WorldWideScience

Sample records for non-radiative electron capture

  1. Supernova electron capture rates

    CERN Document Server

    Martínez-Pinedo, G

    1999-01-01

    We have calculated the Gamow-Teller strength distributions for the ground states and low lying states of several nuclei that play an important role in the precollapse evolution of supernova. The calculations reproduce the experimental GT distributions nicely. The GT distribution are used to calculate electron capture rates for typical presupernova conditions. The computed rates are noticeably smaller than the presently adopted rates. The possible implications for the supernova evolution are discussed.

  2. On neutrinoless double electron capture

    CERN Document Server

    Drukarev, E G

    2016-01-01

    We found the probability for the neutrinoless double electron capture in the case of $KK$ capture. We clarified the mechanism of the energy transfer from the nucleus to the bound electrons. This enabled us to obtain the equations for the probability of the $2EC0\

  3. Electron capture in carbon dwarf supernovae

    Science.gov (United States)

    Mazurek, T. J.; Truran, J. W.; Cameron, A. G. W.

    1974-01-01

    The rates of electron capture on heavier elements under the extreme conditions predicted for dwarf star supernovae have been computed, incorporating modifications that seem to be indicated by present experimental results. An estimate of the maximum possible value of such rates is also given. The distribution of nuclei in nuclear statistical equilibrium has been calculated for the range of expected supernovae conditions, including the effects of the temperature dependence of nuclear partition functions. These nuclide abundance distributions are then used to compute nuclear equilibrium thermodynamic properties. The effects of the electron capture on such equilibrium matter are discussed. In the context of the 'carbon detonation' supernova model, the dwarf central density required to ensure core collapse to a neutron star configuration is found to be slightly higher than that obtained by Bruenn (1972) with the electron capture rates of Hansen (1966).-

  4. Electron capture from coherent elliptic Rydberg states

    Energy Technology Data Exchange (ETDEWEB)

    Day, J.C.; DePaola, B.D.; Ehrenreich, T.; Hansen, S.B.; Horsdal-Pedersen, E.; Leontiev, Y.; Mogensen, K.S. [Institute of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark)

    1997-12-01

    Experimental relative cross sections for electron capture by singly charged ions (Na{sup +}) from coherent elliptic states of principal quantum number n=25 are presented. An interval of reduced impact velocities from about 1{endash}2 is covered. Absolute reaction cross sections could not be determined precisely, but the eccentricity of the coherent elliptic states and their orientation relative to the ion-impact velocity were varied to expose the dependence of the electron-capture process on the initial motion of the electron. The dependencies on eccentricity and orientation are generally strong and they vary sharply with impact velocity. Qualitatively, the observations agree fairly well with classical trajectory Monte Carlo (CTMC) calculations, as expected for the large quantum numbers involved, but significant deviations of a systematic nature do remain, showing that some aspects of the capture reactions studied are described poorly by classical physics as represented by the CTMC model. {copyright} {ital 1997} {ital The American Physical Society}

  5. Electron capture cross sections for stellar nucleosynthesis

    CERN Document Server

    Giannaka, P G

    2015-01-01

    In the first stage of this work, we perform detailed calculations for the cross sections of the electron capture on nuclei under laboratory conditions. Towards this aim we exploit the advantages of a refined version of the proton-neutron quasi-particle random-phase approximation (pn-QRPA) and carry out state-by-state evaluations of the rates of exclusive processes that lead to any of the accessible transitions within the chosen model space. In the second stage of our present study, we translate the above mentioned $e^-$-capture cross sections to the stellar environment ones by inserting the temperature dependence through a Maxwell-Boltzmann distribution describing the stellar electron gas. As a concrete nuclear target we use the $^{66}Zn$ isotope, which belongs to the iron group nuclei and plays prominent role in stellar nucleosynthesis at core collapse supernovae environment.

  6. Double electron capture searches in $^{74}$Se

    CERN Document Server

    Lehnert, B; Degering, D; Sommer, D; Wagner, L; Zuber, K

    2016-01-01

    A search for various double electron capture modes of $^{74}$Se has been performed using an ultralow background Ge-detector in the Felsenkeller laboratory, Germany. Especially for the potentially resonant transition into the 1204.2 keV excited state of $^{74}$Ge a lower half-life limit of $0.70\\cdot 10^{19}$ yr (90% credibility) has been obtained. Serious concerns are raised about the validity of obtained $^{74}$Se limits in some recent publications.

  7. Testing Lorentz invariance in orbital electron capture

    CERN Document Server

    Vos, K K; Timmermans, R G E

    2015-01-01

    Searches for Lorentz violation were recently extended to the weak sector, in particular neutron and nuclear $\\beta$ decay [1]. From experiments on forbidden $\\beta$-decay transitions strong limits in the range of $10^{-6}$-$10^{-8}$ were obtained on Lorentz-violating components of the $W$-boson propagator [2]. In order to improve on these limits strong sources have to be considered. In this Brief Report we study isotopes that undergo orbital electron capture and allow experiments at high decay rates and low dose. We derive the expressions for the Lorentz-violating differential decay rate and discuss the options for competitive experiments and their required precision.

  8. Calculation of fractional electron capture probabilities

    CERN Document Server

    Schoenfeld, E

    1998-01-01

    A 'Table of Radionuclides' is being prepared which will supersede the 'Table de Radionucleides' formerly issued by the LMRI/LPRI (France). In this effort it is desirable to have a uniform basis for calculating theoretical values of fractional electron capture probabilities. A table has been compiled which allows one to calculate conveniently and quickly the fractional probabilities P sub K , P sub L , P sub M , P sub N and P sub O , their ratios and the assigned uncertainties for allowed and non-unique first forbidden electron capture transitions of known transition energy for radionuclides with atomic numbers from Z=3 to 102. These results have been applied to a total of 28 transitions of 14 radionuclides ( sup 7 Be, sup 2 sup 2 Na, sup 5 sup 1 Cr, sup 5 sup 4 Mn, sup 5 sup 5 Fe, sup 6 sup 8 Ge , sup 6 sup 8 Ga, sup 7 sup 5 Se, sup 1 sup 0 sup 9 Cd, sup 1 sup 2 sup 5 I, sup 1 sup 3 sup 9 Ce, sup 1 sup 6 sup 9 Yb, sup 1 sup 9 sup 7 Hg, sup 2 sup 0 sup 2 Tl). The values are in reasonable agreement with measure...

  9. Electron Capture in a Fully Ionized Plasma

    CERN Document Server

    Widom, A; Srivastava, Y N

    2014-01-01

    Properties of fully ionized water plasmas are discussed including plasma charge density oscillations and the screening of the Coulomb law especially in the dilute classical Debye regime. A kinetic model with two charged particle scattering events determines the transition rate per unit time for electron capture by a nucleus with the resulting nuclear transmutations. Two corrections to the recent Maiani et al. calculations are made: (i) The Debye screening length is only employed within its proper domain of validity. (ii) The WKB approximation employed by Maiani in the long De Broglie wave length limit is evidently invalid. We replace this incorrect approximation with mathematically rigorous Calogero inequalities in order to discuss the scattering wave functions. Having made these corrections, we find a verification for our previous results based on condensed matter electro-weak quantum field theory for nuclear transmutations in chemical batteries.

  10. Effects of Electron Screening on Electron Capture Rates in High Density Presupernova Core

    Institute of Scientific and Technical Information of China (English)

    蒋广飞; 彭秋和; 邹志刚

    2003-01-01

    Considering that the electron capture rate can be greatly reduced by the electron screening effect in the regime of high temperature and high density, we calculate the effect of electron screening on the electron capture rate for two important elements 56Ni and 55Co in the high density condition of a pre-supernova star. The effect of electron screening is so effective that the electron capture rate may be reduced to about 20%.

  11. Single ionization and electron capture in He2++Na collisions

    NARCIS (Netherlands)

    Knoop, S; Olson, RE; Ott, H; Hasan, VG; Morgenstern, R; Hoekstra, R

    2005-01-01

    Single-electron capture and ionization in He2+ + Na collisions at energies around the matching velocity (2-13 keV amu(-1)) have been studied both experimentally and theoretically. State-selective cross section for capture into the n = 2, 3, 4 and n >= 5, and the ionization cross section as well as d

  12. Electron Capture Dissociation of Trivalent Metal Ion-Peptide Complexes

    National Research Council Canada - National Science Library

    Flick, Tawnya G; Donald, William A; Williams, Evan R

    2013-01-01

    .... ECD of these doubly charged complexes containing MT results in significantly higher electron capture efficiency and sequence coverage than peptide-divalent metal ion complexes that have the same net charge...

  13. Investigation of the electron capture process in semiclassical plasma

    Directory of Open Access Journals (Sweden)

    Seisembayeva Madina M.

    2016-06-01

    Full Text Available In this work, the process of electron capture in partially ionized plasma is considered. Electron-atom interaction was described by the effective interaction potential, which takes into account the screening effect at large distances and the diffraction effect at the small distances. The results of numerical calculations of the electron capture radius, differential cross-section for different values of the coupling and density parameters are presented. The differential cross-section was obtained on the basis of perturbation theory and also by solving of the equation of motion of the projectile electron.

  14. Resonant electron capture by orotic acid molecules

    Science.gov (United States)

    Muftakhov, M. V.; Shchukin, P. V.; Khatymov, R. V.

    2017-09-01

    Resonant electron attachment by orotic acid molecules (6-COOH-uracil) are studied in the energy range of 0-14 eV via negative ion mass spectrometry. Molecular ions, whose lifetimes relative to electron autodetachment are found to be 300 μs are recorded in the region of thermal electron energies; they form in the valence state through a vibration-excited resonance mechanism. Unlike unsubstituted uracil, most dissociative processes occur in the low-energy region of <4 eV and are due to carboxylic anions. An absolute cross section of 2.4 × 10-17 cm2 is found for the most intense fragment ions [M-H]- at an output energy of 1.33 eV. The kinetics of decarboxylation is considered for these ions. This could be a model reaction for the last stage of uridine monophosphate biosynthesis.

  15. Electron capture by highly charged ions from surfaces and gases

    Energy Technology Data Exchange (ETDEWEB)

    Allen, F.

    2008-01-11

    In this study highly charged ions produced in Electron Beam Ion Traps are used to investigate electron capture from surfaces and gases. The experiments with gas targets focus on spectroscopic measurements of the K-shell x-rays emitted at the end of radiative cascades following electron capture into Rydberg states of Ar{sup 17+} and Ar{sup 18+} ions as a function of collision energy. The ions are extracted from an Electron Beam Ion Trap at an energy of 2 keVu{sup -1}, charge-selected and then decelerated down to 5 eVu{sup -1} for interaction with an argon gas target. For decreasing collision energies a shift to electron capture into low orbital angular momentum capture states is observed. Comparative measurements of the K-shell x-ray emission following electron capture by Ar{sup 17+} and Ar{sup 18+} ions from background gas in the trap are made and a discrepancy in the results compared with those from the extraction experiments is found. Possible explanations are discussed. For the investigation of electron capture from surfaces, highly charged ions are extracted from an Electron Beam Ion Trap at energies of 2 to 3 keVu{sup -1}, charge-selected and directed onto targets comprising arrays of nanoscale apertures in silicon nitride membranes. The highly charged ions implemented are Ar{sup 16+} and Xe{sup 44+} and the aperture targets are formed by focused ion beam drilling in combination with ion beam assisted thin film deposition, achieving hole diameters of 50 to 300 nm and aspect ratios of 1:5 to 3:2. After transport through the nanoscale apertures the ions pass through an electrostatic charge state analyzer and are detected. The percentage of electron capture from the aperture walls is found to be much lower than model predictions and the results are discussed in terms of a capillary guiding mechanism. (orig.)

  16. Neutrino Mass, Electron Capture and the Shake-off Contributions

    CERN Document Server

    Faessler, Amand; Simkovic, Fedor

    2016-01-01

    Electron capture can determine the electron neutrino mass, while the beta decay of Tritium measures the electron antineutrino mass and the neutrinoless double beta decay observes the Majorana neutrino mass. Electron capture e. g. on 163Ho plus bound electron to 163Dy* plus neutrino can determine the electron neutrino mass from the upper end of the decay spectrum of the excited Dy*, which is given by the Q-Value minus the neutrino mass. The Dy* states decay by X-ray and Auger electron emissions. The total decay energy is measured in a bolometer. These excitations have been studied by Robertson and by Faessler et al.. In addition the daughter atom Dy can also be excited by moving in the capture process one electron into the continuum. The escape of these continuum electrons is automatically included in the experimental bolometer spectrum. Recently a method developed by Intemann and Pollock was used by DeRujula and Lusignoli for a rough estimate of this shake-off process for "s" wave electrons in capture on 163H...

  17. Influence of electron screening on electron capture rate under high density of stellar interior

    Institute of Scientific and Technical Information of China (English)

    罗志全; 彭秋和

    1996-01-01

    The influence of electron screening on electron capture rate in strong screening is investigated, in which the Gamow-Teller resonance transition is considered and the matrix elements for the resonance transition are calculated on the basis of a shell model. The effect of electron screening on electron capture by 56Co is discussed. It is shown that the screening decreases evidently the capture rates in lower temperature and higher density. The effect of electron screening on other nuclear capture rates is estimated. The conclusion derived may influence the research for late stellar evolution and supernova explosion.

  18. EVOLUTION OF IONS AFTER MULTIPLE ELECTRON-CAPTURE FROM SURFACES

    NARCIS (Netherlands)

    MORGENSTERN, R; DAS, J

    1993-01-01

    A comparison is made of the electronic processes which occur when a multiply charged ion is approaching an atomic target on the one hand or a metal surface on the other hand. In both caws three collision phases can be identified: those of attraction, of electron capture and of decay in the vacuum; i

  19. Measurement of internal conversion electrons from Gd neutron capture

    Energy Technology Data Exchange (ETDEWEB)

    Kandlakunta, P. [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Cao, L.R., E-mail: cao.152@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Mulligan, P. [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States)

    2013-03-21

    Gadolinium (Gd) is a suitable material for neutron conversion because of its superior neutron absorption cross-section. However, the principal secondary particles that generate electron-hole pairs in a semiconductor detector after Gd neutron capture are low-energy internal conversion (IC) electrons. We measured the IC electron spectrum due to Gd neutron capture by using a thermal neutron beam and a digitizer-based multidetector spectroscopy. We also discussed the effective use of the IC electrons in the context of a twin-detector design and the associated gamma-ray rejection issues. Extensive simulations of the spectra of IC electrons and gamma rays agreed well with the experimental results; both types of results support the feasibility of the proposed n–γ separation method.

  20. Searching of Double Electron Capture in the TGV Experiment

    CERN Document Server

    Brudanin, V B; Briançon, C; Benes, P; Vylov, T D; Gusev, K N; Egorov, V G; Klimenko, A A; Kovalenko, V E; Korolev, N A; Salamatin, A V; Timkov, V V; Cermák, P; Shirchenko, M V; Shitov, Yu A; Stekl, I

    2004-01-01

    The first investigations of the rare nuclear process - double electron capture of $^{106}$Cd have been performed using the low-background multi-detector spectrometer TGV-2 (Telescope Germanium Vertical). The preliminary results of calculations of experimental data obtained using 11.3 and 10 g of enriched $^{106}$Cd, and 14.5 g of natural Cd were presented. The sensitivity of T$_{1/2}^{EC/EC}>2.6\\cdot10^{19}$y (90\\% CL) was obtained for the searching of double electron capture of $^{106}$Cd ($0^{+} - 0^{+}$) in the investigation of natural Cd.

  1. Photons shedding light on electron capture by highly charged ions

    NARCIS (Netherlands)

    Hoekstra, Romke Anne

    1990-01-01

    In this thesis charge transfer is studied in collisions of highly charged ions (Aq+) with neutral particles (B). Because the electron is captured resonantly (i.e. without its binding energy) by the ion, a limited number of highly excited states (characterized by the quantum numbers nlm) is preferent

  2. ELECTRON-CAPTURE AND EXCITATION IN HE-2+-NA COLLISIONS

    NARCIS (Netherlands)

    SCHLATMANN, AR; HOEKSTRA, R; FOLKERTS, HO; MORGENSTERN, R

    1992-01-01

    State-selective charge transfer and target excitation in collisions of He2+ ions with Na has been studied by means of far ultraviolet and visible light spectroscopy. Generally, the experimental results confirm the theoretical predictions by Shingal, Noble and Bransden for electron capture and for

  3. Photons shedding light on electron capture by highly charged ions

    NARCIS (Netherlands)

    Hoekstra, Romke Anne

    1990-01-01

    In this thesis charge transfer is studied in collisions of highly charged ions (Aq+) with neutral particles (B). Because the electron is captured resonantly (i.e. without its binding energy) by the ion, a limited number of highly excited states (characterized by the quantum numbers nlm) is

  4. Modeling of the Dynamics of Non-radiative Energy Transfer in Tm3+, Tb3+: LiYF4-Based Electronic Materials

    Science.gov (United States)

    Castañeda-Miranda, A.; Castaño, V. M.

    2017-08-01

    The fluorescent decay of the levels 3H4 and 3F4 of Tm3+ in LiYF4 crystals doped with Tb3+ and Eu3+ was mathematically modeled to estimate the optimal doping levels to maximize the laser emission at 1.5 μm of the transition 3H4 → 3F4. The analysis is carried out both through the solution of the master energy transfer equations that govern the non-radiative processes of energy and Monte Carlo simulations. The analysis is improved with the experimental data of the fluorescence decay to include quadrupole and dipole interactions simultaneously. The importance of considering these interactions is that the optimal concentrations of impurities predicted for these luminescent systems are lower than those reported with the use of traditional models.

  5. Electron Capture by Tetra- and di-Chlorobenzene Molecules

    DEFF Research Database (Denmark)

    Pedersen, Niels Jørgen; Anisimov, O. A.; Lozouy, V. V.;

    1985-01-01

    ), their lifetimes being longer than roughly 10 ps and shorter than 10–30 ns. The cross section of electron capture by p-C6H4Cl2 in squalane is nearly one-tenth of that by 1,2,4,5-C6H2Cl4 and CCl4 at concentration ⩽ 0.02 M, while 10% of the electrons cannot be trapped even at 0.25 M p-C6H4Cl2. Probably the electrons......Experiments on inhibition and anti-inhibition of Ps formation and also on optical detection of ESR spectra in squalene solutions with 1,2,4,5-C6H2Cl4 and p-C6H4Cl2 have demonstrated the presence of short-lived molecular radical-anions (products of the spur electron capture by additives...... in the high-electric-field (0.3–3 MV/cm) regions of the spurs cannot be effectively captured by p-C6H4Cl2, which is a shallow electron trap. Similar effects of the high electric fields of the charged spur series seem to influence the Ps formation appreciably, along with the other effects discussed in previous...

  6. A combined beta-beam and electron capture neutrino experiment

    CERN Document Server

    Bernabeu, J; Orme, C; Palomares-Ruiz, S; Pascoli, S

    2009-01-01

    The next generation of long baseline neutrino experiments will aim at determining the value of the unknown mixing angle, theta_{13}, the type of neutrino mass hierarchy and the presence of CP-violation in the lepton sector. Beta-beams and electron capture experiments have been studied as viable candidates for long baseline experiments. They use a very clean electron neutrino beam from the beta-decays or electron capture decays of boosted ions. In the present article we consider an hybrid setup which combines a beta-beam with an electron capture beam by using boosted Ytterbium ions. We study the sensitivity to the CP-violating phase delta and the theta_{13} angle, the CP-discovery potential and the reach to determine the type of neutrino mass hierarchy for this type of long baseline experiment. The analysis is performed for different neutrino beam energies and baselines. Finally, we also discuss how the results would change if a better knowledge of some of the assumed parameters was achieved by the time this e...

  7. Influence of Magnetic Field Decay on Electron Capture in Magnetars

    Indian Academy of Sciences (India)

    Jie Zhang

    2014-09-01

    The de-excited energy of electron capture (EC) induced by magnetic field decay may be a new source for heating magnetar crust, so we do a quantitative calculation on EC process near the outer crust and analyse their influence on persistent X-ray radiation of magnetars, adopting the experimental data or the results of theoretical model (including the large-scale shell model and quasi-particle random phase approximation).

  8. Dissociative electron capture by. pi. -allyliron tricarbonyl halide molecules

    Energy Technology Data Exchange (ETDEWEB)

    Nekrasov, Y.S.; Avakyan, N.P.; Khvostenko, V.I.; Kritskaya, I.I.; Maurodiev, V.K.; Mazunov, V.A.

    1985-12-20

    Result are given for a study of dissociative electron impact by complexes (I)-(III), C/sub 3/H/sub 5/Fe (CO)/sub 3/ /SUP X/ , where X - C1 (I), Br (II), and of -allyliron tricarbonyl halides upon dissociative electron capture. The mechanisms for the formation of C/sub 3/H/sub 5/Fe (CO)/sup -//sub 3/ anions in the gas phase and under electrochemical reduction conditions on a dropping mercury electrode were shown to differ. A predominant effect was proposed for solvation factors on the electrochemical reduction in the condensed phase.

  9. Multiple electron capture in close ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Schlachter, A.S.; Stearns, J.W.; Berkner, K.H.; Bernstein, E.M.; Clark, M.W.; DuBois, R.D.; Graham, W.G.; Morgan, T.J.; Mueller, D.W.; Stockli, M.P.; Tanis, J.A.; Woodland, W.T. (Lawrence Berkeley Lab., CA (USA); Western Michigan Univ., Kalamazoo, MI (USA); Pacific Northwest Lab., Richland, WA (USA); Queen' s Univ., Belfast, Northern Ireland (UK); Wesleyan Univ., Middletown, CT (USA); University of North Tex

    1989-07-24

    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.

  10. Radiative Capture of Twisted Electrons by Bare Ions

    CERN Document Server

    Matula, Oliver; Serbo, Valeriy G; Surzhykov, Andrey; Fritzsche, Stephan

    2014-01-01

    Recent advances in the production of twisted electron beams with a subnanometer spot size offer unique opportunities to explore the role of orbital angular momentum (OAM) in basic atomic processes. In the present work, we address one of these processes: radiative recombination of twisted electrons with bare ions. Based on the density matrix formalism and the non-relativistic Schr\\"odinger theory, analytical expressions are derived for the angular distribution and the linear polarization of photons emitted due to the capture of twisted electrons into the ground state of (hydrogen-like) ions. We show that these angular and polarization distributions are sensitive to both, the transverse momentum and the topological charge of the electron beam. To observe in particular the value of this charge, we propose an experiment that makes use of the coherent superposition of two twisted beams.

  11. Theory and Application of Dissociative Electron Capture in Molecular Identification

    CERN Document Server

    Havey, C D; Jones, T; Voorhees, K J; Laramee, J A; Cody, R B; Clougherty, D P; Eberhart, Mark; Voorhees, Kent J.; Laramee, James A.; Cody, Robert B.; Clougherty, Dennis P.

    2006-01-01

    The coupling of an electron monochromator (EM) to a mass spectrometer (MS) has created a new analytical technique, EM-MS, for the investigation of electrophilic compounds. This method provides a powerful tool for molecular identification of compounds contained in complex matrices, such as environmental samples. EM-MS expands the application and selectivity of traditional MS through the inclusion of a new dimension in the space of molecular characteristics--the electron resonance energy spectrum. However, before this tool can realize its full potential, it will be necessary to create a library of resonance energy scans from standards of the molecules for which EM-MS offers a practical means of detection. Here, an approach supplementing direct measurement with chemical inference and quantum scattering theory is presented to demonstrate the feasibility of directly calculating resonance energy spectra. This approach makes use of the symmetry of the transition-matrix element of the captured electron to discriminat...

  12. Scalable sensing electronics towards a motion capture suit

    Science.gov (United States)

    Xu, Daniel; Gisby, Todd A.; Xie, Shane; Anderson, Iain A.

    2013-04-01

    Being able to accurately record body motion allows complex movements to be characterised and studied. This is especially important in the film or sport coaching industry. Unfortunately, the human body has over 600 skeletal muscles, giving rise to multiple degrees of freedom. In order to accurately capture motion such as hand gestures, elbow or knee flexion and extension, vast numbers of sensors are required. Dielectric elastomer (DE) sensors are an emerging class of electroactive polymer (EAP) that is soft, lightweight and compliant. These characteristics are ideal for a motion capture suit. One challenge is to design sensing electronics that can simultaneously measure multiple sensors. This paper describes a scalable capacitive sensing device that can measure up to 8 different sensors with an update rate of 20Hz.

  13. Simulations of electron capture supernovae with approximate neutrino transport

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Heiko [TU Darmstadt (Germany); Fischer, Tobias [University of Wroclaw (Poland); Jones, Sam [Keele University (United Kingdom); Martinez-Pinedo, Gabriel [TU Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

    2014-07-01

    We have performed simulations of electron capture supernovae in a spherically symmetric general relativistic radiation hydrodynamics model with approximate neutrino treatment. We base our study on an 8.8 M {sub CircleDot} O-Ne-Mg core progenitor (Nomoto, 1984, 1987). We successfully obtain an explosion and compare our results with a reference run performed with an state-of-the-art three-flavor Boltzmann neutrino transport scheme implemented into the same hydrodynamic code. In general, we find good agreement in the the electron-flavor neutrino spectra. However, we find shorter explosion timescales and also significantly lower explosion energies of only 1.4 . 10{sup 48} erg. This result is in agreement with the explosion energy of SN 2008S as derived by Tominaga et al. (2013) based on light curve studies. Currently we are extending our simulations to the recently published super-AGB star progenitor models by Jones et al. (2013) with regard to their evolution towards an electron capture supernova. Our study also explores the role of weak interaction rates in determining the evolution and shaping the spectra of the emitted neutrinos.

  14. Electron capture by bare ions on water molecules

    Science.gov (United States)

    Rivarola, Roberto; Montenegro, Pablo; Monti, Juan; Fojón, Omar

    2016-05-01

    Single electron capture from water molecules by impact of bare ions is theoretically investigated at intermediate and high collision energies. This reaction is of fundamental importance to determine the deposition of energy in biological matter irradiated with ion beams (hadrontherapy), dominating other ionizing processes of the target at low-intermediate impact velocities and giving principal contributions to the energetic region where electronic stopping power maximizes. The dynamics of the interaction between the aggregates is described within the one active-electron continuum distorted wave-eikonal initial state theory. The orbitals of the target in the ground state are represented using the approximate self-consistent complete neglect of differential orbitals (SC-CNDO) model. The contribution of different molecular orbitals on the partial cross sections to selected n-principal quantum number projectile states is discriminated as well as the collaboration of these n-states on total cross sections. The latter ones are dominated by capture to n=1 states at high enough energies decreasing their contribution as n increases.

  15. Theory of nuclear excitation by electron capture for heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Gagyi-Palffy, A.

    2006-07-01

    The resonant process of nuclear excitation by electron capture (NEEC) in collisions involving highly-charged ions has been investigated theoretically. NEEC is a rare recombination process in which a free electron is captured into a bound shell of an ion with the simultaneous excitation of the nucleus. Total cross sections for NEEC followed by the radiative decay of the excited nucleus are presented for various collision systems. The possibility to observe the NEEC in scattering experiments with trapped or stored ions was discussed focusing on the cases with the largest calculated resonance strength. As the photons emitted in different channels of the electron recombination process are indistinguishable in the total cross section, the interference between NEEC followed by the radiative decay of the nucleus and radiative recombination was investigated. The angular distribution of the emitted photons in the recombination process provides means to discern the two processes. Angular differential cross sections for the emitted photons in the case of E2 nuclear transitions were presented for several heavy elements. (orig.)

  16. Neutrino Signals in Electron-Capture Storage-Ring Experiments

    Directory of Open Access Journals (Sweden)

    Avraham Gal

    2016-06-01

    Full Text Available Neutrino signals in electron-capture decays of hydrogen-like parent ions P in storage-ring experiments at GSI are reconsidered, with special emphasis placed on the storage-ring quasi-circular motion of the daughter ions D in two-body decays P → D + ν e . It is argued that, to the extent that daughter ions are detected, these detection rates might exhibit modulations with periods of order seconds, similar to those reported in the GSI storage-ring experiments for two-body decay rates. New dedicated experiments in storage rings, or using traps, could explore these modulations.

  17. Electron capture dissociation of singly and multiply phosphorylated peptides

    DEFF Research Database (Denmark)

    Stensballe, A; Jensen, Ole Nørregaard; Olsen, J V

    2000-01-01

    Analysis of phosphotyrosine and phosphoserine containing peptides by nano-electrospray Fourier transform ion cyclotron resonance (FTICR) mass spectrometry established electron capture dissociation (ECD) as a viable method for phosphopeptide sequencing. In general, ECD spectra of synthetic...... and native phosphopeptides appeared less complex than conventional collision activated dissociation (CAD) mass spectra of these species. ECD of multiply protonated phosphopeptide ions generated mainly c- and z(.)-type peptide fragment ion series. No loss of water, phosphate groups or phosphoric acid from......(III)-affinity chromatography combined with nano-electrospray FTMS/ECD facilitated phosphopeptide analysis and amino acid sequencing from crude proteolytic peptide mixtures....

  18. Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

    DEFF Research Database (Denmark)

    Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A;

    2002-01-01

    We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers...... as well as specific complexes of modified glycopeptide antibiotics with their target peptide. The weak nature of bonding is substantiated by blackbody infrared dissociation, low-energy collisional excitation and force-field simulations. The results are consistent with a non-ergodic ECD cleavage mechanism....

  19. CP-violation reach of an electron capture neutrino beam

    CERN Document Server

    Orme, Christopher

    2009-01-01

    This article extends the work of Bernabeu and Espinoza by examining the CP-violation reach of a $^{150}$Dy electron capture beam through the variation of the two Lorentz boosts, the number of useful electron capture decays, the relative run time of each boost and the number of atmospheric backgrounds. The neutrinos are assumed to be sourced at CERN with an upgraded SPS and are directed towards a 440 kton Water Cerenkov detector located at the Canfranc laboratory. Two large `CP-coverage' choices for the boost pairings are found; a $\\delta$-symmetrical coverage for $(\\gamma_{1}, \\gamma_{2})$ = (280, 160) and an $\\delta$-asymmetric coverage for $(\\gamma_{1}, \\gamma_{2})$ = (440,150). With a nominal useful decay rate of $N_{\\rm ions} = 10^{18}$ per year, the $\\delta$-symmetric setup can rule out CP-conservation down to $\\sin^{2}2\\theta_{13} = 3\\cdot 10^{-4}$. To reach $\\sin^{2}2\\theta_{13} = 1\\cdot 10^{-3}$ for both $\\delta 0$ requires a useful decay rate of $N_{\\rm ions} = 6\\cdot 10^{17}$ per year.

  20. CP-violation reach of an electron capture neutrino beam

    Science.gov (United States)

    Orme, Christopher

    2010-07-01

    This article extends the work of Bernabeu and Espinoza by examining the CP-violation reach of a 150Dy electron capture beam through the variation of the two Lorentz boosts, the number of useful electron capture decays, the relative run time of each boost and the number of atmospheric backgrounds. The neutrinos are assumed to be sourced at CERN with an upgraded SPS and are directed towards a 440 kton Water Cerenkov detector located at the Canfranc laboratory. Two large ‘CP-coverage’ choices for the boost pairings are found; a δ-symmetrical coverage for ( γ 1, γ 2) = (280, 160) and an δ-asymmetric coverage for ( γ 1 , γ 2) = (440,150). With a nominal useful decay rate of N ions = 1018 ions per year, the δ-symmetric setup can rule out CP-conservation down to sin2 2 θ 13 = 3•10-4. To reach sin2 2 θ 13 =1•10-3 for both δ 0 requires a useful decay rate of N ions = 6•1017 ions per year.

  1. Single electron capture in fast ion-atom collisions

    Science.gov (United States)

    Milojević, Nenad

    2014-12-01

    Single-electron capture cross sections in collisions between fast bare projectiles and heliumlike atomic systems are investigated by means of the four-body boundary-corrected first Born (CB1-4B) approximation. The prior and post transition amplitudes for single charge exchange encompassing symmetric and asymmetric collisions are derived in terms of twodimensional real integrals in the case of the prior form and five-dimensional quadratures for the post form. The dielectronic interaction V12 = 1/r12 = 1/|r1 - r2| explicitly appears in the complete perturbation potential Vf of the post transition probability amplitude T+if. An illustrative computation is performed involving state-selective and total single capture cross sections for the p - He (prior and post form) and He2+, Li3+Be4+B5+C6+ - He (prior form) collisions at intermediate and high impact energies. We have also studied differential cross sections in prior and post form for single electron transfer from helium by protons. The role of dynamic correlations is examined as a function of increased projectile energy. Detailed comparisons with the measurements are carried out and the obtained theoretical cross sections are in reasonable agreement with the available experimental data.

  2. Implementation of electronic data capture systems: barriers and solutions.

    Science.gov (United States)

    Welker, James A

    2007-05-01

    Although increasing in pace, the conversion to Electronic Data Capture (EDC) has been a slow progression. The use of EDC systems should confer improved data integrity, cost savings and a shorter time to study database closure. This will reduce the time to market and cost of new medications. With the current sentiment of the industry suggesting the cost analysis has been accepted to be in favor of EDC, the likely limitation to disseminated use is an inability to implement these systems. If the leadership at the sponsor, clinical research organization and investigator site is cognizant of the barriers to implementation, they can anticipate and mitigate them prior to the users becoming disgruntled and resistant to the new method of data capture. Once understood, barriers such as user input, technical support, user motivation, regulatory requirements, communication with users, timing of implementation, software installation, graphical user interface, identification of bridgers, patient participation, availability of technology, and costs can be better addressed at the beginning of the implementation process and successfully averted. This review discusses these barriers and potential solutions that can assist the clinical trial industry in achieving more wide-spread EDC use and the resulting improvement in operating efficiencies.

  3. Mutual neutralization in H+ - H- collisions by electron capture

    Science.gov (United States)

    Mančev, Ivan; Milojević, Nenad; Belkić, Dževad

    2013-07-01

    State-selective and total cross-sections for single-electron capture from H- by H+ covering the incident energy range from 10 to 3000 keV are computed by means of the four-body boundary corrected first Born (CB1-4B) approximation. A crucial connection between the Coulomb-distorted asymptotic state in the entrance channel and the pertinent perturbation, which causes the transition in the H+ - H- collisions, is consistently used in our computations of the “prior” version of cross-sections. The obtained results from the CB1-4B method clearly outperform the earlier findings by the close-coupling methods for the same problem. Comparisons with the available measurements are carried out and excellent agreement with the CB1 method is recorded down to impact energies as low as 10 keV.

  4. Electron correlations in single-electron capture from helium by fast protons and α particles

    Science.gov (United States)

    Mančev, Ivan; Milojević, Nenad

    2010-02-01

    Single-electron capture from heliumlike atomic systems by bare projectiles is investigated by means of the four-body boundary-corrected first Born approximation (CB1-4B). The effect of the dynamic electron correlation is explicitly taken into account through the complete perturbation potential. The quantum-mechanical post and prior transition amplitudes for single charge exchange encompassing symmetric and/or asymmetric collisions are derived in terms of two-dimensional real integrals in the case of the prior form and five-dimensional quadratures for the post form. An illustrative computation is performed for single-electron capture from helium by protons and α particles at intermediate and high impact energies. The role of dynamic correlations is examined as a function of increased projectile energy. The validity and utility of the proposed CB1-4B method is critically assessed in comparison with the existing experimental data for total cross sections, and excellent agreement is obtained.

  5. Midwife to the greens: the electron capture detector.

    Science.gov (United States)

    Lovelock, J E

    1997-03-01

    James E. Lovelock makes an account of the path he has followed since he started his scientific research at the National Institute for Medical Research (NIMR) in London in the 1940s, emphasizing the aspects related to environmental sciences. Lovelock explains the origins of the electron capture detector (ECD). So far, the ECD is the most sensitive, easily portable and inexpensive analytical apparatus capable of detecting substances present in the atmosphere at concentrations as low as parts per trillion (10(-12)). It has been the first device specifically sensitive to pollutants, and its use has provided the grounds for the development of environmental sciences, and green politics. The data gathered by the ECD about the persistence of pesticides in the environment led American biologist Rachel Carson to write her seminal book Silent Spring; data regarding the global presence of chlorofluorocarbons (CFC) in the atmosphere led Sherwood Rowland and Mario Molina to develop their theory of ozone depletion. The results of his research over the years led Lovelock himself to the development of the Gaia theory.

  6. ELECTRON-CAPTURE SUPERNOVAE AS SOURCES OF {sup 60}Fe

    Energy Technology Data Exchange (ETDEWEB)

    Wanajo, Shinya [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Janka, Hans-Thomas; Mueller, Bernhard, E-mail: shinya.wanajo@nao.ac.jp [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

    2013-09-01

    We investigate the nucleosynthesis of the radionuclide {sup 60}Fe in electron-capture supernovae (ECSNe). The nucleosynthetic results are based on a self-consistent, two-dimensional simulation of an ECSN as well as models in which the densities are systematically increased by some factors (low-entropy models). {sup 60}Fe is found to be appreciably made in neutron-rich ejecta during the nuclear quasi-equilibrium phase with greater amounts being produced in the lower-entropy models. Our results, combining them with the yields of core-collapse supernovae in the literature, suggest that ECSNe account for at least 4%-30% of live {sup 60}Fe in the Milky Way. ECSNe co-produce neutron-rich isotopes, {sup 48}Ca, {sup 50}Ti, {sup 54}Cr, some light trans-iron elements, and possibly weak r-process elements including some radionuclides such as {sup 93}Zr, {sup 99}Tc, and {sup 107}Pd, whose association with {sup 60}Fe might have been imprinted in primitive meteorites or in the deep ocean crust on the Earth.

  7. Validation of undergraduate clinical data by electronic capture (barcode).

    Science.gov (United States)

    Chadwick, Barbara L; Oliver, Richard G; Gyton, Jane

    2002-03-01

    Assessment of clinical activity is common in dental schools. An audit project to confirm that dental undergraduate clinical activity recorded by electronic data capture is an accurate representation of the clinical case entry is reported. A printout of clinical activity for a period of a week was generated retrospectively and used to identify case notes. Activity recorded in the case notes was compared with the computer printout. All discrepancies were noted. A total of 125 patient files with 270 barcoded items of treatment were retrieved; 29 of 78 (37.1%) paediatric and 23 of 47 (48.9%) orthodontic cases had discrepancies between the case notes and the computer entry. However, some items recorded in the notes do not require barcoding and vice versa. When these were accounted for, only 19 items of treatment appeared in the notes that should have been barcoded, a 7% shortfall in recording of clinical activity. The barcode system is an accurate and reliable way of recording undergraduate clinical activity.

  8. HE-2+-H2 COLLISIONS - NONDISSOCIATIVE AND DISSOCIATIVE ONE-ELECTRON CAPTURE

    NARCIS (Netherlands)

    HOEKSTRA, R; FOLKERTS, HO; BEIJERS, JPM; MORGENSTERN, R; DEHEER, FJ

    1994-01-01

    Electron-redistribution processes in collisions of He-2+ ions on H-2 are studied for energies from 1 to 25 keV amu-1. One-electron capture and target excitation cross sections are determined by photon-emission spectroscopy. At energies exceeding approximately 5 keV amu-1 capture into excited states

  9. Determination of the Electron Neutrino Mass from Experiments on Electron-Capture Beta-Decay (EC)

    CERN Multimedia

    2002-01-01

    The aim of the programme is to measure the electron-neutrino mass, for which at present an upper limit of 500~eV is known. \\\\ \\\\ The experiment studies the shape of the internal bremsstrahlung spectrum in electron-capture near its upper end-point and deduces a mass from small shape changes completely analogous to those in the well-known determination of the electron antineutrino mass in the tritium beta-minus decay. \\\\ \\\\ In a low-energy bremsstrahlung process, the capture takes place from a virtual S state associated with a radiative P~@A~S electromagnetic transition, and the resonant nature of the process leads to important enhancements of the photon intensities at low energy, in particular near the resonance energies co (X-rays). This effect gives this type of experiment a chance to compete with experiments on continuous beta spectra. \\\\ \\\\ The programme concentrates on two long-lived isotopes: \\\\ \\\\ 1)~~|1|6|3Ho. The Q value for this isotope has been found to be 2.6-2.7 keV. A detector specially construct...

  10. Correlated double electron capture in slow, highly charged ion-atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Stolterfoht, N.; Havener, C.C.; Phaneuf, R.A.; Swenson, J.K.; Shafroth, S.M.; Meyer, F.W.

    1986-01-01

    Recent measurements of autoionization electrons produced in slow, highly charged ion-atom collisions are reviewed. Mechanisms for double electron capture into equivalent and nonequivalent configurations are analyzed by comparing the probabilities for the creation of L/sub 1/L/sub 23/X Coster Kronig electrons and L-Auger electrons. It is shown that the production of the Coster-Kronig electrons is due to electron correlation effects whose analysis leads beyond the independent-particle model. The importance of correlation effects on different capture mechanisms is discussed. 28 refs., 6 figs.

  11. Ionization and single electron capture in collision of highly charged Ar16+ ions with helium

    Institute of Scientific and Technical Information of China (English)

    Wang Fei; Gou Bing-Cong

    2008-01-01

    This paper uses the two-centre atomic orbital close-coupling method to study the ionization and the single electron capture in collision of highly charged Ar16+ ions with He atoms in the velocity range of 1.2-1.9 a.u.. The relative importance of single ionization (SI) to single capture (SC) is explored. The comparison between the calculation and experimental data shows that the SI/SC cross section ratios from this work are in good agreement with experimental data. The total single electron ionization cross sections and the total single electron capture cross sections are also given for this collision. The investigation of the partial electron capture cross section shows a general tendency of capture to larger n and l with increasing velocity from 1.2 to 1.9 a.u..

  12. Level-resolved quantum statistical theory of electron capture into many-electron compound resonances in highly charged ions

    CERN Document Server

    Berengut, J C; Dzuba, V A; Flambaum, V V; Gribakin, G F

    2015-01-01

    The strong mixing of many-electron basis states in excited atoms and ions with open $f$ shells results in very large numbers of complex, chaotic eigenstates that cannot be computed to any degree of accuracy. Describing the processes which involve such states requires the use of a statistical theory. Electron capture into these 'compound resonances' leads to electron-ion recombination rates that are orders of magnitude greater than those of direct, radiative recombination, and cannot be described by standard theories of dielectronic recombination. Previous statistical theories considered this as a two-electron capture process which populates a pair of single-particle orbitals, followed by 'spreading' of the two-electron states into chaotically mixed eigenstates. This method is similar to a configuration-average approach, as it neglects potentially important effects of spectator electrons and conservation of total angular momentum. In this work we develop a statistical theory which considers electron capture in...

  13. Limit on the radiative neutrinoless double electron capture of ^{36}Ar from GERDA Phase I

    Science.gov (United States)

    Agostini, M.; Allardt, M.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Barros, N.; Baudis, L.; Bauer, C.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; di Vacri, A.; Domula, A.; Doroshkevich, E.; Egorov, V.; Falkenstein, R.; Fedorova, O.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gooch, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hakenmüller, J.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Csáthy, J. Janicskó; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Kish, A.; Klimenko, A.; Kneißl, R.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Medinaceli, E.; Miloradovic, M.; Mingazheva, R.; Misiaszek, M.; Moseev, P.; Nemchenok, I.; Palioselitis, D.; Panas, K.; Pandola, L.; Pelczar, K.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salamida, F.; Salathe, M.; Schmitt, C.; Schneider, B.; Schönert, S.; Schreiner, J.; Schütz, A.-K.; Schulz, O.; Schwingenheuer, B.; Selivanenko, O.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Stepaniuk, M.; Vanhoefer, L.; Vasenko, A. A.; Veresnikova, A.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wiesinger, C.; Wilsenach, H.; Wojcik, M.; Yanovich, E.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

    2016-12-01

    Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of ^{36}Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array ( Gerda) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of ^{36}Ar was established: T_{1/2} > 3.6 × 10^{21} years at 90% CI.

  14. Limit on the radiative neutrinoless double electron capture of {sup 36}Ar from GERDA Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, M.; Balata, M.; D' Andrea, V.; Di Vacri, A.; Junker, M.; Laubenstein, M. [INFN Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, Assergi (Italy); Allardt, M.; Domula, A.; Lehnert, B.; Schneider, B.; Wester, T.; Wilsenach, H.; Zuber, K. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, Dresden (Germany); Bakalyarov, A.M.; Belyaev, S.T.; Lebedev, V.I.; Zhukov, S.V. [National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Barabanov, I.; Bezrukov, L.; Doroshkevich, E.; Fedorova, O.; Gurentsov, V.; Kazalov, V.; Kuzminov, V.V.; Lubsandorzhiev, B.; Moseev, P.; Selivanenko, O.; Veresnikova, A.; Yanovich, E. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Barros, N. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, Dresden (Germany); University of Pennsylvania, Philadelphia, PA (United States); Baudis, L.; Benato, G.; Kish, A.; Miloradovic, M.; Mingazheva, R.; Walter, M. [Physik Institut der Universitaet Zuerich, Zurich (Switzerland); Bauer, C.; Hakenmueller, J.; Heisel, M.; Heusser, G.; Hofmann, W.; Kihm, T.; Kirsch, A.; Knoepfle, K.T.; Lindner, M.; Maneschg, W.; Salathe, M.; Schreiner, J.; Schwingenheuer, B.; Simgen, H.; Smolnikov, A.; Stepaniuk, M.; Wagner, V.; Wegmann, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bellotti, E. [Universita Milano Bicocca, Dipartimento di Fisica, Milan (Italy); INFN Milano Bicocca, Milan (Italy); Belogurov, S.; Kornoukhov, V.N. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Institute for Theoretical and Experimental Physics NRC ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Bettini, A.; Brugnera, R.; Garfagnini, A.; Medinaceli, E.; Sada, C.; Sturm, K. von [Dipartimento di Fisica e Astronomia dell' Universita di Padova, Padua (Italy); INFN Padova, Padua (Italy); Bode, T.; Csathy, J.J.; Lazzaro, A.; Schoenert, S.; Wiesinger, C. [Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Munich (Germany); Borowicz, D. [Jagiellonian University, Institute of Physics, Krakow (Poland); Joint Institute for Nuclear Research, Dubna (Russian Federation); Brudanin, V.; Egorov, V.; Kochetov, O.; Nemchenok, I.; Rumyantseva, N.; Zhitnikov, I.; Zinatulina, D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Caldwell, A.; Gooch, C.; Kneissl, R.; Liao, H.Y.; Majorovits, B.; Palioselitis, D.; Schulz, O.; Vanhoefer, L. [Max-Planck-Institut fuer Physik, Munich (Germany); Cattadori, C.; Salamida, F. [INFN Milano Bicocca, Milan (Italy); Chernogorov, A.; Demidova, E.V.; Kirpichnikov, I.V.; Vasenko, A.A. [Institute for Theoretical and Experimental Physics NRC ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Falkenstein, R.; Freund, K.; Grabmayr, P.; Hegai, A.; Jochum, J.; Schmitt, C.; Schuetz, A.K. [Eberhard Karls Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Frodyma, N.; Misiaszek, M.; Panas, K.; Pelczar, K.; Wojcik, M.; Zuzel, G. [Jagiellonian University, Institute of Physics, Krakow (Poland); Gangapshev, A. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Gusev, K. [Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Technische Universitaet Muenchen, Physik Department and Excellence Cluster Universe, Munich (Germany); Hemmer, S.; Lippi, I.; Stanco, L. [INFN Padova, Padua (Italy); Hult, M.; Lutter, G. [European Commission, JRC-Geel, Geel (Belgium); Inzhechik, L.V. [Institute for Nuclear Research of the Russian Academy of Sciences, Moscow (Russian Federation); Moscow Institute of Physics and Technology, Moscow (Russian Federation); Klimenko, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); International University for Nature, Society and Man ' ' Dubna' ' , Dubna (Russian Federation); Lubashevskiy, A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Macolino, C. [INFN Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, Assergi (Italy); LAL, CNRS/IN2P3, Universite Paris-Saclay, Orsay (France); Pandola, L. [INFN Laboratori Nazionali del Sud, Catania (Italy); Pullia, A.; Riboldi, S. [Universita degli Studi di Milano, Dipartimento di Fisica, Milan (Italy); INFN Milano (Italy); Shirchenko, M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); National Research Centre ' ' Kurchatov Institute' ' , Moscow (Russian Federation); Collaboration: GERDA collaboration

    2016-12-15

    Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of {sup 36}Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (Gerda) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of {sup 36}Ar was established: T{sub 1/2} > 3.6 x 10{sup 21} years at 90% CI. (orig.)

  15. Limit on the Radiative Neutrinoless Double Electron Capture of $^{36}$Ar from GERDA Phase I

    CERN Document Server

    Agostini, M; Bakalyarov, A M; Balata, M; Barabanov, I; Barros, N; Baudis, L; Bauer, C; Bellotti, E; Belogurov, S; Belyaev, S T; Benato, G; Bettini, A; Bezrukov, L; Bode, T; Borowicz, D; Brudanin, V; Brugnera, R; Caldwell, A; Cattadori, C; Chernogorov, A; D'Andrea, V; Demidova, E V; di Vacri, A; Domula, A; Doroshkevich, E; Egorov, V; Falkenstein, R; Fedorova, O; Freund, K; Frodyma, N; Gangapshev, A; Garfagnini, A; Gooch, C; Grabmayr, P; Gurentsov, V; Gusev, K; Hakenmüller, J; Hegai, A; Heisel, M; Hemmer, S; Heusser, G; Hofmann, W; Hult, M; Inzhechik, L V; Csáthy, J Janicskó; Jochum, J; Junker, M; Kazalov, V; Kihm, T; Kirpichnikov, I V; Kirsch, A; Kish, A; Klimenko, A; Kneißl, R; Knöpfle, K T; Kochetov, O; Kornoukhov, V N; Kuzminov, V V; Laubenstein, M; Lazzaro, A; Lebedev, V I; Lehnert, B; Liao, H Y; Lindner, M; Lippi, I; Lubashevskiy, A; Lubsandorzhiev, B; Lutter, G; Macolino, C; Majorovits, B; Maneschg, W; Medinaceli, E; Miloradovic, M; Mingazheva, R; Misiaszek, M; Moseev, P; Nemchenok, I; Palioselitis, D; Panas, K; Pandola, L; Pelczar, K; Pullia, A; Riboldi, S; Rumyantseva, N; Sada, C; Salamida, F; Salathe, M; Schmitt, C; Schneider, B; Schönert, S; Schreiner, J; Schütz, A -K; Schulz, O; Schwingenheuer, B; Selivanenko, O; Shirchenko, M; Simgen, H; Smolnikov, A; Stanco, L; Stepaniuk, M; Vanhoefer, L; Vasenko, A A; Veresnikova, A; von Sturm, K; Wagner, V; Walter, M; Wegmann, A; Wester, T; Wiesinger, C; Wilsenach, H; Wojcik, M; Yanovich, E; Zhitnikov, I; Zhukov, S V; Zinatulina, D; Zuber, K; Zuzel, G

    2016-01-01

    Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of $^{36}$Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (GERDA) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of $^{36}$Ar was established: $T_{1/2} > $ 4.0 $\\times$ 10$^{21}$ yr at 90 % C.I.

  16. Measurements of Pair Production and Electron Capture from the Continuum in Heavy Particle Collisions

    CERN Multimedia

    2002-01-01

    Large transient Coulomb fields, which are generated in collisions of high-Z systems at sufficiently high energies, lead to copious production of electron-positron pairs. It has been suggested that these lepton pairs might mask signals arising from plasma phase interaction. Pair-production cross sections have been calculated by several authors with results which differ significantly from each other. Some of the electrons produced may be captured into bound states of the ion, thereby, reducing its charge state by one unit. This process which has been termed ``Electron Capture from Pair Production``, represents the only electron capture pro which increases with energy, and as such, will dominate all others in the ultrarelativistic energy regime. Ions having undergone this process would be lost from storage-type accelerators. The absolute cross sections for capture have been calculated with results which differ by as much as an order of magnitude. If as large as some of the calculations predict, Relativistic Heav...

  17. Electron capture dissociation proceeds with a low degree of intramolecular migration of peptide amide hydrogens

    DEFF Research Database (Denmark)

    Rand, Kasper D; Adams, Christopher M; Zubarev, Roman A;

    2008-01-01

    scrambling) that occurs during vibrational excitation of gas-phase ions. Unlike traditional collisional ion activation, electron capture dissociation (ECD) is not associated with substantial vibrational excitation. We investigated the extent of intramolecular backbone amide hydrogen (1H/2H) migration upon...... ECD using peptides with a unique selective deuterium incorporation. Our results show that only limited amide hydrogen migration occurs upon ECD, provided that vibrational excitation prior to the electron capture event is minimized. Peptide ions that are excessively vibrationally excited...

  18. Differential cross sections for single-electron capture in He{sup 2+}-D collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, D.; Dagnac, R. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France)]|[Toulouse-3 Univ., 31 (France)

    1995-06-14

    A translational energy spectroscopy technique was used to study single-electron capture into the He{sup +} (n = 2) and He{sup +} (n 3) states in He{sup 2+}-D collisions. Differential cross sections were determined at 4, 6 and 8 keV in the angular range 5`-1{sup o}30` (laboratory frame). As expected, single-electron capture into the n = 2 state was found to be the dominant process; total cross sections for capture into the He{sup +} (n = 3) state were compared to other experimental and theoretical results. (author).

  19. Non-radiative excitation fluorescence microscopy

    Science.gov (United States)

    Riachy, Lina; Vézy, Cyrille; Jaffiol, Rodolphe

    2016-03-01

    Non-radiative Excitation Fluorescence Microscopy (NEFM) constitutes a new way to observe biological samples beyond the diffraction limit. Non-radiative excitation of the samples is achieved by coating the substrate with donor species, such as quantum dots (QDs). Thus the dyes are not excited directly by the laser source, as in common fluorescence microscopy, but through a non-radiative energy transfer. To prevent dewetting of the donor film, we have recently implemented a silanization process to covalently bond the QDs on the substrate. An homogeneous monolayer of QDs was then deposited on only one side of the coverslips. Atomic force microscopy was then used to characterize the QD layer. We highlight the potential of our method through the study of Giant Unilamellar Vesicles (GUVs) labeled with DiD as acceptor, in interaction with surface functionalized with poly-L-lysine. In the presence of GUVs, we observed a quenching of QDs emission, together with an emission of DiD located in the membrane, which clearly indicated that non-radiative energy transfer from QDs to DiD occurs.

  20. Double-electron capture by highly-ionized atoms isolated at very low energy

    Science.gov (United States)

    Fogwell Hoogerheide, Shannon; Dreiling, Joan M.; Sahiner, Arda; Tan, Joseph N.

    2016-05-01

    Charge exchange with background gases, also known as electron capture processes, is important in the study of comets, controlled fusion energy, anti-matter atoms, and proposed one-electron ions in Rydberg states. However, there are few experiments in the very low energy regime that could be useful for further theoretical development. At NIST, highly-charged ions extracted from an electron-beam ion trap can be isolated with energy state. Analysis using a system of rate equations yields information about the ion cloud expansion and single-electron capture rates. A substantial amount of double-electron capture is also observed. We present the relative rates and discuss the error budget. SFH and JMD were funded by National Research Council Research Associateship Awards during some of this work.

  1. Calculations of energies and absolute intensities of Auger electrons and X-rays arising from electron capture decay

    Institute of Scientific and Technical Information of China (English)

    ZHOU Chun-Mei; WU Zhen-Dong; HUANG Xiao-Long

    2005-01-01

    Calculations of energies and absolute intensities of Auger electron and X-ray arising from electron capture are introduced briefly. The calculation codes and main process are also presented. The application is also given by taking 55Fe ε decay as an example.

  2. STATE-SELECTIVE ELECTRON-CAPTURE IN HE2+ -H2 COLLISIONS

    NARCIS (Netherlands)

    MENG, L; OLSON, RE; FOLKERTS, HO; HOEKSTRA, R

    1994-01-01

    A classical phase-space model of the hydrogen molecule which includes both electrons and nuclear centers is utilized to study state selective electron capture for collisions with alpha particles at intermediate impact energies (30-200 keV amu-1). The calculations am performed within the framework of

  3. Electron Capture in 163Ho and Overlap plus Exchange Corrections and the Neutrino Mass

    CERN Document Server

    Faessler, Amand; Simkovic, M F

    2014-01-01

    Holmium offers perhaps the best chance to determine the neutrino mass by electron capture. This contribution treats the electron capture in 163Holmium completely relativistic for the overlap and exchange corrections. The theoretical expressions are derived consistently in second quantisation with the help of Wick's theorem assuming single Slater determinants for the initial Ho and the final Dy atoms with holes in the final ns1/2 and np1/2 states. No hand waving arguments are needed to derive the exchange terms. It seems, that for the first time the multiplicity of electrons in the orbital overlaps are included in the numerical treatment. Electron capture e + p --> n + neutrino is proportional to the probability to find the captured electron in the parent atom at the nucleus. Non-relativistically this is only possible for ns1/2 electron states. Relativistically also p1/2 electrons have a probability to be at the nucleus due to the lower part of the relativistic electron spinor, which does not disappear at the ...

  4. On the cascade capture of electrons at donors in GaAs quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Aleshkin, V. Ya., E-mail: aleshkin@ipmras.ru [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2015-09-15

    The impact parameter for the cascade capture of electrons at a charged donor in a GaAs quantum well is calculated. A simple approximate analytical expression for the impact parameter is suggested. The temperature dependence of the impact parameter for the case of electron scattering by the piezoelectric potential of acoustic phonons is determined.

  5. DOUBLE ELECTRON-CAPTURE INTO HIGHLY CHARGED IONS - CORRELATED OR INDEPENDENT

    NARCIS (Netherlands)

    POSTHUMUS, JH; LUKEY, P; MORGENSTERN, R

    1991-01-01

    We propose an independent-electron model for describing quantitatively the population of doubly excited (nlnl') states formed by two-electron capture into multiply charged ions. Population probabilities calculated by this model reproduce experimentally determined ones if one assumes that the

  6. THE INFLUENCE OF ANGULAR-MOMENTUM ON DOUBLE ELECTRON-CAPTURE BY HIGHLY CHARGED IONS

    NARCIS (Netherlands)

    POSTHUMUS, JH; LUKEY, P; MORGENSTERN, R

    1992-01-01

    Double electron capture during collisions of highly charged ions with H-2 or He is studied by measuring and analysing energy spectra of the resulting autoionization electrons and by comparing the experimentally determined population probabilities for the various states with those calculated from a

  7. Axisymmetric Magnetic Fields, Electron Capture and Pycnonuclear Reactions in Magnetized White Dwarfs

    CERN Document Server

    Otoniel, Edson; Malheiro, Manuel; Schramm, Stefan; Weber, Fridolin

    2016-01-01

    In this work, we study the properties of magnetized white dwarfs taking into account possible instabilities due to electron capture and pycnonuclear fusion reactions in the cores of such objects. The structure of white dwarfs is obtained by solving the Einstein-Maxwell equations with a poloidal magnetic field in a fully general relativistic approach. The stellar interior is composed of a regular crystal lattice made of carbon ions immersed in a degenerate relativistic electron gas. The onsets of electron capture reactions and pycnonuclear reactions are determined with and without magnetic fields. We find that magnetized white dwarfs violate the standard Chandrasekhar mass limit significantly, even when electron capture and pycnonuclear instabilities are present in the stellar interior. We obtain a maximum white dwarf mass of around $2.12\\,M_{\\odot}$ with a central magnetic field of $\\sim 1.74\\times 10^{14}$G, which indicates that magnetized white dwarfs may be the progenitor candidates of superluminous type I...

  8. Neutrinoless double positron decay and positron emitting electron capture in the interacting boson model

    CERN Document Server

    Barea, J; Iachello, F

    2015-01-01

    Neutrinoless double-$\\beta$ decay is of fundamental importance for determining the neutrino mass. Although double electron ($\\beta^-\\beta^-$) decay is the most promising mode, in very recent years interest in double positron ($\\beta^+\\beta^+$) decay, positron emitting electron capture ($EC\\beta^+$), and double electron capture ($ECEC$) has been renewed. We present here results of a calculation of nuclear matrix elements for neutrinoless double-$\\beta^+$ decay and positron emitting electron capture within the framework of the microscopic interacting boson model (IBM-2) for $^{58}$Ni, $^{64}$Zn, $^{78}$Kr, $^{96}$Ru, $^{106}$Cd, $^{124}$Xe, $^{130}$Ba, and $^{136}$Ce decay. By combining these with a calculation of phase space factors we calculate expected half-lives.

  9. Measurements of Pair Production and Electron Capture from the Continuum in Heavy Particle Collisions

    CERN Multimedia

    2002-01-01

    % WA99 \\\\ \\\\ Large transient Coulomb fields, which are generated in collisions of high-Z systems at sufficiently high energies, lead to copious production of electron-positron pairs. It has been suggested that these lepton pairs might mask signals arising from plasma phase interaction. Pair-production cross-sections have been calculated by several authors with results that differ significantly from each other. For very heavy ions and high energies, multiple pairs are expected to be formed even in single peripheral collisions. Perturbative and nonperturbative treatments lead to various predictions for the fractions of multiple pair formation out of the total cross-sections. Some of the electrons produced will be captured into bound states of the ion, thereby, reducing its charge state by one unit. This process which has been termed $^{\\prime\\prime}$Electron Capture from Pair Production$^{\\prime\\prime}$, represents the only electron capture process which increases with energy, and as such, will dominate all oth...

  10. Search for new candidates for the neutrino-oriented mass determination by electron-capture

    CERN Multimedia

    Herfurth, F; Boehm, C; Blaum, K; Beck, D

    2008-01-01

    This proposal is part of an extended program dedicated to the neutrino-mass determination in the electron-capture sector, which aims at ultra-precise mass measurements by Penning traps in combination with cryogenic micro-calorimetry for atomic de-excitation measurements. Here, precise mass measurements with ISOLTRAP are proposed for the orbital electron-capture nuclides $^{194}$Hg and $^{202}$Pb, as well as their daughters, with the goal to determine accurately their Q-values. These values are expected to be the smallest ones among a great variety of known electron-capture precursors. Therefore, these nuclides are strong candidates for an improved electron-neutrino mass determination. We ask for 8 shifts of on-line beam at ISOLDE for mass measurements of $^{194}$Hg, $^{194}$ Au, $^{202}$Pb, and $^{202}$Tl at ISOLTRAP.

  11. Development of holmium-163 electron-capture spectroscopy with transition-edge sensors

    CERN Document Server

    Croce, M P; Mocko, V; Kunde, G J; Birnbaum, E R; Bond, E M; Engle, J W; Hoover, A S; Nortier, F M; Pollington, A D; Taylor, W A; Weisse-Bernstein, N R; Wolfsberg, L E; Hays-Wehle, J P; Schmidt, D R; Swetz, D S; Ullom, J N; Barnhart, T E; Nickles, R J

    2015-01-01

    Calorimetric decay energy spectroscopy of electron-capture-decaying isotopes is a promising method to achieve the sensitivity required for electron neutrino mass measurement. The very low total nuclear decay energy (QEC < 3 keV) and short half-life (4570 y) of 163Ho make it attractive for high-precision electron capture spectroscopy (ECS) near the kinematic endpoint, where the neutrino momentum goes to zero. In the ECS approach, an electron-capture-decaying isotope is embedded inside a microcalorimeter designed to capture and measure the energy of all the decay radiation except that of the escaping neutrino. We have developed a complete process for proton-irradiation-based isotope production, isolation, and purification of 163Ho. We have developed transition-edge sensors for this measurement and methods for incorporating 163Ho into high-resolution microcalorimeters, and have measured the electron-capture spectrum of 163Ho. We present our work in these areas and discuss the measured spectrum and its compari...

  12. Absolute measurements of electron capture cross sections of C3+ from atomic and molecular hydrogen

    Science.gov (United States)

    Sant'Anna, M. M.; Melo, W. S.; Santos, A. C. F.; Shah, M. B.; Sigaud, G. M.; Montenegro, E. C.

    2000-02-01

    Absolute measurements of single- and double-electron-capture cross sections by C3+ projectiles on atomic and molecular hydrogen targets were performed for projectile energies between 1.0 and 3.5 MeV for the single- and 1.0 and 2.0 MeV for the double-capture processes. The icons/Journals/Common/sigma" ALT="sigma" ALIGN="TOP"/> H /icons/Journals/Common/sigma" ALT="sigma" ALIGN="TOP"/> H2 cross section ratios were measured using an absolutely calibrated tungsten-tube furnace for the production of atomic hydrogen. The single-capture data are compared with calculations based on the boundary-corrected first Born approximation, the eikonal approximation and a semiclassical model, presenting a good overall agreement. Calculations for the double capture using an analytical expression, obtained within the independent electron approximation and based on the same semiclassical model, give a reasonable qualitative description of the data.

  13. Double electron capture by protons in collisions with H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Salazar-Zepeda, M.H. [Departamento de Fisica, Centro Universitario de Ciencias Exactas e Ingenieria de la Universidad de Guadalajara, Boulevard Marcelino Garcia Barragan 1421, Colonia Olimpica, Codigo Postal 44430, Guadalajara, Jalisco (Mexico); Gleason, Cristian [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Avenida Universidad 1001, Colonia Chamilpa, Codigo Postal 62209, Cuernavaca, Morelos (Mexico); Gonzalez, Eduardo; Gonzalez-Magana, O. [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Universidad 3000, Circuito Exterior SN, Codigo Postal 04510, Ciudad Universitaria (Mexico); Hinojosa, Guillermo, E-mail: hinojosa@fis.unam.m [Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Avenida Universidad SN, Colonia Chamilpa, Apartado Postal 48-3, Cuernavaca 62210 (Mexico)

    2010-05-15

    Double electron capture of protons in collisions with molecular hydrogen in the energy range 1.5-10 keV was studied by measuring the resulting H{sup -} velocity distributions. In this paper, a technique that provides experimental evidence about double capture mechanisms is proposed. In addition, cross-sections for this process were measured in the energy range of 1-5 keV.

  14. Single-electron capture in He[sup 2+]-D[sub 2] collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, D.; Dagnac, R. (Toulouse-3 Univ., 31 (France))

    1994-02-14

    Doubly differential cross sections of single-electron capture were measured for He[sup 2+] impinging on a molecular deuterium target. The investigated collision energies are 4, 6 and 8 keV and the scattering angles range from 10' to 2[sup o]30' (laboratory frame). The exothermic capture leading to He[sup +] (1s) + D[sub 2][sup +*] was found to be the most important process at low energies and angles, whereas the endothermic channels leading to dissociative capture become the main processes at high scattering angles, i.e. at small impact parameters. (author).

  15. Double K-shell vacancy production in the electron capture decay of 139Ce

    Science.gov (United States)

    Hindi, M. M.; Kozub, R. L.

    1991-02-01

    The probability of double K-shell vacancy production in the electron capture decay of 139Ce to the 166-keV level of 139La has been investigated. Triple coincidences between the 166-keV gamma ray, the La satellite Kα x ray, and the La hypersatellite Kα x ray were measured using two intrinsic Ge detectors. We looked for the sum of two of the three radiations in one detector in coincidence with the third radiation in the other detector. The probability of double K-shell vacancy production per K-shell electron capture (PKK) was found to be (2.0+/-1.6)×10-6. From this and the known PKK for 131Cs we estimate a probability for zero K-shell vacancy production (shakedown) per K-shell electron capture of <~2.4×10-5 for 139Ce.

  16. The Sensitivity of Core-Collapse Supernovae to Nuclear Electron Capture

    CERN Document Server

    Sullivan, Chris; Zegers, Remco G T; Grubb, Thomas; Austin, Sam M

    2015-01-01

    A weak-rate library aimed at investigating the sensitivity of astrophysical environments to variations of electron-capture rates on medium-heavy nuclei has been developed. With this library, the sensitivity of the core-collapse and early post-bounce phases of core-collapse supernovae to nuclear electron-capture is examined by systematically and statistically varying electron-capture rates of individual nuclei. The rates are adjusted by factors consistent with uncertainties indicated by comparing theoretical rates to those deduced from charge-exchange and $\\beta$-decay measurements. To ensure a model independent assessment, sensitivity studies across a comprehensive set of progenitors and equations of state are performed. In our systematic study, we find a +16/-4 % range in the mass of the inner-core at the time of shock formation and a $\\pm$20% range of peak {\

  17. Search for Two-Neutrino Double Electron Capture of $^{124}$Xe with XENON100

    CERN Document Server

    Aprile, E; Agostini, F; Alfonsi, M; Amaro, F D; Anthony, M; Arneodo, F; Barrow, P; Baudis, L; Bauermeister, B; Benabderrahmane, M L; Berger, T; Breur, P A; Brown, A; Brown, E; Bruenner, S; Bruno, G; Budnik, R; Bütikofer, L; Calvén, J; Cardoso, J M R; Cervantes, M; Cichon, D; Coderre, D; Colijn, A P; Conrad, J; Cussonneau, J P; Decowski, M P; de Perio, P; Di Gangi, P; Di Giovanni, A; Diglio, S; Duchovni, E; Fei, J; Ferella, A D; Fieguth, A; Franco, D; Fulgione, W; Rosso, A Gallo; Galloway, M; Gao, F; Garbini, M; Geis, C; Goetzke, L W; Greene, Z; Grignon, C; Hasterok, C; Hogenbirk, E; Itay, R; Kaminsky, B; Kessler, G; Kish, A; Landsman, H; Lang, R F; Lellouch, D; Levinson, L; Calloch, M Le; Levy, C; Lin, Q; Lindemann, S; Lindner, M; Lopes, J A M; Manfredini, A; Undagoitia, T Marrodán; Masbou, J; Massoli, F V; Masson, D; Mayani, D; Meng, Y; Messina, M; Micheneau, K; Miguez, B; Molinario, A; Murra, M; Naganoma, J; Ni, K; Oberlack, U; Orrigo, S E A; Pakarha, P; Pelssers, B; Persiani, R; Piastra, F; Pienaar, J; Piro, M -C; Plante, G; Priel, N; Rauch, L; Reichard, S; Reuter, C; Rizzo, A; Rosendahl, S; Rupp, N; Santos, J M F dos; Sartorelli, G; Scheibelhut, M; Schindler, S; Schreiner, J; Schumann, M; Lavina, L Scotto; Selvi, M; Shagin, P; Silva, M; Simgen, H; Sivers, M v; Stein, A; Thers, D; Tiseni, A; Trinchero, G; Tunnell, C D; Wall, R; Wang, H; Weber, M; Wei, Y; Weinheimer, C; Wulf, J; Zhang, Y

    2016-01-01

    Two-neutrino double electron capture is a rare nuclear decay where two electrons are simultaneously captured from the atomic shell. For $^{124}$Xe this process has not yet been observed and its detection would provide a new reference for nuclear matrix element calculations. We have conducted a search for two-neutrino double electron capture from the K-shell of $^{124}$Xe using 7636 kg$\\cdot$d of data from the XENON100 dark matter detector. Using a Bayesian analysis we observed no significant excess above background, leading to a lower 90 % credibility limit on the half-life $T_{1/2}>6.5\\times10^{20}$ yr. We also evaluated the sensitivity of the XENON1T experiment, which is currently being commissioned, and find a sensitivity of $T_{1/2}>6.1\\times10^{22}$ yr after an exposure of 2 t$\\cdot$yr.

  18. The Skyrme-TQRPA calculations of electron capture on hot nuclei in pre-supernova environment

    CERN Document Server

    Dzhioev, Alan A; Stoyanov, Ch

    2016-01-01

    We combine the thermal QRPA approach with the Skyrme energy density functional theory (Skyrme-TQRPA) for modelling the process of electron capture on nuclei in supernova environment. For a sample nucleus, $^{56}$Fe, the Skyrme-TQRPA approach is applied to analyze thermal effects on the strength function of GT$_+$ transitions which dominate electron capture at $E_e\\le 30$~MeV. Several Skyrme interactions are used in order to verify the sensitivity of the obtained results to the Skyrme force parameters. Finite-temperature cross sections are calculated and the results are compared with those of the other model calculations.

  19. The Skyrme-TQRPA calculations of electron capture on hot nuclei in pre-supernova environment

    Energy Technology Data Exchange (ETDEWEB)

    Dzhioev, Alan A., E-mail: dzhioev@theor.jinr.ru; Vdovin, A. I., E-mail: vdovin@theor.jinr.ru [JINR, Bogoliubov Laboratory of Theoretical Physics (Russian Federation); Stoyanov, Ch., E-mail: stoyanov@inrne.bas.bg [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria)

    2016-11-15

    We combine the thermal QRPA approach with the Skyrme energy density functional theory (Skyrme–TQRPA) for modelling the process of electron capture on nuclei in supernova environment. For a sample nucleus, {sup 56}Fe, the Skyrme–TQRPA approach is applied to analyze thermal effects on the strength function of GT{sub +} transitions which dominate electron capture at E{sub e} ≤ 30 MeV. Several Skyrme interactions are used in order to verify the sensitivity of the obtained results to the Skyrme force parameters. Finite-temperature cross sections are calculated and the results are comparedwith those of the other model calculations.

  20. The Skyrme-TQRPA calculations of electron capture on hot nuclei in pre-supernova environment

    Science.gov (United States)

    Dzhioev, Alan A.; Vdovin, A. I.; Stoyanov, Ch.

    2016-11-01

    We combine the thermal QRPA approach with the Skyrme energy density functional theory (Skyrme-TQRPA) for modelling the process of electron capture on nuclei in supernova environment. For a sample nucleus, 56Fe, the Skyrme-TQRPA approach is applied to analyze thermal effects on the strength function of GT+ transitions which dominate electron capture at E e ≤ 30 MeV. Several Skyrme interactions are used in order to verify the sensitivity of the obtained results to the Skyrme force parameters. Finite-temperature cross sections are calculated and the results are comparedwith those of the other model calculations.

  1. Double K-shell vacancy production in the electron capture decay of 125I

    Science.gov (United States)

    Hindi, M. M.; Kozub, R. L.

    1992-03-01

    We have measured the probability of double K-shell vacancy production in the electron capture decay of 125I to the 35-keV level of 125Te. The probability was deduced from the number of triple coincidences between the Te hypersatellite and satellite x rays produced in filling the double vacancy, and the subsequent normal x ray accompanying the K internal conversion of the 35-keV level. The probability of double K-shell vacancy production per K-shell electron capture (PKK) was found to be (1.35+/-0.15)×10-5.

  2. A search for the radiative neutrinoless double electron capture of $^{58}$Ni

    CERN Document Server

    Lehnert, B; Frotscher, A; Michel, T; Zuber, K

    2016-01-01

    A search for the radiative neutrinoless double electron capture with single \\gray\\ emission has been performed in $^{58}$Ni. Gamma radiation from a 7286 g nickel sample in natural isotope composition was measured for 58.3 d with an ultra low background HPGe detector in the Felsenkeller underground laboratory in Dresden, Germany. A new lower half-life limit of $2.1 \\times 10^{21}$ yr (90% CL) was obtained for this decay mode. This half-life limit is two orders of magnitude higher than the existing limit for $^{58}$Ni and among the best half-life limits for neutrinoless double electron capture decays.

  3. Electronic data capture platform for clinical research based on mobile phones and near field communication technology.

    Science.gov (United States)

    Morak, Jürgen; Schwetz, Verena; Hayn, Dieter; Fruhwald, Friedrich; Schreier, Gunter

    2008-01-01

    Electronic data capture systems support data acquisition for clinical research and enable the evaluation of new investigational medical devices. In case of evaluating a device the most challenging part is the user interface i.e. the solution how to acquire the data within a clinical setting and to synchronize them with a web-based data centre. The aim of this paper is to describe the development of an electronic data capture system with a mobile data input solution based on mobile phones and Near Field Communication technology. This system was evaluated within a real clinical setting and demonstrated high usability, security and reliability.

  4. Electron Capture and Electron Transport by Fast Ions Penetrating Solids: An open Quantum System Approach with Sources and Sinks

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, M. [Institute of Physics, Karl-Franzens Universitat Graz

    2007-03-01

    We present a joint theoretical and experimental study of the time evolution of electronic states of highly charged hydrogenic ions formed by capture during transmission through solids as they undergo multiple collisions and radiative decay. For this transport problem we have developed an inhomogeneous nonunitary Lindblad master equation that allows for a description of open quantum systems with both sinks (electron loss) and source (capture) present. We apply this theoretical framework to study transient coherences created in electron capture by 13.6 MeV/amu Ar18+ ions transmitted through amorphous carbon foils and decoherence during subsequent interaction with the foil. In the limit of thin targets we can directly probe electron capture cross sections under single collision conditions, while for thicker targets we follow the partially coherent dynamics of the open quantum system in interaction with the solid as a function of interaction time. The calculated results are in close agreement with experimental data obtained at the LISE facility in GANIL. Photon intensities from excited argon ions were determined through high resolution x-ray spectroscopy in which individual fine structure components were resolved. Measurements were performed for a wide range of carbon foil thickness to study the time development of the excited state populations.

  5. Testing the electron-capture supernova scenario using universal relations between neutron star properties

    Science.gov (United States)

    Newton, William

    2017-01-01

    8-10 solar mass stars may end their lives in electron-capture supernovae (ECSNe), in which ONeMg cores are destabilized by electron captures onto Neon and Magnesium. Strong circumstantial evidence exists that the Crab pulsar and PSR J0737-3039b were formed in ECSNe. Evidence for the existence of the ECSN mechanism has important implications for the rate of production of Be/X-ray binaries and the rate of binary neutron star mergers.I will discuss how supernova modeling suggests that neutron stars formed via the electron-capture mechanism have a specific gravitational binding energy. Recently, universal relations between neutron star properties including their binding energy, moment of inertia, quadrupole moments and tidal polarizability have been carefully examined. I will show how these relations, coupled with measurements of the post-Newtonian parameters of the PSR J0737-3039 system and of the acceleration of the Crab supernova remnant, can provide evidence for or against the electron-capture supernova formation scenario.

  6. HE2+-HE COLLISIONS - ONE-ELECTRON CAPTURE AND TARGET-ION EXCITATION

    NARCIS (Netherlands)

    FOLKERTS, HO; BLIEK, FW; MENG, L; OLSON, RE; MORGENSTERN, R; VONHELLERMANN, M; SUMMERS, HP; HOEKSTRA, R

    1994-01-01

    By means of photon emission spectroscopy we have studied state selective one-electron capture and target-ion excitation in collisions of He-2+ with He. The collision energy has been varied from 1 to 75 keV amu-1 Four-body classical trajectory Monte Carlo calculations have been performed in the energ

  7. Transition Operators Entering Neutrinoles Double Electron Capture to Excited Nuclear States

    CERN Document Server

    Vergados, J D

    2011-01-01

    We construct the effective transition operators relevant for neutrinoless double electron capture leading to final nuclear states different than $0^{+}$. From the structure of these operators we see that, if such a process is observed experimentally, it will be very helpful in singling out the very important light neutrino mass contribution from the other lepton violating mechanisms

  8. First state selective electron capture measurements with trapped highly charged ions

    NARCIS (Netherlands)

    Bliek, F.W.; Woestenenk, G.R.; Hoekstra, R.A.; Morgenstern, R.W.H.

    1997-01-01

    The first state selective electron capture cross section measurements at eV energies are reported for collisions between C4+ ions and H-2 molecules. The cross sections are measured in a crossed beam experiment by means of Photon Emission Spectroscopy. The ion beams are decelerated in an octopole ion

  9. Interatomic Coulombic electron capture in atomic, molecular, and quantum dot systems

    Directory of Open Access Journals (Sweden)

    Bande Annika

    2015-01-01

    Full Text Available The interatomic Coulombic electron capture (ICEC process has recently been predicted theoretically for clusters of atoms and molecules. For an atom A capturing an electron e(ε it competes with the well known photorecombination, because in an environment of neutral or anionic neighboring atoms B, A can transfer its excess energy in the ultrafast ICEC process to B which is then ionized. The cross section for e(ε + A + B → A− + B+ + e(ε′ has been obtained in an asymptotic approximation based on scattering theory for several clusters [1,2]. It was found that ICEC starts dominating the PR for distances among participating species of nanometers and lower. Therefore, we believe that the ICEC process might be of importance in the atmosphere, in biological systems, plasmas, or in nanostructured materials. As an example for the latter, ICEC has been investigated by means of electron dynamics in a model potential for semiconductor double quantum dots (QDs [3]. In the simplest case one QD captures an electron while the outgoing electron is emitted from the other. The reaction probability for this process was found to be relatively large.

  10. Single-photon emission associated with double electron capture in F9+ + C collisions

    CERN Document Server

    Elkafrawy, Tamer; Tanis, John A; Warczak, Andrzej

    2016-01-01

    Radiative double electron capture (RDEC), the one-step process occurring in ion-atom collisions, has been investigated for bare fluorine ions colliding with carbon. RDEC is completed when two target electrons are captured to a bound state of a projectile simultaneously with the emission of a single photon. This work is a follow-up to our earlier measurement of RDEC for bare oxygen projectiles, thus providing a recipient system free of electron-related Coulomb fields in both cases and allowing for the comparison between the two collision systems as well as with available theoretical studies. The most significant mechanisms of x-ray emission that may contribute to the RDEC energy region as background processes are also addressed.

  11. Experimental investigations of electron capture from atomic hydrogen and deuterium by alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Gay, T.J.; Park, J.T.

    1992-01-01

    We report progress made during the period 15 September 1991--14 September 1992 on the project Experimental Investigations of Electron Capture from Atomic Hydrogen and Deuterium by Alpha Particles''. In the past year we have developed reliable, narrow energy spread, high-current sources of He[sup ++] based on direct-current magentron and electron-cyclotron resonance discharges. These sources have been proven on our test bench accelerator which has been upgraded to also allow us to test atomic hydrogen effusive targets. We have thus made substantial progress toward our goal of studying single electron capture from atomic hydrogen by doubly-ionized helium. A research plan for the upcoming year is also presented.

  12. Nuclear electron capture rate in stellar interiors and the case of 7Be

    CERN Document Server

    Quarati, P

    2008-01-01

    Nuclear electron capture rate from continuum in an astrophysical plasma environment (like solar core) is calculated using a modified Debye-Huckel screening potential and the related non-Gaussian q-distribution of electron momenta. For q=1 the well-known Debye-Huckel results are recovered. The value of q can be derived from the fluctuation of number of particles and temperature inside the Debye sphere. For 7Be continuum electron capture in solar core, we find an increase of 7 -- 10 percent over the rate calculated with standard Debye-Huckel potential. The consequence of this results is a reduction of the same percentage of the SSM 8B solar neutrino flux, leaving unchanged the SSM 7Be flux.

  13. Double K-shell ionization in the electron capture decay of 55Fe

    Science.gov (United States)

    Campbell, J. L.; Maxwell, J. A.; Teesdale, W. J.

    1991-04-01

    The probability per K capture for double K-shell ionization in the electron capture decay of 55Fe was obtained by fitting a model spectrum to the x-ray spectrum recorded to very high statistics in a high-resolution Si(Li) detector. The result, PKK=(1.3+/-0.2)×10-4, confirms the trend wherein experimental data decrease smoothly with Z, and are intermediate between the theoretical predictions of Intemann and of Suzuki and Law. Corrections to some recently published PKK values reconcile them with this trend.

  14. Double electron capture of He sup 2+ from He at high velocity

    Energy Technology Data Exchange (ETDEWEB)

    Schuch, R.; Justiniano, E.; Vogt, H. (Heidelberg Univ. (Germany, F.R.). Physikalisches Inst.); Deco, G.; Gruen, N. (Giessen Univ. (Germany, F.R.). Inst. fuer Theoretische Physik)

    1991-03-14

    The double electron capture process by He{sup 2+} ions in collisions with helium is studied in the high velocity regime with the measurement of total cross sections at 1.5, 4 and 6 MeV beam energy and angular differential cross sections for 1.5 MeV. The experimental results compare well with theoretical calculations which include correlation effects in the initial and final He ground states for the derivation of the capture amplitude in a continuum distorted-wave approximation. (author).

  15. Intrinsic non-radiative voltage losses in fullerene-based organic solar cells

    Science.gov (United States)

    Benduhn, Johannes; Tvingstedt, Kristofer; Piersimoni, Fortunato; Ullbrich, Sascha; Fan, Yeli; Tropiano, Manuel; McGarry, Kathryn A.; Zeika, Olaf; Riede, Moritz K.; Douglas, Christopher J.; Barlow, Stephen; Marder, Seth R.; Neher, Dieter; Spoltore, Donato; Vandewal, Koen

    2017-06-01

    Organic solar cells demonstrate external quantum efficiencies and fill factors approaching those of conventional photovoltaic technologies. However, as compared with the optical gap of the absorber materials, their open-circuit voltage is much lower, largely due to the presence of significant non-radiative recombination. Here, we study a large data set of published and new material combinations and find that non-radiative voltage losses decrease with increasing charge-transfer-state energies. This observation is explained by considering non-radiative charge-transfer-state decay as electron transfer in the Marcus inverted regime, being facilitated by a common skeletal molecular vibrational mode. Our results suggest an intrinsic link between non-radiative voltage losses and electron-vibration coupling, indicating that these losses are unavoidable. Accordingly, the theoretical upper limit for the power conversion efficiency of single-junction organic solar cells would be reduced to about 25.5% and the optimal optical gap increases to 1.45-1.65 eV, that is, 0.2-0.3 eV higher than for technologies with minimized non-radiative voltage losses.

  16. First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of $^{163}$Ho

    CERN Document Server

    Ranitzsch, P. C. -O.; Wegner, M.; Kempf, S.; Fleischmann, A.; Enss, C.; Gastaldo, L.; Herlert, A.; Johnston, K.

    2014-01-01

    The isotope $^{163}$Ho undergoes an electron capture process with a recommended value for the energy available to the decay, $Q_{\\rm EC}$, of about 2.5 keV. According to the present knowledge, this is the lowest $Q_{\\rm EC}$ value for electron capture processes. Because of that, $^{163}$Ho is the best candidate to perform experiments to investigate the value of the electron neutrino mass based on the analysis of the calorimetrically measured spectrum. We present for the first time the calorimetric measurement of the atomic de-excitation of the $^{163}$Dy daughter atom upon the capture of an electron from the 5s shell in $^{163}$Ho, OI-line. The measured peak energy is 48 eV. This measurement was performed using low temperature metallic magnetic calorimeters with the $^{163}$Ho ion implanted in the absorber. We demonstrate that the calorimetric spectrum of $^{163}$Ho can be measured with high precision and that the parameters describing the spectrum can be learned from the analysis of the data. Finally, we dis...

  17. STRONG VELOCITY DEPENDENCE OF ELECTRON-CAPTURE IN COLLISIONS BETWEEN ALIGNED NA-ASTERISK(3P) AND HE-2+

    NARCIS (Netherlands)

    SCHLATMANN, AR; HOEKSTRA, R; MORGENSTERN, R; OLSON, RE; PASCALE, J

    1993-01-01

    By analyzing spectra of emitted photons, we have studied state-selective electron capture in collisions of He2+ on aligned Na*(3p) atoms that span the ''velocity-matching'' energy between projectile and target electron. We find a strong dependence of the capture cross sections on the Na*(3p) orbital

  18. 75 FR 8115 - In the Matter of Certain Electronic Devices Having Image Capture or Display Functionality and...

    Science.gov (United States)

    2010-02-23

    .... 5,995,767, 5,774,131, and 6,281,895. 74 FR 14157 (2009). The complainant named Eastman Kodak Company... COMMISSION In the Matter of Certain Electronic Devices Having Image Capture or Display Functionality and... sale within the United States after importation of certain electronic devices having image capture...

  19. Two-dimensional electron-hole capture in a disordered hopping system

    Science.gov (United States)

    Greenham, N. C.; Bobbert, P. A.

    2003-12-01

    We model the two-dimensional recombination of electrons and holes in a system where the mean free path is short compared with the thermal capture radius. This recombination mechanism is relevant to the operation of bilayer organic light-emitting diodes (LED’s), where electrons and holes accumulate on either side of the internal heterojunction. The electron-hole recombination rate can be limited by the time taken for these charge carriers to drift and diffuse to positions where electrons and holes are directly opposite to each other on either side of the interface, at which point rapid formation of an emissive neutral state can occur. In this paper, we use analytical and numerical techniques to find the rate of this two-dimensional electron-hole capture process. Where one species of carrier is significantly less mobile than the other, we find that the recombination rate depends superlinearly on the density of the less mobile carrier. Numerical simulations allow the effects of disorder to be taken into account in a microscopic hopping model. Direct solution of the master equation for hopping provides more efficient solutions than Monte Carlo simulations. The rate constants extracted from our model are consistent with efficient emission from bilayer LED’s without requiring independent hopping of electrons and holes over the internal barrier at the heterojunction.

  20. Stellar electron-capture rates calculated with the finite-temperature relativistic random-phase approximation

    CERN Document Server

    Niu, YiFei; Vretenar, Dario; Meng, Jie

    2011-01-01

    We introduce a self-consistent microscopic theoretical framework for modelling the process of electron capture on nuclei in stellar environment, based on relativistic energy density functionals. The finite-temperature relativistic mean-field model is used to calculate the single-nucleon basis and the occupation factors in a target nucleus, and $J^{\\pi} = 0^{\\pm}$, $1^{\\pm}$, $2^{\\pm}$ charge-exchange transitions are described by the self-consistent finite-temperature relativistic random-phase approximation. Cross sections and rates are calculated for electron capture on 54,56Fe and 76,78Ge in stellar environment, and results compared with predictions of similar and complementary model calculations.

  1. Electron and Positron Capture Rates on $\\bf{^{55}}$Co in Stellar Matter

    CERN Document Server

    Nabi, Jameel-Un; Sajjad, Muhammad

    2014-01-01

    Cobalt-55 is not only present in abundance in presupernova phase but is also advocated to play a decisive role in the core collapse of massive stars. The spectroscopy of electron capture and emitted neutrinos yields useful information on the physical conditions and stellar core composition. B(GT) values to low-lying states are calculated microscopically using the pn-QRPA theory. Our rates are enhanced compared to the shell model rates. The enhancement is attributed partly to the liberty of selecting a huge model space, allowing consideration of many more parent excited states in our rate calculation. Unlike previous calculations, the so-called Brink's hypothesis is not assumed leading to a more realistic estimate of the rates. The electron and positron capture rates are calculated over a wide temperature and density grid.

  2. Warm dark matter sterile neutrinos in electron capture and beta decay spectra

    CERN Document Server

    Moreno, O; Medrano, M Ramón

    2016-01-01

    We briefly review the motivation to search for sterile neutrinos in the keV mass scale, as dark matter candidates, and the prospects to find them in beta decay or electron capture spectra. We describe the fundamentals of the neutrino flavor-mass eigenstate mismatch that opens the possibility of detecting sterile neutrinos in such ordinary nuclear processes. Results are shown and discussed for the effect of heavy neutrino emission in electron capture in Holmium 163 and in two isotopes of Lead, 202 and 205, as well as in the beta decay of Tritium. Ratios of observables in different regions of the atomic de-excitation spectrum or of the charged lepton spectrum are defined that may guide the analysis of possible future measurements.

  3. The role of electron capture and energy exchange of positively charged particles passing through matter

    CERN Document Server

    Ulmer, W

    2011-01-01

    The conventional treatment of the Bethe-Bloch equation for protons accounts for electron capture at the end of the projectile track by the small Barkas correction. This is only a possible way for protons, whereas for light and heavier charged nuclei the exchange of energy and charge along the track has to be accounted for by regarding the projectile charge q as a function of the residual energy. This leads to a significant modification of the Bethe-Bloch equation, otherwise the range in a medium is incorrectly determined. The LET in the Bragg peak domain and distal end is significantly influenced by the electron capture. A rather significant result is that in the domain of the Bragg peak the superiority of carbon ions is reduced compared to protons.

  4. Experimental study of K-electron capture probability in the decay of {sup 111}In

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.R.; Kalyani, V.D.M.L.; Maldhusudhana Rao, P.V.; Vara Prasad, N.V.; Chandrasekhar Rao, M.V.S.; Satyanarayana, G.; Sastry, D.L. [Visakhapatnam, Andhra Univ. (India). Swami Jnanananda Lab. for Nuclear Research; Chintalapudi, S.N. [Calcutt, Inter-Univ. Consortium for DAEW Facilities (India)

    1998-03-01

    The K-electron capture probability in the decay of {sup 111}In to the 416.64 keV level of the daughter nucleus {sup 111}Cd was measured to be 0.853 {+-}0.037 in agreement with the theoretical value 0.865. The experimental value is seen to be consistent with the mass prediction of the relationship due to Wapstra and Bos.

  5. Electron capture collisions involving low-energy highly-stripped projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Cocke, C.L.; Gray, T.J.; Justiniano, E.; Can, C.; Waggoner, B.; Varghese, S.L.; Mann, R. (Kansas State Univ., Manhattan (USA). Dept. of Physics)

    1983-01-01

    Recoil ions produced by fast-ion bombardment of dilute gases are in use at Kansas State University as a source of low-energy highly-charged ions to study electron capture by these projectiles on neutral targets in the 10/sup 6/-10/sup 7/ cm s/sup -1/ velocity range. A progress report on several phases of this program is summarized.

  6. Warm Dark Matter Sterile Neutrinos in Electron Capture and Beta Decay Spectra

    Directory of Open Access Journals (Sweden)

    O. Moreno

    2016-01-01

    Full Text Available We briefly review the motivation to search for sterile neutrinos in the keV mass scale, as dark matter candidates, and the prospects to find them in beta decay or electron capture spectra, with a global perspective. We describe the fundamentals of the neutrino flavor-mass eigenstate mismatch that opens the possibility of detecting sterile neutrinos in such ordinary nuclear processes. Results are shown and discussed for the effect of heavy neutrino emission in electron capture in Holmium 163 and in two isotopes of Lead, 202 and 205, as well as in the beta decay of Tritium. We study the deexcitation spectrum in the considered cases of electron capture and the charged lepton spectrum in the case of Tritium beta decay. For each of these cases, we define ratios of integrated transition rates over different regions of the spectrum under study and give new results that may guide and facilitate the analysis of possible future measurements, paying particular attention to forbidden transitions in Lead isotopes.

  7. Electron capture of nuclides 52,53,54,55,56Fe in magnetars

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Jing

    2013-01-01

    Based on the theory of relativity in superstrong magnetic fields (SMFs),we have carried out an estimation on electron capture (EC) rates of nuclides 52,53,54,55,56Fe in the SMFs in magnetars.The rates of change of electronic fraction (RCEF) in the EC process are also discussed.The results show that the EC rates increase greatly and even exceeds by 4 orders of magnitude (e.g.54Fe,55Fe and 56Fe) in SMF.On the contrary,the RCEF decreases largely and even exceeds by 5 orders of magnitude in the SMF.

  8. Theoretical investigation of the electron capture and loss processes in the collisions of He2+ + Ne.

    Science.gov (United States)

    Hong, Xuhai; Wang, Feng; Jiao, Yalong; Su, Wenyong; Wang, Jianguo; Gou, Bingcong

    2013-08-28

    Based on the time-dependent density functional theory, a method is developed to study ion-atom collision dynamics, which self-consistently couples the quantum mechanical description of electron dynamics with the classical treatment of the ion motion. Employing real-time and real-space method, the coordinate space translation technique is introduced to allow one to focus on the region of target or projectile depending on the actual concerned process. The benchmark calculations are performed for the collisions of He(2+) + Ne, and the time evolution of electron density distribution is monitored, which provides interesting details of the interaction dynamics between the electrons and ion cores. The cross sections of single and many electron capture and loss have been calculated in the energy range of 1-1000 keV/amu, and the results show a good agreement with the available experiments over a wide range of impact energies.

  9. Proton-induced single electron capture on DNA/RNA bases.

    Science.gov (United States)

    Champion, C; Weck, P F; Lekadir, H; Galassi, M E; Fojón, O A; Abufager, P; Rivarola, R D; Hanssen, J

    2012-05-21

    In this work, we report total cross sections for the single electron capture process induced on DNA/RNA bases by high-energy protons. The calculations are performed within both the continuum distorted wave and the continuum distorted wave-eikonal initial state approximations. The biological targets are described within the framework of self-consistent methods based on the complete neglect of differential overlap model whose accuracy has first been checked for simpler bio-molecules such as water vapour. Furthermore, the multi-electronic problem investigated here is reduced to a mono-electronic one using a version of the independent electron approximation. Finally, the obtained theoretical predictions are confronted with the scarcely available experimental results.

  10. Studies of electron correlation effects in multicharged ion atom collisions involving double capture

    Energy Technology Data Exchange (ETDEWEB)

    Stolterfoht, N.; Sommer, K.; Griffin, D.C.; Havener, C.C.; Huq, M.S.; Phaneuf, R.A.; Swenson, J.K.; Meyer, F.W.

    1988-01-01

    We review measurements of L-Coster Kronig and Auger electron production in slow, multicharged collision systems to study electron correlation effects in the process of double electron capture. The n/sup /minus/3/ law was confirmed for the production of the Coster-Kronig configurations 1s/sup 2/2pn/ell/ (n greater than or equal to 6) in O/sup 6 +/ + He collisions. Enhancement of high angular momentum /ell/ in specific 1s/sup 2/2pn/ell/ configurations was observed by means of high-resolution measurements of the Coster-Kronig lines. The importance of electron correlation effects in couplings of potential energy curves leading to the 1s/sup 2/2pn/ell/ configurations is verified by means of Landau-Zener model calculations. 32 refs., 4 figs.

  11. Multiple capture investigated by coincident electron spectroscopy in X{sup 7+}+Ar, at 70 keV

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A. [Universite Paul Sabatier, Toulouse (France). Lab. Collisions-Agregats-Reactivite

    1999-11-01

    The multiple electron capture in N{sup 7+} + Ar and F{sup 7+}(1s{sup 2}) + Ar systems is investigated at 70 keV with a new electron-recoil ion charge coincidence experiment. The whole electron energy range has been studied. Up to six electrons are found to be captured into autoionizing states. The recoil ion charge distribution associated with the emission of electrons is similar for both systems and found to be in good agreement with the prediction of Niehaus`s model roughly adapted to take into account autoionizing cascades. New findings for the coincident double and triple captures are briefly discussed. A capture of an inner L-shell electron of Ar into the K-shell of the projectile is also observed in N{sup 7+} + Ar collisions. (orig.) 10 refs.

  12. Double-electron capture in relativistic U{sup 92+} collisions at the ESR gas-jet target

    Energy Technology Data Exchange (ETDEWEB)

    Bednarz, G. E-mail: d.sierpowski@gsi.deufsierpo@if.uj.edu.pl; Sierpowski, D.; Stoehlker, Th.; Warczak, A.; Beyer, H.; Bosch, F.; Braeuning-Demian, A.; Braeuning, H.; Cai, X.; Gumberidze, A.; Hagmann, S.; Kozhuharov, C.; Liesen, D.; Ma, X.; Mokler, P.H.; Muthig, A.; Stachura, Z.; Toleikis, S

    2003-05-01

    Total cross-sections for radiative single- and double-electron capture are measured in collisions of fast highly charged ions with light target atoms. Cross-sections for non-correlated double capture are in accordance with theoretical predictions. No significant line structure at twice the single K-radiative electron capture (K-REC) photon energy was observed. Angular distributions single K-REC photons associated with single- and double-charge exchange exhibit the same pattern. The corresponding REC lines are almost by a factor of two broader for double-charge exchange than in the single capture case.

  13. Identification and measurement of chlorinated organic pesticides in water by electron-capture gas chromatography

    Science.gov (United States)

    Lamar, William L.; Goerlitz, Donald F.; Law, LeRoy M.

    1965-01-01

    Pesticides, in minute quantities, may affect the regimen of streams, and because they may concentrate in sediments, aquatic organisms, and edible aquatic foods, their detection and their measurement in the parts-per-trillion range are considered essential. In 1964 the U.S. Geological Survey at Menlo Park, Calif., began research on methods for monitoring pesticides in water. Two systems were selected--electron-capture gas chromatography and microcoulometric-titration gas chromatography. Studies on these systems are now in progress. This report provides current information on the development and application of an electron-capture gas chromatographic procedure. This method is a convenient and extremely sensitive procedure for the detection and measurement of organic pesticides having high electron affinities, notably the chlorinated organic pesticides. The electron-affinity detector is extremely sensitive to these substances but it is not as sensitive to many other compounds. By this method, the chlorinated organic pesticide may be determined on a sample of convenient size in concentrations as low as the parts-per-trillion range. To insure greater accuracy in the identifications, the pesticides reported were separated and identified by their retention times on two different types of gas chromatographic columns.

  14. Multiple electron capture from isolated protein poly-anions in collision with slow highly charged ions.

    Science.gov (United States)

    Milosavljević, A R; Rousseau, P; Domaracka, A; Huber, B A; Giuliani, A

    2017-08-02

    Collisions of 375 keV Xe(25+) ions with trapped mass/charge selected poly-anions of the cytochrome C protein (∼12.5 kDa) were studied by coupling a linear quadrupole ion trap with low-energy ion beam facility. Tandem mass spectra were recorded for the protein precursor charge states ranging from -9 to -17. The present work reports the first study of slow highly charged ion collisions with poly-anions. A high signal to noise ratio allowed the study of the intensity of single and multiple electron removal by a projectile, as well as associated neutral losses, as a function of the target charge state. Relative single and double electron detachment cross sections were found to increase with increasing charge state of the precursor anion. The experimental findings are supported by the calculations of the total electron capture cross sections, based on the classical over-the-barrier model, restricted to a simple uniformly charged linear protein structure and a near-end electron capture.

  15. Electron Beam Analysis of Micrometeoroids Captured in Aerogel as Stardust Analogues

    Science.gov (United States)

    Graham, G. A.; Sheffield-Parker, J.; Bradley, P.; Kearsley, A. T.; Dai, Z. R.; Mayo, S. C.; Teslich, N.; Snead, C.; Westphal, A. J.; Ishii, H.

    2005-01-01

    In January 2004, NASA s Stardust spacecraft passed through the tail of Comet 81P/Wild-2. The on-board dust flux monitor instrument indicated that numerous micro- and nano-meter sized cometary dust particles were captured by the dedicated silica aerogel capture cell. The collected cometary particles will be returned to Earth in January 2006. Current Stardust analogues are: (i) Light-gas-gun accelerated individual mineral grains and carbonaceous meteoritic material in aerogels at the Stardust encounter velocity ca.approximately 6 kilometers per second. (ii) Aerogels exposed in low-Earth orbit (LEO) containing preserved cosmic dust grains. Studies of these impacts offer insight into the potential state of the captured cometary dust by Stardust and the suitability of various analytical techniques. A number of papers have discussed the application of sophisticated synchrotron analytical techniques to analyze Stardust particles. Yet much of the understanding gained on the composition and mineralogy of interplanetary dust particles (IDPs) has come from electron microscopy studies. Here we discuss the application of scanning electron microscopy (SEM) for Stardust during the preliminary phase of post-return investigations.

  16. Search for two-neutrino double electron capture on $^{124}$Xe with the XMASS-I detector

    CERN Document Server

    Abe, K; Ichimura, K; Kishimoto, Y; Kobayashi, K; Kobayashi, M; Moriyama, S; Nakagawa, K; Nakahata, M; Norita, T; Ogawa, H; Sekiya, H; Takachio, O; Takeda, A; Yamashita, M; Yang, B S; Kim, N Y; Kim, Y D; Tasaka, S; Liu, J; Martens, K; Suzuki, Y; Fujita, R; Hosokawa, K; Miuchi, K; Ohnishi, Y; Oka, N; Takeuchi, Y; Kim, Y H; Lee, J S; Lee, K B; Lee, M K; Fukuda, Y; Itow, Y; Kegasa, R; Masuda, K; Takiya, H; Uchida, H; Nishijima, K; Fujii, K; Murayama, I; Nakamura, S

    2015-01-01

    Double electron capture is a rare nuclear decay process in which two orbital electrons are captured simultaneously in the same nucleus. Measurement of its two-neutrino mode would provide a new reference for the calculation of nuclear matrix elements whereas observation of its neutrinoless mode would demonstrate lepton number violation. A search for two-neutrino double electron capture on $^{124}$Xe is performed using 165.9 days of data collected with the XMASS-I detector. No significant excess above background was observed and we set a lower limit on the half-life as $4.7 \\times 10^{21}$ years at 90% confidence level.

  17. Fine-grid calculations for stellar electron and positron capture rates on Fe isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Nabi, Jameel-Un, E-mail: jameel@giki.edu.pk [Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Faculty of Engineering Sciences (Pakistan); Tawfik, Abdel Nasser, E-mail: a.tawfik@eng.mti.edu.eg [MTI University, Egyptian Center for Theoretical Physics (ECTP) (Egypt)

    2013-03-15

    The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio (Y{sub e}) of the corematerial. It is suggested that the temporal variation of Y{sub e} within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly {sup 54-56}Fe, are considered to be key players in controlling Y{sub e} ratio via electron capture on these nuclides. Recently an improved microscopic calculation of weak-interaction-mediated rates for iron isotopes was introduced using the proton-neutron quasiparticle random-phase-approximation (pn-QRPA) theory. The pn-QRPA theory allows a microscopic state-by-state calculation of stellar capture rates which greatly increases the reliability of calculated rates. The results were suggestive of some fine-tuning of the Y{sub e} ratio during various phases of stellar evolution. Here we present for the first time the fine-grid calculation of the electron and positron capture rates on {sup 54-56}Fe. The sensitivity of the pn-QRPA calculated capture rates to the deformation parameter is also studied in this work. Core-collapse simulators may find this calculation suitable for interpolation purposes and for necessary incorporation in the stellar evolution codes.

  18. Electronic data capture and DICOM data management in multi-center clinical trials

    Science.gov (United States)

    Haak, Daniel; Page, Charles-E.; Deserno, Thomas M.

    2016-03-01

    Providing eligibility, efficacy and security evaluation by quantitative and qualitative disease findings, medical imaging has become increasingly important in clinical trials. Here, subject's data is today captured in electronic case reports forms (eCRFs), which are offered by electronic data capture (EDC) systems. However, integration of subject's medical image data into eCRFs is insufficiently supported. Neither integration of subject's digital imaging and communications in medicine (DICOM) data, nor communication with picture archiving and communication systems (PACS), is possible. This aggravates the workflow of the study personnel, in special regarding studies with distributed data capture in multiple sites. Hence, in this work, a system architecture is presented, which connects an EDC system, a PACS and a DICOM viewer via the web access to DICOM objects (WADO) protocol. The architecture is implemented using the open source tools OpenClinica, DCM4CHEE and Weasis. The eCRF forms the primary endpoint for the study personnel, where subject's image data is stored and retrieved. Background communication with the PACS is completely hidden for the users. Data privacy and consistency is ensured by automatic de-identification and re-labelling of DICOM data with context information (e.g. study and subject identifiers), respectively. The system is exemplarily demonstrated in a clinical trial, where computer tomography (CT) data is de-centrally captured from the subjects and centrally read by a chief radiologists to decide on inclusion of the subjects in the trial. Errors, latency and costs in the EDC workflow are reduced, while, a research database is implicitly built up in the background.

  19. Improving the Electronic Capture of Advance Care Directives in a Healthcare Delivery System.

    Science.gov (United States)

    Kamo, Norifumi; Williams, Barbara L; Smith, Donna L; Blackmore, C Craig

    2017-05-01

    To determine the effectiveness of a multifaceted quality improvement intervention in outpatient clinics at an integrated healthcare delivery system on capture rate of advance directives (ADs) in the electronic medical record (EMR). Interrupted time series analysis with control groups between January 2010 and June 2015. Oncology, nephrology, and primary care outpatient clinics in an integrated healthcare delivery system. All individuals aged 65 and older with at least one office visit in any outpatient clinic in the care delivery system (n = 77,350 with 502,446 office visits). A series of quality improvement interventions to improve rates of advance care planning discussions and capture of those discussions in the EMR between 2010 and 2014. Capture rate of ADs in the EMR. Visits in the intervention primary care clinic were twice as likely to mention ADs in the EMR (53.4%) than visits in nonintervention primary care clinics (26.5%). Visits in the intervention oncology clinic were more than eight times as likely to mention ADs in the EMR (49.3% vs 6.0%), and visits in the intervention nephrology clinic were 2.5 times as likely to mention ADs (15.4% vs 6.0%) than visits in other specialty clinics. A series of quality improvement interventions to increase discussions about advance care planning and capture of advance care directives in the EMR significantly increased the rate of capture in primary care and specialty care outpatient settings. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  20. Electron Capture in Collisions of Slow Highly Charged Ions with an Atom and a Molecule: Processes and Fragmentation Dynamics

    Directory of Open Access Journals (Sweden)

    Xavier Husson

    2002-03-01

    Full Text Available Abstract : Processes involved in slow collisions between highly charged ions (HCI and neutral targets are presented. First, the mechanisms responsible for double electron capture are discussed. We show that, while the electron-nucleus interaction is expected to be dominant at projectile velocities of about 0.5 a.u., the electron-electron interaction plays a decisive role during the collision and gains importance when the projectile velocity decreases. This interaction has also to be invoked in the capture of core electrons by HCI. Finally, the molecular fragmentation of H2 following the impact of HCI is studied.

  1. Polarized [sup 3]He ion source based on polarized electron capture

    Energy Technology Data Exchange (ETDEWEB)

    Ohshima, Takashi (Osaka Univ., Toyonaka (Japan). Faculty of Science)

    1993-11-01

    The [sup 3]He[sup +] ions which are formed by [sup 3]He[sup 2+] ions capturing the polarized electrons of the sodium atoms polarized by optical pumping become nuclear polarized beam, as electron polarization shifts to nuclei by ultrafine interaction. When the current of [sup 3]He[sup 2+] ions was 2 e[mu]A, and the degree of polarization of sodium atoms was 0.30[+-]0.05, the [sup 3]He[sup +] beam of nuclear polarization degree 0.0415[+-]0.0061 and beam current 40 nA was obtained. By carrying out the improvement such as the increase of the degree of polarization of sodium or the current of [sup 3]He[sup 2+], it can be expected to form the polarized beam of current more than 10 [mu]A and degree of polarization close to 30%. The polarization experiment carried out so far was mostly on protons and deuterons, and as for [sup 3]He, there was only one polarization experiment. In Research Center for Nuclear Physics, Osaka University, the [sup 3]He beam up to 530 MeV can be obtained by using the ring cyclotron, therefore, it was decided to develop the polarized [sup 3]He ion source using polarized electron capture. The principle of polarization formation, the experimental equipment consisting of ECR ion source, polarized Na target and [sup 3]He nuclear polarization measuring part, and the experimental results are reported. (K.I.).

  2. Neutrino energy loss by electron capture in magnetic field at the crusts of neutron stars

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Jing; LUO Zhi-Quan

    2008-01-01

    Based on the p-f shell model,the effect of strong magnetic field on neutrino energy loss rates by electron capture is investigated.The calculations show that the magnetic field has only a slight effect on the neutrino energy loss rates in the range of 108-1013 G on the surfaces of most neutron stars.But for some magnetars,the range of the magnetic field is 1013-1018 G,and the neutrino energy loss rates are greatly reduced,even by more than four orders of magnitude due to the strong magnetic field.

  3. Single electron capture measurements in collisions of K{sup +} on N{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Alarcón, F.B. [Laboratorio de Espectroscopia, Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62210 Cuernavaca, Morelos (Mexico); Fuentes, B.E., E-mail: beatriz.fuentes@ciencias.unam.mx [Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior, Cd. Universitaria, 04510 México D.F. (Mexico); Martínez, H. [Laboratorio de Espectroscopia, Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Apartado Postal 48-3, 62210 Cuernavaca, Morelos (Mexico); Yousif, F.B. [Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad #1000, Col. Chamilpa, C.P. 62210, Cuernavaca, Morelos (Mexico)

    2014-08-01

    Absolute total charge transfer cross sections have been measured for K{sup +}–N{sub 2} collisions, at impact energies between 1.0 and 3.5 keV. The charge transfer cross sections show a monotonic increasing behaviour as a function of the incident energy. Agreement with other groups is observed as the present measurements extend to lower energies. A semi-empirical calculation shows a similar behaviour to the present data with respect to the electron capture cross sections as a function of energy.

  4. Determination of fluoxetine and norfluoxetine in plasma by gas chromatography with electron-capture detection

    Energy Technology Data Exchange (ETDEWEB)

    Nash, J.F.; Bopp, R.J.; Carmichael, R.H.; Farid, K.Z.; Lemberger, L.

    1982-10-01

    This gas-chromatographic method for assay of fluoxetine and norfluoxetine in human plasma involves extraction of the drugs and use of a /sup 63/Ni electron-capture detector. The linear range of detection is 25 to 800 micrograms/L for each drug. Overall precision (CV) in the concentration range of 10 to 100 micrograms/L for both drugs was approximately 10%. Accuracy (relative error) in the same concentration range was approximately +10%. None of the commonly prescribed antidepressants or tranquilizers that we tested interfere with the assay.

  5. Determination of desmethyldiazepam in plasma by electron-capture GLC: application to pharmacokinetic studies of clorazepate.

    Science.gov (United States)

    Greenblatt, D J

    1978-03-01

    Plasma desmethyldiazepam concentrations were quantitated by a rapid and sensitive technique using electron-capture GLC. Following addition of diazepam as the internal standard, plasma is extracted at physiological pH into benzene-isoamyl alcohol. The extract is evaporated to dryness and reconstituted with toluene-isoamyl alcohol prior to chromatography. Both diazepam and desmethyldiazepam are quantitatively extracted. The variation of identical samples is 5%, and the sensitivity is 5 ng of desmethyldiazepam/ml of original sample. The method is applicable to pharmacokinetic studies of clorazepate, a benzodiazepine derivative transformed to desmethyldiazepam prior to absorption.

  6. Electron Capture and Beta-Decay Rates for the Collapse of O+Ne+Mg Cores

    Directory of Open Access Journals (Sweden)

    Hua Lam Yi

    2014-03-01

    Full Text Available We present a new set of electron (e− capture and β-decay rates that improves previous calculations by Takahara et al. and Oda et al. by: (a incorporation of recent charge-exchange and β-decay data, (b contributions of forbidden transitions, and (c inclusion of e− screening corrections. The experimental nuclear input is supplemented by theoretical data based on large-scale shell model calculations in the full sd-shell space using the USDB interaction. The impact of these new rates on the late-stage stellar evolution of 8.8M⊙ star is demonstrated.

  7. Search for two-neutrino double electron capture on 124Xe with the XMASS-I detector

    Directory of Open Access Journals (Sweden)

    K. Abe

    2016-08-01

    Full Text Available Double electron capture is a rare nuclear decay process in which two orbital electrons are captured simultaneously in the same nucleus. Measurement of its two-neutrino mode would provide a new reference for the calculation of nuclear matrix elements whereas observation of its neutrinoless mode would demonstrate lepton number violation. A search for two-neutrino double electron capture on 124Xe is performed using 165.9 days of data collected with the XMASS-I liquid xenon detector. No significant excess above background was observed and we set a lower limit on the half-life as 4.7×1021 years at 90% confidence level. The obtained limit has ruled out parts of some theoretical expectations. We obtain a lower limit on the 126Xe two-neutrino double electron capture half-life of 4.3×1021 years at 90% confidence level as well.

  8. Search for two-neutrino double electron capture on 124Xe with the XMASS-I detector

    Science.gov (United States)

    Abe, K.; Hiraide, K.; Ichimura, K.; Kishimoto, Y.; Kobayashi, K.; Kobayashi, M.; Moriyama, S.; Nakagawa, K.; Nakahata, M.; Norita, T.; Ogawa, H.; Sekiya, H.; Takachio, O.; Takeda, A.; Yamashita, M.; Yang, B. S.; Kim, N. Y.; Kim, Y. D.; Tasaka, S.; Liu, J.; Martens, K.; Suzuki, Y.; Fujita, R.; Hosokawa, K.; Miuchi, K.; Oka, N.; Onishi, Y.; Takeuchi, Y.; Kim, Y. H.; Lee, J. S.; Lee, K. B.; Lee, M. K.; Fukuda, Y.; Itow, Y.; Kegasa, R.; Kobayashi, K.; Masuda, K.; Takiya, H.; Uchida, H.; Nishijima, K.; Fujii, K.; Murayama, I.; Nakamura, S.

    2016-08-01

    Double electron capture is a rare nuclear decay process in which two orbital electrons are captured simultaneously in the same nucleus. Measurement of its two-neutrino mode would provide a new reference for the calculation of nuclear matrix elements whereas observation of its neutrinoless mode would demonstrate lepton number violation. A search for two-neutrino double electron capture on 124Xe is performed using 165.9 days of data collected with the XMASS-I liquid xenon detector. No significant excess above background was observed and we set a lower limit on the half-life as 4.7 ×1021 years at 90% confidence level. The obtained limit has ruled out parts of some theoretical expectations. We obtain a lower limit on the 126Xe two-neutrino double electron capture half-life of 4.3 ×1021 years at 90% confidence level as well.

  9. Stellar electron capture rates on neutron-rich nuclei and their impact on core-collapse

    CERN Document Server

    Raduta, Ad R; Oertel, M

    2016-01-01

    During the late stages of gravitational core-collapse of massive stars, extreme isospin asymmetries are reached within the core. Due to the lack of microscopic calculations of electron capture (EC) rates for all relevant nuclei, in general simple analytic parameterizations are employed. We study here several extensions of these parameterizations, allowing for a temperature, electron density and isospin dependence as well as for odd-even effects. The latter extra degrees of freedom considerably improve the agreement with large scale microscopic rate calculations. We find, in particular, that the isospin dependence leads to a significant reduction of the global EC rates during core collapse with respect to fiducial results, where rates optimized on calculations of stable $fp$-shell nuclei are used. Our results indicate that systematic microscopic calculations and experimental measurements in the $N\\approx 50$ neutron rich region are desirable for realistic simulations of the core-collapse.

  10. Electron correlations in single-electron capture into any state of fast projectiles from heliumlike atomic systems

    Science.gov (United States)

    Mančev, Ivan; Milojević, Nenad; Belkić, Dževad

    2013-11-01

    State-selective and total single-electron capture cross sections in fast collisions of a bare projectile with a heliumlike target are examined in the four-body formalism. A special emphasis is given to a proper inclusion of dynamic electron-electron correlation effects. For this purpose, the post form of the four-body boundary-corrected first Born approximation (CB1-4B) is utilized. With regard to our related previous study, where the prior version has been considered, in the present work an extensive analytical study of the post-transition amplitude for electron capture into the arbitrary final states nflfmf of the projectile is carried out. The post-transition amplitude for single charge exchange encompassing symmetric and asymmetric collisions is derived in terms of five-dimensional integrals over real variables. The dielectronic interaction V12=1/r12≡1/|r⃗1-r⃗2| explicitly appears in the perturbation potential Vf of the post-transition probability amplitude Tif+, such that the CB1-4B method can provide information about the relative significance of the dynamic interelectron correlation in the collisions under study. An illustrative computation is performed involving state-selective and total single capture cross sections for the p-He collisions at intermediate and high impact energies. The so-called post-prior discrepancy, which plagues almost all the existing distorted wave approximations, is presently shown to be practically nonexistent in the CB1-4B method. The validity of our findings is critically assessed in comparisons with the available experimental data for both state-selective and total cross sections summed over all the discrete energy levels of the hydrogenlike atom formed with the projectile. Overall, excellent performance of the CB1-4B method is recorded, thus robustly establishing this formalism as the leading first-order description of high-energy single charge exchange, which is a collision of paramount theoretical and practical

  11. Atmospheric measurements of carbonyl sulfide, dimethyl sulfide, and carbon disulfide using the electron capture sulfur detector

    Science.gov (United States)

    Johnson, James E.; Bates, Timothy S.

    1993-01-01

    Measurements of atmospheric dimethyl sulfide (DMS), carbonyl sulfide (COS), and carbon disulfide (CS2) were conducted over the Atlantic Ocean on board the NASA Electra aircraft during the Chemical Instrumentation Test and Evaluation (CITE 3) project using the electron capture sulfur detector (ECD-S). The system employed cryogenic preconcentration of air samples, gas chromatographic separation, catalytic fluorination, and electron capture detection. Samples collected for DMS analysis were scrubbed of oxidants with NaOH impregnated glass fiber filters to preconcentration. The detection limits (DL) of the system for COS, DMS, and CS2 were 5, 5, and 2 ppt, respectively. COS concentrations ranged from 404 to 603 ppt with a mean of 489 ppt for measurements over the North Atlantic Ocean (31 deg N to 41 deg N), and from 395 to 437 ppt with a mean of 419 ppt for measurements over the Tropical Atlantic Ocean (11 deg S to 2 deg N). DMS concentrations in the lower marine boundary layer, below 600-m altitude, ranged from below DL to 150 ppt from flights over the North Atlantic, and from 9 to 104 ppt over the Tropical Atlantic. CS2 concentrations ranged from below DL to 29 ppt over the North Atlantic. Almost all CS2 measurements over the Tropical Atlantic were below DL.

  12. Identification and systematical studies of the electron-capture delayed fission (ECDF) in the lead region

    CERN Multimedia

    Pauwels, D B; Lane, J

    2008-01-01

    In our recent experiment (March 2007) at the velocity filter SHIP(GSI) we observed the electron-capture delayed fission of the odd-odd isotope $^{194}$At. This is the first unambiguous identification of this phenomenon in the very neutron-deficient nuclei in the vicinity of the proton shell closure at Z=82. In addition, the total kinetic energy (TKE) for the daughter nuclide $^{194}$Po was measured, despite the fact that this isotope does not decay via spontaneous fission. Semi-empirical analysis of the electron-capture Q$_{EC}$ values and fission barriers B$_{f}$ shows that a relatively broad island of ECDF must exist in this region of the Nuclide Chart, with some of the nuclei having unusually high ECDF probabilities. Therefore, this Proposal is intended to initiate the systematic identification and study of $\\beta$-delayed fission at ISOLDE in the very neutron-deficient lead region. Our aim is to provide unique low-energy fission data (e.g. probabilities, TKE release, fission barriers and their isospin dep...

  13. Search for Oscillation of the Electron-Capture Decay Probability of Pm-142

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, Paul A; Vetter, Paul; Clark, Roderick; Dvorak, Jan; Freedman, Stuart; Gregorich, Kenneth; Jeppesen, Henrik; Mittelberger, Daniel; Wiedeking, Mathis

    2008-07-03

    We have searched for time modulation of the electron capture decay probability of 142Pm in an attempt to confirm a recent claim from a group at the Gesellschaft fur Schwerionenforschung (GSI). We produced 142Pm via the 124Sn(23Na, 5n)142Pm reaction at the Berkeley 88-Inch Cyclotron with a bombardment time short compared to the reported modulation period. Isotope selection by the Berkeley Gas-filled Separator is followed by implantation and a long period of monitoring the 142Nd K alpha x-rays from the daughter. The decay time spectrum of the x-rays is well-described by a simple exponential and the measured half-life of 40.68(53) seconds is consistent with the accepted value. We observed no oscillatory modulation at the proposed frequency at a level 31 times smaller than that reported by Litvinov (Phys. Lett. B 664 (2008) 162). A literature search for previous experiments that might have been sensitive to the reported modulation uncovered another example in 142Eu electron-capture decay. A reanalysis of the published data shows no oscillatory behavior.

  14. Electron Capture from Linear Stark Rydberg States above the Matching Velocity

    Science.gov (United States)

    Ciocca, M.; Creasey, C.; MacAdam, K. B.

    1998-05-01

    The relative cross section for electron capture by singly charged ions from linear Stark Rydberg states of Na has been measured, both as a function of the angle of impact and of projectile velocity. The target, the topmost state of the n = 24 Stark manifold, was prepared by two-step laser excitation from the Na ground state, via 3p_3/2, in an electric field F_Stark= 160 V/cm. By means of a device perfected in our laboratory (the "Stark Barrel"), we aligned the target by adiabatically switching the electric field, after excitation, down to a preset low value and a desired direction in the plane determined by the ion and Na beams. Thermionic emission ion sources of Li and Na were operated at accelerating voltages 400-2000 V to allow study of electron capture in the reduced velocity range v = 1.0 - 2.5. This augments an earlier study by Homan footnote D. M. Homan, Ph. D. Dissertation, University of Kentucky 1997, unpublished. at lower velocities.

  15. Multiple electron capture from thin C-foils into 46 MeV/u U{sup 91+}

    Energy Technology Data Exchange (ETDEWEB)

    Braeuning, H. E-mail: harald.braeuning@strz.uni-giessen.de; Braeuning-Demian, A.; Bednarz, G.; Bosch, F.; Cai, X.; Cohen, C.; Dauvergne, D.; Gumberidze, A.; Kirsch, R.; Kozhuharov, C.; Liesen, D.; Mokler, P.H.; Rozet, J.-P.; Stachura, Z.; Stoehlker, Th.; Terasawa, M.; Toleikis, S.; Warczak, A

    2003-05-01

    Absolute yields for multiple electron capture as well as projectile ionization have been measured for 46 MeV/u U{sup 91+} ions traversing thin carbon foils with different surface topologies. Multiple electron capture yields vary strongly, depending on the target manufacturer. The samples including the one with the smoothest surface show a deviation of the yield from the expected scaling based on subsequent single capture for decreasing target thickness. This indicates a strong contribution of the surface, whose nature cannot be identified by the current data.

  16. Neutrino energy loss by electron capture on strongly screened iron group nuclei

    Institute of Scientific and Technical Information of China (English)

    Liu Jing-Jing; Luo Zhi-Quan

    2007-01-01

    The influences on the neutrino energy loss rates in iron group nuclei at the same density are investigated in the presence of strong electron screening and in the absence of electron screening. The results show that at a temperature of 15 × 109 K, the neutrino energy loss rates which come from the electron capture processfor most iron group nuclei decrease no more than 2 orders of magnitude but for the others (such as 53,55,56,57,58,59,60Co, 56,59Ni) they can decrease about 3 orders of magnitude due to strong electron screening (SES), whereas, at a temperature of 109K the neutrino energy loss rates of the most iron group nuclei can be diminished greatly due to the SES. For example, 61Fe, 60Fe,and 62Ni the neutrino energy loss rates decrease about 4, 15 and 16 orders of magnitude and for 57Cr, 58Cr, and 60Cr decrease about 18, 12, and 10 orders of magnitude respectively. According to our calculations the neutrino energy loss rates of nuclei 58Mn, 59Mn, 60Mn, and 62Mn may decrease about 13 orders of magnitude at a temperature of 109 K due to the SES.

  17. COINCIDENCES BETWEEN ELECTRONS AND TARGET IONS TO IDENTIFY CAPTURE CHANNELS IN COLLISIONS OF MULTIPLY CHARGED IONS ON GAS TARGETS

    NARCIS (Netherlands)

    POSTHUMUS, JH; MORGENSTERN, R

    1992-01-01

    We have investigated multielectron capture processes in collisions of Ar9+ on Ar by measuring the resulting Auger electrons in coincidence with charge-state-analyzed target ions. In this way it was possible to reconstruct partial electron energy spectra, each corresponding to a particular number of

  18. Capturing buried defects in metal interconnections with electron beam inspection system

    Science.gov (United States)

    Xiao, Hong; Jiang, Ximan; Trease, David; Van Riet, Mike; Ramprasad, Shishir; Bhatia, Anadi; Lefebvre, Pierre; Bastard, David; Moreau, Olivier; Maher, Chris; MacDonald, Paul; Campochiaro, Cecelia

    2013-04-01

    In this paper we present a novel mode of electron beam inspection (EBI), entitled super wide optics (SWO) mode, which can effectively detect buried defects in tungsten (W) plugs and copper (Cu) wires. These defects are defects of interest (DOI) to integrated circuit (IC) manufacturers because they are not detectable in optical inspection, voltage contrast (VC) mode EBI or physical mode EBI. We used engineering systems to study two samples, a tungsten chemical mechanical polish (CMP) wafer and a copper CMP wafer with a silicon carbon nitride (SiCN) cap layer. EBI with our novel SWO mode was found to capture many dark defects on these two wafers. Furthermore, defect review with all three EBI modes found some of these dark defects were unique to SWO mode. For verification, physical failure analysis was performed on some SWO-unique DOI. The cross-sectional scanning electron microscope (SEM) images and transmission electron microscope (TEM) images confirmed that the unique DOI were buried voids in W-plugs and copper wire thinning caused by either buried particles or buried particle induced metal trench under-etch. These DOI can significantly increase the resistance of metal interconnects of IC chip and affect the chip yield. This new EBI mode can provide an in-line monitoring solution for these DOI, which does not exist before this study.

  19. Effect of piezoelectric field of threading dislocations on electron transport and capture in nitride semiconductors

    Science.gov (United States)

    Romanov, Dmitri; Auner, Gregory

    2001-03-01

    In nitride semiconductor structures, stress is known to induce considerable electric fields due to piezoelectric effect. We consider an AlN layer grown on a sapphire substrate and containing a number of threading dislocations. Most them are edge dislocations running in the growth direction. The strain field of such a dislocation results in electric field aligned with the dislocation axis and having alternate directions in the areas of compression and tension. These electric fields make for anisotropic electron diffusion in the layer. They also change the rates of electron capture by impurities, depending on the distance to the dislocation core. We apply these results to photoexcited electrons in a GaN/AlN quantum dot system where the dot nucleation occurred preferably in the tension regions near the dislocations [1]. The biased diffusion leads to photoinduced polarization of the dot-containing layer even in the absence of external electric field. [1] J.L. Rouviere, J. Simon, N. Pelekanos, B. Daudin, and G. Feuillet, Appl. Phys. Lett., 75, 2632-2634 (1999)

  20. Capturing relativistic wakefield structures in plasmas using ultrashort high-energy electrons as a probe.

    Science.gov (United States)

    Zhang, C J; Hua, J F; Xu, X L; Li, F; Pai, C-H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W

    2016-07-11

    A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.

  1. Capturing relativistic wakefield structures in plasmas using ultrashort high-energy electrons as a probe

    Science.gov (United States)

    Zhang, C. J.; Hua, J. F.; Xu, X. L.; Li, F.; Pai, C.-H.; Wan, Y.; Wu, Y. P.; Gu, Y. Q.; Mori, W. B.; Joshi, C.; Lu, W.

    2016-07-01

    A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.

  2. Gamow-Teller strength distributions at finite temperatures and electron capture in stellar environments

    CERN Document Server

    Dzhioev, Alan A; Ponomarev, V Yu; Wambach, J; Langanke, K; Martínez-Pinedo, G

    2009-01-01

    We propose a new method to calculate stellar weak-interaction rates. It is based on the Thermo-Field-Dynamics formalism and allows the calculation of the weak-interaction response of nuclei at finite temperatures. The thermal evolution of the GT$_+$ distributions is presented for the sample nuclei $^{54, 56}$Fe and ~$^{76,78,80}$Ge. For Ge we also calculate the strength distribution of first-forbidden transitions. We show that thermal effects shift the GT$_+$ centroid to lower excitation energies and make possible negative- and low-energy transitions. In our model we demonstrate that the unblocking effect for GT$_+$ transitions in neutron-rich nuclei is sensitive to increasing temperature. The results are used to calculate electron capture rates and are compared to those obtained from the shell model.

  3. Double lepton pair production with electron capture in relativistic heavy--ion collisions

    CERN Document Server

    Artemyev, A N; Surzhykov, A

    2014-01-01

    We present a theoretical study of a double lepton pair production in ultra--relativistic collision between two bare ions. Special emphasis is placed to processes in which creation of (at least one) $e^+ e^-$ pair is accompanied by the capture of an electron into a bound ionic state. To evaluate the probability and cross section of these processes we employ two approaches based on (i) the first--order perturbation theory and multipole expansion of Dirac wavefunctions, and (ii) the equivalent photon approximation. With the help of such approaches, detailed calculations are made for the creation of two bound--free $e^+ e^-$ pairs as well as of bound--free $e^+ e^-$ and free--free $\\mu^+ \\mu^-$ pairs in collisions of bare lead ions Pb$^{82+}$. The results of the calculations indicate that observation of the double lepton processes may become feasible at the LHC facility.

  4. Monitoring compliance with transfusion guidelines in hospital departments by electronic data capture

    DEFF Research Database (Denmark)

    Norgaard, Astrid; De Lichtenberg, Trine Honnens; Nielsen, Jens

    2014-01-01

    -transfusion haemoglobin levels at the departmental level. In a tertiary care hospital, no such data were produced before this study. Our aim was to establish a Patient Blood Management database based on electronic data capture in order to monitor compliance with transfusion guidelines at departmental and hospital levels......BACKGROUND: The practice of transfusing red blood cells is still liberal in some centres suggesting a lack of compliance with guidelines recommending transfusion of red blood cells at haemoglobin levels of 6-8 g/dL in the non-bleeding patient. Few databases provide ongoing feedback of data on pre....... MATERIALS AND METHODS: Hospital data on admissions, diagnoses and surgical procedures were used to define the populations of patients. Data on haemoglobin measurements and red blood cell transfusions were used to calculate pre-transfusion haemoglobin, percentage of transfused patients and transfusion...

  5. Resonant antineutrino induced electron capture with low energy bound-beta beams

    CERN Document Server

    Oldeman, R G C; Saitta, B

    2009-01-01

    Antineutrino induced electron capture is a resonant process that can have a larg e cross-section for beams of monochromatic antineutrinos. We calculate the cross-section of this process and investigate an experimental setup where monochromatic antineutrinos are produced from the bound-beta decay of fully ionized radioactive atoms in a storage ring. If the energy between the source and the target is well matched, the cross-sections can be significantly larger than the cross-sections of commonly used non-resonant processes. The rate that can be achieved at a small distance between the source and two targets of $10^3$ kg is up to one interaction per $8 .3\\cdot10^{18}$ decaying atoms. For a source-target distance corresponding to the first atmospheric neutrino osc illation maximum, the largest rate is one interaction per $3.2\\cdot10^{21}$ decaying atoms.

  6. Oscillating decay rate in electron capture and the neutrino mass difference

    Energy Technology Data Exchange (ETDEWEB)

    Peshkin, Murray

    2015-04-09

    Reported oscillations in the rate of decay of certain ions by K -electron capture have raised questions about whether and how such oscillations can arise in quantum-mechanical theory and whether they can measure the neutrino mass difference. Here I show that simple principles of quantum mechanics answer some questions and clarify what must be performed theoretically or experimentally to answer some others. The principal result is that quantum mechanics does allow mass-difference-dependent oscillations in principle, but it imposes conditions not obeyed by the approximate dynamical models that have been put forth up to now. In particular, indirect coupling between two neutrino mass channels must be taken into account. What needs to be done experimentally and theoretically is discussed.

  7. Oscillating decay rate in electron capture and the neutrino mass difference

    Science.gov (United States)

    Peshkin, Murray

    2015-04-01

    Reported oscillations in the rate of decay of certain ions by K -electron capture have raised questions about whether and how such oscillations can arise in quantum-mechanical theory and whether they can measure the neutrino mass difference. Here I show that simple principles of quantum mechanics answer some questions and clarify what must be performed theoretically or experimentally to answer some others. The principal result is that quantum mechanics does allow mass-difference-dependent oscillations in principle, but it imposes conditions not obeyed by the approximate dynamical models that have been put forth up to now. In particular, indirect coupling between two neutrino mass channels must be taken into account. What needs to be done experimentally and theoretically is discussed.

  8. Electron capture rates in stars studied with heavy ion charge exchange reactions

    CERN Document Server

    Bertulani, C A

    2015-01-01

    Indirect methods using nucleus-nucleus reactions at high energies (here, high energies mean $\\sim$ 50 MeV/nucleon and higher) are now routinely used to extract information of interest for nuclear astrophysics. This is of extreme relevance as many of the nuclei involved in stellar evolution are short-lived. Therefore, indirect methods became the focus of recent studies carried out in major nuclear physics facilities. Among such methods, heavy ion charge exchange is thought to be a useful tool to infer Gamow-Teller matrix elements needed to describe electron capture rates in stars and also double beta-decay experiments. In this short review, I provide a theoretical guidance based on a simple reaction model for charge exchange reactions.

  9. The Knowledge Program: an innovative, comprehensive electronic data capture system and warehouse.

    Science.gov (United States)

    Katzan, Irene; Speck, Micheal; Dopler, Chris; Urchek, John; Bielawski, Kay; Dunphy, Cheryl; Jehi, Lara; Bae, Charles; Parchman, Alandra

    2011-01-01

    Data contained in the electronic health record (EHR) present a tremendous opportunity to improve quality-of-care and enhance research capabilities. However, the EHR is not structured to provide data for such purposes: most clinical information is entered as free text and content varies substantially between providers. Discrete information on patients' functional status is typically not collected. Data extraction tools are often unavailable. We have developed the Knowledge Program (KP), a comprehensive initiative to improve the collection of discrete clinical information into the EHR and the retrievability of data for use in research, quality, and patient care. A distinct feature of the KP is the systematic collection of patient-reported outcomes, which is captured discretely, allowing more refined analyses of care outcomes. The KP capitalizes on features of the Epic EHR and utilizes an external IT infrastructure distinct from Epic for enhanced functionality. Here, we describe the development and implementation of the KP.

  10. Electron-capture GLC determination of clobazam and desmethylclobazam in plasma.

    Science.gov (United States)

    Greenblatt, D J

    1980-11-01

    Electron-capture GLC was utilized for simultaneous quantitation of clobazam, a 1,5-benzodiazepine derivative, and its active metabolite, desmethylclobazam, in human plasma and serum. After addition of diazepam as the internal standard, samples were extracted into benzene--isopentanol. The organic extracts were evaporated to dryness, reconstituted, and subjected to chromatographic analysis without derivatization or cleanup. All three compounds were resolved completely and had favorable chromatographic properties using an OV-101 liquid phase. The limits of detection are 3--5 ng/ml for clobazam and 5--10 ng/ml for desmethylclobazam. Relative standard deviations for identical samples do not exceed 6%. The application of the method to a clinical pharmacokinetic study is demonstrated.

  11. New Limits on Double Electron Capture of 40Ca and 180W

    CERN Document Server

    Angloher, G; Bauer, P; Bavykina, I; Bento, A; Bucci, C; Canonica, L; Ciemniak, C; Defay, X; Deuter, G; Erb, A; Feilitzsch, F v; Iachellini, N Ferreiro; Gorla, P; Gütlein, A; Hauff, D; Huff, P; Isaila, C; Jochum, J; Kiefer, M; Kimmerle, M; Kluck, H; Kraus, H; Lanfranchi, J -C; Loebell, J; Münster, A; Pagliarone, C; Petricca, F; Pfister, S; Potzel, W; Pröbst, F; Reindl, F; Roth, S; Rottler, K; Sailer, C; Schäffner, K; Schieck, J; Schmaler, J; Scholl, S; Schönert, S; Seidel, W; Sivers, M v; Stodolsky, L; Strandhagen, C; Strauss, R; Tanzke, A; Tretyak, V; Thi, H H Trinh; Türkoğlu, C; Uffinger, M; Ulrich, A; Usherov, I; Wawoczny, S; Willers, M; Wüstrich, M; Zöller, A

    2016-01-01

    We analyzed low-background data from the CRESST-II experiment with a total net exposure of 730 kg days to extract limits on double electron capture processes. We established new limits for 40Ca with T1/2 2v2K >9.9x10^21 y and T1/2 0v2EC >1.4x10^22 y and for 180W with T1/2 2v2K >3.1x10^19 y and T1/2 0v2EC >9.4x10^18 y at 90% CL. These values improve the currently best limits by up to a factor of ~30.

  12. Do electron-capture supernovae make neutron stars? First multidimensional hydrodynamic simulations of the oxygen deflagration

    CERN Document Server

    Jones, Samuel; Pakmor, Ruediger; Seitenzahl, Ivo R; Ohlmann, Sebastian T; Edelmann, Philipp V F

    2016-01-01

    In the classical picture, electron-capture supernovae and the accretion-induced collapse of oxygen-neon white dwarfs undergo an oxygen deflagration phase before gravitational collapse produces a neutron star. Such core collapse events are postulated to explain several astronomical phenomena. In this work, the oxygen deflagration phase is simulated for the first time using multidimensional hydrodynamics. By simulating the oxygen deflagration with multidimensional hydrodynamics and a level-set based flame approach, new insights can be gained into the explosive deaths of 8--10 solar-mass stars and oxygen-neon white dwarfs accreting material from a binary companion star. The main aim is to determine whether these events are thermonuclear or core-collapse supernova explosions, and hence whether neutron stars are formed by such phenomena. The oxygen deflagration is simulated in oxygen-neon cores with three different central ignition densities. The intermediate density case is perhaps the most realistic based on rec...

  13. Q value and half-life of double-electron capture in Os-184

    CERN Document Server

    Smorra, C; Beyer, T; Blaum, K; Block, M; Düllmann, Ch E; Eberhardt, K; Eibach, M; Eliseev, S; Langanke, K; Martinez-Pinedo, G; Nagy, Sz; Nörtershäuser, W; Renisch, D; Shabaev, V M; Tupitsyn, I I; Zubova, N A

    2012-01-01

    Os-184 has been excluded as a promising candidate for the search of neutrinoless double-electron capture. High-precision mass measurements with the Penning-trap mass spectrometer TRIGA-TRAP resulted in a marginal resonant enhancement with = -8.89(58) keV excess energy to the 1322.152(22) keV 0+ excited state in W-184. State-of-the-art energy density functional calculations are applied for the evaluation of the nuclear matrix elements to the excited states predicting a strong suppression due to the large deformation of mother and daughter states. The half-life of the transition in Os-184 exceeds T_{1/2} > 1.3 10^{29} years for an effective neutrino mass of 1 eV.

  14. Electron capture decay of {sup 116}In and nuclear structure of double {beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, M.; Garcia, A.; Ortiz, C.E.; Kaloskamis, N.I. [University of Notre Dame, Notre Dame, Indiana 46556 (United States); Hindi, M.M. [Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Norman, E.B. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Davids, C.N. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Civitarese, O. [Department of Physics, University of La Plata, C. C. 67, 1900-La Plata (Argentina); Suhonen, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35, SF-40351, Jyvaeskylae (Finland)

    1998-08-01

    Quasiparticle-random-phase-approximation (QRPA) calculations of double {beta} decays have not been able to reproduce data in the A=100 system. We propose the A=116 system{emdash}because of its smaller deformation{emdash}as a simpler system to test QRPA calculations. We present results of two experiments we performed, which determine the electron-capture-decay branch of {sup 116}In to be (2.27{plus_minus}0.63){times}10{sup {minus}2}{percent}, from which we deduce logft=4.39{sub {minus}0.15}{sup +0.10}. We present QRPA calculations and compare their predictions to experimental data. Finally we use these calculations to predict the 2{nu} double-{beta}-decay rate of {sup 116}Cd to the ground and excited states of {sup 116}Sn. {copyright} {ital 1998} {ital The American Physical Society}

  15. A review of electron-capture and electron-transfer dissociation tandem mass spectrometry in polymer chemistry.

    Science.gov (United States)

    Hart-Smith, Gene

    2014-01-15

    Mass spectrometry (MS)-based studies of synthetic polymers often characterise detected polymer components using mass data alone. However when mass-based characterisations are ambiguous, tandem MS (MS/MS) offers a means by which additional analytical information may be collected. This review provides a synopsis of two particularly promising methods of dissociating polymer ions during MS/MS: electron-capture and electron-transfer dissociation (ECD and ETD, respectively). The article opens with a summary of the basic characteristics and operating principles of ECD and ETD, and relates these techniques to other methods of dissociating gas-phase ions, such as collision-induced dissociation (CID). Insights into ECD- and ETD-based MS/MS, gained from studies into proteins and peptides, are then discussed in relation to polymer chemistry. Finally, ECD- and ETD-based studies into various classes of polymer are summarised; for each polymer class, ECD- and ETD-derived data are compared to CID-derived data. These discussions identify ECD and ETD as powerful means by which unique and diagnostically useful polymer ion fragmentation data may be generated, and techniques worthy of increased utilisation by the polymer chemistry community.

  16. The Electron Capture Decay of 163-Ho to Measure the Electron Neutrino Mass with sub-eV Accuracy and Beyond

    CERN Document Server

    Gatti, Flavio; Lusignoli, Maurizio; Nucciotti, Angelo; Ragazzi, Stefano

    2012-01-01

    We have investigated the possibility of measuring the electron neutrino mass with sub-eV sensitivity by studying the electron capture decay of 163-Ho with cryogenic microcalorimeters. In this paper we will introduce an experiment's concept, discuss the technical requirements, and identify a roadmap to reach a sensitivity of 0.1 eV and beyond.

  17. Electron-capture supernovae as the origin of elements beyond iron

    CERN Document Server

    Wanajo, Shinya; Mueller, Bernhard

    2010-01-01

    We examine electron-capture supernovae (ECSNe) as sources of elements heavier than iron in the solar system and in Galactic halo stars. Nucleosynthesis calculations are performed on the basis of thermodynamic histories of mass elements from a fully self-consistent, two-dimensional (2D) hydrodynamic explosion model of an ECSN. We find that neutron-rich convective lumps with an electron fraction down to Ye,min=0.40, which are absent in the one-dimensional (1D) counterpart, allow for interesting production of elements between the iron group and N=50 nuclei (from Zn to Zr, with little Ga) in nuclear statistical equilibrium and by the alpha-process. Our models yield very good agreement with the Ge, Sr, Y, and Zr abundances of r-process deficient Galactic halo stars and constrain the occurrence of ECSNe to ~4% of all stellar core-collapse events. If tiny amounts of additional material with slightly lower Ye,min down to ~0.30-0.35 were also ejected - which presently cannot be excluded because of the limitations of r...

  18. Modification of magicity towards the dripline and its impact on electron-capture rates for stellar core-collapse

    CERN Document Server

    Raduta, Ad R; Oertel, M

    2015-01-01

    The importance of microphysical inputs from laboratory nuclear experiments and theoretical nuclear structure calculations in the understanding of the core collapse dynamics, and the subsequent supernova explosion, is largely recognized in the recent literature. In this work, we analyze the impact of the masses of very neutron rich nuclei on the matter composition during collapse, and the corresponding electron capture rate. To this aim, we introduce an empirical modification of the popular Duflo-Zuker mass model to account for possible shell quenching far from stability, and study the effect of the quenching on the average electron capture rate. We show that the preeminence of the $N=50$ and $N=82$ closed shells in the collapse dynamics is considerably decreased if the shell gaps are reduced in the region of $^{78}$Ni and beyond. As a consequence, local modifications of the overall electron capture rate up to 30\\% can be expected, with integrated values strongly dependent on the stiffness of magicity quenchin...

  19. A search for double-electron capture in 74Se using coincidence/anticoincidence gamma-ray spectrometry

    CERN Document Server

    Jeskovsky, M; Kovacik, A; Povinec, P P; Puppe, P; Stanicek, J; Sykora, I; Simkovic, F; Thies, J H

    2015-01-01

    Evaluation of single, coincidence and anticoincidence gamma-ray spectrometry methods has been carried out with the aim to search for double-electron capture in 74Se. This process is unique, because there is probability for transition to the 2+ excited state in 74Ge (1204 keV), and de-excitation through two gamma-quanta cascade with energies of 595.9 keV and 608.4 keV. Long-term measurements with anticosmic shielded HPGe spectrometer and the coincidence HPGe-NaI(Tl) spectrometer did not show any evidence for the double-electron capture in 74Se. The best limit for the half-life of the double electron capture in 74Se (both for the neutrinoless and two neutrino processes) was estimated to be >1.5x10E19 years.

  20. Electronic data capture in a rural African setting: evaluating experiences with different systems in Malawi.

    Science.gov (United States)

    King, Carina; Hall, Jenny; Banda, Masford; Beard, James; Bird, Jon; Kazembe, Peter; Fottrell, Ed

    2014-12-01

    Background As hardware for electronic data capture (EDC), such as smartphones or tablets, becomes cheaper and more widely available, the potential for using such hardware as data capture tools in routine healthcare and research is increasing. Objective We aim to highlight the advantages and disadvantages of four EDC systems being used simultaneously in rural Malawi: two for Android devices (CommCare and ODK Collect), one for PALM and Windows OS (Pendragon), and a custom-built application for Android (Mobile InterVA - MIVA). Design We report on the personal field and development experience of fieldworkers, project managers, and EDC system developers. Results Fieldworkers preferred using EDC to paper-based systems, although some struggled with the technology at first. Highlighted features include in-built skip patterns for all systems, and specifically the 'case' function that CommCare offers. MIVA as a standalone app required considerably more time and expertise than the other systems to create and could not be customised for our specific research needs; however, it facilitates standardised routine data collection. CommCare and ODK Collect both have user-friendly web-interfaces for form development and good technical support. CommCare requires Internet to build an application and download it to a device, whereas all steps can be done offline with ODK Collect, a desirable feature in low connectivity settings. Pendragon required more complex programming of logic, using a Microsoft Access application, and generally had less technical support. Start-up costs varied between systems, and all were considered more expensive than setting up a paper-based system; however running costs were generally low and therefore thought to be cost-effective over the course of our projects. Conclusions EDC offers many opportunities for efficient data collection, but brings some issues requiring consideration when designing a study; the decision of which hardware and software to use should

  1. Determination of phenoxy acid herbicides in water by electron-capture and microcoulometric gas chromatography

    Science.gov (United States)

    Goerlitz, D.F.; Lamar, William L.

    1967-01-01

    A sensitive gas chromatographic method using microcoulometric titration and electron-capture detection for the analysis of 2,4-D, silvex, 2,4,5-T, and other phenoxy acid herbicides in water is described. The herbicides are extracted from unfiltered water samples (800-1,000 ml) by use of ethyl ether ; then the herbicides are concentrated and esterilied. To allow the analyst a choice, two esterilication procedures--using either boron trifluoride-methanol or diazomethane--are evaluated. Microcoulometric gas chromatography is specific for the detection of halogenated compounds such as the phenoxy acid herbicides whereas it does not respond to nonhalogenated components. Microcoulometric gas chromatography requires care and patience. It is not convenient for rapid screening of l-liter samples that contain less than 1 microgram of the herbicide. Although electroncapture gas chromatography is less selective and more critically affected by interfering substances, it is, nevertheless, convenient and more sensitive than microcoulometric gas chromatography. Two different liquid phases are used in the gas chromatographic columns--DC-200 silicone in one column and QF-1 silicone in the other. The performance of both columns is improved by the addition of Carbowax 20M. The Gas Chrom Q support is coated with the liquid phases by the 'frontal-analysis' technique. The practical lower limits for measurement of the phenoxy acid herbicides in water primarily depend upon the sample size, interferences present, anal instrumentation used. With l-liter samples of water, the practical lower limits of measurement are 10 ppt (parts per trillion) for 2,4-D and 2 ppt for silvex and 2,4,5-T when electron-capture detection is used, and approximately 20 ppt for each herbicide when analyzed by microcoulometric-titration gas chromatography. Recoveries of the herbicides immediately after addition to unfiltered water samples averaged 92 percent for 2,4-D, 90 percent for silvex, and 98 percent for 2

  2. Theoretical investigation of energy deposition and electron capture cross-sections for helium ion impact on formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Trujillo, R. [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States); Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, Cuernavaca, Morelos, 62251 (Mexico); Sabin, John R. [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States)]. E-mail: sabin@qtp.ufl.edu; Deumens, Erik [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States); Ohrn, Yngve [Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611-8435 (United States)

    2007-08-15

    The subject of the work presented here is related to damage caused by energetic, charged particle radiation such as electrons, protons, and alpha particles to prebiotic matter such as that found in interstellar space. The calculations are carried out using an all electron, all nuclei, scheme that explicitly treats the electron-nuclear coupling. We present results for the no-capture, as well as the single and double electron capture probabilities, as well as for the 1s and 2l (l = s, p) contributions to the electron capture cross-sections of {sup 3}He{sup 2+} projectiles on formaldehyde molecules. We find that the summed cross-section peaks at 10 keV/amu, and has a plateau between 0.1 and 1 keV/amu. We also present preliminary results for the nuclear, ro-vibrational and electronic stopping cross-section. We find a large contribution to the electronic stopping cross-section and a maximum shifted towards higher energies in the nuclear stopping cross-section, when compared to SRIM results. We interpret this to be a consequence of molecular bonding.

  3. Evaluation of a mandatory quality assurance data capture in anesthesia: a secure electronic system to capture quality assurance information linked to an automated anesthesia record.

    Science.gov (United States)

    Peterfreund, Robert A; Driscoll, William D; Walsh, John L; Subramanian, Aparna; Anupama, Shaji; Weaver, Melissa; Morris, Theresa; Arnholz, Sarah; Zheng, Hui; Pierce, Eric T; Spring, Stephen F

    2011-05-01

    Efforts to assure high-quality, safe, clinical care depend upon capturing information about near-miss and adverse outcome events. Inconsistent or unreliable information capture, especially for infrequent events, compromises attempts to analyze events in quantitative terms, understand their implications, and assess corrective efforts. To enhance reporting, we developed a secure, electronic, mandatory system for reporting quality assurance data linked to our electronic anesthesia record. We used the capabilities of our anesthesia information management system (AIMS) in conjunction with internally developed, secure, intranet-based, Web application software. The application is implemented with a backend allowing robust data storage, retrieval, data analysis, and reporting capabilities. We customized a feature within the AIMS software to create a hard stop in the documentation workflow before the end of anesthesia care time stamp for every case. The software forces the anesthesia provider to access the separate quality assurance data collection program, which provides a checklist for targeted clinical events and a free text option. After completing the event collection program, the software automatically returns the clinician to the AIMS to finalize the anesthesia record. The number of events captured by the departmental quality assurance office increased by 92% (95% confidence interval [CI] 60.4%-130%) after system implementation. The major contributor to this increase was the new electronic system. This increase has been sustained over the initial 12 full months after implementation. Under our reporting criteria, the overall rate of clinical events reported by any method was 471 events out of 55,382 cases or 0.85% (95% CI 0.78% to 0.93%). The new system collected 67% of these events (95% confidence interval 63%-71%). We demonstrate the implementation in an academic anesthesia department of a secure clinical event reporting system linked to an AIMS. The system enforces

  4. Effect of collective response on electron capture and excitation in collisions of highly charged ions with fullerenes.

    Science.gov (United States)

    Kadhane, U; Misra, D; Singh, Y P; Tribedi, Lokesh C

    2003-03-07

    Projectile deexcitation Lyman x-ray emission following electron capture and K excitation has been studied in collisions of bare and Li-like sulphur ions (of energy 110 MeV) with fullerenes (C(60)/C(70)) and different gaseous targets. The intensity ratios of different Lyman x-ray lines in collisions with fullerenes are found to be substantially lower than those for the gas targets, both for capture and excitation. This has been explained in terms of a model based on "solidlike" effect, namely, wakefield induced stark mixing of the excited states populated via electron capture or K excitation: a collective phenomenon of plasmon excitation in the fullerenes under the influence of heavy, highly charged ions.

  5. Fine-Grid Calculations for Stellar Electron and Positron Capture Rates on Fe-Isotopes

    CERN Document Server

    Nabi, Jameel-Un

    2011-01-01

    The acquisition of precise and reliable nuclear data is a prerequisite to success for stellar evolution and nucleosynthesis studies. Core-collapse simulators find it challenging to generate an explosion from the collapse of the core of massive stars. It is believed that a better understanding of the microphysics of core-collapse can lead to successful results. The weak interaction processes are able to trigger the collapse and control the lepton-to-baryon ratio ($Y_{e}$) of the core material. It is suggested that the temporal variation of $Y_{e}$ within the core of a massive star has a pivotal role to play in the stellar evolution and a fine-tuning of this parameter at various stages of presupernova evolution is the key to generate an explosion. During the presupernova evolution of massive stars, isotopes of iron, mainly $^{54,55,56}$Fe, are considered to be key players in controlling $Y_{e}$ ratio via electron capture on these nuclide. Recently an improved microscopic calculation of weak interaction mediated...

  6. Capturing relativistic wake eld structures in plasmas using ultrashort high-energy electrons as a probe

    CERN Document Server

    Zhang, C J; Xu, X L; Li, F; Pai, C -H; Wan, Y; Wu, Y P; Gu, Y Q; Mori, W B; Joshi, C; Lu, W

    2016-01-01

    A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime...

  7. Rapid determination of acrylamide contaminant in conventional fried foods by gas chromatography with electron capture detector.

    Science.gov (United States)

    Zhang, Yu; Dong, Yi; Ren, Yiping; Zhang, Ying

    2006-05-26

    Gas chromatography coupled with electron capture detector (GC-ECD) was successfully developed and applied for the rapid determination of acrylamide in conventional fried foods, such as potato crisps, potato chips, and fried chicken wings. The method included defatting with n-hexane, extraction with aqueous solution of sodium chloride (NaCl), derivatization with potassium bromate (KBrO3) and potassium bromide (KBr), and liquid-liquid extraction with ethyl acetate. The final acrylamide extract was analyzed by GC-ECD for quantification and by GC-MS for confirmation. The chromatographic analysis was performed on the HP-INNOWax capillary column, and good retention and peak response of acrylamide were achieved under the optimal conditions (numbers of theoretical plates N = 83,815). The limit of detection (LOD) was estimated to be 0.1 microg kg(-1) on the basis of ECD technique. Recoveries of acrylamide from conventional samples spiked at levels of 150, 500 and 1000 microg kg(-1) (n = 4 for each level) ranged between 87 and 97% with relative standard deviations (RSD) of less than 4%. Furthermore, the GC-ECD method showed that no clean-up steps of acrylamide derivative would be performed prior to injection and was slightly more sensitive than the MS/MS-based methods. Validation and quantification results demonstrated that this method should be regarded as a new, low-cost, and robust alternative for conventional investigation of acrylamide.

  8. Determination of guaifenesin in human serum by capillary gas chromatography and electron capture detection.

    Science.gov (United States)

    Sharaf, Maged H M; Stiff, Dwight D

    2004-06-29

    A method for the quantitation of guaifenesin in human serum has been developed and validated. The procedure involves liquid-liquid extraction of the serum sample in the presence of mephenesin as an internal standard, followed by derivatization and analysis using capillary gas chromatography (GC) and electron capture detection (ECD). Different solvents were tested for extraction of guaifenesin from serum. n-Hexane/dichloromethane (1:1, v/v) gave the highest recovery and the lowest background and was chosen as the extraction solvent. After extraction, the residue of guaifenesin was derivatized at 60 degrees C for 30 min, with trifluoroacetic acid anhydride (TFAA) in toluene in the presence of pyridine. Excess trifluoroacetic acid anhydride was removed using dilute solution of ammonium hydroxide. The method proved to be linear over the range of 25.0-1000 ng/ml. Recovery of guaifenesin from spiked samples was consistent, averaging 75.5% at 50.0 ng/ml with a range of 72.0-80.0% (N = 8 determinations) and averaging 78% at 800 ng/ml with a range of 76.0-81.0% (N = 8 determinations). The internal standard recovery was also consistent averaging 72.8% with a range of 67.0-76.0% (N = 16 determinations). Copyright 2004 Elsevier B.V.

  9. Octopamine Levels in Blattella Germanica L. Tissues by Capillary Gas Chromatography with Electron Capture Detection

    Directory of Open Access Journals (Sweden)

    Shuren Jiang

    2005-05-01

    Full Text Available Abstract: Distribution and levels of octopamine (OA, one of the biogenic amines in the invertebrate nervous system, may have significant effects on insect physiological processes including growth, feeding and reproduction. In this paper capillary gas chromatography with electron capture detection (GC-ECD and mass selective detection (GC-MS were used to determine the content of OA in Blattella germanica L. central nervous system (CNS, and that of OA in cockroach stressed by kinds of insecticides, known octopaminergic agonists and some essential oils. A derivatization method for organic extracts via reaction with pentafluoropropionic anhydride (PFPA was developed. The resulting OA derivatives were confirmed by GC-MS to be tris-pentafluoropropionyl-OA. The method was used to quantify the amount of OA in insect issues by capillary GC-ECD through an extraction-derivatization-liquid/liquid partition procedure. Average OA content in normal cockroaches was determined to be 68.49 ± 7.31 ng/g tissue (N=5 determinations. It was shown that insecticides including chlordimeform, methomyl, permethrin, chlorfluazuron, malathion, trichlorfon and some oxazolidine agonists, essential oils including eugenol, cinnamic alcohol, phenyl ethyl alcohol could led to significant increase of OA levels in the cockroach CNS comparing with which in insect treated by 1-butanone. Malathion, trichlorfon, chlorfluazuron and cinnamic alcohol were shown to be able to cause a 20- fold increase in OA levels.

  10. A study of resonance electron capture ionization on a quadrupole tandem mass spectrometer.

    Science.gov (United States)

    Wei, J; Liu, S; Fedoreyev, S A; Voinov, V G

    2000-01-01

    Procedures that allow the realization of resonance electron capture (REC) mode on a commercial triple-quadrupole mass spectrometer, after some simple modifications, are described. REC mass spectrometry (MS) and tandem mass spectrometry (MS/MS) experiments were performed and spectra for some compounds were recorded. In particular, the charge-remote fragmentation (CRF) spectra of [M - H](-) ions of docosanoic and docosenoic acids under low-energy collisionally activated dissociation (CAD) conditions were obtained, and showed that there were no significant differences for [M - H](-) ions produced at different resonances (i.e. for [M - H](-) ions with different structures). This observation was explained on the basis of results obtained from deuterium-labeled fatty acids, which showed that different CRF ions (but with the same m/z value in the absence of labels) could be produced by different mechanisms, and all of them were obviously realized under CAD conditions that made spectra practically indistinguishable. The other example, which compared the REC-MS/MS spectrum of [M - H](-) ions and EI-MS/MS spectrum of M(+.) ions of daidzein, demonstrated the potential of the REC-MS/MS technique for more complex structure elucidation.

  11. The Impact of Phosphorylation on Electron Capture Dissociation of Proteins: A Top-Down Perspective

    Science.gov (United States)

    Chen, Bifan; Guo, Xiao; Tucholski, Trisha; Lin, Ziqing; McIlwain, Sean; Ge, Ying

    2017-09-01

    Electron capture dissociation (ECD) is well suited for the characterization of phosphoproteins, with which labile phosphate groups are generally preserved during the fragmentation process. However, the impact of phosphorylation on ECD fragmentation of intact proteins remains unclear. Here, we have performed a systematic investigation of the phosphorylation effect on ECD of intact proteins by comparing the ECD cleavages of mono-phosphorylated α-casein, multi-phosphorylated β-casein, and immunoaffinity-purified phosphorylated cardiac troponin I with those of their unphosphorylated counterparts, respectively. In contrast to phosphopeptides, phosphorylation has significantly reduced deleterious effects on the fragmentation of intact proteins during ECD. On a global scale, the fragmentation patterns are highly comparable between unphosphorylated and phosphorylated precursors under the same ECD conditions, despite a slight decrease in the number of fragment ions observed for the phosphorylated forms. On a local scale, single phosphorylation of intact proteins imposes minimal effects on fragmentation near the phosphorylation sites, but multiple phosphorylations in close proximity result in a significant reduction of ECD bond cleavages. [Figure not available: see fulltext.

  12. Determination of fluvalinate residues in beeswax by gas chromatography with electron-capture detection.

    Science.gov (United States)

    Tsigouri, A; Menkissoglu-Spiroudi, U; Thrasyvoulou, A T; Diamantidis, G C

    2000-01-01

    A simple, rapid, and accurate method is described for the determination of residual fluvalinate in beeswax. The procedure consists of partitioning on a disposable column of diatomaceous earth (Extrelut), followed by chromatographic cleanup on a Florisil cartridge. The final extract is analyzed by capillary gas chromatography with electron-capture detection (GC-ECD). Briefly, wax samples were dissolved in n-hexane, and the solutions were sonicated and transferred to Extrelut columns. The fluvalinate was extracted with acetonitrile, and a portion of the extract was cleaned up on a Florisil cartridge. The fluvalinate was eluted with diethyl ether-n-hexane (1 + 1) and directly determined by GC-ECD. Recoveries from wax samples spiked at 5 fortification levels (100-1500 microg/kg) ranged from 77.4 to 87.3%, with coefficients of variation of 5.12-8.31%. The overall recovery of the method was 81.4 +/- 3.2%, and the limit of determination was 100 microg/kg.

  13. Determination of toxaphene enantiomers by comprehensive two-dimensional gas chromatography with electron-capture detection.

    Science.gov (United States)

    Bordajandi, Luisa R; Ramos, Lourdes; González, María José

    2006-09-01

    Comprehensive two-dimensional gas chromatography with micro electron-capture detection (GC x GC-microECD) has been evaluated for the enantioseparation of five chiral toxaphenes typically found in real-life samples (Parlar 26, 32, 40, 44 and 50). From the two enantioselective beta-cyclodextrin-based columns evaluated as first dimension column, BGB-176SE and BGB-172, the latter provided the best results and was further combined with three non-enantioselective columns in the second dimension: HT-8, BPX-50 and Supelcowax-10. The combination BGB-172 x BPX-50 was finally selected because it provided a complete separation among all enantiomers. A satisfactory repeatability and reproducibility of the retention times in both the first and the second dimension were observed for all target compounds (RSDs below 0.8%, n = 4). Linear responses in the tested range of 10-200 pg/microl and limits of detection in the range of 2-6 pg/microl were obtained. The repeatability and reproducibility at a concentration of 100 pg/microl, evaluated as the RSDs calculated for the enantiomeric fraction (EF), was better than 11% (n = 4) in all instances. The feasibility of the method developed for real-life analyses was illustrated by the determination of the enantiomeric ratios and concentration levels of the test compounds in four commercial fish oil samples. These results were compared to those obtained by heart-cut multidimensional gas chromatography using the same enantioselective column.

  14. Electron capture strength on odd-A nucleus $\\mathbf{^{59}}$Co in explosive astrophysical environment

    CERN Document Server

    Rahman, Muneeb-Ur

    2014-01-01

    The Gamow-Teller (GT) transitions within massive stars play sumptuous role in the dynamics of core collapse supernovae. GT strength distributions and electron capture rates have been calculated for odd-A nucleus $^{59}$Co within the proton-neutron quasiparticles random phase approximation (pn-QRPA) formalism. The pn-QRPA results are compared with other model calculations and (n, p) reaction experiment carried out at TRIUMF charge-exchange facility. The pn-QRPA calculated a total $B(GT_{+})$ strength of 3.3 for $^{59}$Co to be compared with the shell model value of 2.5 and the 1.9 $\\pm$ 0.1 in the (n, p) charge-exchange reaction. Aufderheide et. al. \\cite{Aufderheide93} extracted total strength equaling 2.4 $\\pm$ 0.3. The placement of GT centroid at 5.6 MeV by the pn-QRPA model is in reasonable agreement with the shell model centroid at 5.1 MeV whereas the measured GT centroid was placed at 4.4 $\\pm$ 0.3 MeV in the (n, p) experiment. Fuller, Fowler and Newman (FFN) \\cite{FFN80, FFN82, FFN82b}, placed the GT ce...

  15. Electronic data capture for registries and clinical trials in orthopaedic surgery: open source versus commercial systems.

    Science.gov (United States)

    Shah, Jatin; Rajgor, Dimple; Pradhan, Shreyasee; McCready, Mariana; Zaveri, Amrapali; Pietrobon, Ricardo

    2010-10-01

    Collection and analysis of clinical data can help orthopaedic surgeons to practice evidence based medicine. Spreadsheets and offline relational databases are prevalent, but not flexible, secure, workflow friendly and do not support the generation of standardized and interoperable data. Additionally these data collection applications usually do not follow a structured and planned approach which may result in failure to achieve the intended goal. Our purposes are (1) to provide a brief overview of EDC systems, their types, and related pros and cons as well as to describe commonly used EDC platforms and their features; and (2) describe simple steps involved in designing a registry/clinical study in DADOS P, an open source EDC system. WHERE ARE WE NOW?: Electronic data capture systems aimed at addressing these issues are widely being adopted at an institutional/national/international level but are lacking at an individual level. A wide array of features, relative pros and cons and different business models cause confusion and indecision among orthopaedic surgeons interested in implementing EDC systems. WHERE DO WE NEED TO GO?: To answer clinical questions and actively participate in clinical studies, orthopaedic surgeons should collect data in parallel to their clinical activities. Adopting a simple, user-friendly, and robust EDC system can facilitate the data collection process. HOW DO WE GET THERE?: Conducting a balanced evaluation of available options and comparing them with intended goals and requirements can help orthopaedic surgeons to make an informed choice.

  16. Electron capture sulfur detector: reduced sulfur species detection at the femtomole level

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.E.; Lovelock, J.E.

    1988-04-15

    The authors have developed a new technique to detect reduced sulfur compounds by fluorination with F/sub 2/ (at 200 ppm) on a heated Ag catalyst after GC separation. The excess F/sub 2/ is removed by conversion to HF by reaction with H/sub 2/ on a heated Pd catalysts. The fluorination product, presumably SF/sub 6/, is then detected in an electron capture detector (ECD). The Pd catalyst also destroys the response from halocarbons making the system sulfur specific. This ECD sulfur detector has a calculated minimum detectable level (MDL) for H/sub 2/S, OCS, CH/sub 3/SH, DMS, and CS/sub 2/ of less than 2 fmol/s for each compound, 2 orders of magnitude lower than the best FPD systems. The ratio of the detected molar response of each of these sulfur compounds to the molar response of SF/sub 6/ ranges from 2% to 20% and increases with increasing AgF/sub 2/ temperature.

  17. Trace analysis of sulfamethazine in animal feed, human urine, and wastewater by electron capture gas chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Holder, C.L.; Thompson, H.C. Jr.; Bowman, M.C.

    1981-12-01

    Sulfamethazine, a widely used antibacterial drug additive in feeds for swine, chickens, and cattle, was scheduled for toxicological evaluation because of potential human health hazards associated with its residues in edible animal tissues. Analytical chemical procedures that would ensure proper concentration, homogeneity, and stability of the drug in dosed feed and its safe usage during the animal studies were prerequisites for such toxicological tests. Electron capture gas chromatographic (EC/GC) methods were therefore devised for the analysis of sulfamethazine residues in animal feed, human urine, and wastewater at levels as low as 100, 10, and 10 ppb, respectively. Sample extracts were cleaned up by using liquid/liquid partitioning, and the extracts were subjected to two derivatizations followed by cleanup on a silica gel column. The derivatizations of sulfamethazine consisted of methylation followed by trifluoroacetylation of the primary amine function. Ancillary data concerning stability of the compound in animal feed, water, and as a dry residue on glass, extraction efficiencies, partition values with various solvents, and the analysis of residues in feed by high pressure liquid chromatography (HPLC) at levels as low as 1.0 ppm are presented.

  18. Rapidly evolving faint transients from stripped-envelope electron-capture supernovae

    Science.gov (United States)

    Moriya, Takashi J.; Eldridge, J. J.

    2016-09-01

    We investigate the expected rates and bolometric light-curve properties of stripped-envelope electron-capture supernovae (ECSNe) using stellar models from the Binary Population and Spectral Synthesis code. We find that 0.8 per cent (Z = 0.020) and 1.2 per cent (Z = 0.004) of core-collapse supernovae are stripped-envelope ECSNe. Their typical ejecta masses are estimated to be about 0.3 M⊙(Z = 0.020) and 0.6 M⊙ (Z = 0.004). Assuming ECSN explosion properties from numerical explosion simulations, an explosion energy of 1.5 × 1050 erg and a 56Ni mass of 2.5 × 10-3 M⊙, we find that stripped-envelope ECSNe have a typical rise time of around 7 d (Z = 0.020) or 13 d (Z = 0.004) and peak luminosity of around 1041 ergs-1 (-13.8 mag, Z = 0.020) or 7 × 1040 erg s-1 (-13.4 mag, Z = 0.004). Their typical ejecta velocities are around 7000 km s-1 (Z = 0.020) or 5000 km s-1 (Z = 0.004). Thus, stripped-envelope ECSNe are observed as rapidly evolving faint transients with relatively small velocities. SN 2008ha-like supernovae, which are the faintest kind of SN 2002cx-like (also known as Type Iax) supernovae, may be related to stripped-envelope ECSNe.

  19. Comparison of peptide mass mapping and electron capture dissociation as assays for histone posttranslational modifications

    Science.gov (United States)

    Zhang, Liwen; Freitas, Michael A.

    2004-05-01

    Posttranslational modifications of core histones play a critical role in the structure of chromatin and the regulation of gene activities. Improved techniques for determining these modification sites may lead to a better understanding of histone regulation at the molecular level. LC-MS peptide mass mapping was performed on pepsin, trypsin and Glu-C digests of bovine thymus H4 using a QqTOF instrument. The well established modification sites of H4 (acetylation of K8, 12, 16 and methylation of K20) were observed in addition to several recently discovered modifications including: methylation of K31, 44, 59 and acetylation of K20, 77, 79. For comparison, electron capture dissociation (ECD) was performed on intact H4 along with several peptides from enzymatic digestion. The results from the ECD experiments of histone H4 indicated the acetylation of K5, 12, 16, 31, 91 and the methylation of K20 and 59 in good agreement with the result from peptide mapping. The work is dedicated to Alan G. Marshall on his 60th birthday. His endeavors in the advancement of FT-ICR facilitated experiments reported herein.

  20. Electron-capture delayed fission properties of neutron-deficient einsteinium nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Shaughnessy, Dawn A. [Univ. of California, Berkeley, CA (United States)

    2000-01-01

    Electron-capture delayed fission (ECDF) properties of neutron-deficient einsteinium isotopes were investigated using a combination of chemical separations and on-line radiation detection methods. 242Es was produced via the 233U(14N,5n)242Es reaction at a beam energy of 87 MeV (on target) in the lab system, and was found to decay with a half-life of 11 ± 3 seconds. The ECDF of 242Es showed a highly asymmetric mass distribution with an average pre-neutron emission total kinetic energy (TKE) of 183 ± 18 MeV. The probability of delayed fission (PDF) was measured to be 0.006 ± 0.002. In conjunction with this experiment, the excitation functions of the 233U(14N,xn)247-xEs and 233U(15N,xn)248-xEs reactions were measured for 243Es, 244Es and 245Es at projectile energies between 80 MeV and 100 MeV.

  1. Correlated Two-Electron Capture by Ion with Emission of Photon

    Science.gov (United States)

    Mikhailov, A. I.

    2005-05-01

    The correlated double electron capture into the K shell of bare ions with emission of a single photon is considered. The process is treated as a time-reversed atomic double photoionization. For ten years of experimental investigations there is no evidence of existence of the reaction. There is a theoretical prediction (Phys. Rev. A 55 (1997) 1952), that a probability of the process grows rapidly with the ion charge due to relativistic effects and that the cross section does not depend on target atoms. However the recent experiment (GSI Scien.Rep., ISSN 174 (2001) 98) failed to observe this process under the recommended conditions. The present work reveals an incorrectness of those theoretical predictions and provides an expression to determine optimal experimental conditions for observing the process. We suggest to use ion beams slower than those in the experiment (NIM B98 (1995)303), and do not recommend to use heavy ions. We show that the cross section can increase significantly for solid-state targets and decelerated ion beams. The novel technique of deceleration of multicharged ions planned at GSI can be applied to perform such experiments.

  2. Study of the inner Bremsstrahlung following the electron-capture decay of {sup 193} Pt

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, J.Y.Z.; Cruz, M.T.F. da; Martins, M.N.; Santos, R.T. dos [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Zamboni, C.B.; Hamada, M.M.; Camargo, S.P. de; Medeiros, J.A.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Hindi, M.M. [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Physics

    1997-12-31

    We are measuring the inner Bremsstrahlung (I B) photons emitted in some of the electron-capture decays of {sup 193} Pt. The source was prepared with highly pure metal Pt. It was irradiated with neutron for 52 days and let to cool down for eight months. The remaining activities were due to {sup 193} Pt{sup g} (half-life 50 yr) and {sup 192} Ir (half-life 74 d), the latter coming from (n, {gamma}) reactions on a small content of Ir. We have used a radiochemistry method to reduce the Ir content of the source. The resulting Pt compound will be dissolved in a plastic scintillator disk. Most of the {sup 192} Ir decays are {beta}{sup -} and their signal in the plastic will be used as a veto for the I B-photon detector. We have performed simulations of the efficiency and absorption effects in the detection geometry. (author) 6 refs., 1 fig.; juan at if.usp.br; czamboni at net.ipen.br; hindi at hindi.physics.tntech.edu

  3. Kuang's Semi-Classical Formalism for Calculating Electron Capture Cross Sections and Sample Application for ENA Modeling

    Science.gov (United States)

    Barghouty, A. F.

    2013-01-01

    Accurate estimates of electron-capture cross sections at energies relevant to ENA modeling (approx. few MeV per nucleon) and for multi-electron ions must rely on detailed, but computationally expensive, quantummechanical description of the collision process. Kuang's semi-classical approach is an elegant and efficient way to arrive at these estimates. Motivated by ENA modeling efforts, we shall briefly present this approach along with sample applications and report on current progress.

  4. State-selective electron-capture measurements for N4+-H and N4+-H-2 collisions

    NARCIS (Netherlands)

    Bliek, FW; Woestenenk, GR; Hoekstra, R; Morgenstern, R

    1998-01-01

    State-selective electron-capture cross-section measurements in the energy range between 1 and 4 keV/amu are reported for collisions between N4+ ions and atomic and molecular hydrogen. The cross sections are measured in a crossed-beam experiment by means of photon emission spectroscopy. The singlet a

  5. Comparison of quantification methods for the analysis of polychlorinated alkanes using electron capture negative ionisation mass spectrometry

    NARCIS (Netherlands)

    Rusina, T.; Korytar, P.; Boer, de J.

    2011-01-01

    Four quantification methods for short-chain chlorinated paraffins (SCCPs) or polychlorinated alkanes (PCAs) using gas chromatography electron capture negative ionisation low resolution mass spectrometry (GC-ECNI-LRMS) were investigated. The method based on visual comparison of congener group pattern

  6. DEPENDENCE OF ELECTRON-CAPTURE FROM NA-ASTERISK(3P) ON ORBITAL ALIGNMENT - A KINEMATIC EFFECT

    NARCIS (Netherlands)

    SCHLATMANN, AR; MORGENSTERN, R

    1993-01-01

    Recent experimental data of electron capture into He+(4l) states from SIGMA and PI aligned Na*(3p) orbitals are interpreted. Calculations of the overlap integral of the initial Na*(3p) and the final He+(4l) wavefunctions in momentum space reproduce the velocity dependence of the measured cross secti

  7. Electronic data capture in a rural African setting: evaluating experiences with different systems in Malawi

    Directory of Open Access Journals (Sweden)

    Carina King

    2014-10-01

    Full Text Available Background: As hardware for electronic data capture (EDC, such as smartphones or tablets, becomes cheaper and more widely available, the potential for using such hardware as data capture tools in routine healthcare and research is increasing. Objective: We aim to highlight the advantages and disadvantages of four EDC systems being used simultaneously in rural Malawi: two for Android devices (CommCare and ODK Collect, one for PALM and Windows OS (Pendragon, and a custom-built application for Android (Mobile InterVA – MIVA. Design: We report on the personal field and development experience of fieldworkers, project managers, and EDC system developers. Results: Fieldworkers preferred using EDC to paper-based systems, although some struggled with the technology at first. Highlighted features include in-built skip patterns for all systems, and specifically the ‘case’ function that CommCare offers. MIVA as a standalone app required considerably more time and expertise than the other systems to create and could not be customised for our specific research needs; however, it facilitates standardised routine data collection. CommCare and ODK Collect both have user-friendly web-interfaces for form development and good technical support. CommCare requires Internet to build an application and download it to a device, whereas all steps can be done offline with ODK Collect, a desirable feature in low connectivity settings. Pendragon required more complex programming of logic, using a Microsoft Access application, and generally had less technical support. Start-up costs varied between systems, and all were considered more expensive than setting up a paper-based system; however running costs were generally low and therefore thought to be cost-effective over the course of our projects. Conclusions: EDC offers many opportunities for efficient data collection, but brings some issues requiring consideration when designing a study; the decision of which hardware

  8. Human resource requirements for quality-assured electronic data capture of the tuberculosis case register

    Directory of Open Access Journals (Sweden)

    Hoa Nguyen B

    2012-01-01

    Full Text Available Abstract Background The tuberculosis case register is the data source for the reports submitted by basic management units to the national tuberculosis program. Our objective was to measure the data entry time required to complete and double-enter one record, and to estimate the time for the correction of errors in the captured information from tuberculosis case registers in Cambodia and Viet Nam. This should assist in quantifying the additional requirements in human resources for national programs moving towards electronic recording and reporting. Methods Data from a representative sample of tuberculosis case registers from Cambodia and Viet Nam were double-entered and discordances resolved by rechecking the original case register. Computer-generated data entry time recorded the time elapsed between opening of a new record and saving it to disk. Results The dataset comprised 22,732 double-entered records of 11,366 patients (37.1% from Cambodia and 62.9% from Viet Nam. The mean data entry times per record were 97.5 (95% CI: 96.2-98.8 and 66.2 (95% CI: 59.5-73.0 seconds with medians of 90 and 31 s respectively in Cambodia and in Viet Nam. The percentage of records with an error was 6.0% and 39.0% respectively in Cambodia and Viet Nam. Data entry time was inversely associated with error frequency. We estimate that approximately 118-person-hours were required to produce 1,000 validated records. Conclusions This study quantifies differences between two countries for data entry time for the tuberculosis case register and frequencies of data entry errors and suggests that higher data entry speed is partially offset by requiring revisiting more records for corrections.

  9. Development of an electronic research permissions management system to enhance informed consents and capture research authorizations data.

    Science.gov (United States)

    Obeid, Jihad S; Gerken, Katherine; Madathil, Kapil Chalil; Rugg, Daniel; Alstad, Colin E; Fryar, Katrina; Alexander, Randall; Gramopadhye, Anand K; Moskowitz, Jay; Sanderson, Iain C

    2013-01-01

    Informed consents are a critical and essential component of the clinical research process. Currently, most consents and research privacy authorizations are being captured on paper. In this paper we describe a novel method of capturing this information electronically. The objective is to allow easier tracking of research participants' intent for current and future research involvement, enhance consent comprehension and facilitate the research workflow. After multidisciplinary analysis in key hospital registration areas and research participant enrollment, an open source software product was designed to capture this data through a user-friendly touch screen interface. The data may then be fed into a clinical data warehouse for use in cohort discovery or consent tracking. Despite ethical, legal and informatics challenges in clinical and research environments, we propose that this technology opens new avenues for significantly enhancing the consent process and positively impacting recruitment.

  10. Continuous and immediate method for the detection of SF/sub 6/ and other tracer gases by electron capture in atmospheric diffusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, E.L. (Aerosol Lab., Risoe, Denmark); Lovelock, J.E.

    1976-01-01

    In many atmospheric diffusion experiments using tracer gases continuous tracer recording is of decisive importance. The main obstacle to continuous electron capture detection of tracer gases in the atmosphere is presented by the oxygen, which is an electron capturer. A method for removing this difficulty is described. Its practical use in an airborne atmospheric plume diffusion experiment is demonstrated.

  11. Excited states in 168Yb from electron-capture decay of 168Lum (T1/2=6.7 min)

    Science.gov (United States)

    Barci, V.; Ardisson, G.; Trubert, D.; Hussonnois, M.

    1999-08-01

    The electron-capture decay of the 168Lum (T1/2=6.7 min, Jπ=3+) isomer was studied with high purity sources, obtained by using a new radiochemical method consisting of fast continous on-line separation of reaction products. A complex spectrum composed of about 200 γ rays was observed. From these, 162 transitions were assigned to a level scheme of 39 excited levels of 168Yb, primarily by γ-γ coincidence spectroscopic measurements. About 60 transitions were placed for the first time and >90% of the decay intensity was clearly identified. The structure of the levels directly fed by the electron-capture decay was reviewed as particle-hole excitations of the core.

  12. A data capture system for outcomes studies that integrates with electronic health records: development and potential uses.

    Science.gov (United States)

    Yamamoto, Keiichi; Matsumoto, Shigemi; Tada, Harue; Yanagihara, Kazuhiro; Teramukai, Satoshi; Takemura, Tadamasa; Fukushima, Masanori

    2008-10-01

    In conventional clinical studies, the costs of data management for quality control tend to be high and collecting paper-based case report forms (CRFs) tends to be burdensome, because paper-based CRFs must be developed and filled out for each clinical study protocol. Use of electronic health records for this purpose could result in reductions in cost and improvements in data quality in clinical studies. The purpose of this study was to develop a data capture system for observational cancer clinical studies (i.e. outcomes studies) that would integrate with an electronic health records system, to enable evaluation of patient prognosis, prognostic factors, outcomes and drug safety. At the Outpatient Oncology Unit of Kyoto University Hospital, we developed a data capture system that includes a cancer clinical database system and a data warehouse for outcomes studies. We expect that our new system will reduce the costs of data management and analysis and improve the quality of data in clinical studies.

  13. Experimental test of higher-order electron-capture processes in collisions of fast protons with atomic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, H.; Schuch, R.; Justiniano, E.; Schulz, M.; Schwab, W.

    1986-11-03

    We present measurements of the angular distribution of fast hydrogen atoms formed by electron capture of 2.8- and 5.0-MeV protons in atomic hydrogen. In the angular region of the Thomas peak (0.47 mrad) the experimental results obtained with this pure three-body collision system are in reasonable agreement with a strong potential Born calculation and the impulse approximation, but not with other higher-order theories.

  14. A new insight into neutrino energy loss by electron capture of iron group nuclei in magnetars surface

    CERN Document Server

    Liu, Jing-Jing

    2016-01-01

    Based on the relativistic mean-field effective interactions theory, and Lai dong model \\citep{b37, b38, b39}, we discuss the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, nuclear blinding energy, and single-particle level structure in magnetars surface. By using the method of Shell-Model Monte Carlo (SMMC), and the Random Phase Approximation (RPA) theory, we detailed analyze the neutrino energy loss rates(NELRs) by electron capture (EC) for iron group nuclei in SMFs.

  15. Ionization and electron-capture cross sections for single- and multiple-electron removal from H2O by Li3 + impact

    Science.gov (United States)

    Luna, H.; Wolff, W.; Montenegro, E. C.; Tavares, André C.; Lüdde, H. J.; Schenk, G.; Horbatsch, M.; Kirchner, T.

    2016-05-01

    In this work, we report experimental and theoretical ionization and electron-capture cross sections for single-, double- and triple-electron removal from H2O by Li3 + impact at energies ranging from 0.75 to 5.8 MeV. The experiment was carried out by selecting both the final charge state of the projectile and the ejected fragments in coincidence to obtain cross sections associated with ionization and electron-capture channels. The ionic fragments and the emitted electrons produced under single-collision conditions were collected by a time-of-flight spectrometer with single-hit (e.g., OH++H0 ) and double-hit events (e.g., OH++H+ ) properly discriminated. For the one- and two-electron removal cases, the calculations based on the basis generator method for orbital propagation agree well with the experiment for most of the collision channels studied. Auger-electron emission after vacancy production in the inner 2 a1 orbital of H2O is shown to have a substantial effect on the final charge-state distributions over the entire impact-energy interval.

  16. Channeling, volume reflection, and volume capture study of electrons in a bent silicon crystal

    DEFF Research Database (Denmark)

    Wistisen, T. N.; Uggerhoj, U. I.; Wienands, U.;

    2016-01-01

    We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasimosaic silicon crystal. These phenomena were investigated at...

  17. 77 FR 4059 - Certain Electronic Devices for Capturing and Transmitting Images, and Components Thereof; Receipt...

    Science.gov (United States)

    2012-01-26

    ... for capturing and transmitting images, and components thereof. The complaint names Apple Inc. of Cupertino, CA; High Tech Computer Corp. (a/k/a HTC Corp.) of Taiwan; HTC America, Inc. of Bellevue, WA; and Exedea, Inc. of Houston, TX, as respondents. The complainant, proposed respondents, other...

  18. Capturing enveloped viruses on affinity grids for downstream cryo-electron microscopy applications

    Science.gov (United States)

    Electron microscopy cryo-electron microscopy and cryo-electron tomography are essential techniques used for characterizing basic virus morphology and determining the three-dimensional structure of viruses. Enveloped viruses, which contain an outer lipoprotein coat, constitute the largest group of pa...

  19. Neutrino Energy Loss by Electron Capture on Nucleus 56Mn, 56Fe, 56Co and 56Ni in Strong Electron Screening

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Jing; LUO Zhi-Quan

    2007-01-01

    Based on the p-f shell model, the neutrino energy loss rates for nucleus 56Mn, 56Fe, 56Co and 56Ni in the electron capture process are canvassed in and not in a strong electron screening. The results show that the neutrino energy loss rates for 56Mn, 56Fe, 56Co and 56Ni decrease about 15%, 10%, 60% and 1 order of magnitude correspondinglyat the temperature T9 = 15 and even debase 2 orders of magnitude at the temperature T9 = 1.

  20. Total cross sections for electron capture and transfer ionization by highly stripped, slow Ne, Ar, Kr, and Xe projectiles on helium

    Energy Technology Data Exchange (ETDEWEB)

    Justiniano, E.; Cocke, C.L.; Gray, T.J.; Dubois, R.; Can, C.; Waggoner, W.; Schuch, R.; Schmidt-Boecking, H.; Ingwersen, H.

    1984-03-01

    Experimental cross sections are reported for electron capture and transfer ionization for Ne, Ar, Kr, and Xe projectiles on He for charge states (q) between 2 and 13 and for projectile energies between (250 and 1000 eV)q. The double-electron capture is found to be typically an order of magnitude weaker than single-electron capture, and to be dominated in most cases by the transfer ionization channel. While gross features of the cross sections can be qualitatively understood, quantitative agreement with available theoretical model calculations is poor.

  1. Single-electron capture for 2-8 keV incident energy and direct scattering at 6 keV in He[sup 2+]-He collisions

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, D.; Dagnac, R. (Toulouse-3 Univ., 31 (France). Centre de Physique Atomique)

    1992-06-14

    We studied the single-electron capture as well as the direct processes occurring when a He[sup 2+] ion is scattered by a He target. Doubly differential cross sections were measured for single-electron capture with a collision energy ranging from 2 to 8 keV and a scattering angle varying from 10' to 3[sup o]30' (laboratory frame). Single-electron capture into excited states of He[sup +] was found to be the dominant process, confirming a previous experimental study. Elastic scattering and ionization differential cross sections were measured for E = 6 keV. (Author).

  2. The feasibility of using 'bring your own device' (BYOD) technology for electronic data capture in multicentre medical audit and research.

    Science.gov (United States)

    Faulds, M C; Bauchmuller, K; Miller, D; Rosser, J H; Shuker, K; Wrench, I; Wilson, P; Mills, G H

    2016-01-01

    Large-scale audit and research projects demand robust, efficient systems for accurate data collection, handling and analysis. We utilised a multiplatform 'bring your own device' (BYOD) electronic data collection app to capture observational audit data on theatre efficiency across seven hospital Trusts in South Yorkshire in June-August 2013. None of the participating hospitals had a dedicated information governance policy for bring your own device. Data were collected by 17 investigators for 392 individual theatre lists, capturing 14,148 individual data points, 12, 852 (91%) of which were transmitted to a central database on the day of collection without any loss of data. BYOD technology enabled accurate collection of a large volume of secure data across multiple NHS organisations over a short period of time. Bring your own device technology provides a method for collecting real-time audit, research and quality improvement data within healthcare systems without compromising patient data protection.

  3. Double capture in the O/sup 8+/ + He collision investigated by electron spectroscopy (80 keV, 10 deg)

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Benoit-Cattin, P.; Bordenave-Montesquieu, A.; Boudjema, M.; Gleizes, A.; Oza, D.H.; Dousson, S.; Hitz, D.

    1989-01-28

    Double capture into (3,n) autoionising states of O/sup 6+/ is observed in the O/sup 8+/ + He collision system by electron spectroscopy at 80 keV, 10/sup 0/. A comparison of the experimental results with theoretical positions and lifetimes allows the (3,3) states as well as three groups of (3,4) states to be identified. The present experimental findings are compared with earlier data for the N/sup 7+/ + He and Ne/sup 8+/(1s/sup 2/) + He systems. The influence of the core of the multicharged ion is studied by examining the O/sup 8+/ and Ne/sup 8+/(1s/sup 2/) results. The total double capture cross section is found to be large and it is compared with available experimental and theoretical data.

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

    NARCIS (Netherlands)

    MORGENSTERN, R

    1993-01-01

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

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

    NARCIS (Netherlands)

    MORGENSTERN, R

    1993-01-01

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

  6. Analysis of neonicotinoids by gas chromatography coupled to nuclide {sup 63}Ni - Electron Capture Detector - GC/ECD

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V., E-mail: priscilaoamaral@gmail.com, E-mail: claudio.leao@usp.br, E-mail: marceloredigolo@gmail.com, E-mail: caike1995@gmail.com, E-mail: ovega@ipen.bremails [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C{sub 9}H{sub 10}ClN{sub 5}O{sub 2}), clothianidin (C{sub 6}H{sub 8}ClN{sub 5}O{sub 2}S) and thiamethoxam (C{sub 8}H{sub 10}ClN{sub 5}O{sub 3}S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide {sup 63}Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources {sup 63}Ni within carrier gas N{sub 2}. The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  7. Capturing Structural Dynamics in Crystalline Silicon Using Chirped Electrons from a Laser Wakefield Accelerator

    Science.gov (United States)

    He, Z.-H.; Beaurepaire, B.; Nees, J. A.; Gallé, G.; Scott, S. A.; Pérez, J. R. Sánchez; Lagally, M. G.; Krushelnick, K.; Thomas, A. G. R.; Faure, J.

    2016-11-01

    Recent progress in laser wakefield acceleration has led to the emergence of a new generation of electron and X-ray sources that may have enormous benefits for ultrafast science. These novel sources promise to become indispensable tools for the investigation of structural dynamics on the femtosecond time scale, with spatial resolution on the atomic scale. Here, we demonstrate the use of laser-wakefield-accelerated electron bunches for time-resolved electron diffraction measurements of the structural dynamics of single-crystal silicon nano-membranes pumped by an ultrafast laser pulse. In our proof-of-concept study, we resolve the silicon lattice dynamics on a picosecond time scale by deflecting the momentum-time correlated electrons in the diffraction peaks with a static magnetic field to obtain the time-dependent diffraction efficiency. Further improvements may lead to femtosecond temporal resolution, with negligible pump-probe jitter being possible with future laser-wakefield-accelerator ultrafast-electron-diffraction schemes.

  8. Capturing Structural Dynamics in Crystalline Silicon Using Chirped Electrons from a Laser Wakefield Accelerator

    CERN Document Server

    He, Z -H; Nees, J A; Gallé, G; Scott, S A; Pérez, J R Sanchez; Lagally, M G; Krushelnick, K; Thomas, A G R; Faure, J

    2016-01-01

    Recent progress in laser wakefield acceleration has led to the emergence of a new generation of electron and X-ray sources that may have enormous benefits for ultrafast science. These novel sources promise to become indispensable tools for the investigation of structural dynamics on the femtosecond time scale, with spatial resolution on the atomic scale. Here, we demonstrate the use of laser-wakefield-accelerated electron bunches for time-resolved electron diffraction measurements of the structural dynamics of single-crystal silicon nano-membranes pumped by an ultrafast laser pulse. In our proof-of-concept study, we resolve the silicon lattice dynamics on a picosecond time scale by deflecting the momentum-time correlated electrons in the diffraction peaks with a static magnetic field to obtain the time-dependent diffraction efficiency. Further improvements may lead to femtosecond temporal resolution, with negligible pump-probe jitter being possible with future laser-wakefield-accelerator ultrafast-electron-di...

  9. Core-electron effect in state-selective electron capture collisions of highly charged ions with alkali-metal atom targets

    Energy Technology Data Exchange (ETDEWEB)

    Pascale, J. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche sur l`Etat Condense, les Atomes et les Molecules; Jacquet, E. [Caen Univ., 14 (France). Lab. de Spectroscopie Atomique

    1994-12-31

    We study both experimentally and theoretically the influence of the projectile core electrons on the single electron capture process, in medium-energy collisions of partially stripped ions with ground-state alkali-metal atom targets. The effect is clearly demonstrated in the final nl-distributions of the capture electron in Ar{sup 8+} - and Kr{sup 8+} - Li(2s) collisions, by comparisons of experimental data with three-body classical trajectory Monte-Carlo (CTMC) calculations performed for these ions, and also for Ne{sup 8+} and O{sup 8+}. The effect manifests itself by a significant population of low l-values which does not show up in the case of fully or nearly fully stripped ions; it is strongly energy dependent and vanishes at high energies. The CTMC calculations show also a clear influence of the core electrons on the m-distribution of a given final n-level. (authors). 15 refs., 4 figs., 2 tabs.

  10. Influence of spatiotemporal coupling on the capture-and-acceleration-scenario vacuum electron acceleration by ultrashort pulsed laser beam

    Institute of Scientific and Technical Information of China (English)

    Lu Da-Quan; Qian Lie-Jia; Li Yong-Zhong; Fan Dian-Yuan

    2007-01-01

    This paper investigates the properties of the ultrashort pulsed beam aimed to the capture-and-acceleration-scenario(CAS) vacuum electron acceleration. The result shows that the spatiotemporal distribution of the phase velocity, the longitudinal component of the electric field and the acceleration quality factor are qualitatively similar to that of the continuous-wave Gaussian beam, and are slightly influenced by the spatiotemporal coupling of the ultrashort pulsed beam. When the pulse is compressed to an ultrashort one in which the pulse duration TFWHM < 5T0, the variation of the maximum net energy gain due to the carrier-envelope phase is a crucial disadvantage in the CAS acceleration process.

  11. Determination of chloramphenicol residue in fish and shrimp tissues by gas chromatography with a microcell electron capture detector.

    Science.gov (United States)

    Ding, Shuangyang; Shen, Jianzhong; Zhang, Suxia; Jiang, Haiyang; Sun, Zhiwen

    2005-01-01

    A gas chromatography method with microcell electron capture detection was developed for the determination of chloramphenicol residue in fish and shrimp muscle tissues. The tissue samples were extracted with ethyl acetate, defatted with hexane, and derivatized with Sylon BFT [N,O-bis (trimethylsilyl) trifluoroacetamide-trimethylchlorosilane (99 + 1)]. The limit of detection was 0.04 ng/g and the limit of quantitation 0.1 ng/g. Average recoveries were 70.8-90.8% for fish and 69.9-86.3% for shrimp, respectively. The method was validated for the determination of practical samples.

  12. State-selective electron capture in collisions of ground and metastable O{sup 2+} ions with H(1s)

    Energy Technology Data Exchange (ETDEWEB)

    Cabello, C N [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Errea, L F [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Fernandez, L [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Mendez, L [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Macias, A [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Rabadan, I [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain); Riera, A [Departamento de Quimica, Universidad Autonoma de Madrid, Madrid (Spain)

    2003-01-28

    An ab initio calculation of the electron capture cross sections for collisions of ground and metastable states of O{sup 2+} with H(1s) is presented. For impact energies between 0.125 and 3.4 keV amu{sup -1}, we find good agreement between the cross sections from the ground state ion with the mixed beam experimental data of Phaneuf et al (Phaneuf A, Alvarez I, Meyer F W and Crandall D H 1982 Phys. Rev. A 26 1892)

  13. Hydrogen rearrangement to and from radical z fragments in electron capture dissociation of peptides

    DEFF Research Database (Denmark)

    Savitski, Mikhail M; Kjeldsen, Frank; Nielsen, Michael L

    2007-01-01

    capture dissociation (ECD), including previously unreported double H. losses. Consistent with the radical character of H. abstraction, the residue determining the formation rate of z' = z. + H. species is found to be the N-terminal residue in z. species. The size of the complementary c(m)' fragment turned...... out to be another important factor, with z' species dominating over z. ions for m carbon groups of residues composing the c' species, with Gln and His in the c' fragment promoting H. donation and Asp and Ala...

  14. Capturing social and behavioral domains in electronic health records: Phase 1

    National Research Council Canada - National Science Library

    Board on Population Health and Public Health Practice; Institute of Medicine; Committee on the Recommended Social and Behavioral Domains and Measures for Electronic Health Records

    2014-01-01

    .... Electronic health records (EHRs) provide crucial information to providers treating individual patients, to health systems, including public health officials, about the health of populations, and to researchers about the determinants...

  15. Detailed microscopic calculation of stellar electron and positron capture rates on $^{24}$Mg for O+Ne+Mg core simulations

    CERN Document Server

    Nabi, Jameel-Un

    2014-01-01

    Few white dwarfs, located in binary systems, may acquire sufficiently high mass accretion rates resulting in the burning of carbon and oxygen under nondegenerate conditions forming a O+Ne+Mg core. These O+Ne+Mg cores are gravitationally less bound than more massive progenitor stars and can release more energy due to the nuclear burning. They are also amongst the probable candidates for low entropy r-process sites. Recent observations of subluminous Type II-P supernovae (e.g., 2005cs, 2003gd, 1999br, 1997D) were able to rekindle the interest in 8 -- 10 M$_{\\odot}$ which develop O+Ne+Mg cores. Microscopic calculations of capture rates on $^{24}$Mg, which may contribute significantly to the collapse of O+Ne+Mg cores, using shell model and proton-neutron quasiparticle random phase approximation (pn-QRPA) theory, were performed earlier and comparisons made. Simulators, however, may require these capture rates on a fine scale. For the first time a detailed microscopic calculation of the electron and positron captur...

  16. Channeling, volume reflection, and volume capture study of electrons in a bent silicon crystal

    Science.gov (United States)

    Wistisen, T. N.; Uggerhøj, U. I.; Wienands, U.; Markiewicz, T. W.; Noble, R. J.; Benson, B. C.; Smith, T.; Bagli, E.; Bandiera, L.; Germogli, G.; Guidi, V.; Mazzolari, A.; Holtzapple, R.; Tucker, S.

    2016-07-01

    We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasimosaic silicon crystal. These phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5, and 14.0 GeV with a crystal with bending radius of 0.15 m, corresponding to curvatures of 0.053, 0.066, 0.099, 0.16, and 0.22 times the critical curvature, respectively. Based on the parameters of fitting functions we have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission, and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

  17. Mass measurements of neutron rich isotopes in the Fe region and electron capture processes in neutron star crusts

    Energy Technology Data Exchange (ETDEWEB)

    Estrade, Alfredo [National Superconducting Cyclotron Laboratory (NSCL); Matos, M. [Louisiana State University; Schatz, Hendrik [Michigan State University, East Lansing; Amthor, A. M. [National Superconducting Cyclotron Laboratory (NSCL); Beard, Mary [University of Notre Dame, IN; Brown, Edward [Michigan State University, East Lansing; Bazin, D. [National Superconducting Cyclotron Laboratory (NSCL); Becerril, A. [National Superconducting Cyclotron Laboratory (NSCL); Elliot, T [National Superconducting Cyclotron Laboratory (NSCL); Gade, A. [National Superconducting Cyclotron Laboratory (NSCL); Galaviz, D. [National Superconducting Cyclotron Laboratory (NSCL); Gupta, Sanjib [Indian Institute of Technology, Kanpur; Hix, William Raphael [ORNL; Lau, Rita [National Superconducting Cyclotron Laboratory (NSCL); Moeller, Peter [Los Alamos National Laboratory (LANL); Pereira, J. [National Superconducting Cyclotron Laboratory (NSCL); Portillo, M. [National Superconducting Cyclotron Laboratory (NSCL); Rogers, A. M. [National Superconducting Cyclotron Laboratory (NSCL); Shapira, Dan [ORNL; Smith, E. [Ohio State University; Stolz, A. [Michigan State University, East Lansing; Wallace, M. [Los Alamos National Laboratory (LANL); Wiescher, Michael [University of Notre Dame, IN

    2010-01-01

    Experimental knowledge of nuclear masses of exotic nuclei is important for understanding nu- clear structure far from the valley of -stability, and as a direct input into astrophysical models. Electron capture processes in the crust of accreting neutron stars have been proposed as a heat source that can affect the thermal structure of the star. Nuclear masses of very neutron-rich nu- clides are necessary inputs to model the electron capture process. The time-of-flight (TOF) mass measurement technique allows measurements on very short-lived nuclei. It has been effectively applied using the fast fragment beams produced at the National Superconducting Cyclotron Lab (NSCL) to reach masses very far from stability. Measurements were performed for neutron-rich isotopes in the region of the N=32 and N=40 subshells, which coincides with the mass range of carbon superburst ashes. We discuss reaction network calculations performed to investigate the impact of our new measurements and to compare the effect of using different global mass models in the calculations. It is observed that the process is sensitive to the differences in the odd-even mass staggering predicted by the mass models, and our new result for 66Mn has a significant impact on the distribution of heat sources in the crust.

  18. On the Significance of the Contribution of Multiple-Electron Capture Processes to Cometary X-Ray Emission

    Energy Technology Data Exchange (ETDEWEB)

    Ali, R; Neill, P A; Beiersdorfer, P; Harris, C L; Rakovi?, M J; Wang, J G; Schultz, D R; Stancil, P C

    2005-05-12

    We report laboratory studies of the role played by multiple-electron capture (MEC) in solar wind induced cometary X-ray emission. Collisions of Ne{sup 10+} with He, Ne, Ar, CO, and CO{sub 2} have been investigated by means of the traditional singles X-ray spectroscopy in addition to the triple-coincidence measurements of X-rays, scattered projectile, and target recoil ions for the atomic targets. The coincidence measurements enable the reduction of the singles X-ray spectra into partial spectra originating in single-electron capture (SEC) and MEC collisions. The measurements provide unequivocal evidence for a significant role played by MEC, and strongly suggest that models based solely on SEC are bound to yield erroneous conclusions on the solar wind composition and velocities and on cometary atmospheres. The experimental relative importance of MEC collisions is compared with molecular classical-over-the-barrier model (MCBM), classical trajectory Monte Carlo (CTMC), and multi-channel Landau-Zener (MCLZ), calculations which can qualitatively reproduce the experimental trends.

  19. Improving the Capture of Co2 by Substituted Monoethanolamines: Electronic Effects of Fluorine and Methyl Substituents

    NARCIS (Netherlands)

    Gangarapu, S.; Marcelis, A.T.M.; Zuilhof, H.

    2012-01-01

    The influence of electronic and steric effects on the reaction between CO(2) and monoethanolamine (MEA) absorbents is investigated using computational methods. The pK(a) of the alkanolamine, the reaction enthalpy for carbamate formation, and the hydrolytic carbamate stability are important factors f

  20. Multiple Electron Capture Processes in Slow Collisions of Ar9+ Ions with Na Atoms

    Institute of Scientific and Technical Information of China (English)

    ZhuXiaolong; ShaShan; LiuHuiping; WeiBaoren; MaXinwen; WangZhengling; CaoShiping; QianDongbing; YangZhihu

    2003-01-01

    Slow collisions of highly charged ions with neutral atoms and molecules are of great importance in basic atomic collision physics, Recently, we built a new research facility for atomic physics at the Institute of Modern Physics. We report here the multiple electron transfer processes in collisions of Ar9+ with Na gas target at energy of 180 keV.

  1. Dipole-Guided Electron Capture Causes Abnormal Dissociations of Phosphorylated Pentapeptides

    DEFF Research Database (Denmark)

    Moss, Christopher L.; Chung, Thomas W.; Wyer, Jean

    2011-01-01

    in ECD is explained by a distortion of the Rydberg orbital space by the strong dipolar field of the peptide dication framework. The dipolar field steers the incoming electron to preferentially attach to the positively charged arginine side chain to form guanidinium radicals and trigger...

  2. Investigation of the Mechanism of Electron Capture and Electron Transfer Dissociation of Peptides with a Covalently Attached Free Radical Hydrogen Atom Scavenger.

    Science.gov (United States)

    Sohn, Chang Ho; Yin, Sheng; Peng, Ivory; Loo, Joseph A; Beauchamp, J L

    2015-11-15

    The mechanisms of electron capture and electron transfer dissociation (ECD and ETD) are investigated by covalently attaching a free-radical hydrogen atom scavenger to a peptide. The 2,2,6,6-tetramethylpiperidin-l-oxyl (TEMPO) radical was chosen as the scavenger due to its high hydrogen atom affinity (ca. 280 kJ/mol) and low electron affinity (ca. 0.45 ev), and was derivatized to the model peptide, FQX(TEMPO)EEQQQTEDELQDK. The X(TEMPO) residue represents a cysteinyl residue derivatized with an acetamido-TEMPO group. The acetamide group without TEMPO was also examined as a control. The gas phase proton affinity (882 kJ/mol) of TEMPO is similar to backbone amide carbonyls (889 kJ/mol), minimizing perturbation to internal solvation and sites of protonation of the derivatized peptides. Collision induced dissociation (CID) of the TEMPO tagged peptide dication generated stable odd-electron b and y type ions without indication of any TEMPO radical induced fragmentation initiated by hydrogen abstraction. The type and abundance of fragment ions observed in the CID spectra of the TEMPO and acetamide tagged peptides are very similar. However, ECD of the TEMPO labeled peptide dication yielded no backbone cleavage. We propose that a labile hydrogen atom in the charge reduced radical ions is scavenged by the TEMPO radical moiety, resulting in inhibition of N-Cα backbone cleavage processes. Supplemental activation after electron attachment (ETcaD) and CID of the charge-reduced precursor ion generated by electron transfer of the TEMPO tagged peptide dication produced a series of b + H (b(H)) and y + H (y(H)) ions along with some c ions having suppressed intensities, consistent with stable O-H bond formation at the TEMPO group. In summary, the results indicate that ECD and ETD backbone cleavage processes are inhibited by scavenging of a labile hydrogen atom by the localized TEMPO radical moiety. This observation supports the conjecture that ECD and ETD processes involve long

  3. On the viability of heterolytic peptide N-C(α) bond cleavage in electron capture and transfer dissociation mass spectrometry.

    Science.gov (United States)

    Wodrich, Matthew D; Zhurov, Konstantin O; Corminboeuf, Clémence; Tsybin, Yury O

    2014-03-20

    While frequently employed as an experimental technique, the mechanistic picture surrounding the gas-phase dissociation of peptides carrying multiple positive charges during electron capture and electron transfer dissociation tandem mass spectrometry remains incomplete. Despite this mechanistic uncertainty, most proposals agree that the peptide backbone N-Cα bond located to the C-terminal (right) side of an aminoketyl radical formed in a peptide backbone during the electron capture process is homolytically cleaved. Recently, we introduced the "enol" mechanism, which proposes that a backbone N-Cα bond located to the N-terminal (left) side of an aminoketyl radical is cleaved heterolytically. Here, we further validate this mechanism using replica-exchange molecular dynamics to create unbiased representative sets of low-energy conformers for several model tryptic peptide systems (H-Alax-Lys-OH(2+), x = 3-5). Transition state barrier enthalpies for the cleavage of N-Cα bonds proceeding via the homolytic (right-side) and heterolytic (left-side) pathways, determined by density functional computations, identify the preferred cleavage route for each conformer. These findings support our original hypothesis that heterolytic N-Cα cleavage can exist in a competitive balance with homolytic cleavages, independent of the relative energy of the precursor dication species. Smaller peptide systems see decreased heterolytic N-Cα cleavage probabilities, likely resulting from an insufficient hydrogen-bonding network needed to stabilize and ultimately annihilate the transition state zwitterion. This observation may explain the early dismissal of left-side cleavage pathways based on computational studies employing small model systems.

  4. Non-Radiative Step Facets in Semiconductor Nanowires.

    Science.gov (United States)

    Sanchez, Ana M; Zhang, Yunyan; Tait, Edward W; Hine, Nicholas D M; Liu, Huiyun; Beanland, Richard

    2017-03-24

    One of the main advantages of nanowires for functional applications is their high perfection, which results from surface image forces that act on line defects such as dislocations, rendering them unstable and driving them out of the crystal. Here we show that there is a class of linear defects that are stable in nanowires, with no long-range strain field or dislocation character. In zinc-blende semiconductors, they take the form of Ʃ3 (112) facets with heights constrained to be a multiple of three {111} monolayers. Density functional theory calculations show that they act as non-radiative recombination centres and have deleterious effects on nanowire properties. We present experimental observations of these defects on twin boundaries and twins that terminate inside GaAsP nanowires and find that they are indeed always multiples of three monolayers in height. Strategies to use the three-monolayer rule during growth to prevent their formation are discussed.

  5. Structural determination of zinc dithiophosphates in lubricating oils by gas chromatography-mass spectrometry with electron impact and electron-capture negative ion chemical ionization.

    Science.gov (United States)

    Becchi, M; Perret, F; Carraze, B; Beziau, J F; Michel, J P

    2001-01-05

    Pentafluorobenzyl ester derivatives were used to identify zinc dialkyldithiophosphates and diaryldithiophosphates antiwear engine oil additives by GC-electron impact ionization (EI) MS and GC-electron-capture negative ion chemical ionization (ECNCI) MS analysis. GC-EI-MS of the dialkyldithiophosphate-pentafluorobenzyl derivatives afforded characteristic fragment ions corresponding to the cleavage of one and two alkyl radicals. In most cases, information was only obtained on one alkyl chain. Additional and complete information was obtained with retention time indices using synthetic derivatives and with GC-ECNCI-MS analysis. ECNCI afforded characteristic dithiophosphate anions which allowed the determination of the total number of carbon atoms in the alkyl radicals. The diastereoisomer mixtures of 2-hydroxy-sec.-alkyl radicals were completely separated on GC analysis.

  6. The internal architecture of leukocyte lipid body organelles captured by three-dimensional electron microscopy tomography.

    Directory of Open Access Journals (Sweden)

    Rossana C N Melo

    Full Text Available Lipid bodies (LBs, also known as lipid droplets, are complex organelles of all eukaryotic cells linked to a variety of biological functions as well as to the development of human diseases. In cells from the immune system, such as eosinophils, neutrophils and macrophages, LBs are rapidly formed in the cytoplasm in response to inflammatory and infectious diseases and are sites of synthesis of eicosanoid lipid mediators. However, little is known about the structural organization of these organelles. It is unclear whether leukocyte LBs contain a hydrophobic core of neutral lipids as found in lipid droplets from adipocytes and how diverse proteins, including enzymes involved in eicosanoid formation, incorporate into LBs. Here, leukocyte LB ultrastructure was studied in detail by conventional transmission electron microscopy (TEM, immunogold EM and electron tomography. By careful analysis of the two-dimensional ultrastructure of LBs from human blood eosinophils under different conditions, we identified membranous structures within LBs in both resting and activated cells. Cyclooxygenase, a membrane inserted protein that catalyzes the first step in prostaglandin synthesis, was localized throughout the internum of LBs. We used fully automated dual-axis electron tomography to study the three-dimensional architecture of LBs in high resolution. By tracking 4 nm-thick serial digital sections we found that leukocyte LBs enclose an intricate system of membranes within their "cores". After computational reconstruction, we showed that these membranes are organized as a network of tubules which resemble the endoplasmic reticulum (ER. Our findings explain how membrane-bound proteins interact and are spatially arranged within LB "cores" and support a model for LB formation by incorporating cytoplasmic membranes of the ER, instead of the conventional view that LBs emerge from the ER leaflets. This is important to understand the functional capabilities of leukocyte

  7. The internal architecture of leukocyte lipid body organelles captured by three-dimensional electron microscopy tomography.

    Science.gov (United States)

    Melo, Rossana C N; Paganoti, Guillherme F; Dvorak, Ann M; Weller, Peter F

    2013-01-01

    Lipid bodies (LBs), also known as lipid droplets, are complex organelles of all eukaryotic cells linked to a variety of biological functions as well as to the development of human diseases. In cells from the immune system, such as eosinophils, neutrophils and macrophages, LBs are rapidly formed in the cytoplasm in response to inflammatory and infectious diseases and are sites of synthesis of eicosanoid lipid mediators. However, little is known about the structural organization of these organelles. It is unclear whether leukocyte LBs contain a hydrophobic core of neutral lipids as found in lipid droplets from adipocytes and how diverse proteins, including enzymes involved in eicosanoid formation, incorporate into LBs. Here, leukocyte LB ultrastructure was studied in detail by conventional transmission electron microscopy (TEM), immunogold EM and electron tomography. By careful analysis of the two-dimensional ultrastructure of LBs from human blood eosinophils under different conditions, we identified membranous structures within LBs in both resting and activated cells. Cyclooxygenase, a membrane inserted protein that catalyzes the first step in prostaglandin synthesis, was localized throughout the internum of LBs. We used fully automated dual-axis electron tomography to study the three-dimensional architecture of LBs in high resolution. By tracking 4 nm-thick serial digital sections we found that leukocyte LBs enclose an intricate system of membranes within their "cores". After computational reconstruction, we showed that these membranes are organized as a network of tubules which resemble the endoplasmic reticulum (ER). Our findings explain how membrane-bound proteins interact and are spatially arranged within LB "cores" and support a model for LB formation by incorporating cytoplasmic membranes of the ER, instead of the conventional view that LBs emerge from the ER leaflets. This is important to understand the functional capabilities of leukocyte LBs in health and

  8. Kuang's Semi-Classical Formalism for Calculating Electron Capture Cross Sections: A Space- Physics Application

    Science.gov (United States)

    Barghouty, A. F.

    2014-01-01

    Accurate estimates of electroncapture cross sections at energies relevant to the modeling of the transport, acceleration, and interaction of energetic neutral atoms (ENA) in space (approximately few MeV per nucleon) and especially for multi-electron ions must rely on detailed, but computationally expensive, quantum-mechanical description of the collision process. Kuang's semi-classical approach is an elegant and efficient way to arrive at these estimates. Motivated by ENA modeling efforts for apace applications, we shall briefly present this approach along with sample applications and report on current progress.

  9. Absolute activity measurement of the electron-capture-based radionuclides Ce-139, I-125, Ir-192 and Zn-65 by liquid scintillation coincidence counting

    CSIR Research Space (South Africa)

    Van Wyngaardt, WM

    2006-10-01

    Full Text Available measurements formed part of a regional comparison organized by the Asia Pacific Metrology Programme (APMP). Since Ce-139 decays simply by electron-capture to the 166 keV excited state of 139La. This state de-excites through the emission of conversion electrons...

  10. Direct observation of pure one-electron capture from the target inner shell in low-energy p+Na collisions

    NARCIS (Netherlands)

    Knoop, S; Morgenstern, R; Hoekstra, R

    2004-01-01

    One-electron removal in the p+Na collision system has been investigated at low energy (4-25 keV) by means of recoil ion momentum spectroscopy. The focus will be on the contribution of one-electron capture from the Na 2p inner shell into the hydrogen ground state, thereby leaving the Na+ target ion

  11. Electron-capture decay rate of 7Be@C60 by first-principles calculations based on density functional theory

    NARCIS (Netherlands)

    Morisato, T.; Ohno, K.; Ohtsuki, T.; Hirose, K.; Sluiter, M.; Kawazoe, Y.

    2008-01-01

    Carrying out a first-principles calculation assuming linear relationship between the electron density at Be nucleus and the electron-capture (EC) decay rate, we explained why 7Be@C60 shows higher EC decay rate than 7Be crystal, which was originally found experimentally by Ohtsuki et al. [Phys. Rev.

  12. Enhanced non-radiative energy transfer in hybrid III-nitride structures

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R. M.; Athanasiou, M.; Bai, J.; Liu, B.; Wang, T., E-mail: t.wang@sheffield.ac.uk [Department of Electrical and Electronic Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2015-09-21

    The effect of surface states has been investigated in hybrid organic/inorganic white light emitting structures that employ high efficiency, nearfield non-radiative energy transfer (NRET) coupling. The structures utilize blue emitting InGaN/GaN multiple quantum well (MQW) nanorod arrays to minimize the separation with a yellow emitting F8BT coating. Surface states due to the exposed III-nitride surfaces of the nanostructures are found to reduce the NRET coupling rate. The surface states are passivated by deposition of a silicon nitride layer on the III-nitride nanorod surface leading to reduced surface recombination. A low thickness surface passivation is shown to increase the NRET coupling rate by 4 times compared to an un-passivated hybrid structure. A model is proposed to explain the increased NRET rate for the passivated hybrid structures based on the reduction in surface electron depletion of the passivated InGaN/GaN MQW nanorods surfaces.

  13. Enhanced non-radiative energy transfer in hybrid III-nitride structures

    Science.gov (United States)

    Smith, R. M.; Athanasiou, M.; Bai, J.; Liu, B.; Wang, T.

    2015-09-01

    The effect of surface states has been investigated in hybrid organic/inorganic white light emitting structures that employ high efficiency, nearfield non-radiative energy transfer (NRET) coupling. The structures utilize blue emitting InGaN/GaN multiple quantum well (MQW) nanorod arrays to minimize the separation with a yellow emitting F8BT coating. Surface states due to the exposed III-nitride surfaces of the nanostructures are found to reduce the NRET coupling rate. The surface states are passivated by deposition of a silicon nitride layer on the III-nitride nanorod surface leading to reduced surface recombination. A low thickness surface passivation is shown to increase the NRET coupling rate by 4 times compared to an un-passivated hybrid structure. A model is proposed to explain the increased NRET rate for the passivated hybrid structures based on the reduction in surface electron depletion of the passivated InGaN/GaN MQW nanorods surfaces.

  14. A Novel Feature Extraction Approach Using Window Function Capturing and QPSO-SVM for Enhancing Electronic Nose Performance

    Directory of Open Access Journals (Sweden)

    Xiuzhen Guo

    2015-06-01

    Full Text Available In this paper, a novel feature extraction approach which can be referred to as moving window function capturing (MWFC has been proposed to analyze signals of an electronic nose (E-nose used for detecting types of infectious pathogens in rat wounds. Meanwhile, a quantum-behaved particle swarm optimization (QPSO algorithm is implemented in conjunction with support vector machine (SVM for realizing a synchronization optimization of the sensor array and SVM model parameters. The results prove the efficacy of the proposed method for E-nose feature extraction, which can lead to a higher classification accuracy rate compared to other established techniques. Meanwhile it is interesting to note that different classification results can be obtained by changing the types, widths or positions of windows. By selecting the optimum window function for the sensor response, the performance of an E-nose can be enhanced.

  15. Fragmentation dynamics of CO(2)(3+) investigated by multiple electron capture in collisions with slow highly charged ions.

    Science.gov (United States)

    Neumann, N; Hant, D; Schmidt, L Ph H; Titze, J; Jahnke, T; Czasch, A; Schöffler, M S; Kreidi, K; Jagutzki, O; Schmidt-Böcking, H; Dörner, R

    2010-03-12

    Fragmentation of highly charged molecular ions or clusters consisting of more than two atoms can proceed in a one step synchronous manner where all bonds break simultaneously or sequentially by emitting one ion after the other. We separated these decay channels for the fragmentation of CO(2)(3+) ions by measuring the momenta of the ionic fragments. We show that the total energy deposited in the molecular ion is a control parameter which switches between three distinct fragmentation pathways: the sequential fragmentation in which the emission of an O(+) ion leaves a rotating CO(2+) ion behind that fragments after a time delay, the Coulomb explosion and an in-between fragmentation--the asynchronous dissociation. These mechanisms are directly distinguishable in Dalitz plots and Newton diagrams of the fragment momenta. The CO(2)(3+) ions are produced by multiple electron capture in collisions with 3.2 keV/u Ar(8+) ions.

  16. A Novel Feature Extraction Approach Using Window Function Capturing and QPSO-SVM for Enhancing Electronic Nose Performance.

    Science.gov (United States)

    Guo, Xiuzhen; Peng, Chao; Zhang, Songlin; Yan, Jia; Duan, Shukai; Wang, Lidan; Jia, Pengfei; Tian, Fengchun

    2015-06-29

    In this paper, a novel feature extraction approach which can be referred to as moving window function capturing (MWFC) has been proposed to analyze signals of an electronic nose (E-nose) used for detecting types of infectious pathogens in rat wounds. Meanwhile, a quantum-behaved particle swarm optimization (QPSO) algorithm is implemented in conjunction with support vector machine (SVM) for realizing a synchronization optimization of the sensor array and SVM model parameters. The results prove the efficacy of the proposed method for E-nose feature extraction, which can lead to a higher classification accuracy rate compared to other established techniques. Meanwhile it is interesting to note that different classification results can be obtained by changing the types, widths or positions of windows. By selecting the optimum window function for the sensor response, the performance of an E-nose can be enhanced.

  17. Half-life of the electron-capture decay of 97Ru: Precision measurement shows no temperature dependence

    CERN Document Server

    Goodwin, J R; Iacob, V E; Hardy, J C; 10.1103/PhysRevC.80.045501

    2009-01-01

    We have measured the half-life of the electron-capture (ec) decay of 97Ru in a metallic environment, both at low temperature (19K), and also at room temperature. We find the half-lives at both temperatures to be the same within 0.1%. This demonstrates that a recent claim that the ec decay half-life for 7Be changes by $0.9% +/- 0.2% under similar circumstances certainly cannot be generalized to other ec decays. Our results for the half-life of 97Ru, 2.8370(14)d at room temperature and 2.8382(14)d at 19K, are consistent with, but much more precise than, previous room-temperature measurements. In addition, we have also measured the half-lives of the beta-emitters 103Ru and 105Rh at both temperatures, and found them also to be unchanged.

  18. Analytical Method Validation of Selected Organochlorine Pesticides in Fortified Rice Using Gas Chromatography with Electron Capture Detector

    Directory of Open Access Journals (Sweden)

    Mutia Kusuma Wardani

    2014-01-01

    Full Text Available Gas chromatography with electron capture detector (GC-ECD has been validated for simultaneous determination of selected organochlorine pesticides namely heptachlor, endosulfan, dieldrin, dan p,p’-dichlorodiphenyltrichloroethane (p,p’-DDT using aldrin as standard internal. Some parameters for analytical method validation were evaluated, i.e. linearity, precision, sensitivity expressed with limit of detection and limit of quantification, and recovery. GC-ECD was linear for determination of these pesticides with r values ≥ 0.99. The values of LOD obtained were 2.50, 2.97, 1.61, and 2.54 ng/mL for heptachlor, endosulphan, dieldrin, and p,p’-DDT, respectively. Furthermore, the relative standard deviation (RSD values obtained for the assessment of analytical precision were lower than those required by Horwitz. Finally, the used GC-ECD method was accurate for determination of these organochlorine psticides in fortified rice samples which were indicated by the acceptable recovery percentages.

  19. Stellar electron-capture rates in pf-shell nuclei from quasiparticle random-phase approximation calculations

    CERN Document Server

    Sarriguren, P

    2013-01-01

    Electron-capture rates at different density and temperature conditions are evaluated for a set of pf-shell nuclei representative of the constituents in presupernova formations. The nuclear structure part of the problem is described within a quasiparticle random-phase approximation based on a deformed Skyrme Hartree-Fock selfconsistent mean field with pairing correlations and residual interactions in particle-hole and particle-particle channels. The energy distributions of the Gamow-Teller strength are evaluated and compared to benchmark shell-model calculations and experimental data extracted from charge-exchange reactions. The model dependence of the weak rates are discussed and the various sensitivities to both density and temperature are analyzed.

  20. Towards saturation of the electron-capture delayed fission probability: The new isotopes 240Es and 236Bk

    Directory of Open Access Journals (Sweden)

    J. Konki

    2017-01-01

    Full Text Available The new neutron-deficient nuclei 240Es and 236Bk were synthesised at the gas-filled recoil separator RITU. They were identified by their radioactive decay chains starting from 240Es produced in the fusion–evaporation reaction 209Bi(34S,3n240Es. Half-lives of 6(2s and 22−6+13s were obtained for 240Es and 236Bk, respectively. Two groups of α particles with energies Eα=8.19(3MeV and 8.09(3MeV were unambiguously assigned to 240Es. Electron-capture delayed fission branches with probabilities of 0.16(6 and 0.04(2 were measured for 240Es and 236Bk, respectively. These new data show a continuation of the exponential increase of ECDF probabilities in more neutron-deficient isotopes.

  1. After-Effects of the Cobalt-57-Iron-57 Electron-Capture Reaction in Hexacyanocobaltate (III) Complexes

    DEFF Research Database (Denmark)

    Fenger, Jørgen Folkvard; Siekierska, K.E.; Olsen, J.

    1973-01-01

    Isomorphous hexacyanocobaltate(III) complexes with the bivalent metal cations Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ have been labelled with 57Co and used as Mössbauer sources. Whilst the spectrum of the complex Fe3[57Co(CN)6]2 can be resolved into a single line corresponding to the ion Fe II...... (CN)6 4– and a doublet, those of all the other sources result in two doublets, of which one corresponds to the ion Fe III (CN)6 3–. The extra doublet in these spectra shows that the 57Co–57Fe electron-capture reaction gives rise to the formation of a new 57Fe labelled species, tentatively identified...

  2. Longitudinal assessment of pain outcomes in the clinical setting: development of the "APOLO" electronic data capture system.

    Science.gov (United States)

    Hassett, Afton L; Wasserman, Ronald; Goesling, Jenna; Rakovitis, Kevin; Shi, Baorong; Brummett, Chad M

    2012-01-01

    Data to fully evaluate the effectiveness of many commonly used interventions in the clinical pain management setting are inadequate. Clinical data collected for patient management often are not based on validated instruments, and this impedes the ability to conduct longitudinal research. To address these needs, modified patient intake and return visit forms were established and the Assessment of Pain Outcomes Longitudinal Electronic Data Capture system was developed. Data collection has been underway since November 22, 2010. As of December 7, 2011, 951 New Patient and 688 Return Visit forms had been entered. The forms have been well received, with less than 6.5% failing to complete at least 90% of the data requested. Accuracy of data entry is excellent, with an error rate of 1 in 11,250 potential data points. Data output converts easily to standard statistical programs. The creation of a pain outcomes database using validated measures and clinically relevant data is feasible.

  3. Electron capture and transfer-ionization processes in {sup 4}He{sup 2+}+Ar collision at 12.5 keV amu{sup -1}

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Bordenave-Montesquieu, D.; Bordenave-Montesquieu, A.; Benhenni, M. [Laboratoire Collisions, Agregats, Reactivite, IRSAMC, UMR 5589 CNRS and Universite Paul Sabatier, 31062 Toulouse Cedex (France)

    1998-05-14

    Electron emission in the {sup 4}He{sup 2+}+Ar collisional system has been investigated at 35 deg. and 12.5 keV amu{sup -1} collision velocity, in coincidence with the recoil target ion charges. Direct single ionization is found to be negligible with respect to single-electron capture. Contributions of transfer-ionization processes are stressed in the production of Ar{sup 2+} to Ar{sup 4+} ions; those of direct ionization, double excitation of the target and double capture into autoionization states of helium are instead found to be much less probable. Among the two-electron processes which explain the formation of Ar{sup 2+} ions, the double capture into autoionizing states of helium remains unimportant with respect to a pure transfer ionization process (one captured electron plus one ionized electron). The measured predominant production of Ar{sup 3+} ions illustrates the role played by three-electron processes, mainly a two-electron transfer accompanied by a single-target ionization. Finally, the formation of Ar{sup 4+} ions is connected with more complex transfer ionization processes. A qualitative analysis of these results is made within the quasimolecular approach. (author). Letter-to-the-editor.

  4. Molecular treatment of single (dissociative and nondissociative) and double electron capture in He{sup 2+} + H{sub 2} collisions

    Energy Technology Data Exchange (ETDEWEB)

    Errea, L F [Laboratorio Asociado al CIEMAT de Fisica Atomica y Molecular en Plasmas de Fusion, Departamento de Quimica, Universidad Autonoma, 28049 Madrid (Spain); Macias, A [Laboratorio Asociado al CIEMAT de Fisica Atomica y Molecular en Plasmas de Fusion, Departamento de Quimica, Universidad Autonoma, 28049 Madrid (Spain); Mendez, L [Laboratorio Asociado al CIEMAT de Fisica Atomica y Molecular en Plasmas de Fusion, Departamento de Quimica, Universidad Autonoma, 28049 Madrid (Spain); Pons, B [Laboratorio Asociado al CIEMAT de Fisica Atomica y Molecular en Plasmas de Fusion, Departamento de Quimica, Universidad Autonoma, 28049 Madrid (Spain); Riera, A [Laboratorio Asociado al CIEMAT de Fisica Atomica y Molecular en Plasmas de Fusion, Departamento de Quimica, Universidad Autonoma, 28049 Madrid (Spain)

    2003-04-14

    We present close-coupling calculations of total cross sections for single and double electron capture in He{sup 2+} + H{sub 2} collisions in the range 0.5- 25 keV amu{sup -1}, and compare them with experimental data. We confirm the experimental finding that the dominant process for E {approx}> 3 keV amu{sup -1} is the nondissociative capture He{sup 2+} + H{sub 2} {yields} He{sup +}(2l) + H{sub 2}{sup +} (1{sigma} {sub g}), while at lower energies it is dissociative capture leading to He{sup +}(1s) + H{sup +} + H. Our calculations also show that He(1s2l) is the main output of the two electron capture process. (letter to the editor)

  5. S2O - A software tool for integrating research data from general purpose statistic software into electronic data capture systems.

    Science.gov (United States)

    Bruland, Philipp; Dugas, Martin

    2017-01-07

    Data capture for clinical registries or pilot studies is often performed in spreadsheet-based applications like Microsoft Excel or IBM SPSS. Usually, data is transferred into statistic software, such as SAS, R or IBM SPSS Statistics, for analyses afterwards. Spreadsheet-based solutions suffer from several drawbacks: It is generally not possible to ensure a sufficient right and role management; it is not traced who has changed data when and why. Therefore, such systems are not able to comply with regulatory requirements for electronic data capture in clinical trials. In contrast, Electronic Data Capture (EDC) software enables a reliable, secure and auditable collection of data. In this regard, most EDC vendors support the CDISC ODM standard to define, communicate and archive clinical trial meta- and patient data. Advantages of EDC systems are support for multi-user and multicenter clinical trials as well as auditable data. Migration from spreadsheet based data collection to EDC systems is labor-intensive and time-consuming at present. Hence, the objectives of this research work are to develop a mapping model and implement a converter between the IBM SPSS and CDISC ODM standard and to evaluate this approach regarding syntactic and semantic correctness. A mapping model between IBM SPSS and CDISC ODM data structures was developed. SPSS variables and patient values can be mapped and converted into ODM. Statistical and display attributes from SPSS are not corresponding to any ODM elements; study related ODM elements are not available in SPSS. The S2O converting tool was implemented as command-line-tool using the SPSS internal Java plugin. Syntactic and semantic correctness was validated with different ODM tools and reverse transformation from ODM into SPSS format. Clinical data values were also successfully transformed into the ODM structure. Transformation between the spreadsheet format IBM SPSS and the ODM standard for definition and exchange of trial data is feasible

  6. Capturing district nursing through a knowledge-based electronic caseload analysis tool (eCAT).

    Science.gov (United States)

    Kane, Kay

    2014-03-01

    The Electronic Caseload Analysis Tool (eCAT) is a knowledge-based software tool to assist the caseload analysis process. The tool provides a wide range of graphical reports, along with an integrated clinical advisor, to assist district nurses, team leaders, operational and strategic managers with caseload analysis by describing, comparing and benchmarking district nursing practice in the context of population need, staff resources, and service structure. District nurses and clinical lead nurses in Northern Ireland developed the tool, along with academic colleagues from the University of Ulster, working in partnership with a leading software company. The aim was to use the eCAT tool to identify the nursing need of local populations, along with the variances in district nursing practice, and match the workforce accordingly. This article reviews the literature, describes the eCAT solution and discusses the impact of eCAT on nursing practice, staff allocation, service delivery and workforce planning, using fictitious exemplars and a post-implementation evaluation from the trusts.

  7. Full-band structure modeling of the radiative and non-radiative properties of semiconductor materials and devices (Presentation Recording)

    Science.gov (United States)

    Bellotti, Enrico; Wen, Hanqing; Pinkie, Benjamin; Matsubara, Masahiko; Bertazzi, Francesco

    2015-08-01

    Understanding the radiative and non-radiative properties of semiconductor materials is a prerequisite for optimizing the performance of existing light emitters and detectors and for developing new device architectures based on novel materials. Due to the ever increasing complexity of novel semiconductor systems and their relative technological immaturity, it is essential to have design tools and simulation strategies that include the details of the microscopic physics and their dependence on the macroscopic (continuum) variables in the macroscopic device models. Towards this end, we have developed a robust full-band structure based approach that can be used to study the intrinsic material radiative and non-radiative properties and evaluate the same characteristics of low-dimensional device structures. A parallel effort is being carried out to model the effect of substrate driven stress/strain and material quality (dislocations and defects) on microscopic quantities such as non-radiative recombination rate. Using this modeling approach, we have extensively studied the radiative and non-radiative properties of both elemental (Si and Ge) and compound semiconductors (HgCdTe, InGaAs, InAsSb and InGaN). In this work we outline the details of the modelling approach, specifically the challenges and advantages related to the use of the full-band description of the material electronic structure. We will present a detailed comparison of the radiative and Auger recombination rates as a function of temperature and doping for HgCdTe and InAsSb that are two important materials for infrared detectors and emitters. Furthermore we will discuss the role of non-radiatiave Auger recombination processes in explaining the performance of light emitter diodes. Finally we will present the extension of the model to low dimensional structures employed in a number of light emitter and detector structures.

  8. Optimization of metallic magnetic calorimeters for high resolution measurement of the {sup 163}Ho electron capture spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Haehnle, Sebastian [Kirchhoff-Institute for Physics, Heidelberg University (Germany); Collaboration: ECHo-Collaboration

    2015-07-01

    The absolute scale of the neutrino mass eigenstates is one of the puzzles in modern particle physics. One method to investigate the value of the electron neutrino mass is to analyse the high energy region of the {sup 163}Ho electron capture spectrum. In the ECHo experiment low temperature metallic magnetic calorimeters (MMCs) are used for the calorimetric measurements of the EC spectrum of {sup 163}Ho. To ensure 100% quantum efficiency, the {sup 163}Ho ions are implanted into the gold absorber. Experiments carried out with a first detector prototype have demonstrated that MMC-based detectors fulfill the requirements in terms of energy resolution, rise-time and energy calibration. We discuss methods to further optimize the performance of MMCs with implanted {sup 163}Ho. Our aim is to achieve an energy resolution Δ E{sub FWHM} < 5 eV and a signal rise-time τ < 100 ns. An important aspect of this optimization is to define the maximum activity per pixel. This will result from a compromise between allowed unresolved pile-up fraction, additional heat capacity in the absorber due to Ho ions in the absorber material and minimization of the pixel number. We discuss experimental approaches for the determination of the optimal activity per pixel.

  9. Electron capture and beta-decay rates for sd-shell nuclei in stellar environments relevant to high density O-Ne-Mg cores

    CERN Document Server

    Suzuki, Toshio; Nomoto, Ken'ichi

    2015-01-01

    Electron capture and beta-decay rates for nuclear pairs in sd-shell are evaluated at high densities and high temperatures relevant to the final evolution of electron-degenerate O-Ne-Mg cores of stars with the initial masses of 8-10 solar mass. Electron capture induces a rapid contraction of the electron-degenerate O-Ne-Mg core. The outcome of rapid contraction depends on the evolutionary changes in the central density and temperature, which are determined by the competing processes of contraction, cooling, and heating. The fate of the stars are determined by these competitions, whether they end up with electron-capture supernovae or Fe core-collapse supernovae. Since the competing processes are induced by electron capture and beta-decay, the accurate weak rates are crucially important. The rates are obtained for pairs with A=20, 23, 24, 25 and 27 by shell-model calculations in sd-shell with the USDB Hamiltonian. Effects of Coulomb corrections on the rates are evaluated. The rates for pairs with A=23 and 25 ar...

  10. Single electron ionization and electron capture cross sections for (C{sup 6+}, H{sub 2}O) interaction within the Classical Trajectory Monte Carlo (CTMC) approach

    Energy Technology Data Exchange (ETDEWEB)

    Tran, H.N., E-mail: tranngochoang@tdt.edu.vn [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Dao, D.D. [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Incerti, S. [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Karamitros, M. [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); Nhan Hao, T.V. [Center of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Center for Theoretical and Computational Physics, College of Education, Hue University, 34 Le Loi Street, Hue City (Viet Nam); Dang, T.M. [VNUHCM-University of Science (Viet Nam); Francis, Z. [Saint Joseph University, Beyrouth (Lebanon)

    2016-01-01

    In this work, we present a derivation of cross sections for single ionization and electron capture processes within the Classical Trajectory Monte Carlo (CTMC) approach. Specifically, we have used a potential stemming from an ab initio calculation in Green et al.’s framework to describe the dynamics of the water molecule system. Proposing a modified version of the Classical Over-Barrier (COB) potential, we have found that a cut-off of roughly 28 a.u. on the initial distance of the projectile produced a reasonable accuracy. A global agreement has been obtained in our calculations compared to experimental and other theoretical results for C{sup 6+} ion energies ranging from 10 keV/u to 10 MeV/u.

  11. Kuang's Semi-Classical Formalism for Electron Capture Cross-Sections in Ion-Ion Collisions at Approximately to MeV/amu: Application to ENA Modeling

    Science.gov (United States)

    Barghouty, A. F.

    2012-01-01

    Recent discovery by STEREO A/B of energetic neutral hydrogen is spurring an interest and need for reliable estimates of electron capture cross sections at few MeVs per nucleon as well as for multi-electron ions. Required accuracy in such estimates necessitates detailed and involved quantum-mechanical calculations or expensive numerical simulations. For ENA modeling and similar purposes, a semi-classical approach offers a middle-ground approach. Kuang's semiclassical formalism to calculate electron-capture cross sections for single and multi-electron ions is an elegant and efficient method, but has so far been applied to limited and specific laboratory measurements and at somewhat lower energies. Our goals are to test and extend Kuang s method to all ion-atom and ion-ion collisions relevant to ENA modeling, including multi-electron ions and for K-shell to K-shell transitions.

  12. Theoretical state-selective and total cross sections for electron capture from helium atoms by fully stripped ions

    Science.gov (United States)

    Mančev, I.; Milojević, N.; Belkić, Dž.

    2015-03-01

    The four-body boundary-corrected first Born (CB1-4B) approximation is used to compute cross sections for single electron capture from helium targets by fully stripped ions. The projectile ions are H+, He2+, Li3+, Be4+, B5+, C6+, N7+, O8+, and F9+. An extensive list of theoretical state-to-state cross sections in these collisions at energies ranging from 20 to 10 000 keV/amu is given. This list includes the state-selective cross sections Qnlm for each individual triple of the usual quantum numbers { n , l , m } of the final hydrogen-like states alongside Qnl and Qn for the pertinent sub-shells and shells where the respective summations over m and { l , m } have been carried out. The maximal value of the principal quantum number n was chosen to vary from 4 (H+) to 10 (F9+) so as to satisfy the condition n ≥ZP, where ZP is the nuclear charge of the projectile. Usually, the largest cross sections stem from those values of n that match the projectile charge (n =ZP) . The total cross sections for capture summed over all the quantum numbers { n , l , m } are also tabulated. The overall goal of this study is to fill in lacunae in the existing databases of charge exchange cross sections that are needed in several inter-disciplinary fields. For example, in particle transport physics, which is of utmost importance in such emerging branches as hadron therapy, these cross sections constitute a part of the multifaceted input data for stochastic simulations of energy losses of multiply charged ions in matter, including tissue. Other significant uses of the present data are anticipated in charge exchange diagnostics within thermonuclear research project as well as in applications covering the relevant parts of plasma physics and astrophysics.

  13. Multiple ionization of neon induced by Li3+ and C3+ projectiles: influence of projectile screening in the ionization and electron capture channels

    Science.gov (United States)

    Ihani, J. S.; Luna, H.; Wolff, W.; Montenegro, E. C.

    2013-06-01

    Neq + (q = 1,2,3,4) ionization and charge exchange cross sections (total electron capture, single electron capture and transfer ionization) in the collisions with Li3+, with energies between 100 and 900 keV amu-1, and C3+, with energies between 250 and 500 keV amu-1 are reported. Bare Li3+ projectiles give a key benchmark to study the role of projectile screening in collisions involving dressed projectile ions, and the measurements have shown a strong screening effect for all n-fold recoil ion charge states in the ionization channel which, unexpectedly, does not appear for transfer ionization.

  14. A data-capture system for post-marketing surveillance of drugs that integrates with hospital electronic health records

    Directory of Open Access Journals (Sweden)

    Yamamoto K

    2011-04-01

    Full Text Available Keiichi Yamamoto1, Shigemi Matsumoto2, Kazuhiro Yanagihara2, Satoshi Teramukai1, Masanori Fukushima1,2,31Department of Clinical Trial Design and Management, Translational Research Center, Kyoto University Hospital, Kyoto, Japan; 2Outpatient Oncology Unit, Kyoto University Hospital, Kyoto, Japan; 3Translational Research Informatics Center, Foundation for Biomedical Research and Innovation, Kobe, JapanPurpose: In conventional clinical studies, the cost of data management for the purposes of quality control tend to be high and collecting paper-based case report forms (CRFs can be burdensome, because paper-based CRFs must be developed and filled out for each clinical study protocol. Use of electronic health records (EHRs for this purpose could reduce costs and improve data quality in clinical studies. Kyoto University Hospital launched an EHR system in January 2005. At the same time, a replicate of that database was established for other purposes. At the Outpatient Oncology Unit of Kyoto University Hospital we developed a data-capture system that includes a cancer clinical database system and a data warehouse for outcomes studies. This system allows us to accumulate data at low cost and apply it to various uses in clinical or outcomes studies. Here we report on the application of this system to the post-marketing surveillance of drugs.Methods: We evaluated the availability of this system and identified problems for future development. With this system investigators can register cases for post-marketing surveillance, and the registered cases are listed on a screen. When CRFs for a particular case are required, data can be extracted from the list and CRFs are produced in PDF format.Results and conclusion: In this study we confirmed the applicability of our new system to post-marketing surveillance in providing prompt and efficient data exchange. We expect it to reduce the cost of data management and analysis and to improve the quality of data in post

  15. Valence parity to distinguish c' and z• ions from electron capture dissociation/electron transfer dissociation of peptides: effects of isomers, isobars, and proteolysis specificity.

    Science.gov (United States)

    Mao, Yuan; Tipton, Jeremiah D; Blakney, Greg T; Hendrickson, Christopher L; Marshall, Alan G

    2011-10-15

    Valence parity provides a way to distinguish between N-terminal and C-terminal electron capture dissociation/electron transfer dissociation (ECD/ETD) product ions based on their number of hydrogen plus nitrogen atoms determined by accurate mass measurement and forms a basis for de novo peptide sequencing. The effect of mass accuracy (0.1-1 ppm error) on c'/z(•) overlap and unique elemental composition overlap is evaluated for a database of c'/z(•) product ions each based on all possible amino acid combinations and four subset databases containing the same c' ions but with z(•) ions determined by in silico digestion with trypsin, Glu-C, Lys-C, or chymotrypsin. High mass accuracy reduces both c'/z(•) overlap and unique elemental composition overlap. Of the four proteases, trypsin offers slightly better discrimination between N- and C-terminal ECD/ETD peptides. Interestingly, unique elemental composition overlap curves for c'/c' and z(•)/z(•) peptide ions exhibit discontinuities at certain nominal masses for 0.1-1.0 ppm mass error. Also, as noted in the companion article (Polfer et al. Anal. Chem.2011, DOI: 10.1021/ac201624t), the number of ECD/ETD product ion amino acid compositions as a function of nominal mass increases exponentially with mass but with a superimposed modulation due to higher prevalence of certain elemental compositions.

  16. Multicentre clinical trials' data management: a hybrid solution to exploit the strengths of electronic data capture and electronic health records systems.

    Science.gov (United States)

    Fraccaro, Paolo; Dentone, Chiara; Fenoglio, Daniela; Giacomini, Mauro

    2013-12-01

    Clinical Trials (CTs) are indispensable instruments for evidence-based medicine and frequently necessitate the management, sharing and analysis of large amounts of data amongst partners in different locations. To effectively satisfy these requirements, the proposed solution combines a web platform and a Clinical Data Management System (CDMS) to exploit the strengths of Electronic Health Records (EHR) and Electronic Data Capture (EDC) systems. The core of the proposal is a relational database which has high data structuring characteristics and utilises biomedical controlled vocabularies (e.g. LOINC and ICD). In addition, units and normality ranges were collected for data comparison through the application of the Z-score transformation. The obtained CDMS preserves the EDC's flexibility and user autonomy and permits the creation of patient cohorts, as in the EHR. Accordingly, clinical information, after the initial recording, is available for different simultaneous multicentre CTs. Furthermore, interface runtime controls guarantee high data quality during data entering processes. Currently, the proposed system has been developed in the HIV and eye diseases fields in Italy. The proposed solution is flexible and suitable to perform multicentre research within a varying range of medical domains. In the future, the automatic importation of information from hospitals has been planned through an HL7 standard interface which would improve both data quantity and quality.

  17. Impact parameter dependent electron capture by decelerated U{sup 91+} ions at 20 MeV/u using crystal channeling conditions

    Energy Technology Data Exchange (ETDEWEB)

    Dauvergne, D. E-mail: d.dauvergne@ipnl.in2p3.fr; Braeuning-Demian, A.; Bosch, F.; Braeuning, H.; Chevallier, M.; Cohen, C.; Gumberidze, A.; L' Hoir, A.; Kirsch, R.; Kozhuharov, C.; Liesen, D.; Mokler, P.H.; Poizat, J.C.; Ray, C.; Stoehlker, Th.; Tarisien, M.; Testa, E.; Toleikis, S.; Toulemonde, M

    2003-05-01

    We present results of an experiment using decelerated U{sup 91+} ions, extracted from the GSI-ESR storage ring, and transmitted through a thin silicon crystal in channeling conditions. Charge state at emergence, secondary electron multiplicity and X-rays are measured simultaneously. These conditions allow to study the competition between mechanical electron capture (MEC) and radiative electron capture (REC) as a function of impact parameter. We observe that REC is the dominant charge exchange process for the best channeled ions, i.e. those travelling always far from the silicon target core electrons. For ions with high transverse energy, MEC into highly excited states is counterbalanced by enhanced ionization arising from a succession of close collisions along atomic rows.

  18. Native electrospray ionization and electron-capture dissociation for comparison of protein structure in solution and the gas phase.

    Science.gov (United States)

    Zhang, Hao; Cui, Weidong; Gross, Michael L

    2013-11-15

    The importance of protein and protein-complex structure motivates improvements in speed and sensitivity of structure determination in the gas phase and comparison with that in solution or solid state. An opportunity for the gas phase measurement is mass spectrometry (MS) combined with native electrospray ionization (ESI), which delivers large proteins and protein complexes in their near-native states to the gas phase. In this communication, we describe the combination of native ESI, electron-capture dissociation (ECD), and top-down MS for exploring the structures of ubiquitin and cytochrome c in the gas phase and their relation to those in the solid-state and solution. We probe structure by comparing the protein's flexible regions, as predicted by the B-factor in X-ray crystallography, with the ECD fragments. The underlying hypothesis is that maintenance of structure gives fragments that can be predicted from B-factors. This strategy may be applicable in general when X-ray structures are available and extendable to the study of intrinsically disordered proteins.

  19. Probing the Gaseous Structure of a β-Hairpin Peptide with H/D Exchange and Electron Capture Dissociation

    Science.gov (United States)

    Straus, Rita N.; Jockusch, Rebecca A.

    2016-12-01

    An improved understanding of the extent to which native protein structure is retained upon transfer to the gas phase promises to enhance biological mass spectrometry, potentially streamlining workflows and providing fundamental insights into hydration effects. Here, we investigate the gaseous conformation of a model β-hairpin peptide using gas-phase hydrogen-deuterium (H/D) exchange with subsequent electron capture dissociation (ECD). Global gas-phase H/D exchange levels, and residue-specific exchange levels derived from ECD data, are compared among the wild type 16-residue peptide GB1p and several variants. High protection from H/D exchange observed for GB1p, but not for a truncated version, is consistent with the retention of secondary structure of GB1p in the gas phase or its refolding into some other compact structure. Four alanine mutants that destabilize the hairpin in solution show levels of protection similar to that of GB1p, suggesting collapse or (re)folding of these peptides upon transfer to the gas phase. These results offer a starting point from which to understand how a key secondary structural element, the β-hairpin, is affected by transfer to the gas phase. This work also demonstrates the utility of a much-needed addition to the tool set that is currently available for the investigation of the gaseous conformation of biomolecules, which can be employed in the future to better characterize gaseous proteins and protein complexes.

  20. Evaluation of Pentachlorophenol Residues in Some Hygienic Papers Prepared from Virgin and Secondary Pulp by Electron Capture Gas Chromatographic Method

    Directory of Open Access Journals (Sweden)

    Behrouz Akbari-adergani

    2016-01-01

    Full Text Available In this study, residual amount of pentachlorophenol (PCP as the most important paper preservative, which is extremely hazardous pollutant, was determined in some tissue papers and napkins. Twenty-five samples of two producing hygienic paper factories prepared from virgin and secondary pulp were analyzed for the presence of trace amount of PCP. The analytical procedure involved direct extraction of PCP from hygienic paper and its determination by gas chromatography with electron capture detection. The statistical results for the analysis of all samples revealed that there were significant differences between mean of PCP in hygienic papers prepared from virgin and secondary pulp (P<0.05. This method gave recoveries of 86-98% for hygienic paper made from virgin pulp and 79-92% for hygienic paper made from secondary pulp. The limit of detection (LOD and limit of quantification (LOQ for PCP were 6.3 and 21.0 mg/kg, respectively. The analytical method has the requisite sensitivity, accuracy, precision and specificity to assay PCP in hygienic papers. This study demonstrates a concern with exposition to PCP considering that hygienic paper is largely consumed in the society.

  1. Probing the Gaseous Structure of a β-Hairpin Peptide with H/D Exchange and Electron Capture Dissociation

    Science.gov (United States)

    Straus, Rita N.; Jockusch, Rebecca A.

    2017-02-01

    An improved understanding of the extent to which native protein structure is retained upon transfer to the gas phase promises to enhance biological mass spectrometry, potentially streamlining workflows and providing fundamental insights into hydration effects. Here, we investigate the gaseous conformation of a model β-hairpin peptide using gas-phase hydrogen-deuterium (H/D) exchange with subsequent electron capture dissociation (ECD). Global gas-phase H/D exchange levels, and residue-specific exchange levels derived from ECD data, are compared among the wild type 16-residue peptide GB1p and several variants. High protection from H/D exchange observed for GB1p, but not for a truncated version, is consistent with the retention of secondary structure of GB1p in the gas phase or its refolding into some other compact structure. Four alanine mutants that destabilize the hairpin in solution show levels of protection similar to that of GB1p, suggesting collapse or (re)folding of these peptides upon transfer to the gas phase. These results offer a starting point from which to understand how a key secondary structural element, the β-hairpin, is affected by transfer to the gas phase. This work also demonstrates the utility of a much-needed addition to the tool set that is currently available for the investigation of the gaseous conformation of biomolecules, which can be employed in the future to better characterize gaseous proteins and protein complexes.

  2. Mapping a Noncovalent Protein-Peptide Interface by Top-Down FTICR Mass Spectrometry Using Electron Capture Dissociation

    Science.gov (United States)

    Clarke, David J.; Murray, Euan; Hupp, Ted; Mackay, C. Logan; Langridge-Smith, Pat R. R.

    2011-08-01

    Noncovalent protein-ligand and protein-protein complexes are readily detected using electrospray ionization mass spectrometry (ESI MS). Furthermore, recent reports have demonstrated that careful use of electron capture dissociation (ECD) fragmentation allows covalent backbone bonds of protein complexes to be dissociated without disruption of noncovalent protein-ligand interactions. In this way the site of protein-ligand interfaces can be identified. To date, protein-ligand complexes, which have proven tractable to this technique, have been mediated by ionic electrostatic interactions, i.e., ion pair interactions or salt bridging. Here we extend this methodology by applying ECD to study a protein-peptide complex that contains no electrostatics interactions. We analyzed the complex between the 21 kDa p53-inhibitor protein anterior gradient-2 and its hexapeptide binding ligand (PTTIYY). ECD fragmentation of the 1:1 complex occurs with retention of protein-peptide binding and analysis of the resulting fragments allows the binding interface to be localized to a C-terminal region between residues 109 and 175. These finding are supported by a solution-phase competition assay, which implicates the region between residues 108 and 122 within AGR2 as the PTTIYY binding interface. Our study expands previous findings by demonstrating that top-down ECD mass spectrometry can be used to determine directly the sites of peptide-protein interfaces. This highlights the growing potential of using ECD and related top-down fragmentation techniques for interrogation of protein-protein interfaces.

  3. Convolution/deconvolution of generalized Gaussian kernels with applications to proton/photon physics and electron capture of charged particles

    CERN Document Server

    Ulmer, W

    2012-01-01

    Scatter processes of photons lead to blurring of images produced by CT (computed tomography) or CBCT (cone beam computed tomography) in the KV domain or portal imaging in the MV domain (KV: kilovolt age, MV: megavoltage). Multiple scatter is described by, at least, one Gaussian kernel. In various situations, this approximation is crude, and we need two/three Gaussian kernels to account for the long-range tails (Landau tails), which appear in the Moli\\`ere scatter of protons, energy straggling and electron capture of charged particles passing through matter and Compton scatter of photons. The ideal image (source function) is subjected to Gaussian convolutions to yield a blurred image recorded by a detector array. The inverse problem is to obtain the ideal source image from measured image. Deconvolution methods of linear combinations of two/three Gaussian kernels with different parameters s0, s1, s2 can be derived via an inhomogeneous Fredholm integral equation of second kind (IFIE2) and Liouville - Neumann ser...

  4. On decay constants and orbital distance to the Sun—part III: beta plus and electron capture decay

    Science.gov (United States)

    Pommé, S.; Stroh, H.; Paepen, J.; Van Ammel, R.; Marouli, M.; Altzitzoglou, T.; Hult, M.; Kossert, K.; Nähle, O.; Schrader, H.; Juget, F.; Bailat, C.; Nedjadi, Y.; Bochud, F.; Buchillier, T.; Michotte, C.; Courte, S.; van Rooy, M. W.; van Staden, M. J.; Lubbe, J.; Simpson, B. R. S.; Fazio, A.; De Felice, P.; Jackson, T. W.; Van Wyngaardt, W. M.; Reinhard, M. I.; Golya, J.; Bourke, S.; Roy, T.; Galea, R.; Keightley, J. D.; Ferreira, K. M.; Collins, S. M.; Ceccatelli, A.; Verheyen, L.; Bruggeman, M.; Vodenik, B.; Korun, M.; Chisté, V.; Amiot, M.-N.

    2017-02-01

    The hypothesis that seasonal changes in proximity to the Sun cause variation of decay constants at permille level has been tested for radionuclides disintegrating through electron capture and beta plus decay. Activity measurements of 22Na, 54Mn, 55Fe, 57Co, 65Zn, 82+85Sr, 90Sr, 109Cd, 124Sb, 133Ba, 152Eu, and 207Bi sources were repeated over periods from 200 d up to more than four decades at 14 laboratories across the globe. Residuals from the exponential nuclear decay curves were inspected for annual oscillations. Systematic deviations from a purely exponential decay curve differ from one data set to another and appear attributable to instabilities in the instrumentation and measurement conditions. Oscillations in phase with Earth’s orbital distance to the sun could not be observed within 10-4-10-5 range precision. The most stable activity measurements of β + and EC decaying sources set an upper limit of 0.006% or less to the amplitude of annual oscillations in the decay rate. There are no apparent indications for systematic oscillations at a level of weeks or months.

  5. Finite Forward Acceptance Angles for Single Electron Capture by ^3He^2+ Ions in He and H_2

    Science.gov (United States)

    Mawhorter, Rj; Greenwood, J.; Smith; Chutjian, A.

    2004-05-01

    Perhaps surprisingly, electron capture scattering angles of a few degrees or more are observed for slow ions impacting light targets. Gas cells must be designed with this in mind. Indeed the difference between small acceptance angle results(W.L. Nutt, et al., J. Phys. B 8), 1457 (1978) and the larger acceptance-angle studies of both Kusakabe, et al.(T. Kusakabe, et al., J. Phys. Soc. Japan 59), 1218 (1990) and our group at JPL (presented here; energy range 0.33-4.67 keV/amu) for ^3He^2+ in H2 can be ascribed to this effect. Olson and Kimura(R. E. Olson and M. Kimura, J. Phys. B 15), 4231 (1982) have modeled the problem theoretically. We use existing differential cross section data(D. Bordenave-Montesquieu and R. Dagnac, J. Phys. B 27), 543 1994) for both H_2/ D2 and ^4He targets to calculate realistic acceptance angles. The resulting small total cross section corrections provide reliable absolute results for these benchmark systems. This work was carried out at JPL/Caltech, and was supported through agreement with NASA.

  6. LINE EMISSION AND ANISOTROPY EFFECTS IN C6+ ELECTRON-CAPTURE FROM LI(2S), LI-ASTERISK(2P) AND H-ASTERISK(N=2)

    NARCIS (Netherlands)

    OLSON, RE; HOEKSTRA, R

    1995-01-01

    Line emission cross sections for visible transitions after electron capture collisions of C6+ With Li(2s), Li-*(2p), and H-*(n = 2) are calculated for energies up to 50 keV/u; the values agree with available Li(2s) data. Anisotropy parameters are also given for aligned Li-*(2p). The results were obt

  7. Q-Dependence of the double capture cross sections measured by electron spectroscopy at 10 qkeV (q = 4-8). Comparison with other experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, A.; Boudjema, M.; Benoit-Cattin, P.; Gleizes, A.; Moretto-Capelle, P.

    1989-01-01

    The q dependence of cross sections for double capture into autoionising states has been investigated by electron spectroscopy. It is shown that they are independent of the ionic core. Our results are compared with all other available experimental data obtained at 10 qkeV collision energy.

  8. Experimental investigations of electron capture from atomic hydrogen and deuterium by alpha particles. Annual progress report, 15 September 1991--14 September 1992

    Energy Technology Data Exchange (ETDEWEB)

    Gay, T.J.; Park, J.T.

    1992-11-01

    We report progress made during the period 15 September 1991--14 September 1992 on the project ``Experimental Investigations of Electron Capture from Atomic Hydrogen and Deuterium by Alpha Particles``. In the past year we have developed reliable, narrow energy spread, high-current sources of He{sup ++} based on direct-current magentron and electron-cyclotron resonance discharges. These sources have been proven on our test bench accelerator which has been upgraded to also allow us to test atomic hydrogen effusive targets. We have thus made substantial progress toward our goal of studying single electron capture from atomic hydrogen by doubly-ionized helium. A research plan for the upcoming year is also presented.

  9. Capturing Thoughts, Capturing Minds?

    DEFF Research Database (Denmark)

    Nielsen, Janni

    2004-01-01

    Think Aloud is cost effective, promises access to the user's mind and is the applied usability technique. But 'keep talking' is difficult, besides, the multimodal interface is visual not verbal. Eye-tracking seems to get around the verbalisation problem. It captures the visual focus of attention...

  10. Probabilities and energies to obtain the counting efficiency of electron-capture nuclides. KLMN model; Probabilidades y energias de reestructuracion atomica subsiguientes a la captura electronica. Modelo KLMN

    Energy Technology Data Exchange (ETDEWEB)

    Galiano, G.; Grau, A.

    1994-07-01

    An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electro capture in the counting efficiency when the atomic number of the nuclide is high. (Author)

  11. ELECTRON-CAPTURE AND β-DECAY RATES FOR sd-SHELL NUCLEI IN STELLAR ENVIRONMENTS RELEVANT TO HIGH-DENSITY O–NE–MG CORES

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Toshio [Department of Physics and Graduate School of Integrated Basic Sciences, College of Humanities and Sciences, Nihon University Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550 (Japan); Toki, Hiroshi [Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki, Osaka 567-0047 (Japan); Nomoto, Ken’ichi, E-mail: suzuki@phys.chs.nihon-u.ac.jp [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2016-02-01

    Electron-capture and β-decay rates for nuclear pairs in the sd-shell are evaluated at high densities and high temperatures relevant to the final evolution of electron-degenerate O–Ne–Mg cores of stars with initial masses of 8–10 M{sub ⊙}. Electron capture induces a rapid contraction of the electron-degenerate O–Ne–Mg core. The outcome of rapid contraction depends on the evolutionary changes in the central density and temperature, which are determined by the competing processes of contraction, cooling, and heating. The fate of the stars is determined by these competitions, whether they end up with electron-capture supernovae or Fe core-collapse supernovae. Since the competing processes are induced by electron capture and β-decay, the accurate weak rates are crucially important. The rates are obtained for pairs with A = 20, 23, 24, 25, and 27 by shell-model calculations in the sd-shell with the USDB Hamiltonian. Effects of Coulomb corrections on the rates are evaluated. The rates for pairs with A = 23 and 25 are important for nuclear Urca processes that determine the cooling rate of the O–Ne–Mg core, while those for pairs with A = 20 and 24 are important for the core contraction and heat generation rates in the core. We provide these nuclear rates at stellar environments in tables with fine enough meshes at various densities and temperatures for studies of astrophysical processes sensitive to the rates. In particular, the accurate rate tables are crucially important for the final fates of not only O–Ne–Mg cores but also a wider range of stars, such as C–O cores of lower-mass stars.

  12. Anatomical mercury speciation in bay scallops by thio-bearing chelating resin concentration and GC-electron capture detector determination.

    Science.gov (United States)

    Zhang, Qihua; Yang, Guipeng

    2014-01-01

    The highly toxic methyl-, ethyl- and phenylmercury species that may exist in the three main anatomical parts - the adductor muscle, the mantle and the visceral mass - of bay scallops (Argopecten irradias) were quantitatively released by cupric chloride, zinc acetate, sodium chloride and hydrochloric acid (HCl) under ultrasonic extraction. After centrifugation, the mercury species in the supernatant were concentrated by thio (SH)-bearing chelating resins, eluted with HClO4 and HCl and extracted with toluene. Separation was achieved by capillary GC equipped with programmed temperatures, a constant nitrogen flow and detected by a micro-electron capture detector (μECD). Under optimised conditions, the LODs for methyl-, ethyl- and phenylmercury in bay scallop samples were 1.1, 0.65 and 0.80 ng g(-1), respectively. The maximum RSD for three replicate determinations of methyl-, ethyl- and phenylmercury in bay scallop samples were 13.7%, 14.0% and 11.2%, respectively. In the concentration range of 4-200 ng g(-1) in bay scallop samples, the calibration graphs were linear with correlation coefficients not less than 0.997. Recoveries for spiked samples were in the range of 92.7-103.5% (methylmercury), 87.5-108.3% (ethylmercury) and 91.6-106.0% (phenylmercury), respectively. The method was verified by the determination of methylmercury in a CRM GBW10029 (Total Mercury and Methyl Mercury in Fish Tissue), with results in good agreement with the certified values. Methylmercury - the only existing species in bay scallops - was successfully determined by the method.

  13. A New Insight into Neutrino Energy Loss by Electron Capture of Iron Group Nuclei in Magnetar Surfaces

    Science.gov (United States)

    Liu, Jing-Jing; Gu, Wei-Min

    2016-06-01

    Based on the relativistic mean-field effective interactions theory, and the Lai dong model, we discuss the influences of superstrong magnetic fields (SMFs) on electron Fermi energy, nuclear blinding energy, and single-particle level structure in magnetar surfaces. Using the Shell-Model Monte Carlo method and the Random Phase Approximation theory, we analyze the neutrino energy loss rates (NELRs) by electron capture for iron group nuclei in SMFs. First, when B 12 100, the NELRs decrease by more than three orders of magnitude (e.g., at T 9 = 15.53 for 52-61Fe, 55-60Co, and 56-63Ni). Second, for a certain value of magnetic field and temperature, the NELRs increase by more than four orders of magnitude when {ρ }7≤slant {10}3, but as the density increases (i.e., when {ρ }7\\gt {10}3), there is almost no influence on the density of NELRs. For the density around {ρ }7={10}2, there is an abrupt increase in NELRs when B 12 ≥ 103.5. Such jumps are an indication that the underlying shell structure has changed due to single-particle behavior by SMFs. Finally, we compare our NELRs with those of Fuller et al. (FFN) and Nabi & Klapdor-Kleingrothaus (NKK). For the case without SMFs, one finds that our rates for certain nuclei are close to about five orders of magnitude lower than FFN and NKK at relativistic low temperatures (e.g., T 9 = 1). However, at a relativistic high temperature (e.g., T 9 = 3), our results are in good agreement with NKK, but about one order of magnitude lower than FFN. For the case with SMFs, our NELRs for some iron group nuclei can be about five orders of magnitude higher than those of FFN and NKK. (Note that B 12, T 9, and ρ 7 are in units of 1012 G, 109 K, and {10}7 {{g}} {{cm}}-3, respectively.)

  14. Non Radiation Hardened Microprocessors in Spaced Based Remote Sensing Systems

    Science.gov (United States)

    Decoursey, Robert J.; Estes, Robert F.; Melton, Ryan

    2006-01-01

    The CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) mission is a comprehensive suite of active and passive sensors including a 20Hz 230mj Nd:YAG lidar, a visible wavelength Earth-looking camera and an imaging infrared radiometer. CALIPSO flies in formation with the Earth Observing System Post-Meridian (EOS PM) train, provides continuous, near-simultaneous measurements and is a planned 3 year mission. CALIPSO was launched into a 98 degree sun synchronous Earth orbit in April of 2006 to study clouds and aerosols and acquires over 5 gigabytes of data every 24 hours. The ground track of one CALIPSO orbit as well as high and low intensity South Atlantic Anomaly outlines is shown. CALIPSO passes through the SAA several times each day. Spaced based remote sensing systems that include multiple instruments and/or instruments such as lidar generate large volumes of data and require robust real-time hardware and software mechanisms and high throughput processors. Due to onboard storage restrictions and telemetry downlink limitations these systems must pre-process and reduce the data before sending it to the ground. This onboard processing and realtime requirement load may mean that newer more powerful processors are needed even though acceptable radiation-hardened versions have not yet been released. CALIPSO's single board computer payload controller processor is actually a set of four (4) voting non-radiation hardened COTS Power PC 603r's built on a single width VME card by General Dynamics Advanced Information Systems (GDAIS). Significant radiation concerns for CALIPSO and other Low Earth Orbit (LEO) satellites include the South Atlantic Anomaly (SAA), the north and south poles and strong solar events. Over much of South America and extending into the South Atlantic Ocean the Van Allen radiation belts dip to just 200-800km and spacecraft entering this area are subjected to high energy protons and experience higher than normal Single Event Upset

  15. Double electron capture in collisions of the helium-like ions N/sup 5+/, O/sup 6+/ and Ne/sup 8+/ with helium atoms

    Energy Technology Data Exchange (ETDEWEB)

    Boudjema, M.; Moretto-Capelle, P.; Bordenave-Montesquieu, A. and others

    1989-03-28

    A fitting procedure of 1s/sup 2/3l3l' lines observed in A/sup (z-2)+/(1s/sup 2/)+He collisions (Z = 7, 8 and 10), at 10 q keV collision energy (q = Z -2) and 10/sup 0/ observation angle, allows us to compare new theoretical positions and lifetimes, and experimental electron spectra. It is found that the spin conservation rule holds and that only singlet states are populated in these capture processes. As in N/sup 7+/ and O/sup 8+/ + He systems, capture into the highest angular momentum /sup 1/G state is favoured in O/sup 6+/ and Ne/sup 8+/ + He systems and accounts for 26% of the double capture at 10/sup 0/. In N/sup 5+/ + He, the L distribution is broader and no L value is clearly predominant.

  16. Excited states in the doubly odd 168Lu nucleus fed by electron-capture decay of 168Hf (T1/2=25.95 min)

    Science.gov (United States)

    Barci, V.; Ardisson, G.; Trubert, D.; Hussonnois, M.

    1997-05-01

    The low-spin levels of the odd-odd nucleus 168Lu from 168Hf (T1/2=25.95 min) electron-capture decay were investigated by direct γ and γ-γ coincidence measurements. The sources of 168Hf were produced with the 156Gd(16O,4n) reaction and radiochemically separated using chromatographic methods. A level scheme of 39 new levels in the 168Lu nucleus was proposed, accounting for 107 of 119 observed γ transitions assigned to 168Hf electron-capture decay. Transition multipolarities, level-spins, and parities were deduced or proposed. A tentative decay scheme was proposed. Level structure was discussed in the framework of the particle-rotor and Nilsson models.

  17. Kuang's Semi-Classical Formalism for Electron Capture Cross-Sections in Ion-Ion Collisions at few MeV's/nucleon: Application to ENA Modeling

    Science.gov (United States)

    Barghouty, A. F.

    2012-01-01

    Accurate estimates of electron-capture cross sections at energies relevant to energetic neutral atom (ENA) modeling (approx few MeV per nucleon) and for multi-electron ions must rely on first-principles approaches and/or detailed quantum-mechanical simulation of the collision process. Kuang's semi-classical approach offers a middle-ground, elegant and efficient way to arrive at these estimates. We shall present a sample application and current progress in applying and extending Kuang's formalism to ENA modeling.

  18. Boundary-corrected four-body continuum-intermediate-state method: Single-electron capture from heliumlike atomic systems by fast nuclei

    Science.gov (United States)

    Mančev, Ivan; Milojević, Nenad; Belkić, Dževad

    2015-06-01

    Single charge exchange in collisions between bare projectiles and heliumlike atomic systems at intermediate and high incident energies is examined by using the four-body formalism of the first- and second-order theories. The main purpose of the present study is to investigate the relative importance of the intermediate ionization continua of the captured electron compared to the usual direct path of the single electron transfer from a target to a projectile. In order to achieve this goal, comprehensive comparisons are made between the four-body boundary-corrected continuum-intermediate-states (BCIS-4B) method and the four-body boundary-corrected first Born (CB1-4B) method. The perturbation potential is the same in the CB1-4B and BCIS-4B methods. Both methods satisfy the correct boundary conditions in the entrance and exit channels. However, unlike the CB1-4B method, the second-order BCIS-4B method takes into account the electronic Coulomb continuum-intermediate states in either the entrance or the exit channel depending on whether the post or the prior version of the transition amplitude is used. Hence, by comparing the results from these two theories, the relative importance of the intermediate ionization electronic continua can be assessed within the four-body formalism of scattering theory. The BCIS-4B method predicts the usual second-order effect through double scattering of the captured electron on two nuclei as a quantum-mechanical counterpart of the Thomas classical two-step, billiard-type collision. The physical mechanism for this effect in the BCIS-4B method is also comprised of two steps such that ionization occurs first. This is followed by capture of the electron by the projectile with both processes taking place on the energy shell. Moreover, the role of the second, noncaptured electron in a heliumlike target is revisited. To this end, the BCIS-4B method describes the effect of capture of one electron by the interaction of the projectile nucleus with

  19. Activated barrier crossing dynamics in the non-radiative decay of NADH and NADPH

    Energy Technology Data Exchange (ETDEWEB)

    Blacker, Thomas S., E-mail: t.blacker@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Marsh, Richard J., E-mail: richard.marsh@ucl.ac.uk [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Duchen, Michael R., E-mail: m.duchen@ucl.ac.uk [Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Bain, Angus J., E-mail: a.bain@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2013-08-30

    Highlights: ► NADH and NADPH have a high rate of non-radiative excited state decay. ► Conformational relaxation is shown to be a significant non-radiative pathway. ► The Kramers equation describes the barrier crossing dynamics of the relaxation. ► Conformational restriction upon enzyme binding will alter NAD(P)H lifetimes. - Abstract: In live tissue, alterations in metabolism induce changes in the fluorescence decay of the biological coenzyme NAD(P)H, the mechanism of which is not well understood. In this work, the fluorescence and anisotropy decay dynamics of NADH and NADPH were investigated as a function of viscosity in a range of water–glycerol solutions. The viscosity dependence of the non-radiative decay is well described by Kramers and Kramers–Hubbard models of activated barrier crossing over a wide viscosity range. Our combined lifetime and anisotropy analysis indicates common mechanisms of non-radiative relaxation in the two emitting states (conformations) of both molecules. The low frequencies associated with barrier crossing suggest that non-radiative decay is mediated by small scale motion (e.g. puckering) of the nicotinamide ring. Variations in the fluorescence lifetimes of NADH and NADPH when bound to different enzymes may therefore be attributed to differing levels of conformational restriction upon binding.

  20. Photoacoustic Determination of Non-radiative Relaxation Time of Absorbing Centers in Maize Seeds

    Science.gov (United States)

    Domínguez-Pacheco, A.; Hernández-Aguilar, C.; Cruz-Orea, A.

    2017-07-01

    Using non-destructive photothermal techniques, it is possible to characterize non-homogenous materials to obtain its optical and thermal properties through photoacoustic spectroscopy (PAS). In photoacoustic (PA) phenomena, there are transient states of thermal excitation, when samples absorb the incident light; these states manifest an excitation process that generates the PA signal, being in direct relation with the non-radiative relaxation times with the sample absorbent centers. The objective of this study was to determine the non-radiative relaxation times associated with different absorbent centers of corn seeds ( Zea mays L.), by using PAS. A frequency scan was done at different wavelengths (350 nm, 470 nm and 650 nm) in order to obtain the non-radiative relaxation times with different types of maize seeds.

  1. Preparatory studies for a high-precision Penning-trap measurement of the {sup 163}Ho electron capture Q-value

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, F. [Johannes Gutenberg-Universitaet, Institut fuer Kernchemie, Mainz (Germany); Johannes Gutenberg-Universitaet, Institut fuer Physik, Mainz (Germany); Beyer, T.; Blaum, K.; Eibach, M.; Eliseev, S.; Nagy, Sz. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Block, M. [Johannes Gutenberg-Universitaet, Institut fuer Kernchemie, Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Helmholtz-Institut Mainz, Mainz (Germany); Chenmarev, S.; Novikov, Yu.N. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Saint Petersburg State University, Physical Faculty, Saint Petersburg (Russian Federation); Dorrer, H. [Johannes Gutenberg-Universitaet, Institut fuer Kernchemie, Mainz (Germany); Paul Scherrer Institute, Villigen (Switzerland); Universitaet Bern, Bern (Switzerland); Duellmann, C.E. [Johannes Gutenberg-Universitaet, Institut fuer Kernchemie, Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Helmholtz-Institut Mainz, Mainz (Germany); Johannes Gutenberg-Universitaet, PRISMA Cluster of Excellence, Mainz (Germany); Eberhardt, K. [Johannes Gutenberg-Universitaet, Institut fuer Kernchemie, Mainz (Germany); Helmholtz-Institut Mainz, Mainz (Germany); Grund, J. [Johannes Gutenberg-Universitaet, Institut fuer Kernchemie, Mainz (Germany); Johannes Gutenberg-Universitaet, PRISMA Cluster of Excellence, Mainz (Germany); Koester, U. [Institut Laue-Langevin, Grenoble (France); Renisch, D. [Johannes Gutenberg-Universitaet, Institut fuer Kernchemie, Mainz (Germany); Tuerler, A. [Paul Scherrer Institute, Villigen (Switzerland); Universitaet Bern, Bern (Switzerland); Wendt, K. [Johannes Gutenberg-Universitaet, Institut fuer Physik, Mainz (Germany); Johannes Gutenberg-Universitaet, PRISMA Cluster of Excellence, Mainz (Germany)

    2015-07-15

    The ECHo Collaboration (Electron Capture {sup 163}Ho) aims to investigate the calorimetric spectrum following the electron capture decay of {sup 163}Ho to determine the mass of the electron neutrino. The size of the neutrino mass is reflected in the endpoint region of the spectrum, i.e., the last few eV below the transition energy. To check for systematic uncertainties, an independent determination of this transition energy, the Q-value, is mandatory. Using the TRIGA-TRAP setup, we demonstrate the feasibility of performing this measurement by Penning-trap mass spectrometry. With the currently available, purified {sup 163}Ho sample and an improved laser ablation mini-RFQ ion source, we were able to perform direct mass measurements of {sup 163}Ho and {sup 163}Dy with a sample size of less than 10{sup 17} atoms. The measurements were carried out by determining the ratio of the cyclotron frequencies of the two isotopes to those of carbon cluster ions using the time-of-flight ion cyclotron resonance method. The obtained mass excess values are ME({sup 163}Ho)= -66379.3(9) keV and ME({sup 163}Dy)= -66381.7(8) keV. In addition, the Q-value was measured for the first time by Penning-trap mass spectrometry to be Q = 2.5(7) keV. (orig.)

  2. Liquid scintillation counting efficiency in three photomultiplier systems. Pure electron capture; Eficiencia de recuento por centelleo liquido en sistemas con tres fotomultiplicadores. Captura electronica pura

    Energy Technology Data Exchange (ETDEWEB)

    Los Arcos, J. M.; Grau Carles, A.; Grau Malonda, A.

    1990-07-01

    The tables of counting efficiency as a function of the figure of merit for a liquid scintillation counting system working with three phototubes are presented. The evaluation has been carried out for a Toluene-based scintillator with 5, 10 and 15 ml column, and 19 different radionuclides decaying by pure electron capture: 37Ar 41Ca, 49V, 53 Mn, 55Fe, 59Ni, 68Ge 7iGe, 82Sr, 97Tc, 118Te, 131CS, 137La, 140Ca, 157Tb, 165Er, 193Pt, 194Hg, 205Pb. (Author) 22 refs.

  3. Rapid and sensitive electron-capture gas chromatographic method for the determination of pinazepam and its metabolites in human plasma, urine and milk.

    Science.gov (United States)

    Pacifici, G M; Placidi, G F

    1977-05-11

    A rapid, sensitive and specific gas-liquid chromatographic method for the measurement of pinazepam and its metabolites in biological fluids is reported. After a single extraction of the sample with toluene, the organic phase is concentrated and, after chromatography on a 3% OV-17 column, measured with an electron-capture detector. The sensitivity was 1.0 ng/ml for pinazepam and 5.0 ng/ml for its metabolites. Plasma levels and urinary excretion in human volunteers and plasma and milk levels in women suffering from anxiety during breastfeeding are reported.

  4. Capture, Electron-Cooling and Compression of Antiprotons in a Large Penning-Trap for Physics Experiments with an Ultra-Low Energy Extracted Antiproton Beam

    CERN Multimedia

    2002-01-01

    % PS200 \\\\ \\\\The availability of ultra-low energy antiprotons is a crucial ingredient for the execution of the gravity measurements PS200. We have developed a method to provide such low energy antiprotons based on a large Penning trap (the PS200 catching trap). This system can accept a fast-extracted pulse from LEAR, reduce the energy of the antiprotons in the pulse from 5.9~MeV to several tens of kilovolts using a degrading foil, and then capture the antiprotons in a large Penning trap. These antiprotons are cooled by electrons previously admitted to the trap and are collected in a small region at the center of the trap. We have demonstrated our capability to capture up to 1~million antiprotons from LEAR in a single shot, electron cool these antiprotons, and transfer up to 95\\% of them into the inner, harmonic region. A storage time in excess of 1 hour was observed. These results have been obtained with the cryogenic trap vacuum coupled to a room temperature vacuum at about l0$ ^- ^{1} ^0 $ Torr, which is an...

  5. Sub-parts-per-billion determination of nitro-substituted polynuclear aromatic hydrocarbons in airborne particulate matter and soil by electron capture-Tandem mass spectrometry.

    Science.gov (United States)

    Vincenti, M; Minero, C; Pelizzetti, E; Fontana, M; De Maria, R

    1996-12-01

    A procedure for the determination of nitro-substiruted polynuclear aromatic hydrocarbons (nitro-PAH) on crude air-particulate and soil extracts is introduced. Elimination of purification and fractionation procedures was made possible by the use of both a selective ionization method, such as electron-capture chemical ionization, and a specific fragmentation process, in an experiment of tandem mass spectrometry (gas chromatography-electron capture tandem mass spectrometry). Different mass spectrometric procedures were compared. The best performance was observed when the nitro-PAH molecular ions [M](-) were mass-selected by the first analyzer under multiple reaction monitoring conditions and then fragmented to NO 2 (-) (m/z 46). Detection limits were on the order of hundreds of femtograms, as determined in extracts of real environmental samples. This corresponds approximately to 5-15 pg of nitro-PAH per cubic meter of air sampled. Calibration curves were linear over 3 orders of magnitude. Applications to contamination from motor vehicle combustion and the iron industry are briefly discussed.

  6. Comparative study of Gamow-Teller strength distributions in the odd-odd nucleus 50V and its impact on electron capture rates in astrophysical environments

    CERN Document Server

    Nabi, Jameel-Un; 10.1103/PhysRevC.76.055803

    2011-01-01

    Gamow-Teller (GT) strength transitions are an ideal probe for testing nuclear structure models. In addition to nuclear structure, GT transitions in nuclei directly affect the early phases of Type Ia and Type-II supernovae core collapse since the electron capture rates are partly determined by these GT transitions. In astrophysics, GT transitions provide an important input for model calculations and element formation during the explosive phase of a massive star at the end of its life-time. Recent nucleosynthesis calculations show that odd-odd and odd-A nuclei cause the largest contribution in the rate of change of lepton-to-baryon ratio. In the present manuscript, we have calculated the GT strength distributions and electron capture rates for odd-odd nucleus 50V by using the pn-QRPA theory. At present 50V is the first experimentally available odd-odd nucleus in fp-shell nuclei. We also compare our GT strength distribution with the recently measured results of a 50V(d,2He)50Ti experiment, with the earlier work ...

  7. Capturing every patron interaction: the move from paper statistics to an electronic system to track the whole library.

    Science.gov (United States)

    Vardell, Emily; Loper, Kimberly; Vaidhyanathan, Vedana

    2012-01-01

    Reference departments track patron interactions to illustrate the type and number of services provided as well as to tailor librarians' time and expertise to the interest and needs of their patrons. Until 2010 the Reference, Education, and Community Engagement Department at the Calder Memorial Library tracked statistics using a complicated system of paper tic sheets and two Excel™ spreadsheets. After considering different electronic systems, the department decided to employ an electronic form created with SurveyMonkey™ to track patron interactions. After the system had been in place for three months, the authors administered a satisfaction and use survey to collect faculty and staff feedback on the new system. Seven months later the authors undertook usability testing to collect further evaluative data on the electronic form. The patron interaction form continues to be used to collect statistics, provide data for annual reviews, and recognize the contributions of all faculty and staff at the library.

  8. Impact of neutrino flavor oscillations on the neutrino-driven wind nucleosynthesis of an electron-capture supernova

    NARCIS (Netherlands)

    E. Pllumbi; I. Tamborra; S. Wanajo; H.-T. Janka; L. Hüdepohl

    2015-01-01

    Neutrino oscillations, especially to light sterile states, can affect nucleosynthesis yields because of their possible feedback effect on the electron fraction (Ye). For the first time, we perform nucleosynthesis calculations for neutrino-driven wind trajectories from the neutrino-cooling phase of a

  9. Electron capture and deprotonation processes observed in collisions between Xe8+ and multiply protonated cytochrome-C

    NARCIS (Netherlands)

    Martin, S.; Ortega, C.; Chen, L.; Bredy, R.; Vernier, A.; Dugourd, P.; Antoine, R.; Bernard, J.; Reitsma, G.; Gonzalez Magana, Olmo; Hoekstra, Ronnie; Schlathölter, Thomas

    2014-01-01

    Electron-transfer processes in interaction between highly charged ions and multiply protonated proteins have been studied. Collisions between Xe8+ at 96 keV and protonated cytochrome-C at selected charge state (q from 15+ to 19+) result inmass spectra composed mainly of intact molecular ions. From t

  10. THE FINAL FATE OF STARS THAT IGNITE NEON AND OXYGEN OFF-CENTER: ELECTRON CAPTURE OR IRON CORE-COLLAPSE SUPERNOVA?

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Samuel [Department of Physics and Astronomy, University of Victoria, BC V8W 3P6 (Canada); Hirschi, Raphael [Astrophysics Group, Lennard-Jones Building, Keele University, Staffordshire ST5 5BG (United Kingdom); Nomoto, Ken' ichi, E-mail: swjones@uvic.ca [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan)

    2014-12-20

    In the ONeMg cores of 8.8-9.5 M {sub ☉} stars, neon and oxygen burning is ignited off-center. Whether or not the neon-oxygen flame propagates to the center is critical for determining whether these stars undergo Fe core collapse or electron-capture-induced ONeMg core collapse. We present more details of stars that ignite neon and oxygen burning off-center. The neon flame is established in a manner similar to the carbon flame of super-AGB stars, albeit with a narrower flame width. The criteria for establishing a flame can be met if the strict Schwarzschild criterion for convective instability is adopted. Mixing across the interface of the convective shell disrupts the conditions for the propagation of the burning front, and instead the shell burns as a series of inward-moving flashes. While this may not directly affect whether or not the burning will reach the center (as in super-AGB stars), the core is allowed to contract between each shell flash. Reduction of the electron fraction in the shell reduces the Chandrasekhar mass and the center reaches the threshold density for the URCA process to activate and steer the remaining evolution of the core. This highlights the importance of a more accurate treatment of mixing in the stellar interior for yet another important question in stellar astrophysics—determining the properties of stellar evolution and supernova progenitors at the boundary between electron capture supernova and iron core-collapse supernova.

  11. Electronic capture and communication of synoptic cancer data elements from pathology reports: results of the Reporting Pathology Protocols 2 (RPP2) project.

    Science.gov (United States)

    Hassell, Lewis; Aldinger, Wendy; Moody, Cheryl; Winters, Sharon; Gerlach, Ken; Schwenn, Molly; Perriello, Deborah

    2009-01-01

    Pathology reports represent a rich data source for cancer registries. The College of American Pathologists (CAP) Cancer Checklists present pathology reports in synoptic form and allow registries to be updated electronically. To assess the challenge of employing the CAP Cancer Checklists in pathology laboratories and transmitting that information to cancer registries, we conducted a pilot project: the Reporting Pathology Protocols project (RPP2). The RPP2 project was a multi-year, "proof of concept" demonstration that assessed pathology report-generated data for 3 CAP Cancer Checklists (breast, prostate, and melanoma) in several different cancer registry-pathology laboratory combinations in 3 states. Collaborating pathology laboratories and state cancer registries in California, Maine, and Pennsylvania identified key questions (queries) to address in the course of the project, developed and tested standardized HL7 messaging specifications to link senders and recipients, and then assessed the actual process results using either parallel reporting or retrospective-prospective cases for each tumor type. Successful electronic transfer and capture of pertinent data elements for numerous examples of each tumor type was accomplished in each participating cancer registry/reporting laboratory/information system combination. We noted shortcomings in the electronically encoded CAP Checklists as opposed to text-based reports, particularly for breast cancers. We uncovered opportunities to improve Checklists and the information systems that incorporate them. Workflow, productivity, and timeliness of reporting are areas where electronically encoded reports may enhance cancer registry processes. The accuracy and completeness of electronically encoded data appears largely comparable to text-based data, but subject to the degree of synchrony between the formats of text-based and electronic reports.

  12. Capture reactions

    NARCIS (Netherlands)

    Endt, P.M.

    1956-01-01

    Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation proces

  13. Difference of Electron Capture and Transfer Dissociation Mass Spectrometry on Ni2+-, Cu2+-, and Zn2+-Polyhistidine Complexes in the Absence of Remote Protons

    Science.gov (United States)

    Asakawa, Daiki; De Pauw, Edwin

    2016-07-01

    Electron capture dissociation (ECD) and electron transfer dissociation (ETD) in metal-peptide complexes are dependent on the metal cation in the complex. The divalent transition metals Ni2+, Cu2+, and Zn2+ were used as charge carriers to produce metal-polyhistidine complexes in the absence of remote protons, since these metal cations strongly bind to neutral histidine residues in peptides. In the case of the ECD and ETD of Cu2+-polyhistidine complexes, the metal cation in the complex was reduced and the recombination energy was redistributed throughout the peptide to lead a zwitterionic peptide form having a protonated histidine residue and a deprotonated amide nitrogen. The zwitterion then underwent peptide bond cleavage, producing a and b fragment ions. In contrast, ECD and ETD induced different fragmentation processes in Zn2+-polyhistidine complexes. Although the N-Cα bond in the Zn2+-polyhistidine complex was cleaved by ETD, ECD of Zn2+-polyhistidine induced peptide bond cleavage accompanied with hydrogen atom release. The different fragmentation modes by ECD and ETD originated from the different electronic states of the charge-reduced complexes resulting from these processes. The details of the fragmentation processes were investigated by density functional theory.

  14. Effect of structural parameters on the electron capture dissociation and collision-induced dissociation pathways of copper(II)-peptide complexes.

    Science.gov (United States)

    Chen, Xiangfeng; Wang, Ze; Li, Wan; Wong, Y L Elaine; Chan, T-W Dominic

    2015-01-01

    The gas-phase dissociation pathways of proteins/peptides are usually affected by the nature of the charge carrier and the sequence of amino acid residues. The effects of peptide structural parameters, including peptide composition, chain length and amide hydrogen, on the gas-phase dissociation of Cu(II)-model peptide complexes were explored in this study. Polyglycine peptides with flexible frames were used as probes to reduce the complexity of the system and illustrate the mechanism. Results revealed that the types of fragment ions generated in the electron capture dissociation (ECD) of Cu(II)-adducted peptides changed according to the basic amino acid residue composition. Charged or neutral tryptophan side-chain losses were observed in the collision-induced dissociation (CID) of Cu(II)-peptide complexes. Internal electron transfer between tryptophan and metal ion within the complex occurred during the CID reaction, leaving the charge-reduced Cu(+) as a closed d-shell stable electron configuration. The choice of the reaction channel was then determined by the gas-phase basicity of the peptide. Amide hydrogen was critical in the formation of metalated b-/y-ions in the ECD process as determined through mutation of the backbone amide group. Increasing the chain length suppressed the ECD of Cu-metalated peptide species. Our results indicate that the structural parameters of peptides play important roles in the gas-phase dissociation processes of Cu-peptide complexes.

  15. Design of Pass Band Filter in Hybrid Architecture Planar/Non-Radiative Dielectric Waveguide Integration Technology

    Directory of Open Access Journals (Sweden)

    Harizi Hanen

    2012-01-01

    Full Text Available Problem statement: The expansion of RF, microwave and millimeter devices has revolutionized today’s ommunication and sensor systems. Low-cost, high-performance and mass producible millimeter wave technologies are vital for commercial broadband systems. Challenging issues are commonly faced in the design of low-loss integrated circuits for example high-Q band pass filter, which the planar technique is fundamentally limited in performance. Approach: In this study, we present a design of a nonradiative dielectric waveguide band pass filter based on hybrid architecture of micro strip line and non-radiative dielectric waveguide. Results: The simulation with High Frequency Structure Simulator (HFSS three dimensional analyses is presented. Conclusion: The non radiative dielectric resolves most of the drawbacks of dielectric waveguide in connection with the radiation loss."

  16. nIFTy galaxy cluster simulations I: dark matter & non-radiative models

    CERN Document Server

    Sembolini, Federico; Pearce, Frazer R; Knebe, Alexander; Kay, Scott T; Power, Chris; Cui, Weiguang; Beck, Alexander M; Borgani, Stefano; Vecchia, Claudio Dalla; Davé, Romeel; Elahi, Pascal Jahan; February, Sean; Huang, Shuiyao; Hobbs, Alex; Katz, Neal; Lau, Erwin; McCarthy, Ian G; Murante, Giuseppe; Nagai, Daisuke; Nelson, Kaylea; Newton, Richard D A; Puchwein, Ewald; Read, Justin I; Saro, Alexandro; Schaye, Joop; Thacker, Robert J

    2015-01-01

    We have simulated the formation of a galaxy cluster in a $\\Lambda$CDM universe using twelve different codes modeling only gravity and non-radiative hydrodynamics (\\art, \\arepo, \\hydra\\ and 9 incarnations of GADGET). This range of codes includes particle based, moving and fixed mesh codes as well as both Eulerian and Lagrangian fluid schemes. The various GADGET implementations span traditional and advanced smoothed-particle hydrodynamics (SPH) schemes. The goal of this comparison is to assess the reliability of cosmological hydrodynamical simulations of clusters in the simplest astrophysically relevant case, that in which the gas is assumed to be non-radiative. We compare images of the cluster at $z=0$, global properties such as mass, and radial profiles of various dynamical and thermodynamical quantities. The underlying gravitational framework can be aligned very accurately for all the codes allowing a detailed investigation of the differences that develop due to the various gas physics implementations employ...

  17. Observation of non-radiative de-excitation processes in silicon nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Milgram, J.N.; Wojcik, J.; Mascher, P. [Department of Engineering Physics, Centre for Emerging Device Technologies, McMaster University, Hamilton, Ontario (Canada); Crowe, I.; Sherliker, B.; Halsall, M.P. [School of Electrical and Electronic Engineering, University of Manchester (United Kingdom); Gwilliam, R.M. [Surrey Ion Beam Centre, Advanced Technology Institute, University of Surrey, Guildford (United Kingdom); Knights, A.P.

    2009-05-15

    We describe the impact of non-radiative de-excitation mechanisms on the optical emission from silicon nanocrystals formed in SiO{sub 2}. Auger excitation via free carriers deliberately introduced through phosphorus ion implantation, shows a monotonic increase with increasing phosphorus concentration which can be modelled adequately using a simple statistical approach. We also report a reduction in nanocrystal luminescence intensity with increasing exposure to UV radiation and suggest this phenomenon results from the introduction of non-radiative defects in the Si/SiO{sub 2} network. The effect of UV radiation varies significantly depending on the sample preparation. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Nanosolvation by acetonitrile and 18-crown-6 ether induce strongly different effects on the electron-capture induced dissociation of aromatic tripeptide cations in the gas phase

    DEFF Research Database (Denmark)

    MacLot, S.; Rangama, J.; Nielsen, Steen Brøndsted;

    2013-01-01

    , acetonitrile and 18-crown-6 ether (CE), to these tripeptide cations on the relative probabilities of their main fragmentation channels (H loss, NH3 loss and N — Cα bond cleavage) after electron capture from sodium atoms. First, we recorded the spectra of bare peptide ions, and found that N — Cα bond cleavage......-terminal ammonium group. Besides, this experimental result is consistent with our DFT calculations, which suggest a lower abundance of N terminally-protonated [KWK+2H]2+(CE)2 compared to bare tripeptide cations. Extracting the H-loss contribution from ECID data had never been done for tripeptides nanosolvated by CE....... This allowed us to observe the enhancement of H loss from KWK and KYK nanosolvated by two CE, but surprisingly, not by one. This peculiar behavior might be due to H transfer from the reduced radical NH3 group to CE, followed by loss of the [CE+H] radical....

  19. Simultaneous determination of florfenicol and florfenicol amine in fish, shrimp, and swine muscle by gas chromatography with a microcell electron capture detector.

    Science.gov (United States)

    Zhang, Suxia; Sun, Fengyun; Li, Jiancheng; Cheng, Linli; Shen, Jianzhong

    2006-01-01

    A rapid and sensitive gas chromatography method was developed for the simultaneous determination of florfenicol (FF) and its metabolite florfenicol amine (FFA) in fish, shrimp, and swine muscle. The extracted samples were defatted with hexane and cleaned up by solid-phase extraction using Oasis MCX cartridges. The eluate was evaporated to dryness, and residues were derivatized and determined by gas chromatography with a microcell electron capture detector. Overall average recoveries ranged from 81.7 to 109.7% for fish, 94.1 to 103.4% for shrimp, and 71.5 to 91.4% for swine muscle. The detection limit was 0.5 ng/g for FF and 1 ng/g for FFA, respectively. The method was validated for the determination of incurred swine muscle samples in an actual residue study.

  20. Measurement of the double K-shell vacancy creation probability in the electron-capture decay of 55Fe with active-pixel detectors

    Science.gov (United States)

    Michel, Thilo; Bergmann, Benedikt; Durst, Jürgen; Filipenko, Mykaylo; Gleixner, Thomas; Zuber, Kai

    2014-01-01

    Background: In electron-capture decay, a second K-shell vacancy is eventually created with a small probability. Measurements of the double-vacancy creation probability per K-shell electron capture PKK of various nuclei undergoing electron-capture decays have already been performed, but the statistical accuracy of PKK of several nuclides is still not satisfying. Purpose: The purpose of this experiment was to improve the statistical error of PKK in the decay of 55Fe and to demonstrate the possibility of detecting double-vacancy creation events with position resolving pixel detectors. This enables angle resolved measurements. Method: For the first time, two active-pixel detectors (A,B) were used to detect satellite- and hypersatellite-line photons in coincidence either both in two clusters of triggered pixels in only one detector (A,B) or in both detectors (A∧B). PKK was determined for the two detectors regarded as one single, larger detector (PKK), for each detector separately (single-sided analysis: PKK ,A⊻B), and for both detectors in coincidence (double-sided analysis: PKK ,A∧B). Results: The result of the experiment is PKK=(1.531±0.079)×10-4 with a systematic error of (ΔPKK)syst=±0.023×10-4. This value is in agreement with the value previously measured by Campbell et al. of PKK=(1.3±0.2)×10-4. The discrepancy in literature between PKK of 54Mn to the expected value extrapolated from 55Fe almost vanished with our result. The asymmetry between the result of the single-sided analysis (PKK ,A⊻B) and the double-sided analysis (PKK ,A∧B) is consistent with zero: (PKK ,A⊻B-PKK ,A∧B)/(PKK ,A⊻B+PKK ,A∧B)=-0.003±0.051. This supports the assumption that angular correlations between the two photons are negligible within the achieved level of statistical accuracy for the given angular acceptance of our detectors. Conclusions: One can conclude that hybrid photon counting pixel detectors can be used to measure angular correlations between the directions

  1. Interference effect of electron-capture X-rays from an {sup 125}I-labeled protein monolayer in an aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Y.C.; Suzuki, Yoshio; Ishibashi, Tadashi [Hitachi Ltd., Hatoyama, Saitama (Japan). Advanced Research Lab.; Satoh, Isamu

    1995-06-01

    We have measured the vertical distribution of a radioactively labeled protein in an aqueous solution by using the interference effect of electron-capture X-rays from radioisotopes. This interference is between the direct monochromatic emission from radioactive atoms and the emission totally reflected by the substrate surface. Structural information about radioactive atoms can be obtained by analyzing the measured interference fringes, since the period of these fringes depends on the position of the radioactive atoms relative to the substrate surface. In this work we used bovine serum albumin radioiodinated with carrier free {sup 125}I by using Chloramine T. The protein molecules were electrostatically adsorbed in a monolayer form by the positively charged Langmuir layer at the air-water interface. (author).

  2. Screening of priority pesticides in Ulva sp. seaweeds by selective pressurized solvent extraction before gas chromatography with electron capture detector analysis.

    Science.gov (United States)

    Pinto, M I; Micaelo, C; Vale, C; Sontag, G; Noronha, J P

    2014-11-01

    This work reports a fast and reliable analytical method for the screening of priority pesticides (PPs) in Ulva sp. seaweeds by gas chromatography with electron capture detection. Extraction and sample clean-up were performed in one single step by selective pressurized liquid extraction (SPLE). Several parameters affecting SPLE performance were optimized. Method performance was compared with standard Soxhlet extraction. Significant decrease of the time of analysis with better recoveries for a greater number of PPs was achieved by SPLE. Average recoveries ranged from 71 to 103% with RSD < 10%. Field application showed the presence of PP in the range of 3-11 ng g(-1) in seaweeds collected in a coastal lagoon after a long period of heavy rains. These results suggest that Ulva sp. seaweeds tend to accumulate PPs and have the potential to be used as early alert signals of aquatic pollution especially after rains and storm events.

  3. Velocity effect in the l-distribution of the electron capture in collisions of highly charged Ar{sup 8+} ions with a Li(2s) target

    Energy Technology Data Exchange (ETDEWEB)

    Pascale, J. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche sur l`Etat Condense, les Atomes et les Molecules; Jacquet, E.; Boduch, P.; Chantepie, M.; Lecler, D. [Caen Univ., 14 (France). Lab. de Spectroscopie Atomique

    1994-12-31

    The effect of the velocity of the incident ions in the l-distributions of the electron capture in collisions of highly charged Ar{sup 8+} ions with a Li(2s) target is studied. These Ar{sup 8+} - Li(2s) collisions are experimentally studied by means of near UV and visible photon spectroscopy (200-600 nm) and theoretically analysed by means of three-body classical trajectory Monte-Carlo method. In addition to the effect of the projectile core, we show that the final nl-distributions are, for the most populated n = 8 and n = 9 states strongly energy dependent. (authors). 11 refs., 3 figs., 2 tabs.

  4. Moulting of insect tracheae captured by light and electron-microscopy in the metathoracic femur of a third instar locust Locusta migratoria.

    Science.gov (United States)

    Snelling, Edward P; Seymour, Roger S; Runciman, Sue

    2011-09-01

    The insect tracheal system is an air-filled branching network of internal tubing that functions to exchange respiratory gases between the tissues and the environment. The light and electron-micrographs presented in this study show tracheae in the process of moulting, captured from the metathoracic hopping femur of a juvenile third instar locust (Locusta migratoria). The images provide evidence for the detachment of the cuticular intima from the tracheal epithelial cells, the presence of moulting fluid between the new and old cuticle layers, and the withdrawal of the shed cuticular lining through larger upstream regions of the tracheal system during moulting. The micrographs also reveal that the cuticular intima of the fine terminal branches of the tracheal system is cast at ecdysis. Therefore, the hypothesis that tracheoles retain their cuticle lining at each moult may not apply to all insect species or developmental stages.

  5. Comparative study of Gamow-Teller strength distributions in the odd-odd nucleus V50 and its impact on electron capture rates in astrophysical environments

    Science.gov (United States)

    Nabi, Jameel-Un; Sajjad, Muhammad

    2007-11-01

    Gamow-Teller (GT) strength transitions are an ideal probe for testing nuclear structure models. In addition to nuclear structure, GT transitions in nuclei directly affect the early phases of Type Ia and Type-II supernovae core collapse since the electron capture rates are partly determined by these GT transitions. In astrophysics, GT transitions provide an important input for model calculations and element formation during the explosive phase of a massive star at the end of its life-time. Recent nucleosynthesis calculations show that odd-odd and odd-A nuclei cause the largest contribution in the rate of change of lepton-to-baryon ratio. In the present manuscript, we have calculated the GT strength distributions and electron capture rates for odd-odd nucleus V50 by using the pn-QRPA theory. At present V50 is the first experimentally available odd-odd nucleus in fp-shell nuclei. We also compare our GT strength distribution with the recently measured results of a V50(d, He2)Ti50 experiment, with the earlier work of Fuller, Fowler, and Newman (referred to as FFN) and subsequently with the large-scale shell model calculations. One curious finding of the paper is that the Brink's hypothesis, usually employed in large-scale shell model calculations, is not a good approximation to use at least in the case of V50. SNe Ia model calculations performed using FFN rates result in overproduction of Ti50, and were brought to a much acceptable value by employing shell model results. It might be interesting to study how the composition of the ejecta using presently reported QRPA rates compare with the observed abundances.

  6. Non-radiation related osteonecrosis of the jaws in dogs: 14 cases (1996 - 2014

    Directory of Open Access Journals (Sweden)

    Santiago ePeralta

    2015-05-01

    Full Text Available Osteonecrosis of the jaws is an entity of major clinical impact characterized by chronically exposed necrotic mandibular or maxillary bone. Its clinicopathological characteristics and possible inciting or risk factors are well described in humans but only anecdotally reported in dogs. Treatment modalities and outcome vary depending on the inciting factors involved and the extent and severity of the lesions. The objectives of this study were to retrospectively describe the clinicopathological features of non-radiation related osteonecrosis of the jaws in a series of 14 dogs, identify possible inciting or risk factors, and report on the surgical treatment and outcome. For all patients, the medical records were used to collect information regarding signalment, clinical signs, characteristics of the oral, jaw and dental lesions, diagnostic imaging findings, histopathological and microbiological analysis, treatment performed and outcome. The data collected showed that non-radiation related osteonecrosis of the jaws appears to be an infrequent clinical entity but of significant impact in dogs; that a history of systemic antibiotics and dental disease is common among affected dogs; that previous dental extractions are commonly associated with ONJ sites; that using a systematic diagnostic approach is essential for diagnosis; and that thorough surgical débridement combined with a course of oral antibiotics was effective in the described dogs affected by advanced non-radiation related osteonecrosis of the jaws.

  7. Gas-phase doubly charged complexes of cyclic peptides with copper in +1, +2 and +3 formal oxidation states: formation, structures and electron capture dissociation.

    Science.gov (United States)

    Afonso, Carlos; Tabet, Jean-Claude; Giorgi, Gianluca; Tureček, František

    2012-02-01

    Copper complexes with a cyclic D-His-β-Ala-L-His-L-Lys and all-L-His-β-Ala-His-Lys peptides were generated by electrospray which were doubly charged ions that had different formal oxidation states of Cu(I), Cu(II) and Cu(III) and different protonation states of the peptide ligands. Electron capture dissociation showed no substantial differences between the D-His and L-His complexes. All complexes underwent peptide cross-ring cleavages upon electron capture. The modes of ring cleavage depended on the formal oxidation state of the Cu ion and peptide protonation. Density functional theory (DFT) calculations, using the B3LYP with an effective core potential at Cu and M06-2X functionals, identified several precursor ion structures in which the Cu ion was threecoordinated to pentacoordinated by the His and Lys side-chain groups and the peptide amide or enolimine groups. The electronic structure of the formally Cu(III) complexes pointed to an effective Cu(I) oxidation state with the other charge residing in the peptide ligand. The relative energies of isomeric complexes of the [Cu(c-HAHK + H)](2+) and [Cu(c-HAHK - H)](2+) type with closed electronic shells followed similar orders when treated by the B3LYP and M06-2X functionals. Large differences between relative energies calculated by these methods were obtained for open-shell complexes of the [Cu(c-HAHK)](2+) type. Charge reduction resulted in lowering the coordination numbers for some Cu complexes that depended on the singlet or triplet spin state being formed. For [Cu(c-HAHK - H)](2+) complexes, solution H/D exchange involved only the N-H protons, resulting in the exchange of up to seven protons, as established by ultra-high mass resolution measurements. Contrasting the experiments, DFT calculations found the lowest energy structures for the gas-phase ions that were deprotonated at the peptide C(α) positions.

  8. Validation of a new hand-held electronic data capture method for continuous monitoring of subjective appetite sensations

    Directory of Open Access Journals (Sweden)

    King Neil

    2011-06-01

    Full Text Available Abstract Background When large scale trials are investigating the effects of interventions on appetite, it is paramount to efficiently monitor large amounts of human data. The original hand-held Electronic Appetite Ratings System (EARS was designed to facilitate the administering and data management of visual analogue scales (VAS of subjective appetite sensations. The purpose of this study was to validate a novel hand-held method (EARS II (HP® iPAQ against the standard Pen and Paper (P&P method and the previously validated EARS. Methods Twelve participants (5 male, 7 female, aged 18-40 were involved in a fully repeated measures design. Participants were randomly assigned in a crossover design, to either high fat (>48% fat or low fat (ad libitum lunch was provided immediately before completing a final set of appetite sensations. Results Repeated measures ANOVAs were conducted for ratings of hunger, fullness and desire to eat. There were no significant differences between P&P compared with either EARS or EARS II (p > 0.05. Correlation coefficients between P&P and EARS II, controlling for age and gender, were performed on Area Under the Curve ratings. R2 for Hunger (0.89, Fullness (0.96 and Desire to Eat (0.95 were statistically significant (p Conclusions EARS II was sensitive to the impact of a meal and recovery of appetite during the postprandial period and is therefore an effective device for monitoring appetite sensations. This study provides evidence and support for further validation of the novel EARS II method for monitoring appetite sensations during large scale studies. The added versatility means that future uses of the system provides the potential to monitor a range of other behavioural and physiological measures often important in clinical and free living trials. This study was registered as a clinical trial by Current Controlled Trials (Registration Number - ISRCTN47291569.

  9. Investigation by high resolution electron spectroscopy of the helium-like 3lnl' Rydberg series in double capture processes at low collision velocity: auto transfer to Rydberg states and electron stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, A.; Moretto-Capelle, P.; Gonzalez, A.; Benhenni, M. (Toulouse-3 Univ., 31 (France)); Bachau, H.; Sanchez, I. (Bordeaux-1 Univ., 33 - Talence (France). Lab. des Collisions Atomiques)

    1994-09-28

    A high resolution electron spectrometry of the (3lnl') Ryberg series populated in N[sup 7+] + He and Ne[sup 10+] + He collisions at 10 q keV, 10[sup o] allows us to observe, for the first time by this method, two post-collisional effects. First, it is found with nitrogen ions that, when n increases from n = 4 to 9, the L-distribution peaks more and more on the high angular momentum states. This is qualitatively understood as a Stark deformation of the Rydberg orbit by the Coulomb field of the receding ion. Also, in the n range where the double capture process populates symmetrical 4l4l' states (n>9), an enhancement of the intensities of the 3lnl' Rydberg lines is observed for both collisonal systems. This is thought to be a signature of the so-called auto transfer to Rydberg states effect. The transfer of population from the 3l4l' to the 3lnl' states is found to be favoured against a direct autoionization of these 4l4l' states into the n = 2 continuum. These experimental findings together with preliminary spectroscopic calculations concerning the configuration interaction of the Ne[sup 8+] (4l4l') states with the Ne[sup 8+](3lnl') Rydberg series are also discussed within the context of the electron stabilization which follows a double capture. (Author).

  10. The final fate of stars that ignite neon and oxygen off-center: electron capture or iron core-collapse supernova?

    CERN Document Server

    Jones, Samuel; Nomoto, Ken'ichi

    2014-01-01

    In the ONeMg cores of $8.8-9.5~{\\rm M}_\\odot$ stars, neon and oxygen burning is ignited off-center. Whether the neon-oxygen flame propagates to the center is critical to determine whether these stars undergo Fe core collapse or electron capture induced ONeMg core collapse. We present more details of stars that ignite neon and oxygen burning off-center. The neon flame is established in a similar manner to the carbon flame of super-AGB stars, albeit with a narrower flame width. The criteria for establishing a flame are able to be met if the strict Schwarzschild criterion for convective instability is adopted. Mixing across the interface of the convective shell disrupts the conditions for the propagation of the burning front and instead the shell burns as a series of inward-moving flashes. While this may not directly affect whether the burning will reach the center (as in super-AGB stars), the core is allowed to contract between each shell flash. Reduction of the electron fraction in the shell reduces the Chandr...

  11. Sensitivity of stellar electron-capture rates to parent neutron number: A case study on a continuous chain of twenty Vanadium isotopes

    CERN Document Server

    Hitt, G W; Zegers, R G T; Titus, R; Sullivan, C; Brown, B A; Cole, A L; Shams, S

    2016-01-01

    Gamow-Teller (GT) strength distributions (B(GT)) in electron-capture (EC) daughters stemming from the parent ground state are computed with the shell-model in the full pf-shell space, with quasi-particle random-phase approximation (QRPA) in the formalism of Krumlinde and M\\"oller and with an Approximate Method (AM) for assigning an effective B(GT). These are compared to data available from decay and charge-exchange (CE) experiments across titanium isotopes in the pf-shell from A=43 to A=62, the largest set available for any chain of isotopes in the pf-shell. The present study is the first to examine B(GT) and the associated EC rates across a particular chain of isotopes with the purpose of examining rate sensitivities as neutron number increases. EC rates are also computed for a wide variety of stellar electron densities and temperatures providing concise estimates of the relative size of rate sensitivities for particular astrophysical scenarios. This work underscores the astrophysical motivation for CE exper...

  12. Experiences in running a complex electronic data capture system using mobile phones in a large-scale population trial in southern Nepal.

    Science.gov (United States)

    Style, Sarah; Beard, B James; Harris-Fry, Helen; Sengupta, Aman; Jha, Sonali; Shrestha, Bhim P; Rai, Anjana; Paudel, Vikas; Thondoo, Meelan; Pulkki-Brannstrom, Anni-Maria; Skordis-Worrall, Jolene; Manandhar, Dharma S; Costello, Anthony; Saville, Naomi M

    2017-01-01

    The increasing availability and capabilities of mobile phones make them a feasible means of data collection. Electronic Data Capture (EDC) systems have been used widely for public health monitoring and surveillance activities, but documentation of their use in complicated research studies requiring multiple systems is limited. This paper shares our experiences of designing and implementing a complex multi-component EDC system for a community-based four-armed cluster-Randomised Controlled Trial in the rural plains of Nepal, to help other researchers planning to use EDC for complex studies in low-income settings. We designed and implemented three interrelated mobile phone data collection systems to enrol and follow-up pregnant women (trial participants), and to support the implementation of trial interventions (women's groups, food and cash transfers). 720 field staff used basic phones to send simple coded text messages, 539 women's group facilitators used Android smartphones with Open Data Kit Collect, and 112 Interviewers, Coordinators and Supervisors used smartphones with CommCare. Barcoded photo ID cards encoded with participant information were generated for each enrolled woman. Automated systems were developed to download, recode and merge data for nearly real-time access by researchers. The systems were successfully rolled out and used by 1371 staff. A total of 25,089 pregnant women were enrolled, and 17,839 follow-up forms completed. Women's group facilitators recorded 5717 women's groups and the distribution of 14,647 food and 13,482 cash transfers. Using EDC sped up data collection and processing, although time needed for programming and set-up delayed the study inception. EDC using three interlinked mobile data management systems (FrontlineSMS, ODK and CommCare) was a feasible and effective method of data capture in a complex large-scale trial in the plains of Nepal. Despite challenges including prolonged set-up times, the systems met multiple data

  13. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of chlorinated pesticides in aquatic tissue by capillary-column gas chromatography with electron-capture detection

    Science.gov (United States)

    Leiker, Thomas J.; Madsen, J.E.; Deacon, J.R.; Foreman, W.T.

    1995-01-01

    A method for the determination of chlorinated organic compounds in aquatic tissue by dual capillary-column gas chromatography with electron-capture detection is described. Whole-body-fish or corbicula tissue is homogenized, Soxhlet extracted, lipid removed by gel permeation chromatography, and fractionated using alumina/silica adsorption chromatography. The extracts are analyzed by dissimilar capillary-column gas chromatography with electron-capture detection. The method reporting limits are 5 micrograms per kilogram (μg/kg) for chlorinated compounds, 50 μg/kg for polychlorinated biphenyls, and 200 μg/kg for toxaphene.

  14. Measurement of the total cross sections for electron capture of 2. 0-7. 5 MeV H/sup +/ in H, H/sub 2/ and He

    Energy Technology Data Exchange (ETDEWEB)

    Schwab, W.; Baptista, G.B.; Justiniano, E.; Vogt, H.; Weber, E.W.; Schuch, R.

    1987-06-28

    The total cross sections for electron capture of protons in atomic and molecular hydrogen and in helium gas targets are measured in the high proton velocity regime of 2.0, 3.5, 5.0 and 7.5 MeV. The results are compared with first- and higher-order perturbation theories (Oppenheimer-Brinkmann-Kramers, true first Born approximation (TFBA), eikonal approximation (EA), continuum distorted wave (CDW), strong potential Born, strong potential Born full peaking) for electron capture, and are found to be in good agreement with the CDW, EA and TFBA approximations.

  15. Photon spectroscopy of X{sup 7+} ions (X= Ne, Ar, Kr). Applications to the study of the single electron capture in low energy X{sup 8+}-Li collisions; Spectroscopie photonique des ions X{sup 7+} (X=Ne, Ar, Kr). Applications a l`etude de la simple capture electronique lors des collisions X{sup 8+}-Li a basse energie

    Energy Technology Data Exchange (ETDEWEB)

    Pascale, J. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. de Recherche sur l`Etat Condense, les Atomes et les Molecules; Jacquet, E. [Caen Univ., 14 (France). Lab. de Spectroscopie Atomique

    1994-12-31

    The effect of the electronic core of the projectile ion on the single capture electron n1 final states during collisions between X{sup 8+} ions (X= Ne, Ar, Kr) and Li(2s). Experimental cross sections are obtained from X{sup 7+} emission line measurements and are compared to calculations using the Monte Carlo type classical trajectory method. 3 figs., 6 refs.

  16. Correlation of Electrical Noise with Non-radiative Current for High Power QWLs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The characteristics of low-frequency electrical noise, voltage-current (V-I) and electrical derivation for 980nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditions. The correlation of the low-frequency electrical noise with surface non-radiative current of devices is discussed. The results indicate the low-frequency electrical noise of 980nm DQWLs with high power is mainly 1/f noise and has good relation with the device surface current at low injection.

  17. Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop Followed by Gas Chromatography-Electron Capture Detector for Determination of Some Pesticides in Water Samples

    Directory of Open Access Journals (Sweden)

    Mostafa Bashiri Juybari

    2011-01-01

    Full Text Available In this study dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO followed by gas chromatography-electron capture detection (GC-ECD was developed for determination of some pesticides in the water samples. Some important parameters, such as type and volumes of extraction and disperser solvent and salt effect on the extraction recovery of analytes from aqueous solution were investigated. Under the optimum conditions (extraction solvent: 1-undecanol, 15.0 μL; disperser solvent: acetone, 1.0 mL, and without salt addition, the preconcentration factors were obtained ranged from 802 to 915 for analytes. The linear ranges were from 0.05 to 100 μg L−1, and detection limits ranged from 0.05 to 0.008 μg L−1. The relative standard deviations (RSDs%, =5 were between 3.2% and 6.7%. The proposed method was successfully applied to the determination of target analytes in the tap, sea, and river water samples, and satisfactory recoveries were obtained.

  18. Use of green coating (cork) in solid-phase microextraction for the determination of organochlorine pesticides in water by gas chromatography-electron capture detection.

    Science.gov (United States)

    Dias, Adriana Neves; Simão, Vanessa; Merib, Josias; Carasek, Eduardo

    2015-03-01

    A novel method for the determination of organochlorine pesticides in water samples with extraction using cork fiber and analysis by gas chromatography with electron capture detector was developed. Also, the procedure to extract these pesticides with DVB/Car/PDMS fiber was optimized. The optimization of the variables involved in the extraction of organochlorine pesticides using the aforementioned fibers was carried out by multivariate design. The optimum extraction conditions were sample temperature 75 °C, extraction time 60 min and sodium chloride concentration 10% for the cork fiber and sample temperature 50 °C and extraction time 60 min (without salt) for the DVB/Car/PDMS fiber. The quantification limits for the two fibers varied between 1.0 and 10.0 ng L(-1). The linear correlation coefficients were >0.98 for both fibers. The method applied with the use of the cork fiber provided recovery values between 60.3 and 112.7 and RSD≤25.5 (n=3). The extraction efficiency values for the cork and DVB/Car/PDMS fibers were similar. The results show that cork is a promising alternative as a coating for SPME.

  19. Application of the standard addition method for the determination of acrylamide in heat-processed starchy foods by gas chromatography with electron capture detector.

    Science.gov (United States)

    Zhu, Yonghong; Li, Genrong; Duan, Yunpeng; Chen, Shiqi; Zhang, Chun; Li, Yanfei

    2008-08-15

    A gas chromatography electron capture detector (GC-ECD) using the standard addition method was developed for the determination of acrylamide in heat-processed foods. The method entails extraction of acrylamide with water, filtration, defatting with n-hexane, derivatization with hydrobromic acid and saturated bromine-water, and liquid-liquid extraction with ethyl acetate. The sample pretreatment required no SPE clean-up and concentration steps prior to injection. The final extract was analyzed by GC-ECD. The chromatographic analysis was performed on polar columns, e.g. Supelcowax-10 capillary column, and good retention and peak response of the analyte were achieved under the optimal conditions. The qualification of the analyte was by identifying the peak with same retention time as standard compound 2,3-DBPA and confirmed by GC-MS. GC-MS analysis confirmed that 2,3-DBPA was converted to 2-BPA nearly completely on the polar capillary column, whether or not treated with triethylamine. A four-point standard addition protocol was used to quantify acrylamide in food samples. The limit of detection (LOD) was estimated to be 0.6μg/kg on the basis of ECD technique. Validation and quantification results demonstrated that the method should be regarded as a low-cost, convenient, and reliable alternative for conventional investigation of acrylamide.

  20. Group-selective enrichment and determination of pyrethroid insecticides in aquaculture seawater via molecularly imprinted solid phase extraction coupled with gas chromatography-electron capture detection.

    Science.gov (United States)

    Shi, Xizhi; Liu, Jinghua; Sun, Aili; Li, Dexiang; Chen, Jiong

    2012-03-02

    Two types of molecularly imprinted polymers (MIPs) for the simultaneous determination of six pyrethroid insecticides have been developed using deltamethrin (D-MIPs) and cypermethrin (C-MIPs) as template molecules. A comparison of the performance of D-MIPs, C-MIPs, and the corresponding non-imprinted polymers (NIPs) were conducted. Stronger group-selective interactions between the C-MIPs and the six pyrethroid insecticides were achieved. The MISPE method based on the C-MIPs displayed higher extraction recoveries (86.4-96.0%) with RSD values ranging from 2.4 to 7.8% for the six pyrethroid insecticides in aquaculture seawater. After the C-MIP cartridge procedure, the limits of detection and quantification for fenvalerate, deltamethrin, cypermethrin, cyfluthrin, and bifenthrin were in the 16.6-37.0 and 55.3-109.1 ng L⁻¹ ranges, respectively, and 0.68 and 2.26 μg L⁻¹ for phenothrin, respectively. The proposed MISPE method coupled with gas chromatography-electron capture detection was successfully used for the determination of the six pyrethroid insecticides in aquaculture seawater.

  1. Determination of trihalomethanes in soil matrices by simplified quick, easy, cheap, effective, rugged and safe extraction and fast gas chromatography with electron capture detection.

    Science.gov (United States)

    Herrero Martín, Sara; García Pinto, Carmelo; Pérez Pavón, José Luis; Moreno Cordero, Bernardo

    2010-07-23

    A method based on QuEChERS extraction is proposed for the determination of trihalomethanes (chloroform, bromodichloromethane, dibromocloromethane and bromoform) in soil samples. The new version of QuEChERS adapted to soil samples consists of liquid extraction with ethyl acetate, the addition of water to moisten the samples, salting-out partitioning of the water with anhydrous MgSO4, and direct injection of the organic extract, obtained after the centrifugation step, into the gas chromatograph. This simplified extraction procedure maintains the advantages of the original method and avoids some steps, making the final procedure simpler, faster, and cheaper, with the consequent reduction in errors associated with sample manipulation. The experimental conditions of the analytical method, based on fast gas chromatography (FGC) and micro-electron capture detection (microECD), were optimized. The column and oven program used allowed fast separation of the compounds in less than 4 min and the total analysis cycle time was as short as 10 min. The existence of a matrix effect was checked and the analytical conditions of the method were studied in a fortified garden soil sample. The highly sensitive and selective detector used afforded to detection limits in the order of ng/kg for the target compounds. To validate the proposed method two certified reference materials (CRMs) were analyzed.

  2. Measurement of polychlorinated biphenyls in solid waste such as transformer insulation paper by supercritical fluid extraction and gas chromatography electron capture detection.

    Science.gov (United States)

    Chikushi, Hiroaki; Fujii, Yuka; Toda, Kei

    2012-09-21

    In this work, a method for measuring polychlorinated biphenyls (PCBs) in contaminated solid waste was investigated. This waste includes paper that is used in electric transformers to insulate electric components. The PCBs in paper sample were extracted by supercritical fluid extraction and analyzed by gas chromatography-electron capture detection. The recoveries with this method (84-101%) were much higher than those with conventional water extraction (0.08-14%), and were comparable to those with conventional organic solvent extraction. Limit of detection was 0.0074 mg kg(-1) and measurable up to 2.5 mg kg(-1) for 0.5 g of paper sample. Data for real insulation paper by the proposed method agreed well with those by the conventional organic solvent extraction. Extraction from wood and concrete was also investigated and good performance was obtained as well as for paper samples. The supercritical fluid extraction is simpler, faster, and greener than conventional organic solvent extraction. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Semiautomatic method for the screening and determination of 23 organochlorine pesticides in horticultural samples by gas chromatography with electron-capture detection.

    Science.gov (United States)

    Columé, A; Cárdenas, S; Gallego, M; Valcárcel, M

    1999-07-16

    A rapid, simple, efficient device for the extraction-preconcentration of 23 organochlorine pesticides currently applied to vegetables is proposed. Pesticide residues are extracted from chopped samples by using a mixture of distilled water and light petroleum (1:1, v/v). After phase separation, an aliquot of the organic layer is continuously evaporated to dryness under a N2 stream as it is dropped into a glass tube containing distilled water. The aqueous phase, containing the analytes, is then passed through a miniaturized RP-C18 column for preconcentration, clean-up and subsequent elution with 150 microliters of ethyl acetate. A volume of 1 microliter of the extract containing pesticides is injected into the gas chromatograph, fitted with an electron-capture detector, for their selective determination. Limits of detection vary between 0.04 and 10 ng/ml, with linear ranges from 0.2 to 500 ng/ml; the average relative standard deviation at the low nanogram-per-millilitre level is 5.3%. The potential of the proposed method was realized by applying it to the screening/determination of organochlorine pesticides in horticultural commodities.

  4. Searches for massive neutrino emission in 14C beta and 55Fe electron-capture decays

    Energy Technology Data Exchange (ETDEWEB)

    Wietfeldt, Fred Eberhardt [Univ. of California, Berkeley, CA (United States)

    1994-05-01

    In 1985 Simpson reported evidence for the emission of a 17 keV mass neutrino in a small fraction of tritium beta decays. An experimental controversy ensued in which a number of both positive and negative results were reported. The beta spectrum of 14C was collected in a unique 14C-doped planar germanium detector and a distortion was observed that initially confirmed Simpson`s result. Further tests linked this distortion to a splitting of the collected charge between the central detector and the surrounding guard ring in a fraction of the events. A second 14C measurement showed no evidence for emission of a 17 keV mass neutrino. In a related experiment, a high statistics electron-capture internal-bremsstrahlung photon spectrum of 55Fe was collected with a coaxial germanium detector. A local search for departures from a smooth shape near the endpoint was performed, using a second-derivative technique. An upper limit of 0.65% (95% C.L.) for the mixing Of a neutrino in the mass range 5--25 keV was established. The upper limit on the mixing of a 17 keV mass neutrino was 0.14% (95% C.L.).

  5. Comparison of sample preparation methods combined with gas chromatography with electron-capture detection for the analysis of multipesticide residues in lotus seeds.

    Science.gov (United States)

    Miao, Qing; Kong, Weijun; Yang, Shihai; Yang, Meihua

    2013-06-01

    Sample preparation is always the major bottleneck in analytical chemistry for the determination of pesticide residues. Different sample preparation methods have been proposed due to the wide variety of pesticides used and the inherent complexity of the matrices. In this study, different sample preparation methods including SPE, matrix solid-phase dispersion, the quick, easy, cheap, efficient, rugged, and safe method, and a one-step completion method were compared and evaluated for extracting pesticides from lotus seeds. Analysis was carried out using GC with electron-capture detection. The results showed that good recoveries for tested pesticides were obtained by using Florisil in the four methods, and the extraction efficiency of the one-step completion method was superior to the other three methods. The one-step completion method was confirmed to have good linearity, reproducibility, stability, and recovery for the detection of 36 pesticides in lotus seed samples. The data collected from this study are expected to prove useful in regulating the concentration of the residues in lotus seeds, as well as in protecting human health from the hazards posed by these residues.

  6. Phenyl-functionalized silica-coated magnetic nanoparticles for the extraction of chlorobenzenes, and their determination by GC-electron capture detection.

    Science.gov (United States)

    Saraji, Mohammad; Khaje, Nasrin

    2013-03-01

    We have prepared a solid phase for the extraction of chlorobenzenes (CBs) by coating magnetic (Fe3 O4 ) nanoparticles with silica via a sol-gel process using a mixture of tetraethoxysilane and triethoxyphenylsilane. The nanoparticles were characterized by SEM, energy-dispersive spectroscopy, and X-ray diffractometry. The nanoparticles were used for the extraction of 1,4-dichlorobenzene (1,4-DCB), 1,2,3-trichlorobenzene (1,2,3-TCB), 1,2,4-trichlorobenzene (1,2,4-TCB), and 1,2,3,4-tetrachlorobenzene (1,2,3,4-TeCB) from water, followed by their determination by GC-electron capture detection. Under optimal conditions, enrichment factors ranging from 220 to 360 were obtained. All determination coefficients (r(2)) are >0.99, and linear response is found in range 0.025-1.5 μg/L (at the lower end), and 6-120 μg/L (at the higher end). Detection limits are 6, 10, 11, and 500 ng/L for 1,2,3,4-TeCB, 1,2,4-TCB, 1,2,3-TCB, and 1,4-DCB, respectively. All RSDs are <6% (for n = 5). The method was successfully applied to the determination of CBs in environmental water samples.

  7. Solid phase extraction with silicon dioxide microsphere adsorbents in combination with gas chromatography-electron capture detection for the determination of DDT and its metabolites in water samples.

    Science.gov (United States)

    Zhou, Qingxiang; Wu, Wei; Xie, Guohong

    2013-01-01

    The goal of the present study was to investigate the feasibility of silicon dioxide (SiO(2)) microspheres without special modification to enrich dichlorodiphenyltrichloroethane (DDT) and its main metabolites, p,p'-dichlorodiphenyl-2,2-dichloroethylene (p,p'-DDD) and p,p'-dichlorodiphenyldichloroethylene (DDE) in combination with gas chromatography-electron-capture detection. The experimental results indicated that an excellent linear relationship between the recoveries and the concentrations of DDT and its main metabolites was obtained in the range of 0.2-30 ng mL(-1) and the correlation coefficients were in the range of 99.96-99.99%. The detection limits based on the ratio of signal to the baseline noise (S/N = 3) were 2.2, 2.9, 3.8 and 4.1 ng L(-1) for p,p'-DDD, p,p'-DDT, o,p'-DDT, and p,p'-DDE, respectively. The precisions of the proposed method were all below 10% (n = 6). Four real water samples were utilized for validation of the proposed method, and satisfactory spiked recoveries in the range of 72.4-112.9% were achieved. These results demonstrated that the developed method was a simple, sensitive, and robust analytical method for the monitoring of pollutants in the environment.

  8. M-shell electron capture and direct ionization of gold by 25-MeV carbon and 32-MeV oxygen ions

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, M.C.; McDaniel, F.D.; Duggan, J.L.; Miller, P.D.; Pepmiller, P.L.; Krause, H.; Rosseel, T.; Rayburn, L.A.; Mehta, R.; Lapicki, G.

    1984-01-01

    M-shell x-ray production cross sections have been measured for thin solid targets of Au for 25 MeV /sup 12/C/sup q+/ (q = 4, 5, 6) and for 32 MeV /sup 16/O/sup q+/ (q = 5, 7, 8). The microscopic cross sections were determined from measurements made with targets ranging in thickness from 0.5 to 100 ..mu..g/cm/sup 2/. For projectiles with one or two K-shell vacancies, the M-shell x-ray production cross sections are found to be enhanced over those by projectiles without a K-shell vacancy. The sum of direct ionization to the continuum (DI) and electron capture (EC) to the L, M, N ... shells and EC to the K-shell of the projectile have been extracted from the data. The results are compared to the predictions of first Born theories i.e. PWBA for DI and OBK of Nikolaev for EC and the ECPSSR approach that accounts for energy loss, Coulomb deflection and relativistic effects in the perturbed stationary state theory. 25 references, 3 figures, 1 table.

  9. nIFTy galaxy cluster simulations - I. Dark matter and non-radiative models

    Science.gov (United States)

    Sembolini, Federico; Yepes, Gustavo; Pearce, Frazer R.; Knebe, Alexander; Kay, Scott T.; Power, Chris; Cui, Weiguang; Beck, Alexander M.; Borgani, Stefano; Dalla Vecchia, Claudio; Davé, Romeel; Elahi, Pascal Jahan; February, Sean; Huang, Shuiyao; Hobbs, Alex; Katz, Neal; Lau, Erwin; McCarthy, Ian G.; Murante, Guiseppe; Nagai, Daisuke; Nelson, Kaylea; Newton, Richard D. A.; Perret, Valentin; Puchwein, Ewald; Read, Justin I.; Saro, Alexandro; Schaye, Joop; Teyssier, Romain; Thacker, Robert J.

    2016-04-01

    We have simulated the formation of a galaxy cluster in a Λ cold dark matter universe using 13 different codes modelling only gravity and non-radiative hydrodynamics (RAMSES, ART, AREPO, HYDRA and nine incarnations of GADGET). This range of codes includes particle-based, moving and fixed mesh codes as well as both Eulerian and Lagrangian fluid schemes. The various GADGET implementations span classic and modern smoothed particle hydrodynamics (SPH) schemes. The goal of this comparison is to assess the reliability of cosmological hydrodynamical simulations of clusters in the simplest astrophysically relevant case, that in which the gas is assumed to be non-radiative. We compare images of the cluster at z = 0, global properties such as mass and radial profiles of various dynamical and thermodynamical quantities. The underlying gravitational framework can be aligned very accurately for all the codes allowing a detailed investigation of the differences that develop due to the various gas physics implementations employed. As expected, the mesh-based codes RAMSES, ART and AREPO form extended entropy cores in the gas with rising central gas temperatures. Those codes employing classic SPH schemes show falling entropy profiles all the way into the very centre with correspondingly rising density profiles and central temperature inversions. We show that methods with modern SPH schemes that allow entropy mixing span the range between these two extremes and the latest SPH variants produce gas entropy profiles that are essentially indistinguishable from those obtained with grid-based methods.

  10. Suitability of magnetic particle immunoassay for the analysis of PBDEs in Hawaiian freshwater fish and crabs in comparison with gas chromatography/electron capture detection-ion trap mass spectrometry

    Science.gov (United States)

    A gas chromatograph/electron capture detector-ion trap mass spectrometer (GC/ECD-ITMS) was used for the determination of polybrominated diphenyl ethers (PBDEs) in freshwater fish and crabs. The samples were also analyzed with an enzyme-linked immunosorbent assay (ELISA). GC/ECD-ITMS results showed...

  11. Separation of seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans and 12 dioxin-like polychlorinated biphenyls by comprehensive two-dimensional gas chromatography with electron-capture detection

    NARCIS (Netherlands)

    Korytar, P.; Danielsson, C.; Leonards, P.E.G.; Haglund, P.; Boer, de J.; Brinkman, U.A.Th.

    2004-01-01

    Comprehensive two-dimensional gas chromatography (GCxGC) with electron-capture detection (ECD) has been optimized for the separation of seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins and dibenzofurans and 12 dioxin-like polychlorinated biphenyls, with emphasis on the selection of th

  12. Capturing appearance

    Science.gov (United States)

    Rushmeier, Holly E.

    2005-01-01

    For computer graphics applications, capturing the appearance parameters of objects (reflectance, transmittance and small scale surface structures), is as important as capturing the overall shape. We briefly review recent approaches developed by the computer graphics community to solve this problem. Excellent results have been obtained by various researchers measuring spatially varying reflectance functions for some classes of objects. We will consider some challenges from two of the remaining problematic classes of objects. First we will describe our experience scanning and modeling the throne of Tutankhamen. The major difficulties in this case were that the base shape was a highly detailed non-convex geometry with complex topology, and the shape was covered by optically uncooperative gold and silver. Then we will discuss some observations from our ongoing project to scan and model historic buildings on the Yale campus. The major difficulties in this second case are quantity of data and the lack of control over acquisition conditions.

  13. Density functional theory study of the structural, electronic, lattice dynamical, and thermodynamic properties of Li4SiO4 and its capability for CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Yuhua; Parlinski, K.

    2011-01-01

    The structural, electronic, lattice dynamical, optical, thermodynamic, and CO{sub 2} capture properties of monoclinic and triclinic phases of Li{sub 4}SiO{sub 4} are investigated by combining density functional theory with phonon lattice dynamics calculations. We found that these two phases have some similarities in their bulk and thermodynamic properties. The calculated bulk modulus and the cohesive energies of these two phases are close to each other. Although both of them are insulators, the monoclinic phase of Li{sub 4}SiO{sub 4} has a direct band gap of 5.24 eV while the triclinic Li{sub 4}SiO{sub 4} phase has an indirect band gap of 4.98 eV. In both phases of Li{sub 4}SiO{sub 4}, the s orbital of O mainly contributes to the lower-energy second valence band (VB{sub 2}) and the p orbitals contribute to the fist valence band (VB{sub 1}) and the conduction bands (CBs). The s orbital of Si mainly contributes to the lower portions of the VB1 and VB{sub 2}, and Si p orbitals mainly contribute to the higher portions of the VB{sub 1} and VB{sub 2}. The s and p orbitals of Li contribute to both VBs and to CBs, and Li p orbitals have a higher contribution than the Li s orbital. There is possibly a phonon soft mode existing in triclinic {gamma}-Li{sub 4}SiO{sub 4}; in the monoclinic Li{sub 4}SiO{sub 4}, there are three phonon soft modes, which correspond to the one type of Li disordered over a few sites. Their LO-TO splitting indicates that both phases of Li{sub 4}SiO{sub 4} are polar anisotropic materials. The calculated infrared absorption spectra for LO and TO modes are different for these two phases of Li{sub 4}SiO{sub 4}. The calculated relationships of the chemical potential versus temperature and CO{sub 2} pressure for reaction of Li{sub 4}SiO{sub 4} with CO{sub 2} shows that Li{sub 4}SiO{sub 4} could be a good candidate for a high-temperature CO{sub 2} sorbent while used for postcombustion capture technology.

  14. Muon capture at PSI

    CERN Document Server

    Winter, Peter

    2010-01-01

    Measuring the rate of muon capture in hydrogen provides one of the most direct ways to study the axial current of the nucleon. The MuCap experiment uses a negative muon beam stopped in a time projection chamber operated with ultra-pure hydrogen gas. Surrounded by a decay electron detector, the lifetime of muons in hydrogen can be measured to determine the singlet capture rate Lambda_s to a final precision of 1%. The capture rate determines the nucleon's pseudoscalar form factor g_p. A first result, g_p = 7.3 +- 1.1, has been published and the final analysis of the full statistics will reduce the error by a factor of up to 3. Muon capture on the deuteron probes the weak axial current in the two-nucleon system. Within the framework of effective field theories the calculation of such two-nucleon processes involving the axial current requires the knowledge of one additional low energy constant which can be extracted from the doublet capture rate Lambda_d. The same constant then allows to model-independently calcu...

  15. Comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry and simultaneous electron capture detection/nitrogen phosphorous detection for incense analysis

    Science.gov (United States)

    Tran, Tin C.; Marriott, Philip J.

    This study reports comprehensive two-dimensional gas chromatography hyphenated to time-of-flight mass spectrometry detection (GC × GC/TOFMS) for characterisation and identification of components generated by four different types of powdered incense headspace (H/S) and incense smoke. GC × GC/TOFMS allowed simultaneous separation and identification of compounds emitted into the atmosphere as a result of combustion of incense powder. The smoke stream comprised compounds originating from the incense powder, and combustion products such as saturated and unsaturated hydrocarbons, essential oil type compounds, nitromusks, fatty acid methyl esters (FAMEs), polycyclic aromatic hydrocarbons (PAHs, which possibly include oxygenated and nitrated PAH), N-heterocyclics, pyrans and furans, which were detected and tentatively identified by GC × GC/TOFMS. GC × GC-electron capture detector/nitrogen phosphorous detector (ECD/NPD) potentially offers the prospect of providing selective chemical compositional information of incense powder and smoke, such as nitrogen-containing (N-containing) and halogenated compounds. Results of GC×GC-ECD/NPD showed that both incense powder and smoke generated emission of N-containing and halogenated compounds. A significant number of halogenated and N-containing compounds were emitted during the incomplete combustion of incense. However, one further objective of this paper is to demonstrate the capacity of comprehensive two-dimensional gas chromatography coupled to specific and/or selective detectors such as those used in this study (GC × GC-ECD/NPD) for the detection of particular classes of compounds such as N-containing and halogenated compounds at trace level concentrations in complex smoke samples.

  16. Dispersive liquid-liquid microextraction combined with gas chromatography-electron capture detection for the determination of polychlorinated biphenyls in soils

    Energy Technology Data Exchange (ETDEWEB)

    Hu Jia [Department of Chemical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079 (China); Fu Lingyan; Zhao Xinna; Liu Xiujuan [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079 (China); Wang Huili; Wang Xuedong [School of Environmental Science and Public Health, Wenzhou Medical College, Wenzhou 325035 (China); Dai Liyan, E-mail: dailiyan@zju.edu.cn [Department of Chemical Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China)

    2009-04-27

    In this article, dispersive liquid-liquid microextraction (DLLME) and gas chromatography-electron capture detection (GC-ECD) were presented for the extraction and determination of five polychlorinated biphenyls (PCBs) in soil samples. Acetone was used as extraction solvent for the extraction of PCBs from soil samples. In DLLME, the target analytes in the extraction solvent were rapidly transferred from the acetone extract to chlorobenzene when the extraction process began. The main advantages of this method are quick speed, high enrichment factor, high recovery and good repeatability. Under the optimum conditions, the method yields a linear calibration curve in the concentration range from 2 to 2000 {mu}g kg{sup -1}for PCB 52, and 0.4 to 400 {mu}g kg{sup -1} for other target analytes. Coefficients of correlation (r{sup 2}) ranged from 0.9993 to 0.9999. The repeatability was tested by spiking soil samples at a concentration level of 10 {mu}g kg{sup -1} for PCBs. The relative standard deviations (RSDs, n = 11) varied between 2.2% and 6.4%. The limits of detection (LODs), based on signal-to-noise (S/N) of 3, were between 0.20 and 0.50 {mu}g kg{sup -1}. The relative recoveries of the five PCBs from soil S1, S2 and S3 at spiking levels of 10, 20 and 50 {mu}g kg{sup -1} were in the range of 88.70-103.8%, 82.50-106.3% and 82.30-113.6%, respectively. Therefore, DLLME combined with GC-ECD can be successfully applied for the determination of trace PCB residues in real soil samples.

  17. Dispersive liquid-liquid microextraction method based on solidification of floating organic drop combined with gas chromatography with electron-capture or mass spectrometry detection.

    Science.gov (United States)

    Leong, Mei-I; Huang, Shang-Da

    2008-11-21

    A simple dispersive liquid-liquid microextraction (DLLME) method based on solidification of a floating organic drop (DLLME-SFO) technique combined with gas chromatography/electron-capture detection (GC/ECD) or gas chromatography/mass spectrometry (GC/MS) has been developed. The proposed method is simple, low in cost, and of high precision. It overcomes the most important problem in DLLME, the high-toxic solvent used. Halogenated organic compounds (HOCs) in water samples were determined as the model compounds. The parameters optimized for the DLLME-SFO technique were as follows: A mixture of 0.5 mL acetone, containing 10 microL 2-dodecanol (2-DD-OH), was rapidly injected by syringe into the 5 mL water sample. After centrifugation, the fine 2-DD-OH droplets (8+/-0.5 microL) were floated at the top of the screwcap test tube. The test tube was then cooled in an ice bath. After 5 min the 2-DD-OH solvent had solidified and was then transferred into a conical vial; it melted quickly at room temperature and 3 microL (for GC/ECD) or 2 microL (for GC/MS) of it was injected into a gas chromatograph for analysis. The limit of detection (LOD) for this technique was 0.005-0.05microgL(-1) for GC/ECD and was 0.005-0.047 microgL(-1) for GC/MS, respectively. The linear range of the calibration curve of DLLME-SFO was from 0.01 to 500 microgL(-1) with a coefficient of estimation (r2)>0.996 for GC/ECD and was from 0.02 to 500 microgL(-1) with a coefficient of estimation (r2)>0.996 for GC/MS.

  18. Separation and screening of short-chain chlorinated paraffins in environmental samples using comprehensive two-dimensional gas chromatography with micro electron capture detection.

    Science.gov (United States)

    Xia, Dan; Gao, Lirong; Zhu, Shuai; Zheng, Minghui

    2014-11-01

    Short-chain chlorinated paraffins (SCCPs) are highly complex technical mixtures with thousands of isomers and numerous homologs. They are classified as priority candidate persistent organic pollutants under the Stockholm Convention for their persistence, bioaccumulation, and toxicity. Analyzing SCCPs is challenging because of the complexity of the mixtures. Chromatograms of SCCPs acquired using one-dimensional (1D) gas chromatography (GC) contain a large characteristic "peak" with a broad and unresolved profile. Comprehensive two-dimensional GC (GC×GC) shows excellent potential for separating complex mixtures. In this study, GC×GC coupled with micro electron capture detection (μECD) was used to separate and screen SCCPs. The chromatographic parameters, including the GC column types, oven temperature program, and modulation period, were systematically optimized. The SCCP congeners were separated into groups using a DM-1 column connected to a BPX-50 column. The SCCP congeners in technical mixtures were separated according to the number of chlorine substituents for a given carbon chain length and according to the number of carbon atoms plus chlorine atoms for different carbon chain lengths. A fish tissue sample was analyzed to illustrate the feasibility of the GC×GC-μECD method in analyzing biological samples. Over 1,500 compounds were identified in the fish extract, significantly more than were identified using 1D GC. The detection limits for five selected SCCP congeners were between 1 and 5 pg/L using the GC×GC method, and these were significantly lower than those achieved using 1D GC. This method is a good choice for analysis of SCCPs in environmental samples, exhibiting good separation and good sensitivity.

  19. Capturing Patient-Reported Outcome (PRO) Data Electronically: The Past, Present, and Promise of ePRO Measurement in Clinical Trials.

    Science.gov (United States)

    Coons, Stephen Joel; Eremenco, Sonya; Lundy, J Jason; O'Donohoe, Paul; O'Gorman, Hannah; Malizia, William

    2015-08-01

    Patient-reported outcomes (PROs) are an important means of evaluating the treatment benefit of new medical products. It is recognized that PRO measures should be used when assessing concepts best known by the patient or best measured from the patient's perspective. As a result, there is growing emphasis on well defined and reliable PRO measures. In addition, advances in technology have significantly increased electronic PRO (ePRO) data collection capabilities and options in clinical trials. The movement from paper-based to ePRO data capture has enhanced the integrity and accuracy of clinical trial data and is encouraged by regulators. A primary distinction in the types of ePRO platforms is between telephone-based interactive voice response systems and screen-based systems. Handheld touchscreen-based devices have become the mainstay for remote (i.e., off-site, unsupervised) PRO data collection in clinical trials. The conventional approach is to provide study subjects with a handheld device with a device-based proprietary software program. However, an emerging alternative for clinical trials is called bring your own device (BYOD). Leveraging study subjects' own Internet-enabled mobile devices for remote PRO data collection (via a downloadable app or a Web-based data collection portal) has become possible due to the widespread use of personal smartphones and tablets. However, there are a number of scientific and operational issues that must be addressed before BYOD can be routinely considered as a practical alternative to conventional ePRO data collection methods. Nevertheless, the future for ePRO data collection is bright and the promise of BYOD opens a new chapter in its evolution.

  20. Gas-phase structure of amyloid-β (12-28) peptide investigated by infrared spectroscopy, electron capture dissociation and ion mobility mass spectrometry.

    Science.gov (United States)

    Le, Thi Nga; Poully, Jean Christophe; Lecomte, Frédéric; Nieuwjaer, Nicolas; Manil, Bruno; Desfrançois, Charles; Chirot, Fabien; Lemoine, Jerome; Dugourd, Philippe; van der Rest, Guillaume; Grégoire, Gilles

    2013-12-01

    The gas-phase structures of doubly and triply protonated Amyloid-β12-28 peptides have been investigated through the combination of ion mobility (IM), electron capture dissociation (ECD) mass spectrometry, and infrared multi-photon dissociation (IRMPD) spectroscopy together with theoretical modeling. Replica-exchange molecular dynamics simulations were conducted to explore the conformational space of these protonated peptides, from which several classes of structures were found. Among the low-lying conformers, those with predicted diffusion cross-sections consistent with the ion mobility experiment were further selected and their IR spectra simulated using a hybrid quantum mechanical/semiempirical method at the ONIOM DFT/B3LYP/6-31 g(d)/AM1 level. In ECD mass spectrometry, the c/z product ion abundance (PIA) has been analyzed for the two charge states and revealed drastic differences. For the doubly protonated species, N - Cα bond cleavage occurs only on the N and C terminal parts, while a periodic distribution of PIA is clearly observed for the triply charged peptides. These PIA distributions have been rationalized by comparison with the inverse of the distances from the protonated sites to the carbonyl oxygens for the conformations suggested from IR and IM experiments. Structural assignment for the amyloid peptide is then made possible by the combination of these three experimental techniques that provide complementary information on the possible secondary structure adopted by peptides. Although globular conformations are favored for the doubly protonated peptide, incrementing the charge state leads to a conformational transition towards extended structures with 310- and α-helix motifs.

  1. Homogeneous liquid-liquid extraction combined with gas chromatography-electron capture detector for the determination of three pesticide residues in soils

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xuedong [School of Environmental Science and Public Health, Wenzhou Medical College, Wenzhou 325035 (China)], E-mail: zjuwxd@yahoo.com.cn; Zhao Xinna; Liu Xiujuan; Li Yanyan; Fu Lingyan; Hu Jia [Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Central China Normal University, Wuhan 430079 (China); Huang Changjiang [School of Environmental Science and Public Health, Wenzhou Medical College, Wenzhou 325035 (China)

    2008-07-14

    In this study, a new method was developed for analyzing malathion, cypermethrin and lambda-cyhalothrin from soil samples by using homogeneous liquid-liquid extraction (HLLE) and gas chromatography with electron capture detector (GC-ECD). Acetone was used as extraction solvent for the extraction of target pesticides from soil samples. When the extraction process was finished, the target analytes in the extraction solvent were rapidly transferred from the acetone extract to carbon tetrachloride, using HLLE. Under the optimum conditions, linearity was obtained in the range of 0.05-40 {mu}g kg{sup -1} for malathion, 0.04-10 {mu}g kg{sup -1} for lambda-cyhalothrin and 0.05-50 {mu}g kg{sup -1} for cypermethrin, respectively. Coefficients of correlation (r{sup 2}) ranged from 0.9993 to 0.9998. The repeatability was carried out by spiking soil samples at concentration levels of 2.5 {mu}g kg{sup -1} for lambda-cyhalothrin, and 10 {mu}g kg{sup -1} for malathion and cypermethrin, respectively. The relative standard deviations (RSDs) varied between 2.3 and 9.6% (n = 3). The limits of detection (LODs), based on signal-to-noise ratio (S/N) of 3, varied between 0.01 and 0.04 {mu}g kg{sup -1}. The relative recoveries of three pesticides from soil A1, A2 and A3 at spiking levels of 2.5, 5 and 10 {mu}g kg{sup -1} were in the range of 82.20-91.60%, 88.90-110.5% and 77.10-98.50%, respectively. In conclusion, the proposed method can be successfully applied for the determination of target pesticide residues in real soil samples.

  2. In matrix derivatization of trichloroethylene metabolites in human plasma with methyl chloroformate and their determination by solid-phase microextraction-gas chromatography-electron capture detector.

    Science.gov (United States)

    Mudiam, Mohana Krishna Reddy; Jain, Rajeev; Varshney, Meenu; Ch, Ratnasekhar; Chauhan, Abhishek; Goyal, Sudhir Kumar; Khan, Haider A; Murthy, R C

    2013-04-15

    Trichloroethylene (TCE) is a common industrial chemical that has been widely used as metal degreaser and for many industrial purposes. In humans, TCE is metabolized into dichloroacetic acid (DCA), trichloroacetic acid (TCA) and trichloroethanol (TCOH). A simple and rapid method has been developed for the quantitative determination of TCE metabolites. The procedure involves the in situ derivatization of TCE metabolites with methyl chloroformate (MCF) directly in diluted plasma samples followed by extraction and analysis with solid-phase microextraction (SPME) coupled to gas chromatography-electron capture detector (GC-ECD). Factors which can influence the efficiency of derivatization such as amount of MCF and pyridine (PYR), ratio of water/methanol were optimized. The factors which can affect the extraction efficiencies of SPME were screened using 2(7-4) Placket-Burman Design (PBD). A central composite design (CCD) was then applied to further optimize the most significant factors for optimum SPME extraction. The optimum factors for the SPME extraction were found to be 562.5mg of NaCl, pH at 1 and an extraction time of 22 min. Recoveries and detection limits of all three analytes in plasma were found to be in the range of 92.69-97.55% and 0.036-0.068 μg mL(-1) of plasma, respectively. The correlation coefficients were found to be in the range of 0.990-0.995. The intra- and inter-day precisions for TCE metabolites were found to be in the range of 2.37-4.81% and 5.13-7.61%, respectively. The major advantage of this method is that MCF derivatization allows conversion of TCE metabolites into their methyl esters in very short time (≤30 s) at room temperature directly in the plasma samples, thus makes it a solventless analysis. The method developed was successfully applied to the plasma samples of humans exposed to TCE.

  3. Unexpected tolerance of glycosylation by UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferase revealed by electron capture dissociation mass spectrometry: carbohydrate as potential protective groups.

    Science.gov (United States)

    Yoshimura, Yayoi; Matsushita, Takahiko; Fujitani, Naoki; Takegawa, Yasuhiro; Fujihira, Haruhiko; Naruchi, Kentarou; Gao, Xiao-Dong; Manri, Naomi; Sakamoto, Takeshi; Kato, Kentaro; Hinou, Hiroshi; Nishimura, Shin-Ichiro

    2010-07-20

    UDP-GalNAc:polypeptide alpha-N-acetylgalactosaminyltransferases (ppGalNAcTs, EC 2.4.1.41), a family of key enzymes that initiate posttranslational modification with O-glycans in mucin synthesis by introduction of alpha-GalNAc residues, are structurally composed of a catalytic domain and a lectin domain. It has been known that multiple Ser/Thr residues are assigned in common mucin glycoproteins as potential O-glycosylation sites and more than 20 distinct isoforms of this enzyme family contribute to produce densely O-glycosylated mucin glycoproteins. However, it seems that the functional role of the lectin domain of ppGalNAcTs remains unclear. We considered that electron capture dissociation mass spectrometry (ECD-MS), a promising method for highly selective fragmentation at peptide linkages of glycopeptides to generate unique c and z series of ions, should allow for precise structural characterization to uncover the mechanism in O-glycosylation of mucin peptides by ppGalNAcTs. In the present study, it was demonstrated that a system composed of an electrospray source, a linear RFQ ion trap that isolates precursor ions, the ECD device, and a TOF mass spectrometer is a nice tool to identify the preferential O-glycosylation sites without any decomposition of the carbohydrate moiety. It should be noted that electrons used for ECD are accelerated within a range from 1.75 to 9.75 eV depending on the structures of glycopeptides of interest. We revealed for the first time that additional installation of a alpha-GalNAc residue at potential glycosylation sites by ppGalNAcT2 proceeds smoothly in various unnatural glycopeptides having alpha-Man, alpha-Fuc, and beta-Gal residues as well as alpha-GalNAc residues. The results may suggest that ppGalNAcT2 did not differentiate totally presubstituted sugar residues in terms of configuration of functional groups, d-, l-configuration, and even alpha-, beta-stereochemistry at an anomeric carbon atom when relatively short synthetic

  4. The AtChem On-line model and Electronic Laboratory Notebook (ELN): A free community modelling tool with provenance capture

    Science.gov (United States)

    Young, J. C.; Boronska, K.; Martin, C. J.; Rickard, A. R.; Vázquez Moreno, M.; Pilling, M. J.; Haji, M. H.; Dew, P. M.; Lau, L. M.; Jimack, P. K.

    2010-12-01

    AtChem On-line1 is a simple to use zero-dimensional box modelling toolkit, developed for use by laboratory, field and chamber scientists. Any set of chemical reactions can be simulated, in particular the whole Master Chemical Mechanism (MCM2) or any subset of it. Parameters and initial data can be provided through a self-explanatory web form and the resulting model is compiled and run on a dedicated server. The core part of the toolkit, providing a robust solver for thousands of chemical reactions, is written in Fortran and uses SUNDIALS3 CVODE libraries. Chemical systems can be constrained at multiple, user-determined timescales; this enabled studies of radical chemistry at one minute timescales. AtChem On-line is free to use and requires no installation - a web browser, text editor and any compressing software is all the user needs. CPU and storage are provided by the server (input and output data are saved indefinitely). An off-line version is also being developed, which will provide batch processing, an advanced graphical user interface and post-processing tools, for example, Rate of Production Analysis (ROPA) and chainlength analysis. The source code is freely available for advanced users wishing to adapt and run the program locally. Data management, dissemination and archiving are essential in all areas of science. In order to do this in an efficient and transparent way, there is a critical need to capture high quality metadata/provenance for modelling activities. An Electronic Laboratory Notebook (ELN) has been developed in parallel with AtChem Online as part of the EC EUROCHAMP24 project. In order to use controlled chamber experiments to evaluate the MCM, we need to be able to archive, track and search information on all associated chamber model runs, so that they can be used in subsequent mechanism development. Therefore it would be extremely useful if experiment and model metadata/provenance could be easily and automatically stored electronically

  5. Influence of radiation and non-radiation factors on pancreatic cancer incidence among Mayak PA workers

    Energy Technology Data Exchange (ETDEWEB)

    Zhuntova, G.V.; Tokarskaya, Z.B.; Belyaeva, Z.D. [Southern Ural Biophysics Institute (SUBI), Ozyorsk (Russian Federation); Syrchikov, V.A.; Grigoryeva, E.S. [Mayak Production Association (Mayak PA), Ozyorsk (Russian Federation)

    2006-07-01

    The finding of this nested case-control study suggests that high levels of 239 Pu incorporation (239 Pu body burden > 3.7), alcohol abuse and smoking were associated with increasing the risk of pancreatic cancer among Mayak PA workers chronically exposed to ionizing radiation. The contribution of non radiation factors (alcohol abuse and smoking) to pancreatic tumor incidence is greater (AR=51%) than 239 Pu incorporation kBq; AR = 7%). No significant effect of external gamma rays ({<=} 6.8 Gy), prior exposure to chemical agents, or chronic digestive diseases was found on the incidence of pancreatic tumor. Evaluation of the absorbed alpha-radiation pancreatic dose will permit to make more exact the 239 Pu risk estimation in the further extended study.

  6. Radiative and non-radiative recombinations in tensile strained Ge microstrips: Photoluminescence experiments and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Virgilio, M., E-mail: virgilio@df.unipi.it [Dip. di Fisica “E. Fermi,” Università di Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); NEST, Istituto Nanoscienze-CNR, P.za San Silvestro 12, 56127 Pisa (Italy); Schroeder, T.; Yamamoto, Y. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Capellini, G. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Dip. di scienze, Università Roma Tre, viale G. Marconi 446, 00146 Roma (Italy)

    2015-12-21

    Tensile germanium microstrips are candidate as gain material in Si-based light emitting devices due to the beneficial effect of the strain field on the radiative recombination rate. In this work, we thoroughly investigate their radiative recombination spectra by means of micro-photoluminescence experiments at different temperatures and excitation powers carried out on samples featuring different tensile strain values. For sake of comparison, bulk Ge(001) photoluminescence is also discussed. The experimental findings are interpreted in light of a numerical modeling based on a multi-valley effective mass approach, taking in to account the depth dependence of the photo-induced carrier density and of the self-absorption effect. The theoretical modeling allowed us to quantitatively describe the observed increase of the photoluminescence intensity for increasing values of strain, excitation power, and temperature. The temperature dependence of the non-radiative recombination time in this material has been inferred thanks to the model calibration procedure.

  7. The formation of entropy cores in non-radiative galaxy cluster simulations: SPH versus AMR

    CERN Document Server

    Power, C; Hobbs, A

    2013-01-01

    Abridged: We simulate a massive galaxy cluster in a LCDM Universe using three different approaches to solving the equations of non-radiative hydrodynamics: `classic' Smoothed Particle Hydrodynamics (SPH); a novel SPH with a higher order dissipation switch (SPHS); and adaptive mesh refinement (AMR). We find that SPHS and AMR are in excellent agreement, with both forming a well-defined entropy core that rapidly converges with increasing mass and force resolution. By contrast, SPH exhibits rather different behaviour. At low redshift, entropy decreases systematically with decreasing cluster-centric radius, converging on ever lower central values with increasing resolution. At higher redshift, SPH is in better agreement with SPHS and AMR but shows much poorer numerical convergence. We trace these discrepancies to artificial surface tension in SPH at phase boundaries. At early times, the passage of massive substructures close to the cluster centre stirs and shocks gas to build an entropy core. At later times, artif...

  8. Lasing in organic semiconductors - time-resolved studies of non-radiative decay processes

    CERN Document Server

    Zenz, C R

    2000-01-01

    Based on the demonstration of optical gain in an organic single crystal of a soluble oligo-phenylene-vinylene with gain values higher than 60 cm-1 and optically pumped lasing in a longitudinal adjustable microcavity based on laddertype polyparaphenylene, the realization of an organic laserdiode is discussed. The output characteristics of the microcavity can be modeled using classical rate equations, however the obtained threshold values are limited by the short excited state lifetime. A comparison with the lifetime measured on isolated molecules shows, that non-radiative decay processes in the solid state are determining the excited state lifetime. Using conventional and a novel field-assisted differential transmission spectroscopy with femtosecond time resolution, two main decay mechanism could be identified. (i) Triplet exciton in para-hexaphenyl is formed by non-geminate recombination of photo-generated polarons. (ii) Dissociation of the luminescent singlet excitons into polarons is important for two reaso...

  9. Non-Radiative Energy Transfer Mediated by Hybrid Light-Matter States.

    Science.gov (United States)

    Zhong, Xiaolan; Chervy, Thibault; Wang, Shaojun; George, Jino; Thomas, Anoop; Hutchison, James A; Devaux, Eloise; Genet, Cyriaque; Ebbesen, Thomas W

    2016-05-17

    We present direct evidence of enhanced non-radiative energy transfer between two J-aggregated cyanine dyes strongly coupled to the vacuum field of a cavity. Excitation spectroscopy and femtosecond pump-probe measurements show that the energy transfer is highly efficient when both the donor and acceptor form light-matter hybrid states with the vacuum field. The rate of energy transfer is increased by a factor of seven under those conditions as compared to the normal situation outside the cavity, with a corresponding effect on the energy transfer efficiency. The delocalized hybrid states connect the donor and acceptor molecules and clearly play the role of a bridge to enhance the rate of energy transfer. This finding has fundamental implications for coherent energy transport and light-energy harvesting.

  10. Understanding and eliminating non-radiative decay in organic-inorganic perovskites (Conference Presentation)

    Science.gov (United States)

    Stranks, Samuel D.; de Quilettes, Dane

    2016-09-01

    Organic-inorganic perovskites such as CH3NH3PbI3 are highly promising materials for a variety of optoelectronic applications, with certified power conversion efficiencies in solar cells already exceeding 21% and promising applications in light-emitting diodes, lasers and photodetectors also emerging. A key enabling property of the perovskites is their high photoluminescence quantum efficiency, suggesting that these materials could in principle approach the thermodynamic device efficiency limits in which all recombination is radiative. However, non-radiative recombination sites are present which vary heterogeneously from grain to grain and limit device performance. Here, I will present results where we probe the local photophysics of neat CH3NH3PbI3 perovskite films using confocal photoluminescence (PL) measurements and correlate the observations with the local chemistry of the grains using energy-dispersive X-ray spectroscopy (EDX) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). We investigate the connection between grains that are bright or dark in emission and the local Pb:I ratios at the surface and through the grains. We also examine how the photophysics, local chemistry and non-radiative decay pathways change slowly over time under illumination. Our results reveal a "photo-induced cleaning" arising from a redistribution of iodide content in the films, giving strong evidence for photo-induced ion migration. These slow transient effects appear to be related to anomalous hysteresis phenomena observed in full solar cells. I will discuss how immobilizing ions, reducing trap densities and achieving homogenous stoichiometries could suppress hysteresis effects and lead to devices approaching the efficiency limits.

  11. Overlapping $B^{3}_{0u}← X^{1}^{+}_{g}$ and $^{1}_{1u} ← X^{1}^{+}_{g}$ non-radiative characteristic of Br2 vapour in the wavelength region 505–541 nm

    Indian Academy of Sciences (India)

    Ramesh C Sharma; S N Thakur

    2001-01-01

    The vibronic vapour phase photoacoustic spectrum of Br2 in the wavelength region 505–541 nm (19796–18480 cm-1) has been recorded using microphone as well as pump-probe method. Discrete vibronic bands superimposed on a monotonically increasing continuum background towards the dissociation limit results from the overlapping $B^{3}^{+}_{0u}← X^{1}^{+}_{g}$ and $^{1}_{1u}← X^{1}^{+}_{g}$ electronic transitions. Vibronic bands originating from '' = 0 have been used to estimate the relative rate of non-radiative relaxation as a function of the excited state $^{3}_{0u}$ vibrational quantum number '. A comparison with the optical absorption spectroscopy of Br2 leads to the identification of three broad spectral regions between 505 and 541 nm (19796 and 18480 cm-1) on the basis of different non-radiative relaxation processes.

  12. Effect of number of stack on the thermal escape and non-radiative and radiative recombinations of photoexcited carriers in strain-balanced InGaAs/GaAsP multiple quantum-well-inserted solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Aihara, Taketo; Fukuyama, Atsuhiko; Ikari, Tetsuo [Faculty of Engineering, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889-2192 (Japan); Suzuki, Hidetoshi [Interdisciplinary Research Organization, University of Miyazaki, 1-1 Gakuen-Kibanadai-Nishi, Miyazaki 889-2192 (Japan); Fujii, Hiromasa; Nakano, Yoshiaki [Research Center for Advanced Science and Technology, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032 (Japan); Sugiyama, Masakazu [School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032 (Japan)

    2015-02-28

    Three non-destructive methodologies, namely, surface photovoltage (SPV), photoluminescence, and piezoelectric photothermal (PPT) spectroscopies, were adopted to detect the thermal carrier escape from quantum well (QW) and radiative and non-radiative carrier recombinations, respectively, in strain-balanced InGaAs/GaAsP multiple-quantum-well (MQW)-inserted GaAs p-i-n solar cell structure samples. Although the optical absorbance signal intensity was proportional to the number of QW stack, the signal intensities of the SPV and PPT methods decreased at high number of stack. To explain the temperature dependency of these signal intensities, we proposed a model that considers the three carrier dynamics: the thermal escape from the QW, and the non-radiative and radiative carrier recombinations within the QW. From the fitting procedures, it was estimated that the activation energies of the thermal escape ΔE{sub barr} and non-radiative recombination ΔE{sub NR} were 68 and 29 meV, respectively, for a 30-stacked MQW sample. The estimated ΔE{sub barr} value agreed well with the difference between the first electron subband and the top of the potential barrier in the conduction band. We found that ΔE{sub barr} remained constant at approximately 70 meV even with increasing QW stack number. However, the ΔE{sub NR} value monotonically increased with the increase in the number of stack. Since this implies that non-radiative recombination becomes improbable as the number of stack increases, we found that the radiative recombination probability for electrons photoexcited within the QW increased at a large number of QW stack. Additional processes of escaping and recapturing of carriers at neighboring QW were discussed. As a result, the combination of the three non-destructive methodologies provided us new insights for optimizing the MQW components to further improve the cell performance.

  13. The Crab nebula and the class of Type IIn-P supernovae caused by sub-energetic electron-capture explosions

    Science.gov (United States)

    Smith, Nathan

    2013-09-01

    What sort of supernova (SN) gave rise to the Crab nebula? While there are several indications that the Crab arose from a sub-energetic explosion of an 8-10 M⊙ progenitor star, this would appear to conflict with the high luminosity indicated by historical observations. This paper shows that several well-known observed properties of the Crab and SN 1054 are well matched by a particular breed of Type IIn SN. The Crab's properties are best suited to the Type IIn-P subclass (Type IIn spectra with plateau light curves), exemplified by SNe 1994W, 2009kn and 2011ht. These events probably arise from relatively low energy (1050 erg) explosions with low 56Ni yield that may result from electron-capture SN (ecSN) explosions, but their high visual-wavelength luminosity and Type IIn spectra are dominated by shock interaction with dense circumstellar material (CSM) rather than the usual recombination photosphere. In this interaction, a large fraction of the 1050 erg of the total kinetic energy can be converted to visual-wavelength luminosity. After about 120 d, nearly all of the mass outside the neutron star in the CSM and ejecta ends up in a slowly expanding (1000-1500 km s-1) thin dense shell, which is then accelerated and fragmented by the growing pulsar wind nebula in the subsequent 1000 yr, producing the complex network of filaments seen today. There is no need to invoke the extended, invisible fast SN envelope hypothesized to reside outside the Crab. As differentiated from a normal SN II-P, SNe IIn-P provide a much better explanation for several observed features of the Crab: (1) no blast wave outside the Crab nebula filaments, (2) no rapidly expanding SN envelope outside the filaments, (3) a total mass of ˜5 M⊙ swept up in a thin slow shell, (4) a low kinetic energy of the Crab at least an order of magnitude below a normal core-collapse SN, (5) a high peak luminosity (-18 mag) despite the low kinetic energy, (6) chemical abundances consistent with an 8-10 M⊙ star and

  14. Partial {sigma}{sub nl} and total {sigma}{sub tot} cross sections of single electron capture in Ar{sup 8+} -He collision in the 400-2400 eV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Gosselin, A.; Husson, X.; Hennecart, D.; Hicham, S.; Kucal, H.; Lecler, D. [Caen Univ., 14 (France); Cassimi, A.; Grandin, J.P.; Jardin, P.; Lepoutre, A. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France)

    1993-12-31

    The Ar{sup 8+} ions are delivered by a recoil ion source (GANIL), the helium target consists in a supersonic jet. Three energy gain spectra were obtained for 400, 1600 and 2400 eV energy collision; each spectrum exhibits two peaks, the left one corresponds to an electron capture in the 5s level of Ar{sup 7+}, the right one corresponds to an electron capture in 4f and 4d levels. The difference between observed and expected energy position is due to the scattering angle which values allow for corrections and partial cross sections determination. Results are compared to the Landau-Zener calculation of Benmeuraien. 2 figs., 1 tab., 4 refs.

  15. Detection efficiency for radionuclides decaying by electron capture and gamma-Ray; Calculo de la eficiencia de deteccion de nucleidos que se desintegran por captura elec- tronica y emision gamma

    Energy Technology Data Exchange (ETDEWEB)

    Grau, A.; Fernandez, A.

    1985-07-01

    In this paper, the electron capture partial counting efficiency vs the figure of merit for electron-capture and gamma-ray emitters has been computed. The radionuclides tabulated are 48{sup c}r, 54{sup M}n, 57{sup C}o 56{sup N}i, 72{sup S}e, 73{sup A}s, 85{sup S}r, 88{sup Z}r, 92{sup N}b, 103{sup P}d, 111{sup l}n, 119{sup S}b, 125{sup I}, 139{sup C}e and 152{sup D}y. It has been assumed that the liquid is a toluene based scintillator solution in standard glass vials containing 15 cm{sup 3}. (Author) 17 refs.

  16. Two-electron capture into autoionising configurations N/sup 4 +/(1snln'l') with n = 2,3,4 and n' >= n, observed by electron spectrometry in collisions of N/sup 6 +/(1s) with He and H/sub 2/, at 4. 2 keV amu/sup -1/

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A.; Marrakchi, A.I.; Dousson, S.; Hitz, D.

    1984-04-14

    Double electron transfer into autoionising states N/sup 4 +/(1snln'l'), with n = 2,3,4 and n' >= n has been observed in a collision between a one-electron highly charged N/sup 6 +/(1s) ion and a two-electron target (He or H/sub 2/), by electron spectrometry. The same configurations are excited in the two collisional systems but with very different probabilities. Electron capture mainly occurs into 1s2ln'l' in He-systems whereas transfer into 1s3ln'l' is stronger in H/sub 2/ systems.

  17. Three L-subshells atomic model to compute counting efficiency of electron-capture nuclides; Modelo con tres subcapas L para calcular la eficiencia de recuento de nucleidos que se desintegran por captura electronica

    Energy Technology Data Exchange (ETDEWEB)

    Grau, A.; Arcos, J. M. los

    1986-07-01

    The present paper develops a three L-subshell a and K, M-a hells atomic model in order to obtain the counting efficiency in liquid scintillation counting. Mathematical expressions are given to calculate the probabilities of 264 different atomic rearrangement way so as the corresponding effective energies. This new model will permit to test the influence of the different atomic and nuclear parameters upon the counting efficiency nuclides of low and medium atomic number decaying by electron capture. (Author) 8 refs.

  18. Total and state-to-state electron capture and excitation cross-sections for Li+, Be{}^{2+}, and {{\\rm{B}}}^{3+} colliding with {\\rm{H}}(1\\;s) at low-to-intermediate energies

    Science.gov (United States)

    Domínguez-Gutiérrez, F. J.; Cabrera-Trujillo, R.

    2016-01-01

    The electron capture process plays an important role as a diagnostic tool for measuring the temperature, plasma rotation, and impurity densities of plasma in tokamaks. In this work we report the electron capture and excitation cross-sections for Li+, Be{}2+, and {{{B}}}3+ colliding with atomic hydrogen in the collision energy range 0.25-25 keV/amu. For this, we solve numerically the time dependent Schrödinger equation by using a finite difference approach. We model the ion projectile interaction with the target using a pseudopotential obtained within a Hartree-Fock method. We use classical trajectories, obtained self-consistently, for the projectile at collision energies lower than 2 keV/amu and a straight line trajectory at high collision energies. We report new results for the total, n=2,3, and 4 state projectile electron capture cross-section, as well as the n = 2-state target excitation cross-section. We find a good agreement between our cross-section results when compared with available theoretical and experimental data found in the literature. Finally, we find that the electron capture probability, as a function of the impact parameter, shows Stückelberg oscillations at low collision energies for the n = 2 of Be+ and n = 3 of {{{B}}}2+, in the radial range (large impact parameters). Our results assess the validity of the adiabatic basis set at low collision energies and confirm the use of a finite difference method as an accurate approach to study a time-dependent process in charge exchange collisions. A discussion of our results is provided.

  19. Experimental cross sections for two-electron capture into nitrogen autoionising states in Nsup(q+) (q=6,7) on He and H/sub 2/ collisions at 10. 5q keV

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A.; Marrakchi, A.I.; Dousson, S.; Hitz, D.

    1985-07-01

    Singly differential cross sections for two-electron capture into autoionising states (nl,n'l') with n=2,3,4 and n'>=n in Nsup(q+) (q=6,7) on He and H/sub 2/ collisions have been measured at 10,5q ke V collision energy and an observation angle thetasub(lab)=11.6/sup 0/. Total cross sections are estimated assuming isotropic angular distributions. (orig.).

  20. Simultaneous analysis of polychlorinated biphenyls and organochlorine pesticides in seawater samples by membrane-assisted solvent extraction combined with gas chromatography-electron capture detector and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Shi, Xizhi; Tang, Zigang; Sun, Aili; Zhou, Lei; Zhao, Jian; Li, Dexiang; Chen, Jiong; Pan, Daodong

    2014-12-01

    A highly efficient and environment-friendly membrane-assisted solvent extraction system combined with gas chromatography-electron capture detector was applied in the simultaneous determination of 17 polychlorinated biphenyls and organochlorine pesticides in seawater samples. Variables affecting extraction efficiency, including extraction solvent used, stirring rate, extraction time, and temperature, were optimized extensively. Under optimal extraction conditions, recoveries between 76.9% and 104.6% in seawater samples were achieved, and relative standard deviation values below 10% were obtained. The limit of detection (signal-to-noise ratio=3) and limit of quantification (signal-to-noise ratio=10) of 17 polychlorinated biphenyls and organochlorine pesticides in seawater ranged from 0.14ngL(-1) to 0.36ngL(-1) and 0.46ngL(-1) to 1.19ngL(-1), respectively. Matrix effects on extraction efficiency were evaluated by comparing with the results obtained using tap water. The extraction effect of developed membrane-assisted solvent extraction method was further demonstrated by gas chromatography-tandem mass spectrometry which can provide structural information of the analytes for more accurate identification, and results identical to those produced by gas chromatography-electron capture detector were obtained. These findings demonstrate the applicability of the developed membrane-assisted solvent extraction determination method for coupling to gas chromatography-electron capture detector or tandem mass spectrometry for determining polychlorinated biphenyls and organochlorine pesticides in seawater samples.

  1. Non-radiative decay of a dipole emitter close to a metallic nanoparticle: Importance of higher-order multipole contributions

    CERN Document Server

    Moroz, Alexander

    2009-01-01

    The contribution of higher-order multipoles to radiative and non-radiative decay of a single dipole emitter close to a spherical metallic nanoparticle is re-examined. Taking a Ag spherical nanoparticle (AgNP) with the radius of 5 nm as an example, a significant contribution (between 50% and 101% of the total value) of higher-order multipoles to non-radiative rates is found even at the emitter distance of 5 nm from the AgNP surface. On the other hand, the higher-order multipole contribution to radiative rates is negligible. Consequently, a dipole-dipole approximation can yield only an upper bound on the apparent quantum yield. In contrast, the non-radiative rates calculated with the quasistatic Gersten and Nitzan method are found to be in much better agreement with exact electrodynamic results. Finally, the size corrected metal dielectric function is shown to decrease the non-radiative rates near the dipolar surface plasmon resonance.

  2. Evidence from Voyager and ISEE-3 spacecraft. Data for the decay of secondary K-electron capture isotopes during the propagation of cosmic rays in the Galaxy

    Science.gov (United States)

    Soutoul, A.; Legrain, R.; Lukasiak, A.; McDonald, F. B.; Webber, W. R.

    1998-08-01

    New data from the cosmic ray experiment on the Voyager spacecraft confirms and extends earlier data from a similar experiment on the ISEE-3 spacecraft which indicates the possibility of the decay of certain K-capture isotopes during the interstellar propagation of galactic cosmic rays. These cosmic ray measurements, along with the cross section measurements, indicate that ~ 25% of the K-capture isotopes (51Cr and (49V produced as secondaries have decayed at interstellar energy of ~ 400 MeV/nuc. This suggests a possible interstellar energy gain ~ 100 MeV/nuc out of the current interstellar energy ~ 500 MeV/nuc. This measurement suggests that the study of the K-capture isotopes may now have reached a level that will soon provide definitive information on the amount of re-acceleration that may occur during cosmic-ray propagation after an initial acceleration in the cosmic ray sources.

  3. Non-radiation endoscopic retrograde cholangiopancreatography in the management of choledocholithiasis during pregnancy.

    Science.gov (United States)

    Wu, Wenming; Faigel, Douglas O; Sun, Gang; Yang, Yunsheng

    2014-11-01

    Gallstone diseases are common during pregnancy. In most cases, patients are asymptomatic and do not require any treatment. However, choledocholithiasis, cholangitis, and gallstone pancreatitis may potentially become life-threatening for both mother and fetus and often require urgent intervention. Although endoscopic retrograde cholangiopancreatography (ERCP) has become the standard technique for removing common bile duct stones, it is associated with ionizing radiation that could carry teratogenic risk. Non-radiation ERCP (NR-ERCP) is reported to be effective without incurring this risk. Two techniques have been described to confirm bile duct cannulation: bile aspiration and image guidance. With bile aspiration, biliary cannulation is confirmed by applying suction to the cannula to yield bile, thus confirming an intrabiliary position. Image guidance involves using ultrasound or direct visualization (choledochoscopy) to confirm selective biliary cannulation or duct clearance. Once cannulation is achieved, the stones are removed using standard ERCP techniques and tools. Case series and retrospective studies have reported success rates of up to 90% for NR-ERCP with complication rates similar to standard ERCP. Pregnancy outcomes are not adversely affected by NR-ERCP, but whether the avoidance of radiation carries benefit for the baby is unknown. Prospective comparative trials are lacking. NR-ERCP is technically demanding and should be attempted only by skilled biliary endoscopists in properly equipped and staffed health-care institutions, in a multidisciplinary setting. © 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.

  4. Resonant Transparency and Non-Trivial Non-Radiating Excitations in Toroidal Metamaterials

    Science.gov (United States)

    Fedotov, V. A.; Rogacheva, A. V.; Savinov, V.; Tsai, D. P.; Zheludev, N. I.

    2013-01-01

    Engaging strongly resonant interactions allows dramatic enhancement of functionalities of many electromagnetic devices. However, resonances can be dampened by Joule and radiation losses. While in many cases Joule losses may be minimized by the choice of constituting materials, controlling radiation losses is often a bigger problem. Recent solutions include the use of coupled radiant and sub-radiant modes yielding narrow asymmetric Fano resonances in a wide range of systems, from defect states in photonic crystals and optical waveguides with mesoscopic ring resonators to nanoscale plasmonic and metamaterial systems exhibiting interference effects akin to electromagnetically-induced transparency. Here we demonstrate theoretically and confirm experimentally a new mechanism of resonant electromagnetic transparency, which yields very narrow isolated symmetric Lorentzian transmission lines in toroidal metamaterials. It exploits the long sought non-trivial non-radiating charge-current excitation based on interfering electric and toroidal dipoles that was first proposed by Afanasiev and Stepanovsky in [J. Phys. A Math. Gen. 28, 4565 (1995)]. PMID:24132231

  5. Alignment in double capture processes

    Energy Technology Data Exchange (ETDEWEB)

    Moretto-Capelle, P.; Benhenni, M.; Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A. (IRSAMC, URA CNRS 770, Univ. Paul Sabatier, 118 rte de Narbonne, 31062 Toulouse Cedex (France))

    1993-06-05

    The electron spectra emitted when a double capture occurs in N[sup 7+]+He and Ne[sup 8+]+He systems at 10 qkeV collisional energy, allow us to determine the angular distributions of the 3[ell]3[ell] [prime] lines through a special spectra fitting procedure which includes interferences between neighbouring states. It is found that the doubly excited states populated in double capture processes are generally aligned.

  6. Effect of radiation and non radiation environmental factors on children hematopoietic system.

    Science.gov (United States)

    Bebeshko, V G; Bruslova, K M; Stankevych, V V; Tsvietkova, N M; Lyashenko, L O; Galkina, S G; Pushkaryova, T I; Kolos, V I; Kuznetsova, O Ye; Honchar, L O; Yatsemyrskii, S M; Samson, Y M

    2016-12-01

    Identification of impact of radiation and non radiation environmental factors on development of hematopoi etic abnormalities in children and justification of criteria for the increased risk groups of hematologic diseases. The results of clinical and hematological survey of 1465 children living in Kyiv, Zhytomyr and Chernihiv regions for the period from 2008 to 2014 were presented. There were 777 children with anemia, 466 with changes in hemogram, 191 with acute leukemia. The irradiation doses, correlation of integrated pollution degree of territories with hematopoietic parameters and course hematologic diseases were estimated. Metal con tent in hair, nails, and blood was determined in 121 children. We have found the most common cause of anemia in children and peculiarities of acute leukemia depend ing on the area integrated contamination. Number of children living in contaminated areas with pro B ALL and T ALL having an initial leukocytosis and unfavorable course of the disease was higher compared to the number of patients from moderately polluted regions (r = 0.47). There is a direct correlation between percentage of children with monocytosis and degree of territory contamination: the 20.2 % of such children lived in the intensively polluted areas and 10,3 % in moderately contaminated ones (p environmental factors influencing the development of changes in hematopoiesis and characteristics of the blood system diseases in children play a role in leukeima development processes. These findings are the basis for a further research in the field of radiobiology and ecology. V. G. Bebeshko, K. M. Bruslova, V. V. Stankevych, N. M. Tsvietkova, L. О. Lyashenko, S. G. Galkina, T. I. Pushkaryova, V. I. Kolos, O. Ye. Kuznetsova, L. O. Honchar, S. M. Yatsemyrskii, Y. M. Samson.

  7. Experimental investigations of electron capture from atomic hydrogen and deuterium by alpha particles. Final report, September 15, 1984--September 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Gay, T.J.

    1994-06-01

    The authors have succeeded in making state-selective measurements of charge capture by doubly-ionized helium colliding with ground-state neutral helium atoms, but failed to achieve the primary goal, which was to investigate atomic hydrogen targets. They discuss a number of ancillary experiments and calculations of relevance for fusion energy production that they have done. Reprints and preprints of publications resulting from this work are contained in an appendix.

  8. Aging mathematical model of InGaN/GaN LEDs based on non-radiative recombination

    Science.gov (United States)

    Xu, Linwang; Qian, Keyuan

    2017-08-01

    This paper proposes a new aging mathematical model for InGaN/GaN-based light-emitting diodes (LEDs) based on non-radiative recombination. Light attenuation is an important index of the performance of LEDs, Arrhenius model as the main aging mathematical model of light attenuation is poorly targeted and cannot reflect the physical significance. Based on the physical theory of deep level defects and non-radiation recombination centers, we analyze the aging mechanism of LED chips and then establish the aging mathematical model. Meanwhile, a batch of GaN-based blue LED chips are selected to conduct accelerated life tests with constant current stresses, and the experimental data is obtained to verify the new model. The result shows that compared with the traditional Arrhenius model, the new model has many advantages such as more accurate, strong pertinence and obvious physical meaning.

  9. Full wave analysis of non-radiative dielectric waveguide modulator for the determination of electrical equivalent circuit

    Indian Academy of Sciences (India)

    N P Pathak; A Basu; S K Koul

    2008-07-01

    This paper reports the determination of electrical equivalent circuit of ON/OFF modulator in non-radiative dielectric (NRD) guide configurations at Ka-band. Schottky barrier mixer diode is used to realize this modulator and its characteristics are determined experimentally using vector network analyzer. Full wave FEM simulator HFSS is used to determine an equivalent circuit for the mounted diode and modulator in ON and OFF states. This equivalent circuit is used to qualitatively explain the experimental characteristics of modulator.

  10. 高俘获效率电子辐照加速器的设计研究%Design Study on an Electron Linac for Irradiation Processing with a High Capture Efficiency

    Institute of Scientific and Technical Information of China (English)

    刘华昌; 王修龙; 傅世年

    2006-01-01

    The accelerating tube is the core of a linac. The capture efficiency is usually about 50% by ordinary design method in the electron linac for irradiation processing. Nearly half of the injected electrons are lost in the tube, resulting in strong radiation and additional heat load on the accelerating cavity, as well as a bad effect on vacuum. In this paper, a constant gradient accelerating structure is chosen to accelerate the electron beam,and the designed phase velocity is linearly increased along the tube. By adjusting the size of the accelerating cavity and the phase velocity function, a high capture efficiency is reached. After a series of simulations, we obtain a 90% capture efficiency, while the accelerator length is not increased due to the bunching process.%加速管是一台加速器的核心部分.一般电子辐照加速器的俘获效率在50%左右,一半的电子都损失在加速管内.丢失的电子打在加速管内壁,产生轫致辐射、腔体发热量增加、真空变坏等许多负面影响.采用一段等梯度加速结构,相速沿加速管呈线形增加,调整相速变化规律及加速管腔体的尺寸参数,设计出的加速管最终的俘获效率提高到90%以上,同时平均加速梯度没有因此降低,加速管总长度没有增加.

  11. One-electron capture into Li-like autoionising N/sup 4 +/ (1s2ln'l') configurations by metastable N/sup 5 +/ (1s2s/sup 3/S) multicharged ions in collisions with He and H/sub 2/, observed by electron spectrometry at 3. 4 keV amu/sup -1/

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, A.; Benoit-Cattin, P.; Gleizes, A.; Dousson, S.; Hitz, D.

    1985-04-14

    One-electron capture into N/sup 4 +/ (1s2ln'l') configurations, with n'=2 to 4, has been observed by electron spectrometry when a N/sup 5 +/ (1s2s /sup 3/S) multicharged ion beam encounters an He or H/sub 2/ target, at low collision velocity (upsilon=0.37 au) within single-collision conditions. Contributions of other 1s2l metastable states and of the 1s/sup 2/ ground state may be disregarded. A small indication of two-electron capture by 1s2s /sup 3/S ions into (1s2s /sup 3/S)3l3l' configurations is also seen.

  12. Measurement of the L/K electron capture ratio of the {sup 207}Bi decay to the 1633 keV level of {sup 207}Pb with a BGO scintillating bolometer

    Energy Technology Data Exchange (ETDEWEB)

    Coron, N.; Gironnet, J.; Marcillac, P. de; Martinez, M.; Redon, T.; Torres, L. [Universite Paris-Sud 11 et CNRS (UMR 8617), Institut d' Astrophysique Spatiale, Orsay (France); Cuesta, C.; Garcia, E.; Ginestra, C.; Ortigoza, Y.; Pobes, C.; Puimedon, J.; Salinas, A.; Sarsa, M.L. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Watrin, A. [Universidad de Zaragoza, Grupo de Fisica Nuclear y Astroparticulas, Zaragoza (Spain); Universite Louis Pasteur, Ecole nationale superieure de physique de Strasbourg (ENSPS), Illkirch (France)

    2012-06-15

    The ROSEBUD Collaboration has dedicated several underground runs to study different types of bolometers, mainly for the search of dark matter. Some of these runs, profiting from the good energy resolution of one bolometer of BGO and the ultra-low background of the underground laboratory of Canfranc (LSC), allowed the measurement of the L/K electron capture ratio of the {sup 207}Bi decay to the 1633 keV level of {sup 207}Pb. This paper constitutes the first published measurement of this magnitude. (orig.)

  13. The structure and emission of a non-radiative shock. [from supernova remnants of Cygnus Loop

    Science.gov (United States)

    Raymond, J. C.

    1983-01-01

    Observational data and the capabilities of current models for observed filament and shock features of supernova remnants are considered. The filaments emit Balmer lines originating in nonthermal shocks. Models of the generation mechanisms must account for the shock structure and the possibilities of electron thermal precursors to the shock and plasma turbulence, as well as equilibration processes for electron and ion temperatures. It is not yet known if a Maxwellian velocity distribution fits the electrons and ions. An assumption of Coulombic equilibration of ions and electrons has agreed well with some observed forbidden line intensities in the Cygnus Loop, while other lines require detailed radiative transfer calculations.

  14. The Use of Integrated Electronic Data Capture and Analysis for Accelerator Construction and Commissioning Pansophy from the SNS Towards the ILC

    CERN Document Server

    Ozelis, Joseph P; Madre, Bonnie D; Reece, Charles E

    2005-01-01

    Jefferson Lab has extensively used a proprietary web-based system (Pansophy) that integrates commercial database, data analysis, document archiving and retrieval, and user interface software, as a coherent knowledge management product during the construction of the cryomodules for the SNS Superconducting Linac, providing elements of process and procedure control, data capture and review, and data mining and analysis. With near real-time and potentially global access to production data, process monitoring and performance analyses could be pursued in a timely manner, providing crucial feedback. The extensibility, portability, and accessibility of Pansophy via universally available software components provide the essential features needed in any information and project management system capable of meeting the needs of future accelerator construction efforts, requiring an unprecedented level of regional and international coordination and collaboration, to which Pansophy is well suited.

  15. A study of Channeling, Volume Reflection and Volume Capture of 3.35 - 14.0 GeV Electrons in a bent Silicon Crystal

    Energy Technology Data Exchange (ETDEWEB)

    Wistisen, T. N. [Aarhus Univ. (Denmark); Uggerhoj, U. I. [Aarhus Univ. (Denmark); Wienands, U. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Markiewicz, T. W. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Noble, R. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Benson, B. L. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Smith, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bagli, E. [Univ. of Ferrara (Italy); Bandiera, L. [Univ. of Ferrara (Italy); Germogli, G. [Univ. of Ferrara (Italy); Guidi, V. [Univ. of Ferrara (Italy); Mazzolari, A. [Univ. of Ferrara (Italy); Holtzapple, R. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States); Tucker, S. [California Polytechnic State Univ. (CalPoly), San Luis Obispo, CA (United States)

    2015-12-03

    We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasi-mosaic silicon crystal. Additionally, these phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5 and 14.0 GeV with a crystal with bending radius of 0.15m, corresponding to curvatures of 0.070, 0.088, 0.13, 0.22 and 0.29 times the critical curvature respectively. We have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

  16. Non-radiation hardened microprocessors in space-based remote sensing systems

    Science.gov (United States)

    DeCoursey, R.; Melton, Ryan; Estes, Robert R., Jr.

    2006-09-01

    The CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) mission is a comprehensive suite of active and passive sensors including a 20Hz 230mj Nd:YAG lidar, a visible wavelength Earth-looking camera and an imaging infrared radiometer. CALIPSO flies in formation with the Earth Observing System Post-Meridian (EOS PM) train, provides continuous, near-simultaneous measurements and is a planned 3 year mission. CALIPSO was launched into a 98 degree sun synchronous Earth orbit in April of 2006 to study clouds and aerosols and acquires over 5 gigabytes of data every 24 hours. Figure 1 shows the ground track of one CALIPSO orbit as well as high and low intensity South Atlantic Anomaly outlines. CALIPSO passes through the SAA several times each day. Spaced based remote sensing systems that include multiple instruments and/or instruments such as lidar generate large volumes of data and require robust real-time hardware and software mechanisms and high throughput processors. Due to onboard storage restrictions and telemetry downlink limitations these systems must pre-process and reduce the data before sending it to the ground. This onboard processing and realtime requirement load may mean that newer more powerful processors are needed even though acceptable radiation-hardened versions have not yet been released. CALIPSO's single board computer payload controller processor is actually a set of four (4) voting non-radiation hardened COTS Power PC 603r's built on a single width VME card by General Dynamics Advanced Information Systems (GDAIS). Significant radiation concerns for CALIPSO and other Low Earth Orbit (LEO) satellites include the South Atlantic Anomaly (SAA), the north and south poles and strong solar events. Over much of South America and extending into the South Atlantic Ocean (see figure 1) the Van Allen radiation belts dip to just 200-800km and spacecraft entering this area are subjected to high energy protons and experience higher than

  17. Electronic Structure, Phonon Dynamical Properties, and CO2 Capture Capability of Na2 -xMxZr O3 (M =Li ,K): Density-Functional Calculations and Experimental Validations

    Science.gov (United States)

    Duan, Yuhua; Lekse, Jonathan; Wang, Xianfeng; Li, Bingyun; Alcántar-Vázquez, Brenda; Pfeiffer, Heriberto; Halley, J. W.

    2015-04-01

    The electronic structural and phonon properties of Na2 -αMαZr O3 (M =Li ,K, α =0.0 ,0.5,1.0,1.5,2.0) are investigated by first-principles density-functional theory and phonon dynamics. The thermodynamic properties of CO2 absorption and desorption in these materials are also analyzed. With increasing doping level α , the binding energies of Na2 -αLiαZr O3 are increased while the binding energies of Na2 -αKαZrO3 are decreased to destabilize the structures. The calculated band structures and density of states also show that, at the same doping level, the doping sites play a significant role in the electronic properties. The phonon dispersion results show that few soft modes are found in several doped configurations, which indicates that these structures are less stable than other configurations with different doping levels. From the calculated relationships among the chemical-potential change, the CO2 pressure, and the temperature of the CO2 capture reactions by Na2 -αMαZr O3 , and from thermogravimetric-analysis experimental measurements, the Li- and K-doped mixtures Na2 -αMαZr O3 have lower turnover temperatures (Tt ) and higher CO2 capture capacities, compared to pure Na2Zr O3 . The Li-doped systems have a larger Tt decrease than the K-doped systems. When increasing the Li-doping level α , the Tt of the corresponding mixture Na2 -αLiαZr O3 decreases further to a low-temperature range. However, in the case of K-doped systems Na2 -αKαZr O3 , although doping K into Na2Zr O3 initially shifts its Tt to lower temperatures, further increases of the K-doping level α causes Tt to increase. Therefore, doping Li into Na2Zr O3 has a larger influence on its CO2 capture performance than the K-doped Na2Zr O3 . Compared with pure solids M2Zr O3 , after doping with other elements, these doped systems' CO2 capture performances are improved.

  18. Calibration of radionuclides with decay trough beta emission or electron capture by liquid scintillation technique; Calibracao de radionuclideos que decaem por emissao beta ou por captura eletronica pela tecnica de cintilacao liquida

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Jamir dos Santos

    2000-02-01

    In this work is reported a methodology a methodology for pure beta and electron capture radionuclides standardization, suing liquid scintillation technique. In this sense the CIEMAT/NIST method, recently utilized by international laboratories, was implemented and the lack in the Laboratorio Nacional das Radiacoes Ionizantes - LNMRI, of the Comissao Nacional de Energia Nuclear - CNEN, for adequate methodology to standardize this kind if radionuclides was filled, fact that was not present with alpha and gamma radionuclides. The implementation procedure evaluation was provided by concentration activity determination of the following radionuclides: {sup 14} C and {sup 90} Sr, pure beta emitters; {sup 55} Fe, electron capture decay; {sup 204} Tl, electron capture and beta decay and {sup 60} Co, beta-gamma emitter. In this way, a careful analysis of the implementation procedure with these radionuclides types, ranging on a broad energy spectral, was possible. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. To check the calibration results, intercomparisons among our measurements of these radionuclides and the reference values of the CIEMAT/Spain laboratory were provided. Besides this intercomparisons, one was provided with a {sup 204} Tl solution, utilized in the international comparison recently promoted by BIPM, and another one with a {sup 60} C solution calibrated in LNMRI/CNEN previously by a relative calibration system, with a well type pressurized ionization chamber, and an absolute beta-gamma coincidence system, with a pill-box type proportional counter 4 {pi} geometry, coupled with a scintillator system with a sodium iodide cristal of 4x4 inches. The comparisons among LNMRI/CNEN results and the reference values, showed a small deviation of 1,32% for {sup 14} C, 0,40% for {sup 60} Co, 1,12% for {sup 55} Fe, 0,10% for {sup 90} Sr and 0,73% for {sup

  19. Non-Radiative Energy Transfer for Photovoltaic Solar Energy Conversion: Lead Sulfide Quantum Dots on Silicon Nanopillars

    Science.gov (United States)

    Lingley, Zachary R.

    This dissertation comprises a study aimed at understanding the competing dynamics of energy and charge transfer in quantum dot (QD) solids and from QDs to crystalline semiconductor substrates to assess a new type of hybrid solar cell that is based on non-radiative resonant energy transfer (NRET) from light absorbers such as nanocrystal QDs to high mobility charge carrier transport channels such as silicon nanopillars. As a platform to investigate a NRET solar cell we employed lead sulfide nanocrystal QDs as light absorbers and silicon as the acceptor transport channel for the NRET generated electrons and holes. Given NRET as the basic physical process at the core of the new type of solar cell the dissertation focused on examining: (1) synthesis of and surface ligand exchange for high quantum efficiency lead sulfide quantum dots, (2) studies of inter-QD NRET and competing inter-QD charge transfer as a function of inter-QD average separation and temperature, (3) structural and optical characteristics of lead sulfide quantum dots adsorbed on crystalline silicon surfaces, and (4) fabrication and examination of prototype colloidal PbS QD - silicon nanopillar array solar cell. The work in these four areas has each provided insights into and new results for the field of quantum dots, QD-based solids, and QD based opto-electronic devices that are of generic value. The need for maintaining the high quantum efficiency (QE) of the as-synthesized PbS QDs while exchanging the surface ligands with new ones better suited for the device lead us to introduce a new approach to ligand exchange that employs pre-conjugated lead cation -- ligand complexes as units that replace the lead cations bound to their as-grown ligand, thus maintaining the Pb-rich stoichiometry that suppresses defect formation while gaining the ability to control the length of the ligands. The ability to control the length of the ligands allowed control over the QD-QD separation in densely packed films referred to

  20. An investigation of used electronics return flows: a data-driven approach to capture and predict consumers storage and utilization behavior.

    Science.gov (United States)

    Sabbaghi, Mostafa; Esmaeilian, Behzad; Raihanian Mashhadi, Ardeshir; Behdad, Sara; Cade, Willie

    2015-02-01

    Consumers often have a tendency to store their used, old or un-functional electronics for a period of time before they discard them and return them back to the waste stream. This behavior increases the obsolescence rate of used still-functional products leading to lower profitability that could be resulted out of End-of-Use (EOU) treatments such as reuse, upgrade, and refurbishment. These types of behaviors are influenced by several product and consumer-related factors such as consumers' traits and lifestyles, technology evolution, product design features, product market value, and pro-environmental stimuli. Better understanding of different groups of consumers, their utilization and storage behavior and the connection of these behaviors with product design features helps Original Equipment Manufacturers (OEMs) and recycling and recovery industry to better overcome the challenges resulting from the undesirable storage of used products. This paper aims at providing insightful statistical analysis of Electronic Waste (e-waste) dynamic nature by studying the effects of design characteristics, brand and consumer type on the electronics usage time and end of use time-in-storage. A database consisting of 10,063 Hard Disk Drives (HDD) of used personal computers returned back to a remanufacturing facility located in Chicago, IL, USA during 2011-2013 has been selected as the base for this study. The results show that commercial consumers have stored computers more than household consumers regardless of brand and capacity factors. Moreover, a heterogeneous storage behavior is observed for different brands of HDDs regardless of capacity and consumer type factors. Finally, the storage behavior trends are projected for short-time forecasting and the storage times are precisely predicted by applying machine learning methods.

  1. An investigation of used electronics return flows: A data-driven approach to capture and predict consumers storage and utilization behavior

    Energy Technology Data Exchange (ETDEWEB)

    Sabbaghi, Mostafa, E-mail: mostafas@buffalo.edu [Industrial and Systems Engineering Department, State University of New York, University at Buffalo, 437 Bell Hall, Buffalo, NY (United States); Esmaeilian, Behzad, E-mail: b.esmaeilian@neu.edu [Healthcare Systems Engineering Institute, Northeastern University, Boston, MA 02115 (United States); Raihanian Mashhadi, Ardeshir, E-mail: ardeshir@buffalo.edu [Mechanical and Aerospace Engineering, State University of New York, University at Buffalo, 437 Bell Hall, Buffalo, NY (United States); Behdad, Sara, E-mail: sarabehd@buffalo.edu [Industrial and Systems Engineering Department, State University of New York, University at Buffalo, 437 Bell Hall, Buffalo, NY (United States); Mechanical and Aerospace Engineering, State University of New York, University at Buffalo, 437 Bell Hall, Buffalo, NY (United States); Cade, Willie, E-mail: willie@pcrr.com [PC Rebuilder and Recyclers, 4734 W Chicago Ave, Chicago, IL 60651-3322 (United States)

    2015-02-15

    Highlights: • We analyzed a data set of HDDs returned back to an e-waste collection site. • We studied factors that affect the storage behavior. • Consumer type, brand and size are among factors which affect the storage behavior. • Commercial consumers have stored computers more than household consumers. • Machine learning models were used to predict the storage behavior. - Abstract: Consumers often have a tendency to store their used, old or un-functional electronics for a period of time before they discard them and return them back to the waste stream. This behavior increases the obsolescence rate of used still-functional products leading to lower profitability that could be resulted out of End-of-Use (EOU) treatments such as reuse, upgrade, and refurbishment. These types of behaviors are influenced by several product and consumer-related factors such as consumers’ traits and lifestyles, technology evolution, product design features, product market value, and pro-environmental stimuli. Better understanding of different groups of consumers, their utilization and storage behavior and the connection of these behaviors with product design features helps Original Equipment Manufacturers (OEMs) and recycling and recovery industry to better overcome the challenges resulting from the undesirable storage of used products. This paper aims at providing insightful statistical analysis of Electronic Waste (e-waste) dynamic nature by studying the effects of design characteristics, brand and consumer type on the electronics usage time and end of use time-in-storage. A database consisting of 10,063 Hard Disk Drives (HDD) of used personal computers returned back to a remanufacturing facility located in Chicago, IL, USA during 2011–2013 has been selected as the base for this study. The results show that commercial consumers have stored computers more than household consumers regardless of brand and capacity factors. Moreover, a heterogeneous storage behavior is

  2. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of organochlorine pesticides and polychlorinated biphenyls in bottom sediment by dual capillary-column gas chromatography with electron-capture detection

    Science.gov (United States)

    Foreman, William T.; Connor, Brooke F.; Furlong, Edward T.; Vaught, Deborah G.; Merten, Leslie M.

    1995-01-01

    A method for the determination of 30 individual organochlorine pesticides, total toxaphene, and total polychlorinated biphenyls (PCBs) in bottom sediment is described. The method isolates the pesticides and PCBs by solvent extraction with dichlorobenzene, removes inorganic sulfur, large naturally occurring molecules, and other unwanted interferences by gel permeation chromatography, and further cleans up and class fractionates the extract using adsorption chromatography. The com- pounds then are instrumentally determined using dual capillary-column gas chromatography with electron-capture detection. Reporting limits range from 1 to 5 micrograms per kilogram for 30 individual pesticides, 50 micrograms per kilogram for total PCBs, and 200 micrograms per kilogram for total toxaphene. The method also is designed to allow the simultaneous isolation of 79 other semivolatile organic compounds from the sediment, which are separately quantified using gas chromatography with mass spectrometric detection. The method was developed in support of the U.S. Geological Survey's National Water-Quality Assessment program.

  3. Complete characterization of posttranslational modification sites in the bovine milk protein PP3 by tandem mass spectrometry with electron capture dissociation as the last stage

    DEFF Research Database (Denmark)

    Kjeldsen, Frank; Haselmann, Kim F; Budnik, Bogdan A

    2003-01-01

    the PTM site. Chromatographic peak analysis continues until full sequence coverage is obtained, after which the molecular mass is reconstructed and compared with the measured value. An agreement indicates that the PTM characterization was complete. This procedure applied to the bovine milk PP3 protein......A comprehensive approach to protein identification and determination of sites of posttranslational modifications (PTMs) in heavily modified proteins was tested. In this approach, termed "reconstructed molecular mass analysis" (REMMA), the molecular mass distribution of the intact protein...... is measured first, which reveals the extent and heterogeneity of modifications. Then the protein is digested with one or several enzymes, with peptides separated by reversed-phase HPLC, and analyzed by Fourier transform mass spectrometry (FTMS). Vibrational excitation (collisional or infrared) or electron...

  4. Video Screen Capture Basics

    Science.gov (United States)

    Dunbar, Laura

    2014-01-01

    This article is an introduction to video screen capture. Basic information of two software programs, QuickTime for Mac and BlueBerry Flashback Express for PC, are also discussed. Practical applications for video screen capture are given.

  5. Non-radiative relaxation of photoexcited chlorophylls: theoretical and experimental study

    Science.gov (United States)

    Bricker, William P.; Shenai, Prathamesh M.; Ghosh, Avishek; Liu, Zhengtang; Enriquez, Miriam Grace M.; Lambrev, Petar H.; Tan, Howe-Siang; Lo, Cynthia S.; Tretiak, Sergei; Fernandez-Alberti, Sebastian; Zhao, Yang

    2015-09-01

    Nonradiative relaxation of high-energy excited states to the lowest excited state in chlorophylls marks the first step in the process of photosynthesis. We perform ultrafast transient absorption spectroscopy measurements, that reveal this internal conversion dynamics to be slightly slower in chlorophyll B than in chlorophyll A. Modeling this process with non-adiabatic excited state molecular dynamics simulations uncovers a critical role played by the different side groups in the two molecules in governing the intramolecular redistribution of excited state wavefunction, leading, in turn, to different time-scales. Even given smaller electron-vibrational couplings compared to common organic conjugated chromophores, these molecules are able to efficiently dissipate about 1 eV of electronic energy into heat on the timescale of around 200 fs. This is achieved via selective participation of specific atomic groups and complex global migration of the wavefunction from the outer to inner ring, which may have important implications for biological light-harvesting function.

  6. Non-radiative relaxation of photoexcited chlorophylls: theoretical and experimental study.

    Science.gov (United States)

    Bricker, William P; Shenai, Prathamesh M; Ghosh, Avishek; Liu, Zhengtang; Enriquez, Miriam Grace M; Lambrev, Petar H; Tan, Howe-Siang; Lo, Cynthia S; Tretiak, Sergei; Fernandez-Alberti, Sebastian; Zhao, Yang

    2015-09-08

    Nonradiative relaxation of high-energy excited states to the lowest excited state in chlorophylls marks the first step in the process of photosynthesis. We perform ultrafast transient absorption spectroscopy measurements, that reveal this internal conversion dynamics to be slightly slower in chlorophyll B than in chlorophyll A. Modeling this process with non-adiabatic excited state molecular dynamics simulations uncovers a critical role played by the different side groups in the two molecules in governing the intramolecular redistribution of excited state wavefunction, leading, in turn, to different time-scales. Even given smaller electron-vibrational couplings compared to common organic conjugated chromophores, these molecules are able to efficiently dissipate about 1 eV of electronic energy into heat on the timescale of around 200 fs. This is achieved via selective participation of specific atomic groups and complex global migration of the wavefunction from the outer to inner ring, which may have important implications for biological light-harvesting function.

  7. Discrimination of non-radiation backgrounds in the proportional counter of MARDS

    Science.gov (United States)

    Na, Liang; Xiaofeng, Guo; Fei, Luo; Fanhua, Hao; RenDe, Ze; Qingpei, Xiang; Chengsheng, Chu; Yongchun, Xiang; Zhaotong, Yan; Wei, Li

    2017-03-01

    The Movable 37Ar Rapid Detection System (MARDS) was developed by the Institute of Nuclear Physics and Chemistry of the China Academy of Engineering Physics in 2006 for on-site inspections under the Comprehensive Test Ban Treaty. It is a small and portable system that can quickly acquire data at suspected nuclear test sites. In this work, digital pulse shape discrimination (PSD) was used to process data from test samples to reduce electronic noise. The experimental results demonstrate that PSD combined with principal component analysis can classify and reject many noise sources. Thus, the threshold for the signal can be set low, expanding MARDS valid data acquisition capability, especially in very low-level and low-energy counting situations.

  8. Non-radiative relaxation dynamics of pyrrole following excitation in the range 249.5-200 nm

    Science.gov (United States)

    Kirkby, Oliver M.; Parkes, Michael A.; Neville, Simon P.; Worth, Graham A.; Fielding, Helen H.

    2017-09-01

    The non-radiative relaxation dynamics of pyrrole have been investigated using time-resolved photoelectron spectroscopy and quantum dynamics simulations. Following excitation of the A2 (11 πσ∗) state, we observe population flow out of the Franck-Condon region on a ≲ 50 fs timescale. Following excitation of the B2 (21 ππ∗) state, we observe population being transferred to the A2 (11 πσ∗) state on a <50 fs timescale and subsequently out of the Franck-Condon region, also on a <50 fs timescale. Quantum dynamics calculations suggest that population is transferred from the B2 (21 ππ∗) state through the A2 (1 π 3pz) state to the B1 (21 πσ∗) state before being transferred to the A2 (11 πσ∗) state.

  9. High-power electron beam tests of a liquid-lithium target and characterization study of (7)Li(p,n) near-threshold neutrons for accelerator-based boron neutron capture therapy.

    Science.gov (United States)

    Halfon, S; Paul, M; Arenshtam, A; Berkovits, D; Cohen, D; Eliyahu, I; Kijel, D; Mardor, I; Silverman, I

    2014-06-01

    A compact Liquid-Lithium Target (LiLiT) was built and tested with a high-power electron gun at Soreq Nuclear Research Center (SNRC). The target is intended to demonstrate liquid-lithium target capabilities to constitute an accelerator-based intense neutron source for Boron Neutron Capture Therapy (BNCT) in hospitals. The lithium target will produce neutrons through the (7)Li(p,n)(7)Be reaction and it will overcome the major problem of removing the thermal power >5kW generated by high-intensity proton beams, necessary for sufficient therapeutic neutron flux. In preliminary experiments liquid lithium was flown through the target loop and generated a stable jet on the concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power densities of more than 4kW/cm(2) and volumetric power density around 2MW/cm(3) at a lithium flow of ~4m/s, while maintaining stable temperature and vacuum conditions. These power densities correspond to a narrow (σ=~2mm) 1.91MeV, 3mA proton beam. A high-intensity proton beam irradiation (1.91-2.5MeV, 2mA) is being commissioned at the SARAF (Soreq Applied Research Accelerator Facility) superconducting linear accelerator. In order to determine the conditions of LiLiT proton irradiation for BNCT and to tailor the neutron energy spectrum, a characterization of near threshold (~1.91MeV) (7)Li(p,n) neutrons is in progress based on Monte-Carlo (MCNP and Geant4) simulation and on low-intensity experiments with solid LiF targets. In-phantom dosimetry measurements are performed using special designed dosimeters based on CR-39 track detectors.

  10. A first-principles density functional theory study of the electronic structural and thermodynamic properties of M2ZrO3 and M2CO3 (M=Na, K) and their capabilities for CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Yuhua Duan

    2012-01-01

    Alkali metal zirconates could be used as solid sorbents for CO{sub 2} capture. The structural, electronic, and phonon properties of Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3} are investigated by combining the density functional theory with lattice phonon dynamics. The thermodynamics of CO{sub 2} absorption/desorption reactions of these two zirconates are analyzed. The calculated results show that their optimized structures are in a good agreement with experimental measurements. The calculated band gaps are 4.339 eV (indirect), 3.641 eV (direct), 3.935 eV (indirect), and 3.697 eV (direct) for Na{sub 2}ZrO{sub 3}, K{sub 2}ZrO{sub 3}, Na{sub 2}CO{sub 3}, and K{sub 2}CO{sub 3}, respectively.The calculated phonon dispersions and phonon density of states for M{sub 2}ZrO{sub 3} and M{sub 2}CO{sub 3} (M = K, Na, Li) revealed that from K to Na to Li, their frequency peaks are shifted to high frequencies due to the molecular weight decreased from K to Li. From the calculated reaction heats and relationships of free energy change versus temperatures and CO{sub 2} pressures of the M{sub 2}ZrO{sub 3} (M = K, Na, Li) reacting with CO{sub 2}, we found that the performance of Na{sub 2}ZrO{sub 3} capturing CO{sub 2} is similar to that of Li{sub 2}ZrO{sub 3} and is better than that of K{sub 2}ZrO{sub 3}. Therefore, Na{sub 2}ZrO{sub 3} and Li{sub 2}ZrO{sub 3} are good candidates of high temperature CO{sub 2} sorbents and could be used for post combustion CO{sub 2} capture technologies.

  11. Neutron Capture Nucleosynthesis

    CERN Document Server

    Kiss, Miklos

    2016-01-01

    Heavy elements (beyond iron) are formed in neutron capture nucleosynthesis processes. We have proposed a simple unified model to investigate the neutron capture nucleosynthesis in arbitrary neutron density environment. We have also investigated what neutron density is required to reproduce the measured abundance of nuclei assuming equilibrium processes. We found both of these that the medium neutron density has a particularly important role at neutron capture nucleosynthesis. About these results most of the nuclei can formed at medium neutron capture density environment e.g. in some kind of AGB stars. Besides these observations our model is capable to use educational purpose.

  12. Capture ready study

    Energy Technology Data Exchange (ETDEWEB)

    Minchener, A.

    2007-07-15

    There are a large number of ways in which the capture of carbon as carbon dioxide (CO{sub 2}) can be integrated into fossil fuel power stations, most being applicable for both gas and coal feedstocks. To add to the choice of technology is the question of whether an existing plant should be retrofitted for capture, or whether it is more attractive to build totally new. This miscellany of choices adds considerably to the commercial risk of investing in a large power station. An intermediate stage between the non-capture and full capture state would be advantageous in helping to determine the best way forward and hence reduce those risks. In recent years the term 'carbon capture ready' or 'capture ready' has been coined to describe such an intermediate stage plant and is now widely used. However a detailed and all-encompassing definition of this term has never been published. All fossil fuel consuming plant produce a carbon dioxide gas byproduct. There is a possibility of scrubbing it with an appropriate CO{sub 2} solvent. Hence it could be said that all fossil fuel plant is in a condition for removal of its CO{sub 2} effluent and therefore already in a 'capture ready' state. Evidently, the practical reality of solvent scrubbing could cost more than the rewards offered by such as the ETS (European Trading Scheme). In which case, it can be said that although the possibility exists of capturing CO{sub 2}, it is not a commercially viable option and therefore the plant could not be described as ready for CO{sub 2} capture. The boundary between a capture ready and a non-capture ready condition using this definition cannot be determined in an objective and therefore universally acceptable way and criteria must be found which are less onerous and less potentially contentious to assess. 16 refs., 2 annexes.

  13. CAPTURED India Country Evaluation

    NARCIS (Netherlands)

    O'Donoghue, R.; Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health fol

  14. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  15. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  16. CAPTURED India Country Evaluation

    NARCIS (Netherlands)

    O'Donoghue, R.; Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the India Country Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the End Evaluation has assessed that results are commendable. I-AIM was able to design an approach in which health

  17. State selective electron capture at low energies

    NARCIS (Netherlands)

    Bliek, Frederik Willem

    1997-01-01

    Zolang de mensheid al bestaat, vraagt men zich af hoe de sterren zijn ontstaan die we tijdens een heldere nacht aan de hemel zien staan. Om een antwoord te kunnen geven op deze vraag moeten we ons eerst afvragen hoe we iets kunnen leren over een ster die vaak vele duizenden lichtjaren van ons verwij

  18. State selective electron capture at low energies

    NARCIS (Netherlands)

    Bliek, Frederik Willem

    1997-01-01

    Zolang de mensheid al bestaat, vraagt men zich af hoe de sterren zijn ontstaan die we tijdens een heldere nacht aan de hemel zien staan. Om een antwoord te kunnen geven op deze vraag moeten we ons eerst afvragen hoe we iets kunnen leren over een ster die vaak vele duizenden lichtjaren van ons verwij

  19. Testing Lorentz invariance in orbital electron capture

    NARCIS (Netherlands)

    Vos, K. K.; Wilschut, H. W.; Timmermans, R. G. E.

    2015-01-01

    Searches for Lorentz violation were recently extended to the weak sector, in particular neutron and nuclear beta decay [Noordmans, Wilschut, and Timmermans, Phys. Rev. C 87, 055502 (2013)]. From experiments on forbidden beta-decay transitions, strong limits in the range of 10(-6) to 10(-8) were obta

  20. Rapid and simple determination of acrylamide in conventional cereal-based foods and potato chips through conversion to 3-[bis(trifluoroethanoyl)amino]-3-oxopropyl trifluoroacetate by gas chromatography coupled with electron capture and ion trap mass spectrometry detectors.

    Science.gov (United States)

    Russo, Mario Vincenzo; Avino, Pasquale; Centola, Angela; Notardonato, Ivan; Cinelli, Giuseppe

    2014-03-01

    A new, simple, rapid and fully validated method based on gas chromatography coupled with Electron capture and ion trap mass spectrometry detectors (GC-ECD and GC-IT/MS) is presented for quantitative analysis of acrylamide contaminant in conventional cereal-based foods and potato chips. Before analysis acrylamide was efficiently derivatized with trifluoroacetic anhydride, the effects of temperature, reaction time and catalyst on the acylation reaction were evaluated. Chromatographic analysis was performed on SE-54 capillary column; good retention and peak response of the acrylamide derivative achieved under the optimal conditions. The analytical method has been fully validated by assessment of the following parameters: LODs and LOQs (1 and 25ngg(-1) by GC-ECD and 2 and 36ngg(-1) by GC-IT/MS, with a Relative Standard Deviations acrylamide spiked at levels of 1, 20, 50 and 100ngg(-1)). Furthermore, the method proposed requires no clean-up step of the acrylamide derivative to be performed prior to injection. The developed method has been successfully applied to determine acrylamide in different commercial cereal-based foods (including French fries and potato chips).

  1. Suitability of a magnetic particle immunoassay for the analysis of PBDEs in Hawaiian euryhaline fish and crabs in comparison with gas chromatography/electron capture detection-ion trap mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Xu Ting [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 96822 (United States); Cho, Il Kyu; Wang Dongli [Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 96822 (United States); Rubio, Fernando M. [Abraxis LLC, 54 Steamwhistle Drive, Warminster, PA 18974 (United States); Shelver, Weilin L. [USDA-ARS Biosciences Research Laboratory, 1605 Albrecht Boulevard, Fargo, ND 58105 (United States); Gasc, Anne M.E. [Encore, Inc., P.O. Box 47, Waimanalo, HI 96795-0047 (United States); Li, Ji [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Li, Qing X. [Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East-West Road, Honolulu, HI 96822 (United States)], E-mail: qingl@hawaii.edu

    2009-02-15

    A gas chromatograph/electron capture detector-ion trap mass spectrometer (GC/ECD-ITMS) was used for the determination of polybrominated diphenyl ethers (PBDEs) in euryhaline fish and crabs. GC/ECD-ITMS results showed that average recoveries from the spiked fish samples are in a range of 58-123% with relative standard deviations (RSDs) of 5-19%. PBDE concentrations obtained from GC/ECD-ITMS ranged from 28 ng/g to 1845 ng/g lipid weight (lw) in all aquatic species collected from Hawaiian brackish waters. The general BDE congener concentration profile observed in this study is BDE-47 > BDE-100 > BDE-154 > BDE-99 > BDE-153 > BDE-28 > BDE-183. The ELISA results expressed as BDE-47 equivalents correlated well with those of GC/ECD-ITMS, with a correlation coefficient (R{sup 2} = 0.68) and regression coefficient (slope = 0.82). Comparison of ELISA with GC/ECD-ITMS results demonstrated that ELISA provides a timely and cost-effective method to screen PBDEs in fish and crab samples. - PBDEs (with the most abundant being BDE-47) at concentrations of 28-1845 ng/g lipid weight in fish and crabs from Hawaiian freshwater were detected with both ELISA and GC/MS.

  2. 皮革中短链氯化石蜡的GC—ECD测定方法探讨%Determination of Short Chain Chlorinated Paraffins in Leather by Gas Chromatography Combined Electron Capture Detector

    Institute of Scientific and Technical Information of China (English)

    马贺伟

    2012-01-01

    Analysis of short - chain chlorinated paraffins (SCCPs) in leather was studied using gas chromatography combined electron capture detector (GC -ECD). The results show the wide co -eluting chromatogram of SCCPs, and the response factors are dependent on the degree of chlorination. Significant interference problems from medium - chain chlorinated paraffins ( MC- CPs) are expected due to the difficult chromatographic separation. GC - ECD could not provide satisfactory results for scanning SCCPs in leather because of the low selectivity and the complex matrix influences.%采用气相色谱-电子捕获检测器(GC—ECD)对皮革中的短链氯化石蜡(SCCPs)进行测定。结果表明:SCCPs的GC—ECD共流出色谱峰保留时间跨度大,仪器响应值表现出对氯含量的依赖;中链氯化石蜡(MCCPs)的存在对SCCPs的分析过程干扰严重;实际皮革基质非常复杂,导致样品中SCCPs的定性困难。

  3. [Determination of short-chain chlorinated paraffins in ambient air using high-volume sampling combined with high resolutimi gas chromatography-electron capture negative ion-low resolution mass spectrometry].

    Science.gov (United States)

    Shi, Loimeng; Gao, Yuan; Hou, Xiaohong; Zhang, Haijun; Zhang, Yichi; Chen, Jiping

    2016-02-01

    An analytical method for quantifying short-chain chlorinated paraffins (SCCPs) in ambient air using high-volume sampling combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry ( HRGC-ECNI-LRMS) was developed. An acidified silica gel column and a basic alumina column were used to optimize the cleanup procedures. The results showed a good linearity (R2>0. 99) between the total response factors and the degree of chlorination of SCCPs in the content range of 58. 1%-63. 3%. The limits of detection (S/N ≥3) and the limits of quantification (S/N ≥ 10) were 4. 2 and 12 µg, respectively. The method detection limit (MDL) for SCCPs was 0. 34 ng/m3 (n = 7). The recoveries of SCCPs in air samples were in the range of 81. 9% to 94. 2%. It is demonstrated that the method is suitable for the quantitative analysis of SCCPs in air samples.

  4. Rapid and sensitive detection of fipronil and its metabolites in edible oils by solid-phase extraction based on humic acid bonded silica combined with gas chromatography with electron capture detection.

    Science.gov (United States)

    Peng, Xi-Tian; Li, Yu-Nan; Xia, Hong; Peng, Li-Jun; Feng, Yu-Qi

    2016-06-01

    Solid-phase extraction based on humic acid bonded silica followed by gas chromatography with electron capture detection was developed to determine fipronil and its metabolites in edible oil. To achieve the best extraction performance, we systematically investigated a series of solid-phase extraction parameters. Under the optimized conditions, the method was validated according to linearity, recovery, and precision. Good linearities were obtained with R(2) more than 0.9996 for all analytes. The limits of detection were between 0.3 and 0.5 ng/g, and the recoveries ranged from 83.1 to 104.0% at three spiked concentrations with intra- and interday relative standard deviation values less than 8.7%. Finally, the proposed method was applied to determine fipronil and its metabolites in 11 edible oil samples taken from Wuhan markets. Fipronil was detectable in four samples with concentrations ranging from 3.0 to 5.2 ng/g. In China, the maximum residue limits of fipronil in some vegetables and maize are 20 and 100 ng/g (GB/T 2763-2014), respectively. The residues of fipronil and its metabolites in commercial edible oils might exhibit some potential threat to human health as a result of high consumption of edible oil as part of daily intake. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Use of pressurized liquid extraction (PLE)/gas chromatography-electron capture detection (GC-ECD) for the determination of biodegradation intermediates of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in soils.

    Science.gov (United States)

    Zhang, Baohong; Pan, Xiaoping; Cobb, George P; Anderson, Todd A

    2005-09-25

    A rapid, sensitive, and reproducible method was developed for quantitative determination of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and its biodegradation intermediates, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) in soils. RDX, MNX, DNX, or TNX was extracted from soil by pressurized liquid extraction (PLE), followed by cleanup using florisil. Instrumental analysis was performed using gas chromatography with electron capture detection (GC-ECD), which was highly sensitive to the parent explosive and its metabolites. The method detection limits (MDLs) were 0.243, 0.095, 0.138, and 0.057 ng/g for RDX, MNX, DNX, and TNX, respectively. The method gave high recovery (98-102%), good precision (0.22-5.14%), and reproducibility, and proved to be suitable for real world sample analysis.

  6. Toward the understanding of chemical absorption processes for post-combustion capture of carbon dioxide: electronic and steric considerations from the kinetics of reactions of CO2(aq) with sterically hindered amines.

    Science.gov (United States)

    Conway, William; Wang, Xiaoguang; Fernandes, Debra; Burns, Robert; Lawrance, Geoffrey; Puxty, Graeme; Maeder, Marcel

    2013-01-15

    The present study reports (a) the determination of both the kinetic rate constants and equilibrium constants for the reaction of CO(2)(aq) with sterically hindered amines and (b) an attempt to elucidate a fundamental chemical understanding of the relationship between the amine structure and chemical properties of the amine that are relevant for postcombustion capture of CO(2) (PCC) applications. The reactions of CO(2)(aq) with a series of linear and methyl substituted primary amines and alkanolamines have been investigated using stopped-flow spectrophotometry and (1)H NMR measurements at 25.0 °C. The specific mechanism of absorption for each of the amines, that is CO(2) hydration and/or carbamate formation, is examined and, based on the mechanism, the kinetic and equilibrium constants for the formation of carbamic acid/carbamates, including protonation constants of the carbamate, are reported for amines that follow this pathway. A Brønsted correlation relating the kinetic rate constants and equilibrium constants for the formation of carbamic acid/carbamates with the protonation constant of the amine is reported. Such a relationship facilitates an understanding of the effects of steric and electronic properties of the amine toward its reactivity with CO(2). Further, such relationships can be used to guide the design of new amines with improved properties relevant to PCC applications.

  7. Ag colloids and arrays for plasmonic non-radiative energy transfer from quantum dots to a quantum well

    CERN Document Server

    Murphy, Graham P; Higgins, Luke J; Karanikolas, Vasilios D; Wilson, Keith M; Coindreau, Jorge A Garcia; Zubialevich, Vitaly Z; Parbrook, Peter J; Bradley, A Louise

    2016-01-01

    Ag nanoparticles in the form of colloids and ordered arrays are used to demonstrate plasmon-mediated non-radiative energy transfer from quantum dots to quantum wells with varying top barrier thicknesses. Plasmon-mediated energy transfer efficiencies of up to ~25% are observed with the Ag colloids. The distance dependence of the plasmon-mediated energy transfer is found to follow the same d^{-4} dependence as the direct quantum dot to quantum well energy transfer. There is also evidence for an increase in the characteristic distance of the interaction, thus indicating that it follows a F\\"orster-like model with the Ag nanoparticle-quantum dot acting as an enhanced donor dipole. Ordered Ag nanoparticle arrays display plasmon-mediated energy transfer efficiencies up to ~21%. To explore the tunability of the array system, two arrays with different geometries are presented. It is demonstrated that changing the geometry of the array allows a transition from overall quenching of the acceptor quantum well emission to...

  8. Ag colloids and arrays for plasmonic non-radiative energy transfer from quantum dots to a quantum well

    Science.gov (United States)

    Murphy, Graham P.; Gough, John J.; Higgins, Luke J.; Karanikolas, Vasilios D.; Wilson, Keith M.; Garcia Coindreau, Jorge A.; Zubialevich, Vitaly Z.; Parbrook, Peter J.; Bradley, A. Louise

    2017-03-01

    Non-radiative energy transfer (NRET) can be an efficient process of benefit to many applications including photovoltaics, sensors, light emitting diodes and photodetectors. Combining the remarkable optical properties of quantum dots (QDs) with the electrical properties of quantum wells (QWs) allows for the formation of hybrid devices which can utilize NRET as a means of transferring absorbed optical energy from the QDs to the QW. Here we report on plasmon-enhanced NRET from semiconductor nanocrystal QDs to a QW. Ag nanoparticles in the form of colloids and ordered arrays are used to demonstrate plasmon-mediated NRET from QDs to QWs with varying top barrier thicknesses. Plasmon-mediated energy transfer (ET) efficiencies of up to ∼25% are observed with the Ag colloids. The distance dependence of the plasmon-mediated ET is found to follow the same d ‑4 dependence as the direct QD to QW ET. There is also evidence for an increase in the characteristic distance of the interaction, thus indicating that it follows a Förster-like model with the Ag nanoparticle-QD acting as an enhanced donor dipole. Ordered Ag nanoparticle arrays display plasmon-mediated ET efficiencies up to ∼21%. To explore the tunability of the array system, two arrays with different geometries are presented. It is demonstrated that changing the geometry of the array allows a transition from overall quenching of the acceptor QW emission to enhancement, as well as control of the competition between the QD donor quenching and ET rates.

  9. Marine turtle capture data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To estimate abundance, growth, and survival rate and to collect tissue samples, marine turtles are captured at nesting beaches and foraging grounds through various...

  10. Preparing to Capture Carbon

    National Research Council Canada - National Science Library

    Daniel P. Schrag

    2007-01-01

    .... Scientific and economic challenges still exist, but none are serious enough to suggest that carbon capture and storage will not work at the scale required to offset trillions of tons of carbon...

  11. LIGHT AND ELECTRON-MICROSCOPIC DEMONSTRATION OF THE OUABAIN-SENSITIVE, POTASSIUM-DEPENDENT P-NITROPHENYLPHOSPHATASE ACTIVITY (K-NPPASE) USING A CE-MG-DOUBLE CAPTURE TECHNIQUE

    NARCIS (Netherlands)

    GLIESING, M; KALICHARAN, D; HALBHUBER, KJ

    The cerium-based method of Kobayashi et al. for the histochemical demonstration of K-NPPase activity was improved. Besides Ce3+ additionally Mg2+ ions as orthophosphate capture were employed (double capture technique). For light microscopical purposes the Mg-phosphate was converted into Ce-phosphate

  12. Low density solvent based dispersive liquid-liquid microextraction with gas chromatography-electron capture detection for the determination of cypermethrin in tissues and blood of cypermethrin treated rats.

    Science.gov (United States)

    Mudiam, Mohana Krishna Reddy; Jain, Rajeev; Maurya, Shailendra Kumar; Khan, Haider A; Bandyopadhyay, Sanghamitra; Murthy, R C

    2012-05-01

    A simple and rapid method to determine the cypermethrin (CYP) insecticide in rat tissues (kidney, liver and brain) and blood has been developed for the first time using low density solvent-dispersive liquid-liquid microextraction (LDS-DLLME) followed by gas chromatography-electron capture detector (GC-ECD) analysis. Initially, tissue samples containing CYP were homoginized in acetone. Subsequently, homogenate was mixed with n-hexane (extraction solvent) and the mixture was rapidly injected into water. The upper n-hexane layer was collected in a separate microtube and injected into GC-ECD for analysis. Blood samples were diluted with ultrapure water and subjected to DLLME through similar procedure. Parameters such as type and volume of disperser and extraction solvent, salting out effect and extraction time, which can affect the extraction efficiency of DLLME, were optimized. Method was validated by investigating linearity, precision, recovery, limit of detection (LOD) and quantification (LOQ). LODs in tissue were in the range of 0.043-0.314 ng mg(-1) and for blood it was 8.6 ng mL(-1) with a signal to noise ratio of 3:1. LOQs in tissue were in the range of 0.143-1.03 ng mg(-1) and for blood it was 28.3 ng mL(-1) with a signal to noise ratio of 10:1. Mean recoveries of CYP at three different concentation levels in all the matrices were found to be in the range of 81.6-103.67%. The results show that, LDS-DLLME coupled with GC-ECD offers a simple, rapid and efficient technique for extraction and determination of CYP in rat tissues and blood samples, which in turn would be useful for toxicological studies of CYP.

  13. Application of modified hollow fiber liquid phase microextraction in conjunction with chromatography-electron capture detection for quantification of acrylamide in waste water samples at ultra-trace levels.

    Science.gov (United States)

    Sobhi, Hamid Reza; Ghambarian, Mahnaz; Behbahani, Mohammad; Esrafili, Ali

    2017-03-03

    Herein, a simple and sensitive method was successfully developed for the extraction and quantification of acrylamide in water samples. Initially, acrylamide was derivatized through a bromination process. Subsequently, a modified hollow-fiber liquid-phase microextraction was applied for the extraction of the brominated acrylamide from a 10-ml portion of an aqueous sample. Briefly, in this method, the derivatized acrylamide (2,3-dibromopropionamide) was extracted from the aqueous sample into a thin layer of an organic solvent sustained in pores of a porous hollow fiber. Then, it was back-extracted using a small volume of organic acceptor solution (acetonitril, 25μl) located inside the lumen of the hollow fiber followed by gas chromatography-electron capture detection (GC-ECD). The optimal conditions were examined for the extraction of the analyte such as: the organic solvent: dihexyl ether+10% tri-n-octyl phosphine oxide; stirring rate: 750rpm; no salt addition and 30min extraction time. These optimal extraction conditions allowed excellent enrichment factor values for the method. Enrichment factor, detection limit (S/N=3) and dynamic linear range of 60, 2ngL(-1) and 50-1000ngL(-1) to be determined for the analyte. The relative standard deviations (RSD%) representing precision of the method were in the range of 2.2-5.8 based on the average of three measurements. Accuracy of the method was tested by the relative recovery experiments on spiked samples, with results ranging from 93 to 108%. Finally, the method proved to be simple, rapid, and cost-effective for routine screen of acrylamide-contaminated highly-complicated untreated waste water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Determination of acrylamide in Chinese traditional carbohydrate-rich foods using gas chromatography with micro-electron capture detector and isotope dilution liquid chromatography combined with electrospray ionization tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yu [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang Province (China); Ren Yiping [Zhejiang Provincial Center for Disease Prevention and Control, Hangzhou 310009, Zhejiang Province (China); Zhao Hangmei [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang Province (China); Zhang Ying [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, Zhejiang Province (China)]. E-mail: y_zhang@zju.edu.cn

    2007-02-19

    The present study developed two analytical methods for quantification of acrylamide in complex food matrixes, such as Chinese traditional carbohydrate-rich foods. One is based on derivatization with potassium bromate and potassium bromide without clean-up prior to gas chromatography with micro-electron capture detector (GC-MECD). Alternatively, the underivatized acrylamide was detected by high-performance liquid chromatography coupled to quadrupole tandem mass spectrometry (HPLC-MS/MS) in the positive electrospray ionization mode. For both methods, the Chinese carbohydrate-rich samples were homogenized, defatted with petroleum ether and extracted with aqueous solution of sodium chloride. Recovery rates for acrylamide from spiked Chinese style foods with the spiking level of 50, 500 and 1000 {mu}g kg{sup -1} were in the range of 79-93% for the GC-MECD including derivatization and 84-97% for the HPLC-MS/MS method. Typical quantification limits of the HPLC-MSMS method were 4 {mu}g kg{sup -1} for acrylamide. The GC-MECD method achieved quantification limits of 10 {mu}g kg{sup -1} in Chinese style foods. Thirty-eight Chinese traditional foods purchased from different manufacturers were analyzed and compared with four Western style foods. Acrylamide contaminant was found in all of samples at the concentration up to 771.1 and 734.5 {mu}g kg{sup -1} detected by the GC and HPLC method, respectively. The concentrations determined with the two different quantitative methods corresponded well with each other. A convenient and fast pretreatment procedure will be optimized in order to satisfy further investigation of hundreds of samples.

  15. Determination of acrylamide in Chinese traditional carbohydrate-rich foods using gas chromatography with micro-electron capture detector and isotope dilution liquid chromatography combined with electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Zhang, Yu; Ren, Yiping; Zhao, Hangmei; Zhang, Ying

    2007-02-19

    The present study developed two analytical methods for quantification of acrylamide in complex food matrixes, such as Chinese traditional carbohydrate-rich foods. One is based on derivatization with potassium bromate and potassium bromide without clean-up prior to gas chromatography with micro-electron capture detector (GC-MECD). Alternatively, the underivatized acrylamide was detected by high-performance liquid chromatography coupled to quadrupole tandem mass spectrometry (HPLC-MS/MS) in the positive electrospray ionization mode. For both methods, the Chinese carbohydrate-rich samples were homogenized, defatted with petroleum ether and extracted with aqueous solution of sodium chloride. Recovery rates for acrylamide from spiked Chinese style foods with the spiking level of 50, 500 and 1000 microg kg(-1) were in the range of 79-93% for the GC-MECD including derivatization and 84-97% for the HPLC-MS/MS method. Typical quantification limits of the HPLC-MSMS method were 4 microg kg(-1) for acrylamide. The GC-MECD method achieved quantification limits of 10 microg kg(-1) in Chinese style foods. Thirty-eight Chinese traditional foods purchased from different manufacturers were analyzed and compared with four Western style foods. Acrylamide contaminant was found in all of samples at the concentration up to 771.1 and 734.5 microg kg(-1) detected by the GC and HPLC method, respectively. The concentrations determined with the two different quantitative methods corresponded well with each other. A convenient and fast pretreatment procedure will be optimized in order to satisfy further investigation of hundreds of samples.

  16. Simultaneous analysis of organochlorine pesticides and polychlorinated biphenyls in air samples by using accelerated solvent extraction (ASE) and solid-phase micro-extraction (SPME) coupled to gas chromatography dual electron capture detection.

    Science.gov (United States)

    Mokbel, Haifaa; Al Dine, Enaam Jamal; Elmoll, Ahmad; Liaud, Céline; Millet, Maurice

    2016-04-01

    An analytical method associating accelerated solvent extraction (ASE) and solid-phase micro-extraction (SPME) in immersion mode combined with gas chromatography dual electrons capture detectors (SPME-GC-2ECD) has been developed and studied for the simultaneous determination of 19 organochlorine pesticides (OCPs) and 22 polychlorinated biphenyls (PCBs) in air samples (active and XAD-2 passive samplers). Samples were extracted with ASE with acetonitrile using the following conditions: temperature, 150 °C; pressure, 1500 psi; static, 15 min; cycles, 3; purge, 300 s; flush, 100 %. Extracts were reduced to 1 mL, and 500 μL of this extract, filled with deionised water, was subject to SPME extraction. Experimental results indicated that the proposed method attained the best extraction efficiency under the optimised conditions: extraction of PCB-OCP mixture using 100-μm PDMS fibre at 80 °C for 40 min with no addition of salt. The performance of the proposed ASE-SPME-GC-2ECD methodology with respect to linearity, limit of quantification and detection was evaluated by spiking of XAD-2 resin with target compounds. The regression coefficient (R (2)) of most compounds was found to be high of 0.99. limits of detection (LODs) are between 0.02 and 4.90 ng m(-3), and limits of quantification (LOQs) are between 0.05 and 9.12 ng m(-3) and between 0.2 and 49 ng/sampler and 0.52 and 91 ng/sampler, respectively, for XAD-2 passive samplers. Finally, a developed procedure was applied to determine selected PCBs and OCPs in the atmosphere.

  17. Hollow fiber liquid-liquid-liquid microextraction followed by solid-phase microextraction and in situ derivatization for the determination of chlorophenols by gas chromatography-electron capture detection.

    Science.gov (United States)

    Saraji, Mohammad; Ghani, Milad

    2015-10-30

    A method based on the combination of hollow fiber liquid-liquid-liquid microextraction and solid-phase microextraction (SPME) followed by gas chromatography-electron capture detection was developed for the determination of chlorophenols in water and wastewater samples. Silica microstructures fabricated on the surface of a stainless steel wire were coated by an organic solvent and used as a SPME fiber. The analytes were extracted through a hollow fiber membrane containing n-decane from sample solution to an alkaline aqueous acceptor phase. They were then extracted and in situ derivatized on the SPME fiber using acetic anhydride. Experimental parameters such as the type of extraction solvent, acceptor phase NaOH concentration, donor phase HCl concentration, the amount of derivatizing reagent, salt concentration, stirring rate and extraction time were investigated and optimized. The precision of the method for the analytes at 0.02-30μgL(-1) concentration level ranged from 7.1 to 10.2% (as intra-day relative standard deviation) and 6.4 to 9.8% (as inter-day relative standard deviation). The linear dynamic ranges were in the interval of 5-500μgL(-1), 0.05-5μgL(-1), 0.02-1μgL(-1) and 0.001-0.5μgL(-1) for 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol, respectively. The enrichment factors were between 432 and 785. The limits of detection were in the range of 0.0004-1.2μgL(-1). Tap water, well water and wastewater samples were also analyzed to evaluate the method capability for real sample analysis.

  18. Polymer-functionalized single-walled carbon nanotubes as a novel sol-gel solid-phase micro-extraction coated fiber for determination of poly-brominated diphenyl ethers in water samples with gas chromatography-electron capture detection.

    Science.gov (United States)

    Zhang, Weiya; Sun, Yin; Wu, Caiying; Xing, Jun; Li, Jianying

    2009-04-15

    Single-walled carbon nanotubes (SWNTs) were functionalized with a hydroxyl-terminated silicone oil (TSO-OH). It is synthesized by the reactions of carbonyl chloride groups on the surface of SWNTs and hydroxyl groups of silicone oil (TSO-OH). The functionalized product SWNTs-TSO-OH was first used as precursor and selective stationary phase to prepare the sol-gel derived poly(SWNTs-TSO-OH) solid-phase microextraction (SPME) fiber for determination of polybrominated diphenyl ethers (PBDEs) in water samples. The possible major reaction of the sol-gel coating process was discussed and confirmed by IR spectra, Raman spectroscopy, and scanning electron microscopy. Some parameters of SPME fiber for the determination of PBDEs were investigated by headspace SPME/gas chromatography with electron-capture detection (HS-SPME/GC-ECD). Compared with the commercial SPME fiber, the new coated fiber showed higher extraction efficiency to PBDEs, better thermal stability (over 340 degrees C), and longer life span (over 200 times). All of these advantages are mainly due to the incorporation of SWNTs, which enhanced the pi-pi interaction with PBDEs and increased the surface area of extraction in contact with the sample. Moreover, the sol-gel coating technology additionally provided the porous structure of the 3-D silica network and the strong chemical binding provided which also will improve the extraction efficiency. Under optimized conditions, the method detection limits for seven PBDEs were 0.08-0.8 ng/L (S/N = 3) and the precision (RSD, n = 5) was 2.2-7.5% at the 50 ng/L level. The linearity of the developed method is in the range of 5-500 ng/L with coefficients of correlation greater than 0.995. The developed method was successfully applied for the analysis of trace PBDEs in reservoir water and wastewater samples. The recoveries obtained at spiking 50 ng/L were between 74% and 109% (n = 5) for PBDEs in water samples.

  19. Extent and distribution of in-stent intimal hyperplasia and edge effect in a non-radiation stent population.

    Science.gov (United States)

    Weissman, N J; Wilensky, R L; Tanguay, J F; Bartorelli, A L; Moses, J; Williams, D O; Bailey, S; Martin, J L; Canos, M R; Rudra, H; Popma, J J; Leon, M B; Kaplan, A V; Mintz, G S

    2001-08-01

    Intimal hyperplasia within the body of the stent is the primary mechanism for in-stent restenosis; however, stent edge restenosis has been described after brachytherapy. Our current understanding about the magnitude of in vivo intimal hyperplasia and edge restenosis is limited to data obtained primarily from select, symptomatic patients requiring repeat angiography. The purpose of this study was to determine the extent and distribution of intimal hyperplasia both within the stent and along the stent edge in relatively nonselect, asymptomatic patients scheduled for 6-month intravascular ultrasound (IVUS) as part of a multicenter trial: Heparin Infusion Prior to Stenting. Planar IVUS measurements 1 mm apart were obtained throughout the stent and over a length of 10 mm proximal and distal to the stent at index and follow-up. Of the 179 patients enrolled, 140 returned for repeat angiography and IVUS at 6.4 +/- 1.9 months and had IVUS images adequate for analysis. Patients had 1.2 +/- 0.6 Palmaz-Schatz stents per vessel. There was a wide individual variation of intimal hyperplasia distribution within the stent and no mean predilection for any location. At 6 months, intimal hyperplasia occupied 29.3 +/- 16.2% of the stent volume on average. Lumen loss within 2 mm of the stent edge was due primarily to intimal proliferation. Beyond 2 mm, negative remodeling contributed more to lumen loss. Gender, age, vessel location, index plaque burden, hypercholesterolemia, diabetes, and tobacco did not predict luminal narrowing at the stent edges, but diabetes, unstable angina at presentation, and lesion length were predictive of in-stent intimal hyperplasia. In a non-radiation stent population, 29% of the stent volume is filled with intimal hyperplasia at 6 months. Lumen loss at the stent edge is due primarily to intimal proliferation.

  20. Muon capture in deuterium

    Science.gov (United States)

    Ricci, P.; Truhlík, E.; Mosconi, B.; Smejkal, J.

    2010-06-01

    Model dependence of the capture rates of the negative muon capture in deuterium is studied starting from potential models and the weak two-body meson exchange currents constructed in the tree approximation and also from an effective field theory. The tree one-boson exchange currents are derived from the hard pion chiral Lagrangians of the NΔπρωa system. If constructed in conjunction with the one-boson exchange potentials, the capture rates can be calculated consistently. On the other hand, the effective field theory currents, constructed within the heavy baryon chiral perturbation theory, contain a low energy constant d that cannot be extracted from data at the one-particle level nor determined from the first principles. Comparative analysis of the results for the doublet transition rate allows us to extract the constant d.

  1. Electronic processes in uniaxially stressed p-type germanium

    Energy Technology Data Exchange (ETDEWEB)

    Dubon, Jr., Oscar Danilo [Univ. of California, Berkeley, CA (United States)

    1996-02-01

    Effect of uniaxial stress on acceptor-related electronic processes in Ge single crystals doped with Ga, Be, and Cu were studied by Hall and photo-Hall effect measurements in conjunction with infrared spectroscopy. Stress dependence of hole lifetime in p-type Ge single crystals is used as a test for competing models of non-radiative capture of holes by acceptors. Photo-Hall effect shows that hole lifetime in Ga- and Be-doped Ge increases by over one order of magnitude with uniaxial stress at liq. He temps. Photo-Hall of Ge:Be shows a stress-induced change in the temperature dependence of hole lifetime. This is consistent with observed increase of responsivity of Ge:Ga detectors with uniaxial stress. Electronic properties of Ge:Cu are shown to change dramatically with uniaxial stress; the results provide a first explanation for the performance of uniaxially stressed, Cu-diffused Ge:Ga detectors which display a high conductivity in absence of photon signal and therefore have poor sensitivity.

  2. US Spacesuit Knowledge Capture

    Science.gov (United States)

    Chullen, Cinda; Thomas, Ken; McMann, Joe; Dolan, Kristi; Bitterly, Rose; Lewis, Cathleen

    2011-01-01

    The ability to learn from both the mistakes and successes of the past is vital to assuring success in the future. Due to the close physical interaction between spacesuit systems and human beings as users, spacesuit technology and usage lends itself rather uniquely to the benefits realized from the skillful organization of historical information; its dissemination; the collection and identification of artifacts; and the education of those in the field. The National Aeronautics and Space Administration (NASA), other organizations and individuals have been performing United States (U.S.) Spacesuit Knowledge Capture since the beginning of space exploration. Avenues used to capture the knowledge have included publication of reports; conference presentations; specialized seminars; and classes usually given by veterans in the field. More recently the effort has been more concentrated and formalized whereby a new avenue of spacesuit knowledge capture has been added to the archives in which videotaping occurs engaging both current and retired specialists in the field presenting technical scope specifically for education and preservation of knowledge. With video archiving, all these avenues of learning can now be brought to life with the real experts presenting their wealth of knowledge on screen for future learners to enjoy. Scope and topics of U.S. spacesuit knowledge capture have included lessons learned in spacesuit technology, experience from the Gemini, Apollo, Skylab and Shuttle programs, hardware certification, design, development and other program components, spacesuit evolution and experience, failure analysis and resolution, and aspects of program management. Concurrently, U.S. spacesuit knowledge capture activities have progressed to a level where NASA, the National Air and Space Museum (NASM), Hamilton Sundstrand (HS) and the spacesuit community are now working together to provide a comprehensive closed-looped spacesuit knowledge capture system which includes

  3. Specific complex of non-radiation risk factors for socially significant pathologies could affect the liquidators of Chernobyl nuclear power plant accident

    Directory of Open Access Journals (Sweden)

    Koterov A.N.

    2014-12-01

    Full Text Available The review considers the complex of non-radiation factors that could affect the liquidators of the Chernobyl accident: the demographic, social and professional group heterogeneity to warrant differentiation of risk, the effects of heavy metals, 'hot particles', chemicals, psychogenic stress, social dislocation in the post-perestroika period, alcohol abuse, smoking, and the effect of screening. All these factors tend to have a significant intensity, unlike the radiation exposure for the majority of subjects. It is concluded that the increased frequency and severity of some large socially significant pathologies in contingent liquidators may be due to a unique set of predominantly non-radiation factors associated, however, with a particular radiation accident.

  4. Non-radiative recombination centres in catalyst-free ZnO nanorods grown by atmospheric-metal organic chemical vapour deposition

    Science.gov (United States)

    Montenegro, D. N.; Hortelano, V.; Martínez, O.; Martínez-Tomas, M. C.; Sallet, V.; Muñoz-Sanjosé, V.; Jiménez, J.

    2013-06-01

    We have investigated the cathodoluminescence (CL) emission and the Raman spectra along individual ZnO nanorods grown by a catalyst-free method. The spatial correlation between the CL emission and the defect related Raman modes permits establishing a correspondence between the non-radiative recombination centres (NRRCs) and the defects responsible for the 275 cm-1 Raman band. According to this relation, the NRRCs in these nanorods are tentatively associated with complexes of zinc interstitials.

  5. Double carriers pulse DLTS for the characterization of electron-hole recombination process in GaAsN grown by chemical beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Bouzazi, Boussairi, E-mail: sd08503@toyota-ti.ac.j [Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan); Suzuki, Hidetoshi; Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi [Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511 (Japan)

    2011-03-01

    A nitrogen-related electron trap (E1), located approximately 0.33 eV from the conduction band minimum of GaAsN grown by chemical beam epitaxy, was confirmed by investigating the dependence of its density with N concentration. This level exhibits a high capture cross section compared with that of native defects in GaAs. Its density increases significantly with N concentration, persists following post-thermal annealing, and was found to be quasi-uniformly distributed. These results indicate that E1 is a stable defect that is formed during growth to compensate for the tensile strain caused by N. Furthermore, E1 was confirmed to act as a recombination center by comparing its activation energy with that of the recombination current in the depletion region of the alloy. However, this technique cannot characterize the electron-hole (e-h) recombination process. For that, double carrier pulse deep level transient spectroscopy is used to confirm the non-radiative e-h recombination process through E1, to estimate the capture cross section of holes, and to evaluate the energy of multi-phonon emission. Furthermore, a configuration coordinate diagram is modeled based on the physical parameters of E1. -- Research Highlights: {yields} Double carrier pulse DLTS method confirms the existence of SRH center. {yields} The recombination center in GaAsN depends on nitrogen concentration. {yields} Minority carrier lifetime in GaAsN is less than 1 ns. {yields} A non-radiative recombination center exits in GaAsN.

  6. Capturing the Market

    Science.gov (United States)

    Ramaswami, Rama

    2009-01-01

    Digital lecture capture and broadcast solutions have been around for only about 10 years, but are poised for healthy growth. Frost & Sullivan research analysts estimate that the market (which amounts to $25 million currently) will quadruple by 2013. It's still dominated by a few key players, however: Sonic Foundry holds a hefty 40 percent-plus…

  7. Neutron capture therapies

    Energy Technology Data Exchange (ETDEWEB)

    Yanch, Jacquelyn C. (Cambridge, MA); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)

    1999-01-01

    In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  8. Neutron capture therapies

    Energy Technology Data Exchange (ETDEWEB)

    Yanch, J.C.; Shefer, R.E.; Klinkowstein, R.E.

    1999-11-02

    In one embodiment there is provided an application of the {sup 10}B(n,{alpha}){sup 7}Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  9. Simultaneous analysis of non-steroidal anti-inflammatory drugs and estrogenic hormones in water and wastewater samples using gas chromatography-mass spectrometry and gas chromatography with electron capture detection

    Energy Technology Data Exchange (ETDEWEB)

    Migowska, Natalia; Caban, Magda; Stepnowski, Piotr; Kumirska, Jolanta, E-mail: kumirska@chem.univ.gda.pl

    2012-12-15

    Non-steroidal anti-inflammatory drugs are the group of pharmaceuticals that is most often found in the environment, whereas estrogenic hormones are considered to be potent endocrine disruptors. However, the fate and persistence of these compounds in the environment are still unclear. In this study we propose two approaches for determining these compounds in environmental water samples: GC-MS using time windows and operating in selected ion-monitoring mode (SIM) and, for the first time, gas chromatography with electron capture detection (GC-ECD). The identification criteria of both methods fulfilled the requirements of Directive 2002/657/EC. The use of time windows improved the sensitivity of GC-MS measurements. In GC-MS analysis the pharmaceuticals were determined as trimethylsilyl, in GC-ECD as pentafluoropropionyl derivatives. The influence of such parameters as the type of reagent, type of solvent, reaction time, reaction temperature and microwave irradiation in a household microwave oven on the efficacy of silylation was investigated. Derivatization using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and 1% trimethylchlorosilane (TMCS) in pyridine (1:1, v/v) for 30 min in 60 Degree-Sign C was found to be optimal. Optimization of the solid phase extraction procedure (SPE) confirmed that the application of Oasis HLB cartridges, the acidification of loading samples to pH 2 and the use of methanol as eluent gave the best absolute recoveries (ARs) of the target compounds. The following ARs of all the compounds were achieved: 58.2-106.8% in influent wastewater, 77.8-103.4% in effluent wastewater and 81.2-101.9% in surface water samples. Validation of the SPE-GC-MS method enables 13 pharmaceuticals to be determined with MDLs between 3.3 and 343.6 ng/L, depending on the analytes and matrices. GC-ECD analysis enables the determination of 6 pharmaceuticals in surface water samples with MDLs between 0.7 and 5.4 ng/L. The proposed methods were successfully used for

  10. CAPTURED End Evaluation Synthesis Report

    NARCIS (Netherlands)

    Brouwers, J.H.A.M.

    2012-01-01

    This report provides the findings of the Synthesis Study of the CAPTURED Evaluation and is produced as part of the overall CAPTURED End Evaluation. After five years of support by the CAPTURED project the three CAPTURED partners have achieved commendable results. Ten lessons learned are formulated th

  11. Hot electron pump: a plasmonic rectifying antenna (Presentation Recording)

    Science.gov (United States)

    Yanik, Ahmet A.; Hossain, Golam I.

    2015-09-01

    Plasmonic nanostructures have been widely explored to improve absorption efficiency of conventional solar cells, either by employing them as a light scatterer, or as a source of local field enhancement. Unavoidable ohmic loss associated with the plasmonic metal nanostructures in visible spectrum, limits the efficiency improvement of photovoltaic devices by employing this local photon density of states (LDOS) engineering approach. Instead of using plasmonic structures as efficiency improving layer, recently, there has been a growing interest in exploring plasmoinc nanoparticle as the active medium for photovoltaic device. By extracting hot electrons that are created in metallic nanoparticles in a non-radiative Landau decay of surface plasmons, many novel plasmonic photovoltaic devices have been proposed. Moreover, these hot electrons in metal nanoparticles promises high efficiency with a spectral response that is not limited by the band gap of the semiconductors (active material of conventional solar cell). In this work, we will show a novel photovoltaic configuration of plasmonic nanoparticle that acts as an antenna by capturing free space ultrahigh frequency electromagnetic wave and rectify them through an ultrafast hot electron pump and eventually inject DC current in the contact of the device. We will introduce a bottom-up quantum mechanical approach model to explain fundamental physical processes involved in this hot electron pump rectifying antenna and it's ultrafast dynamics. Our model is based on non-equilibrium Green's function formalism, a robust theoretical framework to investigate transport and design nanoscale electronic devices. We will demonstrate some fundamental limitations that go the very foundations of quantum mechanics.

  12. State selective capture by highly charged Xe ions

    NARCIS (Netherlands)

    Hasan, V. G.; Knoop, S.; Morgenstern, R.; Hoekstra, R.; McCullough, RW; Currell, FJ; Greenwood, J; Gribakin, G; Scott, MP

    2007-01-01

    Single-electron capture in collisions of highly charged ions Xe18+ and Xe24+ with Na atoms is investigated by measuring the momenta of the Na recoil ions. The Q-value spectrum in Xe18+ + Na collisions shows capture into lower n states compared with Classical over-barrier model (CBM) calculations.

  13. Motion-induced X-ray and terahertz radiation of electrons captured in laser standing wave%电子在激光驻波场中运动产生的太赫兹及X射线辐射研究∗

    Institute of Scientific and Technical Information of China (English)

    朱卫卫; 张秋菊; 张延惠; 焦扬

    2015-01-01

    The motions of charged particles in electromagnetic fields composed of two or more laser beams show a variety of forms due to the adjustable properties of electromagnetic fields. In this paper, we consider the periodic laser standing wave field composed of two laser beams with opposite propagating directions. The movement of electrons in the standing wave field shows a periodic behavior, accompanied with the obvious radiation, especially when electrons are captured by the laser standing wave field. This phenomenon has aroused much interest of us. Under the existing experimental conditions, the free electron beam with low energy from an electron gun or the relativistic electron beam generated from laser acceleration can be easily obtained and injected into the periodic standing wave field. In this paper, using the single-electron model and the classical radiation theory of charged particles, we study the motion and radiation processes of low and high energy electrons in the polarized laser standing wave field. The results show that when the direction of incident electrons with low-speed is perpendicular to the direction of the laser standing wave electric field, the one-dimensional nearly periodic motion of electrons evolves into a two-dimensional folded movement by gradually increasing the light intensity of the laser standing wave field, and the strong terahertz radiation at micrometer wavelength is produced. High energy electrons generate the high-frequency radiation with the wavelength at several nanometers when the incident direction of high energy electrons is perpendicular or parallel to the direction of the laser standing wave electric field. In the case of low-energy electron, the motion of electron, frequency and intensity of radiation are affected by the laser intensity. In the case of incident high-energy electrons, the laser intensity affects the intensity of electronic radiation, and the initial electron energy influences radiation frequency. The

  14. Capturing the Future: Direct and Indirect Probes of Neutron Capture

    Energy Technology Data Exchange (ETDEWEB)

    Couture, Aaron Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-31

    This report documents aspects of direct and indirect neutron capture. The importance of neutron capture rates and methods to determine them are presented. The following conclusions are drawn: direct neutron capture measurements remain a backbone of experimental study; work is being done to take increased advantage of indirect methods for neutron capture; both instrumentation and facilities are making new measurements possible; more work is needed on the nuclear theory side to understand what is needed furthest from stability.

  15. Capturing Near Earth Objects

    OpenAIRE

    Baoyin, Hexi; CHEN Yang; Li, Junfeng

    2011-01-01

    Recently, Near Earth Objects (NEOs) have been attracting great attention, and thousands of NEOs have been found to date. This paper examines the NEOs' orbital dynamics using the framework of an accurate solar system model and a Sun-Earth-NEO three-body system when the NEOs are close to Earth to search for NEOs with low-energy orbits. It is possible for such an NEO to be temporarily captured by Earth; its orbit would thereby be changed and it would become an Earth-orbiting object after a small...

  16. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to capture greater than 90 percent of sulfur gases evolved during thermal treatment of lunar soils....

  17. Neutron capture reactions at DANCE

    Science.gov (United States)

    Bredeweg, T. A.

    2008-05-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) is a 4π BaF2 array consisting of 160 active detector elements. The primary purpose of the array is to perform neutron capture cross section measurements on small (>~100 μg) and/or radioactive (DANCE we have performed neutron capture cross section measurements on a wide array of medium to heavy mass nuclides. Measurements to date include neutron capture cross sections on 241,243Am, neutron capture and neutron-induced fission cross sections and capture-to-fission ratio (α = σγ/σf) for 235U using a new fission-tagging detector as well as neutron capture cross sections for several astrophysics branch-point nuclei. Results from several of these measurements will be presented along with a discussion of additional physics information that can be extracted from the DANCE data.

  18. Robust automated knowledge capture.

    Energy Technology Data Exchange (ETDEWEB)

    Stevens-Adams, Susan Marie; Abbott, Robert G.; Forsythe, James Chris; Trumbo, Michael Christopher Stefan; Haass, Michael Joseph; Hendrickson, Stacey M. Langfitt

    2011-10-01

    This report summarizes research conducted through the Sandia National Laboratories Robust Automated Knowledge Capture Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding of the influence of individual cognitive attributes on decision making. The project has developed a quantitative model known as RumRunner that has proven effective in predicting the propensity of an individual to shift strategies on the basis of task and experience related parameters. Three separate studies are described which have validated the basic RumRunner model. This work provides a basis for better understanding human decision making in high consequent national security applications, and in particular, the individual characteristics that underlie adaptive thinking.

  19. Capturing the uncultivated majority

    Energy Technology Data Exchange (ETDEWEB)

    Green, Brian D.; Keller, Martin

    2007-04-02

    The metagenomic analysis of environmental microbialcommunities continues to be a rapidly developing area of study. DNAisolation, the first step in capturing the uncultivated majority, hasseen many advances in recent years. Protocols have been developed todistinguish DNA from live versus dead cells and to separate extracellularfrom intracellular DNA. Looking to increase our understanding of the rolethat members of a microbial community play in ecological processes,several techniques have been developed that are enabling greater indepthanalysis of environmental metagenomes. These include the development ofenvironmental gene tags and the serial analysis of 16S rRNA gene sequencetags. In addition, new screening methods have been designed to select forspecific functional genes within metagenomic libraries. Finally, newcultivation methods continue to be developed to improve our ability tocapture a greater diversity of microorganisms within theenvironment.

  20. Capturing the Daylight Dividend

    Energy Technology Data Exchange (ETDEWEB)

    Peter Boyce; Claudia Hunter; Owen Howlett

    2006-04-30

    Capturing the Daylight Dividend conducted activities to build market demand for daylight as a means of improving indoor environmental quality, overcoming technological barriers to effective daylighting, and informing and assisting state and regional market transformation and resource acquisition program implementation efforts. The program clarified the benefits of daylight by examining whole building systems energy interactions between windows, lighting, heating, and air conditioning in daylit buildings, and daylighting's effect on the human circadian system and productivity. The project undertook work to advance photosensors, dimming systems, and ballasts, and provided technical training in specifying and operating daylighting controls in buildings. Future daylighting work is recommended in metric development, technology development, testing, training, education, and outreach.

  1. Double carriers pulse DLTS for the characterization of electron-hole recombination process in GaAsN grown by chemical beam epitaxy

    Science.gov (United States)

    Bouzazi, Boussairi; Suzuki, Hidetoshi; Kojima, Nobuaki; Ohshita, Yoshio; Yamaguchi, Masafumi

    2011-03-01

    A nitrogen-related electron trap (E1), located approximately 0.33 eV from the conduction band minimum of GaAsN grown by chemical beam epitaxy, was confirmed by investigating the dependence of its density with N concentration. This level exhibits a high capture cross section compared with that of native defects in GaAs. Its density increases significantly with N concentration, persists following post-thermal annealing, and was found to be quasi-uniformly distributed. These results indicate that E1 is a stable defect that is formed during growth to compensate for the tensile strain caused by N. Furthermore, E1 was confirmed to act as a recombination center by comparing its activation energy with that of the recombination current in the depletion region of the alloy. However, this technique cannot characterize the electron-hole (e-h) recombination process. For that, double carrier pulse deep level transient spectroscopy is used to confirm the non-radiative e -h recombination process through E1, to estimate the capture cross section of holes, and to evaluate the energy of multi-phonon emission. Furthermore, a configuration coordinate diagram is modeled based on the physical parameters of E1.

  2. Trojan capture by terrestrial planets

    CERN Document Server

    Schwarz, Richard

    2016-01-01

    The paper is devoted to investigate the capture of asteroids by Venus, Earth and Mars into the 1:1 mean motion resonance especially into Trojan orbits. Current theoretical studies predict that Trojan asteroids are a frequent by-product of the planet formation. This is not only the case for the outer giant planets, but also for the terrestrial planets in the inner Solar System. By using numerical integrations, we investigated the capture efficiency and the stability of the captured objects. We found out that the capture efficiency is larger for the planets in the inner Solar System compared to the outer ones, but most of the captured Trojan asteroids are not long term stable. This temporary captures caused by chaotic behaviour of the objects were investigated without any dissipative forces. They show an interesting dynamical behaviour of mixing like jumping from one Lagrange point to the other one.

  3. Captured by Aliens

    Science.gov (United States)

    Achenbach, Joel

    2000-03-01

    Captured by Aliens is a long and twisted voyage from science to the supernatural and back again. I hung out in Roswell, N.M., spent time with the Mars Society, met a guy who was figuring out the best way to build a spaceship to go to Alpha Centauri. I visited the set of the X-Files and talked to Mulder and Scully. One day over breakfast I was told by NASA administrator Dan Goldin, We live in a fog, man! He wants the big answers to the big questions. I spent a night in the base of a huge radio telescope in the boondocks of West Virginia, awaiting the signal from the aliens. I was hypnotized in a hotel room by someone who suspected that I'd been abducted by aliens and that this had triggered my interest in the topic. In the last months of his life, I talked to Carl Sagan, who believed that the galaxy riots with intelligent civilizations. He's my hero, for his steadfast adherence to the scientific method. What I found in all this is that the big question that needs immediate attention is not what's out THERE, but what's going on HERE, on Earth, and why we think the way we do, and how we came to be here in the first place.

  4. Inland capture fisheries.

    Science.gov (United States)

    Welcomme, Robin L; Cowx, Ian G; Coates, David; Béné, Christophe; Funge-Smith, Simon; Halls, Ashley; Lorenzen, Kai

    2010-09-27

    The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production.

  5. Capture-recapture methodology

    Science.gov (United States)

    Gould, William R.; Kendall, William L.

    2013-01-01

    Capture-recapture methods were initially developed to estimate human population abundance, but since that time have seen widespread use for fish and wildlife populations to estimate and model various parameters of population, metapopulation, and disease dynamics. Repeated sampling of marked animals provides information for estimating abundance and tracking the fate of individuals in the face of imperfect detection. Mark types have evolved from clipping or tagging to use of noninvasive methods such as photography of natural markings and DNA collection from feces. Survival estimation has been emphasized more recently as have transition probabilities between life history states and/or geographical locations, even where some states are unobservable or uncertain. Sophisticated software has been developed to handle highly parameterized models, including environmental and individual covariates, to conduct model selection, and to employ various estimation approaches such as maximum likelihood and Bayesian approaches. With these user-friendly tools, complex statistical models for studying population dynamics have been made available to ecologists. The future will include a continuing trend toward integrating data types, both for tagged and untagged individuals, to produce more precise and robust population models.

  6. The Generic Data Capture Facility

    Science.gov (United States)

    Connell, Edward B.; Barnes, William P.; Stallings, William H.

    The Generic Data Capture Facility, which can provide data capture support for a variety of different types of spacecraft while enabling operations costs to be carefully controlled, is discussed. The data capture functions, data protection, isolation of users from data acquisition problems, data reconstruction, and quality and accounting are addressed. The TDM and packet data formats utilized by the system are described, and the development of generic facilities is considered.

  7. Resource capture by single leaves

    Energy Technology Data Exchange (ETDEWEB)

    Long, S.P.

    1992-05-01

    Leaves show a variety of strategies for maximizing CO{sub 2} and light capture. These are more meaningfully explained if they are considered in the context of maximizing capture relative to the utilization of water, nutrients and carbohydrates reserves. There is considerable variation between crops in their efficiency of CO{sub 2} and light capture at the leaf level. Understanding of these mechanisms indicate some ways in which efficiency of resource capture could be level cannot be meaningfully considered without simultaneous understanding of implications at the canopy level. 36 refs., 5 figs., 1 tab.

  8. Fluorescence quenching and photobleaching in Au/Rh6G nanoassemblies: impact of competition between radiative and non-radiative decay

    Science.gov (United States)

    Dong, L.; Ye, F.; Hu, J.; Popov, S.; Friberg, A. T.; Muhammed, M.

    2011-04-01

    Fluorescence quenching from nanoassemblies formed by Rhodamine 6G and gold nanoparticles (Au NPs) of 2.6 nm radius has been investigated. The presence of Au NPs also induces long-term degradation of the photostability (photobleaching) of Rhodamine 6G used as gain medium in a Fabry-Perot laser cavity. We found that the degradation gets profound when the Au NPs concentration is significantly increased. Calculation of the radiative rate and direct time-resolved measurement of the fluorescence decay indicates that both the decrease of radiative decay rate and increase of non-radiative decay rate are responsible for the fluorescence quenching and photostability degradation. An energy transfer from the dye molecules to gold nanoparticles is dominating within the small distance between them and suppresses the quantum efficiency of Rhodamine 6G drastically. In long time scale, the photobleaching rate was slowing down, and laser output intensity reached a stabilized level which depends on the gold nanoparticles concentration.

  9. Controlling non-radiative energy transfer in organic binary blends: a route towards colour tunability and white emission from single-active-layer light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Pisignano, Dario [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy); Mazzeo, Marco [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy); Gigli, Giuseppe [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy); Barbarella, Giovanna [Consiglio Nazionale delle Ricerche (CNR), ICOCEA, Area della Ricerca di Bologna, via Gobetti 101, I-40129 Bologna (Italy); Favaretto, Laura [Consiglio Nazionale delle Ricerche (CNR), ICOCEA, Area della Ricerca di Bologna, via Gobetti 101, I-40129 Bologna (Italy); Cingolani, Roberto [NNL, National Nanotechnology Laboratory of Istituto Nazionale di Fisica della Materia (INFM), c/o Dipartimento di Ingegneria dell' Innovazione, via Arnesano, I-73100 Lecce (Italy)

    2003-10-21

    We show how colour tunability (including white) can be achieved by controlling non-radiative intermolecular energy transfer from the donor to the acceptor in binary blends of oligomeric compounds. Blends of different concentrations of a novel functionalized thiophene-based oligomer and a low-molar-mass diamine derivative (N, N'-diphenyl-N, N'-bis(3-methylphenyl)-1, 1'-biphenyl-4.4'diamine) are used to tune both the photoluminescence and the electroluminescence (EL) from red to blue, including balanced white, according to the standards of the Commission Internationale de l'Eclairage. The single-active-layer light-emitting devices, realized by spin-coating, exhibit good EL performance. In particular, the white-emitting device shows an EL efficiency of 5 x 10{sup -1} cd A{sup -1} and a luminance of more than 180 cd m{sup -2}.

  10. Nanoantenna enhanced emission of light-harvesting complex 2: the role of resonance, polarization, and radiative and non-radiative rates.

    Science.gov (United States)

    Wientjes, Emilie; Renger, Jan; Curto, Alberto G; Cogdell, Richard; van Hulst, Niek F

    2014-12-01

    Nanoantennae show potential for photosynthesis research for two reasons; first by spatially confining light for experiments which require high spatial resolution, and second by enhancing the photon emission of single light-harvesting complexes. For effective use of nanoantennae a detailed understanding of the interaction between the nanoantenna and the light-harvesting complex is required. Here we report how the excitation and emission of multiple purple bacterial LH2s (light-harvesting complex 2) are controlled by single gold nanorod antennae. LH2 complexes were chemically attached to such antennae, and the antenna length was systematically varied to tune the resonance with respect to the LH2 absorption and emission. There are three main findings. (i) The polarization of the LH2 emission is fully controlled by the resonant nanoantenna. (ii) The largest fluorescence enhancement, of 23 times, is reached for excitation with light at λ = 850 nm, polarized along the long antenna-axis of the resonant antenna. The excitation enhancement is found to be 6 times, while the emission efficiency is increased 3.6 times. (iii) The fluorescence lifetime of LH2 depends strongly on the antenna length, with shortest lifetimes of ∼40 ps for the resonant antenna. The lifetime shortening arises from an 11 times resonant enhancement of the radiative rate, together with a 2-3 times increase of the non-radiative rate, compared to the off-resonant antenna. The observed length dependence of radiative and non-radiative rate enhancement is in good agreement with simulations. Overall this work gives a complete picture of how the excitation and emission of multi-pigment light-harvesting complexes are influenced by a dipole nanoantenna.

  11. Muon capture on Chlorine-35

    CERN Document Server

    Arole, S; Gorringe, T P; Hasinoff, M D; Kovash, M A; Kuzmin, V; Moftah, B A; Sedlar, R; Stocki, T J; Tetereva, T

    2002-01-01

    We report measurements of $\\gamma$--ray spectra from muon capture on $^{35}$Cl. For the allowed Gamow--Teller transitions to the $^{35}$S$(2939, 3/2^+)$ state and the $^{35}$S$(3421, 5/2^+)$ state we obtained their capture rates, hyperfine dependences and $\\gamma$--$\

  12. Iodine neutron capture therapy

    Science.gov (United States)

    Ahmed, Kazi Fariduddin

    A new technique, Iodine Neutron Capture Therapy (INCT) is proposed to treat hyperthyroidism in people. Present thyroid therapies, surgical removal and 131I treatment, result in hypothyroidism and, for 131I, involve protracted treatment times and excessive whole-body radiation doses. The new technique involves using a low energy neutron beam to convert a fraction of the natural iodine stored in the thyroid to radioactive 128I, which has a 24-minute half-life and decays by emitting 2.12-MeV beta particles. The beta particles are absorbed in and damage some thyroid tissue cells and consequently reduce the production and release of thyroid hormones to the blood stream. Treatment times and whole-body radiation doses are thus reduced substantially. This dissertation addresses the first of the several steps needed to obtain medical profession acceptance and regulatory approval to implement this therapy. As with other such programs, initial feasibility is established by performing experiments on suitable small mammals. Laboratory rats were used and their thyroids were exposed to the beta particles coming from small encapsulated amounts of 128I. Masses of 89.0 mg reagent-grade elemental iodine crystals have been activated in the ISU AGN-201 reactor to provide 0.033 mBq of 128I. This activity delivers 0.2 Gy to the thyroid gland of 300-g male rats having fresh thyroid tissue masses of ˜20 mg. Larger iodine masses are used to provide greater doses. The activated iodine is encapsulated to form a thin (0.16 cm 2/mg) patch that is then applied directly to the surgically exposed thyroid of an anesthetized rat. Direct neutron irradiation of a rat's thyroid was not possible due to its small size. Direct in-vivo exposure of the thyroid of the rat to the emitted radiation from 128I is allowed to continue for 2.5 hours (6 half-lives). Pre- and post-exposure blood samples are taken to quantify thyroid hormone levels. The serum T4 concentration is measured by radioimmunoassay at

  13. 无接触电能传输实验系统的开发与实践%The Development and Implementation of a Wireless Non-Radiative Energy Transfer Experimental System

    Institute of Scientific and Technical Information of China (English)

    白亚男; 李兴根; 卢慧芬; 杨西同

    2015-01-01

    Synchronizing with the state of the art of wireless power transfers,this paper reports the development and implementation of a wireless non-radiative energy transfer experimental system. The experiment covers not only the theory and technology of wireless power transfers,but also converges to the power electronics,single chip micro-computer,and stepping motor disciplines. It is expected that,through the development and practice of the experi-mental system,it will promote students comprehensive ability to innovate,and thus stimulate their interest and en-thusiasm for learning advanced technologies and innovation work.%本文同步于无接触电能传输理论和技术的发展进程,进行了基于磁耦合谐振式无线电能传输实验系统的开发与实践。实验内容不仅涵盖了磁耦合谐振式无线电能传输技术的基本内涵,更综合应用了电力电子、单片机和步进电机等理论和知识。通过本实验系统的开发与实践,希望能够促进学生综合创新能力的培养,进而激发学生的学习兴趣和进行科研创新工作的热情。

  14. Materials For Gas Capture, Methods Of Making Materials For Gas Capture, And Methods Of Capturing Gas

    KAUST Repository

    Polshettiwar, Vivek

    2013-06-20

    In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure, in one aspect, relate to materials that can be used for gas (e.g., CO.sub.2) capture, methods of making materials, methods of capturing gas (e.g., CO.sub.2), and the like, and the like.

  15. ZnO@Ag2S core-shell nanowire arrays for environmentally friendly solid-state quantum dot-sensitized solar cells with panchromatic light capture and enhanced electron collection.

    Science.gov (United States)

    Zhang, Xiaoliang; Liu, Jianhua; Zhang, Jindan; Vlachopoulos, Nick; Johansson, Erik M J

    2015-05-21

    A solid-state environmentally friendly Ag2S quantum dot-sensitized solar cell (QDSSC) is demonstrated. The photovoltaic device is fabricated by applying ZnO@Ag2S core-shell nanowire arrays (NWAs) as light absorbers and electron conductors, and poly-3-hexylthiophene (P3HT) as a solid-state hole conductor. Ag2S quantum dots (QDs) were directly grown on the ZnO nanowires by the successive ionic layer adsorption and reaction (SILAR) method to obtain the core-shell nanostructure. The number of SILAR cycles for QD formation and the length of the core-shell NWs significantly affect the photocurrent. The device with a core-shell NWAs photoanode shows a power conversion efficiency increase by 32% compared with the device based on a typical nanoparticle-based photoanode with Ag2S QDs. The enhanced performance is attributed to enhanced collection of the photogenerated electrons utilizing the ZnO nanowire as an efficient pathway for transporting the photogenerated electrons from the QD to the contact.

  16. Provenance Datasets Highlighting Capture Disparities

    Science.gov (United States)

    2014-01-01

    the Web pages of the universities and institutes.1 Notes are made and links pasted in a variety of formats. Files are saved on a shared drive. When...institutions/ 3. Capture Methods There are several capture methods that are available for use [4]: • Manual capture. • Scraping of logs or...the high-level user desktop. Save links App: Word, SharePoint User: Alice Web Data Web Data Web Data Web Data Web Data Web Data Notes.txt Create

  17. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim......The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  18. Lunar Sulfur Capture System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Lunar Sulfur Capture System (LSCS) is an innovative method to recover sulfur compounds from lunar soil using sorbents derived primarily from in-situ resources....

  19. Methane capture from livestock manure.

    Science.gov (United States)

    Tauseef, S M; Premalatha, M; Abbasi, Tasneem; Abbasi, S A

    2013-03-15

    It has been estimated that livestock manure contributes about 240 million metric tons of carbon dioxide equivalent of methane to the atmosphere and represents one of the biggest anthropogenic sources of methane. Considering that methane is the second biggest contributor to global warming after carbon dioxide, it is imperative that ways and means are developed to capture as much of the anthropogenic methane as possible. There is a major associated advantage of methane capture: its use as a source of energy which is comparable in 'cleanness' to natural gas. The present review dwells upon the traditional ways of methane capture used in India, China, and other developing countries for providing energy to the rural poor. It then reviews the present status of methane capture from livestock manure in developed countries and touches upon the prevalent trends.

  20. Cross sections of electron loss and capture for beams of O{sup +} in water vapor from the energy range of 0,2 to 1,2 MeV; Secoes de choque de perda e captura eletronica para feixes de O{sup +} em vapor de agua em uma faixa de energia entre 0,2 e 1,2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Vitor Jesus de

    2015-06-01

    The study of the interactions between atoms and molecules is important for the knowledge of the cross sections of the processes that contribute to the deposition of energy by charged particle beams used in radiotherapy planning and transport particle simulation codes. Heavy ions, such as oxygen, induce many cellular and molecular damages in human cells.as a result of interaction between the projectile and atoms and molecules. The use of proton and carbon as the projectile interacting with water molecules is well characterized, however there are few studies with oxygen ions. In this work we are interested in the study of electron loss (projectile ionization) and electron capture with charge state 1+. The Pelletron accelerator of 1.7 MeV from the Federal University of Rio de Janeiro housed in the Atomic and Molecular collisions Laboratory (LACAM) has been used, which can accelerate atomic and molecular ions up to speeds of the order of hundredths of light speed, and consists of the source of negative ions, the Wien filter, the accelerator itself and the magnet load selector. The detection device used to evaluate the processes of interaction (capture and loss) between the beam of the O{sup +} and the water molecule is a Microchannel Plate (MCP) at the position sensitive anode. The collisions of O{sup +} beans are being studied in the range of 0.2 to 1.2 MeV with water vapor (Z = 10). Were obtained the respective absolute cross sections for electron loss and electron capture and compared with the cross sections of the molecule methane (CH4 → Z = 10), the isoelectronic water molecule. The experimental results show an agreement between the measurements with water and methane. Comparisons were made with results of theoretical models for electron loss using the 'Free Collision Model' and for capture the Bohr and Lindhard model. The theoretical results for electron loss show an agreement of experimental data with the model used. The model of Bohr and Lindhard

  1. Cyclic electron flow around photosystem I is required for adaptation to high temperature in a subtropical forest tree, Ficus concinna

    Institute of Scientific and Technical Information of China (English)

    Song-heng JIN; Xue-qin LI; Jun-yan HU; Jun-gang WANG

    2009-01-01

    Dissipation mechanisms of excess photon energy under high-temperature stress were studied in a subtropical forest tree seedling, Ficus concinna. Net CO2 assimilation rate decreased to 16% of the control after 20 of high-temperature stress, and thus the absorption of photon energy exceeded the energy required for CO2 assimilation. The efficiency of excitation energy capture by open photosystem Ⅱ (PSII) reaction centres (Fv'/Fm') at moderate irradiauce, photochemical quenching (qp), and the quantum yield of PSII electron transport (φPSII) were significantly lower after high-temperature stress. Nevertheless, non-photochemical quenching (qHP) and energy-dependent quenching (qE) were significantly higher under such conditions. The post-irradiation transient of chlorophyll (Chl) fluorescence significantly increased after the turnoff of the actinic light (AL), and this increase was considerably higher in the 39 ℃-grown seedlings than in the 30 ℃-grown ones. The increased post-irradiation fluorescence points to enhanced cyclic electron transport around PSI under high growth temperature conditions, thus helping to dissipate excess photon energy non-radiatively.

  2. Toward transformational carbon capture systems

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David C. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Litynski, John T. [Office of Fossil Energy, U.S. Dept. of Energy, Washington DC (United States); Brickett, Lynn A. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States); Morreale, Bryan D. [National Energy Technology Laboratory, U.S. Dept. of Energy, Pittsburgh PA (United States)

    2015-10-28

    This paper will briefly review the history and current state of Carbon Capture and Storage (CCS) research and development and describe the technical barriers to carbon capture. it will argue forcefully for a new approach to R&D, which leverages both simulation and physical systems at the laboratory and pilot scales to more rapidly move the best technoogies forward, prune less advantageous approaches, and simultaneously develop materials and processes.

  3. Radiative muon capture on hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Bertl, W. (Paul Scherrer Inst. (PSI), Villigen (Switzerland)); Ahmad, S.; Chen, C.Q.; Gumplinger, P.; Hasinoff, M.D.; Larabee, A.J.; Sample, D.G.; Schott, W.; Wright, D.H. (British Columbia Univ., Vancouver (Canada)); Armstrong, D.S.; Blecher, M. (Virginia Polytechnic Inst., Blacksburg, VA (United States) Virginia State Univ., Blacksburg, VA (United States)); Azuelos, G. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility Montreal Univ., Quebec (Canada)); Depommier, P.; Jonkmans, G. (Montreal Univ., Quebec (Canada)); Gorringe, T.P. (Kentucky Univ., Lexington, KY (United States)); Henderson, R. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility Melbourne Univ., Parkville (Australia)); Macdonald, J.A.; Poutissou, J.M.; Poutissou, R.; Von Egidy, T.; Zhang, N.S. (British Columbia Univ., Vancouver (Canada). TRIUMF Facility); McDonald, S.C.; Taylor, G.N. (Melbourne Univ., Parkville (Australia)); Robertson, B.D. (Queen' s Univ., Kingston, Ontario (Canada))

    1992-01-01

    The radiative capture of negative muons by protons can be used to measure the weak induced pseudoscalar form factor. Brief arguments why this method is preferable to ordinary muon capture are given followed by a discussion of the experimental difficulties. The solution to these problems as attempted by experiment no. 452 at TRIUMF is presented together with preliminary results from the first run in August 1990. An outlook on the expected final precision and the experimental schedule is also given. (orig.).

  4. Gold nanoparticle capture within protein crystal scaffolds

    Science.gov (United States)

    Kowalski, Ann E.; Huber, Thaddaus R.; Ni, Thomas W.; Hartje, Luke F.; Appel, Karina L.; Yost, Jarad W.; Ackerson, Christopher J.; Snow, Christopher D.

    2016-06-01

    DNA assemblies have been used to organize inorganic nanoparticles into 3D arrays, with emergent properties arising as a result of nanoparticle spacing and geometry. We report here the use of engineered protein crystals as an alternative approach to biologically mediated assembly of inorganic nanoparticles. The protein crystal's 13 nm diameter pores result in an 80% solvent content and display hexahistidine sequences on their interior. The hexahistidine sequence captures Au25(glutathione)~17 (nitrilotriacetic acid)~1 nanoclusters throughout a chemically crosslinked crystal via the coordination of Ni(ii) to both the cluster and the protein. Nanoparticle loading was validated by confocal microscopy and elemental analysis. The nanoparticles may be released from the crystal by exposure to EDTA, which chelates the Ni(ii) and breaks the specific protein/nanoparticle interaction. The integrity of the protein crystals after crosslinking and nanoparticle capture was confirmed by single crystal X-ray crystallography.DNA assemblies have been used to organize inorganic nanoparticles into 3D arrays, with emergent properties arising as a result of nanoparticle spacing and geometry. We report here the use of engineered protein crystals as an alternative approach to biologically mediated assembly of inorganic nanoparticles. The protein crystal's 13 nm diameter pores result in an 80% solvent content and display hexahistidine sequences on their interior. The hexahistidine sequence captures Au25(glutathione)~17 (nitrilotriacetic acid)~1 nanoclusters throughout a chemically crosslinked crystal via the coordination of Ni(ii) to both the cluster and the protein. Nanoparticle loading was validated by confocal microscopy and elemental analysis. The nanoparticles may be released from the crystal by exposure to EDTA, which chelates the Ni(ii) and breaks the specific protein/nanoparticle interaction. The integrity of the protein crystals after crosslinking and nanoparticle capture was

  5. The Capture of Jupiter Trojans

    Science.gov (United States)

    Morbidelli, A.; Nesvorny, D.; Vokrouhlicky, D.

    2013-09-01

    The origin of Jupiter Trojans remained mysterious for decades. Particularly, it was difficult to explain the excitation of the inclinations of the Trojan population [1]. In 2005, Morbidelli et al. [2] proposed a scenario of capture from the trans-Neptunian disk, in the framework of the so-called "Nice model" [3,4]. This scenario explained in a natural way the observed orbital distribution of Trojans. The Nice model, however, evolved in the years, in order to satisfy an increasingly large number of constraints. It now appears that the dynamical evolution of the giant planets was different from that envisioned in [2]. Here, we assess again the process of capture of Trojans within this new evolution. We show that (6-8)×10 - 7 of the original trans-Neptunian planetesimals are captured in the Trojan region, with an orbital distribution consistent with the one observed. Relative to [2], the new capture mechanism has the potential of explaining the asymmetry between the L4 and L5 populations. Moreover, the resulting population of Trojans is consistent with that of the Irregular Satellites of Jupiter, which are captured in the same process; a few bodies from the main asteroid belt could also be captured in the Trojan cloud.

  6. Capture by colour: evidence for dimension-specific singleton capture.

    Science.gov (United States)

    Harris, Anthony M; Becker, Stefanie I; Remington, Roger W

    2015-10-01

    Previous work on attentional capture has shown the attentional system to be quite flexible in the stimulus properties it can be set to respond to. Several different attentional "modes" have been identified. Feature search mode allows attention to be set for specific features of a target (e.g., red). Singleton detection mode sets attention to respond to any discrepant item ("singleton") in the display. Relational search sets attention for the relative properties of the target in relation to the distractors (e.g., redder, larger). Recently, a new attentional mode was proposed that sets attention to respond to any singleton within a particular feature dimension (e.g., colour; Folk & Anderson, 2010). We tested this proposal against the predictions of previously established attentional modes. In a spatial cueing paradigm, participants searched for a colour target that was randomly either red or green. The nature of the attentional control setting was probed by presenting an irrelevant singleton cue prior to the target display and assessing whether it attracted attention. In all experiments, the cues were red, green, blue, or a white stimulus rapidly rotated (motion cue). The results of three experiments support the existence of a "colour singleton set," finding that all colour cues captured attention strongly, while motion cues captured attention only weakly or not at all. Notably, we also found that capture by motion cues in search for colour targets was moderated by their frequency; rare motion cues captured attention (weakly), while frequent motion cues did not.

  7. Do grain boundaries dominate non-radiative recombination in CH 3 NH 3 PbI 3 perovskite thin films?

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mengjin; Zeng, Yining; Li, Zhen; Kim, Dong Hoe; Jiang, Chun-Sheng; van de Lagemaat, Jao; Zhu, Kai

    2017-01-13

    Here, we examine GBs with respect to non-GB regions (grain surfaces (GSs) and grain interiors (GIs)) in high-quality micrometer-sized perovskite CH3NH3PbI3 (or MAPbI3) thin films using high-resolution confocal fluorescence-lifetime imaging microscopy in conjunction with kinetic modeling of charge-transport and recombination processes. We show that, contrary to previous studies, GBs in our perovskite MAPbI3 thin films do not lead to increased recombination but that recombination in these films happens primarily in the non-GB regions (i.e., GSs or GIs). We also find that GBs in these films are not transparent to photogenerated carriers, which is likely associated with a potential barrier at GBs. Even though GBs generally display lower luminescence intensities than GSs/GIs, the lifetimes at GBs are no worse than those at GSs/GIs, further suggesting that GBs do not dominate non-radiative recombination in MAPbI3 thin films.

  8. ICP-MS Analysis of Lanthanide-Doped Nanoparticles as a Non-Radiative, Multiplex Approach to Quantify Biodistribution and Blood Clearance

    Science.gov (United States)

    Crayton, Samuel H.; Elias, Andrew; Al-Zaki, Ajlan; Cheng, Zhiliang; Tsourkas, Andrew

    2011-01-01

    Recent advances in material science and chemistry have led to the development of nanoparticles with diverse physicochemical properties, e.g. size, charge, shape, and surface chemistry. Evaluating which physicochemical properties are best for imaging and therapeutic studies is challenging not only because of the multitude of samples to evaluate, but also because of the large experimental variability associated with in vivo studies (e.g. differences in tumor size, injected dose, subject weight, etc.). To address this issue, we have developed a lanthanide-doped nanoparticle system and analytical method that allows for the quantitative comparison of multiple nanoparticle compositions simultaneously. Specifically, superparamagnetic iron oxide (SPIO) with a range of different sizes and charges were synthesized, each with a unique lanthanide dopant. Following the simultaneous injection of the various SPIO compositions into tumor-bearing mice, inductively coupled plasma mass spectroscopy (ICP-MS) was used to quantitatively and orthogonally assess the concentration of each SPIO composition in serial blood samples and the resected tumor and organs. The method proved generalizable to other nanoparticle platforms, including dendrimers, liposomes, and polymersomes. This approach provides a simple, cost-effective, and non-radiative method to quantitatively compare tumor localization, biodistribution, and blood clearance of more than 10 nanoparticle compositions simultaneously, removing subject-to-subject variability. PMID:22100983

  9. Shape Isomer in 236U Populated by Thermal Neutron Capture

    DEFF Research Database (Denmark)

    Andersen, Verner; Christensen, Carl Jørgen; Borggreen, J.

    1976-01-01

    The 116 ns shape isomer in 236U was populated by thermal neutron capture. Conversion electrons and X-rays were detected simultaneously in delayed coincidence with fission. The ratio of delayed to prompt fission was measured with the result, σIIf/σf = (1.0±0.2) × 10−5. A branching of the isomeric...

  10. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  11. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    ) are chemically merged together to form cruciform-like structures that are an essential part of the thesis. The cruciform molecules were subjected to molecular conductance measurements to explore their capability towards single-crystal field-effect transistors (Part 1), molecular wires, and single electron......This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF......, however, was obtained by a study of a single molecular transistor. The investigated OPE5-TTF compound was captured in a three-terminal experiment, whereby manipulation of the molecule’s electronic spin was possible in different charge states. Thus, we demonstrated how the cruciform molecules could...

  12. Managing electronic records

    CERN Document Server

    McLeod, Julie

    2005-01-01

    For records management courses, this book covers the theory and practice of managing electronic records as business and information assets. It focuses on the strategies, systems and procedures necessary to ensure that electronic records are appropriately created, captured, organized and retained over time to meet business and legal requirements.

  13. Optic capture pars plana lensectomy

    Directory of Open Access Journals (Sweden)

    Lee JE

    2012-10-01

    Full Text Available Joo Eun LeeDepartment of Ophthalmology, Inje University College of Medicine, Busan, South KoreaObjective: To describe an optic capture pars plana lensectomy technique.Methods: After core vitrectomy, pars plana lensectomy is performed with preservation of the anterior capsule. Capsulorhexis is performed on the preserved anterior capsule through a 2.8 mm clear corneal incision. An intraocular lens (IOL is placed in the ciliary sulcus, and then the optic of the IOL is pushed back to the vitreous cavity so that the optic is captured by the surrounding capsulorhexis margin.Results: The captured IOL-capsule diaphragm remained stable during air–fluid exchange and prevented air prolapse to the anterior chamber. IOL stability and a clear visual axis were preserved during the follow-up period.Conclusion: With this modified pars plana lensectomy technique, stable IOL position and clear visual axis can be maintained when a pars plana approach is needed during combined cataract and vitreoretinal surgery.Keywords: lensectomy, optic capture, pars plana lensectomy, vitrectomy

  14. 49 CFR 563.9 - Data capture.

    Science.gov (United States)

    2010-10-01

    ... frontal or side air bag deployment crash, capture and record the current deployment data, up to two events... 49 Transportation 6 2010-10-01 2010-10-01 false Data capture. 563.9 Section 563.9 Transportation..., DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.9 Data capture. The EDR must capture and record...

  15. Power coupler kick of the TRIUMF ICM capture cavities

    Science.gov (United States)

    Yan, Fang; E. Laxdal, R.; Zvyagintsev, V.; Yu., Chao; C., Gong; Koscielniak, S.

    2011-06-01

    The TRIUMF Injector CryoModule (ICM) adapted two superconducting single cavities as the capture section for the low injecting energy of 100 keV electrons. Coupler kick induced beam deflection and projected emittance growth are one of the prime concerns of the beam stability, especially at low energies. In low energy applications, the electron velocity changes rapidly inside the cavity, which makes the numerical analysis much more complicated. The commonly used theoretical formulas of the direct integral or the Panofsky-Wenzel theorem is not suitable for the kick calculation of β < 1 electrons. Despite that, the above mentioned kick calculation method doesn't consider injecting electron energy, the beam offset due to the coupler kick may not be negligible because of the low injection energy even if the kick is optimized. Thus the beam dynamics code TRACK is used here for the simulation of the power coupler kick perturbation. The coupler kick can be compensated for by a judicious choice of the coupler position in successive cavities from upstream to downstream. The simulation shows that because of the adiabatic damping by the following superconducting 9-cell cavity, even for the worst orbit distortion case after two capture cavities, the kick is still acceptable at the exit of the ICM after reaching 10 MeV. This paper presents the analysis of the transverse kick and the projected emittance growth induced by the coupler for β < 1 electrons. The simulated results of the TRIUMF ICM capture cavities are described and presented.

  16. Power coupler kick of the TRIUMF ICM capture cavities

    Institute of Scientific and Technical Information of China (English)

    YAN Fang; R.E. Laxdal; V. Zvyagintsev; Yu. Chao; C. Gong; S. Koscielniak

    2011-01-01

    The TRIUMF Injector CryoModule (ICM) adapted two superconducting single cavities as the capture section for the low injecting energy of 100 keV electrons. Coupler kick induced beam deflection and projected emittance growth are one of the prime concerns of the beam stability, especially at low energies. In low energy applications, the electron velocity changes rapidly inside the cavity, which makes the numerical analysis much more complicated. The commonly used theoretical formulas of the direct integral or the Panofsky- Wenzel theorem is not suitable for the kick calculation of β <1 electrons. Despite that, the above mentioned kick calculation method doesn't consider injecting electron energy, the beam offset due to the coupler kick may not be negligible because of the low injection energy even if the kick is optimized. Thus the beam dynamics code TRACK is used here for the simulation of the power coupler kick perturbation. The coupler kick can be compensated for by a judicious choice of the coupler position in successive cavities from upstream to downstream. The simulation shows that because of the adiabatic damping by the following superconducting 9-cell cavity, even for the worst orbit distortion case after two capture cavities, the kick is still acceptable at the exit of the ICM after reaching 10 MeV. This paper presents the analysis of the transverse kick and the projected emittance growth induced by the coupler for β <1 electrons. The simulated results of the TRIUMF ICM capture cavities are described and presented.

  17. Spectromicroscopy in Boron Neutron Capture Therapy Research

    Science.gov (United States)

    Gilbert, Benjamin; Redondo, Jose; Andres, Roger; Suda, Takashi; Neumann, Michael; Steen, Steffi; Gabel, Detlef; Mercanti, Delio; Ciotti, Teresa; Perfetti, Paolo; Margaritondo, Giorgio; de Stasio, Gelsomina

    1998-03-01

    The MEPHISTO synchrotron imaging spectromicroscope can analyse ashed cells or tissue sections to reveal the microdistribution of trace elements. MEPHISTO performs core level x-ray absorption spectroscopy with synchrotron radiation, and uses an electron optics system to provide magnified photoelectron images. An application of the MEPHISTO spectromicroscope is in boron neutron capture therapy (BNCT). BNCT is a binary cancer therapy that will selectively destroy cancer cells provided that compounds containing a boron isotope are selectively accumulated in tumor tissue. Important factors for the success of BNCT include the ability to target every cancer cell, and the distribution of boron inside the cell. To investigate the boron distribution in tissue, sections of human glioblastoma containing a BNCT compound, and stained with nickel against a protein found in the nuclei of proliferating (cancer) cells, were studied with MEPHISTO.

  18. CAPTURE OF EVENTS MIDI IN PARALLEL WITH FPGAs'

    Directory of Open Access Journals (Sweden)

    M. Peña

    2004-12-01

    Full Text Available The project consists on designing, in FPGA system, a special dynamic memory MCS-S (MIDI Capture System-Segmented to capture, in real time and in parallel form, musical data that come from a group of instruments whilethey play in an orchestra, as well as to obtain their score. Inside the system, each single memory segment storesthe notes corresponding to each instrument. The control system prepares automatically the necessary memory cellsfor each instrument and inserts new notes in each segment in parallel form. The electronic components of thissystem are programmed in VHDL, to carry out later the implementation in FPGA.

  19. Astrophysical neutron capture rates in s- and r-process nucleosynthesis

    CERN Document Server

    Beer, H; Oberhummer, Heinz; Rauscher, T; Mutti, P; Corvi, F; Sedyshev, P V; Popov, Yu P; Popov, Yu.P.

    1997-01-01

    Astrophysical neutron capture rates of light and heavy nuclei have been measured and calculated. For the measurements the activation technique was applied at the 3.75 MV Karlsruhe Van de Graaff accelerator, and at the Geel electron linear accelerator (GELINA) the time-of-flight (TOF) method was used. The calculations were performed using direct and compound nuclear capture models.

  20. Natural materials for carbon capture.

    Energy Technology Data Exchange (ETDEWEB)

    Myshakin, Evgeniy M. (National Energy Technology Laboratory, Pittsburgh, PA); Romanov, Vyacheslav N. (National Energy Technology Laboratory, Pittsburgh, PA); Cygan, Randall Timothy

    2010-11-01

    Naturally occurring clay minerals provide a distinctive material for carbon capture and carbon dioxide sequestration. Swelling clay minerals, such as the smectite variety, possess an aluminosilicate structure that is controlled by low-charge layers that readily expand to accommodate water molecules and, potentially, carbon dioxide. Recent experimental studies have demonstrated the efficacy of intercalating carbon dioxide in the interlayer of layered clays but little is known about the molecular mechanisms of the process and the extent of carbon capture as a function of clay charge and structure. A series of molecular dynamics simulations and vibrational analyses have been completed to assess the molecular interactions associated with incorporation of CO2 in the interlayer of montmorillonite clay and to help validate the models with experimental observation.

  1. Carbon Capture: A Technology Assessment

    Science.gov (United States)

    2013-10-21

    time. The absence of a significant market for the novel technologies put them at a further disadvantage . This is similar to the situation for CO2...the overall CCS process applied to a power plant or other industrial process. The CO2 produced from carbon in the fossil fuels or biomass feedstock...Air or Oxygen Fossil Fuels; Biomass USEFUL PRODUCTS (e.g., electricity, fuels, chemicals, hydrogen) CO2 CO2 Capture & Compress CO2 Transport CO2

  2. Carbon Capture and Sequestration (CCS)

    Science.gov (United States)

    2009-06-19

    for the pre-combustion capture of CO2 is the use of Integrated Gasification Combined-Cycle ( IGCC ) technology to generate electricity.14 There are...currently four commercial IGCC plants worldwide (two in the United States) each with a capacity of about 250 MW. The technology has yet to make a major... IGCC is an electric generating technology in which pulverized coal is not burned directly but mixed with oxygen and water in a high-pressure gasifier

  3. Investigation of linguistic comprehension processing by capture software

    Directory of Open Access Journals (Sweden)

    Vera Wannmacher Pereira

    2015-01-01

    Full Text Available Among many computer tools that are provided for research development, especially with regard to language, the capture software technologies are important for the study of cognitive processes while performing activities using the computer as an electronic support. This article presents one – the capture software SnagIt – which records videos of the user's movements with the mouse, during the linguistic comprehension process, enabling analysis and reflections on the user’s journey and thereby their cognitive processing. Two psycholinguistic studies developed at the Reference Center for Language Development – CELIN/ FALE/ PUCRS – used this capture software in order to examine the linguistic comprehension strategies applied by the subjects. These studies are presented for demonstration and explanation.

  4. Realistic costs of carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Al Juaied, Mohammed (Harvard Univ., Cambridge, MA (US). Belfer Center for Science and International Affiaris); Whitmore, Adam (Hydrogen Energy International Ltd., Weybridge (GB))

    2009-07-01

    There is a growing interest in carbon capture and storage (CCS) as a means of reducing carbon dioxide (CO2) emissions. However there are substantial uncertainties about the costs of CCS. Costs for pre-combustion capture with compression (i.e. excluding costs of transport and storage and any revenue from EOR associated with storage) are examined in this discussion paper for First-of-a-Kind (FOAK) plant and for more mature technologies, or Nth-of-a-Kind plant (NOAK). For FOAK plant using solid fuels the levelised cost of electricity on a 2008 basis is approximately 10 cents/kWh higher with capture than for conventional plants (with a range of 8-12 cents/kWh). Costs of abatement are found typically to be approximately US$150/tCO2 avoided (with a range of US$120-180/tCO2 avoided). For NOAK plants the additional cost of electricity with capture is approximately 2-5 cents/kWh, with costs of the range of US$35-70/tCO2 avoided. Costs of abatement with carbon capture for other fuels and technologies are also estimated for NOAK plants. The costs of abatement are calculated with reference to conventional SCPC plant for both emissions and costs of electricity. Estimates for both FOAK and NOAK are mainly based on cost data from 2008, which was at the end of a period of sustained escalation in the costs of power generation plant and other large capital projects. There are now indications of costs falling from these levels. This may reduce the costs of abatement and costs presented here may be 'peak of the market' estimates. If general cost levels return, for example, to those prevailing in 2005 to 2006 (by which time significant cost escalation had already occurred from previous levels), then costs of capture and compression for FOAK plants are expected to be US$110/tCO2 avoided (with a range of US$90-135/tCO2 avoided). For NOAK plants costs are expected to be US$25-50/tCO2. Based on these considerations a likely representative range of costs of abatement from CCS

  5. Algal Energy Conversion and Capture

    Science.gov (United States)

    Hazendonk, P.

    2015-12-01

    We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

  6. Automated left ventricular capture management.

    Science.gov (United States)

    Crossley, George H; Mead, Hardwin; Kleckner, Karen; Sheldon, Todd; Davenport, Lynn; Harsch, Manya R; Parikh, Purvee; Ramza, Brian; Fishel, Robert; Bailey, J Russell

    2007-10-01

    The stimulation thresholds of left ventricular (LV) leads tend to be less reliable than conventional leads. Cardiac resynchronization therapy (CRT) requires continuous capture of both ventricles. The purpose of this study is to evaluate a novel algorithm for the automatic measurement of the stimulation threshold of LV leads in cardiac resynchronization systems. We enrolled 134 patients from 18 centers who had existing CRT-D systems. Software capable of automatically executing LV threshold measurements was downloaded into the random access memory (RAM) of the device. The threshold was measured by pacing in the left ventricle and analyzing the interventricular conduction sensed in the right ventricle. Automatic LV threshold measurements were collected and compared with manual LV threshold tests at each follow-up visit and using a Holter monitor system that recorded both the surface electrocardiograph (ECG) and continuous telemetry from the device. The proportion of Left Ventricular Capture Management (LVCM) in-office threshold tests within one programming step of the manual threshold test was 99.7% (306/307) with a two-sided 95% confidence interval of (98.2%, 100.0%). The algorithm measured the threshold successfully in 96% and 97% of patients after 1 and 3 months respectively. Holter monitor analysis in a subset of patients revealed accurate performance of the algorithm. This study demonstrated that the LVCM algorithm is safe, accurate, and highly reliable. LVCM worked with different types of leads and different lead locations. LVCM was demonstrated to be clinically equivalent to the manual LV threshold test. LVCM offers automatic measurement, output adaptation, and trends of the LV threshold and should result in improved ability to maintain LV capture without sacrificing device longevity.

  7. Objects capture perceived gaze direction.

    Science.gov (United States)

    Lobmaier, Janek S; Fischer, Martin H; Schwaninger, Adrian

    2006-01-01

    The interpretation of another person's eye gaze is a key element of social cognition. Previous research has established that this ability develops early in life and is influenced by the person's head orientation, as well as local features of the person's eyes. Here we show that the presence of objects in the attended space also has an impact on gaze interpretation. Eleven normal adults identified the fixation points of photographed faces with a mouse cursor. Their responses were systematically biased toward the locations of nearby objects. This capture of perceived gaze direction probably reflects the attribution of intentionality and has methodological implications for research on gaze perception.

  8. Why capture CO2 from the atmosphere?

    National Research Council Canada - National Science Library

    Keith, David W

    2009-01-01

    Air capture is an industrial process for capturing CO2 from ambient air; it is one of an emerging set of technologies for CO2 removal that includes geological storage of biotic carbon and the acceleration of geochemical weathering...

  9. CAPTURING RNA-DEPENDENT PATHWAYS FOR CRYO-EM ANALYSIS

    Directory of Open Access Journals (Sweden)

    Justin R. Tanner

    2012-04-01

    Full Text Available Cryo-Electron Microscopy (EM is a powerful technique to visualize biological processes at nanometer resolution. Structural studies of macromolecular assemblies are typically performed on individual complexes that are biochemically isolated from their cellular context. Here we present a molecular imaging platform to capture and view multiple components of cellular pathways within a functionally relevant framework. We utilized the bacterial protein synthesis machinery as a model system to develop our approach. By using modified Affinity Grid surfaces, we were able to recruit multiple protein assemblies bound to nascent strands of mRNA. The combined use of Affinity Capture technology and single particle electron microscopy provide the basis for visualizing RNA-dependent pathways in a remarkable new way.

  10. Capturing RNA-dependent pathways for cryo-EM analysis

    Directory of Open Access Journals (Sweden)

    Deborah F Kelly

    2012-04-01

    Full Text Available Cryo-Electron Microscopy (EM is a powerful technique to visualize biological processes at nanometer resolution. Structural studies of macromolecular assemblies are typically performed on individual complexes that are biochemically isolated from their cellular context. Here we present a molecular imaging platform to capture and view multiple components of cellular pathways within a functionally relevant framework. We utilized the bacterial protein synthesis machinery as a model system to develop our approach. By using modified Affinity Grid surfaces, we were able to recruit multiple protein assemblies bound to nascent strands of mRNA. The combined use of Affinity Capture technology and single particle electron microscopy provide the basis for visualizing RNA-dependent pathways in a remarkable new way.

  11. Non-Statistical Effects in Neutron Capture

    Science.gov (United States)

    Koehler, P. E.; Bredeweg, T. A.; Guber, K. H.; Harvey, J. A.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wiarda, D.; Wouters, J. M.

    2009-01-01

    There have been many reports of non-statistical effects in neutron-capture measurements. However, reports of deviations of reduced-neutron-width (Γn0) distributions from the expected Porter-Thomas (PT) shape largely have been ignored. Most of these deviations have been reported for odd-A nuclides. Because reliable spin (J) assignments have been absent for most resonances for such nuclides, it is possible that reported deviations from PT might be due to incorrect J assignments. We recently developed a new method for measuring spins of neutron resonances by using the DANCE detector at the Los Alamos Neutron Science Center (LANSCE). Measurements made with a 147Sm sample allowed us to determine spins of almost all known resonances below 1 keV. Furthermore, analysis of these data revealed that the Γn0 distribution was in good agreement with PT for resonances below 350 eV, but in disagreement with PT for resonances between 350 and 700 eV. Our previous (n,α) measurements had revealed that the α strength function also changes abruptly at this energy. There currently is no known explanation for these two non-statistical effects. Recently, we have developed another new method for determining the spins of neutron resonances. To implement this technique required a small change (to record pulse-height information for coincidence events) to a much simpler apparatus: A pair of C6D6 γ-ray detectors which we have employed for many years to measure neutron-capture cross sections at the Oak Ridge Electron Linear Accelerator (ORELA). Measurements with a 95Mo sample revealed that not only does the method work very well for determining spins, but it also makes possible parity assignments. Taken together, these new techniques at LANSCE and ORELA could be very useful for further elucidation of non-statistical effects.

  12. Advanced Docking System With Magnetic Initial Capture

    Science.gov (United States)

    Lewis, James L.; Carroll, Monty B.; Morales, Ray; Le, Thang

    2004-01-01

    An advanced docking system is undergoing development to enable softer, safer docking than was possible when using prior docking systems. This system is intended for original use in docking of visiting spacecraft and berthing the Crew Return Vehicle at the International Space Station (ISS). The system could also be adapted to a variety of other uses in outer space and on Earth, including mating submersible vehicles, assembling structures, and robotic berthing/handling of payloads and cargo. Heretofore, two large spacecraft have been docked by causing the spacecraft to approach each other at a speed sufficient to activate capture latches - a procedure that results in large docking loads and is made more difficult because of the speed. The basic design and mode of operation of the present advanced docking system would eliminate the need to rely on speed of approach to activate capture latches, thereby making it possible to reduce approach speed and thus docking loads substantially. The system would comprise an active subsystem on one spacecraft and a passive subsystem on another spacecraft with which the active subsystem will be docked. The passive subsystem would include an extensible ring containing magnetic striker plates and guide petals. The active subsystem would include mating guide petals and electromagnets containing limit switches and would be arranged to mate with the magnetic striker plates and guide petals of the passive assembly. The electromagnets would be carried on (but not rigidly attached to) a structural ring that would be instrumented with load sensors. The outputs of the sensors would be sent, along with position information, as feedback to an electronic control subsystem. The system would also include electromechanical actuators that would extend or retract the ring upon command by the control subsystem.

  13. Capturing Reality at Centre Block

    Science.gov (United States)

    Boulanger, C.; Ouimet, C.; Yeomans, N.

    2017-08-01

    The Centre Block of Canada's Parliament buildings, National Historic Site of Canada is set to undergo a major rehabilitation project that will take approximately 10 years to complete. In preparation for this work, Heritage Conservation Services (HCS) of Public Services and Procurement Canada has been completing heritage documentation of the entire site which includes laser scanning of all interior rooms and accessible confined spaces such as attics and other similar areas. Other documentation completed includes detailed photogrammetric documentation of rooms and areas of high heritage value. Some of these high heritage value spaces present certain challenges such as accessibility due to the height and the size of the spaces. Another challenge is the poor lighting conditions, requiring the use of flash or strobe lighting to either compliment or completely eliminate the available ambient lighting. All the spaces captured at this higher level of detail were also captured with laser scanning. This allowed the team to validate the information and conduct a quality review of the photogrammetric data. As a result of this exercise, the team realized that in most, if not all cases, the photogrammetric data was more detailed and at a higher quality then the terrestrial laser scanning data. The purpose and motivation of this paper is to present these findings, as well provide the advantages and disadvantages of the two methods and data sets.

  14. CAPTURING REALITY AT CENTRE BLOCK

    Directory of Open Access Journals (Sweden)

    C. Boulanger

    2017-08-01

    Full Text Available The Centre Block of Canada’s Parliament buildings, National Historic Site of Canada is set to undergo a major rehabilitation project that will take approximately 10 years to complete. In preparation for this work, Heritage Conservation Services (HCS of Public Services and Procurement Canada has been completing heritage documentation of the entire site which includes laser scanning of all interior rooms and accessible confined spaces such as attics and other similar areas. Other documentation completed includes detailed photogrammetric documentation of rooms and areas of high heritage value. Some of these high heritage value spaces present certain challenges such as accessibility due to the height and the size of the spaces. Another challenge is the poor lighting conditions, requiring the use of flash or strobe lighting to either compliment or completely eliminate the available ambient lighting. All the spaces captured at this higher level of detail were also captured with laser scanning. This allowed the team to validate the information and conduct a quality review of the photogrammetric data. As a result of this exercise, the team realized that in most, if not all cases, the photogrammetric data was more detailed and at a higher quality then the terrestrial laser scanning data. The purpose and motivation of this paper is to present these findings, as well provide the advantages and disadvantages of the two methods and data sets.

  15. The Effectiveness of Classroom Capture Technology

    Science.gov (United States)

    Ford, Maire B.; Burns, Colleen E.; Mitch, Nathan; Gomez, Melissa M.

    2012-01-01

    The use of classroom capture systems (systems that capture audio and video footage of a lecture and attempt to replicate a classroom experience) is becoming increasingly popular at the university level. However, research on the effectiveness of classroom capture systems in the university classroom has been limited due to the recent development and…

  16. The Effectiveness of Classroom Capture Technology

    Science.gov (United States)

    Ford, Maire B.; Burns, Colleen E.; Mitch, Nathan; Gomez, Melissa M.

    2012-01-01

    The use of classroom capture systems (systems that capture audio and video footage of a lecture and attempt to replicate a classroom experience) is becoming increasingly popular at the university level. However, research on the effectiveness of classroom capture systems in the university classroom has been limited due to the recent development and…

  17. Marker-Free Human Motion Capture

    DEFF Research Database (Denmark)

    Grest, Daniel

    Human Motion Capture is a widely used technique to obtain motion data for animation of virtual characters. Commercial optical motion capture systems are marker-based. This book is about marker-free motion capture and its possibilities to acquire motion from a single viewing direction. The focus...

  18. Halo Effect on Direct Neutron Capture Process

    Institute of Scientific and Technical Information of China (English)

    刘祖华; 周宏余

    2004-01-01

    We calculate the capture cross sections of the 10Be(n,γ) 11 Be reaction by means of the asymptotic normalization coefficient method and demonstrate the halo effects on the capture cross sections for the direct radiative neutron capture where a p-, s- or d-wave neutron is captured into an s-orbit or p-orbit in 11 Be by emitting an E1 γ-ray,respectively. The result shows that the enormous enhancement of the capture cross section is just due to the large overlap of the incident neutron wave with the extended tail of the halo, which is clearly illustrated by the reduced transition amplitude function.

  19. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    performed recently has focused on CO2capture from fossil fuel-based power plants. Inherently,this process is especially suitablefor cement plants, as CaO used for CO2capture is also a majoringredient for clinker production. Thus, a detailed investigation was carried outto study the applicationof......% of the inlet CO2 was captured by highly deactivated limestone, which had a maximum CO2 capture capacity of 11.5%, with an inlet Ca/C ratio of 13. So, the performance of the carbonator can be defined by the inlet Ca/C ratio, which can be estimated if the maximum capture capacity of limestone is known...

  20. Capture of Irregular Satellites at Jupiter

    CERN Document Server

    Nesvorny, D; Deienno, R

    2014-01-01

    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early Solar System instability when encounters between the outer planets occurred (Nesvorny, Vokrouhlicky & Morbidelli 2007, AJ 133; hereafter NVM07). NVM07 already showed that the irregular satellites of Saturn, Uranus and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary d...