WorldWideScience

Sample records for eleven heavy-atom derivatives

  1. Membrane's Eleven: heavy-atom derivatives of membrane-protein crystals

    DEFF Research Database (Denmark)

    Morth, Jens Preben; Sørensen, Thomas Lykke-Møller; Nissen, Poul

    2006-01-01

    A database has been assembled of heavy-atom derivatives used in the structure determination of membrane proteins. The database can serve as a guide to the design of experiments in the search for heavy-atom derivatives of new membrane-protein crystals. The database pinpoints organomercurials...

  2. A rational approach to heavy-atom derivative screening

    International Nuclear Information System (INIS)

    Joyce, M. Gordon; Radaev, Sergei; Sun, Peter D.

    2010-01-01

    In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom-derivative screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing

  3. A rational approach to heavy-atom derivative screening

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, M. Gordon; Radaev, Sergei; Sun, Peter D., E-mail: psun@nih.gov [Structural Immunology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12441 Parklawn Drive, Rockville, Maryland 20852 (United States)

    2010-04-01

    In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom-derivative screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the ‘classical’ heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing.

  4. Towards a rational approach for heavy-atom derivative screening in protein crystallography

    International Nuclear Information System (INIS)

    Agniswamy, Johnson; Joyce, M. Gordon; Hammer, Carl H.; Sun, Peter D.

    2008-01-01

    Heavy-atom derivatization is routinely used in protein structure determination and is thus of critical importance in structural biology. In order to replace the current trial-and-error heavy-atom derivative screening with a knowledge-based rational derivative-selection method, the reactivity of more than 40 heavy-atom compounds over a wide range of buffer and pH values was systematically examined using peptides which contained a single reactive amino-acid residue. Heavy-atom derivatization is routinely used in protein structure determination and is thus of critical importance in structural biology. In order to replace the current trial-and-error heavy-atom derivative screening with a knowledge-based rational derivative-selection method, the reactivity of more than 40 heavy-atom compounds over a wide range of buffer and pH values was systematically examined using peptides which contained a single reactive amino-acid residue. Met-, Cys- and His-containing peptides were derivatized against Hg, Au and Pt compounds, while Tyr-, Glu-, Asp-, Asn- and Gln-containing peptides were assessed against Pb compounds. A total of 1668 reactive conditions were examined using mass spectrometry and were compiled into heavy-atom reactivity tables. The results showed that heavy-atom derivatization reactions are highly linked to buffer and pH, with the most accommodating buffer being MES at pH 6. A group of 21 compounds were identified as most successful irrespective of ligand or buffer/pH conditions. To assess the applicability of the peptide heavy-atom reactivity to proteins, lysozyme crystals were derivatized with a list of peptide-reactive compounds that included both known and new compounds for lysozyme derivatization. The results showed highly consistent heavy-atom reactivities between the peptides and lysozyme

  5. A rapid and rational approach to generating isomorphous heavy-atom phasing derivatives.

    Science.gov (United States)

    Lu, Jinghua; Sun, Peter D

    2014-09-01

    In attempts to replace the conventional trial-and-error heavy-atom derivative search method with a rational approach, we previously defined heavy metal compound reactivity against peptide ligands. Here, we assembled a composite pH- and buffer-dependent peptide reactivity profile for each heavy metal compound to guide rational heavy-atom derivative search. When knowledge of the best-reacting heavy-atom compound is combined with mass spectrometry assisted derivatization, and with a quick-soak method to optimize phasing, it is likely that the traditional heavy-atom compounds could meet the demand of modern high-throughput X-ray crystallography. As an example, we applied this rational heavy-atom phasing approach to determine a previously unknown mouse serum amyloid A2 crystal structure. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  6. Relativistic heavy-atom effects on heavy-atom nuclear shieldings

    Science.gov (United States)

    Lantto, Perttu; Romero, Rodolfo H.; Gómez, Sergio S.; Aucar, Gustavo A.; Vaara, Juha

    2006-11-01

    The principal relativistic heavy-atom effects on the nuclear magnetic resonance (NMR) shielding tensor of the heavy atom itself (HAHA effects) are calculated using ab initio methods at the level of the Breit-Pauli Hamiltonian. This is the first systematic study of the main HAHA effects on nuclear shielding and chemical shift by perturbational relativistic approach. The dependence of the HAHA effects on the chemical environment of the heavy atom is investigated for the closed-shell X2+, X4+, XH2, and XH3- (X =Si-Pb) as well as X3+, XH3, and XF3 (X =P-Bi) systems. Fully relativistic Dirac-Hartree-Fock calculations are carried out for comparison. It is necessary in the Breit-Pauli approach to include the second-order magnetic-field-dependent spin-orbit (SO) shielding contribution as it is the larger SO term in XH3-, XH3, and XF3, and is equally large in XH2 as the conventional, third-order field-independent spin-orbit contribution. Considering the chemical shift, the third-order SO mechanism contributes two-thirds of the difference of ˜1500ppm between BiH3 and BiF3. The second-order SO mechanism and the numerically largest relativistic effect, which arises from the cross-term contribution of the Fermi contact hyperfine interaction and the relativistically modified spin-Zeeman interaction (FC/SZ-KE), are isotropic and practically independent of electron correlation effects as well as the chemical environment of the heavy atom. The third-order SO terms depend on these factors and contribute both to heavy-atom shielding anisotropy and NMR chemical shifts. While a qualitative picture of heavy-atom chemical shifts is already obtained at the nonrelativistic level of theory, reliable shifts may be expected after including the third-order SO contributions only, especially when calculations are carried out at correlated level. The FC/SZ-KE contribution to shielding is almost completely produced in the s orbitals of the heavy atom, with values diminishing with the principal

  7. Initiating heavy-atom-based phasing by multi-dimensional molecular replacement.

    Science.gov (United States)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu; Karlsen, Jesper Lykkegaard; Nissen, Poul

    2016-03-01

    To obtain an electron-density map from a macromolecular crystal the phase problem needs to be solved, which often involves the use of heavy-atom derivative crystals and concomitant heavy-atom substructure determination. This is typically performed by dual-space methods, direct methods or Patterson-based approaches, which however may fail when only poorly diffracting derivative crystals are available. This is often the case for, for example, membrane proteins. Here, an approach for heavy-atom site identification based on a molecular-replacement parameter matrix (MRPM) is presented. It involves an n-dimensional search to test a wide spectrum of molecular-replacement parameters, such as different data sets and search models with different conformations. Results are scored by the ability to identify heavy-atom positions from anomalous difference Fourier maps. The strategy was successfully applied in the determination of a membrane-protein structure, the copper-transporting P-type ATPase CopA, when other methods had failed to determine the heavy-atom substructure. MRPM is well suited to proteins undergoing large conformational changes where multiple search models should be considered, and it enables the identification of weak but correct molecular-replacement solutions with maximum contrast to prime experimental phasing efforts.

  8. HASSP and HEAVY: Tools for automated heavy atom searches and refinement

    International Nuclear Information System (INIS)

    Terwilliger, T.T.

    1994-06-01

    In this tutorial, a simple example using model data for one derivative with anomalous information will be used to demonstrate the use of HASSP and HEAVY in heavy atom determination and refinement. The data used here will actually be based on model MAD data that has been converted to MIR format using MADMRG, but the treatment is identical to that for any other SIR+anomalous data. The data nd most of the programs discussed here can be obtained by e-mail from ''terwil at sign prov2.lanl.gov'' along with VAX-specific command files to run the data through

  9. Initiating Heavy-atom Based Phasing by Multi-Dimensional Molecular Replacement

    DEFF Research Database (Denmark)

    Pedersen, Bjørn Panyella; Gourdon, Pontus; Liu, Xiangyu

    2014-01-01

    -based approaches, which however may fail when only poorly diffracting derivative crystals are available, as often the case for e.g. membrane proteins. Here we present an approach for heavy atom site identification based on a Molecular Replacement Parameter Matrix (MRPM) search. It involves an n-dimensional search...... to test a wide spectrum of molecular replacement parameters, such as clusters of different conformations. The result is scored by the ability to identify heavy-atom positions, from anomalous difference Fourier maps, that allow meaningful phases to be determined. The strategy was successfully applied...... but correct molecular replacement solutions with maximum contrast to prime experimental phasing efforts....

  10. The UKB prescription and the heavy atom effects on the nuclear magnetic shielding of vicinal heavy atoms.

    Science.gov (United States)

    Maldonado, Alejandro F; Aucar, Gustavo A

    2009-07-21

    Fully relativistic calculations of NMR magnetic shielding on XYH3 (X = C, Si, Ge and Sn; Y = Br, I), XHn (n = 1-4) molecular systems and noble gases performed with a fully relativistic polarization propagator formalism at the RPA level of approach are presented. The rate of convergence (size of basis set and time involved) for calculations with both kinetic balance prescriptions, RKB and UKB, were investigated. Calculations with UKB makes it feasible to obtain reliable results for two or more heavy-atom-containing molecules. For such XYH3 systems, the influence of heavy vicinal halogen atoms on sigma(X) is such that heavy atom effects on heavy atoms (vicinal plus their own effects or HAVHA + HAHA effects) amount to 30.50% for X = Sn and Y = I; being the HAHA effect of the order of 25%. So the vicinal effect alone is of the order of 5.5%. The vicinal heavy atom effect on light atoms (HALA effect) is of the order of 28% for X = C and Y = I. A similar behaviour, but of opposite sign, is observed for sigma(Y) for which sigmaR-NR (I; X = C) (HAHA effect) is around 27% and sigmaR-NR(I; X = Sn) (HAVHA + HAHA effects) is close to 21%. Its electronic origin is paramagnetic for halogen atoms but both dia- and paramagnetic for central atoms. The effect on two bond distant hydrogen atoms is such that the largest variation of sigma(H) within the same family of XYH3 molecules appears for X = Si and Y = I: around 20%. In this case sigma(H; X = Sn, Y = I) = 33.45 ppm and sigma(H; X = Sn, Y = H) = 27.82 ppm.

  11. Investigations in atomic physics by heavy ion projectiles

    International Nuclear Information System (INIS)

    Berenyi, D.

    1983-01-01

    The utilization of heavy ion reactions in atomic physics is surveyed. The basic collision mechanisms and their consequences in atomic physics are summarized. The atomic and electronic processes during and after heavy ion collisions are reviewed as functions of the projectile energy. The main detection and measuring methods are described. Reviews of new information about the structure of electronic cloud and about fundamental processes based on the analysis of heavy ion reaction data are given. (D.Gy.)

  12. Basic atomic interactions of accelerated heavy ions in matter atomic interactions of heavy ions

    CERN Document Server

    Tolstikhina, Inga; Winckler, Nicolas; Shevelko, Viacheslav

    2018-01-01

    This book provides an overview of the recent experimental and theoretical results on interactions of heavy ions with gaseous, solid and plasma targets from the perspective of atomic physics. The topics discussed comprise stopping power, multiple-electron loss and capture processes, equilibrium and non-equilibrium charge-state fractions in penetration of fast ion beams through matter including relativistic domain. It also addresses mean charge-states and equilibrium target thickness in ion-beam penetrations, isotope effects in low-energy electron capture, lifetimes of heavy ion beams, semi-empirical formulae for effective cross sections. The book is intended for researchers and graduate students working in atomic, plasma and accelerator physics.

  13. From heavy ions to exotic atoms

    OpenAIRE

    Indelicato, Paul; Trassinelli, Martino

    2005-01-01

    We review a number of experiments and theoretical calculations on heavy ions and exotic atoms, which aim at providing informations on fundamental interactions. Among those are propositions of experiments for parity violation measurements in heavy ions and high-precision mesurements of He-like transition energies in highly charged ions. We also describe recent experiments on pionic atoms, that make use of highly-charged ion transitions to obtain accurate measurements of strong interaction shif...

  14. Investigations in atomic physics by heavy ion projectiles

    International Nuclear Information System (INIS)

    Berenyi, D.

    1983-01-01

    Investigations in atomic physics by high-energy heavy ions are discussed. The main attention is paid to collision mechanisms (direct Coulomb interaction, quasi-molecular collision mechanism and other models) and the structure of highly ionized and excited atoms. Some problems of fundamental issues (Lamb shift of H-like heavy ions, the superheavy quasi-atoms and the position production in supercritical fields) are conside-- red in detail

  15. Effective stopping of relativistic structural heavy ions at collisions with atoms

    International Nuclear Information System (INIS)

    Matveev, V.I.

    2002-01-01

    One develops the unperturbed theory of energy losses at collision of atoms with structural high-charged heavy ions moving with relativistic velocity. One derived a simple formula for efficient braking. The structural ions in terms of this paper are considered to mean partially ionized ions of heavy elements compressing ion nucleus and some bound electrons compensating partially for ion nucleus charge. Account of ion charge magnitude is determined to result in essential increase of efficient braking of ion in contrast to braking of point nucleus of Z* charge [ru

  16. Halogenated salicylaldehyde azines: The heavy atom effect on aggregation-induced emission enhancement properties

    International Nuclear Information System (INIS)

    Chen, Xiao-tong; Tong, Ai-jun

    2014-01-01

    This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. For this purpose, a series of halogenated salicylaldehyde azine derivatives, namely, chloro-salicylaldehyde azine (1), bromo-salicylaldehyde azine (2) and iodo-salicylaldehyde azine (3) are synthesized. 1 and 2 display typical AIEE characteristics of salicylaldehyde azine compounds; whereas for the iodo-substituent in 3, is found to be effective “external” heavy atom quenchers to salicylaldehyde azine fluorescence in aggregated state. Based on its weak fluorescence in aggregated state and relative strong fluorescence in dispersed state, 3 can also be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction. -- Highlights: • This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. • Chloro- and bromo-salicylaldehyde display typical AIEE properties of salicylaldehyde azine, whereas the iodo-substitute quenches AIEE in aggregated state. • Iodo-salicylaldehyde can be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction

  17. Two-photon decay in heavy atoms and ions

    International Nuclear Information System (INIS)

    Mokler, P.H.; Dunford, R.W

    2003-08-01

    We review the status of and comment on current developments in the field of two-photon decay in atomic physics research. Recent work has focused on two-photon decays in highly-charged ions and two-photon decay of inner-shell vacancies in heavy neutral atoms. We emphasize the importance of measuring the shape of the continuum emission in two-photon decay as a probe of relativistic effects in the strong central fields found in heavy atomic systems. New experimental approaches and their consequences will be discussed. (orig.)

  18. HISTRAP proposal: heavy-ion storage ring for atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, D K; Alton, G D; Datz, S; Dittner, P F; Dowling, D T; Haynes, D L; Hudson, E D; Johnson, J W; Lee, I Y; Lord, R S

    1987-04-01

    HISTRAP, Heavy-Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, decelerate, and store beams of highly charge very-heavy ions at energies appropriate for advanced atomic physics research. The ring is designed to allow studies of electron-ion, photon-ion, ion-atom, and ion-ion interactions. An electron cooling system will provide ion beams with small angular divergence and energy spread for precision spectroscopic studies and also is necessary to allow the deceleration of heavy ions to low energies. HISTRAP will have a maximum bending power of 2.0 T m and will be injected with ions from either the existing Holifield Heavy Ion Research Facility 25-MV tandem accelerator or from a dedicated ECR source and 250 keV/nucleon RFQ linac.

  19. STATISTICAL ANALYSIS OF THE HEAVY NEUTRAL ATOMS MEASURED BY IBEX

    International Nuclear Information System (INIS)

    Park, Jeewoo; Kucharek, Harald; Möbius, Eberhard; Galli, André; Livadiotis, George; Fuselier, Steve A.; McComas, David J.

    2015-01-01

    We investigate the directional distribution of heavy neutral atoms in the heliosphere by using heavy neutral maps generated with the IBEX-Lo instrument over three years from 2009 to 2011. The interstellar neutral (ISN) O and Ne gas flow was found in the first-year heavy neutral map at 601 keV and its flow direction and temperature were studied. However, due to the low counting statistics, researchers have not treated the full sky maps in detail. The main goal of this study is to evaluate the statistical significance of each pixel in the heavy neutral maps to get a better understanding of the directional distribution of heavy neutral atoms in the heliosphere. Here, we examine three statistical analysis methods: the signal-to-noise filter, the confidence limit method, and the cluster analysis method. These methods allow us to exclude background from areas where the heavy neutral signal is statistically significant. These methods also allow the consistent detection of heavy neutral atom structures. The main emission feature expands toward lower longitude and higher latitude from the observational peak of the ISN O and Ne gas flow. We call this emission the extended tail. It may be an imprint of the secondary oxygen atoms generated by charge exchange between ISN hydrogen atoms and oxygen ions in the outer heliosheath

  20. Sub-Angstrom Atomic-Resolution Imaging of Heavy Atoms to Light Atoms

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, Michael A.; Shao-Horn, Yang

    2003-05-23

    Three decades ago John Cowley and his group at ASU achieved high-resolution electron microscope images showing the crystal unit cell contents at better than 4Angstrom resolution. Over the years, this achievement has inspired improvements in resolution that have enabled researchers to pinpoint the positions of heavy atom columns within the cell. More recently, this ability has been extended to light atoms as resolution has improved. Sub-Angstrom resolution has enabled researchers to image the columns of light atoms (carbon, oxygen and nitrogen) that are present in many complex structures. By using sub-Angstrom focal-series reconstruction of the specimen exit surface wave to image columns of cobalt, oxygen, and lithium atoms in a transition metal oxide structure commonly used as positive electrodes in lithium rechargeable batteries, we show that the range of detectable light atoms extends to lithium. HRTEM at sub-Angstrom resolution will provide the essential role of experimental verification for the emergent nanotech revolution. Our results foreshadow those to be expected from next-generation TEMs with Cs-corrected lenses and monochromated electron beams.

  1. Giant resonance phenomena in the electron impact ionization of heavy atoms and ions

    International Nuclear Information System (INIS)

    Younger, S.M.

    1986-01-01

    Heavy atoms and ions offer an interesting opportunity to study atomic physics in a region where the atomic structure is dominated by the interelectronic interactions. One illustration of this is the profound term dependence of atomic orbitals for certain configurations of heavy atoms and ions. The appearance of giant scattering resonances in the cross sections for ionization of heavy atoms by electron impact is a manifestation of resonance behavior. Such resonant structures arise from the double well nature of the scattering potential and have recently been identified in the cross sections for the electron impact ionization of several xenon-like ions. The results of calculations showing effects for a variety of other ions are summarized. 7 refs., 4 figs

  2. Semiclassical perturbation theory for diffraction in heavy atom surface scattering.

    Science.gov (United States)

    Miret-Artés, Salvador; Daon, Shauli; Pollak, Eli

    2012-05-28

    The semiclassical perturbation theory formalism of Hubbard and Miller [J. Chem. Phys. 78, 1801 (1983)] for atom surface scattering is used to explore the possibility of observation of heavy atom diffractive scattering. In the limit of vanishing ℏ the semiclassical theory is shown to reduce to the classical perturbation theory. The quantum diffraction pattern is sensitive to the characteristics of the beam of incoming particles. Necessary conditions for observation of quantum diffraction are derived for the angular width of the incoming beam. An analytic expression for the angular distribution as a function of the angular and momentum variance of the incoming beam is obtained. We show both analytically and through some numerical results that increasing the angular width of the incident beam leads to decoherence of the quantum diffraction peaks and one approaches the classical limit. However, the incoherence of the beam in the parallel direction does not destroy the diffraction pattern. We consider the specific example of Ar atoms scattered from a rigid LiF(100) surface.

  3. Electron-impact ionization of heavy atomic ions

    International Nuclear Information System (INIS)

    Pindzola, M.S.; Griffin, D.C.; Bottcher, C.

    1987-01-01

    General theoretical methods for the calculation of direct and indirect processes in the electron-impact ionization of heavy atomic ions are reviewed. Cross section results for Xe 8+ and U 89+ are presented. 12 refs., 4 figs

  4. Lattice design of HISTRAP: Heavy ion storage ring for atomic physics

    International Nuclear Information System (INIS)

    Lee, I.Y.; Martin, J.A.; McGrory, J.B.; Milner, W.T.; Olsen, D.K.; Young, G.R.

    1987-01-01

    HISTRAP, a Heavy-Ion Storage Ring for Atomic Physics, is a proposed 46.8-m-circumference synchrotron-cooling-storage ring optimized to accelerate, cool, decelerate, and store beams of highly charged very-heavy ions at energies appropriate for advanced atomic physics research. This four-fold symmetrical ring has a maximum bending power of 2 Tm. It has achromatic bends and uses quadrupole triplets for focusing

  5. Effect of heavy atoms on the thermal stability of α-amylase from Aspergillus oryzae.

    Directory of Open Access Journals (Sweden)

    Michihiro Sugahara

    Full Text Available Currently, there are no versatile and established methods for improving stability of proteins. In an entirely different approach from conventional techniques such as mutagenesis, we attempted to enhance enzyme stability of α-amylase from Aspergillus oryzae using a heavy-atom derivatization technique. We evaluated changes in stability using differential scanning calorimetry (DSC. Candidate heavy atoms were identified using the Heavy-Atom Database System HATODAS, a Web-based tool designed to assist in heavy-atom derivatization of proteins for X-ray crystallography. The denaturation temperature of α-amylase derivatized with gadolinium (Gd or samarium (Sm ions increased by 6.2 or 5.7°C, respectively, compared to that of the native protein (60.6°C. The binding of six Gd ions was confirmed by X-ray crystallography of the enzyme at 1.5 Å resolution. DSC and dynamic light-scattering data revealed a correlation between stability and the aggregation state upon addition of Gd ions. These results show that HATODAS search is an effective tool for selecting heavy atoms for stabilization of this protein.

  6. Direct excitation in heavy atom collisions: A propensity rule for charge cloud orientation

    International Nuclear Information System (INIS)

    Andersen, N.; Aarhus Univ.; Nielsen, S.E.; Royal Danish School of Pharmacy, Copenhagen)

    1985-01-01

    The Massey Criterion prescribes maximum electronic excitation of atoms in heavy particle collisions for collision velocities v where Δε a/ℎv ≅ π. Here Δε is the energy defect and a is the effective interaction length. Experiments with planar symmetry have revealed a preferred way of rotation of the excited charge cloud in this velocity region. We demonstrate by analysis of a simple, yet realistic model why excitation favors states with a specific orientation. A general propensity rule is derived and its validity evaluated for a specific case, the Na-He system. Implications for future experiments are pointed out. In particular, the propensity rule predicts very different collisions behaviors of oppositely oriented atoms, as prepared e.g. by circular polarized laser light. (orig.)

  7. Charge-state-distributions of foil-excited heavy Rydberg atoms

    International Nuclear Information System (INIS)

    Faibis, A.; Kanter, E.P.; Koenig, W.; Zabransky, B.J.

    1985-01-01

    Studies of foil-excited fast (MeV/amu) heavy ions have demonstrated large yields of high Rydberg atoms formed in such beams. Further experiments have suggested a strong target-thickness dependence of the yields of such atoms. These results have been puzzling in view of the supposed short mean free paths of such atoms in solids. In an effort to better understand these results, the authors have measured the yields of Rydberg atoms (napprox.100-200) in foil-excited 32 S ions at an incident energy of 125 MeV

  8. Proceedings of the workshop on atomic physics with fast heavy-ion beams

    International Nuclear Information System (INIS)

    Kanter, E.P.; Minchinton, A.

    1983-01-01

    The Workshop on Atomic Physics with Fast Heavy-Ion Beams was held in the Physics Division, Argonne National Laboratory on January 20 and 21, 1983. The meeting brought together approx. 50 practitioners in the field of accelerator-based atomic physics. The workshop was held to focus attention on possible areas of atomic physics research which would benefit from use of the newest generation of accelerators designed to produce intense high-quality beams of fast heavy ions. Abstracts of individual paper were prepared separately for the data base

  9. Atomic x-ray production by relativistic heavy ions

    International Nuclear Information System (INIS)

    Ioannou, J.G.

    1977-12-01

    The interaction of heavy ion projectiles with the electrons of target atoms gives rise to the production, in the target, of K-, L- or higher shell vacancies which are in turn followed by the emission of characteristic x-rays. The calculation of the theoretical value of the K- and L-shells vacancy production cross section was carried out for heavy ion projectiles of any energy. The transverse component of the cross section is calculated for the first time in detail and extensive tables of its numerical value as a function of its parameters are also given. Experimental work for 4.88 GeV protons and 3 GeV carbon ions is described. The K vacancy cross section has been measured for a variety of targets from Ti to U. The agreement between the theoretical predictions and experimental results for the 4.88 GeV protons is rather satisfactory. For the 3 GeV carbon ions, however, it is observed that the deviation of the theoretical and experimental values of the K vacancy production becomes larger with the heavier target element. Consequently, the simple scaling law of Z 1 2 for the cross section of the heavy ion with atomic number Z 1 to the proton cross section is not true, for the K-shell at least. A dependence on the atomic number Z 2 of the target of the form (Z 1 - αZ 2 ) 2 , instead of Z 1 2 , is found to give extremely good agreement between theory and experiment. Although the exact physical meaning of such dependence is not yet clearly understood, it is believed to be indicative of some sort of screening effect of the incoming fast projectile by the fast moving in Bohr orbits K-shell electrons of the target. The enhancement of the K-shell ionization cross section by relativistic heavy ions on heavy targets is also discussed in terms of its practical applications in various branches of science and technology

  10. Photoelectron spectroscopy of heavy atoms and molecules

    International Nuclear Information System (INIS)

    White, M.G.

    1979-07-01

    The importance of relativistic interactions in the photoionization of heavy atoms and molecules has been investigated by the technique of photoelectron spectroscopy. In particular, experiments are reported which illustrate the effects of the spin-orbit interaction in the neutral ground state, final ionic states and continuum states of the photoionization target

  11. Localization and orientation of heavy-atom cluster compounds in protein crystals using molecular replacement

    International Nuclear Information System (INIS)

    Dahms, Sven O.; Kuester, Miriam; Streb, Carsten; Roth, Christian; Sträter, Norbert; Than, Manuel E.

    2013-01-01

    A new approach is presented that allows the efficient localization and orientation of heavy-atom cluster compounds used in experimental phasing by a molecular replacement procedure. This permits the calculation of meaningful phases up to the highest resolution of the diffraction data. Heavy-atom clusters (HA clusters) containing a large number of specifically arranged electron-dense scatterers are especially useful for experimental phase determination of large complex structures, weakly diffracting crystals or structures with large unit cells. Often, the determination of the exact orientation of the HA cluster and hence of the individual heavy-atom positions proves to be the critical step in successful phasing and subsequent structure solution. Here, it is demonstrated that molecular replacement (MR) with either anomalous or isomorphous differences is a useful strategy for the correct placement of HA cluster compounds. The polyoxometallate cluster hexasodium α-metatungstate (HMT) was applied in phasing the structure of death receptor 6. Even though the HA cluster is bound in alternate partially occupied orientations and is located at a special position, its correct localization and orientation could be determined at resolutions as low as 4.9 Å. The broad applicability of this approach was demonstrated for five different derivative crystals that included the compounds tantalum tetradecabromide and trisodium phosphotungstate in addition to HMT. The correct placement of the HA cluster depends on the length of the intramolecular vectors chosen for MR, such that both a larger cluster size and the optimal choice of the wavelength used for anomalous data collection strongly affect the outcome

  12. HIAF: New opportunities for atomic physics with highly charged heavy ions

    Science.gov (United States)

    Ma, X.; Wen, W. Q.; Zhang, S. F.; Yu, D. Y.; Cheng, R.; Yang, J.; Huang, Z. K.; Wang, H. B.; Zhu, X. L.; Cai, X.; Zhao, Y. T.; Mao, L. J.; Yang, J. C.; Zhou, X. H.; Xu, H. S.; Yuan, Y. J.; Xia, J. W.; Zhao, H. W.; Xiao, G. Q.; Zhan, W. L.

    2017-10-01

    A new project, High Intensity heavy ion Accelerator Facility (HIAF), is currently being under design and construction in China. HIAF will provide beams of stable and unstable heavy ions with high energies, high intensities and high quality. An overview of new opportunities for atomic physics using highly charged ions and radioactive heavy ions at HIAF is given.

  13. Effect of heavy atoms on photochemically induced dynamic nuclear polarization in liquids

    Science.gov (United States)

    Okuno, Yusuke; Cavagnero, Silvia

    2018-01-01

    Given its short hyperpolarization time (∼10-6 s) and mostly non-perturbative nature, photo-chemically induced dynamic nuclear polarization (photo-CIDNP) is a powerful tool for sensitivity enhancement in nuclear magnetic resonance. In this study, we explore the extent of 1H-detected 13C nuclear hyperpolarization that can be gained via photo-CIDNP in the presence of small-molecule additives containing a heavy atom. The underlying rationale for this methodology is the well-known external-heavy-atom (EHA) effect, which leads to significant enhancements in the intersystem-crossing rate of selected photosensitizer dyes from photoexcited singlet to triplet. We exploited the EHA effect upon addition of moderate amounts of halogen-atom-containing cosolutes. The resulting increase in the transient triplet-state population of the photo-CIDNP sensitizer fluorescein resulted in a significant increase in the nuclear hyperpolarization achievable via photo-CIDNP in liquids. We also explored the internal-heavy-atom (IHA) effect, which is mediated by halogen atoms covalently incorporated into the photosensitizer dye. Widely different outcomes were achieved in the case of EHA and IHA, with EHA being largely preferable in terms of net hyperpolarization.

  14. Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

    International Nuclear Information System (INIS)

    Swaczyna, Paweł; Bzowski, Maciej

    2017-01-01

    Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10 6 times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

  15. Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

    Energy Technology Data Exchange (ETDEWEB)

    Swaczyna, Paweł; Bzowski, Maciej, E-mail: pswaczyna@cbk.waw.pl [Space Research Centre of the Polish Academy of Sciences (CBK PAN), Bartycka 18A, 00-716 Warsaw (Poland)

    2017-09-10

    Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10{sup 6} times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

  16. Fast Heavy-Atom Tunneling in Trifluoroacetyl Nitrene.

    Science.gov (United States)

    Wu, Zhuang; Feng, Ruijuan; Li, Hongmin; Xu, Jian; Deng, Guohai; Abe, Manabu; Bégué, Didier; Liu, Kun; Zeng, Xiaoqing

    2017-12-04

    Chemical reactions involving quantum mechanical tunneling (QMT) increasingly attract the attention of scientists. In contrast to the hydrogen-tunneling as frequently observed in chemistry and biology, tunneling solely by heavy atoms is rare. Herein, we report heavy-atom tunneling in trifluoroacetyl nitrene, CF 3 C(O)N. The carbonyl nitrene CF 3 C(O)N in the triplet ground state was generated in cryogenic matrices by laser (193 or 266 nm) photolysis of CF 3 C(O)N 3 and characterized by IR and EPR spectroscopy. In contrast to the theoretically predicted activation barriers (>10 kcal mol -1 ), CF 3 C(O)N undergoes rapid rearrangement into CF 3 NCO with half-life times of less than 10 min and unprecedentedly large 14 N/ 15 N kinetic isotope effects (1.18-1.33) in solid Ar, Ne, and N 2 matrices even at 2.8 K. The tunneling disappearance of CF 3 C(O)N becomes much slower in the chemically active toluene and in 2-methyltetrahydrofuran at 5 K. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Delta-electron emission in fast heavy ion atom collisions

    International Nuclear Information System (INIS)

    Schmidt-Boecking, H.; Ramm, U.; Berg, H.; Kelbch, C.; Feng Jiazhen; Hagmann, S.; Kraft, G.; Ullrich, J.

    1991-01-01

    The δ-electron emission processes occuring in fast heavy ion atom collisons are explained qualitatively. The different spectral structures of electron emission arising from either the target or the projectile are explained in terms of simple models of the kinetics of momentum transfer induced by the COULOMB forces. In collisions of very heavy ions with matter, high nuclear COULOMB forces are created. These forces lead to a strong polarization of the electronic states of the participated electrons. The effects of this polarization are discussed. (orig.)

  18. Localization and orientation of heavy-atom cluster compounds in protein crystals using molecular replacement.

    Science.gov (United States)

    Dahms, Sven O; Kuester, Miriam; Streb, Carsten; Roth, Christian; Sträter, Norbert; Than, Manuel E

    2013-02-01

    Heavy-atom clusters (HA clusters) containing a large number of specifically arranged electron-dense scatterers are especially useful for experimental phase determination of large complex structures, weakly diffracting crystals or structures with large unit cells. Often, the determination of the exact orientation of the HA cluster and hence of the individual heavy-atom positions proves to be the critical step in successful phasing and subsequent structure solution. Here, it is demonstrated that molecular replacement (MR) with either anomalous or isomorphous differences is a useful strategy for the correct placement of HA cluster compounds. The polyoxometallate cluster hexasodium α-metatungstate (HMT) was applied in phasing the structure of death receptor 6. Even though the HA cluster is bound in alternate partially occupied orientations and is located at a special position, its correct localization and orientation could be determined at resolutions as low as 4.9 Å. The broad applicability of this approach was demonstrated for five different derivative crystals that included the compounds tantalum tetradecabromide and trisodium phosphotungstate in addition to HMT. The correct placement of the HA cluster depends on the length of the intramolecular vectors chosen for MR, such that both a larger cluster size and the optimal choice of the wavelength used for anomalous data collection strongly affect the outcome.

  19. Relativistic Spin-Orbit Heavy Atom on the Light Atom NMR Chemical Shifts: General Trends Across the Periodic Table Explained.

    Science.gov (United States)

    Vícha, Jan; Komorovsky, Stanislav; Repisky, Michal; Marek, Radek; Straka, Michal

    2018-05-10

    The importance of relativistic effects on the NMR parameters in heavy-atom (HA) compounds, particularly the SO-HALA (Spin-Orbit Heavy Atom on the Light Atom) effect on NMR chemical shifts, has been known for about 40 years. Yet, a general correlation between the electronic structure and SO-HALA effect has been missing. By analyzing 1 H NMR chemical shifts of the sixth-period hydrides (Cs-At), we discovered general electronic-structure principles and mechanisms that dictate the size and sign of the SO-HALA NMR chemical shifts. In brief, partially occupied HA valence shells induce relativistic shielding at the light atom (LA) nuclei, while empty HA valence shells induce relativistic deshielding. In particular, the LA nucleus is relativistically shielded in 5d 2 -5d 8 and 6p 4 HA hydrides and deshielded in 4f 0 , 5d 0 , 6s 0 , and 6p 0 HA hydrides. This general and intuitive concept explains periodic trends in the 1 H NMR chemical shifts along the sixth-period hydrides (Cs-At) studied in this work. We present substantial evidence that the introduced principles have a general validity across the periodic table and can be extended to nonhydride LAs. The decades-old question of why compounds with occupied frontier π molecular orbitals (MOs) cause SO-HALA shielding at the LA nuclei, while the frontier σ MOs cause deshielding is answered. We further derive connection between the SO-HALA NMR chemical shifts and Spin-Orbit-induced Electron Deformation Density (SO-EDD), a property that can be obtained easily from differential electron densities and can be represented graphically. SO-EDD provides an intuitive understanding of the SO-HALA effect in terms of the depletion/concentration of the electron density at LA nuclei caused by spin-orbit coupling due to HA in the presence of a magnetic field. Using an analogy between the SO-EDD concept and arguments from classic NMR theory, the complex question of the SO-HALA NMR chemical shifts becomes easily understandable for a wide

  20. Limits on visibility of single heavy atoms in the scanning transmission electron microscope: an experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Wall, J.S.

    1979-01-01

    Theoretical calculations of the visibility of single heavy atoms on thin carbon substrates have predicted higher signal to noise ratios then experimentally observed. Six experimental measurements were performed to determine where the theory is inadequate, five to determine the absolute value of heavy atom scattering cross sections in practical units, and one to determine substrate noise in some practical units. The practical unit of measure was chosen to be the scattering power of one carbon atom as determined by an internal standard, Tobacco Mosaic Virus. Measurements were performed on the following targets on thin carbon substrates: single isolated uranium atoms; silicotungstate clusters; colloidal platinum particles; fd bacteriophage embedded in negative strain; and fd bacteriophage reacted with a known quantity of heavy atom reagent. These measurements suggest that the scattering power of one heavy atom is approximately 9 +- 4 carbon atom equivalents, instead of 15 to 24 predicted by theory. The same techniques were used to measure intensity fluctuations from area to area of a clean substrate. Substrate noise was found to be less than expected for squares of width less than 10A, but up to 2.5 times greater than expected for larger squares. These signal and noise measurements have been combined to give an empirical formula for calculating signal to noise ratios from specimen and microscope parameters.

  1. Derivative flame atomic absorption spectrometry and its application in trace analysis

    International Nuclear Information System (INIS)

    Sun, H. W.; Li, L. Q.

    2005-01-01

    Flame atomic absorption spectrometry is an accepted and widely used method for the determination of trace elements in a great variety of samples. But its sensitivity doesn't meet the demands of trace and ultra-trace analysis for some samples. The derivative signal processing technique, with a very high capability for enhancing sensitivity, was developed for flame atomic absorption spectrometry. The signal models of conventional flame atomic absorption spectrometry are described. The equations of derivative signals are established for flame atomic absorption spectrometry, flow injection atomic absorption spectrometry (FI-FAAS) and atom trapping flame atomic absorption spectrometry (AT-FAAS). The principle and performance of the derivative atomic absorption spectrometry are evaluated. The derivative technique based on determination of variation rate of signal intensity with time (dl/dt) is different from the derivative spectrophotometry based on determination of variation rate of signal intensity with wavelength (dl/dhλ). Derivative flame atomic absorption spectrometry has higher sensitivity, lower detection limits and better accuracy. It has been applied to the direct determination of trace elements without preconcentration. If the derivative technique was combined with several preconcentration techniques, the sensitivity would be enhanced further for ultra-trace analysis with good linearity. The applications of derivative flame atomic absorption spectroscopy are reviewed for trace element analysis in biological, pharmaceutical, environmental and food samples

  2. Atomic data for heavy element impurities in fusion reactors. Summary report of the final research coordination meeting

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2009-04-01

    Eleven experts on the properties of heavy elements of relevance to fusion energy research attended the final Research Coordination Meeting (RCM) on Data for Heavy Element Impurities in Fusion Reactors, held at IAEA Headquarters on 4-6 March 2009. Participants summarized their accomplishments with respect to the revised work plan formulated at the second RCM. The overall work plan for the CRP was assessed and reviewed in detail, and achievements were noted. Discussions, conclusions and recommendations of the RCM are briefly described in this report. (author)

  3. THE STUDY OF HEAVY METAL FROM ENVIRONMENTAL SAMPLES BY ATOMIC TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Ion V. POPESCU

    2011-05-01

    Full Text Available Using the Atomic Absorption Spectrometry (AAS and Energy Dispersive X-ray spectrometry (EDXRF techniques we analyzed the contents of heavy metals ( Cd, Cr, Ni, Pb, Ti, Sr, Co, Bi from eight wild mushrooms and soil substrate samples (48 samples of eight fungal species and 32 underlying soil samples, collected from ten forest sites of Dambovița County Romania. It was determined that the elements, especially heavy metals, in soil were characteristic of the acidic soils of the Romanian forest lands and are influenced by industrial pollution. Analytical possibilities of AAS and EDXRF analytical techniques have been compared and the heavy metal transfer from substrate to mushrooms has been studied. The coefficient of accumulation of essential and heavy metals has been calculated as well. Heavy metal contents of all analyzed mushrooms were generally higher than previously reported in literature.

  4. Eleven-dimensional supergravity from filtered subdeformations of the Poincaré superalgebra

    International Nuclear Information System (INIS)

    Figueroa-O’Farrill, José; Santi, Andrea

    2016-01-01

    We summarise recent results concerning the classification of filtered deformations of graded subalgebras of the Poincaré superalgebra in eleven dimensions, highlighting what could be considered a novel Lie-algebraic derivation of eleven-dimensional supergravity. (paper)

  5. Atomic physics

    International Nuclear Information System (INIS)

    Armbruster, P.; Beyer, H.; Bosch, F.; Dohmann, H.D.; Kozhuharov, C.; Liesen, D.; Mann, R.; Mokler, P.H.

    1984-01-01

    The heavy ion accelerator UNILAC is well suited to experiments in the field of atomic physics because, with the aid of high-energy heavy ions atoms can be produced in exotic states - that is, heavy atoms with only a few electrons. Also, in close collisions of heavy ions (atomic number Z 1 ) and heavy target atoms (Z 2 ) short-lived quasi-atomic 'superheavy' systems will be formed - huge 'atoms', where the inner electrons are bound in the field of the combined charge Z 1 + Z 2 , which exceeds by far the charge of the known elements (Z <= 109). Those exotic or transient superheavy atoms delivered from the heavy ion accelerator make it possible to study for the first time in a terrestrial laboratory exotic, but fundamental, processes, which occur only inside stars. Some of the basic research carried out with the UNILAC is discussed. This includes investigation of highly charged heavy atoms with the beam-foil method, the spectroscopy of highly charged slow-recoil ions, atomic collision studies with highly ionised, decelerated ions and investigations of super-heavy quasi-atoms. (U.K.)

  6. Retention of Halogenated Solutes on Stationary Phases Containing Heavy Atoms

    Directory of Open Access Journals (Sweden)

    Toshio Miwa

    2013-05-01

    Full Text Available To examine the effects of weak intermolecular interactions on solid-phase extraction (SPE and chromatographic separation, we synthesized some novel stationary phases with a heavy atom effect layer by immobilizing halogenated aromatic rings and hydroxyl groups onto the surface of a hydrophilic base polymer. Using SPE cartridges packed with the functionalized materials, we found that the heavy atom stationary phases could selectively retain halophenols in organic solvents, such as 1-propanol which blocks the hydrogen bonding, or acetonitrile which blocks the p-p interaction. The extraction efficiency of the materials toward the halophenols depended on the dipole moments of phenoxy groups present as functional groups. On the other hand, the extraction efficiency of solutes toward the functional group depended on their molar refractions, i.e., induced dipole moments. The retention of the solutes to the stationary phase ultimately depended on not only strong intermolecular interactions, but also the effects of weak interactions such as the dispersion force.

  7. Electron loss from heavy heliumlike projectiles in ultrarelativistic collisions with many-electron atomic targets

    International Nuclear Information System (INIS)

    Mueller, C.; Gruen, N.; Voitkiv, A.B.

    2002-01-01

    We study single- and double-electron loss from heavy heliumlike projectiles in ultrarelativistic collisions with neutral many-electron target atoms. The simultaneous interaction of the target with two projectile electrons is found to be the dominant process in the double-electron loss provided the atomic number of the projectile, Z p , that of the target, Z t , and the collision velocity, v, satisfy the condition Z p Z t /v>0.4. It is shown that for a wide range of projectile and target atomic numbers the asymptotic double-to-single loss ratio strongly depends on the target atomic number but is nearly independent of the nuclear charge of the projectile. It is also demonstrated that many-photon exchange between the target and each of the projectile electrons considerably influences the double loss in collisions with very heavy targets

  8. Hyperthermal (10-500 eV) collisions of noble gases with Ni(100) surface. Comparison between light and heavy atom collisions

    International Nuclear Information System (INIS)

    Kim, C.

    1995-01-01

    Collisional events between 10-500 eV atomic beams (He, Ne, Ar, Kr, and Xe) and a Ni(100) surface are investigated by the classical trajectory method. The calculation employs a molecular dynamics approach combined with a Langevin method for treating energy dissipation to infinite solid. We find that low energy collisions of heavy atoms (Xe and Kr) are characterized by extensive many-body interactions with top layer surface atoms. On the other hand, light atom (Ne and He) collisions can be approximated as a sequence of binary collisions even at these energies. Such a difference in the collisional nature gives rise to the following consequences. Low energy heavy atoms transfer energy mostly to the surface atoms during 45 angle collision. They scatter from the surface with a narrow angular distribution centered in a supraspecular direction. The ratio of the scattered to incident particle energy rapidly decreases with increasing beam energy of heavy atoms. The sputtering yield for Ni atoms by heavy atom bombardment increases quite linearly with beam energy, which is attributed to a linear proportionality between the beam energy and the energy transfered to a surface. Near the threshold energy sputtering can occur more efficiently by light atom bombardment. The energy transfer ratio to solid continuously increases with beam energy for light atoms. For heavy projectiles, on the other hand, this ratio reaches a maximum at the energy of ca, 100 eV, above which it stays nearly constant but slightly decreases. ((orig.))

  9. Charge transfer to the continuum by heavy ions in atomic hydrogen

    International Nuclear Information System (INIS)

    Sellin, I.A.

    1981-01-01

    Design and installation of an atomic hydrogen target for measurements of charge transfer to the continuum by heavy ions are discussed. The design consists of a tungsten gas cell operated at temperatures of 2500 to 2600 0 K. Initial testing is underway

  10. On mechanism of low-energy heavy ions scattering on a target surface with small atomic mass

    CERN Document Server

    Umarov, F F; Kudryashova, L B; Krylov, N M

    2002-01-01

    In the present work, an experimental study of low-energy (E sub 0 =20-500 eV) heavy Cs sup + ions scattering on target surfaces with small atomic masses (Al, Si, Ni) has been performed for more accurate definition of mechanism of scattering and evaluation of an opportunity for use of heavy ions scattering as a tool of surface layer analysis. It is shown that the dependence of the relative energies of scattered ions versus the initial energy E/E sub 0 (E sub 0) for Si (E sub b =4.64 eV/atom) and Ni (E sub b =4.43 eV/atom) approximately coincide despite the fact that the mass of Ni atom is twice as large as that of the Si atom mass. At the same time their binding energies E sub b are approximately equal to each other. It is found that the scattering angles of Cs sup + ions considerably exceed a limiting scattering angle theta sub l sub i sub m in a single collision. It has been established that the scattering of low-energy heavy ions by light targets is described by a non-binary mechanism of many-particle inter...

  11. New Fokker-Planck derivation of heavy gas models for neutron thermalization

    International Nuclear Information System (INIS)

    Larsen, E.W.; Williams, M.M.R.

    1990-01-01

    This paper is concerned with the derivation of new generalized heavy gas models for the infinite medium neutron energy spectrum equation. Our approach is general and can be used to derive improved Fokker-Planck approximations for other types of kinetic equations. In this paper we obtain two distinct heavy gas models, together with estimates for the corresponding errors. The models are shown in a special case to reduce to modified heavy gas models proposed earlier by Corngold (1962). The error estimates show that both of the new models should be more accurate than Corngold's modified heavy gas model, and that the first of the two new models should generally be more accurate than the second. (author)

  12. HISTRAP [Heavy Ion Storage Ring for Atomic Physics] prototype hardware studies

    International Nuclear Information System (INIS)

    Olsen, D.K.; Atkins, W.H.; Dowling, D.T.; Johnson, J.W.; Lord, R.S.; McConnell, J.W.; Milner, W.T.; Mosko, S.W.; Tatum, B.A.

    1989-01-01

    HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed 2.67-Tm synchrotron/cooler/storage ring optimized for advanced atomic physics research which will be injected with ions from either the HHIRF 25-MV tandem accelerator or a dedicated ECR source and RFQ linac. Over the last two years, hardware prototypes have been developed for difficult and long lead-time components. A vacuum test stand, the rf cavity, and a prototype dipole magnet have been designed, constructed, and tested. 7 refs., 8 figs., 2 tabs

  13. Site specific incorporation of heavy atom-containing unnatural amino acids into proteins for structure determination

    Science.gov (United States)

    Xie, Jianming [San Diego, CA; Wang, Lei [San Diego, CA; Wu, Ning [Boston, MA; Schultz, Peter G [La Jolla, CA

    2008-07-15

    Translation systems and other compositions including orthogonal aminoacyl tRNA-synthetases that preferentially charge an orthogonal tRNA with an iodinated or brominated amino acid are provided. Nucleic acids encoding such synthetases are also described, as are methods and kits for producing proteins including heavy atom-containing amino acids, e.g., brominated or iodinated amino acids. Methods of determining the structure of a protein, e.g., a protein into which a heavy atom has been site-specifically incorporated through use of an orthogonal tRNA/aminoacyl tRNA-synthetase pair, are also described.

  14. Heavy Atom Substituents as Molecular Probes for Solvent Effects on the Dynamics of Short-lived Triplet Exciplexes

    OpenAIRE

    Winter, Gerhard; Steiner, Ulrich

    1980-01-01

    The influence of heavy atom substituents (Br, I) in the electron donor aniline on the electron transfer reaction with thiopyronine triplet is investigated by flash spectroscopy in solvents of different viscosity and polarity. Triplet quenching constants and radical yields are determined. The results are analysed in terms of decay constants of an intermediate triplet exciplex where the heavy atom substituents significantly enhance the intersystem crossing process leading to singlet ground stat...

  15. Optically stimulated slowing of polar heavy-atom molecules with a constant beat phase

    Science.gov (United States)

    Yin, Yanning; Xu, Supeng; Xia, Meng; Xia, Yong; Yin, Jianping

    2018-04-01

    Polar heavy-atom molecules have been well recognized as promising candidates for precision measurements and tests of fundamental physics. A much slower molecular beam to increase the interaction time should lead to a more sensitive measurement. Here we theoretically demonstrate the possibility of the stimulated longitudinal slowing of heavy-atom molecules by the coherent optical bichromatic force with a constant beat phase. Taking the YbF meolecule as an example, we show that a rapid and short-distance deceleration of heavy molecules by a phase-compensation method is feasible with moderate conditions. A molecular beam of YbF with a forward velocity of 120 m/s can be decelerated below 10 m/s within a distance of 3.5 cm and with a laser irradiance for each traveling wave of 107.2 W/cm 2 . Our proposed slowing method could be a promising approach to break through the space constraint or the limited capture efficiency of molecules loadable into a magneto-optical trap in traditional deceleration schemes, opening the possibility for a significant improvement of the precision measurement sensitivity.

  16. On mechanism of low-energy heavy ions scattering on a target surface with small atomic mass

    Energy Technology Data Exchange (ETDEWEB)

    Umarov, F.F. E-mail: farid1945@yahoo.com; Bazarbaev, N.N.; Kudryashova, L.B.; Krylov, N.M

    2002-11-01

    In the present work, an experimental study of low-energy (E{sub 0}=20-500 eV) heavy Cs{sup +} ions scattering on target surfaces with small atomic masses (Al, Si, Ni) has been performed for more accurate definition of mechanism of scattering and evaluation of an opportunity for use of heavy ions scattering as a tool of surface layer analysis. It is shown that the dependence of the relative energies of scattered ions versus the initial energy E/E{sub 0} (E{sub 0}) for Si (E{sub b}=4.64 eV/atom) and Ni (E{sub b}=4.43 eV/atom) approximately coincide despite the fact that the mass of Ni atom is twice as large as that of the Si atom mass. At the same time their binding energies E{sub b} are approximately equal to each other. It is found that the scattering angles of Cs{sup +} ions considerably exceed a limiting scattering angle {theta}{sub lim} in a single collision. It has been established that the scattering of low-energy heavy ions by light targets is described by a non-binary mechanism of many-particle interactions (simultaneous ion interaction with several target atoms). It has been shown that during the many-particle interactions the structure of energy spectra disappears; high relative energy of scattering ions and their dependence on energy of bombardment is observed. It has been found that the energy of scattered ions depends on binding energy, melting temperature and packing density of target atoms.

  17. Density-matrix-functional calculations for matter in strong magnetic fields: Ground states of heavy atoms

    DEFF Research Database (Denmark)

    Johnsen, Kristinn; Yngvason, Jakob

    1996-01-01

    We report on a numerical study of the density matrix functional introduced by Lieb, Solovej, and Yngvason for the investigation of heavy atoms in high magnetic fields. This functional describes exactly the quantum mechanical ground state of atoms and ions in the limit when the nuclear charge Z...... and the electron number N tend to infinity with N/Z fixed, and the magnetic field B tends to infinity in such a way that B/Z4/3→∞. We have calculated electronic density profiles and ground-state energies for values of the parameters that prevail on neutron star surfaces and compared them with results obtained...... by other methods. For iron at B=1012 G the ground-state energy differs by less than 2% from the Hartree-Fock value. We have also studied the maximal negative ionization of heavy atoms in this model at various field strengths. In contrast to Thomas-Fermi type theories atoms can bind excess negative charge...

  18. New semi-empirical formula for α-decay half-lives of the heavy and superheavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Manjunatha, H.C. [Government College for Women, Department of Physics, Kolar, Karnataka (India); Sridhar, K.N. [Government First Grade College, Department of Physics, Kolar, Karnataka (India)

    2017-07-15

    We have succesfully formulated the semi-empirical formula for α-decay half-lives of heavy and superheavy nuclei for different isotopes of the wide atomic-number range 94 < Z < 136. We have considered 2627 isotopes of heavy and superheavy nuclei for the fitting. The value produced by the present formula is compared with that of experiments and other eleven models, i.e. ImSahu, Sahu, Royer10, VS2, UNIV2, SemFIS2, WKB. Sahu16, Densov, VSS and Royer formula. This formula is exclusively for heavy and superheavy nuclei. α-decay is one of the dominant decay mode of superheavy nucleus. By identifying the α-decay mode superheavy nuclei can be detected. This formula helps in predicting the α-decay chains of superheavy nuclei. (orig.)

  19. Phosphorescence Tuning through Heavy Atom Placement in Unsymmetrical Difluoroboron β-Diketonate Materials.

    Science.gov (United States)

    Liu, Tiandong; Zhang, Guoqing; Evans, Ruffin E; Trindle, Carl O; Altun, Zikri; DeRosa, Christopher A; Wang, Fang; Zhuang, Meng; Fraser, Cassandra L

    2018-02-06

    Difluoroboron β-diketonates (BF 2 bdks) show both fluorescence (F) and room-temperature phosphorescence (RTP) when confined to a rigid matrix, such as poly(lactic acid). These materials have been utilized as optical oxygen sensors (e.g., in tumors, wounds, and cells). Spectral features include charge transfer (CT) from the major aromatic donor to the dioxaborine acceptor. A series of naphthyl-phenyl dyes (BF 2 nbm) (1-6) were prepared to test heavy-atom placement effects. The BF 2 nbm dye (1) was substituted with Br on naphthyl (2), phenyl (3), or both rings (4) to tailor the fluorescence/phosphorescence ratio and RTP lifetime-important features for designing O 2 sensing dyes by means of the heavy atom effect. Computational studies identify the naphthyl ring as the major donor. Thus, Br substitution on the naphthyl ring produced greater effects on the optical properties, such as increased RTP intensity and decreased RTP lifetime compared to phenyl substitution. However, for electron-donating piperidyl-phenyl dyes (5), the phenyl aromatic is the major donor. As a result, Br substitution on the naphthyl ring (6) did not alter the optical properties significantly. Experimental data and computational modeling show the importance of Br position. The S 1 and T 1 states are described by two singly occupied MOs (SOMOs). When both of these SOMOs have substantial amplitude on the heavy atom, passage from S 1 to T 1 and emission from T 1 to S 0 are both favored. This shortens the excited-state lifetimes and enhances phosphorescence. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Discrimination of solvent from protein regions in native Fouriers as a means of evaluating heavy-atom solutions in the MIR and MAD methods

    International Nuclear Information System (INIS)

    Terwilliger, Thomas C.; Berendzen, Joel

    1999-01-01

    The presence of distinct regions of high and low density variation in electron-density maps is found to be a good indicator of the correctness of a heavy-atom solution in the MIR and MAD methods. An automated examination of the native Fourier is tested as a means of evaluation of a heavy-atom solution in MAD and MIR methods for macromolecular crystallography. It is found that the presence of distinct regions of high and low density variation in electron-density maps is a good indicator of the correctness of a heavy-atom solution in the MIR and MAD methods. The method can be used to evaluate heavy-atom solutions during MAD and MIR structure solutions and to determine the handedness of the structure if anomalous data have been measured

  1. Tau electron atoms at RHIC

    International Nuclear Information System (INIS)

    Weiss, M.S.

    1985-01-01

    An amusement ancillary to the proposed quark-gluon plasma production hypothesized from a relativistic heavy ion collider (RHIC is a sufficient quantity of tau electrons to potentially admit the study of its exotic atoms. In this paper the given wealth of nuclear phenomena is derived from muonic atoms assume a tau atom is more forthcoming of information due to the lower orbits entirely contained within the nucleus. It is the purpose of this brief note to discuss the production mechanism at a RHIC and to delineate some of the more obvious properties of the tau atom. As in the case of the mu, more exotic phenomena derived from resonance ''accidents'' with nuclear transitions takes place, but it would be presumptions to discuss them at this time. Given the complete containment in nuclear matter of the tau lepton in its innermost atomic orbits. An experiment performed with such an exotic species results in the measurement of its lifetime

  2. Immunoglobulin-E reactivity to wine glycoproteins in heavy drinkers

    DEFF Research Database (Denmark)

    Gonzalez-Quintela, Arturo; Gomez-Rial, Jose; Valcarcel, Catalina

    2011-01-01

    and biological significance of IgE antibodies to N-glycans from wine glycoproteins in heavy drinkers. A structured questionnaire, skin prick tests, serum IgE levels, IgE-immunoblotting to wine extracts, and basophil activation tests were used to characterize 20 heavy drinkers and 10 control subjects. Eleven...... heavy drinkers (55%) showed IgE binding to proteins in wine extracts. The proteins were identified by mass spectrometry as grape-derived vacuolar invertase and thaumatin-like protein. Immunoblot reactivity was closely associated with the presence of IgE to CCDs and was inhibited by preincubation...... with a glycoconjugate containing bromelain-type N-glycans. The same conjugate, CCD-bearing allergens, and wine extracts activated basophils in patients with high-titer CCD-specific IgE but not in healthy controls. There was no relationship between immunoblot reactivity and consumption of any specific type of wine...

  3. Determination of heavy metals impurities in low and medium atomic weight matrices

    International Nuclear Information System (INIS)

    Paiano, Silvestre; Prado Souza, Rose M.G. do

    1997-01-01

    Heavy materials have a mass attenuation coefficient in the energy interval from 100 to 400 KeV substantially higher than those corresponding to light and medium atomic weight matrices. They also show, in the same energy range, a more pronounced energy variation of this parameter. In a few cases, this property can be used for the determination of the concentration of impurities constituted by heavy metals in a lighter matrix. An Ytterbium gamma-ray source, which has several energy peaks in the considered interval, is used to supply a number of energy pairs from which the density of impurities can be found without the use of reference materials. (author). 1 ref., 4 figs

  4. Spin-selective depopulation of triplet sublevels in rapidly rotating triplet exciplexes detected by a heavy-atom-induced magnetic field effect

    OpenAIRE

    Steiner, Ulrich

    1980-01-01

    A mechanism is presented explaining a reported heavy-atom-induced magnetic field effect as a consequence of non-equilibrium triplet sublevel population in an intermediate exciplex. The triplet exciplex spin polarization is induced by sub-level-selective intersystem crossing from the exciplex triplet to its singlet ground state and is decreased by an external magnetic field. The theory accounts almost quantitatively for the observed influence of magnetic field strength and heavy-atom substitue...

  5. External heavy atom effect on intersystem crossing reactions of aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Wojnarovits, L.; Foeldiak, G.

    1988-01-01

    The external heavy atom effect by xenon on the S 1 → T n and T 1 → S o transitions of naphthalene and pyrene was investigated in hydrocarbon solvents by fluorescence or absorption spectroscopy. The quencher forms a short-lived encounter complex (that may be called exciplex as well) with the excited molecules in equilibrium process. This exciplex formation in solutions with naphthalene leads to some deviation from the Stern-Volmer type concentration dependence of the quenching. (author)

  6. The influence of nuclear structure on the Lamb shift in hydrogenlike heavy atoms

    International Nuclear Information System (INIS)

    Beier, T.; Plunien, G.; Soff, G.

    1997-01-01

    We evaluate and list the various contributions to the Lamb shift in hydrogenlike heavy atoms which arise from parameters describing shape, size and structure of the nucleus. We compare these contributions with those obtained from quantum electrodynamics. It is found that in heavy nuclei, nuclear contributions depending on experimental parameters and nuclear models are of the same size as QED contributions of order a 2 . Therefore, in these systems the theoretical predictions for binding energies are limited by the exact knowledge of the nuclear parameters. In addition, we tabulate all corrections contributing to the 1s 1/2 Lamb shift in hydrogenlike Pb and U. (orig.)

  7. Enhanced Electromagnetic and Chemical/Biological Sensing. Properties of Atomic Cluster-Derived Materials

    National Research Council Canada - National Science Library

    Schatz, George

    2003-01-01

    The Center for Atomic Clusters-derived Materials performed a broad range of research concerned with synthesizing, characterizing and utilizing atomic and molecular clusters, nanoparticles and nanomaterial...

  8. Bibliography of atomic and molecular excitation in heavy particle collisions, 1950--1975

    International Nuclear Information System (INIS)

    Hawthorne, S.W.; Thomas, E.W.; Barnett, C.F.; Crandall, D.H.; Gilbody, H.B.; Kirkpatrick, M.I.; McDaniel, E.W.; Phaneuf, R.A.

    1979-02-01

    This annotated bibliography lists published work on atomic and molecular excitation in heavy particle collisions for the period 1950 to 1975. Sources include scientific journals, abstract compilations, conference proceedings, books, and reports. The bibliography is arranged alphabetically by author. Each entry indicates whether the work was experimental or theoretical, what energy range was covered, and what reactants were investigated. Following the bibliographical listing are indexes of reactions and authors

  9. On the trends of Fukui potential and hardness potential derivatives in isolated atoms vs. atoms in molecules.

    Science.gov (United States)

    Bhattacharjee, Rituparna; Roy, Ram Kinkar

    2014-10-28

    In the present study, trends of electronic contribution to molecular electrostatic potential [Vel(r¯)(r=0)], Fukui potential [v(+)f|(r=0) and v(-)f|(r=0)] and hardness potential derivatives [Δ(+)h(k) and Δ(-)h(k)] for isolated atoms as well as atoms in molecules are investigated. The generated numerical values of these three reactivity descriptors in these two electronically different situations are critically analyzed through the relevant formalism. Values of Vel(r¯) (when r → 0, i.e., on the nucleus) are higher for atoms in molecules than that of isolated atoms. In contrast, higher values of v(+)|(r=0) and v(-)|(r=0) are observed for isolated atoms compared to the values for atoms in a molecule. However, no such regular trend is observed for the Δ(+)h(k) and Δ(-)h(k) values, which is attributed to the uncertainty in the Fukui function values of atoms in molecules. The sum of Fukui potential and the sum of hardness potential derivatives in molecules are also critically analyzed, which shows the efficacy of orbital relaxation effects in quantifying the values of these parameters. The chemical consequence of the observed trends of these descriptors in interpreting electron delocalization, electronic relaxation and non-negativity of atomic Fukui function indices is also touched upon. Several commonly used molecules containing carbon as well as heteroatoms are chosen to make the investigation more insightful.

  10. Dose enhancement by synchrotron radiation and heavy atoms for the treatment of gliomas

    International Nuclear Information System (INIS)

    Bobyk, L.

    2010-11-01

    High grade gliomas are brain tumors of bad prognosis. The standard therapeutic treatment combines surgery, radiotherapy and sometimes use of temozolomide (chemotherapy agent). Healthy tissues radio-sensitivity is a major limitation for radiotherapy treatment. The stereotactic radiotherapy by synchrotron radiation is an innovative technique which combines a low energy radiation (lower 100 keV) with the presence of heavy atoms in the tumoral zone. Such an approach is used to increase the differential of dose deposited in the tumor compared to surrounding healthy tissues. In this study, several compounds containing heavy atoms such as chemotherapy agents: cisplatin/carbo-platin, a DNA base analog: 5-iodo-2'-deoxyuridine (IUdR) and gold nano-particles were considered. The dose enhancement factor induced by the presence of these compounds located for some of them in the extracellular medium or inside the cells for others, was determined using in vitro studies. Thereafter, in vivo studies on rats bearing gliomas, were performed to study the toxicity, the kinetic of distribution and the localization of these compounds together with their potential efficacy of treatment combining intracerebral injection with low energy radiation. (author)

  11. Probability of K atomic shell ionization by heavy particles impact, in functions of the scattering angle

    International Nuclear Information System (INIS)

    Oliveira, P.M.C. de.

    1976-12-01

    A method of calculation of the K atomic shell ionization probability by heavy particles impact, in the semi-classical approximation is presented. In this approximation, the projectile has a classical trajectory. The potential energy due to the projectile is taken as perturbation of the Hamiltonian of the neutral atom. We use scaled Thomas-Fermi wave function for the atomic electrons. The method is valid for intermediate atomic number elements and particle energies of some MeV. Probabilities are calculated for the case of Ag (Z = 47) and protons of 1 and 2 MeV. Results are given as function of scattering angle, and agree well known experimental data and also improve older calculations. (Author) [pt

  12. Atomic nuclei decay modes by spontaneous emission of heavy ions

    International Nuclear Information System (INIS)

    Poenaru, D.N.; Ivascu, M.; Sandulescu, A.

    1984-01-01

    The great majority of the known nuclei, including the so-called stable nuclides, are in fact metastable with respect to several modes of spontaneous superasymmetric splitting. If the lifetime against these processes is larger than 10 30 s, the phenomenon is not detectable with available experimental techniques, hence one can admit stability from the practical point of view. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relatively to the alpha decay for these natural radioactivities. From a huge amount of systematical calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained for parent nuclei - heavy clusters leading to a magic ( 208 Pb) or almost daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-life n the 10 10 -10 30 s range. The shell structure and pairing effects are clearly manifested in these new decay modes

  13. The projects for heavy water production of the Argentine National Atomic Energy Commission

    International Nuclear Information System (INIS)

    Garcia Bourg, J.M.; Garcia, E.E.

    1982-01-01

    The bases and scope of the projects for heavy water production that are being currently developed by the Argentine National Atomic Energy Commission (CNEA) are described. As an introduction, the following points are presented: a) the fundamentals of heavy water utilization in a nuclear reactor, with a mention of its properties and uses, b) a review of the physicochemical bases of the principal methods for heavy water production: chemical exchange (monothermal and bithermal processes), distillation and electrolysis, with tables summarizing the fundamental characteristics of the first two ones, and an evaluation of the different production methods from the viewpoint of their application in an industrial scale; and c) a synthetic information, in the form of tables, about the world's heavy water production. The subject of heavy water production in Argentina is treated in the principal section, describing the scope, location, main characteristics and chemical processes corresponding to the projects being developed by CNEA, which currently are the installation of an Industrial Plant in Arroyito (Province of Neuquen), purchased on a turnkey basis and using the NH 3 /H 2 isotopic exchange method; the installation of an Experimental Plant in Atucha (Province of Buenos Aires), for the development of the domestic technology of heavy-water production by the SH 2 /H 2 O isotopic exchange method, and the development of the engineering of an industrial plant (''Module 80''), based on the Experimental Plant's technology. (M.E.L.) [es

  14. New experiments on few-electron very heavy atoms

    International Nuclear Information System (INIS)

    Gould, H.

    1985-07-01

    New experiments, to test quantum electrodynamics (QED) in strong Coulomb fields and to study atomic collisions at ultrarelativistic energies, are proposed. A 0.1% measurement of the 2 2 P/sub 1/2/-2 2 S/sub 1/2/ splitting in lithium like uranium (Z=92) and the 2 3 P 0 - 2 3 S 1 splitting in heliumlike uranium is proposed as a sub 1% test of the Lamb shift in a strong Coulomb field. Measurements of the hyperfine splitting of hydrogenlike thallium (Z=81) and the g/sub j/ factor of the ground state of hydrogenlike uranium are propsed as a test of the QED contribution to the magnetic moment of an electron bound in a strong Coulomb field. Measurements of capture cross sections for ultra relativistic very heavy nuclei are proposed to look for the capture of electrons from pair production. 40 refs., 7 figs., 2 tabs

  15. Heavy Water - Industrial Separation Processes

    International Nuclear Information System (INIS)

    Peculea, M.

    1984-01-01

    This monograph devoted to the heavy water production mainly presents the Romanian experience in the field which started in early sixties from the laboratory scale production and reached now the level of large scale industrial production at ROMAG-Drobeta, Romania. The book is structured in eleven chapters entitled: Overview, The main physical properties, Sources, Uses, Separation factor and equilibrium constant, Mathematical modelling of the separation process, Thermodynamical considerations on the isotope separation, Selection criteria for heavy water separation processes, Industrial installations for heavy water production, Prospects, Acknowledgements. 200 Figs., 90 Tabs., 135 Refs

  16. Report on the workshop on atomic and plasma physics requirements for heavy ion fusion, Argonne National Lab., December 13-14, 1979

    International Nuclear Information System (INIS)

    Kin, Y.K.; Magelssen, G.

    1979-01-01

    Atomic, molecular, and plasma physics areas that are relevant to inertial confinement fusion by energetic heavy ions are identified. Discussions are confined to problems related to the design of heavy ion accelerators, accumulation of ions in storage rings, and the beam transport in a reactor vessel

  17. Functionalizing carbon nitride with heavy atom-free spin converters for enhanced 1 O 2 generation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenting; Han, Congcong; Zhang, Qinhua; Zhang, Qinggang; Li, Zhongtao; Gosztola, David J.; Wiederrecht, Gary P.; Wu, Mingbo

    2018-05-01

    advanced photosensitizers for singlet oxygen (1O2) generation. However, the intersystem crossing (ISC) process is quite insufficient in carbon nitride, limiting the 1O2 generation. Here, we report a facile and general strategy to confined benzophenone as a heavy atom-free spin converter dopant in carbon nitride via the facile copolymerization. With proper energy level matching between the heavy atom-free spin converter and various ligands based on carbon nitride precursors, the proper combination can decrease the singlet-triplet energy gap (DEST) and hence generate 1O2 effectively. Due to its significant and selectivity for 1O2 generation, the as-prepared carbon nitride-based photosensitizer shows a high selective photooxidation activity for 1,5-dihydroxy-naphthalene (1,5-DHN). The product yield reached 71.8% after irradiation for 60 min, which was higher than that of cyclometalated PtII complexes (53.6%) in homogeneous photooxidation. This study can broaden the application of carbon nitride in the field of selective heterogeneous photooxidation due to simple operation, low cost, and high efficiency, making it a strong candidate for future industrialization.

  18. Waste Derived Sorbents and Their Potential Roles in Heavy Metal Remediation Applications

    Directory of Open Access Journals (Sweden)

    Chiang Y. W.

    2013-04-01

    Full Text Available Inorganic waste materials that have the suitable inherent characteristics could be used as precursors for the synthesis of micro- and mesoporous materials, which present great potential to be re-utilized as sorbent materials for heavy metal remediation. Three inorganic waste materials were studied in the present work: water treatment residuals (WTRs from an integrated drinking water/wastewater treatment plant, and fly ash and bottom ash samples from a municipal solid waste incinerator (MSWI. These wastes were converted into three sorbent materials: ferrihydrite-like materials derived from drying of WTRs, hydroxyapatite-like material derived from ultrasound assisted synthesis of MSWI fly ash with phosphoric acid solution, and a zeolitic material derived from alkaline hydrothermal conversion of MSWI bottom ash. The performance of these materials, as well as their equivalent commercially available counterparts, was assessed for the adsorption of multiple heavy metals (As, Cd, Co, Ni, Pb, Zn from synthetic solutions, contaminated sediments and surface waters; and satisfactory results were obtained. In addition, it was observed that the combination of sorbents into sorbent mixtures enhanced the performance levels and, where applicable, stabilized inherently mobile contaminants from the waste derived sorbents.

  19. K-Vacancy Production in the Collision of Highly Charged Relativistic Ions With Heavy Atoms

    OpenAIRE

    KHABIBULLAEV, P. K.

    2014-01-01

    A general expression for the cross section of the inelastic collision of relativistic highly charged ion with heavy (relativistic) atoms is obtained using the generalized eikonal approximation. In the ultrarelativistic limit, the obtained formula coincides with a known exact one. As an application of the obtained result, probability and cross section of the K-vacany production in the U92+ - U91+ collision are calculated.

  20. δ-electron spectroscopy and the atomic clock effect in heavy-ion collisions

    International Nuclear Information System (INIS)

    Mueller-Nehler, U.

    1993-11-01

    The properties of strongly bound electrons in superheavy quasimolecular systems with combined nuclear charge numbers Z = Z P + Z T ≥ 110 are investigated. The emission of δ-electrons may serve as an atomic clock for nuclear reactions which is associated with the large overlap of the electron probability density with the nuclear interior. Excitation and emission rates of inner-shell electrons in collisions of very heavy ions with beam energies at or above the nuclear Coulomb barrier depend explicitly on details of the nuclear dynamics. Theoretical and experimental results are reviewed. (orig.)

  1. Estimation of atomic masses of heavy and superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Masahiro [Ministry of Education, Science and Culture, Tokyo (Japan)

    1997-07-01

    To estimate unknown atomic masses of heavy and superheavy elements, three kinds of formula: FRDM (finite range droplet model by Moeller et al.), TUYY (an empirical formula by Tachibana et al.) and our KUTY are explained. KUTY estimates the crude shell energies of spherical nucleus from sum of single-particle energies. Then, the refined shell energies in due consideration of paring and deformation are obtained by mixing with the functions of the crude shell energies. Experimental values of U and Fm isotopes were compared with estimation mass of KUTY and FRDM. In the field with experimental values of U isotopes, the value of KUTY and FRDM separated the same difference from the experimental value. The behavior of KUTY and FRDM for Fm isotopes were same as that of U, but ETFSI deviated a little from the experimental values. (S.Y.)

  2. Heavy metal stabilization in contaminated road-derived sediments.

    Science.gov (United States)

    Rijkenberg, Micha J A; Depree, Craig V

    2010-02-01

    There is increasing interest in the stabilization of heavy metals in road-derived sediments (RDS), to enable environmentally responsible reuse applications and circumvent the need for costly landfill disposal. To reduce the mobility of heavy metals (i.e. Cu, Pb and Zn) the effectiveness of amendments using phosphate, compost and fly ash addition were investigated using batch leaching experiments. In general, phosphate amendments of RDS were found to be ineffective at stabilizing heavy metals, despite being used successfully in soils. Phosphate amendment resulted in enhanced concentrations of dissolved organic carbon (DOC), which increased the solubilisation of heavy metals via complexation. Amendment with humified organic matter (compost) successfully stabilized Cu and Pb in high DOC leaching RDS with an optimum loading of 15-20% (w/w). Compost, however, was ineffective at stabilizing Zn. Increasing the pH by amending RDS/compost blends with 2.5-15% (w/w) coal fly ash resulted in the stabilization of Zn, Cu and Pb. However, above a pH of approximately 7.5 and 8 enhanced leaching of organic matter resulted in an increase in leached Cu and Pb, respectively. Accordingly, the optimum level of fly ash amendment for the RDS/compost blends was estimated to be ca. 10%. Boosted regression trees analysis (BRT) of the data revealed that DOC accounted for 56% and 65% of the Cu and Pb leaching, respectively, whereas pH only accounted for ca. 18% of Cu and Pb leaching. RDS sample characteristics (i.e. metal concentrations, size fractionation and organic matter content) were more important at reconciling the leaching concentrations of copper Cu (27%) than Pb (16%). The most important parameter explaining Zn leaching was pH. Overall, the choice of a suitable stabilization agent/s depends on the composition of RDS with respect to the amount of organic matter present, and the sorption chemistry of the heavy metal of interest. Copyright 2009 Elsevier B.V. All rights reserved.

  3. Multielement preconcentration of trace heavy metals in seawater with an emulsion containing 8-quinolinol for graphite-furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Matsumiya, Hiroaki; Kageyama, Tomohiro; Hiraide, Masataka

    2004-01-01

    A water-in-oil type emulsion containing 8-quinolinol has been used for the concentration of traces of heavy metals from seawater prior to their determinations by graphite-furnace atomic absorption spectrometry. The emulsion used was prepared by dissolving 40 mg of 8-quinolinol and 60 mg of sorbitan monooleate (Span-80) in 3.0 ml of toluene and vigorously mixing with 0.70 ml of aqueous hydrochloric acid solution (1.5 mol l -1 ) by ultrasonic irradiation. The resulting emulsion was gradually injected into 100 ml of sample solution (pH 8.5) and dispersed by stirring as numerous tiny globules. Four heavy metals (Co, Ni, Cu, and Cd) in the sample solution were quantitatively transported through the organic layer into the acidic aqueous droplets encapsulated in the emulsion. After collecting the dispersed emulsion globules, they were demulsified by heating and the heavy metals in the segregated aqueous phase were determined by atomic absorption spectrometry. Owing to the highly efficient concentration (100-fold), these heavy metals at sub-ng ml -1 levels in seawater were determined with satisfactory accuracy and precision, being confirmed with certified reference samples

  4. New small molecule inhibitors of histone methyl transferase DOT1L with a nitrile as a non-traditional replacement for heavy halogen atoms.

    Science.gov (United States)

    Spurr, Sophie S; Bayle, Elliott D; Yu, Wenyu; Li, Fengling; Tempel, Wolfram; Vedadi, Masoud; Schapira, Matthieu; Fish, Paul V

    2016-09-15

    A number of new nucleoside derivatives are disclosed as inhibitors of DOT1L activity. SARs established that DOT1L inhibition could be achieved through incorporation of polar groups and small heterocycles at the 5-position (5, 6, 12) or by the application of alternative nitrogenous bases (18). Based on these results, CN-SAH (19) was identified as a potent and selective inhibitor of DOT1L activity where the polar 5-nitrile group was shown by crystallography to bind in the hydrophobic pocket of DOT1L. In addition, we show that a polar nitrile group can be used as a non-traditional replacement for heavy halogen atoms. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Identification of Heavy Metal Pollution Derived From Traffic in Roadside Soil Using Magnetic Susceptibility.

    Science.gov (United States)

    Yang, Pingguo; Ge, Jing; Yang, Miao

    2017-06-01

    The study integrates surface and vertical distribution of magnetic susceptibility and heavy metal contents (Pb, Cu, Zn and Fe) to characterize the signature of vehicle pollutants in roadside soils at Linfen city, China. Sites with reforestation and without vegetation cover were investigated. The results showed that magnetic susceptibility and heavy metal contents were higher at the roadside without trees than in the reforest belt. The variations of magnetic susceptibility and heavy metal contents decreased both with distance and with depth. The maximum value was observed at 5-10 m away from the roadside edge. The vertical distribution in soil revealed accumulation of pollutants in 0-5 cm topsoils. The average contents were higher than the background values and in the order Fe (107.21 g kg -1 ), Zn (99.72 mg kg -1 ), Pb (90.99 mg kg -1 ), Cu (36.14 mg kg -1 ). Coarse multi domain grains were identified as the dominating magnetic particles. Multivariate statistical and SEM/EDX analyses suggested that the heavy metals derived from traffic sources. Trees act as efficient receptors and green barrier, which can reduce vehicle derived pollution.

  6. The use of dialdehyde starch derivatives in the phytoremediation of soils contaminated with heavy metals.

    Science.gov (United States)

    Antonkiewicz, Jacek; Para, Andrzej

    2016-01-01

    Products of the reaction between dialdehyde starch and Y-NH2 compounds (e.g. semicarbazide or hydrazine) are effective ligands for metal ions. The usefulness of these derivatives was tested in the experiment, both in terms of the immobilization of heavy metal ions in soil and the potential application in phytoextraction processes. The experimental model comprised maize and the ions of such metals as: Zn(II), Pb(II), Cu(II), Cd(II), and Ni(II). The amount of maize yield, as well as heavy metal content and uptake by the aboveground parts and roots of maize, were studied during a three-year pot experiment. The results of the study indicate the significant impact of heavy metals on reduced yield and increased heavy metal content in maize. Soil-applied dialdehyde starch derivatives resulted in lower yields, particularly disemicarbazone (DASS), but in heavy metal-contaminated soils they largely limited the negative impact of these metals both on yielding and heavy metal content in plants, particularly dihydrazone (DASH). It was demonstrated that the application of dihydrazone (DASH) to a soil polluted with heavy metals boosted the uptake of Zn, Pb, Cu, and Cd from the soil, hence there is a possibility to use this compound in the phytoextraction of these metals from the soil. Decreased Ni uptake was also determined, hence the possibility of using this compound in the immobilization of this metal. The study showed that dialdehyde starch disemicarbazone was ineffective in the discussed processes.

  7. Study of heavy metals in the grass-milk product chain by means of neutron activation and atomic absorption

    Energy Technology Data Exchange (ETDEWEB)

    Bruant, C; Bruant, J P; Neuburger, M; Vassal, L; Disant, C; Bittel, R; Fourcy, A

    1974-12-31

    with the heavy metals Hg, Cu, Zn, Pb, and Cd is studied. The first three metals were determined by neutron activation and tae last two by atomic absorption spectrophotometry. The chemical rature of these metals and their biological effect leads to different results from those obtained for tae principal fission products. As a rule the heavy metal concentrations at harvest are much lower than taat of the foods ingested by lactating cows. The cow plays the role of filter. If the concentration of these elements is considered in mu g/g of fresh material there is a reconcentration of these heavy metals in cream and cheese, probably cornected with their physico-chemical affinity for proteins. (JSR)

  8. Atomic inner-shell physics

    International Nuclear Information System (INIS)

    Crasemann, B.

    1985-01-01

    This book discusses: relativistic and quantum electrodynamic effects on atomic inner shells; relativistic calculation of atomic transition probabilities; many-body effects in energetic atomic transitions; Auger Electron spectrometry of core levels of atoms; experimental evaluation of inner-vacancy level energies for comparison with theory; mechanisms for energy shifts of atomic K-X rays; atomic physics research with synchrotron radiation; investigations of inner-shell states by the electron energy-loss technique at high resolution; coherence effects in electron emission by atoms; inelastic X-ray scattering including resonance phenomena; Rayleigh scattering: elastic photon scattering by bound electrons; electron-atom bremsstrahlung; X-ray and bremsstrahlung production in nuclear reactions; positron production in heavy-ion collisions, and X-ray processes in heavy-ion collisions

  9. Atomic collision studies at moderate projectile velocities using highly charged, decelerated heavy ions from the GSI-UNILAC

    International Nuclear Information System (INIS)

    Mokler, P.H.; Hoffmann, D.H.H.; Schoenfeldt, W.A.; Maor, D.

    1984-01-01

    Beams of highly ionized, very heavy atoms at moderate velocities have been produced at the UNILAC using the acceleration-stripping-deceleration method. The available ion species range from Kr 33+ to U 66+ in the energy region between 2 and 5 MeV/u. A survey on first experiments at GSI using these moderate velocity, few electron, heavy ion beams is given. The effectiveness of the method is demonstrated for Xesup(q+)-Xe collision experiments with 41 <= q <= 45. Results on vacancy transfer between inner quasimolecular levels for close collisions, and on distant collision electron capture are reported. (orig.)

  10. Collective processes in heavy-ion collisions with atomic nuclei. Dissipation of energy and angular momentum

    International Nuclear Information System (INIS)

    Kuzminski, J.

    1980-01-01

    The collective processes in collision of heavy-ions with atomic nuclei are discussed. Measured data on the S+Ti collision at Esub(LAB)=105, 130 and 144 MeV have been analysed in terms of a ''fission-like'' processes which seem to be a special case of deep inelastic collisions whose total available kinetic energy is completely dissipated. Applying transport theory it was possible to introduce a ''clock'' for measuring the time scale of nuclear processes in collision of heavy-ions by measuring the FWHM of mass distribution of emitted reaction products. Experimental data on continuum gamma spectra from Cu+Au collision at Esub(LAB)=400 MeV are presented and the angular momentum dissipation in this reaction is discussed. (author)

  11. Direct determination of arsenic in petroleum derivatives by graphite furnace atomic absorption spectrometry: A comparison between filter and platform atomizers

    OpenAIRE

    Becker, Emilene M.; Rampazzo, Roger T.; Dessuy, Morgana B.; Vale, Maria Goreti R.; Silva, Márcia M. da; Welz, Bernhard; Katskov, Dmitri A.

    2011-01-01

    Acesso restrito: Texto completo. In the present work a direct method for the determination of arsenic in petroleum derivatives has been developed, comparing the performance of a commercial transversely heated platform atomizer (THPA) with that of a transversely heated filter atomizer (THFA). The THFA results in a reduction of background absorption and an improved sensitivity as has been reported earlier for this atomizer. The mixture of 0.1% (m/v) Pd+0.03% (m/v) Mg+0.05% (v/v) Triton X-...

  12. Investigation of the intermediate LK molecular orbital radiation in heavy ion-atom collisions

    International Nuclear Information System (INIS)

    Frank, W.; Kaun, K.-H.; Manfrass, P.

    1981-01-01

    The continuum consisting of an intensive low-energy and a high-energy components in heavy-ion atom collision systems with atomic numbers Z 1 , Z 2 > 28 is studied. The aim of the study is to prove that the C1 continuum cannot be caused by ridiative electron capture (REC) being molecular orbital (MO) radiation to the 2ptau level. It is shown that the comparison of the C1 yields obtained in Kr+Nb asymmetric collisions in gas and solid targets is associated with the formation of vacancies in the lower-Z collision partner and can be interpreted as quasimolecular radiation to the 2ptau orbital level. The strong suppression of the C2 component in the gas target experimets indicates that the MO radiation to the 1stau orbit is emitted preferentially in the two-collision process in symmetric and near-symmetric systems with Z 1 , Z 2 [ru

  13. Progress Report. Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, Department of Heavy Ion Physics. 1992-1993

    International Nuclear Information System (INIS)

    Grama, C.; Ionescu-Bujor, M.; Poenaru, D.; Pop, A.

    1994-01-01

    A brief account of the research and development activities carried out in the Department of Heavy Ion Physics, Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, Bucharest, during the period January 1992 to December 1993 is presented. The main topics concern nuclear structure models and methods, heavy-ion-induced reactions, and general properties of nuclei and nuclear energy levels. Also, works dealing with particle detection, measuring instruments and methods are reported. The report contains two sections. The first covers the research in progress in the fields of nuclear structure, nuclear reactions, atomic physics, accelerator, instrumentation, methods and computer codes. The second one, the appendix, contains the list of publications of the Department staff in journals and proceedings, books, and preprints, the conference contributions, the academic degrees awarded, the scientific exchanges, and the list of scientific personnel

  14. Low-energy heavy-atom impact as a tool for production and classification of doubly excited states

    International Nuclear Information System (INIS)

    Andersen, N.

    1985-01-01

    Low-energy heavy-atom impact may be an efficient way of preferentially populating doubly excited levels. Using neon as an example, this paper discusses why this is so. The similarity of the structure of the energy level diagrams for doubly excited neon and the level scheme for neutral magnesium is pointed out, suggesting that collective quantum numbers may describe the electron pair. (orig.)

  15. Monte Carlo simulation of heavy ion induced kinetic electron emission from an Al surface

    CERN Document Server

    Ohya, K

    2002-01-01

    A Monte Carlo simulation is performed in order to study heavy ion induced kinetic electron emission from an Al surface. In the simulation, excitation of conduction band electrons by the projectile ion and recoiling target atoms is treated on the basis of the partial wave expansion method, and the cascade multiplication process of the excited electrons is simulated as well as collision cascade of the recoiling target atoms. Experimental electron yields near conventional threshold energies of heavy ions are simulated by an assumption of a lowering in the apparent surface barrier for the electrons. The present calculation derives components for electron excitations by the projectile ion, the recoiling target atoms and the electron cascades, from the calculated total electron yield. The component from the recoiling target atoms increases with increasing projectile mass, whereas the component from the electron cascade decreases. Although the components from the projectile ion and the electron cascade increase with...

  16. The energy-deposition model. Electron loss of heavy ions in collisions with neutral atoms at low and intermediate energies

    International Nuclear Information System (INIS)

    Shevelko, V.P.; Litsarev, M.S.; Kato, D.; Tawara, H.

    2010-09-01

    Single- and multiple-electron loss processes in collisions of heavy many-electron ions (positive and negative) in collisions with neutral atoms at low and intermediate energies are considered using the energy-deposition model. The DEPOSIT computer code, created earlier to calculate electron-loss cross sections at high projectile energies, is extended for low and intermediate energies. A description of a new version of DEPOSIT code is given, and the limits of validity for collision velocity in the model are discussed. Calculated electron-loss cross sections for heavy ions and atoms (N + , Ar + , Xe + , U + , U 28+ , W, W + , Ge - , Au - ), colliding with neutral atoms (He, Ne, Ar, W) are compared with available experimental and theoretical data at energies E > 10 keV/u. It is found that in most cases the agreement between experimental data and the present model is within a factor of 2. Combining results obtained by the DEPOSIT code at low and intermediate energies with those by the LOSS-R code at high energies (relativistic Born approximation), recommended electron-loss cross sections in a wide range of collision energy are presented. (author)

  17. Quasi-atoms

    International Nuclear Information System (INIS)

    Armbruster, P.

    1976-01-01

    The concept of a quasi-atom is discussed, and several experiments are described in which molecular or quasi-atomic transitions have been observed. X-ray spectra are shown for these experiments in which heavy ion projectiles were incident on various targets and the resultant combined system behaved as a quasi-atom. This rapidly developing field has already given new insight into atomic collision phenomena. (P.J.S.)

  18. Experimental atomic physics

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The experimental atomic physics program within the physics division is carried out by two groups, whose reports are given in this section. Work of the accelerator atomic physics group is centered around the 6.5-MV EN tandem accelerator; consequently, most of its research is concerned with atomic processes occurring to, or initiated by, few MeV/amu heavy ions. Other activities of this group include higher energy experiments at the Holifield Heavy Ion Research Facility (HHIRF), studies of electron and positron channeling radiation, and collaborative experiments at other institutions. The second experimental group concerns itself with lower energy atomic collision physics in support of the Fusion Energy Program. During the past year, the new Electron Cyclotron Resonance Source has been completed and some of the first data from this facility is presented. In addition to these two activities in experimental atomic physics, other chapters of this report describe progress in theoretical atomic physics, experimental plasma diagnostic development, and atomic data center compilation activities

  19. Fast atom bombardment mass spectrometry of condensed tannin sulfonate derivatives

    Science.gov (United States)

    J.J. Karchesy; L.Y. Foo; Richard W. Hemingway; E. Barofsky; D.F. Barofsky

    1989-01-01

    Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of...

  20. Fast calculator for X-ray emission due to Radiative Recombination and Radiative Electron Capture in relativistic heavy-ion atom collisions

    Science.gov (United States)

    Herdrich, M. O.; Weber, G.; Gumberidze, A.; Wu, Z. W.; Stöhlker, Th.

    2017-10-01

    In experiments with highly charged, fast heavy ions the Radiative Recombination (RR) and Radiative Electron Capture (REC) processes have significant cross sections in an energy range of up to a few GeV / u . They are some of the most important charge changing processes in collisions of heavy ions with atoms and electrons, leading to the emission of a photon along with the formation of the ground and excited atomic states. Hence, for the understanding and planning of experiments, in particular for X-ray spectroscopy studies, at accelerator ring facilities, such as FAIR, it is crucial to have a good knowledge of these cross sections and the associated radiation characteristics. In the frame of this work a fast calculator, named RECAL, for the RR and REC process is presented and its capabilities are demonstrated with the analysis of a recently conducted experiment at the Experimental Storage Ring (ESR) at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany. A method is presented to determine unknown X-ray emission cross sections via normalization of the recorded spectra to REC cross sections calculated by RECAL.

  1. Control of triplet state generation in heavy atom-free BODIPY-anthracene dyads by media polarity and structural factors

    KAUST Repository

    Filatov, Mikhail A.

    2018-02-12

    A family of heavy atom-free BODIPY-anthracene dyads (BADs) exhibiting triplet excited state formation from charge-transfer states is reported. Four types of BODIPY scaffolds, different in the alkyl substitution pattern, and four anthracene derivatives have been used to access BADs. The fluorescence and intersystem crossing (ISC) in these dyads depend on donor-acceptor couplings and can be accurately controlled by the substitution or media polarity. Under conditions that do not allow charge transfer (CT), the dyads exhibit fluorescence with high quantum yields. Formation of charge-transfer states triggers ISC and the formation of long-lived triplet excited states in the dyads. The excited state properties were studied by steady-state techniques and ultrafast pump-probe spectroscopy to determine the parameters of the observed processes. Structural information for various BADs was derived from single crystal X-ray structure determinations alongside DFT molecular geometry optimization, revealing the effects of mutual orientation of subunits on the photophysical properties. The calculations showed that alkyl substituents on the BODIPY destabilize CT states in the dyads, thus controlling the charge transfer between the subunits. The effect of the dyad structure on the ISC efficiency was considered at M06-2X level of theory and a correlation between mutual orientation of the subunits and the energy gap between singlet and triplet CT states was studied using multireference CASSCF method.

  2. Control of triplet state generation in heavy atom-free BODIPY-anthracene dyads by media polarity and structural factors

    KAUST Repository

    Filatov, Mikhail A.; Karuthedath, Safakath; Polestshuk, Pavel M; Callaghan, Susan; Flanagan, Keith; Telitchko, Maxime; Wiesner, Thomas; Laquai, Fré dé ric; Senge, Mathias O

    2018-01-01

    A family of heavy atom-free BODIPY-anthracene dyads (BADs) exhibiting triplet excited state formation from charge-transfer states is reported. Four types of BODIPY scaffolds, different in the alkyl substitution pattern, and four anthracene derivatives have been used to access BADs. The fluorescence and intersystem crossing (ISC) in these dyads depend on donor-acceptor couplings and can be accurately controlled by the substitution or media polarity. Under conditions that do not allow charge transfer (CT), the dyads exhibit fluorescence with high quantum yields. Formation of charge-transfer states triggers ISC and the formation of long-lived triplet excited states in the dyads. The excited state properties were studied by steady-state techniques and ultrafast pump-probe spectroscopy to determine the parameters of the observed processes. Structural information for various BADs was derived from single crystal X-ray structure determinations alongside DFT molecular geometry optimization, revealing the effects of mutual orientation of subunits on the photophysical properties. The calculations showed that alkyl substituents on the BODIPY destabilize CT states in the dyads, thus controlling the charge transfer between the subunits. The effect of the dyad structure on the ISC efficiency was considered at M06-2X level of theory and a correlation between mutual orientation of the subunits and the energy gap between singlet and triplet CT states was studied using multireference CASSCF method.

  3. HISTRAP [Heavy Ion Storage Ring for Atomic Physics] vacuum test stand for pressures of 10-12 Torr

    International Nuclear Information System (INIS)

    Johnson, J.W.; Atkins, W.H.; Dowling, D.T.; McConnell, J.W.; Milner, W.T.; Olsen, D.K.

    1988-01-01

    HISTRAP, Heavy Ion Storage Ring for Atomic Physics, is a proposed synchrotron/cooler/storage ring accelerator optimized for advanced atomic physics research. The ring has a circumference of 46.8 m, a bore diameter of about 15 cm, and requires a vacuum of 10 -12 Torr in order to decelerate highly-charged very-heavy ions down to low energies. To be able to test components and procedures to achieve this pressure, a test stand approximately modeling one-sixteenth of the ring vacuum chamber has been built. The 3.5-m-long test stand has been fabricated from 10-cm-diameter components, with 316LN stainless steel flanges. Prior to assembly, these components were vacuum fired at 950/degree/C at a pressure of 10 -4 Torr. The test stand is bakeable in situ at 300/degree/C. Pumping is achieved with two 750-L/s titanium sublimator pumps and one 60-L/s ion pump. Pressure is measured with two extractor ion gauges and a 10 -14 PP RGA. The roughing for the test stand consists of cryosorption pumps followed by a cryopump. A pressure of 4 x 10 -12 Torr has been achieved. 7 refs., 5 figs

  4. Atomic data for heavy element impurities in fusion reactors. Summary report of first IAEA research co-ordination meeting

    International Nuclear Information System (INIS)

    Clark, R.E.H.

    2006-01-01

    Twelve international experts discussed in detail the properties of heavy elements relevant to fusion energy research participated at the first Research Coordination Meeting (RCM) of the Coordinated Research Project (CRP) on 'Atomic data for heavy element impurities in fusion reactors' at IAEA Headquarters on 14-15 November 2005. The participants summarized all recent relevant developments in their research efforts. Detailed discussions took place to formulate specific objectives for the CRP. From a list of data needs and a review of current research capabilities, a detailed work plan was formulated for the first phase of the CRP. The discussions, conclusions and recommendations of the RCM are briefly described in this report. (author)

  5. Study of inter sub-shell and inter shell electron correlations in 4d open-shell heavy atomic ions

    International Nuclear Information System (INIS)

    Koike, Fumihiro

    2009-01-01

    The effect of correlations between 4p, 4d, and 4f has been studied extensively. The characteristic spectral structures of 4p - 4d and 4d - 4f optical transitions, due to the unique structures of N = 4 open sub-shells in heavy atomic ions, have been studied theoretically. To gain an insight of this effect, a series of careful MCDF calculations for 4d q (q = 0 to 10) atomic ions with atomic numbers Z = 48 to 56 has been carried out. The difference of orbital energy differences between 4p and 4d orbitals and 4d and 4f orbitals coincidently falls within the range of a few % for almost all the atomic ions investigated. The 4p 6 4d4f and 4p 5 4d 3 configurations may mix strongly, and the optical 4p - 4d and 4d - 4f transitions may take place coherently, providing us with quite a peculiar EUV emission spectrum. The effect of spectral narrowing and shift is expected to be quite common to the atomic specieds with the atomic numbers in the range Z = 48 to 56.

  6. Cascade Processes in Muonic Hydrogen Atoms

    International Nuclear Information System (INIS)

    Faifman, M. P.; Men'Shikov, L. I.

    2001-01-01

    The QCMC scheme created earlier for cascade calculations in heavy hadronic atoms of hydrogen isotopes has been modified and applied to the study of cascade processes in the μp muonic hydrogen atoms. The distribution of μp atoms over kinetic energies has been obtained and the yields of K-series X-rays per one stopped muon have been calculated.Comparison with experimental data indicated directly that for muonic and pionic atoms new types of non-radiative transitions are essential, while they are negligible for heavy (kaonic, antiprotonic, etc.) atoms. These processes have been considered and their probabilities have been estimated.

  7. Effect of organic solvents on desorption and atomic absorption determination of heavy metal ions after ion exchange concentration

    International Nuclear Information System (INIS)

    Pilipenko, A.T.; Safronova, V.G.; Zakrevskaya, L.V.

    1986-01-01

    The effect of organic solvents (acetone, methylethylketone, dioxane, ethanol) on desorption of Cu, Mn, Co, Cd, Zn, Pb, Ni from cationite KU-23 ion exchange resin and on the detection limits of their atomic absorption determination has been examined. Cobalt and cadmium can be separated quantitatively using desorption by a mixture of HCl and acetone. Addition of an organic solvent results in a higher absorbance, mainly due to a high rate and efficiency of atomization. Acetone has proved to be the best solvent: addition of 60 vol. % of this solvent to the concentrate provides 2 times lower detection limits for the heavy metas in water

  8. Standardization of digestion procedure for the determination of heavy metals in biological materials by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Khalid, N.; Chaudhri, S.A.

    1999-01-01

    Proper decomposition of the sample is one of the basic requirements of the atomic absorption spectroscopic analysis. In the present studies, heavy metals (Cu, Fe, Mn and Zn) were determined in biological samples by designating them in a mixture of nitric acid and perchloric acid. The quantification was made with atomic absorption spectrometry using an air-acetylene flame. The reliability of the procedure used was checked by analysing standard reference materials from NBS and IAEA, such as Rice flour (NBS-SRM-1568), Horse Kidney (IAEA H-8), Mixed Human diet(IAEA H-9), Copepod (IAEA MA-A-1) and fish flesh (IAEA MA-A-2) under identical conditions. A good agreement was observed between determined and the certified values reported by NBS and IAEA. (author)

  9. N = 1 supercurrents of eleven-dimensional supergravity

    Science.gov (United States)

    Becker, Katrin; Becker, Melanie; Butter, Daniel; Linch, William D.

    2018-05-01

    Eleven-dimensional supergravity can be formulated in superspaces locally of the form X × Y where X is 4D N = 1 conformal superspace and Y is an arbitrary 7-manifold admitting a G 2-structure. The eleven-dimensional 3-form and the stable 3-form on Y define the lowest component of a gauge superfield on X × Y that is chiral as a superfield on X. This chiral field is part of a tensor hierarchy giving rise to a superspace Chern-Simons action and its real field strength defines a lifting of the Hitchin functional on Y to the G 2 superspace X × Y . These terms are those of lowest order in a superspace Noether expansion in seven N = 1 conformal gravitino superfields Ψ. In this paper, we compute the O(Ψ) action to all orders in the remaining fields. The eleven-dimensional origin of the resulting non-linear structures is parameterized by the choice of a complex spinor on Y encoding the off-shell 4D N = 1 subalgebra of the eleven-dimensional super-Poincaré algebra.

  10. Local functional derivative of the total energy and the shell structure in atoms and molecules

    NARCIS (Netherlands)

    Pino, R.; Markvoort, Albert. J.; Santen, van R.A.; Hilbers, P.A.J.

    2003-01-01

    The full and local Thomas–Fermi–Dirac energy functional derivatives are evaluated at Hartree–Fock densities for several atoms and molecules. These functions are interpreted as local chemical potentials and related mainly to kinetic energy functional derivatives. They are able to reveal the shell

  11. Eleven papers in analysis

    CERN Document Server

    Shabalin, P L; Yakubenko, A A; Pokhilevich, VA; Krein, M G

    1986-01-01

    This collection of eleven papers covers a broad spectrum of topics in analysis, from the study of certain classes of analytic functions to the solvability of singular problems for differential and integral equations to computational schemes for the partial differential equations and singular integral equations.

  12. Phase contrast scanning transmission electron microscopy imaging of light and heavy atoms at the limit of contrast and resolution.

    Science.gov (United States)

    Yücelen, Emrah; Lazić, Ivan; Bosch, Eric G T

    2018-02-08

    Using state of the art scanning transmission electron microscopy (STEM) it is nowadays possible to directly image single atomic columns at sub-Å resolution. In standard (high angle) annular dark field STEM ((HA)ADF-STEM), however, light elements are usually invisible when imaged together with heavier elements in one image. Here we demonstrate the capability of the recently introduced Integrated Differential Phase Contrast STEM (iDPC-STEM) technique to image both light and heavy atoms in a thin sample at sub-Å resolution. We use the technique to resolve both the Gallium and Nitrogen dumbbells in a GaN crystal in [[Formula: see text

  13. Atomic displacement distributions for light energetic atoms incident on heavy atom targets

    International Nuclear Information System (INIS)

    Brice, D.K.

    1975-01-01

    The depth distributions of atomic displacements produced by 4 to 100 keV H, D, and He ions incident on Cr, Mo, and W targets have been calculated using a sharp displacement threshold, E/sub d/ = 35 eV, and a previously described calculational procedure. These displacement depth distributions have been compared with the depth distributions of energy deposited into atomic processes to determine if a proportionality (modified Kinchin--Pease relationship) can be established. Such a relationship does exist for He ions and D ions incident on these metals at energies above 4 keV and 20 keV, respectively. For H ions the two distributions have significantly different shapes at all incident energies considered

  14. Code ATOM for calculation of atomic characteristics

    International Nuclear Information System (INIS)

    Vainshtein, L.A.

    1990-01-01

    In applying atomic physics to problems of plasma diagnostics, it is necessary to determine some atomic characteristics, including energies and transition probabilities, for very many atoms and ions. Development of general codes for calculation of many types of atomic characteristics has been based on general but comparatively simple approximate methods. The program ATOM represents an attempt at effective use of such a general code. This report gives a brief description of the methods used, and the possibilities of and limitations to the code are discussed. Characteristics of the following processes can be calculated by ATOM: radiative transitions between discrete levels, radiative ionization and recombination, collisional excitation and ionization by electron impact, collisional excitation and ionization by point heavy particle (Born approximation only), dielectronic recombination, and autoionization. ATOM explores Born (for z=1) or Coulomb-Born (for z>1) approximations. In both cases exchange and normalization can be included. (N.K.)

  15. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    CERN Document Server

    Oganessian, Yu T; Dmitriev, S N; Itkis, M G; Gulbekyan, G G; Khabarov, M V; Bekhterev, V V; Bogomolov, S L; Efremov, A A; Pashenko, S V; Stepantsov, S V; Yeremin, A V; Yavor, M I; Kalimov, A G

    2003-01-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10 sup - sup 3. The set up can work in the wide mass range from A approx 20 to A approx 500, its mass acceptance is as large as +-2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90 deg. electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considere...

  16. Hidden twelve-dimensional super Poincare symmetry in eleven dimensions

    International Nuclear Information System (INIS)

    Bars, Itzhak; Deliduman, Cemsinan; Pasqua, Andrea; Zumino, Bruno

    2004-01-01

    First, we review a result in our previous paper, of how a ten-dimensional superparticle, taken off-shell, has a hidden eleven-dimensional super Poincare symmetry. Then, we show that the physical sector is defined by three first-class constraints which preserve the full eleven-dimensional symmetry. Applying the same concepts to the eleven-dimensional superparticle, taken off-shell, we discover a hidden twelve-dimensional super Poincare symmetry that governs the theory

  17. Different levels of brain-derived neurotrophic factor and cortisol in healthy heavy smokers.

    Science.gov (United States)

    Neves, C D C; Lacerda, A C R; Lima, L P; Lage, V K S; Balthazar, C H; Leite, H R; Mendonça, V A

    2017-10-19

    Studies suggest that brain-derived neurotrophic factor (BDNF) and the hypothalamic-pituitary-adrenal (HPA) axis modulate dopaminergic activity in response to nicotine and that the concentrations of BDNF and cortisol seem to be dependent on the amount and duration of smoking. Therefore, we investigated BDNF and cortisol levels in smokers ranked by daily cigarette consumption. Twenty-seven adult males (13 non-smokers and 14 smokers) participated in the study. The smokers were divided in two groups: light (n=7) and heavy smokers (n=7). Anthropometric parameters and age were paired between the groups, and plasma BDNF and salivary cortisol levels were measured. Saliva samples were collected on awakening, 30 min after awakening, at 10:00 and 12:00 am, 5:00 and 10:00 pm. Additionally, cotinine serum levels were measured in smokers. Heavy smokers had higher mean values of BDNF compared to the control group (P=0.01), whereas no difference was observed in light smokers. Moreover, heavy smokers presented lower cortisol levels in the last collection (10:00 pm) than the control group (P=0.02) and presented statically higher values of cotinine than the light smokers (P=0.002). In conclusion, changes in BDNF and cortisol levels (10:00 pm) appear to be dependent on heavy cigarette smoking and can be involved in activation and in the relationship between the mesolimbic system and the HPA axis.

  18. Charge states of fast heavy ions in solids; target atomic number dependence

    International Nuclear Information System (INIS)

    Shima, Kunihiro

    1985-01-01

    Discussions were carried out on the origin of Z 2 (atomic number) dependent charge states with respect to projectile electron loss and capture process, and on relationship between the Z 2 dependence and that of mean charge states for heavy ions of 1 MeV/u energy region. Present and previously reported results were examined on the equilibrium charge distributions, 9-bar, of 120 MeV 63 Cu, 25 and 40 MeV 35 Cl, 109 MeV Si and 59 MeV F ions. It was clarified that 9-bar became generally higher for lower Z 2 depending on increasing energy, and osillatory behavior with energy-depending amplitude was seen in 9-bar vs Z 2 . Discussions were carrid out on these phenomena and related matters. Z 2 oscillations of 9-bar of fast heavy ions might be due to those of electron capture cross section into projectile K and L vacancies for high and intermediate charge states, respectively. A quantitative interpretation of the Z 2 -dependent 9-bar values is in progress based on collision process and observation of projectile x-ray. The 9-bar value dependency on Z 2 in ion passing foils and decrease of Z 2 oscillation amplitude with increasing collision energy were quite similar to the Z 2 dependence in stopping powers or in effective charge states estimated from stopping powers. But there was some discrepancies in the Z 2 oscillation of 9-bar and that of stopping powers. (Takagi, S.)

  19. Heavy-ion dosimetry

    International Nuclear Information System (INIS)

    Schimmerling, W.

    1980-03-01

    This lecture deals with some of the more important physical characteristics of relativistic heavy ions and their measurement, with beam delivery and beam monitoring, and with conventional radiation dosimetry as used in the operation of the BEVALAC biomedical facility for high energy heavy ions (Lyman and Howard, 1977; BEVALAC, 1977). Even so, many fundamental aspects of the interaction of relativistic heavy ions with matter, including important atomic physics and radiation chemical considerations, are not discussed beyond the reminder that such additional understanding is required before an adequte perspective of the problem can be attained

  20. Progress in atomic spectroscopy

    International Nuclear Information System (INIS)

    Beyer, H.J.; Kleinpoppen, H.

    1984-01-01

    This book presents reviews by leading experts in the field covering areas of research at the forefront of atomic spectroscopy. Topics considered include the k ordering of atomic structure, multiconfiguration Hartree-Fock calculations for complex atoms, new methods in high-resolution laser spectroscopy, resonance ionization spectroscopy (inert atom detection), trapped ion spectroscopy, high-magnetic-field atomic physics, the effects of magnetic and electric fields on highly excited atoms, x rays from superheavy collision systems, recoil ion spectroscopy with heavy ions, investigations of superheavy quasi-atoms via spectroscopy of electron rays and positrons, impact ionization by fast projectiles, and amplitudes and state parameters from ion- and atom-atom excitation processes

  1. Binding properties of oxacalix[4]arenes derivatives toward metal cations; Interactions entre cations metalliques et derives des oxacalix[4]arenes

    Energy Technology Data Exchange (ETDEWEB)

    Mellah, B

    2006-11-15

    The objective of this work was to establish the binding properties of oxacalix[4]arene derivatives with different numbers of the oxa bridges, functional groups (ketones, pyridine, ester, amide and methoxy) and conformations. Their interactions with alkali and alkaline-earth, heavy and transition metal cations have been evaluated according to different approaches: (i) extraction of corresponding picrates from an aqueous phase into dichloromethane; (ii) determination of the thermodynamic parameters of complexation in methanol and/or acetonitrile by UV-spectrophotometry and micro-calorimetry; (iii) determination of the stoichiometry of the complexes by ESI-MS; (iv) {sup 1}H-NMR titrations allowing to localize the metal ions in the ligand cavity. In a first part dealing on homo-oxacalix[4]arenes, selectivities for Na{sup +}, K{sup +}, Ca{sup 2+}, Pb{sup 2+} and Mn{sup 2+} of ketones derivatives was shown. The presence of oxa bridge in these derivatives increases their efficiency while decreasing their selectivity with respect to related calixarenes. The pyridine derivative prefers transition and heavy metal cations, in agreement with the presence of the soft nitrogen atoms. In the second part, di-oxacalix[4]arene ester and secondary amide derivatives were shown to be less effective than tertiary amide counterparts but to present high selectivities for Li{sup +}, Ba{sup 2+}, Zn{sup 2+} and Hg{sup 2+}. A third part devoted to the octa-homo-tetra-oxacalix[4]arene tetra-methoxy shows that the 1:1 metal complexes formed are generally more stable than those of calixarenes, suggesting the participation of the oxygen atoms of the bridge in the complexation. Selectivity for Cs{sup +}, Ba{sup 2+}, Cu{sup 2+} and Hg{sup 2+} were noted. (author)

  2. Derivation of a configuration space Hamiltonian for heavy atoms: three body potentials

    International Nuclear Information System (INIS)

    Mittleman, M.H.

    1981-01-01

    A brief history of the difficulties associated with the derivation of a configuration space Hamiltonian is presented. One of the problems encountered is the definition of the projection operators which must occur. A variational definition is obtained and, with simplifying assumptions, the optimum projection operators are those which project onto Hartree-Fock orbitals. This puts many previously performed numerical calculations on a firm footing. The form of the two body interactions is discussed in the context of the gauge freedom. The Coulomb gauge is the favored one but it is pointed out that it has never been proven to be the best one. Finally a form for the relativistic three election potential is given and the possibility of its observation is discussed

  3. Collisional Cooling of Light Ions by Cotrapped Heavy Atoms.

    Science.gov (United States)

    Dutta, Sourav; Sawant, Rahul; Rangwala, S A

    2017-03-17

    We experimentally demonstrate cooling of trapped ions by collisions with cotrapped, higher-mass neutral atoms. It is shown that the lighter ^{39}K^{+} ions, created by ionizing ^{39}K atoms in a magneto-optical trap (MOT), when trapped in an ion trap and subsequently allowed to cool by collisions with ultracold, heavier ^{85}Rb atoms in a MOT, exhibit a longer trap lifetime than without the localized ^{85}Rb MOT atoms. A similar cooling of trapped ^{85}Rb^{+} ions by ultracold ^{133}Cs atoms in a MOT is also demonstrated in a different experimental configuration to validate this mechanism of ion cooling by localized and centered ultracold neutral atoms. Our results suggest that the cooling of ions by localized cold atoms holds for any mass ratio, thereby enabling studies on a wider class of atom-ion systems irrespective of their masses.

  4. STRATEGI PROMOSI BUKU ???CRITICAL ELEVEN??? OLEH AKUN INSTAGRAM IKA NATASSA

    OpenAIRE

    -, AULIANTI SASILIA

    2016-01-01

    2016 AULIANTI SASILIA. Strategi Promosi Buku ???Critical Eleven??? oleh Akun Instagram Ika Natassa (Dibimbing oleh Kahar dan Andi Subhan Amir). Tujuan penelitian ini adalah: (1) Untuk mengetahui motif akun Instagram digunakan sebagai akun aktivitas promosi; (2) Untuk mengetahui strategi promosi buku ???Critical Eleven??? oleh akun Instagram Ika Natassa; (3) Untuk mengetahui faktor yang mempengaruhi aktivitas promosi buku ???Critical Eleven??? menggunakan media Instagram....

  5. Different levels of brain-derived neurotrophic factor and cortisol in healthy heavy smokers

    Directory of Open Access Journals (Sweden)

    C.D.C. Neves

    2017-10-01

    Full Text Available Studies suggest that brain-derived neurotrophic factor (BDNF and the hypothalamic-pituitary-adrenal (HPA axis modulate dopaminergic activity in response to nicotine and that the concentrations of BDNF and cortisol seem to be dependent on the amount and duration of smoking. Therefore, we investigated BDNF and cortisol levels in smokers ranked by daily cigarette consumption. Twenty-seven adult males (13 non-smokers and 14 smokers participated in the study. The smokers were divided in two groups: light (n=7 and heavy smokers (n=7. Anthropometric parameters and age were paired between the groups, and plasma BDNF and salivary cortisol levels were measured. Saliva samples were collected on awakening, 30 min after awakening, at 10:00 and 12:00 am, 5:00 and 10:00 pm. Additionally, cotinine serum levels were measured in smokers. Heavy smokers had higher mean values of BDNF compared to the control group (P=0.01, whereas no difference was observed in light smokers. Moreover, heavy smokers presented lower cortisol levels in the last collection (10:00 pm than the control group (P=0.02 and presented statically higher values of cotinine than the light smokers (P=0.002. In conclusion, changes in BDNF and cortisol levels (10:00 pm appear to be dependent on heavy cigarette smoking and can be involved in activation and in the relationship between the mesolimbic system and the HPA axis.

  6. Immobilization of Thiadiazole Derivatives on Magnetite Mesoporous Silica Shell Nanoparticles in Application to Heavy Metal Removal from Biological Samples

    International Nuclear Information System (INIS)

    Emadi, Masoomeh; Shams, Esmaeil

    2010-01-01

    In this report magnetite was synthesized by a coprecipitation method, then coated with a layer of silica. Another layer of mesoporous silica was added by a sol-gel method, then 5-amino-1,3,4-thiadiazole-thiol (ATT) was immobilized onto the synthesized nanoparticles with a simple procedure. This was followed by a series of characterizations, including transmission electron microscopy (TEM), FT-IR spectrum, elemental analysis and XRD. Heavy metal uptake of the modified nanoparticles was examined by atomic absorption spectroscopy. For further investigation we chose Cu 2+ as the preferred heavy metal to evaluate the amount of adsorption, as well as the kinetics and mechanism of adsorption. Finally, the capacity of our nanoparticles for the heavy metal removal from blood was shown. We found that the kinetic rate of Cu 2+ adsorption was 0.05 g/mg/min, and the best binding model was the Freundlich isotherm.

  7. Physico-Chemical and Structural Interpretation of Discrete Derivative Indices on N-Tuples Atoms

    Science.gov (United States)

    Martínez-Santiago, Oscar; Marrero-Ponce, Yovani; Barigye, Stephen J.; Le Thi Thu, Huong; Torres, F. Javier; Zambrano, Cesar H.; Muñiz Olite, Jorge L.; Cruz-Monteagudo, Maykel; Vivas-Reyes, Ricardo; Vázquez Infante, Liliana; Artiles Martínez, Luis M.

    2016-01-01

    This report examines the interpretation of the Graph Derivative Indices (GDIs) from three different perspectives (i.e., in structural, steric and electronic terms). It is found that the individual vertex frequencies may be expressed in terms of the geometrical and electronic reactivity of the atoms and bonds, respectively. On the other hand, it is demonstrated that the GDIs are sensitive to progressive structural modifications in terms of: size, ramifications, electronic richness, conjugation effects and molecular symmetry. Moreover, it is observed that the GDIs quantify the interaction capacity among molecules and codify information on the activation entropy. A structure property relationship study reveals that there exists a direct correspondence between the individual frequencies of atoms and Hückel’s Free Valence, as well as between the atomic GDIs and the chemical shift in NMR, which collectively validates the theory that these indices codify steric and electronic information of the atoms in a molecule. Taking in consideration the regularity and coherence found in experiments performed with the GDIs, it is possible to say that GDIs possess plausible interpretation in structural and physicochemical terms. PMID:27240357

  8. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    Science.gov (United States)

    Oganessian, Yu. Ts.; Shchepunov, V. A.; Dmitriev, S. N.; Itkis, M. G.; Gulbekyan, G. G.; Khabarov, M. V.; Bekhterev, V. V.; Bogomolov, S. L.; Efremov, A. A.; Pashenko, S. V.; Stepantsov, S. V.; Yeremin, A. V.; Yavor, M. I.; Kalimov, A. G.

    2003-05-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10 -3. The set up can work in the wide mass range from A≈20 to A≈500, its mass acceptance is as large as ±2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90° electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considered. Description of its elements and subsystems is given.

  9. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    International Nuclear Information System (INIS)

    Oganessian, Yu.Ts.; Shchepunov, V.A.; Dmitriev, S.N.; Itkis, M.G.; Gulbekyan, G.G.; Khabarov, M.V.; Bekhterev, V.V.; Bogomolov, S.L.; Efremov, A.A.; Pashenko, S.V.; Stepantsov, S.V.; Yeremin, A.V.; Yavor, M.I.; Kalimov, A.G.

    2003-01-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10 -3 . The set up can work in the wide mass range from A∼20 to A∼500, its mass acceptance is as large as ±2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90 deg. electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considered. Description of its elements and subsystems is given

  10. The project of the mass separator of atomic nuclei produced in heavy ion induced reactions

    Energy Technology Data Exchange (ETDEWEB)

    Oganessian, Yu.Ts.; Shchepunov, V.A. E-mail: shchepun@sunhe.jinr.rushchepun@cv.jinr.ru; Dmitriev, S.N.; Itkis, M.G.; Gulbekyan, G.G.; Khabarov, M.V.; Bekhterev, V.V.; Bogomolov, S.L.; Efremov, A.A.; Pashenko, S.V.; Stepantsov, S.V.; Yeremin, A.V.; Yavor, M.I.; Kalimov, A.G

    2003-05-01

    A new separator and mass analyzer, named MASHA (mass analyzer of super heavy atoms), has been designed at the Flerov Laboratory JINR Dubna to separate and measure masses of nuclei and molecules with precision better than 10{sup -3}. The set up can work in the wide mass range from A{approx}20 to A{approx}500, its mass acceptance is as large as {+-}2.8%. In particular, it allows unambiguous mass identification of super heavy nuclei with a resolution better than 1 amu at the level of 300 amu. Synthesized in nuclear reactions nuclides are emitted from an ECR ion source at energy E=40 kV and charge state Q=+1. Then they pass the following steps of separation and analysis: the first section of rough separation, the second section of separation and mass analysis and the final section of separation with a 90 deg. electrostatic deflector. In the focal plane of the device, a focal plane detector determines positions (masses) of studied nuclei. Ion optics of the analyzer, optimized up to the second order, is considered. Description of its elements and subsystems is given.

  11. Forward electron production in heavy ion-atom and ion-solid collisions

    International Nuclear Information System (INIS)

    Sellin, I.A.

    1984-01-01

    A sharp cusp in the velocity spectrum of electrons, ejected in ion-atom and ion-solid collisions, is observed when the ejected electron velocity vector v/sub e/ matches that of the emergent ion vector v/sub p/ in both speed and direction. In ion-atom collisions, the electrons originate from capture to low-lying, projectile-centered continuum states (ECC) for fast bare or nearly bare projectiles, and from loss to those low-lying continuum states (ELC) when loosely bound projectile electrons are available. Most investigators now agree that ECC cusps are strongly skewed toward lower velocities, and exhibit full widths half maxima roughly proportional to v/sub p/ (neglecting target-shell effects, which are sometimes strong). A close examination of recent ELC data shows that ELC cusps are instead nearly symmetric, with widths nearly independent on v/sub p/ in the velocity range 6 to 18 a.u., a result only recently predicted by theory. Convoy electron cusps produced in heavy ion-solid collisions at MeV/u energies exhibit approximately velocity-independent widths very similar to ELC cusp widths. While the shape of the convoy peaks is approximately independent of projectile Z, velocity, and of target material, it is found that the yields in polycrystalline targets exhibit a strong dependence on projectile Z and velocity. While attempts have been made to link convoy electron production to binary ECC or ELC processes, sometimes at the last layer, or alternatively to a solid-state wake-riding model, our measured dependences of cusp shape and yield on projectile charge state and energy are inconsistent with the predictions of available theories. 10 references, 8 figures, 1 table

  12. Binding properties of oxacalix[4]arenes derivatives toward metal cations

    International Nuclear Information System (INIS)

    Mellah, B.

    2006-11-01

    The objective of this work was to establish the binding properties of oxacalix[4]arene derivatives with different numbers of the oxa bridges, functional groups (ketones, pyridine, ester, amide and methoxy) and conformations. Their interactions with alkali and alkaline-earth, heavy and transition metal cations have been evaluated according to different approaches: (i) extraction of corresponding picrates from an aqueous phase into dichloromethane; (ii) determination of the thermodynamic parameters of complexation in methanol and/or acetonitrile by UV-spectrophotometry and micro-calorimetry; (iii) determination of the stoichiometry of the complexes by ESI-MS; (iv) 1 H-NMR titrations allowing to localize the metal ions in the ligand cavity. In a first part dealing on homo-oxacalix[4]arenes, selectivities for Na + , K + , Ca 2+ , Pb 2+ and Mn 2+ of ketones derivatives was shown. The presence of oxa bridge in these derivatives increases their efficiency while decreasing their selectivity with respect to related calixarenes. The pyridine derivative prefers transition and heavy metal cations, in agreement with the presence of the soft nitrogen atoms. In the second part, di-oxacalix[4]arene ester and secondary amide derivatives were shown to be less effective than tertiary amide counterparts but to present high selectivities for Li + , Ba 2+ , Zn 2+ and Hg 2+ . A third part devoted to the octa-homo-tetra-oxacalix[4]arene tetra-methoxy shows that the 1:1 metal complexes formed are generally more stable than those of calixarenes, suggesting the participation of the oxygen atoms of the bridge in the complexation. Selectivity for Cs + , Ba 2+ , Cu 2+ and Hg 2+ were noted. (author)

  13. A Hidden Twelve-Dimensional SuperPoincare Symmetry In Eleven Dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Bars, Itzhak; Deliduman, Cemsinan; Pasqua, Andrea; Zumino, Bruno

    2003-12-13

    First, we review a result in our previous paper, of how a ten-dimensional superparticle, taken off-shell, has a hidden eleven-dimensional superPoincare symmetry. Then, we show that the physical sector is defined by three first-class constraints which preserve the full eleven-dimensional symmetry. Applying the same concepts to the eleven dimensional superparticle, taken off-shell, we discover a hidden twelve dimensional superPoincare symmetry that governs the theory.

  14. Transformation of heavy gas oils derived from oil sands to petrochemical feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Du Plessis, D.; Laureshen, C. [Alberta Energy Research Inst., Edmonton, AB (Canada)

    2006-07-01

    Alberta's petrochemical industry is primarily based on ethane. However, ethane could potentially impede future growth of Alberta's petrochemical industry because of increasing cost and diminishing supplies. Alternately, the rapidly growing oil sands production could provide abundant new feedstocks. Different integration schemes and technologies were evaluated in this study. Research on converting bitumen-derived heavy gas oil into petrochemical feedstock has resulted in the development of two novel technologies and process integration schemes, notably the NOVA heavy oil laboratory catalyst (NHC) process and the aromatic ring cleavage (ARORINCLE) process. This paper described progress to date on these two projects. The paper presented the experimental results for each scheme. For the ARORINCLE process, results were discussed in terms of the effect of process parameters on the hydrogenation step; effect of process parameters on the ring cleavage step; and integrating the upgrading and petrochemical complex. Early laboratory stage results of these two technologies were found to be encouraging. The authors recommended that work should progress to larger scale demonstration of the NHC and ARORINCLE technologies., 13 refs., 2 tabs., 5 figs.

  15. 7-Eleven Melejit Lewat Lifestyle

    Directory of Open Access Journals (Sweden)

    Freddy P. Simbolon

    2012-05-01

    Full Text Available The landscape of convenient store businesses or minimarkets now have changed. Location base strategy has not been sufficient any longer now. Psychographic and Demographic approaches tend to share a newly built power. Two main variables that have been managed concern at retail level are the store image and the store atmosphere. While the store image dimensions that can be put into considerations are the items offered, services committed, who and the amount of customers, physical facilities, promotion and convenience, store atmosphere, especially the involvement of affections through built emotions status in store which possibly uncautioned wholly by the customers when doing shopping. Since officially opened, the 7-Eleven had offered unique facilities. Instead of providing instant foods and beverages for 24 hours, the 7-Eleven also provides convenient corners and tables to eat and drink and provides chatting facilities for customers who need it. These make other modern retailers following the concept: opened for 24 hours and providing chatting facilities for young people.

  16. NATO Advanced Study Institute on Atoms in Unusual Situations

    CERN Document Server

    1986-01-01

    Atomic Physics is certainly the oldest field in which Quantum Mechanics has been used and has provided the most significant proofs of this new theory. Most of the basic concepts, except those more recently developed in field quantization, have been understood for quite a time. Atomic Physics began to serve as a basis for other fields such as molecu­ lar, solid state or nuclear physics. A renewal of interest in Atomic Physics began in the sixties, after the discovery of Quantum Electro­ dynamics, and later when it provided some basic tests of fundamental questions like parity violation, time reversal or Dirac theory. More recently the development of new technologies led to the ex­ ploration of very extreme cases in which the most secrete aspects of atoms have been observed. - Rydberg states where the atoms are so big that they can be described by classical theories; - Heavy or super-heavy ions or exotic atoms where unknown QED or relativistic effects can be observed (very heavy hydrogenlike or heliu...

  17. Effects of impurities in biodiesel-derived glycerol on growth and expression of heavy metal ion homeostasis genes and gene products in Pseudomonas putida LS46.

    Science.gov (United States)

    Fu, Jilagamazhi; Sharma, Parveen; Spicer, Vic; Krokhin, Oleg V; Zhang, Xiangli; Fristensky, Brian; Wilkins, John A; Cicek, Nazim; Sparling, Richard; Levin, David B

    2015-07-01

    Biodiesel production-derived waste glycerol (WG) was previously investigated as potential carbon source for medium chain length polyhydroxyalkanoate (mcl-PHA) production by Pseudomonas putida LS46. In this study, we evaluated the effect of impurities in the WG on P. putida LS46 physiology during exponential growth and corresponding changes in transcription and protein expression profiles compared with cells grown on pure, reagent grade glycerol. High concentration of metal ions, such as Na(+), and numbers of heavy metals ion, such as copper, ion, zinc, were detected in biodiesel-derived WG. Omics analysis from the corresponding cultures suggested altered expression of genes involved in transport and metabolism of ammonia and heavy metal ions. Expression of three groups of heavy metal homeostasis genes was significantly changed (mostly upregulated) in WG cultures and included the following: copper-responded cluster 1 and 2 genes, primarily containing cusABC; two copies of copAB and heavy metal translocating P-type ATPase; Fur-regulated, TonB-dependent siderophore receptor; and several cobalt/zinc/cadmium transporters. Expression of these genes suggests regulation of intracellular concentrations of heavy metals during growth on biodiesel-derived glycerol. Finally, a number of genes involved in adapting to, or metabolizing free fatty acids and other nonheavy metal contaminants, such as Na(+), were also upregulated in P. putida LS46 grown on biodiesel-derived glycerol.

  18. Parity nonconservation in Zeeman atomic transitions

    International Nuclear Information System (INIS)

    Kraftmakher, A.Ya.

    1990-01-01

    The abilities to observe the parity violation at the radiofrequency transitions between the hyperfine and Zeeman terms of the atomic levels are considered. The E-1 amplitudes fo the Zeeman transitions of heavy atoms in weak magnetic fields are larger, than for the light atoms hyperfine transitions at the same wavelength. 9 refs

  19. Accelerated ions as a tool in atomic physics

    International Nuclear Information System (INIS)

    Hansteen, J.M.

    1977-01-01

    Some of the aspects of atomic physics which are being brought into focus by the construction and completion of a new generation of heavy-ion accelerators are dealt with. Various types of processes occurring in the overlapping electron clouds are visualised in an elementary way, using among others, some recent observations on the formation of quasi-molecules and quasi-atoms. Phenomena connected with the inner electron shells in superheavy atoms are touched upon, in particular those processes possibly leading to the production of positrons. In such cases the crucial importance of an atomic Coulomb excitation mechanism is stressed. In conclusion the view is emphasized that inner shell ionization phenomena in heavy ion collisions form a bridge between processes originating respectively from nuclear and atomic physics. (Auth.)

  20. Heavy-Atom Tunneling Calculations in Thirteen Organic Reactions: Tunneling Contributions are Substantial, and Bell's Formula Closely Approximates Multidimensional Tunneling at ≥250 K.

    Science.gov (United States)

    Doubleday, Charles; Armas, Randy; Walker, Dana; Cosgriff, Christopher V; Greer, Edyta M

    2017-10-09

    Multidimensional tunneling calculations are carried out for 13 reactions, to test the scope of heavy-atom tunneling in organic chemistry, and to check the accuracy of one-dimensional tunneling models. The reactions include pericyclic, cycloaromatization, radical cyclization and ring opening, and S N 2. When compared at the temperatures that give the same effective rate constant of 3×10 -5  s -1 , tunneling accounts for 25-95 % of the rate in 8 of the 13 reactions. Values of transmission coefficients predicted by Bell's formula, κ Bell  , agree well with multidimensional tunneling (canonical variational transition state theory with small curvature tunneling), κ SCT . Mean unsigned deviations of κ Bell vs. κ SCT are 0.08, 0.04, 0.02 at 250, 300 and 400 K. This suggests that κ Bell is a useful first choice for predicting transmission coefficients in heavy-atom tunnelling. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. L X-ray emission induced by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Pajek, M. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Banaś, D., E-mail: d.banas@ujk.edu.pl [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Braziewicz, J.; Majewska, U.; Semaniak, J. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Fijał-Kirejczyk, I. [The Institute of Atomic Energy, 05-400 Otwock-Świerk (Poland); Jaskóła, M.; Czarnacki, W.; Korman, A. [The National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Kretschmer, W. [Physikalisches Institut, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Mukoyama, T. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), H-4026 Debrecen (Hungary); Trautmann, D. [Institut für Physik, Universität Basel, Basel (Switzerland)

    2015-11-15

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster–Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L{sub 2}-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  2. Perhydropolysilazane derived silica coating protecting Kapton from atomic oxygen attack

    Energy Technology Data Exchange (ETDEWEB)

    Hu Longfei [China Academy of Aerospace Aerodynamics, Beijing 100074 (China); Li Meishuan, E-mail: mshli@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Xu Caihong; Luo Yongming [Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2011-11-30

    By using surface sol-gel method with perhydropolysilazane (PHPS) as a precursor, a silica coating was prepared on a Kapton substrate as an atomic oxygen (AO) protective coating. The AO exposure tests were conducted in a ground-based simulator. It is found that the erosion yield of Kapton decreases by about three orders of magnitude after the superficial application of the coating. After AO exposure, the surface of the coating is smooth and uniform, no surface shrinkage induced cracks or undercutting erosion are observed. This is because that during AO exposure the PHPS is oxidized directly to form SiO{sub 2} without through intermediate reaction processes, the surface shrinkage and cracking tendency are prohibited. Meanwhile, this PHPS derived silica coating also presents self-healing effect due to the oxidation of free Si. Compared with other kinds of silica or organic polymer coatings, this PHPS derived silica coating exhibits a superior AO erosion resistance.

  3. Perhydropolysilazane derived silica coating protecting Kapton from atomic oxygen attack

    International Nuclear Information System (INIS)

    Hu Longfei; Li Meishuan; Xu Caihong; Luo Yongming

    2011-01-01

    By using surface sol–gel method with perhydropolysilazane (PHPS) as a precursor, a silica coating was prepared on a Kapton substrate as an atomic oxygen (AO) protective coating. The AO exposure tests were conducted in a ground-based simulator. It is found that the erosion yield of Kapton decreases by about three orders of magnitude after the superficial application of the coating. After AO exposure, the surface of the coating is smooth and uniform, no surface shrinkage induced cracks or undercutting erosion are observed. This is because that during AO exposure the PHPS is oxidized directly to form SiO 2 without through intermediate reaction processes, the surface shrinkage and cracking tendency are prohibited. Meanwhile, this PHPS derived silica coating also presents self-healing effect due to the oxidation of free Si. Compared with other kinds of silica or organic polymer coatings, this PHPS derived silica coating exhibits a superior AO erosion resistance.

  4. Quantum delayed-choice experiment with a single neutral atom.

    Science.gov (United States)

    Li, Gang; Zhang, Pengfei; Zhang, Tiancai

    2017-10-01

    We present a proposal to implement a quantum delayed-choice (QDC) experiment with a single neutral atom, such as a rubidium or cesium atom. In our proposal, a Ramsey interferometer is adopted to observe the wave-like or particle-like behaviors of a single atom depending on the existence or absence of the second π/2-rotation. A quantum-controlled π/2-rotation on target atom is realized through a Rydberg-Rydberg interaction by another ancilla atom. It shows that a heavy neutral atom can also have a morphing behavior between the particle and the wave. The realization of the QDC experiment with such heavy neutral atoms not only is significant to understand the Bohr's complementarity principle in matter-wave and matter-particle domains but also has great potential on the quantum information process with neutral atoms.

  5. Physico-Chemical and Structural Interpretation of Discrete Derivative Indices on N-Tuples Atoms

    Directory of Open Access Journals (Sweden)

    Oscar Martínez-Santiago

    2016-05-01

    Full Text Available This report examines the interpretation of the Graph Derivative Indices (GDIs from three different perspectives (i.e., in structural, steric and electronic terms. It is found that the individual vertex frequencies may be expressed in terms of the geometrical and electronic reactivity of the atoms and bonds, respectively. On the other hand, it is demonstrated that the GDIs are sensitive to progressive structural modifications in terms of: size, ramifications, electronic richness, conjugation effects and molecular symmetry. Moreover, it is observed that the GDIs quantify the interaction capacity among molecules and codify information on the activation entropy. A structure property relationship study reveals that there exists a direct correspondence between the individual frequencies of atoms and Hückel’s Free Valence, as well as between the atomic GDIs and the chemical shift in NMR, which collectively validates the theory that these indices codify steric and electronic information of the atoms in a molecule. Taking in consideration the regularity and coherence found in experiments performed with the GDIs, it is possible to say that GDIs possess plausible interpretation in structural and physicochemical terms.

  6. Scaling behaviour of leptonic decay constants for heavy quarkonia and heavy mesons

    International Nuclear Information System (INIS)

    Kiselev, V.V.

    1994-01-01

    In the framework of QCD sum rules one uses a scheme, allowing one to apply the conditions of both nonrelativistic heavy quark motion inside mesons and the heavy quark flavour independence of nonsplitting nS-state density. In the leading order an analitic expression is derived for leptonic constants of both heavy quarkonia and heavy mesons with a single heavy quark. The expression allows one explicitly to determine scaling properties of the constants. 24 refs., 2 tabs

  7. Collective vs atomic models of the hadrons

    International Nuclear Information System (INIS)

    Stokar, S.

    1983-02-01

    We examine the relationship between heavy and light quark systems. Using a Bogoliubov-Valatin transformation we show how to interpolate continuously between heavy quark atomic models and light quark collective models of the hadrons. (author)

  8. On the resonant coherent excitation of relativistic heavy ions

    International Nuclear Information System (INIS)

    Pivovarov, Y.L.; Geissel, H.; Filimonov, Yu.M.; Krivosheev, O.E.; Scheidenberger, C.

    1995-07-01

    New accelerator facilities open up an interesting new field of experiments on basic channeling as well as on atomic and nuclear resonant coherent exitation (RCE) of heavy ions penetrating through aligned crystals at relativistic energies. Results of computer simulations are presented to characterize the resonant coherent excitation of atomic levels of relativistic hydrogen-like heavy ions. Nuclear resonant coherent excitation reveals interesting different characteristics compared to the corresponding atomic excitation inside crystals. An important result of our model calculations is that poorly-channeled ions have a higher nuclear excitation probability than well-channeled ions. (orig.)

  9. Production of heavy water in India

    International Nuclear Information System (INIS)

    Deshpande, P.G.; Bimbhat, K.S.; Bhargava, R.K.

    India's first heavy water plant, using electrolysis of water followed by liquid hydrogen distillation, has been operating in association with a fertilizer plant at Nangal since 1962. A dual-temperature process plant at Kota uses heat from the Rajasthan Atomic Power Station. The heavy water plants at Baroda and Tuticorin use ammonia-hydrogen exchange and are integrated with fertilizer ammonia plants. Choice of a particular process for heavy water production depends upon local conditions as well as the extent of the heavy water requirement

  10. Annual progress report for atomic and nuclear research with accelerators and fusion related atomic physics. Reporting period, October 1, 1974--September 30, 1975

    International Nuclear Information System (INIS)

    1975-10-01

    Topics covered include: laboratory operation and development; atomic collision cross sections in gases; ionization cross sections in thin solid materials; experimental impact-parameter dependent probabilities for k-shell vacancy production by fast heavy-ion projectiles; x-ray spectroscopy with high energy ions; atomic lifetime measurements; polarization studies of ion-induced x rays; theoretical spectra in ion-induced reactions; theoretical atomic cross section calculations; search for heavy-ion resonances; lifetimes of low energy states in 21 Ne; nuclear scattering and reactions; and trace element analysis

  11. Heavy atoms as molecular probes in studying the solvent dependence of the dynamics of triplet exciplexes

    International Nuclear Information System (INIS)

    Steiner, U.; Winter, G.

    1981-01-01

    Electron transfer reactions between thiopyronine triplet (acceptor 3 A + ) and the electron donors (D), aniline, p-Br-aniline and p-I-aniline, are investigated by flash spectroscopy in solvents of different viscosity and polarity. Due to the heavy-atom effect the radical yield becomes very sensitive to the solvent influence, which can be explained by the dynamic properties of a triplet exciplex ( 3 (AD + )) formed as a primary product in the reaction between acceptor triplet and donor. Whereas on variation of solvent viscosity the solvent cage effect on the dissociation of 3 (AD + ) is observed, a change in solvent polarity is suggested to affect the radiationless deactivation of 3 (AD + ) to the ground state of the components. (author)

  12. Gold volatile species atomization and preconcentration in quartz devices for atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Yasin [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Mehmet Akif Ersoy University, Faculty of Arts & Sciences, Chemistry Department, 15030 Burdur (Turkey); Musil, Stanislav; Matoušek, Tomáš; Kratzer, Jan [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Dědina, Jiří, E-mail: dedina@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

    2015-01-01

    The on-line atomization of gold volatile species was studied and the results were compared with thermodynamic calculations in several quartz atomizers, namely: diffusion flame, flame-in-gas-shield, flame-in-plain-tube, externally heated T-tube and externally heated flame-in-T-tube. Atomization mechanism in the explored devices is proposed, where volatile species are converted to thermodynamically stable AuH at elevated temperature over 500 °C and then atomized by an interaction with a cloud of hydrogen radicals. Because of its inherent simplicity and robustness, diffusion flame was employed as a reference atomizer. It yielded atomization efficiency of 70 to 100% and a very good long time reproducibility of peak area sensitivity: 1.6 to 1.8 s μg{sup −1}. Six and eleven times higher sensitivity, respectively, was provided by atomizers with longer light paths in the observation volume, i.e. externally heated T-tube and externally heated flame-in-T-tube. The latter one, offering limit of detection below 0.01 μg ml{sup −1}, appeared as the most prospective for on-line atomization. Insight into the mechanism of atomization of gold volatile species, into the fate of free atoms and into subsequent analyte transfer allowed to assess possibilities of in-atomizer preconcentration of gold volatile species: it is unfeasible with quartz atomizers but a sapphire tube atomizer could be useful in this respect. - Highlights: • On-line atomization of gold volatile species for AAS in quartz devices was studied. • Atomization mechanism was proposed and atomization efficiency was estimated. • Possibilities of in-atomizer preconcentration of gold volatile species were assessed.

  13. Polythiophenes and fullerene derivatives based donor-acceptor system: topography by atomic force microscopy

    International Nuclear Information System (INIS)

    Marcakova, M. L.; Repovsky, D.; Cik, G.; Velic, D.

    2017-01-01

    The goal of this work is to examine the surface of a polythiophene/fullerene film in order to understand the structure. In this work polythiophene is used as electron donor and fullerene-derivative is used as electron acceptor. Atomic force microscopy (AFM), is an ideal method to study surfaces and nanostructures. Surfaces of fullerene C60 , fullerene-derivates PCBM, polythiophene P12 and a mixture of P12 and PCBM are characterized. In all samples, the average roughness, the arithmetical value of divergence from the high of the surface, is determined concluding that P12 and PCBM mix together well and form a film with specific topography. (authors)

  14. Experimental atomic and molecular physics research

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The Atomic Physics research in the Physics Division consists of five ongoing experimental programs: dissociation and other interactions of energetic molecular ions in solid and gaseous targets; beam-foil research and collision dynamics of heavy ions; photoionization-photoelectron research; spectroscopy of free atoms and molecules, high precision laser-rf double-resonance spectroscopy with atomic and molecular beams; and Moessbauer effect research

  15. Positron production in heavy ion-atom collisions

    International Nuclear Information System (INIS)

    Kienle, P.

    1985-08-01

    Following an introduction into the concept of an atom with an overcritical field, established by a nucleus with a charge larger than 173, the spontaneous positron emission from such an atom with an 1s binding energy exceeding 2mc 2 is presented. Such a process, in which an electron is bound and a monoenergetic positron emitted turns the neutral into a charged vacuum. In a U-U di-nuclear system (Z=184) the spontaneous positron emission proceeds with an energy of about 300 keV corresponding to a decay time of 3x10 -19 sec. (orig./WL)

  16. Analysis of heavy radiological accidents in NPP and gamma-irradiators

    Energy Technology Data Exchange (ETDEWEB)

    Angelov, V [Civil Defence Administration, Sofia (Bulgaria); Semova, T; Bonchev, Ts [Sofia Univ. (Bulgaria). Fizicheski Fakultet

    1996-12-31

    A review of several heavy radiological accidents, their cause, character, radioactivity emission, victims and economical impact is presented in the form of uniform tables. Eleven cases of incidents in power plants and 4 cases of accidents involving powerful gamma irradiators are considered. Radiological accidents in Bulgaria, not connected with the Kozloduy NPP, are listed. The human factor has been identified as the main cause for most of the accidents. It is stressed that the probability of heavy accident increases at the time of reactor refuelling, repair or testing. Technical failures could be eliminated by improved check and diagnostics procedures. 2 tabs., 12 refs.

  17. Analysis of heavy radiological accidents in NPP and gamma-irradiators

    International Nuclear Information System (INIS)

    Angelov, V.; Semova, T.; Bonchev, Ts.

    1995-01-01

    A review of several heavy radiological accidents, their cause, character, radioactivity emission, victims and economical impact is presented in the form of uniform tables. Eleven cases of incidents in power plants and 4 cases of accidents involving powerful gamma irradiators are considered. Radiological accidents in Bulgaria, not connected with the Kozloduy NPP, are listed. The human factor has been identified as the main cause for most of the accidents. It is stressed that the probability of heavy accident increases at the time of reactor refuelling, repair or testing. Technical failures could be eliminated by improved check and diagnostics procedures. 2 tabs., 12 refs

  18. Semiclassical derivation of a local optical potential for heavy-ion elastic scattering. [Coupling to other processes

    Energy Technology Data Exchange (ETDEWEB)

    Donangelo, R; Canto, L F [Rio de Janeiro Univ. (Brazil). Inst. de Fisica; Hussein, M S [Sao Paulo Univ. (Brazil). Inst. de Fisica

    1979-05-21

    A semiclassical method to determine the contribution to the optical potential in the elastic channel due to the coupling to other processes taking place in heavy-ion collisions is developed. An application is made to the case of Coulomb excitation. The lowest-order term of the potential used is shown to be identical to the potential derived by Baltz et al.

  19. Tuning the electronic structure of graphene through alkali metal and halogen atom intercalation

    Science.gov (United States)

    Ahmad, Sohail; Miró, Pere; Audiffred, Martha; Heine, Thomas

    2018-04-01

    The deposition, intercalation and co-intercalation of heavy alkali metals and light halogens atoms in graphene mono- and bilayers have been studied using first principles density-functional calculations. Both the deposition and the intercalation of alkali metals gives rise to n-type doping due to the formation of M+-C- pairs. The co-intercalation of a 1:1 ratio of alkali metals and halogens derives into the formation of ionic pairs among the intercalated species, unaltering the electronic structure of the layered material.

  20. Asymptotics for Two-dimensional Atoms

    DEFF Research Database (Denmark)

    Nam, Phan Thanh; Portmann, Fabian; Solovej, Jan Philip

    2012-01-01

    We prove that the ground state energy of an atom confined to two dimensions with an infinitely heavy nucleus of charge $Z>0$ and $N$ quantum electrons of charge -1 is $E(N,Z)=-{1/2}Z^2\\ln Z+(E^{\\TF}(\\lambda)+{1/2}c^{\\rm H})Z^2+o(Z^2)$ when $Z\\to \\infty$ and $N/Z\\to \\lambda$, where $E^{\\TF}(\\lambd......We prove that the ground state energy of an atom confined to two dimensions with an infinitely heavy nucleus of charge $Z>0$ and $N$ quantum electrons of charge -1 is $E(N,Z)=-{1/2}Z^2\\ln Z+(E^{\\TF}(\\lambda)+{1/2}c^{\\rm H})Z^2+o(Z^2)$ when $Z\\to \\infty$ and $N/Z\\to \\lambda$, where $E......^{\\TF}(\\lambda)$ is given by a Thomas-Fermi type variational problem and $c^{\\rm H}\\approx -2.2339$ is an explicit constant. We also show that the radius of a two-dimensional neutral atom is unbounded when $Z\\to \\infty$, which is contrary to the expected behavior of three-dimensional atoms....

  1. Origin of the heavy elements in binary neutron-star mergers from a gravitational-wave event.

    Science.gov (United States)

    Kasen, Daniel; Metzger, Brian; Barnes, Jennifer; Quataert, Eliot; Ramirez-Ruiz, Enrico

    2017-11-02

    The cosmic origin of elements heavier than iron has long been uncertain. Theoretical modelling shows that the matter that is expelled in the violent merger of two neutron stars can assemble into heavy elements such as gold and platinum in a process known as rapid neutron capture (r-process) nucleosynthesis. The radioactive decay of isotopes of the heavy elements is predicted to power a distinctive thermal glow (a 'kilonova'). The discovery of an electromagnetic counterpart to the gravitational-wave source GW170817 represents the first opportunity to detect and scrutinize a sample of freshly synthesized r-process elements. Here we report models that predict the electromagnetic emission of kilonovae in detail and enable the mass, velocity and composition of ejecta to be derived from observations. We compare the models to the optical and infrared radiation associated with the GW170817 event to argue that the observed source is a kilonova. We infer the presence of two distinct components of ejecta, one composed primarily of light (atomic mass number less than 140) and one of heavy (atomic mass number greater than 140) r-process elements. The ejected mass and a merger rate inferred from GW170817 imply that such mergers are a dominant mode of r-process production in the Universe.

  2. ADAS: Atomic data, modelling and analysis for fusion

    International Nuclear Information System (INIS)

    Summers, H. P.; O'Mullane, M. G.; Whiteford, A. D.; Badnell, N. R.; Loch, S. D.

    2007-01-01

    The Atomic Data and Analysis Structure, ADAS, comprises extensive fundamental and derived atomic data collections, interactive codes for the manipulation and generation of collisional-radiative data and models, off-line codes for large scale fundamental atomic data production and codes for diagnostic analysis in the fusion and astrophysical environments. ADAS data are organized according to precise specifications, tuned to application and are assigned to numbered ADAS data formats. Some of these formats contain very large quantities of data and some have achieved wide-scale adoption in the fusion community.The paper focuses on recent extensions of ADAS designed to orient ADAS to the needs of ITER. The issue of heavy atomic species, expected to be present as ITER wall and divertor materials, dopants or control species, will be addressed with a view to the economized handling of the emission and ionisation state data needed for diagnostic spectral analysis. Charge exchange and beam emission spectroscopic capabilities and developments in ADAS will be reviewed from an ITER perspective and in the context of a shared analysis between fusion laboratories. Finally an overview and summary of current large scale fundamental data production in the framework of the ADAS project will be given and its intended availability in both fusion and astrophysics noted

  3. Proceedings of the 2nd joint seminar on atomic collisions and heavy ion induced nuclear reactions

    International Nuclear Information System (INIS)

    Harada, Kichinosuke; Ozawa, Kunio; Kamitsubo, H.; Nomura, T.; Awaya, Y.; Watanabe, T.

    1982-11-01

    The meeting of the 2nd joint seminar on atomic collisions and heavy ion induced nuclear reactions was held at the University of Tokyo, May 13 and 14, 1982. The aim of this seminar has been not only to recognize the common problems lying between above two research fields, but also to obtain an overview of the theoretical and experimental approaches to clear the current problems. In the seminar, more than 50 participants gathered and presented 16 papers. These are two general reviews and fourteen comprehensive surveys on topical subjects which have been developed very intensively in recent years. The editors would like to thank all participants for their assistance and cooperation in making possible a publication of these proceedings. (author)

  4. Fluorescence quenching of derivatives of anthracene by organic electron donors and acceptors in acetonitrile. Electron and proton transfer mechanism

    Science.gov (United States)

    Mac, Marek; Najbar, Jan; Wirz, Jakob

    1995-03-01

    Fluorescence quenching of anthracene derivatives by organic electron donors (amines) and acceptors was investigated using stationary fluorescence measurements. The dependence of log( kq) on Δ Get shows Rehm-Weller-type behavior. The formation of anion radicals of anthracene, bianthryl, and 9-cyanoanthracene was detected by flash photolysis in systems containing aromatic amines (aniline, 2-bromoaniline, 4-bromoaniline, N,N-dimethylaniline, 4-bromo-N,N-dimethylaniline, N,N-diethylaniline, and 1,4-diazabicyclo[2.2.2]octane). The radical yields decreased and triplet yields increased when bromo derivatives of amines were used as donor quenchers, indicating the heavy-atom effect on spin conversion within radical pairs. The importance of the heavy-atom effect decreased when the energy gap between the charge transfer and molecular triplet states was small. The formation of separated radicals decreased when primary amines were used as quenchers which indicated the existence of an additional path of deactivation of the radical pair. The behavior of amines as quenchers of bianthryl and anthracene is compared with that of inorganic anion quenchers.

  5. Pion correlations as a function of atomic mass in heavy ion collisions

    International Nuclear Information System (INIS)

    Chacon, A.D.

    1989-01-01

    The method of two pion interferometry was used to obtain source-size and lifetime parameters for the pions produced in heavy ion collisions. The systems used were 1.70 · A GeV 56 Fe + Fe, 1.82 · A GeV 40 Ar + KCl and 1.54 · A GeV 93 Nb + Nb, allowing for a search for dependences on the atomic number. Two acceptances (centered, in the lab., at ∼ 0 degrees and 45 degrees) were used for each system, allowing a search for dependences on the viewing angle. The correlation functions were calculated by comparing the data samples to background (or reference) samples made using the method of event mixing, where pions from different events are combined to produce a data sample in which the Bose-Einstein correlation effect is absent. The effect of the correlation function on the background samples is calculated, and a method for weighting the events to remove the residual correlation effect is presented. The effect of the spectrometer design on the measured correlation functions is discussed, as are methods for correcting for these effects during the data analysis. 58 refs., 39 figs., 18 tabs

  6. Energy distribution of projectile fragment particles in heavy ion therapeutic beam

    Energy Technology Data Exchange (ETDEWEB)

    Matsufuji, Naruhiro; Tomura, Hiromi; Futami, Yasuyuki [National Inst. of Radiological Sciences, Chiba (Japan)] [and others

    1998-03-01

    Production of fragment particles in a patient`s body is one of important problems for heavy charged particle therapy. It is required to know the yield and the energy spectrum for each fragment element - so called `beam quality` to understand the effect of therapeutic beam precisely. In this study, fragment particles produced by practical therapeutic beam of HIMAC were investigated with using tissue-equivalent material and a detector complex. From the results, fragment particles were well identified by difference of their atomic numbers and the beam quality was derived. Responses of the detectors in this energy region were also researched. (author)

  7. Electron population uncertainty and atomic covalency

    International Nuclear Information System (INIS)

    Chesnut, D.B.

    2006-01-01

    The atoms-in-molecules (AIM) index of atomic covalency is directly related to the AIM atomic population uncertainty. The covalent bond order, delocalization index, and, therefore, the atomic covalency are maximal when electron pairs are equally shared by the atoms involved. When polarization effects are present, these measures of covalent bond character decrease. We present atomic covalences for the single- and double-heavy atom hydrides of elements of the first and second low rows of the periodic table to illustrate these effects. Some usual behavior is seen in hydrogen-bridged species due in some cases to stronger than expected multicenter bonds and in other cases to many atoms contributing to the covalency index

  8. Assessment of heavy metal contamination, levels in topsoil at selected auto-workshops in Accra, Ghana

    International Nuclear Information System (INIS)

    Ziblim, M. Y.

    2015-07-01

    The research was conducted to assess the levels of contamination of heavy metals in the topsoil at selected auto-workshops in Accra to determine the anthropogenic and crustal contributions and the human heath risk associated with them. Soil samples collected from four auto-workshops were analysed using Atomic Absorption Spectrometer. Eleven (11) elements: Co, Fe, Cu, Mn, Cr, As, Hg, Zn, Pb, Ni, and Cd were identified in each sample collected from the auto-workshops. Pollution indices; contamintion factor (Cf) index of geoaccumulation (Igeo) and pollution load index (PLI) were used to assess the contamination levels. It revealed the extent of contamination at the auto-workshops for most of the elements which range from low to considerate contamintion. Lead (Pb) recorded the greatest contamination levels at the auto-electrical location. The results from the index of geoccumulation showed no pollution to highly pollution indicting high variations of pollution levels at different locations. The results of the PLI in almost all locations ranged from moderately to extremely polluted. Noncancer effect on children and adults due to exposure to the topsoil were also estimated with some selected metal elements. The hazard quotient (HQ) evaluation, showed ingestion to be the route of exposure to soil dust that results in a higher risk for heavy metals, followed by dermal contact. The effect due to inhalation of resuspended dust particles through the mouth and nose is relatively low. It was observed that, the auto-workshops are generally polluted with heavy metals and therefore posing ill-health effect to the humans and the environment. (au)

  9. Experimental atomic physics

    International Nuclear Information System (INIS)

    Sellin, I.A.; Elston, S.B.; Forester, J.P.; Liao, K.H.; Pegg, D.J.; Peterson, R.S.; Thoe, R.S.; Hayden, H.C.; Griffin, P.M.

    1976-01-01

    The atomic structure and collision phenomena of highly stripped ions in the range Z = 6 to 35 were studied. Charge-transfer and multiple-electron-loss cross sections were determined. Absolute x-ray-production cross sections for incident heavy ions were measured. 10 figures, 1 table

  10. Estimated H-atom anisotropic displacement parameters: a comparison between different methods and with neutron diffraction results

    DEFF Research Database (Denmark)

    Munshi, Parthapratim; Madsen, Anders Ø; Spackman, Mark A

    2008-01-01

    systems and identify systematic discrepancies for several atom types. A revised and extended library of internal H-atom mean-square displacements is presented for use with Madsen's SHADE web server [J. Appl. Cryst. (2006), 39, 757-758; http://shade.ki.ku.dk], and the improvement over the original SHADE...... in the agreement with neutron results. The SHADE2 library, now incorporated in the SHADE web server, is recommended as a routine procedure for deriving estimates of H-atom ADPs suitable for use in charge-density studies on molecular crystals, and its widespread use should reveal remaining deficiencies and perhaps...... results is substantial, suggesting that this is now the most readily and widely applicable of the three approximate procedures. Using this new library--SHADE2--it is shown that, in line with expectations, a segmented rigid-body description of the heavy atoms yields only a small improvement...

  11. Highly charged atomic physics at HIRFL-CSR

    International Nuclear Information System (INIS)

    Ma Xinwen; Wang Youde; Hou Mingdong; Jin Gengmin

    1996-01-01

    HIRFL-CSR is a proposed electron cooling storage ring optimized to accelerate and store beams of highly charged heavy ions. Several possibilities for advanced atomic physics studies are discussed, such as studies of electron-ion, ion-atoms, photon-ion-electron interactions and high resolution spectroscopy

  12. Electron spectroscopy with fast heavy ions

    International Nuclear Information System (INIS)

    Schneider, D.

    1983-01-01

    Since about 1970 the spectroscopy of Auger-electrons and characteristic x-rays following energetic ion-atom collisions has received a great deal of attention. An increasing number of accelerators, capable of providing a large number of projectile ion species over a wide range of projectile energies, became available for studying ion-atom collision phenomena. Many charged particles from protons up to heavy ions like uranium can be accelerated to energies ranging over six orders of magnitude. This allows us to study systematically a great variety of effects accompanied by dynamic excitation processes of the atomic shells in either the projectile- or target-atoms. The studies yield fundamental information regarding the excitation mechanism (e.g., Coulomb and quasi-molecular excitation) and allow sensitive tests of atomic structure theories. This information in turn is valuable to other fields in physics like plasma-, astro-, or solid-state (surface) physics. It is a characteristic feature of fast heavy-ion accelerators that they can produce highly stripped ion species which have in turn the capability to highly ionize neutral target atoms or molecules in a single collision. The ionization process, mainly due to the strong electrical fields that are involved, allows us to study few-electron atoms with high atomic numbers Z. High resolution spectroscopy performed with these atoms allows a particularly good test of relativistic and QED effects. The probability of producing these few electron systems is determined by the charge state and the velocity of the projectile ions. In this contribution the possibilities of using electron spectroscopy as a tool to investigate fast ion-atom collisions is discussed and demonstrated with a few examples. 30 references

  13. assessment of heavy metals concentration in drinking water ...

    African Journals Online (AJOL)

    userpc

    guidelines (WHO 2005). Findings suggest that continues water quality monitoring should be carried out to check the concentration levels of heavy metals in that area, to prevent them from been above the limit of WHO. Keywords: Atomic Absorption Spectrophotometers, Heavy Metals, Water, Kauru Local. Government Area.

  14. Synthesis and photophysical properties of indium(III) phthalocyanine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Özceşmeci, İbrahim, E-mail: ozcesmecii@itu.edu.tr [Department of Chemistry, Technical University of Istanbul, Maslak 34469, Istanbul (Turkey); Gelir, Ali [Department of Physics, Technical University of Istanbul, Maslak 34469, Istanbul (Turkey); Gül, Ahmet [Department of Chemistry, Technical University of Istanbul, Maslak 34469, Istanbul (Turkey)

    2014-03-15

    Three chloroindium(III) phthalocyanine derivatives bearing four aromatic (naphthalene or pyrene) or aliphatic (hexylthio) groups were prepared from corresponding phthalonitrile compounds. The indium(III) phthalocyanine derivatives were characterized with elemental analyses, mass, proton nuclear magnetic resonance ({sup 1}H NMR), Fourier transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopy (UV–vis) techniques. Quantum yields and the energy transfer from the substituents to phthalocyanine core were examined. No energy transfer was observed for 5. The energy transfer efficiency from pyrene units to indium phthalocyanine core was calculated as 0.27 for 6. Quantum yields of all samples were very small due to heavy atom effect of indium atom in the core. It was also observed that upon binding of pyrene and naphthalene units to indium phthalocyanine as substituents, the quantum yields of indium phthalocyanine parts of 5 and 6 decreased. -- Highlights: • Three chloroindium(III) phthalocyanines were prepared and characterized. • Aggregation properties of these compounds were investigated. • The energy transfer efficiency was examined. • Quantum yield of these systems were calculated.

  15. The heavy ion injection scheme for RHIC [Relativistic Heavy Ion Collider

    International Nuclear Information System (INIS)

    Rhoades-Brown, M.J.

    1989-01-01

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven has a multi-component injection system. The Collider requires very heavy ions such as 79 197 Au to be injected fully stripped of atomic electrons, at a kinetic energy of approximately 10 GeV/nucleon. However, the heavy ions are produced initially at a negative ion source and accelerated first in a 15 MV Tandem. These partially stripped ions have a kinetic energy of approximately 1 MeV/nucleon on leaving the Tandem. In order to achieve the injection requirements for RHIC, the partially stripped ions are accelerated in the Booster (currently under construction) and pass through a stripping foil on their way to the Alternating Gradient Synchrotron (AGS), where they are further accelerated before injection into RHIC. Recent theoretical calculations have shown quite convincingly that very heavy ions with 2 electrons in the filled K-shell may be accelerated with negligible loss in the AGS. 13 refs., 3 figs., 3 tabs

  16. An investigation of one- versus two-dimensional semiclassical transition state theory for H atom abstraction and exchange reactions.

    Science.gov (United States)

    Greene, Samuel M; Shan, Xiao; Clary, David C

    2016-02-28

    We investigate which terms in Reduced-Dimensionality Semiclassical Transition State Theory (RD SCTST) contribute most significantly in rate constant calculations of hydrogen extraction and exchange reactions of hydrocarbons. We also investigate the importance of deep tunneling corrections to the theory. In addition, we introduce a novel formulation of the theory in Jacobi coordinates. For the reactions of H atoms with methane, ethane, and cyclopropane, we find that a one-dimensional (1-D) version of the theory without deep tunneling corrections compares well with 2-D SCTST results and accurate quantum scattering results. For the "heavy-light-heavy" H atom exchange reaction between CH3 and CH4, deep tunneling corrections are needed to yield 1-D results that compare well with 2-D results. The finding that accurate rate constants can be obtained from derivatives of the potential along only one dimension further validates RD SCTST as a computationally efficient yet accurate rate constant theory.

  17. Analisis Industri pada Ritel Convenience Store: Kasus 7-Eleven (Sevel

    Directory of Open Access Journals (Sweden)

    Son Wandrial

    2013-05-01

    Full Text Available 7-Eleven, a Japanese retailer is very popular and loved in Jakarta. 7-Eleven or commonly abbreviated to Sevel is now reaping a lot of fans because of the concept of 7-Eleven Indonesia, found only in Indonesia. With the rising middle classes in Indonesia, 7-Eleven becomes a luxurious place for hanging-out but affordable. Consequently, it is attracting the interest of investors to make such a kind of convenience store like Sevel, and it is likely the competition in this sector will be increasingly fierce. PT. Modern’s initial plans are to focus onopening stores in Jakarta, targeting densely-populated commercial and office areas, to offer Indonesian workersa convenient place to shop for lunch, snacks, and emergency items. The company’s goal is to focus on opening stores in Jakarta in its first years of operation. Other major cities, such as Bandung, Semarang, and Surabaya offer for future expansion opportunities. The objective of this article is to describe the competitive condition in convenience store industries using Porter’s Five Forces model. Although the competition is fierce andunfavorable industry condition, Sevel is still leading and dominating the convenience store market in Indonesia.

  18. KX radiation of quasi-molecules in heavy ion interaction

    International Nuclear Information System (INIS)

    Kaun, K.G.

    1976-01-01

    The object of investigation is the KX radiation of quasimolecules produced at collision of heavy ions with atoms. In collision, electron may change their states adiabatically and form, at sufficiently small distances R between nuclei, quasimolecular states, which transform, in the limiting case of R → 0, to the states of a quasiatom with an atomic number of Z = Z 1 + Z 2 , where Z 1 and Z 2 are the atomic numbers of the heavy ion and atom. The discussion is restricted to collision experiments of Z = Z 1 + Z 2 > 50. The obtained and published data on the systems Ni+Ni, Nb+Nb, Zr+Nb, La+La, La+Xe, Pb+Pb, and Bi+Bi are analyzed. At a sufficiently high ion energy, one observes an asymmetry of a quasimolecular spectrum, the asymmetry having maximum in the range of the characteristic KX energy of a quasiatom. Data on the absolute yield Y(Ksub(α)) of individual high-energy components of X-rays excited on collision of heavy ions are presented. A considerable drop in yield Y(Ksub(α)) with increasing Z is noted

  19. Multivariate statistical analysis of heavy metals in street dust of Baoji, NW China

    International Nuclear Information System (INIS)

    Lu Xinwei; Wang Lijun; Li, Loretta Y.; Lei Kai; Huang Li; Kang Dan

    2010-01-01

    The concentrations of Pb, Cu, Zn, Mn, Ni, Co and Cr in street dust samples from Baoji in north-west China were measured by wavelength dispersive X-ray fluorescence spectrometry, while As and Hg in street dust samples were determined by atomic fluorescence spectrometry. Principal component analysis and cluster analysis, coupled with correlation coefficient analysis, were used to analyze the data and to identify possible sources of these heavy metals. The results indicate that street dust in Baoji has elevated heavy metal concentrations, especially Hg, Pb, Zn and Cu, which are 16-77, 7-92, 6-26 and 4-12 times the background levels in Shaanxi soil, respectively. The mean heavy metal concentrations in street dust divided by the corresponding background values of Shaanxi soil decrease in the order of Hg > Pb > Zn > Cu > Cr > As > Ni > Co > Mn > V. Three main sources of these heavy metals were identified. As, V, Pb and Co originated from nature and traffic. Cu, Zn, Hg and Mn, especially the former two, mainly derive from industry sources, as well as traffic. Cr and Ni mainly originate from soil.

  20. High-resolution spectroscopy of deeply-bound pionic atoms in heavy nuclei by pion-transfer reactions of inverse kinematics using the GSI cooler ring ESR

    International Nuclear Information System (INIS)

    Yamazaki, Toshimitsu.

    1991-02-01

    Many studies published in the past are reviewed first in relation to high-resolution spectroscopy of deeply-bound pionic atoms in heavy nuclei. The report then describes a procedure for applying the method of inverse kinematics to the case of (d, 3 He) reactions. The (d, 3 He) reaction in inverse kinematics is feasible from practical viewpoints. Thus a discussion is made of the inverse kinematics in which a heavy-ion beam ( 208 Pb for instance) with a projectile kinetic energy hits a deuteron target and ejected recoil 3 He nuclei are measured in the forward direction. The recoil momentum is calculated as a function of the Q value. Analysis shows that the recoil spectroscopy with inverse kinematics can be applied to the case of (d, 3 He) reaction, which will yield a very high mass resolution. The experimental setup for use in the first stage is then outlined, and a simple detector configuration free of magnetic field is discussed. These investigations demonstrate that the (d, 3 He) reaction in inverse kinematics provides a promising tool for obtaining high-resolution spectra of deeply-bound pionic atoms. (N.K.)

  1. Multiple ionization and coupling effects in L-subshell ionization of heavy atoms by oxygen ions

    International Nuclear Information System (INIS)

    Pajek, M.; Banas, D.; Semaniak, J.; Braziewicz, J.; Majewska, U.; Chojnacki, S.; Czyzewski, T.; Fijal, I.; Jaskola, M.; Glombik, A.; Kretschmer, W.; Trautmann, D.; Lapicki, G.; Mukoyama, T.

    2003-01-01

    The multiple-ionization and coupling effects in L-shell ionization of atoms by heavy-ion impact have been studied by measuring the L x-ray production cross sections in solid targets of Au, Bi, Th, and U bombarded by oxygen ions in the energy range 6.4-70 MeV. The measured L x-ray spectra were analyzed using the recently proposed method accounting for the multiple-ionization effects, such as x-ray line shifting and broadening, which enables one to obtain the ionization probabilities for outer shells. The L-subshell ionization cross sections have been obtained from measured x-ray production cross sections for resolved Lα 1,2 , Lγ 1 , and Lγ 2,3 transitions using the L-shell fluorescence and Coster-Kronig yields being substantially modified by the multiple ionization in the M and N shells. In particular, the effect of closing of strong L 1 -L 3 M 4,5 Coster-Kronig transitions in multiple-ionized atoms was evidenced and discussed. The experimental ionization cross sections for the L 1 , L 2 , and L 3 subshells have been compared with the predictions of the semiclassical approximation (SCA) and the ECPSSR theory that includes the corrections for the binding-polarization effect within the perturbed stationary states approximation, the projecticle energy loss, and Coulomb deflection effects as well as the relativistic description of inner-shell electrons. These approaches were further modified to include the L-subshell couplings within the ''coupled-subshell model'' (CSM). Both approaches, when modified for the coupling effects, are in better agreement with the data. Particularly, the predictions of the SCA-CSM calculations reproduce the experimental L-subshell ionization cross section reasonably well. Remaining discrepancies are discussed qualitatively, in terms of further modifications of the L-shell decay rates caused by a change of electronic wave functions in multiple-ionized atoms

  2. Some possible atomic physics experiments with 15 UD pelletron machine

    International Nuclear Information System (INIS)

    Mandal, A.

    1995-01-01

    Some possible experiments in atomic physics using medium energy heavy ion beam from the Pelletron are discussed. Main discussions is on x-ray spectroscopy using heavy ion beam. Different excitation mechanisms of inner atomic shells, experimental results and comparison with different theoretical models are presented. Effects of multiple vacancies in outer shells on K-shell ionisation, projectile charge state and target thickness effects are discussed. High resolution x-ray spectroscopy using curved crystal spectrometer is useful for studying these effects. Special emphasis is given to the study of quasi-molecular orbit (MO) formation during adiabatic collision of heavy ion with atom. Different aspects of MO x-ray study are presented. Other continuum x-rays e.g. radiative electron capture (REC), secondary electron Bremsstrahlung (SEB) nucleus-nucleus Bremsstrahlung (NNB) etc are also discussed. (author). 16 refs., 5 figs

  3. Slowing down of relativistic heavy ions and new applications

    International Nuclear Information System (INIS)

    Geissel, H.; Scheidenberger, C.

    1997-10-01

    New precision experiments using powerful accelerator facilities and high-resolution spectrometers have contributed to a better understanding of the atomic and nuclear interactions of relativistic heavy ions with matter. Experimental results on stopping power and energy-loss straggling of bare heavy projectiles demonstrate large systematic deviations from theories based on first order perturbation. The energy-loss straggling is more than a factor of two enhanced for the heaviest projectiles compared to the relativistic Bohr formula. The interaction of cooled relativistic heavy ions with crystals opens up new fields for basic research and applications, i. e., for the first time resonant coherent excitations of both atomic and nuclear levels can be measured at the first harmonic. The spatial monoisotopic separation of exotic nuclei with in-flight separators and the tumor therapy with heavy ions are new applications based on a precise knowledge of slowing down. (orig.)

  4. X-ray holography with an atomic scatterer

    Energy Technology Data Exchange (ETDEWEB)

    Mityureva, A.A.; Smirnov, V.V., E-mail: valery_smirnov@mail.ru

    2016-08-15

    X-ray holography scheme with reference scatterer consisting of heavy atom as reference center and its link to an object consisting of several light atoms and using controlled variation of the alignment is represented. The scheme can reproduce an object in three dimensions with atomic resolution. The distorting factors of reconstruction are considered. - Highlights: • X-ray holography scheme with a reference wave formed by atomic scatterer. • 3D object reconstruction with atomic resolution from the set of holograms. • Simple formula for the distorting factor in reconstruction.

  5. Heavy metals content in the stem bark of Detarium microcarpum ...

    African Journals Online (AJOL)

    The heavy metal analysis was carried out on the stem bark of D. microcarpum using an atomic absorption spectrophotometer (AAS). The heavy metals screened for include: lead, chromium, manganese, zinc and iron. The levels of manganese, zinc and iron were 13.91, 4.89 and 21.89 mg/L respectively. These heavy metals ...

  6. Hydrotreating of heavy distillate derived from Wandoan coal liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Y. [National Institute for Resources and Environment, Osaka (Japan). Hydrocarbon Research Lab.

    1997-12-03

    The paper reports how the hydrotreatment of coal-derived heavy distillate, obtained from the liquefaction of Wandoan coal using a 1 t/day bench unit, was performed to clarify the effects of catalyst species, reaction temperature and hydrogen pressure on the chemical composition of the product. Experimental runs were carried out over alumina-supported Go-Mo and Ni-Mo catalysts in a fixed bed reactor of 20 ml in volume at 350-390{degree}C under hydrogen pressure of 50-150 kg/cm{sup 2}G with liquid hourly space velocity (LHSV) of 0.5-2 h{sup -1}. The product, as analyzed by gas chromatography, indicated that larger amounts of alkylbenzenes such as toluene or xylenes were produced at the elevated temperature of 390{degree}C, but the concentrations of condensed aromatics such as naphthalene, biphenyl, fluorene and phenanthrene decreased with the severity of reaction conditions. Pyrene and methylpyrene decreased in amount with a shorter LHSV and higher hydrogen pressure, but increased at higher temperature of 390{degree}C. Shorter LHSV and higher hydrogen pressure are much more effective in hydrogenation, hydrodnitrogenation and hydrodeoxygenation than the higher reaction temperature up to 390{degree}C.

  7. The physics of highly charged heavy ions revealed by storage/cooler rings

    International Nuclear Information System (INIS)

    Mokler, P.H.; Stoehlker, T.

    1996-01-01

    With the successful commissioning of storage and cooler rings for bright beams of very heavy ions near the threshold of the last decade of this century, not only did a prosperous development in heavy ion accelerator technology come to its present summit, but also fundamental fields in heavy ion physics were opened widely for exciting explorations. Now, essential aspects in this area are accessible, aspects one only dared to dream of another decade ago. In the meantime, great progress already has been made in the fundamental physics in this field. This is particularly true for achievements in the atomic physics of highly charged heavy ions. In this chapter, we present a review of the current advances in this rapidly developing field. There are two general domains to be considered in the atomic physics of highly charged heavy ions: the fields of collisions and of atomic structure. Both aspects have to be explored equally, as they are strongly interconnected. One has to investigate the interaction processes to know, for instance, the population of excited states to help answer questions on the atomic structure; and conversely, one has to know the structure to understand the interactions. In both the fields, fundamental principles can be studied uniquely. This is in particular true for the heaviest ion species with only a few- or even zero-electrons left. 140 refs., 39 figs

  8. Probing Efimov discrete scaling in an atom-molecule collision

    Science.gov (United States)

    Shalchi, M. A.; Yamashita, M. T.; Hadizadeh, M. R.; Garrido, E.; Tomio, Lauro; Frederico, T.

    2018-01-01

    The discrete Efimov scaling behavior, well known in the low-energy spectrum of three-body bound systems for large scattering lengths (unitary limit), is identified in the energy dependence of an atom-molecule elastic cross section in mass-imbalanced systems. That happens in the collision of a heavy atom with mass mH with a weakly bound dimer formed by the heavy atom and a lighter one with mass mL≪mH . Approaching the heavy-light unitary limit, the s -wave elastic cross section σ will present a sequence of zeros or minima at collision energies following closely the Efimov geometrical law. Our results, obtained with Faddeev calculations and supplemented by a Born-Oppenheimer analysis, open a perspective to detecting the discrete scaling behavior from low-energy scattering data, which is timely in view of the ongoing experiments with ultracold binary mixtures having strong mass asymmetries, such as lithium and cesium or lithium and ytterbium.

  9. Stopping powers and ranges for the heaviest atoms

    International Nuclear Information System (INIS)

    Sagaidak, Roman N.; Utyonkov, Vladimir K.; Dmitriev, Sergey N.

    2015-01-01

    Slowing down and stopping of the heaviest atoms, products of the fusion–evaporation nuclear reactions, during their passage through the Dubna gas-filled recoil separator has been studied using TRIM simulations. The study is important for experiments on the synthesis of super-heavy elements (SHEs) with atomic numbers around Z_P = 114 produced with accelerated heavy ion (HI) beams and extracted with a separator for their detection. The average Mylar stopping power (SP) values obtained with the simulations for HIs with 82 ⩽ Z_P ⩽ 92 reveal almost the same magnitudes, allowing extrapolation to the region of Z_P > 92. Similar extrapolation of the ranges in an He + Ar gas mixture leads to rather small values for the heaviest atoms (Z_P ⩾ 102) as compared to the range for U. The extrapolated values have large uncertainties and should be verified with different approaches. Available SP data obtained for HIs with 18 ⩽ Z_P ⩽ 92 at energies E < 20 MeV/u have been analysed within various semi-empirical approaches. The analysis has shown that existing parameterizations give Mylar SP values for Z_P ⩾ 82 that are very different from each other at energies of interest (around 0.1 MeV/u). We propose to use a general approach based on the HI effective charge parameterization obtained with available SP data for HIs and the hydrogen SP and effective charge corresponding to the same velocity and stopping medium as those for HIs. In this manner, the SPs of the gases H_2, He, C_4H_1_0, and Ar as well as those of the solids Mylar, C, Al, and Ti have been obtained for any atoms with Z_P ⩾ 18 (including the heaviest ones) at their reduced velocities 0.03 ⩽ V_r_e_d ⩽ 5.0. The SP values derived in such a way seem to be more reliable compared to the existing semi-empirical calculations and can be used in the conditioning of experiments on the synthesis of SHEs.

  10. IR analyzer spots heavy water leaks

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    A correlation spectrometer developed by Barringer Research Ltd. (in collaboration with Atomic Energy of Canada and Ontario Hydro) is used to measure HDO concentrations in DTO in the final (distillation) stage of heavy-water production. A unit has been installed at Bruce Heavy Water Plant. Previously, such spectrometers had been installed to detect heavy-water leaks in CANDU reactors. The principle on which the instrument works is explained, with illustrations. It works by comparing the absorption at 2.9 μm, due to HDO, with that at 2.6 μm, due to both HDO and D 2 O. (N.D.H.)

  11. Exotic phenomena in collisions of heavy ions

    International Nuclear Information System (INIS)

    Soff, G.; Schramm, S.; Reus, T. de; Mehler, G.; Reinhardt, J.; Mueller, B.; Greiner, W.; Mueller, U.

    1985-08-01

    To exemplify current theoretical investigations we discuss three different topics. After a presentation of the underlying theoretical framework for ionization processes we will sketch the possibility to employ delta-electron emission as a clock to measure nuclear reaction times in intermediate energy collisions of very heavy ions. Besides the phenomenon of vacuum decay into a new twofold negatively charged stable vacuum ground state, electron excitation in heavy ion collisions may be employed for the determination of delay and deceleration times on the nuclear time scale, i.e. offering an atomic clock, operating in the range 10 -21 -10 -24 s. In deep-inelastic heavy ion collisions this provides a test for classical nuclear reaction models. In collisions at intermediate energies an independent measurement of the deceleration time is of interest for comparison, e.g., with the results of the pion bremsstrahlung model. After that we investigate the influence of one or more pockets in the ion scattering potential on the energy distribution of emitted positrons within a quantum mechanical framework. Finally we very briefly consider some phenomenological corrections to the Dirac equation and its consequences on electron binding energies in heavy and superheavy atoms. (orig./HSI)

  12. Leaching of heavy metals from contaminated soils using inductively coupled plasma optical emission spectrometer (ICP-OES) and atomic absorption spectrometer (AAS)

    International Nuclear Information System (INIS)

    Hussain, Z.; Islam, M.

    2010-01-01

    The clean-up of soils contaminated with heavy metals is one of the most difficult tasks for environmental engineering. Heavy metals are highly persistent in soil and a number of techniques have been developed that aim to remove heavy metals from contaminated soil. A method has been adopted to evaluate dynamic leaching of metal contaminants from industrial soil samples obtained from textile industrial sites in Lahore, Pakistan. In the extraction procedures employed five different leaching liquors were used: 0.01 M CaCl/sub 2/, 1 M HNO/sub 3/, a 1:1 mixture of 0.1M HCl and 0.1M NaCl, 0.01 M EDTA and pH controlled 0.5 M acetic acid. The qualitative and quantitative analyses were carried out by Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). The results indicate that Cu, Zn, Cd, Ni, Pb, Fe and As were extracted in the soil samples in varying concentration when using the different leach liquors. The predominant metals which were leached were As 78.7 ng/ml in 0.01 M EDTA; Zn 1.81 mu g/ml and Fe 898.96 macro g/ml in HNO/sub 3/. (author)

  13. Direct determination of arsenic in petroleum derivatives by graphite furnace atomic absorption spectrometry: A comparison between filter and platform atomizers

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Emilene; Rampazzo, Roger T.; Dessuy, Morgana B. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R., E-mail: mgrvale@ufrgs.br [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq - INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Silva, Marcia M. da [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Welz, Bernhard [Instituto Nacional de Ciencia e Tecnologia do CNPq - INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Katskov, Dmitri A. [Tshwane University of Technology (TUT), Faculty of Science, Chemistry Department, Pretoria 0001 (South Africa)

    2011-05-15

    In the present work a direct method for the determination of arsenic in petroleum derivatives has been developed, comparing the performance of a commercial transversely heated platform atomizer (THPA) with that of a transversely heated filter atomizer (THFA). The THFA results in a reduction of background absorption and an improved sensitivity as has been reported earlier for this atomizer. The mixture of 0.1% (m/v) Pd + 0.03% (m/v) Mg + 0.05% (v/v) Triton X-100 was used as the chemical modifier for both atomizers. The samples (naphtha, gasoline and petroleum condensate) were stabilized in the form of a three-component solution (detergentless microemulsion) with the sample, propan-1-ol and 0.1% (v/v) HNO{sub 3} in a ratio of 3.0:6.4:0.6. The characteristic mass of 13 pg found in the THFA was about a factor of two better than that of 28 pg obtained with the THPA; however, the limits of detection (LOD) and quantification (LOQ) were essentially the same for both atomizers (1.9 and 6.2 {mu}g L{sup -1}, respectively, for THPA, and 1.8 and 5.9 {mu}g L{sup -1}, respectively, for THFA) due to the increased noise observed with the THFA. A possible explanation for that is a partial blockage of the radiation from the hollow cathode lamp by the narrow inner diameter of this tube and the associated loss of radiation energy. Due to the lack of an appropriate certified reference material, recovery tests were carried out with inorganic and organic arsenic standards and the results were between 89% and 111%. The only advantage of the THFA found in this work was a reduction of the total analysis time by about 20% due to the 'hot injection' that could be realized with this furnace. The arsenic concentrations varied from < LOQ to 43.3 {mu}g L{sup -1} in the samples analyzed in this work.

  14. The Knights’ Eleven Oars: In Praise of Phormio? (Ar. Eq. 546-7)

    DEFF Research Database (Denmark)

    Lech, Marcel Lysgaard

    2009-01-01

    The curious “eleven oars” of the chorus of Knights in Aristophanes’ eponymous play recall the victory of Phormio and his eleven triremes in the gulf of Naupactus in 429 B.C., and echo a lost victory ode performed at the celebration of this victory....

  15. Spectroscopy of highly ionized atoms

    International Nuclear Information System (INIS)

    Livingston, A.E.

    1987-01-01

    The atomic structure and decay characteristics of excited states in multiply ionized atoms represent a fertile testing ground for atomic calculations ranging from accurate ab initio theory for few-electron systems to practical semi-empirical approaches for many-electron species. Excitation of fast ions by thin foils generally produces the highest ionization stages for heavy ions in laboratory sources. The associated characteristics of spectroscopic purity and high time resolution provide unique capabilities for studying the atomic properties of highly-ionized atoms. This report is limited to a brief discussion of three classes of atomic systems that are experiencing current theoretical and experimental interest: precision structure of helium-like ions, fine structure of doubly-excited states, and lifetimes of metastable states. Specific measurements in each of these types of systems are mentioned, with emphasis on the relation to studies involving slow, highly-charged ions

  16. Biomonitoring of heavy metals in feathers of eleven common bird species in urban and rural environments of Tiruchirappalli, India.

    Science.gov (United States)

    Manjula, Menon; Mohanraj, R; Devi, M Prashanthi

    2015-05-01

    Heavy metals continue to remain as a major environmental concern in spite of emission control measures. In this study, we analyzed the concentrations of heavy metals (Fe, Cr, Mn, Ni, Cu, Zn, and Cd) in the feathers of 11 species of birds collected from urban and rural areas of Tiruchirappalli, Southern India. Metal concentrations followed the order: Fe > Cu > Zn > Cr > Mn > Ni > Cd. Irrespective of sample locations, heavy metals such as Fe, Cr, Ni, Zn, and Cu were detected in high concentrations, while Cd and Mn were observed in lower concentrations. In contrary to our assumption, there were no statistically significant intraspecific and urban-rural differences in the metal concentrations except for Zn. Pairwise comparisons among species irrespective of metal type showed significant interspecific differences between Acridotheres tristis and Centropus phasianinus, A. tristis and Milvus migrans, C. phasianinus and M. migrans, M. migrans and Eudynamys scolopaceus, and Psittacula krameri and E. scolopaceus. Principal component analysis carried out for urban data extracted Ni, Mn, Zn, Fe, and Cu accounting for 48% variance implying dietary intake and external contamination as important sources for metals. In the rural, association of Zn, Cd, Ni, and Cr suggests the impact of metal fabrication industries and leather tanning operations.

  17. Physical aspects of heavy charged particle beams for radiotherapy

    International Nuclear Information System (INIS)

    Kawashima, Katsuhiro

    1989-01-01

    Physical properties of heavy ion beams are discussed to improve the physical dose distributions in view of radiotherapy. Preservation of the structural and functional integrity of adjacent normal tissue is required to achieve great probability of tumor control. This will be accomplished with the reduction of irradiated volume of normal tissues and with greater relative biological effectiveness (RBE) on tumor cells than that on surrounding normal cells. This suggests the use of heavy ion beams as new source of radiation that increases the therapeutic ratio. The basis of the improvement in the physical dose distribution by use of heavy charged particles is due to the finite range of the beams and to the less multiple coulomb scattering of the particles having a heavier atomic mass than proton. The depth dose distributions and dose profiles of heavy particle beams are discussed in this article. The lateral sharpness of heavy charged particles is comparable to the penumbra of high energy photon and electron beams and is not of clinical concern due to less coulomb scattering of heavy ions to lateral direction in traversing a medium. The dose gradient at the end of range of primary beam is dependent upon the energy spread and range straggling of the particles. The magnitude of range straggling is nearly proportional to the range and inversely proportional to the inverse square root of the particle mass. Heavy ion beams also undergo nuclear interactions, in which the primary beam may produce lower atomic number particles. Therefore, the dose beyond the Bragg peak is due to those fragments. Fragmentation increases as a function of the atomic mass to the 2/3 power and with the energy of the particles. Thus, the production of fragments diminishes the depth dose advantages of heavy ions. The choice of ion for radiotherapy may depend on evaluation of important parameter for tumor control. (J.P.N.)

  18. Accelerator-based atomic physics experiments with photon and ion beams

    International Nuclear Information System (INIS)

    Johnson, B.M.; Jones, K.W.; Meron, M.

    1984-01-01

    Accelerator-based atomic physics experiments at Brookhaven presently use heavy-ion beams from the Dual MP Tandem Van de Graaff Accelerator Facility for atomic physics experiments of several types. Work is presently in progress to develop experiments which will use the intense photon beams which will be available in the near future from the ultraviolet (uv) and x-ray rings of the National Synchrotron Light Source (NSLS). Plans are described for experiments at the NSLS and an exciting development in instrumentation for heavy-ion experiments is summarized

  19. Safety Evaluation of Osun River Water Containing Heavy Metals and ...

    African Journals Online (AJOL)

    Summary: This study evaluated the pH, heavy metals and volatile organic compounds (VOCs) in Osun river water. It also evaluated its safety in rats. Heavy metals were determined by atomic absorption spectrophotometry (AAS) while VOCs were determined by gas chromatography coupled with flame ionization detector ...

  20. Aryl nitrene rearrangements: spectroscopic observation of a benzazirine and its ring expansion to a ketenimine by heavy-atom tunneling.

    Science.gov (United States)

    Inui, Hiroshi; Sawada, Kazuhiro; Oishi, Shigero; Ushida, Kiminori; McMahon, Robert J

    2013-07-17

    In the photodecompositions of 4-methoxyphenyl azide (1) and 4-methylthiophenyl azide (5) in argon matrixes at cryogenic temperatures, benzazirine intermediates were identified on the basis of IR spectra. As expected, the benzazirines photochemically rearranged to the corresponding ketenimines and triplet nitrenes. Interestingly, with the methylthio substituent, the rearrangement of benzazirine 8 to ketenimine 7 occurred at 1.49 × 10(-5) s(-1) even in the dark at 10 K, despite a computed activation barrier of 3.4 kcal mol(-1). Because this rate is 10(57) times higher than that calculated for passing over the barrier and because it shows no temperature dependence, the rearrangement mechanism is interpreted in terms of heavy-atom tunneling.

  1. Insights into the Hydrogen-Atom Transfer of the Blue Aroxyl.

    Science.gov (United States)

    Bächle, Josua; Marković, Marijana; Kelterer, Anne-Marie; Grampp, Günter

    2017-10-19

    An experimental and theoretical study on hydrogen-atom transfer dynamics in the hydrogen-bonded substituted phenol/phenoxyl complex of the blue aroxyl (2,4,6-tri-tert-butylphenoxyl) is presented. The experimental exchange dynamics is determined in different organic solvents from the temperature-dependent alternating line-width effect in the continuous-wave ESR spectrum. From bent Arrhenius plots, effective tunnelling contributions with parallel heavy-atom motion are concluded. To clarify the transfer mechanism, reaction paths for different conformers of the substituted phenol/phenoxyl complex are modelled theoretically. Various DFT and post-Hartree-Fock methods including multireference methods are applied. From the comparison of experimental and theoretical data it is concluded that the system favours concerted hydrogen-atom transfer along a parabolic reaction path caused by heavy-atom motion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Conduction of molecular electronic devices: Qualitative insights through atom-atom polarizabilities

    International Nuclear Information System (INIS)

    Stuyver, T.; Fias, S.; De Proft, F.; Geerlings, P.; Fowler, P. W.

    2015-01-01

    The atom-atom polarizability and the transmission probability at the Fermi level, as obtained through the source-and-sink-potential method for every possible configuration of contacts simultaneously, are compared for polycyclic aromatic compounds. This comparison leads to the conjecture that a positive atom-atom polarizability is a necessary condition for transmission to take place in alternant hydrocarbons without non-bonding orbitals and that the relative transmission probability for different configurations of the contacts can be predicted by analyzing the corresponding atom-atom polarizability. A theoretical link between the two considered properties is derived, leading to a mathematical explanation for the observed trends for transmission based on the atom-atom polarizability

  3. Conduction of molecular electronic devices: Qualitative insights through atom-atom polarizabilities

    Energy Technology Data Exchange (ETDEWEB)

    Stuyver, T.; Fias, S., E-mail: sfias@vub.ac.be; De Proft, F.; Geerlings, P. [ALGC, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel (Belgium); Fowler, P. W. [Department of Chemistry, University of Sheffield, Sheffield S3 7HF (United Kingdom)

    2015-03-07

    The atom-atom polarizability and the transmission probability at the Fermi level, as obtained through the source-and-sink-potential method for every possible configuration of contacts simultaneously, are compared for polycyclic aromatic compounds. This comparison leads to the conjecture that a positive atom-atom polarizability is a necessary condition for transmission to take place in alternant hydrocarbons without non-bonding orbitals and that the relative transmission probability for different configurations of the contacts can be predicted by analyzing the corresponding atom-atom polarizability. A theoretical link between the two considered properties is derived, leading to a mathematical explanation for the observed trends for transmission based on the atom-atom polarizability.

  4. Conduction of molecular electronic devices: qualitative insights through atom-atom polarizabilities.

    Science.gov (United States)

    Stuyver, T; Fias, S; De Proft, F; Fowler, P W; Geerlings, P

    2015-03-07

    The atom-atom polarizability and the transmission probability at the Fermi level, as obtained through the source-and-sink-potential method for every possible configuration of contacts simultaneously, are compared for polycyclic aromatic compounds. This comparison leads to the conjecture that a positive atom-atom polarizability is a necessary condition for transmission to take place in alternant hydrocarbons without non-bonding orbitals and that the relative transmission probability for different configurations of the contacts can be predicted by analyzing the corresponding atom-atom polarizability. A theoretical link between the two considered properties is derived, leading to a mathematical explanation for the observed trends for transmission based on the atom-atom polarizability.

  5. Determination of concentration of heavy metals (Pb, Cd, Fe) in animal tissues using atomic absorption spectrometry

    International Nuclear Information System (INIS)

    RAZAFINTSALAMA, V.T.

    2009-01-01

    Heavy metals are classified among the inorganic compounds. The latter type of metal is found in rocks, fertilizers, urban mud but may also originate from the atmospheric pollution. A particular characteristic of heavy metals is their bioaccumulation in the food chain. Therefore, lead and cadmium, which are classified as heavy metals may be easily found in animal products and can lead to food poisoning if their concentrations are higher than the maximum permissible values as requested by international agencies such as the c odex alimentarius . The values are set down and differ according to types of food for human consuption and the trading companies take action accordingly. Therefore, it is necessary to set up a quality control system through analytical laboratory measurements and testings. This study underlies the method of determination of lead, cadmium and iron in animal tissues by atomic absorption spectrometry. The results showed that the method is sensitive and reliable. For each analyte, the Z-score lies between -2 and 2, indicating that the method is working properly. The analytical results showed that: (i) only beef and chicken meats and beef liver contain lead [0,09μg.g - 1; 0,29μg.g - 1]. The limit value of 0,1μg.g - 1 is almost reached in beef and chicken meats, (ii) as far as cadmium is concerned, the five studied samples contain this analyte [0,02μg.g - 1; 0,9μg.g - 1]. Except the chicken liver of which the concentration (0,15μg.g - 1) exceeds the maximum permissible value (0,1μg.g - 1), the others are in conformity with the standards and appropriate to be consumed,(iii) iron is higher in the liver and kidney samples: beef liver 282mg.g - 1, chicken liver 250 mg.g - 1, pork kidney 247mg.g - 1. The study also showed that the calcium concentration in animal tissues is low and they can be classified as poor-calcium food. [fr

  6. Heavy metals burden of Keenjhar Lake, District Thatta, Sindh, Pakistan

    African Journals Online (AJOL)

    Detection of heavy metals (HMs) content from Keenjhar Lake water was carried out monthly from January to December, 2003. Zinc, chromium, copper, iron, manganese, nickel and cadmium were analyzed by dual mode of analytical methods flame atomic absorption spectrometry and electrothermal atomic absorption ...

  7. Atomic physics of strongly correlated systems

    International Nuclear Information System (INIS)

    Lin, C.D.

    1986-01-01

    This abstract summarizes the progress made in the last year and the future plans of our research in the study of strongly correlated atomic systems. In atomic structure and atomic spectroscopy we are investigating the classification and supermultiplet structure of doubly excited states. We are also beginning the systematic study of triply excited states. In ion-atom collisions, we are exploring an AO-MO matching method for treating multi-electron collision systems to extract detailed information such as subshell cross sections, alignment and orientation parameters, etc. We are also beginning ab initio calculations on the angular distributions for electron transfer processes in low-energy (about 10-100eV/amu) ion-atom collisions in a full quantum mechanical treatment of the motion of heavy particles

  8. Study of the heavy water regeneration processes

    International Nuclear Information System (INIS)

    Cavcic, E.

    1965-11-01

    Experience derived from heavy water reactor operation showed degradation and dilution of heavy water to be inevitable and depends on the type of reactor. Dilution of heavy water during operation of the RA and the RB reactors is shown in this report. Principles and procedures of heavy water regeneration by electrolysis, fractional distillation, cleaning, prevention of tritium contamination are described as well as separation columns

  9. Spectrophotometric Determination Of Heavy Metals In Cosmetics

    African Journals Online (AJOL)

    ISSN 1597-6343. Spectrophotometric Determination Of Heavy Metals In Cosmetics ... analysed using atomic absorption spectrophotometer – coupled with a hydride ... presence of arsenic (As), mercury (Hg), cadmium (Cd) and lead. (Pb) in ...

  10. Uncertainty estimates for theoretical atomic and molecular data

    International Nuclear Information System (INIS)

    Chung, H-K; Braams, B J; Bartschat, K; Császár, A G; Drake, G W F; Kirchner, T; Kokoouline, V; Tennyson, J

    2016-01-01

    Sources of uncertainty are reviewed for calculated atomic and molecular data that are important for plasma modeling: atomic and molecular structures and cross sections for electron-atom, electron-molecule, and heavy particle collisions. We concentrate on model uncertainties due to approximations to the fundamental many-body quantum mechanical equations and we aim to provide guidelines to estimate uncertainties as a routine part of computations of data for structure and scattering. (topical review)

  11. Physicochemical determinations of petroleum, heavy fuel derivative and combustion nanoparticles

    International Nuclear Information System (INIS)

    Frias Bullain, Jorge; Padron Rodriguez, M.; Perez Barcala, B.; Lopez Guerra, S.

    2016-01-01

    In the investigation, a crude from Cuban Northern Heavy Oil Belt and its fuel oil fraction was characterized by chemical and physical techniques. Subsequent to the characterization of the derivative, MSI gas analyzer was performed, to identify and quantify concentrations of chemical species, in correspondence with EPA (2007) for external sources. Total suspended particles collected in filter holder were identified using the gravimetric method (ISO 9096). With the intention of knowing the magnitude of polycyclic aromatic hydrocarbons reported in literature were chosen the higher and lower molecular mass and measured on the basis of its polar covalent radii. Total aromatic hydrocarbons were identified using activated charcoal with subsequent elution with nhexane for analysis by ultraviolet spectroscopy in a Genesys 10 UV spectrophotometer. Environmental pollution control in the oil sector, is evaluated in three states. The particles in the states mentioned above, whose dimensions are between (1-100) x10-9 meters are called nanoparticles. Nanotechnology currently offers firm steps in the development of different nanoparticles, which are applied directly to the mineralogical industry. Contributions stand out sharply operations: exploration, drilling and refining oil. (Author)

  12. Heavy atom induced room temperature fluorescence quenching of PAH from a glucose glass

    Energy Technology Data Exchange (ETDEWEB)

    Marlow, Matt, E-mail: matthew.marlow@nicholls.edu

    2017-06-15

    Sugar glasses are a relatively new matrix for solid-matrix luminescence. Molecular interactions within the sugar glass are not well understood. Fluorescence quenching was used to investigate molecular interactions within the sugar glass matrix. The room temperature fluorescence quenching of pyrene and naphthalene was observed from a glucose glass. The heavy atom salt NaI was the quencher. Two solvent compositions 50/50 and 60/40 MeOH/water, used for glass preparation, were examined for their effect on glass rigidity and molecular interactions. A complex static mechanism was observed for glasses prepared with 50/50 MeOH/water. This data was fit to the sphere of action model and associations constants determined. A Stern-Volmer static mechanism of quenching was observed for glasses prepared with 60/40 MeOH/water. This data fit the Stern-Volmer equation and association constants were determined. A larger association constant was observed for pyrene compared to naphthalene for both solvent systems used. Pyrene had a larger association constant with a sugar glass prepared with 60/40 MeOH/water compared to 50/50 MeOH/water implying a greater association between pyrene and iodide. The greater association is a reflection of a more rigid internal environment for the sugar glass prepared with 60/40 MeOH/water.

  13. Exotic phenomena in collisions of very heavy ions

    International Nuclear Information System (INIS)

    Soff, G.; Mueller, U.; Schramm, S.; de Reus, T.; Mehler, G.; Reinhardt, J.; Mueller, B.; Greiner, W.

    1987-01-01

    Over the last decade their knowledge on atomic structure of superheavy quasimolecules in the range 110 ≤ Z/sub tot/ ≤ 188 has increased considerably. Heavy ion collisions, in which superheavy quasimolecules are formed for a short period of time, offer them a unique tool to investigate the electronic structure of ultra-high Z-systems, which are not otherwise accessible to experiment. Comparison of K-vacancy formation, δ-electron and positron emission with available experimental data suggests the validity of the quasimolecular picture, which will be taken as the theoretical framework of these calculations. To exemplify current theoretical investigations three different topics will be discussed. After a presentation of the underlying theoretical framework for ionization processes the possibility to employ δ-electron emission as a clock to measure nuclear reaction times in intermediate energy collisions of very heavy ions will be sketched. Besides the phenomenon of vacuum decay into a new twofold negatively charged stable vacuum ground state, electron excitation in heavy ion collisions may be employed for the determination of delay and deceleration times on the nuclear time scale, i.e. offering an atomic clock, operating in the range 10 -21 - 10 -24 s. In deep-inelastic heavy ion collisions this provides a test for classical nuclear reaction models. In collisions at intermediate energies an independent measurement of the deceleration time is of interest for comparison, e.g., with the results of the pion bremsstrahlung model. After that the influence of one or more pockets in the ion scattering potential on the energy distribution of emitted positrons within a quantum mechanical framework is investigated. Finally phenomenological corrections to the Dirac equation and its consequences on electron binding energies in heavy and superheavy atoms is briefly considered. 42 references, 5 figures

  14. Elliptic flow and energy loss of heavy quarks in ultrarelativistic heavy ion collisions

    International Nuclear Information System (INIS)

    Uphoff, Jan; Fochler, Oliver; Greiner, Carsten; Xu, Zhe

    2011-01-01

    The space-time propagation of heavy quarks in ultrarelativistic heavy ion collisions is studied within the partonic transport model Boltzmann approach of multiparton scatterings (BAMPS). In this model heavy quarks interact with the partonic medium via binary scatterings. The cross sections for these interactions are calculated with leading-order perturbative QCD, but feature a more precise Debye screening derived within the hard thermal loop approximation and obey the running of the coupling. Within this framework the elliptic flow and the nuclear modification factor of heavy quarks are computed for the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC) energies and compared to available experimental data. It is found that binary scatterings alone cannot reproduce the data and therefore radiative corrections have to be taken into account.

  15. Synthesis of pyrido[1,2-a]benzimidazoles and other fused imidazole derivatives with a bridgehead nitrogen atom

    Science.gov (United States)

    Begunov, Roman S.; Ryzvanovich, Galina A.

    2013-01-01

    Main methods for the synthesis of fused imidazole derivatives with a bridgehead nitrogen atom are systematically considered and summarized. The reaction mechanisms that underlie the methods for the synthesis of pyrido[1,2-a]benzimidazoles and related compounds are described. Biological properties and mechanisms of the biological activity of fused azaheterocycles are discussed. The bibliography includes 152 references.

  16. APIPIS: the Atomic Physics Ion-Photon Interaction System

    International Nuclear Information System (INIS)

    Johnson, B.M.; Jones, K.W.; Meron, M.; Kostroun, V.O.

    1985-01-01

    A proposed new facility for the study of highly charged heavy ions is described. The basic elements of APIPIS, the Atomic Physics Ion-Photon Interaction System, are: (1) a source of multiply-charged ions; (2) a linear accelerator; (3) a synchrotron storage ring; and (4) a source of high brightness x rays. The placement of a heavy ion storage ring at the x-ray ring of the National Synchrotron Light Source will provide unique opportunities for the study of photo-excitation of heavy ions

  17. Very heavy iron-punching concretes

    International Nuclear Information System (INIS)

    Dubois, F.

    1966-01-01

    The present report deals with all the heavy iron-punching concretes, metallic wastes produced by the transformation industry. After a detailed description of the physical properties of metallic aggregates, a classification of heavy mortars is given, into three main categories: steel-shot grouts d = 5,3 - 6; steel-shot grouts mixed with a mineral d = 3,7 - 4,2; injection heavy grouts d = 3,5 - 4. The following chapter describes iron-punching concretes the most used in the atomic industry: iron-punching concretes mixed with cast-iron - iron-punching concretes mixed with magnetite; iron-punching concretes mixed with barite; iron-punching concretes mixed with limonite; iron-punching concretes mixed with boron. The compositions of these concretes are given together with their physical and mechanical characteristics. Numerous diagrams make it possible to find rapidly the proportions of the constituents of these concretes as a function of the required density. Technical advice and specifications are given in an appendix together with a bibliography of these heavy concretes. (author) [fr

  18. Quantum fluctuations and spontaneous compactification of eleven-dimensional gravity

    International Nuclear Information System (INIS)

    Nguen Van Hieu.

    1985-01-01

    The reduction of the eleven-dimensional pure gravity to the field theory in the four-dimensional Minkowski space-time by means of the spontaneous compactification of the extra dimensions is investigated. The contribution of the quantum fluctuations of the eleven-dimen-- sonal second rank symmetric tensor field to the curvatures of the space-time and the compactified space of the extra dimensions are calculated in the one-loop approximation. It is shown that there exist the values of the cosmological constant for which tachions are absent. As a result, self-consistent quantum field theory is obtained in spontaneous compactified Minkowski space M 4 xS 7 ,is where M 4 is Minkowski space-time, and S 7 is seven-dimensional sphere

  19. SIS: an accelerator installation for heavy ions of high energy

    International Nuclear Information System (INIS)

    The two major sections of the report cover the scientific experimental program and the accelerator installation. Topics covered in the first include: heavy ion physics in the medium energy region; nuclear physics at relativistic energies; atomic physics loss and capture cross sections for electrons; spectroscopy of few-electron systems; atomic collision processes; biological experiments; nuclear track techniques in biology; and experiments with protons and secondary radiation. The second includes: concept for the total installation; technical description of the SIS 12; technical description of the SIS 100; status of the UNILAC injector; development options for the SIS installations; properties of the heavy ion beam; and structural work and technical supply provisions. In this SIS project proposal, an accelerator installation based on two synchrotrons is described with which atomic nuclei up to uranium can be accelerated to energies of more than 10 GeV/μ. With the SIS 12, which is the name of the first stage, heavy ion physics at intermediate energies can be pursued up to 500 MeV/μ. The second stage, a larger synchrotron, the SIS 100, has a diameter of 250 m. With this device, it is proposed to open up the domain of relativistic heavy ion physics up to 14 GeV/μ (for intermediate mass particles) and 10 GeV/μ (for uranium)

  20. 5. International workshop on autoionization phenomena in atoms. Abstracts

    International Nuclear Information System (INIS)

    Balashov, V.V.

    1995-01-01

    Summaries of the reports presented at the 5 International Workshop on Autoionization Phenomena in Atoms (Dubna, 12-14 December 1995). The main topics of these 53 reports are the following ones: photoexcitation of autoionizing states in atoms and ions, autoionization in electron-atom collisions, autoionization in heavy particle collisions, coincidence experiments in autoionization studies, investigations of autoionizing states with lasers and wave functions and decay characteristics of autoionizing states

  1. Selectively improving the bio-oil quality by catalytic fast pyrolysis of heavy-metal-polluted biomass: take copper (Cu) as an example.

    Science.gov (United States)

    Liu, Wu-Jun; Tian, Ke; Jiang, Hong; Zhang, Xue-Song; Ding, Hong-Sheng; Yu, Han-Qing

    2012-07-17

    Heavy-metal-polluted biomass derived from phytoremediation or biosorption is widespread and difficult to be disposed of. In this work, simultaneous conversion of the waste woody biomass into bio-oil and recovery of Cu in a fast pyrolysis reactor were investigated. The results show that Cu can effectively catalyze the thermo-decomposition of biomass. Both the yield and high heating value (HHV) of the Cu-polluted fir sawdust biomass (Cu-FSD) derived bio-oil are significantly improved compared with those of the fir sawdust (FSD) derived bio-oil. The results of UV-vis and (1)H NMR spectra of bio-oil indicate pyrolytic lignin is further decomposed into small-molecular aromatic compounds by the catalysis of Cu, which is in agreement with the GC-MS results that the fractions of C7-C10 compounds in the bio-oil significantly increase. Inductively coupled plasma-atomic emission spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy analyses of the migration and transformation of Cu in the fast pyrolysis process show that more than 91% of the total Cu in the Cu-FSD is enriched in the char in the form of zerovalent Cu with a face-centered cubic crystalline phase. This study gives insight into catalytic fast pyrolysis of heavy metals, and demonstrates the technical feasibility of an eco-friendly process for disposal of heavy-metal-polluted biomass.

  2. Earthworm biomass as additional information for risk assessment of heavy metal biomagnification: a case study for dredged sediment-derived soils and polluted floodplain soils

    International Nuclear Information System (INIS)

    Vandecasteele, Bart; Samyn, Jurgen; Quataert, Paul; Muys, Bart; Tack, Filip M.G.

    2004-01-01

    The important role of earthworms in the biomagnification of heavy metals in terrestrial ecosystems is widely recognised. Differences in earthworm biomass between sites is mostly not accounted for in ecological risk assessment. These differences may be large depending on soil properties and pollution status. A survey of earthworm biomass and colonisation rate was carried out on dredged sediment-derived soils (DSDS). Results were compared with observations for the surrounding alluvial plains. Mainly grain size distribution and time since disposal determined earthworm biomass on DSDS, while soil pollution status of the DSDS was of lesser importance. Highest earthworm biomass was observed on sandy loam DSDS disposed at least 40 years ago. - Polluted clayey dredged sediment-derived soils have a relatively low risk for heavy metal biomagnification due to slow earthworm colonisation

  3. Penetration of relativistic heavy ions through matter

    International Nuclear Information System (INIS)

    Scheidenberger, C.; Geissel, H.

    1997-07-01

    New heavy-ion accelerators covering the relativistic and ultra-relativistic energy regime allow to study atomic collisions with bare and few-electron projectiles. High-resolution magnetic spectrometers are used for precise stopping-power and energy-loss straggling measurements. Refined theories beyond the Born approximation have been developed and are confirmed by experiments. This paper summarizes the large progress in the understanding of relativistic heavy-ion penetration through matter, which has been achieved in the last few years. (orig.)

  4. Atomic physics in the Tandar Laboratory

    International Nuclear Information System (INIS)

    Nemirovsky, I.B.

    1987-01-01

    The research activities carried out in the Tandar Laboratory of Physics Department of Argentine National Atomic Energy Comission are presented. The processes of heavy ion collisions with solids as thin lamellae investigated in the Laboratory are described. (M.C.K.) [pt

  5. Atomic nucleus and elementary particles

    International Nuclear Information System (INIS)

    Zakrzewski, J.

    1976-01-01

    Negatively charged leptons and hadrons can be incorporated into atomic shells forming exotic atoms. Nucleon resonances and Λ hyperons can be considered as constituents of atomic nuclei. Information derived from studies of such exotic systems enriches our knowledge of both the interactions of elementary particles and of the structure of atomic nuclei. (author)

  6. Nuclear and atomic physics at one gigaflop

    International Nuclear Information System (INIS)

    Bottcher, C.; Strayer, J.B.

    1989-01-01

    A three-day workshop on problems in atomic and nuclear physics which depend on and are, at present, severely limited by access to supercomputing at effective rates of one gigaflop or more, was held at Oak Ridge, Tennessee, April 14-16, 1988. The participants comprised researchers from universities, industries and laboratories in the United States and Europe. In this volume are presented talks from that meeting on atomic and nuclear physics topics and on modern parallel processing concepts and hardware. The physics topics included strong fields in atomic and nuclear physics, the role of quarks in nuclear physics, the nuclear few-body problem, relativistic descriptions of heavy-ion collisions, nuclear hydrodynamics, Monte Carlo techniques for many-body problems, precision calculation of atomic QED effects, classical simulation of atomic processes, atomic structure, atomic many-body perturbation theory, quantal studies of small and large molecular systems, and multi-photon atomic and molecular problems

  7. Heavy particle scattering by atomic and nuclear systems

    International Nuclear Information System (INIS)

    Lazauskas, R.

    2003-10-01

    In this thesis quantum mechanical non-relativistic few-body problem is discussed. Basing on fundamentals ideas from Faddeev and Yakubovski three and four body equations are formulated and solved for fermionic atomic and nuclear systems. Former equations are modified to include long range interactions. Original results for nuclear and molecular physics were obtained: -) positively charged particle scattering on hydrogen atoms was considered; predictions for π + → H, μ + → H and p + → H scattering lengths were given. Existence of an unknown, very weakly bound H + 2 bound state was predicted. -) Motivated by the possible observation of bound four neutron structure at GANIL we have studied compatibility of such an existence within the current nuclear interaction models. -) 4 nucleon scattering at low energies was investigated. Results for n → 3 H, p → 3 H and p → 3 He systems were compared with the experimental data. Validity of realistic nucleon-nucleon interaction models is questioned. (author)

  8. Electrons with continuous energy distribution from energetic heavy ion collisions

    International Nuclear Information System (INIS)

    Berenyi, D.

    1984-01-01

    The properties and origin of continuous electron spectrum emitted in high energy heavy ion collisions are reviewed. The basic processes causing the characteristic regions of the continuous spectrum are described. The contribution of electrons ejected from the target and from the projectile are investigated in detail in the cases of light and heavy projectiles. The recently recognized mechanisms, electron-capture-to-continuum (ECC) and electron-loss-to-continuum (ELC), leading to a cusp in forward direction, and their theoretical interpretations are discussed. The importance of data from ion-atom collisions in the field of atomic physics and in applications are briefly summarized. (D.Gy)

  9. Collisional alignment and orientation of atomic outer shells. Pt. 1

    International Nuclear Information System (INIS)

    Andersen, N.; Gallagher, J.W.; Hertel, I.V.

    1988-01-01

    The study of polarization of atomic radiation emitted after impact excitation has yielded an enormous wealth of detailed information on the mechanism and dynamics of collisional excitation and energy transfer, both in electron and heavy particle impact studies. In these studies, the beam of electrons, ions or fast atoms used to excite the target atoms provides a suitable quantization axis with respect to which the polarization of the fluorescent light of the excited atoms is detected. From these data information on the cross sections for the different magnetic substates of the excited atom is extracted, imparting a great deal of insight into impact mechanisms for both outer and inner shell excitation. It is our aim to provide a comprehensive review including all data available in the literature presented in a standardized and easily accessible fashion. In this review we include only alignment and orientation studies, which have a well-defined planar symmetry, i.e., in which the initial and final relative momentum of the interacting particles are well defined by differential scattering techniques. We do not make a major distinction between heavy-particle and electron impact excitation: In fact, one of our aims is to demonstrate similarities between the two fields from a technical as well as from a conceptual point of view. The review is divided into three parts: This first part (I) deals with direct excitation of atoms by electrons and fast atoms or ions. Section 2 gives an introduction to the general concepts and ideas behind this kind of study and a description of typical experimental setups. Section 3 deals with electron impact excitation of atoms, starting with the simplest case of electron-helium collisions which may be fully described by two parameters, followed by more complex cases such as electron impact excitation of hydrogen and the heavy rare gases. Section 4 describes the results for direct excitation by atomic impact. (orig./AH)

  10. Translocations affecting human immunoglobulin heavy chain locus

    Directory of Open Access Journals (Sweden)

    Sklyar I. V.

    2014-03-01

    Full Text Available Translocations involving human immunoglobulin heavy chain (IGH locus are implicated in different leukaemias and lymphomas, including multiple myeloma, mantle cell lymphoma, Burkitt’s lymphoma and diffuse large B cell lymphoma. We have analysed published data and identified eleven breakpoint cluster regions (bcr related to these cancers within the IgH locus. These ~1 kbp bcrs are specific for one or several types of blood cancer. Our findings could help devise PCR-based assays to detect cancer-related translocations, to identify the mechanisms of translocations and to help in the research of potential translocation partners of the immunoglobulin locus at different stages of B-cell differentiation.

  11. Recoil ion spectroscopy with heavy ions

    International Nuclear Information System (INIS)

    Beyer, H.F.; Mann, R.

    1984-01-01

    This chapter examines the production of very high charge state ions in single ion-atom collisions. Topics considered include some aspects of highly ionized atoms, experimental approaches, the production of highly charged target ions (monoatomic targets, recoil energy distribution, molecular fragmentation, outer-shell rearrangement, lifetime measurements, a comparison of projectile-, target-, and plasma-ion stripping), and secondary collision experiments (selective electron capture, potential applications). The heavy-ion beams for the described experiments were provided by accelerators such as tandem Van de Graaff facility and the UNILAC

  12. Atomic mirrors for a Λ-type three-level atom

    International Nuclear Information System (INIS)

    Felemban, Nuha; Aldossary, Omar M; Lembessis, Vassilis E

    2014-01-01

    We propose atom mirror schemes for a three-level atom of Λ-type interacting with two evanescent fields, which are generated as a result of the total internal reflection of two coherent Gaussian laser beams at the interface of a dielectric prism with vacuum. The forces acting on the atom are derived by means of optical Bloch equations, based on the atomic density matrix elements. The theory is illustrated by setting up the equations of motion for 23 Na atom. Two types of excited schemes are examined, namely the cases in which the evanescent fields have polarization types of σ + −σ − and σ + −π. The equations are solved numerically and we get results for atomic trajectories for different parameters. The performance of the mirror for the two types of polarization schemes is quantified and discussed. The possibility of reflecting atoms at pre-determined directions is also discussed. (paper)

  13. Heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel and its application to a flow analytical system using flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mori, Masanobu; Suzuki, Toshinobu; Sugita, Tsuyoshi; Nagai, Daisuke; Hirayama, Kazuo; Onozato, Makoto; Itabashi, Hideyuki

    2014-01-01

    Highlights: • Calcium-alginate-modified dien-silica gel adsorbed multivalent metal ions. • Metal ions adsorbed on CaAD were eluted using low acidic concentrations. • Flow system with CaAD-packed column enriched metal concentrations up to 50-fold. - Abstract: This study aimed to evaluate the heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel (CaAD) and incorporate this biosorbent into a flow analytical system for heavy metal ions using flame atomic absorption spectrometry (FAAS). The biosorbent was synthesized by electrostatically coating calcium alginate onto diethylenetriamine (dien)-silica gel. Copper ion adsorption tests by a batch method showed that CaAD exhibited a higher adsorption rate compared with other biosorbents despite its low maximum adsorption capacity. Next, CaAD was packed into a 1 mL microcolumn, which was connected to a flow analytical system equipped with an FAAS instrument. The flow system quantitatively adsorbed heavy metals and enriched their concentrations. This quantitative adsorption was achieved for pH 3–4 solutions containing 1.0 × 10 −6 M of heavy metal ions at a flow rate of 5.0 mL min −1 . Furthermore, the metal ions were successfully desorbed from CaAD at low nitric acid concentrations (0.05–0.15 M) than from the polyaminecarboxylic acid chelating resin (Chelex 100). Therefore, CaAD may be considered as a biosorbent that quickly adsorbs and easily desorbs analyte metal ions. In addition, the flow system enhanced the concentrations of heavy metals such as Cu 2+ , Zn 2+ , and Pb 2+ by 50-fold. This new enrichment system successfully performed the separation and determination of Cu 2+ (5.0 × 10 −8 M) and Zn 2+ (5.7 × 10 −8 M) in a river water sample and Pb 2+ (3.8 × 10 −9 M) in a ground water sample

  14. Partition coefficients of methylated DNA bases obtained from free energy calculations with molecular electron density derived atomic charges.

    Science.gov (United States)

    Lara, A; Riquelme, M; Vöhringer-Martinez, E

    2018-05-11

    Partition coefficients serve in various areas as pharmacology and environmental sciences to predict the hydrophobicity of different substances. Recently, they have also been used to address the accuracy of force fields for various organic compounds and specifically the methylated DNA bases. In this study, atomic charges were derived by different partitioning methods (Hirshfeld and Minimal Basis Iterative Stockholder) directly from the electron density obtained by electronic structure calculations in a vacuum, with an implicit solvation model or with explicit solvation taking the dynamics of the solute and the solvent into account. To test the ability of these charges to describe electrostatic interactions in force fields for condensed phases, the original atomic charges of the AMBER99 force field were replaced with the new atomic charges and combined with different solvent models to obtain the hydration and chloroform solvation free energies by molecular dynamics simulations. Chloroform-water partition coefficients derived from the obtained free energies were compared to experimental and previously reported values obtained with the GAFF or the AMBER-99 force field. The results show that good agreement with experimental data is obtained when the polarization of the electron density by the solvent has been taken into account, and when the energy needed to polarize the electron density of the solute has been considered in the transfer free energy. These results were further confirmed by hydration free energies of polar and aromatic amino acid side chain analogs. Comparison of the two partitioning methods, Hirshfeld-I and Minimal Basis Iterative Stockholder (MBIS), revealed some deficiencies in the Hirshfeld-I method related to the unstable isolated anionic nitrogen pro-atom used in the method. Hydration free energies and partitioning coefficients obtained with atomic charges from the MBIS partitioning method accounting for polarization by the implicit solvation model

  15. Heavy ion accelerator GANIL

    International Nuclear Information System (INIS)

    1975-04-01

    This article presents GANIL, a large national heavy ion accelerator. The broad problems of nuclear physics, atomic physics, astrophysics and physics of condensed media which can be approached and studied with this machine are discussed first, after which the final construction project is described. The project comprises a circular injector, a separated sector cyclotron up beam stripper, and a second separated cyclotron downstream [fr

  16. Intrinsic Electric Dipole Moments of Paramagnetic Atoms: Rubidium and Cesium

    OpenAIRE

    Nataraj, H. S.; Sahoo, B. K.; Das, B. P.; Mukherjee, D.

    2008-01-01

    The electric dipole moment (EDM) of paramagnetic atoms is sensitive to the intrinsic EDM contribution from that of its constituent electrons and a scalar--pseudo-scalar (S-PS) electron-nucleus interactions. The electron EDM and the S-PS EDM contribution to atomic EDM scales as Z^3. Thus, the heavy paramagnetic atomic systems will exhibit large enhancement factors. However, the nature of the coupling is so small that it becomes an interest of high precision atomic experiments. In this work, we...

  17. Study of elementary transfer mechanisms during a collision between a swift multi-charged heavy ion and a neutral atom

    International Nuclear Information System (INIS)

    Jardin, P.

    1995-01-01

    This work is dedicated to the study of the energy transfer mechanisms which occur during a collision between a swift multicharged heavy ion and a neutral atom. The elementary energy energy transfer mechanisms (scattering, excitation, ionization, capture) and their consequences on the target velocity after the collision (recoil velocity) are recalled in the first chapter. In the case of small projectile diffusion angles, we show that the recoil velocity component, transverse to the incident projectile direction, results principally from the diffusion mechanism, while the longitudinal component is due essentially to the mass transfer and the inelastic energy transfer mechanisms. Since the target recoil velocities are very small, we have built an experimental set-up which reduces the impreciseness on their measurement due to the target thermal spread using, as targets, cooled atoms of a supersonic jet (temperature 44+ (6.7 MeV/A) + Ar => Xe 44 + Ar q+ +qe - (q ranging from 1 to 7); Xe 44+ (6.7 MeV/A) + He => Xe 44+ He 1+,2+ +1e - ,2e - . We show that it is possible to interpret the recoil velocity in terms of kinetic energy transferred to the target and to the electrons ejected from the target. (author)

  18. Bound states of a light atom and two heavy dipoles in two dimensions

    DEFF Research Database (Denmark)

    Rosa, D. S.; Bellotti, F. F.; Jensen, Aksel Stenholm

    2016-01-01

    We study a three-body system, formed by a light particle and two identical heavy dipoles, in two dimensions in the Born-Oppenheimer approximation. We present the analytic light-particle wave function resulting from an attractive zero-range potential between the light and each of the heavy particles...

  19. Respectives of heavy ion physics in JINR

    International Nuclear Information System (INIS)

    Flerov, G.N.

    1983-01-01

    Perspectives of heavy ion physics in JINR are discussed. The main attention is paid to directions that are connected with the application of intensive beams of U-400 cyclotron. Experiments into studying stability limits of heavy atomic nuclei are considered. The possibility of using beams of heavy ions in applied fields, particularly for the production of very thin nuclear filters is noted. Prospects of synthesis of superheavy elements (SHE) and SHE search in nature are also considered. The data on the events of spontaneous fission found in meteorite and hydrotherms and the data on lengths of tracks in olivines from meteorite prove the possibility of obtaining evidences of SHE existence in nature

  20. Proton exchange in acid–base complexes induced by reaction coordinates with heavy atom motions

    International Nuclear Information System (INIS)

    Alavi, Saman; Taghikhani, Mahdi

    2012-01-01

    Highlights: ► Proton exchange in acid–base complexes is studied. ► The structures, binding energies, and normal mode vibrations are calculated. ► Transition state structures of proton exchange mechanism are determined. ► In the complexes studied, the reaction coordinate involves heavy atom rocking. ► The reaction coordinate is not simply localized in the proton movements. - Abstract: We extend previous work on nitric acid–ammonia and nitric acid–alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid–strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are −1 . This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm −1 . Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

  1. HEAVY METALS AS UNWANTED COMPONENTS OF BACKWASH WATER DERIVED FROM GROUNDWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    Robert Nowak

    2016-06-01

    Full Text Available The paper presents some aspects of the problem of heavy metals presence in wastewater and sewage sludge from water treatment. In the first part, issues on quality of wastewaters and sludge produced during water treatment along with actions aimed at the neutralization of such wastes, were discussed. Subsequent parts of the work present the example of 12 groundwater treatment stations in a particular municipality, and the problem of backwash water quality, in particular, heavy metals contents. The analysis covered a period of three years: 2013, 2014, and 2015. The authors, using the discussed examples, have shown that besides hydrated iron and manganese oxides, also other toxic contaminants can be present in backwash water from groundwater treatment. In particular, the qualitative analysis of the backwash water revealed the presence of heavy metals, mainly zinc. The test results for backwash water were compared with those of filtrate qualitative assessment, wherein the heavy metals were not found. This fact indicated the metal retention in the filter bed and their unsustainable immobilization resulting in penetration of heavy metals from deposit to the backwash water along with other impurities, mainly iron and manganese oxides. The main conclusion from the study is to demonstrate the need for constant monitoring of the backwash water quality, including the presence of toxic heavy metals. This is also important because of the requirement to minimize the negative environmental impact of wastes generated during the water treatment process.

  2. Inner shell coulomb ionization by heavy charged particles studied by the SCA model

    International Nuclear Information System (INIS)

    Hansteen, J.M.

    1976-06-01

    An outline is given of the development of and some achievements hitherto gained from the semi-classical approximation (SCA) model of atomic Coulomb excitation by heavy charged particles. A few very recent results (1975-1976) are incorporated in the discussion. The SCA model has by now reached a mature state. Hence it seems reasonable to regard the atomic Coulomb excitation phenomenon as part of the extremely complicated excitation mechanism operative in the general ion-atom collision. A clear understanding of the complicated X-ray producing mechanisms in heavy-ion-atom collisions is lacking at present. Despite these facts, the conceptually simple SCA model has furthered our understanding far beyond initial expectations. Moreover, this model has at the same time provided a well-founded starting point for continued researches in this rapidly expanding field of physics. (JIW)

  3. Atom electron scattering

    International Nuclear Information System (INIS)

    Santoso, B.

    1976-01-01

    Green Lippmann-Schwinger functions operator representations, derivation of perturbation method using Green function and atom electron scattering, are discussed. It is concluded that by using complex coordinate places where resonances occur, can be accurately identified. The resonance can be processed further for practical purposes, for example for the separation of atom. (RUW)

  4. Aspects of Landau condensation in atomic physics

    International Nuclear Information System (INIS)

    Gay, J.C.

    1980-01-01

    Some aspects of Landau condensation in atomic physics are reviewed both as regards current work on Rydberg states under laboratory conditions and from the viewpoint of the prospects of spontaneous decay of neutral vacuum with superheavy elements. The characteristics of the hydrogen-atom spectrum in a strong magnetic field are presented and discussed using essentially semiclassical arguments. Some schematic attempt at a global interpretation of the Rydberg spectrum near the ionization limit is also given. Then the action of an electric field on the quasi-Landau spectrum is discussed. The conditions for spontaneous production of positrons from neutral vacuum decay with superheavy elements are reconsidered for the case when the system experiences ultrastrong magnetic fields, as in pulsars and white dwarfs. It is shown that spontaneous decay of neutral vacuum may occur at lower Z values than 169. The possible importance of such effects during heavy-ion collisions is briefly discussed. We deal with some qualitative trends of the problem of an atom in a magnetic field with particular emphasis on diamagnetic effects. In the last few years, we have had the capability of making accurate experimental investigations of Rydberg atoms, and perhaps in the future we will develop fundamentally new means of studying heavy-ion collisions. Accordingly it seems of interest to make qualitative remarks regarding the present state of the problem and the possible importance of Landau condensation in various domains of atomic physics now under active development. (author)

  5. Shorter Exciton Lifetimes via an External Heavy-Atom Effect: Alleviating the Effects of Bimolecular Processes in Organic Light-Emitting Diodes.

    Science.gov (United States)

    Einzinger, Markus; Zhu, Tianyu; de Silva, Piotr; Belger, Christian; Swager, Timothy M; Van Voorhis, Troy; Baldo, Marc A

    2017-10-01

    Multiexcited-state phenomena are believed to be the root cause of two exigent challenges in organic light-emitting diodes; namely, efficiency roll-off and degradation. The development of novel strategies to reduce exciton densities under heavy load is therefore highly desirable. Here, it is shown that triplet exciton lifetimes of thermally activated delayed-fluorescence-emitter molecules can be manipulated in the solid state by exploiting intermolecular interactions. The external heavy-atom effect of brominated host molecules leads to increased spin-orbit coupling, which in turn enhances intersystem crossing rates in the guest molecule. Wave function overlap between the host and the guest is confirmed by combined molecular dynamics and density functional theory calculations. Shorter triplet exciton lifetimes are observed, while high photoluminescence quantum yields and essentially unaltered emission spectra are maintained. A change in the intersystem crossing rate ratio due to increased dielectric constants leads to almost 50% lower triplet exciton densities in the emissive layer in the steady state and results in an improved onset of the photoluminescence quantum yield roll-off at high excitation densities. Efficient organic light-emitting diodes with better roll-off behavior based on these novel hosts are fabricated, demonstrating the suitability of this concept for real-world applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Atomic data for controlled fusion research

    International Nuclear Information System (INIS)

    Barnett, C.F.; Ray, J.A.; Ricci, E.; Wilker, M.I.; McDaniel, E.W.; Thomas, E.W.; Gilbody, H.B.

    1977-02-01

    Presented is an evaluated graphical and tabular compilation of atomic and molecular cross sections of interest to controlled thermonuclear research. The cross sections are tabulated and graphed as a function of energy for collision processes involving heavy particles, electrons, and photons with atoms and ions. Also included are sections on data for particle penetration through macroscopic matter, particle transport properties, particle interactions with surfaces, and pertinent charged particle nuclear cross sections and reaction rates. In most cases estimates have been made of the data accuracy

  7. Progress of highly charged atomic physics at IMP

    International Nuclear Information System (INIS)

    Ma, X; Zhu, X L; Liu, H P; Li, B; Wei, B R; Sha, S; Cao, S P; Chen, L F; Zhang, S F; Feng, W T; Zhang, D C; Qian, D B

    2007-01-01

    The progress of atomic physics researches at the Institute of Modern Physics (IMP) is reviewed, covering the studies on ion-atom/molecule collisions, ion-cluster interaction, negative ion formation, state-selective electron capture studied by COLTRIMS, as well as the progress of a new experimental area dedicated for atomic researches at moderate energies, and the advances of the cooler storage rings at the Heavy Ion Research Facility in Lanzhou (HIRFL). New opportunities to study collision dynamics from femto-second to atto-second regime are opened based on the present facilities and the on-going projects

  8. Deeply bound pionic atom

    International Nuclear Information System (INIS)

    Toki, Hiroshi; Yamazaki, Toshimitsu

    1989-01-01

    The standard method of pionic atom formation does not produce deeply bound pionic atoms. A study is made on the properties of deeply bound pionic atom states by using the standard pion-nucleus optical potential. Another study is made to estimate the cross sections of the formation of ls pionic atom states by various methods. The pion-nucleus optical potential is determined by weakly bound pionic atom states and pion nucleus scattering. Although this potential may not be valid for deeply bound pionic atoms, it should provide some hint on binding energies and level widths of deeply bound states. The width of the ls state comes out to be 0.3 MeV and is well separated from the rest. The charge dependence of the ls state is investigated. The binding energies and the widths increase linearly with Z azbove a Z of 30. The report then discusses various methods to populate deeply bound pionic atoms. In particular, 'pion exchange' reactions are proposed. (n, pπ) reaction is discussed first. The cross section is calculated by assuming the in- and out-going nucleons on-shell and the produced pion in (n1) pionic atom states. Then, (n, dπ - ) cross sections are estimated. (p, 2 Heπ - ) reaction would have cross sections similar to the cross section of (n, dπ - ) reaction. In conclusion, it seems best to do (n, p) experiment on heavy nuclei for deeply bound pionic atom. (Nogami, K.)

  9. Effective atomic number, energy loss and radiation damage studies in some materials commonly used in nuclear applications for heavy charged particles such as H, C, Mg, Fe, Te, Pb and U

    Science.gov (United States)

    Kurudirek, Murat

    2016-05-01

    Commonly used nuclear physics materials such as water, concrete, Pb-glass, paraffin, freon and P 10 gases, some alloys such as brass, bronze, stainless-steel and some scintillators such as anthracene, stilbene and toluene have been investigated with respect to the heavy charged particle interaction as means of projected range and effective atomic number (Zeff) in the energy region 10 keV to 10 MeV. Calculations were performed for heavy ions such as H, C, Mg, Fe, Te, Pb and U. Also, the energy loss and radiation damage were studied using SRIM Monte Carlo code for anthracene for different heavy ions of 100 keV kinetic energy. It has been observed that the variation in Zeff becomes less when the atomic number of the ions increase. Glass-Pb, bronze, brass, stainless-steel and Freon gas were found to vary less than 10% in the energy region 10 keV to 10 MeV. For total proton interaction, discrepancies up to 10% and 18% between two databases namely PSTAR and SRIM were noted in mass stopping power and Zeff of water, respectively. The range calculations resulted with a conclusion that the metal alloys and glass-Pb have lowest values of ranges confirming best shielding against energetic heavy ions whereas freon and P 10 gases have the highest values of ranges in the entire energy region. The simulation results showed that the energy loss (%) to target electrons decreases as the Z of the incident ion increases. Also, it was observed that the radiation damage first increases with Z of the ion and then keeps almost constant for ions with Z≥52.

  10. Atomic and solid state physics with the 14UD

    International Nuclear Information System (INIS)

    Newton, C.S.

    1975-02-01

    The use of energetic heavy ions in atomic and solid state physics is discussed. Topics that are discussed include: 1) Properties of excited ions, 2) radiation damage studies by channeling, 3) energy loss of ions and range measurements, 4) oscillating effects in channeling, 5) x-ray production in solids, 6) coherence effects in channeling and 7) formation of united atoms. (author)

  11. Ectodermal Dysplasia: Report and Analysis of Eleven South Indian Patients with Review of Literature

    Directory of Open Access Journals (Sweden)

    Renuka Ammanagi

    2010-01-01

    Full Text Available Ectodermal dysplasia represents a rare syndrome affecting two or more ectodermally derived structures. The condition is thought to occur in approximately 1 in every 100,000 live births. It affects men more frequently and severely, while women being the carriers and heterozygote usually show minor defects. There are more than 150 different variants of ectodermal dysplasia (ED reported in the literature. Most commonly encountered among them is hypohidrotic ED which frequently exhibits the most severe dental anomalies like hypodontia or anodontia along with hypohidrosis and hypotrichosis. Here we make an attempt to collectively report and discuss eleven South Indian patients who reported to our department during the year 1998 to 2004. An added emphasis is laid on family history of consanguineous marriage among the parents of these patients.

  12. X-ray spectroscopy of highly ionized heavy ions as an advanced research for controlled nuclear fusion power

    International Nuclear Information System (INIS)

    Zschornack, G.; Musiol, G.

    1988-01-01

    Diagnostics and modelling of nuclear fusion plasmas require a detailed knowledge of atomic and molecular data for highly ionized heavy ions. Experimental verification of atomic data is made on the basis of IAEA recommendations using the method of high-resolution wavelength-dispersive X-ray spectroscopy in order to obtain contributions extensioning the available atomic data lists. Basic facilities for producing highly charged heavy ions are the electron-ion rings of the heavy ion collective accelerator and the electron beam ion source KRYON-2 at the Joint Institute for Nuclear Research at Dubna. For high-resolution X-ray spectroscopy with these sources a computer-aided crystal diffraction spectrometer has been developed the precision of which is achieved by using advanced principles of measurement and control. Relativistic atomic structure calculations have been carried out for a great number of elements and configurations to obtain data in ionization regions heavily accessible to the experiment. (author)

  13. Looking back 2005. Eleven studies evaluated

    International Nuclear Information System (INIS)

    2005-01-01

    Between December 2000 and June 2002 the Netherlands Court of Audit ('Algemene Rekenkamer') carried out a study on the title subject, focusing on the effect of energy saving measures on the energy consumption per product unit in the greenhouse sector in the Netherlands for the period 1994-2000, including the effect of the energy conservation policy for the period 1997-1999. In this retrospective the Court of Audit looks back at the results of eleven studies, among which the fore-mentioned study, in order to assess if and how the ministeries involved followed and implemented the recommendations of the Court of Audit [nl

  14. Alchemical derivatives of reaction energetics

    Science.gov (United States)

    Sheppard, Daniel; Henkelman, Graeme; von Lilienfeld, O. Anatole

    2010-08-01

    Based on molecular grand canonical ensemble density functional theory, we present a theoretical description of how reaction barriers and enthalpies change as atoms in the system are subjected to alchemical transformations, from one element into another. The change in the energy barrier for the umbrella inversion of ammonia is calculated along an alchemical path in which the molecule is transformed into water, and the change in the enthalpy of protonation for methane is calculated as the molecule is transformed into a neon atom via ammonia, water, and hydrogen fluoride. Alchemical derivatives are calculated analytically from the electrostatic potential in the unperturbed system, and compared to numerical derivatives calculated with finite difference interpolation of the pseudopotentials for the atoms being transformed. Good agreement is found between the analytical and numerical derivatives. Alchemical derivatives are also shown to be predictive for integer changes in atomic numbers for oxygen binding to a 79 atom palladium nanoparticle, illustrating their potential use in gradient-based optimization algorithms for the rational design of catalysts.

  15. Heavy metal extraction from produced water in the petroleum industry utilizing vegetal oil derivatives as the extractant; Extracao de metais pesados a partir de aguas produzidas na industria do petroleo utilizando derivados de oleo vegetal como extratante

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Dulcineia de Castro [Centro Federal de Educacao Tecnologica de Goias (CEFET/GO), Goiania (Brazil). Coordenacao de Mineracao], e-mail: dcs@cefetgo.br, e-mail: dcs@eq.ufrn.br; Paulo, Joao Bosco de Araujo [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Centro de Tecnologia. Dept. de Engenharia Quimica], e-mail: jbosco@eq.ufrn.br; Lima, Raquel Franco de Souza [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Centro de Ciencias Exatas e da Terra. Dept. de Geologia], e-mail: raquel@geologia.ufrn.br; Brandao, Paulo Roberto Gomes [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia], e-mail: pbrandao@demin.ufmg.br; Fernandes Junior, Wilaci Eutropio [PETROBRAS, RN/CE (Brazil). Unidade de Negocio de Exploracao e Producao do Rio Grande do Norte e Ceara. Gerencia de Desenvolvimento da Producao], e-mail: wilaci@petrobras.com.br

    2007-12-15

    It is well known today that, although being a renewable resource, potable water could also be finite. In the environmental context, very often due to operational costs, the development of new water recycling techniques become significant when faced with the simple adaptation of effluent treatment before final disposal. Produced water comes from exploration operations and/or the production of oil and gas and is generally treated. Following the treatment, part of the produced water is recycled in secondary re-injection operations or steam generation. The remainder, which is the biggest amount, is expelled into the sea through underwater outlets. Millions of liters of water are expelled per day, containing heavy metals such as lead (Pb), cadmium (Cd) and nickel (Ni) in low concentrations. Some of this volume could be recycled for use in the irrigation of oleaginous cultures after this water has been given a suitable post-treatment. This treatment being specified in agreement with Class 3, of CONAMA Resolution No 357 (Brazil, 2005), which establishes the contents as <0,033 mg/L for Pb, <0,01 mg/L for Cd and <0,025 mg/L for Ni. Liquid-liquid extraction is a well known technology for the recovery of metals in aqueous mediums. This work studies the extraction of Pb, Cd, and Ni from a synthetic solution, using QAV solvent (aviation kerosene); and vegetal oil derivatives as the extractant. It is well known that vegetal oil derivatives have a strong complexation power on metals. A bench test basic investigation was made with the objective of studying the selectivity of coconut oil derivatives in the extraction of metals from synthetic solutions. The determination of the heavy metal concentrations in a complex matrix was made by using the atomic absorption spectrometry technique (AAS). The results of the preliminary experiments were promising. (author)

  16. Relativistic total energy and chemical potential of heavy atoms and positive ions

    International Nuclear Information System (INIS)

    Hill, S.H.; Grout, P.J.; March, N.H.

    1984-01-01

    The relativistic Thomas-Fermi theory, with a finite nucleus, is used to study the variation of the chemical potential μ with atomic number Z and number of electrons N (N <= Z). The difference between the total energy of positive ions and that of the corresponding neutral atom has been obtained. The scaling predictions are confirmed by numerical calculations. The first principles calculation of the relativistic Thomas-Fermi total energy of neutral atoms is also studied. (author)

  17. High energy heavy ions: techniques and applications

    International Nuclear Information System (INIS)

    Alonso, J.R.

    1985-04-01

    Pioneering work at the Bevalac has given significant insight into the field of relativistic heavy ions, both in the development of techniques for acceleration and delivery of these beams as well as in many novel areas of applications. This paper will outline our experiences at the Bevalac; ion sources, low velocity acceleration, matching to the synchrotron booster, and beam delivery. Applications discussed will include the observation of new effects in central nuclear collisions, production of beams of exotic short-lived (down to 1 μsec) isotopes through peripheral nuclear collisions, atomic physics with hydrogen-like uranium ions, effects of heavy ''cosmic rays'' on satellite equipment, and an ongoing cancer radiotherapy program with heavy ions. 39 refs., 6 figs., 1 tab

  18. Determination of trace heavy metals in soil and sediments by atomic spectrometry following preconcentration with Schiff bases on Amberlite XAD-4

    Energy Technology Data Exchange (ETDEWEB)

    Kara, Derya, E-mail: dkara@balikesir.edu.tr [Department of Chemistry, Art and Science Faculty, Balikesir University, 10100 Balikesir (Turkey); Fisher, Andrew; Hill, Steve J. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA (United Kingdom)

    2009-06-15

    A matrix separation and analyte preconcentration system using Amberlite XAD copolymer resins functionalized by Schiff base reactions coupled with atomic spectrometry has been developed. Three different functionalized Amberlite XAD resins were synthesized using 4-phenylthiosemicarbazide, 2,3-dihydroxybenzaldehyde and 2-thiophenecarboxaldehyde as reagents. These resins could be used to preconcentrate transition and other trace heavy metal analytes from nitric acid digests of soil and sediment samples. Analyte retention was shown to work well at pH 6.0. After treatment of the digests with sodium fluoride and buffering to pH 6, samples that contain extremely large concentrations of iron were analysed for trace analytes without the excess iron overloading the capacity of the resin. The analytes Cd, Co, Cu, Ni and Pb were preconcentrated from acid extracts of certified soil/sediment samples and then eluted with 0.1 M HNO{sub 3} directly to the detection system. Flame atomic absorption spectrometry was used as a means of detection during the studies. The efficiency of the chelating resin and the accuracy of the proposed method were evaluated by the analysis of soil (SO-2) and sediment (LGC 6157 and MESS-3) certified reference materials.

  19. Preliminary evaluation of heavy metal contamination in the Zarrin-Gol River sediments, Iran.

    Science.gov (United States)

    Malvandi, Hassan

    2017-04-15

    The major objectives of the study were to test the hypothesis of the Zarrin-Gol River as a reference site for ecotoxicological studies and to assess the contamination degree of heavy metals and metalloids in the river using four contamination indices. For these purposes, eleven heavy metal and metalloid concentrations were analyzed. The average concentrations (mgkg -1 ) in the sediments were: 37.67 (chromium) 286.28 (manganese), 13,751.04 (iron), 8.79 (cobalt), 12.39 (nickel), 32.68 (zinc), 21.91 (arsenic), 40.59 (selenium), 2923.86 (aluminum), ND (silver) and 785.96 (magnesium). Contamination factor, enrichment factor, pollution load index, and geoaccumulation index were calculated to evaluate the contamination degree and influence of human activities on heavy metal levels. The contamination indices of the sediment samples showed that arsenic and selenium were the highest pollutants. The results indicated that the Zarrin-Gol River could not be used as a reference site at least for arsenic and selenium. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. V L Ginzburg and the Atomic Project

    Science.gov (United States)

    Ritus, V. I.

    2017-04-01

    This paper is an expanded version of the author's talk presented at a session of the Physical Sciences Division of the Russian Academy of Sciences celebrating the 100th anniversary of V L Ginzburg's birth. Tamm's Special group was organized in June 1948 with the task to clarify the feasibility of constructing a hydrogen bomb. Having verified and confirmed the calculated results by Ya B Zel'dovich's group, the Tamm group proposed an original hydrogen bomb design, which, following A D Sakharov's idea, consisted of an atomic bomb surrounded spherically by nested uranium and heavy water layers: the heavy water, on V L Ginzburg's suggestion, was replaced by higher-calorie solid lithium-6 deuteride. The ionization implosion of deuterium by uranium, both heated by the atomic bomb's explosion, greatly accelerates nuclear reactions in deuterium and uranium and increases the total energy release. Upon their approval by the KB-11 top researchers, the Atomic project leadership, and the government, the proposals were implemented in the RDS-6s bomb, which was successfully tested on 12 August 1953. Lithium-6 deuteride turned out to be a convenient multipurpose nuclear fuel. The paper highlights the recognition by the leaders of the country and of the Atomic project that fundamental science plays a crucial role in promoting scientists' ideas and proposals.

  1. Prevalence of cheese molars in eleven-year-old Dutch children.

    Science.gov (United States)

    Weerheijm, K L; Groen, H J; Beentjes, V E; Poorterman, J H

    2001-01-01

    In the Netherlands, first permanent molars with idiopathic enamel disturbances (IED) are called cheese molars. Though concern is expressed about their prevalence, adequate figures on the subject are missing. The porous enamel of cheese molars can be very sensitive to cold air and can decay rapidly. The aim of the present study was to investigate the prevalence in eleven-year-old Dutch children of cheese molars (IED). During an epidemiological study performed in four cities in the Netherlands, the first permanent molars and central incisors of eleven-year-old children were examined for hypoplasia, opacities, posteruptive enamel loss, premature extraction, and atypical restorations. The observation of a hypoplasia excluded the possibility of cheese molar. A total of 497 children were examined. Six percent (n = 128) of the molars (n = 1988) showed signs of IED (cheese molars), 10 percent of the children had cheese molars of which 8 percent two or more. Incisors (4 percent) with opacities were found in 3 percent in combination with two or more cheese molars. Among the four cities, no significant differences in occurrence were found. The results of this study showed that in 10 percent of the Dutch children eleven years of age, cheese molars (IED) were found. The cause for the phenomenon called cheese molars appears to be child centered. Further studies on prevalence, causes and prevention are mandatory.

  2. Pretreatment Hepatoprotective Effect of the Marine Fungus Derived from Sponge on Hepatic Toxicity Induced by Heavy Metals in Rats

    Directory of Open Access Journals (Sweden)

    Nehad M. Abdel-Monem

    2013-01-01

    Full Text Available The aim of this study was to evaluate the pretreatment hepatoprotective effect of the extract of marine-derived fungus Trichurus spiralis Hasselbr (TS isolated from Hippospongia communis sponge on hepatotoxicity. Twenty-eight male Sprague-Dawley rats were divided into four groups (n=7. Group I served as −ve control, group II served as the induced group receiving subcutaneously for seven days 0.25 mg heavy metal mixtures, group III received (i.p. TS extract of dose 40 mg for seven days, and group IV served as the protected group pretreated with TS extract for seven days as a protection dose, and then treated with the heavy metal-mixture. The main pathological changes within the liver after heavy-metal mixtures administrations marked hepatic damage evidenced by foci of lobular necrosis with neutrophilic infiltration, adjacent to dysplastic hepatocytes. ALT and AST measurements show a significant increase in group II by 46.20% and 45.12%, respectively. Total protein, elevated by about 38.9% in induction group compared to the −ve control group, in contrast to albumin, decreased as a consequence of metal administration with significant elevation on bilirubin level. The results prove that TS extract possesses a hepatoprotective property due to its proven antioxidant and free-radical scavenging properties.

  3. Derivation of Elastic Stress Concentration Factor Equations for Debris Fretting Flaws in Pressure Tubes of Pressurized Heavy Water Reactors

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Oh, Young Jin

    2014-01-01

    If volumetric flaws such as bearing pad fretting flaws and debris fretting flaws are detected in the pressure tubes of pressurized heavy water reactors during in-service inspection, the initiation of fatigue cracks and delayed hydrogen cracking from the detected volumetric flaws shall be assessed by using elastic stress concentration factors in accordance with CSA N285.8-05. The CSA N285.8-05 presents only an approximate formula based on linear elastic fracture mechanics for the debris fretting flaw. In this study, an engineering formula considering the geometric characteristics of the debris fretting flaw in detail was derived using two-dimensional finite element analysis and Kinectrics, Inc.'s engineering procedure with slight modifications. Comparing the application results obtained using the derived formula with the three-dimensional finite element analysis results, it is found that the results obtained using the derived formula agree well with the results of the finite element analysis

  4. Two-photon decay of K-shell vacancy states in heavy atoms

    International Nuclear Information System (INIS)

    Ilakovac, K.; Uroic, M.; Majer, M.; Pasic, S.; Vukovic, B.

    2006-01-01

    Two-photon decay has been extensively studied in atomic, nuclear and particle physics since the 1930s when the problem of stability of the 2s state of the hydrogen atom emerged. Since then, many theoretical and experimental investigations have been made on hydrogen and one-electron (H-like) ions and on helium and two-electron (He-like) ions. The work on two-photon decay in many-electron systems involving inner shells started about 30 years ago and, in the meantime, two-photon decay of the K-shell vacancy state has been the subject of many theoretical and experimental studies. Experimental results have been obtained for 2s->1s and higher-state electron ->1s two-photon transitions in molybdenum, and for 2s -> 1s, 3s -> 1s, 3d -> 1s and 4sd -> 1s two-photon transitions in silver, xenon, hafnium and mercury. Nonrelativistic and relativistic calculations of the processes have been made. The relativistic calculations for transitions in molybdenum, silver and xenon atoms are in a reasonable agreement with the experimental results, but some problems remain to be solved. A review of investigations of two-photon transitions in atomic systems is presented

  5. From Atomic Resolution to Molecular Giants: an Overview of Crystallographic Studies of Biological Macromolecules with Synchrotron Radiation

    International Nuclear Information System (INIS)

    Jaskolski, M.

    2010-01-01

    Protein crystals have huge unit cells ( ≅100 A) filled not only with ordered protein molecules but also in about 50% with liquid water. The phase problem in protein crystallography can be solved by molecular replacement (using a suitable model molecule), by isomorphous replacement (using heavy atom derivatives), or by multiwavelength anomalous diffraction (using resonant scattering of synchrotron-generated X-rays by anomalous atoms, such as Se). X-ray diffraction by protein crystals produces thousands of reflections but since the models are very complex (many thousands of atoms), paucity of data is a serious problem and stereochemical restraints are necessary. In consequence, the highest possible resolution (minimum d-spacing in Bragg's Equation) should always be the experimental goal. Protein structures determined by crystallography are deposited in protein data bank, which currently holds more than 62000 entries. Recent methodological advancements, stimulated by a wide-spread use of powerful synchrotron sources and by structural genomics, have resulted in rapid acceleration of the structure elucidation process, and in addition help to obtain a better data. Protein crystallography has produced atomic models of gigantic macromolecular assemblies, including the ribosome. It is also providing accurate targets for structure-guided development of drugs. (author)

  6. From atomic resolution to molecular giants: an overview of crystallographic studies of biological macromolecules with synchrotron radiation

    International Nuclear Information System (INIS)

    Jaskolski, M.

    2010-01-01

    Protein crystals have huge unit cells (∼ 100 A) filled not only with ordered protein molecules but also in about 50% with liquid water. The phase problem in protein crystallography can be solved by molecular replacement (using a suitable model molecule), by isomorphous replacement (using heavy atom derivatives), or by multiwavelength anomalous diffraction (using resonant scattering of synchrotron-generated X-rays by anomalous atoms, such as Se). X-ray diffraction by protein crystals produces thousands of reflections but since the models are very complex (many thousands of atoms), paucity of data is a serious problem and stereochemical restraints are necessary. In consequence, the highest possible resolution (minimum d-spacing in Bragg's Equation) should always be the experimental goal. Protein structures determined by crystallography are deposited in Protein Data Bank, which currently holds more than 65 000 entries. Recent methodological advancements, stimulated by a wide-spread use of powerful synchrotron sources and by structural genomics, have resulted in rapid acceleration of the structure elucidation process, and in addition help to obtain better data. Protein crystallography has produced atomic models of gigantic macromolecular assemblies, including the ribosome. It is also providing accurate targets for structure-guided development of drugs. (author)

  7. Heavy particle atomic collisions in astrophysics: Beyond H and He targets

    Energy Technology Data Exchange (ETDEWEB)

    Stancil, P.C.; Krstic, P.S.; Schultz, D.R.

    1998-06-01

    The physical conditions relating to the emission of x-rays from Jovian and cometary atmospheres and to supernova ejecta are briefly described. Emphasis is placed on elucidating the relevance and importance of atomic collision processes, the availability of data, and the outstanding data needs for modeling these environments. Some preliminary theoretical studies of electron capture for important collisions systems, involving molecular and atomic metal targets, are presented.

  8. Higher derivatives in Type II and M-theory on Calabi-Yau threefolds

    Science.gov (United States)

    Grimm, Thomas W.; Mayer, Kilian; Weissenbacher, Matthias

    2018-02-01

    The four- and five-dimensional effective actions of Calabi-Yau threefold compactifications are derived with a focus on terms involving up to four space-time derivatives. The starting points for these reductions are the ten- and eleven-dimensional supergravity actions supplemented with the known eight-derivative corrections that have been inferred from Type II string amplitudes. The corrected background solutions are determined and the fluctuations of the Kähler structure of the compact space and the form-field back-ground are discussed. It is concluded that the two-derivative effective actions for these fluctuations only takes the expected supergravity form if certain additional ten- and eleven-dimensional higher-derivative terms for the form-fields are included. The main results on the four-derivative terms include a detailed treatment of higher-derivative gravity coupled to Kähler structure deformations. This is supplemented by a derivation of the vector sector in reductions to five dimensions. While the general result is only given as an expansion in the fluctuations, a complete treatment of the one-Kähler modulus case is presented for both Type II theories and M-theory.

  9. Heavy-Load Lifting

    DEFF Research Database (Denmark)

    Bloomquist, Kira; Oturai, Peter; Steele, Megan L

    2018-01-01

    of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal....... repetition maximum (RM), two sets of 15-20 repetitions) and heavy-load (85-90% 1RM, three sets of 5-8 repetition) upper-extremity resistance exercise separated by a one-week wash-out period. Swelling was determined by bioimpedance spectroscopy and dual energy x-ray absorptiometry, with breast cancer......-related lymphedema symptoms (heaviness, swelling, pain, tightness) reported using a numeric rating scale (0-10). Order of low- versus heavy-load was randomized. All outcomes were assessed pre-, immediately post-, and 24- and 72-hours post-exercise. Generalized estimating equations were used to evaluate changes over...

  10. Assessment of Heavy Metal Content of Branded Pakistani Herbal ...

    African Journals Online (AJOL)

    Erah

    analyzed using a flame atomic absorption spectrometer. Results: Most of the products exceeded the permissible limits for lead (100 %), cadmium (68 %), .... absorption spectrometry. M e ta l n a m ..... Determination of Heavy Metals in Medicinal.

  11. Improvement in fuel utilization in pressurized heavy water reactors due to increased heavy water purity

    International Nuclear Information System (INIS)

    Balakrishnan, M.R.

    1991-01-01

    This paper reports that in a pressurized heavy water reactor (PHWR), the reactivity of the reactor and, consequently, the discharge burnup of the fuel depend on the isotopic purity of the heavy water used in the reactor. The optimal purity of heavy water used in PHWRs, in turn, depends on the cost of fabricated uranium fuel and on the incremental cost incurred in improving the heavy water purity. The physics and economics aspects of the desirability of increasing the heavy water purity in PHWRs in India were first examined in 1978. With the cost data available at that time, it was found that improving the heavy water purity from 99.80% to 99.95% was economically attractive. The same problem is reinvestigated with current cost data. Even now, there is sufficient incentive to improve the isotopic purity of heavy water used in PHWRs. Admittedly, the economic advantage that can be derived depends on the cost of the fabricated fuel. Nevertheless, irrespective of the economics, there is also a fairly substantial saving in natural uranium. That the increase in the heavy water purity is to be maintained only in the low-pressure moderator system, and not in the high-pressure coolant system, makes the option of achieving higher fuel burnup with higher heavy water purity feasible

  12. Direction of Heavy Water Projects

    International Nuclear Information System (INIS)

    1984-07-01

    Summary of the activities performed by the Heavy Water Projects Direction of the Argentine Atomic Energy Commission from 1950 to 1983. It covers: historical data; industrial plant (based on ammonia-hydrogen isotopic exchange); experimental plant (utilizing hydrogen sulfides-water process); Module-80 plant (2-3 tons per year experimental plant with national technology) and other related tasks on research and development (E.A.C.) [es

  13. Automation in trace-element chemistry - Development of a fully automated on-line preconcentration device for trace analysis of heavy metals with atomic spectroscopy

    International Nuclear Information System (INIS)

    Michaelis, M.R.A.

    1990-01-01

    Scope of this work was the development of an automated system for trace element preconcentration to be used and integrated to analytic atomic spectroscopic methods like flame atomic absorption spectrometry (FAAS), graphite furnace atomic absorption spectrometry (GFAAS) or atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Based on the newly developed cellulose-based chelating cation exchangers ethylene-diamin-triacetic acid cellulose (EDTrA-Cellulose) and sulfonated-oxine cellulose a flexible, computer-controlled instrument for automation of preconcentration and/or of matrix separation of heavy metals is described. The most important properties of these materials are fast exchange kinetics, good selectivity against alkaline and alkaline earth elements, good flow characteristics and good stability of the material and the chelating functions against changes in pH-values of reagents necessary in the process. The combination of the preconcentration device for on-line determinations of Zn, Cd, Pb, Ni, Fe, Co, Mn, V, Cu, La, U, Th is described for FAAS and for ICP-AES with a simultaneous spectrometer. Signal enhancement factors of 70 are achieved from preconcentration of 10 ml and on-line determination with FAAS due to signal quantification in peak-height mode. For GFAAS and for sequential ICP methods for off-line preconcentration are given. The optimization and adaption of the interface to the different characteristics of the analytical instrumentation is emphasized. For evaluation and future developments with respect to determination and/or preconcentration of anionic species like As, Se, Sb etc. instrument modifications are proposed and a development software is described. (Author)

  14. Comparison of twin-fluid atomizers using a phase Doppler analyser

    Energy Technology Data Exchange (ETDEWEB)

    Zaremba, Matouš, E-mail: y116215@stud.fme.vutbr.cz, E-mail: y145527@stud.fme.vutbr.cz, E-mail: jedelsky@fme.vutbr.cz, E-mail: jicha@fme.vutbr.cz; Malý, Milan, E-mail: y116215@stud.fme.vutbr.cz, E-mail: y145527@stud.fme.vutbr.cz, E-mail: jedelsky@fme.vutbr.cz, E-mail: jicha@fme.vutbr.cz; Jedelský, Jan, E-mail: y116215@stud.fme.vutbr.cz, E-mail: y145527@stud.fme.vutbr.cz, E-mail: jedelsky@fme.vutbr.cz, E-mail: jicha@fme.vutbr.cz; Jícha, Miroslav, E-mail: y116215@stud.fme.vutbr.cz, E-mail: y145527@stud.fme.vutbr.cz, E-mail: jedelsky@fme.vutbr.cz, E-mail: jicha@fme.vutbr.cz [Brno University of technology, Technická 2896/2, 616 69 Brno (Czech Republic)

    2014-08-06

    The quality of atomization is crucial in combustion processes, especially in cases of highly viscous fuels. Twin-fluid atomizers have been developed for atomizing heavy and waste fuels and they have undergone significant development in the last decades. Nevertheless, in order to design an atomizer for a given industrial application, a comparison of different atomizers at similar operating conditions is required. This paper focuses on the description and comparison of two internally mixed twin-fluid atomizers at the same operating regime. The Y-jet and the Inverse-effervescent atomizers were examined. The phase-Doppler analyzer was used to measure the velocity and size of droplets in a radial profile in the spray. Data were sorted out into classes with respect to the droplet size and the motion analysis was done for both atomizers.

  15. Kinetic-energy density functional: Atoms and shell structure

    International Nuclear Information System (INIS)

    Garcia-Gonzalez, P.; Alvarellos, J.E.; Chacon, E.

    1996-01-01

    We present a nonlocal kinetic-energy functional which includes an anisotropic average of the density through a symmetrization procedure. This functional allows a better description of the nonlocal effects of the electron system. The main consequence of the symmetrization is the appearance of a clear shell structure in the atomic density profiles, obtained after the minimization of the total energy. Although previous results with some of the nonlocal kinetic functionals have given incipient structures for heavy atoms, only our functional shows a clear shell structure for most of the atoms. The atomic total energies have a good agreement with the exact calculations. Discussion of the chemical potential and the first ionization potential in atoms is included. The functional is also extended to spin-polarized systems. copyright 1996 The American Physical Society

  16. Modified-surface-energy methods for deriving heavy-ion potentials

    International Nuclear Information System (INIS)

    Sierk, A.J.

    1977-01-01

    The use of a modified-surface-energy approach for the calculation of heavy-ion interaction potentials is discussed. It is not possible to simultaneously fit elastic scattering, ion interaction barriers, and fission barriers with the same set of constants in this model. Possible explanations of this deficiency are discussed

  17. Evaluation of Physicochemical Properties and Heavy Metals ...

    African Journals Online (AJOL)

    Physicochemical properties of municipal dumpsite compost in Kano metropolis and concentration of heavy metals were investigated. Analysis was carried out by atomic absorption spectrometry (Buck Scientific VPG 210). The results shows that the compost pH (6.63-8.19), electric conductivity of compost (638-933μs/cm), ...

  18. Using heavy atom rare gas matrix to control the reactivity of 4-methoxybenzaldehyde: A comparison with benzaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Kus, Nihal [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Department of Physics, Anadolu University, 26470 Eskisehir (Turkey); Sharma, Archna; Reva, Igor; Fausto, Rui [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Lapinski, Leszek [Institute of Physics, Polish Academy of Sciences, Warsaw (Poland)

    2012-04-14

    Different patterns of photochemical behavior were observed for 4-methoxybenzaldehyde (p-anisaldehyde) isolated in xenon and in argon matrices. Monomers of the compound isolated in solid Xe decarbonylate upon middle ultraviolet irradiation, yielding methoxybenzene (anisole), and CO. On the other hand, p-anisaldehyde isolated in an Ar matrix and subjected to identical irradiation, predominantly isomerizes to the closed-ring isomeric ketene (4-methoxycyclohexa-2,4-dien-1-ylidene) methanone. Experimental detection of a closed-ring ketene photoproduct, generated from an aromatic aldehyde, constitutes a rare observation. The difference between the patterns of photochemical transformations of p-anisaldehyde isolated in argon and xenon environments can be attributed to the external heavy-atom effect, where xenon enhances the rate of intersystem crossing from the singlet to the triplet manifold in which decarbonylation (via p-methoxybenzoyl radical) takes place. The parent compound, benzaldehyde, decarbonylates (to benzene + CO) when subjected to middle ultraviolet irradiation in both argon and xenon matrices. This demonstrates the role of the methoxy p-anisaldehyde substituent in activation of the reaction channel leading to the formation of the ketene photoproduct.

  19. Electronic structure of fractionally nuclear charged atoms

    International Nuclear Information System (INIS)

    Pavao, Antonio C.; Bastos, Cristiano C.; Ferreira, Joacy V.

    2008-01-01

    Different properties of quark chemistry are studied by performing accurate ab initio Hartree- Fock calculations on fractionally nuclear charged atoms. Ground and first excited states of sodium atoms with quarks attached to the nucleus are obtained using CI calculations. It is suggested that the sodium 2 P -> 2 S electronic transition can be used as a guide in searching for unconfined quarks. Also, the variation of the binding electronic energy with nuclear charge in the isoelectronic series of fractionally nuclear charged atoms A ±2/3 and A ±1/3 (A = H, Li, Na, P and Ca) is analyzed. The present calculations suggest that unconfined colored particles have large appetite for heavy nuclei and that quark-antiquark pairs could be stabilized in presence of the atomic matter. (author)

  20. Heavy water cycle in the CANDU reactor

    International Nuclear Information System (INIS)

    Nanis, R.

    2000-01-01

    Hydrogen atom has two isotopes: deuterium 1 H 2 and tritium 1 H 3 . The deuterium oxide D 2 O is called heavy water due to its density of 1105.2 Kg/m 3 . Another important physical property of the heavy water is the low neutron capture section, suitable to moderate the neutrons into natural uranium fission reactor as CANDU. Due to the fact that into this reactor the fuel is cooled into the pressure tubes surrounded by a moderator, the usage of D 2 O as primary heat transport (PHT) agent is mandatory. Therefore a large amount of heavy water (approx. 500 tons) is used in a CANDU reactor. Being a costly resource - it represents 20% of the initial plant capital cost, D 2 O management is required to preserve it. (author)

  1. Determination of Heavy Metals and Radioactive Elements in Alluvial Soil using Atomic Absorption and Gamma Spectroscopy

    International Nuclear Information System (INIS)

    Hamed, S.S.; Walley EI Dine, N.; Soliman, S.I.; Moussa, W.M.

    2008-01-01

    The paper describes some methods dealing with measurements of some heavy and radioactive elements (U, Th and K) in Egyptian cultivated soil samples. Samples were collected from Toshka area. Also, soil and plant samples were collected from Kalube and EI - Gabal EI - Asfar to compare the obtained results from both region. Flame atomic absorption spectrometry (FAAS),Neutron activation analysis (INAA) and Natural radioactivity techniques were followed. FAAS and INAA techniques agreed fairly well for the compared elements Co,Zn and Fe which determined by the two techniques. Also for K which was determined by FAAS and natural radioactivity. It was found that the concentration range in soil samples for Co, Fe, K and Zn lies between 4.18 and 29.2 μg/g, 3.0 and 3.8 mg/g, 3.49 and 13.28 mg/g and 120 and 663 μg/g respectively while in plant samples the concentration of Co was from 3.02 to 4.02 μg/g, Fe from 1.18 to 1.35 mg/g and Zn from 29.63 to 73.02 μg/g

  2. Seismic analysis of two 1050 mm diameter heavy water upgrading towers for 235 MWe Kaiga Atomic Power Plant Site

    International Nuclear Information System (INIS)

    Soni, R.S.; Kushwaha, H.S.; Mahajan, S.C.; Kakodkar, A.; Narwaria, Suresh; Vardarajan, T.G.; Sadhukhan, H.K.

    1992-01-01

    This report deals with the analysis carried out for the evaluation of earthquake induced stresses and deflections in two 1050 mm diameter heavy water upgrading towers for Kaiga Atomic Power Plant Site. The analysis of upgrading tower has been carried out for two mutually perpendicular horizontal excitations and one vertical excitation applied simultaneously. The upgrading towers have been analysed using beam model taking into account soil-structure interaction. Response spectrum analysis has been carried out using site spectra for 235 MWe Kaiga reactor site. The seismic analysis has been performed for both the towers with supporting structure along with concrete pedestals and raft foundation. The towers have been checked for its stability due to compressive stresses to avoid buckling so that the nearby safety related structures are not geopardised in the event of safe shutdown earthquake (SSE) loading. (author). 14 refs., 12 figs., 18 tabs

  3. Accelerator based atomic physics experiments: an overview

    International Nuclear Information System (INIS)

    Moak, C.D.

    1976-01-01

    Atomic Physics research with beams from accelerators has continued to expand and the number of papers and articles at meetings and in journals reflects a steadily increasing interest and an increasing support from various funding agencies. An attempt will be made to point out where interdisciplinary benefits have occurred, and where applications of the new results to engineering problems are expected. Drawing from material which will be discussed in the conference, a list of the most active areas of research is presented. Accelerator based atomic physics brings together techniques from many areas, including chemistry, astronomy and astrophysics, nuclear physics, solid state physics and engineering. An example is the use of crystal channeling to sort some of the phenomena of ordinary heavy ion stopping powers. This tool has helped us to reach a better understanding of stopping mechanisms with the result that now we have established a better base for predicting energy losses of heavy ions in various materials

  4. Implications of heavy-ion induced satellite x-ray emission. I. Introduction

    International Nuclear Information System (INIS)

    Raman, S.; Vane, C.R.

    1983-01-01

    Regardless of how they are induced, x-ray spectra are sensitive to the chemical environment of the emitting atom and can yield information on the atomic and electronic structure of host materials. Those spectra resulting from light ion and heavy ion excitations are the main topics covered in this series of papers. Highly energetic heavy ions are capable of producing multiple innershell ionization. The resulting spectrum of x-rays from a particular target atom is composed of a complex series of satellite lines. Environmental effects give rise to the redistribution of intensity from one satellite group to another. These changes can be correlated with one satellite group to another. These changes can be correlated with bulk chemical properties (valence electron densities, effective charges, covalencies, etc.). The possibility of obtaining new chemical information (for example, in implanted materials and in metal alloys) exists but requires greater experimental and theoretical understanding of both parametric variations and the fine structure of satellite lines

  5. Amorphization of complex ceramics by heavy-particle irradiations

    International Nuclear Information System (INIS)

    Ewing, R.C.; Wang, L.M.

    1994-11-01

    Complex ceramics, for the purpose of this paper, include materials that are generally strongly bonded (mixed ionic and covalent), refractory and frequently good insulators. They are distinguished from simple, compact ceramics (e.g., MgO and UO 2 ) by structural features which include: (1) open network structures, best characterized by a consideration of the shape, size and connectivity of coordination polyhedra; (2) complex compositions which characteristically lead to multiple cation sites and lower symmetry; (3) directional bonding; (4) bond-type variations within the structure. The heavy particle irradiations include ion-beam irradiations and recoil-nucleus damage resulting from a-decay events from constituent actinides. The latter effects are responsible for the radiation-induced transformation to the metamict state in minerals. The responses of these materials to irradiation are complex, as energy may be dissipated ballistically by transfer of kinetic energy from an incident projectile or radiolytically by conversion of radiation-induced electronic excitations into atomic motion. This results in isolated Frenkel defect pairs, defect aggregates, isolated collision cascades or bulk amorphization. Thus, the amorphization process is heterogeneous. Only recently have there been systematic studies of heavy particle irradiations of complex ceramics on a wide variety of structure-types and compositions as a function of dose and temperature. In this paper, we review the conditions for amorphization for the tetragonal orthosilicate, zircon [ZrSiO 4 ]; the hexagonal orthosilicate/phosphate apatite structure-type [X 10 (ZO 4 ) 6 (F,Cl,O) 2 ]; the isometric pyrochlores [A 1-2 B 2 O 6 (O,OH,F) 0-1p H 2 O] and its monoclinic derivative zirconotite [CaZrTi 2 O 7 ]; the olivine (derivative - hcp) structure types, α- VI A 2 IV BO 4 , and spinel (ccp), γ- VI A 2 IV BO 4

  6. Electron induced atomic inner-shell ionization

    International Nuclear Information System (INIS)

    Quarles, C.A.

    1974-01-01

    The current status of cross section measurements for atomic inner-shell ionization by electron bombardment is reviewed. Inner shell ionization studies using electrons as projectiles compliment the similar studies being done with heavy particles, and in addition can provide tests of the theory in those cases when relativistic effects and exchange effects are expected to be important. Both total cross sections and recently measured differential cross sections will be discussed and compared with existing theories where possible. Prospects for further experimental and theoretical work in this area of atomic physics using small electron accelerators will also be discussed

  7. Logistics Management in Retail Industry : A case study of 7-Eleven in Thailand

    OpenAIRE

    Supasansanee, Latika; Kasiphongphaisan, Patthaveekarn

    2009-01-01

    Master’s thesis in International Logistics and Supply Chain Management Title:  Logistics Management in Retail Industry: a case study 7-Eleven in Thailand Author:  Latika Supasansanee and Patthaveekarn Kasiphongphaisan Tutor:     Susanne Hertz and Benedikte Borgström Date:      June 1, 2009 Keywords: 7-Eleven Thailand, Logistics, Retail     Convenience, Distribution Center and Warehouse, IT-Apply in retail store, and Competitive advantage Introduction: In today’s challenging competition ...

  8. The Battle for Heavy Water Three physicists' heroic exploits

    CERN Multimedia

    2002-01-01

    Up until the end of the 1970s you could still catch a glimpse of his massive silhouette in the corridors of CERN. Lew Kowarksi, one of the pioneers of the Laboratory, was not only a great physicist; he was also a genuine hero of World War II. In 1940, along with Frédéric Joliot and Hans von Halban, Lew Kowarski managed to get the entire world supply of heavy water away to safety from the Nazis after a fantastic escape from occupied France. At the end of the war, the three physicists played themselves in a film about their adventures entitled 'la Bataille de l'eau lourde'. This film, which has been loaned to us by the French National Film Library, will be shown at CERN for the first time next Thursday. At the beginning of the war, heavy water (D20, two atoms of deuterium and one oxygen atom) was of strategic importance. In 1939 Frédéric Joliot, aided by Hans von Halban and Lew Kowarski, demonstrated the nuclear chain reaction and the moderator role that heavy water plays in it. A few weeks before the inv...

  9. Content Heavy Metal Pb, Cd In Perna viridis And Sediments In Semarang Bay

    Science.gov (United States)

    Suprapto, D.; Suryanti, S.; Latifah, N.

    2018-02-01

    Waste disposal from human activities, generally contain heavy metals such as Pb and Cd which derived from industrial activities. The aims of the study were to know the concentration of Pb and Cd heavy metals contained in Perna viridis tissue, sediment and water at Semarang Bay. This study was conducted in May 2017 at Semarang Bay. - Samples were collected using purposive sampling method. The heavy metal content in the water and clam was observed using- APHA method and was analyzed using AAS (Atomic Absorption Spectrophotometer). The results showed that concentration of heavy metal of Pb in the water was 0.00-50.5mg/L and the Cd content was of 26.9-51.7 mg/L, whereas the concentration of Pb in the sediment is 445.5-2.053.0mg/L and Cd 963.3-2,150.0 mg/L. Pb content in soft tissue of Perna viridis - is 67.1-1.933.9 mg/L and the concentration of Cd was 203.5-5.787.3 mg/L. The analysis of Pb and Cd in seawater, sediment and soft tissue of Perna viridis according to Enviroment Ministerial decree (KepMenLH ) number 51 of 2004 and applied by NOAA 1999 does not exceed the quality standard, that meant that the Perna viridis has been contaminated by metal Pb it is controversial with the above sentence and Cd. It concluded that the metal content of Pb and Cd in Perna viridis tissue exceeds the quality standard, so it is not suitable to be consumed, especially in high quantity

  10. Simulation of multiple scattering background in heavy ion backscattering spectrometry

    International Nuclear Information System (INIS)

    Li, M.M.; O'Connor, D.J.

    1999-01-01

    With the development of heavy ion backscattering spectrometry (HIBS) for the detection of trace quantities of heavy-atom impurities on Si surfaces, it is necessary to quantify the multiple scattering contribution to the spectral background. In the present work, the Monte Carlo computer simulation program TRIM has been used to study the backscattering spectrum and the multiple scattering background features for heavy ions C, Ne, Si, Ar and Kr impinging on four types of targets: (1) a single ultra-thin (free standing) Au film of 10 A thickness, (2) a 10 A Au film on a 50 A Si surface, (3) a 10 A Au film on an Si substrate (10 000 A), and (4) a thick target (10 000 A) of pure Si. The ratio of the signal from the Au thin layer to the background due to multiple scattering has been derived by fitting the simulation results. From the simulation results, it is found that the Au film contributes to the background which the Si plays a role in developing due to the ion's multiple scattering in the substrate. Such a background is generated neither by only the Au thin layer nor by the pure Si substrate independently. The corresponding mechanism of multiple scattering in the target can be explained as one large-angle scattering in the Au layer and subsequently several small angle scatterings in the substrate. This study allows an appropriate choice of incident beam species and energy range when the HIBS is utilized to analyse low level impurities in Si wafers

  11. Electronic structure of super heavy atoms revisited

    International Nuclear Information System (INIS)

    Gitman, D M; Levin, A D; Tyutin, I V; Voronov, B L

    2013-01-01

    The electronic structure of an atom with Z ⩽ Z c = 137 can be described by the Dirac equation with the Coulomb field of a point charge Ze. It was believed that the Dirac equation with Z > Z c poses difficulties because the formula for the lower energy level of the Dirac Hamiltonian formally gives imaginary eigenvalues. But a strict mathematical consideration shows that difficulties with the electronic spectrum for Z > Z c do not arise if the Dirac Hamiltonian is correctly defined as a self-adjoint operator. In this paper, we briefly summarize the main physical results of that consideration in a form suitable for physicists with some additional new details and numerical calculations of the electronic spectra. (comment)

  12. Theoretical study of heavy metal Cd, Cu, Hg, and Ni(II) adsorption on the kaolinite(0 0 1) surface

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jian, E-mail: zhaojian0209@aliyun.com [Institute of Applied Physics and Computational Mathematics, PO Box 8009, Beijing 100088 (China); State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083 (China); He, Man-Chao [State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Beijing 100083 (China)

    2014-10-30

    Highlights: • We investigated the adsorption of Cd, Cu, Hg, and Ni(II) on kaolinite(0 0 1) surface. • The adsorption capabilities of the kaolinite for HM atoms were Ni > Cu > Cd > Hg(II). • The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms. • The adsorption energy decreases with the coverage for Ni(II) atoms. - Abstract: Heavy metal pollution is currently of great concern because it has been recognized as a potential threat to air, water, and soil. Adsorption was one of the most popular methods for the removal of heavy metal. The adsorption of heavy metal Cd, Cu, Hg, and Ni(II) atoms on the hydroxylated (0 0 1) surface of kaolinite was investigated using density-functional theory within the generalized gradient approximation and a supercell approach. The coverage dependence of the adsorption structures and energetics were systematically studied for a wide range of coverage Θ [from 0.11 to 1.0 monolayers (ML)] and adsorption sites. The most stable among all possible adsorption sites for Cd(II) atom was the two-fold bridge site followed by the one-fold top site, and the top site was the most favorite adsorption site for Cu and Ni(II) atoms, while the three-fold hollow site was the most stable adsorption site for Hg(II) atom followed by the two-fold bridge site. The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms, thus indicating the higher stability of surface adsorption and a tendency to the formation of adsorbate islands (clusters) with increasing the coverage. However, the adsorption energy of Ni(II) atoms decreases when increasing the coverage. The adsorption capabilities of the kaolinite clay for the heavy metal atoms were in the order of Ni > Cu > Cd > Hg(II). The other properties of the Cd, Cu, Hg, and Ni(II)/kaolinite(0 0 1) system including the different charge distribution, the lattice relaxation, and the electronic density of states were also studied and discussed in detail.

  13. Theoretical study of heavy metal Cd, Cu, Hg, and Ni(II) adsorption on the kaolinite(0 0 1) surface

    International Nuclear Information System (INIS)

    Zhao, Jian; He, Man-Chao

    2014-01-01

    Highlights: • We investigated the adsorption of Cd, Cu, Hg, and Ni(II) on kaolinite(0 0 1) surface. • The adsorption capabilities of the kaolinite for HM atoms were Ni > Cu > Cd > Hg(II). • The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms. • The adsorption energy decreases with the coverage for Ni(II) atoms. - Abstract: Heavy metal pollution is currently of great concern because it has been recognized as a potential threat to air, water, and soil. Adsorption was one of the most popular methods for the removal of heavy metal. The adsorption of heavy metal Cd, Cu, Hg, and Ni(II) atoms on the hydroxylated (0 0 1) surface of kaolinite was investigated using density-functional theory within the generalized gradient approximation and a supercell approach. The coverage dependence of the adsorption structures and energetics were systematically studied for a wide range of coverage Θ [from 0.11 to 1.0 monolayers (ML)] and adsorption sites. The most stable among all possible adsorption sites for Cd(II) atom was the two-fold bridge site followed by the one-fold top site, and the top site was the most favorite adsorption site for Cu and Ni(II) atoms, while the three-fold hollow site was the most stable adsorption site for Hg(II) atom followed by the two-fold bridge site. The adsorption energy increases with the coverage for Cd, Cu, and Hg(II) atoms, thus indicating the higher stability of surface adsorption and a tendency to the formation of adsorbate islands (clusters) with increasing the coverage. However, the adsorption energy of Ni(II) atoms decreases when increasing the coverage. The adsorption capabilities of the kaolinite clay for the heavy metal atoms were in the order of Ni > Cu > Cd > Hg(II). The other properties of the Cd, Cu, Hg, and Ni(II)/kaolinite(0 0 1) system including the different charge distribution, the lattice relaxation, and the electronic density of states were also studied and discussed in detail

  14. Atomic and molecular physics of controlled thermonuclear fusion

    International Nuclear Information System (INIS)

    Joachain, C.J.; Post, D.E.

    1983-01-01

    This book attempts to provide a comprehensive introduction to the atomic and molecular physics of controlled thermonuclear fusion, and also a self-contained source from which to start a systematic study of the field. Presents an overview of fusion energy research, general principles of magnetic confinement, and general principles of inertial confinement. Discusses the calculation and measurement of atomic and molecular processes relevant to fusion, and the atomic and molecular physics of controlled thermonuclear research devices. Topics include recent progress in theoretical methods for atomic collisions; current theoretical techniques for electron-atom and electronion scattering; experimental aspects of electron impact ionization and excitation of positive ions; the theory of charge exchange and ionization by heavy particles; experiments on electron capture and ionization by multiply charged ions; Rydberg states; atomic and molecular processes in high temperature, low-density magnetically confined plasmas; atomic processes in high-density plasmas; the plasma boundary region and the role of atomic and molecular processes; neutral particle beam production and injection; spectroscopic plasma diagnostics; and particle diagnostics for magnetic fusion experiments

  15. Biochars derived from wasted marine macro-algae (Saccharina japonica and Sargassum fusiforme) and their potential for heavy metal removal in aqueous solution.

    Science.gov (United States)

    Poo, Kyung-Min; Son, Eun-Bi; Chang, Jae-Soo; Ren, Xianghao; Choi, Yun-Jung; Chae, Kyu-Jung

    2018-01-15

    For the purpose of reusing wasted marine macro-algae generated during cultivation, harvesting, processing and selling processes, biochars derived from Saccharina japonica (known as kelp) and Sargassum fusiforme (known as hijikia) were characterized and their removal capacities for Cu, Cd, and Zn in aqueous solution were assessed. Feedstocks, S. japonica, S. fusiforme, and also pinewood sawdust as a control, were pyrolyzed at 250, 400, 500, 600 and 700 °C. In evaluating heavy metal removal capacities, SJB (S. japonica biochar) showed the best performance, with removal efficiencies of more than 98% for the three heavy metals when pyrolyzed at over 400 °C. SFB (S. fusiforme biochar) also showed good potential as an adsorbent, with removal efficiencies for the three heavy metals of more than 86% when pyrolyzed at over 500 °C. On the contrary, the maximum removal efficiencies of PSB (pinewood sawdust biochar) were 81%, 46%, and 47% for Cu, Cd, and Zn, respectively, even at 700 °C, the highest pyrolysis temperature. This demonstrates that marine macro-algae were advantageous in terms of production energy for removing heavy metals even at relatively low pyrolysis temperatures, compared with PSB. The excellent heavy metal adsorption capacities of marine macro-algae biochars were considered due to their higher pH and more oxygen-containing functional groups, although the specific surface areas of SJB and SFB were significantly lower than that of PSB. This research confirmed that the use of marine macro-algae as a heavy metal adsorbent was suitable not only in the removal of heavy metals, but also in terms of resource recycling and energy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Heavy chain only antibodies

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein; Rahbarizadeh, Fatemeh; Ahmadvand, Davoud

    2013-01-01

    Unlike conventional antibodies, heavy chain only antibodies derived from camel contain a single variable domain (VHH) and two constant domains (CH2 and CH3). Cloned and isolated VHHs possess unique properties that enable them to excel conventional therapeutic antibodies and their smaller antigen...

  17. Future Perspectives for the Application of Low Temperature Detectors in Heavy Ion Physics

    International Nuclear Information System (INIS)

    Egelhof, P.; Kraft-Bermuth, S.

    2009-01-01

    Calorimetric low temperature detectors have the potential to become powerful tools for applications in many fields of heavy ion physics. A brief overview of heavy ion physics is given, and the next generation heavy ion facility FAIR is described with a special emphasis on the potential advantage of Low Temperature Detectors (LTDs) for applications in heavy ion physics. For prototype LTDs for the energy sensitive detection of heavy ions excellent results with respect to energy resolution down to δE/E = 1-2x10 -3 for a wide range of incident energies, and with respect to other detector properties, such as energy linearity with no indication of pulse height defects even for the heaviest ions, have been obtained. In addition, prototype detectors for hard X-rays have shown energy resolutions down to δE = 30-40eV at 60 keV. Consequently, both detector schemes have already been successfully used for first experiments. At present, the design and setup of large solid angle detector arrays is in progress. With the already achieved performance, LTDs promise a large potential for applications in atomic and nuclear heavy ion physics. A brief overview of prominent examples, including high-resolution nuclear spectroscopy, nuclear structure studies with radioactive beams, superheavy element research, as well as high-resolution atomic spectroscopy on highly charged ions and tests of QED in strong electromagnetic fields is presented.

  18. Deformation effects in the heavy ion quarter-point angle

    International Nuclear Information System (INIS)

    Almeida, F.I.A. de; Hussein, M.S.

    1984-01-01

    The effects of static and dynamic deformation on the heavy-ion elastic scattering quarter-point angle are discussed and analyzed in the sudden approximation. Simple expressions are derived within the Fresnel model and applications to several heavy-ion systems are presented. (Author) [pt

  19. Atomic Parity Violation Overview and Perspectives

    CERN Document Server

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    Optical experiments have demonstrated cases in which mirror symmetry in stable atoms is broken during absorption or emission of light. Such results are in conflict with standard electromagnetic (EM) theory, but can be explained within the unified electroweak theory. Their interpretation is based on exchanges of virtual weak neutral Z_0 bosons between the electrons and the atomic nucleus. These effects were predicted to increase in heavy atoms a little faster than the cube of the atomic number. Moreover, in a highly forbidden transition, like the 6S-7S transition in cesium, the EM interaction is suppressed, leaving the Z_0 exchange a chance to show up. For achieving the determination of the Cs nucleus weak charge, Q_W(Cs), the basic experimental parameter playing in Z_0, exchange the same role as the nuclear charge in the Coulomb interaction, both experimental and theoretical hurdles had to be overcome: first, the excitation and detection of an atomic line with a transition rate about 10^{14} times less than a...

  20. Department of Atomic Energy: Annual report, 1983-84

    International Nuclear Information System (INIS)

    1984-01-01

    The annual report of the Department of Atomic Energy for the financial year 1983-84 describes its activities under the headings: Nuclear Power, Research and Development, Public Sector Undertakings, and Other Activities. The report surveys: (1) the performance of nuclear power plants at Tarapur, Kota and Kalpakkam, heavy water plants, fuel fabrication and reprocessing plants, and waste management facilities, (2) the research and development activities of Bhabha Atomic Research Centre at Bombay and its constituent units at various locations in the country, Reactor Research Centre at Kalpakkam, the aided institutes, namely, Tata Institute of Fundamental Research and Tata Memorial Centre, both at Bombay, and Saha Institute of Nuclear Physics at Calcutta, (3) performance of public sector undertakings: Indian Rare Earths Ltd., Uranium Corporation of India Ltd., and Electronics Corporation of India Ltd., (4) progress of nuclear power projects at Narora and Kakrapar, Orissa Sand Complex Project, MHD project at Tiruchirapalli, DHRUVA (formerly known as R-5) project at Bombay, Fast Breeder Test Reactor and 500 MW Prototype Fast Breeder Reactor projects at Kalpakkam, and heavy water projects at Thal-Vaishet and Manuguru, and (5) other activities including technology transfer; training; service to industry, agriculture and medicine in use of radioisotopes and radiation, export of radioisotopes, allied products and nuclear instruments; international relations; countrywide radiation safety programme, exploration of atomic minerals; information and publicity etc. An Atomic Energy Regulatory Board was established during the report year for the special purpose of carrying out regulatory and safety functions specified in the Atomic Energy Act of the Government of India. (M.G.B.)

  1. Ionization of heavy targets by impact of relativistic projectiles

    International Nuclear Information System (INIS)

    Deco, G.R.; Fainstein, P.D.; Comision Nacional de Energia Atomica, San Carlos de Bariloche; Rivarola, R.D.

    1988-01-01

    Electron ejection from atomic targets by impact of bare heavy projectiles at relativistic collision energies is studied theoretically. First-order Born calculations are presented by using initial Darwin and final Sommerfeld-Maue wavefunctions. Comparisons with other calculations and experimental data are given. (orig.)

  2. Heavy metal hazards of Nigerian herbal remedies

    International Nuclear Information System (INIS)

    Obi, E.; Akunyili, Dora N.; Ekpo, B.; Orisakwe, Orish E.

    2006-01-01

    The uses of herbal products are not regulated in Nigeria and in many low-income countries and are freely available to everyone. The safety of these herbal medicines is poorly understood. This study characterizes the content of cadmium, copper, iron, nickel, selenium, zinc, lead and mercury in a random sample of Nigerian traditional products. Ready-to-use herbal products were purchased from the open market and digested using HNO 3 .The heavy metal content of the digested filtrate was determined by atomic absorption spectrometry Uni-cam Model 929. The result showed that 100% of the samples contained elevated amounts of heavy metals. These data alert us to the possibility of heavy metal toxicity from herbal products in Nigeria. The public health hazards from ingestion of herbal medicines should be identified and disclosed by in-depth risk assessment studies

  3. Heavy metal hazards of Nigerian herbal remedies

    Energy Technology Data Exchange (ETDEWEB)

    Obi, E. [Toxicology Unit, Department of Pharmacology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi (Nigeria); Akunyili, Dora N. [National Agency of Food and Drug Administration and Control (NAFDAC), Lagos (Nigeria); Ekpo, B. [Department of Biochemistry, College of Medical Sciences, Abia State University, Uturu (Nigeria); Orisakwe, Orish E. [Toxicology Unit, Department of Pharmacology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi (Nigeria)]. E-mail: eorish@yahoo.com

    2006-10-01

    The uses of herbal products are not regulated in Nigeria and in many low-income countries and are freely available to everyone. The safety of these herbal medicines is poorly understood. This study characterizes the content of cadmium, copper, iron, nickel, selenium, zinc, lead and mercury in a random sample of Nigerian traditional products. Ready-to-use herbal products were purchased from the open market and digested using HNO{sub 3}.The heavy metal content of the digested filtrate was determined by atomic absorption spectrometry Uni-cam Model 929. The result showed that 100% of the samples contained elevated amounts of heavy metals. These data alert us to the possibility of heavy metal toxicity from herbal products in Nigeria. The public health hazards from ingestion of herbal medicines should be identified and disclosed by in-depth risk assessment studies.

  4. Potential of Brassic rapa, Cannabis sativa, Helianthus annuus and Zea mays for phytoextraction of heavy metals from calcareous dredged sediment derived soils.

    Science.gov (United States)

    Meers, E; Ruttens, A; Hopgood, M; Lesage, E; Tack, F M G

    2005-10-01

    Remediation of soil pollution is one of the many current environmental challenges. Anthropogenic activity has resulted in the contamination of extended areas of land, the remediation of which is both invasive and expensive by conventional means. Phytoextraction of heavy metals from contaminated soils has the prospect of being a more economic in situ alternative. In addition, phytoextraction targets ecotoxicologically the most relevant soil fraction of these metals, i.e. the bioavailable fraction. Greenhouse experiments were carried out to evaluate the potential of four high biomass crop species in their potential for phytoextraction of heavy metals, with or without with the use of soil amendments (EDTA or EDDS). A calcareous dredged sediment derived surface soil, with high organic matter and clay content and moderate levels of heavy metal pollution, was used in the experiments. No growth depression was observed in EDTA or EDDS treated pots in comparison to untreated controls. Metal accumulation was considered to be low for phytoextraction purposes, despite the use of chelating agents. The low observed shoot concentrations of heavy metals were attributed to the low phytoavailability of heavy metals in this particular soil substrate. The mobilising effects induced by EDTA in the soil were found to be too long-lived for application as a soil amendment in phytoextraction. Although EDDS was found to be more biodegradable, higher effect half lives were observed than reported in literature or observed in previous experiments. These findings caution against the use of any amendment, biodegradable or otherwise, without proper investigation of its effects and the longevity thereof.

  5. Laser cooling of neutral atoms

    International Nuclear Information System (INIS)

    1993-01-01

    A qualitative description of laser cooling of neutral atoms is given. Two of the most important mechanisms utilized in laser cooling, the so-called Doppler Cooling and Sisyphus Cooling, are reviewed. The minimum temperature reached by the atoms is derived using simple arguments. (Author) 7 refs

  6. Excited, bound and resonant positron-atom systems

    International Nuclear Information System (INIS)

    Bromley, M W J; Mitroy, J

    2010-01-01

    Calculations have demonstrated that eleven neutral atoms can bind positrons, while many more can bind positronium. This is a short review of recent progress made in understanding some of the underlying mechanisms. The emphasis here being on configuration interaction calculations with excited state configurations. These have demonstrated the existence of a 2 P o excited state of e + Ca, which consists predominantly of a positronium cluster orbiting the Ca + ion in the L = 1 partial wave. Preliminary results are presented of excited state positron binding to a model alkali atom, where the excited 1 P o states are stable over a limited region. Implications for the unnatural parity, 2,4 S o , states of PsH, LiPs, NaPs and KPs are also discussed. The e + Mg, e + Cu, e + Zn and e + Cd systems show a lack of a 2 P o excited state, each instead possessing a low-energy p-wave shape resonance of varying strength.

  7. Novel thiosalicylate-based ionic liquids for heavy metal extractions

    Energy Technology Data Exchange (ETDEWEB)

    Leyma, Raphlin; Platzer, Sonja [Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna (Austria); Jirsa, Franz [Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna (Austria); Department of Zoology, University of Johannesburg, PO Box 524, Auckland Park, 2006, Johannesburg (South Africa); Kandioller, Wolfgang, E-mail: wolfgang.kandioller@univie.ac.at [Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna (Austria); Krachler, Regina; Keppler, Bernhard K. [Institute of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Waehringer Str. 42, A-1090 Vienna (Austria)

    2016-08-15

    Highlights: • Six thiosalicylate-based ammonium and phosphonium ionic liquids (ILs) were newly synthesized. • ILs showed good extraction of cadmium, copper, and zinc. • Phosphonium ILs showed better extraction efficiencies than their ammonium counterparts. - Abstract: This study aims to develop novel ammonium and phosphonium ionic liquids (ILs) with thiosalicylate (TS) derivatives as anions and evaluate their extracting efficiencies towards heavy metals in aqueous solutions. Six ILs were synthesized, characterized, and investigated for their extracting efficacies for cadmium, copper, and zinc. Liquid-liquid extractions of Cu, Zn, or Cd with ILs after 1–24 h using model solutions (pH 7; 0.1 M CaCl{sub 2}) were assessed using flame atomic absorption spectroscopy (F-AAS). Phosphonium-based ILs trihexyltetradecylphosphonium 2-(propylthio)benzoate [P{sub 66614}][PTB] and 2-(benzylthio)benzoate [P{sub 66614}][BTB] showed best extraction efficiency for copper and cadmium, respectively and zinc was extracted to a high degree by [P{sub 66614}][BTB] exclusively.

  8. Atoms, radiation, and radiation protection

    International Nuclear Information System (INIS)

    Turner, J.E.

    1986-01-01

    This book describes basic atomic and nuclear structure, the physical processes that result in the emission of ionizing radiations, and external and internal radiation protection criteria, standards, and practices from the standpoint of their underlying physical and biological basis. The sources and properties of ionizing radiation-charged particles, photons, and neutrons-and their interactions with matter are discussed in detail. The underlying physical principles of radiation detection and systems for radiation dosimetry are presented. Topics considered include atomic physics and radiation; atomic structure and radiation; the nucleus and nuclear radiation; interaction of heavy charged particles with matter; interaction of beta particles with matter; phenomena associated with charged-particle tracks; interaction of photons with matter; neutrons, fission and criticality; methods of radiation detection; radiation dosimetry; chemical and biological effects of radiation; radiation protection criteria and standards; external radiation protection; and internal dosimetry and radiation protection

  9. Comparison of atomic-level and coarse-grained models for liquid hydrocarbons from molecular dynamics configurational entropy estimates

    NARCIS (Netherlands)

    Baron, R; de Vries, AH; Hunenberger, PH; van Gunsteren, WF

    2006-01-01

    Molecular liquids can be modeled at different levels of spatial resolution. In atomic-level (AL) models, all (heavy) atoms can be explicitly simulated. In coarse-grained (CG) models, particles (beads) that represent groups of covalently bound atoms are used as elementary units. Ideally, a CG model

  10. Heavy metals in sea turtles

    Energy Technology Data Exchange (ETDEWEB)

    Witkowski, S.A. (Millersville State College, PA); Frazier, J.G.

    1982-07-01

    Bone and barnacle samples from sea turtles (Hepidochelys olivacea) in Ecuador were analyzed for manganese, iron, copper, zinc and lead. Analysis was performed by flame atomic absorption spectroscopy. Results show that zinc and iron levels in bone and barnacles were greater than copper, manganese and lead levels. The significance of the findings is difficult to interpret because so little is known about baseline levels and physiological effects of heavy metals in the animals. (JMT)

  11. The effect of various quantum mechanically derived partial atomic charges on the bulk properties of chloride-based ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Zolghadr, Amin Reza, E-mail: arzolghadr@shirazu.ac.ir [Department of Chemistry, Shiraz University, Shiraz 71946-84795 (Iran, Islamic Republic of); Ghatee, Mohammad Hadi [Department of Chemistry, Shiraz University, Shiraz 71946-84795 (Iran, Islamic Republic of); Moosavi, Fatemeh [Department of Chemistry, Ferdowsi University of Mashhad, Mashhad 91779 (Iran, Islamic Republic of)

    2016-08-22

    Partial atomic charges using various quantum mechanical calculations for [C{sub n}mim]Cl (n = 1, 4) ionic liquids (ILs) are obtained and used for development of molecular dynamics simulation (MD) force fields. The isolated ion pairs are optimized using HF, B3LYP, and MP2 methods for electronic structure with 6-311++G(d,p) basis set. Partial atomic charges are assigned to the atomic center with CHELPG and NBO methods. The effect of these sets of partial charges on the static and dynamic properties of ILs is evaluated by performing a series of MD simulations and comparing the essential thermodynamic properties with the available experimental data and available molecular dynamics simulation results. In contrast to the general trends reported for ionic liquids with BF{sub 4}, PF{sub 6}, and iodide anions (in which restrained electrostatic potential (RESP) charges are preferred), partial charges derived by B3LYP-NBO method are relatively good in prediction of the structural, dynamical, and thermodynamic energetic properties of the chloride based ILs.

  12. Changes in muscle size and MHC composition in response to resistance exercise with heavy and light loading intensity

    DEFF Research Database (Denmark)

    Holm, L.; Reitelseder, S.; Pedersen, T.G.

    2008-01-01

    resonance imaging, muscle biopsies were obtained bilaterally from vastus lateralis for determination of myosin heavy chain (MHC) composition, and maximal muscle strength was assessed by 1RM testing and in an isokinetic dynamometer at 60 degrees /s. Quadriceps muscle cross-sectional area increased (P ...Muscle mass accretion is accomplished by heavy-load resistance training. The effect of light-load resistance exercise has been far more sparsely investigated with regard to potential effect on muscle size and contractile strength. We applied a resistance exercise protocol in which the same...... individual trained one leg at 70% of one-repetition maximum (1RM) (heavy load, HL) while training the other leg at 15.5% 1RM (light load, LL). Eleven sedentary men (age 25 +/- 1 yr) trained for 12 wk at three times/week. Before and after the intervention muscle hypertrophy was determined by magnetic...

  13. Effective-field theories for heavy quarkonium

    International Nuclear Information System (INIS)

    Brambilla, Nora; Pineda, Antonio; Soto, Joan; Vairo, Antonio

    2005-01-01

    This article reviews recent theoretical developments in heavy-quarkonium physics from the point of view of effective-field theories of QCD. We discuss nonrelativistic QCD and concentrate on potential nonrelativistic QCD. The main goal will be to derive Schroedinger equations based on QCD that govern heavy-quarkonium physics in the weak- and strong-coupling regimes. Finally, the review discusses a selected set of applications, which include spectroscopy, inclusive decays, and electromagnetic threshold production

  14. Acute myeloblastic leukemia with minimal myeloid differentiation (FAB AML-M0): a study of eleven cases.

    Science.gov (United States)

    Sempere, A; Jarque, I; Guinot, M; Palau, J; García, R; Sanz, G F; Gomis, F; Pérez-Sirvent, M L; Senent, L; Sanz, M A

    1993-12-01

    The main clinical, morphological, cytochemical, immunological features and therapy results of eleven patients diagnosed as acute myeloblastic leukemia M0 (AML-M0) are reported here. There were no clinical characteristics, abnormalities on physical examination or initial laboratory parameters that distinguished these eleven patients. Bone marrow aspirates were hypocellular in four patients. The leukemic cells were undifferentiated by light microscopy and myeloperoxidase (MPO) and/or Sudan Black B (SBB) stains were negative in all cases. Myeloid differentiation antigens were present on the leukemic cells of all eleven patients, whereas B and T cell markers were clearly negative except for CD4 and CD7 antigens. Whatever the treatment employed survival was very short. Eight of the eleven patients were treated and two achieved complete remission (CR) but only one of them is alive in continuous CR. Our results like those previously reported, suggest that AML-M0 patients have a very poor prognosis with standard induction therapies and should perhaps be considered for experimental therapeutic approaches.

  15. Heavy ion elastic recoil detection analysis of optoelectronic and semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Dytlewski, N.; Cohen, D.D. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Johnston, P.; Walker, S. [Royal Melbourne Inst. of Tech., VIC (Australia); Whitlow, H.; Hult, M. [Lund Univ. (Sweden); Oestling, M.; Zaring, C. [Royal Inst. of Tech., Stockholm (Sweden)

    1993-12-31

    In recent years, the use of heavy ion time-of-flight elastic recoil spectrometry (HIERDA) has been applied to analyse multi-phase, thin layer devices used in optoelectronics, semiconductors and solar power generation. HIERDA gives simultaneously, mass resolved elemental concentration vs depth profiles of the matrix constituents, and is particularly suited to the determination of light elements in a heavy matrix. The beam/target interaction process is similar to RBS, but has the difference that the recoiling target atoms are detected instead of the scattered projectile. High energy, heavy ions beams bombard the sample, ejecting recoil atoms which are detected at a forward angle of 45 deg. A time-of-flight and total energy detection system enables the ejected particle`s mass to be identified, and allows energy spectra to be obtained and interpreted in an analogous way to RBS, but with the important difference that the elemental spectra are separated, and not superimposed on a background as in RBS. Some of the measurements made with a HIERDA system on the ANTARES Tandem Accelerator at ANSTO are described. 1 refs., 4 figs.

  16. Heavy ion elastic recoil detection analysis of optoelectronic and semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Dytlewski, N; Cohen, D D [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Johnston, P; Walker, S [Royal Melbourne Inst. of Tech., VIC (Australia); Whitlow, H; Hult, M [Lund Univ. (Sweden); Oestling, M; Zaring, C [Royal Inst. of Tech., Stockholm (Sweden)

    1994-12-31

    In recent years, the use of heavy ion time-of-flight elastic recoil spectrometry (HIERDA) has been applied to analyse multi-phase, thin layer devices used in optoelectronics, semiconductors and solar power generation. HIERDA gives simultaneously, mass resolved elemental concentration vs depth profiles of the matrix constituents, and is particularly suited to the determination of light elements in a heavy matrix. The beam/target interaction process is similar to RBS, but has the difference that the recoiling target atoms are detected instead of the scattered projectile. High energy, heavy ions beams bombard the sample, ejecting recoil atoms which are detected at a forward angle of 45 deg. A time-of-flight and total energy detection system enables the ejected particle`s mass to be identified, and allows energy spectra to be obtained and interpreted in an analogous way to RBS, but with the important difference that the elemental spectra are separated, and not superimposed on a background as in RBS. Some of the measurements made with a HIERDA system on the ANTARES Tandem Accelerator at ANSTO are described. 1 refs., 4 figs.

  17. Coulomb ionization of inner shells by heavy charged particles

    International Nuclear Information System (INIS)

    Lapicki, G.

    1975-01-01

    The theory of inner-shell Coulomb ionization by heavy charged particles, of atomic number small compared to the target atomic number, is developed through the extension of work by Brandt and his coworkers for K shells to L shells. In slow collisions relative to the characteristic times of the inner shell electrons, the quantum-mechanical predictions in the plane-wave Born approximation (PWBA) can exceed experimental cross sections by orders of magnitude. The effects of the perturbation of the atom by and the Coulomb deflection of the particle during collisions are included in the theory. The perturbed atomic states amount to a binding of the inner-shell electrons to the moving particle in slow collisions, and to a polarization of the inner shells by the particle passing at large impact parameters during nonadiabatic collisions. These effects, not contained in the PWBA, are treated in the framework of the perturbed stationary state (PSS) theory for slow collisions and in terms of the harmonic oscillator model of Ashley, Brandt, and Ritchie for stopping powers in fast collisions. The effect of the Coulomb deflection of the particle in the field of the target nucleus on the cross sections is incorporated in the semiclassical approximation of Bang and Hansteen. Except for the lightest target atoms, the contribution of electron capture by the particles to inner-shell ionizations is shown to be negligible. The theory as developed earlier for the K shell, and here for L shells, agrees well with the vast body of experimental data on inner-shell Coulomb ionization by heavy charged particles

  18. ELECTRON-CAPTURE IN HIGHLY-CHARGED ION-ATOM COLLISIONS

    NARCIS (Netherlands)

    MORGENSTERN, R

    1993-01-01

    An attempt is made to identify the most important mechanisms responsible for the rearrangement of electrons during collisions between multiply charged ions and atoms at keV energies. It is discussed to which extent the influence of binding energy, angular momentum of heavy particles and electrons,

  19. [Mixed valent and heavy ferimons and related systems

    International Nuclear Information System (INIS)

    Schlottmann, P.

    1991-01-01

    The main objective of the project is to gain a better understanding of highly correlated fermion systems. High correlations appear in a variety of solid state phenomena: mixed-valence and heavy-fermions or Kondo systems, superfluid and normal He 3 , high-temperature superconductors, magnetism in low dimensions, quantum Hall effect, spin-fluctuations in transition metals, giant magnetic moments, tunneling of an atom interacting with a degenerate electron gas, quantum dissipative systems, organic superconductors, etc. The primary focus of the work is on valence mixing and heavy fermions, but elated highly correlated systems are also studied. In this paper a brief summary of the achievements grouped under four headings, namely (1) heavy fermions-mixed valence-Kondo, (2) magnetism in low dimensions, (3) narrow band phenomena/Hubbard model and (4) collaborations with experimentalists

  20. Threshold law for electron-atom impact ionization

    International Nuclear Information System (INIS)

    Temkin, A.

    1982-01-01

    The threshold law for electron-atom ionization is derived on the basis of the Coulomb-dipole theory. The result is a modulated quasilinear law for the yield: QproportionalE(lnE) -2 [1+C sin(αlnE+μ)]. The derivation depends on a more accurate description of the dipole moment seen by the outer electron as the distance of the inner electron from the nucleus. The derivation also implies Capprox. =α -1 , and it also suggests that α is large. The same law also applies to positron-atom impact ionization

  1. Rotational Spectroscopy Unveils Eleven Conformers of Adrenaline

    Science.gov (United States)

    Cabezas, C.; Cortijo, V.; Mata, S.; Lopez, J. C.; Alonso, J. L.

    2013-06-01

    Recent improvements in our LA-MB-FTMW instrumentation have allowed the characterization of eleven and eight conformers for the neurotransmitters adrenaline and noradrenaline respectively. The observation of this rich conformational behavior is in accordance with the recent observation of seven conformers for dopamine and in sharp contrast with the conformational reduction proposed for catecholamines. C. Cabezas, I. Peña, J. C. López, J. L. Alonso J. Phys. Chem. Lett. 2013, 4, 486. H. Mitsuda, M. Miyazaki, I. B. Nielsen, P. Carcabal,C. Dedonder, C. Jouvet, S. Ishiuchi, M. Fujii J. Phys. Chem. Lett. 2010, 1, 1130.

  2. Designing coarse grained-and atom based-potentials for protein-protein docking

    Directory of Open Access Journals (Sweden)

    Tobi Dror

    2010-11-01

    Full Text Available Abstract Background Protein-protein docking is a challenging computational problem in functional genomics, particularly when one or both proteins undergo conformational change(s upon binding. The major challenge is to define a scoring function soft enough to tolerate these changes and specific enough to distinguish between near-native and "misdocked" conformations. Results Using a linear programming (LP technique, we developed two types of potentials: (i Side chain-based and (ii Heavy atom-based. To achieve this we considered a set of 161 transient complexes and generated a large set of putative docked structures (decoys, based on a shape complementarity criterion, for each complex. The demand on the potentials was to yield, for the native (correctly docked structure, a potential energy lower than those of any of the non-native (misdocked structures. We show that the heavy atom-based potentials were able to comply with this requirement but not the side chain-based one. Thus, despite the smaller number of parameters, the capability of heavy atom-based potentials to discriminate between native and "misdocked" conformations is improved relative to those of the side chain-based potentials. The performance of the atom-based potentials was evaluated by a jackknife test on a set of 50 complexes taken from the Zdock2.3 decoys set. Conclusions Our results show that, using the LP approach, we were able to train our potentials using a dataset of transient complexes only the newly developed potentials outperform three other known potentials in this test.

  3. Physicochemical properties of meat of Italian Heavy Draft horses slaughtered at the age of eleven months.

    Science.gov (United States)

    Tateo, A; De Palo, P; Ceci, E; Centoducati, P

    2008-05-01

    To investigate rheological and chemical characteristics of the meat from Italian Heavy Draft horse, 24 foals (12 males and 12 females) were weaned at 6 mo, reared and fed in the same way, and slaughtered at 11 mo of age. The results obtained showed that there were no significant differences between the sexes but that the muscle type is a significant variation source. The rectus femoris muscle was lighter, and the biceps femoris had a lower a* index than longissimus dorsii, rectus femoris, and semimembranosus muscle. The most tender muscle was the semitendinosus, and the toughest even after cooking was the biceps femoris. The male animals had a greater protein and lipid percentage. The acidic composition of the intramuscular fat showed a greater presence of MUFA (P meat produced had low redness due to the low myoglobin content and high lightness. Besides, the low collagen content and its high solubility indicates an appreciable tenderness. The high level of unsaturation of the intramuscular fat resulted in a high ratio of unsaturated to saturated fat, making horse meat favorable from a health point of view.

  4. Experiments in atomic and applied physics using synchrotron radiation

    International Nuclear Information System (INIS)

    Jones, K.W.

    1987-01-01

    A diverse program in atomic and applied physics using x rays produced at the X-26 beam line at the Brookhaven National Synchrotron Light Source is in progress. The atomic physics program studies the properties of multiply-ionized atoms using the x rays for photo-excitation and ionization of neutral atoms and ion beams. The applied physics program builds on the techniques and results of the atomic physics work to develop new analytical techniques for elemental and chemical characterization of materials. The results are then used for a general experimental program in biomedical sciences, geo- and cosmochemistry, and materials sciences. The present status of the program is illustrated by describing selected experiments. Prospects for development of new experimental capabilities are discussed in terms of a heavy ion storage ring for atomic physics experiments and the feasibility of photoelectron microscopy for high spatial resolution analytical work. 21 refs., 11 figs., 2 tabs

  5. International bulletin on atomic and molecular data for fusion. No. 52

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, J A [ed.

    1997-08-01

    This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In part 1 the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, interatomic potentials); (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions); and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). Part 2 contains the bibliographic data, essentially for the above listed topics.

  6. International bulletin on atomic and molecular data for fusion. No. 52

    International Nuclear Information System (INIS)

    Stephens, J.A.

    1997-08-01

    This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In part 1 the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, interatomic potentials); (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions); and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). Part 2 contains the bibliographic data, essentially for the above listed topics

  7. Fragmentation functions of polarized heavy quarkonium

    International Nuclear Information System (INIS)

    Ma, Yan-Qing; Qiu, Jian-Wei; Zhang, Hong

    2015-01-01

    Investigating the production of polarized heavy quarkonia in terms of recently proposed QCD factorization formalism requires the knowledge of a large number of input fragmentation functions (FFs) from a single parton or a heavy quark-antiquark pair to a polarized heavy quarkonium. We study these universal FFs at the input factorization scale μ 0 ≳2m Q , with heavy quark mass m Q , in the framework of nonrelativistic QCD (NRQCD) factorization. We express these FFs in terms of perturbatively calculable coefficients for producing a heavy quark-antiquark pair in all possible NRQCD states, multiplied by corresponding NRQCD long-distance matrix elements for the pair to transmute into a polarized heavy quarkonium. We derive all relevant NRQCD operators for the long-distance matrix elements based on symmetries, and introduce a self-consistent scheme to define them in arbitrary d-dimensions. We compute, up to the first non-trivial order in α s , the perturbative coefficients for producing a heavy quark pair in all possible S-wave and P-wave NRQCD states. We also discuss the role of the polarized FFs in generating QCD predictions for the polarization of J/ψ produced at collider energies.

  8. Cascade processes in kaonic and muonic atoms

    International Nuclear Information System (INIS)

    Faifman, M.P.; Men'shikov, L.I.

    2003-01-01

    Cascade processes in exotic (kaonic and muonic) hydrogen/deuterium have been studied with the quantum-classical Monte Carlo code (QCMC) developed for 'ab initio' - calculations. It has been shown that the majority of kaonic hydrogen atoms during cascade are accelerated to high energies E ∼ 100 eV, which leads to a much lower value for the calculated yields Y of x-rays than predicted by the 'standard cascade model'. The modified QCMC scheme has been applied to the study of the cascade in μp and μd muonic atoms. A comparison of the calculated yields for K-series x-rays with experimental data directly indicates that the molecular structure of the hydrogen target and new types of non-radiative transitions are essential for the light muonic atoms, while they are negligible for heavy (kaonic) atoms. These processes have been considered and estimates of their probabilities are presented. (author)

  9. The relationship between vacuum and atomic collisions in solids

    International Nuclear Information System (INIS)

    Carter, G.; Armour, D.G.

    1980-01-01

    Atomic collision events in solids are frequently stimulated by external irradiation with energetic heavy ions. This requires production, acceleration and manipulation of ion beams in vacuum system with ensuing problems arising in perturbations to ion beam quality from gas phase collisions. In addition the dynamic interaction between the gas phase and any surfaces at which atomic collisions are under investigation can lead to perturbation to the collision events by adsorbed contaminant. This review discusses both gas phase requirements for ion accelerators to minimize deleterious effects and outlines some of the processes which occur in atomic collisions due to the presence of adsorbed impurities. Finally it is shown how certain atomic collision processes involving elastic scattering may be employed to investigate surface adsorption and related effects. (author)

  10. Rate-controlling two-proton transfer coupled with heavy-atom motion in the 2-pyridinone-catalyzed mutarotation of tetramethylglucose. Experimental and calculated deuterium isotope effects

    International Nuclear Information System (INIS)

    Engdahl, K.A.; Bivehed, H.; Ahlberg, P.; Saunders, W.H. Jr.

    1983-01-01

    Primary and secondary deuterium isotope effects have been measured by polarimetry, and primary isotope effects have been calculated for the classical bifunctional catalysis: 2-pyridinone-catalyzed mutarotation of 2,3,4,6-tetra-O-methyl-α-D-glucopyranose (α-TMG) in benzene. From the positively curved plot of the specific rate of epimerization vs. the mole fraction of 2 H in the ''pool'' of OH and NH hydrogens, the isotope effects k/sub HH//k/sub DD/ = 3.66 +/- 0.09, k/sub HH//k/sub DH/ = 1.5, and k/sub HH//k/sub HD/ = 2.4 have been calculated. A secondary isotope effect of 1.14 +/- 0.02 has been measured by using α-TMG and (1- 2 H)-2,3,4,6-tetra-O-methyl-α-D-glucopyranose [(l- 2 H)-α-TMG], the synthesis of which is described in detail, together with those for (N- 2 H)-2-pyridinone and (1-O- 2 H)-2,3,4,6-tetra-O-methyl-α-D-glucopyranose [(1-O- 2 H)-α-TMG]. The rate data obtained have also been analyzed by fractionation theory, yielding approximately equal fractionation factors (0.5). The interpretation of the results has been assisted by calculations of the primary deuterium isotope effects using the BEBOVIB IV program. Two models involving small and considerable coupling, respectively, of the transferring protons to heavy-atom motion have been considered. In the favored structure for the transition state of the rate-limiting step, two protons are in transit, and their motion is governed either by a potential with a barrier or by one without. Their motion is considerably coupled to the heavy-atom motion (i.e., the breakage of the ring C-O bond), and tunnel corrections to the isotope effects are found to be negligible

  11. Actinide targets for the synthesis of super-heavy elements

    International Nuclear Information System (INIS)

    Roberto, J.B.; Alexander, C.W.; Boll, R.A.; Burns, J.D.; Ezold, J.G.; Felker, L.K.; Hogle, S.L.; Rykaczewski, K.P.

    2015-01-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of "4"8Ca beams on actinide targets. These target materials, including "2"4"2Pu, "2"4"4Pu, "2"4"3Am, "2"4"5Cm, "2"4"8Cm, "2"4"9Cf, and "2"4"9Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including "2"4"9Bk, "2"5"1Cf, and "2"5"4Es are described.

  12. Pengaruh Komunikasi Pelayanan dan Kepuasan terhadap Loyalitas Pelanggan di 7-Eleven Buaran

    Directory of Open Access Journals (Sweden)

    Jerry Marcellinus Logahan

    2013-11-01

    Full Text Available This research was motivated by low communication in the business retail in terms of service from employees to customers. It influences the decline in customer satisfaction and leads to customer loyalty at a very low level. This study aims to identify and analyze the significance of the influence of customer service (X1 and customer satisfaction (X2 on customer loyalty (Y. Research was conducted in February - May 2013 held at 7-Eleven Buaran Jakarta. Research used quantitative method by using questionnaires filled directly by the visitors of 7-Eleven Buaran with a population of 19.920 people and a sample of 100 people, calculated using the Slovin formula. Validity test, reliability, normality, correlation, regression, hypothesis, and the determination carried out in this study using the data processed using SPSS (Statistical Product and Service Solutions version 16.0. Results indicated that customer service has significant influence by 14.6% on customer loyalty, customer satisfaction has a significant effect of 8.5% on customer loyalty, and customer service and customer satisfaction have significant influence amounted to 15,2%. Thus, this study showed that customer service and customer satisfaction have a significant effect on customer loyalty in 7-eleven Buaran Jakarta.

  13. Investigation of polymer derived ceramics cantilevers for application of high speed atomic force microscopy

    Science.gov (United States)

    Wu, Chia-Yun

    High speed Atomic Force Microscopy (AFM) has a wide variety of applications ranging from nanomanufacturing to biophysics. In order to have higher scanning speed of certain AFM modes, high resonant frequency cantilevers are needed; therefore, the goal of this research is to investigate using polymer derived ceramics for possible applications in making high resonant frequency AFM cantilevers using complex cross sections. The polymer derived ceramic that will be studied, is silicon carbide. Polymer derived ceramics offer a potentially more economic fabrication approach for MEMS due to their relatively low processing temperatures and ease of complex shape design. Photolithography was used to make the desired cantilever shapes with micron scale size followed by a wet etching process to release the cantilevers from the substrates. The whole manufacturing process we use borrow well-developed techniques from the semiconducting industry, and as such this project also could offer the opportunity to reduce the fabrication cost of AFM cantilevers and MEMS in general. The characteristics of silicon carbide made from the precursor polymer, SMP-10 (Starfire Systems), were studied. In order to produce high qualities of silicon carbide cantilevers, where the major concern is defects, proper process parameters needed to be determined. Films of polymer derived ceramics often have defects due to shrinkage during the conversion process. Thus control of defects was a central issue in this study. A second, related concern was preventing oxidation; the polymer derived ceramics we chose is easily oxidized during processing. Establishing an environment without oxygen in the whole process was a significant challenge in the project. The optimization of the parameters for using photolithography and wet etching process was the final and central goal of the project; well established techniques used in microfabrication were modified for use in making the cantilever in the project. The techniques

  14. Symplectic Tracking of Multi-Isotopic Heavy-Ion Beams in SixTrack

    CERN Document Server

    Hermes, Pascal; De Maria, Riccardo

    2016-01-01

    The software SixTrack provides symplectic proton tracking over a large number of turns. The code is used for the tracking of beam halo particles and the simulation of their interaction with the collimators to study the efficiency of the LHC collimation system. Tracking simulations for heavy-ion beams require taking into account the mass to charge ratio of each particle because heavy ions can be subject to fragmentation at their passage through the collimators. In this paper we present the derivation of a Hamiltonian for multi-isotopic heavy-ion beams and symplectic tracking maps derived from it. The resulting tracking maps were implemented in the tracking software SixTrack. With this modification, SixTrack can be used to natively track heavy-ion beams of multiple isotopes through a magnetic accelerator lattice.

  15. Opto-chemical response of Makrofol-KG to swift heavy ion irradiation

    Indian Academy of Sciences (India)

    transform infrared spectroscopy; atomic force spectroscopy. PACS Nos ... [8–10], electron beam [11], neutrons [12] and heavy ions [13]. The present .... Makrofol detector with proton and Xe ions, respectively and reported that at higher doses.

  16. Searching for a placental derived ES-62-like molecule to explain rheumatoid arthritis amelioration in pregnancy

    Directory of Open Access Journals (Sweden)

    Craig D. Scoville

    2014-11-01

    Full Text Available The majority of women with rheumatoid arthritis (RA experience disease amelioration during pregnancy for unclear reasons. One possible explanation pursued and described here is whether the placenta produces a protein similar to the immunomodulating protein, ES-62, excreted by filarial nematodes. This protein has also been shown to reduce disease activity in animal models of RA. Eleven human placentas were prepared and a polyclonal anti-ES-62 antiserum was used to identify if any ES-62-like molecule exists from human placental tissues. Any bands identified were then excised from the gel and sent for mass spectrometry and protein identification. The anti-serum showed consistent cross reactivity with the heavy chain from immunoglobulin G (IgG from the eleven human placentas by mass spectrometry. No primary sequence homology between the heavy chain of IgG and ES-62 was identified. The placenta does not produce an ES-62-like molecule. However the binding of the antiserum to the Fc region of IgG suggests that this may be a possible mechanism for rheumatoid factor production in some patients with chronic filarial infections.

  17. Total cross section for relativistic positronium interaction with atom

    International Nuclear Information System (INIS)

    Pak, A.S.; Tarasov, A.V.

    1985-01-01

    Total cross sections of interaction of positronium relativistic atoms with atoms are calculated. Calculations are conducted within the framework of potential theory in Born approximaton. Contributions in total cross section of coherent (σsub(coh)) and incoherent (σsub(inc)) parts are analyzed. It is shown that for light elements σsub(inc) value is comparable with σsub(coh), and for heavy ones the ratio σsub(inc)/σsub(coh) sufficiently exceeds Zsup(-1) (Z-charge of the atomic nucleus. Numerical calculation results are presented. A conclusion is made on importance of the coherent part account during the calculation of total cross sections

  18. High-accuracy coupled cluster calculations of atomic properties

    Energy Technology Data Exchange (ETDEWEB)

    Borschevsky, A. [School of Chemistry, Tel Aviv University, 69978 Tel Aviv, Israel and Centre for Theoretical Chemistry and Physics, The New Zealand Institute for Advanced Study, Massey University Auckland, Private Bag 102904, 0745 Auckland (New Zealand); Yakobi, H.; Eliav, E.; Kaldor, U. [School of Chemistry, Tel Aviv University, 69978 Tel Aviv (Israel)

    2015-01-22

    The four-component Fock-space coupled cluster and intermediate Hamiltonian methods are implemented to evaluate atomic properties. The latter include the spectra of nobelium and lawrencium (elements 102 and 103) in the range 20000-30000 cm{sup −1}, the polarizabilities of elements 112-114 and 118, required for estimating their adsorption enthalpies on surfaces used to separate them in accelerators, and the nuclear quadrupole moments of some heavy atoms. The calculations on superheavy elements are supported by the very good agreement with experiment obtained for the lighter homologues.

  19. High-accuracy coupled cluster calculations of atomic properties

    International Nuclear Information System (INIS)

    Borschevsky, A.; Yakobi, H.; Eliav, E.; Kaldor, U.

    2015-01-01

    The four-component Fock-space coupled cluster and intermediate Hamiltonian methods are implemented to evaluate atomic properties. The latter include the spectra of nobelium and lawrencium (elements 102 and 103) in the range 20000-30000 cm −1 , the polarizabilities of elements 112-114 and 118, required for estimating their adsorption enthalpies on surfaces used to separate them in accelerators, and the nuclear quadrupole moments of some heavy atoms. The calculations on superheavy elements are supported by the very good agreement with experiment obtained for the lighter homologues

  20. Hydrogen atoms can be located accurately and precisely by x-ray crystallography.

    Science.gov (United States)

    Woińska, Magdalena; Grabowsky, Simon; Dominiak, Paulina M; Woźniak, Krzysztof; Jayatilaka, Dylan

    2016-05-01

    Precise and accurate structural information on hydrogen atoms is crucial to the study of energies of interactions important for crystal engineering, materials science, medicine, and pharmacy, and to the estimation of physical and chemical properties in solids. However, hydrogen atoms only scatter x-radiation weakly, so x-rays have not been used routinely to locate them accurately. Textbooks and teaching classes still emphasize that hydrogen atoms cannot be located with x-rays close to heavy elements; instead, neutron diffraction is needed. We show that, contrary to widespread expectation, hydrogen atoms can be located very accurately using x-ray diffraction, yielding bond lengths involving hydrogen atoms (A-H) that are in agreement with results from neutron diffraction mostly within a single standard deviation. The precision of the determination is also comparable between x-ray and neutron diffraction results. This has been achieved at resolutions as low as 0.8 Å using Hirshfeld atom refinement (HAR). We have applied HAR to 81 crystal structures of organic molecules and compared the A-H bond lengths with those from neutron measurements for A-H bonds sorted into bonds of the same class. We further show in a selection of inorganic compounds that hydrogen atoms can be located in bridging positions and close to heavy transition metals accurately and precisely. We anticipate that, in the future, conventional x-radiation sources at in-house diffractometers can be used routinely for locating hydrogen atoms in small molecules accurately instead of large-scale facilities such as spallation sources or nuclear reactors.

  1. Advanced electrolytic cascade process for tritium recovery from irradiated heavy water moderator (Preprint No. PD-15)

    International Nuclear Information System (INIS)

    Ragunathan, P.; Mitra, S.K.; Jain, D.K.; Nayar, M.G.; Ramani, M.P.S.

    1989-04-01

    The paper briefly describes a design study of an electrolytic cascade process plant for enrichment and recovery of tritium from irradiated heavy water moderators from Rajasthan Atomic Power Station Reactors. In direct multistage electrolysis process, tritiated heavy water from the reactor units is fed to the electrolytic cell modules arranged in the form of a cascade where it is enriched and decomposed into O 2 gas stream and D 2 /DT gas stream. The direct electrolysis of tritiated heavy water allows tritium to be concentrated in the aqueous phase. Several stages are used to achieve the necessary enrichment. The cascade plant incorporates the advanced electrolyser technology developed in Bhabha Atomic Research Centre (Bombay) using porous nickel electrodes, capable o f high current density operation at reduced energy consumption for electrolysis. (author). 3 tabs

  2. Heavy Metal Pollution, Fractionation, and Potential Ecological Risks in Sediments from Lake Chaohu (Eastern China) and the Surrounding Rivers

    Science.gov (United States)

    Zhang, Lei; Liao, Qianjiahua; Shao, Shiguang; Zhang, Nan; Shen, Qiushi; Liu, Cheng

    2015-01-01

    Heavy metal (Cr, Ni, Cu, Zn, Cd, and Pb) pollution, fractionation, and ecological risks in the sediments of Lake Chaohu (Eastern China), its eleven inflowing rivers and its only outflowing river were studied. An improved BCR (proposed by the European Community Bureau of Reference) sequential extraction procedure was applied to fractionate heavy metals within sediments, a geoaccumulation index was used to assess the extent of heavy metal pollution, and a risk assessment code was applied to evaluate potential ecological risks. Heavy metals in the Shuangqiao and Nanfei Rivers were generally higher than the other studied sites. Of the three Lake Chaohu sites, the highest concentrations were identified in western Chaohu. Heavy metal pollution and ecological risks in the lake’s only outflowing river were similar to those in the eastern region of the lake, to which the river is connected. Heavy metal concentrations occurred in the following order: Cd > Zn > Cu > Pb ≈ Ni ≈ Cr. Cr, Ni, and Cu made up the largest proportion of the residual fraction, while Cd was the most prominent metal in the exchangeable and carbonate-included fraction. Cd posed the greatest potential ecological risk; the heavy metals generally posed risks in the following order: Cd > Zn > Cu > Ni > Pb > Cr. PMID:26561822

  3. Evaluation of Eleven Macro and Micro Elements Present in Various Hybrids of Millet (Pennisetum glaucum, or P. Americanum

    Directory of Open Access Journals (Sweden)

    Ghulam Qadir Shar

    2012-06-01

    Full Text Available Maize and Millet Research Institute (MMRI situated in Yousuf wala, District Sahiwal, Punjab, Pakistan was selected to grow nine different hybrids/cultivars of millet for study to comprehend the variable concentration of macro, micro and trace and toxic elements in their grains. Wet digestion method was used for the preparation of samples and flame atomic absorption spectrophotometer for analysis of eleven major and minor elements. High values of macro-elements i.e. sodium and potassium was found in ICMP-451 and magnesium in ICMP-53506. The high value of essential micro-elements i.e.zinc (50mg/kg, manganese (8mg/kg, and copper (8mg/kg was calculated in ICMP-53506, Bullo-94-1, and ICMP-83720 respectively. In case of trace and toxic micro-elements, high concentration of nickel, cobalt, chromium and cadmium was found in O.B.V, Bullo-7704, ICMP-83401, and ICMP-83720 in the edible part of millet plants (grains cultivars respectively.

  4. Evaluation of eleven macro and micro elements present in various hybrids of millet (pennisetum glucum, or P. americanum)

    International Nuclear Information System (INIS)

    Shar, G.Q.; Shar, L.A.

    2012-01-01

    Maize and Millet Research Institute (MMRI) situated in Yousuf wala, District Sahiwal, Punjab, Pakistan was selected to grow nine different hybrids/cultivars of millet for study to comprehend the variable concentration of macro, micro and trace and toxic elements in their grains. Wet digestion method was used for the preparation of samples and flame atomic absorption spectrophotometer for analysis of eleven major and minor elements. High values of macro-elements i.e. sodium and potassium was found in ICMP-45 I and magnesium in ICMP-53506. The high value of essential micro-elements i.e. zinc (50 mg/kg), manganese (8 mg/kg), and copper (8mg/kg) was calculated in ICMP-53506, Bullo-94-1, and ICMP-83120 respectively. In case of trace and toxic micro-elements, high concentration of nickel, cobalt, chromium and cadmium was found in O.B.V, Bullo-1104, ICMP-83401, and ICMP-83120 in the edible part of millet plants (grains) cultivars respectively. (author)

  5. Recent heavy-ion results from the LHC and future perspectives

    CERN Document Server

    Mischke, Andre

    2016-01-01

    Strongly interacting matter at high densities and temperatures can be created in high-energy collisions of heavy atomic nuclei. Since 2010, the Large Hadron Collider at CERN provides proton-proton, proton-lead and lead-lead collisions at an unprecedented energy to study the so-called quark-gluon plasma (QGP) state. Several experimental probes have been proposed to determine the properties of the QGP. In this contribution, a selection of recent results from the heavy-ion programme at RHIC and the LHC are reviewed and discussed.

  6. Structure of very heavy few-electron ions - new results from the heavy ion storage ring, ESR

    International Nuclear Information System (INIS)

    Mokler, P.H.; Stoehlker, T.; Kozhuharov, C.; Moshammer, R.; Rymuza, P.; Bosch, F.; Kandler, T.

    1993-08-01

    The heavy ion synchrotron/storage ring facility at GSI, SIS/ESR, provides intense beams of cooled, highly-charged ions up to naked uranium (U 92+ ). By electron capture during ion-atom collisions in the gas target of the ESR or by recombination at ion-electron encounters in the ''electron cooler'' excited states are populated. The detailed structure of very heavy one-, two- and three-electron ions is studied. The different mechanisms leading to the excited states are described, as well as the new experimental tools now available for a detailed spectroscopy of these interesting systems. Special emphasis is given to X-ray transitions to the groundstates in H- and He-like systems. For the heaviest species the groundstate Lambshift can now be probed on an accuracy level of better than 10% using solid-state X-ray detectors. Applying dispersive X-ray analyzing techniques, this accuracy will certainly be improved in future. However, utilizing the dielectronic resonances for a spectroscopy, the structure in Li-like heavy ions can already be probed now on the sub eV level. (orig.)

  7. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  8. Critical evaluation of heavy water project at Thal (Preprint No. PM-5)

    International Nuclear Information System (INIS)

    Jayakumar, N.S.

    1989-04-01

    The project known as Thal Ammonia Extension was a heavy water project successfully completed by Rashtriya Chemicals and Fertilizers (RCF) Ltd. The project consisted of erecting a heavy water plant of 110 tons/year capacity at Thal. The process Know-how and engineering of the plant was supplied by the Heavy Water Projects Division of the Department of Atomic Energy. Salient features of the project, management features which resulted in fast completion of erection, bottlenecks faced and engineering innovations adopted for efficient operation of the plant are described. Some modifications which can lead to smoother operation are listed. (M.G.B.)

  9. Interaction of heavy ions with matter. Progress report and summary report

    International Nuclear Information System (INIS)

    Boring, J.W.; Johnson, R.E.

    1976-07-01

    The processes that occur when a heavy atomic particle (ion, atom, etc.) interacts with matter, particularly the effects produced on biological systems, were investigated. Results of the investigations over a three year period are reviewed. Areas covered include: energy loss, straggling and stopping; projected ranges and first-order moments; damage cross section for inactivation of RNase; and spatial distribution of damage in RNase. History and objectives of the research program are included

  10. Energy dependence of the ionization of highly excited atoms by collisions with excited atoms

    International Nuclear Information System (INIS)

    Shirai, T.; Nakai, Y.; Nakamura, H.

    1979-01-01

    Approximate analytical expressions are derived for the ionization cross sections in the high- and low-collision-energy limits using the improved impulse approximation based on the assumption that the electron-atom inelastic-scattering amplitude is a function only of the momentum transfer. Both cases of simultaneous excitation and de-excitation of one of the atoms are discussed. The formulas are applied to the collisions between two excited hydrogen atoms and are found very useful for estimating the cross sections in the wide range of collisions energies

  11. Nuclear-bound quarkonia and heavy-flavor hadrons

    Science.gov (United States)

    Krein, G.; Thomas, A. W.; Tsushima, K.

    2018-05-01

    In our quest to win a deeper understanding of how QCD actually works, the study of the binding of heavy quarkonia and heavy-flavor hadrons to atomic nuclei offers enormous promise. Modern experimental facilities such as FAIR, Jefferson Lab at 12 GeV and J-PARC offer exciting new experimental opportunities to study such systems. These experimental advances are complemented by new theoretical approaches and predictions, which will both guide these experimental efforts and be informed and improved by them. This review will outline the main theoretical approaches, beginning with QCD itself, summarize recent theoretical predictions and relate them both to past experiments and those from which we may expect results in the near future.

  12. Protein dynamics and stability: The distribution of atomic fluctuations in thermophilic and mesophilic dihydrofolate reductase derived using elastic incoherent neutron scattering

    International Nuclear Information System (INIS)

    Meinhold, Lars; Clement, David; Tehei, M.; Daniel, R.M.; Finney, J.L.; Smith, Jeremy C.

    2008-01-01

    The temperature dependence of the dynamics of mesophilic and thermophilic dihydrofolate reductase is examined using elastic incoherent neutron scattering. It is demonstrated that the distribution of atomic displacement amplitudes can be derived from the elastic scattering data by assuming a (Weibull) functional form that resembles distributions seen in molecular dynamics simulations. The thermophilic enzyme has a significantly broader distribution than its mesophilic counterpart. Furthermore, although the rate of increase with temperature of the atomic mean-square displacements extracted from the dynamic structure factor is found to be comparable for both enzymes, the amplitudes are found to be slightly larger for the thermophilic enzyme. Therefore, these results imply that the thermophilic enzyme is the more flexible of the two

  13. Acquisition of a novel eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site confers intracellular cleavage of an H7N7 influenza virus hemagglutinin

    International Nuclear Information System (INIS)

    Hamilton, Brian S.; Sun, Xiangjie; Chung, Changik; Whittaker, Gary R.

    2012-01-01

    A critical feature of highly pathogenic avian influenza viruses (H5N1 and H7N7) is the efficient intracellular cleavage of the hemagglutinin (HA) protein. H7N7 viruses also exist in equine species, and a unique feature of the equine H7N7 HA is the presence of an eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site. Here, we show that three histidine residues within the unique insertion of the equine H7N7 HA are essential for intracellular cleavage. An asparagine residue within the insertion-derived glycosylation site was also found to be essential for intracellular cleavage. The presence of the histidine residues also appear to be involved in triggering fusion, since mutation of the histidine residues resulted in a destabilizing effect. Importantly, the addition of a tetrabasic site and the eleven amino acid insertion conferred efficient intracellular cleavage to the HA of an H7N3 low pathogenicity avian influenza virus. Our studies show that acquisition of the eleven amino acid insertion offers an alternative mechanism for intracellular cleavage of influenza HA.

  14. Acquisition of a novel eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site confers intracellular cleavage of an H7N7 influenza virus hemagglutinin

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Brian S.; Sun, Xiangjie; Chung, Changik [Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca NY 14853 (United States); New York Center of Excellence for Influenza Research and Surveillance, University of Rochester Medical Center, Rochester NY 14627 (United States); Whittaker, Gary R., E-mail: grw7@cornell.edu [Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca NY 14853 (United States); New York Center of Excellence for Influenza Research and Surveillance, University of Rochester Medical Center, Rochester NY 14627 (United States)

    2012-12-05

    A critical feature of highly pathogenic avian influenza viruses (H5N1 and H7N7) is the efficient intracellular cleavage of the hemagglutinin (HA) protein. H7N7 viruses also exist in equine species, and a unique feature of the equine H7N7 HA is the presence of an eleven amino acid insertion directly N-terminal to a tetrabasic cleavage site. Here, we show that three histidine residues within the unique insertion of the equine H7N7 HA are essential for intracellular cleavage. An asparagine residue within the insertion-derived glycosylation site was also found to be essential for intracellular cleavage. The presence of the histidine residues also appear to be involved in triggering fusion, since mutation of the histidine residues resulted in a destabilizing effect. Importantly, the addition of a tetrabasic site and the eleven amino acid insertion conferred efficient intracellular cleavage to the HA of an H7N3 low pathogenicity avian influenza virus. Our studies show that acquisition of the eleven amino acid insertion offers an alternative mechanism for intracellular cleavage of influenza HA.

  15. Ultrarelativistic heavy ion collisions: the first billion seconds

    Energy Technology Data Exchange (ETDEWEB)

    Baym, Gordon

    2016-12-15

    I first review the early history of the ultrarelativistic heavy ion program, starting with the 1974 Bear Mountain Workshop, and the 1983 Aurora meeting of the U.S. Nuclear Science Committtee, just one billion seconds ago, which laid out the initial science goals of an ultrarelativistic collider. The primary goal, to discover the properties of nuclear matter at the highest energy densities, included finding new states of matter – the quark-gluon plasma primarily – and to use collisions to open a new window on related problems of matter in cosmology, neutron stars, supernovae, and elsewhere. To bring out how the study of heavy ions and hot, dense matter in QCD has been fulfilling these goals, I concentrate on a few topics, the phase diagram of matter in QCD, and connections of heavy ion physics to cold atoms, cosmology, and neutron stars.

  16. The Shape and Flow of Heavy Ion Collisions (490th Brookhaven Lecture)

    Energy Technology Data Exchange (ETDEWEB)

    Schenke, Bjoern [BNL Physics Department

    2014-12-18

    The sun can’t do it, but colossal machines like the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab and Large Hadron Collider (LHC) in Europe sure can. Quarks and gluons make up protons and neutrons found in the nucleus of every atom in the universe. At heavy ion colliders like RHIC and the LHC, scientists can create matter more than 100,000 times hotter than the center of the sun—so hot that protons and neutrons melt into a plasma of quarks and gluons. The particle collisions and emerging quark-gluon plasma hold keys to understanding how these fundamental particles interact with each other, which helps explain how everything is held together—from atomic nuclei to human beings to the biggest stars—how all matter has mass, and what the universe looked like microseconds after the Big Bang. Dr. Schenke discusses theory that details the shape and structure of heavy ion collisions. He will also explain how this theory and data from experiments at RHIC and the LHC are being used to determine properties of the quark-gluon plasma.

  17. On-line atomic data access

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, D.R. [Oak Ridge National Lab., TN (United States); Nash, J.K. [Lawrence Livermore National Lab., CA (United States)

    1996-04-01

    The need for atomic data is one which continues to expand in a wide variety of applications including fusion energy, astrophysics, laser- produced plasma research, and plasma processing. Modern computer database and communications technology nables this data to be placed on-line and obtained by users of the Internet. Presented here is a summary of the observations and conclusions regarding such on-line atomic data access derived from a forum held at the Tenth APS Topical Conference on Atomic Processes in Plasmas.

  18. Informal proposal for an Atomic Physics Facility at the National Synchrotron Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.W.; Johnson, B.M.; Meron, M.

    1986-01-01

    An Atomic Physics Facility (APF) for experiments that will use radiation from a superconducting wiggler on the NSLS X-13 port is described. The scientific justification for the APF is given and the elements of the facility are discussed. It is shown that it will be possible to conduct a uniquely varied set of experiments that can probe most aspects of atomic physics. A major component of the proposal is a heavy-ion storage ring capable of containing ions with energies of about 10 MeV/nucleon. The ring can be filled with heavy ions produced at the BNL MP Tandem Laboratory or from independent ion-source systems. A preliminary cost estimate for the facility is presented.

  19. Momentum diffusion for coupled atom-cavity oscillators

    International Nuclear Information System (INIS)

    Murr, K.; Maunz, P.; Pinkse, P. W. H.; Puppe, T.; Schuster, I.; Rempe, G.; Vitali, D.

    2006-01-01

    It is shown that the momentum diffusion of free-space laser cooling has a natural correspondence in optical cavities when the internal state of the atom is treated as a harmonic oscillator. We derive a general expression for the momentum diffusion, which is valid for most configurations of interest: The atom or the cavity or both can be probed by lasers, with or without the presence of traps inducing local atomic frequency shifts. It is shown that, albeit the (possibly strong) coupling between atom and cavity, it is sufficient for deriving the momentum diffusion to consider that the atom couples to a mean cavity field, which gives a first contribution, and that the cavity mode couples to a mean atomic dipole, giving a second contribution. Both contributions have an intuitive form and present a clear symmetry. The total diffusion is the sum of these two contributions plus the diffusion originating from the fluctuations of the forces due to the coupling to the vacuum modes other than the cavity mode (the so-called spontaneous emission term). Examples are given that help to evaluate the heating rates induced by an optical cavity for experiments operating at low atomic saturation. We also point out intriguing situations where the atom is heated although it cannot scatter light

  20. Cluster radioactivity of Z=125 super heavy nuclei

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Seenappa, L.

    2015-01-01

    For atomic numbers larger than 121 cluster decay and spontaneous fission may compete with α decay. Hence there is a need to make reliable calculations for the cluster decay half-lives of superheavy nuclei to predict the possible isotopes super heavy nuclei. So, in the present work, we have studied the decay of clusters such as 8 Be, 10 Be, 12 C, 14 C, 16 C, 18 O, 20 O, 22 Ne, 24 Ne, 25 Ne, 26 Ne, 28 Mg, 30 Mg, 32 Si, 34 Si, 36 Si, 40 S, 48 Ca, 50 Ca and 52 Ti from the super heavy nuclei Z=125

  1. Atomic force microscope observation of branching in single transcript molecules derived from human cardiac muscle

    International Nuclear Information System (INIS)

    Reed, Jason; Hsueh, Carlin; Gimzewski, James K; Mishra, Bud

    2008-01-01

    We have used an atomic force microscope to examine a clinically derived sample of single-molecule gene transcripts, in the form of double-stranded cDNA, (c: complementary) obtained from human cardiac muscle without the use of polymerase chain reaction (PCR) amplification. We observed a log-normal distribution of transcript sizes, with most molecules being in the range of 0.4-7.0 kilobase pairs (kb) or 130-2300 nm in contour length, in accordance with the expected distribution of mRNA (m: messenger) sizes in mammalian cells. We observed novel branching structures not previously known to exist in cDNA, and which could have profound negative effects on traditional analysis of cDNA samples through cloning, PCR and DNA sequencing

  2. Positronium collisions with atoms and molecules

    Science.gov (United States)

    Fabrikant, I. I.; Gribakin, G. F.; Wilde, R. S.

    2017-11-01

    We review recent theoretical efforts to explain observed similarities between electron-atom and positronium(Ps)-atom scattering which also extends to molecular targets. In the range of the projectile velocities above the threshold for Ps ionization (break-up) this similarity can be explained in terms of quasi-free electron scattering and impulse approximation. However, for lower Ps velocities more sophisticated methods should be developed. Our calculations of Ps scattering by heavy noble-gas atoms agree well with experiments at Ps velocities above the Ps ionization threshold. However, in contrast to electron scattering cross sections, at lower velocities they exhibit maxima whereas the experimental cross sections tend to decrease toward lower velocities indicating the same similarity with electron scattering cross section observed above the threshold. Our preliminary results for Ps-N2 scattering confirm experimental observation of a resonance similar to the ∏ g resonance in electron-N2 scattering.

  3. Enhancing atom densities in solid hydrogen by isotopic substitution

    International Nuclear Information System (INIS)

    Collins, G.W.; Souers, P.C.; Mapoles, E.R.; Magnotta, F.

    1991-01-01

    Atomic hydrogen inside solid H 2 increases the energy density by 200 MegaJoules/m 3 , for each percent mole fraction stored. How many atoms can be stored in solid hydrogen? To answer this, we need to know: (1) how to produce and trap hydrogen atoms in solid hydrogen, (2) how to keep the atoms from recombining into the ground molecular state, and (3) how to measure the atom density in solid hydrogen. Each of these topics will be addressed in this paper. Hydrogen atoms can be trapped in solid hydrogen by co-condensing atoms and molecules, external irradiation of solid H 2 , or introducing a radioactive impurity inside the hydrogen lattice. Tritium, a heavy isotope of hydrogen, is easily condensed as a radioactive isotopic impurity in solid H 2 . Although tritium will probably not be used in future rockets, it provides a way of applying a large, homogenious dose to solid hydrogen. In all of the data presented here, the atoms are produced by the decay of tritium and thus knowing how many atoms are produced from the tritium decay in the solid phase is important. 6 refs., 6 figs

  4. Study on accumulation of heavy metals in Mangrove sediments, Gabrik Creek (Jask)

    International Nuclear Information System (INIS)

    Zarezadeh, R.; Rezaee, P.

    2016-01-01

    Gabrik in the East of Hormozgan province is Mangrove habitat and one of the important Mangrove protected area. This area is located in Oman coasts. This zone because of building Jagin dam on Gabrick River and existence of sand barrier and exposure of pollution, it is possible to destroy or to be important threats of this planet. Base on importance of this sea inhabitation some of sedimentology parameters and geochemical Mangrove's sediments have been analyzed. In this study for sieve used Hydrometric method and for Identification of organic matter used electronic furnace heat 500 degree centigrade for 6 hours. Quantity of calcium carbonate analyzed by titration and for condenses of heavy metal Zn, Pb and Ni chemical decomposition atomic absorption by Thermo-solaar (±1µg/g). Results showed that mean content of carbonate and organic matter in the sediments is 27 percent and 3.36 percent respectively. Contamination heavy metals Pb, Zn and Ni in the sediments of this mangrove, were studied throughout Gabrik creek. Metal concentration analyses were performed using atomic absorption spectrometry (AAS). Mean concentration of the heavy metals Pb, Zn and Ni in sediments was measured 67.63, 69.63 and 76.53 µg/g dry weights respectively. According to determine geoaccumulation index (Igeo), contamination factor (CF), the degree of contamination correction (mCd) and compared the heavy metal concentrations with to the mean concentrations of heavy metals in sedimentary rock (shales) and China and American standards. The results in this study showed that there is no pollution from Zn metal but there are pollutions from Ni and Pb metals and concentration this heavy metals aren't critical. The origin of these heavy metals can be a result of maintenance of fishing vessels in Gabrik Creek, activities or fuel smuggling and perhaps oil compounds spill into the water and human refuse in the region.

  5. Effects of metal-contaminated soils on the accumulation of heavy metals in gotu kola (Centella asiatica) and the potential health risks: a study in Peninsular Malaysia.

    Science.gov (United States)

    Ong, Ghim Hock; Wong, Ling Shing; Tan, Ai Li; Yap, Chee Kong

    2016-01-01

    Centella asiatica is a commonly used medicinal plant in Malaysia. As heavy metal accumulation in medicinal plants which are highly consumed by human is a serious issue, thus the assessment of heavy metals in C. asiatica is important for the safety of consumers. In this study, the heavy metal accumulation in C. asiatica and the potential health risks were investigated. Samples of C. asiatica and surface soils were collected from nine different sites around Peninsular Malaysia. The concentration of six heavy metals namely Cd, Cu, Ni, Fe, Pb and Zn were determined by air-acetylene flame atomic absorption spectrophotometer (AAS). The degree of anthropogenic influence was assessed by calculating the enrichment factor (EF) and index of geoaccumulation (Igeo). The heavy metal uptake into the plant was estimated through the calculation of translocation factor (TF), bioconcentration factor (BCF) and correlation study. Estimated daily intakes (EDI) and target hazard quotients (THQ) were used to determine the potential health risk of consuming C. asiatica. The results showed that the overall surface soil was polluted by Cd, Cu and Pb, while the uptake of Zn and Ni by the plants was high. The value of EDI and THQ showed that the potential of Pb toxicity in C. asiatica was high as well. As heavy metal accumulation was confirmed in C. asiatica, daily consumption of the plant derived from polluted sites in Malaysia was not recommended.

  6. Evaluation of biochars from different stock materials as carriers of bacterial strain for remediation of heavy metal-contaminated soil.

    Science.gov (United States)

    Wang, Ting; Sun, Hongwen; Ren, Xinhao; Li, Bing; Mao, Hongjun

    2017-09-21

    Two kinds of biochars, one derived from corn straw and one from pig manure, were studied as carriers of a mutant genotype from Bacillus subtilis (B38) for heavy metal contaminated soil remediation. After amendment with biochar, the heavy metal bioavailability decreased. Moreover, the heavy metal immobilization ability of the biochar was enhanced by combining it with B38. The simultaneous application of B38 and pig manure-derived biochar exhibited a superior effect on the promotion of plant growth and the immobilization of heavy metals in soil. The plant biomass increased by 37.9% and heavy metal concentrations in the edible part of lettuce decreased by 69.9-96.1%. The polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) profiles revealed that pig manure-derived biochar could enhance the proliferation of both exotic B38 and native microbes. These results suggest that B38 carried by pig manure-derived biochar may be a promising candidate for the remediation of soils contaminated by multiple heavy metals.

  7. Distribution of heavy metals (Cu, Zn and Cr in groundwater from the area of a future radioactive waste repository Saligny – Romania

    Directory of Open Access Journals (Sweden)

    Tudorache A.

    2013-04-01

    Full Text Available A study of some heavy metals (Cu, Zn and Cr concentrations in natural groundwater has been conducted, by considering samples collected from the area located in the neighbourhood of Saligny village (Cernavodă, Romania. Atomic absorption spectrometry methods with thermal and electrothermal atomization has been developed, tested and used for some heavy metals content determination. The results show various concentrations of Cu, Zn and Cr in groundwater samples.

  8. Heavy accelerated nuclei in biomedical research

    International Nuclear Information System (INIS)

    Tobias, C.A.

    1987-01-01

    Accelerated atomic nuclei in physics accelerators have been used in basic biological research and in applied medical diagnostic and therapeutic studies for the past 50 years. The passage of single heavy particles through the cell nucleus is capable of producing multiple DNA double-strand scission and chromatin breaks. According to the Repair-Misrepair model, the high biological effectiveness of high-LET particles is due to misrepair and misrejoining of the breaks. The Bragg depth ionization effect allows heavy particles to deposit considerably more energy deep in tissue than at the surface, and this property has been used for great improvements in the radiation therapy of localized tumors. Recent advances in producing radioactive beams will allow verification of therapeutic administration of such beams. The radioactive beams also open a new field of Nuclear Medicine. There is increasing interest in building special biomedical light and heavy-ion accelerators. These will be used not only for therapy but also for diagnosis, for the study of radiation hazards in space flight, and for basic molecular and cellular understanding of the mechanisms of radiation effect

  9. Physics of atoms and molecules

    International Nuclear Information System (INIS)

    Bransden, B.H.; Joachain, C.J.

    1983-01-01

    This book presents a unified account of the physics of atoms and molecules at a level suitable for second- and third-year undergraduate students of physics and physical chemistry. Following a brief historical introduction to the subject the authors outline the ideas and approximation methods of quantum mechanics to be used later in the book. Six chapters look at the structure of atoms and the interactions between atoms and electromagnetic radiation. The authors then move on to describe the structure of molecules and molecular spectra. Three chapters deal with atomic collisions, the scattering of electrons by atoms and the scattering of atoms by atoms. The concluding chapter considers a few of the many important applications of atomic physics within astrophysics, laser technology, and nuclear fusion. Problems are given at the end of each chapter, with hints at the solutions in an appendix. Other appendices include various special topics and derivations together with useful tables of units. (author)

  10. Plasmid Mediated Antibiotic and Heavy Metal Resistance in Bacillus Strains Isolated From Soils in Rize, Turkey

    Directory of Open Access Journals (Sweden)

    Elif SEVİM

    2015-09-01

    Full Text Available Fifteen Bacillus strains which were isolated from soil samples were examined for resistance to 17 different antibiotics (ampicillin, methicillin, erythromycin, norfloxacin, cephalotine, gentamycin, ciprofloxacin, streptomycin, tobramycin, chloramphenicol, trimethoprim-sulfamethoxazole, tetracycline, vancomycin, oxacilin, neomycin, kanamycin and, novabiocin and to 10 different heavy metals (copper, lead, cobalt, chrome, iron, mercury, zinc, nickel, manganese and, cadmium and for the presence of plasmid DNA. A total of eleven strains (67% were resistant to at least one antibiotic. The most common resistance was observed against methicillin and oxacillin. The most resistance strains were found as Bacillus sp. B3 and Bacillus sp. B11. High heavy metal resistance against copper, chromium, zinc, iron and nickel was detected, but mercury and cobalt resistance was not detected, except for 3 strains (B3, B11, and B12 which showed mercury resistance. It has been determined that seven Bacillus strains have plasmids. The isolated plasmids were transformed into the Bacillus subtilis W168 and it was shown that heavy metal and antibiotic resistance determinants were carried on these plasmids. These results showed that there was a correlation between plasmid content and resistance for both antibiotic and heavy metal resistance

  11. Searching for Heavy Photons with Detached Verices in the Heavy Photon Search Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Szumila-Vance, Holly [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2017-08-01

    The Jefferson Lab Heavy Photon Search (HPS) experiment is searching for a hypothetical massive particle called the heavy photon which could mediate a dark electromagnetic-type force. If heavy photons kinetically mix with Standard Model photons, they may be radiated by electrons scattering from a heavy nucleus and then decay to e+e- pairs. HPS uniquely searches for heavy photons that either decay at the target or a measurable distance after. The experiment utilizes a silicon vertex tracker (SVT) for momentum and vertex reconstruction, together with an electromagnetic calorimeter for measuring particle energies and triggering events. The HPS experiment took its first data during the spring 2015 engineering run using a 1 GeV electron beam incident on a tungsten target and its second data in the spring of 2016 at a beam energy of 2.3 GeV. The 2015 run obtained two days of production data that was used for the first physics results. The analysis of the data was conducted as a blinded analysis by tuning cuts on 10% of the data. This dissertation discusses the displaced vertex search for heavy photons in the 2015 engineering run. It describes the theoretical motivation for looking for heavy photons and provides an overview of the HPS experimental design and performance. The performance details of the experiment are primarily derived from the 2015 engineering run with some discussion from the higher energy running in 2016. This dissertation further discusses the cuts used to optimize the displaced vertex search and the results of the search. The displaced vertex search did not set a limit on the heavy photon but did validate the methodology for conducting the search. Finally, we used the full data set to make projections and guide future analyses.

  12. Heavy water at Aswan

    International Nuclear Information System (INIS)

    1959-01-01

    A fertilizer factory is being built by Egyptian Chemical Industries (Kima) at Aswan on the upper Nile; it will produce a mixture of ammonium nitrate and calcium carbonate adjusted to contain 20.5% nitrogen. It is also proposed to construct a heavy water plant to be located at and integrated with the fertilizer factory. At the request of the Government of the United Arab Republic, the International Atomic Energy Agency sent an expert to carry out investigation of the technical, economic and other related aspects of the proposed production of heavy water. A report was submitted to the IAEA Director General. Its main conclusions can be summarized as follows: (1) Production of heavy water as a by-product of fertilizer manufacture at Aswan is technically feasible. Separation of deuterium from industrial hydrogen for this purpose could be done either by catalytic exchange or by liquefaction and distillation; the choice should depend on economic considerations. (2) The heavy water produced at Aswan should be competitive in cost with that produced elsewhere; this, however, would depend on whether firm contracts are obtained for the delivery of equipment at guaranteed prices and with guaranteed performance, and whether such prices are in reasonable agreement with preliminary estimates. (3) The future market for heavy water is difficult to predict. For one thing, there is a very large production capacity in the USA, most of which is idle due to lack of demand. Secondly, there is a relatively small production outside the USA that is sold at prices higher than that charged by the US Government. The future of the market is necessarily contingent upon the possibility of future free sale by the US Government. At the end of his report, the expert has also given his comments on possible further assistance to the project by IAEA

  13. Spatial distribution and risk assessment of heavy metals in sediments of Shuangtaizi estuary, China

    International Nuclear Information System (INIS)

    Li, Chen; Song, Chengwen; Yin, Yanyan; Sun, Menghan; Tao, Ping; Shao, Mihua

    2015-01-01

    Highlights: • Five heavy metals are analyzed in the sediments from Shuangtaizi estuary. • Particle size of the sediment effects the concentration of heavy metals. • Pb, Cu, Zn and Hg pose low ecological risks in the Shuangtaizi estuary. • Heavy metal pollution in Shuangtaizi estuary is mainly dominated by Cd. - Abstract: In order to evaluate the spatial distribution and potential ecological risk of Pb, Cu, Zn, Cd, and Hg, the surface sediments were collected from 18 sites in the Shuangtaizi estuary. The concentrations of Pb, Cu, Zn, Cd, and Hg were analyzed by atomic absorption spectrophotometry and atomic fluorescence spectrometry after digestion. The particle sizes of the sediments were analyzed using a laser diffraction particle size analyzer. The results show that the heavy metal contents in the sediments are observed in the following order: Zn (18.25–126.75 mg/kg) > Pb (4.38–9.65 mg/kg) > Cu (1.80–17.68 mg/kg) > Cd (0.241–0.764 mg/kg) > Hg (0.007–0.021 mg/kg). In comparison with the concentrations of heavy metals in other regions, the concentrations of Pb, Cu, and Zn in the Shuangtaizi estuary are generally low, and the Cd concentrations are close to those reported in other regions. Both the potential ecological risk index and the geoaccumulation index reveal that the heavy metal pollution in Shuangtaizi estuary is mainly dominated by Cd

  14. MICROBIAL REMOVAL OF HEAVY METALS FROM WASTEWATER

    Directory of Open Access Journals (Sweden)

    Justyna Koc-Jurczyk

    2014-10-01

    Full Text Available Industrialization and urbanization result in increase of heavy metals released into the environment (soil, lakes, rivers, seas, oceans, groundwater. Studies on biosorption of heavy metals are aimed to specify types of microorganisms which could efficiently bind metals. This approach has a very important significance for both slowing down metals exploitation by recovery, and also reduction of environmental pollution by decrease of their excessive concentration. Recent studies have reported about the capabilities of fungi, algae, yeasts, bacteria, waste and agricultural residues or materials containing chitosan derived from crustacean shells as a biosorbents. Biohydrometallurgy could be considered as a new “green” technology of heavy metals removal from wastewater.

  15. O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

    Directory of Open Access Journals (Sweden)

    Roman Sommer

    2016-12-01

    Full Text Available Selenoglycosides are used as reactive glycosyl donors in the syntheses of oligosaccharides. In addition, such heavy atom analogs of natural glycosides are useful tools for structure determination of their lectin receptors using X-ray crystallography. Some lectins, e.g., members of the tectonin family, only bind to carbohydrate epitopes with O-alkylated ring hydroxy groups. In this context, we report the first synthesis of an O-methylated selenoglycoside, specifically methyl 2-O-methyl-L-selenofucopyranoside, a ligand of the lectin tectonin-2 from the mushroom Laccaria bicolor. The synthetic route required a strategic revision and further optimization due to the intrinsic lability of alkyl selenoglycosides, in particular for the labile fucose. Here, we describe a successful synthetic access to methyl 2-O-methyl-L-selenofucopyranoside in 9 linear steps and 26% overall yield starting from allyl L-fucopyranoside.

  16. O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside.

    Science.gov (United States)

    Sommer, Roman; Hauck, Dirk; Varrot, Annabelle; Imberty, Anne; Künzler, Markus; Titz, Alexander

    2016-01-01

    Selenoglycosides are used as reactive glycosyl donors in the syntheses of oligosaccharides. In addition, such heavy atom analogs of natural glycosides are useful tools for structure determination of their lectin receptors using X-ray crystallography. Some lectins, e.g., members of the tectonin family, only bind to carbohydrate epitopes with O-alkylated ring hydroxy groups. In this context, we report the first synthesis of an O -methylated selenoglycoside, specifically methyl 2- O -methyl-L-selenofucopyranoside, a ligand of the lectin tectonin-2 from the mushroom Laccaria bicolor . The synthetic route required a strategic revision and further optimization due to the intrinsic lability of alkyl selenoglycosides, in particular for the labile fucose. Here, we describe a successful synthetic access to methyl 2- O -methyl-L-selenofucopyranoside in 9 linear steps and 26% overall yield starting from allyl L-fucopyranoside.

  17. Future atomic physics researches at HIRFL-CSR

    International Nuclear Information System (INIS)

    Cai Xiaohong; Xia Jiawen; Zhan Wenlong

    1999-01-01

    A new storage ring system, HIRFL-CSR, is now in construction in the National Laboratory of Heavy Ion Research Facility of Lanzhou, China. The new facility consists of a main ring (CSRm) and an experimental ring (CSRe). With the flexibility of the production and the investigation of highly charged ions and radioactive ion beams the new HIRFL-CSR facility will make many frontier atomic physics researches possible in near future. The future physics researches at the HIRFL-CSR are now under consideration. In this paper an overview of the HIRFL-CSR project is given, and the main atomic physics programs to be carried at the HIRFL-CSR are presented. (orig.)

  18. Survey of atomic and molecular data needs for fusion

    International Nuclear Information System (INIS)

    Lorenz, A.; Phillips, J.; Schmidt, J.J.; Lemley, J.R.

    1976-01-01

    Atomic and molecular data needs in five areas of plasma research and fusion technology are considered: Injection Systems (plasma heating by neutral particle beam injection and particle cluster beam injection); Plasma-Surface Interaction (sputtering, absorption, adsorption, reflection, evaporation, surface electron emission, interactions of atomic hydrogen isotopes, synchrotron radiation); Plasma Impurities and Cooling (electron impact ionization and excitation, recombination processes, charge exchange, reflection of H from wall surfaces); Plasma Diagnostics (atomic structure and transition probabilities, X-ray wave-length shift for highly ionized metals, electron capture collisions with H + and D + , heavy-ion collision ionization probe, photon scattering, emission spectroscopy); Laser-fusion Compression (microexplosion physics, diagnostics, microtarget design, laser systems requirements, laser development, reactor design needs)

  19. Nuclear polarization contribution to the Lamb-shift in heavy atoms

    International Nuclear Information System (INIS)

    Plunien, G.; Mueller, B.; Greiner, W.

    1988-08-01

    The energy shift of the 1s 1/2 -state in 238 92 U due to virtual excitation of nuclear rotational modes is shown to be considerable correction for atomic high precision experiments. In contrast to this nuclear polarization effects are of minor importance for Lamb-shift studies in 208 82 Pb. (orig.)

  20. Materials science symposium 'heavy ion science in tandem energy region'

    International Nuclear Information System (INIS)

    Iwamoto, Akira; Yoshida, Tadashi; Takeuchi, Suehiro

    2001-11-01

    The facility of the JAERI tandem accelerator and its booster has been contributing to obtain plenty of fruitful results in the fields of nuclear physics, nuclear chemistry, atomic and solid state physics and materials science, taking an advantage of its prominent performances of heavy ion acceleration. The previous meeting held in 1999 also offered an opportunity to scientists from all over the heavy ion science fields, including nuclear physics, solid state physics and cross-field physics to have active discussions. This meeting included oral presentations with a new plan and with a new scope of fields expected from now on, as an occasion for opening the 21st century in heavy ion science. The 50 of the presented papers are indexed individually. (J.P.N.)

  1. Eleven cases of breast conservation

    International Nuclear Information System (INIS)

    Matsuoka, Toshio; Sekine, Kenshi; Miyagawa, Akira; Sugimoto, Toichi

    1991-01-01

    Eleven patients with T1 and small T2 breast cancer were treated by a combination of quadrantectomy, axillary dissection and radiotherapy. The mean age of the patients was 44.6 years. Mean follow-up period was 7.1 months. Six patients had clinical stage I, and five patients had clinical stage II. Four patients had involvement of axillary content (36.3%) on histological examination. There were eight scirrhous carcinomas and three papillotubular carcinomas. The incidence of local and distant recurrence was none in our group. The multifocality of breast cancer based on pathologic studies had been shown. On the basis of these findings we concluded that the patients undergoing breast conservation should be subjected to postoperative radiotherapy. Psychological morbidity was compared in 10 patients treated by breast conservation and 23 patients treated by mastectomy. There were no statistically significant differences between two groups in the estimation of adjustment disorder, depression, anxiety and stress. The patients in breast conservation group had a significant excess or nervousness and the patients of the mastectomy group had an anger. (author)

  2. Applications to particle and atomic physics of a ''theorem'' on the order of energy levels

    International Nuclear Information System (INIS)

    Grosse, H.; Pflug, A.; Martin, A.

    1984-01-01

    The sign of the Laplacian of the potential, in the Schroedinger equation, indicates in which way Coulomb degeneracy is lifted. We propose three applications of this property. The first one concerns the order of levels in heavy quark systems, the second the effects of the finite size of nuclei in mesic atoms, and the third the filling of atomic shells and the order of levels in alkaline atoms [fr

  3. Excited, bound and resonant positron-atom systems

    Energy Technology Data Exchange (ETDEWEB)

    Bromley, M W J [Department of Physics and Computational Science Research Center, San Diego State University, San Diego CA 92182 (United States); Mitroy, J, E-mail: mbromley@physics.sdsu.ed [ARC Centre for Antimatter-Matter Studies and Faculty of Education, Health and Science, Charles Darwin University, Darwin NT 0909 (Australia)

    2010-01-01

    Calculations have demonstrated that eleven neutral atoms can bind positrons, while many more can bind positronium. This is a short review of recent progress made in understanding some of the underlying mechanisms. The emphasis here being on configuration interaction calculations with excited state configurations. These have demonstrated the existence of a {sup 2}P{sup o} excited state of e{sup +}Ca, which consists predominantly of a positronium cluster orbiting the Ca{sup +} ion in the L = 1 partial wave. Preliminary results are presented of excited state positron binding to a model alkali atom, where the excited {sup 1}P{sup o} states are stable over a limited region. Implications for the unnatural parity, {sup 2,4}S{sup o}, states of PsH, LiPs, NaPs and KPs are also discussed. The e{sup +}Mg, e{sup +}Cu, e{sup +}Zn and e{sup +}Cd systems show a lack of a {sup 2}P{sup o} excited state, each instead possessing a low-energy p-wave shape resonance of varying strength.

  4. Heavy Metal Stars

    Science.gov (United States)

    2001-08-01

    atomic mass and hence, increasing positive charge of the nuclei, the electric repulsion between the nuclei becomes stronger and stronger. In fact, the fusion process only works up to a certain mass limit, corresponding to the element Iron [2]. All elements that are heavier than Iron cannot be produced via this path. But then, how were those heavy elements we now find on the Earth produced in the first place? From where comes the Zirconium in artificial diamonds, the Barium that colours fireworks, the Tungsten in the filaments in electric bulbs? Which process made the Lead in your car battery? Beyond iron The production of elements heavier than Iron takes place by adding neutrons to the atomic nuclei . These neutral particles do not feel any electrical repulsion from the charged nuclei. They can therefore easily approach them and thereby create heavier nuclei. This is indeed the way the heaviest chemical elements are built up. There are actually two different stellar environments where this process of "neutron capture" can happen. One place where this process occurs is inside very massive stars when they explode as supernovae . In such a dramatic event, the build-up proceeds very rapidly, via the so-called "r-process" ( "r" for rapid ). The AGB stars But not all heavy elements are created in such an explosive way. A second possibility follows a more "peaceful" road. It takes place in rather normal stars, when they burn their Helium towards the end of their lives. In the so-called "s-process" ( "s" for slow ), heavier elements are then produced by a rather gentle addition of neutral neutrons to atomic nuclei. In fact, roughly half of all the elements heavier than Iron are believed to be synthesized by this process during the late evolutionary phases of stars. This process takes place during a specific stage of stellar evolution, known as the "AGB" phase [3]. It occurs just before an old star expels its gaseous envelope into the surrounding interstellar space and sometime

  5. Study of heavy metals bioaccumulation in the process of ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... The bioaccumulation of heavy metals (Cd, Zn, Ni, Pb and Cr) and the relationship between them was investigated on ... this elements in 14 days) exposure, the metal accumulation was measured using atomic absorption spectroscopy. ... sed to the point that it endangers human life in some areas, and the ...

  6. Influence of the nuclear autocorrelation function on the positron production in heavy-ion collisions

    International Nuclear Information System (INIS)

    Tomoda, T.; Weidenmueller, H.A.

    1983-01-01

    The influence of a nuclear reaction on atomic positron production in heavy-ion collisions is investigated. Using statistical concepts, we describe the nuclear S matrix for a heavy-ion induced reaction as a statistically fluctuating function of energy. The positron production rate is then dependent on the autocorrelation function of this S matrix, and on the ratio of the ''direct'' versus the ''fluctuating'' part of the nuclear cross section. Numerical calculations show that in this way, current experimental results on positron production in heavy-ion collisions can be reproduced in a semiquantitative fashion

  7. Auger transitions in singly and multiply ionized atoms

    International Nuclear Information System (INIS)

    Mehlhorn, W.

    1978-01-01

    Some recent progress in Auger and autoionizing electron spectrometry of free metal atoms and of multiply ionized atoms is reviewed. The differences which arise between the spectra of atoms in the gaseous and the solid state are due to solid state effects. This will be shown for Cd as an example. The super Coster-Kronig transitions 3p-3d 2 (hole notation) and Coster-Kronig transitions 3p-3d 4s have been measured and compared with free-atom calculations for free Zn atoms. The experimental width GAMMA(3p)=(2.1+-0.2)eV found for the free atom agrees with the value obtained for solid Zn but is considerably smaller than the theoretical value for the free atom. Autoionizing spectra of Na following an L-shell excitation or ionization by different particles are compared and discussed. The nonisotropic angular distribution of electrons from the transition 2p 5 3s 2 2 Psub(3/2)→2p 6 +e - is compared with theoretical calculations. Two examples for Auger spectrometry of multiply ionized atoms are given: (1) excitation of neon target atoms by light and heavy ions, and (2) excitation of projectile ions Be + and B + in single gas collisions with CH 4 . A strong alignment of the excited atoms has also been found here

  8. Atom diffraction with a 'natural' metastable atom nozzle beam

    International Nuclear Information System (INIS)

    Karam, J-C; Wipf, N; Grucker, J; Perales, F; Boustimi, M; Vassilev, G; Bocvarski, V; Mainos, C; Baudon, J; Robert, J

    2005-01-01

    The resonant metastability-exchange process is used to obtain a metastable atom beam with intrinsic properties close to those of a ground-state atom nozzle beam (small angular aperture, narrow velocity distribution). The estimated effective source diameter (15 μm) is small enough to provide at a distance of 597 mm a transverse coherence radius of about 873 nm for argon, 1236 nm for neon and 1660 nm for helium. It is demonstrated both by experiment and numerical calculations with He*, Ne* and Ar* metastable atoms, that this beam gives rise to diffraction effects on the transmitted angular pattern of a silicon-nitride nano-slit grating (period 100 nm). Observed patterns are in good agreement with previous measurements with He* and Ne* metastable atoms. For argon, a calculation taking into account the angular aperture of the beam (0.35 mrad) and the effect of the van der Waals interaction-the van der Waals constant C 3 1.83 +0.1 -0.15 au being derived from spectroscopic data-leads to a good agreement with experiment

  9. Photoelectrochemical detection of toxic heavy metals

    CSIR Research Space (South Africa)

    Chamier, J

    2010-09-01

    Full Text Available on various substrates introduced the possibility for portable and on-site instant verification of heavy metal pollutants. In this work, the favorable properties of the mercury-sensitive fluorescent molecule, Rhodamine 6G hydrozone derivative (RS), were...

  10. International bulletin on atomic and molecular data for fusion. Nos. 50-51

    International Nuclear Information System (INIS)

    Botero, J.; Stephens, J.A.

    1996-10-01

    This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In part 1 the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, polarizabilities, electric moments, interatomic potentials); (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions); and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). Part 2 contains the bibliographic data, essentially for the above listed topics

  11. Mitigation of heavy metals in different vegetables through biological washing techniques

    Directory of Open Access Journals (Sweden)

    Muhammad Umair Sattar

    2015-12-01

    Full Text Available Availability of nutritious and healthy food is the foremost challenging issue in all over the word. Vegetables are essential part in human diet and considered as natural reserves of nutrients gifted by Almighty Allah to human beings. Heavy metals are among the most toxic food pollutants and their intake through diet leads to several disorders. The sources of heavy metal contamination include waste water irrigation, industrial emissions, transportation and application of metal-based pesticides. In Pakistan this situation is more alarming as vegetables grown in peri-urban areas have shown high incidence of heavy metals accumulation. In this study effort was made to mitigate different heavy metals (Ar, Cd, Cr and Pb in cauliflower, spinach, okra and brinjal collected from peri-urban areas through washing with different biological solutions. Heavy metals contents were determined by using Atomic Absorption Spectrophotometry (AAS. Vegetable showed high load of heavy metals in unwashed form that reduced significantly by washing with different biological solutions. Among the different biological solutions, washing of vegetables with 8% ginger solution was found to be more effective.

  12. Simultaneous K plus L shell ionized atoms during heavy-ion ...

    Indian Academy of Sciences (India)

    The fraction of simultaneous K plus L shell ionized atoms is estimated in Fe, Co and Cu elements using carbon ions at different projectile energies. The present results indicate that the fraction of simultaneous K plus L shell ionization probability decreases with increase in projectile energy as well as with increase in the ...

  13. International bulletin on atomic and molecular data for fusion. No. 54-55

    International Nuclear Information System (INIS)

    Stephens, J.A.

    1998-12-01

    This bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In the first part the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths, transition probabilities, oscillator strengths, polarizabilities, electric moments, interatomic potentials), (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy-particle collisions), and (iii) surface interactions (sputtering, chemical reactions, trapping and detrapping, adsorption, desorption, reflection, and secondary electron emission). There are also chapters with beam-matter interactions and data on interactions of atomic particles with fields. In the second Part contains the bibliographic data, essentially for the above listed topics

  14. Atomic structure of highly-charged ions. Final report

    International Nuclear Information System (INIS)

    Livingston, A. Eugene

    2002-01-01

    Atomic properties of multiply charged ions have been investigated using excitation of energetic heavy ion beams. Spectroscopy of excited atomic transitions has been applied from the visible to the extreme ultraviolet wavelength regions to provide accurate atomic structure and transition rate data in selected highly ionized atoms. High-resolution position-sensitive photon detection has been introduced for measurements in the ultraviolet region. The detailed structures of Rydberg states in highly charged beryllium-like ions have been measured as a test of long-range electron-ion interactions. The measurements are supported by multiconfiguration Dirac-Fock calculations and by many-body perturbation theory. The high-angular-momentum Rydberg transitions may be used to establish reference wavelengths and improve the accuracy of ionization energies in highly charged systems. Precision wavelength measurements in highly charged few-electron ions have been performed to test the most accurate relativistic atomic structure calculations for prominent low-lying excited states. Lifetime measurements for allowed and forbidden transitions in highly charged few-electron ions have been made to test theoretical transition matrix elements for simple atomic systems. Precision lifetime measurements in laser-excited alkali atoms have been initiated to establish the accuracy of relativistic atomic many-body theory in many-electron systems

  15. Perturbative effect of heavy particles in an effective-Lagrangian approach

    International Nuclear Information System (INIS)

    Hagiwara, T.; Nakazawa, N.

    1981-01-01

    An effective-Lagrangian approach is summarized to estimate the perturbative effect of heavy-mass particles in the leading-logarithmic approximation: the logarithmic corrections to mass-suppressed amplitudes are given in a concise form. We apply the formalism to a simplified model with two scalar fields where one is heavy and the other is light. We derive an effective Lagrangian by calculating heavy-particle one-loop diagrams. Solving renormalization-group equations derived from the effective Lagrangian by light-particle one-loop corrections, we obtain logarithmic corrections to the mass-suppressed amplitudes. The results are confirmed by explicit two-loop calculation in the full theory, up to order O((1/M 2 )1nM 2 ), where M is a heavy scalar mass. It is found that the boundary condition for solving the renormalization-group equations must be specified by the renormalization at the heavy-particle mass. It must also be emphasized that in an effective-Lagrangian approach minimal subtraction is not a proper method of renormalization. The necessity to adopt the conventional momentum-shell subtraction is stressed. Several applications of this formalism are also mentioned

  16. Study of the heavy water regeneration processes; Studija procesa za regeneraciju teske vode

    Energy Technology Data Exchange (ETDEWEB)

    Cavcic, E [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-11-15

    Experience derived from heavy water reactor operation showed degradation and dilution of heavy water to be inevitable depends on the type of reactor. Dilution of heavy water during operation of the RA and the RB reactors is shown in this report. Principles and procedures of heavy water regeneration by electrolysis, fractional distillation, cleaning, prevention of tritium contamination are described as well as separation columns.

  17. Investigation of novel composite material based on extra-heavy concrete and basalt fiber for gamma radiation protection properties

    International Nuclear Information System (INIS)

    Romanenko, Yi.M.; Nosovs'kij, A.V.; Gulyik, V.Yi.; Golyuk, M.Yi.

    2018-01-01

    The paper presents a new composite material for radiation protection based on extra-heavy concrete reinforced by basalt fiber. Basalt fiber is a new material for concrete reinforcement, which provides improved mechanical characteristics of concrete, reduces the level of microcracks and increases the durability of concrete. Within the scope of present work, the gamma-ray radiation protection properties of concrete reinforced with basalt fiber was modeled. Two types of extra-heavy concrete were used for this paper. The main gamma-ray attenuation coefficients such as mean atomic number, mean atomic mass, mean electron density, effective atomic number, effective electron density, Murty effective atomic number were analyzed with help of WinXCom software. It has been shown that the addition of basalt fiber to concrete does not impair its gamma-ray radiation shielding properties. With increasing the basalt fiber dosage in concrete, the radiation properties against gamma radiation are improved.

  18. International bulletin on atomic and molecular data for fusion. No. 48

    International Nuclear Information System (INIS)

    1994-10-01

    This bulletin provides atomic and molecular data references relevant to thermonuclear fusion research and technology. In part I the indexing of the papers is given separately for (i) structure and spectra (energy levels, wavelengths; transition probabilities, oscillator strengths; interatomic potentials), (ii) atomic and molecular collisions (photon collisions, electron collisions, heavy particle collisions), and (iii) surface interactions (sputtering, surface damage, blistering, flaking, arcing, chemical reactions). Part II contains the bibliographic data for the above listed topics and for plasma composition and impurities, plasma heating, cooling and fuelling, high energy laser- and beam- matter interaction, bibliographic and numerical data collections, and on interaction of atomic particles with fields. Also included are sections on atomic and molecular data needs for fusion research and on news about ALADDIN (A Labelled Atomic Data Interface) and evaluated-data bases

  19. Analysis Of Non-Volatile Toxic Heavy Metals (Cd, Pb, Cu,Cr And Zn) In ALLIUM SATIVUM (Garlic) And Soil Samples ,Collected From Different Locations Of Punjab, Pakistan By Atomic Absorption Spectroscopy

    OpenAIRE

    Ata S.; Tayyab S.; Rasool A.

    2013-01-01

    Garlic is one of the most widely used medicinal plants. The monitoring of toxic metals such as lead, Cadmium, Chromium, Copper and Zinc in garlic and the soil of garlic fields collected from ten different cities of Punjab is critical for preventing public health against the hazards of metal toxicity. The levels of toxic heavy metals in garlic and soil samples were investigated using Atomic absorption spectrometer. The metal content in garlic samples was found to be in increasing order as Cr> ...

  20. Department of Atomic Energy [India]: Annual report 1979-1980

    International Nuclear Information System (INIS)

    1980-01-01

    The work of the research establishments, projects undertaken and public sector undertakings of the Department of Atomic Energy during the financial year 1979-80 is surveyed. The research and development activities of the Bhabha Atomic Research Centre at Bombay, the Reactor Research Centre at Kalpakkam, the Tata Institute of Fundamental Research at Bombay, the Saha Institute of Nuclear Physics at Calcutta and the Tata Memorial Centre at Bombay are described. An account of the progress of heavy water production plant projects, the Madras and Narora Atomic Power Projects, the MHD project and the 100 MW thermal research reactor R-5 Project at Trombay is given. Performance of the Tarapur and Rajasthan Atomic Power Stations, Nuclear Fuel Complex at Hyderabad, Atomic Minerals Division, ISOMED (the radiation sterilisation plant for medical products) at Bombay, the Indian Rare Earths Ltd., the Uranium Corporation of India Ltd., and the Electronics Corporation of India Ltd., Hyderabad is reported. (M.G.B.)

  1. Derivative interactions and perturbative UV contributions in N Higgs doublet models

    Energy Technology Data Exchange (ETDEWEB)

    Kikuta, Yohei [KEK Theory Center, KEK, Tsukuba (Japan); The Graduate University for Advanced Studies, Department of Particle and Nuclear Physics, Tsukuba (Japan); Yamamoto, Yasuhiro [Universidad de Granada, Deportamento de Fisica Teorica y del Cosmos, Facultad de Ciencias and CAFPE, Granada (Spain)

    2016-05-15

    We study the Higgs derivative interactions on models including arbitrary number of the Higgs doublets. These interactions are generated by two ways. One is higher order corrections of composite Higgs models, and the other is integration of heavy scalars and vectors. In the latter case, three point couplings between the Higgs doublets and these heavy states are the sources of the derivative interactions. Their representations are constrained to couple with the doublets. We explicitly calculate all derivative interactions generated by integrating out. Their degrees of freedom and conditions to impose the custodial symmetry are discussed. We also study the vector boson scattering processes with a couple of two Higgs doublet models to see experimental signals of the derivative interactions. They are differently affected by each heavy field. (orig.)

  2. Assessment of heavy metal contents of green leafy vegetables

    Directory of Open Access Journals (Sweden)

    V. Jena

    2013-01-01

    Full Text Available Vegetables are rich sources of vitamins, minerals, and fibers, and have beneficial antioxidative effects. Ingestion of vegetables containing heavy metals is one of the main routes through which these elements enter the human body. Slowly released into the body, however, heavy metals can cause an array of diseases. In this study we investigated the concentrations of copper, chromium, zinc, and lead in the most frequently consumed vegetables including Pimpinella anisum, Spinacia oleracea, Amaranthus viridis, Coriandrum sativum, and Trigonella foenum graecum in various sites in Raipur city, India. Atomic absorption spectrophotometry was used to estimate the levels of these metals in vegetables. The mean concentration for each heavy metal in the samples was calculated and compared with the permissible levels set by the Food and Agriculture Organization and World Health Organization. The intake of heavy metals in the human diet was also calculated to estimate the risk to human health. Our findings indicated the presence of heavy metals in vegetables in the order of Cr > Zn > Cu > Pb. Based on these findings, we conclude that the vegetables grown in this region are a health hazard for human consumption.

  3. An Eleven Year Review of Failed Female Sterilisation in Ile-Ife, Nigeria

    African Journals Online (AJOL)

    An Eleven Year Review of Failed Female Sterilisation in Ile-Ife, Nigeria. ... Teaching Hospitals Complex, Ile-Ife, Nigeria from October 1 1987 to September 30 1998. ... (Tropical Journal of Obstetrics and Gynaecology, 2001, 18(1): 8-11) ...

  4. Atomic energy: agreement between Canada and the Socialist Republic of Romania

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The governments of Canada and Romania agreed to cooperate in the development and application of atomic energy for peaceful purposes, including joint research and development projects, the application of atomic energy for electricity generation and other peaceful purposes, industrial enterprises; the supply of information, material, nuclear material, equipment and facilities; licensing arrangements; access to equipment and facilities; technical assistance; scientific visits; and training. Reprocessing, enrichment, and heavy water technology are excluded. Safeguards measures are spelled out. (LL)

  5. Distribution of heavy metals in Lumbricus terrestris, Aporrectodea longa and A. rosea measured by atomic absorption and X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Andersen, C.; Laursen, J.

    1982-01-01

    Distribution of Ca, Pb, Cd, Zn, Fe and Mn has been investigated in the earthworm species Lumbricus terrestris, Aporectodea longa and A. rosea by atomic absorption and X-ray fluorescence spectrometry measurements. The material of L. terrestris originated from the garden of the Royal Veterinary and Agricultural University in central Copenhagen. Material of the other two species was sampled in sewage sludge treated plots. It was found that lead and cadmium are accumulated in the gut wall and from here transferred to waste nodules (brown bodies). In L. terrestris more lead was transferred to waste nodules than cadmium. Also large amounts of zinc were accumulated in the gut wall. Analyses of L. terrestris calciferous glands showed that these take part in regulation and excretion of a number of heavy metals. Lead and cadmium content was low in the ventral nerve chord and seminal vesicles. A. longa with poorly developed calciferous glands seems to rely more on waste nodule formation in the ultimate immobilization of lead. (author)

  6. Imaging Lithium Atoms at Sub-Angstrom Resolution

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, Michael A.; Shao-Horn, Yang

    2005-01-03

    John Cowley and his group at ASU were pioneers in the use of transmission electron microscopy (TEM) for high-resolution imaging. Three decades ago they achieved images showing the crystal unit cell content at better than 4A resolution. Over the years, this achievement has inspired improvements in resolution that have enabled researchers to pinpoint the positions of heavy atom columns within the cell. More recently, this ability has been extended to light atoms as resolution has improved. Sub-Angstrom resolution has enabled researchers to image the columns of light atoms (carbon, oxygen and nitrogen) that are present in many complex structures. By using sub-Angstrom focal-series reconstruction of the specimen exit surface wave to image columns of cobalt, oxygen, and lithium atoms in a transition metal oxide structure commonly used as positive electrodes in lithium rechargeable batteries, we show that the range of detectable light atoms extends to lithium. HRTEM at sub-Angstrom resolution will provide the essential role of experimental verification for the emergent nanotech revolution. Our results foreshadow those to be expected from next-generation TEMs with CS-corrected lenses and monochromated electron beams.

  7. levels of heavy metals in drinking water, cosmetics and fruit juices ...

    African Journals Online (AJOL)

    Dr John A. M. Mahugija

    Heavy metals were determined in samples of drinking water, cosmetics (nail polish, lip glosses ... The samples were analyzed using Atomic. Absorption Spectrometry (AAS) after digestion with concentrated acids, filtration and dilution. Lead, zinc ... concentrations of lead in cosmetics exceeded the EU/US permissible limits.

  8. Thermal Width for Heavy Quarkonium in the Static Limit

    International Nuclear Information System (INIS)

    Shi Chao-Yi; Zhu Jia-Qing; Ma Zhi-Lei; Li Yun-De

    2015-01-01

    The thermal widths for heavy quarkonia are calculated for both Coulomb gauge (CG) and Feynman gauge (FG), and the comparisons between these results with the hard thermal loop (HTL) approximation ones are illustrated. The dissociation temperatures of heavy quarkonia in thermal medium are also discussed for CG, FG and HTL cases. It is shown that the thermal widths, derived from the HTL approximation and used in many research studies, cause some errors in the practical calculations at the temperature range accessible in the present experiment, and the problem of gauge dependence cannot be avoided when the complete self energy is used in the derivation of potential. (paper)

  9. Fundamental symmetries studies with cold trapped francium atoms at ISAC

    International Nuclear Information System (INIS)

    Gwinner, G.; Gomez, E.; Orozco, L. A.; Perez Galvan, A.; Sheng, D.; Zhao, Y.; Sprouse, G. D.; Behr, J. A.; Jackson, K. P.; Pearson, M. R.; Aubin, S.; Flambaum, V. V.

    2006-01-01

    Francium combines a heavy nucleus (Z = 87) with the simple atomic structure of alkalis and is a very promising candidate for precision tests of fundamental symmetries such as atomic parity non-conservation measurements. Fr has no stable isotopes, and the ISAC radioactive beam facility at TRIUMF, equipped with an actinide target, promises to provide record quantities of Fr atoms, up to 10 10 /s for some isotopes. We discuss our plans for a Fr on-line laser trapping facility at ISAC and experiments with samples of cold Fr atoms. We outline our plans for a measurement of the nuclear anapole moment - a parity non-conserving, time-reversal conserving moment that arises from weak interactions between nucleons - in a chain of Fr isotopes. Its measurement is a unique probe for neutral weak interactions inside the nucleus.

  10. Experiments with highly-charged heavy-ions performed at the storage ring ESR

    International Nuclear Information System (INIS)

    Mokler, P.H.

    1992-01-01

    The new heavy ion accelerator facility SIS/ESR was inaugurated in April 1990. During 1991 the experimental storage ring, ESR, has been commissioned. Highly-charged heavy ions from O 8+ up to Bi 82+ were successfully accumulated, cooled, and stored in the ring. Now all highly-charged, heavy ions can be provided for experiments at comfortable storage times and at energies roughly between 100 and 500 MeV/u. A report on the achievements and on the first experimental results will be given. For the experiments, special emphasis is put on capture processes in the electron cooler, i.e. on radiative and dielectronic recombination processes as well as on capture events of bound target electrons from a gas jet. In this case, the capture leads either directly (REC) or by cascading to X-ray emission, which is also exploited for a precision spectroscopy of the structure of the heaviest ions. Another exciting topic is the radioactive decay of highly charged ions: For instance the β-decay into bound atomic states, which is not possible for neutral atoms, was studied for stored naked Dy ions. (orig.)

  11. Determination of Levels of Essential and Toxic Heavy Metals in ...

    African Journals Online (AJOL)

    The concentrations of trace essential metals (Co, Cu, Fe, Mn, Ni and Zn) and toxic heavy metals (Cd and Pb) in lentil samples collected from Dejen (East Gojjam), Boset (East Shewa) and Molale (North Shewa), Ethiopia, were determined by flame atomic absorption spectrometry. A wet digestion procedure, using mixtures of ...

  12. Heavy metals and inorganic constituents in medicinal plants of ...

    African Journals Online (AJOL)

    Heavy metals such as Cr, Fe, Zn, Mn, Ni, Pb, Cu and Cd, and inorganic ions like HCO3-, CO32-, Ca2+, Mg2+, Cl-, Na+, SO42-, NO3-, Fe2+ and F- were investigated in medicinally important plants: Taraxacam officinale, Cichorium intybus and Figonia critica, applying atomic absorption spectrophotometer techniques. In the ...

  13. Heavy metal concentrations in, and human health risk assessment ...

    African Journals Online (AJOL)

    Water, sediment and fish samples were collected for six months and heavy metals were determined using an Atomic Absorption Spectrometer. Fe ranked highest in water and sediment, with concentrations of 2.74 mg l−1 and 61.60 mg kg−1, respectively. Metals followed the magnitude of Fe > Mn > Ni > V > Pb in the water ...

  14. Adsorption of heavy metals from aqueous solution by UV-mutant Bacillus subtilis loaded on biochars derived from different stock materials.

    Science.gov (United States)

    Wang, Ting; Sun, Hongwen; Ren, Xinhao; Li, Bing; Mao, Hongjun

    2018-02-01

    Two kinds of biochars, one derived from corn straw (CBC) and one from pig manure (PBC), were used as the carriers of a bacterium (B38) to adsorb heavy metals in solution. CBC exhibited high affinity to Hg(II), while PBC showed large adsorption capacity of Pb(II). After loading with B38, the sorption capacity of the co-sorbents were enhanced for Pb(II), but weakened for Hg(II). In a binary system, the overall adsorption capacity to Hg-Pb (CBC+B38, 136.7mg/g; PBC+B38, 181.3mg/g) on co-sorbents was equal to the sum of the single-component values for Hg(II) and Pb(II). Electrostatic interactions and precipitation are the major mechanisms in the adsorption of Hg(II). In contrast, cation-π interactions and precipitation were involved in the sorption process of Pb(II). Moreover, the sorption sites of Hg(II) and Pb(II) partially overlapped on the biochar surface, but were different on co-sorbents. Hence, the co-sorbents have an advantage over the biochar alone in the removal of heavy metal mixtures. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Quantum mechanical theory of positron production in heavy ion collisions with nuclear contact

    International Nuclear Information System (INIS)

    Heinz, U.

    1986-01-01

    The interplay between atomic and nuclear interactions in heavy ion collisions with nuclear contact is studied. The general theoretical description is outlined and analyzed in a number of different limits (semiclassical approximation, DWBA, fully quantal description). The two most important physical mechanisms for generating atomic-nuclear interference, i.e., energy conservation and the introduction of additional phase shifts by nuclear reactions, are extracted. The resulting typical coupling matrix elements are analyzed for their relative importance in atomic and nuclear excitations. The description of nuclear influence on atomic excitations in terms of a classical time delay caused by nuclear reactions is reviewed, and its relationship to the underlying quantal character of the nuclear reaction is discussed. The theory is applied to spontaneous positron emission in supercritical heavy-ion collisions (Z/sub tot/ ≥ 173). It is shown that nuclear contact can lead to line structures in the positron energy spectra if the probability distribution for nuclear delay times caused by the contact has contributions for T ≥ 10 -19 sec. We explicitly evaluate a model where a pocket in the internuclear potential near the touching configuration leads to formation of nuclear molecules, and predict a resonance-like excitation function for the positron peak. 25 refs., 7 figs

  16. Heavy-Quark Symmetry Implies Stable Heavy Tetraquark Mesons Q_{i}Q_{j}q[over ¯]_{k}q[over ¯]_{l}.

    Science.gov (United States)

    Eichten, Estia J; Quigg, Chris

    2017-11-17

    For very heavy quarks Q, relations derived from heavy-quark symmetry predict the existence of novel narrow doubly heavy tetraquark states of the form Q_{i}Q_{j}q[over ¯]_{k}q[over ¯]_{l} (subscripts label flavors), where q designates a light quark. By evaluating finite-mass corrections, we predict that double-beauty states composed of bbu[over ¯]d[over ¯], bbu[over ¯]s[over ¯], and bbd[over ¯]s[over ¯] will be stable against strong decays, whereas the double-charm states ccq[over ¯]_{k}q[over ¯]_{l}, mixed beauty+charm states bcq[over ¯]_{k}q[over ¯]_{l}, and heavier bbq[over ¯]_{k}q[over ¯]_{l} states will dissociate into pairs of heavy-light mesons. Observation of a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

  17. Multi-dimensional microanalysis of masklessly implanted atoms using focused heavy ion beam

    International Nuclear Information System (INIS)

    Mokuno, Yoshiaki; Iiorino, Yuji; Chayahara, Akiyoshi; Kiuchi, Masato; Fujii, Kanenaga; Satou, Mamoru

    1992-01-01

    Multi-dimensional structure fabricated by maskless MeV gold implantation in silicon wafer was analyzed by 3 MeV carbon ion microprobe using a microbeam line developed at GIRIO. The minimum line width of the implanted region was estimated to be about 5 μm. The advantages of heavy ions for microanalysis were demonstrated. (author)

  18. Implantation of 111In in NTDSi by heavy ion recoil technique

    International Nuclear Information System (INIS)

    Thakare, S.V.; Tomar, B.S.

    1998-01-01

    Heavy ion recoil implantation technique has been used to implant 111 In in n-type silicon using medium energy heavy ion accelerator Pelletron, at TIFR, Colaba, Mumbai. The nuclear reaction used for this purpose was 109 Ag( 7 Li,p4n) 111 In. The beam energy was optimised to be 50 MeV for maximum concentration of the implanted probe atoms. The gamma-ray spectrum of the implanted sample after 24 hours was found to contain only 171 and 245 keV gamma rays of 111 In. The penetration depth of ion is increased to 1.6 μm by heavy ion recoil implantation technique as compared to 0.16 μm with the conventional ion implantation technique. (author)

  19. Assessment of heavy metal pollution in Ghana by nuclear-related techniques

    International Nuclear Information System (INIS)

    Akoto Bamford, S.; Aboh, I.; Osae, E.

    1992-01-01

    X-ray fluorescence analysis and atomic absorption spectrophotometry was used to test for the presence and levels of heavy metals in solid wastes discharged from the gold mining industry. This report contains the results of the analysis of vegetation and river sediment samples. 2 refs, 2 tabs

  20. Comparative Study of Heavy Metals in Soil and Selected Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Afzal Shah

    2013-01-01

    Full Text Available Essential and nonessential heavy metals like iron (Fe, nickel (Ni, manganese (Mn, zinc (Zn, copper (Cu, cadmium (Cd, chromium (Cr, and lead (Pb were analyzed in four selected medicinal plants such as Capparis spinosa, Peganum harmala, Rhazya stricta, and Tamarix articulata by flame atomic absorption spectrophotometer (FAAS. These medicinal plants are extensively used as traditional medicine for treatment of various ailments by local physicians in the area from where these plants were collected. The concentration level of heavy metals in the selected plants was found in the decreasing order as Fe > Zn > Mn > Cu > Ni > Cr > Cd > Pb. The results revealed that the selected medicinal plants accumulate these elements at different concentrations. Monitoring such medicinal plants for heavy metals concentration is of great importance for physicians, health planners, health care professionals, and policymakers in protecting the public from the adverse effects of these heavy metals.

  1. New technology for producing petrochemical feedstock from heavy oils derived from Alberta oil sands

    International Nuclear Information System (INIS)

    Oballa, M.; Simanzhenkov, V.; Clark, P.; Laureshen, C.; Plessis du, D.

    2006-01-01

    This paper presented the results of a study demonstrating the feasibility of producing petrochemical feedstock or petrochemicals from vacuum gas oils derived from oil sands. A typical bitumen upgrader flow scheme was integrated with several new technologies and coupled with an ethane/propane cracker. Technologies included steam cracking, fluid catalytic cracking (FCC); and the catalytic pyrolysis process (CPP). The scheme was then integrated with the Nova Heavy Oil Cracking (NHC) technology. The NHC process uses a reactor to perform catalytic cracking followed by a main tower that separates gas and liquid products. Aromatic ring cleavage (ARORINCLE) technology was explored as a method of catalytic treatment. Experimental runs were conducted in a laboratory scale fixed bed reactor. A stacked catalyst bed was used, followed by a zeolite-based noble metal catalyst. Examples from process run results were presented. Results indicated that the NHC technology should be used on an FCC unit technology platform. The ARORINCLE technology was considered for use on a hydrotreating unit technology platform. Once the catalysts are fully developed and demonstrated, the economics of the technologies will be enhanced through the construction of world-scale complexes integrating upgrading, refining and petrochemical plants. refs., tabs., figs

  2. The ECR heavy-ion source for ATLAS

    International Nuclear Information System (INIS)

    Pardo, R.C.; Billquist, P.J.

    1989-01-01

    The ATLAS PII-ECR ion source is the first ECR ion source to be designed for operation in a high voltage platform. The source system is required to provide beams of heavy ions with a velocity of 0.01c for subsequent acceleration by the superconducting ATLAS Positive Ion Injector Linac. At present, the ability of the system to provide high charge state ions with velocities up to .01c is probably unique and as such has generated significant interest in the atomic physics community. A beamline for atomic physics has been installed and is now in use. The source began operation in October, 1987. The source capabilities and operating experiences to date will be discussed. 6 refs., 3 figs., 3 tabs

  3. Study of heavy quark production with the Mark II at PEP

    International Nuclear Information System (INIS)

    Abrams, G.; Amidei, D.; Baden, A.

    1983-10-01

    The methods adopted by the Mark II collaboration to study heavy quark production at PEP are described. Two complementary techniques are used: D* tagging using the decay chain D* + . D 0 π + , D 0 → K - π + , and inclusive lepton tagging using the characteristic p/sub T/ distributions to distinguish contributions from b and c quarks. These techniques are used to derive information about heavy quark fragmentation and about the weak coupling of heavy quarks

  4. Scaling properties of S-wave level density for heavy quarkonium from QCD sum rules

    International Nuclear Information System (INIS)

    Kiselev, V.V.

    1994-01-01

    In the framework of a specific scheme of the QCD sum rules for S-wave of the heavy quarkonium one derives an expression, relating the energetic density of quarkonium states and universal characteristics in the heavy quarkonium physics, such as the difference between the masses of a heavy quark Q and meson and the number of heavy quarkonium levels below the threshold decay. 20 refs

  5. Effects of atomic-level nano-structured hydroxyapatite on adsorption of bone morphogenetic protein-7 and its derived peptide by computer simulation.

    Science.gov (United States)

    Wang, Qun; Wang, Menghao; Lu, Xiong; Wang, Kefeng; Fang, Liming; Ren, Fuzeng; Lu, Guoming

    2017-11-09

    Hydroxyapatite (HA) is the principal inorganic component of bones and teeth and has been widely used as a bone repair material because of its good biocompatibility and bioactivity. Understanding the interactions between proteins and HA is crucial for designing biomaterials for bone regeneration. In this study, we evaluated the effects of atomic-level nano-structured HA (110) surfaces on the adsorption of bone morphogenetic protein-7 (BMP-7) and its derived peptide (KQLNALSVLYFDD) using molecular dynamics and density functional theory methods. The results indicated that the atomic-level morphology of HA significantly affected the interaction strength between proteins and HA substrates. The interactions of BMP-7 and its derived peptide with nano-concave and nano-pillar HA surfaces were stronger than those with flat or nano-groove HA surfaces. The results also revealed that if the groove size of nano-structured HA surfaces matched that of residues in the protein or peptide, these residues were likely to spread into the grooves of the nano-groove, nano-concave, and nano-pillar HA, further strengthening the interactions. These results are helpful in better understanding the adsorption behaviors of proteins onto nano-structured HA surfaces, and provide theoretical guidance for designing novel bioceramic materials for bone regeneration and tissue engineering.

  6. A Rare Case of Salmonella typhi Meningitis in an Eleven Month Old ...

    African Journals Online (AJOL)

    Non-typhoidal Salmonella are infrequent causes of childhood meningitis. Most reports of Salmonella typhi meningeal infections are confined to neonates. A rare instance of S. typhi in an otherwise healthy eleven month old infant is being reported. Keywords: Salmonella typhi, meningitis, infant.

  7. Determination of the Content of Heavy Metals in Pyrite Contaminated Soil and Plants

    Directory of Open Access Journals (Sweden)

    Miroslava Marić

    2008-09-01

    Full Text Available Determination of a pyrite contaminated soil texture, content of heavy metals in the soil and soil pH, was the aim in the investigation. Acidification of damaged soil was corrected by calcium carbonate. Mineral nutrients and organic matter (NPK, dung, earthworm cast, straw and coal dust were added to damaged soil. Afterwards, the soil was used for oat production. Determination of total heavy metal contents (Cu, Pb, Zn, Fe in soil was performed by atomic absorption spectrofotometry. Plant material (stems, seeds was analysed, too. Total concentration of the heavy metals in the plant material were greater than in crop obtained in unaffected soil.

  8. Heavy Ion Physics with the ATLAS Detector

    CERN Multimedia

    Takai, H

    2003-01-01

    I guess the first thing that comes to people's mind is why is an experiment such as ATLAS interested in heavy ion physics. What is heavy ion physics anyway? The term heavy ion physics refers to the study of collisions between large nuclei such as lead, atomic number 208. But why would someone collide something as large and extensive as lead nuclei? When two nuclei collide there is a unique opportunity to study QCD at extreme energy densities. This said why do we think ATLAS is a good detector to study this particular physics? Among many of the simultaneous collisions that takes place when two nuclei encouter, hard scattering takes place. The unique situation now is that before hadronization partons from hard scattering may feel the surrounding media serving as an ideal probe for the matter formed in these collisions. As a consequence of this, jets may be quenched and their properties, e.g. fragmentation function or cone radius, modified when compared to proton-proton collisions. This is precisely where ATL...

  9. Evaluation of electon and nuclear bremsstrahlung in heavy ion collisions

    International Nuclear Information System (INIS)

    Gippner, P.

    1975-01-01

    The detection of quasimolecular X-ray continua provides the possibility of investigating the electron shells of quasimolecules transiently formed during adiabatic heavy ion-atomic collision. The contribution of the electron and nuclear bremsstrahlung to quasimolecular X-ray continua observed in bombarding various targets with 65 and 96 MeV Nb ions were estimated

  10. Sensory profile of eleven peach cultivars

    Directory of Open Access Journals (Sweden)

    Francine Lorena Cuquel

    2012-03-01

    Full Text Available The goal of this study was to evaluate the sensory profile of eleven peach cultivars grown in an experimental orchard located in the city of Lapa (PR, Brazil in two seasons. The peach cultivars analyzed were Aurora I, Chimarrita, Chiripá, Coral, Eldorado, Granada, Leonense, Maciel, Marli, Premier, and Vanguarda. The sensory analysis was performed by previously trained panelists; 20 of them in the first season and 10 in the second season. The sensory evaluation was performed using Quantitative Descriptive Analysis, in which the following attributes were measured: appearance, aroma, flesh color, flesh firmness, flavor, and juiciness. The results showed preference for sweet, soft, and juicy fruits. Chimarrita, Chiripá, and Coral fruits showed better sensorial performance than the other peach cultivars. It was also verified that the analysis of the attributes aroma, flesh firmness, and flavor is enough for performing the sensory profile of peach fruits for in natura consumption.

  11. Heavy-quark physics in quantum chromodynamics

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1991-04-01

    Heavy quarks can expose new symmetries and novel phenomena in QCD not apparent in ordinary hadronic systems. In these lectures I discuss the use of effective-Lagrangian and light-cone Fock methods to analyze exclusive heavy hadron decays such as Υ → p bar p and B → ππ, and also to derive effective Schroedinger and Dirac equations for heavy quark systems. Two contributions to the heavy quark structure functions of the proton and other light hadrons are identified: an ''extrinsic'' contribution associated with leading twist QCD evolution of the gluon distribution, and a higher twist ''intrinsic'' contribution due to the hardness of high-mass fluctuations of multi-gluon correlations in hadronic wavefunctions. A non-perturbative calculation of the heavy quark distribution of a meson in QCD in one space and one time is presented. The intrinsic higher twist contributions to the pion and proton structure functions can dominate the hadronic production of heavy quark systems at large longitudinal momentum fraction x F and give anomalous contributions to the quark structure functions of ordinary hadrons at large x bj . I also discuss a number of ways in which heavy quark production in nuclear targets can test fundamental QCD phenomena and provide constraints on hadronic wavefunctions. The topics include color transparency, finite formation time, and predictions for charm production at threshold, including nuclear-bound quarkonium. I also discuss a number of QCD mechanisms for the suppression of J/ψ and Υ production in nuclear collisions, including gluon shadowing, the peripheral excitation of intrinsic heavy quark components at large x F , and the coalescence of heavy quarks with co-moving spectators at low x F

  12. Biochemical and morphological characterization of light and heavy sarcoplasmic reticulum vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, K.P.

    1978-01-01

    Light and heavy sarcoplasmic reticulum vesicles isolated from rabbit leg muscle have been used in a study of chloride-induced calcium release. The biochemical and morphological data indicate that light sarcoplasmic reticulum vesicles are derived from the longitudinal reticulum and heavy sarcoplasmic reticulum vesicles are derived from the terminal cisternae of the sarcoplasmic reticulum. The light and heavy sarcoplasmic reticulum vesicles were both able to accumulate calcium in the presence of ATP to amounts greater than 100 nmoles Ca/sup + +/ per mg of protein in less than one minute. Light and heavy sarcoplasmic reticulum vesicles each had a biphasic time course of calcium uptake. The initial uptake was followed by a rapid release after approximately one minute, of 30 to 40% of the accumulated calcium, which was then followed by a slower phase of calcium accumulation. Results indicate that the chloride induced release of calcium may be acting by two mechanisms, osmotic swelling and depolarization. The release of calcium from the light SR vesicles is probably due to osmotic swelling and the release of calcium from the heavy SR vesicles is probably due to depolarization.

  13. Activities of the JILA Atomic Collisions Cross Sections Data Center

    International Nuclear Information System (INIS)

    Gallagher, J.W.

    1983-01-01

    The JILA Atomic Collisions Cross Sections Data Center compiles, critically evaluates, and reviews cross sections and rates for low energy (<100 keV) collisions of electrons, photons, and heavy particles with atoms, ions, and simple molecules. Reports are prepared which provide easily accessible recommended data with error limits, list the fundamental literature related to specific topics, identify regions where data are missing, and point out inconsistencies in existing data. The general methodology used in producing evaluated compilations is described. Recently completed projects and work in progress are reported

  14. International bulletin on atomic and molecular data for fusion. No. 46

    International Nuclear Information System (INIS)

    Botero, J.

    1993-06-01

    The bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In Part I the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths; transition probabilities, oscillator strengths; interatomic potentials); (ii) atomic and molecular collisions (photon collisions; electron collisions; heavy-particle collisions; homonuclear sequences; isoelectronic sequences), and (iii) surface interactions (sputtering; chemical reactions; trapping and detrapping; surface damage; blistering, flaking; secondary electron emission). Part II contains the bibliographic data for the above listed topics and for high energy laser- and beam-matter interaction; interaction of atomic particles with fields. The atomic and molecular data needs in fusion research, as identified during the IAEA Consultants' Meeting on 'Atomic and Molecular Database for Hydrogen Recycling and Helium Exhaust from Fusion Reactors', June 1992, Vienna, are listed, covering (i) atomic and molecular collision processes, (ii) particle-surface interaction processes, and (iii) the status of data bases on atomic and molecular data and plasma-surface interactions. News on the ALADDIN (A labelled Atomic Data INterface) system is provided. Finally, a list of evaluated atomic and molecular data bases is provided

  15. Mechanisms and energetics of surface atomic processes

    International Nuclear Information System (INIS)

    Tsong, T.T.

    1991-01-01

    The energies involved in various surface atomic processes such as surface diffusion, the binding of small atomic clusters on the surface, the interaction between two adsorbed atoms, the dissociation of an atom from a small cluster or from a surface layer, the binding of kink size atoms or atoms at different adsorption sites to the surface etc., can be derived from an analysis of atomically resolved field ion microscope images and a kinetic energy measurement of low temperature field desorbed ions using the time-of-flight atom-probe field ion microscope. These energies can be used to compare with theories and to understand the transport of atoms on the surface in atomic reconstructions, epitaxial growth of surface layers and crystal growth, adsorption layer superstructure formation, and also why an atomic ordering or atomic reconstruction at the surface is energetically favored. Mechanisms of some of the surface atomic processes are also clarified from these quantitative, atomic resolution studies. In this paper work in this area is bris briefly reviewed

  16. Heavy metals in vegetables and potential risk for human health

    Directory of Open Access Journals (Sweden)

    Fernando Guerra

    2012-02-01

    Full Text Available Ingestion of vegetables containing heavy metals is one of the main ways in which these elements enter the human body. Once entered, heavy metals are deposited in bone and fat tissues, overlapping noble minerals. Slowly released into the body, heavy metals can cause an array of diseases. This study aimed to investigate the concentrations of cadmium, nickel, lead, cobalt and chromium in the most frequently consumed foodstuff in the São Paulo State, Brazil and to compare the heavy metal contents with the permissible limits established by the Brazilian legislation. A value of intake of heavy metals in human diets was also calculated to estimate the risk to human health. Vegetable samples were collected at the São Paulo General Warehousing and Centers Company, and the heavy metal content was determined by atomic absorption spectrophotometry. All sampled vegetables presented average concentrations of Cd and Ni lower than the permissible limits established by the Brazilian legislation. Pb and Cr exceeded the limits in 44 % of the analyzed samples. The Brazilian legislation does not establish a permissible limit for Co contents. Regarding the consumption habit of the population in the São Paulo State, the daily ingestion of heavy metals was below the oral dose of reference, therefore, consumption of these vegetables can be considered safe and without risk to human health.

  17. Some new approaches to the synthesis of heavy and superheavy elements

    International Nuclear Information System (INIS)

    Flerov, G.N.

    1980-01-01

    The results of work on the synthesis of heavy and superheavy elements are considered. It is shown that the new regularity of the systematics of spontaneous-fission half-lives, established for heavy nuclei at Dubna, has made it possible to extend the region of the nuclei being synthesized. In particular, it becomes possible to produce relatively long-lived heavy isotopes of Z>=107. The results of experiments to study the emission of energetic α-particles in the collision of heavy nuclei are presented. It is noted that such reactions can be used to produce atomic nuclei with low excitation energy and large angular momentum. The possible use of similar reactions in the synthesis of heavy and superheavy elements is discussed. In case the existence of a naturally occurring superheavy element has been established, a possibility will arise to synthesize in nuclear reactions a number of isotopes belonging to the island of stability, and to investigate their properties. The present state of work on the search for superheavy elements in nature is briefly described

  18. Description of the general properties of pionic atoms

    International Nuclear Information System (INIS)

    Cervantes S, B.R.

    1979-01-01

    The effects of the finite dimension of the nucleus and the strong interaction effects in the energy levels ls and 2p of pionic atoms are considered. The energy transition between these two levels are calculated using the method of perturbations of first order, considering a uniform distribution of nuclear charge, for the effect of the finite dimension of the nucleus and one local optical potential as a model for the strong interaction. The calculations were realized for 13 elements and the results were compared with the experimentally obtained, founding a relative difference around of 4%. In conclusion the author observed that the effects of the finite dimension and the strong interaction can be considered as first order perturbations in light atoms, and for heavy atoms this effects can be considered as of second order or higher perturbations. (author)

  19. Investigation of heavy metals content in medicinal plant, eclipta alba L

    International Nuclear Information System (INIS)

    Hussain, I.; Khan, H.

    2010-01-01

    Heavy metal such as Cr, Fe, Zn, Mn, Ni, Pb, Cu and Cd were investigated in a= medicinally important plant, Eclipta alba L. as well as in the soil it was grown using atomic absorption spectrophotometer. The plant samples were collected from their natural habitat at three different locations of Peshawar Pakistan. The whole plant materials (roots, stems and leaves) were found to contain all heavy metals except Cd, which corresponds to their concentration in the soil it was grown. Among all the heavy metals, Fe was found to be at the highest level (8.95 to 27.7 mg/kg) followed by Mn (0.44 to 14.0 mg/kg) and Zn (1.04 to 4.50 mg/kg), while the rest of metals were at low concentration. The present study showed that E. alba L. is suitable for the control of environmental pollutants such as heavy metals, however, for medicinal purposes; it should be collected from those areas which are not contaminated with heavy metals. The purpose of the current study was to standardize various indigenous medicinal plants for heavy metals contamination and to make awareness among the public regarding its safer use and collection areas, containing high level of heavy metals and their adverse health affects. (author)

  20. Various analytical techniques used for the measurement of isotopic purity of heavy water at Madras Atomic Power Station

    International Nuclear Information System (INIS)

    Satyanarayanan, V.; Umapathy, P.; Bhaskaran, R.; Nagarajan, J.; Pradeep, Jeena; Ayyar, S.R.

    2008-01-01

    The paper deals with the various techniques used for the measurement of isotopic purity of heavy water samples received from different sources viz. reactor systems, heavy water upgrading plant and fresh consignment from heavy water production plants. Heavy water is used in PHWRs as moderator and primary coolant. Isotopic Purity is an important parameter to be monitored/analysed regularly for both the systems. There is a minimum isotopic purity level to be maintained in the moderator system due to neutron economy/fuel burnup and in the case of coolant system the measurement is of paramount importance due to its safety considerations. The selection of the method of analysis depends on the isotopic range. The techniques used to measure the isotopic purity of heavy water are a) Infrared Spectrophotometry b) Refractometry c) Densitometry. Infrared spectrometer uses the property of molecular absorption of IR radiation by HOD species and the absorbance is the measure of isotopic purity. This technique is generally used for measuring high isotopic (80-99.98%) and low isotopic samples. Refractometer uses the property of refractive index of heavy water. The difference in refractive indices of light water and heavy water is 0.0048. A 1 % change in D 2 O concentration would thus equal to 0.000048 refractive index units. This method is used for determining the approximate isotopic value of a sample. Density meter uses the property of difference in densities of light and heavy water. The difference in density of 99.999% D 2 O and light water is 0.107540 which covers the whole range of interest. The experience gained with these techniques in the measurements of isotopic purity of various samples are presented in this paper. (author)

  1. Determination of heavy metals in soils from dump site of tanneries ...

    African Journals Online (AJOL)

    Heavy metals were determined in soil samples at the dump site, Challawa town, Karfi Irrigation site and farmlands near the dump site by flame Atomic Absorption Spectrophotometer (AAS). The results showed that soil at the dump site contains significant amount of toxic elements. Hence remediation processes were ...

  2. On the way to unveiling the atomic structure of superheavy elements

    International Nuclear Information System (INIS)

    Laatiaoui, Mustapha

    2016-01-01

    Optical spectroscopy of the transfermium elements (atomic number Z > 100) is nowadays one of the most fascinating and simultaneously challenging tasks in atomic physics. On the one hand, key atomic and even nuclear ground-state properties may be obtained by studying the spectral lines of these heaviest elements. On the other hand, these elements have to be produced “online” by heavy-ion induced fusion-evaporation reactions yielding rates on the order of a few atoms per second at most, which renders their optical spectroscopy extremely difficult. Only recently, a first foray of laser spectroscopy into this heaviest element region was reported. Several atomic transitions in the element nobelium (Z = 102) were observed and characterized, using an ultra-sensitive and highly efficient resonance ionization technique. The findings confirm the predictions and additionally provide a benchmark for theoretical modelling. The work represents an important stepping stone towards experimental studies of the atomic structure of superheavy elements.

  3. When the uncertainty principle goes up to 11 or how to explain quantum physics with heavy metal

    CERN Document Server

    Moriarty, Philip

    2018-01-01

    There are deep and fascinating links between heavy metal and quantum physics. No, there are. Really. While teaching at the University of Nottingham, physicist Philip Moriarty noticed something odd--a surprising number of his students were heavily into metal music. Colleagues, too: a Venn diagram of physicists and metal fans would show a shocking amount of overlap. What's more, it turns out that heavy metal music is uniquely well-suited to explaining quantum principles. In When the Uncertainty Principle Goes Up to Eleven, Moriarty explains the mysteries of the universe's inner workings via drum beats and feedback: You'll discover how the Heisenberg uncertainty principle comes into play with every chugging guitar riff, what wave interference has to do with Iron Maiden, and why metalheads in mosh pits behave just like molecules in a gas. If you're a metal fan trying to grasp the complexities of quantum physics, a quantum physicist baffled by heavy metal, or just someone who'd like to know how the fundamental sci...

  4. Sedimentology and economic potential of a storm-derived heavy-mineral deposit in the Witteberg group, Cape Province

    Energy Technology Data Exchange (ETDEWEB)

    Cole, D I; Labuschagne, L S

    1982-06-01

    Two heavy-mineral-bearing, very fine-grained sandstone beds occur in the upper part of the Weltevrede Formation of the Witteberg Group, 35 km east-north-east of Willowmore, Cape Province. The beds are located within a 10-m-thick stratigraphic interval approximately 100 m below the base of the Witpoort Formation. The beds are amalgamated and consist of up to 5 units, each representing deposition from a storm-surge ebb current. Nine samples taken from the upper bed and one from the lower were analysed for heavy-mineral content. In order of decreasing abundance the heavy-minerals are rutile, zircon, ilmenite, magnetite, monazite, staurolite and sphene. The zircon contains uranium and the monazite is thorium bearing. Simple linear regression analysis of three elements, three oxides, the heavy mineral fraction and the radiometric response indicate that the proportion of heavy minerals does not vary significantly between samples and that the radiometric response of the beds (determined with a portable gamma-ray scintillometer) is directly related to the heavy mineral content. The heavy minerals are concentrated in the upper 20 cm of each bed where deposition from suspension, during the final phase of storm activity, was predominant. Significant concentrations are limited to the upper bed.

  5. Sedimentology and economic potential of a storm-derived heavy-mineral deposit in the Witteberg group, Cape Province

    International Nuclear Information System (INIS)

    Cole, D.I.; Labuschagne, L.S.

    1982-06-01

    Two heavy-mineral-bearing, very fine-grained sandstone beds occur in the upper part of the Weltevrede Formation of the Witteberg Group, 35 km east-north-east of Willowmore, Cape Province. The beds are located within a 10-m-thick stratigraphic interval approximately 100 m below the base of the Witpoort Formation. The beds are amalgamated and consist of up to 5 units, each representing deposition from a storm-surge ebb current. Nine samples taken from the upper bed and one from the lower were analysed for heavy-mineral content. In order of decreasing abundance the heavy-minerals are rutile, zircon, ilmenite, magnetite, monazite, staurolite and sphene. The zircon contains uranium and the monazite is thorium bearing. Simple linear regression analysis of three elements, three oxides, the heavy mineral fraction and the radiometric response indicate that the proportion of heavy minerals does not vary significantly between samples and that the radiometric response of the beds (determined with a portable gamma-ray scintillometer) is directly related to the heavy mineral content. The heavy minerals are concentrated in the upper 20 cm of each bed where deposition from suspension, during the final phase of storm activity, was predominant. Significant concentrations are limited to the upper bed

  6. Heavy metal and abiotic stress inducible metallothionein isoforms from Prosopis juliflora (SW) D.C. show differences in binding to heavy metals in vitro.

    Science.gov (United States)

    Usha, B; Venkataraman, Gayatri; Parida, Ajay

    2009-01-01

    Prosopis juliflora is a tree species that grows well in heavy metal laden industrial sites and accumulates heavy metals. To understand the possible contribution of metallothioneins (MTs) in heavy metal accumulation in P. juliflora, we isolated and compared the metal binding ability of three different types of MTs (PjMT1-3). Glutathione S-transferase fusions of PjMTs (GSTMT1-3) were purified from Escherichia coli cells grown in the presence of 0.3 mM cadmium, copper or zinc. Analysis of metal bound fusion proteins using atomic absorption spectrometry showed that PjMT1 bound higher levels of all three heavy metals as compared to PjMT2 and PjMT3. A comparative analysis of the genomic regions (including promoter for all three PjMTs) is also presented. All three PjMTs are induced by H(2)O(2) and ABA applications. PjMT1 and PjMT2 are induced by copper and zinc respectively while PjMT3 is induced by copper, zinc and cadmium. Variation in induction of PjMTs in response to metal exposure and their differential binding to metals suggests that each MT has a specific role in P. juliflora. Of the three MTs analyzed, PjMT1 shows maximum heavy metal sequestration and is thus a potential candidate for use in heavy metal phytoremediation.

  7. Heavy metals concentrations in coal and sediments from River ...

    African Journals Online (AJOL)

    The levels of some heavy metals such as; Mn, Cr, Cd, As, Ni, and Pb were analysed in coal and sediment samples from River Ekulu in Enugu, Coal City using Atomic Absorption Spectrophotometer (AAS) model Spectra-AA-10 variant. Mean concentrations of Mn (0.256-0.389mg/kg) and Cr (0.214-0.267 mg/kg) are high ...

  8. Heavy metals burden in Kidney and heart tissues of Scarus ...

    African Journals Online (AJOL)

    Levels of selected heavy metals (Pb, Co, Cu, Ni, Zn, Mn and Cd) in the heart and kidney tissues of parrot fish, collected from the Arabian Gulf, Eastern Province of Saudi Arabia, were determined by wet-digestion based atomic absorption method. The results showed that accumulation pattern of analyzed metals in the kidney ...

  9. Topical problems of accelerator and applied heavy ion physics

    International Nuclear Information System (INIS)

    Becker, R.; Deitinghoff, H.; Junior, P.H.; Schempp, A.

    1990-12-01

    These proceedings contain the articles presented at the named seminar. They deal with high-intensity linacs for heavy ions, the free-electron laser, applications of heavy-ion beams, MEQALAC, the ESR Schottky-diagnosis system, the analysis of GaAs by ion-beam methods, a light-ion synchrotron for cancer therapy, a device for the measurement of the momentum spread of ion beams, the European Hadron facility, the breakdown fields at electrons in high vacuum, a computer program for the calculation of electric quadrupoles, a focusing electrostatic mirror, storage and cooling of Ar beams, the visualization of heavy ion tracks in photographic films, the motion of ions in magnetic fields, the CERN heavy ion program, linear colliders, the beam injection from a linac into a storage ring, negative-ion sources, wake field acceleration, RFQ's, a dense electron target, the matching of a DC beam into the RFQ, electron emission and breakdown in vacuum, and 1-1.5 GeV 300 mA linear accelerator, the production of high-current positive-ion beams, high-current beam experiments at GSI, improvement of the Frankfurt EBIS, the physics of the violin, double layers, beam formation with coupled RFQ's, atomic nitrogen beam for material modification, compact superconducting synchrotron-radiation sources, industrial property rights, a RF ion source for thin film processes, beam-cavity interactions in the RFQ linac, atomic physics with crossed uranium beams, proton linacs, the interdigital H-type structure, injection of H - beams into a RFQ accelerator, the production of MOS devices by ion implantation, the application of RFQ's, the Frankfurt highly-charged ion facility, RF acceleration techniques for beam current drive in tokamaks, space-charge neutralized transport, and storage rings for synchrotron radiation and free electron lasers. (HSI)

  10. Environmental health scoping study at Bruce Heavy Water Plant

    International Nuclear Information System (INIS)

    Prior, M.; Mostrom, M.; Coppock, R.; Florence, Z.

    1995-10-01

    There are concerns that hydrogen sulfide released from the Heavy Water Plant near Kincardine, Ontario may be the cause of the mortalities and morbidities observed in a nearby flock of sheep. The Philosopher's Wool sheep farm is about four kilometres south-southeast of the Bruce Heavy Water Plant. Ontario Hydro, the owner and operator of the Bruce Heavy Water Plant, claims that hydrogen sulphide emissions from the Bruce Heavy Water Plant are within regulatory limits and well below levels that cause harm. Accordingly, the Atomic Energy Control Board commissioned the Alberta Environmental Centre, Alberta Department of Environmental Protection, to develop a scoping study for this environmental health issue. The first objective was to describe a field investigation model to define clearly the environmental health and operation of the sheep farm. The second objective was to describe possible exposure patterns and develop a holistic environmental pathway model. If appropriate, the third study objective was to describe animal models of the actual situation to elucidate specific aspects of the environmental health concerns. It was not the objective of this report to provide a definitive answer to the present environmental health issue. Ontario Hydro provided data to the Alberta Environmental Centre, as di the sheep farmer, the attending veterinarian, the University of Guelph study team, and the Atomic Energy Control Board. A six-tiered strategy of sequential evaluations of the ovine health problem is based on the multiple-response paradigm. It assumes the observed ovine health results are the result of multiple effector events. Each tier constitutes a separate, but inter-related, study. Sequential evaluation and feedback of each tier allow sound scientific judgements and efficient use of resources. (author). 59 refs., 11 tabs., 22 figs

  11. Synthesis of the New Element with Z=117

    International Nuclear Information System (INIS)

    Hamilton, J H; Ramayya, A V; Oganessian, Yu Ts; Abdullin, F Sh; Dmitriev, S N; Itkis, M G; Lobanov, Yu V; Mezentsev, A N; Polyakov, A N; Bailey, P D; Benker, D; Ezold, J; Porter, C E; Riley, F; Roberto, J B; Bennett, M E; Henderson, R A; Moody, K J; Nelson, S L; Ryabinin, M A

    2011-01-01

    The synthesis of the new chemical element with atomic number Z=117 is presented. The isotopes 293 117 and 294 117were produced in fusion reactions between 48 Ca and 249 Bk. The 249 Bk was produced in the High Flux Isotope Reactor and chemically separated at Oak Ridge. Decay chains involving eleven new nuclei were identified by means of the Dubna Gas Filled Recoil Separator. The measured decay properties show a strong rise of stability for super-heavy nuclei toward N=184.

  12. Atomic electron spectrometry with synchrotron radiation

    International Nuclear Information System (INIS)

    Sorensen, S.L.

    1989-01-01

    Techniques of atomic electron spectrometry were applied to atoms in the gaseous and solid states to derive information about fundamental atomic properties. A new method was developed to measure Coster-Kronig yields in metals by photoionization with synchrotron radiation. Photon-energy sensitive Si L-VV Auger satellites were investigated via electron spectrometry. The krypton 1s photoionization spectrum was measured in an experiment which was motivated by the need to understand the krypton 1s satellite spectrum for calibration of an experiment to measure the mass of the electron antineutrino

  13. Phasing and structure of bestrophin-1: a case study in the use of heavy-atom cluster compounds with multi-subunit transmembrane proteins

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Veronica Kane (Cambridge)

    2016-03-01

    The purification and three-dimensional crystallization of membrane proteins are commonly affected by a cumulation of pathologies that are less prevalent in their soluble counterparts. This may include severe anisotropy, poor spot shape, poor to moderate-resolution diffraction, crystal twinning, translational pseudo-symmetry and poor uptake of heavy atoms for derivatization. Such challenges must be circumvented by adaptations in the approach to crystallization and/or phasing. Here, an example of a protein that exhibited all of the above-mentioned complications is presented. Bestrophin-1 is a eukaryotic calcium-activated chloride channel, the structure of which was recently determined in complex with monoclonal antibody fragments using SAD phasing with tantalum bromide clusters (Ta6Br12·Br2). Some of the obstacles to obtaining improved diffraction and phasing for this particular channel are discussed, as well as the approach and adaptations that were key to determining the structure.

  14. Analysis of heavy metals and minerals elements in the turmeric using Total-Reflection X-ray Fluorescence analysis technique and Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Andriamisetra, V.M.Z.

    2014-01-01

    Currently, many studies demonstrate anti-cancer and anti-inflammatory benefits of turmeric. The aims of this work is to perform analysis of metals such as calcium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, bromine, rubidium, strontium, cadmium and lead in the turmeric collected from various places in Madagascar. The analysis by total reflection X-ray fluorescence technique is used to determine the concentrations of heavy metals, while the atomic absorption spectrometry is used for the determination of trace elements. Analysis results show that the concentration of calcium in the turmeric is very high, its average concentration is 1025.8 mg.kg -1 . The average concentrations of manganese, of copper and of iron are respectively 44.7 mg.kg -1 ; 19.7 mg.kg -1 and 53.6 mg.kg -1 . The average concentrations of zinc, of rubidium and of strontium are respectively 17.3 mg.kg -1 ; 35.2 mg.kg -1 and 21.7 mg.kg -1 [fr

  15. Compact time-zero detector for heavy ions

    International Nuclear Information System (INIS)

    Weissenberger, E.; Kast, W.; Goennenwein, F.

    1979-01-01

    A time-zero detector for flight-time measurements with heavy ions is described. The ions traverse a thin foil and the secondary electrons splashed from the foil are detected in a channel plate multiplier. A timing signal is derived from the multiplier pulse. The novel features of the detector are its simplicity and compactness of design. The time resolution achieved for the full energy and mass span of fission fragments from the spontaneous fission of 252 Cf used as a heavy ion source is 115 ps (fwhm). (Auth.)

  16. Relation of sulfur with hydrocarbons in Brazilian heavy and extra-heavy crude oil; Relacao do enxofre com os hidrocarbonetos em petroleos pesados e extra pesados brasileiros

    Energy Technology Data Exchange (ETDEWEB)

    Iorio, Sonia Maria Badaro Mangueira; Guimaraes, Regina Celia Lourenco; Silva, Maria do Socorro A. Justo da [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Costa, Alexander Vinicius Moraes da [Fundacao Gorceix, Ouro Preto, MG (Brazil)

    2008-07-01

    As the occurrence of heavy and extra-heavy oils increases sensitively, their participation in the refineries feeding also becomes greater. Heavy oils usually have lower price than a light one, because they produce lower quality derivatives and it's more difficult to meet the specifications. Crude oils are a complex mixture, mostly compounded by carbon and hydrogen and also by impurities like sulfur, nitrogen, oxygen and metals. Sulfur is the third most abundant component of crude oils, following carbon and hydrogen. In general there is a strong positive correlation between the concentrations of polar compounds (aromatics, resins and asphaltenes), and the sulfur content. This work presents graphically sulfur content and polar compounds concentrations for Brazilian and foreign heavy and extra-heavy oils (< 20 deg API). The results of the data analysis indicate that Brazilian crude oils behave differently from foreign heavy and extra-heavy oils. (author)

  17. Are there superheavy atomic nuclei

    International Nuclear Information System (INIS)

    Herrmann, G.

    1982-04-01

    The author presents a populary introduction to the formation of nuclei with special regards to superheavy nuclei. After a general description of the methods of physics the atomic hypothesis is considered. Thereafter the structure of the nucleus is discussed, and the different isotopes are considered. Then radioactivity is described as an element transmutation. Thereafter the thermonuclear reactions in the sun are considered. Then the synthesis of elements using heavy ion reactions is described. In this connection the transuranium elements and the superheavy elements are considered. (orig./HSI) [de

  18. HRTEM imaging of atoms at sub-Angstroem resolution

    International Nuclear Information System (INIS)

    O'Keefe, Michael A.; Allard, Lawrence F.; Blom, Douglas A.

    2005-01-01

    John Cowley and his group at Arizona State University pioneered the use of transmission electron microscopy for high-resolution imaging. Images were achieved three decades ago showing the crystal unit cell content at better than 4 A resolution. This achievement enabled researchers to pinpoint the positions of heavy atom columns within the unit cell. Lighter atoms appear as resolution is improved to sub-Angstroem levels. Currently, advanced microscopes can image the columns of the light atoms (carbon, oxygen, nitrogen) that are present in many complex structures, and even the lithium atoms present in some battery materials. Sub-Angstroem imaging, initially achieved by focal-series reconstruction of the specimen exit surface wave, will become commonplace for next-generation electron microscopes with C s -corrected lenses and monochromated electron beams. Resolution can be quantified in terms of peak separation and inter-peak minimum, but the limits imposed on the attainable resolution by the properties of the microscope specimen need to be considered. At extreme resolution the 'size' of atoms can mean that they will not be resolved even when spaced farther apart than the resolution of the microscope. (author)

  19. HRTEM Imaging of Atoms at Sub-Angstrom Resolution

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, Michael A.; Allard, Lawrence F.; Blom, Douglas A.

    2005-04-06

    John Cowley and his group at Arizona State University pioneered the use of transmission electron microscopy (TEM) for high-resolution imaging. Images were achieved three decades ago showing the crystal unit cell content at better than 4 Angstrom resolution. This achievement enabled researchers to pinpoint the positions of heavy atom columns within the unit cell. Lighter atoms appear as resolution is improved to sub-Angstrom levels. Currently, advanced microscopes can image the columns of the light atoms (carbon, oxygen, nitrogen) that are present in many complex structures, and even the lithium atoms present in some battery materials. Sub-Angstrom imaging, initially achieved by focal-series reconstruction of the specimen exit surface wave, will become common place for next-generation electron microscopes with CS-corrected lenses and monochromated electron beams. Resolution can be quantified in terms of peak separation and inter-peak minimum, but the limits imposed on the attainable resolution by the properties of the micro-scope specimen need to be considered. At extreme resolution the ''size'' of atoms can mean that they will not be resolved even when spaced farther apart than the resolution of the microscope.

  20. Observation of Global Hyperon Polarization in Ultrarelativistic Heavy-Ion Collisions

    Czech Academy of Sciences Publication Activity Database

    Upsal, I.; Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Bielčík, J.; Bielčíková, Jana; Chaloupka, P.; Federič, Pavol; Rusňák, Jan; Rusňáková, O.; Šimko, Miroslav; Šumbera, Michal; Vértési, Robert

    2017-01-01

    Roč. 967, č. 11 (2017), s. 760-763 ISSN 0375-9474 R&D Projects: GA MŠk LG15001; GA MŠk LM2015054 Institutional support: RVO:61389005 Keywords : STAR collaboration * heavy ion collisions * quark-gluon plasma Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.916, year: 2016

  1. Symmetries in eleven dimensional supergravity compactified on a parallelized seven sphere

    CERN Document Server

    Englert, F; Spindel, P

    1983-01-01

    We analyse, in eleven-dimensional supergravity compactified on S7, the spontaneous symmetry breaking induced by a spontaneous parallelization of the sphere. The eight supersymmetries are broken at a common scale and the SO(8) gauge group is reduced to Spin (7). Such a large residual symmetry has a simple geometrical significance revealed through use of octonions; this is explained in elementary terms.

  2. Synthesis with Perfect Atom Economy: Generation of Furan Derivatives by 1,3-Dipolar Cycloaddition of Acetylenedicarboxylates at Cyclooctynes

    Directory of Open Access Journals (Sweden)

    Klaus Banert

    2014-09-01

    Full Text Available Cyclooctyne and cycloocten-5-yne undergo, at room temperature, a 1,3-dipolar cycloaddition with dialkyl acetylenedicarboxylates 1a,b to generate furan-derived short-lived intermediates 2, which can be trapped by two additional equivalents of 1a,b or alternatively by methanol, phenol, water or aldehydes to yield polycyclic products 3b–d, orthoesters 4a–c, ketones 5 or epoxides 6a,b, respectively. Treatment of bis(trimethylsilyl acetylenedicarboxylate (1c with cyclooctyne leads to the ketone 7 via retro-Brook rearrangement of the dipolar intermediate 2c. In all cases, the products are formed with perfect atom economy.

  3. Materials science symposium 'heavy ion science in tandem energy region'

    Energy Technology Data Exchange (ETDEWEB)

    Iwamoto, Akira; Yoshida, Tadashi; Takeuchi, Suehiro (eds.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-11-01

    The facility of the JAERI tandem accelerator and its booster has been contributing to obtain plenty of fruitful results in the fields of nuclear physics, nuclear chemistry, atomic and solid state physics and materials science, taking an advantage of its prominent performances of heavy ion acceleration. The previous meeting held in 1999 also offered an opportunity to scientists from all over the heavy ion science fields, including nuclear physics, solid state physics and cross-field physics to have active discussions. This meeting included oral presentations with a new plan and with a new scope of fields expected from now on, as an occasion for opening the 21st century in heavy ion science. The 50 of the presented papers are indexed individually. (J.P.N.)

  4. Off-resonant transitions in the collective dynamics of multi-level atomic ensembles

    DEFF Research Database (Denmark)

    Miroshnychenko, Yevhen; Mølmer, Klaus

    2013-01-01

    We study the contributions of off-resonant transitions to the dynamics of a system of N multi-level atoms sharing one excitation and interacting with the quantized vector electromagnetic field. The rotating wave approximation significantly simplifies the derivation of the equations of motion...... describing the collective atomic dynamics, but it leads to an incorrect expression for the dispersive part of the atom–atom interaction terms. For the case of two-level atoms and a scalar electromagnetic field, it turns out that the atom–atom interaction can be recovered correctly if integrals over...... the photon mode frequencies are extended to incorporate negative values. We explicitly derive the atom–atom interaction for multi-level atoms, coupled to the full vector electromagnetic field, and we recover also in this general case the validity of the results obtained by the extension to negative...

  5. Deriving fuel-based emission factor thresholds to interpret heavy-duty vehicle roadside plume measurements.

    Science.gov (United States)

    Quiros, David C; Smith, Jeremy D; Ham, Walter A; Robertson, William H; Huai, Tao; Ayala, Alberto; Hu, Shaohua

    2018-04-13

    Remote sensing devices have been used for decades to measure gaseous emissions from individual vehicles at the roadside. Systems have also been developed that entrain diluted exhaust and can also measure particulate matter (PM) emissions. In 2015, the California Air Resources Board (CARB) reported that 8% of in-field diesel particulate filters (DPF) on heavy-duty (HD) vehicles were malfunctioning and emitted about 70% of total diesel PM emissions from the DPF-equipped fleet. A new high-emitter problem in the heavy-duty vehicle fleet had emerged. Roadside exhaust plume measurements reflect a snapshot of real-world operation, typically lasting several seconds. In order to relate roadside plume measurements to laboratory emission tests, we analyzed carbon dioxide (CO 2 ), oxides of nitrogen (NO X ), and PM emissions collected from four HD vehicles during several driving cycles on a chassis dynamometer. We examined the fuel-based emission factors corresponding to possible exceedances of emission standards as a function of vehicle power. Our analysis suggests that a typical HD vehicle will exceed the model year (MY) 2010 emission standards (of 0.2 g NO X /bhp-hr and 0.01 g PM/bhp-hr) by three times when fuel-based emission factors are 9.3 g NO X /kg fuel and 0.11 g PM/kg using the roadside plume measurement approach. Reported limits correspond to 99% confidence levels, which were calculated using the detection uncertainty of emissions analyzers, accuracy of vehicle power calculations, and actual emissions variability of fixed operational parameters. The PM threshold was determined for acceleration events between 0.47 and 1.4 mph/sec only, and the NO X threshold was derived from measurements where aftertreatment temperature was above 200°C. Anticipating a growing interest in real-world driving emissions, widespread implementation of roadside exhaust plume measurements as a compliment to in-use vehicle programs may benefit from expanding this analysis to a larger

  6. International bulletin on atomic and molecular data for fusion. No. 42-45

    International Nuclear Information System (INIS)

    Botero, J.

    1991-01-01

    The bulletin is published by the International Atomic Energy Agency to provide atomic and molecular data relevant to fusion research and technology. In Part I the indexed papers are listed separately for (i) structure and spectra (energy levels, wavelengths; transition probabilities, oscillator strengths; polarizabilities, electric moments; interatomic potentials); (ii) atomic and molecular collisions (photon collisions; electro collisions; heavy-particle collisions; homonuclear sequences), and (iii) surface interactions (sputtering; trapping, detrapping; adsorption, desorption; surface damage; blistering, flaking; chemical reactions). Part II contains the bibliographic data for the above listed topics and for plasma composition and impurities; plasma heating, cooling and fuelling; fusion research of general interest; high energy laser- and beam-matter interaction; interaction of atomic particles with fields. A list of evaluated data bases on atomic and molecular collisions and on particle-surface interactions is also given

  7. Heavy metal dynamics in the soil-leaf-fruit system under intensive apple cultivation

    Directory of Open Access Journals (Sweden)

    Murtić Senad

    2014-01-01

    Full Text Available One of the major problems confronting agricultural production is heavy metal contamination of agricultural soils, which imposes considerable limitations on productivity and leads to great consumer health and safety concerns about the products obtained on these soils. The objective of this study was to evaluate heavy metal dynamics in the soil-leaf-fruit system in an intensive apple cv. 'Idared' planting located in the Municipality of Goražde. Heavy metal contents in the soil samples and plant material were determined by atomic absorption spectrophotometry using a Shimadzu 7000 AA device, according to the instructions specified in the ISO 11047 method. The dynamics of the heavy metals analyzed, excepting zinc, in the soil-leaf-fruit system was characterized by relatively high total levels of heavy metals in the soil and a very low degree of their accumulation in the leaves and in particular the fruits. No fruit sample was found to have toxic levels of any of the heavy metals analyzed. In terms of soil contamination, this suggests the suitability of the study location for safe apple fruit production.

  8. Poultry litter-based activated carbon for removing heavy metal ions in water.

    Science.gov (United States)

    Guo, Mingxin; Qiu, Guannan; Song, Weiping

    2010-02-01

    Utilization of poultry litter as a precursor material to manufacture activated carbon for treating heavy metal-contaminated water is a value-added strategy for recycling the organic waste. Batch adsorption experiments were conducted to investigate kinetics, isotherms, and capacity of poultry litter-based activated carbon for removing heavy metal ions in water. It was revealed that poultry litter-based activated carbon possessed significantly higher adsorption affinity and capacity for heavy metals than commercial activated carbons derived from bituminous coal and coconut shell. Adsorption of metal ions onto poultry litter-based carbon was rapid and followed Sigmoidal Chapman patterns as a function of contact time. Adsorption isotherms could be described by different models such as Langmuir and Freundlich equations, depending on the metal species and the coexistence of other metal ions. Potentially 404 mmol of Cu2+, 945 mmol of Pb2+, 236 mmol of Zn2+, and 250-300 mmol of Cd2+ would be adsorbed per kg of poultry litter-derived activated carbon. Releases of nutrients and metal ions from litter-derived carbon did not pose secondary water contamination risks. The study suggests that poultry litter can be utilized as a precursor material for economically manufacturing granular activated carbon that is to be used in wastewater treatment for removing heavy metals.

  9. ONE-DIMENSIONAL ORDERING OF IN ATOMS IN A CU(100) SURFACE

    NARCIS (Netherlands)

    BREEMAN, M; BARKEMA, GT; BOERMA, DO

    1994-01-01

    A Monte Carlo study of the ordering of In atoms embedded in the top layer of a Cu(100) surface is presented. The interaction energies between the In and Cu atoms were derived from atom-embedding calculations, with Finnis-Sinclair potentials. It was found that the interaction between In atoms in the

  10. Electron emission from solids induced by swift heavy ions

    International Nuclear Information System (INIS)

    Xiao Guoqing

    2000-01-01

    The recent progresses in experimental and theoretical studies of the collision between swift heavy ion and solids as well as electron emission induced by swift heavy ion in solids were briefly reviewed. Three models, Coulomb explosion, thermal spike and repulsive long-lived states, for interpreting the atomic displacements stimulated by the electronic energy loss were discussed. The experimental setup and methods for measuring the electron emission from solids were described. The signification deviation from a proportionality between total electron emission yields and electronic stopping power was found. Auger-electron and convoy-electron spectra are thought to be a probe for investigating the microscopic production mechanisms of the electronic irradiation-damage. Electron temperature and track potential at the center of nuclear tracks in C and polypropylene foils induced by 5 MeV/u heavy ions, which are related to the electronic excitation density in metals and insulators respectively, were extracted by measuring the high resolution electron spectra

  11. Scalar Aharonov–Bohm Phase in Ramsey Atom Interferometry under Time-Varying Potential

    Directory of Open Access Journals (Sweden)

    Atsuo Morinaga

    2016-08-01

    Full Text Available In a Ramsey atom interferometer excited by two electromagnetic fields, if atoms are under a time-varying scalar potential during the interrogation time, the phase of the Ramsey fringes shifts owing to the scalar Aharonov–Bohm effect. The phase shift was precisely examined using a Ramsey atom interferometer with a two-photon Raman transition under the second-order Zeeman potential, and a formula for the phase shift was derived. Using the derived formula, the frequency shift due to the scalar Aharonov–Bohm effect in the frequency standards utilizing the Ramsey atom interferometer was discussed.

  12. Temporal-spatial trends in heavy metal contents in sediment-derived soils along the Sea Scheldt river (Belgium)

    International Nuclear Information System (INIS)

    Vandecasteele, B.; Vos, B. de; Tack, F.M.G.

    2003-01-01

    The alluvial plain upstream in the Sea Scheldt was more affected by upland disposal of polluted sediments. - The aim of this study was to survey the alluvial plains of the Sea Scheldt river in Belgium for the presence of old sediment-derived soils, and to appraise the heavy metal contamination at these sites. Historically, sediments of periodical dredging operations have been disposed in the alluvial plain without concern for the potential presence of contaminants. Up to 96% of the areas that were affected by sediment disposal (ca. 120 ha) was found to be polluted by at least one of the metals Cd, Cr, Zn or Pb. Concentrations of Cd, Cr and Zn were, in 10% of the cases, higher than 14, 1400 and 2200 mg/kg DM, respectively. Based on the Flemish decree on soil sanitation, Cu and Ni concentrations were of less environmental concern on any site. The pollution in the Sea Scheldt alluvial plain nevertheless is lower than for the Upper Scheldt alluvial plain. The sediment-derived soils in the most upstream part near Ghent were used for disposal of sediments from dredging operations elsewhere. Metal concentrations were explored and both spatial and temporal trend were analysed. The pollution levels encountered warrant caution as most of the soils affected by historical dredged sediment disposal are currently in use for pasture

  13. Preparation of nano-biomaterials with Leptolyngbia foveolarum and heavy metal biosorption by free and immobilized algal cells

    International Nuclear Information System (INIS)

    Toncheva-Panova, T.; Pouneva, I.; Sholeva, M.; Chernev, G.

    2010-01-01

    Using the sol-gel procedure nano-biomaterials with incorporation of Leptolyngbia foveolarum in the silica matrix were manufactured. The immobilization of algal cells was confirmed with Scanning Electron Microscopy (SEM) investigations and photos. Observation of nano-biomaterials with Atomic Force Microscopy (AFM) shows nanostructure with well-defined nanounits and their aggregates. The potential of the Antarctic isolate L. foveolarum for sorption of Cu 2+ and Cd 2+ was studied by incubation of free algal cells and those immobilized in nano-biomaterials in the salts solutions of the two heavy metals. The rest of the heavy metal was determined with inductively coupled plasma atomic emission spectrometer (ICP-AES). It was established that the heavy metal biosorption capacity demonstrated by the free Leptolyngbia cells was retained after their incorporation in the nano-matrices. Free cells as well as embedded in silica nano-matrix sequestered the two heavy metals with greater affinity for copper. The highest binding capacity, 76% of the initial Cu 2+ concentration possessed nano-biomaterials with incorporated vegetative L. foveolarum cells, compared to 68% of free cells. For cadmium the degree of biosorption was lower - 35% by free cells and 30.2% by those incorporated in the biocer. (authors)

  14. Bioaccumulation of heavy metals in organs of fresh water fish Cyprinus carpio (Common carp)

    International Nuclear Information System (INIS)

    Vinodhini, R.; Narayanan, M.

    2008-01-01

    The objective of the present study is to determine the bioaccumulation of heavy metals in various organs of the fresh water fish exposed to heavy metal contaminated water system. The experimental fish was exposed to Cr. Ni, Cd and Pb at sublethal concentrations for periods of 32 days. The elements Cd, Pb, Ni and Cr were assayed using Shimadzu AA 6200 atomic absorption spectrophotometry and the results were given as μg/g dry wt. The accumulation of heavy metal gradually increases in liver during the heavy metal exposure period. All the results were statistically significant at p Pb > Ni > Cr and Pb > Cd > Ni > Cr. Similarly, in case of kidney and flesh tissues, the order was Pb > Cd > Cr > Ni and Pb > Cr > Cd > Ni. In all heavy metals, the bioaccumulation of lead and cadmium proportion was significantly increased in the tissues of Cyprinus carpio (Common carp)

  15. Systematic analysis of neutron yields from thick targets bombarded by heavy ions and protons with moving source model

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Takashi; Kurosawa, Tadahiro; Nakamura, Takashi E-mail: nakamura@cyric.tohoku.ac.jp

    2002-03-21

    A simple phenomenological analysis using the moving source model has been performed on the neutron energy spectra produced by bombarding thick targets with high energy heavy ions which have been systematically measured at the Heavy-Ion Medical Accelerator (HIMAC) facility (located in Chiba, Japan) of the National Institute of Radiological Sciences (NIRS). For the bombardment of both heavy ions and protons in the energy region of 100-500 MeV per nucleon, the moving source model incorporating the knock-on process could be generally successful in reproducing the measured neutron spectra within a factor of two margin of accuracy. This phenomenological analytical equation is expressed having several parameters as functions of atomic number Z{sub p}, mass number A{sub p}, energy per nucleon E{sub p} for projectile, and atomic number Z{sub T}, mass number A{sub T} for target. By inputting these basic data for projectile and target into this equation we can easily estimate the secondary neutron energy spectra at an emission angle of 0-90 deg. for bombardment with heavy ions and protons in the aforementioned energy region. This method will be quite useful to estimate the neutron source term in the neutron shielding design of high energy proton and heavy ion accelerators.

  16. Atomic parity nonconservation: Electroweak parameters and nuclear structure

    International Nuclear Information System (INIS)

    Pollock, S.J.; Fortson, E.N.; Wilets, L.

    1992-01-01

    There have been suggestions to measure atomic parity nonconservation (PNC) along an isotopic chain, by taking ratios of observables in order to cancel complicated atomic-structure effects. Precise atomic PNC measurements could make a significant contribution to tests of the standard model at the level of one-loop radiative corrections. However, the results also depend upon certain features of nuclear structure, such as the spatial distribution of neutrons in the nucleus. To examine the sensitivity to nuclear structure, we consider the case of Pb isotopes using various recent relativistic and nonrelativistic nuclear model calculations. Contributions from nucleon internal weak structure are included, but found to be fairly negligible. The spread among present models in predicted sizes of nuclear-structure effects may preclude using Pb isotope ratios to test the standard model at better than a 1% level, unless there are adequate independent tests of the nuclear models by various alternative strong and electroweak nuclear probes. On the other hand, sufficiently accurate atomic PNC experiments would provide a unique method to measure neutron distributions in heavy nuclei

  17. Topics in atomic physics

    CERN Document Server

    Burkhardt, Charles E

    2006-01-01

    The study of atomic physics propelled us into the quantum age in the early twentieth century and carried us into the twenty-first century with a wealth of new and, in some cases, unexplained phenomena. Topics in Atomic Physics provides a foundation for students to begin research in modern atomic physics. It can also serve as a reference because it contains material that is not easily located in other sources. A distinguishing feature is the thorough exposition of the quantum mechanical hydrogen atom using both the traditional formulation and an alternative treatment not usually found in textbooks. The alternative treatment exploits the preeminent nature of the pure Coulomb potential and places the Lenz vector operator on an equal footing with other operators corresponding to classically conserved quantities. A number of difficult to find proofs and derivations are included as is development of operator formalism that permits facile solution of the Stark effect in hydrogen. Discussion of the classical hydrogen...

  18. Quantum-mechanical transport equation for atomic systems.

    Science.gov (United States)

    Berman, P. R.

    1972-01-01

    A quantum-mechanical transport equation (QMTE) is derived which should be applicable to a wide range of problems involving the interaction of radiation with atoms or molecules which are also subject to collisions with perturber atoms. The equation follows the time evolution of the macroscopic atomic density matrix elements of atoms located at classical position R and moving with classical velocity v. It is quantum mechanical in the sense that all collision kernels or rates which appear have been obtained from a quantum-mechanical theory and, as such, properly take into account the energy-level variations and velocity changes of the active (emitting or absorbing) atom produced in collisions with perturber atoms. The present formulation is better suited to problems involving high-intensity external fields, such as those encountered in laser physics.

  19. The relative stabilities of cyclic dicationic derivatives of diphosphanes with three (3P) or four (4P) linked phosphorus atoms.

    Science.gov (United States)

    Bashforth, Rachel; Boyall, Alice J; Coffer, Philippa K; Dillon, Keith B; Goeta, Andrés E; Howard, Judith A K; Kenwright, Alan M; Probert, Michael R; Shepherd, Helena J; Thompson, Amber L

    2012-01-28

    Reaction of a diphosphane with a chlorophosphane in the presence of SnCl(2) or AlCl(3) leads to the formation of dicationic heterocycles with three (3P) or four (4P) linked phosphorus atoms. Some 3P derivatives with small alkyl substituents may also be prepared by direct alkylation of cyclic triphosphenium ions. Several new species were prepared in solution, some of which were isolated and characterised by single-crystal X-ray diffraction. Investigations into the factors favouring formation of 3P or 4P species are described.

  20. Eleven cases of neonatal intracranial hemorrhage

    International Nuclear Information System (INIS)

    Matsuda, Tadashi; Asao, Toyohiko; Shibata, Takeo

    1981-01-01

    Eleven cases of neonatal intracranial hemorrhage were diagnosed and followed up by CT scanning. By CT, hemorrhagic lesions were shown as high density areas in an acute stage and imaged as low density areas after the hemorrhage was absorbed. The time of absorption varies depending upon the site and the severity of hemorrhage. Intraventricular hemorrhage, petechial hemorrhage and subdural hematoma were absorbed rapidly in more than 70% of the exanimed cases, CT scanning 1 - 2 weeks after the onset revealed absorption of hemorrhage. However, the absorption delayed in intracerebral hematoma; CT scan taken after one month showed hemorrhagic lesions remaining in 75% of the cases. In nine cases who survived, following the absorption of the hemorrhagic lesions, cerebral atrophy was observed in 4 cases (44%), ventricular enlargement in 3 cases (33%), and complete recovery in 2 cases (22%). From these results, CT scanning for diagnosis of neonatal intracranial hemorrhage should be done before the hemorrhagic lesion is absorbed (within 7 days of the onset). Follow-up study by CT is important for observing changes and predicting prognosis of intracranial hemorrhage. (Ueda, J.)

  1. A novel interaction fingerprint derived from per atom score contributions: exhaustive evaluation of interaction fingerprint performance in docking based virtual screening.

    Science.gov (United States)

    Jasper, Julia B; Humbeck, Lina; Brinkjost, Tobias; Koch, Oliver

    2018-03-16

    Protein ligand interaction fingerprints are a powerful approach for the analysis and assessment of docking poses to improve docking performance in virtual screening. In this study, a novel interaction fingerprint approach (PADIF, protein per atom score contributions derived interaction fingerprint) is presented which was specifically designed for utilising the GOLD scoring functions' atom contributions together with a specific scoring scheme. This allows the incorporation of known protein-ligand complex structures for a target-specific scoring. Unlike many other methods, this approach uses weighting factors reflecting the relative frequency of a specific interaction in the references and penalizes destabilizing interactions. In addition, and for the first time, an exhaustive validation study was performed that assesses the performance of PADIF and two other interaction fingerprints in virtual screening. Here, PADIF shows superior results, and some rules of thumb for a successful use of interaction fingerprints could be identified.

  2. Heavy-heavy and heavy-light quarks interactions generated by QCD vacuum

    Directory of Open Access Journals (Sweden)

    Musakhanov Mirzayusuf

    2017-01-01

    Full Text Available The QCD vacuum is populated by instantons that correspond to the tunneling processes in the vacuum. This mechanism creates the strong vacuum gluon fields. As result, the QCD vacuum instantons induce very strong interactions between light quarks, initially almost massless. Such a strong interactions bring a large dynamical mass M of the light quarks and bound them to produce almost massless pions in accordance with the spontaneous breaking of the chiral symmetry (SBCS. On the other hand, the QCD vacuum instantons also interact with heavy quarks and responsible for the generation of the heavy-heavy and heavy-light quarks interactions, with a traces of the SBCS. If we take the average instanton size ρ¯=0.33$\\bar \\rho = 0.33$ fm, and the average inter-instanton distance R¯=1$\\bar R = 1$ fm we obtain the dynamical light quark mass to be M = 365 MeV and the instanton media contribution to the heavy quark mass ΔM=70 MeV. These factors define the coupling between heavy-light and heavy-heavy quarks induced by the QCD vacuum instantons. We consider first the instanton effects on the heavy-heavy quarks potential, including its spin-dependent part. We also discuss those effects on the masses of the charmonia and their hyperfine mass splittings. At the second part we discuss the interaction between a heavy and light quarks generated by instantons and it’s effects.

  3. Heavy-quark production in gluon fusion at two loops in QCD

    International Nuclear Information System (INIS)

    Czakon, M.

    2007-07-01

    We present the two-loop virtual QCD corrections to the production of heavy quarks in gluon fusion. The results are exact in the limit when all kinematical invariants are large compared to the mass of the heavy quark up to terms suppressed by powers of the heavy-quark mass. Our derivation uses a simple relation between massless and massive QCD scattering amplitudes as well as a direct calculation of the massive amplitude at two loops. The results presented here together with those obtained previously for quark-quark scattering form important parts of the next-to-next-to-leading order QCD corrections to heavy-quark production in hadron-hadron collisions. (orig.)

  4. Dosimetry in heavy ion beams using various detectors

    Czech Academy of Sciences Publication Activity Database

    Brabcová, Kateřina; Jadrníčková, Iva; Molokanov, A. G.; Spurný, František

    2010-01-01

    Roč. 45, č. 10 (2010), s. 1384-1386 ISSN 1350-4487. [Neutron and Ion Dosimetry Symposium /11./. Cape Town, 12.10.2009-16.10.2009] R&D Projects: GA ČR GA205/09/0171; GA AV ČR IAA100480902 Institutional research plan: CEZ:AV0Z10480505 Keywords : tack-etched detectors * LET spectra * TLD * heavy ion beams Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.019, year: 2010

  5. Transport of heavy ions through matter within ion optical systems

    International Nuclear Information System (INIS)

    Schwab, T.

    1991-04-01

    In this thesis for the first time higher-order ion-optical calculations were connected with the whole phase-space changes of the heavy ions in passing through matter. With the developed programs and the newly proposed analytical methods atomic and nuclear interactions of the heavy ions within ion optical systems can be described realistically. The results of this thesis were applied to the conception of the fragment separator (FRS) and to the planning and preparation of experiments at the new GSI accelerator facility. Especially for the description of the ion-optical combination of FRS and the storage ring ESR the developed programs and methods proved to be necessary. A part of the applied theories on the atomic stopping could be confirmed in the framework of this thesis in an experiment with the high-resolving spectrometer SPEC at GANIL. The method of the isotopically pure separation of projectile fragments by means of magnetic analysis and the electronic energy loss could be also experimentally successfully tested at several energies (60-400 MeV/u). Furthermore in this thesis also application-related problems regarding a tumor therapy with heavy ions were solved. A concept for a medical separator (BMS) was developed, which separates light diagnosis beams isotopically purely and beyond improves the energy sharpness by means of an especially shaped (monoenergetic) stopper so that an in-situ range determination is possible with an accuracy of about one millimeter. (orig./HSI) [de

  6. Determination of relative populations of the magnetic sub-levels of the 4 1D level of HeI excited by heavy ion impact

    International Nuclear Information System (INIS)

    Carre, M.; Zgainski, A.; Gaillard, M.; Nouh, M.; Lombardi, M.

    1981-01-01

    The theoretical study of the depolarization of a transition, emitted from an excited atomic level J = 2, by a static electric field leads to the development of a new experimental method and the measurement of the relative population of the Zeeman sub-levels. This method is applied to the study of the 4 1 D level of HeI excited by several heavy ions (Li + , Ne + , Na + and Mg + ) at intermediate energy between 6 and 40 keV. From the obtained results, we derive informations on the target excitation phenomena: in particular present evidence for a long-range interaction, due to the ion charge, in the output channel of the collision [fr

  7. Laser-induced fluorescence of metal-atom impurities in a neutral beam

    International Nuclear Information System (INIS)

    Burrell, C.F.; Pyle, R.V.; Sabetimani, Z.; Schlachter, A.S.

    1984-10-01

    The need to limit impurities in fusion devices to low levels is well known. We have investigated, by the technique of laser-induced fluorescence, the concentration of heavy-metal atoms in a neutral beam caused by their evaporation from the hot filaments in a conventional high-current multifilament hydrogen-ion source

  8. Assessment of arsenic and heavy metal contents in cockles (Anadara granosa) using multivariate statistical techniques

    International Nuclear Information System (INIS)

    Abbas Alkarkhi, F.M.; Ismail, Norli; Easa, Azhar Mat

    2008-01-01

    Cockles (Anadara granosa) sample obtained from two rivers in the Penang State of Malaysia were analyzed for the content of arsenic (As) and heavy metals (Cr, Cd, Zn, Cu, Pb, and Hg) using a graphite flame atomic absorption spectrometer (GF-AAS) for Cr, Cd, Zn, Cu, Pb, As and cold vapor atomic absorption spectrometer (CV-AAS) for Hg. The two locations of interest with 20 sampling points of each location were Kuala Juru (Juru River) and Bukit Tambun (Jejawi River). Multivariate statistical techniques such as multivariate analysis of variance (MANOVA) and discriminant analysis (DA) were applied for analyzing the data. MANOVA showed a strong significant difference between the two rivers in term of As and heavy metals contents in cockles. DA gave the best result to identify the relative contribution for all parameters in discriminating (distinguishing) the two rivers. It provided an important data reduction as it used only two parameters (Zn and Cd) affording more than 72% correct assignations. Results indicated that the two rivers were different in terms of As and heavy metal contents in cockle, and the major difference was due to the contribution of Zn and Cd. A positive correlation was found between discriminate functions (DF) and Zn, Cd and Cr, whereas negative correlation was exhibited with other heavy metals. Therefore, DA allowed a reduction in the dimensionality of the data set, delineating a few indicator parameters responsible for large variations in heavy metals and arsenic content. Taking into account of these results, it can be suggested that a continuous monitoring of As and heavy metals in cockles be performed in these two rivers

  9. Experiments with stored heavy ions

    International Nuclear Information System (INIS)

    Fick, D.; Habs, D.; Jaeschke, E.

    1985-02-01

    The success of newly-developed methods of phase space cooling in proton and antiproton storage rings was sufficient for an examination of whether these methods could also be applied in storage rings for heavy ions. An expansion of these methods to heavy ion beams seems attractive for all sorts of reasons. Recently, this area was extensively discussed in a series of working meetings with the result that heavy ion storage rings are to be built for use in atomic and nuclear physics, with integrated radiation cooling and stochastic cooling, but primarily electron cooling. The current state of research and planning for the storage experiment is described. It is not intended to be a structural specification worked out in detail. The general design of the ring, however, has been established, and experimental details have deliberately been kept flexible, to thereby allow very different sorts of experiments to be conducted. The ring described with a maximum magnetic rigidity of Bp = 1.5 Tm, is designed in quadripartite symmetry. The total circumference is approximately 35 m, and there are four straight sections each 3.5 m long for the electron cooling sections, the experimental equipment, as well as HF system and injection. One of the most desirable properties of the reservoir is the multi-charge mode, which will significantly improve the operation which heavy ion beams, which reverse charge in electron cooling sections, target and residual vacuum. Initial considerations are presented with regard to stochastic and electron cooling. A review of possible classes of experiments is given and the schedule and financing of the project is outlined. 46 refs

  10. Analytic properties of the relativistic Thomas-Fermi equation and the total energy of atomic ions

    International Nuclear Information System (INIS)

    March, N.H.; Senatore, G.

    1985-06-01

    The analytic properties of solutions of the relativistic Thomas-Fermi equation which tend to zero at infinity are first examined, the neutral atom solution being a member of this class. A new length is shown to enter the theory, proportional to the square root of the fine structure constant. This information is used to develop a perturbation expansion around the neutral atom solution, corresponding to positive atomic ions with finite but large radii. The limiting law relating ionic radius to the degree of ionization is thereby displayed in functional form, and solved explicitly to lowest order in the fine structure constant. To embrace this knowledge of heavy positive ions, as well as results from the one-electron Dirac equation, a proposal is then advanced as to the analytic form of the relativistic total energy E(Z,N) of an atomic ion with nuclear charge Ze and total number of electrons N. The fact that, for N>1, the nucleus is known only to bind Z+n electrons, where n is 1 or 2, indicates non-analyticity in the complex Z plane, represented by a circle of radius Z approx.= N. Such non-analyticity is also a property of the non-relativistic energy derived from the many-electron Schroedinger equation. The relativistic theory, however, must also embody a second type of non-analyticity associated with the known property for N=1 that the Dirac equation predicts electron-positron pair production when the electronic binding energy becomes equal to twice the electron rest mass energy. This corresponds to a second circle of non-analyticity in E(Z,N), and hence to a Taylor-Laurent expansion of this quantity in the atomic number Z. The relation of this expansion to the Layzer-Bahcall series is finally discussed. (author)

  11. HEAVY ION LINEAR ACCELERATOR

    Science.gov (United States)

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  12. Moving NRQCD for heavy-to-light form factors on the lattice

    International Nuclear Information System (INIS)

    Horgan, R.R.; Khomskii, L.; Meinel, S.

    2009-06-01

    We formulate Non-Relativistic Quantum Chromodynamics (NRQCD) on a lattice which is boosted relative to the usual discretization frame. Moving NRQCD (mNRQCD) allows us to treat the momentum for the heavy quark arising from the frame choice exactly. We derive mNRQCD through O(1/m 2 ,v 4 rel ), as accurate as the NRQCD action in present use, both in the continuum and on the lattice with O(a 4 ) improvements. We have carried out extensive tests of the formalism through calculations of two-point correlators for both heavy-heavy (bottomonium) and heavy-light (B s ) mesons in 2+1 flavor lattice QCD and obtained nonperturbative determinations of energy shift and external momentum renormalization. Comparison to perturbation theory at O(α s ) is also made. The results demonstrate the effectiveness of mNRQCD. In particular we show that the decay constants of heavy-light and heavy-heavy mesons can be calculated with small systematic errors up to much larger momenta than with standard NRQCD. (orig.)

  13. Superfluid response in heavy fermion superconductors

    Science.gov (United States)

    Zhong, Yin; Zhang, Lan; Shao, Can; Luo, Hong-Gang

    2017-10-01

    Motivated by a recent London penetration depth measurement [H. Kim, et al., Phys. Rev. Lett. 114, 027003 (2015)] and novel composite pairing scenario [O. Erten, R. Flint, and P. Coleman, Phys. Rev. Lett. 114, 027002 (2015)] of the Yb-doped heavy fermion superconductor CeCoIn5, we revisit the issue of superfluid response in the microscopic heavy fermion lattice model. However, from the literature, an explicit expression for the superfluid response function in heavy fermion superconductors is rare. In this paper, we investigate the superfluid density response function in the celebrated Kondo-Heisenberg model. To be specific, we derive the corresponding formalism from an effective fermionic large- N mean-field pairing Hamiltonian whose pairing interaction is assumed to originate from the effective local antiferromagnetic exchange interaction. Interestingly, we find that the physically correct, temperature-dependent superfluid density formula can only be obtained if the external electromagnetic field is directly coupled to the heavy fermion quasi-particle rather than the bare conduction electron or local moment. Such a unique feature emphasizes the key role of the Kondo-screening-renormalized heavy quasi-particle for low-temperature/energy thermodynamics and transport behaviors. As an important application, the theoretical result is compared to an experimental measurement in heavy fermion superconductors CeCoIn5 and Yb-doped Ce1- x Yb x CoIn5 with fairly good agreement and the transition of the pairing symmetry in the latter material is explained as a simple doping effect. In addition, the requisite formalism for the commonly encountered nonmagnetic impurity and non-local electrodynamic effect are developed. Inspired by the success in explaining classic 115-series heavy fermion superconductors, we expect the present theory will be applied to understand other heavy fermion superconductors such as CeCu2Si2 and more generic multi-band superconductors.

  14. Proceedings of the international conference on dynamical properties of heavy-ion reactions held at the University of the Witwatersrand, v. 1

    International Nuclear Information System (INIS)

    Engelbrecht, C.A.; Lemmer, R.H.; Sellschop, J.P.F.; Toeppfer, C.

    1978-01-01

    The report contains abstracts of the papers delivered at the conference. The abstracts have been grouped into the following chapters: Very heavy nuclei; Deep inelastic reactions and fusion; Resonances; Elastic and quasi-elastic scattering; Atomic physics with heavy ions; Miscellaneous; Post-deadline contributions. Each abstract has been submitted to INIS separately

  15. Heavy and Light chain amyloidosois presenting as complete heart block: A rare presentation of a rare disease.

    Science.gov (United States)

    Priyamvada, P S; Morkhandikar, S; Srinivas, B H; Parameswaran, S

    2015-01-01

    Amyloidosis is an uncommon disease characterized by deposition of proteinaceous material in the extracellular matrix, which results from abnormal protein folding. Even though more than 25 precursor proteins are identified, majority of systemic amyloidosis results from deposition of abnormal immunoglobulin (Ig) light chains. In heavy chain amyloidosis (AH), deposits are derived from both heavy chain alone, whereas in heavy and light chain amyloidosis (AHL), the deposits are derived from Ig heavy chains and light chains. Both AH and AHL are extremely rare diseases. Here, we report an unusual presentation of IgG (lambda) AHL amyloidosis in the background of multiple myeloma, where the initial clinical presentation was complete heart block, which preceded the definitive diagnosis by 18 months.

  16. Analysis of heavy metals concentration in water and sediment in the Hara biosphere reserve, southern Iran.

    Science.gov (United States)

    Nowrouzi, Mohsen; Mansouri, Borhan; Nabizadeh, Sahar; Pourkhabbaz, Alireza

    2014-02-01

    This study determined the concentration of heavy metals (Al, Cr, Cu, and Zn) in water and sediments at nine sites in the Hara biosphere reserve of southern Iran during the summer and winter 2010. Determination of Al, Cr, Cu, and Zn in water was carried out by graphite furnace atomic absorption spectrometer (Shimadzu, AA 610s) and in sediment by flame atomic absorption spectrometer (Perkin Elmer, AA3030). Results showed that the heavy metal concentrations in the water samples decreased in the sequence of Zn > Al > Cu > Cr, while in sediment samples were Cr > Zn > Cu > Al. Data analysis indicated that with the exception of Al, there was a Pearson's correlation coefficient between pH and Cu, Zn, and Cr at α = 0.01, 0.05, and 0.001 in sediment (in winter), respectively. There were also significant differences between heavy metals of Cr, Cu, and Zn during the two seasons (p < 0.001) in the water and sediment.

  17. Inelastic processes in interaction of an atom with ultrashort pulse of an electromagnetic field

    International Nuclear Information System (INIS)

    Matveev, V.I.; Gusarevich, E.S.; Pashev, I.N.

    2005-01-01

    Electron transitions occurring when a heavy relativistic atom interacts with a spatially inhomogeneous ultrashort electromagnetic pulse are considered. Transition probabilities are expressed in terms of the known inelastic atomic form factors. By way of example, the inelastic processes accompanying the interaction of ultrashort pulses with hydrogen-like atoms are considered. The probabilities of ionization and production of a bound-free electron-positron pair on a bare nucleus, which are accompanied by the formation of a hydrogen-like atom in the final state and a positron in the continuum, are calculated. The developed technique makes it possible to take into exact account magnetic interaction besides spatial inhomogeneity of an ultrashort electromagnetic pulse [ru

  18. Spectrophotometry of peculiar B and A stars. II. Eleven mercury-manganese stars

    International Nuclear Information System (INIS)

    Adelman, S.J.; Pyper, D.M.

    1979-01-01

    Spectrophotometry of eleven HgMn stars is presented for the optical region. As found in Paper I, the HgMn stars have systematically larger Δiota* and Δa values than the normal main sequence stars due to differences with respect to the mean continuum particularly of the lambda4464 values and the lambda5200 region, respectively. The HgMn stars exhibit a continuous range in the behavior of both the lambda4200 and lambda5200 regions between those stars that have index values larger than the appropriate criterion of presence and present definite evidence for the features to those stars with only a slight possibility of such features. The strengths of the lambda4200 and lambda5200 features appear not to be correlated. In the HgMn stars, both features may be due to differential line blocking. In the energy distribution of all eleven stars, the Balmer jump regions best fit the predictions of slightly hotter solar composition, log g=4.0, fully line blanketed model atmospheres than do the corresponding Paschen continua

  19. Rutherford-Bohr atom

    Science.gov (United States)

    Heilbron, J. L.

    1981-03-01

    Bohr used to introduce his attempts to explain clearly the principles of the quantum theory of the atom with an historical sketch, beginning invariably with the nuclear model proposed by Rutherford. That was sound pedagogy but bad history. The Rutherford-Bohr atom stands in the middle of a line of work initiated by J.J. Thomson and concluded by the invention of quantum mechanics. Thompson's program derived its inspiration from the peculiar emphasis on models characteristic of British physics of the 19th century. Rutherford's atom was a late product of the goals and conceptions of Victorian science. Bohr's modifications, although ultimately fatal to Thomson's program, initially gave further impetus to it. In the early 1920s the most promising approach to an adequate theory of the atom appeared to be the literal and detailed elaboration of the classical mechanics of multiply periodic orbits. The approach succeeded, demonstrating in an unexpected way the force of an argument often advanced by Thomson: because a mechanical model is richer in implications than the considerations for which it was advanced, it can suggest new directions of research that may lead to important discoveries.

  20. HEAVY METALS (Ni, Cu, Zn AND Cd CONTENT IN SERUM OF RAT FED GREEN MUSSELS

    Directory of Open Access Journals (Sweden)

    Muhammad Yudhistira Azis

    2015-11-01

    Full Text Available Green mussel (Perna viridis can playing role as bio-indicator or biomonitoring agent for heavy-metalcontaminations in the sea. In this research, the concentrations of four elements Ni, Cu, Zn and Cd in P. viridis and in the serum of rat which orally feed by P. viridis were determined by Atomic Absorption Spectrometry (AAS following dry acid digestion. Parameter analysis was evaluated by determining confidence limit for the obtained results. The result showed that there was a sequence of heavy-metal content in green mussels sample and laboratory rats serum, such as Ni < Cd < Cu < Zn. Keywords: heavy metals, green mussels, laboratory rats serum, AAS