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

International Nuclear Information System (INIS)

Hoffman, D.C.

1990-08-01

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

Superheavy element chemistry. Achievements and perspectives

International Nuclear Information System (INIS)

Schaedel, M.

2007-01-01

Superheavy elements have been synthesized and chemically characterized one-atom-at-a-time up to element 108. Presently, the quest for element 112 is one of the hottest topics in this field. The transactinide elements 104 to 108 are members of group 4 to 8 of the Periodic Table and element 112 belongs into group 12. Chemical properties of some of these elements, like elements 104 and 105, show stunning deviations from simple extrapolations within their respective group while others exhibit great similarities with their lighter homologues elements. First experiments to investigate seaborgium (Sg, element 106) in aqueous solution were performed. Again, in large international collaborations at the GSI, several gas-phase chemistry experiments were performed with hassium (Hs, element 108). Recently, the highly efficient and very clean separation of Hs was applied for nuclear studies of various Hs nuclides investigating their cross section and their nuclear decay properties in the region of the doubly-magic 270 Hs (Z=108, N=162). To overcome certain limitations of the presently used on-line chemical separations the new TransActinide Separation and Chemistry Apparatus (TASCA) - with a gas-filled recoil separator as a front-end tool - was designed and built at the GSI in a collaborative effort. Presently in its commissioning phase, TASCA shall be a key instrument for a big leap into quantitatively and qualitatively new experiments in the region of superheavy elements. (author)

Advances in chemical investigations of the heaviest elements

Directory of Open Access Journals (Sweden)

Türler Andreas

2016-01-01

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

Model Experiments on Chemical Properties of Superheavy Elements in Aqueous Solutions

CERN Document Server

Szeglowski, Z

2003-01-01

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

Electronic structure and chemistry of the heaviest elements

International Nuclear Information System (INIS)

Pershina, V.; Fricke, B.

1998-04-01

Progress in the development of relativistic molecular codes has allowed for an adequate description of the electronic structure of the very heavy element compounds, and for the interpretation and prediction of their molecular properties. Most of the theoretical investigations for compounds, interesting from the experimental point of view, have been carried out using the LDF methods. The studied species were group 4, 5 and 6 gas-phase compounds of the transactinides along with their lighter homologs, and their complexes in aqueous solutions. As a result of these calculations, trends within the transition-element groups and within the beginning of the transactinide series for molecular properties such as ionicity, covalence, stability towards oxidation or reduction, crystal-field and spin-orbit effects, bonding, and the influence of relativistic effects on them have been established. In combination with some other models, these calculations allowed for predicting properties measured experimentally: volatility of compounds, redox potentials in solutions and complex formation. Especially promising were predictions of equilibria of reaction using the DS-DV method. Agreement between results of the calculations and experiment confirmed the necessity of doing relativistic MO calculations and the unreliability of the straightforward extrapolations of properties within the chemical groups. (orig.)

Automated rapid chemistry in heavy element research

International Nuclear Information System (INIS)

Schaedel, M.

1994-01-01

With the increasingly short half-lives of the heavy element isotopes in the transition region from the heaviest actinides to the transactinide elements the demand for automated rapid chemistry techniques is also increasing. Separation times of significantly less than one minute, high chemical yields, high repetition rates, and an adequate detection system are prerequisites for many successful experiments in this field. The development of techniques for separations in the gas phase and in the aqueous phase for applications of chemical or nuclear studies of the heaviest elements are briefly outlined. Typical examples of results obtained with automated techniques are presented for studies up to element 105, especially those obtained with the Automated Rapid Chemistry Apparatus, ARCA. The prospects to investigate the properties of even heavier elements with chemical techniques are discussed

Chemistry of the heaviest elements

International Nuclear Information System (INIS)

Schaedel, M.

1992-08-01

The experimentally known chemical properties of elements 103,104, and 105, and the experimental techniques to obtain these properties on a one-atom- at-a-time base, are summarized. The chemical properties are compared with the lighter group 3,4 and 5 homologs and with the expected behaviour as obtained from theoretical calculations. In this transition region from the last actinide element to the beginning of the transactinide series one may expect to find evidence for increasingly strong relativistic effects altering the chemical behaviour. (orig.)

The Chemistry of Superheavy Elements

CERN Document Server

Schädel, M

2003-01-01

The chemistry of transactinide or superheavy elements has reached element 108. Preparations are under way to leap to element 112 and beyond. The current status of this atom-at-a-time chemical research and its future perspectives are reviewed from an experimental point of view together with some of the interesting results from n -rich nuclides near and at the N=162 neutron shell. Experimental techniques and important results enlightening typical chemical properties of elements 104 through 108 are presented in an exemplary way. From the results of these experiments it is justified to place these elements in the Periodic Table of the Elements in to groups 4 through 8, respectively. However, mainly due to the influence of relativistic effects, it is no longer possible to deduce detailed chemical properties of these superheavy elements simply from this position.

Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh

International Nuclear Information System (INIS)

Nelson, Sarah L; Nelson, Sarah L

2008-01-01

Several reactions producing odd-Z transactinide compound nuclei were studied with the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus at or near the same excitation energy with similar values of angular momentum via different nuclear reactions. In doing so, it can be determined if there is a preference in entrance channel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' model is nearly identical for the two reactions. Additionally, because the same compound nucleus is produced, the exit channel is the same. Four compound nuclei were examined in this study: 258Db, 262Bh, 266Mt, and 272Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: 50Ti + 209Bi vs. 51V + 208Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs; cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrance channel in these paired reactions. Charge equilibration immediately prior to fusion leading to a decreased fusion barrier is the likely cause of this phenomenon. In addition to this systematic study, the lightest isotope of element 107, bohrium, was discovered in the 209Bi(52Cr,n) reaction. 260Bh was found to decay by emission of a 10.16 MeV alpha particle with a half-life of 35 ms. The cross section is 59 pb at an excitation energy of 15.0 MeV. The effect of the N = 152 shell is also seen in this isotope's alpha particle energy, the first evidence of such an effect in Bh. All reactions studied are also compared to model predictions by Swiatecki, Siwek-Wilcznska, and Wilczynski's 'Fusion By Diffusion' theory

Behaviour at the indicator scale of the elements Zr, Hf and 104, Nb,Ta and Pa (105) in very complexation media; Comportement a l`echelle des indicateurs des elements Zr, Hf, et 104, Nb, Ta, et Pa (105) en milieux tres complexants

Energy Technology Data Exchange (ETDEWEB)

Monroy Guzman, F. [Institut de Physique Nucleaire, CNRS - IN2P3 Universite Paris Sud, 91406 Orsay Cedex (France)

1997-12-31

In order to determine the chemical properties of the trans-actinide elements of Z = 104 and 105 in aqueous solutions we studied their behaviour to ion exchange resin in different complex media. Due to the very short lifetimes (some tens of seconds) et to the low yield of these elements (a few atoms per irradiation hour) only very fast radiochemical techniques can be used. These severe constraints impose comparative studies of these elements with their most likely homologues to be carried out. The corresponding homologues were the elements of group 4 (Zr and Hf) for the element 104 and the elements of group 5 (Nb and Ta) and also Pa for the element 105. The complexation properties of the elements at indicator scale were determined in the media of HF, NH{sub 4}/HClO{sub 4}, NH{sub 4}SCN/HClO{sub 4}, NH{sub 4}SCN/HF and HCl/HF by ion exchange chromatography. The studies in fluorides media allowed us to identify the complexes in solution and to explain the shape of the experimentally observed sorption curves. The decrease of sorption for higher acid concentration in case of HF/HCl medium was interpreted by formation of chloro-fluoro-complexes. In case of the mixture NH{sub 4}SCN/HF, the particularly pronounced anti-synergic effects were observed and discussed. At the same time studies of the Hf and Ta short-lived isotopes were carried out by means of the RACHEL facility operating by the Orsay Tandem accelerator. These realistic simulations allowed optimization of different production, transportation and separation stages of the trans-actinide elements. The two experiments of 104 element production showed that this element forms in HF very stable anionic complexes similarly to its homologues Zr and Hf. (authors). 181 refs.

Behaviour at the indicator scale of the elements Zr, Hf and 104, Nb,Ta and Pa (105) in very complexation media; Comportement a l`echelle des indicateurs des elements Zr, Hf, et 104, Nb, Ta, et Pa (105) en milieux tres complexants

Energy Technology Data Exchange (ETDEWEB)

Monroy Guzman, F [Institut de Physique Nucleaire, CNRS - IN2P3 Universite Paris Sud, 91406 Orsay Cedex (France)

1998-12-31

In order to determine the chemical properties of the trans-actinide elements of Z = 104 and 105 in aqueous solutions we studied their behaviour to ion exchange resin in different complex media. Due to the very short lifetimes (some tens of seconds) et to the low yield of these elements (a few atoms per irradiation hour) only very fast radiochemical techniques can be used. These severe constraints impose comparative studies of these elements with their most likely homologues to be carried out. The corresponding homologues were the elements of group 4 (Zr and Hf) for the element 104 and the elements of group 5 (Nb and Ta) and also Pa for the element 105. The complexation properties of the elements at indicator scale were determined in the media of HF, NH{sub 4}/HClO{sub 4}, NH{sub 4}SCN/HClO{sub 4}, NH{sub 4}SCN/HF and HCl/HF by ion exchange chromatography. The studies in fluorides media allowed us to identify the complexes in solution and to explain the shape of the experimentally observed sorption curves. The decrease of sorption for higher acid concentration in case of HF/HCl medium was interpreted by formation of chloro-fluoro-complexes. In case of the mixture NH{sub 4}SCN/HF, the particularly pronounced anti-synergic effects were observed and discussed. At the same time studies of the Hf and Ta short-lived isotopes were carried out by means of the RACHEL facility operating by the Orsay Tandem accelerator. These realistic simulations allowed optimization of different production, transportation and separation stages of the trans-actinide elements. The two experiments of 104 element production showed that this element forms in HF very stable anionic complexes similarly to its homologues Zr and Hf. (authors). 181 refs.

Toward an accurate description of solid-state properties of superheavy elements

Directory of Open Access Journals (Sweden)

Schwerdtfeger Peter

2016-01-01

Full Text Available In the last two decades cold and hot fusion experiments lead to the production of new elements for the Periodic Table up to nuclear charge 118. Recent developments in relativistic quantum theory have made it possible to obtain accurate electronic properties for the trans-actinide elements with the aim to predict their potential chemical and physical behaviour. Here we report on first results of solid-state calculations for Og (element 118 to support future atom-at-a-time gas-phase adsorption experiments on surfaces such as gold or quartz.

Revamped half-lives of super heavy elements (SHE) in trans-actinide region

International Nuclear Information System (INIS)

Carmel Vigila Bai, G.M.; Umai Parvathiy, J.

2015-01-01

Analyzation of alpha decay properties and identification of Island of Stability has illuminated the theories of nuclear physics. This fundamental scientific research is the current ongoing work in the field of super heavy elements. In order to study the decay properties of super heavy elements a realistic model called as Cubic plus Yukawa plus Exponential (CYE) model is used here. This model uses a cubic potential in the pre-scission region connected by Coulomb plus Yukawa plus Exponential potential in the post scission region

Chemistry of superheavy elements

International Nuclear Information System (INIS)

Schaedel, M.

2012-01-01

The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

Odd-Z Transactinide Compound Nucleus Reactions Including the Discovery of 260Bh

Energy Technology Data Exchange (ETDEWEB)

Nelson, Sarah L. [Univ. of California, Berkeley, CA (United States)

2008-01-01

Several reactions producing odd-Z transactinide compound nuclei were studiedwith the 88-Inch Cyclotron and the Berkeley Gas-Filled Separator at the Lawrence Berkeley National Laboratory. The goal was to produce the same compound nucleus ator near the same excitation energy with similar values of angular momentum via differentnuclear reactions. In doing so, it can be determined if there is a preference in entrancechannel, because under these experimental conditions the survival portion of Swiatecki, Siwek-Wilcznska, and Wilczynski's"Fusion By Diffusion" model is nearly identical forthe two reactions. Additionally, because the same compound nucleus is produced, theexit channel is the same. Four compound nuclei were examined in this study: ²⁵⁸Db, ²⁶²Bh, ²⁶⁶Mt, and ²⁷²Rg. These nuclei were produced by using very similar heavy-ion induced-fusion reactions which differ only by one proton in the projectile or target nucleus (e.g.: ⁵⁰Ti + ²⁰⁹Bi vs. ⁵¹V + ²⁰⁸Pb). Peak 1n exit channel cross sections were determined for each reaction in each pair, and three of the four pairs' cross sections were identical within statistical uncertainties. This indicates there is not an obvious preference of entrancechannel in these paired reactions. Charge equilibration immediately prior to fusionleading to a decreased fusion barrier is the likely cause of this phenomenon. In addition to this systematic study, the lightest isotope of element 107, bohrium, was discovered in the ²⁰⁹Bi(⁵²Cr,n) reaction. ²⁶⁰Bh was found to decay by emission of a 10.16 MeV alpha particle with a half-life of 35$+19\\atop{-9}$ ms. The cross section is 59 pb at an excitation energy of 15.0 MeV. The effect of the N = 152 shell is also seen in this isotope's alpha particle energy, the first evidence of such an effect in Bh. All reactions studied are also compared to model predictions by Swiatecki

The chemistry of the actinide elements. Volume I

International Nuclear Information System (INIS)

Katz, J.J.; Seaborg, G.T.; Morss, L.R.

1986-01-01

The Chemistry of the Actinide Elements is a comprehensive, contemporary and authoritative exposition of the chemistry and related properties of the 5f series of elements: actinium, thorium, protactinium, uranium and the first eleven. This second edition has been completely restructured and rewritten to incorporate current research in all areas of actinide chemistry and chemical physics. The descriptions of each element include accounts of their history, separation, metallurgy, solid-state chemistry, solution chemistry, thermo-dynamics and kinetics. Additionally, separate chapters on spectroscopy, magnetochemistry, thermodynamics, solids, the metallic state, complex ions and organometallic compounds emphasize the comparative chemistry and unique properties of the actinide series of elements. Comprehensive lists of properties of all actinide compounds and ions in solution are given, and there are special sections on such topics as biochemistry, superconductivity, radioisotope safety, and waste management, as well as discussion of the transactinides and future elements

Atom-at-a-time chemistry

International Nuclear Information System (INIS)

Nagame, Yuichiro

2009-01-01

Several techniques of the analytical chemistry in 'Atom-at-a-time chemistry' for transactinide elements have been developed. In this report a representative example in these techniques is introduced with the results. The contents are the single-atom chemistry, the chemical experiments on transactinide elements, liquid phase chemistry (the ion exchange behavior of Rutherfordium), gas phase chemistry (the chemistry of atomic No.112 element), and future development. (M.H.)

Theoretical Studies of the Electronic Structure of the Compounds of the Actinide Elements

International Nuclear Information System (INIS)

Kaltsoyannis, Nikolas; Hay, P.J.; Li, Jun; Blaudeau, Jean-Philippe; Bursten, Bruce E.

2006-01-01

studies, and have been greatly facilitated by the extraordinary recent advances in high-performance computational technology. We will focus on computational studies of the electronic structure of discrete (molecular or ionic) actinide-containing systems. We begin by discussing some of the general tenets of bonding that are relevant to the actinide elements and some of the challenges that are unique to this field. We then present the results of computational electronic structure studies on a variety of molecular actinide systems. The literature of molecular electronic structure of actinide systems has been compiled by Pyykko (1986, 1993, 2001), as well as being available as a database on the web (http://www.csc.fi/rtam). Pepper and Bursten (1991) reviewed the methodology and applications in the field in 1991. The reader is referred to those reviews for some of the details on earlier studies in this field. We restrict our discussion in this chapter to molecular actinide systems and do not discuss the extensive body of research in the use of theoretical electronic structure methods to model solid-state actinide chemistry. The reader is referred to Chapter 21 and some recent review articles (Lander et al., 1994; Soderlind, 1998; Wills and Eriksson, 2000) for discussions of theoretical electronic structure methods applied to the metallic actinide elements and solid-state actinide compounds. We will also have minimal discussion of compounds of the transactinide elements in this chapter. The electronic structure of compounds of the transactinides is discussed in Chapter 14 and in the excellent review by Pershina (1996)

Volatilization behavior of transactinides from metal surfaces and melts (thermochemical calculation); Verfluechtigungsverhalten der Transaktinoide von Metalloberflaechen und aus Schmelzen (Thermochemische Kalkulation)

Energy Technology Data Exchange (ETDEWEB)

Eichler, B

2003-01-01

Volatilization properties of elements with the atomic numbers Z=104 to 116 are determined on the basis of empirical relations. These empirical correlations are deduced from the analysis of thermochemical data of metallic elements in the periodic table and their relations to the material constant: Structure specific connections are shown to exist between the electron densities at the 'Wigner-Seitz' cell borders of metals and the specific surface energies of solid metals with hexagonal, cubic face-centred, cubic body-centred and rhombohedral lattices. Analogously, structure specific relations can be found between the standard enthalpies of the gaseous monoatomic metals and their surface energies. Linear correlations with exceptionally high correlation coefficients are observed between the standard sublimation enthalpies of isotypic metals in the dimeric state and the surface energies. Volatilization properties are deduced for the transactinides on the basis of these established relations, applying a predicted structure and further empirical correlations. These volatilization properties are in detail: the standard enthalpies of the gaseous monomers; the standard sublimation enthalpies of the dimers; the standard dissociation enthalpies of the dimers; the standard enthalpies of adsorption on metal surfaces; the volatilization enthalpies from molten metals, and the standard formation enthalpies of hetero binuclear intermetallic molecules. Thermochemical constants required for the calculation of the intermetallic interactions are determined using the Miedema model. The closed systematic approach facilitate: the assessment of the calculated data considering the agreement with known rules of metal chemistry, trends in the 7{sup t}h row and along the groups of the periodic table, the coherence of the data, and the action of closed shell effects in the electron configurations. From the obtained data conclusions are possible regarding the design of volatilization

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Evolution and applications of radiochemical procedures. From Marie Curie to Darleane Hoffman

International Nuclear Information System (INIS)

Contis, E. T.; Rengan, K.

1996-01-01

Marie Curie carried out the first radiochemical separations which eventually lead to the discovery of polonium and radium, two new elements. Nearly a century later Darleane Hoffman and her collaborators are devising new radiochemical separation procedures for studying the chemical properties of newly discovered transactinide elements. Safety requirements as well as changes necessitated by fast decaying radionuclides have transformed the nature of radiochemical separations. Further, applications in a wide variety of areas such as analysis of trace elements in food to radioimmunoassay have broadened the use of radiochemical separations. Examples of some early, historically important, radiochemical separations are described in this article. In addition, recent trends in the use of radiochemical separations in neutron activation analysis, in dating applications, in fission product studies and in the study of transactinide elements are briefly described with specific examples. (author). 52 refs

Chemistry of the superheavy elements.

Science.gov (United States)

Schädel, Matthias

2015-03-13

The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently 'known' SHEs (11 are officially 'discovered' and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe 'relativistically' influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

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

Preparation of {sup 183,184}Re samples for modelling a rapid gas phase chemistry of Nielsbohrium (Ns), element 107

Energy Technology Data Exchange (ETDEWEB)

Eichler, R.; Gaeggeler, H.W.; Eichler, B.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

Chemical gas phase reactions of the heavier group 7 elements in the system O{sub 2}/H{sub 2}O are presumably best suited for a separation of Nielsbohrium from the lighter transactinides. We expect a higher reaction velocity using the more reactive gas system O{sub 3}/H{sub 2}O{sub 2}. For the experimental verification of this idea we prepared {sup 183}Re/{sup 184}Re samples for thermochromatography experiments with both gas systems. (author) 8 refs.

First superheavy element experiments at the GSI recoil separator TASCA: The production and decay of element 114 in the 244Pu(48Ca,3-4n) reaction

International Nuclear Information System (INIS)

Gates, J. M.; Duellmann, Ch. E.; Schaedel, M.; Ackermann, D.; Block, M.; Bruechle, W.; Essel, H. G.; Hartmann, W.; Hessberger, F. P.; Huebner, A.; Jaeger, E.; Khuyagbaatar, J.; Kindler, B.; Krier, J.; Kurz, N.; Lommel, B.; Schaffner, H.; Schausten, B.; Schimpf, E.; Steiner, J.

2011-01-01

Experiments with the new recoil separator, Transactinide Separator and Chemistry Apparatus (TASCA), at the GSI were performed by using beams of 48 Ca to irradiate targets of 206-208 Pb, which led to the production of 252-254 No isotopes. These studies allowed for evaluation of the performance of TASCA when coupled to a new detector and electronics system. By following these studies, the isotopes of element 114 ( 288-291 114) were produced in irradiations of 244 Pu targets with 48 Ca beams at compound nucleus excitation energies around 41.7 and 37.5 MeV, demonstrating TASCA's ability to perform experiments with picobarn-level cross sections. A total of 15 decay chains were observed and were assigned to the decay of 288-291 114. A new α-decay branch in 281 Ds was observed, leading to the new nucleus 277 Hs.

From alchemy to super-actinides. The preparation, physical-chemical properties and the limits of the Periodic Table

International Nuclear Information System (INIS)

Kuruc, J.

2016-01-01

In this review a brief history of the discovery of the periodic law, discoveries of elements from the epoch of alchemy to the synthesis of actinides and transactinides is described. The preparation of transactinides (elements with Z ≥ 104 to Z = 118) is discussed, using already proposed names of the elements with Z = 113, 115, 117 and 118: nihonium, moscovium, tennessine and oganesson. The Periodic Tables are presented in short form, the long 18-column and 32-column form. The periodic table containing elements of 8"t"h and 9"t"h periods and its possible range is discussed. By extrapolation of decay half-time of the heaviest isotopes of elements from thorium up to oganesson decay half-time of unbihexium (Z = 126) was predicted about 378 seconds. (author

Development, relevance, and applications of 'atom-at-a-time' techniques

International Nuclear Information System (INIS)

Hoffman, D.C.

2012-01-01

A brief history of the development and some of the first uses of 'atom-at-a-time' techniques to investigate the chemical and nuclear properties of the actinide and transactinide elements are presented. The currently known transactinides (all elements with Z > 103) were discovered using physical (nuclear) techniques rather than chemical separation techniques because of their short half-lives and low production rates and the difficulty in accurately predicting chemical properties of the heaviest elements because of relativistic effects. Some of the constraints on systems suitable for such studies and whether these tracer-scale results can be extended to the macro-scale are discussed. The relevance and importance of the methods and their potential for application to some current problems such as nuclear forensics and proliferation and environmental concerns are considered. The value of graduate research utilizing such techniques in helping to attract and educate the next generation of nuclear scientists is highlighted. (author)

Proceedings of the workshop on the nuclear sciences of the heaviest elements

Energy Technology Data Exchange (ETDEWEB)

Nagame, Yuichiro; Haba, Hiromitsu; Ikezoe, Hiroshi [eds.

2000-03-01

The workshop on the nuclear sciences of the heaviest elements took place on July 21-22, 1999 at the Japan Atomic Energy Research Institute (JAERI), Tokai. Approximately 40 scientists and 15 graduate students participated in the workshop which was organized by the Advanced Science Research Center, JAERI. The successful syntheses of three new super-heavy elements in 1999, Z=114 at the Joint Institute for Nuclear Research in Dubna, Russia, and Z=118 (with Z=116 following from {alpha}-decay of Z=118) at the Lawrence Berkeley National Laboratory (LBNL) in USA, are tremendous progress in the field of the heavy element research. The 1st International Conference on the Chemistry and Physics of the Transactinide Elements (TAN99) was held in Germany from September 26 to 30, 1999 to discuss in a larger context all scientific aspects of the heaviest elements. Thus, it was timely to hold the present domestic workshop to summarize what has been done in recent years, to see what has come true, and to discuss the perspectives in the near feature. The subjects in the workshop were classified into; (1) synthesis of heavy elements, (2) decay properties of heavy nuclei, (3) chemistry of the heaviest elements, and (4) future plans of the heavy element research in Japan. This volume contains the papers presented in the workshop. The 14 papers are indexed individually. (J.P.N.)

32-element beta detector developed at the Institute of Electron Technology (ITE)

Science.gov (United States)

Wegrzecki, Maciej; Yakushev, Alexander; Bar, Jan; Budzyński, Tadeusz; Grabiec, Piotr; Kłos, Helena; Panas, Andrzej; Słysz, Wojciech; Stolarski, Maciej; Szmigiel, Dariusz; Wegrzecka, Iwona; Zaborowski, Michał

2014-08-01

The paper presents the design, technology and parameters of a new .silicon detector for detection of electrons (below named as beta detector) developed at the Institute of Electron Technology (ITE). The detector will be used for research on transactinide elements at the GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (GSI). The detector consists of a monolithic 32-element array with an active area diameter of 90 mm and a thickness of 0.9 mm. The starting material is a high-resistivity ν silicon wafer (5 kΩcm resistivity). 32 planar p+-ν junctions are formed by boron diffusion on the top side of the wafer. On the bottom side, an n+ region, which forms a common cathode, is formed on the entire surface by phosphorus diffusion. The array is mounted on a special epoxy-glass laminate substrate, copper-clad on both sides. Two model detectors have been fabricated and studied. Very good electrical parameters have been achieved. For the first array, with supply voltage VR = 20 V, the minimum dark current was 8 nA, the maximum dark current 97.1 nA, and the average dark current 25.1 nA. For the second array, it was 11.5 nA, 378.8 nA and 40.0 nA respectively.

Behaviour of the homologues of Rf and Db in complexing media

International Nuclear Information System (INIS)

Trubert, D.; Monroy Guzman, F.; Hussonnois, M.; Brillard, L.; Le Naour, C.; Servajean, V.; Constantinescu, O.; Constantinescu, M.; Ardisson, G.; Barci, V.; Weiss, B.

1999-01-01

In order to study the chemical behaviour of the trans-actinide elements, the chemical properties of their most probable homologues have been investigated by ion exchange methods in various complexing media. A new chromatographic method allowing the determination of distribution coefficients in the case o short-lived isotopes has been developed and successfully tested with the RACHEL device. (authors)

A 212Pb generator for model experiments on aqueous chemistry of element 114

International Nuclear Information System (INIS)

Szeglowski, Z.; Kubica, B.; Tuteja-Krysa, M.; Godunowa, H.; Misiak, R.; Stobinski, M.

2005-01-01

Describes the device for continuous preparation of the 212 Pb, 212 Bi, 208 Tl isotopes from natural thorium is described. The generator operates in on-line mode. The simplicity of gamma activity measurements of obtained isotopes makes these tracers very convenient in both chemical researches of transactinides and nuclear medicine. (author)

Design and properties of silicon charged-particle detectors developed at the Institute of Electron Technology (ITE)

Science.gov (United States)

Wegrzecki, Maciej; Bar, Jan; Budzyński, Tadeusz; CieŻ, Michal; Grabiec, Piotr; Kozłowski, Roman; Kulawik, Jan; Panas, Andrzej; Sarnecki, Jerzy; Słysz, Wojciech; Szmigiel, Dariusz; Wegrzecka, Iwona; Wielunski, Marek; Witek, Krzysztof; Yakushev, Alexander; Zaborowski, Michał

2013-07-01

The paper discusses the design of charged-particle detectors commissioned and developed at the Institute of Electron Technology (ITE) in collaboration with foreign partners, used in international research on transactinide elements and to build personal radiation protection devices in Germany. Properties of these detectors and the results obtained using the devices are also presented. The design of the following epiplanar detector structures is discussed: ♢ 64-element chromatographic arrays for the COMPACT (Cryo On-line Multidetector for Physics And Chemistry of Transactinides) detection system used at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt (GSI) for research on Hassium, Copernicium and Flerovium, as well as elements 119 and 120, ♢ 2-element flow detectors for the COLD (Cryo On-Line Detector) system used for research on Copernicium and Flerovium at the Joint Institute for Nuclear Research, Dubna, ♢ detectors for a radon exposimeter and sensors for a neutron dosimeter developed at the Institut für Strahlenschutz, Helmholtz Zentrum München. The design of planar detectors - single-sided and double-sided strip detectors for the Focal Plane Detector Box used at GSI for research on Flerovium and elements 119 and 120 is also discussed.

Extraction systems for the study of dubnium

International Nuclear Information System (INIS)

Gates, J.M.; Sudowe, R.; Ali, M.N.; Calvert, M.G.; Dragojevic, I.; Ellison, P.A.; Garcia, M.A.; Gharibyan, N.; Gregorich, K.E.; Nelson, S.L.; Neumann, S.H.; Parsons-Moss, T.; Stavsetra, L.; Nitsche, H.

2007-01-01

The chemistry of transactinide elements (Z (ge) 104) is a topic of great interest in current nuclear chemistry research. The chemical systems that can be used in these studies are limited by the short half-lives of the isotopes and the small production rates of atoms per minute or even atoms per week. In the initial investigations, the chemistry used had to be very selective to the periodic group of interest to separate the transactinide atom from all the other unwanted nuclear reaction products, e.g., transfer products. By using the Berkeley Gas-filled Separator (BGS) as a physical pre-separator, we are able concentrate on systems that are selective between the members of the group of interest, because all other interfering products and the beam are being suppressed by the BGS [1]. We are developing suitable extraction systems for the study of element 105, dubnium. For this purpose we have studied the extraction of niobium and tantalum, the lighter homologs of dubnium, from mineral acids with different organophosphorus compounds. All studies were performed online, using short-lived niobium and tantalum produced in the 124 Sn( 51 V,5n) 170 Ta and 74 Se( 18 O,p3n) 88 Nb reactions. This allowed for the study of the lighter homologues at metal concentrations of 10 -16 M. At these low metal concentrations, the formation of polymeric species is largely prohibited. As seen in Fig. 1, by varying the extractant and the hydrochloric acid concentration from 1 to 11 M, we are able to see a difference in extraction behavior between niobium and tantalum. While the system is suitable for determining chemical differences between the lighter homologues, the extraction of tantalum from hydrochloric acid shows slow kinetics. Figure 2 shows that after 90 seconds of mixing, the system is not in equilibrium. However, experiments indicate that equilibrium is reached faster at higher acid concentrations. We have studied the influence of hydrogen ion concentration on the extraction

Measurement of the first ionization potential of lawrencium, element 103.

Science.gov (United States)

Sato, T K; Asai, M; Borschevsky, A; Stora, T; Sato, N; Kaneya, Y; Tsukada, K; Düllmann, Ch E; Eberhardt, K; Eliav, E; Ichikawa, S; Kaldor, U; Kratz, J V; Miyashita, S; Nagame, Y; Ooe, K; Osa, A; Renisch, D; Runke, J; Schädel, M; Thörle-Pospiech, P; Toyoshima, A; Trautmann, N

2015-04-09

The chemical properties of an element are primarily governed by the configuration of electrons in the valence shell. Relativistic effects influence the electronic structure of heavy elements in the sixth row of the periodic table, and these effects increase dramatically in the seventh row--including the actinides--even affecting ground-state configurations. Atomic s and p1/2 orbitals are stabilized by relativistic effects, whereas p3/2, d and f orbitals are destabilized, so that ground-state configurations of heavy elements may differ from those of lighter elements in the same group. The first ionization potential (IP1) is a measure of the energy required to remove one valence electron from a neutral atom, and is an atomic property that reflects the outermost electronic configuration. Precise and accurate experimental determination of IP1 gives information on the binding energy of valence electrons, and also, therefore, on the degree of relativistic stabilization. However, such measurements are hampered by the difficulty in obtaining the heaviest elements on scales of more than one atom at a time. Here we report that the experimentally obtained IP1 of the heaviest actinide, lawrencium (Lr, atomic number 103), is 4.96(+0.08)(-0.07) electronvolts. The IP1 of Lr was measured with (256)Lr (half-life 27 seconds) using an efficient surface ion-source and a radioisotope detection system coupled to a mass separator. The measured IP1 is in excellent agreement with the value of 4.963(15) electronvolts predicted here by state-of-the-art relativistic calculations. The present work provides a reliable benchmark for theoretical calculations and also opens the way for IP1 measurements of superheavy elements (that is, transactinides) on an atom-at-a-time scale.

17. radiochemical conference. Booklet of abstracts

International Nuclear Information System (INIS)

Bečková, Věra; Ekberg, Christian; Feldman, Vladimir I.

2014-05-01

The conference was divided into the following sessions: Plenary Session; Radionuclides in the environment, radioecology; Nuclear analytical methods; Chemistry of actinide and trans-actinide elements; Radiation chemistry; Production and application of radionuclides; Separation methods, speciation; Chemistry of nuclear fuel cycle; Radiopharmaceutical chemistry, labelled compounds; and Education / coordination. (P.A.)

Berkeley Off-line Radioisotope Generator (BORG)

International Nuclear Information System (INIS)

Sudowe, Ralf; Patin, Joshua B.

2001-01-01

Development of chemical separations for the transactinides has traditionally been performed with longer-lived tracer activities purchased commercially. With these long-lived tracers, there is always the potential problem that the tracer atoms are not always in the same chemical form as the short-lived atoms produced in on-line experiments. This problem is especially severe for elements in groups 4 and 5 of the periodic table, where hydrolysis is present. The long-lived tracers usually are stored with a complexing agent to prevent sorption or precipitation. Chemistry experiments performed with these long-lived tracers are therefore not analogous to those chemical experiments performed in on-line experiments. One way to eliminate the differences between off-line and on-line chemistry experiments is through the use of a 252 Cf fission fragment collection device. A 252 Cf fission fragment collection device has already been constructed [1]. This device is limited in its capabilities. A new fission fragment device would allow the study of the chemical properties of the homologues of the heaviest elements. This new device would be capable of producing fission fragments for fast gas chemistry and aqueous chemistry experiments, long-lived tracers for model system development and neutrons for neutron activation. Fission fragment activities produced in this way should have the same chemical form as those produced in Cyclotron irradiations. The simple operation of this source will allow more rapid and reliable development of radiochemical separations with homologues of transactinide elements

Collected radiochemical procedures (radiochemistry group CNC-11)

International Nuclear Information System (INIS)

Smith, H.L.

1975-04-01

Separation techniques are given for: Am, Sb, As, Ba, Be, Bi, C, Cd, Ca, Ce, Cs, Cl, Cr, Co, Cm, Ge, Au, In, Fe, lanthanides, Pb, Mg, Mn, Mo, Np, Ni, Nb, Pd, P, Pu, Pa, Rh, Ru, Sc, Ag, Na, Sr, sulfate, Ta, Te, Tl, Th, Sn, transactinides, tritium, W, U, Y, and Zr. Combined procedures and group separations of the heavy elements are also included

SISAK liquid-liquid extraction experiments with preseparated 257Rf

International Nuclear Information System (INIS)

Omtvedt, Jon Petter; Alstad, J.; Breivik, H.; Dyve, J.E.; Eberhardt, K.; Folden III, C.M.; Ginter, T.; Gregorich, K.E.; Hult, E.A.; Johansson, M.; Kirbach, U.W.; Lee, D.M.; Mendel, M.; Nahler, A.; Ninov, V.; Omtvedt, L.A.; Patin, J.B.; Skarnemark, G.; Stavsetra, L.; Sudowe, R.; Wiehl, N.; Wierczinski, B.; Wilk, P.A.; Zielinski, P.M.; Kratz, J.V.; Trautmann, N.; Nitsche, H.; Hoffman, D.C.

2002-01-01

The SISAK liquid-liquid extraction system was used to extract 4.0-s 257Rf. The 257Rf was produced in the reaction 208Pb(50Ti, 1n)257Rf with 237-MeV beam energy on target, separated in the Berkeley Gas-filled Separator (BGS) and transferred to a gas jet using the Recoil Transfer Chamber (RTC). The activity delivered by the gas jet was dissolved in 6-M HNO3 and Rf was extracted into 0.25-M dibutyl-phosphoric acid in toluene. This was the first time a transactinide, i.e., an element with Z >= 104, was extracted and unequivocally identified by the SISAK system. Thus, this pilot experiment demonstrates that the fast liquid-liquid extraction system SISAK, in combination with liquidscintillation detectors, can be used for investigating the chemical properties of the transactinides. The extraction result is in accordance with the behaviour shown by the Rf group IV homologues Zr and Hf

SISAK liquid-liquid extraction experiments with preseparated {sup 257}Rf

Energy Technology Data Exchange (ETDEWEB)

Omtvedt, Jon Petter; Alstad, J.; Breivik, H. [University of Oslo, Department of Chemistry, Oslo (NO)] (and others)

2002-06-01

The SISAK liquid-liquid extraction system was used to extract 4.0-s {sup 257}Rf. The {sup 257}Rf was produced in the reaction {sup 208}Pb({sup 50}Ti, 1n){sup 257}Rf with 237-MeV beam energy on target, separated in the Berkeley Gas-filled Separator (BGS) and transferred to a gas jet using the Recoil Transfer Chamber (RTC). The activity delivered by the gas jet was dissolved in 6-M HNO{sub 3} and Rf was extracted into 0.25-M dibutyl-phosphoric acid in toluene. This was the first time a transactinide, i.e., an element with Z{>=}104, was extracted and unequivocally identified by the SISAK system. Thus, this pilot experiment demonstrates that the fast liquid-liquid extraction system SISAK, in combination with liquid-scintillation detectors, can be used for investigating the chemical properties of the transactinides. The extraction result is in accordance with the behaviour shown by the Rf group IV homologues Zr and Hf. (author)

Collected radiochemical procedures (radiochemistry group CNC-11)

Energy Technology Data Exchange (ETDEWEB)

Smith, H.L. (ed.)

1975-04-01

Separation techniques are given for: Am, Sb, As, Ba, Be, Bi, C, Cd, Ca, Ce, Cs, Cl, Cr, Co, Cm, Ge, Au, In, Fe, lanthanides, Pb, Mg, Mn, Mo, Np, Ni, Nb, Pd, P, Pu, Pa, Rh, Ru, Sc, Ag, Na, Sr, sulfate, Ta, Te, Tl, Th, Sn, transactinides, tritium, W, U, Y, and Zr. Combined procedures and group separations of the heavy elements are also included. (DLC)

Proceedings of 26. annual academic conference of China Chemical Society--modern nuclear chemistry and radiochemistry

International Nuclear Information System (INIS)

2008-08-01

26. annual academic conference of China Chemical Society was held in Tianjing, 13-16 July, 2008. This proceedings is about modern nuclear chemistry and radiochemistry, the contents include: new elements and new nuclides; advanced nuclear chemistry; radiochemistry and national security; new radiopharmaceutical chemistry; modern radiological analytical chemistry and large scientific facilities; radiological environmental chemistry and nuclear radioactive waste; actinide chemistry and transactinide chemistry; radiochemistry and cross discipline, etc.

14th radiochemical conference. Booklet of abstracts

International Nuclear Information System (INIS)

2002-03-01

The contributions dealt with the following topics: Radionuclides in the environment, radioecology; Nuclear analytical methods; Chemistry of actinide and trans-actinide elements; Ionizing radiation in science, technology, and arts and cultural heritage preservation; Production and application of radionuclides; Separation methods, speciation; Chemistry of nuclear fuel cycle, radiochemical problems in nuclear waste management; and Nuclear methods in medicine, radiopharmaceuticals, and radiodiagnostics, labelled compounds. Of the verbal and poster presentation, 192 have been input to INIS. (P.A.)

Experimental Study of Elements Promoting Mixing in Fuel Elements

International Nuclear Information System (INIS)

Silin, Nicolas; Juanico, Luis; Delmastro, Dario

2003-01-01

In the present work a thermal tracing technique is used to measure the increase of the mixing between subchannels in the presence of different mixing elements.As representative elements a spacer, a spacer with mixing vanes and turbulence promoter buttons were considered.The performance of these elements was evaluated by studying the behavior of a thermal trace in each case.Also the pressure drop for each case is presented.The results present a qualitative and quantitative guide for the application of each one of these appendages in future nuclear elements

Investigation of the 168Hf electron capture decay using fast radiochemical separation

International Nuclear Information System (INIS)

Trubert, D.; Hussonnois, M.; Brillard, L.; Barci, V.; Ardisson, G.; Szeglowski, Z.; Constantinescu, O.

1995-01-01

The (EC + β + ) decay of 168 Hf, produced by the 156 Gd ( 16 O,4n) reaction, has been studied, with high efficiency HPGe coaxial detectors, using on-line measurements carried out with the RACHEL setup, built to investigate the chemical properties of transactinide elements. Off-line measurements were also carried out using catcher collection technique. Energies and intensities of 119 γ-lines are reported among which only two were known in the earlier study of Chu and Reednick. The 168 Lu level scheme built on the basis of single and γ-γ coincidence measurements, allows the interpretation of more than 79 γ-transitions, between 38 excited states reported for the first time. (orig.)

Multi Elemental Study Using Prompt Gamma Technique

International Nuclear Information System (INIS)

Normanshah Dahing; Muhamad Samudi Yasir; Normanshah Dahing; Hanafi Ithnin; Mohd Fitri Abdul Rahman; Hearie Hassan

2016-01-01

In this study, principle of prompt gamma neutron activation analysis has been used as a technique to determine the elements in the sample. The system consists of collimated isotopic neutron source, Cf-252 with HPGe detector and Multichannel Analysis (MCA). Concrete with size of 10x10x10 cm 3 and 15x15x15 cm 3 were analysed as sample. When neutrons enter and interact with elements in the concrete, the neutron capture reaction will occur and produce characteristic prompt gamma ray of the elements. The preliminary result of this study demonstrate the major element in the concrete was determined such as Si, Mg, Ca, Al, Fe and H as well as others element, such as Cl by analysis the gamma ray lines respectively. The results obtained were compared with computer simulation, NAA and XRF as a part of reference and validation. The potential and the capability of neutron induced prompt gamma as tool for multi elemental analysis qualitatively to identify the elements present in the concrete sample discussed. (author)

A study on human hair element content as monitor for trace elements pollution in Eg

International Nuclear Information System (INIS)

Tadros, N.; Metwally, E.

2004-01-01

Trace element content in human is a suitable indicator of exposure to trace element pollutants. Concentration levels of 12 trace elements in human head hair samples collected from more than 23 individuals have been determined. The collected hair samples were classified into four groups collected from workers at nuclear research center and others far away from the center. Neutron activation analysis technique was used in the preset study. The data reported for trace elements content in different hair samples were discussed. Significant differences were observed for several elements levels. comparative studies demonstrated that the concentration of some elements in hair of exposed workers, are greater than those corresponding to non exposed workers. Also, there was no clear significant correlation between the elements content of different hair samples and the age of the donors

Spectroscopic studies of the transplutonium elements

International Nuclear Information System (INIS)

Carnall, W.T.; Conway, J.G.

1983-01-01

The challenging opportunity to develop insights into both atomic structure and the effects of bonding in compounds makes the study of actinide spectroscopy a particularly fruitful and exciting area of scientific endeavor. It is also the interpretation of f-element spectra that has stimulated the development of the most sophisticated theoretical modeling attempted for any elements in the periodic table. The unique nature of the spectra and the wealth of fine detail revealed make possible sensitive tests of both physical models and the results of Hartree-Fock type ab initio calculations. This paper focuses on the unique character of heavy actinide spectroscopy. It discusses how it differs from that of the lighter member of the series and what are the special properties that are manifested. Following the introduction, the paper covers the following: (1) the role of systematic studies and the relationships of heavy-actinide spectroscopy to ongoing spectroscopic investigations of the lighter members of the series; (2) atomic (free-ion) spectra which covers the present status of spectroscopic studies with transplutonium elements, and future needs and directions in atomic spectroscopy; (3) the spectra of actinide compounds which covers the present status and future directions of spectroscopic studies with compounds of the transplutonium elements; and other spectroscopies. 1 figure, 2 tables

Trace element studies at University of Pittsburgh

International Nuclear Information System (INIS)

Cohen, B.L.; Chan, K.C.; Shabason, L.; Wedberg, G.; Rudolph, H.

1974-01-01

Seven areas of research are discussed. A method was developed for analyzing samples for their major constituent elements by irradiating with protons and detecting prompt gamma rays, mostly produced in (p,p'γ) reactions. Among other applications, the method was used to analyze air particulates for C, N, O, Al, Si, S, Co, and Fe. Trace element analysis by proton or alpha particle induced x-ray fluorescence was used on thin samples in a study of the variations of Pb, Br, Fe, and Zn in air particulates as a function of time. Among other applications this method was also used in studying trace elements in rainwater. An x-ray fluorescence method that is effective in the analysis of thick samples was developed. A method based on measuring energies of elastically scattered protons was developed for the analysis of light elements. The use of proton and neutron activation analyses, as well as methods for studying depth profiles for hydrogen and helium in materials are discussed

13th Radiochemical Conference. Booklet of Abstracts

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

The Conference included the following sessions: (i) Opening plenary presentations (6 contributions); (ii) Chemistry of natural radionuclides, discovery of radium and polonium (6 verbal presentations + 5 poster presentations); (iii) Radionuclides in the environment, radioecology (29 + 48); (iv) Activation analysis and other radioanalytical methods (36 + 49); (v) Ionizing radiation in science and technology (12 + 12); (vi) Chemistry of actinide and trans-actinide elements (11 + 14); (vii) Separation methods, speciation (18 + 41); (viii) Production and application of radionuclides (14 + 29); and (ix) Radiochemical problems in nuclear waste management (12 + 22). The majority of verbal presentations has been input to INIS, mostly in the form of the full authors` abstracts. (P.A.)

13th Radiochemical Conference. Booklet of Abstracts

International Nuclear Information System (INIS)

1998-04-01

The Conference included the following sessions: (i) Opening plenary presentations (6 contributions); (ii) Chemistry of natural radionuclides, discovery of radium and polonium (6 verbal presentations + 5 poster presentations); (iii) Radionuclides in the environment, radioecology (29 + 48); (iv) Activation analysis and other radioanalytical methods (36 + 49); (v) Ionizing radiation in science and technology (12 + 12); (vi) Chemistry of actinide and trans-actinide elements (11 + 14); (vii) Separation methods, speciation (18 + 41); (viii) Production and application of radionuclides (14 + 29); and (ix) Radiochemical problems in nuclear waste management (12 + 22). The majority of verbal presentations has been input to INIS, mostly in the form of the full authors' abstracts. (P.A.)

Speciation of trace elements in the environmental studies

International Nuclear Information System (INIS)

Reddy, A.V.R.

2012-01-01

Elements present at trace levels, often referred as trace elements, play an important role in the environment and in the functioning of life on our planet. Trace elements in environment present as free metal ions or incorporated into colloids or attached to particulate matter or exist in different physical and chemical forms. It is well established that some elements are highly toxic and some are essential, but can become toxic at higher doses. It is also now known that the forms of elements (speciation) and their amounts are more important than the chemical dose of the elements as their interaction depends on different species. For example, Cr(VI) ions are considered far more toxic than Cr(III), whereas As(III) is more toxic than As(V). Similarly, in the case of mercury, both methylmercury and inorganic mercury are toxic but they show different levels of toxicity. Thus the adverse effects depend on the nature of species of the elements and therefore speciation studies are of paramount importance in many areas like toxicology, environmental chemistry and geochemisty. In view of this, speciation studies is a challenge to analytical chemists as the measurement methodologies have to be carefully developed, validated and applied. The grand challenge is to obtain quality data ensuring traceability, as the data obtained will be used in modeling for predicting the environmental impacts. In this talk importance of speciation and challenges to environmental analytical chemists will be discussed along with the following three speciation studies on Cr, U and Hg which were carried out in our laboratories

Model studying the processes arising during fuel element overheating

International Nuclear Information System (INIS)

Usynin, G.B.; Anoshkin, Yu.I.; Vlasichev, G.N.; Galitskikh, Yu.N.; Semenychev, M.A.

1986-01-01

A calculational technique for studying heating and melting of fuel elements in the BN type reactors during an accident with heat release failure and a simulator with central rod heater intended for out-of-pile experiments is developed. The time rangeof the characteristic melting steps for the most thermally stressed fuel element at the reactor nominal power is calculated. The experimental study of the fuel element melting using a simulator with a tungsten heater has proved that the technique for the simultor and fuel can melting, respectively, is correct. The developed technique is used for determining the geometrical values and operational conditions for experiments with simulators, when quantitative and qualitative characteristics of the process under study are rather close to those natural for fuel elements

Studies on tender wheatgrass: estimation of elemental content, bioaccessibility of essential elements and antioxidant activity

International Nuclear Information System (INIS)

Reddy, A.V.R.; Acharya, R.; Nair, A.G.C.; Kulkarni, S.D.; Rajurkar, N.S.

2008-08-01

Tender wheatgrass is being consumed by human beings in juice form or as it is due to its antioxidant potential and medicinal value. Systematic studies were carried out to (i) estimate elemental profiles as a function of growth period and conditions, bioaccessibility of different elements and the antioxidant potential of the tender wheatgrass, (ii) determine the optimum growth period for obtaining maximum benefit and (iii) examine the possible correlation between antioxidant potential and mineral content. Wheatgrass was grown in four different conditions namely (i) tap water, (ii) tap water with nutrients, (iii) soil and tap water and (iv) soil with nutrient solution. The studies were carried out on the wheatgrass of 5-20 days old. For comparison with laboratory grown wheatgrass, a set of commercially available wheatgrass tablets and wheat seeds were also studied. Instrumental neutron activation analysis (INAA) was used for concentration determination of elements in the wheatgrass, wheat seeds and wheatgrass tablets. A total of 15 elements like Na, K, Ca, Mg, Mn, Br, Fe and Zn were determined in the samples of shoots and roots of tender wheatgrass. A comparison with the recommended dietary allowance (RDA) of different essential elements with that in tender wheatgrass revealed that wheatgrass is a good source of minerals for health benefits rather than a food supplement. Bioaccessible fractions of various elements were estimated by a chemical NAA method by subjecting the samples to in vitro gastric and gastro-intestinal digestion followed by NAA. The bioaccessibility concentrations by both the measurements were in the range of 9-60%. It was found that bioaccessibility of the elements studied was the highest from fresh wheatgrass and the lowest from wheat seeds. Accuracy of the NAA method was evaluated by analyzing two biological reference materials, SRM 1573a (Tomato leaves) from NIST, USA and ICHTJ CTA-vtl-2 (Tobacco leaves) from INCT, Poland. The antioxidant

Spontaneous-fission half-lives for even nuclei with Z> or =92

International Nuclear Information System (INIS)

Randrup, J.; Larsson, S.E.; Moller, P.; Nilsson, S.G.; Pomorski, K.; Sobiczewski, A.

1976-01-01

The spontaneous-fission process for doubly even nuclei with Z> or =92 is studied in a semiempirical WKB framework. One-dimensional fission barrier potentials are established from theoretical deformation-energy surfaces based on the droplet model and the modified-oscillator model. The effects of axial asymmetry as well as reflection asymmetry have been taken into account. Macroscopic (irrotational flow) inertial-mass functions and, alternatively, microscopic (cranking model) inertial mass parameters have been employed for the calculation of the fission half-lives. With one over-all normalization parameter it is possible to fit the experimental half-lives to within a factor of 20 on the average. The resulting effective inertial-mass functions are used to estimate the stability of the transactinide elements. Only minor differences with previous estimates for the r process and superheavy nuclei are encountered

Elemental bioaccumulators in air pollution studies

International Nuclear Information System (INIS)

Freitas, M.C.

1995-01-01

K 0 -Based instrumental neutron activation analysis (k 0 INAA) was used to determine the concentrations of Cr, Fe, Co, Zn, Se, Sb and Hg in the vascular plants Cistus salvifolius and Inula viscosa and in the lichen Parmelia sulcata. The samples were collected in the neighbourhood of industrial complexes. The elemental accumulation in the vascular plants and the lichen are compared to optimize the choice of the bioaccumulator. It is concluded that P.sulcata seems to be the best accumulator of the three species for the element studied; Cistus salvifolius is sensitive to the contents of Zn, Fe, Cr and Sb in the air; Inula viscosa seems to accumulate Fe, Sb, Co, Cr and Zn. Nevertheless, it is concluded that lichen is a good air pollution indicator, while the vascular plants are not due to the large seasonal variations found in the elemental concentrations. (author) 11 refs.; 7 figs.; 2 tabs

15th radiochemical conference: Booklet of abstracts and conference programme

International Nuclear Information System (INIS)

John, J.; Benes, P.; Kucera, J.; Havela, L.; Bartonicek, B.; Vobecky, M.; Krizova, V.; Kopicka, K.; Prasil, Z.

2006-04-01

The conference was structured as follows: Opening plenary lectures (6 lectures); Topic 1 - radionuclides in the environment, radioecology (22 verbal presentations (VPs), 23 poster presentations (PPs)); Topic 2 - nuclear analytical methods (22 VPs, 32 PPs); Topic 3 - chemistry of actinide and transactinide elements (8 VPs, 10 PPs); Topic 4 - radiation chemistry (9 VPs, 5 PPs); Topic 5 - production and application of radionuclides (17 VPs, 6 PPs); Topic 6 - separation methods, speciation (21 VPs, 23 PPs); Topic 7 - chemistry of nuclear fuel cycle, radiochemical problems in nuclear waste management (20 VPs, 16 PPs); Topic 8 - nuclear methods in medicine, radiopharmaceuticals, and radiodiagnostics, labelled compounds (8 VPs, 7 PPs); and Panels (2 introductions). (P.A.)

Relativistic quantum chemistry of the superheavy elements. Closed-shell element 114 as a case study

International Nuclear Information System (INIS)

Schwerdtfeger, Peter; Seth, Michael

2002-01-01

The chemistry of superheavy element 114 is reviewed. The ground state of element 114 is closed shell [112]7s 2 7p 1/2 2 and shows a distinct chemical inertness (low reactivity). This inertness makes it rather difficult to study the atom-at-a-time chemistry of 114 in the gas or liquid phase. (author)

A Study on the Effect of Cohesive Laws on Finite Element Analysis of Crack Propagation Using Cohesive Elements

Energy Technology Data Exchange (ETDEWEB)

Seo, Hyeongseok; Baek, Hyungchan; Kim, Hyungyu [Seoul Nat' l Univ. of Sci. and Tech., Seoul (Korea, Republic of)

2014-04-15

In this paper, the effect of cohesive laws on the finite element analysis of crack propagation using cohesive elements is investigated through three-point bending and double cantilever beam problems. The cohesive elements are implemented into ABAQUS/Standard user subroutines(UEL), and the shape of cohesive law is varied by changing parameters in polynomial functions of cohesive traction-separation relations. In particular, crack propagation behaviors are studied by comparing load-displacement curves of the analysis models which have different shapes of cohesive laws with the same values of fracture energy and cohesive strength. Furthermore, the influence of the element size on crack propagation is discussed in this study.

Studies of Flerovium and Element 115 Homologs with Macrocyclic Extractants

Energy Technology Data Exchange (ETDEWEB)

Despotopulos, John D. [Univ. of Nevada, Las Vegas, NV (United States)

2015-03-12

Study of the chemistry of the heaviest elements, Z ≥ 104, poses a unique challenge due to their low production cross-sections and short half-lives. Chemistry also must be studied on the one-atom-at-a-time scale, requiring automated, fast, and very efficient chemical schemes. Recent studies of the chemical behavior of copernicium (Cn, element 112) and flerovium (Fl, element 114) together with the discovery of isotopes of these elements with half-lives suitable for chemical studies have spurred a renewed interest in the development of rapid systems designed to study the chemical properties of elements with Z ≥ 114. This dissertation explores both extraction chromatography and solvent extraction as methods for development of a rapid chemical separation scheme for the homologs of flerovium (Pb, Sn, Hg) and element 115 (Bi, Sb), with the goal of developing a chemical scheme that, in the future, can be applied to on-line chemistry of both Fl and element 115. Carrier-free radionuclides, used in these studies, of the homologs of Fl and element 115 were obtained by proton activation of high-purity metal foils at the Lawrence Livermore National Laboratory (LLNL) Center for Accelerator Mass Spectrometry (CAMS): ^natIn(p,n)¹¹³Sn, ^natSn(p,n)¹²⁴Sb, and Au(p,n)^197m,gHg. The carrier-free activity was separated from the foils by novel separation schemes based on ion exchange and extraction chromatography techniques. Carrier-free Pb and Bi isotopes were obtained from development of a novel generator based on cation exchange chromatography using the ²³²U parent to generate ²¹²Pb and ²¹²Bi. Macrocyclic extractants, specifically crown ethers and their derivatives, were chosen for these studies; crown ethers show high selectivity for metal ions. Finally. a potential chemical system for Fl was established based on the Eichrom Pb resin, and insight to an improved system based on thiacrown ethers is

Study of Superheavy Elements

International Nuclear Information System (INIS)

Hofmann, Sigurd

2007-01-01

The nuclear shell model predicts that the next doubly magic shell-closure beyond 208 Pb is at a proton number Z = 114, 120, or 126 and at a neutron number N = 172 or 184. The outstanding aim of experimental investigations is the exploration of this region of spherical 'SuperHeavy Elements' (SHEs). Experimental methods are described, which allowed for the identification of elements produced on a cross-section level of about 1 pb. The decay data reveal that for the heaviest elements, the dominant decay mode is alpha emission, not fission. Decay properties as well as reaction cross-sections are compared with results of theoretical investigations. Finally, plans are presented for the further development of the experimental set-up and the application of new techniques, as for instance the precise mass measurement of the produced nuclei using ion traps. At increased sensitivity, the detailed exploration of the region of spherical SHEs will start, after first steps on the island were made in recent years. (Author)

Study of trace elements distribution in various tissues structures

International Nuclear Information System (INIS)

Kwiatek, W.M.; Marczewska, E.

1994-01-01

Many papers have been written during the past ten years about TE study in cancer and normal tissues describing the use of different methods for detection of trace elements. Concentration of TE depends strongly on the sample measured. However, according to our knowledge, the role of TE in cancerous tissue is still known. Therefore, we propose to perform an experiment which will hopefully given us more information about the relationship between the concentration of elements in different tissues. The developing industry localised near Cracow becomes a serious danger for health of it's inhabitants. The negative influence of the air pollution to the living organisms is seen not only in the nature but also in humans. Therefore we want to analyse the trace element contents in the air. Such investigation will give the information about the pollution level in the City. The pollution has its obvious negative influence to health and toxic element concentration level in blood. It is interesting to check if placenta plays an effective role in foetus protection against toxic metals. In order to study this problem, the trace element analysis of placenta tissues will be done by means of synchrotron microbeam. (author). 1 ref

STUDIES OF CHOSEN TOXIC ELEMENTS CONCENTRATION IN MULTIFLOWER BEE HONEY

Directory of Open Access Journals (Sweden)

Ewa Popiela

2011-04-01

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

Elemental concentration distribution in human fingernails – A 3D study

International Nuclear Information System (INIS)

Pineda-Vargas, C.A.; Mars, J.A.; Gihwala, D.

2012-01-01

The verification of pathologies has normally been based on analysis of blood (serum and plasma), and physiological tissue. Recently, nails and in particular human fingernails have become an important medium for pathological studies, especially those of environmental origin. The analytical technique of PIXE has been used extensively in the analysis of industrial samples and human tissue specimens. The application of the analytical technique to nails has been mainly to bulk samples. In this study we use micro-PIXE and -RBS, as both complementary and supplementary, to determine the elemental concentration distribution of human fingernails of individuals. We report on the 3D quantitative elemental concentration distributions (QECDs) of various elements that include C, N and O as major elements (10–20%), P, S, Cl, K and Ca as minor elements (1–10%) and Fe, Mn, Zn, Ti, Na, Mg, Cu, Ni, Cr, Rb, Br, Sr and Se as trace elements (less than 1%). For PIXE and RBS the specimens were bombarded with a 3 MeV proton beam. To ascertain any correlations in the quantitative elemental concentration distributions, a linear traverse analysis was performed across the width of the nail. Elemental distribution correlations were also obtained.

Energy-dispersive X-ray fluorescence study of elemental uptake in ...

Indian Academy of Sciences (India)

The present study suggests that the elemental concentrations in the root soils and leaves of the samples vary from farm to farm, whereby the concentrations of Cu, ... But, the most notable feature of this study is the strikingly similar elemental concentrations in the edible flower part of all samples irrespective of the type of soil.

Study on the fragility of structure with several elements in its story. Part 2: structure with ductile elements

International Nuclear Information System (INIS)

Kai, Y.; Fukushima, S.

1995-01-01

The relationship among the fragility of element, that of story and that of system, is examined using the Monte Carlo simulation. In this study, 2-story models whose stories consist of 2 ductile elements are employed. A method is proposed which includes a nonlinear effect into the evaluation of elements capacities. This method does not require the nonlinear MCS, therefore saving computational efforts. Also, a method to estimate the stories and the system fragilities is proposed. (author). 2 refs., 7 figs., 3 tabs

Study on boiling heat transfer from diode elements in an integrated circuit chip

Energy Technology Data Exchange (ETDEWEB)

Hijikata, Kunio; Nagasaki, Takao; Kurata, Naoki (Tokyo Institute of Technology Faculty of Engineering (Japan))

1989-02-25

By temperature measurement of elements in boiling experiments with diodes in an integrated circuit (IC) chip, characteristics of boiling heat transfer from tiny heat generating elements in an IC chip and thermal transfer characteristics of multiple heating elements adjoining positioned were studied. The Package of an IC was removed by acid to expose the IC chip. Electricity is applied to the diode in the IC to study the heat transfer properties. The heat transfer rate from a tiny heating element on an IC is greater than that from the conventional continual heated surface. In the case of heat generation by two adjoining elements, the relationship between the total amount of heat and the temperature of elements shows the same characteristics as in the case with a single element. The boiling heat transfer properties of an element in an IC chip are influenced by such microstructure surrounding the element as the pattern of wiring. Heat transfer increases with the decreasing size of the heating element by the heat transfer to the substrate beneath the element. 10 refs., 15 figs.

Preparation and study of elemental californium-249

International Nuclear Information System (INIS)

Noe, M.; Peterson, J.R.

1975-01-01

Bulk samples of 249 Cf metal were prepared on the 10 μg scale via the Li metal vapor reduction of 249 CfF 3 . Above about 725 0 C elemental Cf exhibits a face-centered cubic (fcc) structure with an average, room-temperature lattice parameter of 5.75(1)A. Between about 600 0 C and 725 0 C, the stable form of Cf metal is another fcc structure with an average, room-temperature lattice parameter of 4.94(1)A. Below 600 0 C metallic Cf exhibits a double hexagonal closest packed (dhcp) structure with average, room temperature lattice parameters of a 0 = 3.39(1)A and c 0 = 11.01(5)A. By comparison of the metallic radii calculated for these three forms with those of the receding transuranium elements, it is suggested that the two, lower temperature modifications represent Cf with a metallic valence of three, while the highest temperature form represents a metallic valence of two. Although the data reported here are from the most complete study to date of elemental Cf, the limitations accompanying such microscale research are duly noted. (U.S.)

A study on some trace elements in Chilean seafood

Energy Technology Data Exchange (ETDEWEB)

Gras, N; Munoz, L; Thieck, M; Hurtado, S [Comision Chilena de Energia Nuclear, Santiago (Chile). Lab. of Activation Analysis

1993-03-01

Levels of essential and toxic trace elements in six marine species greatly in demand in the international market (canned pink clams, razor clams, clams, king crab, sardines, and frozen albacore tuna fish) were studied. A special laboratory adequately equipped for handling and preparing biological materials, is described. The elements As, Br, Na, Se, Hg, Cr, Fe, Zn and Rb were determined by INAA, while copper and cadmium content were determined using RNAA. Significant differences were found on comparing the contents of some toxic elements in mollusk and other samples of marine food. Various certified reference materials (CRMs) of the IAEA, NIST and NIES were analyzed for quality assurance purposes. (author) 11 refs.; 1 fig.; 1 tab.

A study on some trace elements in Chilean seafood

International Nuclear Information System (INIS)

Gras, N.; Munoz, L.; Thieck, M.; Hurtado, S.

1993-01-01

Levels of essential and toxic trace elements in six marine species greatly in demand in the international market (canned pink clams, razor clams, clams, king crab, sardines, and frozen albacore tuna fish) were studied. A special laboratory adequately equipped for handling and preparing biological materials, is described. The elements As, Br, Na, Se, Hg, Cr, Fe, Zn and Rb were determined by INAA, while copper and cadmium content were determined using RNAA. Significant differences were found on comparing the contents of some toxic elements in mollusk and other samples of marine food. Various certified reference materials (CRMs) of the IAEA, NIST and NIES were analyzed for quality assurance purposes. (author) 11 refs.; 1 fig.; 1 tab

Studies on absorption coefficient near edge of multi elements

International Nuclear Information System (INIS)

Eisa, M.H.; Shen, H.; Yao, H.Y.; Mi, Y.; Zhou, Z.Y.; Hu, T.D.; Xie, Y.N.

2005-01-01

X-ray absorption near edge structure (XANES) was used to study the near edge mass-absorption coefficients of seven elements, such as, Ti, V, Fe, Co, Ni, Cu and Zn. It is well known that, on the near edge absorption of element, when incident X-ray a few eV change can make the absorption coefficient an order magnitude alteration. So that, there are only a few points mass-absorption coefficient at the near edge absorption and that always average value in published table. Our results showed a wide range of data, the total measured data of mass-absorption coefficient of the seven elements was about 505. The investigation confirmed that XANES is useful technique for multi-element absorption coefficient measurement. Details of experimental methods and results are given and discussed. The experimental work has been performed at Beijing Synchrotron Radiation Facility. The measured values were compared with the published data. Good agreement between experimental results and published data is obtained

Studies on absorption coefficient near edge of multi elements

Science.gov (United States)

Eisa, M. H.; Shen, H.; Yao, H. Y.; Mi, Y.; Zhou, Z. Y.; Hu, T. D.; Xie, Y. N.

2005-12-01

X-ray absorption near edge structure (XANES) was used to study the near edge mass-absorption coefficients of seven elements, such as, Ti, V, Fe, Co, Ni, Cu and Zn. It is well known that, on the near edge absorption of element, when incident X-ray a few eV change can make the absorption coefficient an order magnitude alteration. So that, there are only a few points mass-absorption coefficient at the near edge absorption and that always average value in published table. Our results showed a wide range of data, the total measured data of mass-absorption coefficient of the seven elements was about 505. The investigation confirmed that XANES is useful technique for multi-element absorption coefficient measurement. Details of experimental methods and results are given and discussed. The experimental work has been performed at Beijing Synchrotron Radiation Facility. The measured values were compared with the published data. Good agreement between experimental results and published data is obtained.

Collective Quadrupole Excitations of Transactinide Nuclei

CERN Document Server

Zajac, K; Pomorski, K; Rohozinski, S G; Srebrny, J

2003-01-01

The quadrupole excitations of transuranic nuclei are described in the frame of the microscopic Bohr Hamiltonian modified by adding the coupling with the collective pairing vibrations. The energies of the states from the ground-state bands in U to No even-even isotopes as well as the B(E2) transition probabilities are reproduced within the model containing no adjustable parameters.

Preparation and intercalation study of ternary transition elements chalcogenides AxMXn

International Nuclear Information System (INIS)

Kassem, M.

1999-01-01

The crystalline powders of transition elements chalcogenides have been prepared by solid-solid reaction method starting from elemental powders in evacuated and sealed quartz tubes heated at various temperatures depending on the compound to be prepared. The structures and composition of the obtained compounds have been studied by X-ray diffraction and X-ray fluorescence techniques. Intercalation compounds Co x MX 2 have been obtained by heating the powder with elemental cobalt at 500 Centigrade. The results of the structural studies show that the intercalation of cobalt is a regular phenomena and the cobalt atoms play the role of staples for the layers constructing the crystalline structure of starting materials. This stapling phenomena is accompanied by changes in distance between the layers and therefore changes in the length of bonds between the elements of compound. The changes in the length of bonds have been confirmed by the results of FTIR studies.(author)

Study of mobilization and speciation of trace elements in coal pyrolysis

International Nuclear Information System (INIS)

Ting, B.T.G.

1979-01-01

Various types of coal contain high levels of a number of trace elements. Little is known of the fates of these trace elements during the conversion of coal to liquid and gaseous products. Studies were undertaken of mobilization and speciation of trace elements in coal pyrolysis, one of the major coal conversion processes. The bituminous coal was pyrolyzed to produce liquid and gaseous products. The pyrolysis products were collected in traps in an inert gas stream. In addition mildly hydrogenated coal was prepared by mixing with tetralin, a hydrogen donor solvent, at boiling temperature. In order to characterize each element specifically during pyrolysis, base samples of coal and mildly hydrogenated coal (H-coal) were spiked with heavy metal sulfides, trace metals bound to partially oxidized coal (coal humates), and halide salts prior to carrying out pyrolysis. Eight elements were investigated in this research. They are As, Br, Cl, Co, Cr, Mn, Se, and V. Pre-spiked hydrogenated coal, i.e., pulverized coal spiked with halide salts and heavy metal sulfides then hydrogenated with tetralin, was prepared and studied for the fates of these elements during pyrolysis. Chlorinated and brominated coals were also prepared to compare the volatility differences between organically and inorganically bound halogens during the pyrolysis reaction. These products and the coal char residues were analyzed for the spiked elements mainly by neutron activation analysis for the spiked elements to determine their degree of volatility. Volatility and recovery (mass balance) will be discussed for those elements that appeared highly volatile during pyrolysis. In order to understand the halogenated compounds in the pyrolysis products, gas chromatograms were taken to the collected pyrolysis products of coal, hydrogenated coal, NaCl spiked coal, NaBr spiked coal, chlorinated coal, and brominated coal

The interplay of contextual elements in implementation: an ethnographic case study.

Science.gov (United States)

McCullough, Megan B; Chou, Ann F; Solomon, Jeffrey L; Petrakis, Beth Ann; Kim, Bo; Park, Angela M; Benedict, Ashley J; Hamilton, Alison B; Rose, Adam J

2015-02-14

Contextual elements have significant impact on uptake of health care innovations. While existing conceptual frameworks in implementation science suggest contextual elements interact with each other, little research has described how this might look in practice. To bridge this gap, this study identifies the interconnected patterns among contextual elements that influence uptake of an anticoagulation clinic improvement initiative. We completed 51 semi-structured interviews and ethnographic observations across five case study sites involved in an evidence-based practice (EBP) quality improvement initiative. We analyzed data in NVivo 10 using an a priori approach based on the Promoting Action on Research Implementation in Health Services (PARIHS) model and an emergent thematic analysis. Key contextual elements, such as leadership, teamwork, and communication, interacted with each other in contributing to site-level uptake of the EBP, often yielding results that could not be predicted by looking at just one of these elements alone. Sites with context conducive to change in these areas predictably had high uptake, while sites with uniformly weak contextual elements had low uptake. Most sites presented a mixed picture, with contextual elements being strongly supportive of change in some areas and weak or moderate in others. In some cases, we found that sites with strong context in at least one area only needed to have adequate context in other areas to yield high uptake. At other sites, weak context in just one area had the potential to contribute to low uptake, despite countervailing strengths. Even a site with positive views of EBPs could not succeed when context was weak. Interrelationships among different contextual elements can act as barriers to uptake at some sites and as facilitators at others. Accounting for interconnections among elements enables PARIHS to more fully describe the determinants of successful implementation as they operate in real-world settings.

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

International Nuclear Information System (INIS)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker

2015-01-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s -1 (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Principal elements of the Basalt Waste Isolation Project performance assessment studies

International Nuclear Information System (INIS)

Baca, R.G.; Wilde, R.T.

1983-12-01

In this paper, three of the principal elements of the Basalt Waste Isolation Project (BWIP) performance assessment studies are focused on: (1) development of a methodology for probabilistic risk assessment, (2) performance analyses of repository subsystems, and (3) selection and ranking of disruptive event scenarios. Other elements of the BWIP performance assessment studies are briefly outlined. 12 references, 5 figures

Progress Report 1994-1995

International Nuclear Information System (INIS)

1996-01-01

This third volume of 1994 to 1995 activity report, of Nuclear Physics Institute (Orsay, France) gives a general overview of the research programs conducted in the fields of nuclear structure (exotic nuclei, discrete high spin states). Other topics have been studied in high excitation energy states and giant resonances, and in nucleus-nucleus collision and hot nuclei. Other topics deal with radiochemistry, in particular for optical spectroscopy and physico-chemical studies on actinides and trans-actinides. (D.L.)

Multitracer study on uptake of elements by plants

Energy Technology Data Exchange (ETDEWEB)

Ambe, Shizuko [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

1996-12-31

A disk target of Au or Ag was irradiated with a 135-MeV/nucleon {sup 12}C, {sup 14}N, or {sup 16}O beam. Multitracer solutions were prepared radiochemically from the targets in carrier- and salt-free states. Rice and soybean plants were cultured in a nutrient solution or on soil containing a multitracer. In the experiment of absorption of elements through leaves, either soybean plants were grown in the atmosphere where multitracer-adsorbed cellulose particles were floating in the air or two drops of a multitracer solution was applied onto leaves of Japanese radish. After cultivation, the plants were harvested and they were dried at 65degC for one day and subjected to {gamma}-ray measurement with HPGe detectors. In the case of hydroponically cultured plants, large amounts of almost all of the metal ions in the nutrient solution were absorbed by the roots. In contrast, plants grown on the soil gave extremely low percentage distributions for all the elements examined. This difference is explained by the low distribution of metal ions in soil water and the dilution of radioisotopes with the corresponding elements in soil. When the multitracer is added to soil, adsorption of each radioisotope takes place, resulting in the small partition in soil water. Relatively large amounts of Se, Rb, and Co were accumulated in the seeds of soybean plants which were grown in the presence of floating multitracer-adsorbed cellulose particles in the air. Since the seeds were not directly exposed, the elements detected in the seeds are considered to be transported to the seeds after absorption through leaves. When the multitracer solution were applied onto the leaves, Zn, Rb, Sr, and Mn were absorbed and transported quickly compared with other elements from the application site to other parts of the plant. These results obtained demonstrate that the multitracer technique is powerful in studies on absorption and transport of trace elements in plants. (J.P.N.)

Multitracer study on uptake of elements by plants

International Nuclear Information System (INIS)

Ambe, Shizuko

1996-01-01

A disk target of Au or Ag was irradiated with a 135-MeV/nucleon 12 C, 14 N, or 16 O beam accelerated by the RIKEN Ring Cyclotron. Multitracer solutions were prepared radiochemically from the targets in carrier- and salt-free states. Rice and soybean plants were cultured in a nutrient solution or on soil containing a multitracer. In the experiment of absorption of elements through leaves, either soybean plants were grown in the atmosphere where multitracer-adsorbed cellulose particles were floating in the air or two drops of a multitracer solution was applied onto leaves of Japanese radish. After cultivation, the plants were harvested and they were dried at 65degC for one day and subjected to γ-ray measurement with HPGe detectors. In the case of hydroponically cultured plants, large amounts of almost all of the metal ions in the nutrient solution were absorbed by the roots. In contrast, plants grown on the soil gave extremely low percentage distributions for all the elements examined. This difference is explained by the low distribution of metal ions in soil water and the dilution of radioisotopes with the corresponding elements in soil. When the multitracer is added to soil, adsorption of each radioisotope takes place, resulting in the small partition in soil water. Relatively large amounts of Se, Rb, and Co were accumulated in the seeds of soybean plants which were grown in the presence of floating multitracer-adsorbed cellulose particles in the air. Since the seeds were not directly exposed, the elements detected in the seeds are considered to be transported to the seeds after absorption through leaves. When the multitracer solution were applied onto the leaves, Zn, Rb, Sr, and Mn were absorbed and transported quickly compared with other elements from the application site to other parts of the plant. These results obtained demonstrate that the multitracer technique is powerful in studies on absorption and transport of trace elements in plants. (J.P.N.)

A study of trace elements in the atmosphere of PINSTECH, Nilore

International Nuclear Information System (INIS)

Rusheed, A.; Ahmed, S.; Mannan, A.; Qureshi, I. H.

1987-06-01

Atmospheric aerosol particulates of inorganic elements are usually transported to long distances from their source of emmision. The measurement of these elements in air provides useful information for understanding aerosol effects. Therefore studies were undertaken to determine the atmospheric concentration of some inorganic elements, 23 air filter samples of 24 hour duration were collected at Nilore, Islamabad area and analysed for 16 elements by neutron activation analysis (NAA). The concentration of 9 elements were determined in more than 12 samples. Comparison of the average concentration of these elements with those observed at other sites in U.S.A and U.K., indicate a distribution pattern similar to a non-urban site with very little pollution from industerial sources. Binary collection coefficients were calculated using the data of 9 principal elements of identify particulate sources. Co, Cr, Cs, Eu, Fe, Sc and Rb were assigned a crustal source, whereas Sb could possible has an anthropogenic source. Zn was found to have a constant nearby source the exact nature of which could be ascertained after a complete analysis of local soil and other possible sources near the site. (orign./A.B.)

Geochemical study of main elements and trace elements in soils of three profiles in the state of Santa Catarina

International Nuclear Information System (INIS)

Santelli, R.E.

1985-01-01

The total concentrations of the main components (Si, Al, Fe, Ca, Mg, Mn, Ti, Na and K) and of nine trace elements (Ba, Co, Cu, La, Li, Mo, Ni, V and Zn are measured. The elements are determined by several atomic absorption and emission spectroscopic methods. Some properties such as granulometry, mineralogy of the clay fraction, organic matter, etc, are studied. (M.J.C.) [pt

Mixed Element Formulation for the Finite Element-Boundary Integral Method

National Research Council Canada - National Science Library

Meese, J; Kempel, L. C; Schneider, S. W

2006-01-01

A mixed element approach using right hexahedral elements and right prism elements for the finite element-boundary integral method is presented and discussed for the study of planar cavity-backed antennas...

Progress Report 1994-1995; Rapport d`Activite 1994-1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This third volume of 1994 to 1995 activity report, of Nuclear Physics Institute (Orsay, France) gives a general overview of the research programs conducted in the fields of nuclear structure (exotic nuclei, discrete high spin states). Other topics have been studied in high excitation energy states and giant resonances, and in nucleus-nucleus collision and hot nuclei. Other topics deal with radiochemistry, in particular for optical spectroscopy and physico-chemical studies on actinides and trans-actinides. (D.L.). 340 refs.

Progress Report 1994-1995; Rapport d`Activite 1994-1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

This third volume of 1994 to 1995 activity report, of Nuclear Physics Institute (Orsay, France) gives a general overview of the research programs conducted in the fields of nuclear structure (exotic nuclei, discrete high spin states). Other topics have been studied in high excitation energy states and giant resonances, and in nucleus-nucleus collision and hot nuclei. Other topics deal with radiochemistry, in particular for optical spectroscopy and physico-chemical studies on actinides and trans-actinides. (D.L.). 340 refs.

Synthesis Study of a 6-Element Non-Uniform Array with Tilted Elements for CLARREO Project

Science.gov (United States)

Jamnejad, Vahraz; Hoorfar, Ahmad

2012-01-01

This paper presents the results of a preliminary study of the gain/pattern properties of a 6-element Radio Occultation (RO) array for the proposed CLARREO (Climate Absolute Radiance and Refractivity Observatory (CLARREO) Project. CLARREO is one of the 4 highest priority missions recommended in the National Research Council Earth Science Decadal Survey.

Study of fuel element characteristic of SM and SMP (SM-PRIMA) fuel assemblies

International Nuclear Information System (INIS)

Klinov, A.V.; Kuprienko, V.A.; Lebedev, V.A.; Makhin, V.M.; Tuchnin, L.M.; Tsykanov, V.A.

1999-01-01

The paper discusses the techniques and results of reactor tests and post-reactor investigations of the SM reactor fuel elements and fuel elements developed in the process of designing the specialized PRIMA test reactor with the SM reactor fuel elements used as a prototype and which are referred to as the SMP fuel elements. The behavior of fuel elements under normal operating conditions and under deviation from normal operating conditions was studied to verify the calculation techniques, to check the calculation results during preparation of the SM reactor safety substantiation report and to estimate the possibility of using such fuel elements in other projects. During tests of fuel rods under deviation from normal operating conditions their advantages were shown over fuel elements, the components of which were produced using the Al-based alloys. (author)

An introductory study of the convergence of the direct boundary element method

DEFF Research Database (Denmark)

Juhl, Peter Møller

1997-01-01

of an axisymmetric boundary element formulation is studied using linear, quadratic or superparametric elements. It is demonstrated that the rate of convergence of these formulations is reduced for calculations involving bodies with edges (geometric singularities). Two methods for improving the rate of convergence...

Biomonitoring of trace metal elements by lichens of the Western Pyrenees.Study of elemental and isotopic signature of mercury

OpenAIRE

Queipo Abad, Silvia

2012-01-01

The lichens, organisms originated by symbiotic relationship between an algae and a fungus, have shown good properties as biomonitors of pollution from Trace Metal Elements. They can be used as indicators of local and long-range atmospheric pollution. The assessment of deposition of atmospheric pollutants results difficult to know their long term impact. This happens specially when the study is focalized in remote areas. In this project it has been developed the elemental and isotopic analy...

Studies of trace element imbalances in Alzheimer's disease using sequential NAA

International Nuclear Information System (INIS)

Ehmann, W.D.; Markesbery, W.R.; Thompson, C.M.; Vance, D.E.; Mao, Y.

1986-01-01

Evidence has accumulated in the literature that trace elements may be implicated in the etiology of Alzheimer's disease (AD) and other age-related neurological diseases. Even if elemental imbalances do not prove to be causative factors, observed perturbations may be markers that could aid in diagnosis, or help elucidate pathological processes. In this paper the authors present new data for trace element levels in three areas of the human brain most severely affected by AD (hippocampus, amygdala, and nucleus basalis) and in AD hair and nail samples. In some cases the specific imbalances seen previously in the bulk brain analyses are amplified in these regions. Elevated bromine levels seen in AD brain are also observed in AD hair and nail. Significant alkali metal and mercury imbalances with respect to controls occur in AD nail samples. The role of these trace element alterations in the etiology of AD has still not been determined. However, some possible physiological effects include: membrane dysfunction (alkali metals), enzyme inhibition (mercury and bromine), and interference with neurotransmitter functions (mercury, bromine, and alkali metals). The simultaneous multielement capability of this sequential NAA procedure also permits interelement correlation studies. Elemental associations may help identify potential environmental factors that could contribute to the observed trace element imbalances

The study of the elemental composition of peppermint (Mentha piperita

Directory of Open Access Journals (Sweden)

K. V. Andrianov

2014-12-01

Full Text Available Introduction Our attention was drawn by quite widespread plant, namely peppermint (Mentha piperita of mint family (Lamiaceae L.. It isn’t known as a wild-growing plant, this plant is the hybrid received from crossing water mint (Mentha aquatica with a spicate mint (Mentha spicata or green mint (Mentha viridis. Therapeutic action of plant is caused by the BAS complex, among which essential oil, alkaloids, saponins, organic acids, vitamins, macro - and microelements are. Accumulation of elements in a plant directly depends on sort and species of this plant, climatic conditions and geographical places of growth. Thus, using pharmacognosic research of peppermint, it would be expedient to carry out the comparative analysis of the elements content in leaf of widespread species of this plant, and also to compare to element structure of peppermint from other region of preparation. Studying qualitative structure and quantitative content of macro - and microelements in leaf of 3 samples of peppermint became the purpose of our research. Materials and methods of research The peppermint leaves of 3 samples were the object of our research. They are ‘Chornolistaya’ sort – the sample #1, ‘Zgadka’ sort – the sample #2 (the stocking up place is Dnepropetrovsk region, 2013 and peppermint - the sample #3 (the stocking place is Lebanon, Baalbek surroundings, 2013. In order to study elemental structure of peppermint leaves, atomic emission spectrometry with photographic registration was used. Results and discussions All types of raw materials had identical element structure. According to the content in each type of raw materials, compositions can be divided into some groups: the first one – the content of element was near or above 1000 mg /100 g, the content was higher than 100 mg /100 g, the content of composition was lower than 100 mg /100 g and below than 1 mg /100 g. Thus, the ambit between these groups was deeply emphasized. The following

Digital liquid-scintillation counting and effective pulse-shape discrimination with artificial neural networks

Energy Technology Data Exchange (ETDEWEB)

Langrock, Gert; Wiehl, Norbert; Kling, Hans-Otto; Mendel, Matthias; Naehler, Andrea; Tharun, Udo; Eberhardt, Klaus; Trautmann, Norbert; Kratz, Jens Volker [Mainz Univ. (Germany). Inst. fuer Kernchemie; Omtvedt, Jon-Petter [Oslo Univ. (Norway). Dept. of Chemistry; Skarnemark, Gunnar [Chalmers Univ. of Technology, Goeteborg (Sweden)

2015-05-01

A typical problem in low-level liquid scintillation (LS) counting is the identification of α particles in the presence of a high background of β and γ particles. Especially the occurrence of β-β and β-γ pile-ups may prevent the unambiguous identification of an α signal by commonly used analog electronics. In this case, pulse-shape discrimination (PSD) and pile-up rejection (PUR) units show an insufficient performance. This problem was also observed in own earlier experiments on the chemical behaviour of transactinide elements using the liquid-liquid extraction system SISAK in combination with LS counting. α-particle signals from the decay of the transactinides could not be unambiguously assigned. However, the availability of instruments for the digital recording of LS pulses changes the situation and provides possibilities for new approaches in the treatment of LS pulse shapes. In a SISAK experiment performed at PSI, Villigen, a fast transient recorder, a PC card with oscilloscope characteristics and a sampling rate of 1 giga samples s{sup -1} (1 ns per point), was used for the first time to record LS signals. It turned out, that the recorded signals were predominantly α β-β and β-γ pile up, and fission events. This paper describes the subsequent development and use of artificial neural networks (ANN) based on the method of 'back-propagation of errors' to automatically distinguish between different pulse shapes. Such networks can 'learn' pulse shapes and classify hitherto unknown pulses correctly after a learning period. The results show that ANN in combination with fast digital recording of pulse shapes can be a powerful tool in LS spectrometry even at high background count rates.

Experimental study on radiation resistant properties of seismic isolation elements

International Nuclear Information System (INIS)

Yoneda, G.; Nojima, O.; Aizawa, S.; Uchiyama, Y.; Ikenaga, M.; Yoshizawa, T.

1991-01-01

Recently, studies on the application of a seismic isolation system to a reactor building and or the equipment of a nuclear power plant has been carried out. This study aims at investigating the influence which is exerted upon the mechanical properties of the seismic isolation elements by radiation. The authors conducted irradiation tests, using γ rays, on natural rubber bearings (NRB), lead rubber bearings (LRB), high damping rubber bearings (HRB), and the viscous fluid used in viscous dampers. The maximum radiation intensity was 5 x 10 7 R (Roentgen). The comparison between the mechanical properties of each seismic isolation element before and after the irradiation test are reported in the following. (author)

Studies of flerovium and element 115 homologs with macrocyclic extractants

Science.gov (United States)

Despotopulos, John Dustin

Study of the chemistry of the heaviest elements, Z ? 104, poses a unique challenge due to their low production cross-sections and short half-lives. Chemistry also must be studied on the one-atom-at-a-time scale, requiring automated, fast, and very efficient chemical schemes. Recent studies of the chemical behavior of copernicium (Cn, element 112) and flerovium (Fl, element 114) together with the discovery of isotopes of these elements with half-lives suitable for chemical studies have spurred a renewed interest in the development of rapid systems designed to study the chemical properties of elements with Z ≥ 114. This dissertation explores both extraction chromatography and solvent extraction as methods for development of a rapid chemical separation scheme for the homologs of flerovium (Pb, Sn, Hg) and element 115 (Bi, Sb), with the goal of developing a chemical scheme that, in the future, can be applied to on-line chemistry of both Fl and element 115. Macrocyclic extractants, specifically crown ethers and their derivatives, were chosen for these studies. Carrier-free radionuclides, used in these studies, of the homologs of Fl and element 115 were obtained by proton activation of high purity metal foils at the Lawrence Livermore National Laboratory (LLNL) Center for Accelerator Mass Spectrometry (CAMS): natIn(p,n)113Sn, natSn(p,n)124Sb, and Au(p,n)197m,gHg. The carrier-free activity was separated from the foils by novel separation schemes based on ion exchange and extraction chromatography techniques. Carrier-free Pb and Bi isotopes were obtained from development of a novel generator based on cation exchange chromatography using the 232U parent to generate 212Pb and 212Bi. Crown ethers show high selectivity for metal ions based on their size compared to the negatively charged cavity of the ether. Extraction by crown ethers occur based on electrostatic ion-dipole interactions between the negatively charged ring atoms (oxygen, sulfur, etc.) and the positively

Studies on rare earth elements in seawater and uptake by marine organisms

International Nuclear Information System (INIS)

Suzuki, H.; Koyanagi, T.; Saiki, M.

1975-01-01

The contents of rare earth elements in marine environmental samples were determined by neutron activation analysis to examine the existing state in coastal seawater and the concentration by marine organisms of the elements. Seawater was filtered through a Millipore filter GS (pore size 0.22 μm), before the analysis. Some of the seawater was treated with HC1 solution before filtration and some after filtration. Certain marine organisms were also analysed for determination of rare earth elements. These were: flounder (Paralichthys olivaceus); yellowtails (Seriola quinqueradiata); immature anchovy (Engraulis japonica); clams (Meretrix lusoria); green algae (Ulva pertusa); brown algae (Hizikia fusiforme, Sargassum fulvellum, Undaria pinnatifida). In the seawater without HC1 treatment before filtration, considerable amounts of the elements existed in residue on the filter, whereas in the seawater treated with HC1 before filtration, the greater part remained in the dissolved state. Concentration factors calculated from the contents of stable elements, therefore, are affected remarkably by the existing state of the elements in seawater. If only the dissolved state is assumed available for marine organisms, values one order higher are attained compared with the case where total amounts of the elements were used for the calculation. However, the contribution of the insoluble state seems to be not negligible with some organisms. The higher concentration factors for immature anchovy and clams observed in this study were considered to be caused by surface adsorption of elements in particulate form and also ingested sediment with high element concentration. (author)

Studies of kinematic elements in two multicenter sunspot groups

International Nuclear Information System (INIS)

Korobova, Z.B.

1983-01-01

Some features of kinematic elements (KE) in two multicenter sunspot groups were studied using Tashkent full-disc white light heliograms. KE and morphological elements do not reveal any relationship. A KE coincides with a unipolar or multipolar spot or with part of a spot. It may also contain an extended stream including several spots. Relation of KE to large-scale photospheric magnetic fields is less clear. The line of polarity reversal is, in most cases, the deviding line between two adjacent KE. At the same time, a KE can contain spots of both polarities. Sunspot trajectories in the leading polarity regions show the best similarity. Interactions of KE are greatly influenced by the meridional drift. (author)

The Study Abroad Experience: A Crucial Element in Globalizing Business School Programs

Science.gov (United States)

Mangiero, George A.; Kraten, Michael

2011-01-01

Globalization is a fundamental reality of modern business practice. Participation in a study abroad program is a crucial element in helping students become well rounded global business leaders; it is an increasingly important element of a well rounded business curriculum. A semester or summer abroad, properly conceived and designed, can provide…

Geochemical study of trace elements in micrograin minerals

Energy Technology Data Exchange (ETDEWEB)

Toyoda, Kazuhiro; Shinozuka, Yoshitsugu; Imai, Shiho; Baba, Naoho; Machii, Tami; Shimada, Mitsuo; Hasebe, Kiyoshi [Hokkaido Univ., Sapporo (Japan)

1998-01-01

Abstract of five papers are contained in this paper. 1. Neutron activation analysis of iridium in Japan P/T boundary layer sample. Iridium of Permian/Triassic (P/T) boundary layer samples in Japan are determined. A collision of materials outside of the earth was not proved. 2. Adsorbability of rare earth elements by biogenic phosphate salt particles. Phosphate minerals are very strong adsorbent of rare earth elements, so that they can use as the removal materials of them in radioactive waste. 3. Analysis of undecomposed minerals and irresoluble compounds in acid decomposed residue. In order to investigate the past global changes, a micro wave heat method was studied and good results were obtained. 4. Determination of iridium in tsunami deposits in Cuba. Very small amount of iridium was discovered in the samples. 5. Activation analysis of iridium in the sample of 300 m core of Baikal lake. (Plan). (S.Y.)

Aerodynamic and thermal studies of cans of gas cooled fuel elements

International Nuclear Information System (INIS)

Gelin, P.

1964-01-01

Research on clusters was undertaken at the CEA in 1959, while studies on herring-bone cans were developed at the EDF Laboratory at Chatou and the CEA laboratory at Saclay at the end of 1959. In 1962, a general study on corrugations was begun at the Saclay Laboratory with a view to improving the clusters, and continued later in both laboratories relative to the internal cooling of annular fuel elements. As these studies progressed, trial facilities were extended while experimental methods have improved constantly. At the present time, both laboratories, working in complete collaboration, have powerful means at their disposal. Work on the clusters has been concerned chiefly with pressure losses due to the assembly parts, and with the temperature variations around the elements of the cluster. In this way, we have been able to determine satisfactorily the hot points of the can, the deformations of the rods and the conditions of stability of these deformations. In the case of the herring-bone cans, studies have been directed to the evolution of performances as a function of the geometric parameters on the one hand, and to the special aerodynamic and thermal features caused by the fins and by interruptions of cartridge on the other hand. These studies have led to a very thorough knowledge of the cartridges chosen for the reactors EDF 2 and EDF 3, and now open up very hopeful prospects for future reactors, particularly those fitted with annular elements; among the alternatives suitable for the inner surface of the annular element can, corrugations and longitudinal fins have been fairly extensively tested over a wide range of Reynolds number. (authors) [fr

Quantifying Volcanic Emissions of Trace Elements to the Atmosphere: Ideas Based on Past Studies

Science.gov (United States)

Rose, W. I.

2003-12-01

Extensive data exist from volcanological and geochemical studies about exotic elemental enrichments in volcanic emissions to the atmosphere but quantitative data are quite rare. Advanced, highly sensitive techniques of analysis are needed to detect low concentrations of some minor elements, especially during major eruptions. I will present data from studies done during low levels of activity (incrustations and silica tube sublimates at high temperature fumaroles, from SEM studies of particle samples collected in volcanic plumes and volcanic clouds, from geochemical analysis of volcanic gas condensates, from analysis of treated particle and gas filter packs) and a much smaller number that could reflect explosive activity (from fresh ashfall leachate geochemistry, and from thermodynamic codes modeling volatile emissions from magma). This data describes a highly variable pattern of elemental enrichments which are difficult to quantify, generalize and understand. Sampling in a routine way is difficult, and work in active craters has heightened our awareness of danger, which appropriately inhibits some sampling. There are numerous localized enrichments of minor elements that can be documented and others can be expected or inferred. There is a lack of systematic tools to measure minor element abundances in volcanic emissions. The careful combination of several methodologies listed above for the same volcanic vents can provide redundant data on multiple elements which could lead to overall quantification of minor element fluxes but there are challenging issues about detection. For quiescent plumes we can design combinations of measurements to quantify minor element emission rates. Doing a comparable methodology to succeed in measuring minor element fluxes for significant eruptions will require new strategies and/or ideas.

Experimental Study of the Partitioning of Siderophile Elements in a Crystallizing Lunar Magma Ocean

Science.gov (United States)

Galenas, M.; Righter, K.; Danielson, L.; Pando, K.; Walker, R. J.

2012-01-01

The distributions of trace elements between the lunar interior and pristine crustal rocks were controlled by the composition of starting materials, lunar core formation, and crystallization of the lunar magma ocean (LMO) [1]. This study focuses on the partitioning of highly siderophile elements (HSE) including Re, Os, Ir, Ru, Pt, Rh, Pd and Au as well as the moderately siderophile elements Mo and W, and the lithophile elements of Hf and Sr. Our experiments also include Ga, which can be slightly siderophile, but is mostly considered to be chalcophile. Partitioning of these elements is not well known at the conditions of a crystallizing LMO. Previous studies of HSE partitioning in silicate systems have yielded highly variable results for differing oxygen fugacity (fO2) and pressure [2-4]. For example, under certain conditions Pt is compatible in clinopy-roxene [2] and Rh and Ru are compatible in olivine [3]. The silicate compositions used for these experiments were nominally basaltic. Ruthenium, Rh, and Pd are incompatible in plagioclase under these conditions[4]. However, this latter study was done at extremely oxidizing conditions and at atmospheric pressure, possibly limiting the applicability for consideration of conditions of a crystallizing LMO. In this study we address the effects of pressure and oxygen fugacity on the crystal/liquid partition coefficients of these trace elements. We are especially interested in the plagioclase/melt partition coefficients so that it may be possible to use reverse modeling to constrain the concentrations of these elements in the lunar mantle through their abundances in pristine crustal rocks.

A Study of the Renewal Cycle of Hotel Building Elements in Malaysia

Directory of Open Access Journals (Sweden)

Zhen Wei

2014-01-01

Full Text Available Penang is the main tourism island which appeals an increasing number of travellers each year. Therefore, the hotels in Penang play a crucial role in the field of Penang tourism. However, recently some problems with the Penang hotels have been brought to light frequently by travellers including domestic and foreign tourists. The reason for this may be due to irregular maintenance as well as the fact that the renewal of the building elements may not have been duly carried out. In light of that, this research investigated the condition of the maintenance and renewal cycle of the building elements of the hotels in Penang. This study was conducted with a quantitative method, using a questionnaire to collect information regarding the condition of maintenance, evaluation of the condition of the building elements and the frequency of building elements renewal. The results revealed that each building element renewal cycle is differing according to the effects of maintenance and its lifespan. In terms of comparison with the renewals in Singapore hotels, there are shortcomings involved in the schedule of element renewals carried out in Penang.

Theoretical study of fuel element reliability in the BRIG-300 fast reactor

International Nuclear Information System (INIS)

Kulikov, I.S.; Nesterenko, V.B.; Tverkovkin, B.E.

1983-01-01

The theoretical results on studies of the reliability of cermet symmetrically heated fuel elements under conditions of the BRIG-300 fast gas cooled reactor are presented. The investigations have been conducted at the Nuclear Power Engineering Institute of the Byelorussian Academy of Sciences. Two variants of the fuel elements are considered :the fuel element with the gas gap between fuel and can and the fuel element with tight contact between cermet fuel and can. The estimated data on can resistance, swelling of the fuel rods and cans, strains and stresses in cans, change of the gap and its thermal coductivity during the reactor operation are obtained. The results of the analysis show that cermet fuel has sufficient reliability upon oparational conditions of the reactor with dissociating gas coolant in a steady-state regime

Separation by sequential chromatography of americium, plutonium and neptunium elements: application to the study of trans-uranian elements migration in a European lacustrine system

International Nuclear Information System (INIS)

Michel, H.

1999-01-01

The nuclear tests carried out in the atmosphere in the Sixties, the accidents and in particular that to the power station of Chernobyl in 1986, were at the origin of the dispersion of a significant quantity of transuranic elements and fission products. The study of a lake system, such that of the Blelham Tarn in Great Britain, presented in this memory, can bring interesting answers to the problems of management of the environment. The determination of the radionuclides in sediment cores made it possible not only to establish the history of the depositions and consequently the origin of the radionuclides, but also to evaluate the various transfers which took place according to the parameters of the site and the properties of the elements. The studied transuranic elements are plutonium 238, 239-240, americium 241 and neptunium 237. Alpha emitting radionuclides, their determination requires complex radiochemical separations. A method was worked out to successively separate the three radioelements by using a same chromatographic column. Cesium 137 is the studied fission product, its determination is done by direct Gamma spectrometry. Lead 210, natural radionuclide, whose atmospheric flow can be supposed constant. makes it possible to obtain a chronology of the various events. The detailed vertical study of sediment cores showed that the accumulation mode of the studied elements is the same one and that the methods of dating converge. The cesium, more mobile than transuranic elements in the atmosphere, was detected in the 1963 and 1986 fallout whereas an activity out of transuranic elements appears only for the 1963 fallout. The activity of the 1963 cesium fallout is of the same order of magnitude as that of 1986. The calculation of the diffusion coefficients of the elements in the sediments shows an increased migration of cesium compared to transuranic elements. An inventory on the whole of the lake made it possible to note that the atmospheric fallout constitute the

XRF Studies of Trace Elements and Essential hypertension

International Nuclear Information System (INIS)

Chaudhri, M.A.; Paul, U.; Chaudhri, M.N.

2011-01-01

The elemental concentrations in the blood of fully mature spontaneously hypertensive rats [SHR] were compared with that of normotensive Wistar Kyoto rats [WKy] with an energy- dispersive XRF-system using a Rhodium X-ray tube. A number of elements, Na, Mg, P, Cl, S, K, Ca, Fe, Cu, Zn, Rb and Br, ranging in concentrations from a few ppm to around 1 % were measured in all the blood samples. It has been observed that the concentrations of elements Na, Cu, Zn and Br in whole blood of SHR are about 5%, 17%, 7% and 21% higher respectively than in the WKy- group

Elemental diet as prophylaxis against radiation injury. Histological and ultrastructural studies

International Nuclear Information System (INIS)

McArdle, A.H.; Wittnich, C.; Freeman, C.R.; Duguid, W.P.

1985-01-01

The authors investigated whether elemental diet feeding would protect the intestine from radiation injury. Five dogs were fed an elemental diet for three days before receiving pelvic irradiation (500 rad/day for four days) and were maintained on the diet during the days of irradiation. These dogs were compared with five dogs that were fed normal kennel ration, but were treated similarly otherwise. One day and five days following completion of the radiation treatment, the dogs were anesthetized and a biopsy specimen of terminal ileum was taken for histologic and electron microscopic studies. In the dogs fed the elemental diet, there was no significant damage to the intestine seen on histological examination, and electron microscopy disclosed elongated microvilli and no organelle damage. However, both histological and electron microscopic examination of the intestine from dogs maintained on normal kennel ration showed that severe damage had occurred from the irradiation procedure. It seems, therefore, that the feeding of an elemental diet to dogs as a prophylaxis can afford protection to the intestine from the acute phase of radiation injury

The radiochemistry, a multi-disciplinary science for the 21. century

International Nuclear Information System (INIS)

David, F.

1999-04-01

The basic radiochemistry occupies an avant-garde place in inorganic chemistry. It covers a very vast multi-disciplinary field, important for about 40% of the periodic table. It allows understanding better the periodic classification and it is directly connected with various disciplines: metal physical chemistry, solid compounds, solutions, thermodynamics, etc. The applications are also multi-disciplinary, mainly in nuclear industries but also in analysis, geology, biochemistry, medicine, archaeology, astrophysics. This report is a short variant of the document delivered in 1988 for CNRS. It treats neither all the aspects of radiochemistry or the priorities in this field but points out the main directions of this discipline and the fields of research which should be studied in more details. The content is as follows: - Introduction; - I. Definition and radiochemistry's domain of action; - II. The actinides constitute a particularly interesting series of the periodic table; - III. Research on actinides to be developed; III.1 Metals; III.2 Solid compounds; III.3 Gas compounds; III.4 Chemistry in solution (water ions, oxidation degrees, thermodynamic properties, chemical species in solution, non-aqueous media, chemical kinetics, chemistry at the atom scale); IV. Other radioelements; IV.1 The trans-actinide elements; IV.2 The long-lived fission products; V. Radiochemical methods; VI. Study of the 4f and 5f elements is interesting from the point of view of physico-chemical theories; VII. The heavy elements are implied in the nuclear power production; VII.1 Reprocessing the nuclear fuels; VII.2 Waste management; VIII. Conclusions

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

Energy Technology Data Exchange (ETDEWEB)

Wei, Wei; Shi, Shiyuan; Fei, Jun; Wang, Yifan; Chen, Chunyue [Hangzhou Red Cross Hospital, Hangzhou, Zhejiang, (China); Liao, Shenhui [School of Information Science and Engineering, Central South University, Changsha, Hunan (China)

2013-03-15

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Trace element determination study in human hair by neutron activation analysis

International Nuclear Information System (INIS)

Frazao, Selma Violato

2008-01-01

Human hair analysis studies have been subject of continuous interest due to the fact that they can be used as an important tool to evaluate trace element levels in the human body. These determinations have been carried out to use hair for environmental and occupational monitoring, to identify intoxication or poisoning by toxic metals, to assess nutritional status, to diagnose and to prevent diseases and in forensic sciences. Although hair analysis presents several advantages over other human tissue or fluid analyses, such as organ tissue, blood, urine and saliva, there are some controversies regarding the use of hair analysis data. These controversies arise from the fact that it is difficult to establish reliable reference values for trace elements in hair. The purpose of this study was to evaluate the factors that affect element concentrations in hair samples from a population considered healthy and residing in the Sao Paulo metropolitan area. The collected human head hair was cut in small pieces, washed, dried and analyzed by neutron activation analysis (NAA). Aliquots of hair samples and synthetic elemental standards were irradiated at the IEA-R1 nuclear research reactor for 16 h under a thermal neutron flux of about 5x10 12 n cm -2 s -1 for As, Br, Ca, Co, Cr, Cs, Cu, Fe, K, La, Na, Sb, Sc, Se and Zn determinations. The induced gamma activities of the standards and samples were measured using a gamma ray spectrometer coupled to an hiperpure Ge detector. For quality control of the results, IAEA- 85 Human Hair and INCT-TL-1 Tea Leaves certified reference materials (CRMs) were analyzed. Results obtained in these CRMs presented for most of elements, good agreement with the values of the certificates (relative errors less than 10%) and good precision (variation coefficients less than 13.6%). Results of replicate hair sample analysis showed good reproducibility indicating homogeneity of the prepared sample. Results obtained in the analyses of dyed and non-dyed hair

Studies of generalized elemental imbalances in neurological disease patients using INAA [instrumental neutron activation analysis

International Nuclear Information System (INIS)

Ehmann, W.D.; Vance, D.E.; Khare, S.S.; Kasarskis, E.J.; Markesbery, W.R.

1988-01-01

Evidence has been presented in the literature to implicate trace elements in the etiology of several age-related neurological diseases. Most of these studies are based on brain analyses. Using instrumental neutron activation analysis (INAA), we have observed trace element imbalances in brains of patients with Alzheimer's disease, amyotrophic lateral sclerosis (ALS), and Picks's disease. The most prevalent elemental imbalances found in the brain were for bromine, mercury, and the alkali metals. In this study the authors report INAA studies of trace elements in nonneural tissues from Alzheimer's disease and ALS patients. Samples from household relatives were collected for use as controls wherever possible. Hair samples were washed according to the International Atomic Energy Agency recommended procedure. Fingernail samples were scraped with a quartz knife prior to washing by the same procedure. For ALS patients, blood samples were also collected. These data indicate that elemental imbalances in Alzheimer's disease and ALS are not restricted to the brain. Many elements perturbed in the brain are also altered in the several nonneural tissues examined to date. The imbalances in different tissues, however, are not always in the same direction. The changes observed may represent causes, effects, or simply epiphenomena. Longitudinal studies of nonneural tissues and blood, as well as tissue microprobe analyses at the cellular and subcellular level, will be required in order to better assess the role of trace elements in the etiology of these diseases

Modelling optimization involving different types of elements in finite element analysis

International Nuclear Information System (INIS)

Wai, C M; Rivai, Ahmad; Bapokutty, Omar

2013-01-01

Finite elements are used to express the mechanical behaviour of a structure in finite element analysis. Therefore, the selection of the elements determines the quality of the analysis. The aim of this paper is to compare and contrast 1D element, 2D element, and 3D element used in finite element analysis. A simple case study was carried out on a standard W460x74 I-beam. The I-beam was modelled and analyzed statically with 1D elements, 2D elements and 3D elements. The results for the three separate finite element models were compared in terms of stresses, deformation and displacement of the I-beam. All three finite element models yield satisfactory results with acceptable errors. The advantages and limitations of these elements are discussed. 1D elements offer simplicity although lacking in their ability to model complicated geometry. 2D elements and 3D elements provide more detail yet sophisticated results which require more time and computer memory in the modelling process. It is also found that the choice of element in finite element analysis is influence by a few factors such as the geometry of the structure, desired analysis results, and the capability of the computer

Transuranium element behavior in the environment: What speciation studies can tell us

International Nuclear Information System (INIS)

Cleveland, J.M.

1989-01-01

Some of the transuranium elements - especially plutonium - can exist in the environment in several different oxidation states which differ chemically from one another as much as if they were different elements. Hence an understanding of the environmental chemistry of these elements requires knowledge of their oxidation-state distribution, or speciation, under a variety of realistic conditions. Such studies are in their infancy, but already several chemical speciation methods have yielded results indicating the uniqueness of transuranic environment chemistry; for example, dioxoplutonium(V), which is unstable in the acid solutions employed in laboratory and processing plant, is often the most prevalent plutonium oxidation state in natural waters. More sensitive and less invasive physical speciation methods under development will hopefully permit the extension of these studies to a wider variety of environmental conditions and to determinations of sorbed species necessary for an understanding of sorption processes

Study of osteoporosis through the measurement of bone mineral density and trace elements

International Nuclear Information System (INIS)

Aras, N.K.; Yilmaz, G.; Alkanl, S.; Korkusuz, F.; Ungan, M.; Kuscu, L.; Laleli, Y.; Eksioglu, F.; Sepici, B.; Gunel, U.

2000-01-01

The main purpose of this study was to establish a relation, if any, between bone mineral density, BMD, of the healthy Turkish population of the ages between 15 and 50 with social and demographic information, family history of fractures, personal and inherited characteristic, smoking and alcohol habit, history of fertility, level of physical activity, food consumption especially trace elements and other variables. Most of these relations were discussed in the last RCM in San Diego, CA, October 7-10,1996. Since then we have concentrated our work on more BMD and trace element measurements in bone. To this end, bone mineral density measurements, trace element studies, neutron activation analysis, fluoride analysis and atomic absorption analysis were undertaken and resulting data were analysed

Trace elements in cocoa solids and chocolate: an ICPMS study.

Science.gov (United States)

Yanus, Rinat Levi; Sela, Hagit; Borojovich, Eitan J C; Zakon, Yevgeni; Saphier, Magal; Nikolski, Andrey; Gutflais, Efi; Lorber, Avraham; Karpas, Zeev

2014-02-01

The concentrations of eight trace elements: lead (Pb), cadmium (Cd), chromium (Cr), manganese (Mn), cobalt (Co), arsenic (As), bismuth (Bi) and molybdenum (Mo), in chocolate, cocoa beans and products were studied by ICPMS. The study examined chocolate samples from different brands and countries with different concentrations of cocoa solids from each brand. The samples were digested and filtered to remove lipids and indium was used as an internal standard to correct matrix effects. A linear correlation was found between the level of several trace elements in chocolate and the cocoa solids content. Significant levels of Bi and As were found in the cocoa bean shells but not in the cocoa bean and chocolate. This may be attributed to environmental contamination. The presence of other elements was attributed to the manufacturing processes of cocoa and chocolate products. Children, who are big consumers of chocolates, may be at risk of exceeding the daily limit of lead; whereas one 10 g cube of dark chocolate may contain as much as 20% of the daily lead oral limit. Moreover chocolate may not be the only source of lead in their nutrition. For adults there is almost no risk of exceeding daily limits for trace metals ingestion because their digestive absorption of metals is very poor. © 2013 Published by Elsevier B.V.

Comparative study of the suitability of two lichen species for trace element atmospheric monitoring

Energy Technology Data Exchange (ETDEWEB)

Saiki, Mitiko; Alves, Edson R.; Genezini, Frederico A., E-mail: mitiko@ipen.br, E-mail: eralves@ipen.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN-SP), Sao Paulo, SP (Brazil); Saldiva, Paulo H.N., E-mail: pepino@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina

2013-07-01

Lichens have been widely used in monitoring studies. Consequently, it is very useful to study the suitability of lichen species to monitor pollutants allowing in this way the best choice. The aim of this study was to compare the accumulation of trace elements by two epiphytic lichen species Canoparmelia texana (Tuck) Elix and Hale and Usnea amblyoclada (Mull. Arg.) Zahlbr. Five samples of each species were collected during the period from November 2010 in a same site far from downtown Sao Paulo city. Lichens collected from tree barks were cleaned, freeze-dried, ground and analyzed by neutron activation analysis. Aliquots of lichen samples and synthetic elemental standards were irradiated at the IEA-R1 nuclear research reactor. The induced gamma activities were measured using a hyperpure Ge detector coupled to a digital spectrum analyzer. Concentrations of As, Ba, Cd, Cr, Cs, Fe, Mg, Mn, Na, Rb, V and Zn were determined in both lichen species. The results demonstrated that both species can be used for evaluating air quality. The element concentrations showed difference between lichen species and also among their sampling periods. These differences may be attributed to the distinct mechanisms of element absorption by lichens as well as various other factors that affect their element accumulation. The comparative evaluation made calculating the ratios between C. texana species sample and that in Usnea amblyoclada for elemental concentrations indicated that, in general, foliose C. texana present similar or higher concentrations than those presented by fruticose Usnea. (author)

A study on the shielding element using Monte Carlo simulation

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki Jeong [Dept. of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of); Shim, Jae Goo [Dept. of Radiologic Technology, Daegu Health College, Daegu (Korea, Republic of)

2017-06-15

In this research, we simulated the elementary star shielding ability using Monte Carlo simulation to apply medical radiation shielding sheet which can replace existing lead. In the selection of elements, mainly elements and metal elements having a large atomic number, which are known to have high shielding performance, recently, various composite materials have improved shielding performance, so that weight reduction, processability, In consideration of activity etc., 21 elements were selected. The simulation tools were utilized Monte Carlo method. As a result of simulating the shielding performance by each element, it was estimated that the shielding ratio is the highest at 98.82% and 98.44% for tungsten and gold.

The effect of packaging elements on purchase intention: case study of Algerian customers

Directory of Open Access Journals (Sweden)

Sidi Mohammed Benachenhou

2018-04-01

Full Text Available The aim of this article is to study the impact of marketing innovation and the visual and verbal ele-ments of packaging on customers purchase intentions. After a brief literature review, an empirical study is conducted among 140 customers of Coca-Cola brand in Tlemcen city. To this end, a model of intention has been developed to be tested by structural equations modeling. The results of this study showed that marketing innovation and the visual and verbal elements of packaging directly affect the purchase intentions of the customers of this brand.

Comparative Study on Interface Elements, Thin-Layer Elements, and Contact Analysis Methods in the Analysis of High Concrete-Faced Rockfill Dams

Directory of Open Access Journals (Sweden)

Xiao-xiang Qian

2013-01-01

Full Text Available This paper presents a study on the numerical performance of three contact simulation methods, namely, the interface element, thin-layer element, and contact analysis methods, through the analysis of the contact behavior between the concrete face slab and the dam body of a high concrete-faced rockfill dam named Tianshengqiao-I in China. To investigate the accuracy and limitations of each method, the simulation results are compared in terms of the dam deformation, contact stress along the interface, stresses in the concrete face slab, and separation of the concrete face slab from the cushion layer. In particular, the predicted dam deformation and slab separation are compared with the in-situ observation data to classify these methods according to their agreement with the in-situ observations. It is revealed that the interface element and thin-layer element methods have their limitations in predicting contact stress, slab separation, and stresses in the concrete face slab if a large slip occurs. The contact analysis method seems to be the best choice whether the separation is finite or not.

Study of the circumstance influence on the elemental distribution in ancient animal bone using μ-XRF

International Nuclear Information System (INIS)

Yan Lingtong; Feng Songlin; Li Li; Xu Wei; Feng Xiangqian; Xie Guoxi

2010-01-01

Elemental analysis of archaeological bone plays an important role in the study of the dietary habits of ancient animals. The elemental characteristic of diagenetic skeletons depends on the surrounding circumstance. The study of environmental influence on the elemental concentration of ancient bone is significant. In this paper, the diagenetic influence on archaeological skeletons is analyzed by microbeam X-ray fluorescence (μ-XRF). The results show that the enamel is an excellent barrier to the diagenesis and the element Sr in bone isn't susceptible to contamination from the buried environment. (authors)

Generalized finite elements

International Nuclear Information System (INIS)

Wachspress, E.

2009-01-01

Triangles and rectangles are the ubiquitous elements in finite element studies. Only these elements admit polynomial basis functions. Rational functions provide a basis for elements having any number of straight and curved sides. Numerical complexities initially associated with rational bases precluded extensive use. Recent analysis has reduced these difficulties and programs have been written to illustrate effectiveness. Although incorporation in major finite element software requires considerable effort, there are advantages in some applications which warrant implementation. An outline of the basic theory and of recent innovations is presented here. (authors)

Study of characterization of trace elements in marine shells of Sambaqui: correlation between recent and old shells

International Nuclear Information System (INIS)

Gomez, Mauro Roger Batista Pousada; Rocha, Flavio Roberto; Silva, Paulo Sergio Cardoso da

2013-01-01

Calcium carbonate of recent and ancient C. rhizophorae oyster shells was analyzed for the determination of trace elements by instrumental neutron activation analysis. The ancient shells belong to a Sambaqui located in Cananeia region, South of Sao Paulo state and the recent ones are from an oyster production farm in the same region Studies related to the element concentrations in molluscs shell has been done as a tentative of establishing the element concentrations with palio-environmental factor. In this study it was aimed to verify differences in the elemental constitution of recent and ancient oyster shells that present potential for being used as indicator of marine changes. Results indicated that the elements Br, Ce, La, Na, Sm and An are higher in recent shells and the elements Cr, Fe Sc and Th are higher in ancient shells. Statistical analyses performed indicated that the enrichment of the light rare earth elements related to Ca are possibly good candidates for these palio-environmental studies. (author)

Statistical study on the strength of structural materials and elements

International Nuclear Information System (INIS)

Blume, J.A.; Dalal, J.S.; Honda, K.K.

1975-07-01

Strength data for structural materials and elements including concrete, reinforcing steel, structural steel, plywood elements, reinforced concrete beams, reinforced concrete columns, brick masonry elements, and concrete masonry walls were statistically analyzed. Sample statistics were computed for these data, and distribution parameters were derived for normal, lognormal, and Weibull distributions. Goodness-of-fit tests were performed on these distributions. Most data, except those for masonry elements, displayed fairly small dispersion. Dispersion in data for structural materials was generally found to be smaller than for structural elements. Lognormal and Weibull distributions displayed better overall fits to data than normal distribution, although either Weibull or lognormal distribution can be used to represent the data analyzed. (auth)

Total hip reconstruction in acetabular dysplasia : a finite element study

NARCIS (Netherlands)

Schüller, H.M.; Dalstra, M.; Huiskes, H.W.J.; Marti, R.K.

1993-01-01

In acetabular dysplasia, fixation of the acetabular component of a cemented total hip prosthesis may be insecure and superolateral bone grafts are often used to augment the acetabular roof. We used finite element analysis to study the mechanical importance of the lateral acetabular roof and found

Quality-assurance study of the special - purpose finite-element program - SPECTROM: I. Thermal, thermoelastic, and viscoelastic problems

International Nuclear Information System (INIS)

Wagner, R.A.

1980-12-01

This comparison study involves a preliminary verification of finite element calculations. The methodology of the comparison study consists of solving four example problems with both the SPECTROM finite element program and the MARC-CDC general purpose finite element program. The results show close agreement for all example problems

Molybdenite Mineral Evolution: A Study Of Trace Elements Through Time

Science.gov (United States)

McMillan, M. M.; Downs, R. T.; Stein, H. J.; Zimmerman, A.; Beitscher, B. A.; Sverjensky, D. A.; Papineau, D.; Armstrong, J. T.; Hazen, R. M.

2010-12-01

Mineral evolution explores changes through time in Earth’s near-surface mineralogy, including diversity of species, relative abundances of species, and compositional ranges of major, minor and trace elements. Such studies elucidate the co-evolution of the geosphere and biosphere. Accordingly, we investigated trace and minor elements in molybdenite (MoS2) with known ages from 3 billion years to recent. Molybdenite, the commonest mineral of Mo, may prove to be a useful case study as a consequence of its presence in Earth’s early history, the effects of oxidation on Mo mobility, and the possible role of Mo mineral coevolution with biology via its role in the nitrogen fixation enzyme nitrogenase. We employed ICPMS, SEM and electron microprobe analyses to detect trace and minor elements. We detected significant amounts of Mn and Cu (~100 ppm) and greater amounts of Fe, W, and Re (to ~4000 ppm). Molybdenites commonly contain micro inclusions, resulting in local concentrations in otherwise homogeneous samples. Inhomogeneities in Fe, Zn and Sn concentrations, for example, point to the presence of pyrite, sphalerite and cassiterite inclusions, respectively. Analyses examined as a function of time reveal that samples containing significant concentrations (>200 ppm, compared to average values < 100 ppm) of W and Re formed primarily within the last billion years. These trends may reflect changes in the mobility of W and Re in oxic hydrothermal fluids at shallow crustal conditions following the Great Oxidation Event.

Correlation study of chemical elements in phosphate ores

International Nuclear Information System (INIS)

Braganca, Maura Julia Camara da Silva

1999-07-01

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

Preparation Technology and Study of Properties of New Detectors for Transuranium Elements

International Nuclear Information System (INIS)

Andrushchenko, G.Yu.; Blank, A.B.; Budakovsky, S.V.; Zelenska, O.V.; Shevtsov, M.I.

2006-01-01

A porous composite materials is described for determination of radionuclides in aquatic objects of the environment. Possibilities have been studied for the use of this material in monitoring of α-nuclides content in natural waters. The composite is a scintillator with through pores, the surface of which is impregnated by a sorbent that is selective with respect to transuranium elements. The structure of the material allows combination of two processes - concentrating the radionuclide and measuring its activity. as selective sorbent to transuranium elements an anion-exchange resin VP-1Ap was used. Studies of material functionality were carried out using the model systems based on reference radioactive solutions 239 Pu

Space-Based Space Surveillance Logistics Case Study: A Qualitative Product Support Element Analysis

Science.gov (United States)

2017-12-01

REPORT TYPE AND DATES COVERED Joint applied project 4. TITLE AND SUBTITLE SPACE-BASED SPACE SURVEILLANCE LOGISTICS CASE STUDY: A QUALITATIVE ...INTENTIONALLY LEFT BLANK v ABSTRACT This research provides a qualitative analysis of the logistics impacts, effects, and sustainment challenges...provides a qualitative product support element-by-element review for both research questions. Chapters IV and V present the findings, results

A STUDY ON THE HIERARCHY OF MANAGEMENT ELEMENTS

Science.gov (United States)

Suzuki, Nobuyuki; Watanabe, Tadashi

Compared to the late 20th century, the Japanese construction industry has drastically changed its business methodology, outlook and approach in response to global issues and the incredible advances in technology. Such influences, non-exhaustively include the; WTO Government procurement agreement, updating conditions of tendering and contracting, client demands for cost reduction and the rapid penetration of ICT (Information and Communication Technology) into modern society. These days, the significance of controlling Quality, Cost and Time (the so-called QCT) has been recognized as an eternal-triangle by almost all countries, Government organizations and the private sector. However, as the construction industry is exposed to , and influenced by, more and more internal and external dynamic factors, continued reliance on managing and controlling QCT elements on their own is no longer adequate in meeting the growing demands and expectations, and as such control of additional management elements is now essential to avoid problems, or minimize their potential impacts should they occur. This paper utilizes the results of a survey carried out amongst construction managers and consultants in Japan and overseas to develop a spatial network that defines the interaction of management factors as a weighted graphical model. The calculated closeness centrality index of the developed management network model is adopted to identify the initialelement hierarchy, which is then further analyzed using the minimum distance of independent relationships of management elements (Warshall-Floyd algorism methodology), to identify the optimum potential hierarchy for effective construction management. A key result of the analysis is the significance of "Human Resource" in the construction industry management element hierarchy alongside the traditional QCT elements.

Study of Finite Element Number Influence over the Obtained Results in Finite Element Analyses of a Mechanical Structure

Directory of Open Access Journals (Sweden)

Ana-Maria Budai

2013-05-01

Full Text Available This paper present the results of a study that was made to establish the influence of finite element number used to determined the real load of a structure. Actually, the study represent a linear static analyze for a link gear control mechanism of a Kaplan turbine. The all analyze was made for the normal condition of functioning having like final scope to determine de life time duration of mentioned mechanism.

Berkeley Off-line Radioisotope Generator (BORG)

CERN Document Server

Sudowe, R

2001-01-01

Development of chemical separations for the transactinides has traditionally been performed with longer-lived tracer activities purchased commercially. With these long-lived tracers, there is always the potential problem that the tracer atoms are not always in the same chemical form as the short-lived atoms produced in on-line experiments. This problem is especially severe for elements in groups 4 and 5 of the periodic table, where hydrolysis is present. The long-lived tracers usually are stored with a complexing agent to prevent sorption or precipitation. Chemistry experiments performed with these long-lived tracers are therefore not analogous to those chemical experiments performed in on-line experiments. One way to eliminate the differences between off-line and on-line chemistry experiments is through the use of a sup 2 sup 5 sup 2 Cf fission fragment collection device. A sup 2 sup 5 sup 2 Cf fission fragment collection device has already been constructed [1]. This device is limited in its capabilities. A ...

Treatment of data in the study of elemental concentration of biological materials

International Nuclear Information System (INIS)

Ng, K. H.; Bradeley, D.A.; Looi, L.M.

1994-01-01

In the present work on the breast tissue, we detail the use of rigorous statistical methodology. We have carried out a multi-elemental analysis of 46 pairs of normal and malignant human breast tissue by instrumental neutron activation analysis. The TRIGA Mark II research reactor which was used provided a thermal neutron flux of the order of 10 sup 1 sup 2 neutrons cm sup -2 s sup -1. Twelve elements were determined. Sampling theory was used to determine the minimum number of paired samples required to yield a given discrimination power. Probability plots were applied to illustrate the log-normal and quasi-normal behaviour of distributions for all 12 of the elements which were examined. Statistically significant differences between malignant and normal tissue have been observed in respect of all elements using the Wilcoxon signed-ranks test. Finally, Spearman ranked correlation coefficients have been obtained, yielding a number of significant correlations between pairs of variables. We illustrate the value of such treatment by making comparisons with the results of a number of other studies of breast tissue. 2 figs., 2 refs. (Author)

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

Science.gov (United States)

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

2011-01-01

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

Trace elemental correlation study in malignant and normal breast tissue by PIXE technique

International Nuclear Information System (INIS)

Raju, G.J. Naga; Sarita, P.; Kumar, M. Ravi; Murty, G.A.V. Ramana; Reddy, B. Seetharami; Lakshminarayana, S.; Vijayan, V.; Lakshmi, P.V.B. Rama; Gavarasana, Satyanarayana; Reddy, S. Bhuloka

2006-01-01

Particle induced X-ray emission technique was used to study the variations in trace elemental concentrations between normal and malignant human breast tissue specimens and to understand the effects of altered homeostasis of these elements in the etiology of breast cancer. A 3 MeV proton beam was used to excite the biological samples of normal and malignant breast tissues. The elements Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb and Sr were identified and their relative concentrations were estimated. Almost all the elements were found to be elevated (p < 0.05, Wilcoxon signed-ranks test) in the cancerous tissues when compared with normal tissues. The excess levels of trace elements observed in the cancerous breast tissues could either be a cause or a consequence of breast cancer. Regarding their role in the initiation or promotion of breast cancer, one possible interpretation is that the elevated levels of Cu, Fe and Cr could have led to the formation of free radicals or other reactive oxygen species (ROS) that adversely affect DNA thereby causing breast cancer, which is mainly attributed to genetic abnormalities. Moreover, since Cu and Fe are required for angiogenesis, elevated concentrations of these elements are likely to promote breast cancer by increasing the blood supply for tumor growth. On the other hand elevated concentrations of elements in breast cancer tissues might also be a consequence of the cancer. This can be understood in terms of the biochemical and histological differences between normal and cancerous breast tissues. Tumors, characterized by unregulated multiplication of cells, need an ever-increasing supply of essential nutrients including trace elements. This probably results in an increased vascularity of malignant tissues, which in turn leads to enhancement of elemental concentrations in tumors

A study of pollution extent in some drinking water resources by heavy elements in Hadramout governorate

International Nuclear Information System (INIS)

Barheyan, Saad Awadh

2001-01-01

The paper is considered as a preliminary study of pollution extent in some drinking water resources in Hadramout governorate by heavy elements which differ in their toxicity. The elements subjected to study are Cd, Pb, Fe, Cr, Mn, Zn, Co and Cu. Atomic absorption spectrometric method of analysis (AAS) is used for the determination of heavy elements concentrations. The elemental analysis of drinking water samples shows that the concentration of the above-mentioned elements in drinking water resources, lies in the permissible limit given by the WHO. Similarity of elements content is observed in Thela and Fuwah waters, bu the case is different for Ghail Bawzeer and Asshihir waters due to their different lithospheric structures. Drinking water used by the civilians is not subjected to physical, biological or chemical treatment which may lead to total or partial removal of heavy elements and other rejected impurities. Drinking water running in distribution nets is a hard water and has a weak base (Ph which explains the reason why heavy elements are absorbed and precipitated inside drinking water pipes before they reach consumers. This type of hard water causes accumulation of salt precipitates inside the water pipes which results in many economic and health disturbances to consumers. The slight increase of Cr, Mn, and Co concentration in drinking water flowing in the pipes may be due to the effect of some anions such as nitrates which form soluble compounds with the elements contained in the chemical composition of the drinking water pipes. This paper is a strong indicator for determination of heavy elements concentrations in different drinking water resources in Hadramout govemorate. Such approach seeks a further comprehensive work with special focus on the study of lithospheric structure of the feeding water regions of Hadramout aquifers. (author)

Australis: AMS for ultra sensitive trace element and isotopic studies

Energy Technology Data Exchange (ETDEWEB)

Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1994-12-31

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig.

Australis: AMS for ultra sensitive trace element and isotopic studies

International Nuclear Information System (INIS)

Sie, S.H.; Suter, G.F.

1993-01-01

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig

Australis: AMS for ultra sensitive trace element and isotopic studies

Energy Technology Data Exchange (ETDEWEB)

Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1993-12-31

The accelerator mass spectrometer (AMS) at the CSIRO HIAF laboratory is being upgraded to enable in-situ measurements of ultratraces and isotopic-ratios in mineralogical applications. The upgraded system will include a microbeam Cs ion source which is designed to produce better than 50 micrometre diameter Cs beam to enable analyses of monomineralic grains. The Cs primary beam will be mass analysed in order to minimize contamination of the sample. The detection system will be upgraded to enable analyses of elements up to U, at 2 MV terminal voltage for charge states 4 and 5. The system will be known as AUSTRALIS: A.M.S. for Ultra Sensitive TRAce eLement and Isotopic Studies. An overview of the system and the anticipated applications in minerals exploration and mining research are presented. 4 refs., 1 fig.

Field studies on the terrestrial behavior of actinide elements in East Tennessee

International Nuclear Information System (INIS)

Garten, C.T. Jr.; Bondietti, E.A.; Trabalka, J.R.; Walker, R.L.; Scott, T.G.

1984-01-01

Field studies on the comparative uptake of various actinide elements ( 232 Th, 233 U, 238 U, 239 Pu, 241 Am, and 244 Cm) by plants and animals inhabiting historically contaminated environments on the Oak Ridge National Laboratory (ORNL) reservation in East Tennessee are summarized. The present-day pattern of actinide element bioaccumulation from a flood plain site contaminated with Pu in 1944 is U > Th approx. Pu. Thus the environmentally dispersed 239 Pu exhibits a transfer from floodplain soil to biota comparable to that of indigenous 232 Th and less than that of the indigenous 238 U. This ranking agrees with the chemical extractability of U, Th, and Pu from soil, using either weak acids or strongly basic reagents. The pattern of actinide element uptake from the shoreline of a historically contaminated pond is Pu 238 U = 233 U. This ranking also agrees with the chemical extractability of Pu, Am, Cm, and U from shoreline sediment, using weak acids. Results from field studies at ORNL agree with what has been generally inferred about the relative food chain transfer of the actinides, based on laboratory studies and field studies at other sites in the United States. Because they share the same valence state, there are apparent strong similarities in soil sorption, plant uptake, and animal uptake between trivalent Am and Cm and between tetravalent Pu and Th. Available evidence suggests that knowledge of the behavior of naturally occurring 232 Th in the terrestrial food chain can be useful for predicting the long-term fate of environmentally dispersed 239 Pu, while data on 238 U might be used to place an upper limit on the expected long-term food chain transfer of all transuranic elements except Np. 33 references, 5 figures, 1 table

An Atomistic Modeling Study of Alloying Element Impurity Element, and Transmutation Products on the cohesion of A Nickel E5 {001} Twist Grain Boundary

International Nuclear Information System (INIS)

Young, G.A. Jr.; Najafabadi, R.; Strohmayer, W.; Baldrey, D.G.; Hamm, B.; Harris, J.; Sticht, J.; Wimmer, E.

2003-01-01

Atomistic modeling methods were employed to investigate the effects of impurity elements on the metallurgy, irradiation embrittlement, and environmentally assisted cracking of nickel-base alloys exposed to nuclear environments. Calculations were performed via ab initio atomistic modeling methods to ensure the accuracy and reliability of the results. A Griffith-type fracture criterion was used to quantitatively assess the effect of elements or element pairs on the grain boundary cohesive strength. In order of most embrittling to most strengthening, the elements are ranked as: He, Li, S, H, C, Zr, P, Fe, Mn, Nb, Cr, and B. Helium is strongly embrittling (-2.04 eV/atom lowering of the Griffith energy), phosphorus has little effect on the grain boundary (0.1 eV/atom), and boron offers appreciable strengthening (1.03 eV/atom increase in the Griffith energy). Calculations for pairs of elements (H-Li, H-B, H-C, H-P, and H-S) show little interaction on the grain boundary cohesive energy, so that for the conditions studied, linear superposition of elemental effects is a good approximation. These calculations help explain metallurgical effects (e.g. why boron can strengthen grain boundaries), irradiation embrittlement (e.g. how boron transmutation results in grain boundary embrittlement), as well as how grain boundary impurity elements can affect environmentally assisted cracking (i.e. low temperature crack propagation and stress corrosion cracking) of nickel-base alloys

Fundamental study on the extraction of transuranium elements from high-level liquid waste

International Nuclear Information System (INIS)

Kubota, Masumitsu; Morita, Yasuji; Tochiyama, Osamu; Inoue, Yasushi.

1988-01-01

A great many extractants have been studied for the separation of transuranium elements. The present study deals with the survey and classification of the extractants appearing in literature, bearing in mind the relationship between the molecular structure of extractants and their extractability for the transuranium elements from the standpoint of their selective separation from high-level liquid waste (HLW) generated from fuel reprocessing. The extractants surveyed were classified into six groups; unidentate neutral organophosphorus compounds, bidentate neutral organophosphorus compounds, acidic organophosphorus compounds, amines and ammonium salts, N,N-disubstituted amides and the other compounds. These extractants are not always applicable to the separation of transuranium elements from HLW because of their limitations in extractability and radiation durability. Only a limited number of extractants belonging to the bidentate neutral organophosphorus compounds and the acidic organophosphorus compounds are considered to be suitable for the present purpose. (author)

Studies in the Philippines on ingestion and organ content of trace elements of importance to radiological protection

International Nuclear Information System (INIS)

Natera, E.S.

1998-01-01

The first Coordinated Research Program on Reference Asian Man (RAM) was conducted for a period of six years. The study dealt with the collection of data in four areas namely: (1) anthropometric measurements, (2) organ mass measurements, (3) nutritional and dietary intake, and (4) pulmonary and water balance studies. Based on the research needs with reference to radiation protection, dietary intake and tissue analysis appear to be important aspects of the RAM. Information to be generated from the elemental analysis of food and tissue would be used to characterize the intake, retention and release of radioactive elements coming from different population groups. This study also aims to establish the elemental composition profile of the average Filipino using simple and accurate methods of measurements. This report will present the protocol which is based to the extent possible on prescribed procedures required for the study. A standardized Protocol to be used in the study is important since stable elements are present only in trace quantities in biological samples of interest. The procedures presented in this document include: collection of one day diet samples and tissue samples (lung, liver, skeletal muscle, thyroid, bone and kidney) from average healthy adult Filipino. The sample treatment and preparation, analytical measurements, data evaluation and reporting will complete said protocol. The elements that are of importance to radiation protection are iodine, cesium, strontium, thorium, and uranium. The essential minor elements are calcium, potassium and sodium. Trace elements like copper. manganese, iron, selenium and zinc will also be included in the analysis. Concentrations of common toxic elements such as mercury, cadmium and lead may likewise be reported in this study. (author)

Study of the stress-strain state of compressed concrete elements with composite reinforcement

Directory of Open Access Journals (Sweden)

Bondarenko Yurii

2017-01-01

Full Text Available The efficiency analysis of the application of glass composite reinforcement in compressed concrete elements as a load-carrying component has been performed. The results of experimental studies of the deformation-strength characteristics of this reinforcement on compression and compressed concrete cylinders reinforced by this reinforcement are presented. The results of tests and mechanisms of sample destruction have been analyzed. The numerical analysis of the stress-strain state has been performed for axial compression of concrete elements with glasscomposite reinforcement. The influence of the reinforcement percentage on the stressed state of a concrete compressed element with the noted reinforcement is estimated. On the basis of the obtained results, it is established that the glass-composite reinforcement has positive effect on the strength of the compressed concrete elements. That is, when calculating the load-bearing capacity of such structures, the function of composite reinforcement on compression should not be neglected.

Space station accommodations for lunar base elements: A study

Science.gov (United States)

Weidman, Deene J.; Cirillo, William; Llewellyn, Charles; Kaszubowski, Martin; Kienlen, E. Michael, Jr.

1987-01-01

The results of a study conducted at NASA-LaRC to assess the impact on the space station of accommodating a Manned Lunar Base are documented. Included in the study are assembly activities for all infrastructure components, resupply and operations support for lunar base elements, crew activity requirements, the effect of lunar activities on Cape Kennedy operations, and the effect on space station science missions. Technology needs to prepare for such missions are also defined. Results of the study indicate that the space station can support the manned lunar base missions with the addition of a Fuel Depot Facility and a heavy lift launch vehicle to support the large launch requirements.

Contaminant transport, revegetation, and trace element studies at inactive uranium mill tailings piles

International Nuclear Information System (INIS)

Dreesen, D.R.; Marple, M.L.; Kelley, N.E.

1978-01-01

The stabilization of inactive uranium mill tailings piles is presently under study. These studies have included investigations of stabilizing tailings by attempting to establish native vegetation without applying irrigation. Examination of processes which transport tailings or associated contaminants into the environment has been undertaken to better understand the containment provided by various stabilization methods. The uptake of toxic trace elements and radionuclides by vegetation has been examined as a mechanism of contaminant transport. The source terms of 222 Rn from inactive piles have been determined as well as the attenuation of radon flux provided by shallow soil covers. The possibility of shallow ground water contamination around an inactive pile has been examined to determine the significance of ground water transport as a mode of contaminant migration. The rationale in support of trace element studies related to uranium milling activities is presented including the enrichment, migration, and toxicities of trace elements often associated with uranium deposits. Some concepts for the stabilization of inactive piles are presented to extrapolate from research findings to practical applications. 25 references, 8 tables

Study on trace elements in gangue in Huainan mining area

Energy Technology Data Exchange (ETDEWEB)

Cai, F.; Liu, Z.; Lin, B.; Li, W.; Lu, Z. [Anhui University of Science and Technology, Huainan (China)

2008-08-15

46 samples were gathered from coal seams and rocks of various lithological types. In these samples, trace elements were analyzed by inductively coupled plasma-mass spectrometry (IAP-MS)and instrumental neutron activation analysis (IAA). Hg was analyzed by cold-vapor atomic absorption spectrometry (KVASS), F by ion-selective electrode (IS) and major elements by chemical methods. Eleven trace elements (Cd, Cu, Ni, Sn, Hg, Mn, As, Cr, Pb, Zn, F) were selected for study, and five of them, Cd, Cu, Ni, Sn, Hg, were above the background soil level (B.L.) of Huainan City, China and world averages. Respectively: Cd is 40 and 7 times the B.L. of Huainan City and the world; Cu is about 2 and 1.5 times the B.L. of Huainan City and the world; Ni is 8 and 7 times the B.L. of Huainan City and the world; Sn is 3 and 2 times the B.L. of Huainan City and the world; and Hg is 3,602 and 1,381 times the B.L. of Huainan City and the world. Their hazards caused to the environment of the mining area are explored primarily. It is thought that their hazards may be cumulative. 15 refs., 1 fig., 3 tabs.

Study of rare earth elements as material for control rods

International Nuclear Information System (INIS)

1975-03-01

The properties of rare earth elements as the material for control rods were studied. The rare earth elements, especially europium oxide, has the nuclear property corresponding to boron carbide, and its neutron absorption process does not emit alpha particles. The elements produced as a result of neutron capture also have large capture cross sections. This paper presents survey report on the properties and nuclear properties of rare earth elements, and comparison with other materials. Preliminary experiment was performed to make the pellets of europium oxide, and is described in this paper. Because of large density, the crystal form to be made was monoclinic system. Europium hydroxide was decomposed at 1000 0 C and 10 -5 torr. The obtained powder was dipped into benzene, and dryed in the air at 450 0 C. This powder was pressed and sintered in the air for one hour at 1500 0 C. The density of the obtained pellets was 97.0% of the theoretical density. The cross section of europium for fast neutron absorption is not yet accurately obtained, and is in the range between 4.65 and 8.5 barn for 151 Eu(n,γ) reaction. Since chain absorption reaction is caused in Eu, the overall capability of neutron absorption is not much changed by the loss of original material due to absorption. The pellets of europium oxide may be handled in air, but must be kept in dry atmosphere. The reactions of europium oxide with various metals were also investigated. The characteristic behavior in case of irradiation depends on the amount of silicon contained, and it was very good if the amount was less than 0.03%. (Kato, T.)

Atmospheric deposition of trace elements in Norway studied by means of moss analysis

International Nuclear Information System (INIS)

Steinnes, E.

1977-02-01

The atmospheric deposition of 28 elements in different parts of Norway was studied by means of moss analysis. The species Hylocomium splendens was selected after a comparison of different species. For several elements large regional differences were found. The highest concentration of these elements were found in the southernmost part of the country and in places near the west coast with high annual precipitation. The lowest values were found in places with low annual precipitation in Eastern Norway and the interior parts of the more northerly parts of the country. Within each region the highest deposition was observed in places with high annual precipitation. For the elements Pb, Sb, As, and Se the observed concentration range amounted to a factor of about 20. In the case of Ag, Cd, Cs, and V the range was smaller, but still amounting to a factor of 10 or more. A lower but still distinct spread was observed for Cr, Mo, Cu, and Zn. For all these elements long distance transport from sources in the densely populated and heavily industrialized parts of Europe probably are of importance for the obsreved distribution. (Auth.)

Translating the Elements of Health Governance for Integrated Care from Theory to Practice: A Case Study Approach.

Science.gov (United States)

Nicholson, Caroline; Hepworth, Julie; Burridge, Letitia; Marley, John; Jackson, Claire

2018-01-31

Against a paucity of evidence, a model describing elements of health governance best suited to achieving integrated care internationally was developed. The aim of this study was to explore how health meso-level organisations used, or planned to use, the governance elements. A case study design was used to offer two contrasting contexts of health governance. Semi-structured interviews were conducted with participants who held senior governance roles. Data were thematically analysed to identify if the elements of health governance were being used, or intended to be in the future. While all participants agreed that the ten elements were essential to developing future integrated care, most were not used. Three major themes were identified: (1) organisational versus system focus, (2) leadership and culture, and, (3) community (dis)engagement. Several barriers and enablers to the use of the elements were identified and would require addressing in order to make evidence-based changes. Despite a clear international policy direction in support of integrated care this study identified a number of significant barriers to its implementation. The study reconfirmed that a focus on all ten elements of health governance is essential to achieve integrated care.

Study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Pyrovan, H.; Raoffi, N.J.; Taherpoor, H.

1985-01-01

This work is part of project with the IAEA in a coordinated program on 'Trace Elements in Human and Bio-environmental Systems' to evaluate their nutritional requierements, interrelations and the role of trace elements in health, metabolism, etc. Cow's milk is regarded to be one of the most important and most nutritious foodstuffs of mankind. Hence, as a first step, an elemental analysis for milk was carried out: a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of the project was the assessment of various analytical techniques involved. AAS, PIXE and NAA are presented here. The latter was applied both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is, however, some justification to clarify this internal inconsistency. PIXE analysis is very fast and rather routine, but the technique for trace element analysis needs certain adaptations and improvement. (author)

Element budgets of forest biomass combustion and ash fertilisation - a Danish case-study

DEFF Research Database (Denmark)

Ingerslev, Morten; Skov, Simon; Sevel, Lisbeth

2011-01-01

Harvest of forest biomass for energy production may lead to a significant export of nutrients from the forest. Ash spreading and recycling of nutrients from wood chip combustion to the forest has come into focus as a means for counteracting the nutrient export. This study was carried out to examine...... the retention of various elements in the different ash fractions and utilise the nutrient recovery to evaluate the fertiliser quality of the examined ash. The mass and element flux of wood chips, bottom ash, cyclone fly ash and condensation sludge at Ebeltoft central heating plant was studied over a four day...

A study on discontinuous Galerkin finite element methods for elliptic problems

NARCIS (Netherlands)

Janivita Joto Sudirham, J.J.S.; Sudirham, J.J.; van der Vegt, Jacobus J.W.; van Damme, Rudolf M.J.

2003-01-01

In this report we study several approaches of the discontinuous Galerkin finite element methods for elliptic problems. An important aspect in these formulations is the use of a lifting operator, for which we present an efficient numerical approximation technique. Numerical experiments for two

The synthetic elements

Energy Technology Data Exchange (ETDEWEB)

Hoffman, D.C.

1990-05-01

Prior to 1940, the heaviest element known was uranium, discovered in 1789. Since that time the elements 93 through 109 have been synthesized and identified and the elements 43, 61, 85, and 87 which were missing form the periodic tables of the 1930's have been discovered. The techniques and problems involved in these discoveries and the placement of the transuranium elements in the periodic table will be discussed. The production and positive identification of elements heavier than Md (Z=101), which have very short half-lives and can only be produced an atom-at-a-time, are very difficult and there have been controversies concerning their discovery. Some of the new methods which have been developed and used in these studies will be described. The prospects for production of still heavier elements will be considered.

The synthetic elements

International Nuclear Information System (INIS)

Hoffman, D.C.

1990-05-01

Prior to 1940, the heaviest element known was uranium, discovered in 1789. Since that time the elements 93 through 109 have been synthesized and identified and the elements 43, 61, 85, and 87 which were missing form the periodic tables of the 1930's have been discovered. The techniques and problems involved in these discoveries and the placement of the transuranium elements in the periodic table will be discussed. The production and positive identification of elements heavier than Md (Z=101), which have very short half-lives and can only be produced an atom-at-a-time, are very difficult and there have been controversies concerning their discovery. Some of the new methods which have been developed and used in these studies will be described. The prospects for production of still heavier elements will be considered

Study of alkaline-earth element complexes in anhydrous acetic acid

International Nuclear Information System (INIS)

Petit, N.

1968-10-01

We have studied the complexes of alkaline-earth elements in anhydrous acetic acid. Using glass-electrode potentiometry we have studied the titration of alkaline earth acetates with perchloric acid which is the strongest acid in anhydrous acetic acid. These titrations have shown that the basic strength of these acetates increases as follows: Mg 4 ); the mixed acetate-acid sulfate complex of barium: Ba (OAc)(HSO 4 ); the mixed acetate-chloride of barium: Ba (OAc)(Cl). (author) [fr

Elemental and structural studies at the bone-cartilage interface

Energy Technology Data Exchange (ETDEWEB)

Kaabar, W., E-mail: w.kaabar@surrey.ac.uk [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Daar, E. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Bunk, O. [Swiss Light Source, Paul Scherrer Institute, 5232 Villigen (Switzerland); Farquharson, M.J. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4K1 (Canada); Laklouk, A. [Al-Fateh University, Tripoli (Libya); Bailey, M.; Jeynes, C. [Surrey Ion Beam Centre, University of Surrey, Guildford GU2 7XH (United Kingdom); Gundogdu, O. [Umuttepe Campus, University of Kocaeli, 41380 Kocaeli (Turkey); Bradley, D.A. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

2011-10-01

Micro-Proton Induced X-ray Emission ({mu}-PIXE) and Proton Induced Gamma-ray Emission (PIGE) techniques were employed in the investigation of trace and essential elements distribution in normal and diseased human femoral head sections affected by osteoarthritis (OA). PIGE was exploited in the determination of elements of low atomic number z<15 such as Na and F whereas elements with z>15 viz Ca, Z, P and S were determined by PIXE. Accumulations of key elements in the bone and cartilage sections were observed, significant S and Na concentrations being found in the cartilage region particularly in normal tissues. Zn showed enhanced concentrations at the bone-cartilage interface. At a synchrotron facility, small angle X-ray scattering (SAXS) was utilized on a decalcified human femoral head section affected by OA, direct measurements being made of spatial alterations of collagen fibres. The SAXS results showed a slight decrease in the axial periodicity between normal collagen type I and that in diseased tissue in various sites, in contrast with the findings of others.

Evaluation and calculation of neutron transactinide cross-sections

International Nuclear Information System (INIS)

Konshin, V.A.

1980-01-01

This paper reviews the state of the art of nuclear theory and its application to the evaluation and calculation of neutron reaction cross sections of transactinium isotopes. In particular, the paper describes the current evaluation of the total files of neutron reaction data for 240 Pu and 241 Pu in the energy range between 10 -5 eV and 15 MeV based on a thorough analysis of available experimental data and on the use of modern theoretical concepts, and the work in progress on the evaluation of the total neutron reaction data file for 242 Pu and 241 Am. (author)

Finite Element Method Application in Areal Rainfall Estimation Case Study; Mashhad Plain Basin

Directory of Open Access Journals (Sweden)

M. Irani

2016-10-01

Full Text Available Introduction: The hydrological models are very important tools for planning and management of water resources. These models can be used for identifying basin and nature problems and choosing various managements. Precipitation is based on these models. Calculations of rainfall would be affected by displacement and region factor such as topography, etc. Estimating areal rainfall is one of the basic needs in meteorological, water resources and others studies. There are various methods for the estimation of rainfall, which can be evaluated by using statistical data and mathematical terms. In hydrological analysis, areal rainfall is so important because of displacement of precipitation. Estimating areal rainfall is divided to three methods: 1- graphical. 2-topographical. 3-numerical. This paper represented calculating mean precipitation (daily, monthly and annual using Galerkin’s method (numerical method and it was compared with other methods such as kriging, IDW, Thiessen and arithmetic mean. In this study, there were 42 actual gauges and thirteen dummies in Mashhad plain basin which is calculated by Galerkin’s method. The method included the use of interpolation functions, allowing an accurate representation of shape and relief of catchment with numerical integration performed by Gaussian quadrature and represented the allocation of weights to stations. Materials and Methods:The estimation of areal rainfall (daily, monthly,… is the basic need for meteorological project. In this field ,there are various methods that one of them is finite element method. Present study aimed to estimate areal rainfall with a 16-year period (1997-2012 by using Galerkin method ( finite element in Mashhad plain basin for 42 station. Therefore, it was compared with other usual methods such as arithmetic mean, Thiessen, Kriging and IDW. The analysis of Thiessen, Kriging and IDW were in ArcGIS10.0 software environment and finite element analysis did by using of Matlab

A study of association between fingernail elements and osteoporosis by laser-induced breakdown spectroscopy

Science.gov (United States)

Bahreini, Maryam; Hosseinimakarem, Zahra; Hassan Tavassoli, Seyed

2012-09-01

Laser induced breakdown spectroscopy (LIBS) is used to investigate the possible effect of osteoporosis on the elemental composition of fingernails. Also, the ability to classify healthy, osteopenic, and osteoporotic subjects based on their fingernail spectra has been examined. 46 atomic and ionic emission lines belonging to 13 elements, which are dominated by calcium and magnesium, have been identified. Measurements are carried out on fingernail clippings of 99 subjects including 27 healthy, 47 osteopenic, and 25 osteoporotic subjects. The Pearson correlations between spectral intensities of different elements of fingernail and age and bone mineral densities (BMDs) in nail samples are calculated. Correlations between line intensities of some elements such as sodium and potassium, calcium and iron, magnesium and silicon and also between some fingernail elements, BMD, and age are observed. Although some of these correlations are weak, some information about mineral metabolism can be deduced from them. Discrimination between nail samples of healthy, osteopenic, and osteoporotic subjects is shown to be somehow possible by a discriminant function analysis using 46 atomic emission lines of the LIBS spectra as input variables. The results of this study provide some evidences for association between osteoporosis and elemental composition of fingernails measured by LIBS.

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

International Nuclear Information System (INIS)

Sanches, Thalita Pinheiro; Saiki, Mitiko

2013-01-01

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

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

International Nuclear Information System (INIS)

Sanches, Thalita Pinheiro

2012-01-01

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

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

A Study of the Temperature Distribution in UO2 Reactor Fuel Elements

International Nuclear Information System (INIS)

Devold, I.

1968-05-01

Thermal conductivity is one of the most important properties of nuclear reactor fuels. Accurate knowledge of this property is vital because, among other things, it determines the maximum power that can be taken out of the fuel element per unit length of the material without exceeding the safety limits of the fuel elements. This report consists of a study of the thermal behaviour of uranium dioxide in the form of reactor fuel. The experimental part of the report describes measurements performed at the OECD Halden Reactor Project, Halden, Norway. The experiment was originally set up in order to measure the temperature at the center of a UO 2 fuel element as a function of element power, in order to determine the safe operation limit of the fuel assembly. However, in analysing the data obtained, very interesting thermal conductivity values were obtained and comparison with existing correlations could be performed. This comparison shows that a certain agreement is obtained between the measured data at Halden and a theory published by J.L. Bates in 1961, which predicts an increase in the thermal conductivity above 1500 deg C. The data obtained below 1300 deg C are also in good agreement with measurements performed by Vogt, Grandell and Runfors in 1964. The report contains a mathematical description of the heat transfer mechanisms in cylindrical fuel elements. The model is coded in FORTRAN IV-code and referred to as FUELTEMP

Uptake of Elements From Aerosols by Humans ~ A Case Study From Delhi & Bangalore Cities

Science.gov (United States)

Anand, S.; Yadav, S.; Jain, V. K.

2006-05-01

Aerosol research has gained tremendous importance globally due to the cumulative effects of increasing industrialization and urbanization on aerosol production which can have an alarming impact on the climate of the planet as well as the health of its inhabitants. Therefore, there is an increasing need to study aerosols for all of their physicochemical and biological aspects on both local and global scales. World over extensive research has gone into studying the physical and the chemical aspects of aerosols. However, little information is yet available on the health impacts of aerosols particularly in the Asian context. Here we report uptake of various elements that are concentrated in aerosols by the human body in Delhi and Bangalore cities and their possible health effects. In many urban areas, for example in Delhi, inhalable fractions of aerosols are known to have high concentrations of elements such as Cu, Zn, Pb, Ba, Ni and Cr (Yadav and Rajamani 2004). Also aerosols in the North West part of India seem to be particularly enriched in these elements. If so, there is a high possibility of these elements getting into the human system either directly or indirectly through water and food. To determine the concentrations of these elements that are present in significant concentrations in the inhalable fractions of aerosols, human hair and blood samples are used as proxies. Both these regions have contrasting geographic and climatic conditions. Delhi (altitude : 213-305m above MSL) located on the fringes of the Thar desert which supplies considerable amount of dust, is semi-arid with annual rainfall of 60-80 cms & temperatures varying between 1° - 45°. Bangalore (altitude of 900m above MSL) receives a high annual rainfall of 80-100 cms and being located on the fringes of tropical forests of the Sahyadri Mountains (Western Ghats) receives little crustal contribution to the aerosols. Samples from least polluted mountainous areas of Himalayas (Gangothri) and Sahyadri

Study of the elemental content in mollusk from Uruguayan's coast by X-ray fluorescence

International Nuclear Information System (INIS)

Bernasconi, G.; Odino, R.; Souto, B.; Mendez, Silvia

1992-01-01

The main objective of the study is to establish a starting point on the content of trace elements, either with a toxic and/or nutritional interest, in Uruguayan coastal mollusks. The River Plate is located between Argentina and Uruguay and has an estuarine nature. It is thus a zone with distinctive features among the South American Atlantic coasts. The analysis techniqe employed is X-ray fluroescence, which is non-destructive and multi-elemental. A simple way of sample preparation is proposed, which does not use reagents that may introduce foreign elements, and is therefore low cost. tabs

A study on the nonlinear finite element analysis of reinforced concrete structures: shell finite element formulation

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Jin; Seo, Jeong Moon

2000-08-01

The main goal of this research is to establish a methodology of finite element analysis of containment building predicting not only global behaviour but also local failure mode. In this report, we summerize some existing numerical analysis techniques to be improved for containment building. In other words, a complete description of the standard degenerated shell finite element formulation is provided for nonlinear stress analysis of nuclear containment structure. A shell finite element is derived using the degenerated solid concept which does not rely on a specific shell theory. Reissner-Mindlin assumptions are adopted to consider the transverse shear deformation effect. In order to minimize the sensitivity of the constitutive equation to structural types, microscopic material model is adopted. The four solution algorithms based on the standard Newton-Raphson method are discussed. Finally, two numerical examples are carried out to test the performance of the adopted shell medel.

A study on the nonlinear finite element analysis of reinforced concrete structures: shell finite element formulation

International Nuclear Information System (INIS)

Lee, Sang Jin; Seo, Jeong Moon

2000-08-01

The main goal of this research is to establish a methodology of finite element analysis of containment building predicting not only global behaviour but also local failure mode. In this report, we summerize some existing numerical analysis techniques to be improved for containment building. In other words, a complete description of the standard degenerated shell finite element formulation is provided for nonlinear stress analysis of nuclear containment structure. A shell finite element is derived using the degenerated solid concept which does not rely on a specific shell theory. Reissner-Mindlin assumptions are adopted to consider the transverse shear deformation effect. In order to minimize the sensitivity of the constitutive equation to structural types, microscopic material model is adopted. The four solution algorithms based on the standard Newton-Raphson method are discussed. Finally, two numerical examples are carried out to test the performance of the adopted shell medel

Atomic pile Directorate, Department of Metallurgy, Departments of Technology, Department of Fuel Elements and Structures, Division of Study of Fuel Elements - Semi annual report on the 1968-10-1

International Nuclear Information System (INIS)

Arnaud, M.; Tortel, J.; Viallet, H.; Marinot, R.; Rulleau, A.; Lestiboudois, G.; Rousseau, G.; Faussat, A.; Ollier, H.; Truffert, J.; Ferrier, C.; Courcon, P.; Rendu, M.; Dieumegard, M.; Bret, A.

1968-01-01

This document gathers a set of reports of studies performed on nuclear fuel elements. The addressed topics are: creep behaviour of UMo and UMoAl tubes and pellets under the action of an external pressure (creep strength of tubes under external pressure, creep strength of pellets under external pressure, uncertainties on irradiation parameters in Pegase), problems related to centring devices (measurements and tests), irradiations of ring elements in power reactors, uranium/sheath metallurgical relationship for Bugey and influence of irradiation (cartridge behaviour in Pegase, long duration irradiation in power reactors, extrapolation in Bugey of results obtained in G2), theoretical study of kinetic oxidation phenomena in metal fuels, tests of leaking cartridges in EdF2, evolution of pressure in EL4 type irradiated fuel rods with ZrCu liners with respect to the conductivity integral, a focus on irradiations of Z0 type fuel elements in Pegase, cluster safety tests with uranium carbide in pile and out of pile, a review of studies performed on fuel elements with blowhole, and application of neutrography to fuel elements

Aerodynamic and thermal studies of cans of gas cooled fuel elements; Etudes aerodynamiques et thermiques de gaines d'elements combustibles refroidis par gaz

Energy Technology Data Exchange (ETDEWEB)

Gelin, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Milliat, J P [Electricite de France (EDF), 75 - Paris (France)

1964-07-01

Research on clusters was undertaken at the CEA in 1959, while studies on herring-bone cans were developed at the EDF Laboratory at Chatou and the CEA laboratory at Saclay at the end of 1959. In 1962, a general study on corrugations was begun at the Saclay Laboratory with a view to improving the clusters, and continued later in both laboratories relative to the internal cooling of annular fuel elements. As these studies progressed, trial facilities were extended while experimental methods have improved constantly. At the present time, both laboratories, working in complete collaboration, have powerful means at their disposal. Work on the clusters has been concerned chiefly with pressure losses due to the assembly parts, and with the temperature variations around the elements of the cluster. In this way, we have been able to determine satisfactorily the hot points of the can, the deformations of the rods and the conditions of stability of these deformations. In the case of the herring-bone cans, studies have been directed to the evolution of performances as a function of the geometric parameters on the one hand, and to the special aerodynamic and thermal features caused by the fins and by interruptions of cartridge on the other hand. These studies have led to a very thorough knowledge of the cartridges chosen for the reactors EDF 2 and EDF 3, and now open up very hopeful prospects for future reactors, particularly those fitted with annular elements; among the alternatives suitable for the inner surface of the annular element can, corrugations and longitudinal fins have been fairly extensively tested over a wide range of Reynolds number. (authors) [French] Les etudes de grappes ont ete entreprises au C.E.A. en 1959, tandis que les etudes de gaines a chevrons se sont developpees au Laboratoire de Chatou de l'EDF et au Laboratoire de Saclay du C.E.A. a la fin de l'annee 1959. En 1962, une etude generale sur les corrugations a ete commencee au Laboratoire de Saclay pour

Finite element simulations with ANSYS workbench 17 theory, applications, case studies

CERN Document Server

Lee, Huei-Huang

2017-01-01

Finite Element Simulations with ANSYS Workbench 17 is a comprehensive and easy to understand workbook. Printed in full color, it utilizes rich graphics and step-by-step instructions to guide you through learning how to perform finite element simulations using ANSYS Workbench. Twenty seven real world case studies are used throughout the book. Many of these case studies are industrial or research projects that you build from scratch. Prebuilt project files are available for download should you run into any problems. Companion videos, that demonstrate exactly how to perform each tutorial, are also available. Relevant background knowledge is reviewed whenever necessary. To be efficient, the review is conceptual rather than mathematical. Key concepts are inserted whenever appropriate and summarized at the end of each chapter. Additional exercises or extension research problems are provided as homework at the end of each chapter. A learning approach emphasizing hands-on experiences spreads though this entire boo...

Finite element simulations with ANSYS Workbench 18 theory, applications, case studies

CERN Document Server

Lee,\tHuei-huang

2018-01-01

Finite Element Simulations with ANSYS Workbench 18 is a comprehensive and easy to understand workbook. Printed in full color, it utilizes rich graphics and step-by-step instructions to guide you through learning how to perform finite element simulations using ANSYS Workbench. Twenty seven real world case studies are used throughout the book. Many of these case studies are industrial or research projects that you build from scratch. Prebuilt project files are available for download should you run into any problems. Companion videos, that demonstrate exactly how to perform each tutorial, are also available. Relevant background knowledge is reviewed whenever necessary. To be efficient, the review is conceptual rather than mathematical. Key concepts are inserted whenever appropriate and summarized at the end of each chapter. Additional exercises or extension research problems are provided as homework at the end of each chapter. A learning approach emphasizing hands-on experiences is utilized though this entire...

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Nuclear analytical methods for trace element studies in calcified tissues

International Nuclear Information System (INIS)

Chaudhry, M.A.; Chaudhry, M.N.

2001-01-01

Full text: Various nuclear analytical methods have been developed and applied to determine the elemental composition of calcified tissues (teeth and bones). Fluorine was determined by prompt gamma activation analysis through the 19 F(p,ag) 16 O reaction. Carbon was measured by activation analysis with He-3 ions, and the technique of Proton-Induced X-ray Emission (PIXE) was applied to simultaneously determine Ca, P, and trace elements in well-documented teeth. Dental hard tissues, enamel, dentine, cement, and their junctions, as well as different parts of the same tissue, were examined separately. Furthermore, using a Proton Microprobe, we measured the surface distribution of F and other elements on and around carious lesions on the enamel. The depth profiles of F, and other elements, were also measured right up to the amelodentin junction

Nuclear microprobe studies of elemental distribution in the seagrass Thalassodendron ciliatum

Energy Technology Data Exchange (ETDEWEB)

Barnabas, A.D. E-mail: alban@pixie.udw.ac.za; Przybylowicz, W.J.; Mesjasz-Przybylowicz, J.; Pineda, C.A

1999-09-02

Elemental levels and distributions in various organs (leaves, upright stems, rhizomes and roots) of the seagrass Thalassodendron ciliatum were determined using the NAC nuclear microprobe. Elemental distributions were obtained using the true elemental imaging system Dynamic Analysis (DA). Cl was the most abundant element present in the organs, occurring in all tissues, but present in relatively low concentrations in epidermal cells of leaves and roots. Na, K, S and Mg were also abundant and occurred in all organ tissues. Ca concentration was highest in the leaves, especially in the epidermis. Low concentrations of P were found and its tissue distribution was limited. Although Fe, Cu, Zn, Mn, Br, Ti and Si were present in relatively small amounts, enrichment of the epidermis with Fe, Ti and Si in all organs, was observed. Fe concentration was the highest in rhizomes while Si concentration was highest in upright stems. The significance of these elemental distribution patterns and the value of the nuclear microprobe in elemental analysis of seagrasses are discussed.

Neutron activation studies of trace elements in tree rings

International Nuclear Information System (INIS)

Tout, R.E.; Gilboy, W.B.; Spyrou, N.M.

1977-01-01

The levels of twelve elements most of which are either considered essential to plant growth or have been detected in air filter samples in an air pollution survey have been monitored in three transverse sections of trees, two elms (ring-porous trees) and one cedar (a conifer). An irradiation time of 10 minutes and a waiting time of 1 minute were selected followed by a 10-minute count. The activated samples were placed on a specially shaped perspex disc situated on a 45-cm 3 Ge(Li) detector. The gamma-ray spectra were subsequently analysed on a 6600 computer, using the library program 'SAMPO' to which subroutines have been added for peak identification and for calculating the mass of elements present. All irradiations were carried out using a thermal neutron flux of 1.5x10 12 ncm -2 sec -1 . Two dimensional distributions of the elements around the tree rings of the section and radially from ring to ring, have been obtained to see if tree rings can be analysed for use as a record of historical pollution. Definite movement of most of these elements between the two main parts of the xylem has occured in all three trees. This makes it seem unlikely that any pollution products taken up from the atmosphere would be retained in the same ring in which they were originally accumulated. Exceptions may occur in the sapwood rings, where a few elements, especially Cl, show directional peaks which do not persist in the heartwood. (T.G.)

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)

Chemical elements in invertebrate orders for environmental quality studies

International Nuclear Information System (INIS)

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

2013-01-01

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

Study on trace and rare earth elements in Indonesian oil sands

Energy Technology Data Exchange (ETDEWEB)

Bai, Jing-ru; Wang, Qing; Liu, Hong-peng; Bai, Zhang [Northeast Dianli Univ., Jilin (China). Engineering Research Centre

2013-07-01

Major, trace elements and rare earth and mineral composition of the oil sand samples (ST1, ST2, ST3) and the oil sand retorting residue (semi-coke: SC1, SC2, SC3) from Indonesian were determined by XFS, ICP-MS and XRD methods. The trace elements content in oil sand is pretty much the same thing in Earth's Clarke value. The trace element is abundantly in earth's Clarke, in oil sand yet, for Ti, Mn, Ba, Sr, but these elements are lower enrichment. However, the Cr (EF = 16.8) and Mo (EF = 11.8) are ''enrichment'' in ST1; the Ni (EF =10.5), Se (EF = 17.5), Sr (EF = 28.7), Mo (EF = 106.5), Sc (EF = 12.8) and U (EF = 43.2) are ''enrichment'' in ST2; the Se (EF = 12.6), Sr (EF = 18.4), Mo (EF = 47.5), and U (EF = 27.8) are ''enrichment'' in ST3. Calculations show that trace elements in sime-coke have lower evaporation rate during Fischer Assay. Trace elements in raw oil sand are so stable that trace elements can't move easily to other pyrolysis product but enrich to sime-coke. After retorting, more elements are EF > 10, such as B, V, Ni, As, Se, Sr, Mo, Hg, Cs and U. It is essential to take the pollution produced by trace elements in sime-coke during the sime-coke utilization into consideration. The REEs content had a high correlation with the ash in oil sand. The REE is closely related to terrigenous elastic rocks.

Dietary intakes of essential trace elements. Results from total diet studies supported by the IAEA

International Nuclear Information System (INIS)

Parr, R.M.; Iyengar, G.V.; Aras, N.K.

2006-01-01

The International Atomic Energy Agency (IAEA) has, for many years, supported research on human dietary intakes of trace elements taking advantage, for analysis, of the possibilities offered by nuclear techniques, particularly neutron activation analysis (NAA). This paper summarizes the results obtained from studies in more than 20 countries in which special emphasis was placed on the application of reliable methodologies (written protocols, special equipment, analytical quality control, etc.). Considerable variation was observed among dietary intakes of essential minor and trace elements though most elements showed a pattern of adequate nutrition in most countries. However, for some elements such as calcium, iodine, iron and zinc, the intakes in many countries were lower than the dietary requirements. (author)

High-pressure on f-element materials

International Nuclear Information System (INIS)

Haire, R.G.

1991-01-01

540Studies of the f-elements under pressure provide important insights into their solid state chemistry and physics. From such studies of the elements and their alloys, it has been established that the normally localized f-electrons of several of these elements can become involved in bonding under pressure. The electronic behavior of f-element compounds under pressure tend to be more difficult to interpret, due to the variety and the nature of electronic orbitals that are present. The 4f-elements and some 60% of the 5f-elements have been studied under pressure. The systematic comparisons that have been established for these materials are discussed. 76 refs., 3 figs

Study of rare earth elements, uranium and thorium migration in rocks from Espinharas uranium deposit, Paraiba - Brazil

International Nuclear Information System (INIS)

Conceicao, Cirilo C.S.

2009-01-01

The determination of rare earth elements as natural analogue in patterns geologic has grown as a tool for predicting the long-term safety of nuclear disposal in geological formation. Migration of natural radionuclides is one of the most serious problems in the waste deposit from nuclear fuel cycle. Rare earth elements show the same kinetic behavior in rocks as natural radionuclides. This similar property of the analogues allows perform studies and models on the subject of radionuclides migration. The aim of this study was to determine the distribution of rare earth elements in rocks located at Espinharas - Paraiba - Brazil, uranium deposit. In this work are presented the results from the study above the distribution of rare earth elements in function of the degree of mineralized rocks, composition and the conditions of radioactive equilibrium of the uranium and thorium in some fractures on the rocks from radioactive occurrence of Espinharas-Brazil. The results show that there is a correlation of heavy rare earth elements, uranium and Thorium concentrations to oxidation factor of the rocks. However this correlation was not observed for light rare earth elements. It means that heavy rare earth elements follow the natural radionuclides in oxidation process of rocks. The samples were analyzed by ICP-MS, alpha and gamma spectrometry, X-ray diffraction and fluorimetry. (author)

Transplutonium elements

Energy Technology Data Exchange (ETDEWEB)

Sivaramakrishnan, C. K.; Jadhav, A. V.; Reghuraman, K.; Mathew, K. A.; Nair, P. S.; Ramaniah, M. V.

1973-07-01

Research progress is reported on studies of the transplutonium elements including recovery and purification of americium, preparation of /sup 238/Pu, extraction studies using diethylhexyl phosphate. (DHM)

Parametric study of the low-enriched uranium integrated Fort-Saint-Vrain element; comparative evaluation with the interacting tubular element

International Nuclear Information System (INIS)

Cerles, J.M.; Carvallo, G.; Vallepin, C.

1971-11-01

This paper presents a study of the influence of the different geometric and neutronic parameters on the calculation of the cycle with low-enriched uranium in a Fort-Saint-Vrain type brick. The study is divided in two parts: a stage of physics, essentially neutronics; an economical part where the costs are taken into account. At the level of studies of neutronics and costs, a parallel comparison is developed between the brick Fort-Saint-Vrain and the interacting tubular element, and even thorium. 6 refs. 29 figs [fr

A computational study of nodal-based tetrahedral element behavior.

Energy Technology Data Exchange (ETDEWEB)

Gullerud, Arne S.

2010-09-01

This report explores the behavior of nodal-based tetrahedral elements on six sample problems, and compares their solution to that of a corresponding hexahedral mesh. The problems demonstrate that while certain aspects of the solution field for the nodal-based tetrahedrons provide good quality results, the pressure field tends to be of poor quality. Results appear to be strongly affected by the connectivity of the tetrahedral elements. Simulations that rely on the pressure field, such as those which use material models that are dependent on the pressure (e.g. equation-of-state models), can generate erroneous results. Remeshing can also be strongly affected by these issues. The nodal-based test elements as they currently stand need to be used with caution to ensure that their numerical deficiencies do not adversely affect critical values of interest.

Study of trace elements in milk by nuclear analytical techniques

Energy Technology Data Exchange (ETDEWEB)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H. (Atomic Energy Organization of Iran, Teheran. Nuclear Research Centre)

This work is part of a project with the IAEA, in a coordinated programme on ''trace elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of trace elements in health, metabolism etc. Cow's milk is regarded as one of the most important and nutritious foodstuffs consumed by people. Hence, as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is very fast and rather routine, the technique of trace element analysis needs certain adaptations and developments.

Study on elements concentrations on seabird feathers by instrumental neutron activation analysis

Energy Technology Data Exchange (ETDEWEB)

Theophilo, Carolina Y.S.; Moreira, Edson G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), São Paulo, SP (Brazil); Figueira, Rubens C.L.; Colabuono, Fernanda I., E-mail: carolina.theophilo@gmail.com, E-mail: emoreira@ipen.br, E-mail: rfigueira@usp.br, E-mail: ficolabuono@gmail.com [Universidade de São Paulo (USP), São Paulo, SP (Brazil). Instituto Oceanográfico

2017-07-01

Seabirds are very sensitive to environmental changes and because of their large longevity they are also sensitive to cumulative impacts. These birds usually occupy the higher trophic levels. White-chinned petrel (Procellaria aequinoctialis) and black-browed albatross (Thalassarche melanophris) are Procellariiformes, which is a seabird order, composed of 4 families. In the last years, researches are being done and actions are being taken to reduce the mortality of albatrosses and petrels caused by human activities. Due to the great ecological importance of these birds and the developed work with Procellariiformes, this study purpose is to quantify the Br, Cl, Cu, K, Mg, Mn, Na and V elements in white-chinned petrel and black-browed albatross feathers. Bird specimens were killed accidentally by pelagic longline fisheries operating off southern Brazil. Feathers were cleaned with acetone and then milled in a cryogenic mill. Instrumental Neutron Activation Analysis (INAA) was used for quantification of the element concentrations and measurements of induced activities were performed in a HPGe detector for gamma ray spectrometry. The obtained results on feathers showed that concentrations in these birds are not higher than others studies with the same species and, with exception of Br, there are no significant differences between elements mean concentrations in the two seabirds. (author)

Study on elements concentrations on seabird feathers by instrumental neutron activation analysis

International Nuclear Information System (INIS)

Theophilo, Carolina Y.S.; Moreira, Edson G.; Figueira, Rubens C.L.; Colabuono, Fernanda I.

2017-01-01

Seabirds are very sensitive to environmental changes and because of their large longevity they are also sensitive to cumulative impacts. These birds usually occupy the higher trophic levels. White-chinned petrel (Procellaria aequinoctialis) and black-browed albatross (Thalassarche melanophris) are Procellariiformes, which is a seabird order, composed of 4 families. In the last years, researches are being done and actions are being taken to reduce the mortality of albatrosses and petrels caused by human activities. Due to the great ecological importance of these birds and the developed work with Procellariiformes, this study purpose is to quantify the Br, Cl, Cu, K, Mg, Mn, Na and V elements in white-chinned petrel and black-browed albatross feathers. Bird specimens were killed accidentally by pelagic longline fisheries operating off southern Brazil. Feathers were cleaned with acetone and then milled in a cryogenic mill. Instrumental Neutron Activation Analysis (INAA) was used for quantification of the element concentrations and measurements of induced activities were performed in a HPGe detector for gamma ray spectrometry. The obtained results on feathers showed that concentrations in these birds are not higher than others studies with the same species and, with exception of Br, there are no significant differences between elements mean concentrations in the two seabirds. (author)

Study on the correlation between the trace elements with cerebrovascular diseases

Energy Technology Data Exchange (ETDEWEB)

Dazhong, Zhang; Mingsong, Tai; Suqing, Chen [Sichuan Univ., Chengdu, SC (China). Inst. of Nuclear Science and Technology; and others

1990-11-01

In the paper, the correlation between the cerebroscular diseases, as haemorrhage, cerebral atherosclerosis, cerebral embolism, with trace element contents in hair and tissues of controls and diseases has been studied by PIXE. Biochemistry test for diseased cerebral atheroselerosis patientes were done. The distinction between the controls and diseases were revealed.

Finite element analysis of an inflatable torus considering air mass structural element

Science.gov (United States)

Gajbhiye, S. C.; Upadhyay, S. H.; Harsha, S. P.

2014-01-01

Inflatable structures, also known as gossamer structures, are at high boom in the current space technology due to their low mass and compact size comparing to the traditional spacecraft designing. Internal pressure becomes the major source of strength and rigidity, essentially stiffen the structure. However, inflatable space based membrane structure are at high risk to the vibration disturbance due to their low structural stiffness and material damping. Hence, the vibration modes of the structure should be known to a high degree of accuracy in order to provide better control authority. In the past, most of the studies conducted on the vibration analysis of gossamer structures used inaccurate or approximate theories in modeling the internal pressure. The toroidal shaped structure is one of the important key element in space application, helps to support the reflector in space application. This paper discusses the finite-element analysis of an inflated torus. The eigen-frequencies are obtained via three-dimensional small-strain elasticity theory, based on extremum energy principle. The two finite-element model (model-1 and model-2) have cases have been generated using a commercial finite-element package. The structure model-1 with shell element and model-2 with the combination of the mass of enclosed fluid (air) added to the shell elements have been taken for the study. The model-1 is computed with present analytical approach to understand the convergence rate and the accuracy. The convergence study is made available for the symmetric modes and anti-symmetric modes about the centroidal-axis plane, meeting the eigen-frequencies of an inflatable torus with the circular cross section. The structural model-2 is introduced with air mass element and analyzed its eigen-frequency with different aspect ratio and mode shape response using in-plane and out-plane loading condition are studied.

Electrochemical Studies on Important Elements for Zirconium Recovery Form Irradiated Zircaloy-4 Cladding

International Nuclear Information System (INIS)

Park, J.; Sohn, S.; Hwang, I.S.

2015-01-01

Since Zircaloy cladding accounts for about 16 wt. % of used nuclear fuel assembly, decontamination process is required to reduce the final waste volume from spent nuclear fuel. To develop Zircaloy-4 electrorefining process as an irradiated Zircaloy cladding decontamination process, electrochemical studies on Sn, Cr, Fe and Co which are major or important elements in the irradiated cladding were conducted based on cyclic voltammetry in LiCl-KCl at 500 deg. C. Cyclic voltammetry for Sn, Fe, Cr and Co elements that should be eliminated was conducted and revealed that redox reactions of these ions are much simpler than Zr and more reductive than Zr. The reliability of cyclic voltammetry was verified by comparing diffusion coefficients and formal reduction potentials of these ions obtained in this study to previous studies. (authors)

Contributions to multiple element speciation in vegetable plants: Studies on the type of bonding of numerous elements, particularly zinc and cadmium

International Nuclear Information System (INIS)

Guenther, K.

1997-03-01

In the first part of the study, the total contents and the solubility characteristics of Zn, Cd, Fe, Mn, Cu, Ca, Sr, K and Rb in 26 different vegetable plants, the majority of them commercially available, are reported, obtained by post-decomposition analyses. The data are given for avocados, bananas, cauliflower, chicory, Chinese cabbage, dill, ice lettuce (two specimens), endive, field salad, cucumbers, kohlrabi, lettuce, chard beet, carrots, peppers, leek, radish, red cabbage, loose leaved lettuce, celery (two specimens), spinach, topinambur, white cabbage, and parsley. Cell decomposition was done by treatment of the plant material with an electric dispersing apparatus (Ultra-Turrax) in buffer solution (liquid shearing). The homogenates were separated into supernatants (cytosoles)and pellets by means of centrifugation. Cell decomposition of the plants by crushing with quartz sand after lyophilization (solid shearing) required much more technical effort and for some elements created problems with the blind values. At least 50% on the average of the elements Zn, Cd, Rb, and K could be transferred to the solutions by the dispersing treatment with Ultra-Turrax. In many cases, the cytosole-borne detectable contents of these 5 elements were above 70%. The solubility of Zn and Cd was more strongly dependent on the plant species than that of Cu, Rb, and K. All five elements thus can be analysed by conventional methods for further enhanced speciation. Mn, Ca, and especially Fe and Sr for the most part were found to be bonded to solid cell constituents. However, the solubility characteristics of Ca and Mn and Sr in particular was very homogeneous. In some plants, the contents of Mn and Sr in the cytosoles was approx. 90%, so that comprehensive speciation of these elements is possible. (orig./AJ) [de

Solar power satellite rectenna design study: Directional receiving elements and parallel-series combining analysis

Science.gov (United States)

Gutmann, R. J.; Borrego, J. M.

1978-01-01

Rectenna conversion efficiencies (RF to dc) approximating 85 percent were demonstrated on a small scale, clearly indicating the feasibility and potential of efficiency of microwave power to dc. The overall cost estimates of the solar power satellite indicate that the baseline rectenna subsystem will be between 25 to 40 percent of the system cost. The directional receiving elements and element extensions were studied, along with power combining evaluation and evaluation extensions.

Micromechanical Study of Interface Stress in a Fiber-Reinforced Composite under Transverse Loading Using Boundary Element Method

National Research Council Canada - National Science Library

Eren, Hakan

2000-01-01

.... The objective of this study is, by using Boundary Element Method, to examine different shapes of reinforcement elements under unit traction and unit displacement boundary conditions in transversal...

A Literature Study of Matrix Element Influenced to the Result of Analysis Using Absorption Atomic Spectroscopy Method (AAS)

International Nuclear Information System (INIS)

Tyas-Djuhariningrum

2004-01-01

The gold sample analysis can be deviated more than >10% to those thrue value caused by the matrix element. So that the matrix element character need to be study in order to reduce the deviation. In rock samples, the matrix elements can cause self quenching, self absorption and ionization process, so there is a result analysis error. In the rock geochemical process, the elements of the same group at the periodic system have the tendency to be together because of their same characteristic. In absorption Atomic Spectroscopy analysis, the elements associate can absorb primer energy with similar wave length so that it can cause deviation in the result interpretation. The aim of study is to predict matrix element influences from rock sample with application standard method for reducing deviation. In quantitative way, assessment of primer light intensity that will be absorbed is proportional to the concentration atom in the sample that relationship between photon intensity with concentration in part per million is linier (ppm). These methods for eliminating matrix elements influence consist of three methods : external standard method, internal standard method, and addition standard method. External standard method for all matrix element, internal standard method for elimination matrix element that have similar characteristics, addition standard methods for elimination matrix elements in Au, Pt samples. The third of standard posess here accuracy are about 95-97%. (author)

Environmental pollution studies. Quantitative determination of elements in the air particulate matter by NAA

International Nuclear Information System (INIS)

Sutisna; Hidayat, Achmad; Muhayatun; Supriatna, Dadang

2006-01-01

Regarding to the 2002 PNCA Program for the Utilization of INAA in the Environmental Study, the elemental determination of air particulate matter have been done. Two sampling site were chosen to collect a PMs samples, i.e. Lembang and Bandung that represent the rural and the urban region respectively. The period of sampling was January 2002 to November 2002. Air sample was collect by GANT Stacked air sampler using 47 mm diameter cellulose filter which have a pore size of 0.45 μm and 8 μm for fine and coarse particle respectively. Quantitative elemental determination has been done using Instrumental Neutron Activation Analysis based on a comparative method. The elemental distributions on fine and coarse fraction of air particulate matter have been analyzed for both sampling sites as well as the enrichment factor (EF) for all elements interest. The result shows that the average annual concentrations of fine and coarse PMs in the Lembang sampling site were 7.8 μg.m -3 and 1.6 μg.m -3 respectively. Meanwhile at Bandung sampling site, the PMs are higher than that a Lembang sampling site, i.e. 14.4 μg.m -3 and 22.5 μg.m -3 for fine and coarse PMs respectively. The fine fraction was higher than the coarse fraction at Lembang sampling site, but at Bandung sampling site the fine fraction was lower than the coarse fraction. Fifteen elements of Na, Al, V, Mn, Br, I, Cl, Sc, Co, Fe, Cr, Zn, La, Sb and Sm were analyzed for both sampling site. Among those elements concerned, Na, Al, Br, Cl and Fe were major constituent elements in all fractions that have a concentration more than 40 ng.cm -3 . Generally, the concentration of elements determined in the urban sampling site was higher than that in the rural site. Al, V, Mn, Sc, Co and Fe are relatively higher in concentration in coarse fraction of urban site. Br element concentration was not significantly different for both sampling site. The EF values of most elements concerned are generally also higher for the fine fraction

Systematic studies of radioactive elements in various rocks in northern Thailand

Energy Technology Data Exchange (ETDEWEB)

Wattananikorn, K; Teeyasoontranont, V; Vilaithong, T; Lerdthusnee, S

1985-12-31

An investigation into the concentrations of the main heat producing radioactive elements, uranium, thorium and potassium in various rock samples was carried out by gamma ray spectrometry. The samples included igneous, metamorphic and sedimentary rocks of different ages. They were collected mainly from the northern part of the country. Results of the investigation show relatively high concentrations of radioactive elements in most rock types, compared to the average values commonly cited. However, for granitic rocks the values obtained are, more or less, comparable to those obtained by Amnuaychai Thienprasert and his colleagues, who worked in the same area using different methods of investigation. Apart from that granitic samples of triassic and cretaceous ages also have a similar radioactive elements concentration to those of the Darby pluton in Southeastern Seward Peninsular, Alaska, the Granite Mountain in Wyoming and the Conway Granite of New Hampshire which has been cited as a low-grade uranium-thorium resource. As a consequence of such high radioactive element concentrations, heat generations of most rock samples investigated are much higher than reported average values. The heat generations seem to have some influence on the nature of heat sources of hot springs in northern Thailand, especially at Ban Pong, Nam Ron hot spring Amphoe Mae Chan. Furthermore the radiogenic heat productions also affect to a great extent surface heat flow in the region provided that the radioactive element concentrations do not decrease with depth. Surface heat flow in northern Thailand was recently reported to be very high compared to the average value of the earth. This high heat flow was suspected to be caused by extensional tectonics resulting indirectly from sea-floor spreading in the Andaman Sea during the last 10 million years. However, from this study it can be shown that heat generations could be another factor which has much influence on the value of the surface heat flow.

Trace elements in nail polish as a source of contamination of nail clippings when used in epidemiological studies

International Nuclear Information System (INIS)

Favaro, P.C.; Bode, P.; De Nadai Fernandes, E.A.

2005-01-01

Trace elements were determined in 27 brands of nail polish using INAA so as to estimate the impact of nail polish remainders when using (finger, toe) nail clippings as a bioindicator for epidemiological studies. Fe was found to be present up to almost 1.7% in one brand. No unambiguous correlation between trace elements and color was established, though transparent polish has the lowest trace element concentrations. An estimate of the maximum effect (no removal of the paint) indicates that over-estimates of some trace element levels in nail with more than 200.000% may occur. If nail clippings will be used to study trace elements, very high demands have to be set to the efficiency and selectivity of the cleaning procedure. (author)

Studies on Elemental Contents of Some Biological and Environmental Materials Using Nuclear And Atomic Techniques

International Nuclear Information System (INIS)

Abd-El Aziz, W.M.M.

2013-01-01

study raises ethical and medical concerns about the implications of using eye-liners with high toxic elemental content in Egypt.

Elemental analysis of edible grains by micro-PIXE: Common buckwheat case study

Energy Technology Data Exchange (ETDEWEB)

Vogel-Mikus, K. [Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Pelicon, P.; Vavpetic, P. [Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Kreft, I. [Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia)], E-mail: ivan.kreft@guest.arnes.si; Regvar, M. [Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia)

2009-09-01

The aim of this study was the adaptation of the micro-PIXE method for analysis of nutritionally relevant heavy elements in different tissues of the grain of common buckwheat (Fagopyrum esculentum), as a representative nutritionally interesting grain food source. At 57% of the buckwheat grain biomass, the endosperm was a modest nutrient source when compared to the cotyledons, at 17% of the biomass. These latter contained high concentrations of trace elements, representing 91% of the total grain Zn, 87% for P, 70% for S, 62% for Mg, 60% for K, 54% for Cu, 53% for Mn and 35% for Fe. The husk provided storage for 85% of the total Ca, 84% for Al, 83% for Si, 76% for Cl, 69% for Ti and 46% for Fe. Knowledge on these preferential elemental constitutions of the different grain tissues makes the possibility of designing target products with nutritionally optimal constitution more feasible. These data represent a basis for a more targeted approach to nutritional improvement of grains intended for human consumption.

Elemental analysis of edible grains by micro-PIXE: Common buckwheat case study

International Nuclear Information System (INIS)

Vogel-Mikus, K.; Pelicon, P.; Vavpetic, P.; Kreft, I.; Regvar, M.

2009-01-01

The aim of this study was the adaptation of the micro-PIXE method for analysis of nutritionally relevant heavy elements in different tissues of the grain of common buckwheat (Fagopyrum esculentum), as a representative nutritionally interesting grain food source. At 57% of the buckwheat grain biomass, the endosperm was a modest nutrient source when compared to the cotyledons, at 17% of the biomass. These latter contained high concentrations of trace elements, representing 91% of the total grain Zn, 87% for P, 70% for S, 62% for Mg, 60% for K, 54% for Cu, 53% for Mn and 35% for Fe. The husk provided storage for 85% of the total Ca, 84% for Al, 83% for Si, 76% for Cl, 69% for Ti and 46% for Fe. Knowledge on these preferential elemental constitutions of the different grain tissues makes the possibility of designing target products with nutritionally optimal constitution more feasible. These data represent a basis for a more targeted approach to nutritional improvement of grains intended for human consumption.

Studies of biaxial mechanical properties and nonlinear finite element modeling of skin.

Science.gov (United States)

Shang, Xituan; Yen, Michael R T; Gaber, M Waleed

2010-06-01

The objective of this research is to conduct mechanical property studies of skin from two individual but potentially connected aspects. One is to determine the mechanical properties of the skin experimentally by biaxial tests, and the other is to use the finite element method to model the skin properties. Dynamic biaxial tests were performed on 16 pieces of abdominal skin specimen from rats. Typical biaxial stress-strain responses show that skin possesses anisotropy, nonlinearity and hysteresis. To describe the stress-strain relationship in forms of strain energy function, the material constants of each specimen were obtained and the results show a high correlation between theory and experiments. Based on the experimental results, a finite element model of skin was built to model the skin's special properties including anisotropy and nonlinearity. This model was based on Arruda and Boyce's eight-chain model and Bischoff et al.'s finite element model of skin. The simulation results show that the isotropic, nonlinear eight-chain model could predict the skin's anisotropic and nonlinear responses to biaxial loading by the presence of an anisotropic prestress state.

Process development for elemental recovery from PGM tailings by thermochemical treatment: Preliminary major element extraction studies using ammonium sulphate as extracting agent.

Science.gov (United States)

Mohamed, Sameera; van der Merwe, Elizabet M; Altermann, Wladyslaw; Doucet, Frédéric J

2016-04-01

Mine tailings can represent untapped secondary resources of non-ferrous, ferrous, precious, rare and trace metals. Continuous research is conducted to identify opportunities for the utilisation of these materials. This preliminary study investigated the possibility of extracting major elements from South African tailings associated with the mining of Platinum Group Metals (PGM) at the Two Rivers mine operations. These PGM tailings typically contain four major elements (11% Al2O3; 12% MgO; 22% Fe2O3; 34% Cr2O3), with lesser amounts of SiO2 (18%) and CaO (2%). Extraction was achieved via thermochemical treatment followed by aqueous dissolution, as an alternative to conventional hydrometallurgical processes. The thermochemical treatment step used ammonium sulphate, a widely available, low-cost, recyclable chemical agent. Quantification of the efficiency of the thermochemical process required the development and optimisation of the dissolution technique. Dissolution in water promoted the formation of secondary iron precipitates, which could be prevented by leaching thermochemically-treated tailings in 0.6M HNO3 solution. The best extraction efficiencies were achieved for aluminium (ca. 60%) and calcium (ca. 80%). 35% iron and 32% silicon were also extracted, alongside chromium (27%) and magnesium (25%). Thermochemical treatment using ammonium sulphate may therefore represent a promising technology for extracting valuable elements from PGM tailings, which could be subsequently converted to value-added products. However, it is not element-selective, and major elements were found to compete with the reagent to form water-soluble sulphate-metal species. Further development of this integrated process, which aims at achieving the full potential of utilisation of PGM tailings, is currently underway. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemistry of the heaviest elements

International Nuclear Information System (INIS)

Hoffman, D.C.

1996-01-01

Studies of the chemical properties of the elements at the uppermost end of the periodic table are discussed. Some historical perspective is given, but major emphasis is on recent studies. Isotopes of these elements are short-lived and, therefore, must be studied near the site of production. They must be produced with charged-particle beams at accelerators rather than via neutron capture. The use of radioactive heavy actinide targets is often required and the number of atoms produced is so small that any chemistry to be performed must be done on an ''atom-at-a-time'' basis. Furthermore, a knowledge of their nuclear properties is required in order to identify and detect them. To date, both gas and aqueous phase properties of elements as heavy as element 104 (rutherfordium) and element 105 (hahnium) have been investigated, even though their longest-lived known isotopes have half-lives of only 65 and 35 seconds, respectively. The experimental results show that their chemical properties cannot be simply extrapolated from the known properties of their lighter homologs in the periodic table, emphasizing the importance of obtaining additional experimental information for the heaviest elements to compare with predictions and help assess the influence of relativistic effects. The feasibility of the extension of chemical studies to still heavier elements is also discussed. (orig.)

Fluid element in SAP IV

International Nuclear Information System (INIS)

Yilmaz, C.; Akkas, N.

1979-01-01

In previous studies a fluid element is incorporated in the widely used general purpose finite element program SAPIV. This type of problem is of interest in the design of nuclear components involving geometric complexities and nonlinearities. The elasticity matrix of a general-purpose finite element program is modified in such a way that it becomes possible to idealize fluid as a structural finite element with zero shear modulus and a given bulk modules. Using the modified version of SAPIV, several solid-fluid interactions problems are solved. The numerical solutions are compared with the available analytical solutions. They are shown to be in reasonable aggrement. It is also shown that by solving an exterior-fluid interaction problem, the pressure wave propagation in the acoustic medium can be solved with the same approach. In this study, two of the problem not studied in the previous work will be presented. These problems are namely the effects of the link elements used at solid-fluid interfaces and of the concentrated loads on the response of the fluid medium. Truss elements are used as the link elements. After these investigations, it is decided that general purpose finite element programs with slight modifications can be used in the safety analysis of nuclear reactor plants. By this procedure it is possible to handle two-dimensional plane strain and tridimensional axisymmetric problems of this type. (orig.)

Spectrophotometric studies of transcurium element halides and oxyhalides in the solid state

International Nuclear Information System (INIS)

Young, J.P.; Haire, R.G.; Fellows, R. L.; Peterson, J.R.

1978-01-01

The present state of a microscale spectrophotometric technique is described. The application of spectrophotometry to transcurium elements (Bk, Cf, Es) requires some rather specialized microtechniques for the following reasons: only small amounts of these elements are available; their radioactivity makes the use of μg-sized samples desirable; and spectral study of solids requires thin samples. A schematic diagram of the microscope-spectrophotometer used for spectrophotometric study of the transcurium element compounds is shown. The spectrophotometer, of local design, consists of two microscopes equipped with Cassegrainian reflecting microscope objective lenses, a quartz field lens, and a Jarrell Ash 1/2 meter scanning monochromator equipped with a 1180 line/mm grating blazed at 4000 A. The photomultiplier used in this system is an S-1 type RCA 7102 operated at approximately -50 deg C. This grating-photomultiplier combination provides a continuous response free of discontinuities over the useful wavelength range of the system from 3000 to 11 000 A. The microscope-spectrophotometer is a single beam instrument. Each spectral trace is registered as photomultiplier current on a strip chart recorder. In order to obtain true absorption spectra, however, the output from the photometer is also simultaneously digitized for on-line processing. The unique advantages of applying both spectrophotometric and X-ray powder diffraction methods on the sample, in order to identify and characterize newly synthesized compounds, are also discussed. (T.G.)

Thermohydraulic study of a MTR fuel element aimed at the construction of an irradiation facility

International Nuclear Information System (INIS)

Coragem, Helio Boemer de Oliveira

1980-01-01

A thermohydraulic study of MTR fuel element is presented as a basic requirement for the development of an irradiation facility for testing fuel elements. A computer code named 'Thermo' has been developed for this purpose, which can stimulate different working conditions, such as, cooling, power elements and neutron flux, performing all pertinent thermohydraulic calculations. Thermocouples were used to measure the temperature gradients of the cooling fluid throughout the IEAR-1 reactor core. All experimental data are in good agreement with the theoretical model applied in this work. Finally, a draft of the proposed facility and its safety system is presented. (author)

A Study of the Temperature Distribution in UO{sub 2} Reactor Fuel Elements

Energy Technology Data Exchange (ETDEWEB)

Devold, I

1968-05-15

Thermal conductivity is one of the most important properties of nuclear reactor fuels. Accurate knowledge of this property is vital because, among other things, it determines the maximum power that can be taken out of the fuel element per unit length of the material without exceeding the safety limits of the fuel elements. This report consists of a study of the thermal behaviour of uranium dioxide in the form of reactor fuel. The experimental part of the report describes measurements performed at the OECD Halden Reactor Project, Halden, Norway. The experiment was originally set up in order to measure the temperature at the center of a UO{sub 2} fuel element as a function of element power, in order to determine the safe operation limit of the fuel assembly. However, in analysing the data obtained, very interesting thermal conductivity values were obtained and comparison with existing correlations could be performed. This comparison shows that a certain agreement is obtained between the measured data at Halden and a theory published by J.L. Bates in 1961, which predicts an increase in the thermal conductivity above 1500 deg C. The data obtained below 1300 deg C are also in good agreement with measurements performed by Vogt, Grandell and Runfors in 1964. The report contains a mathematical description of the heat transfer mechanisms in cylindrical fuel elements. The model is coded in FORTRAN IV-code and referred to as FUELTEMP.

Elemental and structural studies at the bone-cartilage interface

International Nuclear Information System (INIS)

Kaabar, W.; Daar, E.; Bunk, O.; Farquharson, M.J.; Laklouk, A.; Bailey, M.; Jeynes, C.; Gundogdu, O.; Bradley, D.A.

2011-01-01

Micro-Proton Induced X-ray Emission (μ-PIXE) and Proton Induced Gamma-ray Emission (PIGE) techniques were employed in the investigation of trace and essential elements distribution in normal and diseased human femoral head sections affected by osteoarthritis (OA). PIGE was exploited in the determination of elements of low atomic number z 15 viz Ca, Z, P and S were determined by PIXE. Accumulations of key elements in the bone and cartilage sections were observed, significant S and Na concentrations being found in the cartilage region particularly in normal tissues. Zn showed enhanced concentrations at the bone-cartilage interface. At a synchrotron facility, small angle X-ray scattering (SAXS) was utilized on a decalcified human femoral head section affected by OA, direct measurements being made of spatial alterations of collagen fibres. The SAXS results showed a slight decrease in the axial periodicity between normal collagen type I and that in diseased tissue in various sites, in contrast with the findings of others.

Study on essential and toxic elements intake from drinking of Chinese tea

International Nuclear Information System (INIS)

Hai-Qing Zhang; Bang-Fa Ni; Wei-Zhi Tian; Gui-Ying Zhang; Dong-Hui Huang; Cun-Xiong Liu; Cai-Jin Xiao; Hong-Chao Sun; Chang-Jun Zhao

2011-01-01

Twenty different brands of Chinese tea were analyzed for multiple trace elements, including some essential and toxic elements, by neutron activation analysis (NAA). A comparison among tea brands from China, India, US and other countries was made for the ranges and averages of concentrations for Na, K, Mn, Cu, and Br. It has been observed that the trace element contents in tea leaves are largely dependent upon the soil and the environment where the tea grows. Chinese tea is rich in Mn and Cu comparing with those of other counties surveyed, but is indigent in Na. The transference ratio for each element determined (i.e., the fraction of an element in tea leave transferred into solution when tea is leached by percolation) is also reported. Adult daily intakes of some essential and toxic elements from tea drinking were also estimated. (author)

Studies to single subassembly flow monitoring with a complete 7 element array under sodium

International Nuclear Information System (INIS)

Hess, B.; Ruppert, E.; Stehle, H.; Vinzens, K.

1975-01-01

As part of the SNR-300 R and D programme a complete clamped array, consisting of 4 full size fuel elements and 3 blanket elements was tested for more than 4000 hours at 600 deg C in the AKB sodium loop at Interatom, Bensberg. The test was split into two phases and the total cluster was prestrained in the second phase to simulate 15 mm subassembly displacement at the level of the upper bearing pads. Although this test was mainly considered as an endurance test to demonstrate the integrity of prestrained core elements, efforts were made to study the feasibility of single subassembly flow monitoring with this full size model of a core section. The results of these investigations are presented and discussed in this paper

Using isoelectric focussing and neutron activation analysis to study protein-bound tracer elements

International Nuclear Information System (INIS)

Schmelzer, W.

1976-01-01

A method to determine protein-bound tracer elements was determined by combining a protein separation method with neutron activation analysis. Gel filtration, disk electrophoresis, and isoelectric focussing were studied with regard to their suitability as separation methods. Using isoelectric focussing, human serum protein could be separated with good resolution on a preparative scale. The Se, Cr, Ag, Sc, Fe, Zn, Co, Br, Na, Rb, and Cs contents of the various protein fractions were determined by instrumental neutron activation analysis and by gamma-spectroscopic identification of their long-lived nuclides. Particular attention was paid to the main source of error with this method, i.e. contamination of the proteins in the course of the separation process. Information on the binding of the elements to protein was obtained by comparing the contents in the serum and in the protein separated by gel chromatography. For example, 75% of the Se and 30% of the Cs are bound to protein. Contamination of the protein fractions was studied by means of tracer elements with the element Se, errors due to contamination could be ruled out. The method was modified for the special imvestigation of Se-protein complexes in the serum. The Se content was determined by activation analysis via the short-lived radionuclide sup(77m)Se, this considerably reducing the duration of analysis. With regard to focussing, discrimination was improved in the pH region in which specific Se complexes were found. The activity distribution in fractionated serum protein labelled in vitro with 75 Se in the presence of erythrocytes showed that specific labelling is possible in this way. It is thus possible to study the distribution of Se carrier proteins with the aid of a radiotracer technique. (orig./RB) [de

Preliminary study of elemental composition in tree leaves for using as bio monitor for air pollution

International Nuclear Information System (INIS)

Chueinta, Wanna; Bunprapob, Supamatthree

2004-10-01

The use of plant tissue as biological monitor of air pollution has been of interest world wild. The study on chemical composition of such biological monitor may provide important information on the levels and pathways of a variety of pollutants including heavy metals and trace toxic elements in atmosphere. The appropriate bio monitors are such as herbaceous plants, tree leaves, bryophytes and lichens, with their possible advantages and/or limitations. In this research an investigation of element composition in leaves was performed. The technique of Instrument Neutron Activation Analysis (INAA) was developed to determine heavy metal and trace elements in 8 species of tree leaves collected from 3 different locations. From the experiments, it was found that content of elements might vary depending on species and environment. Some specific elements are discussed and compared in this report

Study on the high-precision laser welding technology of nuclear fuel elements processing

Energy Technology Data Exchange (ETDEWEB)

Kim, Soo Sung; Yang, M. S.; Kim, W. K.; Lee, D. Y

2001-01-01

The proper welding method for appendage of bearing pads and spacers of PHWR nuclear fuel elements is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of welding defects of the appendage parts is mostly apt to occur and it is connected directly with the safty and life prediction of the nuclear reactor in operation. Recently there has been studied all over the world to develope welding technology by laser in nuclear fuel processing, and the appendage of bearing pads and spacers of PHWR nuclear fuel elements. Therefore, the purpose of this study is to investigate the characteristics of the laser welded specimens and make some samples for the appendage of bearing pads of PHWR nuclear fuel elements. This study will be also provide the basic data for the fabrications of the appendage of bearing pads and spacers. Especially the laser welding is supposed to be used in the practical application such as precise materials manufacturing fields. In this respect this technology is not only a basic advanced technology with wide applications but also likely to be used for the development of directly applicable technologies for industries, with high potential benefits derived in the view point of economy and industry.

Study on the high-precision laser welding technology of nuclear fuel elements processing

International Nuclear Information System (INIS)

Kim, Soo Sung; Yang, M. S.; Kim, W. K.; Lee, D. Y.

2001-01-01

The proper welding method for appendage of bearing pads and spacers of PHWR nuclear fuel elements is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of welding defects of the appendage parts is mostly apt to occur and it is connected directly with the safty and life prediction of the nuclear reactor in operation. Recently there has been studied all over the world to develope welding technology by laser in nuclear fuel processing, and the appendage of bearing pads and spacers of PHWR nuclear fuel elements. Therefore, the purpose of this study is to investigate the characteristics of the laser welded specimens and make some samples for the appendage of bearing pads of PHWR nuclear fuel elements. This study will be also provide the basic data for the fabrications of the appendage of bearing pads and spacers. Especially the laser welding is supposed to be used in the practical application such as precise materials manufacturing fields. In this respect this technology is not only a basic advanced technology with wide applications but also likely to be used for the development of directly applicable technologies for industries, with high potential benefits derived in the view point of economy and industry

Physicochemical and elemental studies of Hydrocotyle javanica Thunb. for standardization as herbal drug

Directory of Open Access Journals (Sweden)

Manab Mandal

2017-11-01

Conclusions: Hence the present physicochemical and elements studies reveals that the plant Hydrocotyle javanica Thunb. could be a potent source of herbal preparation as well as a safe and novel synthetic antibacterial drug.

State of art in experimental studies and theory of superheavy elements

International Nuclear Information System (INIS)

Zvara, I.

2002-01-01

Recent years have seen remarkable progress in synthesizing new, superheavy' elements (SHE). Researchers at Dubna reached the slopes of the expected 'island of stability' (around Z = 114 and N = 184) in a 'sea' of nuclides with very short partial half-lives against spontaneous fission and/or alpha decay. In long bombardments (weeks to months) of isotopes of U, Pu and Cm by very intense (3x10 12 s -1 ) beams of 48 Ca projectiles, they have discovered mostly alpha active isotopes of previously unknown elements 116 and 114, as well as of element 112, all with unusually long half-lives - up to minutes. Only physical methods have been used for isolation and identification of the produced new nuclei. These findings give an impetus to chemical studies. Feasibility of experiments critically depends on half-lives and production cross section. Lifetimes of the order of a second or more are necessary for some gas phase chemistry studies, but at least some 10 seconds for solution chemistry. The production rates of observable atoms might be higher in chemical studies, because chemists can make use of thicker targets, and achieve higher (chemical) yield and detection efficiency than in physical experiments. Work on chemical identification of the 3-min 283 112 is in progress at Dubna and planned in other laboratories. Being a homologue of Hg, element 112 must be even more volatile metal. Thanks to this, hopefully, its single atoms, will be easily separated from interfering activities simultaneously produced in the bombardment. Quantum (theoretical) chemistry studies aim at solving the problem of 'relativistic effects' in chemical properties of SHE; such effects increase with higher Z's. As the available calculational resources fast and steadily grow (unlike the beam time available at accelerators) one can hope that quantum chemists will once be able to advise the experimenters which kind of studies to do to obtain most important and interesting results. This is not yet possible

Study of osteoporosis through the measurement of bone mineral density and trace elements

International Nuclear Information System (INIS)

Aras, N.K.; Yilmaz, G.; Alkan, S.; Korkusuz, F.; Ungan, M.; Kuscu, L.; Laleli, Y.; Eksioglu, F.; Sepici, B.

2002-01-01

The main purpose of this study was to establish a relation, if any, between bone mineral density (BMD) of the healthy Turkish population of the ages between 15 and 50 with social and demographic information, family history of fractures, personal and inherited characteristic, smoking and alcohol habit, history of fertility, level of physical activity, food consumption especially trace elements and other variables. Most of these relations were discussed in the last two Research Coordinated Meetings, in San Diego, CA, October 1996 and Sao Paulo, Brazil, August 1998. Since then we have concentrated our work on more BMD and trace element measurements in bone

A Study of Coal Miners’ Safety Psychological Elements Based on Questionnaire Survey

Directory of Open Access Journals (Sweden)

Li Zeng-bo

2016-01-01

Full Text Available During the production process, the instability of safety psychological elements of coal miners contributes to unsafe behaviors that may result in fatal accident. To search the dominant psychological elements, three types of unsafe psychology, comprising 18 unsafe psychological elements, are obtained by theoretical analysis and site survey. Then, an assessment model is established, and a matched questionnaire is applied to two large modern coal mines in Inner Mongolia Autonomous Region. Based on questionnaire survey results and analytic hierarchy process (AHP, assessment judgment matrixes are constructed, effect weight is calculated, and consistency check is conducted. The analysis results show that safety psychology elements of defective type are the dominant elements that trigger unsafe behaviors of coal miners.

Study on speciation of rare earth elements in soil

International Nuclear Information System (INIS)

Wang Yuqi; Sun Jingxin; Chen Hongmin; Guo Fanqing; Wang Lijun; Zhang Shen

1996-01-01

The contents of rare earth elements (REE) in red soil, yellow brown soil and leached chernozem are studied. After extracted sequentially, REE in these soils are fractionated into seven forms, i.e., (I) water soluble, (II) exchangeable, (III) loosely bound to organic mater, (IV) bound to carbonate and specifically absorbed, (V) bound to Fe-Mn oxides, (VI) tightly bound to organic matter and (VII) residual forms. The contents of REE in every form are determined by NAA (neutron activation analysis). The results show that REE in soils mainly exist in residual form and REE in soluble forms are very limited (<7%)

The study of trace elements in milk by nuclear analytical techniques

International Nuclear Information System (INIS)

Gharib, A.; Rahimi, H.; Peyrovan, H.; Raofei, H.N.J.; Taherpour, H.

1983-01-01

This work is part of a project with the IAEA, in a coordinated programme on ''Trace Elements in Human Nutrition and Bio-Environmental Systems'' to evaluate their nutritional requirements, interrelations and the role of Trace Elements in health, metabolism etc. Cow's milk being regarded as one of the most important and nutritious foodstuffs consumed by people. Hence as a first step, an elemental analysis for milk was carried out for this purpose so a few samples of pasteurized milk and local samples were investigated for essential and toxic trace elements. The secondary aim of this project was the assessment of various analytical techniques involved. However, in the present work, the methods involved were AAS, PIXE and NAA. The latter method applied, both instrumentally and radiochemically. Although the results pertaining to the various methods employed are not in good agreement, there is however, some justification to clarify this internal inconsistency. The precision for NAA and AAS allows greater degree of acceptance respectively. Although PIXE is a very fast and rather a routine but the technique of trace element analysis needs certain adaptations and developments

Trace elements in human milk

Energy Technology Data Exchange (ETDEWEB)

Parr, R M [International Atomic Energy Agency, Vienna (Austria). Div. of Life Sciences

1983-06-01

Trace elements are those elements having a concentration lower than 10 ppm in body fluids or tissues. A total of 24 elements, both trace and minor elements, present in human milk have been analysed in this study, employing neutron activation analysis and absorption spectroscopy. The analyses have been carried out collaboratively by several different laboratories and the Agency which has also served as a coordinating centre. Although the evaluation of the results, altogether 8500 separate values, is still in progress, enough evidence is already available, however, to show some very interesting differences between different study areas and, in some cases, between different socio-economic groups within a single country. The main value of these data will probably be to throw new light on the nutritional requirements of young babies for trace elements.

Finite element study of a lumbar intervertebral disc nucleus replacement device

Directory of Open Access Journals (Sweden)

Jessica S Coogan

2016-12-01

Full Text Available Nucleus replacement technologies are a minimally invasive alternative to spinal fusion and total disc replacement that have the potential to reduce pain and restore motion for patients with degenerative disc disease. Finite element modeling can be used to determine the biomechanics associated with nucleus replacement technologies. The current study focuses on a new nucleus replacement device designed as a conforming silicone implant with an internal void. A validated finite element model of the human lumbar L3-L4 motion segment was developed and used to investigate the influence of the nucleus replacement device on spine biomechanics. In addition, the effect of device design changes on biomechanics was determined. A 3D, L3-L4 finite element model was constructed from medical imaging data. Models were created with the normal intact nucleus, the nucleus replacement device, and a solid silicone implant. Probabilistic analysis was performed on the normal model to provide quantitative validation metrics. Sensitivity analysis was performed on the silicone Shore A durometer of the device. Models were loaded under axial compression followed by flexion/extension, lateral bending, or axial rotation. Compressive displacement, endplate stresses, reaction moment, and annulus stresses were determined and compared between the different models. The novel nucleus replacement device resulted in similar compressive displacement, endplate stress, and annulus stress and slightly higher reaction moment compared with the normal nucleus. The solid implant resulted in decreased displacement, increased endplate stress, decreased annulus stress, and decreased reaction moment compared with the novel device. With increasing silicone durometer, compressive displacement decreased, endplate stress increased, reaction moment increased, and annulus stress decreased. Finite element analysis was used to show that the novel nucleus replacement device results in similar biomechanics

Study of candu fuel elements irradiated in a nuclear power plant

International Nuclear Information System (INIS)

Ionescu, S.; Uta, O.; Mincu, M.; Anghel, D.; Prisecaru, I.

2015-01-01

The object of this work is the behaviour of CANDU fuel elements after service in nuclear power plant. The results are analysed and compared with previous result obtained on unirradiated samples and with the results obtained on samples irradiated in the TRIGA reactor of INR Pitesti. Zircaloy-4 is the material used for CANDU fuel sheath. The importance of studying its behaviour results from the fact that the mechanical properties of the CANDU fuel sheath suffer modifications during normal and abnormal operation. In the nuclear reactor, the fuel elements endure dimensional and structural changes as well as cladding oxidation, hydriding and corrosion. These changes can lead to defects and even to the loss of integrity of the cladding. This paper presents the results of examinations performed in the Post Irradiation Examination Laboratory (PIEL) of INR Pitesti on samples from fuel elements after they were removed out of the nuclear power plant: - dimensional and macrostructural characterization; - microstructural characterization by metallographic analyses; - determination of mechanical properties; - fracture surface analysis by scanning electron microscopy (SEM). A full set of non-destructive and destructive examinations concerning the integrity, dimensional changes, oxidation, hydriding and mechanical properties of the cladding was performed. The obtained results are typical for CANDU 6-type fuel. The obtained data could be used to evaluate the security, reliability and nuclear fuel performance, and for the improvement of the CANDU fuel. (authors)

Boundary element inverse analysis for rebar corrosion detection: Study on the 2004 tsunami-affected structure in Aceh

Directory of Open Access Journals (Sweden)

S. Fonna

2018-06-01

Full Text Available Evaluation of rebar/reinforcing-steel corrosion for the 2004 tsunami-affected reinforced concrete (RC buildings in Aceh was conducted using half-cell potential mapping technique. However, the results only show qualitative meaning as corrosion risk rather than the corrosion itself, such as the size and location of corrosion. In this study, boundary element inverse analysis was proposed to be performed to detect rebar corrosion of the 2004 tsunami-affected structure in Aceh, using several electrical potential measurement data on the concrete surface. One RC structure in Peukan Bada, an area heavily damaged by the tsunami, was selected for the study. In 2004 the structure was submerged more than 5 m by the tsunami. Boundary element inverse analysis was developed by combining the boundary element method (BEM and particle swarm optimization (PSO. The corrosion was detected by evaluating measured and calculated electrical potential data. The measured and calculated electrical potential on the concrete surface was obtained by using a half-cell potential meter and by performing BEM, respectively. The solution candidates were evaluated by employing PSO. Simulation results show that boundary element inverse analysis successfully detected the size and location of corrosion for the case study. Compared with the actual corrosion, the error of simulation result was less than 5%. Hence, it shows that boundary element inverse analysis is very promising for further development to detect rebar corrosion. Keywords: Inverse analysis, Boundary element method, PSO, Corrosion, Reinforced concrete

Feasibility study on using three element TLD badge based on CaSO4:Dy as environmental dosimeter

International Nuclear Information System (INIS)

Choudhary, Sreeletha; BharathiLashmi, G.V.; Yasotha, E.; Devanathan, P.S.; Annalakshmi, O.; Mathiyarasu, R.

2018-01-01

A three element thermoluminescence badge based on CaSO 4 :Dy is used for personnel monitoring in India. The three discs of the badge is heated in sequential manner by hot nitrogen gas and from the amount of light emitted while heating, the doses are estimated. This badge was redesigned as a two element system and is used for environmental monitoring. Though the two element badge has some advantages, the software used for processing of TLDs in the semiautomatic reader has to be modified and separate badges has to be maintained for environmental dose measurements. In this work a feasibility study has been carried out to use the three element personnel monitoring badge itself for environmental monitoring also. This study was also carried out to understand the abnormal pattern of the glow curves observed in some field cards

Preliminary studies on trace element contamination in dumping sites of municipal wastes in India and Vietnam

Science.gov (United States)

Agusa, T.; Kunito, T.; Nakashima, E.; Minh, T. B.; Tanabe, S.; Subramanian, A.; Viet, P. H.

2003-05-01

The disposal of wastes in dumping sites has increasingly caused concem about adverse health effects on the populations living nearby. However, no investigation has been conducted yet on contamination in dumping sites of municipal wastes in Asian developing countries. In this study, concentrations of 11 trace elements (V, Cr, Mn, Co, Cu, Zn, Mo, Ag, Cd, Sb and Pb) were detennined in scalp hair from the population living nearby and in soil from dumping sites and control sites of India and Vietnam. Soil samples in dumping site in India showed significantly higher concentrations of some trace elements than soils in control site, whereas this trend was not notable in Vietnam. This is probably due to the fact that the wastes were covered with the soil in the dumping site of Vietnam. Cadmium concentrations in some hair samples of people living near dumping site in India and Vietnam exceeded the level associated with learning disorder in children. Levels of most of the trace elements in hair were significantly higher in dumping site than those in control site in India and Vietnam, suggesting direct or indirect exposure to those elements from dumping wastes. To our knowledge, this is the first study of trace element contamination in dumping sites in India and Vietnam.

Use of nuclear and nuclear-related analytical techniques in studies of trace and minor elements in air pollution

International Nuclear Information System (INIS)

Smodis, Borut; Stropnik, Boris

1994-01-01

Among nuclear and nuclear-related analytical techniques, neutron activation and X-ray fluorescence analysis are particularly useful for environmental studies owing to their non-destructive character and multi-element capability. In this work, procedures for k o -standardized instrumental neutron activation analysis (INAA) and energy-dispersive X-ray fluorescence (EDXRF) spectrometry for trace and minor elements in air pollution studies were investigated. The methods applied were validated by the analysis of suitable reference materials. Using INAA, 20 experimentally obtained elemental values out of 21 certified and all 29 experimentally obtained values compared with 'consensus' values (for the elements where no certified numbers are available) in two SRMs were statistically indistinguishable. Also, the contents of 28 elements in candidate NIST SRM 1573a Tomato Leaves are reported. The EDXRF results were statistically indistinguishable from certified values for eight out of nine elements in NIST SRM 3087. The detection limit for this method is around at 0.1 μg cm -2 per element, so in BCR CRM No. 128, which is intended for ambient air pollution data, only Fe and Zn out of 14 elements reported in the certificate were detected with acceptable precision (i.e., 10%) owing to the very low air particulate matter loading, lying in the region of only 250 μg cm -2 . (Author)

Instrumental neutron activation analysis in environmental studies of trace elements

International Nuclear Information System (INIS)

Salmon, L.

1975-06-01

The application of a routine instrumental nuclear method is described in relation to environmental surveys and studies. A working rather than formal review is made of the techniques applied with particular reference to the data processing methods involved. The elements measured by instrumental activation analysis were: Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Cd, Co, Cr, Cs, Cu, Fe, Hg, I, In, La, Mn, Na, Ni, Pb, Rb, Sb, Sc, Se, Th, Ti, U, V, W, Zn. (author)

New functionalities in abundant element oxides: ubiquitous element strategy

International Nuclear Information System (INIS)

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

2011-01-01

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

Finite Element Modelling of the Indo-Gangetic Basin to Study Site Amplification

Science.gov (United States)

Sivasubramonian, J.; Jaya, D.; Raghukanth, S. T. G.; Mai, P. M.

2017-12-01

We have developed a finite-element model of the 3D velocity structure of the Indo-Gangetic basin (IG basin) to quantify site amplifications due to seismic waves emanated from regional earthquakes. Estimating seismic wave amplifications is difficult in case of limited instrumentation, thus motivating us to propose a new simulation-based approach. The input required for the finite-element model include the spatial coordinates and the material properties (density, P-wave and S-wave velocities, Q factor) of the basin. Recent studies in the basin demarcate sediment layers of varying thickness, reaching down to a depth of 6 km and S-wave velocities ranging from 0.4-2.4 km/s (Srinivas et al., 2013). In the present study, our regional model has dimensions 900 x 900 x 80 km in x, y and z directions, discretized into 320 x 320 x 53 hexahedral elements. The top 6 km of the IG basin is divided into 8 different sediment layers with varying material properties. We use kinematic rupture models for the earthquake sources to simulate past as well as hypothetical future events. Two past earthquakes (Mw4.9, Delhi; Mw5.2, Chamoli) and two hypothetical earthquakes (Mw7.1; Mw8.5) are considered in our study. The rupture plane dimensions (L and W) and the slip distribution are estimated using the method of Mai and Beroza (2002). Based on focal-mechanism solutions and the depths of seismicity, we define the strike (580, 3090), the dip (650, 210), the rake (160, 770), and the depth of top edge of fault (5 km, 19 km) for the two large hypothetical earthquakes. Based on these parameters, the Centroid Moment Tensor (CMT) solution of the source is obtained. Ground motions are then simulated by solving the three-dimensional wave equation using the spectral element method (Komatitsch and Tromp, 1999). The key observations from our results are: 1) basin amplification factors for Peak Ground Velocity (PGV) are twice as high as Peak Ground Displacement (PGD) 2) PGV amplifications are as high as a

Vaporization studies on elemental tellurium and selenium by Knudsen effusion mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Viswanathan, R., E-mail: rvis1953@gmail.com; Balasubramanian, R., E-mail: rbs@igcar.gov.in; Darwin Albert Raj, D., E-mail: darwinalbertraj1953@gmail.com; Sai Baba, M., E-mail: msb@igcar.gov.in; Lakshmi Narasimhan, T.S., E-mail: tslak@igcar.gov.in

2014-08-01

Highlights: • A detailed KEMS study of vaporization of elemental tellurium and selenium systems. • Clusters Te{sub i}(g) (i = 2 to 7) and Se{sub i}(g) (i = 2 to 9) identified over Te(s) and Se(s). • p–T relations for Te{sub i}(g) (590 to 690 K) and Se{sub i}(g) (380 to 480 K). • Vapor phase of Te dominated by Te{sub 2}(g) (∼95%) while that of Se by Se{sub 6}(g) (∼50%) and Se{sub 5}(g) (∼25%). • Sublimation and atomization enthalpies deduced for Te{sub i}(g) and Se{sub i}(g). - Abstract: Vaporization studies on elemental tellurium and selenium were conducted by Knudsen effusion mass spectrometry in the temperature range of 590–690 K and 380–480 K, respectively. The ionic species Te{sub i}{sup +} (i = 1–7) and Se{sub i}{sup +}(g) (i = 1–9) were detected in the mass spectra over these two condensed phases. Measurement of ion intensities were performed as a function of electron impact energy and as a function of temperature (at different electron impact energies) for identifying the gaseous precursor species as well as for determining the partial pressure–temperature relations and sublimation enthalpies for these species. While the major species over elemental tellurium was confirmed to be Te{sub 2}(g) (with all other gaseous species Te{sub 3}–Te{sub 7} put together constituting less than 5%), the major species over elemental selenium was found to be Se{sub 6}(g), closely followed by Se{sub 5}(g) (with other gaseous species Se{sub 2}–Se{sub 4} and Se{sub 7}–Se{sub 9} put together also moderately constituting ∼25%). From the partial pressures, the thermodynamic data for the sublimation reactions i Te(s) = Te{sub i}(g) and i Se(s) = Se{sub i}(g) were deduced by second- and third-law methods. The atomization enthalpies of tellurium and selenium clusters were also deduced by using the recommended enthalpies of formation of monomeric species. Comparison of the findings obtained in the present study with those in previous studies revealed

A study of element migration in the Maqarin site (Jordan) by the means of column experiments: II. trace elements (Cr, Se, Mo, Re)

International Nuclear Information System (INIS)

Trotignon, L.; Bienvenu, P.; Provitina, O.; Rose, J.; Khoury, H.; Trocellier, P.; Mercier, F.; Raimbault, L.

2005-01-01

Full text of publication follows: The site of Maqarin (Jordan), in which natural cements occur as a result of the combustion metamorphism of a bio-micrite, is studied since 1989 as a natural analogue for the long term evolution of a cementitious repository environment [1]. Several trace elements of interest (Cr, Se, Mo, Re) are mobilized on this site by percolating groundwaters and migrate along high pH plumes. Laboratory scale column experiments were conducted in which crushed materials (cement, bio-micrite) collected on site were submitted to leaching by deionized water or Ca(OH) 2 equilibrated solutions. The evolution of Cr, Mo, Se and Re was monitored in leachates during the experiments. Characterizations of the solid phase using several techniques were also conducted in order to locate these elements in the mineral phases. Comparison of experimental data with records of trace element concentration in Maqarin groundwaters gives some insight on Re, Cr, Se and Mo sources and sinks in this environment. Both the imprint of the past combustion event and present day redox transformations explain several features of the datasets. However, due to the high complexity of the cements, in which trace elements are often distributed among several mineral phases, it is presently not possible to link in a straightforward way individual mineral dissolution processes and trace element signals in waters. [1] Khoury H. N., Salameh E., Clark I. D., Fritz P., Bajjali W., Milodowski A. E., Cave M. R. and Alexander W. R. 1992. A natural analogue of high pH cement pore waters from the Maqarin area of northern Jordan. I: Introduction to the site. J. Geochem. Explor. 46: 117-132. (authors)

Rib fractures under anterior-posterior dynamic loads: experimental and finite-element study.

Science.gov (United States)

Li, Zuoping; Kindig, Matthew W; Kerrigan, Jason R; Untaroiu, Costin D; Subit, Damien; Crandall, Jeff R; Kent, Richard W

2010-01-19

The purpose of this study was to investigate whether using a finite-element (FE) mesh composed entirely of hexahedral elements to model cortical and trabecular bone (all-hex model) would provide more accurate simulations than those with variable thickness shell elements for cortical bone and hexahedral elements for trabecular bone (hex-shell model) in the modeling human ribs. First, quasi-static non-injurious and dynamic injurious experiments were performed using the second, fourth, and tenth human thoracic ribs to record the structural behavior and fracture tolerance of individual ribs under anterior-posterior bending loads. Then, all-hex and hex-shell FE models for the three ribs were developed using an octree-based and multi-block hex meshing approach, respectively. Material properties of cortical bone were optimized using dynamic experimental data and the hex-shell model of the fourth rib and trabecular bone properties were taken from the literature. Overall, the reaction force-displacement relationship predicted by both all-hex and hex-shell models with nodes in the offset middle-cortical surfaces compared well with those measured experimentally for all the three ribs. With the exception of fracture locations, the predictions from all-hex and offset hex-shell models of the second and fourth ribs agreed better with experimental data than those from the tenth rib models in terms of reaction force at fracture (difference rib responses and bone fractures for the loading conditions considered, but coarse hex-shell models with constant or variable shell thickness were more computationally efficient and therefore preferred. Copyright 2009 Elsevier Ltd. All rights reserved.

Feasibility study of power reactor fuel elements factory development: I. Economical aspects

International Nuclear Information System (INIS)

Marwoto; Ratih-Langenati, R.R.; Susanti, P.

1996-01-01

For determining the feasibility study on manufacturing nuclear fuel element from economical aspect point of view, it necessary to fix its capacity which it was found from fuel element reloading requirement for nuclear power plat (PLTN). NEWJEC report which use as a base in this study that is possibly of a complex of NPP as big as 7200 MW in Muria region. If the capacity factor is 80 %, the reload requirement is therefore become from 120 to 142 tons uranium every year. So, its considered to fix the nominal capacity of a fabric for nuclear fuel element manufacturing as much as 200 tons-U per year with economical lifetimes of 20 years. NEWJEC data show, for manufacturing capacity of 200 tons-U per year with, plant have a fixed capital investment of US$ 43.9 million. With working capital as much as 15 % correspond to fixed capital investment (FCI); 10 % of interest rate; US$ 17 million of fixed cost; US$ 106.2/kg-U of variable production cost, its calculated that break even point/BEP is 50 % for price of nuclear fuel is US$ 350/kg-U without uranium cost. On this economic condition, it was found that the return on investment/ROI is 20.2 %; the internal rate of return/IRR is 11.2 % and the benefit cost ration/BCR is 1.22. For all of above, it was assumed that such nuclear fuel element manufacturing service will be operate in the year of 2012. Some of NEWJEC data have been revised, there were the value of FCI; cost of salary; the value in percent of working capital/WC; the cost of non-uranium materials and the price of product service are US$ 68 million; US$ 4.1 million; 30 %; US$ 100/kg-U and US$ 370/kg-U respectively, where the new data appear as higher than old date from NEWJEC, excluding the cost of salary. For all new economical data in the latest, we found that 45 %; 16.73 %; 11.8 % and 1.25 for BEB; IRR and BCR respectively

Anion-exchange Studies of Radioactive Trace Elements in Sulphuric Acid Solutions

Energy Technology Data Exchange (ETDEWEB)

Samsahl, K

1963-01-15

As part of a chemical group separation procedure used as a pretreatment in gamma spectrometric analysis, a study has been made of the adsorption from sulphuric acid solutions on strongly basic anion exchange resins, prepared in the hydroxide and the sulphate forms, of trace activities of Na, P, K, Ca, Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Zr, Nb, Mo, Tc, Ag, Cd, In, Cs, Ba, La, Ce, Hf, Ta, W, Ir, Pa and Np. Besides adsorbing some of the trace elements in the solution, the anion exchange resin in the hydroxide form will neutralize the bulk of the sulphuric acid. This makes possible the subsequent sequential separation of chloride complexes on short anion-exchange columns by a stepwise increasing of the HCl concentration of the solution. On the basis of the results obtained in the present and earlier experiments, a new improved chemical group-separation procedure for mixtures of radioactive trace elements is outlined.

NATO Advanced Study Institute on Fundamental and Technological Aspects of Organo-f-Element Chemistry

CERN Document Server

Fragalà, Ignazio

1985-01-01

The past decade has seen a dramatic acceleration of activity and interest in phenomena surrounding lanthanide and actinide organo­ metallic compounds. Around the world, active research in organo-f­ element synthesis, chemistry, catalysis, crystallography, and quantum chemistry is in progress. This activity has spanned a remarkably wide range of disciplines, from synthetic/mechanistic inorganic and organic chemistry to radiochemistry, catalytic chemistry, spectroscopy (vibra­ tional, optical, magnetic resonance, photoelectron, Mossbauer), X-ray and neutron diffraction structural analysis, as well as to crystal field and molecular orbital theoretical studies at the interface of chemistry and physics. These investigations have been motivated both by fundamental and applied goals. The evidence that f-element organo­ metallic compounds have unique chemical and physical properties which cannot be duplicated by organometallic compounds of d-block elements has suggested many new areas of endeavor and application....

Brain trace elements and aging

International Nuclear Information System (INIS)

Hebbrecht, Geert; Maenhaut, Willy; Reuck, Jacques de

1999-01-01

Degenerative mechanisms involved in the aging process of the brain are to a certain extent counteracted by repair mechanisms. In both degenerative and recovery processes, trace elements are involved. The present study focused on the role of two minor (i.e., K and Ca) and six trace elements (i.e., Mn, Fe, Cu, Zn, Se and Rb) in the aging process. The elements were determined by PIXE in cerebral cortex and white matter, basal ganglia, brainstem and cerebellar cortex of 18 postmortem human brains, from persons without a history of neurologic or psychiatric disease who deceased between the age of 7 and 79. This age range allowed us to study the relationship between elemental concentrations and age. The most prominent findings were a concentration decrease for K and Rb and a concentration increase for the elements Ca, Fe, Zn and Se. The study supports recent findings that Ca and Fe are involved in brain degenerative processes initiated by oxygen free radicals, whereas Zn and Se are involved in immunological reactions counteracting the aging process

A study on the radiometric method for evaluating element migration from plastic packagings to its contents

International Nuclear Information System (INIS)

Soares, Eufemia Paez

2008-01-01

Over the past few years, problems related to food contamination by substances or elements that can be a risk to human health have became a concern, not only to government authorities, but to the general population as well. Within this context, plastic packaging can constitute a source of food contamination since plastic manufacturing processes involve the use of catalysts and different types of additives that may contain toxic elements. When food comes into contact with this packaging, components of the package may migrate to the food. In order to control the material used as food packaging, the National Health Surveillance Agency (ANVISA) in Brazil, has established boundary values of migrant substances and procedures to determine migration from plastic packagings to food. In this study the radiometric method was evaluated for element migration determination from plastic packaging to food simulating or to the food itself. This radiometric method consisted in irradiating plastic packaging samples with a thermal neutron flux from the IEA-R1 nuclear research reactor in order to produce radionuclides of elements present in the packagings. The irradiated plastic was then exposed to food simulant or food for element migration. Gamma ray spectrometry was used to measure radioactivity in the simulant or food in order to quantify the migration. The food simulating types and experimental conditions were established according to the ANVISA regulations. Element migration was studied for plastic packaging used for soft drinks, drinking water, milk, dairy products, juices and fatty foods. In the instrumental neutron activation analysis of these packagings the presence of As, Cd, Cr, Co and Sb II was verified. Results obtained from the migration experiments by the radiometric method indicated that Cd, Co, Cr and Sb present in these plastics migrated to the simulant or to the food. In some packagings, the migration of only some of these elements was observed. In these cases the

Safety studies on oxide fuel elements for the fast neutron programme

International Nuclear Information System (INIS)

Ollier, H.; Truffert, J.

1976-01-01

Studies leading to the definition of a fuel element and instructions for its use overlap with safety studies to the extent that they must guarantee, for nominal running conditions, a failure rate consistent with the working rules of the Station. Given the present state of knowledge on the causes and kinetics of damage affecting the cladding, it is mainly dealt with the principles of this research. The advantages of applying statistical computing methods to the two factors which govern the lifetime of the pins: their working conditions and quality, are demonstrated [fr

Studies to single subassembly flow monitoring with a complete 7 element array under sodium

International Nuclear Information System (INIS)

Hess, B.; Ruppert, E.; Stehle, H.; Vinzens, K.

1975-01-01

A core restraint system in a fast reactor serves to limit fuel element movement leading to reactivity changes and misalignment of control rod drives and instrumentation. To guarantee proper control rod function the upper ring of the passive restraint system for the SNR-300 should keep subassembly displacement below 20 mm, whereas a free bowing up to 25 mm does not impair subassembly handling. With respect to single subassembly instrumentation the influences of subassembly displacement on temperature and flow monitoring were not exactly known. As part of the SNR-300 R and D programme a complete clamped array, consisting of 4 full size fuel elements and 3 blanket elements was tested for more than 4000 hours at 600 0 C in the AKB sodium loop at Interatom, Bensberg. The test was split into two phases and the total cluster was prestrained in the second phase to simulate 15 mm subassembly displacement at the level of the upper pads. Although this test was mainly considered as an endurance test to demonstrate the integrity of prestrained core elements, effort were made to study the feasibility of single subassembly flow monitoring with this full size model of a core section. (Auth.)

Element availability of bivalve with symbiotic zooxanthellae in coral sea area as studied by multielement profiling analysis

Science.gov (United States)

Itoh, A.; Kabe, N.

2008-12-01

In coral sea, a characteristic ecosystem is formed by many kinds of marine animals and plants, although seawater is uneutrophic. This may be explained by the fact that various chemical species with bioessentiality are effectively taken and used by lower animals and plants in coral sea area. A symbiotic relationship often found among different animals and plants in this area is considered to be working as one of such processes. However, the specific bioavailability of the elements for the marine animals and plants in coral reef area has not been studied from the viewpoints of trace and ultratrace elements. It is found by the present authors that bivalve with symbiotic zooxanthellae (Tridacna crocea) living on coral reef had relatively higher bio- accumulation factors for many bio-essential elements than other kinds of bivalves, although they live in the uneutrophic sea area. The present authors focused on Tridacna crocea as one of the symbiotic animals. Thus, in the present study, at first, multielement determination of major-to-ultratrace elements (about 20 elements) in each organ of Tridacna crocea with symbiotic zooxanthellae, were carried out by ICP-AES, ICP- MS, and CHN coder. At Second, the specific bioavailability of trace and ultratrace elements in Tridacna crocea was discussed on the multielement data for seawater, seaweeds, and other bivalves in coral sea area.

Comparative Study of Metadata Elements Used in the Website of Central Library of Universities Subordinate to the Ministry of Science, Research and Technology with the Dublin Core Metadata Elements

Directory of Open Access Journals (Sweden)

Kobra Babaei

2012-03-01

Full Text Available This research has been carried out with the aim of studying the web sites of central libraries of universities subordinate to the Ministry of Science, Research and Technology usage of metadata elements and its comparison with Dublin Core standard elements. This study was a comparative survey, in which 40 websites of academic library by using Internet Explorer browser. Then the HTML pages of these websites were seen through the Source of View menu, and metadata elements of each websites were extracted and entered in the checklist. Then, with using descriptive statistics (frequency, percentage and mean analysis of data was discussed. Research findings showed that the reviewed websites did not use any Dublin Core metadata elements, general metadata Markup language used in design of all websites, the amount of metadata elements used in website, Central Library of Ferdowsi University of Mashhad and Iran Science and Industries with 57% in first ranked and Shahid Beheshti University with 49% in second ranked and the International University of Imam Khomeini with 40% was in third ranked. The approach to web designers was determined too that as follows: the content of source in first ranked and attention to physical appearance source in second ranked and also ownership of source in third position.

A study on temporal variation of elemental composition in tree barks used as air pollution indicators

Energy Technology Data Exchange (ETDEWEB)

Santos, Eliane C.; Saiki, Mitiko, E-mail: eliane_csantos@yahoo.com.br, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The study of air pollution using biological matrices has shown that tree barks may be used as biomonitor due to accumulation of aerosol particles on its porous surface. The bark elemental composition can provide information on pollution sources as well as characterize the aerial pollutants from a wide geographical region. The aim of this study was to investigate the variation in elemental composition in barks with time of exposure. Tree barks from Tipuana (Tipuana tipu) and Sibipiruna (Caesalpinia peltophoroides) species were collected in February 2013 and July 2014 in the city of São Paulo. For analysis, the barks were cleaned, grated, ground and analyzed by neutron activation analysis (NAA). Aliquots of samples and synthetic standards of elements were irradiated with thermal neutron flux at the IEA-R1 nuclear research reactor and after a suitable decay time, the induced gamma activities were analyzed by gamma spectrometry. The elements As, Br, Ca, Co, Cr, Cs, Fe, K, La, Rb, Sb, Sc and Zn were determined and the results indicated variability in the concentrations depending on the element, sampling period and also on tree species, indicating that there are not very well defined temporal trends. The quality control of the analytical results evaluated by analyzing INCT Virginia Tobacco Leaves certified reference material (CRM) presented values of |z-score| < 2, indicating that the procedure of NAA applied is suitable for the analyses. (author)

A study on temporal variation of elemental composition in tree barks used as air pollution indicators

International Nuclear Information System (INIS)

Santos, Eliane C.; Saiki, Mitiko

2015-01-01

The study of air pollution using biological matrices has shown that tree barks may be used as biomonitor due to accumulation of aerosol particles on its porous surface. The bark elemental composition can provide information on pollution sources as well as characterize the aerial pollutants from a wide geographical region. The aim of this study was to investigate the variation in elemental composition in barks with time of exposure. Tree barks from Tipuana (Tipuana tipu) and Sibipiruna (Caesalpinia peltophoroides) species were collected in February 2013 and July 2014 in the city of São Paulo. For analysis, the barks were cleaned, grated, ground and analyzed by neutron activation analysis (NAA). Aliquots of samples and synthetic standards of elements were irradiated with thermal neutron flux at the IEA-R1 nuclear research reactor and after a suitable decay time, the induced gamma activities were analyzed by gamma spectrometry. The elements As, Br, Ca, Co, Cr, Cs, Fe, K, La, Rb, Sb, Sc and Zn were determined and the results indicated variability in the concentrations depending on the element, sampling period and also on tree species, indicating that there are not very well defined temporal trends. The quality control of the analytical results evaluated by analyzing INCT Virginia Tobacco Leaves certified reference material (CRM) presented values of |z-score| < 2, indicating that the procedure of NAA applied is suitable for the analyses. (author)

The Study of the Elemental Concentrations in the Some Rocks and Cements in Myanmar

International Nuclear Information System (INIS)

Khin Mar Kyu; Yi Yi Myint; San Yee

2006-06-01

X-ray fluorescence (XRF) spectrometry is an analytical technique widely used for elemental analysis in both industrial and research laboratories. In this paper, energy dispersive x-ray technique was used in nine rock samples and five cement samples to measure the elemental concentrations. By using EDX-700, silicon was found as major element containedin one rock sample, chorine was found as major element contained in four rock samples, calcium was found as major element contained in two rock samples and iron was found as major element contained in two rock samples. In all cement samples, calcium was found as major element

Design element analysis on juice market Case study: Prigat

Directory of Open Access Journals (Sweden)

Nicoleta Andreea NEACŞU

2015-06-01

Full Text Available : If at the beginning package was considered simply a package that contained a product, now due to the development and modernization of the trade, it is a very valuable component of the marketing policy, being a carrier of messages to the consumer. Classic design elements that are included in any packaging refer to shape, color and graphics. The Romanian Juices Market was marked by originality and innovation in terms of packaging design elements. Thus, from 1998 until now the following have appeared: the first wide mouth square bottle, the first sport opening head PET bottle for Prigat Active, the first opening gable top box produced in our country.

Department of Nuclear Physical Chemistry - Overview

International Nuclear Information System (INIS)

Szeglewski, S.

2002-01-01

Full text: Research in the Department of Nuclear Physical Chemistry concentrates on three main topics: 1. Radiochemistry of transactinide elements; 2. Environmental radioactivity and related problems; 3. Preparation and applications of radioactive isotopes. The investigations on radiochemistry of transactinide elements are carried out in the Laboratory of Chemistry and Radiochemistry. Practical difficulties due to short half-lives and very low cross sections of formation of the superheavy nuclei are being overcome by developing fast and efficient methods of chemical separation, basing mostly on ion-exchange processes which are thoroughly studied via model experiments on lighter homologues of the elements of interest. During the year 2001, work with composite ferrocyanide sorbents was continued, and the efforts resulted in a patent application. The developed ion-exchangers (whose characteristics are constantly checked and improved in the laboratory) can find practical applications in environmental protection as well as in fundamental studies on the most exotic elements: 104 Rf, 105 Db, 106 Sg, 107 Bh, 108 Hs, and more. As to the latter, the discovery in Dubna of the relatively long-lived element 114 (t 1/2 =30s) gives hope that studies on aqueous chemistry of the elements Z =107 would be feasible. In this context, chemical methods of separation and identification of the heaviest elements are necessary to know the behaviour of the whole decay chains, for example: 114 -α-112 -α-110 -α-108 -α-106. The group is contributing its expertise to the top specialist international co-operation, involving the Joint Institute of Nuclear Research, Dubna, Russia, the Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences, Moscow, Russia, and three German institutions: the Technical University of Dresden, the University of Mainz, and the GSI Darmstadt. The Environmental Radioactivity Laboratory is following up traces of α, β, and γ radioactive

Trace element air pollution monitoring studies in Slovenia using nuclear analytical techniques

International Nuclear Information System (INIS)

Smodis, S.B.; Jacimovic, R.; Jeran, Z.; Miklavcic, V.; Stegnar, P.; Stropnik, B.

1994-01-01

In the past, only a few investigations have been performed in Slovenia concerning trace elements, toxic elements, heavy metals and radionuclides in the atmosphere. During recent years, several projects were initiated, involving health-related studies connected to air pollution in highly exposed areas, mapping the status of air pollution in the whole country using biomonitors, as well as some specific research, i.e. involving studies of mercury speciation in the atmosphere around a mercury mine or concentration levels of radionuclides in biomonitors around a uranium mine. Since all these projects were or are of a preliminary nature, in this report, the emphasis is mainly on the methodology and analytical development (neutron activation analysis and X-ray spectrometry), and to a lesser extent on the results obtained up to now. Efforts are being put into co-ordination of all the presently running projects in order to complement the results and to make a unified database for their later evaluation and statistical interpretation. (author). 22 refs, 1 fig., 1 tab

Study of selected trace elements in cancerous and non-cancerous human breast tissues using neutron activation analysis

International Nuclear Information System (INIS)

Ebrahim, A. M.

2006-03-01

This study was performed to investigate the influence of cancer on selected trace elements among sudanese patients with confirmed breast cancer. Eighty samples of cancerous and normal tissues (total of one hundred and sixty) were obtained from the same breast of the same subject from different hospitals in Khartoum State. Samples were freeze dried and analyzed using neutron activation analysis (NAA). Neutron irradiations were performed at Egypt second research reactor with a maximum thermal flux of 2.37 Χ 10 14 n cm -2 s -1 . To examine if there was any difference in the concentrations of elements from normal and malignant tissues; Wilcox on signed ranks test was used. It was found that Al, Mn, Mg, Se, Zn, and Cr elements from the malignant tissues are significantly elevated (p 0.05). The results obtained have shown consistency with results obtained by some previous studies, however, no data could be found for the elements Mg, Cr, and Sc.(Author)

Quality Assurance of Cancer Study Common Data Elements Using A Post-Coordination Approach.

Science.gov (United States)

Jiang, Guoqian; Solbrig, Harold R; Prud'hommeaux, Eric; Tao, Cui; Weng, Chunhua; Chute, Christopher G

2015-01-01

Domain-specific common data elements (CDEs) are emerging as an effective approach to standards-based clinical research data storage and retrieval. A limiting factor, however, is the lack of robust automated quality assurance (QA) tools for the CDEs in clinical study domains. The objectives of the present study are to prototype and evaluate a QA tool for the study of cancer CDEs using a post-coordination approach. The study starts by integrating the NCI caDSR CDEs and The Cancer Genome Atlas (TCGA) data dictionaries in a single Resource Description Framework (RDF) data store. We designed a compositional expression pattern based on the Data Element Concept model structure informed by ISO/IEC 11179, and developed a transformation tool that converts the pattern-based compositional expressions into the Web Ontology Language (OWL) syntax. Invoking reasoning and explanation services, we tested the system utilizing the CDEs extracted from two TCGA clinical cancer study domains. The system could automatically identify duplicate CDEs, and detect CDE modeling errors. In conclusion, compositional expressions not only enable reuse of existing ontology codes to define new domain concepts, but also provide an automated mechanism for QA of terminological annotations for CDEs.

Studies in Bangladesh on ingestion and organ content of trace elements of importance in radiological protection

International Nuclear Information System (INIS)

Begum, M.; Miah, M.F.K.

1998-01-01

In order to characterize a Reference Asian Man for radiation protection a study on the ingestion and organ content of trace elements of importance in radiological protection has been taken up by the IAEA/RCA among the Asian Countries. Representative sampling sample collection, appropriate techniques for analysis, quality assurance etc. for the study of this project are important parameters for accurate measurements. Some elemental composition in drinking supply water (Tap water and ground water) in the Dhaka city in Bangladesh has been presented in this paper. (author)

Gamma-ray scanning of neutron activated geological sediments for studying elemental profile distributions

International Nuclear Information System (INIS)

Ellinger, M.; Janghorbani, M.; Starke, K.

1976-01-01

Gamma-ray scanning for application to elemental profile studies of geological samples was studied with a neutron activated Baltic Shield sediment. Profile distribution of seven elements were measured. The capabilities and limitations of gamma-ray scanning are discussed by comparing the results with profiles obtained after the mechanical subdivision of the sample and the activation of the appropriately sized separates. With respect to the merits and limitations of scanning gamma-ray spectrometry applied to activated complex matrices the following conclusions were drawn. Qualitatively, the scanning method yields the same information as the much more laborious method of mechanical sudbisubdivision. Quantitatively, it is significantly less accurate. The scanning method has the significant advantage of allowing preservation of the sample. This could be important for such speciments as lunar and archeological materials. The method reduces sample preparation time and the possibility of sample contamination. (T.G.)

Model study of acid rain effect on adsorption of trace elements on soils using a multitracer

International Nuclear Information System (INIS)

Wang, H.F.; Ambe, S.; Takematsu, N.; Ambe, F.

1998-01-01

Using a radioactive multitracer and model acid rain (HCl or H 2 SO 4 solution), batch experiments were performed to examine the pH effect on the adsorption-desorption equilibrium of 16 elements on soils as a model study of an acid rain effect. Kaolin, black soil (original and with organic matter almost removed) and Kureha soil (original and with organic matter almost removed) were used as adsorbents. Characteristic dependence on the pH value of the suspension was observed for the adsorption of the elements on kaolin and the soils. The results of this model study indicate that acid rain decreases the retention of cations, while it increases or does not change the adsorption of anions on soils. Organic matter in soils has a positive effect on the extent of adsorption of most elements investigated. (author)

Proton induced X-Ray fluorescence study as a tool trace element analysis

International Nuclear Information System (INIS)

El-Kady, Ahmed A.

1978-01-01

Usefulness and limitations of trace elemental analysis by high energy charged particles and photon induced X-ray have been discussed. Comparison with the well established neutron activation analysis technique is also given. Back-ground radiation due to bremsstrahlung from secondary electrons and due to charged particle bremsstrahlung have been reviewed for different projectiles. The sensitivity of elemental analysis by proton induced X-ray fluorescence have been examined by measuring the characteristic X-ray emission cross section for K and L transitions of many elements and for different proton energies and compared with theroretical values. The discussion given in this report show that with suitable proton generator and a high resolution X-ray detector, proton X-ray fluorescence technique is capable of analyzing many elements simultaneously at the part per million level and offers a rapid and reliable method for trace element analysis. Data on water, blood and tissue samples given in this report are few examples of many possible applications

Multi-element neutron activation analysis of biological tissues: contribution to the study of trace element accumulation as a function of aging

International Nuclear Information System (INIS)

Gaudry, Andre.

1975-01-01

The accumulation of trace elements in various organs as a function of age was studied in rats, in connection with tissue aging phenomena. Part one reviews the various methods available to develop a programme of simultaneous multi-element analysis in biological matrices. Part two studies the precision and accuracy offered by neutron activation analysis. Special attention is paid to the problem of sample contamination by the silica glass irradiation supports. The possible causes of this effect are mentioned and a procedure limiting its harmful influence is proposed. Part three defines the restrictions introduced by the use of a method to separate the activable matrix. The fourth and last chapter describes the development of a multielement chemical separation system, designed to work semi-automatically for the simultaneous treatment of three samples and a standard in a shielded cell of small dimensions. The principles of a multi-comparator calibration where a knowledge of certain conventional but imprecise nuclear data is unnecessary owing to an experimental expedient are outlined briefly. Finally the separation method is tried out on various biological samples, including a reference (bovine liver SRM1577-NBS), and some results are given [fr

Study on the effect of the CANFLEX-NU fuel element bowing on the critical heat flux

Energy Technology Data Exchange (ETDEWEB)

Suk, Ho Chun; Cho, Moon Sung; Jeon, Ji Su

2001-01-01

The effect of the CANFLEX-NU fuel element bowing on the critical heat flux is reviewed and analyzed, which is requested by KINS as the Government design licensing condition for the use of the fuel bundles in CANDU power reactors. The effect of the gap between two adjacent fuel elements on the critical heat flux and onset-of-dryout power is studied. The reduction of the width of a single inter-rod gap from its nominal size to the minimum manufacture allowance of 1 mm has a negligible effects on the thermal-hydraulic performance of the bundle for the given set of boundary conditions applied to the CANFLEX-43 element bundle in an uncrept channel. As expected, the in-reactor irradiation test results show that there are no evidence of the element bow problems on the bundle performance.

Elemental Study in Soybean and Products by Neutron Activation Analysis

International Nuclear Information System (INIS)

Vorapot, Permnamtip; Arporn Busamongkol; Sirinart, Laoharojanaphand

2009-07-01

Full text: Elements were analyzed in soybean and products by Instrumental Neutron Activation Analysis (INAA), Pseudo-Cyclic Instrumental Neutron Activation Analysis (PCINAA) and Epithermal Instrumental Neutron Activation Analysis (EINAA). Elements detected in sample were include Al, Br, Ca, Cl, Cu, Fe, I, K, Mg, Mn Na, Se and Zn. The result showed that the nutritional contents changed after food processing. From experiments (n = 2), it was found that after food processing, the concentration of Cl and Na in soy bean curd increased from 0.0045 and 0.0011% to found 0.91 and 0.39 %, respectively. Other elements did not differ from soybean. Limits of detection for Al, Br, Ca, Cl, Cu, Fe, I, K, Mg, Mn Na, Se and Zn were 0.05, 0.2, 50, 6, 10, 15, 0.05, 30, 40, 5, 5, 0.05 and 1 mg.kg - 1, respectively

PHARMACOPOEIA METHODS FOR ELEMENTAL ANALYSIS OF MEDICINES: A COMPARATIVE STUDY

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Tetiana M. Derkach

2018-01-01

Full Text Available The article is devoted to the problem of quality assurance of medicinal products, namely the determination of elemental impurity concentration compared to permitted daily exposures for and the correct choice analytical methods that are adequate to the formulated tasks. The paper goal is to compare characteristics of four analytical methods recommended by the Pharmacopoeia of various countries to control the content of elemental impurities in medicines, including medicinal plant raw materials and herbal medicines. Both advantages and disadvantages were described for atomic absorption spectroscopy with various atomising techniques, as well as atomic emission spectroscopy and mass spectrometry with inductively coupled plasma. The choice of the most rational analysis method depends on a research task and is reasoned from the viewpoint of analytical objectives, possible complications, performance attributes, and economic considerations. The methods of ICP-MS and GFAAS were shown to provide the greatest potential for determining the low and ultra-low concentrations of chemical elements in medicinal plants and herbal medicinal products. The other two methods, FAAS and ICP-AES, are limited to the analysis of the main essential elements and the largest impurities. The ICP-MS is the most efficient method for determining ultra-low concentrations. However, the interference of mass peaks is typical for ICP-MS. It is formed not only by impurities but also by polyatomic ions with the participation of argon, as well as atoms of gases from the air (C, N and O or matrices (O, N, H, P, S and Cl. Therefore, a correct sample preparation, which guarantees minimisation of impurity contamination and loss of analytes becomes the most crucial stage of analytical applications of ICP-MS. The detections limits for some chemical elements, which content is regulated in modern Pharmacopoeia, were estimated for each method and analysis conditions of medicinal plant raw

Study of the Matrix Effect on the Plasma Characterization of Heavy Elements in Soil Sediments

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Tawfik W.

2007-01-01

Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to perform a study of the matrix effect on the plasma characterization of soil sediment targets. The plasma is generated by focusing a pulsed Nd: YAG laser on the target in air at atmospheric pressure. The plasma emission spectrum was detected using a portable Echelle spectrometer (Mechelle 7500 — Multichannel Instruments, Stockholm, Sweden with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, and electron temperature. Four heavy elements V, Pb, Mn and Co were determined in the obtained spectra. The LTE and optically thin plasma conditions were verified for the produced plasma. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of the spectral lines of the heavy elements in the soil sediments. The electron temperature does not change with concentration. For environmental applications, the obtained results showed the capability of the proposed LIBS setup with the portable Mechelle 7500 spectrometer to be applied in-situ for real-time measurements of the variation of the matrix elemental composition of soil sediments by following up only a single element as a marker for the composition of the soil sediment without need of analysis of the other elements.

The Prosthetic Influence and Biomechanics on Peri-Implant Strain: a Systematic Literature Review of Finite Element Studies

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Julius Maminskas

2016-09-01

Full Text Available Objectives: To systematically review risks of mechanical impact on peri-implant strain and prosthetic influence on stability across finite element studies. Material and Methods: An online literature search was performed on MEDLINE and EMBASE databases published between 2011 and 2016. Following keywords tiered screening and selection of the title, abstract and full-text were performed. Studies of finite element analysis (FEA were considered for inclusion that were written in English and revealed stress concentrations or strain at peri-implant bone level. Results: There were included 20 FEA studies in total. Data were organized according to the following topics: bone layers, type of bone, osseointegration level, bone level, design of implant, diameter and length of implant, implant-abutment connection, type of supra-construction, loading axis, measurement units. The stress or strain at implant-bone contact was measured over all studies and numerical values estimated. Risks of overloading were accented as non-axial loading, misfits, cantilevers and the stability of peri-implant bone was related with the usage of platform switch connection of abutment. Conclusions: Peri-implant area could be affected by non-axial loading, cantilever prosthetic elements, crown/implant ratio, type of implant-abutment connection, misfits, properties of restoration materials and antagonistic tooth. The heterogeneity of finite element analysis studies limits systematization of data. Results of these studies are comparable with other findings of in vitro, in vivo, prospective and retrospective studies.

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

International Nuclear Information System (INIS)

Janposri, K.

1980-01-01

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

Relationship between TQM Elements and Organizational Performance : An Empirical Study of Manufacturing Sector of Pakistan

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Masood ul Hassan

2013-05-01

Full Text Available This study empirically reveals the influence of the TQM elements comprising leadership, people management, process management, customer focus, information & analysis and strategic planning on the organizational performance in the manufacturing sector of Pakistan. The data were collected through a questionnaire survey from the 160 managers and employees of the manufacturing firms. Results using SPSS support the hypotheses that there is a positive relationship between the TQM elements and performance of Pakistani manufacturing firms. Furthermore, it is also found that customer focus is perceived as a dominant TQM practice for enhancing quality performance. Moreover, this study also provides a valuable knowledge to the top managers. Practical implementations along with the limitations have also been discussed in this study.

Theoretical Description of the Fission Process

International Nuclear Information System (INIS)

Witold Nazarewicz

2003-01-01

The main goals of the project can be summarized as follows: Development of effective energy functionals that are appropriate for the description of heavy nuclei. Our goal is to improve the existing energy density (Skyrme) functionals to develop a force that will be used in calculations of fission dynamics. Systematic self-consistent calculations of binding energies and fission barriers of actinide and trans-actinide nuclei using modern density functionals. This will be followed by calculations of spontaneous fission lifetimes and mass and charge divisions using dynamic adiabatic approaches based on the WKB approximation. Investigate novel microscopic (non-adiabatic) methods to study the fission process

Theoretical Description of the Fission Process

Energy Technology Data Exchange (ETDEWEB)

Witold Nazarewicz

2003-07-01

The main goals of the project can be summarized as follows: Development of effective energy functionals that are appropriate for the description of heavy nuclei. Our goal is to improve the existing energy density (Skyrme) functionals to develop a force that will be used in calculations of fission dynamics. Systematic self-consistent calculations of binding energies and fission barriers of actinide and trans-actinide nuclei using modern density functionals. This will be followed by calculations of spontaneous fission lifetimes and mass and charge divisions using dynamic adiabatic approaches based on the WKB approximation. Investigate novel microscopic (non-adiabatic) methods to study the fission process.

A study of the deflections of metal road guardrail elements

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O. Prentkovskis

2009-09-01

Full Text Available Statistical data on traffic accidents in 2008 in Lithuania is presented. Referring to statistical data, ‘grounding on an obstacle’ makes one-tenth of all registered traffic accidents – 9.4% (an obstacle may be a road guardrail, a lamp post, a tree, a bar, a gate, etc.. Road guardrails of various types are installed on the shoulders and dividing strips of urban and suburban roads. They are as follows: reinforced concrete guardrails, cable guardrails and metal guardrails. Metal guardrails, consisting of Σ-shape metal posts and a protective W-shape horizontal beam, are most popular. The authors of the present paper examine the deformation processes of the elements of the above mentioned guardrail. A mathematical model of metal road guardrail was developed. Metal road guardrail was modelled using one-dimensional first-order finite elements, taking into account only elastic deformations, as well as the effect of soil on the buried post section of the guardrail. Based on the developed mathematical model of metal road guardrail, the deflections of its elements caused by the impact of a vehicle moving at varying speed were determined. The obtained values of deflections of guardrail elements (a protective W-shape horizontal beam and a Σ-shape post presented in paper do not exceed the admissible values (of beam deflections.

Study on the dynamics of halogen elements in the agro-environment and these element`s deficiency, toxicity and environmental hazards by the application of the neutron activation analysis method

Energy Technology Data Exchange (ETDEWEB)

Yuita, Kouichi [National Inst. of Agro-Environmental Sciences, Tsukuba, Ibaraki (Japan)

1998-03-01

A neutron activation analysis method is an accurate and highly sensitive method for analyzing halogen elements (iodine, bromine and chlorine) except fluorine. It is unsubstitutable and valuable method especially for iodine (including radioactive {sup 129}I) and bromine which are present at lower levels. Halogen elements have high chemical and physiological activities and move widely in the environment. As a result, deficiency and an excess of halogen elements in plants and animals have occurred and artificial halogen compounds have caused environmental pollution in wide areas. We efficiently utilized the neutron activation analysis method and an activable tracer method to obtain valuable findings which contribute to the clarification of and measures against these actual problems and which are also concerned with the occurrence, distribution and migration of halogen elements in the environment, especially agricultural and forestry ecosystems in space and in time. (author)

Integrative study of the behavior of transuranic elements in the marine environment. Progress report, June 1, 1981-May 31, 1982

International Nuclear Information System (INIS)

Choppin, G.R.; Morse, J.W.

1981-12-01

The laboratory at Florida State University is conducting fundamental research under marine conditions of the speciation of actinide elements in sea water. At the Texas A and M University, the adsorption of actinides from such solutions upon various components of sediments is being studied. This approach should yield radiochemical data directly applicable to the understanding of the distribution and speciation of transuranic elements in the marine environment. A limited number of common sediment components are being studied to determine which factors determine the partitioning of transuranic elements among these components. The individual components then will be combined in synthetic sediments of increasing complexity and the distributions studied between these sediments and solutions. Hopefully, this will lead to studies agreeing with model predictions for the adsorption of transuranic elements in marine sediments

Study on correlation of trace elements in human hair and internal organs by nuclear methods

International Nuclear Information System (INIS)

Cheng Yuandi; Zhuang Guisun; Zhang Yuanxun

1993-01-01

Autopsy samples from 24 human males, aged 35-60 years were collected from Shanghai, People's Republic of China, to study possible relationships between the trace element content in hair and internal tissues. Samples of hair, kidney-cortex and lung were collected and analyzed. A radiochemical neutron activation analysis (RNAA) procedure was developed based on a simple group extraction scheme using zinc-diethyl dithiocarbamate and methyl-isobutyl ketone-iodide. The trace elements As, Cd, Hg, Cu and Zn were measured following this procedure. In addition, the elements Se, Na, Mg, Cl, Br, S, Cr, Co, and Rb were determined using instrumental neutron activation analysis (INAA). The reliability of the analytical procedures were checked analyzing several biological reference materials, such as IAEA-H-8 Horse Kidney, NBS-SRM-1573 Tomato Leaves and NIES-5 Human Hair. The results showed a larger concentration variability for As, Cd and Hg than for Cu, Se and Zn. Some significant positive correlations were found for some elements among different tissues. (author). 15 refs, 22 figs, 4 tabs

Natural analogue study on trace element migration in geological formation at Horonobe area, Japan

International Nuclear Information System (INIS)

Iwatsuki, Teruki; Ishii, Eiichi; Mizuno, Takashi; Honda, T.

2010-01-01

Usefulness of natural analog to study radionuclide transport models for deep geological repositories for high-level and long lived radioactive wastes is widely recognized. As the groundwater flow in the Horonobe area, Hokkaido, Japan is known to be stationary with neutral pH value and of reductive nature for a long-term, the authors began natural analog study by observing atomic distribution of such trace elements as rare earths, uranium, and thorium in carbonate nodules and veins of uranium minerals from several selected faults (Wakkanai F., Ketoi F., etc) in the area with the use of XED, XRF, and ICP-MS. The results give important information as to the maintainability of the rocks for trace elements and help to provide confidence in the safety assessment in the long term. (S. Ohno)

Multidimensional study of the trace elements in the American south western prophyry copper type deposits: mineralogy of uranium

International Nuclear Information System (INIS)

Cesbron, Fabien; Drin, Nicolas.

1981-09-01

The use of the spark source masse spectrometry and data treatment methods (principal component analysis and discriminent analysis) allow to describe the trace elements comportments in the porphyry copper type deposits of Arizona (USA) and Sonora (Mexico). The chemical elements are studied in relationship with the alteration zones of these deposits. A electronic microprobe study specifies the uranium bearing minerals [fr

Study on Characteristics of Soil Elements Bio-availability and Their Interrelationship in Black Soil Area of Jilin Province

Science.gov (United States)

Wang, D. Y.

2015-12-01

Abstract: Based on systematic field investigation and surface soil(0-20cm) sampling in the middle part of Jilin province where the soil type mainly consists of black soil and chernozem, soil total content and bio-available content of Fe, Fe, Ca, Mg, K, P, Cu, Zn, Ni, Cr, B, Cd, As were tested. This paper summarizes the geochemical characteristics of the soil elements and takes the ratio of bio-available content to total content as the bio-availability characteristic of each element in soil and studies the interrelationship between their geochemical characteristics of bio-availability by PCA and correlation analysis. Cd、Cr、Ni、Zn、P、Ca are selected out by PCA due to the similar impact under 4 principal components. And their correlation analysis results indicate: the correlation coefficients between heavy metal elements(Cr, Cd, Zn, Ni) bio-availability are significant positive, i.e., the same spatial variation trends are found between them in study area; the same relationships are also found between the bioavailability of P and 4 heavy metal elements (Cr, Cd, Zn, Ni), the promotion of the bioavailability of heavy metal elements goes with P; However, the correlation coefficients between heavy metal(Cr, Cd, Zn, Ni) bio-availability and Ca are mostly significant negative and the adverse spatial variation trends are found between them. The promotion of the bioavailability of heavy metal elements goes against Ca. Key words: soil geochemistry; soil heavy metals; elements interaction; bio-availability

Pyrometallurgical partitioning of uranium and transuranic elements from rare earth elements by electrorefining and reductive extraction

International Nuclear Information System (INIS)

Uozumi, Koichi; Kinoshita, Kensuke; Inoue, Tadashi; Storvick, T.S.; Krueger, C.L.; Nabelek, C.R.

2001-01-01

High-level liquid waste generated from PUREX reprocessing contains a small amount of transuranic elements, such as Np, Pu, Am, and Cm, with long-lived radioactivities. A pyrometallurgical partitioning process is being developed to recover transuranic elements from such waste. Small amounts of U contained in the high-level liquid waste are also recovered in the process. A key issue for developing the process is effective separation of U and the transuranic elements from the rare-earth elements, because the two elemental groups are chemically analogous. A series of process tests were carried out in the present study to demonstrate that a combination of electrorefining and reductive extraction is useful for separating U and transuranic elements from the rare-earth elements. The results indicate that 99% of U and each transuranic elements is recovered by the combination process as a product, and that the quantity of rare-earth elements contained in the product is smaller than the transuranic elements by weight. The overall mass balance of U and transuranic elements in the system ranged within the experimental errors assigned to sampling and analysis. (author)

Interfering elements in activation analysis. Study of instrumental analysis possibilities for the groups: Sc-Zn, Hg-Se and As-Sb-Br

International Nuclear Information System (INIS)

Figueiredo, A.M.G.; Atalla, L.T.

1979-01-01

The determination of the elements present in the groups Sc-Zn, Hg-Se and As-Sb-Br represents a classical problem in thermal neutron activation analysis, since the energy values of the gamma-ray photopeaks of the radioisotopes of these elements formed by thermal neutron activation are very closely located in the spectrum. A study is presented of the possibility of simultaneous instrumental determination of these elements by means of the spectrum stripping technique. For this purpose, artificial mixtures of the interfering elements, in varying proportions, were prepared. Radiochemical separations procedures for the above mentioned elements were also studied by means of tracers. (Author) [pt

Finite element study of a HDR-RPV-section including a nozzle under thermal shock transient

Energy Technology Data Exchange (ETDEWEB)

Roos, E [Stuttgart Univ. (Germany); Katzenmeier, G [Forschungszentrum Juelich GmbH (Germany); Wanner, R; Mercier, O [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1988-12-31

This document presents a finite element study of a reactor pressure vessel section under thermal stresses. The strength properties of the vessel walls are studied as well as cracks due to the thermo-shock transient. (TEC). 6 refs.

Element-topology-independent preconditioners for parallel finite element computations

Science.gov (United States)

Park, K. C.; Alexander, Scott

1992-01-01

A family of preconditioners for the solution of finite element equations are presented, which are element-topology independent and thus can be applicable to element order-free parallel computations. A key feature of the present preconditioners is the repeated use of element connectivity matrices and their left and right inverses. The properties and performance of the present preconditioners are demonstrated via beam and two-dimensional finite element matrices for implicit time integration computations.

Analog elements for transuranic chemistries

International Nuclear Information System (INIS)

Weimer, W.C.

1982-01-01

The analytical technique for measuring trace concentrations of the analog rare earth elements has been refined for optimal detection. The technique has been used to determine the rare earth concentrations in a series of geological and biological materials, including samples harvested from controlled lysimeter investigations. These studies have demonstrated that any of the trivalent rare earth elements may be used as analog elements for the trivalent transuranics, americium and curium

Studies in China on ingestion and organ content of trace elements of importance in radiological protection

International Nuclear Information System (INIS)

Wang Jixian; Zhu Hongda; Chen Rusong

1998-01-01

In order to ensure the representative sampling for ingestion study a sampling strategy that took account of all relevant ethnic, socioeconomic and geographic variables was devised by the Institute of Nutrition and Food Hygiene, CAPM for the first total diet study in China. Total diet samples was prepared as 'market basket' samples. Based on the information of food consumption, composition and cookery obtained by the diet consumption survey, the 12 categories of food were collected from nearby markets and cooked by local cookery. For investigation the relationship between elements intake and organ content the specimens for organ content study will be collected from the subjects of sudden death inhabited in the region where the diet samples to be collected for ingestion study. The analytical technique that will be used to determine trace elements of interest in specimens of diet and organs have been proposed, for I that is ENAA, for Cs and Sr that is FAAS or ICP-MS, and for U and Th that is ICP-MS. At last the report summarized the information on trace element content of drinking water supplies in China. (author)

Energy Sustainability Evaluation Model Based on the Matter-Element Extension Method: A Case Study of Shandong Province, China

Directory of Open Access Journals (Sweden)

Siqi Li

2017-11-01

Full Text Available Energy sustainability is of vital importance to regional sustainability, because energy sustainability is closely related to both regional economic growth and social stability. The existing energy sustainability evaluation methods lack a unified system to determine the relevant influencing factors, are relatively weak in quantitative analysis, and do not fully describe the ‘paradoxical’ characteristics of energy sustainability. To solve those problems and to reasonably and objectively evaluate energy sustainability, we propose an energy sustainability evaluation model based on the matter-element extension method. We first select energy sustainability evaluation indexes based on previous research and experience. Then, a variation coefficient method is used to determine the weights of these indexes. Finally, the study establishes the classical domain, joint domain, and the matter-element relationship to evaluate energy sustainability through matter-element extension. Data from Shandong Province is used as a case study to evaluate the region’s energy sustainability. The case study shows that the proposed energy sustainability evaluation model, based on the matter-element extension method, can effectively evaluate regional energy sustainability.

A study on the recovery of TRU elements by a container-aided solid cathode

International Nuclear Information System (INIS)

Kwon, S.W.; Lee, J.H.; Woo, M.S.; Shim, J.B.; Kim, E.H.; Yoo, J.H.; Park, S.W.; Park, H.S.

2005-01-01

Pyroprocessing is a very prominent way for the recovery of the long-lived elements from the spent nuclear fuel. Electrorefining is a key technology of pyroprocessing and generally composed of two recovery steps - deposit of uranium onto a solid cathode and the recovery of TRU (TRansUranic) elements by a liquid cadmium cathode. The liquid cadmium cathode has some problems such as a cadmium volatilization problem, a low separation factor, and a complicates structure. In this study, CASC (Container-Aided Solid Cathode) was proposed as a candidate for replacing a liquid cadmium cathode and the deposition behavior of the cathode was examined during the electrorefining experiments. The CASC is a solid cathode surrounded with a porous ceramic container, where the container is used to capture the dripped deposit from the cathode. In the electrorefining experiment, the uranium used as a surrogate for the TRU elements, was effectively separated from cerium. The anode material and surface area were also investigated during electrolysis experiments for the more efficient electrorefining system. From the results of this study, it is concluded that the container-aided solid cathode can be a potential candidate for replacing a liquid cadmium cathode and the cathode should be developed further for the better electrolysis operation. (author)

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

International Nuclear Information System (INIS)

Moreira, Edson G.; Catharino, Marilia G.M.; Vasconcellos, Marina B.A.; Frutos, Sixto A.; Insaurralde, Mario S.

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-01

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

Trace elements in human milk. Part of a coordinated programme on comparative methods for the study of trace elements in human nutrition

International Nuclear Information System (INIS)

Kosta, L.

1981-01-01

New analytical methods based on radiochemical neutron activation analysis were developed for the determination of Sn, V, I and Se at nanogram levels in biological materials, particularly in milk and other foodstuffs. By the application of these and similar methods, results for trace elements in human and cow's milk were collected from which the normal concentration ranges of up to 12 trace elements were established. Significant data on vanadium levels were also collected allowing assessment of the dietary intake and body pool of this element and a reappraisal of its significance in nutrition. Similar data on a smaller scale were also collected for tin. Results were also obtained for several different trace elements in a range of biological reference materials

Transposable elements in cancer.

Science.gov (United States)

Burns, Kathleen H

2017-07-01

Transposable elements give rise to interspersed repeats, sequences that comprise most of our genomes. These mobile DNAs have been historically underappreciated - both because they have been presumed to be unimportant, and because their high copy number and variability pose unique technical challenges. Neither impediment now seems steadfast. Interest in the human mobilome has never been greater, and methods enabling its study are maturing at a fast pace. This Review describes the activity of transposable elements in human cancers, particularly long interspersed element-1 (LINE-1). LINE-1 sequences are self-propagating, protein-coding retrotransposons, and their activity results in somatically acquired insertions in cancer genomes. Altered expression of transposable elements and animation of genomic LINE-1 sequences appear to be hallmarks of cancer, and can be responsible for driving mutations in tumorigenesis.

Feasibility of Combining Common Data Elements Across Studies to Test a Hypothesis.

Science.gov (United States)

Corwin, Elizabeth J; Moore, Shirley M; Plotsky, Andrea; Heitkemper, Margaret M; Dorsey, Susan G; Waldrop-Valverde, Drenna; Bailey, Donald E; Docherty, Sharron L; Whitney, Joanne D; Musil, Carol M; Dougherty, Cynthia M; McCloskey, Donna J; Austin, Joan K; Grady, Patricia A

2017-05-01

The purpose of this article is to describe the outcomes of a collaborative initiative to share data across five schools of nursing in order to evaluate the feasibility of collecting common data elements (CDEs) and developing a common data repository to test hypotheses of interest to nursing scientists. This initiative extended work already completed by the National Institute of Nursing Research CDE Working Group that successfully identified CDEs related to symptoms and self-management, with the goal of supporting more complex, reproducible, and patient-focused research. Two exemplars describing the group's efforts are presented. The first highlights a pilot study wherein data sets from various studies by the represented schools were collected retrospectively, and merging of the CDEs was attempted. The second exemplar describes the methods and results of an initiative at one school that utilized a prospective design for the collection and merging of CDEs. Methods for identifying a common symptom to be studied across schools and for collecting the data dictionaries for the related data elements are presented for the first exemplar. The processes for defining and comparing the concepts and acceptable values, and for evaluating the potential to combine and compare the data elements are also described. Presented next are the steps undertaken in the second exemplar to prospectively identify CDEs and establish the data dictionaries. Methods for common measurement and analysis strategies are included. Findings from the first exemplar indicated that without plans in place a priori to ensure the ability to combine and compare data from disparate sources, doing so retrospectively may not be possible, and as a result hypothesis testing across studies may be prohibited. Findings from the second exemplar, however, indicated that a plan developed prospectively to combine and compare data sets is feasible and conducive to merged hypothesis testing. Although challenges exist in

Experimental study of some mounting brackets to support fuel elements

International Nuclear Information System (INIS)

Aubert, M.; Poglia, S.; Roche, R.

1958-09-01

In an atomic pile with vertical channels, fuel elements are stacked on one another. According to a possible assembly, fuel element can be contained by a graphite sleeve and be supported by a mounting bracket in this sleeve. Sleeves are then stacked on one another. The authors report the investigation of different designs for these mounting brackets. They describe their mechanical role and their mechanical, aerodynamic, neutronic and test conditions. They report tests performed on brackets made in graphite and on brackets made in stainless steel and graphite, and discuss the obtained results

Finite Element Study on Continuous Rotating versus Reciprocating Nickel-Titanium Instruments.

Science.gov (United States)

El-Anwar, Mohamed I; Yousief, Salah A; Kataia, Engy M; El-Wahab, Tarek M Abd

2016-01-01

In the present study, GTX and ProTaper as continuous rotating endodontic files were numerically compared with WaveOne reciprocating file using finite element analysis, aiming at having a low cost, accurate/trustworthy comparison as well as finding out the effect of instrument design and manufacturing material on its lifespan. Two 3D finite element models were especially prepared for this comparison. Commercial engineering CAD/CAM package was used to model full detailed flute geometries of the instruments. Multi-linear materials were defined in analysis by using real strain-stress data of NiTi and M-Wire. Non-linear static analysis was performed to simulate the instrument inside root canal at a 45° angle in the apical portion and subjected to 0.3 N.cm torsion. The three simulations in this study showed that M-Wire is slightly more resistant to failure than conventional NiTi. On the other hand, both materials are fairly similar in case of severe locking conditions. For the same instrument geometry, M-Wire instruments may have longer lifespan than the conventional NiTi ones. In case of severe locking conditions both materials will fail similarly. Larger cross sectional area (function of instrument taper) resisted better to failure than the smaller ones, while the cross sectional shape and its cutting angles could affect instrument cutting efficiency.

Discovery of element 112

Energy Technology Data Exchange (ETDEWEB)

Hofmann, S. [GSI, Darmstadt (Germany)

1996-12-31

The new elements 110, 111, and 112 were synthesized and unambiguously identified in experiments at SHIP. Due to strong shell effects the dominant decay mode is not fission, but emission of alpha particles. Theoretical investigations predict that maximum shell effects should exist in nuclei near proton number 114 and neutron number 184. Measurements give hope that isotopes of element 114 close to the island of spherical Superheavy Elements could be produced by fusion reactions using {sup 118}Pb as target. systematic studies of the reaction cross-sections indicate that transfer of nucleons is the important process to initiate the fusion.

Multitracer studies on the effects of model acid rain on the adsorption of trace elements on soils

International Nuclear Information System (INIS)

Wang, H.F.; Ambe, S.; Takematsu, N.; Ambe, F.

2001-01-01

Using a multitracer technique, the effects of acid rain pH on the adsorption of 15 trace elements on soil were studied. Kaolin, forest soil (original and with partially removed oxides), black soil (original and without organic matter) and Kureha soil (original, with partially removed oxides, and without organic matter) were employed as the adsorbents. Instead of H 2 SO 4 solution, HCl solution was selected as the model acid rain based on the results of adsorption experiments on kaolin. In general, the percentage adsorption of cationic elements on three original soils and kaolin increased with increasing pH. The adsorption of oxyanionic elements, As and Se, on three soils was high over the entire pH range studied, while that on kaolin was low and decreased with an increase in pH. The differences in the physical and chemical properties of soils were reflected on the adsorption. The organic matter in soil had positive effects on the extent of adsorption of most elements studied, while the oxides apparently showed positive effects only for Fe and Se adsorption. The results indicate that acid rain decreases the retention of cations in soil and that it increases or does not change the adsorption of anions. (orig.)

Study of color-octet matrix elements through J/ψ production in e{sup +}e{sup -} annihilation

Energy Technology Data Exchange (ETDEWEB)

Li, Yi-Jie; Xu, Guang-Zhi; Zhang, Pan-Pan; Liu, Kui-Yong [Liaoning University, Department of Physics, Shenyang (China); Zhang, Yu-Jie [Beihang University, School of Physics, Beijing (China); CAS Center for Excellence in Particle Physics, Beijing (China)

2017-09-15

In this paper, the color-octet long distance matrix elements are studied through the inclusive J/ψ production in e{sup +}e{sup -} annihilation within the framework of non-relativistic QCD factorization. The calculations are up-to next-to-leading order with the radiative and relativistic corrections in the energy region of the B-factory and the near-threshold region of 4.6-5.6 GeV. A constraint of the long distance matrix elements (left angle {sup 1}S{sub 0}{sup 8} right angle, left angle {sup 3}P{sub 0}{sup 8} right angle) is obtained. Through our estimation, the P-wave color-octet matrix element (left angle 0 vertical stroke {sup 3}P{sup 8}{sub 0} vertical stroke 0 right angle) should be of the order of 0.008m{sub c}{sup 2} GeV{sup 3} or less. The constrained region is not compatible with the values of the long distance matrix elements fitted at hadron colliders. (orig.)

Nerva Fuel Element Development Program Summary Report - July 1966 through June 1972 Extrusion Studies

Energy Technology Data Exchange (ETDEWEB)

Napier, J. M.

1973-09-21

This part of the completion report pertaining to the NERVA graphite fuel element program covers data collected during the extrusion studies. The physical properties of the fuel element reached the following values: coefficient of thermal expansion (CTE) - 7.0 x 10-6/o C (25 - l,OOOo C); modulus of elasticity - 1.5 x lo6 psi; flexural strength - - 8,000 psi; ultimate strain to failure - 5,500 pidin; good thermal stress resistance. Matrices were produced which could be vapor coated with crack-free films of zirconium carbide. The CTE of the matrix was almost equal to the CTE of the zirconium carbide coating.

Distribution of 35 Elements in Peat Cores from Ombrotrophic Bogs Studied by Epithermal Neutron Activation Analysis

CERN Document Server

Frontasyeva, M V

2004-01-01

In ombrotrophic bogs the surface peat layer is supplied with chemical substances only from the atmosphere. Peat cores from these bogs therefore can be used to study temporal trends in atmospheric deposition of pollutants. In this work epithermal neutron activation analysis was applied for the first time to study the distribution of 35 elements in peat profiles from ombrotrophic bogs. The selected examples were from Finnmark county in northern Norway: one pristine site far from any local pollution source, and another strongly affected by long-term operation of Russian copper-nickel smelters located close to the border. The elements are classified with respect to their behavior in the uppermost 40 cm of the peat, and similarities and differences between the two profiles are discussed. As compared with other more commonly used analytical techniques based on acid decomposition of the sample ENAA has the advantage of providing the total concentrations of the elements.

Study of cis- and trans-uranium elements by paper chromatography and electrophoresis

International Nuclear Information System (INIS)

Clanet, F.

1968-01-01

In this work, the field of application of paper chromatography and electrophoresis in inorganic chemistry has been extended to elements 90 to 96 in hydrochloric and nitric acid solution. Results obtained concern the following points: 1) - Characterization of the valency states of Np and of Pu using coloured reactions on chromatograms and electrophoregrams. The valency IV is characterized by alizarin, arsenazo-I and thorin-I, whilst diphenylcarbazide is used for the hexavalent state. 2) - Paper chromatography: by using as eluent, mixtures of equal parts of aqueous HCl and HNO 3 solutions and of alcohols (methanol, ethanol and n-butanol), the R f values of elements 90 to 96 have been determined. It has been possible to deduce certain conclusions concerning the complexing of these elements by Cl - and NO 3 - ions. 3) - We have developed an electrophoretic technique on cellulose acetate membranes in order to separate the charged species formed by the elements 90 to 96 in HCl and HNO 3 solutions from 1 to 12 M. Mobility curves have been obtained. It appears from our results that the tendency for the elements considered to form anionic complexes follows the order of the ionic potentials when the valency state is four; this order is reversed for the valency three. The ions Cl - have a smaller tendency to form complexes than the NO 3 - ions with respect to these elements in their oxidation state III or IV, but the reverse phenomenon is observed for U VI and Pu VI . Finally, the complexing of the cations Pu 4+ and PuUO 2 2+ by NO 3 - follows the order of the ionic potentials but occurs in the reverse order for Cl - ions. 4) - Various analytical applications are considered: separation of the various elements from each other and separation of the valency states of Np and of Pu. (author) [fr

Discrete Element Modeling

Energy Technology Data Exchange (ETDEWEB)

Morris, J; Johnson, S

2007-12-03

The Distinct Element Method (also frequently referred to as the Discrete Element Method) (DEM) is a Lagrangian numerical technique where the computational domain consists of discrete solid elements which interact via compliant contacts. This can be contrasted with Finite Element Methods where the computational domain is assumed to represent a continuum (although many modern implementations of the FEM can accommodate some Distinct Element capabilities). Often the terms Discrete Element Method and Distinct Element Method are used interchangeably in the literature, although Cundall and Hart (1992) suggested that Discrete Element Methods should be a more inclusive term covering Distinct Element Methods, Displacement Discontinuity Analysis and Modal Methods. In this work, DEM specifically refers to the Distinct Element Method, where the discrete elements interact via compliant contacts, in contrast with Displacement Discontinuity Analysis where the contacts are rigid and all compliance is taken up by the adjacent intact material.

A study on the bonding residual thermal stress analysis of dissimilar materials using boundary element method

International Nuclear Information System (INIS)

Yi, Won; Yu, Yeong Chul; Jeong, Eui Seob; Lee, Chang Ho

1995-01-01

It is very important to evaluate the bonding residual thermal stress in dissimilar materials such as LSI package. In this study, the bonding residual thermal stress was calculated using the boundary element method, varing with the sub-element, geometry of specimen and adhesive thickness. The present results reveal a stress singularity at the edge of the interface, therefore the bonding strength of metal/resin interface can be estimated by taking into account it.

Finite element model to study calcium distribution in oocytes ...

African Journals Online (AJOL)

Parvaiz Ahmad Naik

2015-03-20

Mar 20, 2015 ... Department of Mathematics, Maulana Azad National Institute of Technology, Bhopal 462051 ... finite element method has been employed to obtain the solution. ..... Nelson MT, Cheng H, Rubart M. Relaxation of arterial smooth.

Studies on concentration of minor stable elements in marine environmental samples

International Nuclear Information System (INIS)

Suzuki, Hamaji; Ishii, Toshiaki; Iimura, Mitsue; Koyanagi, Taku

1978-01-01

Information on the physico-chemical state and quantity of stable elements in marine environments is frequently required to analyze the radioecological behavior of radionuclides released from nuclear facilities into the sea. In this work, determination of stable Mn, Fe, Co, Zn, Zr, Rb, Cs and some rare earth elements (Ce, Eu, Tb, Yb and Lu) in seawater and marine organisms was carried out and the concentration factors were estimated. Seawater and marine organisms were collected on the seashore of Ibaraki Prefecture and analysed by means of neutron activation analysis or atomic absorption spectrometry depending on the elements or samples. Average concentration factors of the rare earth elements by marine organisms are estimated as 3 x 10 1 : muscle of fish, 5 x 10 2 : soft part of clams, and 2 x 10 2 : algae, respectively. Concentration factors by muscle of fishes were 10 3 : Fe, 2 x 10 2 : Co, 5 x 10 2 : Zn, and 5 x 10 1 : Cs, and those by soft part of shellfishes were 10 4 : Fe, 10 3 : Co, 2 x 10 3 : Zn, and 10 1 : Cs, whereas those by algae were 2 x 10 4 : Fe, 5 x 10 2 : Co, 10 3 : Zn, and 3 x 10 1 : Cs, respectively. The high concentration factors for numerous stable elements by shellfishes and algae suggested their suitabilities to the indicator organisms for monitoring of marine pollution by these heavy metals and corresponding radioisotopes and also their significant contribution to the internal radiation exposure to man as radioactive seafoods. (author)

Bounded elements in Locally C*-algebras

International Nuclear Information System (INIS)

El Harti, Rachid

2001-09-01

In order to get more useful information about Locally C*-algebras, we introduce in this paper the notion of bounded elements. First, we study the connection between bounded elements and spectrally bounded elements. Some structural results of Locally C*-algebras are established in Theorems 1 , 2 and 3. As an immediate consequence of Theorem 3, we give a characterization of the connected component of the identity in the group of unitary elements for a Locally C*-algebra. (author)

Scale factor management in the studies of affine models of shockproof garment elements

Directory of Open Access Journals (Sweden)

Denisov Oleg

2018-01-01

Full Text Available New samples of protective garment for performing construction work at height require numerous tests in conditions close to real conditions of extreme vital activity. The article presents some results of shockproof garment element studies and a description of a patented prototype. The tests were carried out on a model which geometric dimensions were convenient for manufacturing it in a limited batch. In addition, the used laboratory equipment (for example, a unique power pendulum, blanks made of a titanium-nickel alloy with a shape memory effect also imposed their limitations. The problem of the adequacy of the obtained experimental results transfer to mass-produced products was solved using tools of the classical similarity theory. Scale factor management influence in the affine modeling of the shockproof element, studied on the basis of the equiatomic titanium-nickel alloy with the shape memory effect, allowed us to assume, with a sufficient degree of reliability, the technical possibility of extrapolating the results of experimental studies to full-scale objects for the formation of the initial data of the mathematical model of shockproof garment dynamics elastoplastic deformation (while observing the similarity of the features of external loading.

Scale factor management in the studies of affine models of shockproof garment elements

Science.gov (United States)

Denisov, Oleg; Pleshko, Mikhail; Ponomareva, Irina; Merenyashev, Vitaliy

2018-03-01

New samples of protective garment for performing construction work at height require numerous tests in conditions close to real conditions of extreme vital activity. The article presents some results of shockproof garment element studies and a description of a patented prototype. The tests were carried out on a model which geometric dimensions were convenient for manufacturing it in a limited batch. In addition, the used laboratory equipment (for example, a unique power pendulum), blanks made of a titanium-nickel alloy with a shape memory effect also imposed their limitations. The problem of the adequacy of the obtained experimental results transfer to mass-produced products was solved using tools of the classical similarity theory. Scale factor management influence in the affine modeling of the shockproof element, studied on the basis of the equiatomic titanium-nickel alloy with the shape memory effect, allowed us to assume, with a sufficient degree of reliability, the technical possibility of extrapolating the results of experimental studies to full-scale objects for the formation of the initial data of the mathematical model of shockproof garment dynamics elastoplastic deformation (while observing the similarity of the features of external loading).

Blocking Mechanism Study of Self-Compacting Concrete Based on Discrete Element Method

Science.gov (United States)

Zhang, Xuan; Li, Zhida; Zhang, Zhihua

2017-11-01

In order to study the influence factors of blocking mechanism of Self-Compaction Concrete (SCC), Roussel’s granular blocking model was verified and extended by establishing the discrete element model of SCC. The influence of different parameters on the filling capacity and blocking mechanism of SCC were also investigated. The results showed that: it was feasible to simulate the blocking mechanism of SCC by using Discrete Element Method (DEM). The passing ability of pebble aggregate was superior to the gravel aggregate and the passing ability of hexahedron particles was bigger than tetrahedron particles, while the tetrahedron particle simulation results were closer to the actual situation. The flow of SCC as another significant factor affected the passing ability that with the flow increased, the passing ability increased. The correction coefficient λ of the steel arrangement (channel section shape) and flow rate γ in the block model were introduced that the value of λ was 0.90-0.95 and the maximum casting rate was 7.8 L/min.

Parametric study of unconstrained high-pressure torsion- Finite element analysis

International Nuclear Information System (INIS)

Halloumi, A; Busquet, M; Descartes, S

2014-01-01

The high-pressure torsion (HPT) experiments have been investigated numerically. An axisymmetric model with twist was developed with commercial finite element software (Abaqus) to study locally the specificity of the stress and strain history within the transformed layers produced during HPT processing. The material local behaviour law in the plastic domain was modelled. A parametric study highlights the role of the imposed parameters (friction coefficient at the interfaces anvil surfaces/sample, imposed pressure) on the stress/strain distribution in the sample bulk for two materials: ultra-high purity iron and steel grade R260. The present modelling provides a tool to investigate and to analyse the effect of pressure and friction on the local stress and strain history during the HPT process and to couple with experimental results

Study of radon, thoron and toxic elements in some textile dyes

International Nuclear Information System (INIS)

Abel-Ghany, H.A.

2013-01-01

Elemental analysis of textile dyes may provide valuable information concerning the content and concentrations of element, especially the toxic ones. Such information monitors the safety of handling and using these dyes in textile industry. In addition to the safety of wearing of clothes stained with these dyes. In the present work, the specific activity of both radon and thoron were measured in nine textile dyes by using alpha emitters registration which are emitted from radon and thoron gases in CR-39 nuclear track detectors. Unexpectedly, the results obtained reports a high concentration of both radon and thoron gases in some samples (samples D5 and D9). Also the concentration of toxic elements (Cu, Pb, Zn, Mn, Cd and Cr) in textile dyes were determined by flame and graphite furnace atomic absorption spectrometry. (author)

Medical student use of communication elements and association with patient satisfaction: a prospective observational pilot study.

Science.gov (United States)

Turner, Joseph S; Pettit, Katie E; Buente, Bryce B; Humbert, Aloysius J; Perkins, Anthony J; Kline, Jeffrey A

2016-05-21

Effective communication with patients impacts clinical outcome and patient satisfaction. We measure the rate at which medical students use six targeted communication elements with patients and association of element use with patient satisfaction. Participants included fourth year medical students enrolled in an emergency medicine clerkship. A trained observer measured use of six communication elements: acknowledging the patient by name, introducing themselves by name, identifying their role, explaining the care plan, explaining that multiple providers would see the patient, and providing an estimated duration of time in the emergency department. The observer then conducted a survey of patient satisfaction with the medical student encounter. A total of 246 encounters were documented among forty medical student participants. For the six communication elements evaluated, in 61% of encounters medical students acknowledged the patient, in 91% they introduced themselves, in 58 % they identified their role as a student, in 64% they explained the care plan, in 80% they explained that another provider would see the patient, and in only 6% they provided an estimated duration of care. Only 1 encounter (0.4%) contained all six elements. Patients' likelihood to refer a loved one to that ED was increased when students acknowledged the patient and described that other providers would be involved in patient care (P = 0.016 and 0.015 respectively, Chi Square). Likewise, patients' likelihood to return to the ED was increased when students described their role in patient care (P = 0.035, Chi Square). This pilot study demonstrates that medical students infrequently use all targeted communication elements. When they did use certain elements, patient satisfaction increased. These data imply potential benefit to additional training for students in patient communication.

Study in Malaysia on ingestion and organ content of trace elements of importance in radiological protection

International Nuclear Information System (INIS)

Zawiah, H.; Khalik Haji Wood, A.; Shahrom, A.W.; Halim Mansar, A.

1998-01-01

Involvement in the Reference Asian man project, Phase 2 began at the project, formulation meeting in Hitachinaka City, Japan in February 1995. The objective of the project is to look into the ingestion and organ content of trace elements of importance in radiological protection. The data on ingestion of radionuclides from diet and deposition in tissues are important for estimating internal dose for radiation protection. The meeting agreed the elements of primary interest are caesium, iodine, strontium, thorium and uranium in samples of representative diets and autopsy specimens of liver, muscle, thyroid, bone, and kidney. This report will highlight the methodology for implementation of the project including defining the study groups, sampling duplicate diet and autopsy specimens and the analytical techniques involved. Emphasis will be given to nuclear-related analytical technique (NAA) together with a complementary technique (AAS) available in our institution. Some data on trace element contents of local marine and fresh water fishes and milk was reported. Included also a brief discussion on drinking water quality in Malaysia and some information on related studies available. The information on drinking water will be very useful to the present study since water is part of daily diet. (author)

WWR-M reactor fuel elements as objects of permanent study and modernization

International Nuclear Information System (INIS)

Kirsanov, G.A.; Konoplev, K.A.; Poltavski, A.S.; Zakharov, A.S.

2005-01-01

Brief description of WWR-M5 thin-walled fuel elements and review of possible improvement of parameters for reactor type WWR-M and WWR-SM during transition from fuel elements HEU and LEU WWR-M2 to LEU WWR-M5 is presented. (author)

Micro-PIXE studies of elemental distribution in Cd-accumulating Brassica juncea L

International Nuclear Information System (INIS)

Schneider, Thorsten; Haag-Kerwer, Angela; Maetz, Mischa; Niecke, Manfred; Povh, Bogdan; Rausch, Thomas; Schuessler, Arthur

1999-01-01

Brassica juncea L. is a high biomass producing crop plant, being able to accumulate Cd and other heavy metals in their roots and shoots. It is a good candidate for efficient phytoextraction of heavy metals - such as Cd - from polluted soils. PIXE and STIM analyses were applied to investigate Cd-uptake in roots and the resulting effects on the elemental distribution of Cd stressed plants. The axial distribution of trace elements as a function of distance from the root tip as well as the radial distribution within cross-sections were analysed. The results are compared with the elemental distribution in control plants

Micro-PIXE studies of elemental distribution in Cd-accumulating Brassica juncea L.

Science.gov (United States)

Schneider, Thorsten; Haag-Kerwer, Angela; Maetz, Mischa; Niecke, Manfred; Povh, Bogdan; Rausch, Thomas; Schüßler, Arthur

1999-10-01

Brassica juncea L. is a high biomass producing crop plant, being able to accumulate Cd and other heavy metals in their roots and shoots. It is a good candidate for efficient phytoextraction of heavy metals - such as Cd - from polluted soils. PIXE and STIM analyses were applied to investigate Cd-uptake in roots and the resulting effects on the elemental distribution of Cd stressed plants. The axial distribution of trace elements as a function of distance from the root tip as well as the radial distribution within cross-sections were analysed. The results are compared with the elemental distribution in control plants.

Micro-PIXE studies of elemental distribution in Cd-accumulating Brassica juncea L

Energy Technology Data Exchange (ETDEWEB)

Schneider, Thorsten E-mail: thorsten.schneider@mpi-hd.mpg.de; Haag-Kerwer, Angela; Maetz, Mischa; Niecke, Manfred; Povh, Bogdan; Rausch, Thomas; Schuessler, Arthur

1999-09-02

Brassica juncea L. is a high biomass producing crop plant, being able to accumulate Cd and other heavy metals in their roots and shoots. It is a good candidate for efficient phytoextraction of heavy metals - such as Cd - from polluted soils. PIXE and STIM analyses were applied to investigate Cd-uptake in roots and the resulting effects on the elemental distribution of Cd stressed plants. The axial distribution of trace elements as a function of distance from the root tip as well as the radial distribution within cross-sections were analysed. The results are compared with the elemental distribution in control plants.

Burnup measurements of leader fuel elements

International Nuclear Information System (INIS)

Henriquez, C; Navarro, G; Pereda, C

2000-01-01

Some time ago the CCHEN authorities decided to produce a set of 50 low enrichment fuel elements. These elements were produced in the PEC (Fuel Elements Plant), located at CCHEN offices in Lo Aguirre. These new fuel elements have basically the same geometrical characteristics of previous ones, which were British and made with raw material from the U.S. The principal differences between our fuel elements and the British ones is the density of fissile material, U-235, which was increased to compensate the reduction in enrichment. Last year, the Fuel Elements Plant (PEC) delivered the shipment's first four (4) fuel elements, called leaders, to the RECH1. A test element was delivered too, and the complete set was introduced into the reactor's nucleus, following the normal routine, but performing a special follow-up on their behavior inside the nucleus. This experimental element has only one outside fuel plate, and the remaining (15) structural plates are aluminum. In order to study the burnup, the test element was taken out of the nucleus, in mid- November 1999, and left to decay until June 2000, when it was moved to the laboratory (High Activity Cell), to start the burnup measurements, with a gamma spectroscopy system. This work aims to show the results of these measurements and in addition to meet the following objectives: (a) Visual test of the plate's general condition; (b) Sipping test of fission products; (c) Study of burn-up distribution in the plate; (d) Check and improve the calculus algorithm; (e) Comparison of the results obtained from the spectroscopy with the ones from neutron calculus

[Hygienic study of an activated fibrous charcoal material as a sorbing filtering element for drinking water afterpurification].

Science.gov (United States)

Prokopov, V A; Mironets, N V; Gakal, R K; Maktaz, E D; Dugan, A M; Teteneva, I A; Tarabarova, S B; Martyshchenko, N V; Nadvornaia, Zh D

1993-01-01

The results of complex toxicological and hygienic study showed that the quality of pipe water filtered through the activated carbonic fibrous material (ACFM) "Dnepr-F" forming a part of absorptive filtering element improved markedly. The content of organic substances decreased drastically as well as that of nitrates and iron. Microbiological indices did not suffer appreciable changes and were within permissible limits. The water filtered through the absorptive element with ACFM had no adverse influence on the organisms of warm-blooded animals. Proceeding from foregoing one can conclude that the "Dnepr-F" may be recommended as a part of absorptive filtering element for the final refinement of drinking water.

How far are we on the way to the superheavy nuclei?

International Nuclear Information System (INIS)

Muenzenberg, G.

1989-10-01

The discovery of the elements 107, 108, and 109 in a region of dominating shell stabilization is the most important step on the way to the superheavy nuclei in recent years. These experiments leading to the presently upper end of the periodic table were possible with the velocity filter SHIP to separate the heavy nuclei produced in complete fusion reactions of heavy ions. The identification of the unknown nuclei was established by α-α mother-daughter correlation of the nuclei decaying after the implantation into position sensitive surface-barrier detectors. With this method it is possible to identify even single nuclei of unknown isotopes unambiguously. The limits of sensitivity are production cross-sections of a few picobarns and about 2 μs of nuclear lifetime. With this method the elements 107, 108, and 109 were observed for the first time by their α-decay and identified unambiguously. For element 107 the isotopes with masses 261 and 262, for the element 108 the isotopes with masses 264 and 265, and for element 109 the isotope with mass 266 were found. The halflives range from 0.1 ms to 0.1 s. The highly fissile transactinide nuclei were produced in cold fusion of heavy ions using 207,208 Pb and 209 Bi targets, respectively, and 50 Ti, 54 Cr, or 58 Fe beams. The evaluation of the excitation functions for the production of very heavy evaporation residues shows a strong decrease above 25 MeV excitation energy caused by a destruction of the groundstate shell effects at high excitation energies. The strong competition of barrier transmission and survival probability results in rather narrow excitation functions and small production cross sections. The maximum cross section is observed close to the Coulomb barrier and corresponding to projectile energies near 5 MeV/u. (orig.) [de

The transuranium elements: From neptunium and plutonium to element 112

International Nuclear Information System (INIS)

Hoffman, D.C.

1996-01-01

Beginning in the 1930's, both chemists and physicists became interested in synthesizing new artificial elements. The first transuranium element, Np, was synthesized in 1940. Over the past six decades, 20 transuranium elements have been produced. A review of the synthesis is given. The procedure of naming the heavy elements is also discussed. It appears feasible to produce elements 113 and 114. With the Berkeley Gas-filled Separator, it should be possible to reach the superheavy elements in the region of the spherical Z=114 shell, but with fewer neutrons than the N=184 spherical shell. 57 refs, 6 figs

Use of neutron activation techniques for studying elements distribution. Applications in geochemistry, ecology and technology

International Nuclear Information System (INIS)

Flitsyan, E.S.

1997-01-01

The essence of the radiography method, sensitivity of which is within a range of 10 -2 - 10 -7 g · mm -2 and resolution ability extend from 0,01 to 100 μm, consists in determining the distributions of ionising irradiation sources on a surface under study by using the two-dimensional field of their irradiation registered by means of photoemulsion or dielectric track detector. Statistical analysis and computer processing of the radiographic images have allowed one to solve the two main tasks of the method , namely, the determination of true distributions of ionising irradiation sources on the surface of an object under study and the quantitative estimation within given accuracy of the content of an element under study in a sample. A complex of radiographic techniques based on the registration of secondary irradiation of the activated nuclei, instantaneous products of the nuclear reactions, and fusion fragments of the transuranium elements, has been developed to solve a series of the problem in geology and geochemistry, as well as for an analysis of technological and environment samples. Upon designing and constructing special comparison standards modelling a sample in composition and structure, the quantitative data on distributions of more than forty elements in rock sections and these of the main microcomponents, including oxygen, in the superconducting ceramics samples have also been obtained. (author)

Scandium - problem of ultra-trace-element essentiality

International Nuclear Information System (INIS)

Kist, A.A.; Zkuk, L.I.; Danilova, E.A.; Makhmudov, E.A.

2006-01-01

Full text: Role of constitutional and essential elements in Life is known quite well. It is also well known that all chemical elements present in the living matter. Nevertheless essentiality of at least 55 chemical elements (more than a half of number of natural elements) is still not accepted. In many cases these elements presumably play important role in the Life. On the other hand their essentiality is still under doubt. One of the 'strange' elements in this connection is scandium. Scandium is an element which is very 'simple' for instrumental neutron activation analysis (INAA). For many years in our laboratory were carried out studies on animals and human tissues and fluids elemental composition using INAA in which data for scandium were obtained as 'redundant' information. Essentiality of scandium was newer proven using accepted criteria of elements. Nevertheless in our studies were found various regularities, statistically significant inter-elemental correlations and correlations between elements in tissues and fluids versus clinic and biochemical data. There are some examples. There were found correlations of scandium hair concentration and blood glucose (r=0.68±0.13), body mass index (r=0.86±0.07), leukocyte with phagocytic activity migration inhibition test (r=0.68±0.18), size of cavity of the left heart auricle (r=-0.65±0.16), final systolic bulk (r=0.80±0.12), stroke output of heart (r=-0.79±0.12), final diastolic bulk (0.88±0.0080) etc. In addition using gel filtration in rat liver cytosol was found peak of scandium in elution curve. Examples and correlations given in the paper say in favor that scandium may play quite important role in biological processes and that the biological role of scandium should be studied more intensive. The most important criterion is an appearance of the organism dysfunction in case of removal of the studied elements from the diet (intake) which in all other sides remains completely valuable and disappearance of all

Studies on the chemistry of element 104 with the centrifuge system SISAK-3

Energy Technology Data Exchange (ETDEWEB)

Eberhardt, K.; Kratz, J.V.; Mendel, M.; Naehler, A.; Trautmann, N.; Wiehl, N. [Mainz Univ. (Germany); Alstadt, J.; Omtvedt, J.P. [Oslo Univ. (Norway); Malmbeck, R.; Skarnemark, G.; Wierczinski, B. [Chalmers Univ. of Technology, Goeteborg (Sweden); Eichler, B.; Gaeggeler, H.W.; Jost, D.T.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

The centrifuge system SISAK-3 combined with a detector for the measurement of {alpha}-particles and spontaneous fission (SF) fragments in a flowing organic liquid has been applied to study the chemical behaviour of element 104 produced in the reaction {sup 248}Cm({sup 18}O,5n){sup 261}104. (author) 2 figs., 2 refs.

Soil-to-potato transfer factors of elements

International Nuclear Information System (INIS)

Tsukada, Hirofumi; Watabe, Teruhisa.

1996-01-01

Transfer factors (TFs) of stable elements from soil to potato were determined for 26 pairs of samples which were collected at different sites in Aomori prefecture, Japan. The concentrations of 31 elements in both soil and potato samples were determined by neutron activation analysis. Several of these elements were divided into two groups, each having different TF characteristics. In the first group of elements, such as Cl, K, Ca, etc., an inverse correlation was seen between the TFs for each element and their concentrations in the soil. The relatively constant concentrations of these elements in potato were independent of the concentrations of the same elements in soil. However, in the second group, the TFs for other elements, such as Sc, Co and so on, in potato were independent of their concentrations in the soil. The fluctuation of TF observed in this study was smaller than that previously reported. It may be attributed to the fact that the experiment was done in a relatively narrow geographic area. In addition, the TFs for stable elements in this study were generally one to three orders of magnitude lower than those compiled for radioactive isotopes in IAEA publications. These differences should be precisely examined hereafter. (author)

Pragmatic trial design elements showed a different impact on trial interpretation and feasibility than explanatory elements

NARCIS (Netherlands)

Nieuwenhuis, Joost B.; Irving, Elaine; Oude Rengerink, Katrien; Lloyd, Emily; Goetz, Iris; Grobbee, Diederick E.; Stolk, Pieter; Groenwold, Rolf H H; Zuidgeest, Mira G P

2016-01-01

OBJECTIVE: To illustrate how pragmatic trial design elements, or inserting explanatory trial elements in pragmatic trials affect validity, generalizability, precision and operational feasibility. STUDY DESIGN AND SETTING: From illustrative examples identified through the IMI Get Real Consortium, we

Finite element simulation of thermal, elastic and plastic phenomena in fuel elements

International Nuclear Information System (INIS)

Soba, Alejandro; Denis, Alicia C.

1999-01-01

Taking as starting point an irradiation experiment of the first Argentine MOX fuel prototype, performed at the HFR reactor of Petten, Holland, the deformation suffered by the fuel element materials during burning has been numerically studied. Analysis of the pellet-cladding interaction is made by the finite element method. The code determines the temperature distribution and analyzes elastic and creep deformations, taking into account the dependency of the physical parameters of the problem on temperature. (author)

A review of Human Biomonitoring studies of trace elements in Pakistan.

Science.gov (United States)

Waseem, Amir; Arshad, Jahanzaib

2016-11-01

Human biomonitoring (HBM) measures the concentration levels of substances or their metabolites in human body fluids and tissues. HBM of dose and biochemical effect monitoring is an effective way of measuring human exposure to chemical substances. Many countries have conducted HBM studies to develop a data base for many chemicals including trace metals of health concern for their risk assessment and risk management. However, in Pakistan, HBM program on large scale for general population does not exist at present or in the past has been reported. Various individual HBM studies have been reported on the assessment of trace elements (usually heavy metals) from Pakistan; most of them are epidemiological cross sectional surveys. In this current review we tried to develop a data base of HBM studies of trace elements namely arsenic, cadmium, copper, chromium, iron, lead, manganese, nickel, and zinc in biological fluids (blood, urine) and tissues (hair, nails) in general population of Pakistan. Studies from all available sources have been explored, discussed and presented in the form of tables and figures. The results of these studies were critically compared with large scale HBM programs of other countries, (US & European communities etc). It was observed from the present study that the most of the toxic metals in biological fluids/tissues in general population of Pakistan, have higher background values comparatively. For example the mean values of toxic metals like As, Cd, Cr, Ni, and Pb in blood of general population were found as 2.08 μg/L, 4.24 μg/L, 60.5 μg/L, 1.95 μg/L, 198 μg/L respectively. Similarly, the urine mean values of 67.6 μg/L, 3.2 μg/L, 16.4 μg/L, 6.2 μg/L and 86.5 μg/L were observed for As, Cd, Cr, Ni, and Pb respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

A neutron activation study of trace element contents in plants growing on soils of different acidity

International Nuclear Information System (INIS)

Caplan, J.; Loebersli, E.; Steinnes, E.; Naeumann, R.

1987-01-01

As a part of a research program on the influence of soil acidification on metal uptake in plants, the present work was carried out in order to investigate the feasibility of instrumental neutron activation analysis for this purpose. The work was restricted to elements yielding medium- or long-lived radionuclides on neutron activation. Elements studied include Na, Sc, Cr, Fe, Co, Zn, Br, Rb, Cs, Ba and La. The material analyzed was from a comparison of trace element contents in natural vegetation from corresponding coniferous forest locations in South Norway, which is considerably exposed to acidic deposition from long-range atmospheric transport, and Central Norway, which is far less affected. In particular, Rb and Cs show pronounced differences between the two regions regarding concentration levels in certain plant species. (author) 8 refs.; 4 figs

A neutron activation study of trace element contents in plants growing on soils of different acidity

International Nuclear Information System (INIS)

Caplan, J.; Loebersli, E.; Naeumann, R.; Steinnes, E.

1986-01-01

As part of a research program on the influence of soil acidification on metal uptake in plants, the present work was carried out in order to investigate the feasibility of instrumental neutron activation analysis for this purpose. The work was restricted to elements yielding medium- or long-lived radionuclides on neutron activation. Elements studied include Na, Sc, Cr, Ge, Co, Zn, Br, Rb, Cs, Ba and La. The material analyzed was from a comparison of trace element contents in natural vegetation from corresponding coniferous forest locations in South Norway, which is considerably exposed to acidic deposition from long-range atmospheric transport, and Central Norway, which is far less affected. In particular Rb and Cs show pronounced differences between the two regions regarding concentration levels in certain plant species. (author)

Experimental search for superheavy elements

International Nuclear Information System (INIS)

Wieloch, A.

2008-12-01

This work reports on the experimental search for superheavy elements (SHE). Two types of approaches for SHE production are studied i.e. '' cold '' fusion mechanism and massive transfer mechanism. First mechanism was studied in normal and inverse kinematics, by using Wien filter at the GANIL facility. The production of SHE elements with Z 106 and 108 is reported while negative results on the synthesis of SHE elements with Z 114 and 118 was received. The other approach i.e. reactions induced by heavy ion projectiles (e.g. 172 Yb, 197 Au) on fissile target nuclei (e.g. 238 U, 232 Th) at near Coulomb barrier incident energies was studied by using superconducting solenoid installed Texas A(and)M University. Preliminary results for the reaction 197 Au(7.5 MeV/u) - 232 Th are presented where three cases of the possible candidates for SHE elements were found. A dedicated detection setup for such studies is discussed and the detailed data analysis is presented. Detection of alpha and spontaneous fission radioactive decays is used to unambiguously identify the atomic number of SHE. Special statistical analysis for a very low detected number of α decays is applied to check consistency of the αradioactive chains. (author)

Limitless Analytic Elements

Science.gov (United States)

Strack, O. D. L.

2018-02-01

We present equations for new limitless analytic line elements. These elements possess a virtually unlimited number of degrees of freedom. We apply these new limitless analytic elements to head-specified boundaries and to problems with inhomogeneities in hydraulic conductivity. Applications of these new analytic elements to practical problems involving head-specified boundaries require the solution of a very large number of equations. To make the new elements useful in practice, an efficient iterative scheme is required. We present an improved version of the scheme presented by Bandilla et al. (2007), based on the application of Cauchy integrals. The limitless analytic elements are useful when modeling strings of elements, rivers for example, where local conditions are difficult to model, e.g., when a well is close to a river. The solution of such problems is facilitated by increasing the order of the elements to obtain a good solution. This makes it unnecessary to resort to dividing the element in question into many smaller elements to obtain a satisfactory solution.

Study of the Reactive-element Effect in Oxidation of Fe-cr Alloys Using Transverse Section Analytical Electron Microscopy

Science.gov (United States)

King, W. E.; Ethridge, E. C.

1985-01-01

The role of trace additions of reactive elements like Y, Ce, Th, or Hf to Cr bearing alloys was studied by applying a new developed technique of transverse section analytical electron microscopy. This reactive-element effect improves the high temperature oxidation resistance of alloys by strongly reducing the high temperature oxidation rate and enhancing the adhesion of the oxide scale, however, the mechanisms for this important effect remain largely unknown. It is indicated that the presence of yttrium affects the oxidation of Fe-Cr-Y alloys in at least two ways. The reactive element alters the growth mechanism of the oxide scale as evidenced by the marked influence of the reactive element on the oxide scale microstructure. The present results also suggest that reactive-element intermetallic compounds, which internally oxidize in the metal during oxidation, act as sinks for excess vacancies thus inhibiting vacancy condensation at the scale-metal interface and possibly enhancing scale adhesion.

Elements of Motivational Structure for Studying Mechanical Engineering

Directory of Open Access Journals (Sweden)

Nikša Dubreta

2017-12-01

Full Text Available The article presents the findings on students' reasons for studying mechanical engineering. These reasons were covered in terms of extrinsic and intrinsic motivation additionally related to selected independent variables of the sample – students' secondary school Grade Point Average, their gender and the socio-economic status. The research was conducted with the first year students of the Faculty of Mechanical Engineering at the University of Zagreb, Croatia. The sample consisted of 282 students (228 males and 54 females and comprised students of all majors. According to descriptive character of the questionnaire type survey characteristics of the sample are presented. Composite variables of extrinsic and intrinsic motivation were dichotomized to present different levels of the students' overall motivational structure. Results indicate a students' interest in the field of science and technology as the most important element of intrinsic motivation, with no significant relation to any of independent variables. By contrast, extrinsic motivation has manifested as significantly related to the variables of Grade Point Average and to parents' education as one component of the socio-economic status. However, a significant level of indecisive respondents regarding the both intrinsic and extrinsic motivation suggests that the choice of the study programme is not always a consistent and an unambiguous process.

Use of multivariate and neutron activation analysis on studying element interrelationships in Brazilian phosphorite

International Nuclear Information System (INIS)

Delgado, J.U.; Carvalho, J.L.S.; Tauhata, L.

1993-01-01

Methods to determine U, Th and other constituent elements in mineral matrices through Instrumental Neutron Activation Analysis (INAA), have been widely utilized due to their capability to extract a large quantity of information from small samples. In the present work, an experimental methodology based on INAA associated to the cluster statistics technique was used to determine the uranium concentration and its correlation with other elements present in the mineral phosphorites from the northeast region of Brazil. Data for 22 elements including rare-earth elements are presented. A good correlation between uranium and rare-earth elements is observed. For the transition metals, correlation with uranium was not noted. (author) 11 refs.; 2 figs.; 1 tab

Technique for mass-spectrometric determination of moisture content in fuel elements and fuel element claddings

International Nuclear Information System (INIS)

Kurillovich, A.N.; Pimonov, Yu.I.; Biryukov, A.S.

1988-01-01

A technique for mass-spectroimetric determination of moisture content in fuel elements and fuek claddings in the 2x10 -4 -1.5x10 -2 g range is developed. The relative standard deviation is 0.13. A character of moisture extraction from oxide uranium fuels in the 20-700 deg C temperature range is studied. Approximately 80% of moisture is extracted from the fuels at 300 deg C. The moisture content in fuel elements with granular uranium oxide fuels is measured. Dependence of fuel element moisture content on conditions of hot vacuum drying is shown. The technique permits to optimize the fuel element fabrication process to decrease the moisture content in them. 4 refs.; 3 figs.; 2 tabs

Some studies on weld bead geometries for laser spot welding process using finite element analysis

International Nuclear Information System (INIS)

Siva Shanmugam, N.; Buvanashekaran, G.; Sankaranarayanasamy, K.

2012-01-01

Highlights: → In this study, a 2 kW Nd:YAG laser welding system is used to conduct laser spot welding trials. → The size and shape of the laser spot weld is predicted using finite element simulation. → The heat input is assumed to be a three-dimensional conical Gaussian heat source. → The result highlights the effect of beam incident angle on laser spot welds. → The achieved results of numerical simulation are almost identical with a real weldment. -- Abstract: Nd:YAG laser beam welding is a high power density welding process which has the capability to focus the beam to a very small spot diameter of about 0.4 mm. It has favorable characteristics namely, low heat input, narrow heat affected zone and lower distortions, as compared to conventional welding processes. In this study, finite element method (FEM) is applied for predicting the weld bead geometry i.e. bead length (BL), bead width (BW) and depth of penetration (DP) in laser spot welding of AISI 304 stainless steel sheet of thickness 2.5 mm. The input parameters of laser spot welding such as beam power, incident angle of the beam and beam exposure time are varied for conducting experimental trials and numerical simulations. Temperature-dependent thermal properties of AISI 304 stainless steel, the effect of latent heat of fusion, and the convective and radiative aspects of boundary conditions are considered while developing the finite element model. The heat input to the developed model is assumed to be a three-dimensional conical Gaussian heat source. Finite-element simulations of laser spot welding were carried out by using Ansys Parametric Design Language (APDL) available in finite-element code, ANSYS. The results of the numerical analysis provide the shape of the weld beads for different ranges of laser input parameters that are subsequently compared with the results obtained through experimentation and it is found that they are in good agreement.

3D element imaging using NSECT for the detection of renal cancer: a simulation study in MCNP

Science.gov (United States)

Viana, R. S.; Agasthya, G. A.; Yoriyaz, H.; Kapadia, A. J.

2013-09-01

This work describes a simulation study investigating the application of neutron stimulated emission computed tomography (NSECT) for noninvasive 3D imaging of renal cancer in vivo. Using MCNP5 simulations, we describe a method of diagnosing renal cancer in the body by mapping the 3D distribution of elements present in tumors using the NSECT technique. A human phantom containing the kidneys and other major organs was modeled in MCNP5. The element composition of each organ was based on values reported in literature. The two kidneys were modeled to contain elements reported in renal cell carcinoma (RCC) and healthy kidney tissue. Simulated NSECT scans were executed to determine the 3D element distribution of the phantom body. Elements specific to RCC and healthy kidney tissue were then analyzed to identify the locations of the diseased and healthy kidneys and generate tomographic images of the tumor. The extent of the RCC lesion inside the kidney was determined using 3D volume rendering. A similar procedure was used to generate images of each individual organ in the body. Six isotopes were studied in this work—32S, 12C, 23Na, 14N, 31P and 39K. The results demonstrated that through a single NSECT scan performed in vivo, it is possible to identify the location of the kidneys and other organs within the body, determine the extent of the tumor within the organ, and to quantify the differences between cancer and healthy tissue-related isotopes with p ≤ 0.05. All of the images demonstrated appropriate concentration changes between the organs, with some discrepancy observed in 31P, 39K and 23Na. The discrepancies were likely due to the low concentration of the elements in the tissue that were below the current detection sensitivity of the NSECT technique.

3D element imaging using NSECT for the detection of renal cancer: a simulation study in MCNP.

Science.gov (United States)

Viana, R S; Agasthya, G A; Yoriyaz, H; Kapadia, A J

2013-09-07

This work describes a simulation study investigating the application of neutron stimulated emission computed tomography (NSECT) for noninvasive 3D imaging of renal cancer in vivo. Using MCNP5 simulations, we describe a method of diagnosing renal cancer in the body by mapping the 3D distribution of elements present in tumors using the NSECT technique. A human phantom containing the kidneys and other major organs was modeled in MCNP5. The element composition of each organ was based on values reported in literature. The two kidneys were modeled to contain elements reported in renal cell carcinoma (RCC) and healthy kidney tissue. Simulated NSECT scans were executed to determine the 3D element distribution of the phantom body. Elements specific to RCC and healthy kidney tissue were then analyzed to identify the locations of the diseased and healthy kidneys and generate tomographic images of the tumor. The extent of the RCC lesion inside the kidney was determined using 3D volume rendering. A similar procedure was used to generate images of each individual organ in the body. Six isotopes were studied in this work - (32)S, (12)C, (23)Na, (14)N, (31)P and (39)K. The results demonstrated that through a single NSECT scan performed in vivo, it is possible to identify the location of the kidneys and other organs within the body, determine the extent of the tumor within the organ, and to quantify the differences between cancer and healthy tissue-related isotopes with p ≤ 0.05. All of the images demonstrated appropriate concentration changes between the organs, with some discrepancy observed in (31)P, (39)K and (23)Na. The discrepancies were likely due to the low concentration of the elements in the tissue that were below the current detection sensitivity of the NSECT technique.

Macro-Elements and Trace Elements in Cereal Grains Cultivated in Latvia

Directory of Open Access Journals (Sweden)

Jākobsone Ida

2015-09-01

Full Text Available Cereal-based foods have great importance in the compensation of micro- and trace element deficiency, because 50% of the foods produced worldwide are made up of cereal grains. The aim of the research was to determine the concentration of macro-elements and trace elements in different cereals cultivated in Latvia. Various cereals were used in the research: rye (n = 45, barley (n = 54, spring wheat (n = 27, winter wheat (n = 53, triticale (n = 45 and oats (n = 42. Thirteen macro- and trace elements (Cd, Pb, Ni, Cr, Al, Cu, K, Na, Mn, Fe, Zn, Mg, Ca were determined in cereal grain samples (n = 266. Macro-elements and trace elements varied significantly (p < 0.01 or p < 0.001. The highest concentrations of macro- and trace elements were found in oats and the lowest in rye. The obtained data will expand the opportunity for food and nutrition scientists to evaluate content of the examined elements in grain products, and dietary consumption (bioavailability of the examined macro-elements and trace elements.

Novel porcine repetitive elements

Directory of Open Access Journals (Sweden)

Nonneman Dan J

2006-12-01

Full Text Available Abstract Background Repetitive elements comprise ~45% of mammalian genomes and are increasingly known to impact genomic function by contributing to the genomic architecture, by direct regulation of gene expression and by affecting genomic size, diversity and evolution. The ubiquity and increasingly understood importance of repetitive elements contribute to the need to identify and annotate them. We set out to identify previously uncharacterized repetitive DNA in the porcine genome. Once found, we characterized the prevalence of these repeats in other mammals. Results We discovered 27 repetitive elements in 220 BACs covering 1% of the porcine genome (Comparative Vertebrate Sequencing Initiative; CVSI. These repeats varied in length from 55 to 1059 nucleotides. To estimate copy numbers, we went to an independent source of data, the BAC-end sequences (Wellcome Trust Sanger Institute, covering approximately 15% of the porcine genome. Copy numbers in BAC-ends were less than one hundred for 6 repeat elements, between 100 and 1000 for 16 and between 1,000 and 10,000 for 5. Several of the repeat elements were found in the bovine genome and we have identified two with orthologous sites, indicating that these elements were present in their common ancestor. None of the repeat elements were found in primate, rodent or dog genomes. We were unable to identify any of the replication machinery common to active transposable elements in these newly identified repeats. Conclusion The presence of both orthologous and non-orthologous sites indicates that some sites existed prior to speciation and some were generated later. The identification of low to moderate copy number repetitive DNA that is specific to artiodactyls will be critical in the assembly of livestock genomes and studies of comparative genomics.

The study on the intake and distribution of elements for 'Reference Japanese'

International Nuclear Information System (INIS)

1978-01-01

From the standpoint of radiological protection, the quantitative description of the physical characteristics and customs of man is the basis for calculating annual limit of intake, estimating dose equivalents and MIRD phantom for radioactive substances (ICRP 77). Committee 2 of ICRP has published compilation of data on the anatomical, chemical and physiological characteristics of man, as Standard Man and Reference Man. The models are, however, mostly based on the data published for Europeans and Americans. Reference Man, as characterized by the Task Group itself, is defined as a Caucasian and is a Western European or North American in habitat and custom. Reference Man, so far, is not directly applicable to other populations, for instance, the Japanese. Because it is known that differences exist between Asians, and Europeans and Americans with respect to race, customs and the pattern of food consumption. In view of this problem, it has become of necessity to seek standard or reference values for Japanese, i.e., mass and dimension of body and organs, and the daily intake, distribution, and metabolism of elements in Japanese, especially on the basis of more recently obtained data. Average mass of organs of the normal Japanese was studied and the results were presented for Reference Japanese Man. Development of chemical methods for determining stable elements in autopsy tissues was carried out to establish a highly reliable analytical system. Thyroidal uptake and biological half-life of ingested 131 I in relation to the dietal stable element intake was determined for two normal Japanese adult male subjects. (author)

Studying apple bruise using a finite element method analysis

Science.gov (United States)

Pascoal-Faria, P.; Alves, N.

2017-07-01

Apple bruise damage from harvesting, handling, transporting and sorting is considered to be the major source of reduced fruit quality, resulting in a loss of profits for the entire fruit industry. Bruising is defined as damage and discoloration of fruit flesh, usually with no breach of the skin. The three factors which can physically cause fruit bruising are vibration, compression load and impact. The last one is the main source of bruise damage. Therefore, prediction of the level of damage, stress distribution and deformation of the fruits under external force has become a very important task. To address these problems a finite element analysis has been developed for studying Portuguese Royal Gala apple bruise. The results obtained will be suitable to apple distributors and sellers and will allow a reduction of the impact caused by bruise damage in apple annual production.

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

International Nuclear Information System (INIS)

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

2016-01-01

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

Studies in Japan on ingestion and organ content of trace elements of importance in radiological protection

International Nuclear Information System (INIS)

Kawamura, H.; Shiraishi, K.; Yukawa, M.

1998-01-01

Data on intake of elements through foods, water and air, and concentration or Content of such elements in body tissues are essential part of the ICRP Reference Man recommended by ICRP for use in setting body composition and also deriving essential parameters for internal dose assessment models particularly for biokinetics or metabolism of radionuclides and their stable elements (1). However, in the RCA region, these data are comparatively scarce and it has been felt necessary to accumulate relevant data of high quality, reflecting the progress in analytical and related methods. In the present CRP (Phase 2), ingestion and organ content of elements of importance in internal dose assessment for the general public, i.e. Sr, Cs, I, Th and U as of the primary priority, are to be studied by performing chemical analysis following collecting representative samples in each participating country under proper quality control and assurance program (2). The data to be accumulated will enrich our knowledge in metabolic characteristics on the national, regional and global basis, after the large amount of data accumulated particularly on the physical characteristics and organ measurements in the first phase of Reference Asian Man CRP. The National Institute of Radiological Sciences (NIRS) of Japan will participate the present phase of CRP following the current concepts on the 'Reference Man'-oriented studies in the RCA region (3). The CRP will supplement the already existing data in Japan and extend them for some elements for which our data are to be further accumulated in ingestion and tissue content in normal and healthy Japanese adult males and females. The NIRS is requested to function as a Central Reference Laboratory (CRL) to promote the CRP in co-operation with the IAEA and the NIST as well as participating laboratories (2)

Studies of trace element determinations in nails by neutron activation analysis method

International Nuclear Information System (INIS)

Aguiar, Amilton Reinaldo; Saiki, Mitiko

1996-01-01

The purpose of this work was to develop the neutron activation analysis for trace element determinations in nails in order to apply this method to the study of the cystic fibrosis disease. It was verified that the elements Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Se and Zn can be determined by using short and long irradiations with thermal neutron flux from 10 11 to 10 13 n.cm -2 . -1 at the IEA-R1 nuclear research reactor. The washing solutions of triton-X100, NH 4 OH and acetone were tested in order to eliminate external contaminants from the nail samples. The nail analyses of the individual fingers from both of hands showed that the samples must be collected from all the fingers from both of hands to have a representative sample. The precision and the accuracy of the results were also examined by analyzing NIES 10C Rice Flour, IUPAC Bowen's Kale and NIST 1572 Citrus Leaves reference materials. (author)

Study of element uptake in plants from the soil to assess environmental contamination by toxic elements

CERN Document Server

En, Z; Tsipin, V V; Tillaev, T; Jumaniyazova, G I

2003-01-01

Uptake of various elements by plants through the root system from the soil was studied. Vegetation experiments with cotton and white beet were carried out in the control and test fields. The test fields were enriched with phyto-bacterial strains capable of dissolving insoluble phosphate compounds. Analytical work involved analysis of blank, control and test soil samples and analysis of plants sampled in different growing periods: periods of first sprouts, florescence and ripening of the plants. Multielement analyses of soil and plant samples were carried out by instrumental neutron activation techniques using our WWR-SM research reactor. Results of the measurements have shown that macro- and microelement composition of the analyzed soil samples were consistent to clark contents except for copper. Our experiments have resulted that the concentration levels of copper in the soils were within 300-450 mg/kg, and its average concentration in cotton leaves was about similar to 35 mg/kg while in beet leaves it reach...

Study on Tourist Carrying Capacity Based on Matter Element Analysis

Institute of Scientific and Technical Information of China (English)

LiuYunguo; FanTing; LiXin; ZhouMing; WangXianhai

2005-01-01

This paper proposes that it is necessary to implement the concept of tourist carrying capacity to facilitate the tourism planning, and presents a method to evaluate the carrying capacity. The method called matter element analysis can solve the uncertain and incompatible problem of the evaluated factors in assessing carrying capacity.The current state of a destination's carrying capacity can be determined by establishing the standard indexes and the matter element model. Through the evaluating of the travel industry zones of the Autonomous Prefecture of Western Hunan, the method is proved to be simple and feasible, and it is improved to be significant for the tourism planning and determination as well as the sustainable development of the regional tourism.

A study on the improvement of shape optimization associated with the modification of a finite element

International Nuclear Information System (INIS)

Sung, Jin Il; Yoo, Jeong Hoon

2002-01-01

In this paper, we investigate the effect and the importance of the accuracy of finite element analysis in the shape optimization based on the finite element method and improve the existing finite element which has inaccuracy in some cases. And then, the shape optimization is performed by using the improved finite element. One of the main stream to improve finite element is the prevention of locking phenomenon. In case of bending dominant problems, finite element solutions cannot be reliable because of shear locking phenomenon. In the process of shape optimization, the mesh distortion is large due to the change of the structure outline. So, we have to raise the accuracy of finite element analysis for the large mesh distortion. We cannot guarantee the accurate result unless the finite element itself is accurate or the finite elements are remeshed. So, we approach to more accurate shape optimization to diminish these inaccuracies by improving the existing finite element. The shape optimization using the modified finite element is applied to a two and three dimensional simple beam. Results show that the modified finite element has improved the optimization results

Development of polygon elements based on the scaled boundary finite element method

International Nuclear Information System (INIS)

Chiong, Irene; Song Chongmin

2010-01-01

We aim to extend the scaled boundary finite element method to construct conforming polygon elements. The development of the polygonal finite element is highly anticipated in computational mechanics as greater flexibility and accuracy can be achieved using these elements. The scaled boundary polygonal finite element will enable new developments in mesh generation, better accuracy from a higher order approximation and better transition elements in finite element meshes. Polygon elements of arbitrary number of edges and order have been developed successfully. The edges of an element are discretised with line elements. The displacement solution of the scaled boundary finite element method is used in the development of shape functions. They are shown to be smooth and continuous within the element, and satisfy compatibility and completeness requirements. Furthermore, eigenvalue decomposition has been used to depict element modes and outcomes indicate the ability of the scaled boundary polygonal element to express rigid body and constant strain modes. Numerical tests are presented; the patch test is passed and constant strain modes verified. Accuracy and convergence of the method are also presented and the performance of the scaled boundary polygonal finite element is verified on Cook's swept panel problem. Results show that the scaled boundary polygonal finite element method outperforms a traditional mesh and accuracy and convergence are achieved from fewer nodes. The proposed method is also shown to be truly flexible, and applies to arbitrary n-gons formed of irregular and non-convex polygons.

Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

Science.gov (United States)

Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

2013-10-01

The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

The Elements and Principles of Design: A Baseline Study

Science.gov (United States)

Adams, Erin

2013-01-01

Critical to the discipline, both professionally and academically, are the fundamentals of interior design. These fundamentals include the elements and principles of interior design: the commonly accepted tools and vocabulary used to create and communicate successful interior environments. Research indicates a lack of consistency in both the…

Comparative Study of Elemental Nutrients in Organic and Conventional Vegetables Using Laser-Induced Breakdown Spectroscopy (LIBS).

Science.gov (United States)

Bhatt, Chet R; Alfarraj, Bader; Ghany, Charles T; Yueh, Fang Y; Singh, Jagdish P

2017-04-01

In this study, the laser-induced breakdown spectroscopy (LIBS) technique was used to identify and compare the presence of major nutrient elements in organic and conventional vegetables. Different parts of cauliflowers and broccolis were used as working samples. Laser-induced breakdown spectra from these samples were acquired at optimum values of laser energy, gate delay, and gate width. Both univariate and multivariate analyses were performed for the comparison of these organic and conventional vegetable flowers. Principal component analysis (PCA) was taken into account for multivariate analysis while for univariate analysis, the intensity of selected atomic lines of different elements and their intensity ratio with some reference lines of organic cauliflower and broccoli samples were compared with those of conventional ones. In addition, different parts of the cauliflower and broccoli were compared in terms of intensity and intensity ratio of elemental lines.

Experimental Study of Fuel Element Motion in HTR-PM Conveying Pipelines

International Nuclear Information System (INIS)

Wang Xin; Zhang Haiquan; Nie Junfeng; Li Hongke; Liu Jiguo; He Ayada

2014-01-01

The motion action of sphere fuel element (FE) inside fuel pipelines in HTR-PM is indeterminate. Fuel motion is closely connected with the interaction of FE and inner surface of fuel conveying pipe. In this paper, motion method of fuel elements in its conveying pipe is Experimental studied. Combined with the measurement of the fuel passing speed in stainless steel pipe and the track left by sphere ball for experiment, interaction modes of fuel and inner-surface of pipe, which is sliding friction, rolling friction and Collision, has been found. The modes of interaction can affect the speed of fuel conveying, amount of sphere waste and operation stability of fuel handling of high temperature reactor-pebble bed modules (HTR-PM). Furthermore, the motion process of fuel passing a big-elbow which is lying on the top of fuel pneumatic hoisting pipe were experimented. The result shows that the speed before and the speed after the elbow is positive correlation. But with the increase of speed before the elbow, the speed after the elbow increase less. Meanwhile the fuel conveying mode changes from friction to collision. And the conveying process is still steady. The effect can be used to controlling the speed of fuel conveying in fuel handling process of HTR-PM. (author)

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

DEFF Research Database (Denmark)

Hou, Xiaolin; Yan, X.J.

1998-01-01

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

Study of grid independence of finite element method on MHD free convective casson fluid flow with slip effect

Science.gov (United States)

Raju, R. Srinivasa; Ramesh, K.

2018-05-01

The purpose of this work is to study the grid independence of finite element method on MHD Casson fluid flow past a vertically inclined plate filled in a porous medium in presence of chemical reaction, heat absorption, an external magnetic field and slip effect has been investigated. For this study of grid independence, a mathematical model is developed and analyzed by using appropriate mathematical technique, called finite element method. Grid study discussed with the help of numerical values of velocity, temperature and concentration profiles in tabular form. avourable comparisons with previously published work on various special cases of the problem are obtained.

Comparative study for toxic elements determination in air particulate reference material by INAA, CCT-ICP-MS, and ICP-MS

International Nuclear Information System (INIS)

Lim, J.M.; Lee, J.H.; Kim, K.H.; Moon, J.H.; Chung, Y.S.

2005-01-01

Although toxic elements are minor components in the atmospheric environment, they play a significant role as important marker for atmospheric science such as risk assessment, long-range transfer study, and source apportionment. Therefore, the techniques, which allow accurate and fast elemental analysis with a minimum pre-treatment, are very important. INAA has a main advantage of non-destruction of air particulate samples, while inductively Coupled plasma with mass spectrometry (ICP-MS) encounters the most significant difficulties in pre-treatment (digestion, fusion, and dilution) and polyatomic spectral interferences for interest toxic elements, Although INAA is still reference method, a number of factors (disadvantages of cost, complexity of the instruments, and scarcity of nuclear reactor) limit its applications. To date, the use of collision cell technology ICP-MS (CCT-ICP-MS) is recommended instead of typical ICP-MS for the analysis of the toxic elements; this is because CCT-ICP-MS technique prevents polyatomic spectral interferences despite of contamination and volatile effects. In this study, a number of toxic elements in reference material, NIST SRM 2783 (air particulate on filter media) were determined by INAA, CCT-ICP-MS, and ICP-MS. For both ICP methods, the filters were decomposed by microwave digestion with 5mL nitric acid. The analytical results by three methods were compared with certificated data; the INAA results showed the most accurate and precise data sets for all target elements among three methods. In detail, the deviation between analytical results and SRM's by INAA fell below 10% for all elements excluding As (14%), while those by CCT-ICP-MS were about 20%. For ICP-MS, the result does not agree with certificated data for several elements, because polyatomic spectral interference (due to 40 Ar 35 Cl, 40 Ar 23 Na, and 35 Cl 16 O) generate positive error of analytical result for As, Cu, and V. Based on our result, INAA is still one of the most

Bejing synchrotron radiation TXRF facility and its applications on trace element study of cells

International Nuclear Information System (INIS)

Yuying, H.; Yingrong, W.; Limin, Z.; Guangcheng, L.; Wie, H.

2000-01-01

In this paper, Beijing synchrotron radiation TXRF facility and experimental method were described. The minimum detection limits of some elements were tested by using several kinds of standard reference materials. The feasibility of using TXRF in biomedical field is discussed. With this technique small intestine cells of both normal and radiated white mice were analyzed, and the elemental average contents of each single cell are also given. The results indicated that the contents of some trace elements for normal and radiated white mice are greatly different, which may be used to provide valuable reference for clinic medicine. On the other hand, the trace elements of cells of lung and cervix cancer before and after apoptosis were determined by SRTXRF and the changes of trace elements in these cells were discussed. (author)

Investigating Planetesimal Evolution by Experiments with Fe-Ni Metallic Melts: Light Element Composition Effects on Trace Element Partitioning Behavior

Science.gov (United States)

Chabot, N. L.

2017-12-01

As planetesimals were heated up in the early Solar System, the formation of Fe-Ni metallic melts was a common occurrence. During planetesimal differentiation, the denser Fe-Ni metallic melts separated from the less dense silicate components, though some meteorites suggest that their parent bodies only experienced partial differentiation. If the Fe-Ni metallic melts did form a central metallic core, the core eventually crystallized to a solid, some of which we sample as iron meteorites. In all of these planetesimal evolution processes, the composition of the Fe-Ni metallic melt influenced the process and the resulting trace element chemical signatures. In particular, the metallic melt's "light element" composition, those elements present in the metallic melt in a significant concentration but with lower atomic masses than Fe, can strongly affect trace element partitioning. Experimental studies have provided critical data to determine the effects of light elements in Fe-Ni metallic melts on trace element partitioning behavior. Here I focus on combining numerous experimental results to identify trace elements that provide unique insight into constraining the light element composition of early Solar System Fe-Ni metallic melts. Experimental studies have been conducted at 1 atm in a variety of Fe-Ni systems to investigate the effects of light elements on trace element partitioning behavior. A frequent experimental examination of the effects of light elements in metallic systems involves producing run products with coexisting solid metal and liquid metal phases. Such solid-metal-liquid-metal experiments have been conducted in the Fe-Ni binary system as well as Fe-Ni systems with S, P, and C. Experiments with O-bearing or Si-bearing Fe-Ni metallic melts do not lend themselves to experiments with coexisting solid metal and liquid metal phases, due to the phase diagrams of these elements, but experiments with two immiscible Fe-Ni metallic melts have provided insight into

Superheavy Elements Challenge Experimental and Theoretical Chemistry

CERN Document Server

Zvára, I

2003-01-01

When reflecting on the story of superheavy elements, the an experimenter, acknowledges the role, which the predictions of nuclear and chemical theories have played in ongoing studies. Today, the problems of major interest for experimental chemistry are the studies of elements 112 and 114 including their chemical identification. Advanced quantum chemistry calculations of atoms and molecules would be of much help. First experiments with element 112 evidence that the metal is much more volatile and inert than mercury.

Studies of the source complex behaviour and of the ultrasound radiation of contact flexible multi-element transducers

International Nuclear Information System (INIS)

Amory, V.

2007-12-01

This work deals with the ultrasonic nondestructive testing of parts with complex geometries using soft multi-element sensors. The different types of contact control configurations are presented first. Then, the difficulties encountered with conventional contact transducers are explained and the multi-element piezoelectric transducers technology, developed to meet these difficulties, is presented. The second chapter presents the results of finite-element calculations showing the complexity of a transducer in a condition of testing utilization. In a same configuration, the radiated far field calculated by finite-elements is compared to the measurement in order to validate the way the source behaviour is calculated. However, despite the efficiency of the finite-elements simulation, this tool is numerically too costly and cannot be used to optimize a full multi-element transducer. Therefore, a realistic source model is built and implemented in a radiation code based on high-frequency asymptotic approximations where only L and T volume waves are calculated. The incapacity of this model to reproduce the behaviour of T waves in some directions of propagation has led to give a particular attention to the fore-waves, neglected in the radiation calculation. Chapter 3 treats of the building of an exact radiation model taking into consideration the fore-waves contribution emitted by a contact transducer exerting a random space-time distribution constraint at the surface of the considered medium. A radiation model, based on the calculation of exact Green functions of the Lamb problem is proposed. The exact model is particularly interesting in the case of sensor geometries with a long length with respect to other dimensions (2D case). Field calculation results are shown for an element of the matrix network (3D case) and for a linear element (2D case). A study of different existing approached models is carried out as well. The last chapter presents some results of the field

Mass distribution studies in 28Si + 232Th

International Nuclear Information System (INIS)

Sodaye, Suparna; Tripathi, R.; Sudarshan, K.; Pujari, P.K.

2014-01-01

Mass distribution is one of the important observables to understand the fusion-fission potential energy landscape. In the fission involving composite systems with Z ∼ 100, the fission barrier is lower and the saddle point is compact. Thus, apart from transfer induced fission,various non compound nucleus (NCN) fission processes like quasi-fission, pre-equilibrium fission and fast fission compete with the complete fusion fission (CFF). This would be further affected by the entrance channel parameters like choice of the target-projectile combination (mass asymmetry) and the projectile energy. Charge and mass distribution studies in such system would provide information about various fission processes such as complete fusion fission, non-compound nucleus fission and transfer induced fission, which would help in understanding the fusion-fission process in heavy ion collisions forming composite system in the heavy and trans-actinide region. In view of this, a systematic study of the charge and mass distribution in 28 Si+ 232 Th reaction was planned at beam energy close to and above the entrance channel Coulomb barrier. The experiments were carried out at the TIFR-LINAC booster facility. Self supporting foils of 232 Th were bombarded with 180 and 160 MeV 28 Si beam in a stack foil arrangement. The recoiling fission products were assayed radiochemically by off-line gamma-ray spectrometry. Results of charge distribution studies at E lab =180 MeV have been reported earlier. In the poster, the data on charge and mass distribution distribution will be presented.The results of the present studies will be compared with those from the reactions involving lighter and heavier composite systems

Contribution to the analysis of light elements using x fluorescence excited by radio-elements

International Nuclear Information System (INIS)

Robert, A.

1964-01-01

In order to study the possibilities of using radioactive sources for the X-fluorescence analysis of light elements, the principle is given, after a brief description of X-fluorescence, of the excitation of this phenomenon by X, β and α emission from radio-elements. The operation and use of the proportional gas counter for X-ray detection is described. A device has been studied for analysing the elements of the 2. and 3. periods of the Mendeleev table. It makes it possible to excite the fluorescence with a radioactive source emitting X-rays or a particles; the X-ray fluorescence penetrates into a window-less proportional counter, this being made possible by the use of an auxiliary electric field in the neighbourhood of the sample. The gas detection pressure leading to the maximum detection yield is given. The spectra are given for the K α lines of 3. period elements excited by 55 Fe, 3 H/Zr and 210 Po sources; for the 2. period the K α spectra of carbon and of fluorine excited by the α particles of 210 Po. (author) [fr

Transposable elements and genetic instabilities in crop plants

Energy Technology Data Exchange (ETDEWEB)

Burr, B.; Burr, F.

1981-04-10

Transposable elements have long been associated with certain unstable loci in maize and have been intensively studied by McClintock and others. It is known that a transposable element can control the expression of the structural genes at the locus where it resides. These controlling elements in maize are now beginning to be studied at the molecular level. Using recombinant molecular probes we have been able to describe the changes induced by the controlling element Ds at the shrunken locus. Ds elements appear to be large and dissimilar insertions into the wild-type locus - two elements actually map within the transcribed region of the gene. Genetic instabilities have been described in other economically important plants but the bases for these phenomena have not been understood. We believe that it is likely that some of these instabilities are the result of transposable element activity much as in the case of maize.

A comparative study of pH modulation and trace elements of various fruit juices on enamel erosion: An in vitro study

Directory of Open Access Journals (Sweden)

S.V.S.G Nirmala

2011-01-01

Full Text Available Fruit juices are popular worldwide with children of all ages as they are sweet and perceived to be healthful. This in vitro study was sought to measure pH of 10 different fruit juices, to find out possible erosive effects on human dental enamel of 40 extracted sound premolars and also to measure fluoride and trace elements of these juices. The estimation of pH of fruit juices was done by using Systronic upH 362 pH meter. The erosive effects of fruit juices were tested by using polarized light microscope. Orion electrode was used to measure fluoride. The trace elements were estimated by using Atomic Absorption Spectrophotometer No. 6501F. The pH values in different juices were observed at different levels, and pH values of these juices were more acidic than baseline after 24 hours. As the time increased, the erosion effect became more in pineapple; grape and sugarcane juices, and they had more cariogenic trace elements like selenium, iron and manganese. So, these juices were found to be cariogenic. To conclude, orange, mousambi, mango, pomegranate, apple, chikku and watermelon juices had no erosive effect on the human enamel, with the presence of highest amount of trace elements like fluoride and phosphorous which are considered as strongly cariostatic.

Application of the Elements of Problem-Based Learning in Professional Foreign Language Studies at LUHS

Directory of Open Access Journals (Sweden)

Liudmila Kirikova

2014-06-01

Full Text Available The increasing significance of science and the new ties with foreign countries affect the education and training of specialists. Continuous updating of specialty knowledge and the possibility to read the most recent scientific literature in a foreign language and to participate in joint conferences together with foreign partners require the education and training of specialists who would be capable of cooperating in scientific and professional activity while fluently communicating in a foreign language. The aim of the study was to reveal the peculiari- ties of the expression of problem-based learning (PBL elements in foreign language studies at Lithuanian University of Health Sciences (LUHS. The results of the pedagogical experiment conducted at LUHS when teaching the foreign language module showed that the application of PBL elements stimulated the formation of students’ deep approach to studies and skills of independent work. The use of group learning aim forma - tion, concept maps, problem solving, discussion, group work, and brainstorming techniques had a significant effect on the students, and allowed for their empowerment for successful studies.

Chemical analysis of rare earth elements

International Nuclear Information System (INIS)

Tsukahara, Ryoichi; Sakoh, Takefumi; Nagai, Iwao

1994-01-01

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

Study of the influencing factors of the blood levels of toxic elements in Africans from 16 countries

International Nuclear Information System (INIS)

Henríquez-Hernández, Luis Alberto; Luzardo, Octavio P.; Boada, Luis D.; Carranza, Cristina; Pérez Arellano, José Luis; González-Antuña, Ana; Almeida-González, Maira; Barry-Rodríguez, Carlos; Zumbado, Manuel; Camacho, María

2017-01-01

Africa's economy is growing faster than any other continent and it has been estimated that the middle class in Africa now exceeds 350 million people. This has meant a parallel increase in the importation of consumer goods and in the implementation of communication and information technologies (ICT), but also in the generation of large quantities of e-waste. However, inadequate infrastructure development remains a major constraint to the continent's economic growth and these highly toxic residues are not always adequately managed. Few studies have been conducted to date assessing the possible association between socioeconomic development factors, including e-waste generation, and blood levels of inorganic elements in African population. To disclose the role of geographical, anthropogenic, and socioeconomic development determinants on the blood levels of Ag, Al, As, Be, Cd, Co, Cr, Hg, Ni, Pb, Sb, and V —all of them frequently found in e-waste—, an immigrant population-based study was made including a total of 245 subjects from 16 countries recently arrived to the Canary Islands (Spain). Women presented higher levels of blood elements than men, and Northern Africans (Moroccans) were the most contaminated. People from low-income countries exhibited significantly lower blood levels of inorganic elements than those from middle-income countries. We found a significant association between the use of motor vehicles and the implementation of information and communication technologies (ICT) and the level of contamination. Immigrants from the countries with a high volume of imports of second-hand electronic equipment, telephone and internet use had higher levels of inorganic elements. In general terms, the higher level of economic development the higher the blood levels of inorganic pollutants, suggesting that the economic development of Africa, in parallel to e-waste generation and the existence of informal recycling sites, have directly affected the level of

Elements beyond uranium

International Nuclear Information System (INIS)

Seaborg, G.T.; Loveland, W.D.

1990-01-01

This book is the 12th volume in a series on transuranium elements. Varied techniques for production of these elements, the methods used in the identification, and the exquisitely refined microchemical techniques required to deal wth samples sometimes involving only a few atoms are described in detail. The chapter on synthesis of the new elements is liberally laced with reminiscences of the proud progenitors as well as the criteria for the discovery of a new chemical element. The authors lament that the superheavy elements (elements in the region of atomic number 114) still elude detection even though their creation should be possible, and some, at least, should survive long enough to be detected. One chapter in the book is devoted to practical applictions of uranium, and the transuranic elements

Some studies on light-element analysis with particle accelerators in South Africa

International Nuclear Information System (INIS)

Peisach, M.; Pillay, A.E.

1993-01-01

The analysis of elements in the range 1 ≤ Z ≤ is often difficult by most contemporary methods. The practical utility of various ion-beam techniques on light-element analysis is examined, and a comprehensive evaluation of the major analytical aspects on determinations of this nature, with particular reference to work done in South Africa, is provided. 40 refs., 8 figs., 3 tabs

Trace element studies in bioenvironmental samples using 3-MeV protons

International Nuclear Information System (INIS)

Walter, R.L.; Willis, R.D.; Gutknecht, W.F.

1974-01-01

Trace metal compositions of a wide range of biological, environmental, medical and clinical samples were investigated using proton-induced x-ray emission analysis (PIXEA). The x-rays were detected with a Si(Li) detector and spectra from over 3000 irradiations have been recorded on magnetic tape. The chi 2 fitting code TRACE developed at our laboratory was used in a semi-automatic mode to extract abundances of elements from S to Cd. Various methods of overcoming analytical problems and specimen preparation difficulties are reported. Results from some samples for typical studies are illustrated along with the reasons for interest in the sample types

Finite Element and Experimental Study of Shunting in Resistance Spot Welding

DEFF Research Database (Denmark)

Seyyedian Choobi, M.; Nielsen, C. V.; Bay, N.

2015-01-01

This research is focused on one of the problems frequently encountered in spot welding in industry. In many applications several spot welds are made close to each other. The spots made after the first spot may become smaller in size due to shunt effect. A numerical and experimental study has been...... conducted to investigate the effect of shunting on nugget size in spot welding of HSLA steel sheets. Different cases with different spacing between weld spots have been examined. The nugget sizes have been measured by metallographic examination and have been compared with 3D finite element simulations...

Studies in China on ingestion and organ content of trace elements of importance in radiological protection. Country report

International Nuclear Information System (INIS)

Wang Jixian; Zhu Hongda; Chen Rusong

2000-01-01

In order to estimate internal dose and derive annual limits of intake for radionuclides in the field of Radiation Protection, it is necessary to study the parameters of ingestion of radionuclides from diet, deposition in tissues and following metabolism of the radionuclides. But these kinds of parameters may be influenced by intake of nutrients and inorganic constituents of diets, for example, a relatively higher uptake rate and longer retention time of radioiodine in thyroid of person who's diet poor of stable iodine. So there is a need to have accurate knowledge of corresponding stable elements intake and their concentration in organs, especially for some trace elements of importance in radiological protection such as Caesium, Iodine, Strontium, Thorium and Uranium. A IAEA RCA CRP on 'Ingestion and organ content of trace elements of importance in Radiological protection' was formulated in 1995 and initiated after the first RCM CRP on the project, held in Manila, Philippine 1-4 July 1996. This is the progress report for studies in China on ingestion and organ content of trace elements of importance in radiological protection after the first RCM

Accelerator based nuclear analytical methods for trace element studies in materials- calcified tissues

International Nuclear Information System (INIS)

Chaudhri, M. Anwar

2006-01-01

Full text: Various nuclear analytical methods have been developed and applied to determine the elemental composition of calcified tissues (teeth and bones). Fluorine was determined by prompt gamma activation analysis through the 19 F(p,αγ) 16 O reaction. Carbon was measured by activation analysis with He-3 ions, and the technique of Proton-Induced X-ray Emission (PIXE) was applied to simultaneously determine Ca, P, and trace elements in well-documented teeth. Dental hard tissues: enamel, dentine, cementum, and their junctions, as well as different parts of the same tissue, were examined separately. Furthermore, using a Proton Microprobe, we measured the surface distribution of F and other elements on and around carious lesions on the enamel. The depth profiles of F, and other elements, were also measured right up to the amelodentin junction. (author)

INCIDENCE OF FUNGAL ELEMENTS IN SINONASAL POLYPOSIS

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Santhosh G. S

2016-12-01

Full Text Available BACKGROUND Nasal polyposis is a disease entity characterised by formation of pseudoedema of sinonasal mucus membrane progressing to form polyps. It presents clinically with nasal obstruction and fleshy masses in the nasal cavity. The nasal mucosa reacts to formation of polypi in allergic fungal sinusitis also. The present study is an attempt to demonstrate possible fungal elements from the polypi removed during surgery by KOH study and HPE study. The aim of the study is to find out the incidence of fungal elements in sinonasal polyposis. MATERIALS AND METHODS 50 patients attending the ENT OPD for nasal obstruction and showing polypi on anterior rhinoscopy were selected. All the patients were subjected to surgery and specimens collected were subjected to KOH study and histopathology to demonstrate fungal elements. RESULTS Among 50 patients, the age range was from 9-57 years; mean age- 36.46 years. The male-to-female ratio was 1.5:1. Deviated nasal septum was found in 38% of patients. Among the unilateral cases, 47% were antrochoanal polyps and 53% were ethmoid polyps. Out of 50 patients, only 3 specimens were positive for fungal elements with KOH study and only 2 cases with fungal culture. Thus, the incidence of fungal elements in sinonasal polyposis was 6%. CONCLUSION The incidence of fungal elements in sinonasal polyposis was 6%. Histopathological examination of polypectomy specimen was negative for invasive fungal disease and showed inflammatory changes only. There is no difference in the detection of the presence of fungal by two methods.

A study of elemental migration from poly(ethylene terephthalate) of food packagings to simulated solutions by radiometric method

International Nuclear Information System (INIS)

Soares, Eufemia Paez; Saki, Mitiko; Silva, Leonardo G.A.

2007-01-01

Brazilian plastic production for food packagings, in recent years, has grown in the same proportion as food consumption. Considering that the plastic manufacturing involves catalytic processes and the use of additives, when the foods are in direct contact with these materials, the components present in plastics may migrate to the food. The Brazilian Health Surveillance Agency (ANVISA) has established boundary-values of migrants as well as procedures to evaluate migration of elements and substances from plastic packaging to food. In this study elemental composition of poly (ethylene terephthalate) - PET - packaging and results of elemental migration were obtained. Instrumental Neutron Activation Analysis (INAA) was used to determine elemental concentrations in PET packagings and the radiometric method was applied for elemental migration determination. This radiometric method consisted of irradiating the PET samples with neutrons, followed by migration exposition and radioactivity measurement in food-simulated solution. Experimental conditions used for migration were 10 days exposure period at 40 deg C. Migration was evaluated for soft drink, juice and water PET packaging. The analytical results indicated that PET packagings contain Co and Sb and those elements are transferred to the simulated solutions. However, these migration results were lower than the maximum tolerance values established by ANVISA. The migration detection limits also indicated high sensitivity of the radiometric method. (author)

Studies in Korea on ingestion of trace elements of importance in radiological protection

International Nuclear Information System (INIS)

Cho, Seung Yeon

2005-01-01

One day representative mixed diet of adult Korean was collected from the data based on the food diary of 77 healthy subjects at the age between 20 to 50. The analytical methods involving both instrumental and radiochemical neutron activation techniques are being developed for the determination of the elements Cs, I, Sr, Th and U in various kinds of biological samples. Concentrations of trace elements including 5 important elements such as U, Th, Cs, Sr and I in Korean total diet and 4 most frequently consuming Korean foodstuffs have been analyzed by neutron activation analysis

Studies in Korea on ingestion of trace elements of importance in radiological protection

Energy Technology Data Exchange (ETDEWEB)

Cho, Seung Yeon [Yonsei University, Seoul (Korea, Republic of)

2005-07-01

One day representative mixed diet of adult Korean was collected from the data based on the food diary of 77 healthy subjects at the age between 20 to 50. The analytical methods involving both instrumental and radiochemical neutron activation techniques are being developed for the determination of the elements Cs, I, Sr, Th and U in various kinds of biological samples. Concentrations of trace elements including 5 important elements such as U, Th, Cs, Sr and I in Korean total diet and 4 most frequently consuming Korean foodstuffs have been analyzed by neutron activation analysis.

Atomic adsorption on graphene with a single vacancy: systematic DFT study through the periodic table of elements

Science.gov (United States)

Pašti, Igor A.; Jovanović, Aleksandar; Dobrota, Ana S.; Mentus, Slavko V.; Johansson, Börje; Skorodumova, Natalia V.

Vacancies in graphene present sites of altered chemical reactivity and open possibilities to tune graphene properties by defect engineering. The understanding of chemical reactivity of such defects is essential for successful implementation of carbon materials in advanced technologies. We report the results of a systematic DFT study of atomic adsorption on graphene with a single vacancy for the elements of rows 1 to 6 of the Periodic Table of Elements (PTE), excluding lanthanides. The calculations have been performed using PBE, long-range dispersion interaction-corrected PBE (PBE+D2 and PBE+D3) and non-local vdW-DF2 functional. We find that most elements strongly bind to the vacancy, except for the elements of groups 11 and 12, and noble gases, for which the contribution of dispersion interaction to bonding is most significant. The strength of the interaction with the vacancy correlates with the cohesive energy of the elements in their stable phases: the higher the cohesive energy is the stronger bonding to the vacancy can be expected. As most atoms can be trapped at the SV site we have calculated the potentials of dissolution and found that in most cases the metals adsorbed at the vacancy are more "noble" than they are in their corresponding stable phases.

Rare earth elements behavior in Peruibe black mud

International Nuclear Information System (INIS)

Torrecilha, Jefferson K.; Carvalho, Leandro P.; Gouvea, Paulo F.M.; Silva, Paulo S.C. da

2015-01-01

Rare earth elements in sediments have been used as powerful tools for environmental studies because of their behavior during geochemical processes and are also widely accepted as reliable provenance tracers because they are largely water-immobile and thus behave conservatively during sedimentary processes. The Peruibe Black Mud (PBM) is a sedimentary deposit originated from the interactions of marine sediments and organic matter in an estuarine environment that originates a peloid currently used for medicinal purposes. The objective of this study was to examine rare earth elements pattern distribution in the Peruibe black mud sedimentary deposit as a proxy for its geochemical development. Elemental ratios such as LaN/YbN, Th/U and La/Th were determined and a normalization of the mean rare earth elements concentrations in the samples related to NASC indicates that the light (La to Eu) rare earth elements present values close to the unity while the heavy (Tb to Lu) rare earth elements are depleted related to NASC. It can be observed that the light rare earth elements present enrichment values slightly enriched over the unity while the heavy rare earth elements present values generally below the unity reflecting the enrichment of the light rare earth elements over the heavy rare earth. Rare earth elements concentrations determined in Peruibe black mud samples showed a distribution similar to that found in the NASC for the light rare earth elements and depleted for the heavy rare earth elements. (author)

Rare earth elements behavior in Peruibe black mud

Energy Technology Data Exchange (ETDEWEB)

Torrecilha, Jefferson K.; Carvalho, Leandro P.; Gouvea, Paulo F.M.; Silva, Paulo S.C. da, E-mail: jeffkoy@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Rare earth elements in sediments have been used as powerful tools for environmental studies because of their behavior during geochemical processes and are also widely accepted as reliable provenance tracers because they are largely water-immobile and thus behave conservatively during sedimentary processes. The Peruibe Black Mud (PBM) is a sedimentary deposit originated from the interactions of marine sediments and organic matter in an estuarine environment that originates a peloid currently used for medicinal purposes. The objective of this study was to examine rare earth elements pattern distribution in the Peruibe black mud sedimentary deposit as a proxy for its geochemical development. Elemental ratios such as LaN/YbN, Th/U and La/Th were determined and a normalization of the mean rare earth elements concentrations in the samples related to NASC indicates that the light (La to Eu) rare earth elements present values close to the unity while the heavy (Tb to Lu) rare earth elements are depleted related to NASC. It can be observed that the light rare earth elements present enrichment values slightly enriched over the unity while the heavy rare earth elements present values generally below the unity reflecting the enrichment of the light rare earth elements over the heavy rare earth. Rare earth elements concentrations determined in Peruibe black mud samples showed a distribution similar to that found in the NASC for the light rare earth elements and depleted for the heavy rare earth elements. (author)

LIBS: study of elemental profile of different layers of the optical window of Tokamak

International Nuclear Information System (INIS)

Maurya, Gulab Singh; Jyotsna, Aradhana; Rai, Awadhesh Kumar; Ajai Kumar

2012-01-01

In the Tokamak, during confinement of plasma, impurities are deposited on optical window, mirror, limiters, etc. of the tokamak. Thus a layer of impurity on the surface of the optical window causes less visibility which creates problem in the study of plasma parameters and other diagnostics of the plasma generated in the tokamak. Laser Induced Breakdown Spectroscopy (LIBS) is a useful atomic spectroscopic technique for analysis of materials in any phase (Solid, Liquid, Gas etc). LIBS spectra of optical window have been recorded in the spectral range of 200-500 nm. In present study we have focused laser on the surface of the window, to study the layer-wise elemental profile of optical window, we have recorded the LIBS spectra with increasing number of laser shots on the same point of the window. In first laser shot, spectral signature of Cr, Fe, and Ni etc. are present in the LIBS spectra, which is related with the impurity but after five to six laser shots at the same point of the optical window spectral signature Si, B are observed which is related to the glass material. Thus our study demonstrates the capability of LIBS as an in-situ monitoring tool for detection of elemental profile in different layers of optical window of the Tokamak. (author)

A Study of Interaction Patterns and Awareness Design Elements in a Massively Multiplayer Online Game

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Tiffany Y. Tang

2008-01-01

Full Text Available Massively multiplayer online games (MMOGs have been known to create rich and versatile social worlds for thousands of millions of players to participate. As such, various game elements and advance technologies such as artificial intelligence have been applied to encourage and facilitate social interactions in these online communities, the key to the success of MMOGs. However, there is a lack of studies addressing the usability of these elements in games. In this paper, we look into interaction patterns and awareness design elements that support the awareness in LastWorld and FairyLand. Experimental results obtained through both in-game experiences and player interviews reveal that not all awareness tools (e.g., an in-game map have been fully exploited by players. In addition, those players who are aware of these tools are not satisfied with them. Our findings suggest that awareness-oriented tools/channels should be easy to interpret and rich in conveying “knowledge” so as to reduce players-cognitive overload. These findings of this research recommend considerations of early stage MMOG design.

Heavy Metals and Trace Elements Atmospheric Deposition Studies in Tula Region Using Moss Biomonitors Technique

CERN Document Server

Ermakova, E V; Steinnes, E

2002-01-01

For the first time the moss biomonitors technique was used in air pollution studies in Tula Region (Central Russia), applying NAA, AAS. Moss samples were collected at 83 sites in accordance with the sampling strategy adopted in European projects on biomonitoring atmospheric deposition. A wide set of trace elements in mosses was determined. The method of epithermal neutron activation at IBR-2 reactor of FLNP JINR has made it possible to identify 33 elements (Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Mo, Sb, I, Cs, Ba, La, Ce, Sm, Tb, Yb, Hf, Ta, W, Th, U) in the large-scale concentration range - from 10000 ppm for K to 0,001 ppm for Tb and Ta. Cu, Cd and Pb were determined by the flame AAS in the Norwegian Institute of Science and Technology. Using the graphical technique and principal component analysis allowed to separate plant, crustal and general pollution components in the moss. The obtained data will be used for constructing coloured maps of the distribution of elements over t...

Elemental mapping of As and other elements in rootless duckweed Wolffia globosa

International Nuclear Information System (INIS)

Zhang Xin; Chen Baodong; Luo Lei; Huang Qing; Zhu Yongguan

2010-01-01

Distribution of arsenic and the relationship with other elements in aquatic macrophytes Wolffia globosa is helpful in understanding mechanisms of arsenic accumulation and detoxification, which will be important for arsenic phytofiltration in contaminated water by aquatic macrophytes. In this paper, we study the distribution features of As and seven more elements in rootless duckweed Wolffia globosa by means of μXRF. The results indicated that the distribution of As was similar to that of K, Mn and Zn while differs from that of Cu, Fe, Ni and Ca. (authors)

Studying the Ability of 7th Grade Students to Define the Circle and Its Elements in the Context of Mathematical Language

Science.gov (United States)

Akarsu, Esra; Yilmaz, Süha

2015-01-01

In this study, it was aimed to study the mathematical language skills that the 7th grade students use in defining the circle and its elements. In the study, the mathematical language skills of students that they use in defining the circle and its elements in a scenario were compared to the mathematical language skills they use in defining them…

Interlaboratory quality assurance studies: Their use in certifying natural waters for major constituents and trace elements

International Nuclear Information System (INIS)

Alkema, H.; Simser, J.; Hjelm, L.

1998-01-01

Environmental programs throughout North America have demonstrated a strong awareness of the usefulness of interlaboratory studies for disclosing the quality of analytical results. The Ecosystem Interlaboratory Quality Assurance Program offered by the National Water Research Institute has a wide participation base of laboratories. Many of these laboratories are accredited and employ a number of recognized analytical methods. The interlaboratory study data archives contain a wealth of data for natural surface and rain waters from across the continent. These archives have proven to be a reliable means of characterizing a variety of constituents. Data assessments from these studies accurately identify the variability of data and the presence of any outliers. Repeated use of selected samples in a regular QA program confirms their stability. Time charts and statistical techniques are used to illustrate this stability and yield the precision of pooled analyses. The availability of archived data from interlaboratory studies has enabled the Institute to develop and certify natural water and trace element standards. The natural water CRM, ION-911, has been available for several years. Its historical aspects are discussed as well as the processes leading to the certification of TMRain-95, a soft water standard certifying 22 trace elements. This paper focuses on the use of select laboratories in round-robin evaluations to provide accurate values for constituent concentrations. Natural water and fortified trace element CRMs meet a recognized need in the generation of accurate data for environmental programs. (orig.)

Structural elements design manual

CERN Document Server

Draycott, Trevor

2012-01-01

Gives clear explanations of the logical design sequence for structural elements. The Structural Engineer says: `The book explains, in simple terms, and with many examples, Code of Practice methods for sizing structural sections in timber, concrete,masonry and steel. It is the combination into one book of section sizing methods in each of these materials that makes this text so useful....Students will find this an essential support text to the Codes of Practice in their study of element sizing'.

Comparative studies of trace elements in two kinds of human gallstones

International Nuclear Information System (INIS)

Vatankhah, S.; Moosavi, K.; Peyrovan, H.; Salimi, J.

2003-01-01

Structural composition of 11 trace elements with Z greater than 13 (Al, P, Si, K, Ca, Mn, Fe, Cu, Zn, Mo, I) was analyzed for the two main groups of human gallstones according to their cholesterol and pigment types by PIXE (Proton Induced X-ray Emission). In both types of stones, the shell and the center were analyzed separately. The gallstones were obtained from 12 patients in wide age group from 22 to 78 years of age during surgical operation. The results show relatively higher values of heavy elements for ages greater than 40. The values of phosphorus in cholesterol type stones are significantly higher than in those of pigment stones. The concentration of calcium in the center of stones is large in comparison with that in the shells. In this paper, a correlation between stone structure and trace elemental concentration has been presented. Comparison of the two essential types of stones (cholesterol and pigment) shows that the center of the pigment stones is very similar to that of the cholesterol type. (author)

A FINITE-ELEMENTS APPROACH TO THE STUDY OF FUNCTIONAL ARCHITECTURE IN SKELETAL-MUSCLE

NARCIS (Netherlands)

OTTEN, E; HULLIGER, M

1994-01-01

A mathematical model that simulates the mechanical processes inside a skeletal muscle under various conditions of muscle recruitment was formulated. The model is based on the finite-elements approach and simulates both contractile and passive elastic elements. Apart from the classic strategy of

FINITE ELEMENT ANALYSIS OF STRUCTURES

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PECINGINA OLIMPIA-MIOARA

2015-05-01

Full Text Available The application of finite element method is analytical when solutions can not be applied for deeper study analyzes static, dynamic or other types of requirements in different points of the structures .In practice it is necessary to know the behavior of the structure or certain parts components of the machine under the influence of certain factors static and dynamic . The application of finite element in the optimization of components leads to economic growth , to increase reliability and durability organs studied, thus the machine itself.

Leaching of major and trace elements from paper-plastic gasification chars. An experimental and modelling study

Energy Technology Data Exchange (ETDEWEB)

Fuente-Cuesta, A.; Lopez-Anton, M.A.; Diaz-Somoano, M.; Martinez-Tarazona, M.R. [Instituto Nacional del Carbon CSIC, C/Francisco Pintado Fe No 26, 33011, Oviedo (Spain); Van Zomeren, A.; Cieplik, M. [Energy research Centre of the Netherlands ECN, Biomass, P.O. Box 1, 1755 ZG, Petten (Netherlands)

2013-01-15

The control of soluble metal species in the sub-product leachate generated in electricity production processes is of great concern from an environmental and health point of view. Unlike fly ash, the leaching behaviour of char materials has received little attention. Yet, these solids are captured together with fly ashes in the particle control devices of power plants and are emitted in the same way as by-products. The present study was carried out using two char samples: (1) a raw char and (2) the same type of char employed in a previous study so that it could serve as a sorbent for mercury species in gas phase. The char samples were by-products (residues) that had been generated during the gasification of plastic and paper waste. The leachates were analyzed for the following elements: Al, Ca, Si, Mg, Ba, Cu, Ni, Pb, Zn, Mo and Hg. In addition, geochemical modelling of the leaching test results was employed to identify the underlying chemical processes that led to the release of toxic elements. The results showed that at alkaline pH values, sorption on the solid surfaces of the char was negligible due to the inorganic complexation of cations in the solution. When the char was used as mercury sorbent slight changes occurred on the reactive surface resulting in the modification of the binding of some elements. As the pH increased, complexation with dissolved organic matter played a more important role in the case of some elements such as Cu because of the greater concentration of dissolved organic matter in solution.

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

International Nuclear Information System (INIS)

Peterson, J.R.

1978-01-01

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

A Study on the Relationship between Design Elements of Outdoor Leisure Spaces and Types of Leisure Activities in Sustainable Community Development - A Case Study on Tainan, Taiwan

Science.gov (United States)

Chang, J. H.; Zhang, H.

2018-01-01

Sustainable community development encompasses three aspects: “Lifestyle”, “Production” and “Ecology”. Among them, “Lifestyle” is closest to people and reflects basic human needs. Creating outdoor spaces that encourage residents to engage in leisure activities will not only provide them with spiritual sustenance but also fulfil one of the key criteria in sustainable community development. This study explores the relationship between design elements of outdoor leisure spaces and types of leisure activities from residents' perspective with the goal to inform future spatial planning. The study collected 365 valid questionnaires from Tainan residents. Factor analysis was used to extract factors from design elements of outdoor leisure spaces, and regression analysis was applied to understand the effect level. The result shows design elements have positive effect on the types of leisure activities. In addition, different elements exert different influences on the choice of activities.

Synthesis and radioactive properties of the heaviest nuclei

International Nuclear Information System (INIS)

Oganesyan, Yu.Ts.

1996-01-01

Experimental investigations on the synthesis and study of properties of faraway transactinide elements confirm the predictions of macro-microscopic theory on the existence of closed shells in the region of heavy deformed nuclei. It has been demonstrated experimentally that nuclear structure plays a decisive role in the stability of superheavy nuclides. Based on the experimental confirmation of the main provisions of the theory and after the introduction of a necessary correction into the calculation the properties of heavier nuclides in the region of spherical shells Z=114 and N=180-184 have been predicted. Here a substantial increase in the stability of nuclei is also expected. All the nuclei synthesized by now, were obtained in fusion reactions with a formation of a compound nucleus, the transition of which to the ground state takes place with the emission of neutrons and gamma-rays. Both the reactions of cold and hot fusion of nuclei can be used for the synthesis of new nuclei. Nevertheless, new experimental data on the fusion mechanism are required, since a number of theoretical descriptions of the fusion dynamics of complex nuclear systems need a substantial revising. One can assume that the reactions of the type 244 Pu, 248 Cm + 48 Ca are still within the current potential of the accelerators and experimental technique. This potential, nevertheless, is still to be implemented. 37 refs., 6 figs

Distribution of transuranic elements in bone.

Science.gov (United States)

Durbin, P W

1992-01-01

The transport, retention, and excretion of transuranic elements from the body have been widely studied for many years. A summary of the results is given with an emphasis on the distribution of these elements in bone. Implications of these studies for understanding the relationships between lead in blood and lead in bone are presented. The expected distribution of lead at various bone sites is also considered.

A study of the consistent and the lumped source approximations in finite element neutron diffusion calculations

International Nuclear Information System (INIS)

Ozgener, B.; Azgener, H.A.

1991-01-01

In finite element formulations for the solution of the within-group neutron diffusion equation, two different treatments are possible for the group source term: the consistent source approximation (CSA) and the lumped source approximation (LSA). CSA results in intra-group scattering and fission matrices which have the same nondiagonal structure as the global coefficient matrix. This situation might be regarded as a disadvantage, compared to the conventional (i.e. finite difference) methods where the intra-group scattering and fission matrices are diagonal. To overcome this disadvantage, LSA could be used to diagonalize these matrices. LSA is akin to the lumped mass approximation of continuum mechanics. We concentrate on two different aspects of the source approximations. Although it has been reported that LSA does not modify the asymptotic h 2 convergence behaviour for linear elements, the effect of LSA on convergence of higher degree elements has not been investigated. Thus, we would be interested in determining, p, the asymptotic order of convergence, in: Δk |k eff (analytical) -k eff (finite element)| = Ch p (1) for finite element approximations of varying degree (N) with both of the source approximations. Since (1) is valid in the asymptotic limit, we must use ultra-fine meshes and quadruple precision arithmetic. For our order of convergence study, we used infinite cylindrical geometry with azimuthal symmetry. Hence, the effects of singularities remain uninvestigated. The second aspect we dwell on is the performance of LSA in bilinear 3-D finite element calculations, compared to CSA. LSA has been used quite extensively in 1- and 2-D even-parity transport and diffusion calculations. In this work, we will try to assess the relative merits of LSA and CSA in 3-D problems. (author)

Inorganic elements and organic compounds degradation studies by gamma irradiation in used lubricating oils

International Nuclear Information System (INIS)

Scapin, Marcos Antonio

2008-01-01

The automotive lubricating oils have partial degradation of organic compounds and addition of undesirable inorganic elements, during its use. These substances classify the used lubricating oils as dangerous and highly toxic. According to global consensus, concerning the environmental conservation, the best is to perform a reuse treatment of these lubricating oils. For this purpose, the uses of an alternative and effective technology have been sought. In this work, the efficacy and technical feasibility of the advanced oxidation process (AOP), by gamma radiation, for used automotive lubricating oil treatment has been studied. Different quantities of hydrogen peroxide and water Milli-Q were added to oil samples. They were submitted to the Cobalt-60 irradiator, type Gammacell, with 100, 200 and 500 kGy absorbed doses. The inorganic analysis by X-ray fluorescence (WDXRF) showed inorganic elements removal, mainly to sulphur, calcium, iron and nickel elements at acceptable levels by environmental protection law for oils reusing. The gas chromatography (GC/MS) analysis showed that the advanced oxidation process promotes the organic compounds degradation. The main identified compounds were tridecane, 2-methyl-naphthalene, and trietilamina-tetramethyl urea, which have important industrial applications. The multivariate analysis, Cluster Analysis, showed that advanced oxidation process application is a viable and promising treatment for used lubricating oil reusing. (author)

Experimental study of water flow in nuclear fuel elements

International Nuclear Information System (INIS)

Rodrigues, Lorena Escriche; Rezende, Hugo Cesar; Mattos, Joao Roberto Loureiro de; Barros Filho, Jose Afonso; Santos, Andre Augusto Campagnole dos

2013-01-01

This work aims to develop an experimental methodology for investigating the water flow through rod bundles after spacer grids of nuclear fuel elements of PWR type reactors. Speed profiles, with the device LDV (Laser Doppler Velocimetry), and the pressure drop between two sockets located before and after the spacer grid, using pressure transducers were measured

Studies on the numerical solution of three-dimensional stationary diffusion equations using the finite element method

International Nuclear Information System (INIS)

Franke, H.P.

1976-05-01

The finite element method is applied to the solution of the stationary 3D group diffusion equations. For this, a programme system with the name of FEM3D is established which also includes a module for semi-automatic mesh generation. Tetrahedral finite elements are used. The neutron fluxes are described by complete first- or second-order Lagrangian polynomials. General homogeneous boundary conditions are allowed. The studies show that realistic three-dimensional problems can be solved at less expense by iterative methods, in particular so when especially adapted matrix handling and storage schemes are used efficiently. (orig./RW) [de

Studies on elemental analysis of widely consumed traditional herbs in Libya by ko instrumental neutron activation analysis

International Nuclear Information System (INIS)

Abugassa, I. O.; Abunawael, M. E.

2012-12-01

Herbs are accepted as an alternative medicine for specific treatment of illness of among different ethnic groups worldwide. It is vital to know the contents of these herbs used in Libya were analysed by k-0 instrumental neutron activation analysis. A total of 32 trace and major elements (Ag, As, Au, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, Hg, K, La, Mo, Na, Nd, Rb, Sb, Sc, Se, Sm, Sr, Tb, Th, Tm, U, Yb and Zn) were determined. The concentration of elements varied depending on the origin of the herb. The study showed that the toxic elements found in the samples were below the levels prescribed by health regulations. The method was justified by analyzing two SRM. All the results are in good agreement with the certified values. (Author)

Soil fertility affects elemental distribution in needles of the conifer Araucaria angustifolia: A microanalytical study

Science.gov (United States)

Araucaria angustifolia is a conifer species found in South American subtropical forests that comprises less than 3% of the native vegetation. Thus, little is known concerning the accumulation of nutritional elements in its needles. In this study, scanning electron microscopy (SEM) coupled with energ...

Study on the extraction of rare earth elements in liquid bismuth

International Nuclear Information System (INIS)

Harada, M.; Adachi, M.; Kai, Y.; Koike, K.

1987-01-01

Three factors, which are important for the extraction of rare earth elements in liquid bismuth - molten salt system, were studied, i. e., the equilibrium distribution of neodymium, samarium and bismuth between molten LiCl - liquid Bi-Li alloys, the extraction rate of rare earths, and the characteristics of the extractor with drop dispersion. The rare earth elements were extracted through redox reactions. In high range of Li-mole fraction in the alloy phase, X Li , the distribution of neodymium and bismuth in the salt phase markedly increased as X Li increased. The anomalous increase is attributed to the formation of the compound comprised of Nd, Li, Bi and oxygen in the salt phase. The redox reaction processes were very fast and the extraction rates for rare earths are controlled by the diffusion processes of the solute and the metallic lithium. The process for the formation of liquid metal drops in the continuous phase is predictable from semiempirical correlations reported for aqueous solution - organic solvent systems. The height of droplet bed being accumulated on drop settling portion is predictable from the coalescence time of single drop to a flat metal interface. The coalescence of metal drop to clean interface was very fast. The extractor type of liquid metal dispersion in molten salt is suitable for the extraction process in the fuel reprocessing of MSR or MSBR. (author)

Trace elemental imaging of rare earth elements discriminates tissues at microscale in flat fossils.

Science.gov (United States)

Gueriau, Pierre; Mocuta, Cristian; Dutheil, Didier B; Cohen, Serge X; Thiaudière, Dominique; Charbonnier, Sylvain; Clément, Gaël; Bertrand, Loïc

2014-01-01

The interpretation of flattened fossils remains a major challenge due to compression of their complex anatomies during fossilization, making critical anatomical features invisible or hardly discernible. Key features are often hidden under greatly preserved decay prone tissues, or an unpreparable sedimentary matrix. A method offering access to such anatomical features is of paramount interest to resolve taxonomic affinities and to study fossils after a least possible invasive preparation. Unfortunately, the widely-used X-ray micro-computed tomography, for visualizing hidden or internal structures of a broad range of fossils, is generally inapplicable to flattened specimens, due to the very high differential absorbance in distinct directions. Here we show that synchrotron X-ray fluorescence spectral raster-scanning coupled to spectral decomposition or a much faster Kullback-Leibler divergence based statistical analysis provides microscale visualization of tissues. We imaged exceptionally well-preserved fossils from the Late Cretaceous without needing any prior delicate preparation. The contrasting elemental distributions greatly improved the discrimination of skeletal elements material from both the sedimentary matrix and fossilized soft tissues. Aside content in alkaline earth elements and phosphorus, a critical parameter for tissue discrimination is the distinct amounts of rare earth elements. Local quantification of rare earths may open new avenues for fossil description but also in paleoenvironmental and taphonomical studies.

Preliminary study of elemental mass size distribution of urban aerosol collected in Debrecen

International Nuclear Information System (INIS)

Kertesz, Zs.; Borbely-Kiss, I.; Kiss, A.Z.; Koltay, E.; Szabo, Gy.

2000-01-01

peak appeared in the 8-16 μm and in the 16-30 μm size fraction. The size distribution of these was very similar in both periods, although in summer there is a tendency towards smaller aerodynamic diameters. The mass size distribution of the elements S, K, Cl, Zn, Cu has two modes: one peak occurs between 0.25 and 0.5 μm, the coarse particles has a peak around 16 μm. Usually an indication of a third peak appears in the 1-2 μm size fraction. This can be mainly observed in the samples collected in the winter period. In the case of Cl we observed a coarse and a condensation peak in winter, in summer only a condensation peak appeared. The distribution of K has a bimodial shape (originates from biomass burning and from soil), but there is no significant difference between the summer and winter concentrations, on the contrary as it should have been expected. This is a preliminary study, we plan to carry on campaign samplings with the PCI, and usual sampling with the streaker sampler. (author)

Study of the Internal Mechanical response of an asphalt mixture by 3-D Discrete Element Modeling

DEFF Research Database (Denmark)

Feng, Huan; Pettinari, Matteo; Hofko, Bernhard

2015-01-01

and the reliability of which have been validated. The dynamic modulus of asphalt mixtures were predicted by conducting Discrete Element simulation under dynamic strain control loading. In order to reduce the calculation time, a method based on frequency–temperature superposition principle has been implemented......In this paper the viscoelastic behavior of asphalt mixture was investigated by employing a three-dimensional Discrete Element Method (DEM). The cylinder model was filled with cubic array of spheres with a specified radius, and was considered as a whole mixture with uniform contact properties....... The ball density effect on the internal stress distribution of the asphalt mixture model has been studied when using this method. Furthermore, the internal stresses under dynamic loading have been studied. The agreement between the predicted and the laboratory test results of the complex modulus shows...

Fuel elements for pressurised-gas reactors; Elements combustibles des piles a gaz sous pression

Energy Technology Data Exchange (ETDEWEB)

Stohr, J A; Englander, M; Gauthron, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The design and fabrication of fuel elements for the first CO{sub 2} pressurized reactors have induced to investigate: various cladding materials, natural uranium base fuels, canning processes. The main analogical tests used in connection with the fuel element study are described. These various tests have enabled, among others, the fabrication of the fuel element for the EL2 reactor. Lastly, future solutions for electrical power producing reactors are foreseen. (author)Fren. [French] L'etude et la realisation d'elements combustibles pour les premieres piles a CO{sub 2} sous pression ont conduit a examiner: les divers materiaux de gaine, les combustibles a base d'uranium naturel, les modes de gainage. Les principaux essais analogiques ayant servi au cours de l'etude de la cartouche sont decrits. Ces divers essais ont notamment permis la realisation de la cartouche de la pile EL2. Enfin sont envisagees les solutions futures pour les piles productrices d'energie electrique. (auteur)

Soil-Framed Structure Interaction Analysis - A New Interface Element

Directory of Open Access Journals (Sweden)

M. Dalili Shoaei

Full Text Available AbstractInterfacial behavior between soil and shallow foundation has been found so influential to combined soil-footing performance and redistribution of forces in the superstructure. This study introduces a new thin-layer interface element formulated within the context of finite element method to idealize interfacial behavior of soil-framed structure interaction with new combination of degrees of freedom at top and bottom sides of the interface element, compatible with both isoparametric beam and quadrilateral element. This research also tends to conduct a parametric study on respective parameters of the new joint element. Presence of interface element showed considerable changes in the performance of the framed structure under quasi-static loading.

A SIMS study of lunar 'komatiitic glasses' - Trace element characteristics and possible origin

Science.gov (United States)

Shearer, C. K.; Papike, J. J.; Galbreath, K. C.; Wentworth, S. J.; Shimizu, N.

1990-01-01

In Apollo 16 regolith breccias, Wentworth and McKay (1988) identified a suite of minute (less than 120 microns) 'komatiitic glass beads'. The wide major element compositional range, and ultra-Mg-prime character of the glasses suggest a variety of possible origins from complex impact processes to complex volcanic processes involving rather unusual and primitive magmatism. The extent of trace element depletion or enrichment in these glasses appears to be correlated to the siderophile character of the element (ionization potential or experimentally determined silicate melt/Fe metal partition coefficients. The ultra-Mg-prime glasses are depleted in Co relative to a bulk Moon Mg/Co exhibited by many lunar samples (volcanic glasses, basalts, regolith breccia, estimated upper mantle). The low Co and high incompatible element concentrations diminish the possibility that these glasses are a product of lunar komatiitic volcanism or impact, excavation, and melting of a very high Mg-prime plutonic unit.

Finite Element Method in Machining Processes

CERN Document Server

Markopoulos, Angelos P

2013-01-01

Finite Element Method in Machining Processes provides a concise study on the way the Finite Element Method (FEM) is used in the case of manufacturing processes, primarily in machining. The basics of this kind of modeling are detailed to create a reference that will provide guidelines for those who start to study this method now, but also for scientists already involved in FEM and want to expand their research. A discussion on FEM, formulations and techniques currently in use is followed up by machining case studies. Orthogonal cutting, oblique cutting, 3D simulations for turning and milling, grinding, and state-of-the-art topics such as high speed machining and micromachining are explained with relevant examples. This is all supported by a literature review and a reference list for further study. As FEM is a key method for researchers in the manufacturing and especially in the machining sector, Finite Element Method in Machining Processes is a key reference for students studying manufacturing processes but al...

The sensitivity of biological finite element models to the resolution of surface geometry: a case study of crocodilian crania

Directory of Open Access Journals (Sweden)

Matthew R. McCurry

2015-06-01

Full Text Available The reliability of finite element analysis (FEA in biomechanical investigations depends upon understanding the influence of model assumptions. In producing finite element models, surface mesh resolution is influenced by the resolution of input geometry, and influences the resolution of the ensuing solid mesh used for numerical analysis. Despite a large number of studies incorporating sensitivity studies of the effects of solid mesh resolution there has not yet been any investigation into the effect of surface mesh resolution upon results in a comparative context. Here we use a dataset of crocodile crania to examine the effects of surface resolution on FEA results in a comparative context. Seven high-resolution surface meshes were each down-sampled to varying degrees while keeping the resulting number of solid elements constant. These models were then subjected to bite and shake load cases using finite element analysis. The results show that incremental decreases in surface resolution can result in fluctuations in strain magnitudes, but that it is possible to obtain stable results using lower resolution surface in a comparative FEA study. As surface mesh resolution links input geometry with the resulting solid mesh, the implication of these results is that low resolution input geometry and solid meshes may provide valid results in a comparative context.

Atlantic Forest. A natural reservoir of chemical elements

International Nuclear Information System (INIS)

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

2008-01-01

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

Trace elements distribution in environmental compartments

Energy Technology Data Exchange (ETDEWEB)

Queiroz, Juliana C. de; Peres, Sueli da Silva; Godoy, Maria Luiza D.P., E-mail: suelip@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2017-11-01

Trace elements term defines the presence of low concentrations metals at environment. Some of them are considered biologically essential, as Co, Cu and Mn. Others can cause detriment to environment and human health, as Pb, Cd, Hg, As, Ti and U. A large number of them have radioactive isotopes, implying the evaluation of risks for human health should be done considering the precepts of environmental radiological protection. The ecosystem pollution with trace elements generates changes at the geochemistry cycle of these elements and in environmental quality. Soils have single characteristics when compared with another components of biosphere (air, water and biota), cause they introduce themselves not only as a drain towards contaminants, but also as natural buffer that control the transport of chemical elements and other substances for atmosphere, hydrosphere and biota. The main purpose of environmental monitoring program is to evaluate the levels of contaminants in the various compartments of the environment: natural or anthropogenic, and to assess the contribution of a potential contaminant source on the environment. Elemental Composition for the collected samples was determined by inductively coupled plasma mass spectroscopy. The main objective of this work was to evaluate the map baseline of concentration of interest trace elements in environmental samples of water, sediment and soil from Environmental Monitoring Program of Instituto de Radioprotecao e Dosimetria (IRD). The samples were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS) at IRD. >From the knowledge of trace elements concentrations, could be evaluated the environmental quality parameters at the studied ecosystems. The data allowed evaluating some relevant aspects of the study of trace elements in soil and aquatic systems, with emphasis at the distribution, concentration and identification of main anthropic sources of contamination at environment. (author)

Trace elements distribution in environmental compartments

International Nuclear Information System (INIS)

Queiroz, Juliana C. de; Peres, Sueli da Silva; Godoy, Maria Luiza D.P.

2017-01-01

Trace elements term defines the presence of low concentrations metals at environment. Some of them are considered biologically essential, as Co, Cu and Mn. Others can cause detriment to environment and human health, as Pb, Cd, Hg, As, Ti and U. A large number of them have radioactive isotopes, implying the evaluation of risks for human health should be done considering the precepts of environmental radiological protection. The ecosystem pollution with trace elements generates changes at the geochemistry cycle of these elements and in environmental quality. Soils have single characteristics when compared with another components of biosphere (air, water and biota), cause they introduce themselves not only as a drain towards contaminants, but also as natural buffer that control the transport of chemical elements and other substances for atmosphere, hydrosphere and biota. The main purpose of environmental monitoring program is to evaluate the levels of contaminants in the various compartments of the environment: natural or anthropogenic, and to assess the contribution of a potential contaminant source on the environment. Elemental Composition for the collected samples was determined by inductively coupled plasma mass spectroscopy. The main objective of this work was to evaluate the map baseline of concentration of interest trace elements in environmental samples of water, sediment and soil from Environmental Monitoring Program of Instituto de Radioprotecao e Dosimetria (IRD). The samples were analyzed using an inductively coupled plasma mass spectrometer (ICP-MS) at IRD. >From the knowledge of trace elements concentrations, could be evaluated the environmental quality parameters at the studied ecosystems. The data allowed evaluating some relevant aspects of the study of trace elements in soil and aquatic systems, with emphasis at the distribution, concentration and identification of main anthropic sources of contamination at environment. (author)

Instrumental trace element analysis of California market milk

International Nuclear Information System (INIS)

Ragaini, R.C.; Langhorst, A.L.; Ralston, H.R.; Heft, R.

1975-01-01

Trace element analysis for 15 elements (Zn, Na, Br, Rb, Sr, Mg, Al, Ca, Cl, I, K, Fe, Co, Se, Cs) was carried out on 32 samples of California market milk and 6 samples of Colorado milk in a pilot study of toxic and nutrient trace elements in the soil-forage-cow-milk food chain. The techniques of instrumental neutron activation analysis and x-ray fluorescence analysis are described. Sample collection, preparation, analysis, and data reduction procedures are discussed. The mean values and variations of trace element concentrations in milk are compared to data from other studies. (U.S.)

Finite element modeling and simulation with ANSYS workbench

CERN Document Server

Chen, Xiaolin

2014-01-01

IntroductionSome Basic ConceptsAn Example in FEA: Spring SystemOverview of ANSYS WorkbenchSummaryProblemsBars and TrussesIntroductionReview of the 1-D Elasticity TheoryModeling of TrussesFormulation of the Bar ElementExamples with Bar ElementsCase Study with ANSYS WorkbenchSummaryProblemsBeams and FramesIntroductionReview of the Beam TheoryModeling of Beams and FramesFormulation of the Beam ElementExamples with Beam ElementsCase Study with ANSYS WorkbenchSummaryProblemsTwo-Dimensional ElasticityIntroductionReview of 2-D Elasticity TheoryModeling of 2-D Elasticity ProblemsFormulation of the Pla

Review of even element super-heavy nuclei and search for element 120

Energy Technology Data Exchange (ETDEWEB)

Hofmann, S. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Goethe-Universitaet Frankfurt, Institut fuer Physik, Frankfurt (Germany); Heinz, S.; Mann, R.; Maurer, J.; Barth, W.; Burkhard, H.G.; Dahl, L.; Kindler, B.; Kojouharov, I.; Lang, R.; Lommel, B.; Runke, J.; Scheidenberger, C.; Schoett, H.J.; Tinschert, K. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Muenzenberg, G. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Manipal University, Manipal Centre for Natural Sciences, Manipal, Karnataka (India); Antalic, S.; Saro, S. [Comenius University, Department of Nuclear Physics and Biophysics, Bratislava (Slovakia); Eberhardt, K.; Thoerle-Pospiech, P.; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz (Germany); Grzywacz, R. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of Tennessee, Knoxville, TN (United States); Hamilton, J.H. [Vanderbuilt University, Department of Physics and Astronomy, Nashville, TN (United States); Henderson, R.A.; Kenneally, J.M.; Moody, K.J.; Shaughnessy, D.A.; Stoyer, M.A. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Miernik, K. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); University of Warsaw, Warsaw (Poland); Miller, D. [University of Tennessee, Knoxville, TN (United States); Morita, K. [RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama (Japan); Nishio, K. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan); Popeko, A.G.; Yeremin, A.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Roberto, J.B.; Rykaczewski, K.P. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Uusitalo, J. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland)

2016-06-15

The reaction {sup 54}Cr + {sup 248}Cm was investigated at the velocity filter SHIP at GSI, Darmstadt, with the intention to study production and decay properties of isotopes of element 120. Three correlated signals were measured, which occurred within a period of 279ms. The heights of the signals correspond with the expectations for a decay sequence starting with an isotope of element 120. However, a complete decay chain cannot be established, since a signal from the implantation of the evaporation residue cannot be identified unambiguously. Measured properties of the event chain are discussed in detail. The result is compared with theoretical predictions. Previously measured decay properties of even element super-heavy nuclei were compiled in order to find arguments for an assignment from the systematics of experimental data. In the course of this review, a few tentatively assigned data could be corrected. New interpretations are given for results which could not be assigned definitely in previous studies. The discussion revealed that the cross-section for production of element 120 could be high enough so that a successful experiment seems possible with presently available techniques. However, a continuation of the experiment at SHIP for a necessary confirmation of the results obtained in a relatively short irradiation of five weeks is not possible at GSI presently. Therefore, we decided to publish the results of the measurement and of the review as they exist now. In the summary and outlook section we also present concepts for the continuation of research in the field of super-heavy nuclei. (orig.)

Study of behavior of cermet fuel elements on IGR reactor under RIA type accident condition

International Nuclear Information System (INIS)

Vasil'ev, Yu.S.; Vurim, A.D.; Koltyshev, S.M.; Pakhnits, V.A.; Tukhvatulin, Sh.T.; Popov, V.V.; Ryzhkov, A.N.

1996-01-01

In 1993 December in IGR reactor of Inst. of Atomic Energy of National Nuclear Center of Republic of Kazakstan the second batch of in-pile testing of perspective cermet fuel elements under the condition, simulating RIA type accident was conducted. In the second batch of testing during eight start-ups 10 cermet fuel elements were examined. Among which 8 of monolith type and 2 fuel elements with false jacket beside cladding (FJF), as well as, 6 standard fuel elements of WWER-1000 type reactor with dioxide fuel were tested. 2 fuel elements - cermet and standard were placed into capsule filled with water. To measure energy release for the each start-up two fission monitor and inside core control gauge were placed. In all the start-ups operation mode of IGR was neutron pulse. Power of fuel element kept changing from 151 to 336 k W; energy release was 38-93 kJ/gr m 235 U; maximum temperature of cermet fuel was 1943-2173 K, of dioxide fuel - 1923-2843 K. The testing has demonstrated that operability of cermet fuel elements under reactivity accident condition with pulse width of 0,2 s is, at least, not less that operability of dioxide fuel elements, through advantages of cermet fuel under these conditions are revealed to the least extent