fossil-bearing sediments reveal that the Bay St. George sample site has the lowest thermal maturity, whereas the sites in Sydney and Stellarton are more mature. IR absorption and elemental analyses of the cordaite compressions corroborate this trend, which suggests that the coalified mesophyll in the leaves follows a maturation path similar to that of vitrinite. Comparison of functional groups of the cordaite cuticles with those from certain pteridosperms previously studied from the Sydney Subbasin shows that in the cordaite cuticles highly conjugated C-O (1632 cm-1) bands dominate over carbonyl stretch that characterizes the pteridosperm cuticles. The differences demonstrate the potential of chemotaxonomy as a valuable tool to assist distinguishing between Carboniferous plant-fossil groups. Published by Elsevier Science B.V.

  10. Functional group analysis by H NMR/chemical derivatization for the characterization of organic aerosol from the SMOCC field campaign

    Directory of Open Access Journals (Sweden)

    E. Tagliavini

    2006-01-01

    Full Text Available Water soluble organic compounds (WSOC in aerosol samples collected in the Amazon Basin in a period encompassing the middle/late dry season and the beginning of the wet season, were investigated by H NMR spectroscopy. HiVol filter samples (PM2.5 and PM>2.5 and size-segregated samples from multistage impactor were subjected to H NMR characterization. The H NMR methodology, recently developed for the analysis of organic aerosol samples, has been improved by exploiting chemical methylation of carboxylic groups with diazomethane, which allows the direct determination of the carboxylic acid content of WSOC. The content of carboxylic carbons for the different periods and sizes ranged from 12% to 20% of total measured carbon depending on the season and aerosol size, with higher contents for the fine particles in the transition and wet periods with respect to the dry period. A comprehensive picture is presented of WSOC functional groups in aerosol samples representative of the biomass burning period, as well as of transition and semi-clean atmospheric conditions. A difference in composition between fine (PM2.5 and coarse (PM>2.5 size fractions emerged from the NMR data, the former showing higher alkylic content, the latter being largely dominated by R-O-H (or R-O-R' functional groups. Very small particles (<0.14 μm, however, present higher alkyl-chain content and less oxygenated carbons than larger fine particles (0.42–1.2 μm. More limited variations were found between the average compositions in the different periods of the campaign.

  11. Calculation of the reactivity worth for TRIGA core fuel elements by means of the two-dimensional, two-group perturbation theory

    International Nuclear Information System (INIS)

    A two-dimensional, two-group perturbation theory calculation method has been proposed for the rapid and accurate calculation of the reactivity worth for TRIGA core fuel elements. The method requires shorter computation times and provides almost the same level of accuracy as a conventional direct eigenvalue calculation method using the CITATION code. Values for changes in macroscopic cross-sections and diffusion coefficients are obtained from cell calculation. The reactivity worth for each individual fuel element is calculated on the basis of the above-mentioned changes, by means of the two-group, first order perturbation method using normal and adjoint neutron fluxes calculated beforehand for a normal core. The method was applied to a 250 kW TRIGA Mark-II reactor. The results of the calculations are in agreement with the experimental values for fuel elements in the locations C3, D8, E7 and F4. The reactivity worth for the TRIGA core fuel element placed in location B2 calculated by means of this method is approximately 5% greater than that calculated by means of the CITATION code which is based on a conventional direct eigenvalue calculation method. (orig.)

  12. Accumulation and distribution characteristics of platinum group elements in roadside dusts in Beijing, China.

    Science.gov (United States)

    Gao, Bo; Yu, Yanke; Zhou, Huaidong; Lu, Jin

    2012-06-01

    The concentrations, distribution, and accumulation of platinum group elements (PGEs) were investigated in roadside dusts collected in four different foundational areas in Beijing during February to May 2010. The results showed that PGE levels in all samples were above the average upper crust values, with mean concentrations of 57.5 ng · g(-1) Pd, 28.2 ng · g(-1) Pt, and 9.8 ng · g(-1) Rh, respectively. Palladium concentration has increased rapidly in recent years. The rank of PGE levels in four different functional regions for roadside dusts was: heavy density traffic area > residential area > educational area > tourism area. Palladium, Pt, and Rh concentrations in dusts showed strong positive correlations, indicating a common traffic-related source of these metals. Meanwhile, PGEs in these samples were not correlated with other traffic-related metals except for Cr. The average PGE ratios of road dusts from Beijing were consistent with those in Germany and Western Australia, but lower than those in the United States and Mexico, indicating that various catalyst productions were used in different countries. In addition, grain-size partitioning of PGEs in dusts indicated that concentrations of PGEs differed from one particle size to another. The coarse fraction had higher PGE concentrations than the fine fraction in roadside dusts. These results showed that autocatalyst PGE contamination estimates in the environment would be significantly underestimated if only a fine-grain size fraction (<0.063 mm) is analyzed. PMID:22505271

  13. Chemical characterization of Flavobacterium odoratum, Flavobacterium breve, and Flavobacterium-like groups IIe, IIh, and IIf.

    OpenAIRE

    Dees, S B; Moss, C W; Hollis, D G; Weaver, R E

    1986-01-01

    The cellular fatty acid, sphingolipid, and isoprenoid quinone compositions of Flavobacterium odoratum, Flavobacterium breve, and Flavobacterium-like groups IIe, IIh, and IIf were determined, using thin-layer, gas-liquid, and reverse-phase high-performance liquid chromatography. The fatty acid data showed that groups IIe, IIh, and IIf were similar to recognized Flavobacterium species by the presence of relatively large amounts of iso-branched hydroxy and nonhydroxy acids. Groups IIe and IIh we...

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

    International Nuclear Information System (INIS)

    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

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

    Indian Academy of Sciences (India)

    Mohammad Reza R Moghaddam; Esmat Motaghi; Mohammad Amin Rostamyari

    2016-02-01

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

  16. Re-187-Os-187, Pt-190-Os-186 Isotopic and Highly Siderophile Element Systematics of Group IVA Irons

    Science.gov (United States)

    Walker, R. J.; McCoy, T. J.; Schulte, R. F.; McDonough, W. F.; Ash, R. D.

    2005-01-01

    We have recently completed Re-187-Os-187 and Pt-190-Os-186 isotopic and elemental studies of the two largest magmatic iron meteorite groups, IIAB and IIIAB [1]. These studies revealed closed-system behavior of both isotopic systems, but complex trace element behavior for Re, Pt and Os in group IIIAB. Here we examine isotopic and trace elemental systematics of group IVA irons. The IVA irons are not as extensively fractionated as IIAB and IIIAB and their apparently less complex crystallization history may make for more robust interpretation of the relative partitioning behavior of Re, Pt and Os, as well as the other highly siderophile elements (HSE) measured here; Pd, Ru and Ir [e.g. 2]. An additional goal of our continuing research plan for iron meteorites is to assess the possibility of relating certain ungrouped irons with major groups via trace element modeling. Here, the isotopic and trace element systematics of the ungrouped irons Nedagolla and EET 83230 are compared with the IVA irons.

  17. Dynamics of Coupled Adaptive Elements : Bursting and Intermittent Oscillations Generated by Frustration in Networks

    CERN Document Server

    Inoue, Masayo

    2009-01-01

    Adaptation to environmental change is a common property of biological systems. Cells initially respond to external changes in the environment, but after some time, they regain their original state. By considering an element consisting of two variables that show such adaptation dynamics, we studied a coupled dynamical system containing such elements to examine the diverse dynamics in the system and classified the behaviors on the basis of the network structure that determined the interaction among elements. For a system with two elements, two types of behaviors, perfect adaptation and simple oscillation, were observed. For a system with three elements, in addition to these two types, novel types of dynamics, namely, rapid burst-type oscillation and a slow cycle, were discovered; depending on the initial conditions, these novel types of dynamics coexisted. These behaviors are a result of the characteristic dynamics of each element, i.e., fast response and slow adaptation processes. The behaviors depend on the n...

  18. Plasma-enhanced CVD preparation of isotopes of group IV and VI elements

    Science.gov (United States)

    Sennikov, P. G.; Kornev, R. A.

    2016-03-01

    The plasma-chemical reduction was studied experimentally of molybdenum, sulfur and germanium fluorides with different isotopic composition by hydrogen in plasmas sustained by inductively coupled (IC) and capacitively-coupled (CC) RF discharges. The emission spectra of plasmas recorded under different experimental conditions are discussed. Reaction mechanisms are proposed. In the case of 98MoF6 reduction in CCP, the combined radical-atomic mechanism including intermediate MoF3 resulting in bulk and powder 98Mo formation was established. In the emission spectrum of the 32SF6 + H2 system in ICP at 0.2 Torr, only lines assigned to SiF2, SiF and F2 * originating from the decomposition of 32SF6 and a fast reaction of its products with the reactor's quartz walls were observed. Due to this etching process, the yield of 32S was moderate. Increasing the pressure in the reactor above 1 Torr resulted in an increase of the 32S yield. The mechanism of 72GeF4 reduction depends on the pressure and plasma type. At 0.25 Torr in ICP, a 72Ge deposit was formed via the 72GeF radical; however, at 3.5 Torr in CCP, the mechanism changed to a molecular one. Results of the study of the structure and the isotopic and chemical purity of isotope samples obtained are briefly presented.

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

    International Nuclear Information System (INIS)

    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

  20. Elements in hair of an exposed group

    International Nuclear Information System (INIS)

    Hair analysis presents a lot of advantages compared to the analysis of biological fluids or tissues. Hair of employers from the National (Brazilian) Nuclear Energy Commission (CNEN) was analyzed and compared with a control group. Samples were heated at 90 deg C with nitric acid, and diluted. Aliquot of these solutions was analyzed in ICP-MS. The concentration of U, Th, Pb and Zn were determined. Student t-test showed that there is no significant difference among the groups for all analyzed elements. The results demonstrated that men had more Pb than women. For Zn, the results showed that the levels are within the 'normal' range, except for a woman that had her hair painted. (author)

  1. Plants and Geographical Names in Croatia

    OpenAIRE

    Čargonja, Hrvoje; Đaković, Branko; Alegro, Antun

    2008-01-01

    The main purpose of this paper is to present some general observations, regularities and insights into a complex relationship between plants and people through symbolic systems like geographical names on the territory of Croatia. The basic sources of data for this research were maps from atlas of Croatia1 of the scale 1:100000. Five groups of maps or areas were selected in order to represent main Croatian phytogeographic regions. A selection of toponyms from each of the map was ma...

  2. Effects of a Low-Element Challenge Course on Abstinence Self-Efficacy and Group Cohesion

    Science.gov (United States)

    Clem, Jamie M.; Smith, Thomas E.; Richards, Kristin V.

    2012-01-01

    Substance abuse researchers identify self-efficacy and group cohesion as important components in alcohol and other drug-dependency treatment. Objectives: The purpose of this single-group, pretest-posttest study is to explore the therapeutic value of a challenge course intervention on the self-efficacy and group cohesion of nine chemically…

  3. Simultaneous determination of trace elements in soils and sediments by polarizing energy dispersive x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Possibilities of polarizing energy dispersive X-ray fluorescence (EDXRF) spectrometry were fully explored to materialize rapid trace element determinations of soil and sediment samples. The pressed powder pellet technique was adopted for sample preparation because of its simplicity. The trace elements examined were V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Sn, Cs, Ba, La, Ce, Pr, Nd, Pb, and Th. The instrument was calibrated by using 26 reference materials. Compton scatter radiation was used as an internal standard to compensate any matrix effects and operating characteristics of the instruments. The correlation coefficients of the calibration lines were greater than 0.98, with the exception of Co and Pr. The results obtained by the proposed EDXRF spectrometry were compared with those obtained by other methods for around 450 samples. Out of the 20 trace elements examined, the results for 10 elements (Ni, Cu, Zn, Rb, Sr, Nb, Cs, Ba, La, Ce and Nd) obtained by the proposed EDXRF spectrometry compared favorably with those determined through conventional wet chemical methods. In contrast, the results for 5 elements (Cr, Co, Zr, Sn, and Pr) exhibited poor agreements with those obtained by the chemical methods. Among these elements, poor agreements of Cr, Zr and Sn were attributable to incomplete dissolution and/or volatilization losses during chemical treatments based on an acid attack, and therefore we concluded that results obtained by EDXRF are superior over those by chemical methods. In the case of Co, however, overlapping of the Fe Kβ line is responsible for the lower correlation coefficient. Although the results of the other 4 analytes (V, Y, Pb and Th) were not as good as those of the first group, they still appeared to be of practical use, considering the time-consuming and potentially hazardous acid digestion pretreatments. (author)

  4. Public Naming of Planets and Planetary Satellites

    CERN Document Server

    Montmerle, T; Cheung, Sze-leung; Christensen, L L; Etangs, A Lecavelier des; Liu, Xiaowei; Lubowich, D; Mamajek, E; Schulz, R; Valsecchi, G; Williams, G; Williams, R

    2016-01-01

    While one of the IAU's missions is to "serve as the internationally recognized authority for assigning designations to celestial bodies and surface features on them", the participation of the public in the naming of celestial objects has been a little-known, but decade-long tradition of the IAU. While reiterating its opposition to having the public pay to give a name to an exoplanet, the IAU Executive Committee nonetheless recognized the right of organizations to invite public, international exoplanet naming or voting campaigns. To this end, clear selection rules were to be defined by the IAU, inviting mutual collaboration, the goal being to sanction the campaign and officially approve the resulting names, for the sake of boosting the public's interest in astronomy and at the same time reaffirm the authority of the IAU. In no way were these names supposed to supersede the designations in use by professional astronomers. Since the field of exoplanet research was still "virgin" for naming but is now becoming sc...

  5. 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. PMID:25666065

  6. Fractional crystallization models for calculating distribution coefficients of chemical elements between magmas and their crystallization products

    International Nuclear Information System (INIS)

    Igneous rock successions can be investigated with respect to their genetic coherence or to the role in fractional crystallization during their generation, respectively, by evaluating element concentration correlations. It is shown that the existence of a linear relation between element concentrations or their logarithms is only a necessary, but not a sufficient condition for fractional crystallization as the dominating factor of graduating element concentrations. The comparison of the slope of such correlation lines with the slope calculated on the basis of the distribution coefficients evaluated by using Schuetze's 18O index reveals whether fractional crystallization is dominant in graduating element concentrations in igneous rocks. Several applications are given. (author)

  7. Separation of chemically similar elements such as trivalent actinides and lanthanides

    International Nuclear Information System (INIS)

    Separation of chemical elements has been during all times an interesting topic and references may be found from ∼ 3000 B.C., i.e. ion exchange for purification of drinking water. With increasing knowledge the separation methods have become more and more refined. There are many methods used for the separation processes, e.g. pyrometallurgy, chromatographic methods, ion exchange and solvent extraction. Of these the solvent extraction technique is widely used today due to its relative simplicity to scale up and use industrially. The solvent extraction processes have been successfully used during the last 100 years in various areas ranging from the mining industry to the reprocessing of spent nuclear fuel. In some cases the elements that are to be separated have quite different chemical properties and a relatively simple process can be used. In the case of separation of trivalent metal ions with similar properties such as trivalent actinides and lanthanides the problem is more difficult. The separation of actinides and lanthanides is an important question when considering future alternatives to take care of waste from reprocessing of spent nuclear fuel (in for instance a transmutation process). To decrease process losses to secondary waste streams it has been decided that only extracting agents containing carbon, hydrogen, oxygen and nitrogen are to be used, which further increases the difficulty level. Two examples of such ligands are 2,2': 6' ,2-terpyridine and 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine. It has been shown that using such ligands, good separation of actinides and lanthanides can be achieved. This is mainly because nitrogen binds more strongly to actinides than to lanthanides due to the more covalent nature of the bond. Often synergistic extraction is used, adding the reagent to e,g. a 2-bromodecanoic acid extraction system in order to increase the extraction and the separation efficiency. In addition it is also possible to separate different

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

    OpenAIRE

    Ping Li; Weidong Luo

    2016-01-01

    The elemental two-dimensional (2D) materials such as graphene, silicene, germanene, and black phosphorus have attracted considerable attention due to their fascinating physical properties. Structurally they possess the honeycomb or distorted honeycomb lattices, which are composed of six-atom rings. Here we find a new structure of 2D allotropes of group V elements composed of eight-atom rings, which we name as the octagonal tiling (OT) structure. First-principles calculations indicate that the...

  9. Investigation into solid-phase interaction between oxides of the second group elements and lead oxide

    International Nuclear Information System (INIS)

    Study of the solidphase interaction of the second group D.I. Mendeleev Periodic System metal oxide with lead dioxide by roentgenophase analysis showed that MeO-PbO2 systems could be divided into two groups, depending on the interaction character: 1 systems with absence of the interaction between the initial components-MgO(ZnO,CdO)-PbO2; 2/systems, in which formation of the lead compounds takes place-CaO(SrO,BaO-PbO2). It was shown that the tendency to the formation of the compounds in the MeO-MeO2 systems was determined by correlation of the crystalchemical characteristics (ion radius, ion potential) of the cations Me2+ and Me4+

  10. Type and distribution of chemical groups from controlled photo-oxidation of gyroid nanoporous 1,2-polybutadiene

    DEFF Research Database (Denmark)

    Sagar, Kaushal Shashikant; Christiansen, Mads Brøkner; Ndoni, Sokol

    2011-01-01

    Photo-oxidation of nanoporous polymers is little studied. The high UV penetration depth and high surface concentration in these materials give unprecedented possibilities both in fundamental work on surface photochemistry and in nanotechnological applications related for example to patterned...... hydrophilicity or refractive index. This is a quantitative study of the photo-oxidation products of nanoporous gyroid 1,2-polybutadiene in air. Irradiation of the porous sample with UV in the wavelength range of 300–400nm enables tuning of the hydrophilicity of the nanoporous polymer through formation of...... hydrophilic chemical groups, carboxyl and hydroxyls, mainly onto the large air–polymer interface. The nature and abundance of the chemical groups induced by photo-oxidation is identified by solid-state 13C-NMR and FTIR spectroscopy. The distribution of photo-oxidation groups, both relative to the nanometre...

  11. Turbulent mixing of chemical elements in galaxies

    Science.gov (United States)

    Pan, Liubin

    Chemical elements synthesized in stars are released into the interstellar medium (ISM) from discrete and localized events such as supernova (SN) explosions and stellar winds. The efficiency of transport and mixing of the new nucleosynthesis products in the ISM determines the degree of chemical inhomogeneity in the galaxy, which is observable in objects of the same age, such as coeval stars and the ISM today. It also has implications for the transition from metal-poor to normal star formation in high-redshift galaxies. We develop a physical mixing model for chemical homogenization in the turbulent ISM of galaxies using modern theories and methods for passive scalar turbulence. A turbulent velocity field stretches, compresses and folds tracers into structures of smaller and smaller scales that can be homogenized faster by microscopic diffusivity, the only physical process that truly mixes. From a model that incorporates this physical process, an evolution equation for the probability distribution of the tracer concentration is derived. Including the processes of new metal release, infall of low metallicity gas and incorporation of metals into new stars in the equation, we establish a new approach to investigate chemical inhomogeneity in galaxies: a kinetic equation for the metallicity probability distribution function, containing all the 1-point statistical information of the metallicity fluctuations. Motivated by a recent interpretation of ultraviolet properties of high-redshift Lyman Break Galaxies, we apply this approach to study mixing of primordial gas in these galaxies and find that primordial gas can survive for ~ 100 Myr in the presence of continuous metal sources and turbulent mixing if the unlikely efficient mixing in SN shells is excluded. Recent observations show that the Galaxy has been extremely homogeneous during most of its history. In an attempt to understand the homogeneity using our approach, we find that standard chemical evolution models without

  12. Growth of primitive elements in free groups

    OpenAIRE

    Puder, D.; Wu, C.

    2014-01-01

    In the free group $F_k$, an element is said to be primitive if it belongs to a free generating set. In this paper, we describe what a generic primitive element looks like. We prove that up to conjugation, a random primitive word of length $N$ contains one of the letters exactly once asymptotically almost surely (as $N \\to \\infty$). This also solves a question from the list `Open problems in combinatorial group theory' [Baumslag-Myasnikov-Shpilrain 02']. Let $p_{k,N}$ be the number of primitiv...

  13. Hemolytic anemia caused by chemicals and toxins

    Science.gov (United States)

    Anemia - hemolytic - caused by chemicals or toxins ... Possible substances that can cause hemolytic anemia include: Anti-malaria drugs (quinine compounds) Arsenic Dapsone Intravenous water infusion (not half-normal saline or normal saline) Metals (chromium/chromates, ...

  14. Trace element measurement in Saliva by NAA and PIXE techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hamidian, M.R.; Vahid Golpayegani, M.; Shojai, S. (Shahid Beheshti Medical Science Univ., Shemiran, Tehran (Iran, Islamic Republic of))

    1993-01-01

    The activity of salivary glands and the chemical and physical properties of saliva, especially in some illnesses in which the activity of salivary glands and the chemical and physical properties alter, sometimes have severe effects on sedimentation and tooth decay. Long-standing investigations have shown the relationship between salivary gland activity and saliva composition in dental carries. Many modern techniques have been employed to measure important elements in saliva. The major elements in saliva include sodium, potassium, calcium, magnesium, chlorine, phosphorus, iodine, and fluorine. It should be pointed out that the amount of minerals changes when the diet changes. The major constituent of saliva is water with a density of 1.007 g/cm[sup 3] in which 0.6% is solid, 0.3% organic material and 0.3% inorganic material. In addition to other effects, the acidity (pH) of saliva has a strong effect on tooth sedimentation. Type of work, degree of stress, and mental condition affect salivary gland activity. When the acidity of salivary fluid in the mouth and consequently over the teeth drops, sedimentation increases. In this paper, the results of trace element measurement in saliva are presented.

  15. Platinum group elements geochemistry of ultramafic and associated rocks from Pindar in Madawara Igneous Complex, Bundelkhand massif, central India

    Indian Academy of Sciences (India)

    V Balaram; S P Singh; M Satyanarayanan; K V Anjaiah

    2013-02-01

    Ultramafic rocks comprising dunite, harburgite, lehzolite, olivine webserite and websterite occur as intrusives in the form of small hillocks at around Pindar into the granite–gneisses of Bundelkhand Gneissic Complex (BnGC). The peridotites are dominated by olivine cumulates where chromite and precious metal-bearing sulphides crystallized along with pyroxenes, subsequent to crystallization of olivine into the interstitial spaces of cumulates during cooling. Ultramafic rocks of Pindar are characterized by high MgO (up to 46.0 wt%) and FeO (up to 5.8 wt%); low SiO2 (40.8 to 48.0 wt%), TiO2 (0.2 to 0.5 wt%), Al2O3 (∼3.2 wt% av.), CaO(∼ 2.7 wt% av.) and Cu (11 to 73 g/g). Cr and Ni values range from 2297 to 3150 g/g and 2434 to 2767 g/g, respectively. Distribution of Ir (up to 20 ng/g), Ru (27 to 90 ng/g), Rh (3 to 14 ng/g), Pt (18 to 72 ng/g), Pd (10 to 27 ng/g) and Au (22 to 57 ng/g) indicate platinum group element (PGE) and associated gold mineralization in these ultramafic rocks. A mineral phase representing sperrylite (PtAs2) was also identified within the sulphides in Scanning electron microscopy with energy dispersive spectrometer (SEM–EDS) studies. The primitive mantle-normalized siderophile elements pattern shows platinum group element PGE (PPGE) enrichment (Rh, Pt, Pd). Discrimination diagrams of Pd/Ir vs. Ni/Cu, Pd/Pt vs. Ni/Cu, Cu/Pd vs. Pd, and Cu vs. Pd for the peridotites of Pindar attribute to affinity towards komatiite magma, derived from high degree of partial melting of prolonged depleted mantle, and the sulphur saturation condition incurred during the crystallization of chromite which was favourable for PGE mineralization.

  16. Recent achievements in chemical studies of heaviest elements

    Science.gov (United States)

    Gäggeler, H. W.

    2011-09-01

    Discovery of heavy elements up to atomic number 118 at FLNR in Dubna has paved the way to also extend chemical knowledge to heavier members of the periodic table. Recent studies on the chemical properties of Cn and element 114 are summarized that have been performed at FLNR in Dubna using the fusion reactions 48Ca + 242/244Pu.

  17. Recent achievements in chemical studies of heaviest elements

    International Nuclear Information System (INIS)

    Discovery of heavy elements up to atomic number 118 at FLNR in Dubna has paved the way to also extend chemical knowledge to heavier members of the periodic table. Recent studies on the chemical properties of Cn and element 114 are summarized that have been performed at FLNR in Dubna using the fusion reactions 48Ca + 242/244Pu.

  18. Fructose: Pure, White, and Deadly? Fructose, by Any Other Name, Is a Health Hazard

    OpenAIRE

    Bray, George A

    2010-01-01

    The worldwide consumption of sucrose, and thus fructose, has risen logarithmically since 1800. Many concerns about the health hazards of calorie-sweetened beverages, including soft drinks and fruit drinks and the fructose they provide, have been voiced over the past 10 years. These concerns are related to higher energy intake, risk of obesity, risk of diabetes, risk of cardiovascular disease, risk of gout in men, and risk of metabolic syndrome. Fructose appears to be responsible for most of t...

  19. Letter Names and Alphabet Book Reading by Senior Kindergarteners: An Eye Movement Study

    Science.gov (United States)

    Evans, Mary Ann; Saint-Aubin, Jean; Landry, Nadine

    2009-01-01

    The study monitored the eye movements of twenty 5-year-old children while reading an alphabet book to examine the manner in which the letters, words, and pictures were fixated and the relation of attention to print to alphabetic knowledge. Children attended little to the print, took longer to first fixate print than illustrations, and labeled…

  20. The Abundances of the Fe Group Elements in Early B Stars in the Magellanic Clouds and Bridge

    Science.gov (United States)

    Peters, Geraldine J.; Adelman, Saul J.

    2016-01-01

    The abundances of three Fe Group elements (V, Cr, and Fe) in 9 early main-sequence band B stars in the LMC, 7 in the SMC , and two in the Magellanic Bridge have been determined from archival FUSE observations and the Hubeny/Lanz NLTE programs TLUSTY/SYNSPEC. Lines from the Fe group elements, except for a few weak multiplets of Fe III, are not observable in the optical spectral region. The best set of lines in the FUSE spectral region are Fe III (UV1), V III 1150 Å, and Cr III 1137 Å. The abundances of these elements in early B stars are a marker for recent SNe Ia activity, as a single exploding white dwarf can deliver 0.5 solar masses of Ni-56 that decays into Fe to the ISM. The Fe group abundances in an older population of stars primarily reflect SNe II activity, in which a single explosion delivers only 0.07 solar masses of Ni-56 to the ISM (the rest remains trapped in the neutron star). The abundances of the Fe group elements in early B stars not only track SNe Ia activity but are also important for computing evolutionary tracks for massive stars. In general, the Fe abundance relative to the sun's value is comparable to the mean abundances for the lighter elements in the Clouds/Bridge but the values of [V,Cr/Fe]sun are smaller. This presentation will discuss the spatial distribution of the Fe Group elements in the Magellanic Clouds, and compare it with our galaxy in which the abundance of Fe declines with radial distance from the center. Support from NASA grants NAG5-13212, NNX10AD66G, STScI HST-GO-13346.22, and USC's Women in Science and Engineering (WiSE) program is greatly appreciated.

  1. Michiel Florent van Langren and Lunar Naming

    OpenAIRE

    van der Krogt, P.C.J.; Ormeling, F.J.

    2014-01-01

    Michiel Florent van Langren produced a lunar map in 1645 in order to present a way to mariners to find their position at sea by observing which craters were either illuminated by solar rays or obscured during the waxing or waning of the moon. This required a detailed map of the moon and in order to be able to refer to lunar objects these had to be named. The lunar map he produced in 1645 bore over 300 names, following the system of subdividing lunar topography into land masses and seas (a dis...

  2. Formazanido complexes of heavier group 13 elements aluminium, gallium, and indium.

    Science.gov (United States)

    Schorn, W; Grosse-Hagenbrock, D; Oelkers, B; Sundermeyer, J

    2016-01-21

    The preparation, molecular structures and physical properties of novel heavy group 13 metal formazanido complexes are described. The trimethyl derivatives MMe3 (M = Al, Ga, In) react with 1,3,5-triphenylformazan (Htpf) in a 1 : 1 ratio to give methane and metallacycles of the type [M(tpf)Me2]. While [Al(tpf)Me2] and [Ga(tpf)Me2] are mononuclear compounds with six-membered rings and coordination number 4 in solution and in the crystalline state, indium derivative [In(tpf)Me2] forms oligomers in non-coordinating solvents according to NMR studies, these are probably N-bridged dimers with coordination number 5 at indium. The oligomer is cleaved by addition of one equivalent of pyridine or 4-dimethylaminopyridine (DMAP). The complexes [M(tpf)Me2] (M = Al, Ga) and [In(tpf)Me2(DMAP)] are characterized by XRD analyses. They are unique examples of main group metal formazane ring systems of the third and higher periods. The UV-Vis solution spectra of the neutral ligand Htpf and its metallated compounds [M(tpf)Me2] (M = Al, Ga, In) are discussed. PMID:26658885

  3. Enhancing the Learning Environment by Learning all the Students' Names

    DEFF Research Database (Denmark)

    Jørgensen, Anker Helms

    Short abstract This paper describes how the teaching environment can be enhanced significantly by a simple method: learning the names of all the students. The method is time-efficient: In a course with 33 students I used 65 minutes in total. My own view of the effect was confirmed in a small study...... after some trials.Im summary, using the method to learn all the students' names enhances the learning environment substantially.  ReferencesCranton, Patricia (2001) Becoming an authentic teacher in higher education. Malabar, Florida: Krieger Pub. Co.Wiberg, Merete (2011): Personal email communication......: The students felt more valued, secure and respected. They also made an effort to learn each other's names. Long abstract In high school teachers know the students' names very soon - anything else is unthinkable (Wiberg, 2011). Not so in universities where knowing the names of all the students is the...

  4. Nanostructured PLD-grown gadolinia doped ceria: Chemical and structural characterization by transmission electron microscopy techniques

    DEFF Research Database (Denmark)

    Rodrigo, Katarzyna Agnieszka; Wang, Hsiang-Jen; Heiroth, Sebastian;

    2011-01-01

    The morphology as well as the spatially resolved elemental and chemical characterization of 10 mol% gadolinia doped ceria (CGO10) structures prepared by pulsed laser deposition (PLD) technique are investigated by scanning transmission electron microscopy accompanied with electron energy loss...

  5. Naming Speed of Adolescents and Young Adults with Attention Deficit Hyperactivity Disorder: Differences in Alphanumeric Versus Color/Object Naming.

    Science.gov (United States)

    Whipple, Brittany D; Nelson, Jason M

    2016-02-01

    This study investigated the performance of adolescents and young adults with Attention Deficit Hyperactivity Disorder (ADHD), Reading Disorder (RD), and ADHD/RD on measures of alphanumeric and nonalphanumeric naming speed and the relationship between naming speed and academic achievement. The sample (N = 203) included students aged 17-28 years diagnosed with ADHD (n = 83), RD (n = 71), or ADHD/RD (n = 49). Individuals with ADHD performed significantly faster on measures of alphanumeric naming compared with RD and comorbid groups and, within group, demonstrated significantly quicker naming of letters/digits compared with colors/objects. Both alphanumeric rapid naming scores and processing speed scores variably predicted academic achievement scores across groups, whereas nonalphanumeric rapid naming only predicted reading comprehension scores within the ADHD group. Results support findings that older individuals with ADHD show relative weakness in rapid naming of objects and colors. Implications of these findings in regard to assessment of older individuals for ADHD are discussed. PMID:26471216

  6. Chemical behaviour of transuranic elements in the natural environment

    International Nuclear Information System (INIS)

    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

  7. 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…

  8. 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...

  9. Distribution and interelement correlation between chemical elements and radionuclides in marine mammals from the southern Baltic Sea

    International Nuclear Information System (INIS)

    Tissues of marine mammals (Phocoena phocoena, Halichoerus grypus, Phoca hispida and Stenella coeruleoalba) from the southern Baltic Sea were analysed for concentration of 26 elements (Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Ga, Li, Mn, Mo, Ni, Pb, Se, Si, Sr, Tl, V, Zn, Ca, K, Mg, Na, P) and radionuclides (137Cs, 40K, 210Po). The trace and macroelements were determined by ICP-MS and ICP-AES while radionuclides using γ-spectrometry and α-spectrometry. To find statistically significant relationship between hepatic concentrations of chemical elements and radionuclides, if any exist, the data obtained were processed by correlation analysis. Significant interelemental correlations (p137Cs were negatively correlated with those of K and Si while 210Po showed positive correlation with Mo. The radioactivity data obtained in the present study are compared to those reported for marine mammals from the North Sea, Norwegian and Barents Sea. It is observed that levels of 137Cs in porpoises from the southern Baltic are mostly attributable to the Chernobyl accident in 1986 while major source of this radionuclide in North Sea porpoises are discharges released from processing plants at Sellafield, England. Unlike the naturally occurring isotope 40K, the 137Cs displays tendency to accumulate significantly in mammals from Polish coast of the Baltic Sea

  10. Language Planning and Personal Naming in Lithuania

    Science.gov (United States)

    Ramoniene, Meilute

    2007-01-01

    This paper deals with the issues of language planning and naming in Lithuania since the restoration of independence in 1990. The aim of the paper is to analyse the challenges of corpus planning with the focus on the use and standardisation of personal names. The paper first presents the historical context of the formation of names in Lithuania and…

  11. PS, SL and LHC Auditoria change names

    CERN Document Server

    2003-01-01

    Following the replacement of the PS, SL and LHC Divisions by the AB and AT Divisions, the Auditoria are also changing their names. PS Auditorium is renamed AB Meyrin SL Auditorium is renamed AB Prévessin LHC Auditorium is renamed AT

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

    International Nuclear Information System (INIS)

    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

  13. Soil chemicals properties and wheat genotype impact on micronutrient and toxic elements content in wheat integral flour

    OpenAIRE

    Krunoslav Karalić; Ante Nevistić; Brigita Popović; Zdenko Lončarić; Zorica Jurković; Meri Engler

    2012-01-01

    Aim To determine impact of soil chemical properties and different wheat genotypes in Croatia on micronutrient and toxic elements content in wheat integral flour. Methods Research was conducted and soil samples were collected from two different production areas in the Republic of Croatia: Ovčara and Dalj. Besides soil samples, grain samples of four different Croatian wheat genotypes were also collected and analyzed. In total, 40 samples of soil and 40 samples of wheat grain were analysed for t...

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

    International Nuclear Information System (INIS)

    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 - CuCO3. 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 TiO2, the red one

  15. Chemically Tagging the HR1614 Moving Group

    CERN Document Server

    De Silva, G M; Bland-Hawthorn, J; Asplund, M; Bessell, M S

    2006-01-01

    We present abundances for a sample of F,G,K dwarfs of the HR1614 moving group based on high resolution, high S/N ratio spectra from AAT/UCLES. Our sample includes stars from Feltzing & Holmberg (2000, A&A, 357, 153), as well as from Eggen (1998, AJ, 115, 2453). Abundances were derived for Na, Mg, Al, Si, Ca, Mn, Fe, Ni, Zr, Ba, Ce, Nd, and Eu. The alpha, Fe, and Fe-peak element abundances show a bimodal distribution, with four stars having solar metallicities while the remaining 14 stars are metal rich [Fe/H] >= 0.25 dex. However the abundances of these two groups converge for the heavier n-capture elements. Based on their photometry and kinematics, three of the four deviating stars are likely non-members or binaries. Although one star cannot be excluded on these grounds, we do expect low-level contamination from field stars within the HR1614 moving group's range of magnitude, color and space velocities. Disregarding these four stars, the abundance scatter across the group members for all elements is ...

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

    International Nuclear Information System (INIS)

    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)

  17. Generation of group B soyasaponins I and III by hydrolysis.

    Science.gov (United States)

    Zhang, Wei; Teng, Su Ping; Popovich, David G

    2009-05-13

    Soyasaponins are a group of oleanane triterpenoids found in soy and other legumes that have been associated with some of the benefits achieved by consuming plant-based diets. However, these groups of compounds are diverse and structurally complicated to chemically characterize, separate from the isoflavones, and isolate in sufficient quantities for bioactive testing. Therefore, the aim of this study was to maximize the extraction of soyasaponins from soy flour, remove isoflavones, separate group B soyasaponins from group A, and produce an extract that contained a majority of non-DDMP (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one)-conjugated group B soyasaponins I and III. Room temperature extraction in methanol for 24 or 48 h resulted in the maximum recovery of soyasaponins, and Soxhlet extraction resulted in the least. A solid-phase extraction using methanol (45%) was found to virtually eliminate the interfering isoflavones as compared to butanol-water liquid-liquid extraction and ammonium sulfate precipitation, while maximizing saponin recovery. Alkaline hydrolysis in anhydrous methanol produced the maximum amount of soyasaponins I and III as compared to aqueous methanol and acid hydrolysis in both aqueous and anhydrous methanol. The soyasaponin I amount was increased by 175%, and soyasaponin III was increased by 211% after alkaline hydrolysis. Furthermore, after alkaline hydrolysis, a majority of DDMP-conjugated group B soyasaponins such as betag, betaa, gammag, and gammaa transformed into the non-DDMP-conjugated soyasaponins I and III without affecting the glycosidic bond at position C-3 of the ring structure. Therefore, we have developed a method that maximizes the recovery of DDMP-conjugated saponins and uses alkaline hydrolysis to produce an extract containing mainly soyasaponins I and III. PMID:19338335

  18. Plant names - sanskrit and latin.

    Science.gov (United States)

    Sensarma, P

    1992-07-01

    Ascertaining the botanical identities of many of the plants described in Sanskrit literature is a difficult task. However, the problem can be solved by basing the studies on an authentic and ancient Sanskrit work. Thus the Garuda Purana was studied and the botanical identities of the numerous plants listed in chapter 202 of the Purvabhaga were ascertained. PMID:22556589

  19. Calculation and Interpretation of the Standard Chemical Exergies of Elements Using the Chemical Reference Species%使用化学参考物质计算和阐明元素的标准化学放射本能

    Institute of Scientific and Technical Information of China (English)

    B(I)LGEN Sel(c)uk

    2009-01-01

    Exergy is the amount of work obtainable when some matter is brought to a state of thermodynamic equilibrium with the common components of the natural surroundings by means of reversible processes, involving interaction only with the above mentioned components of nature. This paper presents standard chemical exergy values for 85 elements. Reference species in the atmosphere (air), dissolved in the hydrosphere (oceans), and contained in the lithosphere (minerals) are used for these calculations. Standard chemical exergy values of elements were calculated from tabulated values obtained for standard conditions (an ambient temperature of 298.15 K and an atmospheric pressure of 0.1 MPa). Very low concentrations of elements in the atmosphere and oceans and the abundance of elements in the Earth's crust are no longer used in determining reference states for chemical elements. Liquid and gas mixtures generally are not useful as reference states. As a result of the work in this paper, a table of the chemical exergy values of many elements in the periodic table under standard conditions was tabulated.

  20. The chemical and biological weapon terrorism by the Aum Shnirikyo

    International Nuclear Information System (INIS)

    The Aum Shinrikyo, an obscure cult religious group, attacked the Tokyo subways employing sarin gas in March 1995, which was viewed as a mark of a new era in terrorism. The Aum Shinrikyo remains the one empirical example of a religiously motivated cult with an affluent amount of financial and human resources and motivations to use unconventional weapons. The Aum Shinrikyo's leaders included the scientific elite of a young generation as well as former Yakuza members who had close ties with organized crime networks. Aum succeeded in establishing an extensive network to procure weapons, material, and drug, primarily in Russia but also other countries including the United States and even North Korea. Despite the fact that the law enforcement authority had already obtained various pieces of information that reasonably indicated that Aum was producing sarin by late 1994, the law enforcement authority became too cautious to advance its investigation to arrest Aum members until it was too late. Japan's experience with the Aum Shinrikyo's threats provides valuable insights for democratic governments seeking to thwart the deadly plans of religiously motivated non-state actors. It reveals the tremendous difficulties for a democratic society to confront the terrorists who were willing to pursue their deadly 'divine' objectives, especially when the society had no experience to encounter such a threat. This presentation will explain the chemical and biological weapon programs of the Aum Shinrikyo, especially focusing on the following elements: Intention and capability of the Aum Shinrikyo; Weapon systems and mode of attacks, including their target selections; The lessons learned from this case for the prevention and crisis/consequence management n the event of CBW terrorism. The views expressed here are those of the author and do not represent those of the Research Institute for Science and Technology for Society or its research sponsors.(author)

  1. Transuranium elements in organic chemical forms

    International Nuclear Information System (INIS)

    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)

  2. The Superheavy Elements and Anti-Gravity

    International Nuclear Information System (INIS)

    The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z < 64 and 63 < Z <145) exist that demonstrate these capabilities. The nuclei of the first group of elements have the masses with only the property of gravity. The nuclei of the elements of the second group have the masses with both properties: gravity and anti-gravity in two different ranges of curved space-time around the nuclei.. The hypothetical element with Z = 145 is the unique among all elements whose nucleus has only anti-gravity property. It is proposed that this element be named Hawking, in honour of Stephen W. Hawking

  3. Estimation of thermal capacity, entropy, and melt enthalpy of europium and ytterbium with elements of I-V I B group of periodic table

    International Nuclear Information System (INIS)

    Thermodynamic properties of europium and ytterbium compounds with elements of I-V I B group of periodic table by means of evaluated methods are found. It is shown that at 'anionic' and at 'cationic' component replacement the thermal capacity, entropy and melting enthalpy of europium and ytterbium compounds are changed in a certain sequence.

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

    International Nuclear Information System (INIS)

    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 SiO2 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 conventional techniques have been achieved. This has resulted in minimum detection limits for transition metals of 8 x 107 atoms/cm2. SR-TXRF studies of the amount of metal contamination deposited on a silicon surface as a function of pH and oxygen content of the etching solutions have provided insights into the mechanisms of metal deposition from solutions containing trace amounts of metals ranging from parts per trillion to parts per billion. Furthermore, by using XANES to understand the chemical state of the metal atmos after deposition, it has been possible to develop chemical models for the deposition processes. Examples will be provided for copper deposition from ultra pure water and acidic solutions. (author)

  5. The Assessment of Comprehensive Vulnerability of Chemical Industrial Park Based on Entropy Method and Matter-element Extension Model

    Directory of Open Access Journals (Sweden)

    Yan Jingyi

    2016-01-01

    Full Text Available The paper focuses on studying connotative meaning, evaluation methods and models for chemical industry park based on in-depth analysis of relevant research results in China and abroad, it summarizes and states the feature of menacing vulnerability and structural vulnerability and submits detailed influence factors such as personnel vulnerability, infrastructural vulnerability, environmental vulnerability and the vulnerability of safety managerial defeat. Using vulnerability scoping diagram establishes 21 evaluation indexes and an index system for the vulnerability evaluation of chemical industrial park. The comprehensive weights are calculated with entropy method, combining matter-element extension model to make the quantitative evaluation, then apply to evaluate some chemical industrial park successfully. This method provides a new ideas and ways for enhancing overall safety of the chemical industrial park.

  6. Analysis of sedimentary rocks from the Jurassic/Cretaceous boundary: INAA and RNAA of platinum group elements

    International Nuclear Information System (INIS)

    Within a geophysical and paleontological project aimed at a detailed and precise correlation of the Jurassic/Cretaceous (J/K) boundary interval in the Tethyan and Boreal region, detailed magnetostratigraphic and biostratigraphic profiles with a well-defined J/K boundary were selected from several sites for a detailed geochemical characterization. Instrumental neutron activation analysis (INAA) was employed in the characterization of a vertical profile around the assumed J/K boundary in the Boreal Realm situated on the Nordvik peninsula, North of Middle Siberia, Russia, for which a platinum group element (PGE) anomaly has been reported in literature. Multimode INAA included short-time and long-time modes of irradiation either with reactor-pile neutrons or with epithermal/fast neutrons (ENAA) under a Cd shielding. The analyses encompassed about 40 major and trace elements. A radiochemical separation procedure for PGE determination consisting in sample decomposition by alkaline-oxidative fusion, reduction of PGE, and precipitation of their sulfides was tested. Despite difficulties, elevated levels of Pt and Ir were determined in selected samples at ppb and sub-ppb levels, respectively

  7. Crystal Field Theory and the Angular Overlap Model Applied to Hydrides of Main Group Elements.

    Science.gov (United States)

    Moore, E. A.

    1990-01-01

    Described is how crystal field theory and the angular overlap model can be applied to very simple molecules which can then be used to introduce such concepts as bonding orbitals, MO diagrams, and Walsh diagrams. The main-group compounds are used as examples and a switch to the transition metal complexes. (KR)

  8. Chemical zoning and colour changes in the phases of the sodalite group from the Mt. Vulture haüynophyre lava (Potenza-italy).

    Science.gov (United States)

    di Muro, A.; Bonaccorsi, E.; Principe, C.

    2003-04-01

    The haüynophyre is a sulfur-rich differentiated lava flow erupted from a parasitic vent of the Vulture volcano (Potenza-Italy). This porphyritic lithotype (43 vol%) is characterised by a very high content (20-30 vol%) of feldspathoids belonging to the sodalite group. Chemical and structural analysis of the sodalite-group minerals has led to the identification of i) a colourless to white nosean, ii) a blue to light-blue haüyne, and iii) a black to grey haüyne. Numerous phenocrysts present a resorbed core and/or a pronounced concentric division into zones with a complex colour sequence. The X-ray diffraction study (XRPD through Gandolfi technique and single crystal structure refinements) has confirmed the occurrence of nosean and has allowed to discard the presence of lazurite. All the analysed crystals, those chromatically homogeneous as well as the zoned ones, have marked core-rim chemical variations. Nosean crystals contain small pyrite inclusions and are characterised by an evolution from a Ca-K poor core to Ca-K rich rim. K_2O content increases towards the rim in blue haüyne, while Na_2O/CaO ratio remains almost constant. Black haüyne has chemical characteristics intermediate between the nosean and the blue haüyne-end members and has the highest S/Cl ratio in the core. Black and blue haüyne have similar patterns of depletion in REE and most other highly lithophile elements relative to the bulk rock. Positive anomaly for the Eu content and spinel composition are indicative of high fO_2 conditions in the magmas in which both haüyne varieties formed. Higher contents of compatible (Sr, Ba) and semicompatible (Ta) elements characterise the black phase. A high Fe content in the black variety could be at least in part responsible for the chromatic difference. Limited contamination by sedimentary evaporites and probably mixing between a sulfur-rich black haüyne-bearing magma and a more cooled magma having stable blue haüyne and nosean is proposed to explain

  9. 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)

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

    International Nuclear Information System (INIS)

    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 En 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)

  11. 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...... 22, 27, 35, and 23 % higher concentrations of K, S, Ca, and total ash than the other clones. In addition to clone and site, appropriate management could further improve the fuel quality of willow biomass. When shoots of Inger were harvested annually (1-year shoots) high concentrations of K and Cl...... were found in all three consecutive harvests, but concentrations decreased significantly when rotation length was extended beyond 1 year of growth. Significant decreases of Mg, Na, P, S, and Zn were also registered from 2- to 3-year-old shoots. No difference in quality of biomass was found between two...

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

    International Nuclear Information System (INIS)

    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)

  13. 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)

  14. Elemental and thermo-chemical analysis of oil palm fronds for biomass energy conversion

    Science.gov (United States)

    Guangul, Fiseha Mekonnen; Sulaiman, Shaharin Anwar; Raghavan, Vijay R.

    2012-06-01

    Oil palm frond is the most abundant yet untapped biomass waste in Malaysia. This paper investigates the characteristics of raw oil palm fronds and its ash to evaluate its potential utilization as a biomass fuel for gasification process using single throat downdraft gasifier. The morphological nature, elemental content, proximate and ultimate analysis and calorific value were studied. Field emission scanning electron microscopy and x-ray fluorescence were used to investigate the surface morphology, elemental and mineralogical nature of oil palm frond and its ash. The results were compared with other agricultural and forestry biomass wastes. From proximate analysis volatile matter, fixed carbon and ash were found to be 83.5%, 15.2% and 1.3%, respectively on dry basis. From ultimate analysis result values of 44.58%, 4.53%, 0.71% and 0.07% for carbon, hydrogen, nitrogen and sulfur were found respectively on dry basis. Oxygen was determined by difference and found to be 48.81%. The proximate and ultimate analysis results indicate that oil palm frond is better than agricultural wastes and less than most forestry wastes to use as a feedstock in the gasification process in order to get a better quality of syngas. The amount of ash content in OPF was found to be much less than in agricultural wastes and higher than most forestry wastes. From x-ray fluorescence analysis CaO and K2O were found as the major oxides in oil palm fronds and rice husk ash with the amount of 28.46% and 15.71% respectively. The overall results of oil palm fronds were found to be satisfactory to use as a feedstock for the process of gasification.

  15. Creating an Adaptive Technology Using a Cheminformatics System to Read Aloud Chemical Compound Names for People with Visual Disabilities

    Science.gov (United States)

    Kamijo, Haruo; Morii, Shingo; Yamaguchi, Wataru; Toyooka, Naoki; Tada-Umezaki, Masahito; Hirobayashi, Shigeki

    2016-01-01

    Various tactile methods, such as Braille, have been employed to enhance the recognition ability of chemical structures by individuals with visual disabilities. However, it is unknown whether reading aloud the names of chemical compounds would be effective in this regard. There are no systems currently available using an audio component to assist…

  16. Element distribution patterns in the ordovician Galena group, Southeastern Minnesota: Indicators of fluid flow and provenance of terrigenous material

    Science.gov (United States)

    Lively, R.S.; Morey, G.B.; Mossler, J.H.

    1997-01-01

    As part of a regional geochemical investigation of lower Paleozoic strata in the Hollandale embayment of southeastern Minnesota, elemental concentrations in acid-insoluble residues were determined for carbonate rock in the Middle Ordovician Galena Group. Elemental distribution patterns within the insoluble residues, particularly those of Ti, Al, and Zr, show that the Wisconsin dome and the Wisconsin arch, which contributed sediment to the embayment prior to Galena time, continued as weak sources of sediment during this period. In contrast, trace metals commonly associated with Mississippi Valley-type lead-zinc mineralization, including Pb, Zn, Cu, Ag, Ni, Co, As, and Mo, show dispersal patterns that are independent of those associated with primary depositional phenomena. These trace metals are concentrated in southern Minnesota in carbonate rocks near the interface between limestone- and dolostone-dominated strata. Dispersal patterns imply that the metals were carried by a north-flowing regional ground-water system. The results show that the geochemical attributes of insoluble residues can be used to distinguish provenance and transport directions of primary sediments within a depositional basin from effects of subsequent regional ground-water flow systems.

  17. 27 CFR 24.112 - Name of proprietor and trade names.

    Science.gov (United States)

    2010-04-01

    ... TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Establishment and Operations Application § 24.112... proprietor's name or the operating trade name, if different than the proprietor's name, and any bottling or packing trade names. However, if a bottling or packing trade name is listed on a basic permit issued...

  18. Newer trace elements measured by RNAA and AAS

    International Nuclear Information System (INIS)

    Very recently, quite attention has been made on a few more trace elements in foodstuff as essential for animal and human health in certain ranges of concentration or intake. These traces are: aluminum, nickel, vanadium and tin. Al and Ni have been measured by atomic absorption spectroscopy (AAS), and the two latter ones measured by radiochemical neutron activation analysis (RNAA) in few references laboratories. Here, scandium was also analysed by instrumental neutron activation analysis (INAA). These measurements were made for the most of the Iranian diets and other participant countries' diets under the framework of a co-ordinated research project (CRP) of the IAEA during the period 1986-1994, but practically it took more years. Here in this work the daily dietary intakes of above mentioned trace elements are given and discussed while the results of 20 other nutritionally important trace elements appeared somewhere else. (author)

  19. Construction of a technique plan repository and evaluation system based on AHP group decision-making for emergency treatment and disposal in chemical pollution accidents

    International Nuclear Information System (INIS)

    Highlights: • Different chemical pollution accidents were simplified using the event tree analysis. • Emergency disposal technique plan repository of chemicals accidents was constructed. • The technique evaluation index system of chemicals accidents disposal was developed. • A combination of group decision and analytical hierarchy process (AHP) was employed. • Group decision introducing similarity and diversity factor was used for data analysis. - Abstract: The environmental pollution resulting from chemical accidents has caused increasingly serious concerns. Therefore, it is very important to be able to determine in advance the appropriate emergency treatment and disposal technology for different types of chemical accidents. However, the formulation of an emergency plan for chemical pollution accidents is considerably difficult due to the substantial uncertainty and complexity of such accidents. This paper explains how the event tree method was used to create 54 different scenarios for chemical pollution accidents, based on the polluted medium, dangerous characteristics and properties of chemicals involved. For each type of chemical accident, feasible emergency treatment and disposal technology schemes were established, considering the areas of pollution source control, pollutant non-proliferation, contaminant elimination and waste disposal. Meanwhile, in order to obtain the optimum emergency disposal technology schemes as soon as the chemical pollution accident occurs from the plan repository, the technique evaluation index system was developed based on group decision-improved analytical hierarchy process (AHP), and has been tested by using a sudden aniline pollution accident that occurred in a river in December 2012

  20. Typification and etymology of Aublet's Rubiaceae names

    OpenAIRE

    Delprete, Piero

    2015-01-01

    The ongoing Rubiaceae treatment for the Flora of the Guianas prompted a detailed study of the rubiaceous taxa described by Aublet ("Fusee Aublet"), one of the earliest botanists to collect in South America. This study led to the recognition that a publication by Lanjouw and Uittien in 1940 wherein the authors reported the discovery of an additional set of Aublet specimens in the Jean-Jacques Rousseau herbarium (P-JJR) also included many previously unrecognized typifications of Aublet names. T...

  1. How to efficiently select an arbitrary Clifford group element

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, Robert [Institute for Quantum Computing and Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Smolin, John A. [IBM T.J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

    2014-12-15

    We give an algorithm which produces a unique element of the Clifford group on n qubits (C{sub n}) from an integer 0≤i<|C{sub n}| (the number of elements in the group). The algorithm involves O(n{sup 3}) operations and provides, in addition to a canonical mapping from the integers to group elements g, a factorization of g into a sequence of at most 4n symplectic transvections. The algorithm can be used to efficiently select random elements of C{sub n} which are often useful in quantum information theory and quantum computation. We also give an algorithm for the inverse map, indexing a group element in time O(n{sup 3})

  2. Mechanism for the formation of elemental sulfur from aqueous sulfide in chemical and microbiological desulfurization processes

    Energy Technology Data Exchange (ETDEWEB)

    Steudel, R. [Technische Univ. Berlin (Germany). Inst. fuer Anorganische und Analytische Chemie

    1996-04-01

    A detailed reaction mechanism is proposed for the formation of crystalline elemental sulfur from aqueous sulfide by oxidation with transition-metal ions like V{sup 5}, Fe{sup 3}, Cu{sup 2}, etc. The first step is the formation of HS{center_dot} radicals by one-electron oxidation of HS{sup {minus}} ions. These radicals exist at pH values near 7 mainly as S{center_dot}{sup {minus}}. Their spontaneous decay results in the formation of the disulfide ion S{sub 2}{sup 2{minus}}. The further oxidation of disulfide either by S{center_dot}{sup {minus}} radicals or by the transition-metal ions yields higher polysulfide ions from which the homocyclic sulfur molecules S{sub 6}, S{sub 7}, and S{sub 8} are formed. In water these hydrophobic molecules form clusters which grow to droplets of liquid sulfur (sulfur sol). Depending on the composition of the aqueous phase, crystallization of the liquid sulfur as either {alpha}- or {beta}-S{sub 8} is rapid or delayed. Surfactants delay this solidification, while certain cations promote it. All these reactions are proposed to take place in desulfurization plants working by the Stretford, Sulfolin, Lo-Cat, SulFerox, or Bio-SR processes. In addition, the sulfur produced from sulfide by oxidizing sulfur bacteria is formed by the same mechanism, which now explains many observations made previously (including the formation of the byproducts thiosulfate, polythionates, and sulfate).

  3. Name Strategy: Its Existence and Implications

    OpenAIRE

    Roberts, Mark D.

    1998-01-01

    It is argued that colour name strategy, object name strategy, and chunking strategy in memory are all aspects of the same general phenomena, called stereotyping, and this in turn is an example of a know-how representation. Such representations are argued to have their origin in a principle called the minimum duplication of resources. For most the subsequent discussions existence of colour name strategy suffices. It is pointed out that the Berlin†- Kay† universal partial ordering of colours an...

  4. Average bond energies between boron and elements of the fourth, fifth, sixth, and seventh groups of the periodic table

    Science.gov (United States)

    Altshuller, Aubrey P

    1955-01-01

    The average bond energies D(gm)(B-Z) for boron-containing molecules have been calculated by the Pauling geometric-mean equation. These calculated bond energies are compared with the average bond energies D(exp)(B-Z) obtained from experimental data. The higher values of D(exp)(B-Z) in comparison with D(gm)(B-Z) when Z is an element in the fifth, sixth, or seventh periodic group may be attributed to resonance stabilization or double-bond character.

  5. Bioaccessibility of platinum group elements in automotive catalytic converter particulates.

    Science.gov (United States)

    Turner, Andrew; Price, Simon

    2008-12-15

    The bioaccessibilities of the platinum group elements (PGE): Rh, Pd, and Pt; and the catalyzator poison, Pb, have been determined in particles derived from milled automotive catalytic converters using a physiologically based extraction test (PBET) that simulates, sequentially, the chemical conditions encountered in the human stomach and intestine. PGE accessibility, relative to total metal concentration, was generally less than a few percent, but increased in the stomach with decreasing pH (from 4 to 1) and/or increasing chloride concentration, and with decreasing particle concentration. In most cases, bioaccessibility increased from the acidic stomach to the neutral, carbonate-rich intestine. Bioaccessibility of Pb displayed similar pH and particle concentration dependencies to PGE in the stomach, but this metal exhibited significantly greater mobilization (up to 80%) overall and a reduction in accessibility from the stomach to intestine. Reaction kinetics of PGE dissolution in the stomach at pH 2.5 were modeled using a combined surface reaction-diffusion controlled mechanism with rate constants of 0.068, 0.031, and 0.015 (microg L(-1))(-1) h(-1) for Rh, Pd, and Pt, respectively. For Pb, however, mobilization proceeded via a different mechanism whose time-dependence was fitted with an empirical, logarithmic equation. Overall, PGE bioaccessibility appeared to be controlled by dissolution rates of metallic nanoparticles in the stomach, and solubility and kinetic constraints on inorganic species (chlorides, hydroxychlorides, and carbanatochlorides) and undefined organic complexes formed in the simulated gastrointestinal tract. Further studies are required to elucidate any effects engendered by the long-term oral exposure of small quantities of these species. PMID:19174929

  6. Os grupos-nome: efeitos da substituição do imaginário pelo virtual na constituição dos grupos sociais Name-groups: the substitution of virtual for imaginary in social groups constitution and its effects

    Directory of Open Access Journals (Sweden)

    João Eduardo Coin de Carvalho

    2002-06-01

    Full Text Available Os grupos sociais categoriais são alvo, desde o pós-guerra, de uma intenso esforço de compreensão e demarcação conceitual, principalmente por parte dos psicólogos sociais europeus. A ampliação desta importância na pauta dos pesquisadores se deve ao aumento da presença relativa deste tipo de grupo no cenário das relações sociais e de suas conseqüências na produção das identidades sociais. Neste trabalho indicamos como o crescimento da importância dada aos grupos categoriais acompanha o esvaziamento progressivo do imaginário dos grupos, que passam a operar socialmente menos a partir das relações efetivas entre os indivíduos que os compõem e mais pela sua borda, isto é, o nome do grupo. Chamamos de grupos-nome a esses grupos virtualizados, que não têm presença material mas apenas imagética. Os grupos-nome tendem a ser mais freqüentes do que os grupos "vivos" na medida em que facilitam um relacionamento mais descompromissado entre os indivíduos e portanto mais confortável pela facilidade com a qual os indivíduos poderiam "trocar" de grupo social. Como efeitos da incidência dos grupos-nome destacam-se a transformação dos grupos face a face, a ampliação de mecanismos de controle e manipulação social e o incremento da violência.Categorial social groups have been studied with more interest by the European social psychologists after Second World War. This research has been supported on the increase of this kind of group in the reality of social relations and in its effects on production of social identities. In this work we indicated how the importance of the categorial social groups goes along with the imaginary group fainting. Groups have become outline presences than organizations based on relations. We nominated name-group these virtual groups, which doesn't have organic but only imagetic existence. Nowadays, name-groups are more common than "live" groups and this contributes to unreliable individual

  7. Synthesis of graphene platelets by chemical and electrochemical route

    International Nuclear Information System (INIS)

    Graphical abstract: A schematic showing the overall reduction process of graphite to reduced graphene platelets by chemical and electrochemical route. - Highlights: • Graphene was prepared by diverse routes viz. chemical and electrochemical methods. • NaBH4 was effective for removing oxygen functional groups from graphene oxide. • Sodium borohydride reduced graphene oxide (SRGO) showed high specific capacitance. • Electrochemical rendered a cheap route for production of graphene in powder form. - Abstract: Graphene platelets were synthesized from graphene oxide by chemical and electrochemical route. Under the chemical method, sodium borohydride and hydrazine chloride were used as reductants to produce graphene. In this paper, a novel and cost effective electrochemical method, which can simplify the process of reduction on a larger scale, is demonstrated. The electrochemical method proposed in this paper produces graphene in powder form with good yield. The atomic force microscopic images confirmed that the graphene samples prepared by all the routes have multilayers of graphene. The electrochemical process provided a new route to make relatively larger area graphene sheets, which will have interest for further patterning applications. Attempt was made to quantify the quantum of reduction using cyclic voltammetry and choronopotentiometry techniques on reduced graphene samples. As a measure in reading the specific capacitance values, a maximum specific capacitance value of 265.3 F/g was obtained in sodium borohydride reduced graphene oxide

  8. Selection Demands and Working Memory Mediate Interference during Naming

    Directory of Open Access Journals (Sweden)

    Julie W Hughes

    2015-05-01

    Analyzing RTs, we replicated previous SI effects in BCN in healthy subjects and patients (reported effects’ p’s < .05. Subjects responded more slowly to items in semantically related vs. unrelated groups, and this interference increased across cycles (evidence of increasing selection demands; Figures 1a/c. Indicative of WM, healthy subjects were faster to name items as the number of unrelated items to be named (i.e., remembered decreased. However, this was attenuated by selection demand, as there was no decrease in RTs across repeated related items (Figure 1b. Converging evidence from patients demonstrated more impaired selection capacity produced increasingly slower RTs across item positions within the related condition (high selection demand (Figure 1d. Larger WM capacity (rhyme probe but not category probe, p = .54 produced increasingly faster RTs across items positions in the unrelated condition (low selection demand (Figure 1e. Together, these findings suggest that both selection demand and phonological WM processes mediate interference during naming.

  9. High-pressure high-temperature synthesis of novel binary and ternary nitride phases of group 4 and 14 elements

    OpenAIRE

    Dzivenko, D. A.; Horvath-Bordon, E.; Zerr, A.; Miehe, G.; Kroll, P.; Boehler, R.; McMillan, P.F.; Riedel, R.

    2008-01-01

    Our recent experiments on high-pressure high-temperature synthesis of novel ternary nitrides of group 4 and 14 elements are presented. Dense carbon nitride imide, C2N2(NH), was synthesized for the first time in a laser heated diamond anvil cell (LH-DAC) at pressures above 27 GPa and temperatures around 2000 K. Based on results of the electron diffraction-, EELS-and SIMS-measurements combined with theoretical calculations the structure of this new C-N-H phase was suggested to be of the defect-...

  10. Trace element evaluation of rice and husk by INAA

    International Nuclear Information System (INIS)

    An instrumental neutron activation analysis technique was used to study the prevailing levels of certain inorganic trace elements in different varieties of rice in Pakistan. The results were compared with those of other countries. The elemental ratios within rice and rice to husk were computed to evaluate indirectly the impact of soil and environment on the rice crops. The dietary spectrum for the inhabitants of Rawalpindi/Islamabad areas was evaluated by estimating the daily intake and comparing with allowances suggested in the literature. (author) 35 refs.; 4 figs.; 4 tabs

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

    International Nuclear Information System (INIS)

    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 Hg2+2, Hg2+, Cd2+2 and Cd2+ 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, O2 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 Al2O3 appears when the oxide concentration is increased; the solubility of Al2O3 versus acidity is determined from the electrochemical results. In a third part, results for the Ni/Ni(II) or HCl/H2O systems are related to dissolved oxide ion presence in chloroaluminate melts; elimination of oxide ions, through H2O formation, by reaction with HCl is noteworthy. (author)

  12. Roadside Accumulation of Pt, Pd, Rh and Other Trace Elements From Automobiles: Catalytic Converter Attrition and Platinum-Group Element Mobility in the Roadside Environment.

    Science.gov (United States)

    Ely, J. C.; Dahlheimer, S. R.; Neal, C. R.

    2003-12-01

    Elemental abundances of Pt, Pd and Rh have been documented across the industrialized world in roadside environments due to attrition of automotive catalytic converters (Zereini and Alt, 2000, Anthropogenic PGE Emissions, Springer, 308pp; Ely et al., 2001, EnvSci&Tech, 35:3816-3822; Whiteley and Murray, 2003, SciTotEnv, in press). In our ongoing study, the highest reported roadside Pt abundance 1.8 ppm has been found immediately adjacent to the road at a field site in South Bend, IN, USA. Furthermore, initial studies show positive correlations of Pt, Pd and Rh with some trace elements (Ni, Cu, Zn and Pb), which has been confirmed by further analysis for these and other elements (Ce, Cr). It has been demonstrated that elements such as Ce are present in catalytic converters at concentrations of 100's ppm to 3-wt.%. These elements are also being attrited with Pt, Pd and Rh and aerially transported and deposited. Our field site was established next to US-933 adjacent to the Notre Dame campus. Areas were cleared of the top 2-4 cm of soil (removing surficial Pt, Pd and Rh) at 1, 5, 10 and 50 meters from the roadside. Within 3 months the 1-meter site contained 67% of the initial Rh and Pt concentrations and 100% of the initial Pd concentration. The sites at 5, 10 and 50 meters showed similar results, in some cases exceeding the initial concentrations. After 6 months the concentrations of Pt, Pd and Rh were all within error of the initial concentrations, indicating steady state abundances had probably been reached. Grass samples from each site showed that washed vs. unwashed samples were within error of each other, and there may be a slight enrichment (approx. 1 ppb) in the grasses of Pd and Pt, but this enrichment was independent of distance from the road. The steady-state situation suggests that the PGEs are being removed from the immediate roadside environment, which requires that the metals are being oxidized and/or complexed in such a way to facilitate transport. The

  13. A Systems Biology Approach for Identifying Hepatotoxicant Groups Based on Similarity in Mechanisms of Action and Chemical Structure.

    Science.gov (United States)

    Hebels, Dennie G A J; Rasche, Axel; Herwig, Ralf; van Westen, Gerard J P; Jennen, Danyel G J; Kleinjans, Jos C S

    2016-01-01

    When evaluating compound similarity, addressing multiple sources of information to reach conclusions about common pharmaceutical and/or toxicological mechanisms of action is a crucial strategy. In this chapter, we describe a systems biology approach that incorporates analyses of hepatotoxicant data for 33 compounds from three different sources: a chemical structure similarity analysis based on the 3D Tanimoto coefficient, a chemical structure-based protein target prediction analysis, and a cross-study/cross-platform meta-analysis of in vitro and in vivo human and rat transcriptomics data derived from public resources (i.e., the diXa data warehouse). Hierarchical clustering of the outcome scores of the separate analyses did not result in a satisfactory grouping of compounds considering their known toxic mechanism as described in literature. However, a combined analysis of multiple data types may hypothetically compensate for missing or unreliable information in any of the single data types. We therefore performed an integrated clustering analysis of all three data sets using the R-based tool iClusterPlus. This indeed improved the grouping results. The compound clusters that were formed by means of iClusterPlus represent groups that show similar gene expression while simultaneously integrating a similarity in structure and protein targets, which corresponds much better with the known mechanism of action of these toxicants. Using an integrative systems biology approach may thus overcome the limitations of the separate analyses when grouping liver toxicants sharing a similar mechanism of toxicity. PMID:27311473

  14. Dynamically- and chemically-induced grain boundary migration in quartz: microstructures, crystallographic fabrics, and trace element contents

    Science.gov (United States)

    Nachlas, Will; Thomas, Jay

    2016-04-01

    Grain boundary migration (GBM) is a common mechanism by which quartz recrystallizes in the Earth. In the most basic sense, GBM occurs as atoms exchange structural positions across a planar defect. Reconstitution of grains via GBM imparts a new crystallographic orientation, but its effect on the geochemistry of recrystallized grains remains uncertain and depends on the kinetic and thermodynamic properties of the moving grain boundary. Two of the dominant driving forces for GBM are lattice strain energy, controlled by the applied stress field, and chemical potential energy, controlled by differences in mineral stability. We present observations from static and dynamic recrystallization experiments showing evidence for GBM in response to both of these driving forces. In static recrystallization experiments, quartz recrystallized in response to local variations in trace-level Ti concentrations, whereas in dynamic recrystallization experiments, quartz recrystallized during dislocation creep in response to the imposed differential stress. Each case produced recrystallized quartz exhibiting diagnostic microstructures, crystallographic fabrics, and trace element contents that can be used to infer the mechanisms of quartz recrystallization and the pressure-temperature conditions at which recrystallization occurred.

  15. 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)

  16. Characterization, feasibility and optimization of Agaricus subrufescens growth based on chemical elements on casing layer

    Science.gov (United States)

    Cunha Zied, D.; Pardo-Giménez, A.; de Almeida Minhoni, M.T.; Villas Boas, R.L.; Alvarez-Orti, M.; Pardo-González, J.E.

    2012-01-01

    The aim of this study was to analyze yields, biological efficiency, earliness (expressed as days to first harvest), and precociousness and establish models for the mushroom growing according to these parameters. The experiment followed a double factorial design with four sources of calcium (calcitic limestone, calcitic limestone + gypsum, dolomitic limestone and dolomitic limestone + gypsum) and 2 application times (25 days before casing and at the moment of casing), with 4 replicates for each treatment. Different calcium sources influenced differently Agaricus subrufescens production, especially as regards earliness, which showed significantly higher values when dolomitic limestone with gypsum was applied. Yield and biological efficiency were negatively correlated with H + AL, organic matter and Mg amount. Furthermore, earliness was positively correlated with H + Al, organic matter, and the amount of Mg and Fe. Finally, negative correlations were observed between precociousness and the amount of Ca, SB (sum of base), CEC (cation exchange capacity) and V% (percentage of base saturation). The models presented in this work are extremely important for predicting the agronomic performance of Agaricus subrufescens on the basis of chemical analysis provided by the casing soil. PMID:23961195

  17. Kinetic modelling of hydro-treatment reactions by study of different chemical groups; Modelisation cinetique des reactions d`hydrotraitement par regroupement en familles chimiques

    Energy Technology Data Exchange (ETDEWEB)

    Bonnardot, J.

    1998-11-19

    Hydro-treatment of petroleum shortcuts permits elimination of unwanted components in order to increase combustion in engine and to decrease atmospheric pollution. Hydro-desulfurization (HDS), Hydro-denitrogenation (HDN) and Hydrogenation of aromatics (HDA) of a LCO (Light Cycle Oil)-Type gas oil have been studied using a new pilot at a fixed temperature with a NiMo/Al{sub 2}O{sub 3} catalyst. A hydrodynamic study showed that reactions occurring in the up-flow fixed bed reactor that has been used during the experiments, were governed exclusively by chemical reaction rates and not by diffusion. Through detailed chemical analysis, height chemical groups have been considered: three aromatics groups, one sulfided group, one nitrogenized and NH{sub 3}, H{sub 2}S, H{sub 2}. Two Langmuir-Hinshelwood-type kinetic models with either one or two types of sites have been established. The model with two types of site - one site of hydrogenation and one site of hydrogenolysis - showed a better fit in the modeling of the experimental results. This model enables to forecast the influence of partial pressure of H{sub 2}S and partial pressure of H{sub 2} on hydro-treatment reactions of a LCO-type gas oil. (author) 119 refs.

  18. Geographic Place Names, Geographic Names; GNIS11; The Geographic Names Information System, developed by the USGS in cooperation with the U.S. Board on Geographic Names, contains information about physical and cultural geographic features in the US and associated areas., Published in 2011, 1:24000 (1in=2000ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Geographic Place Names dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 2011. It is described...

  19. QUANTITY DETERMINATION OF MOLYBDENUM FROM PISUM SATIVUM PLANTS AND THE INFLUENCE OF HEAVY METAL TO CHEMICAL ELEMENTS ACCUMULATION

    Directory of Open Access Journals (Sweden)

    MONICA BUTNARIU

    2013-12-01

    Full Text Available The aim of this study was to test the pea plant as sentinel specie for the heavy metal molybdenum. Evaluation of soil quality after the molybdenum uptake by pea revealed the following results: Pea plant is a bioindicator that concentrates molybdenum with fast reaction to increasing concentrations in soil. Molybdenum had a positive effect concerning the plant growth (throughout all experimental process, pea plants treated with highest concentrated metal solution reached the largest dimensions. Accumulated molybdenum was directly proportional to increasing concentration of the applied solution to roots, stem, leaves and flowers of the experimental plants; however it resided in flowerpot soil too .In the leguminous roots where the nitroreductase and nitrogenese activity is increased, molybdenum content was much higher compared to the aerial parts of the plant. All the way through molybdenum accumulation in the experimental plants up to high concentrations, other chemical elements revealed lower concentration although within the normal limits, with the exception of phosphorus. These plants were found to assimilate high molybdenum quantities without any detrimental consequences for them since molybdenum accumulation occurred in vacuoles in innocuous chemical forms.

  20. Medical and health-related trace element analysis by TXRF

    International Nuclear Information System (INIS)

    The advantages offered with TXRF analysis by direct irradiation with monochromatic X-rays of tissue homogenates and body fluids make the technique appropriate for a number of medical and health related applications. The ability to detect low levels of toxic heavy elements is being used as an aid in accidental poisoning diagnosis and treatment, in treatment-induced toxicity control and as an accessory in medical and health research. Thus lead-in-whole-blood analysis is used in confirmation of diagnosis of victims of poisoning, or monitoring the evolution and efficiency of the clinical treatment. Measurement and control of plasma platinum levels of cancer patients undergoing chemotherapy with Pt-containing drugs includes: establishment of the drug level-tumor remission response, measurement of Pt plasma level curves and establishment of optimum dosage to minimize the nephrotoxicity of platinum, and bioequivalence comparisons of different commercially available platinum containing anticancer drugs. Analysis as an aid in clinical research applications includes: trace element determination of amniotic fluid in fetus malformation studies; analysis of brain specimens and cerebrospinal fluid in diagnosis of central nervous system disorders; the influence of trace elements in cataract genesis and the influence of heavy elements in semen quality in human reproduction studies. Human body samples require the use of monochromatized beams of x-rays in order to derive the special advantage of its use: i) The reduction in the spectrum background allowing direct irradiation of organic matter specimens. Hence human tissue and body fluids are prepared by simple procedures involving dilution, homogenization and standard addition avoiding the need for specimen digestion. This results in faster, cheaper methods that decrease sample contamination problems. ii) The presence of a large Compton scattered signal in the spectrum and its use as an internal standard reference allows further

  1. Assessing the Amount of Chemical Elements in Biodegradable Agricultural Wastes and ASH

    OpenAIRE

    Rasa Kvasauskienė; Pranas Baltrėnas

    2011-01-01

    Biodegradable agricultural wastes such as manure, has long been used as an organic fertilizer that improves soil structure, enriches the soil with micro-organisms and micro-elements necessary for plants and promotes humus formation. Manure can also be successfully used as a renewable energy source directly combusting and extracting energy. The carried out investigation showed that the incineration of manure remaining in ashes could also be used as a fertilizer. Waste combustion reduces its vo...

  2. [Anatomical names of skeletal notches--analysis and classification of Latin names, and comparison with corresponding Japanese names--].

    Science.gov (United States)

    Shikano, Shun-ichi; Yamashita, Yasuo; Sato, Tatsuo

    2006-06-01

    For better understanding of the structures comprising the human body and in view of possible need for future revision, Latin anatomical names (Nomina Anatomica, 3rd edition) of the skeletal notches were analyzed and classified, and compared with the corresponding Japanese anatomical names. The words following Incisura indicated: 1) the structure to which the notch belongs; 2) location of the notch; 3) the structure of which the notch is a component; 4) the bone or osseous structure with which the notch is connected; or 5) non-osseous structure attached to the notch. Analysis of Latin names and comparison with Japanese names clarified some characteristics of both names and revealed some problems in them. PMID:16796122

  3. [Anatomical names of skeletal processes--analysis and classification of Latin names, and comparison with corresponding Japanese names].

    Science.gov (United States)

    Shikano, Shun-ichi; Yamashita, Yasuo; Sato, Tatsuo

    2004-12-01

    For better understanding of the structures comprising the human body and in view of possible need for future revision, Latin anatomical names (Nomina Anatomica, 3rd edition) of the skeletal processes were analyzed and classified, and compared with the corresponding Japanese anatomical names. The words following Processus indicated: 1) morphological resemblance of the process; 2) the structure to which the process belongs; 3) location of the process; 4) direction of the process; 5) an articulation of the process; 6) the bone or one of the bones with which the process is connected; 7) the structure of which the process is a component; 8) the structure attached to the process; 9) the structure contained in the process; 10) homology of the process; 11) participation in another process; or 12) other uncertain information. Comparison between Latin and Japanese anatomical names clarified some characteristics of each name and revealed some problems in Japanese names. PMID:15678993

  4. Predicting Heats of Explosion of Nitroaromatic Compounds through NBO Charges and 15N NMR Chemical Shifts of Nitro Groups

    Directory of Open Access Journals (Sweden)

    Ricardo Infante-Castillo

    2012-01-01

    Full Text Available This work presents a new quantitative model to predict the heat of explosion of nitroaromatic compounds using the natural bond orbital (NBO charge and 15N NMR chemical shifts of the nitro groups (15NNitro as structural parameters. The values of the heat of explosion predicted for 21 nitroaromatic compounds using the model described here were compared with experimental data. The prediction ability of the model was assessed by the leave-one-out cross-validation method. The cross-validation results show that the model is significant and stable and that the predicted accuracy is within 0.146 MJ kg−1, with an overall root mean squared error of prediction (RMSEP below 0.183 MJ kg−1. Strong correlations were observed between the heat of explosion and the charges (R2 = 0.9533 and 15N NMR chemical shifts (R2 = 0.9531 of the studied compounds. In addition, the dependence of the heat of explosion on the presence of activating or deactivating groups of nitroaromatic explosives was analyzed. All calculations, including optimizations, NBO charges, and 15NNitro NMR chemical shifts analyses, were performed using density functional theory (DFT and a 6-311+G(2d,p basis set. Based on these results, this practical quantitative model can be used as a tool in the design and development of highly energetic materials (HEM based on nitroaromatic compounds.

  5. ARABIC PERSON NAMES RECOGNITION BY USING A RULE BASED APPROACH

    Directory of Open Access Journals (Sweden)

    Mohammed Aboaoga

    2013-01-01

    Full Text Available Name Entity Recognition is very important task in many natural language processing applications such as; Machine Translation, Question Answering, Information Extraction, Text Summarization, Semantic Applications and Word Sense Disambiguation. Rule-based approach is one of the techniques that are used for named entity recognition to identify the named entities such as a person names, location names and organization names. The recent rule-based methods have been applied to recognize the person names in political domain. They ignored the recognition of other named entity types such as locations and organizations. We have used the rule based approach for recognizing the named entity type (person names for Arabic. We have developed four rules for identifying the person names depending on the position of name. We have used an in-house Arabic corpus collected from newspaper achieves. The evaluation method that compares the results of the system with the manually annotated text has been applied in order to compute precision, recall and f-measure. In the experiment of this study, the average f-measure for recognizing person names are (92.66, 92.04 and 90.43% in sport, economic and politic domain respectively. The experimental results showed that our rule-based method achieved the highest f-measure values in sport domain comparing with political and economic domains.

  6. Chemical Abundances of Seven Irregular and Three Tidal Dwarf Galaxies in the M81 Group

    CERN Document Server

    Croxall, Kevin V; Lee, Henry; Skillman, Evan D; Lee, Janice C; Côté, Stéphanie; Kennicutt, Robert C; Miller, Bryan W; 10.1088/0004-637X/705/1/723

    2009-01-01

    We have derived nebular abundances for 10 dwarf galaxies belonging to the M81 Group, including several galaxies which do not have abundances previously reported in the literature. For each galaxy, multiple H \\ii regions were observed with GMOS-N at the Gemini Observatory in order to determine abundances of several elements (oxygen, nitrogen, sulfur, neon, and argon). For seven galaxies, at least one H \\ii region had a detection of the temperature sensitive [OIII] $\\lambda$4363 line, allowing a "direct" determination of the oxygen abundance. No abundance gradients were detected in the targeted galaxies and the observed oxygen abundances are typically in agreement with the well known metallicity-luminosity relation. However, three candidate "tidal dwarf" galaxies lie well off this relation, UGC 5336, Garland, and KDG 61. The nature of these systems suggests that UGC 5336 and Garland are indeed recently formed systems, whereas KDG 61 is most likely a dwarf spheroidal galaxy which lies along the same line of sigh...

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

    International Nuclear Information System (INIS)

    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)

  8. Chemical species of metallic elements in the aquatic environment of an ex-mining catchment.

    Science.gov (United States)

    Ashraf, Muhammad Aqeel; Ahmad, Mushtaq; Akib, Shatirah; Balkhair, Khaled S; Abu Bakar, Nor Kartini

    2014-08-01

    This study was conducted to investigate the chemical speciation of dissolved and particulate elements (lead, zinc, copper, chromium, arsenic, and tin) in the mining wastewater of a former tin-mining catchment. The speciation patterns of dissolved elements were estimated by an adsorptive stripping voltammeter (ASV), while particulate elements were analyzed by using a newly developed sequential-extraction leaching procedure. The procedure has been operationally defined among five host fractions, namely exchangeable, carbonate, reducible, organic bound, and residual fractions. A total of six elements (lead, zinc, copper, chromium, arsenic, and tin) were analyzed in thirty samples at ten locations (P1-P10), with three samples taken from each of the ten locations, to get the average value from the former tin-mining catchment. The results showed that the heavy metal pollutions in locations P4 and P8 were more severe than in other sampling sites, especially tin and lead pollution. In the water samples from locations P4 and P8, both the total contents and the most dangerous non-residual fractions of tin and lead were extremely high. More than 90% of the total concentrations of arsenic and chromium existed in the residual fraction. Concentrations of copper and zinc mainly occurred in the residual fraction (more than 60%), while lead and tin presented mostly in the non-residual fractions in surface water. For all of the six dissolved elements, the less-labile species formed the predominant fraction in their speciation patterns. The speciation patterns of particulate elements showed that most of the concentrations of zinc, copper, chromium, and arsenic were found in the reducible fraction; whereas lead and tin were mainly associated with the organic fraction. PMID:25306787

  9. Seasonal and spatial variation of trace elements in multi-size airborne particulate matters of Beijing, China: Mass concentration, enrichment characteristics, source apportionment, chemical speciation and bioavailability

    Science.gov (United States)

    Gao, Jiajia; Tian, Hezhong; Cheng, Ke; Lu, Long; Wang, Yuxuan; Wu, Ye; Zhu, Chuanyong; Liu, Kaiyun; Zhou, Junrui; Liu, Xingang; Chen, Jing; Hao, Jiming

    2014-12-01

    The seasonal and spatial variation characteristics of 19 elements (Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, S, Sb, Se, Zn) in TSP/PM10/PM2.5 samples were investigated, which were collected from April 2011 to January 2012 simultaneously at an urban downtown site, a traffic roadside site, a suburban site, and a rural site in Beijing. The elevated concentrations of several toxic trace elements (As, Cd, Mn, Ni, Pb, etc.) in particles revealed that the contamination of toxic elements in Beijing could not be neglected. Positive matrix factorization method (PMF) was applied for source apportionment of trace elements in PM, and three factors (crust related sources, combustion sources, and traffic and steel industrial related sources) were identified. Furthermore, the chemical speciation and bioavailability of various elements were identified by applying European Community Bureau of Reference (BCR) procedure. Our results showed that eight toxic elements (As, Cd, Cr, Cu, Ni, Pb, Sb and Zn) exhibited higher mobility in PM2.5 than in PM10. Notably, elements of As, Cd, Pb and Zn were presented with higher mobility than the other elements, and these elements were lightly to release into the environment and easily available to human body. Additionally, As, Cd, Pb and Zn also accounted for higher percentages in the bound to mobile fractions at the central urban areas of Beijing. Therefore, special concerns should be paid to these toxic trace elements which had relatively high mobility in fine particles, when planning and implementing the comprehensive air pollution mitigation policies in Beijing.

  10. Thermal Evaporation Synthesis and Properties of ZnO Nano/Microstructures Using Carbon Group Elements as the Reducing Agents

    Directory of Open Access Journals (Sweden)

    Du XB

    2010-01-01

    Full Text Available Abstract ZnO nano/microstructures have been formed by thermal evaporation method using ZnO powders mixed with carbon group elements (C, Si, Ge, Sn, or Pb as the reducing agent. For cases of mixed precursors of ZnO/C, ZnO/Si, and ZnO/Ge, the pure ZnO nano/microstructures are realized, while for ZnO/Sn (ZnO/Pb systems, the phase of Pb2O3(Zn2SnO4 generally are represented in the ZnO products. The appearance of Pb2O3(Zn2SnO4 is attributed to the lower melting point and higher vapor pressure of Sn (Pb in the heating and evaporation processes. The morphologies and sizes of the products are controlled by adjusting the growth regions and/or introducing gaseous argon. Room temperature (RT photoluminescence spectra indicate that the intensity (peak position of the ultraviolet emission is increased (redshift due to the existence of Zn2SnO4 phase in the ZnO products. The Pb2O3(Zn2SnO4 phase in ZnO nano/microstructures plays a important role in enhancing the saturation magnetizations of RT ferromagnetism with respect to the case of pure ZnO products fabricated by the precursor of mixed ZnO and graphite.

  11. Extraction studies of the group VB-VIIB and VIII elements using 1-(2-pyridylazo)-2-naphtol as chelating reagent

    International Nuclear Information System (INIS)

    Extraction behaviour of the chelates of group VB-VIIB and VIII elements using 1-(2-pyridylazo)-2-naphtol (PAN) has been studied as a function of pH. The extractions were performed in glass bottles equipped with conical polyethylene-lined screw caps. A mechanical shaker was used to mix the organic and aqueous phases during extraction. Studies have been made to back-extract the metal ions from the organic phase into the aqueous solution containing the optimum concentration of KCN and HClO4 and buffers of appropriate pH. The masking agents such as citrate, cyanide, thiosulphate, fluoride and thiourea were used to achieve more specific separations. The studies indicate the potentiality of PAN as a useful solvent extracting reagent in devising group chemical separation procedures for activation analysis. (T.G.)

  12. Determination of all platinum-group elements in mantle-derived xenoliths by neutron activation analysis with NiS fire-assay preconcentration

    International Nuclear Information System (INIS)

    A modified NiS fire-assay neutron activation method is developed for the determination of all platinum-group elements (PGEs) in mantle-derived xenoliths. This method is characterized by sub-ppb detection limits, <0.1 ∼ 0.002 ppb procedural blanks and 7 ∼ 15% analytical precision for PGEs. Analyses of PGE standard rocks indicate that this modified NiS fire-assay neutron activation method is as reliable as the method previously proposed for a large scale of samples. The capability of the method for the measurement of PGEs in the upper mantle is also illustrated by some exciting results obtained from mantle-derived xenoliths of Eastern China. (author)

  13. Chemical composition of lateritic ores and its industrial processing products by neutron activation analysis

    International Nuclear Information System (INIS)

    Several techniques of neutron activation analysis for the determination of chemical composition of lateritic ores and in its industrial processing products has been assayed. Instrumental neutron activation analysis with thermal neutrons from reactor combined with short irradiations, allowed the determination of a group of elements, but it was practically not applicable with long irradiations due to the strongly interferences of Co-60, Cr-51, Sc-46 and Fe-59. Reactor epithermal neutron activation analysis (ENAA), significantly reduced such interferences and at least 20 elements had been determined by this technique. An improvement of practical detection limits (10-6%) had been achieved combining the ENAA with one step radiochemical separation by using either the ion exchange in samples of ores and tails or the cobalt liquid extraction in the elaborated products. Nearly 30 elements had been determined by this combination, that also gives a valuable information concerning the distribution of some ''dispersed'' (Se, Ir, Au, etc.) and rare earths elements (La, Sm, Yb, Lu, etc.) during the industrial treatment of lateritic ores in Cuba. 21 refs

  14. Determination of rare earths and other trace elements in samples of Antarctica by neutron activation analysis

    International Nuclear Information System (INIS)

    The concentrations of REE and other trace elements have been determined in samples of Antarctica by Instrumental Neutron Activation Analysis (INAA). The samples were collected from the West Lake area near Great Wall Station. The samples include sediment, residual plants, rock and soil taken from the bottom of the lake to 3.4 m deep. The amounts of samples were very rare. In order to get more information, reactor NAA using both short and long irradiations with 'K0 standardization' has been adopted. Nine rare-earth elements (REE) namely La, Ce, Nd, Sm, Eu, Tb, Dy, Yb and Lu as well as other trace elements (As, Au, Ba, Br, Co, Cr, Hf, Sc, Se, Th, V, Zn) have been determined. The concentrations and distribution patterns of REE in the samples have been given. (author) 9 refs.; 5 figs.; 5 tabs

  15. Elemental assay of Roman silver and copper coins and associated casting items by XRF

    International Nuclear Information System (INIS)

    Energy-dispersive X-ray fluorescence (XRF) was employed for the determination of chemical element abundances in silver and copper coins and associated casting items of a hoard discovered in an antique minting facility. The precise and accurate results obtained lead to conclusions about material batches used in the casting, and about concentration variation phenomena occurring at the coin surfaces. The validity of the present method was checked by participating in an intercomparison. (author)

  16. Sildenafil preserves diastolic relaxation after reduction by L-NAME and increases phosphodiesterase-5 in the intercalated discs of cardiac myocytes and arterioles

    OpenAIRE

    Silvia Elaine Ferreira-Melo; Caroline Demacq; Silvia Lacchini; José Eduardo Krieger; Maria Cláudia Irigoyen; Heitor Moreno

    2011-01-01

    OBJECTIVES: We investigated the influence of sildenafil on cardiac contractility and diastolic relaxation and examined the distribution of phosphodiesterase-5 in the hearts of hypertensive rats that were treated with by NG-nitro-L-arginine methyl ester (L-NAME). METHODS: Male Wistar rats were treated with L-NAME and/or sildenafil for eight weeks. The Langendorff method was used to examine the effects of sildenafil on cardiac contractility and diastolic relaxation. The presence and location of...

  17. 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.

  18. Determination of trace and toxic elements in Koran rice CRM by INAA, ICP and AAS

    International Nuclear Information System (INIS)

    Trace and toxic elements in Certified Reference Material (CRM) made of Korean rice at the Korea Research Institute of Standards and Science have been analyzed by Instrumental Neutron Activation Analysis (INAA). Data intercomparison from the measurement with those of Atomic Absorption Spectrometry (AAS) and Induced Coupled Plasma Spectrometry (ICPS) has been studied. The powdered samples were sterilized at 1.5 x 106 rad in the bottles using a 60Co source after sieving and spiking to specific elements such as As, Cd, Cr, Cu and Hg and then the homogeneity of samples was assessed. Rice flour (SRM 1568a) and standard solutions made by the National Institute of Standards Technology (NIST) were used to construct the calibration curves for the INAA and the chemical methods, respectively. The uncertainties and concentration of constituent elements were determined and the possibility of their use for analytical quality control was considered. (author)

  19. Diagnostic significance of elements in hair with esophageal cancer by computerized pattern recognition and PIXE

    International Nuclear Information System (INIS)

    The concentration of 12 elements in 414 hair samples of male adults from esophageal cancer group(ECG), serious esophagus epithelial cell hyperplasia group (SEECHG) and normal control group (NCG) were determined by PIXE. By at t-test it is found that significant differences exist for 10 elements (Si, S, Ca, Cr, Mn, Fe, Ni, Cu, Pb and Sr) between ECG and NCG and for 9 elements (Si, P, S, Ca, Cr, Mn, Fe, Ni and Zn) between SEECHG and NCG. The three types of persons mentioned above were classified by Mahalanobis distance discriminatory analysis (one of the computerized pattern recognition methods). The results show that the ratio of correct classification is around 72%, suggesting that this may become a promising method for the early diagnosis of esophageal cancer

  20. Linear steady heat transfer analysis by boundary element method

    International Nuclear Information System (INIS)

    The boundary element method for linear steady heat transfer analysis has been developed. Two types of elements, namely, constant elements and linear elements are described. A mention has been made of the analysis of the problems of a square plate subjected to two constant temperature boundaries and other two being insulated, blunt fin with convection boundary condition, and the steady state temperature distribution in circular segment by using this method. (M.G.B.)

  1. A rose by any other name

    International Nuclear Information System (INIS)

    This paper reports that as the number, scope, and cost of utility demand-side management (DSM) programs increase, the need for accurate data grows. Such data are required to document the performance of these programs to be sure that they deliver the cost-effective energy and capacity resources expected of them. Unfortunately, the amount and quality of data available on DSM programs falls far short of what is needed. Lack of explicit, widely used definitions of DSM terms is a key deficiency. Variables that describe program participation, electricity savings, and costs must be carefully defined, and these definitions should then be used throughout the electric-utility industry

  2. 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.

  3. 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...

  4. The origin of the chemical elements in cluster cores

    CERN Document Server

    de Plaa, J

    2012-01-01

    Metals play a fundamental role in ICM cooling processes in cluster cores through the emission of spectral lines. But when and how were these metals formed and distributed through the ICM? The X-ray band has the unique property of containing emission lines from all elements from carbon to zinc within the 0.1-10 keV band. Using XMM-Newton, the abundances of about 11 elements are studied, which contain valuable information about their origin. Most elements were formed in type Ia and core-collapse supernovae, which have very different chemical yields. Massive stars and AGB stars also contribute by providing most of the carbon and nitrogen in the ICM. Because feedback processes suppress star formation in the cluster centre, the element abundances allow us to directly probe the star formation history of the majority of stars that are thought to have formed between z=2-3. The spatial distribution in the core and the evolution with redshift also provide information about how these elements are transported from the me...

  5. Chemical classification of iron meteorites. VIII - Groups IC, IIE, IIIF and 97 other irons

    Science.gov (United States)

    Scott, E. R. D.; Wasson, J. T.

    1976-01-01

    Results are reported for determinations of Ni, Ga, Ge, and Ir concentrations in 106 iron meteorites. Three new groups are defined (IC, IIE, and IIIF) which contain 10, 12, and 5 irons, respectively. It is noted that group IC is a cohenite-rich group distantly related to IA, group IIE consists of those irons previously designated as Weekeroo Station type together with five others having similar compositions but diverse structures, and group IIIF is a well-defined group of low-Ni and low-Ge irons. Several anomalous irons are discussed, including a cluster of five plessitic octahedrites and ataxites with Ge/Ga atomic ratios ranging from 10 to 16 and a meteorite that has the second highest Ni content of any iron. It is shown that the IIE irons are compositionally similar to the mesosiderites and pallasites, and it is suggested that the three groups probably formed at approximately the same heliocentric distance.

  6. Short length trace element fluctuations in hair as measured by NAA and PIXE

    International Nuclear Information System (INIS)

    Since hair receives trace elements through different routes in and outside the follicle an investigation was carried out concerning trace element distributions in various parts of the hair with an emphasis on the route bulb. Microbeam PIXE scans over cross sections and additional overall analyses were made by DNAA and PIXE. It seems that trace elements can be divided into three groups, i.e. those introduced by blood in the initial stage of hair formation (Cu and Zn), those also introduced from blood in a later stage (K, Ca, Fe) and those introduced from sebum or sweat (Pb, As, Se). Consequences for the use of hair as a monitor for the trace element status of a person are discussed. Furthermore, attention is paid to the need for new techniques which provide information on trace elements distributions in biomedical tissues besides or instead of overall analysis methods like NAA. (author)

  7. Solution of the two dimensional diffusion and transport equations in a rectangular lattice with an elliptical fuel element using Fourier transform methods: One and two group cases

    International Nuclear Information System (INIS)

    Highlights: • A rectangular reactor cell with an elliptical fuel element. • Solution of transport and diffusion equations by Fourier expansion. • Numerical examples showing convergence. • Two group cell problems. - Abstract: A method for solving the diffusion and transport equations in a rectangular lattice cell with an elliptical fuel element has been developed using a Fourier expansion of the neutron flux. The method is applied to a one group model with a source in the moderator. The cell flux is obtained and also the associated disadvantage factor. In addition to the one speed case, we also consider the two group equations in the cell which now become an eigenvalue problem for the lattice multiplication factor. The method of solution relies upon an efficient procedure to solve a large set of simultaneous linear equations and for this we use the IMSL library routines. Our method is compared with the results from a finite element code. The main drawback of the problem arises from the very large number of terms required in the Fourier series which taxes the storage and speed of the computer. Nevertheless, useful solutions are obtained in geometries that would normally require the use of finite element or analogous methods, for this reason the Fourier method is useful for comparison with that type of numerical approach. Extension of the method to more intricate fuel shapes, such as stars and cruciforms as well as superpositions of these, is possible

  8. Plutonium and transplutonium element trioxides: molecular structures, chemical bonding, and isomers.

    Science.gov (United States)

    Zaitsevskii, Andréi

    2015-10-14

    Ground-state equilibrium geometries, energetics, and vibrational frequencies of AnO3 molecules, An = Pu through Cf, and their isomers are calculated using an accurate small-core pseudopotential model and the two-component relativistic density functional theory. The qualitative features of chemical bonding in these molecules are discussed in terms of oxidation states and bond orders. The actinide oxidation state (VI) is reached only in the plutonium trioxide molecule, whereas heavier actinide atoms in T-shaped trioxide molecules should be considered as pentavalent. At least at low temperatures, PuO3 and, to a lesser degree, AmO3 and BkO3 molecules should be stable both with respect to the isomerization into oxoperoxides or oxosuperoxides and the decay into dioxides and molecular oxygen. These trioxides can form dimers with significant (above 250 kJ mol(-1)) dissociation energies; the oxidation states of actinide atoms in the lowest-energy configurations of these dimers coincide with those in the corresponding monomers. The ability to reach high oxidation states in oxygen compounds gradually decreases from Pu onwards, with the only exception being the unexpectedly stable Bk(v)O3. PMID:26343514

  9. Environmental risk of particulate and soluble platinum group elements released from gasoline and diesel engine catalytic converters

    Energy Technology Data Exchange (ETDEWEB)

    Moldovan, M.; Palacios, M.A.; Gomez, M.M. [Departamento de Quimica Analitica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, 28040- Madrid (Spain); Morrison, G.; Rauch, S. [Chalmers University of Technology, Gothenburg (Sweden); McLeod, C.; Ma, R. [University of Sheffield, Sheffield (United Kingdom); Caroli, S.; Alimonti, A.; Petrucci, F.; Bocca, B. [Istituto Superiore di Sanita, Rome (Italy); Schramel, P.; Zischka, M. [GSF National Research Centre for Environment and Health, Neuherberg (Germany); Pettersson, C. [Scandiaconsult Sverige AB, Gothenburg (Sweden); Wass, U. [Volvo Technological Development Corporation, Gothenburg (Sweden); Luna, M. [Ford, Madrid (Spain); Saenz, J.C. [INTA Instituto Nacional de Tecnica Aeroespacial, Madrid (Spain); Santamaria, J. [Seat, Barcelona (Spain)

    2002-09-16

    A comparison of platinum-group element (PGE) emission between gasoline and diesel engine catalytic converters is reported within this work. Whole raw exhaust fumes from four catalysts of three different types were examined during their useful lifetime, from fresh to 80000 km. Two were gasoline engine catalysts (Pt-Pd-Rh and Pd-Rh), while the other two were diesel engine catalysts (Pt). Samples were collected following the 91441 EUDC driving cycle for light-duty vehicle testing, and the sample collection device used allowed differentiation between the particulate and soluble fractions, the latter being the most relevant from an environmental point of view. Analyses were performed by inductively coupled plasma-mass spectrometry (ICP-MS) (quadrupole and high resolution), and special attention was paid to the control of spectral interference, especially in the case of Pd and Rh. The results obtained show that, for fresh catalysts, the release of particulate PGE through car exhaust fumes does not follow any particular trend, with a wide range (one-two orders of magnitude) for the content of noble metals emitted. The samples collected from 30000-80000 km present a more homogeneous PGE release for all catalysts studied. A decrease of approximately one order of magnitude is observed with respect to the release from fresh catalysts, except in the case of the diesel engine catalyst, for which PGE emission continued to be higher than in the case of gasoline engines. The fraction of soluble PGE was found to represent less than 10% of the total amount released from fresh catalysts. For aged catalysts, the figures are significantly higher, especially for Pd and Rh. Particulate PGE can be considered as virtually biologically inert, while soluble PGE forms can represent an environmental risk due to their bioavailability, which leads them to accumulate in the environment.

  10. Chemical land improvement salty ground of the Tyumen region and its influence on the maintenance of heavy metals and radioactive elements in soil

    International Nuclear Information System (INIS)

    It is considered after action chemical land improvement salty ground phosphorus laster alter 34 years on the maintenance and redistribution of heavy metals and radioactive elements in a meter structure ground.

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

    Indian Academy of Sciences (India)

    Qingjun Kong

    2012-08-01

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

  12. Peer Groups, Families, and School Failure among Urban Children: Elements of Risk and Successful Interventions.

    Science.gov (United States)

    Henry, David B.

    2000-01-01

    While focusing on the urban context, this article reviews research regarding the family and peer contexts of risk for antisocial behavior and school failure as well as recent empirical evidence supporting strategies for intervention. Early intervention, family interventions, and school environments that discourage aggression are urged. (Contains…

  13. Slope Stability Evaluations by Limit Equilibrium and Finite Element Methods

    OpenAIRE

    Aryal, Krishna Prasad

    2006-01-01

    This thesis deals with slope stability evolutions carried out by commonly used limit equilibrium (LE) and finite element (FE) methods. The study utilizes two LE based software (SLOPE/W and SLIDE) and one FE based software (PLAXIS). The principal difference between these two analyses approaches is that the LE methods are based on the static of equilibrium whereas FE methods utilise the stress‐strain relationship or constitutive law. To fulfil one of the aims of the study, the LE based method...

  14. Slope Stability Evaluations by Limit Equilibrium and Finite Element Methods

    OpenAIRE

    Aryal, Krishna Prasad

    2006-01-01

    This thesis deals with slope stability evolutions carried out by commonly used limit equilibrium (LE) and finite element (FE) methods. The study utilizes two LE based software (SLOPE/W and SLIDE) and one FE based software (PLAXIS). The principal difference between these two analyses approaches is that the LE methods are based on the static of equilibrium whereas FE methods utilise the stress‐strain relationship or constitutive law. To fulfil one of the aims of the study, the LE based methods...

  15. Soil chemicals properties and wheat genotype impact on micronutrient and toxic elements content in wheat integral flour

    Directory of Open Access Journals (Sweden)

    Krunoslav Karalić

    2012-02-01

    Full Text Available Aim To determine impact of soil chemical properties and different wheat genotypes in Croatia on micronutrient and toxic elements content in wheat integral flour. Methods Research was conducted and soil samples were collected from two different production areas in the Republic of Croatia: Ovčara and Dalj. Besides soil samples, grain samples of four different Croatian wheat genotypes were also collected and analyzed. In total, 40 samples of soil and 40 samples of wheat grain were analysed for total (aqua regia and plant available (EDTA extraction heavy metal content of Fe, Mn, Zn, Cu, Pb, Cd. Results Determined soil pHKCl ranged from 5.63 to 6.25 at Ovčara and from 6.95 to 7.37 at Dalj sampling sites. The highest total concentration of heavy metals in soil were determined for Fe, followed by Mn, Zn, Cu, Pb and the lowest total concentration wasrecorded for Cd. The highest EDTA concentrations in soil were determined for Mn, than followed by Fe, Cu, Pb, and the lowest EDTA concentration was recorded for Cd. The highest concentration in integral wheat flour was found for Fe, than lower for Mn, Zn, Cu, Pb and the lowest concentration was found for Cd. If consumers in Croatia used daily 203 g of bread made of integral flour, they would take 2.31 to 8.44 µg Cd daily, depending on soil and wheat genotype.Conclusion The analysed soil and winter wheat genotypes have significant impact on potential daily intake of toxic and essentialheavy metals by integral flour or bread.

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

    Science.gov (United States)

    Wiche, Oliver; Székely, Balázs

    2016-04-01

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

  17. Multielement determination and speciation of major-to-ultratrace elements in green tea leaves by ICP-AES and ICP-MS

    International Nuclear Information System (INIS)

    In order to investigate the multi-elemental composition of green tea leaves as well as chemical species in tea infusions, inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) were used for elemental analysis and elemental speciation with the aid of size exclusion chromatography (SEC). As a result, the multielement determination of major-to-ultratrace elements in green tea leaves and green tea infusions was carried out by ICP-AES and ICP-MS. About 40 elements in these tea samples could be determined in a wide concentration range of over 8 orders of magnitude. The extraction efficiency of each element was estimated as the ratio of its concentration in tea infusion to that in tea leaves. It was found from the experimental results that the elements in tea leaves could be classified into three characteristic groups, depending on their extraction efficiencies. Furthermore, tea infusions were analyzed by a combined system of SEC, UV absorption detector, and ICP-AES (or ICP-MS) for the speciation of major-to-ultratrace elements. Most of the elements in tea infusions were found to be present as associated complexes with large organic molecules. (author)

  18. Chemical modification and pH dependence of kinetic parameters to identify functional groups in a glucosyltransferase from Strep. Mutans

    International Nuclear Information System (INIS)

    A glucosyltransferase, forming a predominantly al-6 linked glucan, was partially purified from the culture filtrate of S. mutans GS-5. The kinetic properties of the enzyme, assessed using the transfer of 14C glucose from sucrose into total glucan, were studied at pH values from pH 3.5 to 6.5. From the dependence of km on pH, a group with pKa = 5.5 must be protonated to maximize substrate binding. From plots of V/sub max/ vs pH two groups, with pKa's of 4.5 and 5.5 were indicated. The results suggest the involvement of either two carboxyl groups (one protonated, one unprotonated in the native enzyme) or a carboxyl group (unprotonated) and some other protonated group such as histidine, cysteine. Chemical modification studies showed that Diethylyrocarbonate (histidine specific) had no effect on enzyme activity while modification with p-phydroxy-mercuribenzoate or iodoacetic acid (sulfhydryl reactive) and carbodimide reagents (carboxyl specific) resulted in almost complete inactivation. Activity loss was dependent upon time of incubation and reagent concentration. The disaccharide lylose, (shown to be an inhibitor of the enzyme with similar affinity to sucrose) offers no protection against modification by the sulfhydryl reactive reagents

  19. Phytoaccumulation of trace elements by wetland plants: 3. Uptake and accumulation of ten trace elements by twelve plant species

    Energy Technology Data Exchange (ETDEWEB)

    Qian, J.H.; Zayed, A.; Zhu, Y.L.; Yu, M.; Terry, N.

    1999-10-01

    Interest is increasing in using wetland plants in constructed wetlands to remove toxic elements from polluted wastewater. To identify those wetland plants that hyperaccumulate trace elements, 12 plant species were tested for their efficiency to bioconcentrate 10 potentially toxic trace elements including As, b, Cd, Cr, Cu, Pb, Mn, Hg, Ni, and Se. Individual plants were grown under carefully controlled conditions and supplied with 1 mg L{sup {minus}1} of each trace element individually for 10 d. Except B, all elements accumulated to much higher concentrations in roots than in shoots. Highest shoot tissue concentrations (mg kg{sup {minus}1} DW) of the various trace elements were attained by the following species: umbrella plant (Cyperus alternifolius L.) for Mn (198) and Cr (44); water zinnia (Wedelia trilobata Hitchc.) for Cd (148) and Ni (80); smartweed (Polygonum hydropiperoides Michx.) for Cu (95) and Pb (64); water lettuce (Pistia stratiotes L.) for Hg (92), As (34), and Se (39); and mare's tail (hippuris vulgaris L.) for B (1132). Whereas, the following species attained the highest root tissue concentrations (mg kg{sup {minus}1} DW); stripped rush (Baumia rubiginosa) for Mn (1683); parrot's feather (Myriophyllum brasiliense Camb.) for Cd (1426) and Ni (1077); water lettuce for Cu (1038), Hg (1217), and As (177); smartweed for Cr (2980) and Pb (1882); mare's tail for B (1277); and monkey flower (Mimulus guttatus Fisch.) for Se (384). From a phytoremediation perspective, smartweed was probably the best plant species for trace element removal from wastewater due to its faster growth and higher plant density.

  20. Transport and deposition of gold with uranium and platinum-group elements in unconformity-related uranium deposits

    International Nuclear Information System (INIS)

    The Jabiluka unconformity-related uranium deposit contains 8 million gms of gold (at an average grade of 10 gms/tonne) in addition to 207,000 tonnes U3O8 and significant palladium (at grades of up to 100 gms/tonne). Other uranium deposits of the Alligators Rivers Uranium Field, Northern Territory, Australia (Koongarra, Nabarlek) also contain traces of gold. The E1 Sherana and Rockhole deposits (South Alligator Valley, Northern Territory) produced minor gold during the nineteen fifties and the Coronation Hill gold palladium and platinum deposit (South Alligator Valley) was originally mined for uranium. It therefore appears that solutions which carry uranium are capable of transporting ore-forming amounts of gold and in some instances palladium and platinum, elements traditionally regarded as immobile. This paper presents evidence on the nature of the ore-forming solutions involved in mineralisation at the Jabiluka, Nabarlek and Koongarra deposits and examines possible transport and depositional mechanisms of U, Au and platinum group elements

  1. Differences in the activities of eight enzymes from ten soil fungi and their possible influences on the surface structure, functional groups, and element composition of soil colloids.

    Science.gov (United States)

    Wang, Wenjie; Li, Yanhong; Wang, Huimei; Zu, Yuangang

    2014-01-01

    How soil fungi function in soil carbon and nutrient cycling is not well understood by using fungal enzymatic differences and their interactions with soil colloids. Eight extracellular enzymes, EEAs (chitinase, carboxymethyl cellulase, β-glucosidase, protease, acid phosphatase, polyphenol oxidase, laccase, and guaiacol oxidase) secreted by ten fungi were compared, and then the fungi that showed low and high enzymatic activity were co-cultured with soil colloids for the purpose of finding fungi-soil interactions. Some fungi (Gomphidius rutilus, Russula integra, Pholiota adiposa, and Geastrum mammosum) secreted 3-4 enzymes with weak activities, while others (Cyathus striatus, Suillus granulate, Phallus impudicus, Collybia dryophila, Agaricus sylvicola, and Lactarius deliciosus) could secret over 5 enzymes with high activities. The differences in these fungi contributed to the alterations of functional groups (stretching bands of O-H, N-H, C-H, C = O, COO- decreased by 11-60%, while P = O, C-O stretching, O-H bending and Si-O-Si stretching increased 9-22%), surface appearance (disappearance of adhesive organic materials), and elemental compositions (11-49% decreases in C1s) in soil colloids. Moreover, more evident changes were generally in high enzymatic fungi (C. striatus) compared with low enzymatic fungi (G. rutilus). Our findings indicate that inter-fungi differences in EEA types and activities might be responsible for physical and chemical changes in soil colloids (the most active component of soil matrix), highlighting the important roles of soil fungi in soil nutrient cycling and functional maintenance. PMID:25398013

  2. First-principles study of high temperature and high-pressure behavior of carbides and nitrides of group IVB elements

    Science.gov (United States)

    Mishra, Vinayak; Chaturvedi, Shashank

    2016-01-01

    Full potential linearized augmented plane wave method combined with quasi-harmonic approximation, has been used to perform the calculations of thermophysical properties of carbides and nitrides of the group IVB elements at high temperature and pressure. Relative accuracy of linear density approximation (LDA) and generalized gradient approximation (GGA) exchange correlation potentials have been tested. Specific heat (?) obtained through LDA and GGA agrees with experimental data up to 1500 K. Above 1500 K, GGA gives better agreement whereas LDA under-estimates the specific heat. LDA overestimates the bulk modulus, GGA gives better agreement with the experimental data. High-temperature bulk modulus follows the Wachtman formula. Calculated ? isotherms agree with published experimental results. The transformation pressures (?) from NaCl-type structure (B? phase) to CsCl-type structure (B? phase), and collapsed volumes (?) at (?) have been predicted. The stability and hardness of these compounds are related with the calculated density of states.

  3. The change of religion and the names

    Directory of Open Access Journals (Sweden)

    John Kousgård Sørensen

    1990-01-01

    Full Text Available What actually happened at the time when Denmark was christianized? An important viewpoint to the topic is the nomenclature, both personal names and place-names. What happened to these in the missionary period? Can they be exploited as evidence about the change of religion? What happened to these and to the naming practices in connection with the introduction of Christianity? These questions are relevant, because several pre-Christian cultic words entered into the personal nomenclature which the Christian mission found in use on its arrival. The fate of the nomenclature in the period does suggest that the change in religion took place reasonably peacefully and gradually. There are, however, certain features about the place-names suggesting that there were local differences in the conduct of the mission.

  4. Investigation on trace and major elements in anti-asthmatic medicinal plants by PIXE and PIGE techniques

    Science.gov (United States)

    Bhanisana Devi, R. K.; Nandakumar Sarma, H.; Kumar, Sanjiv

    2015-01-01

    Five widely used anti-asthmatic medicinal plants of north-eastern region of India have been investigated by using Proton Induced X-ray Emission (PIXE) and Proton Induced Gamma ray Emission (PIGE) techniques. The elements namely K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se and Br were detected with different concentrations (in ppm level) by PIXE technique whereas light elements namely F, Na, Mg, Al, P and Cl by PIGE technique in the studied plants. No toxic heavy metals such as Hg, Pb, Cd were detected. Analysis was performed on thick targets (pellets) prepared using the powders of specimens through a series of processing steps. Thick targets of plant based Certified Reference Materials (CRMs) were served as standardization of PIXE and PIGE set up. The trace elements present in the studied plants have been correlated with their medicinal properties.

  5. Investigation on trace and major elements in anti-asthmatic medicinal plants by PIXE and PIGE techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bhanisana Devi, R.K., E-mail: bhanisanark@gmail.com [Department of Physics, Manipur University, Canchipur 795003 (India); Nandakumar Sarma, H. [Department of Physics, Manipur University, Canchipur 795003 (India); Kumar, Sanjiv [National Centre for Compositional Characterization of Materials (NCCCM), Hyderabad 500062 (India)

    2015-01-15

    Five widely used anti-asthmatic medicinal plants of north-eastern region of India have been investigated by using Proton Induced X-ray Emission (PIXE) and Proton Induced Gamma ray Emission (PIGE) techniques. The elements namely K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se and Br were detected with different concentrations (in ppm level) by PIXE technique whereas light elements namely F, Na, Mg, Al, P and Cl by PIGE technique in the studied plants. No toxic heavy metals such as Hg, Pb, Cd were detected. Analysis was performed on thick targets (pellets) prepared using the powders of specimens through a series of processing steps. Thick targets of plant based Certified Reference Materials (CRMs) were served as standardization of PIXE and PIGE set up. The trace elements present in the studied plants have been correlated with their medicinal properties.

  6. Investigation on trace and major elements in anti-asthmatic medicinal plants by PIXE and PIGE techniques

    International Nuclear Information System (INIS)

    Five widely used anti-asthmatic medicinal plants of north-eastern region of India have been investigated by using Proton Induced X-ray Emission (PIXE) and Proton Induced Gamma ray Emission (PIGE) techniques. The elements namely K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se and Br were detected with different concentrations (in ppm level) by PIXE technique whereas light elements namely F, Na, Mg, Al, P and Cl by PIGE technique in the studied plants. No toxic heavy metals such as Hg, Pb, Cd were detected. Analysis was performed on thick targets (pellets) prepared using the powders of specimens through a series of processing steps. Thick targets of plant based Certified Reference Materials (CRMs) were served as standardization of PIXE and PIGE set up. The trace elements present in the studied plants have been correlated with their medicinal properties

  7. Chemical Safety Vulnerability Working Group report. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    The Chemical Safety Vulnerability (CSV) Working Group was established to identify adverse conditions involving hazardous chemicals at DOE facilities that might result in fires or explosions, release of hazardous chemicals to the environment, or exposure of workers or the public to chemicals. A CSV Review was conducted in 148 facilities at 29 sites. Eight generic vulnerabilities were documented related to: abandoned chemicals and chemical residuals; past chemical spills and ground releases; characterization of legacy chemicals and wastes; disposition of legacy chemicals; storage facilities and conditions; condition of facilities and support systems; unanalyzed and unaddressed hazards; and inventory control and tracking. Weaknesses in five programmatic areas were also identified related to: management commitment and planning; chemical safety management programs; aging facilities that continue to operate; nonoperating facilities awaiting deactivation; and resource allocations. Volume 1 contains the Executive summary; Introduction; Summary of vulnerabilities; Management systems weaknesses; Commendable practices; Summary of management response plan; Conclusions; and a Glossary of chemical terms.

  8. Chemical Safety Vulnerability Working Group report. Volume 1

    International Nuclear Information System (INIS)

    The Chemical Safety Vulnerability (CSV) Working Group was established to identify adverse conditions involving hazardous chemicals at DOE facilities that might result in fires or explosions, release of hazardous chemicals to the environment, or exposure of workers or the public to chemicals. A CSV Review was conducted in 148 facilities at 29 sites. Eight generic vulnerabilities were documented related to: abandoned chemicals and chemical residuals; past chemical spills and ground releases; characterization of legacy chemicals and wastes; disposition of legacy chemicals; storage facilities and conditions; condition of facilities and support systems; unanalyzed and unaddressed hazards; and inventory control and tracking. Weaknesses in five programmatic areas were also identified related to: management commitment and planning; chemical safety management programs; aging facilities that continue to operate; nonoperating facilities awaiting deactivation; and resource allocations. Volume 1 contains the Executive summary; Introduction; Summary of vulnerabilities; Management systems weaknesses; Commendable practices; Summary of management response plan; Conclusions; and a Glossary of chemical terms

  9. Oscillations caused by flexible attached elements of satellite constructions

    Science.gov (United States)

    Shatikhin, V. Ye.; Semenov, L. P.; Artemenko, Yu. H.; Borysenko, V. M.; Helenko, O. O.

    We consider oscillations caused by flexible attached elements of satellite constructions, namely, solar array panels and antenna. An analysis of models of oscillations produced by solar array panels is carried out. We give some recommendations concerning the improvement of calculations of oscillations caused by flexible elements of satellite constructions with allowance made for modern achievements in the space material science.

  10. Characterization of the Lactobacillus casei group and the Lactobacillus acidophilus group by automated ribotyping.

    Science.gov (United States)

    Ryu, C S; Czajka, J W; Sakamoto, M; Benno, Y

    2001-01-01

    A total of 91 type and reference strains of the Lactobacillus casei group and the L acidophilus group were characterized by the automated ribotyping device Riboprinter microbial characterization system. The L. casei group was divided into five (C1-C5) genotypes by ribotyping. Among them, the strain of L. casei ATCC 334 was clustered to the same genotype group as most of L. paracasei strains and L casei JCM 1134T generated a riboprint pattern that was different from the type strain of L. zeae. These results supported the designation of L. casei ATCC 334 as the neotype strain, but were not consistent with the reclassification of L. casei JCM 1134T as L. zeae. The L. acidophilus group was also divided into 14 (A1-A11, B1-B3) genotypes by ribotyping. L. acidophilus, L. amylovorus, L. crispatus and L. gallinarum generated ribotype patterns that were distinct from the patterns produced by L. gasseri and L. johnsonii. This result confirmed previous data that the L. acidophilus group divided to two major clusters. Five strains of L. acidophilus and two strains of L. gasseri were correctly reidentified by ribotyping. Most strains belonging to the L. casei group and the L. acidophilus group were discriminated at the species level by automated ribotyping. Thus this RiboPrinter system yields rapid, accurate and reproducible genetic information for the identification of many strains. PMID:11386416

  11. The name of the son. Fatherhood, motherhood and symbolic competencies

    Directory of Open Access Journals (Sweden)

    María Martina Casullo

    2015-09-01

    Full Text Available Tania Zittoun conceptions on uses of cultural elements as symbolic resources for psychological development are presented. Such uses of symbolic resources are examined through a study of the procedure of choosing first names during the transition to parenthood. The notion of symbolic competencies, as the abilities to use cultural elements as resources for thinking, action and a healthy development, is discussed. 

  12. Scientific Opinion on Flavouring Group Evaluation 74, Revision 3 (FGE.74Rev3): Consideration of Simple Aliphatic Sulphides and Thiols evaluated by the JECFA (53rd and 61st meeting) Structurally related to Aliphatic and Alicyclic Mono-, Di-, Tri-, and Polysulphides with or without Additional Oxygenated Functional Groups from Chemical Group 20 evaluated by EFSA in FGE.08Rev5 (2012)

    OpenAIRE

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF)

    2014-01-01

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The present consideration concerns a group of 19 simple aliphatic sulphides and thiols evaluated by the JECFA at the ...

  13. Effects of cognitive and experiential group therapy on self-efficacy and perceptions of employability of chemically dependent women.

    Science.gov (United States)

    Washington, O

    1999-01-01

    This quasi-experimental study assessed effects of cognitive and experiential group therapy on self-efficacy and perceptions of employability for 52 chemically dependent adult women. The sample was 98% African America