WorldWideScience

Sample records for multiple heavy atom

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

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

    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.

  3. From heavy ions to exotic atoms

    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...

  4. Photoelectron spectroscopy of heavy atoms and molecules

    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

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

    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

  6. Investigations in atomic physics by heavy ion projectiles

    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.)

  7. Former heavy drinkers’ multiple narratives of recovery

    Christensen Anne-Sofie

    2015-06-01

    Full Text Available AIM – This article explores the multiplicity of former heavy drinkers’ narratives. The focus lies on turning points from heavy drinking among people who have recovered through self-change and among those who recovered by participating in Alcoholics Anonymous (AA meetings.

  8. A rational approach to heavy-atom derivative screening

    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

  9. A rational approach to heavy-atom derivative screening

    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.

  10. Investigations in atomic physics by heavy ion projectiles

    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

  11. Electron-impact ionization of heavy atomic ions

    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

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

    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

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

    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.

  14. Two-photon decay in heavy atoms and ions

    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.)

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

    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.

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

    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.

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

    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.

  18. Many-electron model for multiple ionization in atomic collisions

    Archubi, C D; Montanari, C C; Miraglia, J E

    2007-01-01

    We have developed a many-electron model for multiple ionization of heavy atoms bombarded by bare ions. It is based on the transport equation for an ion in an inhomogeneous electronic density. Ionization probabilities are obtained by employing the shell-to-shell local plasma approximation with the Levine and Louie dielectric function to take into account the binding energy of each shell. Post-collisional contributions due to Auger-like processes are taken into account by employing recent photoemission data. Results for single-to-quadruple ionization of Ne, Ar, Kr and Xe by protons are presented showing a very good agreement with experimental data

  19. Many-electron model for multiple ionization in atomic collisions

    Archubi, C D [Instituto de AstronomIa y Fisica del Espacio, Casilla de Correo 67, Sucursal 28 (C1428EGA) Buenos Aires (Argentina); Montanari, C C [Instituto de AstronomIa y Fisica del Espacio, Casilla de Correo 67, Sucursal 28 (C1428EGA) Buenos Aires (Argentina); Miraglia, J E [Instituto de AstronomIa y Fisica del Espacio, Casilla de Correo 67, Sucursal 28 (C1428EGA) Buenos Aires (Argentina)

    2007-03-14

    We have developed a many-electron model for multiple ionization of heavy atoms bombarded by bare ions. It is based on the transport equation for an ion in an inhomogeneous electronic density. Ionization probabilities are obtained by employing the shell-to-shell local plasma approximation with the Levine and Louie dielectric function to take into account the binding energy of each shell. Post-collisional contributions due to Auger-like processes are taken into account by employing recent photoemission data. Results for single-to-quadruple ionization of Ne, Ar, Kr and Xe by protons are presented showing a very good agreement with experimental data.

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

    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

  1. Electronic structure of super heavy atoms revisited

    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)

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

    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.)

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

    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.

  4. Multiple ionization of atoms by ion impact

    DuBois, R.D.

    1988-01-01

    In order to model the energy deposition of fast ions as they slow down in gaseous media, information about the ionization occurring in collisions between ions and target atoms/molecules is required. Our measurements of doubly differential electron emission cross sections provide detailed information about the ionization process but do not provide any information about the final states of the target. They also do not distinguish between the emission of one or more target electrons in a single collision. It is important to know the relative importance of multiple-, with respect to single-, target ionization in order to accurately model the energy deposition. To date, multiple ionization of He, Ne, Ar, Kr, and Xe targets has been studied. Primarily, H and He ions were used, although some data for heavier ions (C,N and O) have also been obtained

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

    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.

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

    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.

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

    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

  8. Atomic x-ray production by relativistic heavy ions

    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

  9. Fast Heavy-Atom Tunneling in Trifluoroacetyl Nitrene.

    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.

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

    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.

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

    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.

  12. Multiple heavy-fragment breakup reactions

    Pelte, D.

    1986-01-01

    Data for heavy ion breakup reactions for projectiles between silicon 28 and argon 40 and targets between carbon 12 and zirconium 90 in the energy range 7 to 15 MeV/n are presented. The experimental method used to cope with the complexity of the exit channels in these reactions is discussed. Data on cross sections, isotopic distribution, charge distribution, energy dependence, Q-value and angular momentum of the target are discussed in relationship to model predictions

  13. Multiple Electron Stripping of Heavy Ion Beams

    Mueller, D.; Grisham, L.; Kaganovich, I.; Watson, R. L.; Horvat, V.; Zaharakis, K. E.; Peng, Y.

    2002-01-01

    One approach being explored as a route to practical fusion energy uses heavy ion beams focused on an indirect drive target. Such beams will lose electrons while passing through background gas in the target chamber, and therefore it is necessary to assess the rate at which the charge state of the incident beam evolves on the way to the target. Accelerators designed primarily for nuclear physics or high energy physics experiments utilize ion sources that generate highly stripped ions in order to achieve high energies economically. As a result, accelerators capable of producing heavy ion beams of 10 to 40 Mev/amu with charge state 1 currently do not exist. Hence, the stripping cross-sections used to model the performance of heavy ion fusion driver beams have, up to now, been based upon theoretical calculations. We have investigated experimentally the stripping of 3.4 Mev/amu Kr 7+ and Xe +11 in N2; 10.2 MeV/amu Ar +6 in He, N2, Ar and Xe; 19 MeV/amu Ar +8 in He, N2, Ar and Xe; 30 MeV He 1 + in He, N2, Ar and Xe; and 38 MeV/amu N +6 in He, N2, Ar and Xe. The results of these measurements are compared with the theoretical calculations to assess their applicability over a wide range of parameters

  14. Element Distribution and Multiplicity of Heavy Fragments

    2002-01-01

    This experiment will measure the energy and angular distribution of heavy fragments produced in the reactions of |1|2C on several targets between |2|7Al and |2|3|8U at 86~MeV/u. The systematic investigation of a highly excited interaction region (fireball) by means of a clean N and Z identification of heavy tar fragments, may result in a better understanding of temperature concept and of the degree of equilibration of the local interaction region with respect to the total system. For this investigation a large-area position sensitive ionization chamber of 50~msr solid angle in conjunction with a time-of-flight telescope consisting of parallel-plate detectors will be used. \\\\ \\\\ In order to get information on the transverse momentum transfer and the inelasticity of the collision, the energy of the PROJECTILE-FRAGMENTS will be measured at forward angles with a plastic scintillator hodoscope. In addition to this inclusive measurement correlations between heavy fragments will be investigated by means of three pos...

  15. New experiments on few-electron very heavy atoms

    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

  16. Estimation of atomic masses of heavy and superheavy elements

    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.)

  17. Multiple photon emission in heavy particle decays

    Asakimori, K.; Burnett, T.H.; Cherry, M.L.

    1994-03-01

    Cosmic ray interactions, at energies above 1 TeV/nucleon, in emulsion chambers flown on high altitude balloons have yielded two events showing apparent decays of a heavy particle into one charged particle and four photons. The photons converted into electron pairs very close to the decay vertex. Attempts to explain this decay topology with known particle decays are presented. Unless both events represent a b → u transition, which is statistically unlikely, then other known decay modes for charmed or bottom particles do not account satisfactorily for these observations. This could indicate, possibly, a new decay channel. (author). 7 refs, 6 figs, 2 tabs

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

    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

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

    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...

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

    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

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

    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.

  2. Multiple scattering problems in heavy ion elastic recoil detection analysis

    Johnston, P.N.; El Bouanani, M.; Stannard, W.B.; Bubb, I.F.; Cohen, D.D.; Dytlewski, N.; Siegele, R.

    1998-01-01

    A number of groups use Heavy Ion Elastic Recoil Detection Analysis (HIERDA) to study materials science problems. Nevertheless, there is no standard methodology for the analysis of HIERDA spectra. To overcome this deficiency we have been establishing codes for 2-dimensional data analysis. A major problem involves the effects of multiple and plural scattering which are very significant, even for quite thin (∼100 nm) layers of the very heavy elements. To examine the effects of multiple scattering we have made comparisons between the small-angle model of Sigmund et al. and TRIM calculations. (authors)

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

    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

  4. Contribution to coherent atom optics - Design of multiple wave devices

    Impens, F.

    2008-03-01

    The theoretical work presented in this manuscript addresses two complementary issues in coherent atom optics. The first part addresses the perspectives offered by coherent atomic sources through the design of two experiment involving the levitation of a cold atomic sample in a periodic series of light pulses, and for which coherent atomic clouds are particularly well-suited. These systems appear as multiple wave atom interferometers. A striking feature of these experiments is that a unique system performs both the sample trapping and interrogation. To obtain a transverse confinement, a novel atomic lens is proposed, relying on the interaction between an atomic wave with a spherical light wave. The sensitivity of the sample trapping towards the gravitational acceleration and towards the pulse frequencies is exploited to perform the desired measurement. These devices constitute atomic wave resonators in momentum space, which is a novel concept in atom optics. A second part develops new theoretical tools - most of which inspired from optics - well-suited to describe the propagation of coherent atomic sources. A phase-space approach of the propagation, relying on the evolution of moments, is developed and applied to study the low-energy dynamics of Bose-Einstein condensates. The ABCD method of propagation for atomic waves is extended beyond the linear regime to account perturbatively for mean-field atomic interactions in the atom-optical aberration-less approximation. A treatment of the atom laser extraction enabling one to describe aberrations in the atomic beam, developed in collaboration with the Atom Optics group at the Institute of Optics, is exposed. Last, a quality factor suitable for the characterization of diluted matter waves in a general propagation regime has been proposed. (author)

  5. Multiple heavy metal removal using an entomopathogenic fungi Beauveria bassiana.

    Gola, Deepak; Dey, Priyadarshini; Bhattacharya, Arghya; Mishra, Abhishek; Malik, Anushree; Namburath, Maneesh; Ahammad, Shaikh Ziauddin

    2016-10-01

    Towards the development of a potential remediation technology for multiple heavy metals [Zn(II), Cu(II), Cd(II), Cr(VI) and Ni(II)] from contaminated water, present study examined the growth kinetics and heavy metal removal ability of Beauveria bassiana in individual and multi metals. The specific growth rate of B. bassiana varied from 0.025h(-1) to 0.039h(-1) in presence of individual/multi heavy metals. FTIR analysis indicated the involvement of different surface functional groups in biosorption of different metals, while cellular changes in fungus was reflected by various microscopic (SEM, AFM and TEM) analysis. TEM studies proved removal of heavy metals via sorption and accumulation processes, whereas AFM studies revealed increase in cell surface roughness in fungal cells exposed to heavy metals. Present study delivers first report on the mechanism of bioremediation of heavy metals when present individually as well as multi metal mixture by entomopathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    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

  7. Heavy ion and proton-induced single event multiple upset

    Reed, R.A.; Carts, M.A.; Marshall, P.W.

    1997-01-01

    Individual ionizing heavy ion events are shown to cause two or more adjacent memory cells to change logic states in a high density CMOS SRAM. A majority of the upsets produced by normally incident heavy ions are due to single-particle events that causes a single cell to upset. However, for grazing angles a majority of the upsets produced by heavy-ion irradiation are due to single-particle events that cause two or more cells to change logic states. Experimental evidence of a single proton-induced spallation reaction that causes two adjacent memory cells to change logic states is presented. Results from a dual volume Monte-Carlo simulation code for proton-induced single-event multiple upsets are within a factor of three of experimental data for protons at normal incidence and 70 degrees

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

    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.

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

    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

  10. Multiple-electron processes in fast ion-atom collisions

    Schlachter, A.S.

    1989-03-01

    Research in atomic physics at the Lawrence Berkeley Laboratory Super-HILAC and Bevalac accelerators on multiple-electron processes in fast ion-atom collisions is described. Experiments have studied various aspects of the charge-transfer, ionization, and excitation processes. Examples of processes in which electron correlation plays a role are resonant transfer and excitation and Auger-electron emission. Processes in which electron behavior can generally be described as uncorrelated include ionization and charge transfer in high-energy ion-atom collisions. A variety of experiments and results for energies from 1 MeV/u to 420 MeV/u are presented. 20 refs., 15 figs

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

    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

  12. Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders

    Ashwini Kumar

    2013-01-01

    Full Text Available The present paper reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for charged hadrons produced in such high energy collisions. Various features of available experimental data, for example, the variations of charged hadron multiplicity and pseudorapidity density with the mass number of colliding nuclei, center-of-mass energies, and the collision centrality obtained from heavy-ion collider experiments, are interpreted in the context of various theoretical concepts and their implications. Finally, several important scaling features observed in the measurements mainly at RHIC and LHC experiments are highlighted in the view of these models to draw some insight regarding the particle production mechanism in heavy-ion collisions.

  13. Investigation of heavy quark and multiple interactions at HERA

    Magro, L.M.

    2005-09-01

    This thesis is oriented to the study of heavy quark photoproduction and multiple interactions, MI. For this reason we search for D* Mesons, in order to tag the charm quark, and we restrict ourselves in the region: Q 2 2 . For the theoretical calculations we use two Monte Carlo event generators: RAPGAP 3.1 and PYTHIA 6.2. Heavy quark production provides a large hard scale and therefore a small α s , which allows to test the perturbative QCD theory. On the other hand, MI has been proven to be important in hadron-hadron collisions. In this thesis, using MC event generators, we search for possible signals of MI in heavy quark production in electron-proton, ep, collisions. The thesis begins with a Theoretical Overview, with an introduction to ep collisions physics and the heavy quark photoproduction. We also give an introduction to the MI model included in PYTHIA. The next chapter introduces the concept of jet and presents some methods for the Heavy Quark Identification. After these two theoretical chapters there is a study of the direct and photon resolved processes, as well as the parton showering with RAPGAP. Since this thesis is oriented to the study of MI, PYTHIA plays a very important role because it includes a MI model also for ep collisions. Therefore, the fourth chapter is oriented to study the different steps in the event generation in PYTHIA. Chapter 7 is a D* Meson photoproduction study, where we include a comparison between the data, taken from the PhD Thesis of Gero Flucke. Finally, chapter 8 is a search for possible signals on MI. In hadron-hadron collisions it is clear that MI play a role. In ep collisions it is not so clear although MI could play a role in resolved photon events. The aim of this chapter is to find signals where HERA measurements could be sensitive to MI. (orig.)

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

    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.

  15. Multiple primary cancer in cases of atomic bomb survivors

    Tanaka, Tsuneo; Matsuda, Masahiro; Matsugu, Yasuhiro; Ishimoto, Tatsuro; Nakahara, Hideki; Kagawa, Naoki; Fukuda, Yasuhiko

    2006-01-01

    Multiple primary cancer was investigated in individual atomic bomb survivors more than 50 years after exposure. During the decade from 1995 to 2004, double cancer was detected in 275 individuals visiting our facility. These 275 patients with multiple primary cancer were divided into an atomic bomb-exposed group and a non-exposed group. In terms of age at the time of definite diagnosis of double cancer and age upon onset of the first cancer, there was no significant difference between the atomic bomb-exposed group and the non-exposed group. In both groups, the percentage of males was higher than that of females. However, the percentage of females was higher in the exposed group than in the non-exposed group. Synchronous double cancer (cases where a second cancer develops within one year after onset of the first cancer) was seen in 32 individuals from the exposed group. Triple cancer was seen in 3 cases. In the exposed group, the site affected by cancer was the stomach in 28% and the colon/rectum in 27% of cases. Thus, cancer affected the stomach or colon/rectum in the majority of cases. The most frequent combination of organs affected by double cancer was the stomach+colon/rectum (20 cases, 25%). In a study of multiple primary cancer patients, the percentage of females was higher in the atomic bomb exposed group compared to the non-exposed group. There was no other difference between the two groups. (author)

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

    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.

  17. Single and multiple ionization of sulfur atoms by electron impact

    Ziegler, D.L.

    1982-01-01

    Laboratory measurements of the cross sections for single, double, triple, and quadruple ionization of sulfur atoms by electron impact are presented for collision energies from threshold to 500 eV. The cross sections for single ionization of sulfur are measured relative to those of several elements whose absolute cross sections for single ionization are known. Cross sections for each multiple ionization process are then measured relative to those for single ionization. The configuration and operation of the apparatus for these measurements are described. The possible effects of excited sulfur reactants are examined, and the reported cross sections are felt to be characteristic of ground state sulfur atoms

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

    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

  19. Study of multiple scattering effects in heavy ion RBS

    Fang, Z; O` Connor, D J [Newcastle Univ., NSW (Australia). Dept. of Physics

    1997-12-31

    Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

  20. Study of multiple scattering effects in heavy ion RBS

    Fang, Z.; O`Connor, D.J. [Newcastle Univ., NSW (Australia). Dept. of Physics

    1996-12-31

    Multiple scattering effect is normally neglected in conventional Rutherford Backscattering (RBS) analysis. The backscattered particle yield normally agrees well with the theory based on the single scattering model. However, when heavy incident ions are used such as in heavy ion Rutherford backscattering (HIRBS), or the incident ion energy is reduced, multiple scattering effect starts to play a role in the analysis. In this paper, the experimental data of 6MeV C ions backscattered from a Au target are presented. In measured time of flight spectrum a small step in front of the Au high energy edge is observed. The high energy edge of the step is about 3.4 ns ahead of the Au signal which corresponds to an energy {approx} 300 keV higher than the 135 degree single scattering energy. This value coincides with the double scattering energy of C ion undergoes two consecutive 67.5 degree scattering. Efforts made to investigate the origin of the high energy step observed lead to an Monte Carlo simulation aimed to reproduce the experimental spectrum on computer. As a large angle scattering event is a rare event, two consecutive large angle scattering is extremely hard to reproduce in a random simulation process. Thus, the simulation has not found a particle scattering into 130-140 deg with an energy higher than the single scattering energy. Obviously faster algorithms and a better physical model are necessary for a successful simulation. 16 refs., 3 figs.

  1. General engineering ethics and multiple stress of atomic energy engineering

    Takeda, Kunihiko

    1999-01-01

    The factors, by which the modern engineering ethics has been profoundly affected, were classified to three categories, namely mental blow, the destruction of human function and environment damage. The role of atomic energy engineering in the ethic field has been shown in the first place. It is pointed out that it has brought about the mental blow by the elucidation of universal truth and discipline and the functional disorder by the power supply. However, the direct effect of radiation to the human kinds is only a part of the stresses comparing to the accumulation of the social stress which should be taken into account of by the possibility of disaster and the suspicion of the atomic energy politics. An increase in the multiple stresses as well as the restriction of criticism will place obstacles on the promotion of atomic energy. (author)

  2. General engineering ethics and multiple stress of atomic energy engineering

    Takeda, Kunihiko [Shibaura Inst. of Tech., Tokyo (Japan)

    1999-08-01

    The factors, by which the modern engineering ethics has been profoundly affected, were classified to three categories, namely mental blow, the destruction of human function and environment damage. The role of atomic energy engineering in the ethic field has been shown in the first place. It is pointed out that it has brought about the mental blow by the elucidation of universal truth and discipline and the functional disorder by the power supply. However, the direct effect of radiation to the human kinds is only a part of the stresses comparing to the accumulation of the social stress which should be taken into account of by the possibility of disaster and the suspicion of the atomic energy politics. An increase in the multiple stresses as well as the restriction of criticism will place obstacles on the promotion of atomic energy. (author)

  3. Positron production in heavy ion-atom collisions

    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)

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

    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....

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

    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.

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

    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

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

    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.

  8. Heavy particle scattering by atomic and nuclear systems

    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)

  9. Reduction of multiple hits in atom probe tomography

    Thuvander, Mattias; Kvist, Anders; Johnson, Lars J.S.; Weidow, Jonathan; Andrén, Hans-Olof

    2013-01-01

    The accuracy of compositional measurements using atom probe tomography is often reduced because some ions are not recorded when several ions hit the detector in close proximity to each other and within a very short time span. In some cases, for example in analysis of carbides, the multiple hits result in a preferential loss of certain elements, namely those elements that frequently field evaporate in bursts or as dissociating molecules. In this paper a method of reducing the effect of multiple hits is explored. A fine metal grid was mounted a few millimeters behind the local electrode, effectively functioning as a filter. This resulted in a decrease in the overall detection efficiency, from 37% to about 5%, but also in a decrease in the fraction of multiple hits. In an analysis of tungsten carbide the fraction of ions originating from multiple hits decreased from 46% to 10%. As a result, the measured carbon concentration increased from 48.2 at%to 49.8 at%, very close to the expected 50.0 at%. The characteristics of the multiple hits were compared for analyses with and without the grid filter. - Highlights: ► APT experiments have been performed with a reduced amount of multiple hits. ► The multiple hits were reduced by placing a grid behind the electrode. ► This resulted in improved carbon measurement of WC

  10. Multiple electromagnetic pair production in ultrarelativistic heavy ion collisions

    Best, C.

    1992-04-01

    The problem of the unitary violation in the pair production in ultrarelativistic heavy ion collisions was studied by a consideration of the field-theoretical foundations. The quantum electrodynamics in an external field were thereby reduced to a Dirac-sea model, the equivalence of which to the non-radiative QED resulted from the equality of the generating functionals. The latter can both be expressed explicitely by means of the complet set of the solutions of the Dirac equation in an external field. This method is based solely on the path-integral approach, which makes it possible to discriminate clearly between the physically given correlation functions and their generating functional at the one hand and at the other hand between the models constructed to their interpretation. From the model expression for the pair production amplitudes and multiplicities could be calculated, for which only the knowledge of the one-particle S matrix is necessary. For the calculation of the multiplicities different forms of the perturbation theory were discussed. Finally an impact-parameter dependent Weizsaecker-Williams approximation for the calculation of arbitrary two-photon graphs was constructed and applied to the given problem. The results indicate that at small distances very high pair multiplicities are to be expected. Finally a new approach to the pair production in an external field was discussed, which is not based on the canonical field theory, but on the formalism of the Wigner functions. (orig./HSI) [de

  11. Multiple vacancy production by high energy heavy ions

    Becker, R.L.; Ford, A.L.; Reading, J.F.

    1984-01-01

    The theory of atomic collisions has two ingredients: collision theory and atomic structure theory. The collision theories differ with respect to (A) the collision dynamics and (B) the treatment of the relative motion of the projectile and target nuclei. With regard to the dynamics multiple vacancy production is of fundamental interest because it is a signature for and probe of strong interactions between the projectile and the target electrons. For projectiles of large nuclear charge, Z/sub p/, especially for those which are highly stripped so as to have a large ionic charge, q, the interaction becomes strong enough to give a high probability of multiple vacancy production and a breakdown of perturbation theory. The familiar first and second Born approximations and their off-shoots cease to be adequate. Not even the recent strong-potential Born approximation (see Taulbjerg 1984) is sufficient, because the weaker of the potentials generated by the projectile and the target nuclei, respectively, is treated in first order. One needs a unitary, non-perturbative collision theory. At present this is generally available for multiple vacancy production only in the form of the highly numerical coupled channels theory (Becker et al. 1983, 1984b). For special problems analytically tractable models have been devised. For example, a simple, unitary, geometrical encounter probability model for the calculation of p/sub L/(0), the inclusive L-shell vacancy probability per electron in collisions with impact parameter B = 0, has been introduced by Sulik et al. (1984) and further developed by Sulik and Hock (1984). Along with earlier coupled-channels calculations (Becker et al. 1984ab) and first Magnus calculations (Becker et al. 1984b), this model is able to describe the saturation of p/sub L/(0) with Z/sub p/ at fixed impact speed, v, whereas all the first-order theories predict p/sub L/ proportional to Z/sub p/ 2 , which eventually exceeds unity

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

    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

  13. Investigations of Atomic Transport Induced by Heavy Ion Irradiation

    Banwell, Thomas Clyde

    The mechanisms of atomic transport induced by ion irradiation generally fall into the categories of anisotropic or isotropic processes. Typical examples of these are recoil implantation and cascade mixing, respectively. We have measured the interaction of these processes in the mixing of Ti/SiO(,2)/Si, Cr/SiO(,2)/Si and Ni/SiO(,2)/Si multi-layers irradiated with Xe at fluences of 0.01 - 10 x 10('15)cm('-2). The fluence dependence of net metal transport into the underlying layers was measured with different thicknesses of SiO(,2) and different sample temperatures during irradiation (-196 to 500C). There is a linear dependence at low fluences. At high fluences, a square-root behavior predominates. For thin SiO(,2) layers (primary recoils is quite pronounced since the gross mixing is small. A significant correlation exists between the mixing and the energy deposited through elastic collisions F(,D ). Several models are examined in an attempt to describe the transport process in Ni/SiO(,2). It is likely that injection of Ni by secondary recoil implantation is primarily responsible for getting Ni into the SiO(,2). Secondary recoil injection is thought to scale with F(,D). Trends in the mixing rates indicate that the dominant mechanism for Ti and Cr could be the same as for Ni. The processes of atomic transport and phase formation clearly fail to be separable at higher temperatures. A positive correlation with chemical reactivity emerges at higher irradiation temperatures. The temperature at which rapid mixing occurs is not much below that for spontaneous thermal reaction. Less Ni is retained in the SiO(,2) at high irradiation temperatures. Ni incorporated in the SiO(,2) by low temperature irradiation is not expelled during a consecutive high temperature irradiation. The Ni remains trapped within larger clusters during a sequential 500C irradiation. (Abstract shortened with permission of author.).

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

    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.

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

    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)

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

    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

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

    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.)

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

    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

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

    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

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

    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

  1. Multiple microflame quartz tube atomizer: Study and minimization of interferences in quartz tube atomizers in hydride generation atomic absorption spectrometry

    Moraes Flores, Erico Marlon de [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil)], E-mail: flores@quimica.ufsm.br; Medeiros Nunes, Adriane; Luiz Dressler, Valderi [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Dedina, Jiri [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, CZ-142 20 Prague (Czech Republic)

    2009-02-15

    A systematic study was performed to evaluate the performance of a multiple microflame (MM) quartz tube atomizer (QTA) for minimizing interferences and to improve the extent of the calibration range using a batch system for hydride generation atomic absorption spectrometry (HG AAS). A comparison of the results with conventional QTA on the determination of antimony, arsenic, bismuth and selenium was performed. The interference of As, Bi, Se, Pb, Sn and Sb was investigated using QTA and MMQTA atomizers. Better performance was found for MMQTA, and no loss of linearity was observed up to 160 ng for Se and Sb and 80 ng for As, corresponding to an enhancement of two times for both analytes when compared to QTA (analyte mass refers to a volume of 200 {mu}l). For Bi, the linear range was the same for QTA and MMQTA (140 ng). With the exception of Bi, the tolerance limits for hydride-forming elements were improved more than 50% in comparison to the conventional QTA system, especially for the interferences of As, Sb and Se. However, for Sn as an interferent, no difference was observed in the determination of Se and Sb using the MMQTA system. The use of MMQTA-HG AAS complied with the relatively high sensitivity of conventional QTA and also provided better performance for interferences and the linear range of calibration.

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

    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.

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

    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

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

    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)

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

    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

  6. REFLOS, Fuel Loading and Cost from Burnup and Heavy Atomic Mass Flow Calculation in HWR

    Boettcher, W.; Schmidt, E.

    1969-01-01

    1 - Nature of physical problem solved: REFLOS is a programme for the evaluation of fuel-loading schemes in heavy water moderated reactors. The problems involved in this study are: a) Burn-up calculation for the reactor cell. b) Determination of reactivity behaviour, power distribution, attainable burn-up for both the running-in period and the equilibrium of a 3-dimensional heterogeneous reactor model; investigation of radial fuel movement schemes. c) Evaluation of mass flows of heavy atoms through the reactor and fuel cycle costs for the running-in, the equilibrium, and the shut down of a power reactor. If the subroutine for treating the reactor cell were replaced by a suitable routine, other reactors with weakly absorbing moderators could be analyzed. 2 - Method of solution: Nuclear constants and isotopic compositions of the different fuels in the reactor are calculated by the cell-burn-up programme and tabulated as functions of the burn-up rate (MWD/T). Starting from a known state of the reactor, the 3-dimensional heterogeneous reactor programme (applying an extension of the technique of Feinberg and Galanin) calculates reactivity and neutron flux distribution using one thermal and one or two fast neutron groups. After a given irradiation time, the new state of the reactor is determined, and new nuclear constants are assigned to the various defined locations in the reactor. Reloading of fuel may occur if the prescribed life of the reactor is reached or if the effective multiplication factor or the power form factor falls below a specified level. The scheme of reloading to be carried out is specified by a load vector, giving the number of channels to be discharged, the kind of movement from one to another channel and the type of fresh fuel to be charged for each single reloading event. After having determined the core states characterizing the equilibrium period, and having decided the fuel reloading scheme for the running-in period of the reactor life, the fuel

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

    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...

  8. A novel method for the sequential removal and separation of multiple heavy metals from wastewater.

    Fang, Li; Li, Liang; Qu, Zan; Xu, Haomiao; Xu, Jianfang; Yan, Naiqiang

    2018-01-15

    A novel method was developed and applied for the treatment of simulated wastewater containing multiple heavy metals. A sorbent of ZnS nanocrystals (NCs) was synthesized and showed extraordinary performance for the removal of Hg 2+ , Cu 2+ , Pb 2+ and Cd 2+ . The removal efficiencies of Hg 2+ , Cu 2+ , Pb 2+ and Cd 2+ were 99.9%, 99.9%, 90.8% and 66.3%, respectively. Meanwhile, it was determined that solubility product (K sp ) of heavy metal sulfides was closely related to adsorption selectivity of various heavy metals on the sorbent. The removal efficiency of Hg 2+ was higher than that of Cd 2+ , while the K sp of HgS was lower than that of CdS. It indicated that preferential adsorption of heavy metals occurred when the K sp of the heavy metal sulfide was lower. In addition, the differences in the K sp of heavy metal sulfides allowed for the exchange of heavy metals, indicating the potential application for the sequential removal and separation of heavy metals from wastewater. According to the cumulative adsorption experimental results, multiple heavy metals were sequentially adsorbed and separated from the simulated wastewater in the order of the K sp of their sulfides. This method holds the promise of sequentially removing and separating multiple heavy metals from wastewater. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    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...

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

    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

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

    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.

  12. Stability of gas atomized reactive powders through multiple step in-situ passivation

    Anderson, Iver E.; Steinmetz, Andrew D.; Byrd, David J.

    2017-05-16

    A method for gas atomization of oxygen-reactive reactive metals and alloys wherein the atomized particles are exposed as they solidify and cool in a very short time to multiple gaseous reactive agents for the in-situ formation of a protective reaction film on the atomized particles. The present invention is especially useful for making highly pyrophoric reactive metal or alloy atomized powders, such as atomized magnesium and magnesium alloy powders. The gaseous reactive species (agents) are introduced into the atomization spray chamber at locations downstream of a gas atomizing nozzle as determined by the desired powder or particle temperature for the reactions and the desired thickness of the reaction film.

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

    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

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

    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)

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

    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.

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

    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

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

    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.)

  18. Collision assisted Zeeman cooling with multiple types of atoms

    Hamilton, Mathew S.; Wilson, Rebekah F.; Roberts, Jacob L.

    2014-01-01

    Through a combination of spin-exchange collisions in a magnetic field and optical pumping, it is possible to cool a gas of atoms without requiring the loss of atoms from the gas. This technique, collision assisted Zeeman cooling (CAZ), was developed theoretically assuming a single atomic species [G. Ferrari, Eur. Phys. J. D 13, 67 (2001)]. We have extended this cooling technique to a system of two atomic species rather than just one and have developed a simple analytic model describing the cooling rate. We find that the two-isotope CAZ cooling scheme has a clear theoretical advantage in systems that are reabsorption limited.

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

    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

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

    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.)

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

    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.

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

    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.

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

    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)

  4. Parallel Low-Loss Measurement of Multiple Atomic Qubits.

    Kwon, Minho; Ebert, Matthew F; Walker, Thad G; Saffman, M

    2017-11-03

    We demonstrate low-loss measurement of the hyperfine ground state of rubidium atoms by state dependent fluorescence detection in a dipole trap array of five sites. The presence of atoms and their internal states are minimally altered by utilizing circularly polarized probe light and a strictly controlled quantization axis. We achieve mean state detection fidelity of 97% without correcting for imperfect state preparation or background losses, and 98.7% when corrected. After state detection and correction for background losses, the probability of atom loss due to the state measurement is state is preserved with >98% probability.

  5. Teaching and Learning Multiple Perspectives: The Atomic Bomb.

    Doppen, Frans H.

    2000-01-01

    Explores how historical empathy can give students a richer understanding of the past, focusing on the development of the students' historical understanding through an analysis of 18 documents on President Truman's decision to use the atomic bomb against Japan. (CMK)

  6. Exclusive description of multiple production on nuclei in the additive quark model. Multiplicity distributions in interactions with heavy nuclei

    Levchenko, B.B.; Nikolaev, N.N.

    1985-01-01

    In the framework of the additive quark model of multiple production on nuclei we calculate the multiplicity distributions of secondary particles and the correlations between secondary particles in πA and pA interactions with heavy nuclei. We show that intranuclear cascades are responsible for up to 50% of the nuclear increase of the multiplicity of fast particles. We analyze the sensitivity of the multiplicities and their correlations to the choice of the quark-hadronization function. We show that with good accuracy the yield of relativistic secondary particles from heavy and intermediate nuclei depends only on the number N/sub p/ of protons knocked out of the nucleus, and not on the mass number of the nucleus (N/sub p/ scaling)

  7. High rate multiplicity detector for relativistic heavy-ion collisions

    Beavis, D.; Bennett, M.J.; Carroll, J.B.; Chiba, J.; Chikanian, A.; Crawford, H.J.; Cronqvist, M.; Dardenne, Y.; Debbe, R.; Doke, T.; Engelage, J.; Flores, I.; Greiner, L.; Hayano, R.S.; Hallman, T.J.; Heckman, H.H.; Kashiwagi, T.; Kikuchi, J.; Kumar, B.S.; Kuo, C.; Lindstrom, P.J.; Mitchell, J.W.; Nagamiya, S.; Nagle, J.L.; Pope, J.K.; Stankus, P.; Tanaka, K.H.; Welsh, R.C.; Zhan, W.

    1995-01-01

    We have constructed and operated a detector to measure the multiplicity of secondary particles produced in nucleus-nucleus collisions in the E878 experiment at the Brookhaven National Laboratory AGS facility. We describe the operation and performance of the detector in a high rate Au beam environment, and interpret the multiplicity data in terms of the impact parameters of the nucleus-nucleus collisions. ((orig.))

  8. High rate multiplicity detector for relativistic heavy-ion collisions

    Beavis, D [Brookhaven National Lab., Upton, NY (United States); Bennett, M J [Yale University, A.W. Wright Nuclear Structure Laboratory, New Haven, CT 06511 (United States); Carroll, J B [University of California at Los Angeles, Los Angeles, CA (United States); Chiba, J [KEK National High Energy Physics, Tsukuba (Japan); Chikanian, A [Yale University, A.W. Wright Nuclear Structure Laboratory, New Haven, CT 06511 (United States); Crawford, H J [University of California Space Sciences Laboratory, Berkeley, CA (United States); Cronqvist, M [University of California Space Sciences Laboratory, Berkeley, CA (United States); Dardenne, Y [University of California Space Sciences Laboratory, Berkeley, CA (United States); Debbe, R [Brookhaven National Lab., Upton, NY (United States); Doke, T [Waseda University, Science and Engineering Research Institute, Waseda (Japan); Engelage, J [University of California Space Sciences Laboratory, Berkeley, CA (United States); Flores, I [University of California Space Sciences Laboratory, Berkeley, CA (United States); Greiner, L [University of California Space Sciences Laboratory, Berkeley, CA (United States); Hayano, R S [University of Tokyo, Tokyo (Japan); Hallman, T J [University of California at Los Angeles, Los Angeles, CA (United States); Heckman, H H [Lawrence Berkeley Lab., CA (United States); Kashiwagi, T [Waseda University, Science and Engineering Research Institute, Waseda (Japan); Kikuchi, J [Waseda University, Science and Engineering Research Institute, Waseda (Japan); Kumar, B S [Yale University, A.W. Wright Nuclear Structure Laboratory, New Haven, CT 06511 (United States); Kuo, C [University of California Space Sciences Laboratory, Berkeley, CA (United States); Lindstrom, P J [Lawrence Berkeley Lab., CA (United States); Mitchell, J W [Universities Space Research Association/Goddard Space Flight Center, Greenbelt, MD (United States); Nagamiya, S; E878 Collaboration

    1995-04-21

    We have constructed and operated a detector to measure the multiplicity of secondary particles produced in nucleus-nucleus collisions in the E878 experiment at the Brookhaven National Laboratory AGS facility. We describe the operation and performance of the detector in a high rate Au beam environment, and interpret the multiplicity data in terms of the impact parameters of the nucleus-nucleus collisions. ((orig.)).

  9. Multiple parton scattering in nuclei: heavy quark energy loss and modified fragmentation functions

    Zhang Benwei; Wang, Enke; Wang Xinnian

    2005-01-01

    Multiple scattering, induced radiative energy loss and modified fragmentation functions of a heavy quark in nuclear matter are studied within the framework of generalized factorization in perturbative QCD. Modified heavy quark fragmentation functions and energy loss are derived in detail with illustration of the mass dependencies of the Landau-Pomeranchuk-Migdal interference effects and heavy quark energy loss. Due to the quark mass dependence of the gluon formation time, the nuclear size dependencies of nuclear modification of the heavy quark fragmentation function and heavy quark energy loss are found to change from a linear to a quadratic form when the initial energy and momentum scale are increased relative to the quark mass. The radiative energy loss of the heavy quark is also significantly suppressed due to limited cone of gluon radiation imposed by the mass. Medium modification of the heavy quark fragmentation functions is found to be limited to the large z region due to the form of heavy quark fragmentation functions in vacuum

  10. Scaling in multiplicity distributions of heavy, black and grey prongs in nuclear emulsions

    Nieminen, M.; Torsti, J.J.; Valtonen, E.

    1979-01-01

    The validity of Koba-Nielsen-Olesen scaling hypothesis was examined in the case of heavy, black, and grey prongs in proton-emulsion collisions ('heavy' means 'either black or grey'). The average multiplicities of these prongs were computed in the region 0.1-400 GeV for the nuclei C, N, O, S, Br, Ag, and I. After the inclusion of the energy-dependent excitation probability of the nuclei of the form P* = b 0 + b 1 ln E 0 into the model, experimental multiplicity distributions in the energy region 6-300 GeV agreed satisfactorily with the scaling hypothesis. The ratio of the dispersion D (D = √ 2 >- 2 ) to the average multiplicity in the scaling functions of heavy, balck, and grey prongs was estimated to be 0.86, 0.84, and 1.04, respectively, in the high energy region. (Auth.)

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

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

    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)

  13. Multiple atomic scale solid surface interconnects for atom circuits and molecule logic gates

    Joachim, C; Martrou, D; Gauthier, S; Rezeq, M; Troadec, C; Jie Deng; Chandrasekhar, N

    2010-01-01

    The scientific and technical challenges involved in building the planar electrical connection of an atomic scale circuit to N electrodes (N > 2) are discussed. The practical, laboratory scale approach explored today to assemble a multi-access atomic scale precision interconnection machine is presented. Depending on the surface electronic properties of the targeted substrates, two types of machines are considered: on moderate surface band gap materials, scanning tunneling microscopy can be combined with scanning electron microscopy to provide an efficient navigation system, while on wide surface band gap materials, atomic force microscopy can be used in conjunction with optical microscopy. The size of the planar part of the circuit should be minimized on moderate band gap surfaces to avoid current leakage, while this requirement does not apply to wide band gap surfaces. These constraints impose different methods of connection, which are thoroughly discussed, in particular regarding the recent progress in single atom and molecule manipulations on a surface.

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

    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.

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

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

    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

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

    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.

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

    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. Multiple pole in the electron--hydrogen-atom scattering amplitude

    Amusia, M.Y.; Kuchiev, M.Y.

    1982-01-01

    It is demonstrated that the amplitude for electron--hydrogen-atom forward scattering has the third-order pole at the point E = -13.6 eV, E being the energy of the incident electron. The coefficients which characterize the pole are calculated exactly. The invalidity of the Born approximation is proved. The contribution of the pole singularity to the dispersion relation for the scattering amplitude is discussed

  20. Pressure atomizer having multiple orifices and turbulent generation feature

    VanBrocklin, Paul G.; Geiger, Gail E.; Moran, Donald James; Fournier, Stephane

    2002-01-01

    A pressure atomizer includes a silicon plate having a top surface and a bottom surface. A portion of the top surface defines a turbulent chamber. The turbulent chamber is peripherally bounded by the top surface of the plate. The turbulent chamber is recessed a predetermined depth relative to the top surface. The silicon plate further defines at least one flow orifice. Each flow orifice extends from the bottom surface of the silicon plate to intersect with and open into the turbulent chamber. Each flow orifice is in fluid communication with the turbulent chamber.

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

    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...

  2. Multiple electron capture in close ion-atom collisions

    Schlachter, A.S.; Stearns, J.W.; Berkner, K.H.

    1989-01-01

    Collisions in which a fast highly charged ion passes within the orbit of K electron of a target gas atom are selected by emission of a K x-ray from the projectile or target. Measurement of the projectile charge state after the collision, in coincidence with the K x-ray, allows measurement of the charge-transfer probability during these close collisions. When the projectile velocity is approximately the same as that of target electrons, a large number of electrons can be transferred to the projectile in a single collision. The electron-capture probability is found to be a linear function of the number of vacancies in the projectile L shell for 47-MeV calcium ions in an Ar target. 18 refs., 9 figs

  3. Pathological study of multiple myeloma in atomic bomb survivors

    Takaki, Y.; Kishikawa, M.; Bundo, K. (Nagasaki Univ. (Japan). School of Medicine)

    1980-11-01

    Pathological records of autopsies carried out in Nagasaki from '46 to '77 were reviewed. Of 9331 autopsies, 5787 were unexposed cases and were used as a control. 9.2% of the deaths were due to hematologic disorders. There was no evidence that the incidence of multiple myeloma among a-bomb survivors increased compared with the control. The incidences of leukemia, lymphoma and aplastic anemia were also listed.

  4. Multiple electron capture in close ion-atom collisions

    Schlachter, A.S.

    1987-10-01

    Multiple electron capture is reported for Ca 17+ in Ar. Close collisions are defined by the observation of a coincident Ca K or Ar K x-ray. A large number of electrons is transferred to the projectile in a single close collision when the Ca ion projectile is of the order of the Ar L-shell electron velocity. The cross section for electron capture is reported

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

    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. Multiple Coulomb excitation effects in heavy ion compound and fusion cross sections

    Carlson, B.V.; Hussein, M.S.

    1981-11-01

    A simple model for the average S-matrix that describes heavy ion direct processes in the presence of absorption due to compound nucleus formation is developed. The fluctuation cross section and the fusion cross section are then calculated for deformed heavy ion systems where multiple Coulomb excitation is important. A simple expression for the fusion cross section valid for above-barrier energies is then obtained. The formula clearly displays the modification, due to Coulomb excitation, in the usual geometrical expression. (Author) [pt

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

    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.))

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

    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

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

    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.

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

    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

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

    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.

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

    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

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

    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.

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

    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.)

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

    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)

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

    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

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

    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

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

    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

  19. Higgsplosion: Solving the hierarchy problem via rapid decays of heavy states into multiple Higgs bosons

    Khoze, Valentin V.; Spannowsky, Michael

    2018-01-01

    We introduce and discuss two inter-related mechanisms operative in the electroweak sector of the Standard Model at high energies. Higgsplosion, the first mechanism, occurs at some critical energy in the 25 to 103 TeV range, and leads to an exponentially growing decay rate of highly energetic particles into multiple Higgs bosons. We argue that this is a well-controlled non-perturbative phenomenon in the Higgs-sector which involves the final state Higgs multiplicities n in the regime nλ ≫ 1 where λ is the Higgs self-coupling. If this mechanism is realised in nature, the cross-sections for producing ultra-high multiplicities of Higgs bosons are likely to become observable and even dominant in this energy range. At the same time, however, the apparent exponential growth of these cross-sections at even higher energies will be tamed and automatically cut-off by a related Higgspersion mechanism. As a result, and in contrast to previous studies, multi-Higgs production does not violate perturbative unitarity. Building on this approach, we then argue that the effects of Higgsplosion alter quantum corrections from very heavy states to the Higgs boson mass. Above a certain energy, which is much smaller than their masses, these states would rapidly decay into multiple Higgs bosons. The heavy states become unrealised as they decay much faster than they are formed. The loop integrals contributing to the Higgs mass will be cut off not by the masses of the heavy states, but by the characteristic loop momenta where their decay widths become comparable to their masses. Hence, the cut-off scale would be many orders of magnitude lower than the heavy mass scales themselves, thus suppressing their quantum corrections to the Higgs boson mass.

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

    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.)

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

    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)

  2. Pion multiplicity as a probe of the deconfinement transition in heavy-ion collisions

    Gorenstejn, M.I.; Shin Nan Yang; Che Ming Ko.

    1991-01-01

    The hydrochemical model is used to calculate the pion multiplicity in relativistic heavy-ion collisions. Chemical reactions are explicitly taken into account in the expansion stage of the hadronic phase. It leads to the absence of chemical equilibrium among hadronic particles and a nonzero value of the pion chemical potential at thermal freeze out. We find a specific structure in the incident energy dependence of the pion multiplicity as a result of the formation of the quark-hadron mixed phase in the initial stage of the collision. 13 refs.; 3 figs

  3. DEP-On-Go for Simultaneous Sensing of Multiple Heavy Metals Pollutants in Environmental Samples

    Madhu Biyani

    2016-12-01

    Full Text Available We describe a simple and affordable “Disposable electrode printed (DEP-On-Go” sensing platform for the rapid on-site monitoring of trace heavy metal pollutants in environmental samples for early warning by developing a mobile electrochemical device composed of palm-sized potentiostat and disposable unmodified screen-printed electrode chips. We present the analytical performance of our device for the sensitive detection of major heavy metal ions, namely, mercury, cadmium, lead, arsenic, zinc, and copper with detection limits of 1.5, 2.6, 4.0, 5.0, 14.4, and, 15.5 μg·L−1, respectively. Importantly, the utility of this device is extended to detect multiple heavy metals simultaneously with well-defined voltammograms and similar sensitivity. Finally, “DEP-On-Go” was successfully applied to detect heavy metals in real environmental samples from groundwater, tap water, house dust, soil, and industry-processed rice and noodle foods. We evaluated the efficiency of this system with a linear correlation through inductively coupled plasma mass spectrometry, and the results suggested that this system can be reliable for on-site screening purposes. On-field applications using real samples of groundwater for drinking in the northern parts of India support the easy-to-detect, low-cost (<1 USD, rapid (within 5 min, and reliable detection limit (ppb levels performance of our device for the on-site detection and monitoring of multiple heavy metals in resource-limited settings.

  4. Multiple quantum phase transitions and superconductivity in Ce-based heavy fermions.

    Weng, Z F; Smidman, M; Jiao, L; Lu, Xin; Yuan, H Q

    2016-09-01

    Heavy fermions have served as prototype examples of strongly-correlated electron systems. The occurrence of unconventional superconductivity in close proximity to the electronic instabilities associated with various degrees of freedom points to an intricate relationship between superconductivity and other electronic states, which is unique but also shares some common features with high temperature superconductivity. The magnetic order in heavy fermion compounds can be continuously suppressed by tuning external parameters to a quantum critical point, and the role of quantum criticality in determining the properties of heavy fermion systems is an important unresolved issue. Here we review the recent progress of studies on Ce based heavy fermion superconductors, with an emphasis on the superconductivity emerging on the edge of magnetic and charge instabilities as well as the quantum phase transitions which occur by tuning different parameters, such as pressure, magnetic field and doping. We discuss systems where multiple quantum critical points occur and whether they can be classified in a unified manner, in particular in terms of the evolution of the Fermi surface topology.

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

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

    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

  7. Event-by-event gluon multiplicity, energy density, and eccentricities in ultrarelativistic heavy-ion collisions

    Schenke, Björn; Tribedy, Prithwish; Venugopalan, Raju

    2012-09-01

    The event-by-event multiplicity distribution, the energy densities and energy density weighted eccentricity moments ɛn (up to n=6) at early times in heavy-ion collisions at both the BNL Relativistic Heavy Ion Collider (RHIC) (s=200GeV) and the CERN Large Hardron Collider (LHC) (s=2.76TeV) are computed in the IP-Glasma model. This framework combines the impact parameter dependent saturation model (IP-Sat) for nucleon parton distributions (constrained by HERA deeply inelastic scattering data) with an event-by-event classical Yang-Mills description of early-time gluon fields in heavy-ion collisions. The model produces multiplicity distributions that are convolutions of negative binomial distributions without further assumptions or parameters. In the limit of large dense systems, the n-particle gluon distribution predicted by the Glasma-flux tube model is demonstrated to be nonperturbatively robust. In the general case, the effect of additional geometrical fluctuations is quantified. The eccentricity moments are compared to the MC-KLN model; a noteworthy feature is that fluctuation dominated odd moments are consistently larger than in the MC-KLN model.

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

    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...

  9. Performance of MBE-4: An experimental multiple beam induction linear accelerator for heavy ions

    Warwick, A.I.; Fessenden, T.J.; Keefe, D.; Kim, C.H.; Meuth, H.

    1988-06-01

    An experimental induction linac, called MBE-4, has been constructed to demonstrate acceleration and current amplification of multiple heavy ion beams. This work is part of a program to study the use of such an accelerator as a driver for heavy ion inertial fusion. MBE-4 is 16m long and accelerates four space-charge-dominated beams of singly-charged cesium ions, in this case from 200 keV to 700 keV, amplifying the current in each beam from 10mA by a factor of nine. Construction of the experiment was completed late in 1987 and we present the results of detailed measurements of the longitudinal beam dynamics. Of particular interest is the contribution of acceleration errors to the growth of current fluctuations and to the longitudinal emittance. The effectiveness of the longitudinal focusing, accomplished by means of the controlled time dependence of the accelerating fields, is also discussed. 4 refs., 5 figs., 1 tab

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

    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...

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

    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

  12. Atoms

    Fuchs, Alain; Villani, Cedric; Guthleben, Denis; Leduc, Michele; Brenner, Anastasios; Pouthas, Joel; Perrin, Jean

    2014-01-01

    Completed by recent contributions on various topics (atoms and the Brownian motion, the career of Jean Perrin, the evolution of atomic physics since Jean Perrin, relationship between scientific atomism and philosophical atomism), this book is a reprint of a book published at the beginning of the twentieth century in which the author addressed the relationship between atomic theory and chemistry (molecules, atoms, the Avogadro hypothesis, molecule structures, solutes, upper limits of molecular quantities), molecular agitation (molecule velocity, molecule rotation or vibration, molecular free range), the Brownian motion and emulsions (history and general features, statistical equilibrium of emulsions), the laws of the Brownian motion (Einstein's theory, experimental control), fluctuations (the theory of Smoluchowski), light and quanta (black body, extension of quantum theory), the electricity atom, the atom genesis and destruction (transmutations, atom counting)

  13. Semiclassical model of atomic collisions: stopping and capture of the heavy charged particles and exotic atom formation

    Beck, W.A.

    2000-01-01

    The semiclassical model of atomic collisions, especially in different areas of the maximum stopping, when proton collides at the velocity of the boron order velocity, providing as the result for interactions of many bodies with an electron target, enabling application of the model with high degree of confidence to a clearly expressed experimental problem, such the antiproton capture on helium, is presented. The semiclassical collision model and stopping energy are considered. The stopping and capture of negatively-charged particles are investigated. The capture and angular moments of antiprotons, captures at the end of the collision cascade, are presented [ru

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

    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)

  15. Charged Particle, Photon Multiplicity, and Transverse Energy Production in High-Energy Heavy-Ion Collisions

    Raghunath Sahoo

    2015-01-01

    Full Text Available We review the charged particle and photon multiplicities and transverse energy production in heavy-ion collisions starting from few GeV to TeV energies. The experimental results of pseudorapidity distribution of charged particles and photons at different collision energies and centralities are discussed. We also discuss the hypothesis of limiting fragmentation and expansion dynamics using the Landau hydrodynamics and the underlying physics. Meanwhile, we present the estimation of initial energy density multiplied with formation time as a function of different collision energies and centralities. In the end, the transverse energy per charged particle in connection with the chemical freeze-out criteria is discussed. We invoke various models and phenomenological arguments to interpret and characterize the fireball created in heavy-ion collisions. This review overall provides a scope to understand the heavy-ion collision data and a possible formation of a deconfined phase of partons via the global observables like charged particles, photons, and the transverse energy measurement.

  16. Transitions from order to disorder in multiple dark and multiple dark-bright soliton atomic clouds

    Wang, Wenlong; Kevrekidis, P. G.

    2015-01-01

    We have performed a systematic study quantifying the variation of solitary wave behavior from that of an ordered cloud resembling a 'crystalline' configuration to that of a disordered state that can be characterized as a soliton 'gas'. As our illustrative examples, we use both one-component, as well as two-component, one-dimensional atomic gases very close to zero temperature, where in the presence of repulsive interatomic interactions and of a parabolic trap, a cloud of dark (dark-bright) solitons can form in the one- (two-) component system. We corroborate our findings through three distinct types of approaches, namely a Gross-Pitaevskii type of partial differential equation, particle-based ordinary differential equations describing the soliton dynamical system, and Monte Carlo simulations for the particle system. In addition, we define an 'empirical' order parameter to characterize the order of the soliton lattices and study how this changes as a function of the strength of the 'thermally' (i.e., kinetically) induced perturbations. As may be anticipated by the one-dimensional nature of our system, the transition from order to disorder is gradual without, apparently, a genuine phase transition ensuing in the intermediate regime

  17. Multiple Coulomb scattering of high-energy heavy charged particle beams used in biology and medicine

    Wong, M.; Schimmerling, W.; Ludewigt, B.; Phillips, M.; Curtis, S.; Tobias, C.A.

    1987-01-01

    The authors measured lateral displacement and angular distributions of high-energy heavy charged particles emerging from a target at the Lawrence Berkeley Laboratory BEVALAC with beams used in radiobiology experiments. Multiple Coulomb scattering occurring in the target material generally spreads the beam laterally and increases its divergence. The apparatus consists of four sets of position-sensitive semiconductor detectors located along the beam line. Each providing two position signals and one energy signal. The difference between the two position signals is used to determine the particle position in one dimension. The two position signals are constrained to add up to the energy deposition signal in order to reject multiple-particle traversals. The vector directions for the incident and emerging particles are reconstructed in three dimensions from their measured coordinated positions. Lateral and angular distributions are reported for beams of high-energy neon, iron and uranium ions incident on targets of aluminum, cooper, lead and water

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

    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)

  19. Inter- and intra-specific competition of duckweed under multiple heavy metal contaminated water.

    Zhao, Zhao; Shi, Huijuan; Kang, Xianjiang; Liu, Cunqi; Chen, Lingci; Liang, Xiaofei; Jin, Lei

    2017-11-01

    The influences of intra- and inter-species competition on ecosystems are poorly understood. Lemna aequinoctialis and Spirodela polyrhiza were used to assess the effects of exposure to different concentrations of multiple heavy metals (copper-cadmium-zinc), when the plants were grown in mixed- or mono-culture. Parameters assessed included relative growth rate (RGR), content of chlorophyll, glutathione (GSH), malondialdehyde (MDA), as well as the activity of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD). Inter-specific competition was affected by metal concentration, with results indicating that inter-specific competition significantly affected duckweed growth and metal uptake in different heavy metal exposure conditions. Inter-specific competition increased growth rate of duckweed under high metal concentrations, although when compared with intra-specific competition, it caused no obvious differences under low metal concentrations. The growth of L. aequinoctialis was further increased in mixed culture when exposed to high metal concentrations, with inter-specific competition increasing the content of cadmium and zinc, while decreasing copper content of L. aequinoctialis compared with under intra-specific conditions. Conversely, inter-specific competition increased the content of copper and cadmium of S. polyrhiza, without causing obvious differences in zinc accumulation under high ambient concentrations. Under high metal conditions, inter-specific competition increased antioxidant enzyme activities in duckweed species, increasing resistance to heavy metals. Results show that inter-specific competition makes duckweed develop mechanisms to increase fitness and survival, such as enhancement of antioxidant enzyme activities, rather than limiting metal uptake when exposed to high concentrations of multiple metals. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    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

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

    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.

  2. Multi-dimensional microanalysis of masklessly implanted atoms using focused heavy ion beam

    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)

  3. Physics and Its Multiple Roles in the International Atomic Energy Agency

    Massey, Charles D.

    2017-01-01

    The IAEA is the world's centre for cooperation in the nuclear field. It was set up as the world's ``Atoms for Peace'' organization in 1957 within the United Nations family. The Agency works with its Member States and multiple partners worldwide to promote the safe, secure and peaceful use of nuclear technologies. Three main areas of work underpin the IAEA's mission: Safety and Security, Science and Technology, and Safeguards and Verification. To carry out its mission, the Agency is authorized to encourage and assist research on, and development and practical application of, atomic energy for peaceful uses throughout the world; foster the exchange of scientific and technical information on peaceful uses of atomic energy; and encourage the exchange of training of scientists and experts in the field of peaceful uses of atomic energy. Nowadays, nuclear physics and nuclear technology are applied in a great variety of social areas, such as power production, medical diagnosis and therapies, environmental protection, security control, material tests, food processing, waste treatments, agriculture and artifacts analysis. This presentation will cover the role and practical application of physics at the IAEA, and, in particular, focus on the role physics has, and will play, in nuclear security.

  4. Spontaneous emission spectra and simulating multiple spontaneous generation coherence in a five-level atomic medium

    Li Jiahua; Liu Jibing; Qi Chunchao; Chen Aixi

    2006-01-01

    We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to SGC reported by Fountoulakis et al. [Phys. Rev. A 73, 033811 (2006)], since no rigorous conditions are required

  5. Atom

    Auffray, J.P.

    1997-01-01

    The atom through centuries, has been imagined, described, explored, then accelerated, combined...But what happens truly inside the atom? And what are mechanisms who allow its stability? Physicist and historian of sciences, Jean-Paul Auffray explains that these questions are to the heart of the modern physics and it brings them a new lighting. (N.C.)

  6. Bioleaching of multiple heavy metals from contaminated sediment by mesophile consortium.

    Gan, Min; Zhou, Shuang; Li, Mingming; Zhu, Jianyu; Liu, Xinxing; Chai, Liyuan

    2015-04-01

    A defined mesophile consortium including Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirilum ferriphilum was applied in bioleaching sediments contaminated with multiple heavy metals. Flask experiments showed that sulfur favored the acidification in the early stage while pyrite led to a great acidification potential in the later stage. An equal sulfur/pyrite ratio got the best acidification effect. Substrate utilization started with sulfur in the early stage, and then the pH decline and the community shift give rise to the utilization of pyrite. Solubilization efficiency of Zn, Cu, Mn, and Cd reached 96.1, 93.3, 92.13, and 87.65%, respectively. Bioleaching efficiency of other elements (As, Hg, Pb) was not more than 30%. Heavy metal solubilization was highly negatively correlated with pH variation. Logistic models were well fitted with the solubilization efficiency, which can be used to predict the bioleaching process. The dominant species in the early stage of bioleaching were A. ferrooxidans and A. thiooxidans, and the abundance of L. ferriphilum increased together with pyrite utilization and pH decline.

  7. A multiple sampling ionization chamber (MUSIC) for measuring the charge of relativistic heavy ions

    Christie, W.B.; Romero, J.L.; Brady, F.P.; Tull, C.E.; Castaneda, C.M.; Barasch, E.F.; Webb, M.L.; Drummond, J.R.; Sann, H.; Young, J.C.

    1987-01-01

    A large area (1 m x 2 m) multiple sampling ionization chamber (MUSIC) has been constructed and tested. The MUSIC detector makes multiple measurements of energy 'loss', dE/dx, for a relativistic heavy ion. Given the velocity, the charge of the ion can be extracted from the energy loss distributions. The widths of the distributions we observe are much narrower than predicted by Vavilov's theory for energy loss while agreeing well with the theory of Badhwar which deals with the energy deposited. The versatile design of MUSIC allows a variety of anode configurations which results in a large dynamic range of charge. In our tests to date we have observed charge resolutions of 0.25e fwhm for 727 MeV/nucleon 40 Ar and 0.30e fwhm for 1.08 GeV/nucleon 139 La and 139 La fragments. Vertical position and multiple track determination are obtained by using time projection chamber electronics. Preliminary tests indicate that the position resolution is also very good with σ≅100 μm. (orig.)

  8. Multiple sampling ionization chamber (MUSIC) for measuring the charge of relativistic heavy ions

    Christie, W.B.; Romero, J.L.; Brady, F.P.; Tull, C.E.; Castaneda, C.M.; Barasch, E.F.; Webb, M.L.; Drummond, J.R.; Crawford, H.J.; Flores, I.

    1987-04-01

    A large area (1 m x 2 m) multiple sampling ionization chamber (MUSIC) has been constructed and tested. The MUSIC detector makes multiple measurements of energy 'loss', dE/dx, for a relativistic heavy ion. Given the velocity, the charge of the ion can be extracted from the energy loss distributions. The widths of the distributions we observe are much narrower than predicted by Vavilov's theory for energy loss while agreeing well with the theory of Badhwar which deals with the energy deposited. The versatile design of MUSIC allows a variety of anode configurations which results in a large dynamic range of charge. In our tests to date we have observed charge resolutions of 0.25e fwhm for 727 MeV/nucleon /sup 40/Ar and 0.30e fwhm for 1.08 GeV/nucleon /sup 139/La and /sup 139/La fragments. Vertical position and multiple track determination are obtained by using time projection chamber electronics. Preliminary tests indicate that the position resolution is also very good with sigmaapprox. =100 ..mu..m.

  9. Charged particle multiplicities in heavy and light quark initiated events above the $Z^0$ peak

    Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Bloodworth, I.J.; Boeriu, O.; Bock, P.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Caron, B.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Csilling, A.; Cuffiani, M.; Dado, S.; Dallison, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Elfgren, E.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Furtjes, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harder, K.; Harel, A.; Harin-Dirac, M.; Hauschild, M.; Hauschildt, J.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Hensel, C.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Homer, R.J.; Horvath, D.; Howard, R.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kormos, Laura L.; Kramer, T.; Kress, T.; Krieger, P.; von Krogh, J.; Krop, D.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Leins, A.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, J.; Macpherson, A.; Mader, W.; Marcellini, S.; Marchant, T.E.; Martin, A.J.; Martin, J.P.; Masetti, G.; Mashimo, T.; Mattig, Peter; McDonald, W.J.; McKenna, J.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Menges, W.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Rick, H.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sahr, O.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schoerner-Sadenius, Thomas; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Siroli, G.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Stephens, K.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Taylor, R.J.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trefzger, T.; Tricoli, A.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vachon, B.; Vollmer, C.F.; Vannerem, P.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

    2002-01-01

    We have measured the mean charged particle multiplicities separately for bbbar, ccbar and light quark (uubar, ddbar, ssbar) initiated events produced in e+e- annihilations at LEP. The data were recorded with the OPAL detector at eleven different energies above Z0 peak, corresponding to the full statistics collected at LPE1.5 and LEP2. The difference in mean charged and particle multiplicities for bbbar and light quark events, delta_bl, measured over this energy range is consistent with an energy independent behaviour, as predicted by QCD, but is inconsistent with the prediction of a more phenomenological approach which assumes that the multiplicity accompanying the decay of a heavy quark is independent of the quark mass itself. Our results, which can be combined into the single measurement delta_bl = 3.44+-0.40(stat)+-0.89(syst) at a luminosity weighted average centre-of mass energy of 195 GeV, are also consistent with an energy independent behaviour as extrapolated from lower energy data.

  10. Trace metal characterization and speciation in geothermal effluent by multiple scanning anodic stripping voltammetry and atomic absorption analysis

    Kowalski, B.R.

    1979-05-25

    Recent studies have shown geothermal power plants to have a significant environmental impact on the ground water of the area. The heavy metals arsenic and mercury are special problems, as both are concentrated by flora and fauna exposed to the effluent waters. Because the toxicity of these and other metallic pollutants present in geothermal effluent depends on the chemical form, or speciation, of the particular metal, any serious study of the environmental impact of a geothermal development should include studies of trace metal speciation, in addition to trace metal concentration. This proposal details a method for determining metal speciation in dilute waters. The method is based on ion-exchange and backed by atomic absorption spectrometry and multiple scanning anodic stripping voltammetry. Special laboratory studies will be performed on mercury, arsenic and selenium speciation in synthetic geothermal water. The method will be applied to three known geothermal areas in Washington and Oregon, with emphasis on the speciation of mercury, arsenic and selenium in these waters. The computer controlled electrochemical instrumentation was built and tested. Using this instrumentation, a new experimental procedure was developed to determine the chemical form (speciation) of metal ions in very dilute solutions (ng/ml). This method was tested on model systems including Pb, Cd, and As with C1/sup -/, CO/sub 3//sup 2 -/ and glycine ligands. Finally, the speciation of lead in a geothermal water was examined and the PbC1/sup +/ complex was observed and quantified.

  11. Charge-sign-clustering observed in high-multiplicity, high-energy heavy-ion collisions

    Takahashi, Y.; Gregory, J.C.; Hayashi, T.

    1989-01-01

    Charge-sign distribution in 200 GeV/amu heavy-ion collisions is studied with the Magnetic-Interferometric-Emulsion-Chamber (MAGIC) for central collision events in 16 O + Pb and 32 S + Pb interactions. Charge-sign clustering is observed in most of the fully-analyzed events. A statistical 'run-test' is performed for each measured event, which shows significant deviation from a Gaussian distribution (0,1) expected for random-charge distribution. Candidates of charge clusters have 5 - 10 multiplicity of like-sign particles, and are often accompanied by opposite-sign clusters. Observed clustering of identical charges is more significant in the fragmentation region than in the central region. Two-particle Bose-Einstein interference and other effects are discussed for the run-test examination. (author)

  12. Cascade Problems in Some Atomic Lifetime Measurements at a Heavy-Ion Storage Ring

    Trabert, E; Hoffmann, J; Krantz, C; Wolf, A; Ishikawa, Y; Santana, J

    2008-10-09

    Lifetimes of 3s{sup 2}3p{sup k} ground configuration levels of Al-, Si-, P-, and S-like ions of Be, Co, and Ni have been measured at a heavy-ion storage ring. Some of the observed decay curves show strong evidence of cascade repopulation from specific 3d levels that feature lifetimes in the same multi-millisecond range as the levels of the ground configuration.

  13. Experimental atomic physics

    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

  14. Multiple atomic dark solitons in cigar-shaped Bose-Einstein condensates

    Theocharis, G.; Kevrekidis, P. G.; Weller, A.; Ronzheimer, J. P.; Gross, C.; Oberthaler, M. K.; Frantzeskakis, D. J.

    2010-01-01

    We consider the stability and dynamics of multiple dark solitons in cigar-shaped Bose-Einstein condensates. Our study is motivated by the fact that multiple matter-wave dark solitons may naturally form in such settings as per our recent work [Phys. Rev. Lett. 101, 130401 (2008)]. First, we study the dark soliton interactions and show that the dynamics of well-separated solitons (i.e., ones that undergo a collision with relatively low velocities) can be analyzed by means of particle-like equations of motion. The latter take into regard the repulsion between solitons (via an effective repulsive potential) and the confinement and dimensionality of the system (via an effective parabolic trap for each soliton). Next, based on the fact that stationary, well-separated dark multisoliton states emerge as a nonlinear continuation of the appropriate excited eigenstates of the quantum harmonic oscillator, we use a Bogoliubov-de Gennes analysis to systematically study the stability of such structures. We find that for a sufficiently large number of atoms, multiple soliton states are dynamically stable, while for a small number of atoms, we predict a dynamical instability emerging from resonance effects between the eigenfrequencies of the soliton modes and the intrinsic excitation frequencies of the condensate. Finally, we present experimental realizations of multisoliton states including a three-soliton state consisting of two solitons oscillating around a stationary one and compare the relevant results to the predictions of the theoretical mean-field model.

  15. Simultaneous K plus L shell ionized atoms during heavy-ion ...

    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 ...

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

    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

  17. Nuclear polarization contribution to the Lamb-shift in heavy atoms

    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.)

  18. Determination of heavy metals in polar snow and ice by laser-excited atomic fluorescence spectrometry

    Bolshov, M.A.; Boutron, C.F.

    1994-01-01

    The new laser-excited atomic fluorescence spectrometry technique offers unrivalled sensitivity for the determination of trace metals in a wide variety of samples. This has allowed the direct determination of Pb, Cd and Bi in Antarctic and Greenland snow and ice down to the sub pg/g level. (authors). 11 refs., 2 figs

  19. Occurrence of breast cancer, renal cancer and multiple myeloma in a Nagasaki atomic bomb survivor

    Yanagisawa, Tsutomu; Kubota, Kazuo; Tamura, Jun'ichi; Kurabayashi, Hitoshi; Shirakura, Takuo; Hayashida, Masayoshi; Nagayama, Tadao.

    1990-01-01

    A 60-year-old female, who was exposed to the Nagasaki atomic bomb at 18 years old, had renal cancer and subsequently was found to have multiple myeloma (IgGk). She underwent the left mastectomy for breast cancer at 43 years old but was not given chemotherapy or radiotherapy. The karyotype of bone marrow cells was 46, XX. The estimated radiation dose was under 10 rads. While the effect of such a low-dose of radiation is considered to be almost negligible, there would be a possibility that in this case the risk of carcinogenesis was enhanced as her age advanced. (author)

  20. Atomic physics

    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.)

  1. Heavy-flavour production as a function of multiplicity in pp collisions at ALICE

    CERN. Geneva

    2015-01-01

    The measurement of inclusive heavy-flavour production cross sections in proton-proton (pp) collisions at LHC energies constituted an important test of perturbative QCD calculations. The measured cross sections can be described within uncertainties by next-to-leading order (NLO) and fixed-order with next-to-leading-log re-summation (FONLL) calculations with collinear factorization, as well as by leading-order (LO) calculations in the kt-factorization approach. More differential measurements of charm and beauty production in pp collisions can provide further information about the particle production mechanisms. The production of prompt D mesons and non-prompt J/psi mesons in proton-proton collisions at a centre-of-mass energy of 7 TeV was measured by the ALICE Collaboration as a function of the multiplicity of charged particles produced in the collision. D0, D+ and D*+ mesons were reconstructed from their hadronic decay channels in the central rapidity region and their yields were measured in different multipl...

  2. Interlayer electron-hole pair multiplication by hot carriers in atomic layer semiconductor heterostructures

    Barati, Fatemeh; Grossnickle, Max; Su, Shanshan; Lake, Roger; Aji, Vivek; Gabor, Nathaniel

    Two-dimensional heterostructures composed of atomically thin transition metal dichalcogenides provide the opportunity to design novel devices for the study of electron-hole pair multiplication. We report on highly efficient multiplication of interlayer electron-hole pairs at the interface of a tungsten diselenide / molybdenum diselenide heterostructure. Electronic transport measurements of the interlayer current-voltage characteristics indicate that layer-indirect electron-hole pairs are generated by hot electron impact excitation. Our findings, which demonstrate an efficient energy relaxation pathway that competes with electron thermalization losses, make 2D semiconductor heterostructures viable for a new class of hot-carrier energy harvesting devices that exploit layer-indirect electron-hole excitations. SHINES, an Energy Frontier Research Center funded by the U.S. Department of Energy, Air Force Office of Scientific Research.

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

    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.

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

    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

  5. Multiple myeloma among atomic bomb survivors, Hiroshima and Nagasaki, 1950 - 76

    Ichimaru, Michito; Ishimaru, Toranosuke; Mikami, Motoko; Matsunaga, Masako.

    1979-10-01

    The relationship between atomic bomb exposure and the occurrence of multiple myeloma has been evaluated in a fixed cohort of approximately 100,000 A-bomb survivors and nonexposed controls during the period from October 1950 to December 1976. Analysis of these data revealed the standardized relative risk adjusted for city, sex, and age at the time of the bombs (ATB) to be significantly greater in the group of individuals who received 100 rad or more of radiation than in their controls. An excess risk became apparent in the high dose group about 20 years after exposure. The excess risk of multiple myeloma in those persons aged 20 - 59 ATB is estimated to be approximately 0.24 per million person-years per rad (PYR) in kerma dose and approximately 0.48 per million PYR in bone marrow dose. The interval between radiation exposure and the occurrence of an excess risk for multiple myeloma in the high dose population is considerably longer than that for leukemia. The cases of multiple myeloma observed in the high dose group showed no unusual clinical features. (author)

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

    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)

  7. Surface modelling on heavy atom crystalline compounds: HfO2 and UO2 fluorite structures

    Evarestov, Robert; Bandura, Andrei; Blokhin, Eugeny

    2009-01-01

    The study of the bulk and surface properties of cubic (fluorite structure) HfO 2 and UO 2 was performed using the hybrid Hartree-Fock density functional theory linear combination of atomic orbitals simulations via the CRYSTAL06 computer code. The Stuttgart small-core pseudopotentials and corresponding basis sets were used for the core-valence interactions. The influence of relativistic effects on the structure and properties of the systems was studied. It was found that surface properties of Mott-Hubbard dielectric UO 2 differ from those found for other metal oxides with the closed-shell configuration of d-electrons

  8. Time-resolved EPR studies of the H atom: A stable heavy isotope of muonium

    Bartels, D.M.

    1994-01-01

    Muonium physicists and chemists, when they talk about ''primary processes,'' are probably concerned mostly about end-of-track phenomena in the slowing down of a many-MeV charged particle, analogous to the proton. The author's experience is with electron accelerators and radiolysis; hence, he will comment briefly on the differences and relative advantages of electron and proton radiolysis for the study of H atoms, as opposed to muonium. Then, he will take the liberty of defining primary processes to include the recombination reactions that may occur between geminate or quasi-geminate free radicals within radiolysis spurs

  9. Radiative double electron capture in fast heavy ion-atom collisions

    Yakhontov, V.L.; Amusia, M.Ya.

    1996-01-01

    Two-electron capture with emission of a single photon (TESP) in collisions of highly charged ions with light atoms is considered. Such a process is actually a time-reversed double photoionization but occurring at specific kinematics. In the lowest order in the inter-electron interaction, the TESP probability is determined by two diagrams which are evaluated analytically by means of the Coulomb Green function. The calculated ratio of the TESP and single recombination cross sections is in fair agreement with the data obtained in the recent experimental study of this phenomena. (orig.)

  10. Determination of heavy metals in solid emission and immission samples using atomic absorption spectroscopy

    Fara, M.; Novak, F. [EGU Prague, PLC, Bichovice, Prague (Czechoslovakia)

    1995-12-01

    Both flame and electrothermal methods of atomic absorption spectroscopy (AAS) have been applied to the determination of Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, TI, Se, V and Zn in emission and emission (deposition) samples decomposed in open PTFE test-tubes by individual fuming-off hydrofluoric, perchloroic and nitric acid. An alternative hydride technique was also used for As and Se determination and Hg was determined using a self-contained AAS analyzer. A graphite platform proved good to overcome non-spectral interferences in AAS-ETA. Methods developed were verified by reference materials (inc. NBS 1633a).

  11. The effective atomic number for gamma ray interactions with heavy metal oxide glasses

    Manohara, S. R.; Hanagodimath, S.M.; Gerward, Leif

    2010-01-01

    The effective atomic number, Z(eff), and the effective electron density, N-el,N-eff, have been calculated at photon energies from 1 keV to 100 GeV for CaO-SrO-B2O3, ZnO-PbO-B2O3, and CdO-PbO-B2O3 glasses with potential applications as gamma ray shielding materials. Appreciable variations are noted...... glasses have gamma ray shielding properties comparable with standard shielding materials, such as concrete....

  12. Heavy atom vibrational modes and low-energy vibrational autodetachment in nitromethane anions

    Thompson, Michael C.; Weber, J. Mathias; Baraban, Joshua H.; Matthews, Devin A.; Stanton, John F.

    2015-01-01

    We report infrared spectra of nitromethane anion, CH 3 NO 2 − , in the region 700–2150 cm −1 , obtained by Ar predissociation spectroscopy and electron detachment spectroscopy. The data are interpreted in the framework of second-order vibrational perturbation theory based on coupled-cluster electronic structure calculations. The modes in the spectroscopic region studied here are mainly based on vibrations involving the heavier atoms; this work complements earlier studies on nitromethane anion that focused on the CH stretching region of the spectrum. Electron detachment begins at photon energies far below the adiabatic electron affinity due to thermal population of excited vibrational states

  13. Design optimization of twin-fluid atomizers with an internal mixing chamber for heavy fuel oils

    Ferreira, German; Garcia, Juan Antonio; Barreras, Felix; Lozano, Antonio [LITEC, CSIC - Univ. Zaragoza, Maria de Luna 10, 50018 - Zaragoza (Spain); Lincheta, Eduardo [CECYEN, Universidad de Matanzas, Highway to Varadero, km 31/2, 44740 - Matanzas (Cuba)

    2009-02-15

    The present work is devoted to determine the magnitude of the main parameters that yield the optimum results for twin-fluid nozzles with an internal mixing chamber. The focus is placed on the study of the interaction of both air and liquid flows at the internal chamber and its effects on the resulting spray. To this end, some experiments have been performed for different air central channel diameters and liquid ports, as well as for several experimental conditions (air and liquid mass flow rates), in order to understand the influence of the flow conditions at the mixing chamber on the size of the droplets produced. It has been demonstrated that under certain experimental conditions the atomizing fluid discharged to the internal chamber is choked. The sonic condition is achieved for different air and liquid mass flow rates as a function of the air central channel diameter. It has also been obtained that to achieve the best results with moderate atomizing fluid flow rates, it is convenient to operate in choked conditions. This is an important result that will help in the optimum design of this type of nozzles. (author)

  14. Single and multiple ionization of noble gas atoms by H0 impact

    Sarkadi, L.; Gulyas, L.; Herczku, P.; Kovacs, S.T.S.; Koever, A.

    2012-01-01

    Complete text of publication follows. The understanding of the mechanisms of collisions between energetic charged particles and neutral atoms is of fundamental significance, and it has large importance in many research fields (plasma physics, astrophysics, materials science, etc.), as well as in number of practical applications. In the present work we measured total direct ionization and electron loss cross sections for the collisions of H 0 atoms with noble gas atoms (He, Ne, Ar, Kr) in the energy range 75-300 keV. The experiment was carried out at the 1.5 MV Van de Graaff accelerator of Atomki by coincident detection of the recoil target ions and the charge-state analyzed scattered projectiles. With this study we wished to obtain information about the role played by the electron of the H 0 projectile in the process of the single and multiple vacancy production induced by the collision. For this purpose we repeated the measurements also with proton projectile under the same experimental conditions. For calibration of the measuring system and normalization of our data we used the cross section values of Ref. [1]. The experimental results were analysed with using the classical trajectory Monte Carlo (CTMC) method. CTMC describes well the experimental data for both projectiles for the single vacancy creation, however we observed increasing deviation between the theory and experiment with increasing number of the created vacancies, as well as with decreasing atomic number of the target atoms. Fig. 1 shows our results obtained for the single, double and triple ionization (q = 1, 2, 3) of Kr at H 0 impact for the two cases when the outgoing projectile is H 0 (a) and H + (b), i.e., for pure ionization of the target, and ionization of the target with simultaneous electron loss of the projectile. The curves in the figure were obtained by two versions of the three-body CTMC theory: a conventional model (dashed curves); and a model taking partially account of the many

  15. Engineering giant magnetic anisotropy in single-molecule magnets by dimerizing heavy transition-metal atoms

    Qu, Jiaxing; Hu, Jun

    2018-05-01

    The search for single-molecule magnets with large magnetic anisotropy energy (MAE) is essential for the development of molecular spintronics devices for use at room temperature. Through systematic first-principles calculations, we found that an Os–Os or Ir–Ir dimer embedded in the (5,5‧-Br2-salophen) molecule gives rise to a large MAE of 41.6 or 51.4 meV, respectively, which is large enough to hold the spin orientation at room temperature. Analysis of the electronic structures reveals that the top Os and Ir atoms play the most important part in the total spin moments and large MAEs of the molecules.

  16. Ion-atom charge-transfer system for a heavy-ion-beam pumped laser

    Ulrich, A.; Gernhaeuser, R.; Kroetz, W.; Wieser, J.; Murnick, D.E.

    1994-01-01

    An Ar target to which Cs vapor could be added, excited by a pulsed beam of 100-MeV 32 S ions, was studied as a prototype ion-atom charge-transfer system for pumping short-wavelength lasers. Low-velocity Ar 2+ ions were efficiently produced; a huge increase in the intensity of the Ar II 4d-4p spectral lines was observed when Cs vapor was added to the argon. This observation is explained by a selective charge transfer of the Cs 6s electron into the upper levels of the observed transitions. A rate constant of (1.4±0.2)x10 -9 cm 3 /s for the transfer process was determined

  17. The Research of Nanoparticle and Microparticle Hydroxyapatite Amendment in Multiple Heavy Metals Contaminated Soil Remediation

    Zhangwei Li

    2014-01-01

    Full Text Available It was believed that when hydroxyapatite (HAP was used to remediate heavy metal-contaminated soils, its effectiveness seemed likely to be affected by its particle size. In this study, a pot trial was conducted to evaluate the efficiency of two particle sizes of HAP: nanometer particle size of HAP (nHAP and micrometer particle size of HAP (mHAP induced metal immobilization in soils. Both mHAP and nHAP were assessed for their ability to reduce lead (Pb, zinc (Zn, copper (Cu, and chromium (Cr bioavailability in an artificially metal-contaminated soil. The pakchoi (Brassica chinensis L. uptake and soil sequential extraction method were used to determine the immobilization and bioavailability of Pb, Zn, Cu, and Cr. The results indicated that both mHAP and nHAP had significant effect on reducing the uptake of Pb, Zn, Cu, and Cr by pakchoi. Furthermore, both mHAP and nHAP were efficient in covering Pb, Zn, Cu, and Cr from nonresidual into residual forms. However, mHAP was superior to nHAP in immobilization of Pb, Zn, Cu, and Cr in metal-contaminated soil and reducing the Pb, Zn, Cu, and Cr utilized by pakchoi. The results suggested that mHAP had the better effect on remediation multiple metal-contaminated soils than nHAP and was more suitable for applying in in situ remediation technology.

  18. Social anxiety and heavy situational drinking: coping and conformity motives as multiple mediators.

    Terlecki, Meredith A; Buckner, Julia D

    2015-01-01

    Individuals with clinically elevated social anxiety are at greater risk for alcohol use disorder, and the relation between social anxiety and drinking problems is at least partially accounted for by drinking more in negative emotional (e.g., feeling sad or angry) and personal/intimate (e.g., before sexual intercourse) situations. Identification of cognitive/motivational factors related to drinking in these high-risk situations could inform the development of treatment and prevention interventions for these high-risk drinkers. The current cross-sectional study examined the mediating effect of drinking motives on the relationship between social anxiety and drinking these high-risk situations among undergraduates (N=232). Clinically elevated social anxiety was associated with greater coping and conformity motives. Both coping and conformity motives mediated the relation between social anxiety and heavier alcohol consumption in negative emotional and personal/intimate contexts. Multiple mediation analyses indicated that these motives work additively to mediate the social anxiety-drinking situations relationship, such that heavy situational drinking among undergraduates with clinically elevated social anxiety can be jointly attributed to desire to cope with negative affect and to avoid social scrutiny. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Evaluation of silkworm excrement and mushroom dreg for the remediation of multiple heavy metal/metalloid contaminated soil using pakchoi.

    Wang, Ruigang; Guo, Junkang; Xu, Yingming; Ding, Yongzhen; Shen, Yue; Zheng, Xiangqun; Feng, Renwei

    2016-02-01

    The economical, environmental friendly and efficient materials to remediate the pollution with multiple heavy metals and metalloids are scarce. Silkworm excrement (SE) and mushroom dregs (MD) are two types of agricultural wastes, and they are widely used to improve the soil fertility in many regions of China. A pot experiment with sixteen treatments was set up to assess the possibility of using SE and MD to stabilize heavy metals and metalloids and reduce their uptake in pakchoi cultivated in slightly contaminated soils with arsenic (As), cadmium (Cd), lead (Pb) and zinc (Zn). The results showed that the single addition of SE obviously stimulated the growth of pakchoi, reduced the contents of all tested heavy metals and metalloids in the edible part of pakchoi and availability of Zn and Cd in soil. The single MD treatment showed an inferior ability to enhance the growth and reduce the contents of heavy metals and metalloids in the edible part of pakchoi. The combined utilization of SE and MD appeared not to show better effects than their individual treatment when using them to remediate this contaminated soil. Some potential mechanisms on the stimulation on pakchoi growth and decreasing the accumulation of heavy metals and metalloids in pakchoi subjected to SE were suggested, including: (1) enhancing soil pH to impact the availability of heavy metals and metalloids; (2) improve the fertility of soil; (3) sulfhydryl groups of organic materials in SE play a role in conjugating heavy metals and metalloids to affect their availability in soil; and (4) stimulating the growth of pakchoi so as to show a "dilution effect" of heavy metals and metalloids. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Reduction of interferences in graphite furnace atomic absorption spectrometry by multiple linear regression modelling

    Grotti, Marco; Abelmoschi, Maria Luisa; Soggia, Francesco; Tiberiade, Christian; Frache, Roberto

    2000-12-01

    The multivariate effects of Na, K, Mg and Ca as nitrates on the electrothermal atomisation of manganese, cadmium and iron were studied by multiple linear regression modelling. Since the models proved to efficiently predict the effects of the considered matrix elements in a wide range of concentrations, they were applied to correct the interferences occurring in the determination of trace elements in seawater after pre-concentration of the analytes. In order to obtain a statistically significant number of samples, a large volume of the certified seawater reference materials CASS-3 and NASS-3 was treated with Chelex-100 resin; then, the chelating resin was separated from the solution, divided into several sub-samples, each of them was eluted with nitric acid and analysed by electrothermal atomic absorption spectrometry (for trace element determinations) and inductively coupled plasma optical emission spectrometry (for matrix element determinations). To minimise any other systematic error besides that due to matrix effects, accuracy of the pre-concentration step and contamination levels of the procedure were checked by inductively coupled plasma mass spectrometric measurements. Analytical results obtained by applying the multiple linear regression models were compared with those obtained with other calibration methods, such as external calibration using acid-based standards, external calibration using matrix-matched standards and the analyte addition technique. Empirical models proved to efficiently reduce interferences occurring in the analysis of real samples, allowing an improvement of accuracy better than for other calibration methods.

  1. The incidence of leukemia, lymphoma, and multiple myeloma among atomic bomb survivors: 1950 – 2001

    Hsu, Wan-Ling; Preston, Dale L.; Soda, Midori; Sugiyama, Hiromi; Funamoto, Sachiyo; Kodama, Kazunori; Kimura, Akiro; Kamada, Nanao; Dohy, Hiroo; Tomonaga, Masao; Iwanaga, Masako; Miyazaki, Yasushi; Cullings, Harry M.; Suyama, Akihiko; Ozasa, Kotaro; Shore, Roy E.; Mabuchi, Kiyohiko

    2013-01-01

    A marked increase in leukemia risks was the first and most striking late effect of radiation exposure seen among the Hiroshima and Nagasaki atomic bomb survivors. This paper presents analyses of radiation effects on leukemia, lymphoma, and multiple myeloma incidence in the Life Span Study cohort of atomic bomb survivors updated 14 years since the last comprehensive report on these malignancies. These analyses make use of tumor- and leukemia-registry-based incidence data on 113,011 cohort members with 3.6 million person-years of follow-up from late 1950 through the end of 2001. In addition to a detailed analysis of the excess risk for all leukemias other than chronic lymphocytic leukemia or adult T-cell leukemia (neither of which appear to be radiation-related), we present results for the major hematopoietic malignancy types: acute lymphoblastic leukemia, chronic lymphocytic leukemia, acute myeloid leukemia, chronic myeloid leukemia, adult T-cell leukemia, Hodgkin and non-Hodgkin lymphoma, and multiple myeloma. Poisson regression methods were used to characterize the shape of the radiation dose response relationship and, to the extent the data allowed, to investigate variation in the excess risks with sex, attained age, exposure age, and time since exposure. In contrast to the previous report that focused on describing excess absolute rates, we considered both excess absolute rate (EAR) and excess relative risk (ERR) models and found that ERR models can often provide equivalent and sometimes more parsimonious descriptions of the excess risk than EAR models. The leukemia results indicated that there was a non-linear dose response for leukemias other than chronic lymphocytic leukemia or adult T-cell leukemia, which varied markedly with time and age at exposure, with much of the evidence for this non-linearity arising from the acute myeloid leukemia risks. Although the leukemia excess risks generally declined with attained age or time since exposure, there was evidence

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

    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.

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

    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.

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

    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.

  5. Quantitative atom probe analysis of nanostructure containing clusters and precipitates with multiple length scales

    Marceau, R.K.W.; Stephenson, L.T.; Hutchinson, C.R.; Ringer, S.P.

    2011-01-01

    A model Al-3Cu-(0.05 Sn) (wt%) alloy containing a bimodal distribution of relatively shear-resistant θ' precipitates and shearable GP zones is considered in this study. It has recently been shown that the addition of the GP zones to such microstructures can lead to significant increases in strength without a decrease in the uniform elongation. In this study, atom probe tomography (APT) has been used to quantitatively characterise the evolution of the GP zones and the solute distribution in the bimodal microstructure as a function of applied plastic strain. Recent nuclear magnetic resonance (NMR) analysis has clearly shown strain-induced dissolution of the GP zones, which is supported by the current APT data with additional spatial information. There is significant repartitioning of Cu from the GP zones into the solid solution during deformation. A new approach for cluster finding in APT data has been used to quantitatively characterise the evolution of the sizes and shapes of the Cu containing features in the solid solution solute as a function of applied strain. -- Research highlights: → A new approach for cluster finding in atom probe tomography (APT) data has been used to quantitatively characterise the evolution of the sizes and shapes of the Cu containing features with multiple length scales. → In this study, a model Al-3Cu-(0.05 Sn) (wt%) alloy containing a bimodal distribution of relatively shear-resistant θ' precipitates and shearable GP zones is considered. → APT has been used to quantitatively characterise the evolution of the GP zones and the solute distribution in the bimodal microstructure as a function of applied plastic strain. → It is clearly shown that there is strain-induced dissolution of the GP zones with significant repartitioning of Cu from the GP zones into the solid solution during deformation.

  6. Multiplicity dependence of matrix-induced frequency shifts for atomic transitions of the group 12 metals in rare gas solids

    Laursen, S.L.; Cartland, H.E.

    1991-01-01

    Atomic resonances of the group 12 metal atoms, Hg, Cd, and Zn, undergo frequency shifts from the gas phase atomic line when trapped in rare gas matrices of Ar, Kr, and Xe at 12 K. As expected, the shifts are approximately linear in polarizability of the rare gas, but the slope of this line depends on whether the transition in question is 1 P 1 left-arrow 1 S 0 or 3 P 1 left-arrow 1 S 0 . Thus the matrix-induced frequency shift is dependent on the singlet or triplet nature of the excited state as well as on the matrix material. This dependence on multiplicity is discussed in terms of interactions between the excited-state atomic orbitals and the matrix. The results are compared to matrix studies of other metals and to related gas-phase work on diatomic van der Waals complexes of group 12 metals with rare gases

  7. Nine cases of multiple myeloma among atomic bomb survivors in Hiroshima

    Niimi, Masanobu; Matsueda, Kazuhiro; Nishida, Kazurou; Kobayashi, Makoto; Kou, Hassei; Mikami, Motoko; Nakamura, Masayoshi; Tanaka, Yoshikiyo; Aisaka, Tadakazu

    1986-03-01

    Nine A-bomb survivors (2 men and 7 women) were diagnosed as having multiple myeloma (MM) 24 years to 38 years after exposure. According to exposure doses, three survivors were exposed at less than or equal to 1,800 m from the hypocenter, three between 2,200 m and 2,500 m, and three between 3,100 m and 4,100 m. Acute atomic radiation injuries, such as epilation and disturbance in bone marrow function, were observed in survivors exposed at less than or equal to 2,400 m. Complications included hypertension in two, diabetes mellitus in one, and cancer of the pharynx in one. Three of the patients are still alive with follow-up periods of 3 years and 6 months to 7 years and 11 months. Two survivors, who showed no evidence of abnormal physical findings, did not meet typical MM criteria according to Abe et al. There has been a continuing discussion regarding the association between A-bomb radiation and intermediate type MM seen in the two survivors. (Namekawa, K.).

  8. Twelve cases of multiple myeloma in Nagasaki (especially seven atomic bombing casualty cases). [In Japanese

    Ichimaru, M; Yasuhi, S; Ouchuru, S

    1963-12-01

    Since 1958, there have been 12 cases of multiple myeloma in Nagasaki, and among them were 7 cases representing atomic bombing casualties, with 3 cases being with 2 km distance from the hypocenter. The age of onset was between 51 and 69 years, and the sex ratio was 8:4, it occurring mostly in males. Symptoms were predominantly low back pain and chest pain caused by the bone changes in 8 cases. Two cases complained of general malaise and palpitation which resulted from anemia. One developed persistent epistaris, and another complained of diplopia caused by the paralysis of the oculomotor nerve. Peripheral blood in all cases showed anemia, 9 with hyperchromic and 3 with normochromic or hypochromic anemia. Low platelet counts were seen in 3 cases. All showed leukopenia. All cases showed typical ..gamma..-globulin change with a myeloma peak, and in 4 cases showed an increase of ..beta..-globulin. Bence-Jones proteinuria was present in 5 cases. Average course was 1 year 4 months. Among complications, myeloma nephrosis, aplastic anemia, and pneumonia were the most important ones.

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

    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

  10. Precise X-Ray spectroscopy of the hydrogenlike and heliumlike heavy ions and of the exotic atoms

    Manil, B.

    2001-10-01

    In this thesis, we present four experiments designed to study hydrogenlike and heliumlike heavy ions, or exotic atoms. These experiments have been run at the Gesellschaft fur Schwerionenforchung (GSI) and the Paul Scherrer Institut (PSI). In the first part of this text, we begin with the description of a focusing, curved-crystal spectrometer in transmission geometry, coupled with a microstrip, germanium position-sensitive detector, which diffract X-ray photons in the range 50-100 keV. With this spectrometer, which can be mounted on the GSI accelerator, we will increase, by one order of magnitude, the accuracy on the measurement of the 1 s Lamb shift in hydrogenlike uranium ions, in order to test QED in strong coulomb field. Next, we detail an experiment that will soon give a new value of the charged-pion mass with a relative accuracy of 1 ppm. For that, we perform X-ray spectroscopy of pionic nitrogen, at PSI. The experimental set-up is made up of a cyclotron trap, a spherical Bragg-crystal focusing spectrometer, in reflection geometry, and a CCD sensitive-position cooled detector. This set-up allows also test QCD and chiral perturbation theory by measurements of radiative transitions of pionic hydrogen. The main subject of the second part is a lifetime measurement of the metastable 2 3 P 0 state in heliumlike gold ions, by Beam Foil Spectroscopy. With this experiment, which provides an important test of relativistic many-body theory, we give, for the first time, an accurate value of the lifetime of this state for an ion with a Z larger than 64, our result is τ(exp) = (22.12 ± 1.21) ps

  11. Supplemental figures: “Dielectron and heavy-quark production in inelastic and high-multiplicity proton-proton collisions at $\\sqrt{s} = 13$ TeV”

    2018-01-01

    This note provides supplemental figures for the paper “Dielectron and heavy-quark production in inelastic and high-multiplicity proton–proton collisions at $\\sqrt{s} = 13$ TeV” [CERN-EP-2018-122].

  12. X-ray fluorescence holography and multiple-energy x-ray holography: A critical comparison of atomic images

    Len, P.M.; Gog, T.; Fadley, C.S.; Materlik, G.

    1997-01-01

    We compare x-ray fluorescence holography (XFH) and multiple-energy x-ray holography (MEXH), two techniques that have recently been used to obtain experimental three-dimensional atomic images. For single-energy holograms, these methods are equivalent by virtue of the optical reciprocity theorem. However, XFH can only record holographic information at the characteristic fluorescence energies of the emitting species, while MEXH can record holographic information at any energy above the fluorescent edge of the emitter, thus enabling the suppression of real-twin overlaps and other aberrations and artifacts in atomic images. copyright 1997 The American Physical Society

  13. Atomic physics with highly-charged heavy ions at the GSI future facility: The scientific program of the SPARC collaboration

    Stoehlker, Th.; Beier, T.; Beyer, H.F.; Bosch, F.; Braeuning-Demian, A.; Gumberidze, A.; Hagmann, S.; Kozhuharov, C.; Kuehl, Th.; Liesen, D.; Mann, R.; Mokler, P.H.; Quint, W.; Schuch, R.; Warczak, A.

    2005-01-01

    In the current report a short overview about the envisioned program of the atomic physics research collaboration SPARC (Stored Particle Atomic Research Collaboration, at the new international accelerator Facility for Antiproton and Ion Research (FAIR) at GSI is given. In addition, a condensed description of the planned experimental areas devoted to atomic physics research at the new facility is presented

  14. Efficient adsorption of multiple heavy metals with tailored silica aerogel-like materials.

    Vareda, João P; Durães, Luisa

    2017-11-10

    Recently developed tailored adsorbents for heavy metal uptake are studied in batch tests with Cu, Pb, Cd, Ni, Cr and Zn, in order to decontaminate polluted environments where these heavy metals are found in solution - water courses and groundwater. The adsorbents feature mercapto or amine-mercapto groups that are capable of complexating the cations. Through the use of equilibrium tests it is found that a remarkably high heavy metal uptake is obtained for all metals (ranging from 84 to 140 mg/g). These uptake values are quite impressive when compared to other adsorbents reported in the literature, which is also due to the double functionalization present in one of the adsorbents. For the best adsorbent, adsorption capacities followed the order Cu(II) > Pb(II) > Zn(II) > Cr(III) > Cd(II) > Ni(II). With these adsorbents, the removal process was fast with most of the metals being removed in less than 1 h. Competitive sorption tests were performed in tertiary mixtures that were based on real world polluted sites. It was found that although competitive sorption occurs, affecting the individual removal of each metal, all the cations in solution still interact with the adsorbent, achieving removal values that make this type of material very interesting for its proposed application.

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

    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.

  16. Multiple myeloma among atomic bomb survivors in Hiroshima and Nagasaki, 1950-76: relationship to radiation dose absorbed by marrow

    Ichimaru, M.; Ishimaru, T.; Mikami, M.; Matsunaga, M.

    1982-01-01

    The relationship between atomic bomb exposure and the incidence of multiple myeloma has been examined in a fixed cohort of atomic bomb survivors and controls in the life-span study sample for Hiroshima and Nagasaki. From October 1950 to December 1976, 29 cases of multiple myeloma were confirmed in this sample. Our analysis shows that the standardized relative risk (RR) adjusted for city, sex, and age at the time of bombings (ATB) increased with marrow-absorbed radiation dose. The increased RR does not appear to differ between cities or sexes and is demonstrable only for those survivors whose age ATB was between 20 and 59 years. The estimated risk in these individuals is approximately 0.48 cases/million person-years/rad for bone marrow total dose. This excess risk did not become apparent in individuals receiving 50 rad or more in marrow total dose until 20 years or more after exposure

  17. Remediation of multiple heavy metal-contaminated soil through the combination of soil washing and in situ immobilization.

    Zhai, Xiuqing; Li, Zhongwu; Huang, Bin; Luo, Ninglin; Huang, Mei; Zhang, Qiu; Zeng, Guangming

    2018-09-01

    The remediation of heavy metal-contaminated soils is a great challenge for global environmental sciences and engineering. To control the ecological risks of heavy metal-contaminated soil more effectively, the present study focused on the combination of soil washing (with FeCl 3 ) and in situ immobilization (with lime, biochar, and black carbon). The results showed that the removal rate of Cd, Pb, Zn, and Cu was 62.9%, 52.1%, 30.0%, and 16.7%, respectively, when washed with FeCl 3 . After the combined remediation (immobilization with 1% (w/w) lime), the contaminated soils showed 36.5%, 73.6%, 70.9%, and 53.4% reductions in the bioavailability of Cd, Cu, Pb, and Zn (extracted with 0.11M acetic acid), respectively, than those of the soils washed with FeCl 3 only. However, the immobilization with 1% (w/w) biochar or 1% (w/w) carbon black after washing exhibited low effects on stabilizing the metals. The differences in effects between the immobilization with lime, biochar, and carbon black indicated that the soil pH had a significant influence on the lability of heavy metals during the combined remediation process. The activity of the soil enzymes (urease, sucrase, and catalase) showed that the addition of all the materials, including lime, biochar, and carbon black, exhibited positive effects on microbial remediation after soil washing. Furthermore, lime was the most effective material, indicating that low soil pH and high acid-soluble metal concentrations might restrain the activity of soil enzymes. Soil pH and nutrition were the major considerations for microbial remediation during the combined remediation. These findings suggest that the combination of soil washing and in situ immobilization is an effective method to amend the soils contaminated with multiple heavy metals. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Various analytical techniques used for the measurement of isotopic purity of heavy water at Madras Atomic Power Station

    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)

  19. Centrality and energy dependence of charged-particle multiplicities in heavy ion collisions in the context of elementary reactions

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; Nieuwenhuizen, G. J. Van; Verdier, R.; Veres, G. I.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    2006-08-01

    The PHOBOS experiment at the BNL Relativistic Heavy Ion Collider has measured the total multiplicity of primary charged particles as a function of collision centrality in Au+Au collisions at sNN= 19.6, 130, and 200 GeV. An approximate independence of / on the number of participating nucleons is observed, reminiscent of “wounded nucleon” scaling (Nch∝Npart) observed in proton-nucleus collisions. Unlike p+A, the constant of proportionality does not seem to be set by the pp/p¯p data at the same energy. Rather, there seems to be a surprising correspondence with the total multiplicity measured in e+e- annihilations, as well as the rapidity shape measured over a large range. The energy dependence of the integrated multiplicity per participant pair shows that e+e- and A+A data agree over a large range of center-of-mass energies (s>20 GeV), and pp/p¯p data can be brought to agree approximately with the e+e- data by correcting for the typical energy taken away by leading particles. This is suggestive of a mechanism for soft particle production that depends mainly on the amount of available energy. It is conjectured that the dominant distinction between A+A and p+p collisions is the multiple collisions per participant, which appears to be sufficient to substantially reduce the energy taken away by leading particles.

  20. Statistics and methodology of multiple cell upset characterization under heavy ion irradiation

    Zebrev, G.I.; Gorbunov, M.S.; Useinov, R.G.; Emeliyanov, V.V.; Ozerov, A.I.; Anashin, V.S.; Kozyukov, A.E.; Zemtsov, K.S.

    2015-01-01

    Mean and partial cross-section concepts and their connections to multiplicity and statistics of multiple cell upsets (MCUs) in highly-scaled digital memories are introduced and discussed. The important role of the experimental determination of the upset statistics is emphasized. It was found that MCU may lead to quasi-linear dependence of cross-sections on linear energy transfer (LET). A new form of function for interpolation of mean cross-section dependences on LET has been proposed

  1. Multiple-electron excitation, ionization, and transfer in high-velocity atomic and molecular collisions

    McGuire, J.H.

    1992-01-01

    This paper reports that the many-body and many-electron problem is common in various areas of physics as well as in chemistry and biology. Basic understanding of phenomena ranging from the nature of matter at the creation of time to the properties of useful materials in the human environment is limited by the boundaries of our knowledge of the many-body problem. There is an advantage in studying the many-body problem in atomic physics since the two-body and parts of the three-body problem are understood. Furthermore, both the mystery of the meanings of quantum mechanics and the mystery of the transition from microscopic time-reversible atomic processes to the dynamics of macroscopic time-irreversible aggregates of atomic particles is inherent in the many-body problems of atomic interactions. Thus, by studying the many-body problem in atomic physics we are able to develop effective tools to discover insights that provide both meaning and utility in our lives

  2. Intrinsic electronic defects and multiple-atom processes in the oxidic semiconductor Ga2O3

    Schmeißer, Dieter; Henkel, Karsten

    2018-04-01

    We report on the electronic structure of gallium oxide (Ga2O3) single crystals as studied by resonant photoelectron spectroscopy (resPES). We identify intrinsic electronic defects that are formed by mixed-atomic valence states. We differentiate three coexisting defect states that differ in their electronic correlation energy and their spatial localization lengths. Their relative abundance is described by a fractional ionicity with covalent and ionic bonding contributions. For Ga2O3, our analyses of the resPES data enable us to derive two main aspects: first, experimental access is given to determine the ionicity based on the original concepts of Pauling and Phillips. Second, we report on multi-atomic energy loss processes in the Ga2p core level and X-ray absorption data. The two experimental findings can be explained consistently in the same context of mixed-atomic valence states and intrinsic electronic defects.

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

    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

  4. Multiple electromagnetic electron-positron pair production in relativistic heavy-ion collisions

    Alscher, A.; Hencken, K.; Trautmann, D.; Baur, G.

    1997-01-01

    We calculate the cross sections for the production of one and more electron-positron pairs due to the strong electromagnetic fields in relativistic heavy-ion collisions. We derive the N-pair amplitude using the generating functional of fermions in an external field and the path-integral formalism. The N-pair production probability is found to be an approximate Poisson distribution. We calculate total cross sections for the production of one pair in lowest order, including corrections from the Poisson distribution up to third order. Furthermore, we calculate cross sections for the production of up to five pairs including corrections from the Poisson distribution. copyright 1997 The American Physical Society

  5. Hydroponic phytoremediation of Cd, Cr, Ni, As, and Fe: can Helianthus annuus hyperaccumulate multiple heavy metals?

    January, Mary C; Cutright, Teresa J; Van Keulen, Harry; Wei, Robert

    2008-01-01

    Sundance sunflowers were subjected to contaminated solutions containing 3, 4, or 5 heavy metals, with and without EDTA. The sunflowers exhibited a metal uptake preference of Cd=Cr>Ni, Cr>Cd>Ni>As and Fe>As>Cd>Ni>Cr without EDTA and Cr>Cd>Ni, Fe>As>Cd>Cr>Ni with EDTA. As uptake was not affected by other metals, but it decreased Cd and Ni concentration in the stems. The presence of Fe improved the translocation of the other metals regardless of whether EDTA was present. In general, EDTA served as a hindrance to metal uptake. For the experiment with all five heavy metals, EDTA decreased Cd in the roots and stems from 2.11 to 1.36 and from 2.83 to 2.3 2mg g(-1) biomass, respectively. For the same conditions, Ni in the stems decreased from 1.98 to 0.94 mg g(-1) total metal uptake decreased from 14.95 mg to 13.89 mg, and total biomass decreased from 2.38 g to 1.99 g. These results showed an overall negative effect in addition of EDTA. However it is unknown whether the negative effect was due to toxicity posed by EDTA or the breaking of phytochelatin-metal bonds. The most important finding was the ability of Sundance sunflowers to achieve hyperaccumulator status for both As and Cd under all conditions studied. Ni hyperaccumulator status was only achieved in the presence of three metals without EDTA.

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

    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)

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

    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.)

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

    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.

  9. New sampling electronics using CCD for DIOGENE: a high multiplicity, 4 π detector for relativistic heavy ions

    Babinet, R.P.

    1987-01-01

    DIOGENE is a small time projection chamber which has been developed to study central collisions of relativistic heavy ions. The maximum multiplicity (up to 40 charged particles) that can be accepted by this detector is limited by the present electronics. In view of the heavier mass ions that should become readily available at the Saturne national facility (France), a new sampling electronics has been tested. In the first part of this talk they will present a brief description of the actual detector, insisting on the performances that have been effectively obtained with α-particles and Neon beams. The motivation for and characteristics of a renewed electronic set-up should thus appear more clearly. The second part of the talk is devoted to results of the tests that have been performed using charged couple devices. They will finally conclude on the future perspectives that have been opened by these developments

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

    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)

  11. Multiplicity-Vertex Detector Electronics Development for Heavy-Ion Detectors

    Britton, C.L., Jr.; Bryan, W.L.; Emery, M.S. [and others

    1995-12-31

    This paper presents the electronics work performed to date for the Multiplicity-Vertex Detector (MVD) for the PHENIX collaboration at RHIC. The detector consists of approximately 34,000 channels of both silicon strips and silicon pads. The per-channel signal processing chain consists of a pre-amplifier gain stage, a current mode summed multiplicity discriminator, a 64 deep analog memory (simultaneous read/write), an analog correlator, and a 10-bit microsecs ADC. The system controller or Heap Manager, supplies all timing control, data buffering, and data formatting for a single 256-channel multi-chip module (MCM). Each chip set is partitioned into 32-channel sets. Prototype performance for the various blocks will be presented as well as the ionizing radiation damage performance of the 1.2 mu nwell CMOS process used for fabrication.

  12. Intertwined and vestigial order with ultracold atoms in multiple cavity modes

    Gopalakrishnan, Sarang; Shchadilova, Yulia E.; Demler, Eugene

    2017-12-01

    Atoms in transversely pumped optical cavities "self-organize" by forming a density wave and emitting superradiantly into the cavity mode(s). For a single-mode cavity, the properties of this self-organization transition are well characterized both theoretically and experimentally. Here, we explore the self-organization of a Bose-Einstein condensate in the presence of two cavity modes—a system that recently was realized experimentally [Léonard et al., Nature (London) 543, 87 (2017), 10.1038/nature21067]. We argue that this system can exhibit a "vestigially ordered" phase in which neither cavity mode exhibits superradiance but the cavity modes are mutually phase locked by the atoms. We argue that this vestigially ordered phase should generically be present in multimode cavity geometries.

  13. Multiple ionization effects in atomic collisions in the K-L matching region

    Piticu, I.; Ciortea, C.; Dumitriu, D.; Enulescu, A.; Fluerasu, D.; Szilagyi, S.Z.; Zoran, V.; Bucur, B.I.

    1994-01-01

    The multiple ionization effect in the determination of 3dσ vacancy production cross sections and sharing probabilities in asymmetric quasimolecular collisions near K-L level matching, for the collision systems Fe, Co, Ni, and Cu + Bi in the energy range 0.25 - 1.75 MeV/u have been studied. The experimental energy and intensity shifts of some projectile and target X-ray lines, as well as Dirac-Hartree-Fock calculations, have been used to estimate average single particle probabilities for multiple ionization of projectile L- and target M-shells. Using these estimates and a standard procedure, the experimental 3dσ vacancy production cross sections and sharing probabilities have been corrected for multiple ionization. The influence of the multiple ionization-induced increase in binding energy of the molecular orbitals implied in vacancy sharing is discussed. (Author)

  14. Forging Fast Ion Conducting Nanochannels with Swift Heavy Ions: The Correlated Role of Local Electronic and Atomic Structure

    Sachan, Ritesh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Cooper, Valentino R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Liu, Bin [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Aidhy, Dilpuneet S. [Univ. of Wyoming, Laramie, WY (United States). Dept. of Mechanical Engineering; Voas, Brian K. [Iowa State Univ., Ames, IA (United States). Dept. of Materials Science and Engineering; Lang, Maik [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Nuclear Engineering; Ou, Xin [Chinese Academy of Sciences (CAS), Shanghai (China). State Key Lab. of Functional Material for Informatics; Trautmann, Christina [GSI Helmholtz Centre for Heavy Ion Research, Darmstadt (Germany); Technical Univ. of Darmstadt (Germany). Dept. of Materials Science; Zhang, Yanwen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Chisholm, Matthew F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division; Weber, William J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Material Science and Technology Division

    2016-12-19

    Atomically disordered oxides have attracted significant attention in recent years due to the possibility of enhanced ionic conductivity. However, the correlation between atomic disorder, corresponding electronic structure, and the resulting oxygen diffusivity is not well understood. The disordered variants of the ordered pyrochlore structure in gadolinium titanate (Gd2Ti2O7) are seen as a particularly interesting prospect due to intrinsic presence of a vacant oxygen site in the unit atomic structure, which could provide a channel for fast oxygen conduction. In this paper, we provide insights into the subangstrom scale on the disordering-induced variations in the local atomic environment and its effect on the electronic structure in high-energy ion irradiation-induced disordered nanochannels, which can be utilized as pathways for fast oxygen ion transport. With the help of an atomic plane-by-plane-resolved analyses, the work shows how the presence of various types of TiOx polyhedral that exist in the amorphous and disordered crystalline phase modify the electronic structures relative to the ordered pyrochlore phase in Gd2Ti2O7. Finally, the correlated molecular dynamics simulations on the disordered structures show a remarkable enhancement in oxygen diffusivity as compared with ordered pyrochlore lattice and make that a suitable candidate for applications requiring fast oxygen conduction.

  15. Contribution to coherent atom optics - Design of multiple wave devices; Contribution a l'optique des ondes atomiques coherentes - Conception de dispositifs multi-ondes

    Impens, F

    2008-03-15

    The theoretical work presented in this manuscript addresses two complementary issues in coherent atom optics. The first part addresses the perspectives offered by coherent atomic sources through the design of two experiment involving the levitation of a cold atomic sample in a periodic series of light pulses, and for which coherent atomic clouds are particularly well-suited. These systems appear as multiple wave atom interferometers. A striking feature of these experiments is that a unique system performs both the sample trapping and interrogation. To obtain a transverse confinement, a novel atomic lens is proposed, relying on the interaction between an atomic wave with a spherical light wave. The sensitivity of the sample trapping towards the gravitational acceleration and towards the pulse frequencies is exploited to perform the desired measurement. These devices constitute atomic wave resonators in momentum space, which is a novel concept in atom optics. A second part develops new theoretical tools - most of which inspired from optics - well-suited to describe the propagation of coherent atomic sources. A phase-space approach of the propagation, relying on the evolution of moments, is developed and applied to study the low-energy dynamics of Bose-Einstein condensates. The ABCD method of propagation for atomic waves is extended beyond the linear regime to account perturbatively for mean-field atomic interactions in the atom-optical aberration-less approximation. A treatment of the atom laser extraction enabling one to describe aberrations in the atomic beam, developed in collaboration with the Atom Optics group at the Institute of Optics, is exposed. Last, a quality factor suitable for the characterization of diluted matter waves in a general propagation regime has been proposed. (author)

  16. Atom localization and center-of-mass wave-function determination via multiple simultaneous quadrature measurements

    Evers, Joerg; Qamar, Shahid; Zubairy, M. Suhail

    2007-01-01

    We discuss localization and center-of-mass wave-function measurement of a quantum particle using multiple simultaneous dispersive interactions of the particle with different standing-wave fields. In particular, we consider objects with an internal structure consisting of a single ground state and several excited states. The transitions between ground and the corresponding excited states are coupled to the light fields in the dispersive limit, thus giving rise to a phase shift of the light field during the interaction. We show that multiple simultaneous measurements allow both an increase in the measurement or localization precision in a single direction and the performance of multidimensional measurements or localization. Further, we show that multiple measurements may relax the experimental requirements for each individual measurement

  17. Multiple ionization effects in M X-ray emission induced by heavy ions

    Wang, Xing; Zhao, Yongtao; Cheng, Rui; Zhou, Xianming; Xu, Ge; Sun, Yuanbo; Lei, Yu; Wang, Yuyu; Ren, Jieru; Yu, Yang; Li, Yongfeng; Zhang, Xiaoan; Li, Yaozong; Liang, Changhui; Xiao, Guoqing

    2012-01-01

    M-shell ionization of tungsten by Ar 12+ ions were investigated in the energy range of 1.2–3.0 MeV. The measurements were also implemented for H, He and Xe ions as a comparative study. A significant shift of the M X-ray lines to the higher energy side caused by multiple ionizations, which was verified by the analysis of the intensity ratios of M γ and M αβ , was observed. The total experimental cross sections of tungsten were compared with the PWBA and ECPSSR theoretical predictions, which are based on two extreme assumptions, namely, single ionization and full ionization. -- Highlights: ► Projectiles with low velocity (near Bohr velocity). ► A significant shift of the M X-ray lines to the higher energy side. ► A large enhancement in the M 3 fluorescence yield. ► Theoretical predictions based on single ionization and full ionization.

  18. Atomic parity violation in heavy alkalis: detection by stimulated emission for cesium and traps for cold francium

    Sanguinetti, St

    2004-07-01

    The present work deals with the recent advances of atomic spectroscopy experiments on cesium and francium, which aim at precise parity violation (PV) measurements in these atoms. Within the framework of a 'double-badged thesis', the candidate devoted himself on the one hand to the preliminary PV measurement (8% accuracy) of the present Cs experiment at the Kastler-Brossel laboratory in Paris and on the other hand to the preparation of a Fr radioactive atomic sample (production and trapping) at the LNL (INFN) in Italy. The two experiments are at very different stages. The measurements reported for cesium were actually made possible thanks to the work initiated in 1991, for the PV detection by stimulated emission. The Italian experiment is instead in a beginning stage: in order to probe the properties of francium, which is unstable, a number of atoms large enough has to be first produced and collected. The PV schemes which proved to be well suited for cesium are a solid starting point for the case of francium. (author)

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

    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)

  20. Probing the specific entropy produced in ultra-relativistic heavy-ion collisions with a silicon pixel multiplicity detector: a simulation study

    Antinori, F.; Balada, A.; Barbera, R.; Staroba, Pavel; Závada, Petr

    2000-01-01

    Roč. 452, - (2000), s. 323-337 ISSN 0168-9002 Institutional research plan: CEZ:AV0Z1010920 Keywords : ultra-relativistic * heavy-ion collisions * nuclear matter * phase diagram * hadron gas * Quark Gluon Plasma * particle multiplicity * transverse momentum spectra Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.964, year: 2000

  1. The evolution of multiple isotypic IgM heavy chain genes in the shark.

    Lee, Victor; Huang, Jing Li; Lui, Ming Fai; Malecek, Karolina; Ohta, Yuko; Mooers, Arne; Hsu, Ellen

    2008-06-01

    The IgM H chain gene organization of cartilaginous fishes consists of 15-200 miniloci, each with a few gene segments (V(H)-D1-D2-J(H)) and one C gene. This is a gene arrangement ancestral to the complex IgH locus that exists in all other vertebrate classes. To understand the molecular evolution of this system, we studied the nurse shark, which has relatively fewer loci, and characterized the IgH isotypes for organization, functionality, and the somatic diversification mechanisms that act upon them. Gene numbers differ slightly between individuals ( approximately 15), but five active IgM subclasses are always present. Each gene undergoes rearrangement that is strictly confined within the minilocus; in B cells there is no interaction between adjacent loci located > or =120 kb apart. Without combinatorial events, the shark IgM H chain repertoire is based on junctional diversity and, subsequently, somatic hypermutation. We suggest that the significant contribution by junctional diversification reflects the selected novelty introduced by RAG in the early vertebrate ancestor, whereas combinatorial diversity coevolved with the complex translocon organization. Moreover, unlike other cartilaginous fishes, there are no germline-joined VDJ at any nurse shark mu locus, and we suggest that such genes, when functional, are species-specific and may have specialized roles. With an entire complement of IgM genes available for the first time, phylogenetic analyses were performed to examine how the multiple Ig loci evolved. We found that all domains changed at comparable rates, but V(H) appears to be under strong positive selection for increased amino acid sequence diversity, and surprisingly, so does Cmicro2.

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

    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.

  3. O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside

    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.

  4. O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside.

    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.

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

    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

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

    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.

  7. Multiple exposure and effects assessment of heavy metals in the population near mining area in South China.

    Ping Zhuang

    Full Text Available The objective of this study was to investigate the levels of Cd, Pb, Cu and Zn in the environment and several important food sources grown and consumed in the vicinity of Dabaoshan mine in Southern China, and evaluate potential health risks among local residents. The Cd, Pb, Cu and Zn concentrations of arable soils and well water near the mines exceeded the quality standard values. The concentrations of Cd and Pb in some food crops (rice grain, vegetable and soybean samples were significantly higher than the maximum permissible level. The Cd and Pb concentrations in half of the chicken and fish meat samples were higher than the national standard. The residents living near Dabaoshan mine had higher Cd and Pb levels in hair than those of a non-exposed population. The intake of rice was identified as a major contributor to the estimated daily intake of these metals by the residents. The hazard index values for adults and children were 10.25 and 11.11, respectively, with most of the estimated risks coming from the intake of home-grown rice and vegetables. This study highlights the importance of multiple pathways in studying health risk assessment of heavy metal exposure in China.

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

    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.

  9. Surface modelling on heavy atom crystalline compounds: HfO{sub 2} and UO{sub 2} fluorite structures

    Evarestov, Robert [Department of Quantum Chemistry, St. Petersburg State University, 26 Universitetsky Prospect, Peterhof, St. Petersburg 198504 (Russian Federation)], E-mail: re1973@re1973.spb.edu; Bandura, Andrei; Blokhin, Eugeny [Department of Quantum Chemistry, St. Petersburg State University, 26 Universitetsky Prospect, Peterhof, St. Petersburg 198504 (Russian Federation)

    2009-01-15

    The study of the bulk and surface properties of cubic (fluorite structure) HfO{sub 2} and UO{sub 2} was performed using the hybrid Hartree-Fock density functional theory linear combination of atomic orbitals simulations via the CRYSTAL06 computer code. The Stuttgart small-core pseudopotentials and corresponding basis sets were used for the core-valence interactions. The influence of relativistic effects on the structure and properties of the systems was studied. It was found that surface properties of Mott-Hubbard dielectric UO{sub 2} differ from those found for other metal oxides with the closed-shell configuration of d-electrons.

  10. Determination of Heavy Metals in Meat, Intestine, Liver, Eggs, and Chicken Using Neutron Activation Analysis and Atomic Absorption Spectrometry

    Surtipanti, S.; Suwirma, S.; Yumiarti, S.; Mellawati, Yune

    1995-01-01

    The elements As, Cd, Co, Cr, Fe, Hg, Ni, Pb, Sb, se and Zn in meat, intestine, and liver of cow and goat, as well as in broiler, local breed chicken and eggs have been determined using Neutron Activation Analysis and Atomic Absorption Spectrometry. Mercury was determined after being separated radiochemically. The results showed that concentration of the essential elements studied i.e. Cr, Cu, Fe, Zn, Co, and Ni were higher in liver and intestine than in the meat, but still in the normal range, while toxic elements As, Cd, and Pb were undetectable in all samples. (author). 8 refs., 6 tabs

  11. Determination of Heavy Metals in Meat, Intestine, Liver, Eggs, and Chicken Using Neutron Activation Analysis and Atomic Absorption Spectrometry

    Surtipanti, S; Suwirma, S; Yumiarti, S; Mellawati, Yune [National Atomic Energy Agency, Jakarta (Indonesia), Center for the Application of Isotopes Radiation

    1995-01-01

    The elements As, Cd, Co, Cr, Fe, Hg, Ni, Pb, Sb, se and Zn in meat, intestine, and liver of cow and goat, as well as in broiler, local breed chicken and eggs have been determined using Neutron Activation Analysis and Atomic Absorption Spectrometry. Mercury was determined after being separated radiochemically. The results showed that concentration of the essential elements studied i.e. Cr, Cu, Fe, Zn, Co, and Ni were higher in liver and intestine than in the meat, but still in the normal range, while toxic elements As, Cd, and Pb were undetectable in all samples. (author). 8 refs., 6 tabs.

  12. Gain assisted multiple surperluminal regions via a Kerr nonlinearity in a double lambda-type atomic configuration

    Bacha, Bakht Amin; Ghafoor, Fazal; Ahmad, Iftikhar; Rahman, A

    2014-01-01

    A four level double lambda-type atomic configuration is extended to polychromatic pump fields driven from the ground to the same excited hyperfine sublevel. Multiple superluminal regions are observed in the gain peak regions and between the two pairs of gain peak regions. Furthermore, the effect of cross Kerr nonlinearity is introduced in the system by applying an additional driving field. Large enhancement in the superluminality is observed as compared to the previously observed superluminality without the Kerr nonlinearity. The results clearly show a small negative group velocity of − 0.72 m s −1 with a negative time delay of −42.2 ms in the presence of the Kerr field. In this connection, useful theoretical techniques are presented for the enhancement of slow and fast light propagation. This generalized model is adjustable with the current applied technologies of cloaking devices and spacial mode images. (paper)

  13. Probing of multiple magnetic responses in magnetic inductors using atomic force microscopy.

    Park, Seongjae; Seo, Hosung; Seol, Daehee; Yoon, Young-Hwan; Kim, Mi Yang; Kim, Yunseok

    2016-02-08

    Even though nanoscale analysis of magnetic properties is of significant interest, probing methods are relatively less developed compared to the significance of the technique, which has multiple potential applications. Here, we demonstrate an approach for probing various magnetic properties associated with eddy current, coil current and magnetic domains in magnetic inductors using multidimensional magnetic force microscopy (MMFM). The MMFM images provide combined magnetic responses from the three different origins, however, each contribution to the MMFM response can be differentiated through analysis based on the bias dependence of the response. In particular, the bias dependent MMFM images show locally different eddy current behavior with values dependent on the type of materials that comprise the MI. This approach for probing magnetic responses can be further extended to the analysis of local physical features.

  14. Calculation of probabilities of rotational transitions of two-atom molecules in the collision with heavy particles

    Vargin, A.N.; Ganina, N.A.; Konyukhov, V.K.; Selyakov, V.I.

    1975-01-01

    The problem of calculation of collisional probabilities of rotational transitions (CPRT) in molecule-molecule and molecule-atom interactions in a three-dimensional space has been solved in this paper. A quasiclassical approach was used. The calculation of collisional probabilities of rotational transitions trajectory was carried out in the following way. The particle motion trajectory was calculated by a classical method and the time dependence of the perturbation operator was obtained, its averaging over wave functions of initial and finite states produced CPRT. The classical calculation of the molecule motion trajectory was justified by triviality of the de Broglie wavelength, compared with characteristic atomic distances, and by triviality of a transfered rotational quantum compared with the energy of translational motion of particles. The results of calculation depend on the chosen interaction potential of collisional particles. It follows from the Messy criterion that the region of nonadiabaticity of interaction may be compared with internuclear distances of a molecule. Therefore, for the description of the interaction a short-range potential is required. Analytical expressions were obtained appropriate for practical calculations for one- and two-quantum rotational transitions of diatomic molecules. The CPRT was averaged over the Maxwell distribution over velocities and analytical dependences on a gas temperature were obtained. The results of the numerical calculation of probabilities for the HCl-HCl, HCl-He, CO-CO interactions are presented to illustrate the method

  15. Heavy metals in brick kiln located area using atomic absorption spectrophotometer: a case study from the city of Peshawar, Pakistan.

    Ishaq, M; Khan, Murad Ali; Jan, F Akbar; Ahmad, I

    2010-07-01

    Environmental pollution is one of the burning issues of the world. In developed countries, there are lot of awareness about the environment and the impact of various industries on their life and surroundings. A little has been done in this direction in developing countries. In Pakistan, a big problem is the rapid conglomeration of the brick kilns in the outskirts of nearly all the urban centers to cope with the rapid construction work in big cities. A huge amount of low-grade coal or rubber tires is used as fuel in a very non-scientific manner. The purpose of the present study was to look into the impact of the brick kilns on the different aspects of environmental pollution caused by these kilns. Concentration of metals Cu, Co, Zn, Pb, Cr, Ni, Cd, and Mn were measured on 36 soil samples collected from the area and the same number of plant samples in order to establish the distribution of heavy metals in the area and to determine the effect of this distribution on the surrounding atmosphere and the possible effects on human life.

  16. Multiple heavy metals extraction and recovery from hazardous electroplating sludge waste via ultrasonically enhanced two-stage acid leaching.

    Li, Chuncheng; Xie, Fengchun; Ma, Yang; Cai, Tingting; Li, Haiying; Huang, Zhiyuan; Yuan, Gaoqing

    2010-06-15

    An ultrasonically enhanced two-stage acid leaching process on extracting and recovering multiple heavy metals from actual electroplating sludge was studied in lab tests. It provided an effective technique for separation of valuable metals (Cu, Ni and Zn) from less valuable metals (Fe and Cr) in electroplating sludge. The efficiency of the process had been measured with the leaching efficiencies and recovery rates of the metals. Enhanced by ultrasonic power, the first-stage acid leaching demonstrated leaching rates of 96.72%, 97.77%, 98.00%, 53.03%, and 0.44% for Cu, Ni, Zn, Cr, and Fe respectively, effectively separated half of Cr and almost all of Fe from mixed metals. The subsequent second-stage leaching achieved leaching rates of 75.03%, 81.05%, 81.39%, 1.02%, and 0% for Cu, Ni, Zn, Cr, and Fe that further separated Cu, Ni, and Zn from mixed metals. With the stabilized two-stage ultrasonically enhanced leaching, the resulting over all recovery rates of Cu, Ni, Zn, Cr and Fe from electroplating sludge could be achieved at 97.42%, 98.46%, 98.63%, 98.32% and 100% respectively, with Cr and Fe in solids and the rest of the metals in an aqueous solution discharged from the leaching system. The process performance parameters studied were pH, ultrasonic power, and contact time. The results were also confirmed in an industrial pilot-scale test, and same high metal recoveries were performed. Copyright 2010 Elsevier B.V. All rights reserved.

  17. [The value of serum heavy/light chain immunoassay to assess therapeutic response in patients with multiple myeloma].

    Yu, X C; Su, W; Zhuang, J L

    2018-04-14

    Objective: To assess the value of immunoglobulin heavy/light chain (HLC) immunoassay on therapeutic response in patients with multiple myeloma(MM). Methods: A total of 45 newly diagnosed MM patients were retrospectively enrolled in Peking Union Medical College Hospital from 2013 to 2016, whose 115 serum samples were consecutively collected. HLC was tested to evaluate response and compare with other methods for M protein detection. Results: ①There were 30 males and 15 females in total of whom the monoclonal immunoglobulin was IgG in 27 (IgGκ∶IgGλ 12∶15) and IgA (IgAκ∶IgAλ 9∶9) in 18. The arerage age of the studied population was 59 (range 43-80) . ② In 34 patients with serum sample at diagnosis, 32 (94.1%) had abnormal HLC ratio (rHLC) while 2 patients with IgG had normal rHLC. The percentages of abnormal rHLC was 81.8% (18/22) at partial response、50.0%(9/18) at very good complete response and 16.0%(4/25) at complete response. ③In 25 patients reaching CR, there were 13 with IgG and 12 with IgA. 4 patients equally split of IgG and IgA had abnormal rHLC at complete response. ④By monitoring the rHLC of some patients consecutively, we found that the remission of rHLC was to some extent behind the remission of SPE and IEF, or even rFLC. Conclusion: Immunoglobulin HLC detection is one feasible method for minimal residual disease detection.

  18. Speciation analysis of arsenic in biological matrices by automated hydride generation-cryotrapping-atomic absorption spectrometry with multiple microflame quartz tube atomizer (multiatomizer).

    This paper describes an automated system for the oxidation state specific speciation of inorganic and methylated arsenicals by selective hydride generation - cryotrapping- gas chromatography - atomic absorption spectrometry with the multiatomizer. The corresponding arsines are ge...

  19. Neutron activation and atomic absorption analyses of heavy metals in corals of Malaysia: historical recorders for sustainable environmental management

    Mazlin Mokhtar; Almah Awaludin; Abdul Khalik Wood; Lim Kim Shenk; Tan Pey Fang; Yasmin Mohd Hasni

    2001-01-01

    This paper reports the determination of total chromium (Cr), manganese (Mn), and zinc (Zn) in skeletons of the corals Porites sp., sediment and sea water samples taken from various locations in waters of Kedah, Johor and Labuan. Sampling was carried out around Pulau Bunting, Pulau Bidan, Pulau Telur, Pulau Songsong, all in Kedah, Pulau Burung in Labuan, and Pulau Lima in Johor. The concentrations of metals were determined using neutron activation analysis (NAA) and atomic absorption spectrophotometry (AAS). The range of concentrations of Cr, Mn and Zn in coral samples of this study were <0.2 - 1.60, 1.20 - 11.10 and 3.55 - 15.08 μg/g, respectively. Concentrations in sediment samples were Cr 0.62 - 5.19 μg/g, Mn 71.0 - 162 μg/g and Zn 28.2 - 57.8 μg/g. The levels in seawater samples were Cr 0.004 - 0.28 mg/l, Mn 0.26 - 0.33 mg/l, and Zn 0.92 - 1.56 mg/l. (Author)

  20. Violence of heavy-ion reactions from neutron multiplicity: 11 to 20A MeV /sup 20/Ne+ /sup 238/U

    Jahnke, U.; Ingold, G.; Hilscher, D.; Lehmann, M.; Schwinn, E.; Zank, P.

    1986-01-01

    The suitability of the neutron multiplicity as a gauge for the violence of medium-energy heavy-ion reactions is investigated for the first time. For this purpose the number of neutrons emitted from fission reactions induced by 220-, 290-, and 400-MeV /sup 20/Ne on /sup 238/U is registered event-by-event with a large 4π scintillator tank. It is shown that the neutron multiplicity is indeed closely related to the two quantities characterizing the violence: the induced total intrinsic excitation and the linear momentum transfer

  1. Adaption of Ulva pertusa to multiple-contamination of heavy metals and nutrients: Biological mechanism of outbreak of Ulva sp. green tide.

    Ge, Changzi; Yu, Xiru; Kan, Manman; Qu, Chunfeng

    2017-12-15

    The multiple-contamination of heavy metals and nutrients worsens increasingly and Ulva sp. green tide occurs almost simultaneously. To reveal the biological mechanism for outbreak of the green tide, Ulva pertusa was exposed to seven-day-multiple-contamination. The relation between pH variation (V pH ), Chl a content, ratio of (Chl a content)/(Chl b content) (R chla/chlb ), SOD activity of U. pertusa (A SOD ) and contamination concentration is [Formula: see text] (pcontamination concentrations of seawaters where Ulva sp. green tide occurred and the contamination concentrations set in the present work, U. pertusa can adapt to multiple-contaminations in these waters. Thus, the adaption to multiple-contamination may be one biological mechanism for the outbreak of Ulva sp. green tide. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Charge fraction of 6.0 MeV/n heavy ions with a carbon foil: Dependence on the foil thickness and projectile atomic number

    Sato, Y; Muramatsu, M; Murakami, T; Yamada, S; Kobayashi, C; Kageyama, Y; Miyoshi, T; Ogawa, H; Nakabushi, H; Fujimoto, T; Miyata, T; Sano, Y

    2003-01-01

    We measured the charge fraction of 6.0 MeV/n heavy ions (C, Ne, Si, Ar, Fe and Cu) with a carbon foil at the NIRS-HIMAC injector. At this energy they are stripped with a carbon foil before being injected into two synchrotron rings with a maximum energy of 800 MeV/n. In order to find the foil thickness (D sub E) at which an equilibrium charge state distribution occurs, and to study the dependence of the D sub E -values on the projectile atomic number, we measured the exit charge fractions for foil thicknesses of between 10 and 350 mu g/cm sup 2. The results showed that the D sub E -values are 21.5, 62.0, 162, 346, 121, 143 mu g/cm sup 2 for C, Ne, Si, Ar, Fe, Cu, respectively. The fraction of Ar sup 1 sup 8 sup + ions was actually improved to 33% at 320 mu g/cm sup 2 from approx 15% at 100 mu g/cm sup 2. For Fe and Cu ions, the D sub E -values were found to be only 121 and 143 mu g/cm sup 2; there is a large gap between Ar and Fe, which is related to the differences in the ratio of the binding energy of the K-...

  3. Distribution of heavy metals in Lumbricus terrestris, Aporrectodea longa and A. rosea measured by atomic absorption and X-ray fluorescence spectrometry

    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)

  4. Phasing and structure of bestrophin-1: a case study in the use of heavy-atom cluster compounds with multi-subunit transmembrane proteins

    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.

  5. Analysis of heavy metals and minerals elements in the turmeric using Total-Reflection X-ray Fluorescence analysis technique and Atomic Absorption Spectrometry

    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

  6. On the possibilities of high-resolution continuum source graphite furnace atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple atomic lines

    Resano, M.; Rello, L.; Florez, M.; Belarra, M.A.

    2011-01-01

    This paper explores the potential of commercially available high-resolution continuum source graphite furnace atomic absorption spectrometry instrumentation for the simultaneous or sequential monitoring of various atomic lines, in an attempt to highlight the analytical advantages that can be derived from this strategy. In particular, it is demonstrated how i) the monitoring of multiplets may allow for the simple expansion of the linear range, as shown for the measurement of Ni using the triplet located in the vicinity of 234.6 nm; ii) the use of a suitable internal standard may permit improving the precision and help in correcting for matrix-effects, as proved for the monitoring of Ni in different biological samples; iii) direct and multi-element analysis of solid samples may be feasible on some occasions, either by monitoring various atomic lines that are sufficiently close (truly simultaneous monitoring, as demonstrated in the determination of Co, Fe and Ni in NIST 1566a Oyster tissue) or, alternatively, by opting for a selective and sequential atomization of the elements of interest during every single replicate. Determination of Cd and Ni in BCR 679 White cabbage is attempted using both approaches, which permits confirming that both methods can offer very similar and satisfactory results. However, it is important to stress that the second approach provides more flexibility, since analysis is no longer limited to those elements that show very close atomic lines (closer than 0.3 nm in the ultraviolet region) with a sensitivity ratio similar to the concentration ratio of the analytes in the samples investigated.

  7. Heavy metal contamination of some vegetables on display for sale along busy roads - a case study of the Haatso-Atomic junction road

    Appiah, G.K.

    2010-01-01

    Heavy metal contamination of food is a major concern due to the potential health risk involved. This work assessed the heavy metal contamination of lettuce and cabbage on display for sale along some busy roads in Accra using instrumental neutron activation analysis and atomic absorption spectrometry. The background levels of Fe, Mn, Cu, Zn, Ni, Cr, Cd and Pb in lettuce and cabbage harvested from a vegetable after deliberate exposure along a busy road for three days were also determined. Background levels of elements in the vegetables in mg/kg were, Fe (162.97) > Mn (58.28) > Zn (10.78) > Cu (4.61) > Cr (4.06) > Ni (2.93) for lettuce and Fe (44.91) > Mn (20.95) > Zn (6.69) > Ni (2.59) > Cr (2.32) > Cu (1.16) for cabbage. The levels of all the elements increased in both vegetables after deliberate exposure with the third day recording the highest levels. The total amount of metals deposited on the vegetables after exposure for three days in mg/kg was Fe (22.27), Mn (11.8), Cu (1.68), Zn (3.17), Ni (1.87) and Cr (1.16 for lettuce and Fe (18.76), Mn (12.83), Cu (1.59), Zn (5.58), Ni (2.38) and Cr (1.8) for cabbage. Rates of contamination of the vegetables by metals in mg/kg/day were, Fe (9.09) > Mn (3.93) > Zn (1.06) > Ni (0.62) > Cu (0.56) = Cr (0.56) for lettuce and Fe (6.25) > Mn (4.28) > Zn (1.86) > Ni (0.79) > Cr (0.6) > Cu (0.53) for cabbage. The estimated daily intakes of the elements through consumption of the contaminated vegetables were all below the upper tolerable intake levels of the elements and pose no health risk. (au)

  8. 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

    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> ...

  9. A practical theoretical formalism for atomic multielectron processes: direct multiple ionization by a single auger decay or by impact of a single electron or photon

    Liu, Pengfei; Zeng, Jiaolong; Yuan, Jianmin

    2018-04-01

    Multiple electron processes occur widely in atoms, molecules, clusters, and condensed matters when they are interacting with energetic particles or intense laser fields. Direct multielectron processes (DMEP) are the most complicated among the general multiple electron processes and are the most difficult to describe theoretically. In this work, a unified and accurate theoretical formalism is proposed on the DMEP of atoms including the multiple auger decay and multiple ionization by an impact of a single electron or a single photon based on the atomic collision theory described by a correlated many-body Green's function. Such a practical treatment is made possible by taking consideration of the different coherence features of the atoms (matter waves) in the initial and final states. We first explain how the coherence characteristics of the ejected continuum electrons is largely destructed, by taking the electron impact direct double ionization process as an example. The direct double ionization process is completely different from the single ionization where the complete interference can be maintained. The detailed expressions are obtained for the energy correlations among the continuum electrons and energy resolved differential and integral cross sections according to the separation of knock-out (KO) and shake-off (SO) mechanisms for the electron impact direct double ionization, direct double and triple auger decay, and double and triple photoionization (TPI) processes. Extension to higher order DMEP than triple ionization is straight forward by adding contributions of the following KO and SO processes. The approach is applied to investigate the electron impact double ionization processes of C+, N+, and O+, the direct double and triple auger decay of the K-shell excited states of C+ 1s2{s}22{p}2{}2D and {}2P, and the double and TPI of lithium. Comparisons with the experimental and other theoretical investigations wherever available in the literature show that our

  10. Transition-state analysis of a Vmax mutant of AMP nucleosidase by the application of heavy-atom kinetic isotope effects

    Parkin, D.W.; Mentch, F.; Banks, G.A.; Horenstein, B.A.; Schramm, V.L.

    1991-01-01

    The transition state of the V max mutant of AMP nucleosidase from Azotobacter vinelandii has been characterized by heavy-atom kinetic isotope effects in the presence and absence of MgATP, the allosteric activator. The enzyme catalyzes hydrolysis of the N-glycosidic bond of AMP at approximately 2% of the rate of the normal enzyme with only minor changes in the K m for substrate, the activation constant for MgATP, and the K i for formycin 5'-phosphate, a tight-binding competitive inhibitor. Isotope effects were measured as a function of the allosteric activator concentration that increases the turnover number of the enzyme from 0.006 s -1 . The kinetic isotope effects were measured with the substrates [1'- 3 H]AMP, [2'- 2 H]AMP, [9- 15 N]AMP, and [1',9- 14 C, 15 N]AMP. All substrates gave significant kinetic isotope effects in a pattern that establishes that the reaction expresses intrinsic kinetic isotope effects in the presence or absence of MgATP. Transition-state analysis using bond-energy and bond-order vibrational analysis indicated that the transition state for the mutant enzyme has a similar position in the reaction coordinate compared to that for the normal enzyme. The mutant enzyme is less effective in stabilizing the carbocation-like intermediate and in the ability to protonate N7 of adenine to create a better leaving group. This altered transition-state structure was confirmed by an altered substrate specificity for the mutant protein

  11. Photochemical heavy-atom effects

    Koziar, J.C.; Cowan, D.O.

    1978-01-01

    The effects of halogenated solvents such as n-butyl chloride, n-propyl bromide, and ethyl iodide, on the photochemistry of several aromatic compounds are reviewed. Dimerization of acenaphthylene is discussed in terms of spin -orbit coupling induced by the solvents. Appropriate wave functions are given for both the solvents and the compound. Cycloaddition reactions, electrocyclic rearrangements, and photochemical cis-trans isomerization are also considered

  12. Comparison of heavy metal contamination during the last decade along the coastal sediment of Pakistan: Multiple pollution indices approach.

    Saher, Noor Us; Siddiqui, Asmat Saleem

    2016-04-15

    Heavy metals concentrations (Fe, Cu, Zn, Ni, Cr, Co, Pb, and Cd) were scrutinized during two monitoring years (2001 and 2011) in the coastal sediment of Pakistan. The status of metal contamination in coastal sediment was interpreted using sediment quality guidelines, and single and combined metal pollution indices. Ni, Cr, and Cd were recognized for their significant (p<0.05) intensification in the sediment during the last decade. Sediment quality guidelines recognized the frequent adverse biological effect of Ni and the occasional adverse biological effect of Cu, Cr, Pb and Cd. Single metal pollution indices (Igeo, EF, CF, and ER) revealed that sediment pollution is predominantly caused by Pb and Cd. Low to moderate contamination was appraised along the coast by multi-metal pollution indices (CD and PERI). Correlation study specifies that heavy metals were presented diverse affiliations and carriers for distribution in the sediment during the last decade. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    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

  14. Quasi-atoms

    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.)

  15. Application of gamma ray spectrometry and atomic absorption spectrometry for monitoring some radionuclides and heavy metals in sediments from the sudanese red sea coast

    Idris, A. M.; Eltayeb, M. A.

    2004-01-01

    A total of 31 surface sediment samples were collected from port-sudan harbour, sawakin harbour and the fringing reefs area that are located along the Sudanese coast of the red sea. The sampling was performed to provide good spatial coverage taking into account man's activity in port-sudan harbour and the fringing reefs area. the bulk samples were analyzed for some natural and anthropogenic radionuclides ( 226 Ra, 228 Ra, 40 K, 137 Cs) using direct gamma-ray spectrometry. Concentration of some heavy metals were determined in five fractions with grain-size of 1.000-0.500 m lm, 0.500-0.250 m lm, 0.250-0.125 m lm, 0.125-0.063 m lm and less than 0.063 m lm. The fractionation process was performed using dry sieving method. A total of 155 sub-samples (fractions) were digested by wet digestion method and analyzed for Mn, Fe, Ni, Cu, Zn, and Pb using flame atomic absorption spectrometry. Quality assurance of the obtained data was achieved through the analysis of certified reference materials. the radioactivity concentration ranges of ( 226 Ra, 228 Ra, and 40 K,) are 2.5-25.1b/kg, 2.1-13.1b q/kg,21.6- 429 Bq/kg, respectively. For ( 137 Cs)measurements, the highest value is 8.3 Bq/kg while most of samples were below the detection limits of the system. The concentration ranges of Mn, Fe, Cu, Zn, and Pb are 53.3-819 mg/kg, 1.4-51 mg/g, 8-131 mg/kg 9.5-113 mg/kg, 18.4-142 mg/kg, and 4.0-26.6 mg/kg, respectively. The granulometric normalization shows that some samples were subjected to anthropogenic activities. This finding was reinforced by results that were obtained from enrichment factor calculations and statistical multivariate analysis that is principal component analysis (Pca), also the Pca indicates that silt/clay fraction (>0.063 m lm ) is the dominant source for the emission of anthropogenic activities. From viewpoint of mineralogical composition the cluster analysis has distributed the samples into tow clusters. Dominant elements in sediments (Mn and Fe ) recorded

  16. L X-ray emission induced by heavy ions

    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.

  17. Development of on-line heavy water analysis by vibrating probe density meter and multiple internal reflectance infrared spectrometry

    Jones, V.D.; Nora, B.

    1984-01-01

    Achieving high productivity in the Savannah River Plant nuclear reactors requires that the heavy water (D 2 O) moderator be maintained at a high purity level. Since the D 2 O purity will degrade with time, a fraction of the moderator must be continually reprocessed to remove H 2 O. This rework process uses a series of fractional distillation columns. The process control is based on laboratory analyses of process samples every four hours. The sample streams, which can range from 0.10 to 99.80 mol % D 2 O, are analyzed using infrared spectrophotometry. An automatic on-line analysis would provide tighter process control and reduce personnel exposure to the tritiated moderator. Two instruments are being evaluated for on-line control; an Anton/Parr DPR 2000 density measuring system and a General Analysis Corporation LAN-I infrared liquid stream monitor

  18. Evolution of corresponding resistance genes in the water of fish tanks with multiple stresses of antibiotics and heavy metals.

    He, Xiaolin; Xu, Yanbin; Chen, Jinliang; Ling, Jiayin; Li, Yafei; Huang, Lu; Zhou, Xiao; Zheng, Li; Xie, Guangyan

    2017-11-01

    Abuse of antibiotics and heavy metals in aquaculture has been widely concerned and might aggravate the spread of resistance genes in environment. To investigate the occurrence and proliferation of antibiotic resistance genes (ARGs) and heavy metal resistance genes (HMRGs), three commonly used antibiotics (tetracycline, sulfanilamide, cefotaxime) and two heavy metals (Zn and Cu) were designed to add individually or jointly in nine fish tanks including five individual exposure tanks of tetracycline (tet), sulfanilamide (sul), cefotaxime (cef), Cu, Zn and four combination exposure tanks of tetracycline + sulfanilamide (tet + sul), tetracycline + sulfanilamide + cefotaxime (tet + sul + cef), tetracycline + sulfanilamide + Cu (tet + sul + Cu), tetracycline + sulfanilamide + Zn (tet + sul + Zn) as well as the control during the experiment period of 180 days. Nineteen ARGs (tetA, tetB, tetC, tetD, tetE, tetG, tetM, tetO, tetQ, tetS, tetW, tetX, tetY, sul1, sul2, sul3, bla DHA , bla MOX , bla FOX ), two HMRGs (copA, czcA) and the class 1 integron gene (intI 1) in fish tanks water were investigated. The results showed that the residual rate of antibiotics and heavy metals ranged from 0.03% to 2.46% and 9.25%-52.97%, respectively, positively related to their original concentration and types. Tetracycline resistance genes were more sensitive to antibiotics and easier to be induced and developed than sulfanilamide resistance genes and AmpC β-lactamase resistance genes. The total relative abundances of ARGs in combined stresses exposure tanks (tet + sul, tet + sul + cef, tet + sul + Cu, tet + sul + Zn) were about 1.01-1.55 times more than the sum of their individual ones. The co-selective effects of cefotaxime on the abundance and diversity of tetracycline resistance genes were stronger than Zn and Cu. Besides, multivariate correlation analysis revealed that tetO, tetQ, tetW and sul3 were in significant correlation with the

  19. Overcoming Matrix Effects in a Complex Sample: Analysis of Multiple Elements in Multivitamins by Atomic Absorption Spectroscopy

    Arnold, Randy J.; Arndt, Brett; Blaser, Emilia; Blosser, Chris; Caulton, Dana; Chung, Won Sog; Fiorenza, Garrett; Heath, Wyatt; Jacobs, Alex; Kahng, Eunice; Koh, Eun; Le, Thao; Mandla, Kyle; McCory, Chelsey; Newman, Laura; Pithadia, Amit; Reckelhoff, Anna; Rheinhardt, Joseph; Skljarevski, Sonja; Stuart, Jordyn; Taylor, Cassie; Thomas, Scott; Tse, Kyle; Wall, Rachel; Warkentien, Chad

    2011-01-01

    A multivitamin tablet and liquid are analyzed for the elements calcium, magnesium, iron, zinc, copper, and manganese using atomic absorption spectrometry. Linear calibration and standard addition are used for all elements except calcium, allowing for an estimate of the matrix effects encountered for this complex sample. Sample preparation using…

  20. 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

    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.

  1. Energy dependence of multiplicity fluctuations in heavy ion collisions at 20A to 158A GeV

    Alt, C.; Baatar, B.; Barna, D.; Bartke, J.; Betev, L.; Bialkowska, Helena; Blume, Christoph; Boimska, B.; Botje, Michiel; Bracinik, J.; Bramm, R.; Buncic, P.; Cerny, V.; Christakoglou, P.; Chung, P.; Chvala, O.; Cramer, J.G.; Csato, P.; Dinkelaker, P.; Eckardt, V.; Flierl, D.; Fodor, Zoltan; Foka, P.; Friese, Volker; Gal, J.; Gazdzicki, Marek; Genchev, V.; Georgopoulos, G.; Gladysz, E.; Grebieszkow, K.; Hegyi, S.; Hohne, C.; Kadija, K.; Karev, A.; Kikola, D.; Kliemant, M.; Kniege, S.; Kolesnikov, V.I.; Kornas, E.; Korus, R.; Kowalski, M.; Kraus, I.; Kreps, M.; Laszlo, A.; Lacey, Roy A.; van Leeuwen, M.; Levai, P.; Litov, Leandar; Makariev, M.; Malakhov, A.I.; Mateev, M.; Melkumov, G.L.; Mischke, A.; Mitrovski, M.; Molnar, J.; Mrowczynski, St.; Nicolic, V.; Palla, G.; Panagiotou, Apostolos D.; Panayotov, D.; Peryt, W.; Pikna, M.; Pluta, J.; Prindle, D.; Puhlhofer, F.; Renfordt, R.; Roland, C.; Roland, Gunther; Rybczynski, M.; Rybicki, A.; Sandoval, Andres; Schmitz, Norbert; Schuster, T.; Seyboth, P.; Sikler, F.; Sitar, B.; Skrzypczak, E.; Slodkowski, M.; Stefanek, Grzegorz; Stock, R.; Strabel, C.; Strobele, H.; Susa, T.; Szentpetery, I.; Sziklai, J.; Szuba, M.; Szymanski, P.; Trubnikov, V.; Utvic, M.; Varga, D.; Vassiliou, M.; Veres, G.I.; Vesztergombi, G.; Vranic, D.; Wetzler, A.; Wlodarczyk, Z.; Wojtaszek, A.; Yoo, I.K.

    2008-01-01

    Multiplicity fluctuations of positively, negatively and all charged hadrons in the forward hemisphere were studied in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV. The multiplicity distributions and their scaled variances $\\omega$ are presented in dependence of collision energy as well as of rapidity and transverse momentum. The distributions have bell-like shape and their scaled variances are in the range from 0.8 to 1.2 without any significant structure in their energy dependence. No indication of the critical point fluctuations are observed. The string-hadronic model UrQMD significantly overpredicts the mean, but approximately reproduces the scaled variance of the multiplicity distributions. The predictions of the statistical hadron-resonance gas model obtained within the grand-canonical and canonical ensembles disagree with the measured scaled variances. The narrower than Poissonian multiplicity fluctuations measured in numerous cases may be explained by the impact of conservation laws on f...

  2. The impact of energy conservation in transport models on the π−/π+ multiplicity ratio in heavy-ion collisions and the symmetry energy

    M.D. Cozma

    2016-02-01

    Full Text Available The charged pion multiplicity ratio in intermediate energy central heavy-ion collisions has been proposed as a suitable observable to constrain the high density dependence of the isovector part of the equation of state. A comparison of various transport model predictions with existing experimental data has led, however, to contradictory results. Using an upgraded version of the Tübingen QMD transport model, which allows the conservation of energy at a local or global level by accounting for the potential energy of hadrons in two-body collisions and leading thus to particle production threshold shifts, we demonstrate that compatible constraints for the symmetry energy stiffness can be extracted from pion multiplicity and elliptic flow observables. However, pion multiplicities and ratios are proven to be highly sensitive to the yet unknown isovector part of the in-medium Δ(1232 potential which hinders, at present, the extraction of meaningful information on the high density dependence of the symmetry energy. A solution to this problem together with the inclusion of contributions presently neglected, such as in-medium pion potentials and retardation effects, are needed for a final verdict on this topic.

  3. Progress in atomic spectroscopy

    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

  4. Code ATOM for calculation of atomic characteristics

    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.)

  5. Remediation Performance and Mechanism of Heavy Metals by a Bottom Up Activation and Extraction System Using Multiple Biochemical Materials.

    Xiao, Kemeng; Li, Yunzhen; Sun, Yang; Liu, Ruyue; Li, Junjie; Zhao, Yun; Xu, Heng

    2017-09-13

    Soil contamination with heavy metals has caused serious environmental problems and increased the risks to humans and biota. Herein, we developed an effective bottom up metals removal system based on the synergy between the activation of immobilization metal-resistant bacteria and the extraction of bioaccumulator material (Stropharia rugosoannulata). In this system, the advantages of biochar produced at 400 °C and sodium alginate were integrated to immobilize bacteria. Optimized by response surface methodology, the biochar and bacterial suspension were mixed at a ratio of 1:20 (w:v) for 12 h when 2.5% sodium alginate was added to the mixture. Results demonstrated that the system significantly increased the proportion of acid soluble Cd and Cu and improved the soil microecology (microbial counts, soil respiration, and enzyme activities). The maximum extractions of Cd and Cu were 8.79 and 77.92 mg kg -1 , respectively. Moreover, details of the possible mechanistic insight into the metal removal are discussed, which indicate positive correlation with the acetic acid extractable metals and soil microecology. Meanwhile, the "dilution effect" in S. rugosoannulata probably plays an important role in the metal removal process. Furthermore, the metal-resistant bacteria in this system were successfully colonized, and the soil bacteria community were evaluated to understand the microbial diversity in metal-contaminated soil after remediation.

  6. Kinetic Modelling of the Removal of Multiple Heavy Metallic Ions from Mine Waste by Natural Zeolite Sorption

    Amanda L. Ciosek

    2017-07-01

    Full Text Available This study investigates the sorption of heavy metallic ions (HMIs, specifically lead (Pb2+, copper (Cu2+, iron (Fe3+, nickel (Ni2+ and zinc (Zn2+, by natural zeolite (clinoptilolite. These HMIs are combined in single-, dual-, triple-, and multi-component systems. The batch mode experiments consist of a total initial concentration of 10 meq/L normality for all systems, acidified to a pH of 2 by concentrated nitric (HNO3 acid. A zeolite dosage of 4 g per 100 mL of synthetic nitrate salt aqueous solution is applied, for a contact period of 5 to 180 min. Existing kinetic models on HMIs sorption are limited for multi-component system combinations. Therefore, this study conducts kinetic analysis by both reaction and diffusion models, to quantify the sorption process. The study concludes that the process correlates best with the pseudo-second-order (PSO kinetic model. In the multi-component system combining all five HMIs, the initial sorption rate and theoretical equilibrium capacity are determined as 0.0033 meq/g·min and 0.1159 meq/g, respectively. This provides significant insight into the mechanisms associated with the sorption process, as well as contributing to the assessment of natural zeolite as a sorbent material in its application in industrial wastewater treatment.

  7. Preparation of Greenberger-Horne-Zeilinger entangled states with multiple superconducting quantum-interference device qubits or atoms in cavity QED

    Yang Chuiping; Han Siyuan

    2004-01-01

    A scheme is proposed for generating Greenberger-Horne-Zeilinger (GHZ) entangled states of multiple superconducting quantum-interference device (SQUID) qubits by the use of a microwave cavity. The scheme operates essentially by creating a single photon through an auxiliary SQUID built in the cavity and performing a joint multiqubit phase shift with assistance of the cavity photon. It is shown that entanglement can be generated using this method, deterministic and independent of the number of SQUID qubits. In addition, we show that the present method can be applied to preparing many atoms in a GHZ entangled state, with tolerance to energy relaxation during the operation

  8. Physical aspects of heavy charged particle beams for radiotherapy

    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.)

  9. Effects of Isospin on Pre-scission Particle Multiplicity of Heavy Systems and Its Excitation Energy Dependence

    YE Wei; CHEN Na

    2004-01-01

    Isospin effects on particle emission of fissioning isobaric sources 202Fr, 202po, 202Tl and isotopic sources 189,202,212Po, and its dependence on the excitation energy are studied via Smoluchowski equations. It is shown that with increasing the isospin of fissioning systems, charged-particle emission is not sensitive to the strength of nuclear dissipation. In addition, we have found that increasing the excitation energy not only increases the influence of nuclear dissipation on particle emission but also greatly enhances the sensitivity of the emission of pre-scission neutrons or charged particles to the isospin of the system. Therefore, in order to extract dissipation strength more accurately by taking light particle multiplicities it is important to choose both a highly excited compound nucleus and a proper kind of particles for systems with different isospins.

  10. Response to heavy, non-floating oil spilled in a Great Lakes river environment: a multiple-lines-of-evidence approach for submerged oil assessment and recovery

    Dollhopf, Ralph H.; Fitzpatrick, Faith A.; Kimble, Jeffrey W.; Capone, Daniel M.; Graan, Thomas P.; Zelt, Ronald B.; Johnson, Rex

    2014-01-01

    The Enbridge Line 6B pipeline release of diluted bitumen into the Kalamazoo River downstream of Marshall, MI in July 2010 is one of the largest freshwater oil spills in North American history. The unprecedented scale of impact and massive quantity of oil released required the development and implementation of new approaches for detection and recovery. At the onset of cleanup, conventional recovery techniques were employed for the initially floating oil and were successful. However, volatilization of the lighter diluent, along with mixing of the oil with sediment during flooded, turbulent river conditions caused the oil to sink and collect in natural deposition areas in the river. For more than three years after the spill, recovery of submerged oil has remained the predominant operational focus of the response. The recovery complexities for submerged oil mixed with sediment in depositional areas and long-term oil sheening along approximately 38 miles of the Kalamazoo River led to the development of a multiple-lines-of-evidence approach comprising six major components: geomorphic mapping, field assessments of submerged oil (poling), systematic tracking and mapping of oil sheen, hydrodynamic and sediment transport modeling, forensic oil chemistry, and net environmental benefit analysis. The Federal On-Scene Coordinator (FOSC) considered this information in determining the appropriate course of action for each impacted segment of the river. New sources of heavy crude oils like diluted bitumen and increasing transportation of those oils require changes in the way emergency personnel respond to oil spills in the Great Lakes and other freshwater ecosystems. Strategies to recover heavy oils must consider that the oils may suspend or sink in the water column, mix with fine-grained sediment, and accumulate in depositional areas. Early understanding of the potential fate and behavior of diluted bitumen spills when combined with timely, strong conventional recovery methods can

  11. Atomic force microscopy reveals multiple patterns of antenna organization in purple bacteria: implications for energy transduction mechanisms and membrane modeling.

    Sturgis, James N; Niederman, Robert A

    2008-01-01

    Recent topographs of the intracytoplasmic membrane (ICM) of purple bacteria obtained by atomic force microscopy (AFM) have provided the first surface views of the native architecture of a multicomponent biological membrane at submolecular resolution, representing an important landmark in structural biology. A variety of species-dependent, closely packed arrangements of light-harvesting (LH) complexes was revealed: the most highly organized was found in Rhodobacter sphaeroides in which the peripheral LH2 antenna was seen either in large clusters or in fixed rows interspersed among ordered arrays of dimeric LH1-reaction center (RC) core complexes. A more random organization was observed in other species containing both the LH1 and LH2 complexes, as typified by Rhododspirillum photometricum with randomly packed monomeric LH1-RC core complexes intermingled with large, paracrystalline domains of LH2 antenna. Surprisingly, no structures that could be identified as the ATP synthase or cytochrome bc (1) complexes were observed, which may reflect their localization at ICM vesicle poles or in curved membrane areas, out of view from the flat regions imaged by AFM. This possible arrangement of energy transducing complexes has required a reassessment of energy tranduction mechanisms which place the cytochrome bc (1) complex in close association with the RC. Instead, more plausible proposals must account for the movement of quinone redox species over considerable membrane distances on appropriate time scales. AFM, together with atomic resolution structures are also providing the basis for molecular modeling of the ICM that is leading to an improved picture of the supramolecular organization of photosynthetic complexes, as well as the forces that drive their segregation into distinct domains.

  12. Study of the multiple ionization in the ion-atom collisions with highly charged sulfur as well as with neutral and lowly charged fluorine projectiles

    Konrad, J.

    1986-01-01

    With the collisional systems 115 MeV S +Q (Q=+13, +15, +16) on He, Ne, Ar, and Kr as well as 4 MeV F +Q (Q=-1, 0, +1) on Ne the multiple ionization in the ion-atom collision was studied. With the collisional system 4 MeV F +Q on Ne the multiple ionization of target and projectile was studied by coincidence measurement between the recoil ions and projectiles with the charge state Q' after the collision (Q'=-1 to +3). In the pure ionization (no change of the projectile charge) the measured ionization cross sections for the single positive and negative charged projectile are equally large, those of the neutral F projectiles are lower. The comparison with the point particles protons and electrons resulted that the ionization cross sections of the F projectiles are larger and more strongly higher charged recoil ions are produced. The measured ionization cross sections of the F projectile are larger than those of the Ne target atom which is to be reduced to the lower ionization energies of the F projectile. With the highly charged S projectiles the multiple ionization with capture into the projectile was studied. By the measurement of triple coincidcences between recoil ions, projectiles, and SKX-radiation the cases with and without capture into the K shell can be discriminated. The charge distribution with is shifted against that without capture into the K shell to higher charges. This shift is to be reduced to the decay of autoionization states which arise by the capture into the K shell. (orig./HSI) [de

  13. First spatial separation of a heavy ion isomeric beam with a multiple-reflection time-of-flight mass spectrometer

    Dickel, T.; Plaß, W. R.; Ayet San Andres, S.; Ebert, J.; Geissel, H.; Haettner, E.; Hornung, C.; Miskun, I.; Pietri, S.; Purushothaman, S.; Reiter, M. P.; Rink, A.-K.; Scheidenberger, C.; Weick, H.; Dendooven, P.; Diwisch, M.; Greiner, F.; Heiße, F.; Knöbel, R.; Lippert, W.; Moore, I. D.; Pohjalainen, I.; Prochazka, A.; Ranjan, M.; Takechi, M.; Winfield, J. S.; Xu, X.

    2015-05-01

    211Po ions in the ground and isomeric states were produced via 238U projectile fragmentation at 1000 MeV/u. The 211Po ions were spatially separated in flight from the primary beam and other reaction products by the fragment separator FRS. The ions were energy-bunched, slowed-down and thermalized in a gas-filled cryogenic stopping cell (CSC). They were then extracted from the CSC and injected into a high-resolution multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). The excitation energy of the isomer and, for the first time, the isomeric-to-ground state ratio were determined from the measured mass spectrum. In the subsequent experimental step, the isomers were spatially separated from the ions in the ground state by an ion deflector and finally collected with a silicon detector for decay spectroscopy. This pioneering experimental result opens up unique perspectives for isomer-resolved studies. With this versatile experimental method new isomers with half-lives longer than a few milliseconds can be discovered and their decay properties can be measured with highest sensitivity and selectivity. These experiments can be extended to studies with isomeric beams in nuclear reactions.

  14. Collective vs atomic models of the hadrons

    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)

  15. Heavy-ion dosimetry

    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

  16. Heavy leptons

    Smith, C.H.L.

    1977-01-01

    The possibility that a new lepton may exist is discussed under the headings; theoretical reasons for the introduction of heavy leptons, classification of heavy leptons (ortho and paraleptons), discrimination between different types of lepton, decays of charged heavy leptons, production of charged heavy leptons (in e + e - storage rings, neutrino production, photoproduction, and hadroproduction), neutral heavy leptons, and hadroleptons. (U.K.)

  17. The effect of multiple autoclave cycles on the surface of rotary nickel-titanium endodontic files: An in vitro atomic force microscopy investigation.

    Nair, Ashish Shashikant; Tilakchand, Mahima; Naik, Balaram Damodar

    2015-01-01

    To observe and study the effect of multiple autoclave sterilization cycles, on the surface of nickel-titanium (NiTi) files. The file used for this study was the Mtwo file (VDW) and ProTaper (Dentsply). The apical 5 mm of the files were attached to a silicon wafer and subjected to autoclave cycles under standardized conditions. They were scanned with an AFM after 1, 5, and 10 cycles. The unsterilized files were used as control, before start of the study. Three vertical topographic parameters namely maximum height (MH), root mean square (RMS) of surface roughness, and arithmetic mean roughness (AMR)were measured with the atomic force microscope (AFM). Analysis of variance along with Tukey's test was used to test the differences. The vertical topographic parameters were higher for both the files, right after the first cycle, when compared with the control (P autoclave cycles, a fact that should be kept in mind during their reuse.

  18. Comparison of a neural network with multiple linear regression for quantitative analysis in ICP-atomic emission spectroscopy

    Schierle, C.; Otto, M.

    1992-01-01

    A two layer perceptron with backpropagation of error is used for quantitative analysis in ICP-AES. The network was trained by emission spectra of two interfering lines of Cd and As and the concentrations of both elements were subsequently estimated from mixture spectra. The spectra of the Cd and As lines were also used to perform multiple linear regression (MLR) via the calculation of the pseudoinverse S + of the sensitivity matrix S. In the present paper it is shown that there exist close relations between the operation of the perceptron and the MLR procedure. These are most clearly apparent in the correlation between the weights of the backpropagation network and the elements of the pseudoinverse. Using MLR, the confidence intervals over the predictions are exploited to correct for the optical device of the wavelength shift. (orig.)

  19. Atomic inner-shell physics

    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

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

    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...

  1. Inner-shell ionization of heavy atoms by slow ions. A study of electronic relativistic effects and projectile Coulomb deflection in the Semiclassical Approximation

    Amundsen, P.A.

    1978-08-01

    Several investigations have been made on K and L shell ionization of the heavy collision partner in slow asymmetric collisions based on the SCA. The use of the SCA can only be defended for slow collisions if the projectile has a charge much less than the target. Thus this approximation should first be tested for proton impact on very heavy target elements. For these elements the inner shell electrons move sufficiently fast for a relativistic description to be mandatory. These relativistic effects are in themselves of some interest, as they can be quite large. After discussion of the formulation of the SCA used throughout this work, a further introduction is given on relativistic effects in Coulomb ionisation. Two papers on electronic relativistic effects in K and L shell ionization follow. The next two papers discuss calculations with an exact Coulomb projectile path. The latter of these also touches upon the inclusion of corrections to the SCA from terms beyond first order perturbation theory. In the last paper of this thesis it is shown how the theoretical apparatus developed for the SCA- calculations can immediately be used also for making calculations of more symmetric systems with the Briggs model. Thus, at least for direct ionization in very slow collisions a unification of the SA and MO approaches has apparently been reached. (JIW)

  2. Heavy ion accelerator GANIL

    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

  3. Heavy atom disorder in the high Tsub(c) superconductor Ba2YCu3Osub(7-delta) studied by means of electron microscopy and electron diffraction

    Tendeloo, G. van; Okabe, T.; Zandbergen, H.W.; Amelinckx, S.

    1987-01-01

    It is shown that on rapid cooling of the compound Ba 2 YCu 3 Osub(7-δ) one obtains a highly disordered material in which the perovskite framework is conserved but in which barium and yttrium atoms exhibit a high degree of disorder. This leads to lattice deformations, which can be visualized in the electron microscope. The electron diffraction patterns also reveal the disorder. As-quenched specimens are no longer high Tsub(c) superconductors, but the superconducting properties can be recovered by an adequate heat treatment whereby the vacancies become ordered. (author)

  4. Heavy particle scattering by atomic and nuclear systems; Etude de la diffusion de particules lourdes sur des systemes atomiques et nucleaires

    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 {pi}{sup +} {yields} H, {mu}{sup +} {yields} H and p{sup +} {yields} H scattering lengths were given. Existence of an unknown, very weakly bound H{sup +}{sub 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 {yields} {sup 3}H, p {yields} {sup 3}H and p {yields} {sup 3}He systems were compared with the experimental data. Validity of realistic nucleon-nucleon interaction models is questioned. (author)

  5. Heavy metals in soils of Hechuan County in the upper Yangtze (SW China): Comparative pollution assessment using multiple indices with high-spatial-resolution sampling.

    Ni, Maofei; Mao, Rong; Jia, Zhongmin; Dong, Ruozhu; Li, Siyue

    2018-02-01

    In order to assess heavy metals (HMs) in soils of the upper Yangtze Basin, a very high-spatial-resolution sampling (582 soil samples) was conducted from Hechuan County, an important agricultural practice area in the Southwest China. Multiple indices including geoaccumulation index (I geo ), enrichment factor (EF), sediment pollution index (SPI) and risk index (RI), as well as multivariate statistics were employed for pollution assessment and source identification of HMs in soils. Our results demonstrated that the averages of eight HMs decreased in the following order: Zn (82.8 ± 15.9) > Cr (71.6 ± 12.2) > Ni (32.1 ± 9.89) > Pb (27.6 ± 13.8) > Cu (25.9 ± 11.8) > As (5.48 ± 3.42) > Cd (0.30 ± 0.077) > Hg (0.082 ± 0.092). Averages of HMs except Cd were lower than threshold value of Environmental Quality Standard for Soils, while 43% of total samples had Cd concentration exceeding the national standard, 1% of samples for Hg and 5% samples for Ni, moreover, Cd and Hg averages were much higher than their background levels. I geo and EF indicated that their levels decreased as follows: Cd > Hg > Zn > Pb > Ni > Cu > Cr > As, with moderate enrichments of Cd and Hg. RI indicated that 61.7% of all samples showed moderate risk, while 6.5% of samples with greater than considerable risk due to human activities should be paid more attention. Multivariate analysis showed lithogenic source of Cu, Cr, Ni and Zn, while Cd and Hg were largely contributed by anthropogenic activities such as agricultural practices. Our study would be helpful for improving soil environmental quality in SW, China, as well as supplying modern approaches for other areas with soil HM pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Frequent expression loss of Inter-alpha-trypsin inhibitor heavy chain (ITIH) genes in multiple human solid tumors: A systematic expression analysis

    Hamm, Alexander; Knuechel, Ruth; Dahl, Edgar; Veeck, Juergen; Bektas, Nuran; Wild, Peter J; Hartmann, Arndt; Heindrichs, Uwe; Kristiansen, Glen; Werbowetski-Ogilvie, Tamra; Del Maestro, Rolando

    2008-01-01

    The inter-alpha-trypsin inhibitors (ITI) are a family of plasma protease inhibitors, assembled from a light chain – bikunin, encoded by AMBP – and five homologous heavy chains (encoded by ITIH1, ITIH2, ITIH3, ITIH4, and ITIH5), contributing to extracellular matrix stability by covalent linkage to hyaluronan. So far, ITIH molecules have been shown to play a particularly important role in inflammation and carcinogenesis. We systematically investigated differential gene expression of the ITIH gene family, as well as AMBP and the interacting partner TNFAIP6 in 13 different human tumor entities (of breast, endometrium, ovary, cervix, stomach, small intestine, colon, rectum, lung, thyroid, prostate, kidney, and pancreas) using cDNA dot blot analysis (Cancer Profiling Array, CPA), semiquantitative RT-PCR and immunohistochemistry. We found that ITIH genes are clearly downregulated in multiple human solid tumors, including breast, colon and lung cancer. Thus, ITIH genes may represent a family of putative tumor suppressor genes that should be analyzed in greater detail in the future. For an initial detailed analysis we chose ITIH2 expression in human breast cancer. Loss of ITIH2 expression in 70% of cases (n = 50, CPA) could be confirmed by real-time PCR in an additional set of breast cancers (n = 36). Next we studied ITIH2 expression on the protein level by analyzing a comprehensive tissue micro array including 185 invasive breast cancer specimens. We found a strong correlation (p < 0.001) between ITIH2 expression and estrogen receptor (ER) expression indicating that ER may be involved in the regulation of this ECM molecule. Altogether, this is the first systematic analysis on the differential expression of ITIH genes in human cancer, showing frequent downregulation that may be associated with initiation and/or progression of these malignancies

  7. Frequent expression loss of Inter-alpha-trypsin inhibitor heavy chain (ITIH genes in multiple human solid tumors: A systematic expression analysis

    Werbowetski-Ogilvie Tamra

    2008-01-01

    Full Text Available Abstract Background The inter-alpha-trypsin inhibitors (ITI are a family of plasma protease inhibitors, assembled from a light chain – bikunin, encoded by AMBP – and five homologous heavy chains (encoded by ITIH1, ITIH2, ITIH3, ITIH4, and ITIH5, contributing to extracellular matrix stability by covalent linkage to hyaluronan. So far, ITIH molecules have been shown to play a particularly important role in inflammation and carcinogenesis. Methods We systematically investigated differential gene expression of the ITIH gene family, as well as AMBP and the interacting partner TNFAIP6 in 13 different human tumor entities (of breast, endometrium, ovary, cervix, stomach, small intestine, colon, rectum, lung, thyroid, prostate, kidney, and pancreas using cDNA dot blot analysis (Cancer Profiling Array, CPA, semiquantitative RT-PCR and immunohistochemistry. Results We found that ITIH genes are clearly downregulated in multiple human solid tumors, including breast, colon and lung cancer. Thus, ITIH genes may represent a family of putative tumor suppressor genes that should be analyzed in greater detail in the future. For an initial detailed analysis we chose ITIH2 expression in human breast cancer. Loss of ITIH2 expression in 70% of cases (n = 50, CPA could be confirmed by real-time PCR in an additional set of breast cancers (n = 36. Next we studied ITIH2 expression on the protein level by analyzing a comprehensive tissue micro array including 185 invasive breast cancer specimens. We found a strong correlation (p Conclusion Altogether, this is the first systematic analysis on the differential expression of ITIH genes in human cancer, showing frequent downregulation that may be associated with initiation and/or progression of these malignancies.

  8. Heavy-ion radiography

    Fabrikant, J.I.; Tobias, C.A.; Holley, W.R.; Benton, E.V.; Woodruff, K.H.; MacFarland, E.W.

    1983-01-01

    High energy, heavy-ion beams offer superior discrimination of tissue electron densities at very low radiation doses. This characteristic has potential for diagnostic medical imaging of neoplasms arising in the soft tissues and organs because it can detect smaller inhomogeneities than x rays. Heavy-ion imaging may also increase the accuracy of cancer radiotherapy planning involving use of accelerated charged particles. In the current physics research program of passive heavy-ion imaging, critical modulation transfer function tests are being carried out in heavy-ion projection radiography and heavy-ion computerized tomography. The research goal is to improve the heavy-ion imaging method until it reaches the limits of its theoretical resolution defined by range straggling, multiple scattering, and other factors involved in the beam quality characteristics. Clinical uses of the imaging method include the application of heavy-ion computerized tomography to heavy-ion radiotherapy planning, to the study of brain tumors and other structures of the head, and to low-dose heavy-ion projection mammography, particularly for women with dense breasts where other methods of diagnosis fail. The ions used are primarily 300 to 570 MeV/amu carbon and neon ions accelerated at the Lawrence Berkeley Laboratory Bevalac

  9. Monitoring of trace amounts of heavy metals in different food and water samples by flame atomic absorption spectrophotometer after preconcentration by amine-functionalized graphene nanosheet.

    Behbahani, Mohammad; Tapeh, Nasim Akbari Ghareh; Mahyari, Mojtaba; Pourali, Ali Reza; Amin, Bahareh Golrokh; Shaabani, Ahmad

    2014-11-01

    We are introducing graphene oxide modified with amine groups as a new solid phase for extraction of heavy metal ions including cadmium(II), copper(II), nickel(II), zinc(II), and lead(II). Effects of pH value, flow rates, type, concentration, and volume of the eluent, breakthrough volume, and the effect of potentially interfering ions were studied. Under optimized conditions, the extraction efficiency is >97 %, the limit of detections are 0.03, 0.05, 0.2, 0.1, and 1 μg L(-1) for the ions of cadmium, copper, nickel, zinc, and lead, respectively, and the adsorption capacities for these ions are 178, 142, 110, 125, and 210 mg g(-1). The amino-functionalized graphene oxide was characterized by thermogravimetric analysis, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectrometry. The proposed method was successfully applied in the analysis of environmental water and food samples. Good spiked recoveries over the range of 95.8-100.0 % were obtained. This work not only proposes a useful method for sample preconcentration but also reveals the great potential of modified graphene as an excellent sorbent material in analytical processes.

  10. The use of new modified poly(acrylamide chelating resin with pendent benzothiazole groups containing donor atoms in the removal of heavy metal ions from aqueous solutions

    Semmedu Selvaraj Kalaivani

    2014-03-01

    Full Text Available The adsorption studies of poly(6-(ethoxybenzothiazole acrylamide (PEBTA, for Cu(II and Zn(II metal ions removal from an aqueous solution have been investigated, as a function of solution pH, adsorbent dose, contact time, initial metal ion concentration and temperature. The chemical and structural characteristics of the adsorbent were determined by the FT-IR, 1H-NMR, TGA, SEM, and EDAX analysis. The maximum adsorption capacities of the adsorbent for Cu(II and Zn(II ions, as calculated from the Langmuir isotherm model, were 273.5 and 216.4 mg/g, respectively. The adsorption kinetic studies show that the adsorption of Cu(II and Zn(II ions onto PEBTA follows the pseudo second order kinetic model. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were also evaluated, and it has been found that the adsorption process is feasible, spontaneous and exothermic in nature. Desorption studies were carried out using 0.3 N HCl, and it revealed that the adsorbed Cu(II and Zn(II ions can be easily removed. The adsorption–desorption process is reversible, and this indicates that PEBTA is an effective adsorbent for the removal of heavy metal ions from an aqueous medium.

  11. Plants as biomarkers for monitoring heavy metal contaminants on landfill sites using sequential extraction and inductively coupled plasma atomic emission spectrophotometry (ICP-AES).

    Murphy, A P; Coudert, M; Barker, J

    2000-12-01

    There have been a number of studies investigating metal uptake in plants on contaminated landfill sites, but little on their role as biomarkers to identify metal mobility for continuous monitoring purposes. Vegetation can be used as a biomonitor of site pollution, by identifying the mobilisation of heavy metals and by providing an understanding of their bioavailability. Plants selected were the common nettle (Uritica Dioica), bramble (Rubus Fruticosa) and sycamore (Acer Pseudoplatanus). A study of the soil fractionation was made to investigate the soil properties that are likely to influence metal mobility and a correlation exercise was undertaken to investigate if variations in concentration of metals in vegetation can reflect variations in concentration of the metals in soil. The soil was digested using aqua regia in a microwave closed vessel. The vegetation was digested using both microwave and a hydrogen peroxide-nitric acid mixture, refluxed on a heating block and a comparison made. The certified reference materials (CRMs) used were Standard Reference Material (SRM) 1547, peach leaves for vegetation (NIST) and for soil CRM 143R, sewage sludge-amended soil (BCR). The relative standard deviations (RSDs) were 2-6% for the analyses. Our findings show evidence of phytoextraction by some plants, (especially bramble and nettle), with certain plants, (sycamore) exhibiting signs of phytostabilisation. The evidence suggests that there is a degree of selectivity in metal uptake and partitioning within the plant compartments. It was also possible to correlate mobility phases of certain metals (Pb, Cu and Zn) using the soil and plant record. Zn and Cu exhibited the greatest potential to migrate from the roots to the leaves, with Pb found principally in the roots of ground vegetation. Our results suggest that analysis of bramble leaves, nettle leaves and roots can be used to monitor the mobility of Pb in the soil with nettle, bramble and sycamore leaves to monitor Cu and Zn.

  12. 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

    Ata S.

    2013-04-01

    Full Text Available 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> Pb> Cd> Cu> Zn. Infield metal content in the soil also followed the same trend. In garlic samples, Pb, Cd, Cr, Zn and Cu ranged from 0.039mg/L to 0.757mg/L, N.D to 1.211mg/L, 0.03mg/L to 0.451mg/L, 0.02mg/Lto0.42mg/L and 0.451mg/L to 0.893mg/L respectively. In soil samples, Pb, Cd, Cr, Zn and Cu were ranged from 0.459mg/L to 0.797mg/L, 0.205mg/L to1.062mg/L, 0.074mg/L to 2.598mg/L, 0.124mg/L to 0.276mg/L and 0.494mg/L to 0.921mg/L respectively. In our study, the Pb and Cd was found more in garlic from Gujranwala and Jaranwala, Cu and Zn were more in samples from Kasur while Cr was predominant in sample from Sheikhupura. Heavy metal content in soil and garlic samples was within the permissible limits proposed by World Health Organization (WHO.

  13. Flame atomic absorption spectrometric determination of trace amounts of heavy metal ions after solid phase extraction using modified sodium dodecyl sulfate coated on alumina

    Ghaedi, Mehrorang [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: m_ghaedi@mail.yu.ac.ir; Niknam, Khodabakhsh [Chemistry Department, Persian Gulf University, Bushehr (Iran, Islamic Republic of); Shokrollahi, Ardeshir; Niknam, Ebrahim; Rajabi, Hamid Reza [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2008-06-30

    A sensitive and selective solid phase extraction procedure for the determination of traces of Cu(II), Zn(II), Pb(II) and Fe(III) has been developed. An alumina-sodium dodecyl sulfate (SDS) coated on with meso-phenyl bis(indolyl) methane (MPBIM) was used for preconcentration and determination of Cu(II), Zn(II), Pb(II) and Fe(III) ions by flame atomic absorption spectrometry. The analyte ions were adsorbed quantitatively on adsorbent due to their complexation with MPBIM. Adsorbed metals were quantitatively eluted using 6 mL of 4 mol L{sup -1} nitric acid. The effects of parameters such as pH, amount of alumina, amount of MBITP, flow rate, type and concentration of eluting agent were examined. The effects of interfering ions on the separation-preconcentration of analytes were also investigated. The relative standard deviation of the method was found to be less than 3.0%. The presented procedure was successfully applied for determination of analytes in real samples.

  14. Experimental atomic physics

    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

  15. Flame atomic absorption spectrometric determination of heavy metals in aqueous solution and surface water preceded by co-precipitation procedure with copper(II) 8-hydroxyquinoline

    Ipeaiyeda, Ayodele Rotimi; Ayoade, Abisayo Ruth

    2017-12-01

    Co-precipitation procedure has widely been employed for preconcentration and separation of metal ions from the matrices of environmental samples. This is simply due to its simplicity, low consumption of separating solvent and short duration for analysis. Various organic ligands have been used for this purpose. However, there is dearth of information on the application of 8-hydroxyquinoline (8-HQ) as ligand and Cu(II) as carrier element. The use of Cu(II) is desirable because there is no contamination and background adsorption interference. Therefore, the objective of this study was to use 8-HQ in the presence of Cu(II) for coprecipitation of Cd(II), Co(II), Cr(III), Ni(II) and Pb(II) from standard solutions and surface water prior to their determinations by flame atomic absorption spectrometry (FAAS). The effects of pH, sample volume, amount of 8-HQ and Cu(II) and interfering ions on the recoveries of metal ions from standard solutions were monitored using FAAS. The water samples were treated with 8-HQ under the optimum experimental conditions and metal concentrations were determined by FAAS. The metal concentrations in water samples not treated with 8-HQ were also determined. The optimum recovery values for metal ions were higher than 85.0%. The concentrations (mg/L) of Co(II), Ni(II), Cr(III), and Pb(II) in water samples treated with 8-HQ were 0.014 ± 0.002, 0.03 ± 0.01, 0.04 ± 0.02 and 0.05 ± 0.02, respectively. These concentrations and those obtained without coprecipitation technique were significantly different. Coprecipitation procedure using 8-HQ as ligand and Cu(II) as carrier element enhanced the preconcentration and separation of metal ions from the matrix of water sample.

  16. Heavy Chain Diseases

    ... of heavy chain produced: Alpha Gamma Mu Alpha Heavy Chain Disease Alpha heavy chain disease (IgA heavy ... the disease or lead to a remission. Gamma Heavy Chain Disease Gamma heavy chain disease (IgG heavy ...

  17. Study of elementary transfer mechanisms during a collision between a swift multi-charged heavy ion and a neutral atom; Etude des mecanismes elementaires de transfert d`energie au cours d`une collision entre un ion lourd rapide multi-charge et un atome neutre

    Jardin, P. [Caen Univ., 14 (France)

    1995-12-31

    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 < 1 K). The association of time of flight and localisation techniques allows us, for each ionised target atom, to determine the three recoil velocity components with a very good accuracy (a few tens of meters per second). In chapter three, we describe the data analysis method. And then we present in the last chapter the results we have obtained for the collision systems Xe{sup 44+}(6.7 MeV/A) + Ar => Xe{sup 44} + Ar{sup q+}+qe{sup -} (q ranging from 1 to 7); Xe{sup 44+} (6.7 MeV/A) + He => Xe{sup 44+} He{sup 1+,2+}+1e{sup -},2e{sup -}. 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) 44 refs.

  18. Deeply bound pionic atom

    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.)

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

    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

  20. Multiple response optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry with sample injection as detergent emulsion

    Brum, Daniel M.; Lima, Claudio F.; Robaina, Nicolle F.; Fonseca, Teresa Cristina O.; Cassella, Ricardo J.

    2011-01-01

    The present paper reports the optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry (GF AAS) employing a strategy based on the injection of the samples as detergent emulsions. The method was optimized in relation to the experimental conditions for the emulsion formation and taking into account that the three analytes (Cu, Fe and Pb) should be measured in the same emulsion. The optimization was performed in a multivariate way by employing a three-variable Doehlert design and a multiple response strategy. For this purpose, the individual responses of the three analytes were combined, yielding a global response that was employed as a dependent variable. The three factors related to the optimization process were: the concentration of HNO 3 , the concentration of the emulsifier agent (Triton X-100 or Triton X-114) in aqueous solution used to emulsify the sample and the volume of solution. At optimum conditions, it was possible to obtain satisfactory results with an emulsion formed by mixing 4 mL of the samples with 1 mL of a 4.7% w/v Triton X-100 solution prepared in 10% v/v HNO 3 medium. The resulting emulsion was stable for 250 min, at least, and provided enough sensitivity to determine the three analytes in the five samples tested. A recovery test was performed to evaluate the accuracy of the optimized procedure and recovery rates, in the range of 88-105%; 94-118% and 95-120%, were verified for Cu, Fe and Pb, respectively.

  1. Multiple response optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry with sample injection as detergent emulsion

    Brum, Daniel M.; Lima, Claudio F. [Departamento de Quimica, Universidade Federal de Vicosa, A. Peter Henry Rolfs s/n, Vicosa/MG, 36570-000 (Brazil); Robaina, Nicolle F. [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de S.J. Batista s/n, Centro, Niteroi/RJ, 24020-141 (Brazil); Fonseca, Teresa Cristina O. [Petrobras, Cenpes/PDEDS/QM, Av. Horacio Macedo 950, Ilha do Fundao, Rio de Janeiro/RJ, 21941-915 (Brazil); Cassella, Ricardo J., E-mail: cassella@vm.uff.br [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de S.J. Batista s/n, Centro, Niteroi/RJ, 24020-141 (Brazil)

    2011-05-15

    The present paper reports the optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry (GF AAS) employing a strategy based on the injection of the samples as detergent emulsions. The method was optimized in relation to the experimental conditions for the emulsion formation and taking into account that the three analytes (Cu, Fe and Pb) should be measured in the same emulsion. The optimization was performed in a multivariate way by employing a three-variable Doehlert design and a multiple response strategy. For this purpose, the individual responses of the three analytes were combined, yielding a global response that was employed as a dependent variable. The three factors related to the optimization process were: the concentration of HNO{sub 3}, the concentration of the emulsifier agent (Triton X-100 or Triton X-114) in aqueous solution used to emulsify the sample and the volume of solution. At optimum conditions, it was possible to obtain satisfactory results with an emulsion formed by mixing 4 mL of the samples with 1 mL of a 4.7% w/v Triton X-100 solution prepared in 10% v/v HNO{sub 3} medium. The resulting emulsion was stable for 250 min, at least, and provided enough sensitivity to determine the three analytes in the five samples tested. A recovery test was performed to evaluate the accuracy of the optimized procedure and recovery rates, in the range of 88-105%; 94-118% and 95-120%, were verified for Cu, Fe and Pb, respectively.

  2. Photo induced multiple fragmentation of atoms and molecules: Dynamics of Coulombic many-particle systems studied with the COLTRIMS reaction microscope

    Czasch, A.; Schmidt, L.Ph.H.; Jahnke, T.; Weber, Th.; Jagutzki, O.; Schoessler, S.; Schoeffler, M.S.; Doerner, R.; Schmidt-Boecking, H.

    2005-01-01

    Many-particle dynamics in atomic and molecular physics has been investigated by using the COLTRIMS reaction microscope. The COLTRIMS technique visualizes photon and ion induced many-particle fragmentation processes in the eV and milli-eV regime. It reveals the complete momentum pattern in atomic and molecular many-particle reactions comparable to the bubble chamber in nuclear physics

  3. Cascade Processes in Muonic Hydrogen Atoms

    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.

  4. Heavy baryons

    Koerner, J.G.

    1994-06-01

    We review the experimental and theoretical status of baryons containing one heavy quark. The charm and bottom baryon states are classified and their mass spectra are listed. The appropriate theoretical framework for the description of heavy baryons is the Heavy Quark Effective Theory, whose general ideas and methods are introduced and illustrated in specific examples. We present simple covariant expressions for the spin wave functions of heavy baryons including p-wave baryons. The covariant spin wave functions are used to determine the Heavy Quark Symmetry structure of flavour-changing current-induced transitions between heavy baryons as well as one-pion and one-photon transitions between heavy baryons of the same flavour. We discuss 1/m Q corrections to the current-induced transitions as well as the structure of heavy to light baryon transitions. Whenever possible we attempt to present numbers to compare with experiment by making use of further model-dependent assumptions as e.g. the constituent picture for light quarks. We highlight recent advances in the theoretical understanding of the inclusive decays of hadrons containing one heavy quark including polarization. For exclusive semileptonic decays we discuss rates, angular decay distributions and polarization effects. We provide an update of the experimental and theoretical status of lifetimes of heavy baryons and of exclusive nonleptonic two body decays of charm baryons. (orig.)

  5. Parity nonconservation in Zeeman atomic transitions

    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

  6. Heavy accelerated nuclei in biomedical research

    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

  7. Atomic energy

    Ramanna, R.

    1978-01-01

    Development of nuclear science in India, particularly the research and development work at the Bhabha Atomic Research Centre (BARC), Bombay, is described. Among the wide range of materials developed for specific functions under rigorous conditions are nuclear pure grade uranium, zirconium and beryllium, and conventional materials like aluminium, carbon steel and stainless steels. Radioisotopes are produced and used for tracer studies in various fields. Various types of nuclear gauges and nuclear instruments are produced. Radiations have been used to develop new high yielding groundnut mutants with large kernals. The sterile male technique for pest control and radiosterilization technique to process potatoes, onions and marine foods for storage are ready for exploitation. Processes and equipment have been developed for production of electrolytic hydrogen, electrothermal phosphorus and desalinated water. Indigenously manufactured components and materials are now being used for the nuclear energy programme. Indian nuclear power programme strategy is to build heavy water reactors and to utilise their byproduct plutonium and depleted uranium to feed fast breeder reactors which will produce more fissile material than burnt. Finally a special mention has been made of the manpower development programme of the BARC. BARC has established a training school in 1957 giving advanced training in physics, chemistry and various branches of engineering and metallurgy

  8. Heavy flavors

    Cox, B.; Gilman, F.J.; Gottschalk, T.D.

    1986-11-01

    A range of issues pertaining to heavy flavors at the SSC is examined including heavy flavor production by gluon-gluon fusion and by shower evolution of gluon jets, flavor tagging, reconstruction of Higgs and W bosons, and the study of rare decays and CP violation in the B meson system. A specific detector for doing heavy flavor physics and tuned to this latter study at the SSC, the TASTER, is described. 36 refs., 10 figs

  9. Ferric Sulfate and Proline Enhance Heavy-Metal Tolerance of Halophilic/Halotolerant Soil Microorganisms and Their Bioremediation Potential for Spilled-Oil Under Multiple Stresses

    Al-Mailem, Dina M.; Eliyas, Mohamed; Radwan, Samir S.

    2018-01-01

    The aim of this study was to explore the heavy-metal resistance and hydrocarbonoclastic potential of microorganisms in a hypersaline soil. For this, hydrocarbonoclastic microorganisms were counted on a mineral medium with oil vapor as a sole carbon source in the presence of increasing concentrations of ZnSO4, HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4. The colony-forming units counted decreased in number from about 150 g-1 on the heavy-metal-free medium to zero units on media with 40–100 mg l-1 of HgCl2, CdSO4, PbNO3, or Na2HAsO4. On media with CuSO4 or ZnSO4 on the other hand, numbers increased first reaching maxima on media with 50 mg l-1 CuSO4 and 90 mg l-1 ZnSO4. Higher concentrations reduced the numbers, which however, still remained considerable. Pure microbial isolates in cultures tolerated 200–1600 mg l-1 of HgCl2, CdSO4, PbNO3, CuSO4, and Na2HAsO4 in the absence of crude oil. In the presence of oil vapor, the isolates tolerated much lower concentrations of the heavy metals, only 10–80 mg l-1. The addition of 10 Fe2(SO4)3 and 200 mg l-1 proline (by up to two- to threefold) enhanced the tolerance of several isolates to heavy metals, and consequently their potential for oil biodegradation in their presence. The results are useful in designing bioremediation technologies for oil spilled in hypersaline areas. PMID:29563904

  10. Charged particles multiplicity in interactions of 3.7 A GeV 28Si with light and heavy target nuclei in nuclear emulsions

    Singh, B.K.; Tuli, S.K.

    1998-01-01

    Results from measurement of multiplicity of different charged particles emitted from the interactions of 3.7 A GeV 28 Si with different target groups in nuclear emulsion and correlations among them are presented. The nature of the dependence of multiplicities of charged particles on the impact parameter is examined. Analysis of data in terms of specific multiplicity for different target groups is performed and the results are discussed in the light of superposition model. (author)

  11. Persistent sample circulation microextraction combined with graphite furnace atomic absorption spectroscopy for trace determination of heavy metals in fish species marketed in Kermanshah, Iran, and human health risk assessment.

    Safari, Yahya; Karimaei, Mostafa; Sharafi, Kiomars; Arfaeinia, Hossein; Moradi, Masoud; Fattahi, Nazir

    2018-06-01

    Persistent sample circulation microextraction (PSCME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was developed as a high pre-concentration technique for the determination of heavy metals in fish species. In this method, a few microliters of organic solvent (40.0 µL carbon tetrachloride) was transferred to the bottom of a conical sample cup. Then 10.0 mL of aqueous solution was transformed to fine droplets while passing through the organic solvent. At this stage, metal-ligand hydrophobic complex was extracted into the organic solvent. After extraction, 20 µL of extraction solvent was injected into the graphite tube using an auto-sampler. Under optimal conditions, enrichment factors and enhancement factor were in the range of 180-240 and 155-214, respectively. The calibration curves were linear in the range of 0.03-200 µg kg -1 and the limits of detection (LODs) were in the range of 0.01-0.05 µg kg -1 . Repeatability (intra-day) and reproducibility (inter-day) for 0.50 µg L -1 Hg and 0.10 µg L -1 Cd and Pb were in the range of 3.1-4.2% (n = 7) and 4.3-6.1% (n = 7), respectively. Potential human health risk assessment was conducted by calculating estimated weekly intake (EWI) of the metals from eating fish and comparison of these values with provisional tolerable weekly intake (PTWI) values. EWI data for the studied metals through fish consumption were lower than the PTWI values. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Spectrophotometric Determination Of Heavy Metals In Cosmetics

    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 ...

  13. [Relativistic heavy ion research

    1990-01-01

    At Brookhaven National Laboratory, participation in the E802 Experiment, which is the first major heavy-ion experiment at the BNL-AGS, was the main focus of the group during the past four years. The emphases of the E802 experiment were on (a) accurate particle identification and measurements of spectra over a wide kinematical domain (5 degree LAB < 55 degree, p < 20 GeV/c); and (b) measurements of small-angle two-particle correlations, with event characterization tools: multiplicity array, forward and large-angle calorimeters. This experiment and other heavy ion collision experiments are discussed in this report

  14. Atom optics

    Balykin, V. I.; Jhe, W.

    1999-01-01

    Atom optics, in analogy to neutron and electron optics, deals with the realization of as a traditional elements, such as lenes, mirrors, beam splitters and atom interferometers, as well as a new 'dissipative' elements such as a slower and a cooler, which have no analogy in an another types of optics. Atom optics made the development of atom interferometer with high sensitivity for measurement of acceleration and rotational possible. The practical interest in atom optics lies in the opportunities to create atom microprobe with atom-size resolution and minimum damage of investigated objects. (Cho, G. S.)

  15. Study of the multiplication and kinetic effects of salt mixtures and salt blanket micromodels on thermal neutron spectra of heavy water MAKET facility

    Titarenko, Yu.E.; Batyaev, V.F.; Borovlev, S.P.; Gladkikh, N.G.; Igumnov, M.M.; Legostaev, V.O.; Karpikhin, E.I.; Konev, V.N.; Kushnerev, Yu.T.; Ryazhsky, V.I.; Spiridonov, V.G.; Chernyavsky, E.V.; Shvedov, O.V.

    2009-10-01

    The main goal of the Project is to study and evaluate nuclear characteristics of materials and isotopes involved in processes of irradiated nuclear fuel transmutation. This principal task is subdivided into 9 subtasks subject to the neutron or proton source used, the type of the nuclear process under study, isotope collection, characteristics of which are to be investigated, etc. In the presented extract of the Project Activity report the measurements there were used the MAKET zero-power heavy-water reactor in the measurements there was employed a large set of minor actinide samples highly enriched with the main isotope. The samples were obtained with mass-separator SM-2 (VNIIEF). At the heavy-water reactor MAKET (ITEP) there were measured multiplying and kinetic characteristics of salt mixtures basing on the spectra of fast and thermal neutrons. The salt mixtures of zirconium and sodium fluorides were available in salt blanket models (SBM) of cylindrical shape. There were measured the neutron spectra formed by this micro-model as well as the effective fission cross-sections of neptunium, plutonium, americium and curium isotopes caused by SBM neutrons. The neutron spectra in the measurement positions were determined from activation reaction rates. (author)

  16. Multiplicity of neutrons from violent heavy-ion collisions: 40Ar + Th and U from 10 to 77 MeV/u

    Jahnke, U.; Cramer, B.; Ingold, G.; Schwinn, E.; Charvet, J.L.; Frehaut, J.; Lott, B.; Morjean, M.; Patin, Y.; Pranal, Y.; Uzureau, J.L.; Doubre, H.; Galin, J.; Guerreau, D.; Jiang, D.X.; Pouthas, J.; Sokolov, A.; Gatty, B.; Jacquet, D.; Magnago, C.

    1988-12-01

    With large 4π scintillator tanks the multiplicity of neutrons released from the most dissipative reactions in 10 to 77 MeV/u 40 Ar induced collisions with Th and U nuclei has been investigated. The central issue is the relation between the fission-fragment folding angle or linear momentum transfer and the multiplicity of evaporated neutrons and charged particles or dissipated energy. Their multiplicity points to a 'soft saturation' of the maximum energy deposit with increasing bombarding energy near 700 MeV of excitation. Unlike the folding-angle distributions, the inclusive neutron multiplicity spectra, which are unbiased by specific decay properties of the intermediate nuclear system, do not show a decline of the most dissipative processes within this range of incident energy. (orig.)

  17. Atom-by-atom assembly

    Hla, Saw Wai

    2014-01-01

    Atomic manipulation using a scanning tunneling microscope (STM) tip enables the construction of quantum structures on an atom-by-atom basis, as well as the investigation of the electronic and dynamical properties of individual atoms on a one-atom-at-a-time basis. An STM is not only an instrument that is used to ‘see’ individual atoms by means of imaging, but is also a tool that is used to ‘touch’ and ‘take’ the atoms, or to ‘hear’ their movements. Therefore, the STM can be considered as the ‘eyes’, ‘hands’ and ‘ears’ of the scientists, connecting our macroscopic world to the exciting atomic world. In this article, various STM atom manipulation schemes and their example applications are described. The future directions of atomic level assembly on surfaces using scanning probe tips are also discussed. (review article)

  18. Environmental health scoping study at Bruce Heavy Water Plant

    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

  19. Burkholderia metalliresistens sp. nov., a multiple metal-resistant and phosphate-solubilising species isolated from heavy metal-polluted soil in Southeast China.

    Guo, Jun Kang; Ding, Yong Zhen; Feng, Ren Wei; Wang, Rui Gang; Xu, Ying Ming; Chen, Chun; Wei, Xiu Li; Chen, Wei Min

    2015-06-01

    A metal-resistant and phosphate-solubilising bacterium, designated as strain D414(T), was isolated from heavy metal (Pb, Cd, Cu and Zn)-polluted paddy soils at the surrounding area of Dabao Mountain Mine in Southeast China. The minimum inhibitory concentrations of heavy metals for strain D414(T) were 2000 mg L(-1) (Cd), 800 mg L(-1) (Pb), 150 mg L(-1) (Cu) and 2500 mg L(-1) (Zn). The strain possessed plant growth-promoting properties, such as 1-aminocyclopropane-1-carboxylate assimilation, indole production and phosphate solubilisation. Analysis of 16S rRNA gene sequence indicated that the isolate is a member of the genus Burkholderia where strain D414(T) formed a distinct phyletic line with validly described Burkholderia species. Strain D414(T) is closely related to Burkholderia tropica DSM 15359(T), B. bannensis NBRC E25(T) and B. unamae DSM 17197(T), with 98.5, 98.3 and 98.3 % sequence similarities, respectively. Furthermore, less than 34 % DNA-DNA relatedness was detected between strain D414(T) and the type strains of the phylogenetically closest species of Burkholderia. The dominant fatty acids of strain D414(T) were C14:0, C16:0, C17:0 cyclo and C18:1 ω7c. The DNA G+C content was 62.3 ± 0.5 mol%. On the basis of genotypic, phenotypic and phylogenetic data, strain D414(T) represents a novel species, for which the name Burkholderia metalliresistens sp. nov. is proposed, with D414(T) (=CICC 10561(T) = DSM 26823(T)) as the type strain.

  20. Spectroscopy of highly ionized atoms

    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

  1. Local particle densities and global multiplicities in central heavy ion interactions at 3.7, 14.6, 60 and 200 A GeV

    Adamovich, M.I.; Alexandrov, Y.A.; Aggarwal, M.M.

    1992-03-01

    The energy and centrality dependence of local particle pseudorapidity densities as well as validity of various parametrizations of the distributions are examined. The dispersion, σ, of the rapidity density distribution of produced particles varies slowly with centrality and is 0.80, 0.98, 1.21 and 1.41 for central interactions at 3.7, 14.6, 60 and 200 A GeV incident energy, respectively. σ is found to be independent of the size of the interacting system at fixed energy. A novel way of representing the window dependence of the multiplicity as normalized variance versus inverse average multiplicity is outlined. (au)

  2. Local particle densities and global multiplicities in central heavy ion interactions at 3.7, 14.6, 60 and 200 A GeV

    Adamovich, M.I.; Alexandrov, Y.A.; Chernyavsky, M.M.; Gerassimov, S.G.; Larionova, V.G.; Maslennikova, N.V.; Orlova, G.I.; Peresadko, N.G.; Rappoport, V.M.; Salmanova, N.A.; Tretyakova, M.I.; Aggarwal, M.M.; Arora, R.; Bhatia, V.S.; Mittra, I.S.; Andreeva, N.P.; Anson, Z.V.; Bubnov, V.I.; Chasnikov, I.Y.; Eligbaeva, G.Z.; Eremenko, L.E.; Gaitinov, A.S.; Kalyachkina, G.S.; Kanygina, E.K.; Lepetan, V.N.; Shakhova, T.I.; Avetyan, F.A.; Marutyan, N.A.; Sarkisova, L.G.; Sarkisyan, V.R.; Badyal, S.K.; Bhasin, A.; Gupta, V.K.; Kachroo, S.; Kaul, G.L.; Kitroo, S.; Mangotra, L.K.; Rao, N.K.; Basova, E.; Nasrulaeva, H.; Nasyrov, S.H.; Petrov, N.V.; Qarshiev, D.A.; Trofimova, T.P.; Tuleeva, U.; Bhalla, K.B.; Gupta, S.K.; Kumar, V.; Lal, P.; Lokanathan, S.; Mookerjee, S.; Palsania, H.S.; Raniwala, R.; Raniwala, S.; Bogdanaov, V.G.; Plyushchev, V.A.; Solovjeva, Z.I.; Burnett, T.H.; Grote, J.; Lord, J.; Skelding, D.; Wilkes, R.J.; Chernova, L.P.; Gulamov, K.G.; Lukicheva, N.S.; Navotny, V.S.; Saidkhanov, N.; Shpilev, S.N.; Surin, E.L.; Svechnikova, L.N.; Zhochova, S.I.; Ganssauge, E.R.; Rhee, J.T.; Garpman, S.; Jakobsson, B.; Nystrand, J.; Otterlund, I.; Soederstroem, K.; Stenlund, E.; Heckman, H.H.; Cai, X.; Huang, H.; Liu, L.S.; Qian, W.Y.; Wang, H.Q.; Zhou, D.C.; Judek, B.; Just, L.; Tothova, M.; Karabova, M.; Vokal, S.; Krasnov, S.A.; Kulikova, S.; Maksimkina, T.N.; Shabratova, G.S.; Tolstov, K.D.; Luo, S.B.; Qin, Y.M.; Zhang, D.H.; Weng, Z.Q.; Xia, Y.L.; Xu, G.F.; Zheng, P.Y.

    1992-01-01

    The energy and centrality dependence of local particle pseudorapidity densities as well as validity of various parameterizations of the distributions are examined. The dispersion, σ, of the rapidity density distribution of produced particles varies slowly with centrality and is 0.80, 0.98, 1.21 and 1.41 for central interactions at 3.7, 14.6, 60 and 200 A GeV incident energy, respectively, σ is found to be independent of the size of the interacting system at fixed energy. A novel, way of representing the window dependence of the multiplicity as normalized variance versus inverse average multiplicity is outlined. (orig.)

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

    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 ...

  4. Heavy ion storage rings

    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

  5. Emissions of toxic pollutants from compressed natural gas and low sulfur diesel-fueled heavy-duty transit buses tested over multiple driving cycles.

    Kado, Norman Y; Okamoto, Robert A; Kuzmicky, Paul A; Kobayashi, Reiko; Ayala, Alberto; Gebel, Michael E; Rieger, Paul L; Maddox, Christine; Zafonte, Leo

    2005-10-01

    The number of heavy-duty vehicles using alternative fuels such as compressed natural gas (CNG) and new low-sulfur diesel fuel formulations and equipped with after-treatment devices are projected to increase. However, few peer-reviewed studies have characterized the emissions of particulate matter (PM) and other toxic compounds from these vehicles. In this study, chemical and biological analyses were used to characterize the identifiable toxic air pollutants emitted from both CNG and low-sulfur-diesel-fueled heavy-duty transit buses tested on a chassis dynamometer over three transient driving cycles and a steady-state cruise condition. The CNG bus had no after-treatment, and the diesel bus was tested first equipped with an oxidation catalyst (OC) and then with a catalyzed diesel particulate filter (DPF). Emissions were analyzed for PM, volatile organic compounds (VOCs; determined on-site), polycyclic aromatic hydrocarbons (PAHs), and mutagenic activity. The 2000 model year CNG-fueled vehicle had the highest emissions of 1,3-butadiene, benzene, and carbonyls (e.g., formaldehyde) of the three vehicle configurations tested in this study. The 1998 model year diesel bus equipped with an OC and fueled with low-sulfur diesel had the highest emission rates of PM and PAHs. The highest specific mutagenic activities (revertants/microg PM, or potency) and the highest mutagen emission rates (revertants/mi) were from the CNG bus in strain TA98 tested over the New York Bus (NYB) driving cycle. The 1998 model year diesel bus with DPF had the lowest VOCs, PAH, and mutagenic activity emission. In general, the NYB driving cycle had the highest emission rates (g/mi), and the Urban Dynamometer Driving Schedule (UDDS) had the lowest emission rates for all toxics tested over the three transient test cycles investigated. Also, transient emissions were, in general, higher than steady-state emissions. The emissions of toxic compounds from an in-use CNG transit bus (without an oxidation

  6. Analysis of the Genome and Mobilome of a Dissimilatory Arsenate Reducing Aeromonas sp. O23A Reveals Multiple Mechanisms for Heavy Metal Resistance and Metabolism

    Witold Uhrynowski

    2017-05-01

    Full Text Available Aeromonas spp. are among the most ubiquitous microorganisms, as they have been isolated from different environmental niches including waters, soil, as well as wounds and digestive tracts of poikilothermic animals and humans. Although much attention has been paid to the pathogenicity of Aeromonads, the role of these bacteria in environmentally important processes, such as transformation of heavy metals, remains to be discovered. Therefore, the aim of this study was a detailed genomic characterization of Aeromonas sp. O23A, the first representative of this genus capable of dissimilatory arsenate reduction. The strain was isolated from microbial mats from the Zloty Stok mine (SW Poland, an environment strongly contaminated with arsenic. Previous physiological studies indicated that O23A may be involved in both mobilization and immobilization of this metalloid in the environment. To discover the molecular basis of the mechanisms behind the observed abilities, the genome of O23A (∼5.0 Mbp was sequenced and annotated, and genes for arsenic respiration, heavy metal resistance (hmr and other phenotypic traits, including siderophore production, were identified. The functionality of the indicated gene modules was assessed in a series of minimal inhibitory concentration analyses for various metals and metalloids, as well as mineral dissolution experiments. Interestingly, comparative analyses revealed that O23A is related to a fish pathogen Aeromonas salmonicida subsp. salmonicida A449 which, however, does not carry genes for arsenic respiration. This indicates that the dissimilatory arsenate reduction ability may have been lost during genome reduction in pathogenic strains, or acquired through horizontal gene transfer. Therefore, particular emphasis was placed upon the mobilome of O23A, consisting of four plasmids, a phage, and numerous transposable elements, which may play a role in the dissemination of hmr and arsenic metabolism genes in the

  7. Analysis of the Genome and Mobilome of a Dissimilatory Arsenate Reducing Aeromonas sp. O23A Reveals Multiple Mechanisms for Heavy Metal Resistance and Metabolism.

    Uhrynowski, Witold; Decewicz, Przemyslaw; Dziewit, Lukasz; Radlinska, Monika; Krawczyk, Pawel S; Lipinski, Leszek; Adamska, Dorota; Drewniak, Lukasz

    2017-01-01

    Aeromonas spp. are among the most ubiquitous microorganisms, as they have been isolated from different environmental niches including waters, soil, as well as wounds and digestive tracts of poikilothermic animals and humans. Although much attention has been paid to the pathogenicity of Aeromonads, the role of these bacteria in environmentally important processes, such as transformation of heavy metals, remains to be discovered. Therefore, the aim of this study was a detailed genomic characterization of Aeromonas sp. O23A, the first representative of this genus capable of dissimilatory arsenate reduction. The strain was isolated from microbial mats from the Zloty Stok mine (SW Poland), an environment strongly contaminated with arsenic. Previous physiological studies indicated that O23A may be involved in both mobilization and immobilization of this metalloid in the environment. To discover the molecular basis of the mechanisms behind the observed abilities, the genome of O23A (∼5.0 Mbp) was sequenced and annotated, and genes for arsenic respiration, heavy metal resistance ( hmr ) and other phenotypic traits, including siderophore production, were identified. The functionality of the indicated gene modules was assessed in a series of minimal inhibitory concentration analyses for various metals and metalloids, as well as mineral dissolution experiments. Interestingly, comparative analyses revealed that O23A is related to a fish pathogen Aeromonas salmonicida subsp. salmonicida A449 which, however, does not carry genes for arsenic respiration. This indicates that the dissimilatory arsenate reduction ability may have been lost during genome reduction in pathogenic strains, or acquired through horizontal gene transfer. Therefore, particular emphasis was placed upon the mobilome of O23A, consisting of four plasmids, a phage, and numerous transposable elements, which may play a role in the dissemination of hmr and arsenic metabolism genes in the environment. The obtained

  8. Analysis of the Genome and Mobilome of a Dissimilatory Arsenate Reducing Aeromonas sp. O23A Reveals Multiple Mechanisms for Heavy Metal Resistance and Metabolism

    Uhrynowski, Witold; Decewicz, Przemyslaw; Dziewit, Lukasz; Radlinska, Monika; Krawczyk, Pawel S.; Lipinski, Leszek; Adamska, Dorota; Drewniak, Lukasz

    2017-01-01

    Aeromonas spp. are among the most ubiquitous microorganisms, as they have been isolated from different environmental niches including waters, soil, as well as wounds and digestive tracts of poikilothermic animals and humans. Although much attention has been paid to the pathogenicity of Aeromonads, the role of these bacteria in environmentally important processes, such as transformation of heavy metals, remains to be discovered. Therefore, the aim of this study was a detailed genomic characterization of Aeromonas sp. O23A, the first representative of this genus capable of dissimilatory arsenate reduction. The strain was isolated from microbial mats from the Zloty Stok mine (SW Poland), an environment strongly contaminated with arsenic. Previous physiological studies indicated that O23A may be involved in both mobilization and immobilization of this metalloid in the environment. To discover the molecular basis of the mechanisms behind the observed abilities, the genome of O23A (∼5.0 Mbp) was sequenced and annotated, and genes for arsenic respiration, heavy metal resistance (hmr) and other phenotypic traits, including siderophore production, were identified. The functionality of the indicated gene modules was assessed in a series of minimal inhibitory concentration analyses for various metals and metalloids, as well as mineral dissolution experiments. Interestingly, comparative analyses revealed that O23A is related to a fish pathogen Aeromonas salmonicida subsp. salmonicida A449 which, however, does not carry genes for arsenic respiration. This indicates that the dissimilatory arsenate reduction ability may have been lost during genome reduction in pathogenic strains, or acquired through horizontal gene transfer. Therefore, particular emphasis was placed upon the mobilome of O23A, consisting of four plasmids, a phage, and numerous transposable elements, which may play a role in the dissemination of hmr and arsenic metabolism genes in the environment. The obtained

  9. In situ stabilization of heavy metals in multiple-metal contaminated paddy soil using different steel slag-based silicon fertilizer.

    Ning, Dongfeng; Liang, Yongchao; Song, Alin; Duan, Aiwang; Liu, Zhandong

    2016-12-01

    Steel slag has been widely used as amendment and silicon fertilizer to alleviate the mobility and bioavailability of heavy metals in soil. The objective of this study was to evaluate the influence of particle size, composition, and application rate of slag on metal immobilization in acidic soil, metals uptake by rice and rice growth. The results indicated that application of slag increased soil pH, plant-available silicon concentrations in soil, and decreased the bioavailability of metals compared with control treatment, whereas pulverous slag (S1) was more effective than granular slag (S2 and S3). The acid-extractable fraction of Cd in the spiked soil was significantly decreased with application of S1 at rates of 1 and 3 %, acid-extractable fractions of Cu and Zn were decreased when treated at 3 %. Use of S1 at both rates resulted in significantly lower Cd, Cu, and Zn concentrations in rice tissues than in controls by 82.6-92.9, 88.4-95.6, and 67.4-81.4 %, respectively. However, use of pulverous slag at 1 % significantly promotes rice growth, restricted rice growth when treated at 3 %. Thus, the results explained that reduced particle size and suitable application rate of slag could be beneficial to rice growth and metals stabilization.

  10. Dielectron and heavy-quark production in inelastic and high-multiplicity proton-proton collisions at $\\sqrt{s} = 13$ TeV

    Acharya, Shreyasi; The ALICE collaboration; Adamova, Dagmar; Adolfsson, Jonatan; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahn, Sang Un; Aiola, Salvatore; Akindinov, Alexander; Al-turany, Mohammad; Alam, Sk Noor; Silva De Albuquerque, Danilo; Aleksandrov, Dmitry; Alessandro, Bruno; Alfaro Molina, Jose Ruben; Ali, Yasir; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altenkamper, Lucas; Altsybeev, Igor; Anaam, Mustafa Naji; Andrei, Cristian; Andreou, Dimitra; Andrews, Harry Arthur; Andronic, Anton; Angeletti, Massimo; Anguelov, Venelin; Anson, Christopher Daniel; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Anwar, Rafay; Apadula, Nicole; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Arnaldi, Roberta; Arnold, Oliver Werner; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barioglio, Luca; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Barth, Klaus; Bartsch, Esther; Bastid, Nicole; Basu, Sumit; Batigne, Guillaume; Batyunya, Boris; Batzing, Paul Christoph; Bazo Alba, Jose Luis; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Espinoza Beltran, Lucina Gabriela; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhaduri, Partha Pratim; Bhasin, Anju; Bhat, Inayat Rasool; Bhatt, Himani; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Antonio; Bianchi, Livio; Bianchi, Nicola; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biro, Gabor; Biswas, Rathijit; Biswas, Saikat; Blair, Justin Thomas; Blau, Dmitry; Blume, Christoph; Boca, Gianluigi; Bock, Friederike; Bogdanov, Alexey; Boldizsar, Laszlo; Bombara, Marek; Bonomi, Germano; Bonora, Matthias; Borel, Herve; Borissov, Alexander; Borri, Marcello; Botta, Elena; Bourjau, Christian; Bratrud, Lars; Braun-munzinger, Peter; Bregant, Marco; Broker, Theo Alexander; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buhler, Paul; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Bashir Butt, Jamila; Buxton, Jesse Thomas; Cabala, Jan; Caffarri, Davide; Caines, Helen Louise; Caliva, Alberto; Calvo Villar, Ernesto; Soto Camacho, Rabi; Camerini, Paolo; Capon, Aaron Allan; Carena, Francesco; Carena, Wisla; Carnesecchi, Francesca; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Ceballos Sanchez, Cesar; Chandra, Sinjini; Chang, Beomsu; Chang, Wan; Chapeland, Sylvain; Chartier, Marielle; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chauvin, Alex; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Cho, Soyeon; Chochula, Peter; Chowdhury, Tasnuva; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Concas, Matteo; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Costanza, Susanna; Crkovska, Jana; Crochet, Philippe; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Dani, Sanskruti; Danisch, Meike Charlotte; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; Dashi, Anisa; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Conti, Camila; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Derradi De Souza, Rafael; Franz Degenhardt, Hermann; Deisting, Alexander; Deloff, Andrzej; Delsanto, Silvia; Deplano, Caterina; Dhankher, Preeti; Di Bari, Domenico; Di Mauro, Antonio; Di Ruzza, Benedetto; Arteche Diaz, Raul; Dietel, Thomas; Dillenseger, Pascal; Ding, Yanchun; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Van Doremalen, Lennart Vincent; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dudi, Sandeep; Duggal, Ashpreet Kaur; Dukhishyam, Mallick; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Endress, Eric; Engel, Heiko; Epple, Eliane; Erazmus, Barbara Ewa; Erhardt, Filip; Ersdal, Magnus Rentsch; Espagnon, Bruno; Eulisse, Giulio; Eum, Jongsik; Evans, David; Evdokimov, Sergey; Fabbietti, Laura; Faggin, Mattia; Faivre, Julien; Fantoni, Alessandra; Fasel, Markus; Feldkamp, Linus; Feliciello, Alessandro; Feofilov, Grigorii; Fernandez Tellez, Arturo; Ferretti, Alessandro; Festanti, Andrea; Feuillard, Victor Jose Gaston; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiorenza, Gabriele; Flor, Fernando; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Francisco, Audrey; Frankenfeld, Ulrich Michael; Fronze, Gabriele Gaetano; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gajdosova, Katarina; Gallio, Mauro; Duarte Galvan, Carlos; Ganoti, Paraskevi; Garabatos Cuadrado, Jose; Garcia-solis, Edmundo Javier; Garg, Kunal; Gargiulo, Corrado; Gasik, Piotr Jan; Gauger, Erin Frances; De Leone Gay, Maria Beatriz; Germain, Marie; Ghosh, Jhuma; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Giubilato, Piero; Glassel, Peter; Gomez Coral, Diego Mauricio; Gomez Ramirez, Andres; Gonzalez, Victor; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Graham, Katie Leanne; Greiner, Leo Clifford; Grelli, Alessandro; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Gronefeld, Julius Maximilian; Grosa, Fabrizio; Grosse-oetringhaus, Jan Fiete; Grosso, Raffaele; Guernane, Rachid; Guerzoni, Barbara; Guittiere, Manuel; Gulbrandsen, Kristjan Herlache; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Bautista Guzman, Irais; Haake, Rudiger; Habib, Michael Karim; Hadjidakis, Cynthia Marie; Hamagaki, Hideki; Hamar, Gergoe; Hamid, Mohammed; Hamon, Julien Charles; Hannigan, Ryan; Haque, Md Rihan; Harlenderova, Alena; Harris, John William; Harton, Austin Vincent; Hassan, Hadi; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Hellbar, Ernst; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Gonzalez Hernandez, Emma; Herrera Corral, Gerardo Antonio; Herrmann, Florian; Hetland, Kristin Fanebust; Hilden, Timo Eero; Hillemanns, Hartmut; Hills, Christopher; Hippolyte, Boris; Hohlweger, Bernhard; Horak, David; Hornung, Sebastian; Hosokawa, Ritsuya; Hota, Jyotishree; Hristov, Peter Zahariev; Huang, Chun-lu; Hughes, Charles; Huhn, Patrick; Humanic, Thomas; Hushnud, Hushnud; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Iddon, James Philip; Iga Buitron, Sergio Arturo; Ilkaev, Radiy; Inaba, Motoi; Ippolitov, Mikhail; Islam, Md Samsul; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacak, Barbara; Jacazio, Nicolo; Jacobs, Peter Martin; Jadhav, Manoj Bhanudas; Jadlovska, Slavka; Jadlovsky, Jan; Jaelani, Syaefudin; Jahnke, Cristiane; Jakubowska, Monika Joanna; Janik, Malgorzata Anna; Jena, Chitrasen; Jercic, Marko; Jevons, Oliver; Jimenez Bustamante, Raul Tonatiuh; Jin, Muqing; Jones, Peter Graham; Jusko, Anton; Kalinak, Peter; Kalweit, Alexander Philipp; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karczmarczyk, Przemyslaw; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Ketzer, Bernhard Franz; Khabanova, Zhanna; Khan, Ahsan Mehmood; Khan, Shaista; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Khatun, Anisa; Khuntia, Arvind; Kielbowicz, Miroslaw Marek; Kileng, Bjarte; Kim, Byungchul; Kim, Daehyeok; Kim, Dong Jo; Kim, Eun Joo; Kim, Hyeonjoong; Kim, Jinsook; Kim, Jiyoung; Kim, Minjung; Kim, Se Yong; Kim, Taejun; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Klay, Jennifer Lynn; Klein, Carsten; Klein, Jochen; Klein-boesing, Christian; Klewin, Sebastian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobdaj, Chinorat; Varga-kofarago, Monika; Kohler, Markus Konrad; Kollegger, Thorsten; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Konopka, Piotr Jan; Konyushikhin, Maxim; Kovalenko, Oleksandr; Kovalenko, Vladimir; Kowalski, Marek; Kralik, Ivan; Kravcakova, Adela; Kreis, Lukas; Krivda, Marian; Krizek, Filip; Kruger, Mario; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kumar, Jitendra; Kumar, Lokesh; Kumar, Shyam; Kundu, Sourav; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kushpil, Svetlana; Kvapil, Jakub; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Lai, Yue Shi; Lakomov, Igor; Langoy, Rune; Lapidus, Kirill; Lardeux, Antoine Xavier; Larionov, Pavel; Laudi, Elisa; Lavicka, Roman; Lea, Ramona; Leardini, Lucia; Lee, Seongjoo; Lehas, Fatiha; Lehner, Sebastian; Lehrbach, Johannes; Lemmon, Roy Crawford; Leon Monzon, Ildefonso; Levai, Peter; Li, Xiaomei; Li, Xing Long; Lien, Jorgen Andre; Lietava, Roman; Lim, Bong-hwi; Lindal, Svein; Lindenstruth, Volker; Lindsay, Scott William; Lippmann, Christian; Lisa, Michael Annan; Litichevskyi, Vladyslav; Liu, Alwina; Ljunggren, Hans Martin; Llope, William; Lodato, Davide Francesco; Loginov, Vitaly; Loizides, Constantinos; Loncar, Petra; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lowe, Andrew John; Luettig, Philipp Johannes; Luhder, Jens Robert; Lunardon, Marcello; Luparello, Grazia; Lupi, Matteo; Maevskaya, Alla; Mager, Magnus; Mahmood, Sohail Musa; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Malik, Qasim Waheed; Malinina, Liudmila; Mal'kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manko, Vladislav; Manso, Franck; Manzari, Vito; Mao, Yaxian; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martin, Nicole Alice; Martinengo, Paolo; Martinez, Jacobb Lee; Martinez Hernandez, Mario Ivan; Martinez-garcia, Gines; Martinez Pedreira, Miguel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Masson, Erwann; Mastroserio, Annalisa; Mathis, Andreas Michael; Toledo Matuoka, Paula Fernanda; Matyja, Adam Tomasz; Mayer, Christoph; Mazzilli, Marianna; Mazzoni, Alessandra Maria; Meddi, Franco; Melikyan, Yuri; Menchaca-rocha, Arturo Alejandro; Meninno, Elisa; Mercado-perez, Jorge; Meres, Michal; Soncco Meza, Carlos; Mhlanga, Sibaliso; Miake, Yasuo; Micheletti, Luca; Mieskolainen, Matti Mikael; Mihaylov, Dimitar Lubomirov; Mikhaylov, Konstantin; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Auro Prasad; Mohanty, Bedangadas; Khan, Mohammed Mohisin; Moreira De Godoy, Denise Aparecida; Perez Moreno, Luis Alberto; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Mrnjavac, Teo; Muccifora, Valeria; Mudnic, Eugen; Muhlheim, Daniel Michael; Muhuri, Sanjib; Mukherjee, Maitreyee; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Munning, Konstantin; Arratia Munoz, Miguel Ignacio; Munzer, Robert Helmut; Murakami, Hikari; Murray, Sean; Musa, Luciano; Musinsky, Jan; Myers, Corey James; Myrcha, Julian Wojciech; Naik, Bharati; Nair, Rahul; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Narayan, Amrendra; Naru, Muhammad Umair; Nassirpour, Adrian Fereydon; Ferreira Natal Da Luz, Pedro Hugo; Nattrass, Christine; Rosado Navarro, Sebastian; Nayak, Kishora; Nayak, Ranjit; Nayak, Tapan Kumar; Nazarenko, Sergey; Negrao De Oliveira, Renato Aparecido; Nellen, Lukas; Nesbo, Simon Voigt; Neskovic, Gvozden; Ng, Fabian; Nicassio, Maria; Niedziela, Jeremi; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Cabanillas Noris, Juan Carlos; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oh, Hoonjung; Ohlson, Alice Elisabeth; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Orava, Risto; Oravec, Matej; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Pachmayer, Yvonne Chiara; Pacik, Vojtech; Pagano, Davide; Paic, Guy; Palni, Prabhakar; Pan, Jinjin; Pandey, Ashutosh Kumar; Panebianco, Stefano; Papikyan, Vardanush; Pareek, Pooja; Park, Jonghan; Parkkila, Jasper Elias; Parmar, Sonia; Passfeld, Annika; Pathak, Surya Prakash; Patra, Rajendra Nath; Paul, Biswarup; Pei, Hua; Peitzmann, Thomas; Peng, Xinye; Pereira, Luis Gustavo; Pereira Da Costa, Hugo Denis Antonio; Peresunko, Dmitry Yurevich; Perez Lezama, Edgar; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrovici, Mihai; Petta, Catia; Peretti Pezzi, Rafael; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Ozelin De Lima Pimentel, Lais; Pinazza, Ombretta; Pinsky, Lawrence; Pisano, Silvia; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pliquett, Fabian; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polishchuk, Boris; Poljak, Nikola; Poonsawat, Wanchaloem; Pop, Amalia; Poppenborg, Hendrik; Porteboeuf, Sarah Julie; Pozdniakov, Valeriy; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Punin, Valery; Putschke, Jorn Henning; Raha, Sibaji; Rajput, Sonia; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Rami, Fouad; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Ratza, Viktor; Ravasenga, Ivan; Read, Kenneth Francis; Redlich, Krzysztof; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reshetin, Andrey; Revol, Jean-pierre; Reygers, Klaus Johannes; Riabov, Viktor; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-lucian; Rode, Sudhir Pandurang; Rodriguez Cahuantzi, Mario; Roeed, Ketil; Rogalev, Roman; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Rokita, Przemyslaw Stefan; Ronchetti, Federico; Dominguez Rosas, Edgar; Roslon, Krystian; Rosnet, Philippe; Rossi, Andrea; Rotondi, Alberto; Roukoutakis, Filimon; Roy, Christelle Sophie; Roy, Pradip Kumar; Vazquez Rueda, Omar; Rui, Rinaldo; Rumyantsev, Boris; Rustamov, Anar; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Saarinen, Sampo; Sadhu, Samrangy; Sadovskiy, Sergey; Safarik, Karel; Saha, Sumit Kumar; Sahoo, Baidyanath; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sandoval, Andres; Sarkar, Amal; Sarkar, Debojit; Sarkar, Nachiketa; Sarma, Pranjal; Sas, Mike Henry Petrus; Scapparone, Eugenio; Scarlassara, Fernando; Schaefer, Brennan; Scheid, Horst Sebastian; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schmidt, Marten Ole; Schmidt, Martin; Schmidt, Nicolas Vincent; Schukraft, Jurgen; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Sefcik, Michal; Seger, Janet Elizabeth; Sekiguchi, Yuko; Sekihata, Daiki; Selyuzhenkov, Ilya; Senyukov, Serhiy; Serradilla Rodriguez, Eulogio; Sett, Priyanka; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shahoyan, Ruben; Shaikh, Wadut; Shangaraev, Artem; Sharma, Anjali; Sharma, Ankita; Sharma, Meenakshi; Sharma, Natasha; Sheikh, Ashik Ikbal; Shigaki, Kenta; Shimomura, Maya; Shirinkin, Sergey; Shou, Qiye; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singh, Randhir; Singhal, Vikas; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Song, Jihye; Soramel, Francesca; Sorensen, Soren Pontoppidan; Sozzi, Federica; Sputowska, Iwona Anna; Stachel, Johanna; Stan, Ionel; Stankus, Paul; Stenlund, Evert Anders; Stocco, Diego; Storetvedt, Maksim Melnik; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Suljic, Miljenko; Sultanov, Rishat; Sumbera, Michal; Sumowidagdo, Suharyo; Suzuki, Ken; Swain, Sagarika; Szabo, Alexander; Szarka, Imrich; Tabassam, Uzma; Takahashi, Jun; Tambave, Ganesh Jagannath; Tanaka, Naoto; Tarhini, Mohamad; Tariq, Mohammad; Tarzila, Madalina-gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terrevoli, Cristina; Teyssier, Boris; Thakur, Dhananjaya; Thakur, Sanchari; Thomas, Deepa; Thoresen, Freja; Tieulent, Raphael Noel; Tikhonov, Anatoly; Timmins, Anthony Robert; Toia, Alberica; Topilskaya, Nataliya; Toppi, Marco; Rojas Torres, Solangel; Tripathy, Sushanta; Trogolo, Stefano; Trombetta, Giuseppe; Tropp, Lukas; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Trzcinski, Tomasz Piotr; Trzeciak, Barbara Antonina; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Umaka, Ejiro Naomi; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vala, Martin; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vazquez Doce, Oton; Vechernin, Vladimir; Veen, Annelies Marianne; Vercellin, Ermanno; Vergara Limon, Sergio; Vermunt, Luuk; Vernet, Renaud; Vertesi, Robert; Vickovic, Linda; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Villatoro Tello, Abraham; Vinogradov, Alexander; Virgili, Tiziano; Vislavicius, Vytautas; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Voscek, Dominik; Vranic, Danilo; Vrlakova, Janka; Wagner, Boris; Wang, Hongkai; Wang, Mengliang; Watanabe, Yosuke; Weber, Michael; Weber, Steffen Georg; Wegrzynek, Adam; Weiser, Dennis Franz; Wenzel, Sandro Christian; Wessels, Johannes Peter; Westerhoff, Uwe; Whitehead, Andile Mothegi; Wiechula, Jens; Wikne, Jon; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Willems, Guido Alexander; Williams, Crispin; Willsher, Emily; Windelband, Bernd Stefan; Witt, William Edward; Xu, Ran; Yalcin, Serpil; Yamakawa, Kosei; Yano, Satoshi; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-kwon; Yoon, Jin Hee; Yurchenko, Volodymyr; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correa Zanoli, Henrique Jose; Zardoshti, Nima; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zhalov, Mikhail; Zhang, Xiaoming; Zhang, Yonghong; Zhang, Zuman; Zhao, Chengxin; Zherebchevskii, Vladimir; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zhu, Ya; Zichichi, Antonino; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zmeskal, Johann; Zou, Shuguang

    2018-01-01

    The measurement of electron-positron pair production is presented as a function of their invariant mass and transverse momentum at midrapidity ($|y_{\\rm e} | < 0.8$) in proton-proton (pp) collisions at a centre-of-mass energy of $\\sqrt{s} = 13$ TeV. The contributions from light-hadron decays can be calculated from their measured cross sections in pp collisions at $\\sqrt{s} = 7$ TeV or $13$ TeV. The remaining continuum originates from correlated semileptonic decays of heavy-flavour hadrons. Fitting the data with templates from two different Monte Carlo event generators, PYTHIA and POWHEG , the charm and beauty cross sections at midrapidity are extracted for the first time at this collision energy: ${\\rm d}\\sigma_{\\rm{c\\overline c}} /{\\rm d}y|{_ {y=0}} = 974 \\pm 138 {\\rm (stat.)} \\pm 140 {\\rm (syst.)}$ $\\mu$b and ${\\rm d}\\sigma_{\\rm{b\\overline b}} /{\\rm d}y|{_ {y=0}} = 79 \\pm 14 {\\rm (stat.)} \\pm 11 {\\rm (syst.)}$ $\\mu$b using PYTHIA simulations and ${\\rm d}\\sigma_{\\rm{c\\overline c}} /{\\rm d}y|{_ {y=0}} = 14...

  11. Heavy water at Aswan

    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

  12. Atomic polarizabilities

    Safronova, M. S.; Mitroy, J.; Clark, Charles W.; Kozlov, M. G.

    2015-01-01

    The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed

  13. Atomic polarizabilities

    Safronova, M. S. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Mitroy, J. [School of Engineering, Charles Darwin University, Darwin NT 0909 (Australia); Clark, Charles W. [Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, Gaithersburg, Maryland 20899-8410 (United States); Kozlov, M. G. [Petersburg Nuclear Physics Institute, Gatchina 188300 (Russian Federation)

    2015-01-22

    The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed.

  14. Atomic physics

    Foot, Christopher J

    2007-01-01

    This text will thoroughly update the existing literature on atomic physics. Intended to accompany an advanced undergraduate course in atomic physics, the book will lead the students up to the latest advances and the applications to Bose-Einstein Condensation of atoms, matter-wave inter-ferometry and quantum computing with trapped ions. The elementary atomic physics covered in the early chapters should be accessible to undergraduates when they are first introduced to the subject. To complement. the usual quantum mechanical treatment of atomic structure the book strongly emphasizes the experimen

  15. Production of heavy water in India

    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

  16. Ultracold atoms on atom chips

    Krüger, Peter; Hofferberth, S.; Haller, E.

    2005-01-01

    Miniaturized potentials near the surface of atom chips can be used as flexible and versatile tools for the manipulation of ultracold atoms on a microscale. The full scope of possibilities is only accessible if atom-surface distances can be reduced to microns. We discuss experiments in this regime...

  17. Heavy flavours

    Buras, Andrzej J

    1998-01-01

    This volume is a collection of review articles on the most outstanding topics in heavy flavour physics. All the authors have made significant contributions to this field. The book reviews in detail the theoretical structure of heavy flavour physics and confronts the Standard Model and some of its extensions with existing experimental data.This new edition covers new trends and ideas and includes the latest experimental information. Compared to the previous edition interesting new activities are included and some of the key contributions are updated. Particular attention is paid to the discover

  18. High-resolution continuum source atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple lines. A critical review of current possibilities

    Resano, M.; Flórez, M.R.; García-Ruiz, E.

    2013-01-01

    This work examines the capabilities and limitations of commercially available high-resolution continuum source atomic absorption spectrometry instrumentation for multi-line monitoring, discussing in detail the possible strategies to develop multi-element methodologies that are truly simultaneous, or else sequential, but from the same sample aliquot. Moreover, the simultaneous monitoring of various atomic or molecular lines may bring other important analytical advantages, such as: i) expansion of the linear range by monitoring multiplets; ii) improvements in the limit of detection and in precision by summing the signals from different lines of the same element or molecule; iii) simple correction for matrix-effects by selecting a suitable internal standard; or iv) accurate mathematical correction of spectral overlaps by simultaneous monitoring of free lines of the interfering molecule or element. This work discusses how authors have made use of these strategies to develop analytical methodologies that permit the straightforward analysis of complex samples. - Highlights: • HR CS AAS potential for simultaneous multi-line monitoring is critically examined. • Strategies to develop simultaneous multi-element methods are discussed. • Other benefits of multi-line monitoring (e.g., use of an IS or LSBC) are highlighted. • Selected examples from the literature are discussed in detail

  19. Tau electron atoms at RHIC

    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

  20. Heavy quarks

    Khoze, V.A.

    1983-10-01

    We discuss the results accumulated during the last five years in heavy quark physics and try to draw a simple general picture of the present situation. The survey is based on a unified point of view resulting from quantum chromodynamics. (orig.)

  1. What invariant one-particle multiplicity distributions and two-particle correlations are telling us about relativistic heavy-ion collisions

    Nix, J.R.; Strottman, D.; Hecke, H.W. van; Schlei, B.R.; Sullivan, J.P.; Murray, M.J.

    1998-02-01

    The authors have used a nine-parameter expanding source model that includes special relativity, quantum statistics, resonance decays, and freeze-out on a realistic hypersurface in spacetime to analyze in detail invariant π + , K + , and K - one-particle multiplicity distributions and π + and π - two-particle correlations in nearly central collisions of Pb + Pb at p lab /A = 158 GeV/c. These studies confirm an earlier conclusion for nearly central collisions of Si + Au at p lab /A = 14.6 GeV/c that the freeze-out temperature is less than 100 meV and that both the longitudinal and transverse collective velocities -- which are anti-correlated with the temperature -- are substantial. The authors also reconciled their current results with those of previous analyses that yielded a much higher freeze-out temperature of approximately 140 meV for both Pb + Pb collisions at p lab /A = 158 GeV/c and other reactions. One type of analysis was based upon the use of a heuristic equation that neglects relativity to extrapolate slope parameters to zero particle mass. Another type of analysis utilized a thermal model in which there was an accumulation of effects from several approximations. The future should witness the arrival of much new data on invariant one-particle multiplicity distributions and two-particle correlations as functions of bombarding energy and/or size of the colliding nuclei. The proper analysis of these data in terms of a realistic model could yield accurate values for the density, temperature, collective velocity, size, and other properties of the expanding matter as it freezes out into a collection of noninteracting hadrons. A sharp discontinuity in the value of one or more of these properties could conceivably be the long-awaited signal for the formation of a quark-gluon plasma or other new physics

  2. Ubiquitous atom

    Spruch, G.M.; Spruch, L.

    1974-01-01

    The fundamentals of modern physics, including the basic physics and chemistry of the atom, elementary particles, cosmology, periodicity, and recent advances, are surveyed. The biology and chemistry of the life process is discussed to provide a background for considering the effects of atomic particles on living things. The uses of atomic power in space travel, merchant shipping, food preservation, desalination, and nuclear clocks are explored. (Pollut. Abstr.)

  3. Validation of a method to the addition the multiple standard in the analysis of Pb in reservoir waters for atomic absorption spectrometric

    Mayari, R.; Espinosa, M.C.; Vazques, J.

    2003-01-01

    The evaluation of a method is presented for the analysis of Pb in reservoir waters for atomic spectrometric with direct aspiration. For the validation of the analytic method a level of concentration of 0.05 mg/L was evaluated. The precision of the method was of 9.97% and the bias was 0.6% 8 samples of surface waters they were collected and of bottom of the tributaries of the reservoir Scorpions and the stocking of the concentrations in the tributaries was from 0,052 + - 0.026 inferior mg/L to the established one in the Cuban norm of evaluation of the hydirc objects of fishing use

  4. Atomic physics

    Anon.

    1976-01-01

    Research activities in atomic physics at Lawrence Berkeley Laboratory during 1976 are described. Topics covered include: experiments on stored ions; test for parity violation in neutral weak currents; energy conservation and astrophysics; atomic absorption spectroscopy, atomic and molecular detectors; theoretical studies of quantum electrodynamics and high-z ions; atomic beam magnetic resonance; radiative decay from the 2 3 Po, 2 levels of helium-like argon; quenching of the metastable 2S/sub 1/2/ state of hydrogen-like argon in an external electric field; and lifetime of the 2 3 Po level of helium-like krypton

  5. Experimental atomic and molecular physics research

    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

  6. Heavy flavours: theory summary

    Corcella, Gennaro

    2005-01-01

    I summarize the theory talks given in the Heavy Flavours Working Group. In particular, I discuss heavy-flavour parton distribution functions, threshold resummation for heavy-quark production, progress in fragmentation functions, quarkonium production, heavy-meson hadroproduction.

  7. Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

    Adam, J.; Adamová, Dagmar; Bielčík, J.; Bielčíková, Jana; Brož, M.; Čepila, J.; Contreras, J. G.; Eyyubova, G.; Ferencei, Jozef; Horák, D.; Křížek, Filip; Kučera, Vít; Mareš, Jiří A.; Petráček, V.; Pospíšil, Jan; Šumbera, Michal; Vaňát, Tomáš; Závada, Petr

    2017-01-01

    Roč. 13, č. 6 (2017), s. 535-539 ISSN 1745-2473 R&D Projects: GA MŠk(CZ) LG15052 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : ALICE collaboration * heavy ion collisions * multiplicity Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders; BF - Elementary Particles and High Energy Physics (FZU-D) OBOR OECD: Nuclear physics; Particles and field physics (FZU-D) Impact factor: 22.806, year: 2016

  8. Artificial neural networks environmental forecasting in comparison with multiple linear regression technique: From heavy metals to organic micropollutants screening in agricultural soils

    Bonelli, Maria Grazia; Ferrini, Mauro; Manni, Andrea

    2016-12-01

    The assessment of metals and organic micropollutants contamination in agricultural soils is a difficult challenge due to the extensive area used to collect and analyze a very large number of samples. With Dioxins and dioxin-like PCBs measurement methods and subsequent the treatment of data, the European Community advises the develop low-cost and fast methods allowing routing analysis of a great number of samples, providing rapid measurement of these compounds in the environment, feeds and food. The aim of the present work has been to find a method suitable to describe the relations occurring between organic and inorganic contaminants and use the value of the latter in order to forecast the former. In practice, the use of a metal portable soil analyzer coupled with an efficient statistical procedure enables the required objective to be achieved. Compared to Multiple Linear Regression, the Artificial Neural Networks technique has shown to be an excellent forecasting method, though there is no linear correlation between the variables to be analyzed.

  9. Cancer in atomic bomb survivors

    Shigematsu, I.; Kagan, A.

    1986-01-01

    This book presents information on the following topics: sampling of atomic bomb survivors and method of cancer detection in Hiroshima and Nagasaki; atomic bomb dosimetry for epidemiological studies of survivors in Hiroshima and Nagasaki; tumor and tissue registries in Hiroshima and Nagasaki; the cancer registry in Nagasaki, with atomic bomb survivor data, 1973-1977; cancer mortality; methods for study of delayed health effects of a-bomb radiation; experimental radiation carcinogenesis in rodents; leukemia, multiple myeloma, and malignant lymphoma; cancer of the thyroid and salivary glands; malignant tumors in atomic bomb survivors with special reference to the pathology of stomach and lung cancer; colorectal cancer among atomic bomb survivors; breast cancer in atomic bomb survivors; and ovarian neoplasms in atomic bomb survirors

  10. Heavy weights

    2001-01-01

    The paper mentions the important thing that it was for the country, exporting the first shipping of crude de Castilla to a company of asphalts in United States. It was not a common sale, as those that it carries out the company with the crude of Cusiana or Cano Limon. The new of this shipping is that it was the first successful test of marketing the Colombian heavy crude in the exterior, since previously it was almost considered a curse to find heavy crude by the difficulties of its transport. Today it can be taken to any refinery of the world and the best test is that, after almost a year of efforts to overcome the barriers of the transport, the company achieved its conduction from the Castilla Field, in proximities to Villavicencio, until the Covenas Port, in the Caribbean Colombian coast

  11. Atomic physics

    Born, Max

    1969-01-01

    The Nobel Laureate's brilliant exposition of the kinetic theory of gases, elementary particles, the nuclear atom, wave-corpuscles, atomic structure and spectral lines, electron spin and Pauli's principle, quantum statistics, molecular structure and nuclear physics. Over 40 appendices, a bibliography, numerous figures and graphs.

  12. Early Atomism

    https://www.ias.ac.in/article/fulltext/reso/015/10/0905-0925. Keywords. Atomic theory; Avogadro's hypothesis; atomic weights; periodic table; valence; molecular weights; molecular formula; isomerism. Author Affiliations. S Ramasesha1. Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, ...

  13. Atom spectroscopy

    Kodling, K.

    1981-01-01

    Experiments on atom photoabsorption spectroscopy using synchrotron radiation in the 10-1000 eV range are reviewed. Properties of the necessary synchrotron radiation and the experiment on absorption spectroscopy are briefly described. Comparison with other spectroscopy methods is conducted. Some data on measuring photoabsorption, photoelectron emission and atom mass spectra are presented [ru

  14. Exotic atoms

    Horvath, D.; Lambrecht, R.M.

    1984-01-01

    This bibliography on exotic atoms covers the years 1939 till 1982. The annual entries are headed by an introduction describing the state of affairs of the branch of science and listing the main applications in quantum electrodynamics, particle physics, nuclear physics, atomic physics, chemical physics and biological sciences. The bibliography includes an author index and a subject index. (Auth.)

  15. Nuclear and atomic physics at one gigaflop

    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

  16. Electron population uncertainty and atomic covalency

    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

  17. Heavy ions

    CERN. Geneva; Antinori, Federico

    2001-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  18. Heavy ions

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    Colliding two heavy nuclei at ultrarelativistic energies allows to create in the laboratory a bulk system with huge density, pressure and temperature and to study its properties. It is estimated that in Pb-Pb collisions at CERN-SPS we reach over an appreciable volume an energy density which exceeds by more than a factor 20 that of normal nuclear matter. At such densities, the hadrons are so closely packed that they interpenetrate; novel physics phenomena are expected to appear. QCD predicts that under such conditions a phase transition from a system composed of colourless hadrons to a Quark-Gluon Plasma (QGP) should occur. A rich ultrarelativistic heavy-ion physics programme is under way both at BNL-AGS and at CERN-SPS since 1986. The results obtained so far have led CERN to officially announce evidence for a new state of matter last year. A long-range programme of heavy-ion physics at higher energies is under way (BNL-RHIC) and in preparation (CERN-LHC). These lectures are meant as an introduction to the phy...

  19. Effect of multiple autoclave cycles on the surface roughness of HyFlex CM and HyFlex EDM files: an atomic force microscopy study.

    Yılmaz, K; Uslu, G; Özyürek, T

    2018-02-13

    To compare the effect of autoclave cycles on the surface topography and roughness of HyFlex CM and HyFlex EDM instruments using atomic force microscopy (AFM) analysis. Eight new files of each brand were subdivided into four subgroups (n = 2/each subgroup). One group was allocated as the control group and not subjected to autoclave sterilization. The other three groups were subjected to different numbers (1, 5, and 10) of autoclave sterilization cycles. After the cycle instruments were subjected to AFM analysis. Roughness average (Ra) and the root mean square (RMS) values were chosen to investigate the surface features of endodontic files. The data was analyzed using one-way ANOVA and post hoc Tamhane tests at 5% significant level. The lowest Ra and RMS values were observed in the HyFlex EDM files that served as the control and in those subjected to a single cycle of autoclave sterilization (P cycles of autoclave sterilization (P cycles, whereas those of the HyFlex EDM group exhibited a significant change after five autoclave cycles (P cycles of autoclave sterilization. In contrast, the surface roughness values of the HyFlex CM files did not increase until 10 cycles of autoclave sterilization. Present study indicated that autoclave sterilization negatively affected the surface roughness of the tested NiTi files.

  20. Heavy metals in sea turtles

    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)

  1. Direction of Heavy Water Projects

    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

  2. Atomic fusion, Gerrard atomic fusion

    Gerrard, T.H.

    1980-01-01

    In the approach to atomic fusion described here the heat produced in a fusion reaction, which is induced in a chamber by the interaction of laser beams and U.H.F. electromagnetic beams with atom streams, is transferred to a heat exchanger for electricity generation by a coolant flowing through a jacket surrounding the chamber. (U.K.)

  3. Heavy ion medical accelerator, HIMAC

    Yamada, Satoru

    1993-01-01

    The heavy ion beam is undoutedly suitable for the cancer treatment. The supriority of the heavy ions over the conventional radiations including protons and neutrons comes mainly from physical characteristics of a heavy particle with multiple charges. A straggling angle due to a multiple Coulomb scattering process in a human body is small for heavy ions, and the small scattering angle results in a good dose localization in a transverse direction. An ionization ratio of the heavy ion beam makes a very sharp peak at the ends of their range. The height of the peak is higher for the heavier ions and shows excellent biomedical effects around Ne ions. In order to apply heavy ion beams to cancer treatment, Heavy Ion Medical Accelerator in Chiba (HIMAC) has been constructed at National Institute of Radiological Sciences. The accelerator complex consists of two ion sources, two successive linac tanks, a pair of synchrotron rings, a beam transport system and an irradiation system. An operation frequency is 100 MHz for two linacs, and the ion energy is 6.0 MeV/u at the output end of the linac. The other four experimental rooms are prepared for basic experiments. The synchrotron accelerates ions up to 800 MeV/u for a charge to mass ratio of 1/2. The long beam transport line provides two vertical beams in addition with two horizontal beams for the treatment. The three treatment rooms are prepared one of which is equipped with both horizontal and vertical beam lines. The whole facility will be open for all scientists who have interests in the heavy ion science as well as the biophysics. The conceptual design study of HIMAC started in 1984, and the construction of the accelerator complex was begun in March 1988. The beam acceleration tests of the injector system was successfully completed in March of this year, and tests of the whole system will be finished throughout this fyscal year. (author)

  4. Superradiators created atom by atom

    Meschede, Dieter

    2018-02-01

    High radiation rates are usually associated with macroscopic lasers. Laser radiation is “coherent”—its amplitude and phase are well-defined—but its generation requires energy inputs to overcome loss. Excited atoms spontaneously emit in a random and incoherent fashion, and for N such atoms, the emission rate simply increases as N. However, if these atoms are in close proximity and coherently coupled by a radiation field, this microscopic ensemble acts as a single emitter whose emission rate increases as N2 and becomes “superradiant,” to use Dicke's terminology (1). On page 662 of this issue, Kim et al. (2) show the buildup of coherent light fields through collective emission from atomic radiators injected one by one into a resonator field. There is only one atom ever in the cavity, but the emission is still collective and superradiant. These results suggest another route toward thresholdless lasing.

  5. Heavy quark effective theory and heavy baryon transitions

    Hussain, F.

    1992-01-01

    The heavy quark effective theory (HQET) is applied to study the weak decay of heavy mesons and heavy baryons and to predict the form factors for heavy to heavy and heavy to light transitions. 28 refs, 10 figs, 2 tabs

  6. Heavy-Ion Fusion Accelerator Research, 1991

    1992-03-01

    This report discusses the following topics: research with multiple- beam experiment MBE-4; induction linac systems experiments; and long- range research and development of heavy-ion fusion accelerators

  7. HEAVY ION LINEAR ACCELERATOR

    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.

  8. Atomic interferometry

    Baudon, J.; Robert, J.

    2004-01-01

    Since the theoretical works of L. De Broglie (1924) and the famous experiment of Davisson and Germer (1927), we know that a wave is linked with any particle of mass m by the relation λ = h/(mv), where λ is the wavelength, v the particle velocity and h is the Planck constant. The basic principle of the interferometry of any material particle, atom, molecule or aggregate is simple: using a simple incident wave, several mutually consistent waves (with well-defined relative phases) are generated and controllable phase-shifts are introduced between them in order to generate a wave which is the sum of the previous waves. An interference figure is obtained which consists in a succession of dark and bright fringes. The atomic interferometry is based on the same principle but involves different techniques, different wave equations, but also different beams, sources and correlations which are described in this book. Because of the small possible wavelengths and the wide range of possible atomic interactions, atomic interferometers can be used in many domains from the sub-micron lithography to the construction of sensors like: inertial sensors, gravity-meters, accelerometers, gyro-meters etc. The first chapter is a preliminary study of the space and time diffraction of atoms. The next chapters is devoted to the description of slit, light separation and polarization interferometers, and the last chapter treats of the properties of Bose-Einstein condensates which are interesting in atomic interferometry. (J.S.)

  9. IR analyzer spots heavy water leaks

    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.)

  10. Respectives of heavy ion physics in JINR

    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

  11. Atomic politics

    Skogmar, G.

    1979-01-01

    The authors basic point is that the military and civil sides of atomic energy cannot be separated. The general aim of the book is to analyze both the military and civil branches, and the interdependence between them, of American foreign policy in the atomic field. Atomic policy is seen as one of the most important imstruments of foreign policy which, in turn, is seen against the background of American imperialism in general. Firstly, the book investigates the most important means by which the United States has controlled the development in the nuclear field in other countries. These means include influencing the conditions of access to nuclear resources of various kinds, influencing the flow of technical-economic information and influencing international organizations and treaties bearing on atomic energy. The time period treated is 1945-1973. 1973 is chosen as the end-year of the study mainly because of the new conditions in the whole energy field initiated by the oil crisis in that year. The sources of the empirical work are mainly hearings before the Joint Committee on Atomic Energy of the U.S. Congress and legal material of various kinds. Secondly, the goals of the American policy are analyzed. The goals identified are armament effect, non-proliferation (horizontal), sales, and energy dependence. The relation between the main goals is discussed.The discussion is centered on the interdependence between the military and the civil aspects, conflict and coincidence of various goals, the relation between short-term and long-term goals, and the possibilities of using one goal as pretext for another. Thirdly, some causes of the changes in the atomic policy around 1953 and 1963 are identified. These are the strategic balance, the competitive situation, the capacity (of the American atomic productive apparatus), and the nuclear technological stage. The specific composition of these four factors at the two time-points can explain the changes of policy. (author)

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

    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.

  13. Atomic secrecy

    Sweet, W.

    1979-01-01

    An article, The H-Bomb Secret: How We Got It, Why We're Telling It, by Howard Morland was to be published in The Progressive magazine in February, 1979. The government, after learning of the author's and the editors' intention to publish the article and failing to persuade them to voluntarily delete about 20% of the text and all of the diagrams showing how an H-bomb works, requested a court injunction against publication. Acting under the Atomic Energy Act of 1954, US District Court Judge Robert W. Warren granted the government's request on March 26. Events dealing with the case are discussed in this publication. Section 1, Progressive Hydrogen Bomb Case, is discussed under the following: Court Order Blocking Magazine Report; Origins of the Howard Morland Article; Author's Motives, Defense of Publication; and Government Arguments Against Disclosure. Section 2, Access to Atomic Data Since 1939, contains information on need for secrecy during World War II; 1946 Atomic Energy Act and its effects; Soviet A-Bomb and the US H-Bomb; and consequences of 1954 Atomic Energy Act. Section 3, Disputed Need for Atomic Secrecy, contains papers entitled: Lack of Studies on H-Bomb Proliferation; Administration's Position on H-Bombs; and National Security Needs vs Free Press

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

    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.

  15. Australia's atomic conspiracy theory

    Binnie, A.

    2001-01-01

    The author questions claims by the Newcastle University historian Wayne Reynolds in his book 'Australia's Bid for the Bomb', that the impetus behind the Snowy Mountains Scheme was to provide a secure source of power for the enrichment of uranium and production of heavy water so that Australia could produce its own atomic bombs. Reynolds also argued that the Australian Atomic Energy Commission (AAEC) was set up so that Australia had a trained scientific workforce to produce plutonium for the bomb. While the book is well researched, Reynolds does not seem to understand the principles of basic science and engineering. After the Second World War, a manufacturing and industrial base with a skilled and trained workforce was needed so it could be converted to war or defence manufacturing when the need arose. This new manufacturing community would require electrical power to sustain it. Hydroelectricity and atomic energy could help provide these needs. Even though war was still raging, Prime Minister John Curtin looked ahead and set up a Department of Post-War Reconstruction. It was through this department that the Snowy Mountains Scheme would be established. Curtin did not live to see this. He died in 1945 but his successor, Ben Chifley, continued the vision. The author believes, an understanding of the science behind these developments and an appreciation of how how humans interact with each others when it comes to getting something they want is likely to give a more balanced view of the past

  16. Physical particularities of nuclear reactors using heavy moderators of neutrons

    Kulikov, G. G.; Shmelev, A. N.

    2016-01-01

    In nuclear reactors, thermal neutron spectra are formed using moderators with small atomic weights. For fast reactors, inserting such moderators in the core may create problems since they efficiently decelerate the neutrons. In order to form an intermediate neutron spectrum, it is preferable to employ neutron moderators with sufficiently large atomic weights, using "2"3"3U as a fissile nuclide and "2"3"2Th and "2"3"1Pa as fertile ones. The aim of the work is to investigate the properties of heavy neutron moderators and to assess their advantages. The analysis employs the JENDL-4.0 nuclear data library and the SCALE program package for simulating the variation of fuel composition caused by irradiation in the reactor. The following main results are obtained. By using heavy moderators with small neutron moderation steps, one is able to (1) increase the rate of resonance capture, so that the amount of fertile material in the fuel may be reduced while maintaining the breeding factor of the core; (2) use the vacant space for improving the fuel-element properties by adding inert, strong, and thermally conductive materials and by implementing dispersive fuel elements in which the fissile material is self-replenished and neutron multiplication remains stable during the process of fuel burnup; and (3) employ mixtures of different fertile materials with resonance capture cross sections in order to increase the resonance-lattice density and the probability of resonance neutron capture leading to formation of fissile material. The general conclusion is that, by forming an intermediate neutron spectrum with heavy neutron moderators, one can use the fuel more efficiently and improve nuclear safety.

  17. Physical particularities of nuclear reactors using heavy moderators of neutrons

    Kulikov, G. G., E-mail: ggkulikov@mephi.ru; Shmelev, A. N. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2016-12-15

    In nuclear reactors, thermal neutron spectra are formed using moderators with small atomic weights. For fast reactors, inserting such moderators in the core may create problems since they efficiently decelerate the neutrons. In order to form an intermediate neutron spectrum, it is preferable to employ neutron moderators with sufficiently large atomic weights, using {sup 233}U as a fissile nuclide and {sup 232}Th and {sup 231}Pa as fertile ones. The aim of the work is to investigate the properties of heavy neutron moderators and to assess their advantages. The analysis employs the JENDL-4.0 nuclear data library and the SCALE program package for simulating the variation of fuel composition caused by irradiation in the reactor. The following main results are obtained. By using heavy moderators with small neutron moderation steps, one is able to (1) increase the rate of resonance capture, so that the amount of fertile material in the fuel may be reduced while maintaining the breeding factor of the core; (2) use the vacant space for improving the fuel-element properties by adding inert, strong, and thermally conductive materials and by implementing dispersive fuel elements in which the fissile material is self-replenished and neutron multiplication remains stable during the process of fuel burnup; and (3) employ mixtures of different fertile materials with resonance capture cross sections in order to increase the resonance-lattice density and the probability of resonance neutron capture leading to formation of fissile material. The general conclusion is that, by forming an intermediate neutron spectrum with heavy neutron moderators, one can use the fuel more efficiently and improve nuclear safety.

  18. Scientific issues in future induction linac accelerators for heavy ion fusion

    Celata, C.M.

    2004-01-01

    Achievement of atomic-resolution electron-beam tomography will allow determination of the three-dimensional structure of nanoparticles (and other suitable specimens) at atomic resolution. Three-dimensional reconstructions will yield ''section'' images that resolve atoms overlapped in normal electron microscope images (projections), resolving lighter atoms such as oxygen in the presence of heavier atoms, and atoms that lie on non-lattice sites such as those in non-periodic defect structures. Our first demonstrations of 3-D reconstruction to atomic resolution used five zone-axis images from test specimens of staurolite consisting of a mix of light and heavy atoms. We propose combining ultra-high (sub-Angstrom) resolution zone-axis images with off-zone images by first using linear reconstruction of the off-zone images while excluding images obtained within a small range of tilts (of the order of 60 milliradian) of any zone-axis orientation, since it has been shown that dynamical effects can be mitigated by slight off-axis tilt of the specimen. The (partial) reconstruction would then be used as a model for forward calculation by image simulation in zone-axis directions and the structure refined iteratively to achieve satisfactory fits with the experimental zone-axis data. Another path to atomic-resolution tomography would combine ''zone-axis tomography'' with high-resolution dark-field hollow-cone (DFHC) imaging. Electron diffraction theory indicates that dynamic (multiple) scattering is much reduced under highly-convergent illumination. DFHC TEM is the analog of HAADF STEM, and imaging theory shows that image resolution can be enhanced under these conditions. Images obtained in this mode could provide the initial reconstruction, with zone-axis images used for refinement

  19. Heavy Menstrual Bleeding (Menorrhagia)

    ... Us Information For… Media Policy Makers Blood Disorders Heavy Menstrual Bleeding Recommend on Facebook Tweet Share Compartir ... It can also be bleeding that is very heavy. How do you know if you have heavy ...

  20. Antimatter atoms

    Anon.

    1996-01-01

    In january 1996, CERN broadcasted the information of the creation of nine anti-hydrogen atoms, observed through disintegration products. The experimental facility was CERN LEAR ring. An antiproton beam scattered a xenon jet, and the resulting antimatter was first selected by its insensitivity to beam bending magnets. Their disintegration was detected in thin NaI detectors, in which the anti-atoms are at once deprived from their positron. Then, magnetic and time-of-flight spectrometers are used. (D.L.)

  1. Atomic theories

    Loring, FH

    2014-01-01

    Summarising the most novel facts and theories which were coming into prominence at the time, particularly those which had not yet been incorporated into standard textbooks, this important work was first published in 1921. The subjects treated cover a wide range of research that was being conducted into the atom, and include Quantum Theory, the Bohr Theory, the Sommerfield extension of Bohr's work, the Octet Theory and Isotopes, as well as Ionisation Potentials and Solar Phenomena. Because much of the material of Atomic Theories lies on the boundary between experimentally verified fact and spec

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

    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 ...

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

    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.

  4. Heavy flavour in ALICE

    Pillot, Philippe

    2008-01-01

    Open heavy flavours and heavy quarkonium states are expected to provide essential informa- tion on the properties of the strongly interacting system fo rmed in the early stages of heavy-ion collisions at very high energy density. Such probes are espe cially promising at LHC energies where heavy quarks (both c and b) are copiously produced. The ALICE detector shall measure the production of open heavy flavours and heavy quarkonium st ates in both proton-proton and heavy-ion collisions at the LHC. The expected performances of ALICE for heavy flavour physics is discussed based on the results of simulation studies on a s election of benchmark channels

  5. Atoms stories

    Radvanyi, P.; Bordry, M.

    1988-01-01

    Physicists from different countries told each evening during one learning week, to an audience of young people, some great discoveries in evoking the difficulties and problems to which the researchers were confronted. From Antiquity to a more recent history, it is a succession of atoms stories. (N.C.)

  6. Atomic physics

    Held, B.

    1991-01-01

    This general book describes the change from classical physics to quantum physics. The first part presents atom evolution since antiquity and introduces fundamental quantities and elements of relativity. Experiments which have contributed to the evolution of knowledge on matter are analyzed in the second part. Applications of wave mechanics to the study of matter properties are presented in the third part [fr

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

    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), ...

  8. Getting the chemistry right: protonation, tautomers and the importance of H atoms in biological chemistry.

    Bax, Ben; Chung, Chun Wa; Edge, Colin

    2017-02-01

    There are more H atoms than any other type of atom in an X-ray crystal structure of a protein-ligand complex, but as H atoms only have one electron they diffract X-rays weakly and are `hard to see'. The positions of many H atoms can be inferred by our chemical knowledge, and such H atoms can be added with confidence in `riding positions'. For some chemical groups, however, there is more ambiguity over the possible hydrogen placements, for example hydroxyls and groups that can exist in multiple protonation states or tautomeric forms. This ambiguity is far from rare, since about 25% of drugs have more than one tautomeric form. This paper focuses on the most common, `prototropic', tautomers, which are isomers that readily interconvert by the exchange of an H atom accompanied by the switch of a single and an adjacent double bond. Hydrogen-exchange rates and different protonation states of compounds (e.g. buffers) are also briefly discussed. The difference in heavy (non-H) atom positions between two tautomers can be small, and careful refinement of all possible tautomers may single out the likely bound ligand tautomer. Experimental methods to determine H-atom positions, such as neutron crystallography, are often technically challenging. Therefore, chemical knowledge and computational approaches are frequently used in conjugation with experimental data to deduce the bound tautomer state. Proton movement is a key feature of many enzymatic reactions, so understanding the orchestration of hydrogen/proton motion is of critical importance to biological chemistry. For example, structural studies have suggested that, just as a chemist may use heat, some enzymes use directional movement to protonate specific O atoms on phosphates to catalyse phosphotransferase reactions. To inhibit `wriggly' enzymes that use movement to effect catalysis, it may be advantageous to have inhibitors that can maintain favourable contacts by adopting different tautomers as the enzyme `wriggles'.

  9. Atoms, radiation, and radiation protection

    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

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

    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 ...

  11. Heavy metal jako subkultura

    KOUTNÁ, Daniela

    2016-01-01

    This bachelor thesis deals with heavy metal subculture. Its aim is to introduce the most important branches and to show broadness of heavy metal. This bachelor thesis describes development and history, briefly shows Czech heavy metal history alongside with the biggest and most popular Czech heavy metal festivals. It shows the most dressing concerns of society against this style.

  12. Electron spectroscopy with fast heavy ions

    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. Deuterium and heavy water

    Vasaru, G.; Ursu, D.; Mihaila, A.; Szentgyorgyi, P.

    1975-01-01

    This bibliography on deuterium and heavy water contains 3763 references (1932-1974) from 43 sources of information. An author index and a subject index are given. The latter contains a list of 136 subjects, arranged in 13 main topics: abundance of deuterium , catalysts, catalytic exchange, chemical equilibria, chemical kinetics, deuterium and heavy water analysis, deuterium and heavy water properties, deuterium and heavy water separation, exchange reactions, general review, heavy water as moderator, isotope effects, synthesis of deuterium compounds

  14. Heavy Metal Stars

    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

  15. Atom-surface potentials and atom interferometry

    Babb, J.F.

    1998-01-01

    Long-range atom-surface potentials characterize the physics of many actual systems and are now measurable spectroscopically in deflection of atomic beams in cavities or in reflection of atoms in atomic fountains. For a ground state, spherically symmetric atom the potential varies as -1/R 3 near the wall, where R is the atom-surface distance. For asymptotically large distances the potential is weaker and goes as -1/R 4 due to retardation arising from the finite speed of light. This diminished interaction can also be interpreted as a Casimir effect. The possibility of measuring atom-surface potentials using atomic interferometry is explored. The particular cases studied are the interactions of a ground-state alkali-metal atom and a dielectric or a conducting wall. Accurate descriptions of atom-surface potentials in theories of evanescent-wave atomic mirrors and evanescent wave-guided atoms are also discussed. (author)

  16. On the resonant coherent excitation of relativistic heavy ions

    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.)

  17. Atomic mixing of metallic bilayers Ni/Ti irradiated with high energy heavy ions; Etude du melange ionique de bicouches metalliques Ni/Ti irradiees avec des ions lourds de haute energie

    Leguay, R

    1994-09-26

    We have studied the ionic mixing of Nl(105 angstrom) bilayers irradiated, at 80 and 300 K. with GeV heavy ions. In this energy range, the energy transfer from the incident ions to the target occurs mainly through electronic excitations. We have shown that this energy transfer induces a strong ionic mixing at the Nl/Ti interface. The thickness of the mixed interlayer increases with the fluence. At low fluences (10{sup 12} ions/cm{sup 2}), the Nl/Ti interface is rough ; at higher fluences (10{sup 13} ions/cm{sup 2}) a homogeneous mixed interlayer appears ; and at even higher fluences (some 10{sup 13} ions/cm{sup 2}) a preferential diffusion of Ni into Ti is clearly seen. The characterization techniques used are: (1) electrical resistivity measurements which allow to follow in situ the damage kinetic. (II) neutron and X-ray reflectometry. (III) elaboration of transverse cuts on which was performed energy loss spectroscopy. (II) and (III) allow the determination of the concentration profiles of the different species present in the sample. (IV) transmission electron microscopy on the transverse cuts which gives a direct image of the different layers. (author). 11 refs., 103 figs., 23 tabs., 2 appends.

  18. Electromagnetic trapping of neutral atoms

    Metcalf, H.J.

    1986-01-01

    Cooling and trapping of neutral atoms is a new branch of applied physics that has potential for application in many areas. The authors present an introduction to laser cooling and magnetic trapping. Some basic ideas and fundamental limitations are discussed, and the first successful experiments are reviewed. Trapping a neutral object depends on the interaction between an inhomogeneous electromagnetic field and a multiple moment that results in the exchange of kinetic for potential energy. In neutral atom traps, the potential energy must be stored as internal atomic energy, resulting in two immediate and extremely important consequences. First, the atomic energy levels will necessarily shift as the atoms move in the trap, and, second, practical traps for ground state neutral atoms atr necessarily very shallow compared to thermal energy. This small depth also dictates stringent vacuum requirements because a trapped atom cannot survive a single collision with a thermal energy background gas molecule. Neutral trapping, therefore, depends on substantial cooling of a thermal atomic sample and is inextricably connected with the cooling process

  19. Atomic physics in the Tandar Laboratory

    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

  20. Exotic atoms

    Kunselman, R.

    1993-01-01

    The experiments use a solid hydrogen layer to form muonic hydrogen isotopes that escape into vacuum. The method relies on transfer of the muon from protium to either a deuteron or a triton. The resulting muonic deuterium or muonic tritium will not immediately thermalize because of the very low elastic cross sections, and may be emitted from the surface of the layer. Measurements which detect decay electrons, muonic x-rays, and fusion products have been used to study the processes. A target has been constructed which exploits muonic atom emission in order to learn more about the energy dependence of transfer and muon molecular formation

  1. Curious behavior of optically trapped neutral atoms

    Wieman, C.; Walker, T.; Sesko, D.; Monroe, C.

    1991-01-01

    We have studied the behavior of clouds of neutral atoms contained in a spontaneous force optical trap. Because of the low temperatures of the atoms ( 5 atoms. These include the expansion of the cloud as the number is increased and dramatic changes in the distribution of the atoms at higher numbers. We can explain much of the collective behavior using a simple model that includes a 1/r 2 force between the atoms arising from the multiple scattering of photons. Finally, we discuss the optical trapping of atoms directly from a low pressure vapor in a small glass cell. We have used these optically trapped atoms to load a magnetostatic trap in the same cell. This provided a high density sample of atoms with a temperature of less than 2 μK

  2. Atom optics in the time domain

    Arndt, M.; Szriftgiser, P.; Dalibard, J.; Steane, A. M.

    1996-05-01

    Atom-optics experiments are presented using a time-modulated evanescent light wave as an atomic mirror in the trampoline configuration, i.e., perpendicular to the direction of the atomic free fall. This modulated mirror is used to accelerate cesium atoms, to focus their trajectories, and to apply a ``multiple lens'' to separately focus different velocity classes of atoms originating from a point source. We form images of a simple two-slit object to show the resolution of the device. The experiments are modelled by a general treatment analogous to classical ray optics.

  3. Sequential injection-bead injection-lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    Wang Jianhua; Hansen, Elo Harald; Miro, Manuel

    2003-01-01

    This communication presents an overview of the state-of-the-art of the exploitation of sequential injection (SI)-bead injection (BI)-lab-on-valve (LOV) schemes for automatic on-line sample pre-treatments interfaced with ETAAS and ICPMS detection as conducted in the authors' group. The discussions are focused on the applications of SI-BI-LOV protocols for on-line microcolumn based solid phase extraction of ultra-trace levels of heavy metals, employing the so-called renewable surface separation and preconcentration manipulatory scheme. Two types of sorbents have been employed as packing material, that is, the hydrophilic SP Sephadex C-25 cation exchange and iminodiacetate based Muromac A-1 chelating resins, and the hydrophobic poly(tetrafluoroethylene) (PTFE) and poly(styrene-divinylbenzene) copolymer alkylated with octadecyl groups (C 18 -PS/DVB). Using ETAAS as detection device, the easy-to-handle hydrophilic renewable reactors hold the features of improved R.S.D.s and LODs as compared to those operated in the conventional, permanent mode, in addition to the elimination of flow resistance. The hydrophobic columns fall into two categories, that is, the renewable one packed with C 18 -PS/DVB beads entails analogous R.S.D.s and LODs with respect to the conventional approach, while those with PTFE beads result in slightly inferior R.S.D.s and LODs by similar comparison, yet offering a wider dynamic range than when using an external permanent column. Moreover, the hydrophilic materials result in much higher enrichment of the analyte than the hydrophobic ones, although PTFE is the packing material that exhibits the best retention efficiency

  4. Heavy Ion Fusion Accelerator Research (HIFAR)

    1991-04-01

    This report discusses the following topics: emittance variations in current-amplifying ion induction lina; transverse emittance studies of an induction accelerator of heavy ions; drift compression experiments on MBE-4 and related emittance; low emittance uniform- density C s + sources for heavy ion fusion accelerator studies; survey of alignment of MBE-4; time-of-flight dependence on the MBE-4 quadrupole voltage; high order calculation of the multiple content of three dimensional electrostatic geometries; an induction linac injector for scaled experiments; induction accelerator test module for HIF; longitudinal instability in HIF beams; and analysis of resonant longitudinal instability in a heavy ion induction linac

  5. Heavy quark energy loss in nuclear medium

    Zhang, Benr-Wei; Wang, Enke; Wang, Xin-Nian

    2003-01-01

    Multiple scattering, modified fragmentation functions and radiative energy loss of a heavy quark propagating in a nuclear medium are investigated in perturbative QCD. Because of the quark mass dependence of the gluon formation time, the medium size dependence of heavy quark energy loss is found to change from a linear to a quadratic form when the initial energy and momentum scale are increased relative to the quark mass. The radiative energy loss is also significantly suppressed relative to a light quark due to the suppression of collinear gluon emission by a heavy quark

  6. Atom Skimmers and Atom Lasers Utilizing Them

    Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.

    2005-01-01

    Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.

  7. Electron scattering studies of selected electric and magnetic dipole and quadrupole transitions in light and heavy nuclei, the new multipole giant resonances and atomic transitions - recent results from the DALINAC

    Richter, A.

    1977-01-01

    Recent experimental work from the Darmstadt electron linear accelerator (DALINAC) is briefly summarized. Particular emphasis is given to the following topics: high resolution inelastic electron scattering (ΔE approximately 30 keV FWHM) has been used to study the radiative width and magnetization density of the 2 + , T = 1 state at 16.11 MeV in 12 C, E2 strength distribution in 28 Si below an excitation energy of 13 MeV and the isospin forbidden E1 electroexcitation of the 1 - , T = 0 state at 6.95 MeV in 40 Ca. High resolution inelastic electron scattering was also employed to determine certain M1 transitions in 14 N, 28 Si, 39 K, 58 Ni, 90 Zr and 208 Pb and the M2 strength distribution in the two heaviest nuclei. At medium energy resolution (ΔE approximately 200 keV FWHM) spectra at various angles and bombarding energies have been measured from (4-31) MeV for 208 Pb. They are being analyzed in order to determine E0, E1, E2, E3 and M1 giant resonance strength in the continuum. The Z and E dependence and the scaling behaviour of the atomic inner shell ionization cross section at relativistic electron impact is studied on gaseous and solid targets. (orig./BJ) [de

  8. Atomic and solid state physics with the 14UD

    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)

  9. Highly charged atomic physics at HIRFL-CSR

    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

  10. Atomic physics of strongly correlated systems

    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

  11. A heavy load for heavy ions

    2003-01-01

    On 25 September, the two large coils for the dipole magnet of ALICE, the LHC experiment dedicated to heavy ions, arrived at Point 2 on two heavy load trucks after a 1200 km journey from their assembly in Vannes, France.

  12. Penetration of relativistic heavy ions through matter

    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.)

  13. X-ray holography with an atomic scatterer

    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.

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

    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

  15. Uncertainty estimates for theoretical atomic and molecular data

    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)

  16. Atomic power project, Kakrapar, Gujarat

    Varadarajan, G.

    1992-01-01

    The atomic power project at Kakrapar, comprising of two units of 235 MW each, went critical very recently in September 1992. The work consisted of construction of reactor and turbine buildings, outer and inner containment walls, calandria vault, natural draught cooling tower, etc. Nearly 152,000m 3 of normal aggregate concrete and 3,500m 3 of heavy aggregate concrete were produced and poured. The paper describes salient innovative construction features of the project. Incidentally, the project received a Certificate of Merit in the Excellence in Concrete competition held by the Maharashtra India Chapter of the American Concrete Institute. (author). 7 figs

  17. Are there superheavy atomic nuclei

    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. Transparency of atom-sized superconducting junctions

    Van-der-Post, N.; Peters, E.T.; Van Ruitenbeek, J.M.; Yanson, I.K.

    1995-01-01

    We discuss the transparency of atom-size superconducting tunnel junctions by comparing experimental values of the normal resistance and Subgap Structure with the theoretical predictions for these phenomena by Landauer's formula and Multiple Andreev Reflection, respectively

  19. Recoil ion spectroscopy with heavy ions

    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

  20. Atomic reactor thermal engineering

    Kim, Gwang Ryong

    1983-02-01

    This book starts the introduction of atomic reactor thermal engineering including atomic reaction, chemical reaction, nuclear reaction neutron energy and soon. It explains heat transfer, heat production in the atomic reactor, heat transfer of fuel element in atomic reactor, heat transfer and flow of cooler, thermal design of atomic reactor, design of thermodynamics of atomic reactor and various. This deals with the basic knowledge of thermal engineering for atomic reactor.

  1. Experiments with stored heavy ions

    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

  2. Bremsstrahlung in atom-atom collisions

    Amus'ya, M.Y.; Kuchiev, M.Y.; Solov'ev, A.V.

    1985-01-01

    It is shown that in the collision of a fast atom with a target atom when the frequencies are on the order of the potentials or higher, there arises bremsstrahlung comparable in intensity with the bremsstrahlung emitted by an electron with the same velocity in the field of the target atom. The mechanism by which bremsstrahlung is produced in atom-atom collisions is elucidated. Results of specific calculations of the bremsstrahlung spectra are given for α particles and helium atoms colliding with xenon

  3. Heavy water cycle in the CANDU reactor

    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)

  4. Heavy metal hazards of Nigerian herbal remedies

    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.

  5. Heavy metal hazards of Nigerian herbal remedies

    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

  6. High energy heavy ions: techniques and applications

    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

  7. Slowing down of relativistic heavy ions and new applications

    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.)

  8. Exotic phenomena in collisions of heavy ions

    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)

  9. Accelerated ions as a tool in atomic physics

    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.)

  10. Electronic structure of fractionally nuclear charged atoms

    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)

  11. Cascade processes in kaonic and muonic atoms

    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)

  12. Atomic weight versus atomic mass controversy

    Holden, N.E.

    1985-01-01

    A problem for the Atomic Weights Commission for the past decade has been the controversial battle over the names ''atomic weight'' and ''atomic mass''. The Commission has considered the arguments on both sides over the years and it appears that this meeting will see more of the same discussion taking place. In this paper, I review the situation and offer some alternatives

  13. Production of heavy nuclides in nuclear devices

    Eccles, Samuel F [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-15

    Since the last Plowshare Symposium in 1964 a number of experiments have been carried out to study the production of heavy nuclei by rapid multiple neutron capture in specially designed nuclear devices. These experiments listed below were conducted underground at the Nevada Test Site and data were obtained radiochemically after sample recovery by drillback. The main characteristics of these experiments are 1) higher neutron fluxes than in the early events, 2) a variety of targets, including 238-U, 242-Pu, 237-Np, 243-Am, 232-Th, 3) the occurrence of an interesting 'reversal of the odd-even effect' in the mass yield curves, and 4) the absence of nuclei in the debris with (Z,A) greater than (100,257). Analysis of data from these experiments have led to capture cross sections for neutron-rich uranium isotopes (out to 249-U), and capture-to-fission ratios for the odd-A neutron-rich plutonium isotopes (out to 253-Pu). General studies of the fission process in neutron-rich nuclei have also been undertaken using the data from these experiments. The large amounts of 250Cm and 257Fm made in the recent Hutch experiment ({approx}1 x 10{sup 20} and {approx}5 x 10{sup 17} atoms, respectively) make it scientifically exciting, and economically feasible, to mine and recover enough material to produce laboratory targets of these isotopes. These targets would be used in investigations of yet-undiscovered, short-lived isotopes of Fm, Md, and No, as well as the possible production of new isotopes of element 104 and even element 105. (author)

  14. Production of heavy nuclides in nuclear devices

    Eccles, Samuel F.

    1970-01-01

    Since the last Plowshare Symposium in 1964 a number of experiments have been carried out to study the production of heavy nuclei by rapid multiple neutron capture in specially designed nuclear devices. These experiments listed below were conducted underground at the Nevada Test Site and data were obtained radiochemically after sample recovery by drillback. The main characteristics of these experiments are 1) higher neutron fluxes than in the early events, 2) a variety of targets, including 238-U, 242-Pu, 237-Np, 243-Am, 232-Th, 3) the occurrence of an interesting 'reversal of the odd-even effect' in the mass yield curves, and 4) the absence of nuclei in the debris with (Z,A) greater than (100,257). Analysis of data from these experiments have led to capture cross sections for neutron-rich uranium isotopes (out to 249-U), and capture-to-fission ratios for the odd-A neutron-rich plutonium isotopes (out to 253-Pu). General studies of the fission process in neutron-rich nuclei have also been undertaken using the data from these experiments. The large amounts of 250Cm and 257Fm made in the recent Hutch experiment (∼1 x 10 20 and ∼5 x 10 17 atoms, respectively) make it scientifically exciting, and economically feasible, to mine and recover enough material to produce laboratory targets of these isotopes. These targets would be used in investigations of yet-undiscovered, short-lived isotopes of Fm, Md, and No, as well as the possible production of new isotopes of element 104 and even element 105. (author)

  15. Relativistic heavy ion research

    1992-01-01

    Experimental work is reported on the following topics: transverse energy production in 10.7-GeV/c/u Au on Au collisions; first results on delta ray production and charged particle multiplicities with the Au beam at 10.7 GeV/c/A; preliminary studies on the feasibility of flow measurement with the E814 participant calorimeter; preliminary results from the E877 telescope; and low-p t baryon distribution in Si+Al, Pb collisions at the AGS. Then the status of the Hadronic Calorimeter project of AGS Experiment E864 (ECOS--Exotic Composite Object Spectrometer) is reviewed. Next, the same is done for work of the STAR RHIC collaboration (Silicon Vertex Tracker (SVT) project evolution and development in FY92, SVT software results from 1992, SVT instrumentation, FY93 SVT pion test beam). The instrumentation section deals with the design and installation of a target rapidity telescope for BNL experiment 814/877 and a repair scheme for the E814/E877 participant calorimeter. Finally, the theory part addresses bosonic kinetics: thermalization of mesons and the pion p perpendicular spectrum in ultrarelativistic heavy-ion collisions and non-equilibrium properties of hadronic mixtures

  16. Heavy flavour production at CMS in heavy ion collisions

    Nguyen, Matthew

    2015-01-01

    We review recent results relating to beauty production in heavy-ion collisions, in both the closed and open heavy flavor sectors, from the CMS experiment at the LHC. The sequential suppression of the ° states in PbPb collisions is thought to be evidence of the dissociation of quarkonia bound states in deconfined matter. Data from pPb collisions demonstrate that while cold nuclear effects appear to be subdominant in minimum bias collisions, there exists a non-trivial dependence on collision multiplicity that remains to be understood. The suppression of high p T particles in heavy-ion collisions, relative to the expectation from pp collisions, is typically interpreted in terms of energy loss of hard scattered parton in the dense nuclear medium. The flavor dependence of the energy loss may be accessed via measurements of b hadrons and b-tagged jets. Measurement of B mesons, via non-prompt J = y , at relatively low p T indicate a smaller suppression factor than D meson or inclusive charged hadrons. Data on b jet...

  17. rf linac approach to heavy ion fusion

    Swenson, D.A.

    1979-01-01

    The necessary properties of funneling particle beams from multiple accelerators into combined beams having higher current are outlined, and methods are proposed which maximize the efficiency of this process. A heavy ion fusion driver system example is presented which shows the large advantages in system efficiency to be gained by proper funneling

  18. Highly excited atoms

    Kleppner, D.; Littman, M.G.; Zimmerman, M.L.

    1981-01-01

    Highly excited atoms are often called Rydberg atoms. These atoms have a wealth of exotic properties which are discussed. Of special interest, are the effects of electric and magnetic fields on Rydberg atoms. Ordinary atoms are scarcely affected by an applied electric or magnetic field; Rydberg atoms can be strongly distorted and even pulled apart by a relatively weak electric field, and they can be squeezed into unexpected shapes by a magnetic field. Studies of the structure of Rydberg atoms in electric and magnetic fields have revealed dramatic atomic phenomena that had not been observed before

  19. Soil heavy metals

    Sherameti, Irena [Jena Univ. (Germany). Inst. fuer Allgemeine Botanik und Pflanzenphysiologie; Varma, Ajit (eds.) [Amity Univ., Uttar Pradesh (India). Amity Inst. of Microbial Technology; Amity Science, Technology and Innovation Foundation, Noida, UP (India)

    2010-07-01

    Human activities have dramatically changed the composition and organisation of soils. Industrial and urban wastes, agricultural application and also mining activities resulted in an increased concentration of heavy metals in soils. How plants and soil microorganisms cope with this situation and the sophisticated techniques developed for survival in contaminated soils is discussed in this volume. The topics presented include: the general role of heavy metals in biological soil systems; the relation of inorganic and organic pollutions; heavy metal, salt tolerance and combined effects with salinity; effects on abuscular mycorrhizal and on saprophytic soil fungi; heavy metal resistance by streptomycetes; trace element determination of environmental samples; the use of microbiological communities as indicators; phytostabilization of lead polluted sites by native plants; effects of soil earthworms on removal of heavy metals and the remediation of heavy metal contaminated tropical land. (orig.)

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

    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)

  1. Laser-assisted atom-atom collisions

    Roussel, F.

    1984-01-01

    The basic layer-assisted atom-atom collision processes are reviewed in order to get a simpler picture of the main physical facts. The processes can be separated into two groups: optical collisions where only one atom is changing state during the collision, the other acting as a spectator atom, and radiative collisions where the states of the two atoms are changing during the collision. All the processes can be interpreted in terms of photoexcitation of the quasimolecule formed during the collisional process. (author)

  2. Aspects of Landau condensation in atomic physics

    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)

  3. Heavy-ion targets

    Adair, H.L.; Kobisk, E.H.

    1985-01-01

    This chapter examines the characteristics of targets required in heavy-ion accelerator physics experiments. The effects of target parameters on heavy-ion experimental results are reviewed. The target fabrication and characterization techniques used to minimize experimental problems during heavy-ion bombardment are described. Topics considered include target thickness and uniformity, target lifetime, target purity, substrate materials, Doppler shift effects, metal preparations, and target preparation methods

  4. Heavy quark masses

    Testa, Massimo

    1990-01-01

    In the large quark mass limit, an argument which identifies the mass of the heavy-light pseudoscalar or scalar bound state with the renormalized mass of the heavy quark is given. The following equation is discussed: m(sub Q) = m(sub B), where m(sub Q) and m(sub B) are respectively the mass of the heavy quark and the mass of the pseudoscalar bound state.

  5. Atomic data for controlled fusion research

    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

  6. Electron induced atomic inner-shell ionization

    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. Heavy quark effective theory and study of heavy hadron spectra

    Dong Yubing

    1995-01-01

    By employing the heavy quark effective theory, the spectra of heavy hadrons, such as heavy mesons (Q-barq), heavy baryons (QQq and Qqq) and heavy multiquark systems (Q-barQ-barqq) are studied systemically. The results are compared with the predictions for Q-barQ-barqq in potential model

  8. Heavy baryon transitions and the heavy quark effective theory

    Hussain, F.

    1992-01-01

    Heavy baryon decays are studied in the context of the Bethe-Salpeter approach to the heavy quark effective theory. A drastic reduction, in the number of independent form factors, is found. Results are presented both for heavy to heavy and heavy to light baryon decays. (orig.)

  9. Heavy ion physics

    Kalpakchieva, R.; Cherepanov, E.A.

    1993-01-01

    The international school-seminar on heavy ion physics had been organized in Dubna in may of 1993. The scientific program of reports covers the following main topics: synthesis and properties of heavy nuclei; synthesis and investigation of properties of exotic nuclei; experiments with radioactive nuclear beams; interaction between complex nuclei at low and intermediate energies. It also includes reports on laser spectroscopy and exotic nuclear beams, on some application of heavy ion beams for the problems of solid state physics, on construction of multidetector facilities and on developing of heavy ion accelerator complexes. Short communication

  10. Production of heavy water

    Spencer, Larry S.; Brown, Sam W.; Phillips, Michael R.

    2017-06-06

    Disclosed are methods and apparatuses for producing heavy water. In one embodiment, a catalyst is treated with high purity air or a mixture of gaseous nitrogen and oxygen with gaseous deuterium all together flowing over the catalyst to produce the heavy water. In an alternate embodiment, the deuterium is combusted to form the heavy water. In an alternate embodiment, gaseous deuterium and gaseous oxygen is flowed into a fuel cell to produce the heavy water. In various embodiments, the deuterium may be produced by a thermal decomposition and distillation process that involves heating solid lithium deuteride to form liquid lithium deuteride and then extracting the gaseous deuterium from the liquid lithium deuteride.

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

    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...

  12. Accelerator based atomic physics experiments: an overview

    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

  13. Multiple ionization produced in Yb due to N-,Si- and Ti-ion impact

    Verma, P.

    2000-01-01

    Heavy ion induced inner shell ionization produces multiple vacancies in the outer shells (M, N etc.) simultaneous to vacancies in the inner-shells (viz. L-shell), which in turn create a very complicated electronic configuration. Three projectiles N 2+,3+ , Si 7+,8+ and Ti 10+,11+ ion beams having a range of 0.3 to 3.5 MeV/u were bombarded on a thin rare earth target of Yb. The recorded L X-ray spectra of Yb have been analyzed in the light of multiple ionization produced due to the heavy ion impact. The outer-shell vacancies acting as spectator vacancies cause a shift in the energy of the various L X-ray diagram lines. A comparison of the shifts in the energies of the various L X-ray transitions of Yb due to the impact of these projectiles, from standard values and that due to proton impact along with the deviation of the intensity ratios from single hole branching ratios, reveal a dependence of multiple ionization on the projectile atomic number (Z) and energy. A further comparison of the degree of multiple ionization produced in Yb, evident by the number of spectator vacancies produced due to the impact of projectiles with 7≤Z≤22 and overlapping MeV/u range lead to explicit conclusions regarding the probability of multiple vacancy production in outer shells simultaneous to a single L-shell vacancy for such projectile target combinations. (orig.)

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

    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.

  15. Projectile ionization in fast heavy-ion--atom collisions

    Schneider, D.; Prost, M.; Stolterfoht, N.; Nolte, G.; Du Bois, R.

    1983-01-01

    Electron emission following the ionization of projectile ions has been investigated systematically in collisions with Ne/sup q/+ and Ar/sup q/+ ions at several hundred MeV incident on different target gases. The projectile electrons are concentrated within one maximum, the electron-loss peak (ELP). The variation of the shape and intensity of the ELP with the projectile energy, its charge state, the observation angle, and the target gas has been measured. Theoretical predictions which are based on the binary-encounter approximation show, in general, good agreement with the experimental data. The contributions of the different subshells to the ELP are deduced. It is shown that electronic screening of the target nucleus plays an important role in the ionization process of the projectile ions

  16. Precision test of vacuum polarization in heavy muonic atoms

    Dubler, T.; Kaeser, K.; Robert-Tissot, B.; Schaller, L.A.; Schellenberg, L.; Schneuwly, H.

    1978-01-01

    In order to test the QED corrections, and in particular the vacuum polarization, muonic 4f-3d transitions in Ba and Ce and 5g-4f transitions in Tl and Pb have been measured using Ge(Li) detectors. An absolute energy accuracy of +- 8 eV corresponding to a relative error of 17-19 ppm has been obtained. The experimental energies agree with theory within the total uncertainty of +- 10 eV. This corresponds to a test of the QED vacuum polarization calculations of between 0.35% and 0.50%. (Auth.)

  17. Ionisation of L subshells of heavy atoms by deuteron collision

    Sokhi, R.S.; Crumpton, D.; Trautmann, D.

    1989-01-01

    L i subshell ionisation cross sections for 1.2-3.0 MeV deuteron impact on thin targets of W, Au, Pb and Bi have been measured experimentally. Measurements were made with the Birmingham University's 3MV Dynamitron accelerator and the cross sections were deduced from the emitted L X-rays. These cross sections and their ratios have been compared graphically with the ECPSSR and RHSCA models. The ECPSSR model underestimates the measured L 2 subshell cross sections but shows very good agreement with the L 3 subshell values. The RHSCA theory in general exhibits good agreement with the measured cross sections for the L 1 and L 2 subshells but overestimates the L 3 cross sections by up to 60%. (orig.)

  18. Double ionization of atomic helium under heavy ion impact

    Presnyakov, L.P.; Uskov, D.B.

    1995-01-01

    Cross sections for double ionization of helium by multiply-charged ion impact and the corresponding ratios of double-to-single ionization are presented as a sum of the contributions given by the one-step (shake-off) and two-step (TS) processes. An analytic form is found for the continuum wavefunction which is valid in both limiting cases of low and high velocities of the relative motion. Using this wavefunction, the TS cross sections are calculated within the independent-event model. The results for the ratios of double-to-single ionization show satisfactory agreement with the experimental data available. (author)

  19. Atomic fountain and applications

    Rawat, H.S.

    2000-01-01

    An overview of the development of working of MOT along with the basic principle of laser atom cooling and trapping is given. A technique to separate the cooled and trapped atoms from the MOT using atomic fountain technique will also be covered. The widely used technique for atomic fountain is, first to cool and trap the neutral atoms in MOT and then launch them in the vertical direction, using moving molasses technique. Using 133 Cs atomic fountain clock, time improvement of 2 to 3 order of magnitude over a conventional 133 Cs atomic clock has been observed

  20. Interferometry with atoms

    Helmcke, J.; Riehle, F.; Witte, A.; Kisters, T.

    1992-01-01

    Physics and experimental results of atom interferometry are reviewed and several realizations of atom interferometers are summarized. As a typical example of an atom interferometer utilizing the internal degrees of freedom of the atom, we discuss the separated field excitation of a calcium atomic beam using four traveling laser fields and demonstrate the Sagnac effect in a rotating interferometer. The sensitivity of this interferometer can be largely increased by use of slow atoms with narrow velocity distribution. We therefore furthermore report on the preparation of a laser cooled and deflected calcium atomic beam. (orig.)

  1. Heavy-Quark Production

    Frixione, Stefano; Nason, Paolo; Ridolfi, Giovanni

    1997-01-01

    We review the present theoretical and experimental status of heavy quark production in high-energy collisions. In particular, we cover hadro- and photoproduction at fixed target experiments, at HERA and at the hadron colliders, as well as aspects of heavy quark production in e+e- collisions at the Z0 peak.

  2. Canadian heavy water production

    Dahlinger, A.; Lockerby, W.E.; Rae, H.K.

    1977-05-01

    The paper reviews Canadian experience in the production of heavy water, presents a long-term supply projection, relates this projection to the anticipated long-term electrical energy demand, and highlights principal areas for further improvement that form the bulk of our research and development program on heavy water processes

  3. Heavy ion fusion

    Bangerter, R.O.

    1986-01-01

    This report on the International Symposium on Heavy Ion Fusion held May 27-29, 1986 summarizes the problems and achievements in the areas of targets, accelerators, focussing, reactor studies, and system studies. The symposium participants recognize that there are large uncertainties in Heavy Ion Fusion but many of them are also optimistic that HIF may ultimately be the best approach to fusion

  4. Removal of dissolved heavy metals and radionuclides by microbial spores

    Revis, N.W.; Hadden, C.T.; Edenborn, H.

    1997-01-01

    Microbial systems have been shown to remove specific heavy metals from contaminated aqueous waste to levels acceptable to EPA for environmental release. However, systems capable of removing a variety of heavy metals from aqueous waste to environmentally acceptable levels remain to be reported. The present studies were performed to determine the specificity of spores of the bacterium Bacillus megaterium for the adsorption of dissolved metals and radionuclides from aqueous waste. The spores effectively adsorbed eight heavy metals from a prepared metal mix and from a plating rinse waste to EPA acceptable levels for waste water. These results suggest that spores have multiple binding sites for the adsorption of heavy metals. Spores were also effective in adsorbing the radionuclides 85 strontium and 197 cesium. The presence of multiple sites in spores for the adsorption of heavy metals and radionuclides makes this biosorbent a good candidate for the treatment of aqueous wastes associated with the plating and nuclear industries. 17 refs., 4 tabs

  5. Multielectron transitions following heavy ion excitation: a comparison of self-consistent field calculations with experiment

    Hodge, W.L. Jr.

    1976-01-01

    A multielectron transition is an atomic transition in which two or three electrons change their states and a single photon is emitted. Although the mechanism was postulated in the thirties and observed in optical spectra, little research has been done since then. Experiments using heavy ion accelerators have measured satellite lines lower in energy than the Kα 12 energy and higher in energy than the Kβ satellite structure. These transitions are multielectron transitions. Experimental spectra of x-ray transitions induced by heavy ion bombardment are presented, and the experimental energies are compared to Hartree-Fock transition energies. The transitions observed lower in energy than the Kα line are two electron--one photon radiative Auger and three electron--one photon radiative electron rearrangement transitions. Experimental data taken at other laboratories have measured satellite lines higher in energy than the Kβ satellite structure. Relativistic Dirac-Fock transition energies will be compared to the experimental energies and the transitions will be shown to be two electron--one photon x-ray transitions. Heavy ion bombardment creates multiple inner shell vacancies so numerous that the satellite lines can be more intense than the diagram lines. Theoretical transition energies from five different self-consistent field atomic physics computer programs will be compared to the Kα satellite and Kα hypersatellite transitions of calcium. Transition energies from Declaux's relativistic Dirac-Fock program will be compared to the diagram lines of uranium and to other theoretical K x-ray transition energies of Z = 120. A discussion of how to calculate the term energies of a given configuration using the Slater F and G integrals is included

  6. Heavy water and nonproliferation

    Miller, M.M.

    1980-05-01

    This report begins with a historical sketch of heavy water. The report next assesses the nonproliferation implications of the use of heavy water-moderated power reactors; several different reactor types are discussed, but the focus is on the natural uranium, on-power fueled, pressure tube reactor CANDU. The need for and development of on-power fueling safeguards is discussed. Also considered is the use of heavy water in plutonium production reactors as well as the broader issue of the relative nuclear leverage that suppliers can bring to bear on countries with natural uranium-fueled reactors as compared to those using enriched designs. The final chapter reviews heavy water production methods and analyzes the difficulties involved in implementing these on both a large and a small scale. It concludes with an overview of proprietary and nonproliferation constraints on heavy water technology transfer

  7. Three-atom clusters

    Pen'kov, F.M.

    1998-01-01

    The Born-Oppenheimer approximation is used to obtain an equation for the effective interaction in three atoms bound by a single electron. For low binding energies in an 'electron + atom' pair, long-range forces arise between the atoms, leading to bound states when the size of the three-atom cluster is a few tens of angstrom. A system made of alkali-metal atoms is considered as an example

  8. Stable atomic hydrogen: Polarized atomic beam source

    Niinikoski, T.O.; Penttilae, S.; Rieubland, J.M.; Rijllart, A.

    1984-01-01

    We have carried out experiments with stable atomic hydrogen with a view to possible applications in polarized targets or polarized atomic beam sources. Recent results from the stabilization apparatus are described. The first stable atomic hydrogen beam source based on the microwave extraction method (which is being tested ) is presented. The effect of the stabilized hydrogen gas density on the properties of the source is discussed. (orig.)

  9. Giant atoms for the production of nuclear fuel

    Fahr, H.J.

    1980-01-01

    Neutral atoms can be blown up to the size of a football, if the electrons of the atomic shell are appropriately excited by photons just below the ionization energy. Such atoms, called Rydberg atoms, behave very differently to the usual ones in multiple respects. The fact that they can very easily be ionized by conventional electrostatic fields is being investigated as a method of isotope separation, for instance in the very important case of U 235 and U 238 . (orig.) [de

  10. Heavy ion and hadron reactions in emulsion

    Otterlund, I.

    1979-04-01

    Recent results from heavy ion and hadron reactions in emulsion are reviewed. General properties of hadron-reaction multiplicities and their correlation to the production of recoiling protons are given. Properties of pseudo-rapidity distributions of shower-particles especially the particle production in the central region of pseudo-rapidity will be discussed. Non-peripheral heavy ion reactions are compared to recent participant-spectator model calculations. Very energetic cosmic ray events will be examined in the light of recent results from hadron-nucleus reactions. (author)

  11. Renormalized sum rules for structure functions of heavy meson decays

    Grozin, A.G.; Korchemsky, G.P.

    1996-01-01

    We consider the properties of the structure functions of inclusive heavy meson decays B→X c and treat the c quark mass as a free parameter. We show that in two extreme cases of heavy and light c quarks the structure functions of heavy-heavy and heavy-light transitions are given by a Fourier transform of the matrix elements of Wilson lines containing a timelike and a lightlike segment, correspondingly. Using the renormalization properties of Wilson lines we find the dependence of the structure functions on the factorization scale, the structure function of the heavy-heavy transition is renormalized multiplicatively, while that of the heavy-light transition obeys the GLAP-type evolution equation. We propose a generalization of the sum rules for the moments of the structure functions (Bjorken, Voloshin, and the open-quote open-quote third close-quote close-quote sum rules) with a soft exponential factorization cutoff, which correctly incorporates both perturbative and nonperturbative effects. We analyze nonperturbative corrections by first considering infrared renormalon contributions to the Wilson lines. Uncertainties induced by the leading renormalon pole at u=1/2 are exactly canceled by a similar uncertainty in the heavy quark pole mass. The leading nonperturbative corrections associated with the next renormalon at u=1 are parametrized by the matrix element μ π 2 which is proportional to the heavy quark kinetic energy. copyright 1996 The American Physical Society

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

    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

  13. Advances in atomic spectroscopy

    Sneddon, J

    2000-01-01

    This fifth volume of the successful series Advances in Atomic Spectroscopy continues to discuss and investigate the area of atomic spectroscopy.It begins with a description of the use of various atomic spectroscopic methods and applications of speciation studies in atomic spectroscopy. The emphasis is on combining atomic spectroscopy with gas and liquid chromatography. In chapter two the authors describe new developments in tunable lasers and the impact they will have on atomic spectroscopy. The traditional methods of detection, such as photography and the photomultiplier, and how they are being replaced by new detectors is discussed in chapter three. The very active area of glow discharge atomic spectrometry is presented in chapter four where, after a brief introduction and historical review, the use of glow discharge lamps for atomic spectroscopy and mass spectrometry are discussed. Included in this discussion is geometry and radiofrequency power. The future of this source in atomic spectroscopy is also dis...

  14. Atomic and molecular manipulation

    Mayne, Andrew J

    2011-01-01

    Work with individual atoms and molecules aims to demonstrate that miniaturized electronic, optical, magnetic, and mechanical devices can operate ultimately even at the level of a single atom or molecule. As such, atomic and molecular manipulation has played an emblematic role in the development of the field of nanoscience. New methods based on the use of the scanning tunnelling microscope (STM) have been developed to characterize and manipulate all the degrees of freedom of individual atoms and molecules with an unprecedented precision. In the meantime, new concepts have emerged to design molecules and substrates having specific optical, mechanical and electronic functions, thus opening the way to the fabrication of real nano-machines. Manipulation of individual atoms and molecules has also opened up completely new areas of research and knowledge, raising fundamental questions of "Optics at the atomic scale", "Mechanics at the atomic scale", Electronics at the atomic scale", "Quantum physics at the atomic sca...

  15. Microfabricated Waveguide Atom Traps.

    Jau, Yuan-Yu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    A nanoscale , microfabricated waveguide structure can in - principle be used to trap atoms in well - defined locations and enable strong photon-atom interactions . A neutral - atom platform based on this microfabrication technology will be prealigned , which is especially important for quantum - control applications. At present, there is still no reported demonstration of evanescent - field atom trapping using a microfabricated waveguide structure. We described the capabilities established by our team for future development of the waveguide atom - trapping technology at SNL and report our studies to overcome the technical challenges of loading cold atoms into the waveguide atom traps, efficient and broadband optical coupling to a waveguide, and the waveguide material for high - power optical transmission. From the atomic - physics and the waveguide modeling, w e have shown that a square nano-waveguide can be utilized t o achieve better atomic spin squeezing than using a nanofiber for first time.

  16. V L Ginzburg and the Atomic Project

    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.

  17. Asymptotics for Two-dimensional Atoms

    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....

  18. Amorphization of complex ceramics by heavy-particle irradiations

    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

  19. Atomic Fisher information versus atomic number

    Nagy, A.; Sen, K.D.

    2006-01-01

    It is shown that the Thomas-Fermi Fisher information is negative. A slightly more sophisticated model proposed by Gaspar provides a qualitatively correct expression for the Fisher information: Gaspar's Fisher information is proportional to the two-third power of the atomic number. Accurate numerical calculations show an almost linear dependence on the atomic number

  20. Evaluation of electon and nuclear bremsstrahlung in heavy ion collisions

    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